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A
DICTIONARY
OF
ARTS, MANUFACTURES,
AND
MINES;
CONTAINING
A CLEAR EXPOSITION OF THEIR PRINCIPLES AND PRACTICE.
BY
ANDREW URE, M.D.,
F.B.S. M.G.S. M.A.S. LOND.; M. ACAD. N.S. PHILAD.; S. PH. SOC. N. GERM.
HANOV.; MULII. ETC. ETO.
ILLUSTRATED WITH NEARLY SIXTEEN HUNDRED ENGRAVINGS ON-WOOD.
REPRINTED FROM THE FOURTH ENGLISH EDITION.
CORRECTED  AND GREATLY  ENLARGED.
IN TWO VOLUMES.-VOL. I.
NEW-YORK:
D. APPLETON AND COMPANY,
200 BROADWAY.
M.DCCC.LIm








PREFACE.
IT is the business of operative industry to produce, transform, and distribute all such material objects as are suited to satisfy the wants of mankind. The primary production of these objects is assigned to the husbandman, the fisherman, and the miner; their transformation to the manufacturer
and artisan; and their distribution to the engineer, shipwright, and sailor.*
The unworked or raw materials are derived, —. from the organic processes
of vegetables and animals, conducted either without or with the fostering
care of man; 2. from the boundless stores of mineral and metallic wealth.
arranged upon or within the surface of the earth by the benignant Parent
of our being, in the fittest condition to exercise our physical and intellectual
powers in turning them to the uses of life.
The task which I have undertaken in the present work, is to describe
and explain the transformitions of these primary materials, by mechanical
and chemical agencies, into general objects of exchangeable value, leaving, on the one hand, to the mechanical engineer, that of investigating the
motive powers of transformation and transport; and, on the other hand, to
the handicraftsman, that of tracing their modifications into objects of special
or local demand.  Contemplated in this view, an art or manufacture may
be defined to be that species of industry which effects a certain change in
a substance, to suit it for the general market, by combining its parts in a
new  order and form, through mechanical or chemical means.  Iron will
serve the purpose of illustrating the nature of the distinctions here laid
down, between mechanical engineering; arts and manufactures; and handicraft trades. The engineer perforates the ground with a shaft, or a drift,
to the level of the ore, erects the pumps for drainage, the ventilating, and
hoisting apparatus, along with the requisite steam or water power; he constructs the roads, the bridges, canals, railways, harbors, docks, cranes, &c.,
subservient to the transport of the ore and metal; he mounts the steam or
water-power, and bellows for working the blast-furnaces, the forges, and
the cupolas; his principal end and aim on all occasions being to overcome
the forces of inertia, gravity, and cohesion. The ores extracted and sorted
*For correct and copious information upon agricultural production, I have great
pleasure in referring my readers to Mr. London's elaborate Encyclopedias of.griculture,
Gardening, and Plants; and for mercantile production and distribution, to Mr. M'Culloch's excellent Dictionary of Commerce and Commercial Navigation.




iv                            PREFACE.
by the miner, and transported by the engineer to the smelting station, are
there skilfully blended by the iron-master (manufacturer), who treats them
in a furnace appropriately constructed, along with their due proportions of
flux and fuel, whereby he reduces them  to cast iron of certain quality,
which he runs off at the right periods into rough pigs or regular moulds;
he then transforms this crude metal, by mechanical and chemical agencies,
into bar and plate iron of various sizes and shapes, fit for the general market;
he finally converts the best of the bars into steel, by the cementation furnace, the forge, and the tilt-hammer; or the best of the plates into tin-plate.
When farther worked by definite and nearly uniform processes into objects
of very general demand in all civilized countries, these iron and steel bars
still belong to the domain of manufactures; as, for example, when made
into anchors, chain-cables, files, nails, needles, wire, &c.; but when the
iron is fashioned, into ever varying and capricious forms, they belong either
to the general business of the founder and cutler, or to the particular calling of some handicraft, as the locksmith, gratesmith, coachsmith, gunsmith,
tinman, &c.
Such are the principles which have served to guide me in selecting articles for the present volume.  By them, as a clew, I have endeavored to
hold a steady course through the vast and otherwise perplexing labyrinth
of arts, manufactures, and mines; avoiding alike engineering and mechanical arts, which cause no change in the texture or constitution of matter,and handicraft operations, which are multiform, capricious, and hardly susceptible of scientific investigation. In fact, had such topics been introduced
into the volume, it would have presented a miscellaneous farrago of incongruous articles, too numerous to allow of their being expounded in a manner either interesting or instructive to the manufacturer and the metallurgist.
I readily acknowledge, however, that T have not been able to adhere always
so rigorously as I could have wished to the above rule of selection; having
been constrained by intelligent and influential friends to introduce a few
articles which I would gladly have left to the mechanical engineer. Of
these Printing is one, which, having had no provision made for it in my
original plan, was too hastily compiled to admit of my describing, with
suitable figures, the flat-printing automatic machine of Mr. Spottiswoode,
wherewith the pages of this volume were worked off; a mechanism which
I regard as the most elegant, precise, and productive, hitherto employed to
execute the best style of letter press.
I have imbodied in this work the results of my long experience as a
Professor of Practical Science.  Since the year i805, when I entered at
an early age upon the arduous task of conducting the schools of chemistry
and manufactures in the Andersonian Institution, up to the present day,
I have been assiduously engaged in the study and improvement of most of
the chemical and many of the mechanical arts.  Consulted professionally
by proprietors of factories, workshops, and mines of various descriptions,
both in this country and abroad, concerning derangements in their operations, or defects in their products, I have enjoyed peculiar opportunities of
becoming familiar with their minutest details, and have frequently had the
good fortune to rectify what was amiss, or to supply what was wanting.
Of the stores of information thus acquired, I have availed myself on the
present occasion; careful, meanwhile, to neglect no means of knowledge
which my extensive intercourse with foreign nations affords.
I therefore humbly hope that this work will prove a valuable contribution
to the literature of science, servingIn the first place, to instruct the Manufacturer, Metallurgist, and Tradesman, in the principles of their respective processes, so as to render them in




PREFACE.                                  v
reality the masters of their business, and to emancipate them from a state
of bondage to such as are too commonly the slaves of blind prejudice and
vicious routine.
Secondly, to afford to Merchants, Brokers, Drysalters, Druggists, and
Officers of the Revenue, characteristic descriptions of the commodities which
pass through their hands.
Thirdly, by exhibiting some of the finest developments of chemistry and
physics, to lay open an excellent practical school to students of these kindred
sciences.
Fourthly, to teach Capitalists, who may be desirous of placing their funds
in some productive bank of industry, to select judiciously among plausible
claimants.
Fifthly, to enable Gentlemen of the Law to become well acquainted with
the nature of those patent schemes which are so apt to give rise to litigation.
Sixthly, to present to our Legislators such a clear exposition of our staple
manufactures, as may dissuade them  from  enacting laws which obstruct
industry, or cherish one branch of it to the injury of many others: and,
Lastly, to give the General Reader, intent chiefly on intellectual cultivation,
a view of many of the noblest achievements of science, in effecting those
grand transformations of matter to which Great Britain owes her paramount
wealth, rank, and power among the kingdoms.
The latest statistics of every important object of manufacture is given from
the best, and, usually, from official authority, at the end of each article.*
The following summary of our manufactures is extracted from  Mr.
Macqueen's General Statistics of the British Empire, published in 1836. It
shows the amount of capital embarked in the various departments of manufacturing industry, and of the returns of that capital:Capital.      Produce.
Cotton manufactures                      -    40,973,872     52,513,586
Woollen   ditto... -    36,000,000          44,250,000
Silk     ditto        --                       8,000,000     10,000,000
Linen    ditto      12,000,000                               15,421,186
Leather   ditto               -     - -    13,000,000        16,000,000
Iron     ditto, to making pig iron-   -   -    10,000,000     7,098,000
Iron, hardware, cutlery, &c.    -             25,000,000     31,072,600
Copper and brass ditto   -      -              3,600,000      4,673,186
China, glass, &c.- -         --          -     8,600,000     10,892,794
Paper, furniture, books, &c.-    10,000,000                  14,000,000
Spirits (British), ales, soap, &c...    37,600,000        47,163,847
Sundries additional  -   --                                   9,000,000
Totals.-                         201,773,872     262,085,199
Although I am conscious of having used much diligence for many years in
collecting information for this work, from every quarter within my reach, the
utmost pains in preparing it for publication, and incessant vigilance during its
passage through the press, yet I am fully aware that it must contain several
errors and defects. These I have studied to rectify in the text of this fourth
edition.
Since this book is not a Methodical Treatise, but a Dictionary, one extensive subject may be necessarily dispersed through many articles. Thus, for
* The statistics of agriculture, trade, and manufactures, are ably and fairly discussed
in Mr. McCulloch's Dictionary already referred to.




vi                            PREFACE.
example, information upon the manufacture of Colors will be found under
azure; black pigment; bone-black; bronze; brown dye; calico-printing;
carmine; carthamus; chromium; cochineal; crayons; dyeing; enamels;
gold; gilding; gamboge; gray dye; green dye; green paints; indigo;
kermes; lac dye; lakes; madder; massicot; mercury, periodide of; Naples
yellow; orange dye; orpiment; paints, grinding of; ochres; paper-hangings; pastes; pearl white; Persian berries; pottery pigments; Prussian blue;
purple of Cassius; red lead; rouge; Scheele's green; Schweinfurth green;
stained glass; terra di Sienna; ultramarine; umber; verditer; vermilion;
vitrifiable colors, weld, white lead; woad, yellow king's.
A casual consulter of the Dictionary, who did not advert to this distribution, might surmise it to be most deficient, where it is in reality most
copious.
The elaborate and costly Encyclopedias and Dictionaries of Arts, which
have appeared from time to time in this country and abroad, have, for the
most part, treated of the mechanical manufactures more fully and correctly
than of the chemical. The operations of the former are, in fact, tolerably obvious and accessible to the inspection of the curious; nor are they difficult to
transfer into a book, with the aid of a draughtsman, even by a person but moderately versed in their principles. But those of the latter are not unfrequently
involved in complicated manipulations, and depend, for their success, upon a
delicate play of affinities, not to be understood without an operative familiarity
with the processes themselves. Having enjoyed the best opportunities of
studying the chemical arts upon the greatest scale, in this kingdom and on
the Continent, I may venture, without the imputation of arrogance, to claim
for my work, in this respect, more precision and copiousness than its predecessors possess. I have gone as far in describing several curious processes
hitherto veiled in mystery, as I felt warranted, without breach of confidence,
to go; regarding it as a sacred duty never to publish any secret whatever,
without the consent of its proprietor. During my numerous tours through
the factory districts of Great Britain, France, Belgium, Germany, and Switzerland, many suggestions, however, have been presented to my mind, which I
am  quite at liberty to communicate in private, or carry into execution, in
other districts too remote to excite injurious competition against the original
inventors. I am also possessed of many plans of constructing manufactories,
of which the limits of these volumes did not permit me to avail myself, but
which I am ready to furnish, upon moderate terms, to proper applicants.
May I venture to point attention to the very insecure tenure by which patents
for chemical or chemico-mechanical inventions are held; of which there is
hardly one on record which may not be readily invaded by a person skilled
in the resources of practical chemistry, or which could stand the ordeal of a
court of law, directed by an experienced chemist.  The specifications of
such patents stand in need of a thorough reform; being for the most part not
only discreditable and delusive to the patentees, but calculated to involve
them in one of the greatest of evils-a chancery suit.
While I gratefully acknowledge the indulgence with which this work has
been received, may I be permitted to advert very briefly to some of my present endeavours to render it less undeserving of public favor, though, after all
my efforts, it will by no means realize either my own wishes and intentions,
or the expectations of all my readers?
To investigate thoroughly any single branch of art, we should examine it
in its origin, objects, connexion with kindred arts, its progressive advancement, latest improved state, and theoretical perfection. The general principles on which it is founded, whether belonging to the mechanical, the physical,




PREFACE.                                vii
the chemical sciences, or to natural history, should be fully expounded, and
tested by an application to its practical working on the great scale. The maximum effect of the machinery which it employs, and the maximum  product
of the chemical mixtures and operations which it involves, should in every case
be calculated and compared with the actual results.
Such -have been my motives in the numerous consultations I have had
with manufacturers relatively to the establishment or amelioration of their factories; and when they are kept steadily in view, they seldom fail to disclose
whatever is. erroneous or defective, and thereby lead to improvement. It
will not be denied by any one conversant with the productive arts, that very
few of them have been either cultivated or described in this spirit. It is to be
hoped, however, that the period is not remote, under the intellectual excitement anti emulation now  so prevalent in a peaceful world, when manufactories will be erected, and conducted upon the most rational and economical principles, for the common benefit of mankind. Meanwhile it is the duty
of every professor of practical science to contribute his mite towards this desirable consummation.
It is under a sense of this responsibility that I have written the leading
articles of this edition, having enjoyed some peculiar advantages in my profession for making the requisite researches and comparisons. I trust that not
many of them deserve to be regarded as trite compilations or as frivolous novelties, with the exception of a few of the notices of recent patents, which I
have intentionally exhibited as beacons to deter from the treacherous quicksands, not as lights to fiiendly havens.  I have sought sincerely to make
them all conducive, more or less, to utility; being either new contributions to
the old stock of knowledge, or additions and corrections to the present double
volume.
Manufacture is a word which, in the vicissitude of language, has come
to signify the reverse of its literal intrinsic meaning; for it now denotes every
extensive product of art which is made by machinery, with little or no aid of
the human hand; so that the most perfect manufacture is that which dispenses
entirely with manual labor.
In every well-governed state of continental Europe there exists a Board
of Health, or Conseil de Salubrite composed of eminent physicians, chemists,
and engineers, appointed to watch over whatever may affect injuriously the
public health and comfort. In France, this commission consists, for the capital, of seven members, who have the surveillance, in this respect, of markets,
factories, places of public amusement, bakeries, shambles, secret medicines,
&c. This tribunal has discharged its functions to the entire satisfaction of
their fellow citizens, as appears from the following authentic report:-~" Non
seulement une foule de causes d'insalubrite disparurent, mais beaucoup de
moyens, de proc6des nouveaux furent proposes pour assainir les Arts et les
Metiers, qui jusque la avaient part inseparables de ces causes d'insalubrite;
la plupart de ces moyens eurent un plein succs.  II n'y a pas d'exemple que
les membres du Conseil appelles, a donner leur avis sur les plaintes formees
contre des fabriques, aient jamais repondu qu'il fallait les supprimer sans
avoir cherche eux-memes a aplanir les difficulties, que presentait aux fabricants, l'assainissement de leur art, et presque toujours ils sont parvenu a resoudre le probleme.  Le Conseil de Salubrit, que l'on ne saurait trop signaler a la reconnaissance du publique, est une institution que les nations etrangeres admirent, et s'efforceront d'imiter sans doute."
From this confident hope of emulation by other nations, the author of
these excellent observations would have excepted the United Kingdom, had
he known how little paternal care is felt by the government for the general
interests of the people.  In Germany, indeed, where the fatherland feeling is




viii                           PREFACE.
strong in the breasts even of those rulers whom we are apt to consider despots,
similar boards of health are universally established, whereas our legislative
oligarchy frames laws chiefly for the benefit of its own class and dependents;
as happened in the old time, when there was no king in Israel to regard alike
the interests of the poor and the rich.
The Prussian municipal law (Allgemeine Landrecht) contains the following enactments with regard to the sale of spoiled or adulterated victuals. Th.
II. Tit. 20.; Abschnitt 11, ~~ 722 to 725. "No person shall knowingly sell
or communicate to other persons for their use, articles of food or drink which
possess properties prejudicial to health under a penalty of fine or bodily punishment.  Whosoever adulterates any such victuals in any manner prejudicial
to health, or mixes them with unwholesome materials, especially by adding
any preparation of lead to liquors, shall, according to the circumstances of the
case, and the degree of danger to health, be liable to imprisonment in a correction house, or in a fortress, during a period varying from one to three years.
Besides this punishment, those who are found guilty of knowingly selling
victuals which are damaged or spoiled (verdorbener), or mixed with deleterious additions, shall be rendered incapable for ever of carrying on the same
branch of business. The articles in question shall be destroyed if incorrigibly
bad, but if otherwise, they are to be improved as far as possible at the cost of
the culprit, and then confiscated for the benefit of the poor. Further, whosoever mixes victuals or other goods with foreign materials, for the purpose of
increasing their weight or bulk, or their seeming good qualities, in a deceitful
manner, shall be punished as a swindler."
It is singular how, amid the law-making mania which has actuated our
senators for many sessions, that not even one bill has been framed for the protection of the people from spoiled and adulterated foods and drinks."*
Many novelties of an interesting and useful nature, first displayed in the
late Grand Exhibition of the Industry of all Nations, which had not been noticed
in the alphabetical places as patent or other inventions, are here described
with merited commendation; though at the hazard, sometimes, of a little repetition. This valuable portion of the Dictionary was accomplished with the
aid of the able abstracts made by the ingenious authors of a series of
articles inserted in successive numbers of "Newton's London Journal of
Science."
The candid critic will take into view the number of original disertations
now introduced, and treated at considerable length. On comparing these
with the usual staple with which similar books are made up, he will recognize my diligence at least, and make allowance for a few oversights. He will
see, that having fully availed myself of the facilities offered by the alphabetical distribution of the subjects, I have been able to amend, under an equivalent
title, what seemed amiss under the main head. Thus, for example, the elegant new art, for which we are indebted to Daguerre, may be considered in
connection with his name, as also under the title Photography, or better perhaps under that of Heliography, or Sun-painting; since the solar rays are the
preferable excitant. As it has been also termed Calotype, under this name
Sun-painting has been briefly noticed.
In the mechanical department of the Dictionary, I have received valuable
contributions from  the two distinguished engineers, Mr. William  and Mr.
Peter Fairbairn, brothers. The first is generally recognized all over the factory world as eminent for the originality, grandeur, and justness of his inventions.  It has been my good fortune to be conversant with his magnificent
workshops, in Manchester and Millwall, during very many years, and I have
*See the article "PROVISIONS, PRlUsRVED."




PREFACE.                                ix
always regarded them as the best mechanical schools in the kingdom. Mr.
Fairbairn commenced his brilliant career as a factory millwright, by discarding the heavy and clumsy square shafts and drums of Arkwright and his compeers, and replacing them  by slender rods of wrought-iron, and cast-iron
pulleys; causing these to revolve with such a velocity as fully compensated
for their diminished weight, according to the true principles of dynamics. He
thus effected an immense and most beneficial revolution in factory-construction, in cotton, corn, flax and silk mills; enabling the machinery to be driven
with far less power and greater precision.
His next important step was a general improvement in mill architecture;
the construction of fire-proof buildings; as also mounting the fly-wheels of
steam-engines, with teeth on their periphery, into first motions. This change
was condemned by some millwrights at the time, but has since become general.
The investigation of the strength of cast-iron beams, and a greatly improved
style of building, by the introduction of pilasters at the corners, completed
his system of fire-proof spinning works. This plan has been since copied in
all the textile factories.
The experiments referred to, and the construction of several iron steamboats, led him to the extensive use of iron as as a material for shipbuilding.
Though Mr. Fairbairn was not the first to build iron boats, yet he and his
then partner, Mr. Lillie, were the first to show how this material should be
best applied.
The system  of working steam-engines expansively, by means of revolving discs, which is also very extensively used, with the saving of one half of
the fuel, was contrived by Mr. Fairbairn about this time.
We have now arrived at the grand consummation of his mechanical
genius-the tubular bridges and tubular cranes.
His bridges across the Conway river and the sea straits of Menai are such
stupendous and marvellous creations of engineering enterprize, as to have
cast all former mechanical exploits into the shade, and to have led to the
notion that nothing of a like description was ever undertaken or executed by
him. Hence, perhaps, I may be blamed for using the expression Fairbairn's
Tubular Bridges. Fifty-two tubular bridges have been already erected in this
and other countries by this unparalleled Pontifex Maximus.
In fact, Mr. Fairbairn's title to the honor of inventing the genuine rectangular tubular bridge,-not the spurious cylindrical or elliptic form, is as clear
as that of Sir Isaac Newton to the invention of the binomial theorem, or Sir
H. Davy to that of the miners' safety lamp.
I am indebted, with my readers, to Peter Fairbairn, Esq., of Leeds, undoubtedly the great and the best manufacturer of flax machinery and flax
mills, for the article FLAX. He has been ably assisted by the engineers
of his princely establishment, and especially by Mr. Robert Busk.
Many most ingenious and instructive disquisitions are due to my worthy
chemical friend, Mr. Lewis Thompson, and that particularly under the head
COAL, in the body of the work; and in the following few remarks.  That
there is nothing personal in the language is clear from this, that it is an exact
transcript of the original Government Report.
Few persons at all alive to the enormous importance of the question at
issue will consider it possible to be too critical in a matter so notoriously associated with our national power, welfare, and prosperity. After all, however, the remarks must speak for themselves. Nevertheless, lest their merits
should be called in question, it becomes necessary to demonstrate, not only
that they are correct and just, but that even the gentlemen engaged in this
coal investigation themselves bear evidence to the scientific accuracy of those




x                              PREFACE.
very remarks, and have actually modified their subsequent reports in accordance with the principles there first developed. But over and beyond all this,
it will now be shown, from practical results obtained during many years by
the most impartial experimentalists, that the views there displayed respecting
the calorific power of fuel are strictly in accordance with facts of the most obvious and certain nature, and should lead to a vast economy in steam navigation.
Without needlessly dilating therefore upon the value of the evidence now
about to be given, I shall at once proceed to offer the evidence itself, and
leave the public to draw an unbiassed conclusion.
In the first Admiralty Report it was attempted to be proved "that the
evaporative value of a bituminous coal is expressed by the evaporative value of
its coke, the heat of combustion of its volatile products proving in practice
little more than that necessary to volatilize them." And this foregone conclusion was found to be verified by column B. of Table VI., which proved
"that, notwithstanding several striking exceptions which might have been expected, the experiments on the whole show the work capable of being performed by the coke alone is actually GREATER than that obtained by experiments with the original coal."
Again, as regards the nitrogen contained in coal, it was asserted, that the
whole system of manufacturing coke is at present very defective; that " an
immense quantity of ammonia is lost by been thrown into the atmosphere;"
and that " by a construction of the most simple kind, the coke ovens now in
use might be made to economize much of the nitrogen which invariably escapes in the form of ammonia." And accordingly a column of Table VI. was
set apart for the purpose of rousing the dormant energies of coke makers by
showing "the amount of sulphate of ammonia" which, "by a construction of
the most simple kind," they could get from the coals.
Again, it was laid down, that it is easy from analysis to examine whether
the duty performed by the coal is to be attributed to its fixed ingredients (ingredient?) or coke;" and hence a column in Table VI. was given to show the
theoretical " number of lbs. of water convertible into steam by the coke left
by the coal."
Again, in the First Report, " the area of the damper open" was for the
most part kept uniform in different trials with the same coal; as, for example,
with the Penterfelin, the Duffryn, Wards Fiery vein, the Binea, the Llangenneck, the Mynydd Newydd, the Graigola, &c. &c. &c., a change in the area
being the exception. Now in all these respects the Reports No. 2. and 3.'differ entirely from Report No. 1., as also in respect to certain proximate analyses which were contained in No. 1. Report.
The "theoretical lbs. of water convertible into steam by the coke" have
disappeared; the ammonia and sulphate of ammonia to be got by "a construction of the most simple kind" have disappeared; the proximate analyses
have disappeared; the foregone conclusion respecting the coke of bituminous
coal has not only disappeared, but met with a direct negative answer upon
practical trial; "the area of the damper open" has been never twice alike with
the same coal, nay the very litharge experiments have been arranged so as to
compensale for the errors arising from iron pyrites; and lastly, we find that it
is not only not " easy from the analysis to examine," &c., but even the calorific
coke theory is abandoned in Report No. 3., for it there appears that the analyses show generally that, although the " quantities of carbon and hydrogen
regulate materially the economic values of the coals," yet in spite of these analyses " the inquiry would have been far from sufficient, had we not elicited
the economic values of the coals by actual trial under the boilers,"-a result




PREFACE.                               xi
not varying much from our former dictum, that "a good stoker was of more
importance than a scientific chemist for such an investigation."  And how
in fact can it be otherwise, when we find that the analyses were made on
such a scale that "more accurate results were obtained by operating upon
three or four grains than upon a larger quantity!! "
The great principle contended for in our previous remarks was that the
volatile constituents of a bituminous coal, so far from being worthless in a
calorific point of view, were on the contrary of the greatest importance. Now
this, though in direct opposition to the deductions of Report No. 1, can be
proved to demonstration from the results of Report No. 2.; and hence no
doubt the reason why we find in Report No. 3 that the quantities of carbon
and hydrogen regulate materially, &c. At page 45 of Report No. 2, a comparative experiment is recorded for the purpose of determining whether the
coke of a bituminous coal or the coal itself possessed the greatest evaporative
power; for as we have seen in Report No. 1, the " work capable of being
performed by the coke alone was actually greater than that obtained with the
original coal." The coal employed in this experiment was the Tanfield, and
it yielded 65 per cent. of coke; the coke was made from the same coal by
Messrs, Cory & Son, of New Barge House, Lambeth, names too well known
for the excellence of their manufacture to require comment here. The experiments were carried on for 34 consecutive hours with each material, and
the total amount of water evaporated was 33,170 lbs. or about 15 tons. So
far, however, from finding that " the evaporative value of a coal is expressed
by the evaporative value of its coke," which in this case was 65 per cent.
only, lo! the experiments prove that the evaporative power of the coal was
20'1 per cent. greater, weight for weight, than that of the coke, or about 50
per cent.  greater than its own amount of coke!!-thus showing that the 35
per cent. of volatile ingredients were absolutely equal in heating power to the
whole of the coke!! i  And strange to say, this is borne out exactly by the
results obtained in the manufacture of gas, in which, as is quite notorious,
each gallon of tar, weighing from 10~ to 11 lbs. is found to have a calorific
power equal to half a bushel of coke weighing from 21 to 23 lbs. There is
not a gas- engineer in Great Britain ignorant of this important fact, nor the
secretary of a gas works, who, with coke at 4d. per bushel, estimates coal
tar as fuel at less than 2Id. per gallon; and we happen to have now before
us a series of actual workings extending over very long periods of time since
the year 1831, and made by the engineer of the largest gas works in the
world, for the express purpose of ascertaining the practical details connected
with the relative economy of coal tar, coal and coke, and from which we have
deduced the following, as the average values of these combustibles expressed
in pounds of coal.carbonized or distilled by the same weight of each:Tar equal                                   5 lbs
Newcastle coal equal            -          4- lbs.
Coke from do. equal -          -     -      3 lbs.
the "breeze" employed with the tar being -deducted and estimated as equal
to Iths of its weight of coke.
In point of fact, however, the relative value of coal and coke may be more
decidedly determined by examining the heating power of the whole of the
products of a ton of coal, and deducting therefrom  the fuel employed in the
distillation.  For example, a ton of Newcastle coal may be distilled practically by 11 bushels of its own coke, and it will then yield about 36 bushels
of coke, 4 bushels of breeze, 10 gallons of tar, and 9500 cubic feet of gas of
specific gravity'400. Consequently the heating power of the tar and gas




xii                              PREFACE.
taken together ought, upon the hypothesis assumed in the Admiralty Report
No. 1, to be equal only to that of 11 bushels of coke, " the heat of the volatile
products, &c., being only sufficient to volatilize them." Now it has been demonstrated over and over again, that every cubic foot of the aforesaid gas will
practically boil off 2950 grs. of water, therefore 9500 cubic feet will boil off
4000 lbs. of water.
But since the 11 bushels of coke employed in carbonizing the coal weigh
only about 460 lbs., and the evaporative value even of the best oven coke,
according to the Admiralty Coals Report, is only 7'91 for every lb. (vide
page 46, Report No. 2), it follows that the 11 bushels in question would only
evaporate 3538 lbs. of water, or less by 462 lbs. than the gas alone, without
taking into account the evaporative power of the 10 gallons of tar, and which
cannot be assumed at less than 2000 lbs. upon the lowest computation. Consequently our facts, and the hypothesis contained in the First Admiralty Report stand as under:
Hypothesis                           Practical Facts.
One ton of coals carbonized by the    One ton of coal carbonized by 11 bushels
heat of its volatile constituents affords 40  of coke affords 9500 cubic feet of gas, 10
bushels or 1680 lbs. of coke, equal to the  gallons of tar, and 40 bushels of coke,
evaporation of 13,378 lbs. of water.   from which latter 11 are to be deducted.
Thus leaving as the total heating power:
lbs of water.
29 bushels, or 1218 lbs. of coke equal
to      -     -      -        9634
9500 cubic feet of gas equal to  -  4000
10 gallons of tar equal at least to   2000
Total lbs. 15,634
or nearly 20 per cent. more than the coke, a result which not only agrees
with the practical experiments made with the Admiralty boiler, but also with
the statements of Mr. Clegg, who indeed makes the difference greater, that
is, 21 per cent. in favor of coal.  Mr. Clegg, in the second edition of his
practical treatise on Coal Gas, just published, gives the following as the relative amounts of coal, coke, or coal tar required to distil one chaldron of
coals:
Coal Tar from 24 to 27 gallons, or from 264 to 297 lbs.
Coal from 5 to 5J cwt., or from 560 to 616 lbs.
Coke from 16 to 18 bushels, or from 67:2 to 756 lbs.
He also estimates coal tar at 3d. per gallon.
If arguments of this kind do not conclusively establish the validity of our
first remarks, we can scarcely hope to demonstrate any truth whatever; for
these conclusions are drawn from actual data, the result of many years of
labor undertaken by several different individuals, in different localities, having discordant interests in all respects but one, and that one the discovery of
the simple truth with a view to practical economy in fuel, in establishments
where the fuel accounts annually reach many thousands of pounds sterling.
If it be demanded how it happens that these results differ so materially
from the great bulk of those arrived at by the Admiralty boiler, we might
very properly refer the question to the fabricators of the three Admiralty Reports; but the causes of that difference are too obvious to escape the most
superficial observer; and therefore, without wearying the reader by a tedious
recapitulation, we will merely collate a few instances from  these Reports,
which prove, beyond the possibility of contradiction that the boiler experi



PREFACE.                                 xiii
ments were totally inconclusive even upon the assumptions of the experimenters themselves.
We have before called attention to the want of varied adjustment in the
open area of the damper in most of the experiments in Report No. 1; this
objection is seen very forcibly in Reports Nos. 2 and  3, where it not
unfrequently happens that between 112 inches of area and 56 inches, the
value of the same coal is found to vary as much as 20 per cent. Such being
the case, it is but reasonable to conclude that where a coal has gone on during three experiments increasing in value as the open area of the damper was
increased, that the value of that coal has not been developed simply because
the proper extent of the open area has not been reached in any of the experiments.  As examples where the area has been too small, we may cite the
following:
Area.              Area.               Area.
Blackbrook Rushy       112                  56                 84
Park coals
Result          8'62 lbs.            7-55 lbs.          7 -89 lbs.
Area               Area                Area
Blackbrook             112                                     84
Little Delf
Result          85'7 lbs.            8-13 lbs.          8'17 lb.
Area               Area                Areas
Johnson and Wir- 
thington's Rushy       112                  56                 85
Park
Result          8-59 lbs.           7'83 lbs.          7'62 lbs.
Arere.                                 Area Area
Lynvi coal             112                 56                 84
Result          9'61 lbs.            8-89 lbs.          9'08 lbs.
Area.              Area.               Area
Balcarras five         112                 56                  84
feet nine              112
Result          779 lbs.             6-60 lbs.          7-23 lbs.
Area.re                                Are Area.
Hastings Hartley       112                  56                 84
Result          8'18 lbs.            7'65 lbs.         7'49 lbs.
And in precisely the same condition are the Balcarras Arley, Carr's Hartley, Hedley's Hartley, Bate's West Hartley, Davison's West Hartley, Cowpen
and Sidney Hartley, Hill's Plymouth Coals, the Willington Coal, the Wigan
Four Foot Seam, and a host of others, in Report No. 3, all of which would
no doubt have given a better result with an increased opening in the damper.
Conversely, we find many others with too large an opening, as for example:
Area.              Arereea
North Percy            112                  56                84
Result'743 lbs.'774 lbs.           1 54 lbs.
Area.              Area                Area
Balcarras Haigh         112                 56                 84
Yard mine
Result          6s79 lbs.            865 lbs.           8-26 lbs.
And about a dozen more throughout Reports 2 and 3, in which the
greatest effect has been produced by the minimum of area, leading therefore
to the inference that a more restricted opening would have increased the
value of the fuel. Taken as a whole, the only honest inference that can be




xiv                            PREFACE.
drawn from the three Reports is, that the question sought to be solved by the
Admiralty coal investigation remains exactly where it was for all practical
purposes; the analyses, whether proximate, ultimate, or lithargic, together
with the boiler experiments, being in all senses of the expression null, void,
and of no effect or value whatever.
And as a proof of the little care taken to insure accuracy to the whole performance, we find at page 10, Report No. 3, that even the simplest rules of
arithmetic have been violated in a Table purporting to show the average
composition of the coals from Wales, Newcastle, Lancashire, Scotland, and
Derbyshire. This table gives, or ought to give, the composition of the respective coals in 100 parts, and strange to say, the results do not amount to
100 in any single instance: the Welsh coal is more, and the others less than
100, though the oxygen was calculated from the loss.
LONDON, 18 Upper Seymour-street,
10th June, 1853.




A
DICTIONARY
OF
ARTS, MANUFACTURES, AND MINES.
ABIETINE. A pale yellow, transparent, viscid exudation from the Abies pectinata,
a species of fir, growing in the neighborhood of Strasburg, and hence called Strasburg
turpentine. It contains 35 per cent. of a volatile oil of an agreeable smell, combined
with a resin, and a small quantity of the acid of amber, as well as the peculiar body
called abietin, a resin of an acid kind, styled therefore by some abietic acid. If the
indifferent resin be removed by absolute alcohol, and the remainder digested with
carbonate of potash, an abietate of potash is obtained. It dissolves in petroleum, and
crystallizes out of it. It resembles Canadian balsam, and is used for attaching microscopic objects to glass slips.
ACETAL, is the subacetate of ether; having for its chemical symbol 3 Ac 0 -- Ae
0. It is a light colorless ethereous liquid.
ACETATE. (Acetate, Fr.; Essigsaure, Germ.) Any saline compound of which the
acetic is the acid constituent; as acetate of soda, of iron, of copper, &c.
ACETATE OF ALUMINA, see RED LIQUOR and MORDANT; of COPPER, see COPPER;
of IRON, see IRON; of LEAD, see LEAD; of LIME, see PYROLIGNOUS ACID.
ACETIC ACID, or, according to the new nomenclature of organic chemistry acetylic
acid hydrate, being a compound of the radical ac6tyl (Ac C4 H3 ) and oxygen (s), with
water (H 0), for it cannot be bought in the dry state. It is formed out of alcohol in
the acetous fermentation, or by its oxygenation with air; it is produced in the dry
distillation of most non-volatile organic compounds, as of wood, gum, starch, &c., in
the spontaneous decomposition of the watery solutions of citric and tartaric acids, as
also by the boiling of several organic substances with sulphuric acid. It exists ready
formed in several vegetable and animal juices. See GERHARDT.
Alcohol is a compound which, even diluted with water and exposed to the air, is
not liable to spontaneous change; but if in this state it is mixed with yeast, at a temperature of from 60~ to 90~ Fahr., it absorbs oxygen, and passes into acetic acid. The
oxygen forms first water, with 2 atoms of the hydrogen of the ethyl, whereby acetyl
is generated; therefore ethyloxide-hydrate (alcohol) becomes acetyloxide hydrate,
(aldehyde), which by absorption of two more atoms of oxygen, constitutes hydrated
acetic acid.
1 Atom Alcohol      -      C4 HtO -0    H O
-  2 Atoms Hydrogen   H= Ha
-  Aldehyde            C4 H3 0 +- H 0
+ 2 Atoms Oxygen              _ O
-        Acetic Acid Hyd.     C4 Hs 0   - +H 0.
Its atomic weight on the hydrogen scale is therefore 60 in the state of hydrate, and
61 dry.
Albumen, gluten, and vegetable matters which contain these substances, such as the
juice of beet-roots, operate also the oxidation of alcohol, and that the more rapidly,
the more ample the exposure of the mixture to the air. While sugar is transmuted
into carbonic acid, and alcohol only through the intervention of gluten, alcohol suffers that change by contact with finely divided platinum. It is hence probable, that
to what is called acetous fermentation, the vital action of the particles of yeast is not
indispensable, and that it belongs rather to the category of chemical combustion; to
the contact action of Liebig, the catalysis of Berzelius, or the polar combination of Lou6ig.
In the vinegar of wine, malt, or that in which organic matter has been infused,
there appears a peculiar mould-plant, belonging to the genus Mycoderma Pers.; which
is usually called vinegar mother. As the plant grows, it decomposes the acid, and
VoL. I.




2                               ACETIC ACID.
leaves eventually nothing but water. It contains proteine, and consequently azote,
but leaves no ashes when burned.
The same circumstances which govern the conversion of alcohol into vinegar, preside over that of wood spirit into formic acid (acid of ants), fusel oil (oil of grain) into
valerianic acid; and probably butyric acid has some such organ. With regard to the
formation of vinegar, M. Dumas observes that every fermentation has for its effect to
dissociate a compound into a more simple state; but the so-called acetous fermentation unites alcohol or aldehyde with the oxygen of the air; being the only case in
which fermentation represents a true combination. He admits, notwithstanding, that
this fermentation, in a certain point of view, possesses the character of the other fermentive actions, namely, the concourse of an organized substance, and of an organic
matter; the one being a ferment (the mother), and the other fermentable. The conversion of alcohol into vinegar never happens in common cases, without the aid of an
albuminous substance, and of circumstances favorable to all fermentations, such as
the presence of air, not only at its commencement, but during its entire course.
The lactic fermentation has however been sometimes mistaken for the acetous; but
it may be distinguished by its requiring no alcohol, but only starchy or saccharine
matters; and after it begins, exposure to air is not needed. It has been supposed that
acetification is analogous to nitrification, as to the utility of porous bodies which divide the liquid and the air; thus ammonia passed along with air through platinum
sponge, gently ignited in a tube, produces nitric acid; and pumicestone, in like circumstances, combines sulphurous acid and oxygen into the sulphuric; and so we have
seen that a mixture of alcohol vapor and air under the influence of the same sponge
is converted by a true oxidation of the ether (of the alcohol), first into aldehyde, and
afterwards into acetic acid. A like oxidation takes place in the wine or beer, which
being purposely left in casks partially filled, rises by capillarity on the wood above
the liquid level, and is there subjected to the porous influence. The vinegar is much
more rapidly generated, however, by the various artificial methods of multiplication
of points of contact with the air, presently to be described.
Vinegars may be arranged under four heads: 1. Malt or sugar vinegar; 2. Wine
and fruit vinegar; 3. Alcohol vinegar; 4. Wood vinegar.
1. Malt vinegar is manufactured most extensively in the United Kingdom, chiefly in
England, to the amount of fully 3,000,000 of gallons, on which an excise duty of 2d.
per gallon is levied, and for the license to manufacture it, 51. annually must be paid.
The total number of vinegar manufactories in this country is about fifty, of which five
of the principal ones are in London, and these carry on at the same time the manufacture of British wines, now happily emancipated from the trammels of the Excise.
From 6 bushels of malt, properly crushed, 100 gallons of wort in whole may be extracted by due mashing, the first water of infusion being of the temperature of 1600
Fahr., and the next two progressively hotter, for exhausting the soluble saccharine
matter.  When the wort is cooled to 75~, from 3 to 4 gallons of good yeast are stirred
into it in the fermenting tun, and when it has been in brisk fermentation for about 40
hours, it is racked off into used vinegar casks, laid upon their sides in a room heated
with a stove for quick work; or otherwise, during summer, in the open air, under exposure to the sun. The casks should be only about i filled, and left unclosed, or loosely covered from the rain at their bung holes, to favor the free acidifying action of
the atmosphere. In the air, the acetic fermentation may not be completed till after
the lapse of three months; but in stove-rooms in much shorter time, according to the
temperature.  The sour liquor is then transferred from the several casks by means of
a flexible pipe, and pumped into the stove-vat, whence it is run into the clarifying and
flavoring casks, called "rapes,"being here made to filter slowly and repeatedly through
condensed heaps of the stalks and skins of raisins, called rape, which is the refuse of
the British wine manufacture. Vinegar thus made contains always a considerable
quantity of gluten, and is therefore liable to become mouldy and to putrify; to counteract which, a certain portion of sulphuric acid may be legally, and is always, mixed
with British-made vinegar; but that portion is too often overpassed through avarice,
and is certainly injurious to health. I have found by analysis in a sample of vinegar,
made by one of the most eminent London manufacturers, with which he supplies the
public, no less than 175 grains of the strongest oil of vitriol per gallon, added to vinegar containing only 3-6 per cent. of real acetic acid; giving it an apparent strength
after all of only 4 per cent.; whereas standard commercial vinegar is rated at 5 per
cent.  It is a remarkable fact, that the people of this country have had their vinegar
palate so depraved, that they prefer the vitriolized vinegar to the pure; and that all
attempts at introducing a better article into general sale has proved abortive,-a fact
discreditable to our nation, of which several instances have come before me.
The complete acidification of malt wort by the above process being very slow, has
given rise to many projects, more or less successful, for accelerating it. So long ago
as the year 1824, Mr. Ham, of Norwich, obtained a patent for exposing worts to the




ACETIC ACID.                                      3
atmospheric air upon a most extensive surface, by means of a revolving pump, which
caused a constant shower of it to fall upon and through a bundle of birch twigs
supported in the middle of a large tun.  The air had free access to the twigs.  The
wash, being kept at a temperature of from 90~ to 1000 Fahr., by steam pipes at the
bottom of the tun, and continually repumped, became moderately acetified in 48 hours,
and was finished into good vinegar, either by that process, or preferably by racking off
into casks, and exposing it in them  to a temperature'of 85~ Fahr. for 15 or 20
days. He also found that a wort made with 1 part of malt mixed with 6 of raw barley,
properly mashed, afforded by this means an excellent vinegar. A wort of sp. gr. 1'060
(60 excise gravity) will yield a vinegar of revenue proof, or of 5 per cent. of real acetic
acid. This quick process belongs rather to the combustion class of chemical transformations than to that of the fermentative, as yeast is not essential, though it is found to
prove serviceable, as in the corresponding formation of acetic acid from the oxygenation of alcohol some stale vinegar is used as a ferment, or as a contact agent.
Under Messrs. Ham's instructions four considerable manufactories of vinegar have
been established, with the products of two of which I am practically conversant, and I
am warranted by experimental proofs in declaring that the vinegar made by Messrs.
Hill, Evans, and Williams, of Worcester, and Messrs. Hills and Underwood, of Norwich and Eastcheap, London, are perfect specimens of acetic acid for family use, and
also for manufacturing purposes.  The latter company liberally displayed, in the
South Gallery of the Royal Exhibition, at No. 7. Class 3. substances used as food, a
model of their acetifying apparatus, as mounted in their works.
An excellent vinegar may be made for domestic purposes by adding to a syrup consisting of one pound and a quarter of sugar for every gallon of water, a quarter of
a pint of good yeast.  The liquor being maintained at a heat of from 75~ to 80~ Fahr.,
acetification will proceed so well that in 2 or 3 days it may be racked off from the
sediment into the ripening cask, where it is to be mixed with 1 oz. of cream of tartar,
and 1 oz. of crushed raisins.  When completely freed from the sweet taste, it should
be drawn off clear into bottles, and closely corked up. The juices of currants, gooseberries, and many other indigenous fruits, may be acetified either alone, or in combination
with syrup.  Vinegar made by the above process from sugar should have fully the
revenue strength. It will keep much better than malt vinegar, on account of the
absence of gluten, and at the present low price of sugar will not cost more, when
fined upon beech chips, than Is. per gallon.
2. Wine vinegar is made of the best quality, and on the greatest scale, at Orleans in
France, out of wines which have become more or less acidulous, and are, therefore, of
inferior value.  When the vinegar is made from well-flavoured wines, it is preferable
to every other for the use of the table. The old method pursued in the vinaigreries
consists merely in partially filling a series of large casks placed in 3 or 4 ranges over
each other in a cellar warmed with a stove to the temperature of 85~ Fahr., with the
wine mixed with a certain proportion of ready-made vinegar as a ferment.  More
wine is added in successive small portions as fast as the first has become acetified, taking care that a free ventilation be maintained, in order to replace the carbonic acid
produced by fresh atmospheric oxygen.  In summer, under a favorable exposure of
the windows and walls of the fermenting room to the sun, artificial heat is not needed.
Each cask is of about 60 gallons capacity, and the whole set is filled up - with vinegar, to which 2 galls. of wine are added, and weekly afterwards 2 galls. more. About
8 gallons are drawn off at the end of four weeks as vinegar, and then successive additions of wine are made as before to the casks. These are laid horizontally in rows
upon their gawntrees, and are pierced at the upper surface of the front end with two
holes: one, called the eye, is two inches in diameter, and serves for pouring in the
charges through a tunnel; the other is a small air-hole alongside. The casks should
never be more than I full, otherwise a sufficient body of air is not present in them for
favouring rapid acetification.  At the end of a certain period, the deposit of tartar and
lees becomes so great, that the casks must be cleared out. This renovation usually
takes place every ten years; but the casks, when made of well-seasoned oak and bound
with iron hoops, will last 25 years.  The wine as well as the vinegar produced should
be clarified by being slowly filtered through beech chips closely packed in a large
open tun.  When wines are new, and somewhat saccharine, or too alcoholic, they
acetify reluctantly, and need the addition of a little yeast or even water to the mixture; and when they are too weak, they should be enriched by the addition of some
sugar or stronger wine, so as to bring them to a uniform state for producing vinegar
of normal strength. To favour the renewal of fresh air into the upper part of the
hogsheads, it would be advisable to pierce a two-inch hole near to the upper level ot
the liquid when the cask is fullest, by which means theheavy carbonic acid would fall
out, and be replaced by the atmospheric air at the superior apertures.
I have had occasion to examine professionally the best wine vinegars imported ino




4                                 ACETIC ACID.
this country from Orleans, and I found their specific gravity to be about 1-019, and their
percentage of acetic acid hydrate (crystalline acid) to be from 6  to nearly 7. One or two
samples were supposed to contain acetified cider. This adulteration may be tested by
neutralizing the vinegar with ammonia, and then adding solution of acetate of lime.
Tartrate of lime is of course precipitated from the wine vinegar, while the pearly malic
acid of the cider affords no precipitate with the lime, but may be detected by acetate of lead, by the glistening pearly scales of malate of lead, hardly soluble in the cold.
3. Alcohol Vinegar.-This species has been hitherto manufactured chiefly in Germany, having commenced soon after Dbbereiner's fine discovery of the combustion of
alcohol into acetic by the agency of platinum  mohr.  Under a large glass bell, he
placed on shelves, an inch or two apart, several saucers, containing spirits of wine, with
slips of blotting paper so suspended as that their lower edges dipped in the spirits.
Over and alongside of these saucers, other smaller ones were set, containing the black
platinum powder moistened with the spirits. The apparatus being exposed to the sunshine, or even put into an apartment moderately warm, a copious formation of vapours
takes place, with a manifest increase of temperature, and streaks of condensed fluid run
down the sides of the bell into the subjacent basin. This fluid is acetic acid, resulting
from the acidification of the elements of the alcohol by the oxygen of the atmospherical
air included. This interesting transformation ceases with the exhaustion of the oxygen,
but it may be renewed from time to time by renovation of the air. One atom of alcohol = CC4  5 O + H 0 = 46 parts; in which compound, two atoms of hydrogen being
replaced by two of oxygen, we have 46 + 14=60 parts, or one atom of hydrated acetic
acid. Hence we see that 46 parts of absolute alcohol afford 60 of radical vinegar; 100
parts therefore afford 130, and require for this conversion nearly 70 parts of oxygen, allowing two atoms of oxygen for the abstraction of the two atoms of hydrogen Since air
in round numbers contains a little more than one fifth its volume of oxygen, then 1000
cubic inches wil contain upwards of 200 of oxygen, which will weigh fully 70 grains,
being the quantity requisite for the transformation of 100 grains of alcohol into acetic
acid in the above process. Two atoms of water are also formed, equal to 18 grains.
In practice it is found that weak alcohol answers best. With a box of 12 cubic feet
capacity, and with 7 or 8 ounces of platinum mohr properly distributed, 1 lb. of alcohol may in the course of a day be converted into pure vinegar, fit for every purpose of
the kitchen or the chemist. I have examined the vinegar manufactured from spirits, and
found it to be excellent, as it contains no gluten, and it is therefore not liable to change.
It is not possible intthis way to make a strong acetic acid, nor can it be made at all
on the large scale in this country, on account of our revenue laws.
In the sequel of Dobereiner's discovery, another German chemist, M. Schutzenbach,
applied the principle of oxygenation to beers and other alcoholic liquors, for the purpose of converting them rapidly into vinegar; and about the same time M. Wagenmann
contrived his graduator, or essigbilder, a simple apparatus for the quick vinegar manufacture. It consists of an oaken tub 52 feet high, 32 feet wide, and 3 feet at bottom, set
upon a wooden frame about 14 inches from the floor. Fifteen inches above the bottom,
the tub is pierced with a horizontal row of eight equidistant holes, one inch in diameter.
Five inches beneath the mouth of the tub a strong beechwood hoop is fastened to the
inner surface, in order to support a circular oaken shelf, the space round the edge of
which is stuffed tight with hemp. This shelf is perforated with at least 400 gimlet holes
of about A of an inch, through each of which a porous cotton wick is let down several
inches, hanging by a knot in the top of the hole at its upper end. In the same circular
shelf there are 4 holes, 1J inch in diameter, and 18 inches apart, into each of whichis
fixed tight the middle of a stout glass tube about 4 inches long. These tubes favour
the circulation of the air admittted by the circumferential holes. One inch above the
bottom of the tub a hole is pierced for the reception of a syphon of discharge, the top
curvature of which must stand about 1 inch below the holes in the side of the tub, to
prevent the liquor collected, to the depth of about 12 inches on the bottom, being spilled.
Into the empty space over this liquor, the bulb of a thermometer is placed, while the
stem and scale project to show the interior temperature. Beneath the lower outer leg
of the syphon a reception cistern is set. The mouth of the tub has a wooden lid, with
a funnel fixed in its middle for the introduction of the liquor to be acetified. The whole
capacity of this tub from the bottom up to within 1 or 2 inches of the perforated shelf, is
to be filled up with shavings of beech-wood (previously boiled in water), or with grape
stalks, or birch-twigs, all well soaked with vinegar. This apparatus being placed in an
apartment, heated to from 80~ to 1000 Fahr., is to have its uppermost compartment filled with liquor. This slowly filters down through the cotton wick threads, thence over
the surfaces of the chips or stalks, and finally into the subjacent receiver, having been
exposed in its transit very freely to the air. The ordinary acetifying mixture consists
of 8 parts of proof spirits, 25 parts of river water, 15 parts of good vinegar, and 15 parts
of clear beer or wine. The water should be heated to about 1500 before the other inigredients are added to it, whereby the mixture acquires a genial temperature. After




ACETIC ACID.                                     5
this has been all transmitted through the apparatus, it will be found imperfectly acetified, and therefore must be passed through once or twice more. And since the more alcohol that is present the slower is the process, it is advisable to keep back part of the spirits at first, and to add it in the subsequent transmissions. The wash-cistern, which contains the acetifying mixture, should be supported on a shelf near the ceiling of the
stove-heated apartment, in order to be kept constantly warm. After the first operation is completed, the interior of the cask becomes so active an oxidizer, that the addition of vinegar to the mixture is no longer necessary; but care should always be taken to
have itas well clarified as possible, in order to prevent the depositing of much gluten
upon the beech-chips. Dr. Kastner prescribes the following manner of making a malt
wine for the quick vinegar process:-Crush together 80lbs. of pale barley malt, and
401bs. of pale wheat malt, and infuse them in 100 quarts of water of 122~ Fahr., and
afterwards mash them properly with 300 quarts of hotter water. The wort thus made
is to be cooled, drawn off from the grains, fermented with yeast for 3 days, then the
beer is to be barrelled up for use.
I have already adverted to the quick acetification of malt-wort by Mr. Ham's patent
process. This has been mounted upon a large scale of late years, the air for oxygenating
the alcohol of the wash, previously fermented with yeast, having been supplied from
two gasometers, alternately moved by steam-engine power. Two circumstances attend
this quick process; which are, that as the materials are not thoroughly acetified, the
product must be left for some time to ripen in casks, and the resulting vinegar has not
the flavor of that slowly made in the old way. I am informed that a vinegar, equivalent not merely to 51 per cent. has been produced, but one five times stronger, by
operating with an apparatus 13 feet high, 14 wide at bottom, and 15 at top, in which
an adequate temperature was generated during the oxidation of the great mass of
materials, without artificial warmth.
3. Chemical process.-Acetic acid from the pure acetate of soda is formed as follows:
-10llbs. of the pulverized salt being put into a hard glazed stoneware receiver, or
deep pan, from 35 to 36 lbs. of concentrated sulphuric acid are poured in one stream
upon the powder, so as to flow under it. The mixture of the salt and acid is to be
made very slowly, in order to moderate the action and the heat generated as much as
possible.  After the materials have been in intimate contact for a few hours, the decomposition is effected; sulphate of soda in crystalline grains will occupy the bottom of
the vessel, and radical vinegar, or acetic acid (hydrate), the upper portion, partly liquid
and partly in crystals. A small portion of pure acetate of lime, added to the acid, will
free it from any remainder of sulphate of soda, leaving only a little acetate in its place;
and though a small portion of sulphate of soda may still remain, it is unimportant,
whereas the presence of any free sulphuric acid would be very injurious. This is easily
detected by evaporating a little of the liquid, at a moderate heat, to dryness, when that
mineral acid can be distinguished from the neutral soda sulphate.  This plan of superseding a troublesome distillation, which is due to M. Mollerat, is one of the greatest
improvements in this process, and depends upon the insolubility of the sulphate of soda in
acetic acid. The sulphate of soda thus recovered, and well drained, serves anew to
decompose acetate of lime; so that nothing but this cheap earth is consumed in carrying
on the manufacture. To obtain absolutely pure acetic acid, the above acid has to be
distilled in a glass retort. That acid, in its crystallizable state, boils at 2300 Fahr., or
110~ C., by my experiments made with a pure acid prepared by M. Lemire, of Paris:
others have rated its boiling point 114~ and even 120~ C.
The following table of the specific gravities of acetic acid, of successive strengths, is
the result of a series of experiments made by me in Glasgow in May, 1819; the liquid
crystallizable hydrate being reckoned 100:Acid.       Sp. Gr.        Acid.        Sp. Gr.        Acid.        Sp. Gr.
100         1 -0620         76         1'0743          52         1'0617
98        1'0650          74         1 -0740          50         1'0603
96        1'0680          72         1 -0733          45         1'0558
94         1'0700         70         1 0725           40         1'0512
92        1 -0715          68         1'0716          35         1 -0459
90        1 -0728          66         1'0712          30        1 -0405
88        1'0730          64         1'0701          25         1'0342
86        1 -0735          62         1'0687          20         1 -0282
84        1'0738          60         1'0675          15         1'0213
82        1'0740          58         1'0665          10         1'0147
80        1'0750          56         1'0647           5         1 -0075
78        1'0748          54         1'0634
~~...........




6                               ACETIC ACID.
In Berzelius Jahres berichte xvi. 192, the table of Van der Toom is given for the
successive quantities of dry acetic acid, corresponding to successive densities. He rates
the sp. gr. of the hydrate at 1'0570, being the acid which contains 85-11 of dry acid.
In my table, the equivalent hydrate is marked 1 062, a gravity as low as is probably
to be obtained by weighing a solution of the drained crystals. An acid of 1-0698
contains, according to him, 51 of the dry; while an acid of 1'0675 corresponds, in my
table, to 60 of the hydrate, or 51 of dry acid. In general his gravities are a little
greater than mine at corresponding degrees of acid strength. The above numbers in
my table are experimental, not interpolated from a few points, and may, I hope, be
relied upon. The greatest density seems to be produced when two atoms of water   18
are mixed with one of the hydrate = 60, or 23 with 77, at which dilution the differences
of density are very small, and minute errors may have occurred. When 6 atoms of
water are added to one of the hydrate, making 7 atoms of water in all, then the acid
acquires its primitive liquid density of about 1'062. A curious analogy exists in this
respect with nitric acid, which suffers the greatest degree of condensation, in the series
of its dilutions, when one atom of the real acid is combined with 7 atoms of water.
Pure acetic acid possesses a peculiar pungent, though not disagreeable smell, and a
strongly acid taste. It crystallizes in needles and plates when cooled to 55~ Fahr., and
melts when heated to 61~. The specific gravity of the crystals (taken by means of
spirits of turpentine) I found to be 1'135 at 55~ Fahr. The vapor of the boiling
acid is highly combustible, and burns with a blue flame. Acetic acid hydrate dissolves
camphor, gliadine, resins, the fibrine of blood, and several organic compounds. When
its vapor is conducted through a slightly ignited porcelain tube, it is converted entirely
into carbonic acid and aceton, an atom of the acid being resolved into an atom of each
of the resultants. At a white heat, the vapor is converted into carbonic acid,
carburetted hydrogen, and water. The acetates comport themselves at elevated temperatures differently, according to the strength of affinity between the acid and the
base. When this is weak the acid escapes unchanged, and the stronger it is, the more
acid is converted into aceton. Acetate of barytes affords most of this spirituous
liquor, and next to it the alkaline acetates and acetate of lead.
Acetate of copper yields, at a heat of 400~ or 500~, a concentrated acetic acid,
mixed with some aceton. This process was formerly employed for preparing radical
vinegar, as also that of decomposing that of acetate of lead, by sulphuric acid; but
both are now renounced for the process by acetate of soda above described.
Acetic acid is a pretty stable compound, as is evinced by its compound with soda
and potash, bearing the heat of 600~ Fahr. without decomposition. Acetate of potash
and soda, dissolved in much water, readily mould and decompose; but acetate of ammonia is not liable to change in close vessels. When acetic acid is distilled along with
peroxide of manganese and sulphuric acid, it is converted into formic acid. lodic acid
has the same effect with precipitation of iodine: it reduces gold from its chloride
without disengagement of carbonic acid; but it does not reduce mercury from its nitrate or sulphate, as formic acid does.
The simplest reagent for purifying common vinegar is recently calcined wood charcoal in fine powder; with which it may be digested, or, what is better, distilled, whereby a portion of the water comes oven first, and may be got rid of, while the stronger
vinegar is a later product. Attempts are often made to give wood vinegar the flavor of
that made from wine, by adding acetic ether, wine, &c., but never with complete effect.
The best disguise is obtained by mixing in some highly flavored Orleans vinegar.
Malt vinegar prepared by very slow fermentation in the air, acquires a peculiar ethereous odor, which cannot be imitated artificially, and hence persons accustomed to the
flavor of such vinegar, by itself or in pickles, do not relish the vinegar made by the
quick oxidizement process, either from malt or spirits. Even subjecting this vinegar
to the action of rape accomplishes imperfectly the object in view.
Were vinegar pure, it would be valued by its specific gravity alone, which at all
strengths under 50 per cent. gives exact indications; but this is seldom the case, for
ordinary vinegar contains more or less gluten and other organic matter, such as caramel,
or burnt sugar, to color and flavor it, besides sulphuric and possibly other acids.
Hence the Excise have adopted the following plan of acetometry suggested by Messrs.
Taylor.  When pure vinegar is saturated with quicklime, the liquid takes a density
double of that due to the acetic acid present. Thus, an acetate of lime of sp. gr. 1-018,
corresponds to a pure vinegar of 1 009; but malt vinegar of that strength has its density
raised to 1'014 by the gluten.  When such vinegar is saturated with quicklime, the
acetate acquires a specific gravity of 1'023, from which, if the five due to the gluten
be deducted, the remainder, 1-018, will be double of the true density. Revenue proof
vinegar, called No. 24, has, according to these gentlemen, the




ACETIC ACID. 
Sp. gr. 1 0085, and contains of real acid 5 in 100.
Do. 1-0170       do.         do.  10  do.
Do. 1'0257       do.          do.  15  do.
Do. 1-0320       do.         do.  20  do.
Do. 1'0470       do.          do.  30  do.
Do. 1-0580       do.         do.  40  do.
The acid of this table is the anhydrous, being stronger by about 15 per cent. than
that of my table given above. The chemical analysis of vinegar consists first in determining the presence and proportion of foreign matter. With this view 500 grains of
it should be evaporated by the heat of a chlor-calcium bath, the residuum weighed and
examined. If it be sour, sulphuric acid may be suspected, and its amount be ascertained by precipitation with nitrate of barytes, and weighing the washed and dried precipitate. Every 118 parts indicate 49 of oil of vitrol; but if saline sulphates be present, their amount may be ascertained by igniting the above residuum and weighing
what remains.  The loss in ignition will be due to organic matter, acetates, and sulphuric acid. If an alkaline acetate be present after ignition, the residuum may be an
alkaline carbonate. Nitric acid is best detected by adding a few drops of a dilute sulphate of indigo to the vinegar, and by boiling the mixture; when the blue will pass into
a dirty brown yellow if nitric acid be present. In common cases a ready mode of estimating the strength of the vinegar is wanted, and no reagent is better for the purpose
than the bicarbonate of potash, two grains of which are equivalent to very nearly one of
anhydrous acetic acid. To 100 or 1000 grs. of the vinegar in question we have only to
add from a weighed parcel of pounded bicarbonate of potash, enough to produce neutralization by the test of litmus paper, and the half number of grains required denotes the
number of grains of acetic acid in 100 or 1000 of the vinegar. Or a normal solution of
the bicarbonate may be kept ready made, of which 1000 water grain measures contain
100 of the salt; then each 20 grain measures expended in neutralizing 1000 water grain
measures of the vinegar denote one grain of real acetic acid. As the extrication of carbonic acid from the bicarbonate is apt, however, in common hands to cause fallacies,
I prefer ammonia as a general acidimetrical test, of which 1000 water grain measures
of specific gravity 0'992 neutralize exactly one atom of acetic acid; that is, 51 grains of
the anhydrous, or 60 of the hydrate; therefore after adding that test ammonia to the
vinegar faintly reddened with litmus, out of a graduated glass tube, till the neutral tint
of color be hit, the number of water grain measures of test expended, being multiplied
either by 51 or 60, will give for a product the per centage of anhydrous or hydrated
acetic acid. This is the method I have pursued for very many years, and which gives
results of perfect precision in a few minutes.
Vinegar is so extensively employed as a condiment, that it should be of better quality
than is commonly on sale in the United Kingdom, where it is almost always contaminated with oil of vitriol. All our pickles participate in the same noxious ingredient.  The fumes of vinegar, and even its odor, as in the vinegar of the Three
Thieves of Marseilles, were long supposed to be counteractive of contagion in sick
rooms; but they are rather injurious, by covering unwholesome smells from want of
due cleanliness and ventilation, and should never be relied upon. In combination with
alumina, and also with oxide of iron, it is extensively used in the dyeing and printing
of cotton, under the names of red liquor and iron liquor, as mordants for bright and
dark colors.
According to Dobereiner and Liebig, in the conversion of alcohol into acetic acid no
carbonic acid is formed. 100 lbs. of alcohol consisting of 52-6 carbon +-12'9 hydrogen
+ 34-5 oxygen, absorb from the air, in the process of acetification, 35-2 lbs. of oxygen,
which abstract 4-4 lbs. of hydrogen from the alcohol, and thus generate 39-6 lbs. of
water, leaving the substance called aldehyde (dehydrogenated alcohol), which consists
of 52-6 carbon + 8-5 hydrogen -- 68-4 oxygen.
In practice we cannot obtain so much acid as the above, but the theoretical maximum
serves as a beacon, and the nearer we can approach to it the better. About 3600
cubic feet of air contain 69 lbs. of oxygen, the quantity barely necessary for acetifying
100 lbs. of alcohol; but as the air is only partially stripped of that element, much
more is needed, and this excessive current carries off some alcohol, aldehyde, and acetic
acid, and so lessens the product. If, on the other hand, air be too sparingly supplied,
volatile aldehyde is chiefly formed, which flies off, and leaves a mawkish putrefying
liquor of no value.
We may complete the preceding view of the production of acetic acid, by showing
the relations which subsist between it and sugar, and starch, through the medium of
alcohol-four correlative compounds, 100 lbs. of cane sugar are convertible into 100 lbs.
of starch sugar or grape sugar, by boiling it with sulphuric or tartaric acid, and abstracting the acid by means of chalk; and that weight of either kind of sugar is capable of




8                               ACETIC ACID.
yielding, by fermentation, 53-7 lbs. of alcohol. 100 lbs. of starch, if well saccharified,
should afford fully 100 lbs. of starch sugar, and, therefore, 537 lbs. alcohol.  These
are the theoretical quantities, but they can never be realized in practice.
A quarter of good malt, weighing 320 lbs., contains by my experiments 144 solid
extract, which should yield, first, 69, alcohol; and next 100 lbs. of acetic acid hydrate,
equivalent to 17 times that weight of revenue proof vinegar =170 gallons nearly.
Before the process for pyroligneous acid, or wood vinegar, was known, there was only
one method of obtaining strong vinegar practised by chemists; and it is still followed by
some operators, to prepare what is called radical or aromatic vinegar. This consists in
decomposing, by heat alone, the crystallized binacetate of copper, commonly, but impro.
perly, called distilled verdigris. With this view, we take a stoneware retort (fig. 1),
of a size suited to the
quantity we wish to operate upon; and coat it with
a mixture of fire clay and
horsedung,  to  make  it
stand  the  heat  better.
^:. +  E^^ 95^               ~ iy~ =~,  When this coating is dry,.C...; ~      > \  -l  we introduce into the re/"\   tort the crystallized acetate slightly bruised, but
~'~ ~'~ ~ g.. 1~_~.  very dry; we fill it as far
E~~igo *~ ~           as it will hold  without
spilling when the beak is considerably inclined. We then set it in a proper furnace.
We attach to its neck an adopter pipe, and two or three globes with opposite tubulures, and a last globe with a vertical tubulure. The apparatus is terminated by a
Welter's tube, with a double branch; the shorter issues from the last globe, and the
other dips into a flask filled with distilled vinegar. Everything being thus arranged,
we lute the joinings with a putty made of pipeclay and linseed oil, and cover them with
glue paper. Each globe is placed in a separate basin of cold water, or the whole may
be put into an oblong trough, through which a constant stream of cold water is made to
flow. The tubes must be allowed a day to dry. Next day we proceed to the distillation, tempering the heat very nicely at the beginning, and increasing it by very slow
degrees till we see the drops follow each other pretty rapidly from the neck of the retort,
or the end of the adopter tube. The vapors which pass over are very hot, whence a series of globes are necessary to condense them. We should renew, from time to time, the
water of the basins, and keep moist pieces of cloth upon the globes; but this demands
great care, especially if the fire be a little too brisk, for the vessels become, in that case,
so hot, that they would infallibly be broken, if touched suddenly with cold water. It is
always easy for us to regulate this operation, according to the emission of gas from the
extremity of the apparatus. When the air bubbles succeed each other with great rapidity, we must damp the fire.
The liquor which passes in the first half hour is weakest; it proceeds, in some measure, from a little water sometimes left in the crystals, which when well made, however,
ought to be anhydrous. A period arrives towards the middle of the process when we
see the extremity of the beak of the retort, and of the adopter, covered with crystals of a
lamellar or needle shape, and of a pale green tint. By degrees these crystals are carried into the condensed liquid by the acid vapors, and give a color to the product. These
crystals are merely some of the cupreous salt forced over by the heat. As the process
approaches its conclusion, we find more difficulty in raising the vapors; and we must
then augment the intensity of the heat, in order to continue their disengagement. Finally,
we judge that the process is altogether finished, when the globes become cold, notwithstanding the furnace is at the hottest, and when no more vapors are evolved. The fire
may then be allowed to go out, and the retort to cool.
As the acid thus obtained is slightly tinged with copper, it must be rectified before
bringing it into the market. For this purpose we may make use of the same apparatus,
only substituting for the stoneware retort a glass one, placed in a sand bath. All the
globes ought to be perfectly clean and dry. The distillation is to be conducted in the
usual way. If we divide the product into thirds, the first yields the feeblest acid, and
the third the strongest. We should not push the process quite to dryness, because
there remain in the last portions certain impurities, which would injure the flavor of
the acid.
The total acid thus obtained forms nearly one half of the weight of the acetate
employed, and the residuum forms three tenths; so that about two tenths of the acid
have been decomposed by the heat, and are lost. As the oxyde of copper is readily
reduced to the metallic state, its oxygen goes to the elements of one part of the acid, and
forms water, which mingles with the products of carbonic acid, carbureted hydrogen, and




ACETIC ACID.                                    9
carbonic oxyde gases which are disengaged: and there remains in the retort some chatcoal mixed with metallic copper. These two combustibles are in such a state of division,
that the residuum is pyrophoric. Hence it often takes fire the moment of its being removed from the cold retort. The very considerable loss experienced in this operation
has induced chemists to try diflerent methods to obtain all the acid contained in the ace.
tate. Thus, for example, a certain addition of sulphuric acid has been prescribed; but,
besides that the radical vinegar obtained in this way always contains sulphurous acid,
from which it is difficult to free it, it is thereby deprived of that spirit called the pyroacetic, which tempers the sharpness of its smell, and gives an agreeable aroma. It is to
be presumed, therefore, that the preceding process will continue to be preferred for making aromatic vinegar. Its odor is often further modified by essential oils, such as those
of rosemary, lavender, &c.
4. Pyroligneous Acid, or Wood Vinegar.-The process for making this acid is founded
upon the general property of heat, to separate the elements of vegetable substances, and
to unite them anew in another order, with the production of compounds which did not
exist in the bodies subjected to its action. The respective proportion of these products
varies, not only in the different substances, but also in the same substance, according as
the degree of heat has been greater or less, or conducted with more or less skill. When
we distil a vegetable body in a close vessel, we obtain at first the included water, or that
of vegetation; there is next formed another portion of water, at the expense of the oxygen and hydrogen of the body; a proportional quantity of charcoal is set free, and, with
the successive increase of the heat, a small portion of charcoal combines with the oxygen
and hydrogen to form acetic acid. This was considered, for some time, as a peculiar acid,
and was accordingly called pyroligneous acid. As the proportion of carbon becomes
preponderant, it combines with the other principles, and then some empyreumatic oil is
volatilized, of little color, but which becomes thicker, and of a darker tint, always getting
more loaded with carbon.
Several elastic fluids accompany these different products. Carbonic acid comes over,
but in small quantity, much carburreted hydrogen, and, towards the end, a considerable
proportion of carbonic oxyde. The remainder of the charcoal, which could not be carried
off in these several combinations, is found in the retort, and preserves, usually, the form
of the vegetable body which furnished it. Since mankind have begun to reason on the
different operations of the arts, and to raise them to a level with scientific researches,
they have introduced into several branches of manufacture a multitude of improvements,
of which, formerly, they would hardly have deemed them susceptible. Thus, in paati! alar, the process for carbonizing wood has been singularly meliorated, and in reference to
the preceding observations, advantage has been derived from several products that formerly were not even collected.
The apparatus employed for obtaining crude vinegar from wood, by the agency of heat,
Fig. 2.          are large iron cylinders. In this country they are made.rr.   ~of cast iron, and are laid horizontally in the furnace; in
France, they are made of sheet iron riveted together, and
I'',                            P8they are set upright in the fire. Fig. 2 will give an ac-,    curate idea of the British plan, which is much the same as
\I   i _ I  I   I! that adopted for decomposing pit coal in gas works, only
LI/,]'   / Lt~.L I' i   that the cylinders for the pyroligneous acid manufacture are
I-J_   7 ~ ^  ii generally larger, being frequently 4 feet in diameter, and
T    For    )  \  i 6 or 8 feet long, and built horizontally in brickwork, so
that the flame of one furnace may play around two ot
them. It would probably answer better, if their size were
brought nearer the dimensions of the gas-light retorts, and
if the whole system of working them  were assimilated to
that of coal gas.
The foliowing arrangement is adopted in an excellent establishment in Glasgow, where the above large cylinders are
-  X-i X L     I        -T'    6 feet long, and both ends of them project a very little beyond
the brickwork. One end has a disc or round plate of cast iron, well fitted, and firmly bolted
to it, from the centre of which disc an iron tube, about 6 inches diameter, proceeds and
enters, at a right angle, the main tube of refrigeration. The diameter of this tube may be
from 9 to 14 inches, according to the number of cylinders. The other end of the cylinder
is called the mouth of the retort; this is closed by a disc of iron, smeared round its edge
by clay lute, and secured in its place by fir wedges. The charge of wood for such a cylinder is about 8 cwt. The hard woods-oak, ash, birch, and beech-are alone used; fir does
not answer. The heat is kept up during the day-time, and the furnace is allowed to cool
during the night. Next morning the door is opened, the charcoal removed, and a new
charge of wood is introduced. The average product of crude vinegar called pyroligicous acid, is 35 gallons. It is much contaminated with tar, is of a deep brown color,




10                              ACETIC ACID.
and has a sp. gr. of 1'025. Its total weight is therefore about 300 lbs., but the residuary
charcoal is found to weigh no more than one fifth of the wood employed; hence nearly
one half of the ponderable matter of the wood is dissipated in incondensable gases.
Count Rumford states, that the charcoal is equal in weight to more than four tenths of
the wood from which, it is made. The count's error seems to have arisen from the slight
heat of an oven to which his wood was exposed in a glass cylinder. The result now
given, is the experience of an eminent manufacturing chemist.
The crude pyroligneous acid is rectified by a second distillation in a copper still, in the
body of which about twenty gallons of viscid tarry matter are left from every 100. It has
now become a transparent brown vinegar, having a considerably empyreumatic smell,
and a sp. gr. of 1'013. Its acid powers are superior to those of the best household
vinegar, in the proportion of three to two. By redistillation, saturation with quicklime, evaporation of the liquid acetate to dryness, and conversion into acetate of soda by
sulphate of soda, the empyreumatic matter is so completely dissipated, that on decomposing the pure acetate of soda by sulphuric acid, a perfectly colorless and grateful vinegar rises in distillation. Its strength will be proportionable to the concentration of the
decomposing acid.
The acetic acid of the chemist may be prepared also in the following modes:-l. Two.
parts of fused acetate of potash, with one of the strongest oil of vitriol, yield, by slow
distillation from a glass retort into a refrigerated receiver, concentrated acetic acid. A
small portion of sulphurous acid, which contaminates it, may be removed by redistillation
from a little acetate of lead. 2. Or four parts of good sugar of lead, with one part of
sulphuric acid, treated in the same way, afford a slightly weaker acetic acid. 3. Gently
calcined sulphate of iron, or green vitriol, mixed with sugar of lead, in the proportion of
I of the former to 24 of the latter, or with acetate of copper, and carefully distilled from
a porcelain retort into a cool receiver, may be also considered an economical process.
But that with binacetate of copper above described, is preferable to any of these.
The manufacture of pyroligneous acid is conducted in. -' -      the following way in France. Into large cylindrical
vessels (fig. 3) made of riveted sheet iron, and having
Fig. 3  \\                 at their top and side a small sheet iron cylinder, the wood
lg. *.  \\ l       intended for making charcoal is introduced. To the
upper part of this vessel a cover of sheet iron, B, is
adapted, which is fixed with bolts. This vessel, thus
closed, represents, as we see, a vast retort. When it is
prepared, as we have said, it is lifted by means of a swing
c \  \   C crane, c, and placed in a furnace, D (fig. 4), of a
form relative to that of the vessel, and the opening of the
furnace is covered with a dome, E, made of masonry or
brickwork. The whole being thus arranged, heat is applied in the furnace at the bottom. The moisture of
the wood is first dissipated, but by degrees the liquor
ceases to be transparent, and becomes sooty. An adopter
tube, A, is then fitted to the lateral cylinder. This adopter
&        b  ^  enters into another tube at the same degree of inclination
which commences the condensing apparatus. The means
c ) __ t    \n  ^of condensation vary according to the localities. In certain works they cool by means of air, by making the
vapor pass through a long series of cylinders, or sometimes, even, through a series of casks connected together;
but most usually water is used for condensing, when it
can be easily procured in abundance. The most simple
^~~-^  p Fig.^    ~.apparatus employed for this
4.g E            A            p*'n^purpose consists of two cy
linders, F, F (fig. 4), the
-  1I p    one within the other, and
which leave between them
1^^^^ &1^~~~~~ I                          P~a sufficient space to allow
l^  1     _          -1 v  It -  a  considerable  body  of
^C wj~lt  I- i —~~~                  ~ water to circulate along afid
cool  the  vapors.  This
— l i' -J =_______  jdouble cylinder is adapted
to the distilling vessel, and
placed at a certain inclina3^^T....         Hi~- ~ -  tion.  To the first double
~ ~i~LL~L —-----— ~I_~' "U tube, F, F, a second, and




ACETIC ACID.                                   11
sometimes a third, entirely similar, are connected, which, to save space, return upon themselves in a zigzag fashion. The water is set in circulation by an ingenious means
now adopted in many different manufactories. From  the lower extremity, G, of the
system of condensers, a perpendicular tube rises, whose length should be a little more
than the most elevated point of the system. The water, furnished by a reservoir, L,
enters by means of the perpendicular tube through the lower part of the system, and
fills the whole space between the double cylinders. When the apparatus is in action,
the vapors, as they condense, raise the temperature of the water, which, by the column
in L G, is pressed to the upper part of the cylinders, and runs over by the spout K. To
this point a very short tube is attached, which is bent towards the ground, and serves as
an overflow.
The condensing apparatus is terminated by a conduit in bricks covered and sunk in
the ground. At the extremity of this species of gutter is a bent tube, E, which discharges the liquid product into the first cistern. When it is full, it empties itself, by
means of an overflow pipe, into a great reservoir: the tube which terminates the gutter
plunges into the liquid, and thus intercepts communication with the inside of the apparatus. The disengaged gas is brought back by means of pipes M L, from one of the sides
of the conduit to the under part of the ash pit of the furnace. These pipes are furnished with stopcocks M, at some distance in front of the furnace, for the purpose of regulating the jet of the gas, and interrupting, at pleasure, communication with the inside of
the apparatus. The part of the pipes which terminates in the furnace rises perpendicularly several inches above the ground, and is expanded like the rose of a watering can, N.
The gas, by means of this disposition, can distribute itself uniformly under the vessel, without suffering the pipe which conducts it to be obstructed by the fuel or the ashes.
The temperature necessary to effect the carbonization is not considerable: however, at
the last it is raised so high as to make the vessels red hot; and the duration of the process
is necessarily proportional to the quantity of wood carbonized. For a vessel which shall
contain about 5 meters cube (nearly 6 cubic yds.), 8 hours of fire is sufficient. It is
known that the carbonization is complete by the color of the flame of the gas: it is
first of a yellowish red; it becomes afterwards blue, when more carbonic oxyde than
carbonic hydrogen is evolved; and towards the end it becomes entirely white,- a circumstance owing, probably, to the furnace being more heated at this period, and the
combustion being more complete. There is still another means of knowing the state of
the process, to which recourse is more frequently had; that is the cooling of the first
tubes, which are not surrounded with water: a few drops of this fluid are thrown upon
their surface, and if they evaporate quietly, it is judged that the calcination is sufficient.
The adopter tube is then unluted, and is slid into its junction pipe; the orifices are
immediately stopped with plates of iron and plaster loam. The brick cover, E, of the
furnace is first removed by means of the swing crane, then the cylinder itself is lifted
out and replaced immediately by another one previously charged. When the cylinder
which has been taken out of the furnace is entirely cooled, its cover is removed, and the
charcoal is emptied. Five cubic meters of wood furnish about 7 chaldrons (voies) and
a half of charcoal. (For modifications of the wood-vinegar apparatus, see CHARCOAL
and PYROLIGNEOUS ACID.)
The different qualities of wood employed in this operation give nearly similar products in reference to the acid; but this is not the case with the charcoal, for it is better
the harder the wood;, and it has been remarked that wood long exposed to the air furnishes a charcoal of a worse quality than wood carbonized soon after it is cut.
Having described the kind of apparatus employed to obtain pyroligneous acid, I shall
now detail the best mode of purifying it. This acid has a reddish brown color; it holds
in solution a portion of empyreumatic oil and of the tar which were formed at the same
time, another portion of these products is in the state of a simple mixture: the latter
may be separated by repose alone. It is stated above, that the distilling apparatus
terminates in a subterranean reservoir, where the products of all the vessels are mixed.
A common pump communicates with the reservoir, and sinks to its very bottom, in order
that it may draw off only the stratum of tar, which, according to its greater density,
occupies the lower part. From time to time the pump is worked to remove the tar as it
is deposited. The reservoir has at its top an overflow pipe, which discharges the clear.
est acid into a cistern, from which it is taken by means of a second pump.
The pyroligneous acid thus separated from the undissolved tar iq transferred from this
cistern into large sheet iron boilers, where its saturation is effected either by quicklime
or by chalk, the latter of which is preferable, as the lime is apt to take some of the air
into combination. The acid parts by saturation with a new portion of the tar, which is
removed by skimmers. The neutral solution is then allon ed to rest for a sufficient time
to let its clear parts be drawn off by decantation.
The acetate of lime thus obtained indicates by the hydrometer, before being mixed with
the waters of edulcoration, a degree corresponding to the acidimetric degree of the acid




12                              ACETIC ACID.
employed. This solution must be evaporated till it reaches a specific gravity of 1 114
(15~ Baume), after which there is added to it a saturated solution of sulphate of soda.
The acids exchange bases; sulphate of lime precipitates, and acetate of soda remains in
solution. In some manufactures, instead of pursuing the above plan, the sulphate of
soda is dissolved in the hot pyroligneous acid, which is afterwards saturated with chalk
or lime. By this means no water need be employed to dissolve the sulphate, and accordingly the liquor is obtained in a concentrated form without evaporation. In both
modes the sulphate of lime is allowed to settle, and the solution of acetate of soda is decanted. The residuum is set aside to be edulcorated, and the last waters are employed
for washing fresh portions.
The acetate of soda which results from this double decomposition is afterwards evaporated till it attains to the density of 1'225 or 1-23, according to the season. This solution is poured into large crystallizing vessels, from which, at the end of 3 or 4 days,
according to their capacity, the mother waters are decanted, and a first crystallization is
obtained of rhomboidal prisms, which are highly colored and very bulky. Their facettes
are finely polished, and their edges very sharp. The mother waters are submitted to
successive evaporations and crystallizations till they refuse to crystallize, and they are
then burnt to convert them into carbonate of soda.
To avoid guesswork proportions, which are always injurious, by the loss of time which
they occasion, and by the bad results to which they often lead, we should determine
experimentally, beforehand, the quantities absolutely necessary for the reciprocal decomposition, especially when we change the acid or the sulphate. But it may be remarked
that, notwithstanding all the precautions we can take, there is always a notable quantity
of sulphate of soda and acetic acid, which disappear totally in this decomposition. This
arises from the circumstance that sulphate of soda and acetate of lime do not completely
decompose each other, as I have ascertained by experiments on a very considerable scale;
and thus a portion of each of them is always lost with the mother waters. It might be
supposed that by calcining the acetate of lime we could completely destroy its empyreumatic oil; but, though I have made many experiments with this view, I never could
abtain an acetate capable of affording a tolerable acid. Some manufacturers prefer to
make the acetate of soda by direct saturation of the acid with the alkali, and think that
the higher price of this substance is compensated by the economy of time and fuel which
it produces.
The acetate of soda is easily purified by crystallizations and torrefaction; the latter
process, when well conducted, freeing it completely from every particle of tar. This
torrefaction, to which the name of fusion may be given, requires great care and dexterity.
It is usually done in shallow cast iron boilers of a hemispherical shape. During all the
time that the heat of about 500~ Fahr. is applied, the fused mass must be diligently worked with rakes; an operation which continues about 24 hours for half a ton of materials.
We must carefully avoid raising the temperature so high as to decompose the acetate,
and be sure that the heat is equally distributed; for if any point of the mass enters into
decomposition, it is propagated with such rapidity, as to be excessively difficult to stop
its progress in destroying the whole. The heat should never be so great as to disengage
any smoke, even when the whole acetate is liquefied. When there is no more frothing
up, and the mass flows like oil, the operation is finished. It is now allowed to cool in a
body, or it may be ladled out into moulds, which is preferable.
When the acetate is dissolved in water, the charcoaly matter proceeding from the
decomposition of the tar must be separated by filtration, or by boiling up the liquor to
the specific gravity 1*114, when the carbonaceous matter falls to the bottom. On evaporating the clear liquor, we obtain an acetate perfectly fine, which yields beautiful
crystals on cooling. In this state of purity it is decomposed by sulphuric acid, in order
to separate its acetic acid.
This last operation, however simple it appears, requires no little care and skill. The.
acetate of soda crystallized and ground is put into a copper, and the necessary quantity
of sulphuric acid of 1'842 (about 35 per cent. of the salt) to decompose almost, but not
all, the acetate, is poured on. The materials are left to act on each other; by decrees
the acetic acid quits its combination, and swims upon the surface; the greater part of
the resulting sulphate of soda falls in a pulverulent form, or in small granular crystals,
to the bottom. Another portion remains dissolved in the liquid, which has a specific
gravity of 1-08. By distillation we separate this remainder of the sulphate, and finally
obtain acetic acid, having a specific gravity of 1'05, an agreeable taste and smell, though
towards the end it becomes a little empyreumatic, and colored; for which reason,
the last portions must be kept apart. The acid destined for table use ought to be
distilled in an alembic whose capital and condensing worm  are of silver; and to
make it very fine, it may be afterwards infused over a little pure animal charcoalthe well-washed residuum of the Prussian-blue-works black.




ACTINISM.                                      18
An excise duty of 2d. is levied on every gallon of the above proof vinegar. Its
strength is not, however, estimated directly by its specific gravity, but by the specific
gravity which it assumes when saturated with quicklime. The decimal fraction of the
specific gravity of the calcareous acetate is very nearly the double of that of the pure
vinegar; or, 1 009 in vinegar becomes 1'018 in acetate of lime. The vinegar of malt
contains so much mucilage or gluten, that when it has only the same acid strength as
the above, it has a density of 1.0014, but it becomes only 1'023 when converted into
acetate of lime: indeed, 0-005 of its density is due to mucilaginous matter. This fact
shows the fallacy of trusting to the hydrometer for determining the strength of vinegars,
which may be more or less loaded with vegetable gluten. The proper test of this, as of
all other acids, is, the quantity of alkaline matter which a given weight or measure of it
will saturate. For this purpose the bicarbonate of potash, commonly called, in the
London shops, carbonate, may be employed very conveniently. As it is a very uniform
substance, and its atomic weight, by the hydrogen radix, is 100-584, while the atomic
weight of acetic acid, by the same radix, is 51'563, if we estimate 2 grains of the bicarbonate as equivalent to 1 of the real acid, we shall commit no appreciable error. Hence,
a solution of the carbonate containing 200 grains in 100 measures, will form an acetimeter of the most perfect and convenient kind; for the measures of test liquid expended
in saturating any measure,-for instance, an ounce or 1000 grains of acid,-will indicate the number of grains of real acetic acid in that quantity. Thus, 1000 grains of the
above proof, would require 50 measures of the acetimetrical alkaline solution, showing
that it contains 50 grains of real acetic acid in 1000, or 5 per cent.
It is common to add to purified wood vinegar, a little acetic ether, or caramelized
(burnt) sugar to color it, also, in France, even wine, to flavor it. Its blanching effect
upon red cabbage, which it has been employed to pickle, is owing to a little sulphurous
acid. This may be removed by redistillation with peroxyde of manganese.  Indeed,
Stoltze professes to purify the pyroligneous acid solely by distilling it with peroxyde of
manganese, and then digesting it with bruised wood charcoal; or by distilling it with a
mixture of sulphuric acid and manganese. But much acid is lost in this case by the forniation of acetate of that metal.
Birch and beech afford most pyroligneous acid, and pine the least. It is exclusively
employed in the arts, for most purposes of which it need not be very highly purified.
It is much used in calico printing, for preparing acetate of iron called IRON LIQUOR, and
acetate of alumina, called RED LIQUOR; which see. It serves also to make sugar of
lead; yet when it contains its usual quantity, after rectification of tarry matter, the
acetate of lead will hardly crystallize, but forms cauliflower concretions. This evil may
be remedied, I believe, by boiling the saline solution with a very little nitric acid, which
causes the precipitation of a brown granular substance, and gives the liquor a reddish
tinge. The solution being afterwards treated with bruised charcoal, becomes colorless,
and furnishes regular crystals of acetate or sugar of lead.
Pyroligneous acid possesses, in a very eminent degree, anti-putrescent properties. Flesh
steeped in it for a few hours may be afterwards dried in the air without corrupting; but
it becomes hard, and somewhat leather-like: so that this mode of preservation does not
answer well for butcher's meat. Fish are sometimes cured with it. See PYRO-ACErIC
SPIRIT; PYROXILIC ETHER; PYROXOLIC SPIRIT; PYROLIGNEOUS ACID and VINEGAR.
In 1838, 2,628,978 gallons of vinegar paid duty in England; in 1839, 2,939,665;
and in 1840, 3,021,130; upon which the gross amount of duty was, respectively,
21,9081. 3s.; 24,4481. 17s. 6d.; and 25,9781. 12s. 9d.
In Scotland, in the same years, 15,626 gallons; 14,532; and 12,967; on which the
duty charged was, respectively, 1301. 4s. 4d.; 1211. 2s.; and 1111. 19s. 7d.
In Ireland, in the same years, 48,158 gallons; 50,508; and 56,812; on which the
duty charged was 4011. 6s. 4s.; 4201. 18s.; and 489/. 12s.
ACETIMETER.  An apparatus for determining the strength of vinegar.  See the
preceding article for a description of my simple method of acetimetry.
ACETONE.  The new chemical name of pyro-acetic spirit.
ACID OF ARSENIC.  (Acide arsenique, Fr.; Arseniksaure, Germ.)  See ARSENIC.
ACIDS.  A class of chemical substances characterized by the property of combining
with and neutralizing the alkaline and other bases, and of thereby forming a peculiar
class of bodies called salts. The acids which constitute objects of special manufacture
for commercial purposes are the following:-acetic, arsenious, carbonic, chromic, citric,
hydrocyanic, malic, muriatic, nitric, oxalic, phosphoric, sulphuric, tartaric, which see.
ACII)IMETER. See LALKALIMETER.
ACROSPIRE.  (Plumule, Fr.; Blattkeim, Germ.)  That part of a germinating seed
which botanists call the plumula, or plumes. See BEER and MALT.
ACTINISM.  Some years ago, Mr. R. Hunt announced that he had discovered that,
associated with the light and heat derived from the sun, there is another principle most
active in producing changes in the organic and inorganic worlds, which he has called




14                               ADIPOCIRE.
Actinism, from the Greek for a ray of the sun. He has given the following striking
evidences of the truth of his discovery, derived from the vegetable world. That the
actinic principle was necessary to germination was shown by the fact, that seeds placed
under the influence of the solar rays transmitted through yellow glass would not germinate, because yellow glass prevents the passage of the actinic principle. Accordingly, during spring the solar beam contained a larger amount of the actinic principle
than at any other, because it was necessary at that season for the germination of seeds
and the development of buds. In summer, again, there was a large proportion of the
light-giving principle necessary to the formation of the woJdy portions of plants; and
towards autumn the calorific heat giving or ripening principle of the solar rays increased. It resulted from these principles that the recent use in greenhouses of white
German sheet glass was most objectionable. Under this kind of glass, plants were
subject to an injurious solar influence which they had not suffered under the old crown
glass. It became therefore necessary to discover some method to cut off those parathermic rays, which, passing'through the white glass, scorched and browned particular
portions of the leaves, without cutting off the other portions of the rays which were
necessary to the growth of the plant. With this view Mr. Hunt has devised and
applied at the Kew observatory a green glass stained with oxide of copper, which
effectually excludes the injurious parathermic rays, while' it admits the other solar
rays necessary for the plant, as freely as ordinary white glass. In the manufacture of
this green glass it was essential that no manganese should be used, as was the case in
white glass. If manganese were used, the glass would after a while assume a pinkish
hue, which would more freely admit the burning rays.
ADDITIONS. Such articles as are added to the fermenting wash of the distiller are
distinguished by this trivial name.
ADIPOCIRE. Fr. (Fettwachs, Germ.)  The fatty matter generated in dead bodies
buried under peculiar circumstances. In 1786 and 1787, when the churchyard of the
Innocents, at Paris, was cleaned out, and the bones transported to the catacombs, it was
discovered that not a few of the cadavres were converted into a saponaceous white substance, more especially many of those which had been interred for fifteen years in one
pit, to the amount of 1500, in coffins closely packed together. These bodies were flat.
tened, in consequence of their mutual pressure; and, though they generally retained
their shape, there was deposited round the bones of several a grayish white, somewhat
soft, flexible substance. Fourcroy presented to the Academy of Sciences, in 1789, a comprehensive memoir upon this phenomenon, which appeared to prove that the fatty body
was an ammoniacal soap, containing phosphate of lime; that the fat was similar to sper.
maceti, as it assumed on slow cooling a foliated crystalline structure; as also to wax, as,
when rapidly cooled, it became granular: hence he called it.dipocire. Its melting point
was 52-5~ C. (126'5~ Fahr.). He likewise compared this soap to the fat of gall-stones,
and supposed it to be a natural product of the slow decomposition of all animal matter,
except bones, nails, and hairs.
This substance was again examined by Chevreul in 1812, and was found by him to
contain margaric acid, oleic acid, combined with a yellow coloring, odorous matter, besides ammonia, a little lime, potash, oxyde of iron, salts of lactic acid, an azotized substance; and was therefore considered as a combination of margaric and oleic acids, in
variable proportions (whence arose its variable fusibility), but that it was not analogous
with either spermaceti or cholesterine (gallstones). These fat acids are obviously generated by the reaction of the ammonia upon the margarine and oleine, though they eventually lose the greater part of that volatile alkali.
According to the views of both Gay Lussac and Chevreul, this adipocire proceeds
solely from the pre-existing fat of the dead body, and not from the flesh, tendons, or cartilages, as had been previously imagined; which had led to some expensive and abortive
attempts, upon the great scale of manufacture, to convert the dead bodies of cattle into
adipocire, for the purposes of the candle-maker or soap-boiler, by exposing them for some
time to the action of moisture.
Von Hartkol made experiments during 25 years upon this subject, from which he
inferred, that there is no formation of adipocire in bodies buried in dry ground; that
in moist earth the fat of the dead body does not increase, but changes into a fetid
saponaceous substance, incapable of being worked into either soap or candles; that the
dead bodies of mammalia immersed in running water, leave behind after 3 years a pure
fat, which is more abundant from young than from old anmials; that the intestines
afford more fat than the muscles; that from this fat, without any purification, candles
may be made, as void of smell, as hard, and as white, as from bleached wax; that from
cadavers immersed for 3 years in stagnant water, more fat is procured than from those
in running water, but that it needs to be purified before it can be made into soap or
candles.
The cause of the difference between Hartkol's and Chevreul's results cannot be
assigned, as the latter has not published his promised remarks upon the subject. At




ALABASTER.                                      15
any rate, dead animal matter can be worked up more profitably than in making
artificial adipocire.
ADIT. The horizontal entrance of a mine.  It is sometimes called the drift.  See
MINING and METALLURGY.
ADULTERATION. The debasing any product of manufacture, especially chemical, by the introduction of cheap materials. The art of ascertaining the genuineness
of the several products will be taught under the specific objects of manufacture.
EITHER.  See ETHER.
AFFINITY.  The chemical term  denoting the peculiar attractive force which produces the combination of dissimilar substances; such as of an alkali with an acid, or
of sulphur with a metal. It is often called elective attraction, to distinguish it from
corpuscular or cohesive attraction, by which particles of like kinds of matter are combined; and because it displays the power of selecting its preferable associates. Its
full discussion belongs to chemistry.
AGARIC. A  species of boletus or fungus, which grows in dunghills; with the
salts of iron it affords a black dye. It is said to be convertible into a kind of china ink.
AGATE. A silicious mineral which is cut into seals and other forms for the coarser
kinds of jewellery. See GEM.
AIR. See VENTILATION.
ALABASTER, is a stone usually white, and soft enough to be scratched by iron.
There are two kinds of it: the gypseous, which is merely a natural semi-crystalline sulphate of lime; and the calcareous alabaster, which is a carbonate of lime. The oriental
alabaster is always of the latter kind, and is most esteemed, because it is agreeably
variegated with lively colors, and especially with zones of honey-yellow, yellow-brown,
red, &c.; it is, moreover, susceptible of taking a marble polish.
The fineness of the grain of alabaster, the uniformity of its texture, the beauty of its
polished surface, and its semi-transparency, are the qualities which render it valuable to
the sculptor and to the manufacturer of ornamental toys.
The limestone alabaster is frequently found as a yellowish-white deposite in certain
fountains. The most celebrated spring of this kind is that of the baths of San Filippo,
in Tuscany. The water, almost boiling hot, runs over an enormous mass of stalactites,
which it has formed, and holds the carbonate of lime in solution by means of sulphureted hydrogen (according to M. Alexandre Brongniard), which escapes by contact of the
atmosphere.  Advantage has been taken of this property to make basso relievos of considerable hardness, by placing moulds of sulphur very obliquely, or almost upright, in
wooden tubs open at the bottom.  These tubs are surmounted at the top with a large
wooden cross.  The water of the spring, after having deposited in an external conduit
or cistern the coarser sediment, is made to flow upon this wooden cross, where it is
scattered into little streamlets, and thence lets fall, upon the sulphur casts, a precipitate
so much the finer the more nearly vertical the mould. From one to four months are required for this operation, according to the thickness of the deposited crust. By analogous processes, the artists have succeeded in moulding vases, figures of animals, and
other objects, in relief, of every different form, which require only to be trimmed a little,
and afterwards polished.
The common alabaster is composed of sulphuric acid and lime, though some kinds of
it effervesce with acids, and therefore contain some carbonate of lime. This alabaster
occurs in many different colors, and of very different degrees of hardness, but it is always
softer than marble. It forms, usually, the lowest beds of the gypsum quarries. The
sculptors prefer the hardest, the whitest, and those of a granular texture, like Carrara
marble, and so like that they can only be distinguished by the hardness.
The alabaster is worked with the same tools as marble; and as it is many degrees
softer, it is so much the more easily cut; but it is more difficult to polish, from its little
solidity. After it has been fashioned into the desired form, and smoothed down with
pumice stone, it is polished with a pap-like mixture of chalk, soap, and milk; and, last
of all, finished by friction with flannel. It is apt to acquire a yellowish tinge.
Besides the harder kinds, employed for the sculpture of large figures, there is a softer
alabaster, pure white and semi-transparent, from \which small ornamental objects are
made, such as boxes, vases, lamps, stands of time-pieces, &c. This branch of business
is much prosecuted in Florence, Leghorn, Milan, &c., and employs a great many turning
lathes. Of all the alabasters, the Florentine merits the preference, on account of its beauty
and uniformity, so that it may be fashioned into figures of considerable size: for which
purpose there are large work-shops where it is cut with steel saws into blocks and masses of various shapes. Other sorts of gypsum, such as that of Salzburg and Austria,
contain sand veins, and hard nodules, and require to be quarried by cleaving and blasting




16                                ALCOHOL.
operations which are apt to crack it, and unfit it for all delicate objects of sculpture.
It is besides of a gray shade, and often stained with darker colors.
The alabaster best adapted for the fine arts is pretty white when newly broken, and
becomes whiter on the surface by drying. It may be easily cut with the knife or chisel,
and formed into many pleasing shapes by suitable steel tools. It is worked either by
the hand alone, or with the aid of a turning lathe. The turning tools should not be too
thin, or sharp-edged; but such as are employed for ivory and brass are most suitable
for alabaster, and are chiefly used to shave and to scratch the surface. The objects
which cannot be turned may be fashioned by the rasping tools, or with minute files,
such as variegated foliage. Fine chisels and graving tools are also used for the better
pieces of statuary.
For polishing such works, a peculiar process is required; pumice stone, in fine
powder, serves to smooth down the surfaces very well, but it soils the whiteness of the
alabaster. To take away the unevenness and roughness, dried shave-grass (equisetum)
answers best. Frictions with this plant and water polish down the asperities left by
the chisel: the fine streaks left by the grass may be removed by rubbing the pieces
with slaked lime, finely pulverized and sifted, made into a paste or putty with water.
The polish and satin-lustre of the surface are communicated by friction, first with soapwater and lime, and finally with powdered and elutriated talc or French chalk.
Such articles as consist of several pieces are joined by a cement composed of quicklime and white of egg, or of well-calcined and well-sifted Paris plaster, mixed with
the least possible quantity of water.
Alabaster objects are liable to become yellow by keeping, and are especially injured
by smoke, dust, &c. They may be in some measure restored by washing with soap
and water, then with clear water, and again polished with shave-grass. Grease-spots
may be removed either by rubbing with talc powder, or with oil of turpentine.
The surface of alabaster may be etched by covering over the parts that are not to
be touched with a solution of wax in oil of turpentine, thickened with white lead,
and immersing the articles in pure water after the varnish has set. The action of
the water is continued from 20 to 50 hours, more or less, according to the depth to
which the etching is to be cut. After removing the varnish with oil of turpentine,
the etched places, which are necessarily deprived of their polish, should be rubbed
with a brush dipped in finely-powdered gypsum, which gives a kind of opacity, contrasting well with the rest of the surface.
Alabaster may be stained either with metallic solutions, with spirituous tinctures
of dyeing plants, or with colored oils, in the same way as marbles.
This substance has been hardened, it is said, by exposing it to the heat of a baker's
oven for 10 or 20 hours, after taking it out of the quarry, and giving it the figure,
roughly, which it is intended to have. After this exposure, it must be dipped for two
minutes in running water; when it is cold, it must be dipped a second time for the
same period.  On being exposed to the air for a few days, alabaster so treated acquires a marble-like hardness. I doubt the truth of this statement.  I believe a much
better means of induration would be by soaking it in solution of alum. Alabaster is
by the mineralogist considered as hydrous gypsum; and consists of one atom of sulphuric acid, one atom of lime, and two atoms of water.
ALBATA. A white metal like silver; see COPPER, of which it is an alloy with
nickel and zinc.
ALBUM  GRZECUM. The white dung of dogs, sometimes used to soften leather
in the process of dressing it after the depilatory action of lime. It is essentially phosphate of lime and mucus.
ALBUMINE, an animal product, like white of egg, which is diffused through the
whole body, and is on account of the multifarious uses which it subserves in the vital
economy called Proteine.  It consists of carbon 55'0; hydrogen 7'07; oxygen 22'0;
azote 15-92.
ALCARAZZAS.  A species of porous earthenware, made in Spain, for cooling
liquors. Alcarazzas are made of a sandy marl, made up into a dough, with a solution
of salt, and very little fired. M. Fourmy has mounted a factory of them in Paris under
the Greek title of Hygroceramen.
ALCOHOL.  The well-known intoxicating liquor procured by distillation from various vegetable juices, and infusions of a saccharine nature, which have undergone the vinous fermentation. Common alcohol, or proof spirit,as it is called,contains about one-half
its weight of water. It may be concentrated till its specific gravity becomes so low as
0-825, by simple redistillation at a steam or water-bath heat; but to make it stronger, we
must mix with it, in the still or retort, dry carbonate of potash, chloride of calcium,
dry lime, or some other substances strongly attractive of water. and then it may be obtainedof a specific gravity so low as 0'791 at 160 Reaumur (68~ Fahr.), water being 1 000.




ALCOHOL.                                      17
At 0-825, it contains, still, II per cent. of water; and in this state it is as volatile as
absolute alcohol, on account of the inferior density of the aqueous vapor, compared to
the alcoholic. Indeed, according to Yelin and Fuchs, the boiling point of anhydrous
alcohol is higher than of that which contains 2 or 3 per cent. of water; hence, in the
distillation of alcohol of 94 per cent., the first portions that come over are more aqueous
than the following. Absolute alcohol has its boiling point at 168-1 Fahr.; but when
it holds more than 6 per cent. of water, the first portions that come over are richest in
alcohol, and the temperature of the boiling point, or of the spirituous vapor, is always
higher the longer the distillation continues. According to Groning's researches, the
following temperatures of the alcoholic vapors correspond to the accompanying contents
of alcohol in per centage of volume, which are disengaged in the boiling of the spirituous
liquid.
Alcoholic con- Alcoholic con-             Alcoholic con- Alcoholic conTemperature.   tent of the  tent of the boil- Temperature.   tent of the  tent of the boilvapor.      ing liquid.                   vapor.      ing liquid.
Fahr. 170 0        93            92       Fahr. 1898         71            20
171 8       92            90              192-0        68            18
172         91            85              164          66            15
172-8       90o           80              196 4       61             12
174         90            70              198 -6       55            10
174 -6      89            70             201           50             7
176         87            65             203           42             5
178 3       85            50             205-4        36              3
180-8       82            40              207-7        28             2
183         80            35              210          13             1
185         78             30             212           0             0
187 -4      76            25
Groning undertook this investigation in order to employ the thermometer as an
alcohol-meter in the distillation of spirits: for which purpose he thrust the bulb of
the thermometer through a cork, inserted into a tube fixed in the capital of the still.
The state of the barometer ought also to be considered in making comparative experiments of this kind. Since, by this method, the alcoholic content may be compared
with the temperature of the vapor that passes over at any time, so, also, the contents
of the whole distillation may be found approximately; and the method serves as a
convenient means of making continual observations on the progress of the distillation.
The Abbe Vidal of Toulon constructed a few years ago an instrument which he
termed the Ebullition Alcoolmetre, for estimating the strength of alcohol from the temperature of its boiling point. It is an awkward apparatus, consisting of a large cylindrical glass bulb, like that of a wheel barometer, containing mercury, and a floating
glass bead, with a thread attached; the other end of which passed over a little pulley,
and was terminated by a counterweight.  Concentric with this pulley a graduated flat
ring of brass was fixed, on which an index traversed with the pulley, as it was moved
by the thread in its ascent by the mercury in its expansions by the heat of the alcohol,
placed in a little cylinder into which the bulb was plunged. This cylinder was subjected to the flame of a little spirit lamp. I found the instrument, as thus made in
France, difficult to manage, easily deranged by a loss of a drop of the mercury, and
difficult to repair. I therefore substituted a simple thermometer, with a very narrow
bore from  212~ to 184~ Fahr. and consequently a long range of scale between these
two points. The scale was divided as follows:
Temp. Fahr.            Sp. Gr.           Temp. Fahr.           Sp. Gr.
178-60          0-920 P.                  186-6          0'9665 50 U. P.
179'75          0-9821 10 U. P.           189-0          0-9729 60
180-4           0-9420 20                 191-8          0-9786 70
182'00          0-9516 30                 196'4          0-9850 80
183-40         0'960  40                  202-0          0-992  90
The above table is the mean of a great many experiments. P. means proof spirits of
the British excise standard; U. P. denotes under proof.-In the Pharmaceutical Jour.
nal, vol. 7. p. 166., there is a detailed account, with engravings, of the two instruments.
The first of the following two tables of the boiling points of alcohol of different
strengths may be compared with my short one given above.




18                                ALCOHOL.
Grining.                                 Yelin.
Alcohol.            Boiling             Alcohol             Boiling
in 100.             Point               in 100.             Point.
5                96-3~ C.             94                76-97~ C.
10                92-9                 95                76-99
15                91'0                 96                T6'92
20                89-1                 9'7                7685
25                87 5                 98'6-85
30                86-2                 99                76'90
35                85'0                100                77'02
40                84'1
45                83-4
50                83'1
55                82-2
60                81'9
65                81-5
70                80-9
75                80-3
80                79'7
85                179'4
90'790
95                78'4
Proof spirit of sp. gr. 0'92 at 60~ Fahr. consists of absolute alcohol of gravity 0'794,
and of distilled water very near equal weights; but in volumes, of 126 of alcohol and
100 of water; therefore 100 measures of such spirits contain 55'75 of the alcohol
= (2- ).  By the table of Gay Lussac, spirits that contain 5575 of absolute alcohol have a specific gravity of 0'9218 instead of 0'9200; while spirits of 0'9200, according to Gay Lussac, contain 56'66 in 100 by volume. By the table of Tralles, spirits
of 0'825 contain 92-43 of the said alcohol; and hence 100 +     56   60-6 of Gilpin's
92-43
alcohol by Gay Lussac; whereas by Gilpin's table, spirits of 0'9200 contain 100 of
alcohol of 0'825+81-2 of water by weight: and 100 =121-2121 by volume.  Again,
0'825
121-2121 +81'2=202'2121; 121'2121 divided by 202-2121 gives a quotient of 59'88 as
the alcohol of 0-825 in the 100 by volume. Now as 60'6 by Gay Lussac's table exceeds 59'88 by 0'72, there must be an error; most probably on the side of the French
chemist.
The temperature, corresponding to a certain per centage of alcohol in vapor, suggests
the employment of a convenient method for obtaining, at one process, a spirit as free from
water as it can be made by mere distillation. We place over the top of the capital a
water-bath, and lead up through it a spiral pipe from the still, which there passes obliquely downwards, and proceeds to the refrigeratory. If this bath be maintained, by a constant
influx of cold water, at a certain temperature, only the alcoholic vapor corresponding to
that temperature will pass over, and the rest will be recondensed and returned into the
still. If we keep the temperature of the water at 174~, for example, the spirituous vapor which passes over will contain 90 per cent. of absolute alcohol, according to the
preceding table. The skilful use of this principle constitutes the main improvement in
modern distilleries. See DISTILLATION and STILL.
Another method for concentrating alcohol is that discovered by S6mmering, founded
upon the property of ox bladders to allow water to pass through and evaporate out of
them, but not to permit alcohol to transpire, or only in a slight degree. Hence, if an
ox's bladder is filled with spirit of wine, well tied at the mouth, and suspended in a warm
place, the water will continually exhaleand the alcohol will become nearly anhydrous;
for in this way alcohol of 97 or 98 per cent. may be obtained.
According to Summering, we should take for this purpose the bladder of an ox or a calf,
soak it for some time in water, then inflate it and free it from the fat and the attached
vessels; which is to be also done to the other surface, by turning it inside out. After it
is again inflated and dried, we must smear over the outer side twice, and the inner side four
times, with a solution of isinglass, by which its texture is made closer, and the concentration of the alcohol goes on better. A bladder so prepared may serve more than a




ALCOHOL.                                    19
hundred times. It must be charged with the spirits to be concentrated, leaving a small
space vacant, it is then to be tightly bound at the mouth, and suspended in a warm
situation, at a temperature of 122~ Fahr., over a sand-bath, or in the neighborhood
of an oven. The surface of the bladder remains moist with the water as long as the
sp. gr. of the contained spirit is greater than 0.952. Weak spirit loses its water quicker
than strong; but in from 6 to 12 hours the alcohol may be concentrated when a
suitable heat is employed. This economical method is particularly applicable in obtaining alcohol for the preparation of varnishes. When the alcohol is to serve for
other purposes it must be freed, by distillation, from certain matters dissolved out of
the bladder. Alcohol may likewise be strengthened, as S6mmering has ascertained,
when the vessel that contains the spirit is bound over with a bladder which does not
come into contact with the liquid. Thus, too, all other liquors containing alcohol and
water, as wine, cider, &c., may be made more spirituous.
To procure absolute alcohol, we must take chloride of calcium recently fused, reduce
it to a coarse powder, and mix it with its own weight of spirits of wine, of sp. gr. 0.833,
in a bottle, which is to be well stoppered, and to be agitated till the salt is dissolved.
The clear solution is to be poured into a retort, and half of the volume of the alcohol
employed, or so much as has the sp. gr. 0.791 at 78~ Fahr., is to be distilled off, drop
by drop, at a gentle heat. Quicklime has also been employed for the same purpose,
but it is less powerful and convenient. Alcohol, nearly free from water, may be obtained without distillation, by adding dry carbonate of potash to a spirit of wine, of
sp. gr. 0-825. The water combines with the potash, and falls to the bottom in a dense
liquid, while the pure spirit floats on the surface. This contains, however, a little
alkali, which can be separated only by distillation.
Anhydrous alcohol is composed by weight of 62'18 carbon, 13'04 hydrogen, and
34'78 of oxygen. It has for its symbol C4 H6 02     C4 14, H12 02; or one atom of
ether + one atom of water; it is therefore a hydrate of ether. It has a very powerful
attraction for water, and absorbs it from the atmosphere; therefore it must be kept in
well-closed vessels. It also robs vegetable and animal bodies of their moisture; and
hence common alcohol is employed for preserving anatomical preparations. Alcohol
is a solvent for many substances: resins, essential oils, camphor, are abundantly dissolved by it, forming varnishes, perfumed spirits, &c. The solution of a resin or essential oil in alcohol becomes milky on the addition of water, which, by its attraction for
alcohol, separates these substances. Several salts, especially the deliquescent, are
dissolved by it, and some of them give a color to its flame; thus the solutions of the
salts of strontia in alcohol burn with a crimson flame; those of copper and borax
green, lime reddish, and baryta yellow.
When water is mixed with alcohol, heat and a condensation of volume are the result;
these effects being greatest with 54 per cent. of alcohol and 46 of water, and thence
decreasing with a greater proportion of water. For alcohol which contains 90 per cent.
of water, this condensation amounts to 1'94 per cent. of the volume; for 80 per cent.,
2'87; for 70 per cent., 3-44; for 60 per cent., 3-73; for 40 per cent., 3-44; for 30 per
cent., 2'72; for 20 per cent., 1'72; for 10 per cent., 0-72. Hence, to estimate the
quantity of alcohol in any spirit, it is necessary that the specific gravity be ascertained
for each determinate proportion of alcohol and water that are mixed together. When
this is done, we may, by means of an aerometer constructed for liquids lighter than
water, determine the strength of the spirit, either by a scale of specific gravities or by
an arbitrary graduation corresponding to certain commercial objects, and thus we may
determine the percentage of alcohol in whisky or brandy of any strength or purity. An
areometer intended for this use has been called an alcoholmeter, in particular when the
scale of it is so graduated that instead of the specific gravity, it indicates immediately
the percentage of anhydrous alcohol in a given weight or volume of the liquid. The
scale graduated according to the percentage of pure alcohol by weight, constitutes the
alcoholmeter of Richter; and that by the percentage in volume, the alcoholmeter of
Tralles and Gay Lussac.
As liquors are sold in general by the measure, not by the weight, it is convenient,
therefore, to know the alcoholic content of the mixtures in the percentage byvolume.
Tralles has constructed new tables upon the principles of those of Gilpin, in which the
proportion is given by volume, and anhydrous alcohol is assumed for the basis which at
60~ Fahr., has a specific gravity of 07 939 compared with water at its maximum density,
or a specific gravity of 0-7946 compared with water of the temperature of 600 Fahr.
Gilpin's alcohol of 0'825 contains 92'6 per cent. by volume of anhydrous alcohol.
According to the experiments of Tralles alcohol contracts between-26~ C. and
+  37 C. with tolerable uniformity; for each degree the contraction is 0-00846 of the
volume of the alcohol. In the following table its contractions are reckoned downwards from the boiling point by Gay Lussac.




20                              ALCOHOL.
Temp.       Volume.      Temp.        Volume.      Temp.       Volume.
78~ 4       1000'    48~ 4        965-3       230~4        938-6'3~'4        994-4        43~'4       960'0       18~-4        934'0
680~4       988-6         38~ 4       954'4       13~04        929-3
63~'4        982-5        33~04       948-9        80~4        924-5
580~4        975-'7       28~ 4       943'6        3~04        919.0
530~4        970'9
Spirituous vapor passed through an ignited tube of glass or porcelain is converted
into carbonic oxide, water, hydrogen, carburetted hydrogen, olefiant gas, naphthaline,
empyreumatic oil, and carbon; according to the degree of heat and nature of the tube
these products vary. Anhydrous alcohol is a non-conductor of electricity, but is decomposed by a powerful voltaic battery. Alcohol burns in the air with a blue flame
into carbonic acid and water; the water being heavier than the spirit, because 46
parts of alcohol contain 6 of hydrogen, which form 54 of water. In oxygen the
combustion is accompanied with great heat, and this flame, directed through a
small tube, powerfully ignites bodies exposed to it.
If we moisten sand in a capsule with absolute alcohol, and cover it with previously
heated nickel powder, protoxide of nickel, cobalt powder, protoxide of cobalt, protoxide of uranium, oxide of tin (these six bodies being procured by ignition of their
oxalates in a crucible), or finely powdered manganese peroxide, combustion takes
place, and continues as long as the spirituous vapor lasts.
The following table exhibits the per centage of anhydrous alcohol by volume, at a
temperature of 60~ Fahr., in correspondence with the specific gravities of the spirits,
water being considered at 60~ Fahr. to have a specific gravity of 0'9991.
Alcoholmetrical Table of Tralles.
Alcohol in 100                         Alcohol in 100
measures of  Specific gravity  Difference of   f   Specifi       Difference of
spirit.   at 60 Fahr.   the sp. gr.    spirit.    at 60 Fahr.   the sp. gr.
0          9991                       51          9315          20
1         9976           15           52          9295          20
2          9961          15           53          9275          20
3          9947          14           54          9254          21
4          9933          14           55          9234          20
5          9919          14           56          9213          21
6          9906          13           57          9192          21
7          9893          13           58          9170          22
8          9881          12           59          9148          22
9          9869          12           60          9126          22
10         9857           12           61          9104         22
11         9845           12           62          9082         22
12         9834           11           63          9059         23
13          9823          11           64          9036         23
14          9812          11           65          9013         23
15         9802           10           66          8989         24
16         9791           11           67          8965         24
17          9781          10           68          8941         24
18         9771           10           69          8917         24
19          9761          10           70          8892         25
20          9751          10           71          8867          25
21          9741          10           72          8842         25
22         9731           10           73          8817         25
23          9720          11           74          8791         26
24         9710           10           75          8765         26
25         9700           10           76          8739         26
26         9689           11           77          8712         27
27          9679          10           78          8685         27
28          9668          11           79          8658         27
29          9657          11           80          8631         27
30          9646          11           81          8603         28
31          9634          12           82          8575          28
32          9622          12           83          8547          28
38          9609          13           84 _        8518          29




ALCOHOL.                                              21
Alcoholmetrical Table of Tralles (continued).
Alcohol in 100                                   Alcohol in 100
measures of   Specific gravity   Difference of   measures of   Specific gravity   Difference of
spirit.     at 600 Fahr.      the sp. gr.        spirit.      at 60 Fahr.       the sp gr.
34            9596               13              85             8488              30
35            9583              13               86             8458              30
36            9570              13               87             8428              30
37            9556              14               88             8397              31
38            9541              15               89             8365              32
39            9526              15              90              8332              33
40            9610              16               91             8299              33
41            9494              16               92             8265              34
42            9478              16              93              8230              35
43            9461              17              94              8194              36
44            9444              17              95              8157              37
45            9427              17              96              8118              39
46            9409              18              97              8077              41
47            9391              18              98              8034              43
48            9373              18              99              7988              46
49            9354              19              100             7939              49
50            9335              19 
Remarks on the preceding Table of alcohol.
The third column of this table exhibits the differences of the specific gravities, which
give the denominator of the fraction for such densities as are not found sufficiently near
in the table; and the difference of their numerators is the next greatest to the density
found  in  the  table.  For example: if the  specific  gravity of the  liquor found  for
60~ Fahr. =  9605 (the per centage will be between 33 and  34), the difference from
9609  (which is the next greatest number in the table)= 4, and the fraction is 4-.
therefore the true per centage is33 4.  From  the construction of this table the per
centage of alcohol by weight may also be found.  For instance: we multiply the number
representing the volumes of aldohol (given in the table for any determinate specific
gravity of the mixture) by the specific gravity of the pure alcohol, that is, by 7939,
and the product is the number of pounds of alcohol in so many pounds as the specific
gravity multiplied by 100 gives. Thus, in the mixture of 9510 specific gravity, there are
40  measures  of alcohol;  hence  there  are  also  in  95,100  pounds of this spirit
7939 +40 = 31*756 pounds of alcohol; and in 100 pounds of the spirits of 0-9510
specific gravity, 33 39 pounds of alcohol are contained.
As the preceding table gives the true alcoholic content when the portion of spirit under
trial has the normal temperature of 60~ Fahr., the following table gives the per centage of
alcohol for the specific gravities corresponding to the accompanying temperatures.
For example: if we have a spirituous liquor at 80~ Fahr., whose specific gravity is
0*9342, the alcohol present is 45 per cent. of the volume, or that specific gravity at that
temperature  is equal to  the  specific  gravity  0*9427 at the normal temperature  of
60~ Fahr.  This table may also be employed for every degree of the thermometer and
~Alcohol        Temperature.                A    l               Temperature.
Alcohol                                          Alcohol
per cent.                                 I''7            F        {
300 F. 350 F. 40  F.450 F. 50~  F. 155  F  per cent. 600 F. 65~  F. 700   750 F. 80~  F. 850 F.
0    9994  9997  9997  9998  9997  9994          0    9991  9987  9991  9976  9970  9962
5    9924  9926  9926  9926  99-25  9922         5    9919  9915  9909  9903  9897  9889
10    9868  9869  9868  9867  9865  9861    10    9857  9852  9845  9839  9831  9823
15    9823  9822  9820  9817  9813  9807    15    9802  9796  9788  9779  9771  9761
20    9786  9782  9777  9772  9766  9759    20    9751  9743  9733  9722  9711  9700
25    9753  9746  9738  9729  9720  9709    25    9700  9690  9678  9665  9652  9638
30    9717  9707  9695  9684  9672  9659    30    9646  9632  9618  9603  9588  9572
35    9671  9658  9644  9629  9614  9599    35    9583  9566  9549  9532  9514  9495
40    9615  9598  9581  9563  9546  9528    40    9510  9491  9472  9452  9433  9412
45    9544  9525  9506  9486  9467  9447    45    9427  9406  9385  9364  9342  9320
50    9460  9440  9420  9399  9378  9356    50    9335  9313  9290  9267  9244  9221
55    9368  9347  9325  9302' 9279  9256    55    9234  9211  9187  9163  9139  9114
60    9267  9245  9222  9198  9174  9150    60    9126  9102  9076  9051  9026  9000
65    9162  9138  9113  9088  9063  9038    65    9013  8988  8962  8936  8909  8882
70    9046  9021  8996  8970  8944  8917    70    8892  8866  8839  8812  8784  875&
75    8925  8899  8873  8847  8820  8792    75    8765  8738  8710  8681  8652  8622
80    8798  8771  8744  8716  8688  8659    80    8631  8602  8573  8544  8514  8483
85    8663  8635  8606  8577  8547  8517    85    8488  8458  8427  8396  8365  8333
90    8517  8486  8455  8425  8395  8363    90    8332  8300  8268   8236  8204  8171




22                                ALCOHOL.
every per centage, so as to save computation for the intervals. It is evident from inspection that a difference of 5~ Fahr. in the temperature changes the specific gravity of
the liquor by a difference nearly equal to 1 volume per cent. of alcohol; thus at 35~
and 85~ Fahr. the very same specific gravity of the liquor shows nearly 10 volumes per
cent. of alcohol more or less; the same, for example, at 60 and 40 per cent.
The importance of extreme accuracy in determining the density of alcoholic mixtures
in the United Kingdom, on account of the great revenue derived from them to the State,.
and their consequent high price in commerce, induced the Lords of the Treasury a few
years ago to request the Royal Society to examine the construction and mode of applying
the instrument now in use for ascertaining and charging the duty on spirits. This instrument, which is known and described in the law as Sikes's hydrometer, possesses, in many
respects, decided advantages over those formerly in use. The committee of the Royal
Society state, that a definite mixture of alcohol and water is as invariable in its value as
absolute alcohol can be; and can be more readily, and with equal accuracy, identified
by that only quality or condition to which recourse can be had in practice, namely,
specific gravity. The committee further proposed, that the standard spirit be that which,
consisting of alcohol and water alone, shall have a specific gravity of 0'92 at the
temperature of 620 Fahr., water being unity at the same temperature; or, in other
words, that it shall at 620 weigh 9-2 or 23  of an equal bulk of water at the same
temperature. 
This standard is rather weaker than the old proof, which was  2, or 0'923; or in the
proportion of nearly 1-1 gallon of the present proof spirit per cent. The proposed
standard will contain nearly one half by weight of absolute alcohol. The hydrometer
ought to be so graduated as to give the indication of strength; not upon an arbitrary
scale, but in terms of specific gravity at the temperature of 62~.
The committee recommend the construction of an equation table, which shall indicate
the same strength of spirit at every temperature. Thus in standard spirit at 62~ the
hydrometer would indicate 920, which in this table would give proof spirit. If that
same spirit were cooled to 40~, the hydrometer would indicate some higher number; but
which, being combined in the table with the temperature as indicated by the thermometer,
should still give proof or standard spirit as the result.
It is considered advisable, in this and the other tables, not to express the quality of the
spirit by any number over or under proof, but to indicate at once the number of gallons of
standard spirit contained in, or equivalent to, 100 gallons of the spirit under examination.
Thus, instead of saying 23 over proof, it is proposed to insert 123; and in place of 35'4
under proof, to insert its difference to 100, or 64-6.
It has been considered expedient to recommend a second table to be constructed, so
as to show the bulk of spirit of any strength at any temperature, relative to a standard
bulk of 100 gallons at 62~. In this table a spirit which had diminished in volume, at
any given temperature, 0'7 per cent., for example, would be expressed by 99'3; and a
spirit which had increased at any given temperature 0-7 per cent., by 100-7.
When a sample of spirit, therefore, has been examined by the hydrometer and
thermometer, these tables will give first the proportion of standard spirit at the observed
temperature, and next the change of bulk of such spirit from what it would be at the
standard temperature. Thus, at the temperature of 51~, and with an indication
(sp. gr.) of 8240, 100 gallons of the spirit under examination would be shown by the
first table to be equal to 164-8 gallons of standard spirit of that temperature; and by the
second table it would appear that 99-3 gallons of the same spirit would become 100 at
62~, or in reality contain the 164'8 gallons of spirit in that state only in which it is to
be taxed.
But as it is considered that neither of these tables can alone be used for charging the
duty (for neither can express the actual quantity of spirit of a specific gravity of 0-92 at
62~ in 100 gallons of stronger or weaker spirit at temperatures above or below 620), it is
considered essential to have a third table, combining the two former, and expressing this
relation directly, so that upon mere inspection it shall indicate the proportion of standard
spirit in 100 gallons of that under examination in its then present state. In this table
the quantities should be set down in the actual number of gallons of standard spirit at
62~, equivalent to 100 of the spirit under examination; and the column of quantities
may be expressed by the term value, as it in reality expresses the proportion of the only
valuable substance present. As this will be the only table absolutely necessary to be
used with the instrument for the purposes of the excise, it may, perhaps, be thought
unnecessary to print the former two.




ALCOHOL.                                                  23
The following specimen table has been given by the committee:Temperature 450.                             Temperature 75~.
Indication.*    Strength.       Value.       Indication.     Strength.       Value.
9074          114 5                          8941          114'5
7         114-3                             4          114'3
9         114'2                             5          114 -2
81         114'0                             8         114-0
3         113'9                            9          113'9
5         113 7                            52          113 7
6         113 6                             3          113 6
9         113 -4                            6          113 -4
90         113 -3                             7         113'3
3         113'1                              9         113'1
The mixture of alcohol and water, taken as spirit in Mr. Gilpin's tables, is that of
which the specific gravity is 0-825 at 60~ Fahr., water being unity at the same temper.
ature. The specific gravity of water at 60~ being 1000, at 62~ it is 99,981. Hence, in
order to compare the specific gravities given  by Mr.-Gilpin with  those which would result when the specific gravity of water at 62~ is taken at unity, all the former numbers
must be divided by 99,981.
Table of the Specific Gravities of different Mixtures, by Weight, of Alcohol and Water,
at different Temperatures; constructed by Mr. Gilpin, for the use of the British Revenue on Spirits.
a.             100      100     100     100     100      100     100     100      100      100
& a    Pure  Al         lcohol Alcohol                  Alcohol          Alcohol Alcohol AlcoholAlchlAlcoholAloholAlohol
Z   Alcohol   5          10      15       20      25      30       35      40      45       50
~             Water. Water. Water. WWater.   ater. Water. Water. Water. Water. Water.
Deg.
30   0-83896 0-84995 0-85957 0-86825 087585 0-88282 088921 0-89511 0-90054 0-90558 091023
35   -83672  -84769'85729  -86587'87357  -88059  -88701  -89294  -89839  -90345  -90811
40   -83445  -84539'8S07'86361'87184  -87838  -88481  -89073  -89617'90127  -90596
45    83214  -84310  -85277  -86131  886905  -87613  -88-255'88849  -89396  -89909  -90380
50   -82977  -84076  -85042'85902'86676'87384  -88030'88626  -89174  -89684  -901160
55   -82736  -83834  -84802  -85664.86441  -87150  -87796  -88393  -88945  -89458  -89933
60'82500'83599  -84568  -85430  -86208  -86918  -87569'88169  -88720  -89232  -89707
65   -82262  -83362  -84334  -85193  -85976  -86686  -87337'87938  88490  -89006  -89479
70    -82023  -83124  -84092  -84951  -85736  -86451  -87105'8770.5  88254  -88773  -89252
75    -81780  -82878  -83851  *84710  -85496  -86212  -86864  -87466  -88018  -88538  -89018
80    -81530  -82631  -83603'84467'85248  -85966  -86622'87228 -87776  -88301  -88781
85   -81291  -82396  -83371'84243  -85036  -85757  -86411'87021  -87590  -88120  -88609
90    -81044'82150  -83126'84001  -84797  -85518  -86172'86787  87360   87889  -88376
95    -80794  -81900  -82877  -83753  -84550  -85272  -85928'86542'87114  -87654  -88146
100   -80548  -81657  -82639'83513  -84038'85031  -85688  -86302'86879  -87421'87915
100     100     100     100      100     100     100      100     100      100
Temperature, AlcoholAlcoh        coholAlcohol Alcohol Alcohol Alcohol Alcohol lcoh   Alcohol
Fahr.        55       60      65     70       75       80      85      90       95      100
Water. Water. Water. Water. Water. Water. Water. Water.  Water. Water
Deg.
30       0-91449 0-91847 0-92217 0-92563 0-92889 0.93191 0-93474 0-93741 1093991 0'94222
35        -91241'91640  -92009  -92355'92680  -92986  -93274  -93541  -93790'94025
40'91026'91428'91799  -92151'92476'92783  -93072  -933411  93592  -93827
45'90812  91211'91584  -91937  -92264'92570  -92859'931311 933821 93621
50'90596'90997'91370  -91723  -92051  -92358  -92647  -92919  -93177  -93419
55'90367'90768'91144  -91502'91837'92145  -92436'92707  -92963'93208
60'901441 90549  90927'91287  -91622  -91933  -92225  -92499'92758'93002
65'89920'90328'90707  -91066  -91400'91715  -92010  -922831 92546'92794
70        -89695  -90104'90484  -90847  -91181'91493  -91793  -920691  92333  -92580
75'89464  -89872'90252  -90617'90952  -91270  -91569  -91849  -921111 92364
80'89225  -89639'90021  -90385'90723'91046  -91340  -91622'91891  -92142
85'89043'89460'89843  -90209  -90558'90882  -91186  -91465  -91729'91969
90'88817  -89230  -89617  -89988  -90342  -90688  -90967  -91248  -91511  -91751
95'88588'89003'89390'89763  -90119'90443'907471 91029'912901 -1531
100        -83571  88769'89158.89536.89889  -90215'90522'90805  -91066'91310
*By specific gravity.




24                                     ALCOHOL.
Table of the Specific Gravities of different Mixtures, &c. (continued).
1     95       90      85      80      75      70      65      60      55      50
-   Alcohol Alcohol Alchol Acoholl Alcoholl Alcohol Alcohol  Alcohol Alohol Alcohol
J      100     100     100    100      100      100    100    100    100    400
~    Water. Water. Water. Water. Water. Water. Water. Water. Water. Water.
Deg.
30  0-94447 0-94675 0-9492095173 09095429 0-95681 095944 0-96209 0-96470 0-96719
35   -94249  -94484  -94734  -94988  95246  -95502  95772  96048  -96315  96579
40'94058  -94295  -94547  94802  95060  -95328  95602  95879  -96159  96434
45   -93860  -94096  -94348  -94605  -94871  -95143'95423  -95703  -95993   9680
50   -93658  -93897  -94149  -94414  -4683  *94958  95243  -95534  -95831  -96126
55   -93452  -93696  -93948'94213  -94486'94767'95057  -953571 95662  959b6
60   -93247  -93493  -93749  -94018  -S4296  -94579'94876  -95181  95493  95804
65   -93040  -93285  -93546  -93822  -94099  -94388  -94689  -95000  -95318  -95635
70   -92828  -93076  -93337  -93616  -93898  -94193  -94500  -94813  -95139  -95469
75    92613  -92865  -93132  -934131  93695  -93989  -94301  -94623  -94957  95292
80   -92393  -92646  -92917  -93201  *93488  -93785  -94102  -94431  -94768  95111
45      40     35      30      25      20       15      10      5
Tenperature, Aleohol Alcohol Alcohol Alcohol Alcohol Alcohol Alcohol Alcohol Alcohol
Fallr.      100    100    100    100        100     100     100     100    100
Water. Water. Water. Water. Water. Water. Water. Water. Watcr.
Degrees.
30      O 96967 0-97200 0-97418 0-97635 0-97860 0-98108 0-98412 0-98804 0-99334
35       -96840'97086  -97319  -97556  -97801  -98076  -98397  -98804  -99344
40       -96706  -96967  -97220  -97472  -97737  -98033  -98373  -98795  -99345
45        -96563  -96840  97110'97384'97666  -97980  -98338  -98774  -99338
50       -96420  -96708'96995  -97284  -97589  -97920  -98293  -98745  99316
55       -96272  -96575  -96877  097181  -97500  -97847  -98239  -98702  -99284
60       -96122  -96437  -96752  -97074  97410  -97771  -98176  -98654  -99244
65       -95962  -96288  -96620  -96959  -97309  -97688  -98106  -98594  -99194
70        -95802  -96143  -96484  -96836  -97203  -97596  -98028  -98527  -99134
75        -95638  -95987  -96344  -96708  -97086  -97495  -97943  -98454  -99066
80        -95467  -95826  -96192  -96568  -96963  -97385  -97845  -98367  -98991 
Experiments were made, by direction  of the committee, to verify  Gilpin's tables,
which showed that the error introduced in ascertaining the strength of spirits by tables
founded on  Gilpin's numbers must be quite insensible  in the practice of the revenue.
The discrepancies thus detected, on a mixture of a given strength, did not amount in any
one instance to unity in the fourth place of decimals. From a careful inspection of such
documents the committee are of opinion, that Gilpin's tables possess a degree of accuracy
far surpassing what could be expected, and sufficiently perfect for all practical or scientific purposes.
The following table is given by Mr. Lubbock, for converting the apparent specific
gravity, or indication, into true specific gravity.
--                Temperature.                +                      ~
-u    30~   32~   37~   42~   470   52~   57~  62~  67~    72~   77~   800 
0~c                                                              71nllP 80~         [
-82  -00083 -00078 -00065 -00052 -00039 -00025 -00012     -00011 -00024 -00035 -00042  -82
-83  -00084 -00079 -00066'00052 -00039 -00026 -00012     -00012 -00024 100036 -00042  -83
84  -00085 -00080 -00066 -00053 -00039 -00026 00013      -00012 -00024 -00036 -00043  -84
-85  -00086 -00081 -00067 -00054 -00040 -00026 -00013     -00012 -00025 -00037 -00043   85
-86  -00087 -00082 00068 -00054 100040 -00027 -00013      -00012 -00025 -00037 -00044  -'8
-87  -00088 -00083 -00069 -00055 -00041 -00027 -00013     -00012 -00025 t00037 00044   87
~88  -00089 -00084 -00070 -00055 -00041 -00027 -00013     -00012 -00026 00038 -00045  -88
-89  -00090 -00085 -00070 -00055 -00042 -00028 -00013     -00012 -00026 -00038 -00045  -89
-90  -00091 -00085 -00071 -00056 -00042 -00028 -00014     -00013'00026 -00039 -00046   90'91  -00092 -00086 -00072 -00057 100043 -00028 -00014     -00013 -00026 -00039 -00046  -91
-92  -00093 -00087 -00073 -00058 -00043 -00029 100014'00013 -00027 -00040 100047  -92
-93  -00094 -00088 -00073 -00059 -00044 -00029 -00014     -00013 -00027 100040 -00047  -93
-94  -00095 -00089 -00074 -00059 -00044 -00029 -00014      -00013 -00027 -00040 -00048  -94
~95  -00096 -00090 -00075 -00060 -00045 -00029 -00014     -00013 -00028 -00041'00048  -95
-96  -00097 -00091 -00076 -00060 -00045 -00030 -00014     -00013 -00028- 00041 100049  -96
~97  -00098 -00092 -00077 -00061 -00046 -00930 -00015      -00014 -00028 -00042 -00049  -97
*98  -00099 -00093 -00077 -00062 -00046 -00030 -00015      -00014 100028 -00042 100050  -98 
~99  -00100 -00094 -00078 -00062 -00047 -00031 -00015      -00014 -00029 -00043 -00050'99
~100  -00101 -00095 -00079 00063 -00047 -00031 -00015             1   100




ALCOHOL.                                    25
The hydrometer constructed, under the directions of the Commissioners of Excise, by
Mr. Bate, has a scale of 4 inches in length divided into 100 parts,
and 9 weights. It has thus a range of 900 divisions, and expresses    Fig. 5.
specific gravities at the temperature of 620 Fahr. In order to render
this instrument so accurate a measurer of the specific gravity, at the
standard temperature, as to involve no error of an appreciable amount,
Mr. Bate has constructed the weights (which in this instrument are immersed in the fluid of different specific gravities) so that each successive weight should have an increase of bulk over the preceding weight
equal to that part of the stem occupied by the scale, and an increase
of weight sufficient to take the whole of the scale, and no more, down 
to the liquid. This arrangement requires great accuracy of workman- 
ship, and enhances the price of the instrument. But it allows of increased strength in the ball, where it is very much required, and it
gives, upon inspection only, the indication (apparent specific gravity)
by which the general table is to be examined and the result ascertained.
Fig. 5 represents this instrument and two of its nine ballast weights.
It comprehends all specific gravities between 820 and 1000. It indicates true specific gravity with almost perfect accuracy at the temperature of 020 Fahr.; but it does not exclude other instruments from
being used in conjunction with tables. The latter are, in fact, independent of the instrument, and may be used with gravimeters, or
any instrument affording indications by specific gravity at a given
temperature. SEE SPIRITrr
The commercial value of spirituous liquors being much lower in
France than in England, a less sensible instrument becomes sufficient
for the wants of that country. Baume's and Cartier's hydrometers,
with short arbitrary scales, are very much employed, but they have been lately superseded by an ingenious and ready instrument contrived by M. Gay Lussac, and called
by him an alcoometre. He takes for the term of comparison pure alcohol by volume,
at the temperature of 15~ Cent., and represents the strength of it by 100 centimes,
or by unity. Consequently, the strength of a spirituous liquid is the number of centimes in volume of pure alcohol which that liquid contains at the temperature of 15~
Cent. The instrument is formed like a common hydrometer, and is graduated for the
temperature of 150 Cent. Its scale is divided into 100 parts or degrees, each of which
denotes a centime of alcohol; the division 0 at the bottom  of the stem  corresponds
to pure water, and the division 100 at its top, to pure alcohol. When immersed in a
spirituous liquor at 15~ Cent. (593 Fahr.) it announces its strength directly. For
example: if in spirits supposed at the temperature of 15~ Cent. it sinks to the division 50,
it indicates that the strength of this liquor is 50 per cent., or that it contains 50 centimes
of pure alcohol. In our new British proof spirit, it would sink to nearly 57, indicating
57 by volume of pure alcohol, allowing for condensation, or 50 by weight. A table of
correction is given for temperature, which he calls " Table of real strength of spirituous
liquors." The first vertical column of this table contains the temperatures, from 0~ to
30~ Cent., and the first horizontal line the indications of the alcoometre. In the same
table we have most ingeniously inserted a correction for the volume of the spirits when
the temperature differs from 15~ Cent. If we take 1000 litres or gallons, measured at
the temperature of 20, of a spirituous liquor whose apparent strength is 44c; its
real strength at 15~ will from the preceding mode of correction be 49c. On heating this
liquid to 15~, in order to find its real specific gravity or strength, its bulk will become
greater; and, instead of 1000 litres or gallons, which it measured at 2~, we shall have
1009 at 15~ C. This number is inscribed in smaller characters in the same square ceil
with the real force, precisely under 49c. All the numbers in small characters, printed
under each real strength, indicate the volume which 1000 litres of a spirituous liquor
would have, when measured at the temperature at which its apparent strength is taken.
In the above example, the quantity in litres or gallons of pure alcohol contained in 1000
litres or gallons of the spirits, measured at the temperature of 2~, will be, therefore,1009 lit. X 0-49 = 494 lit. 41.
This quantity of pure alcohol, thus estimated, is called richness of spirit in alcohol, or
simply richness.
Let us take an example similar to the preceding, but at a higher temperature than
15~ Cent. Suppose we have 1000 litres measured, at the temperature of 25~, of spirits
whose apparent strength is 53c, what is the real quantity of pure alcohol which this
spirit contains at the temperature of 15~? We shall find in the table, first of all, that
the real strength of the spirits is 49c.3. As to its bulk or volume, it is very clear
that the 1000 litres in cooling from 25~ to 15~, will occupy a smaller space. This
volume will be 993 litres; it is inscribed directly below 49c.3, the real strength. We




26                                     ALCOHOL.
shall therefore have of pure alcohol, contained in the 1000 litres of spirits, measured at
the temperature of 25~, or their richness, 993 lit. X 0'493 = 489 lit. 55.
Alcometrical Table of real Strength, by M. Gay Lussac.
Temperature.   31c    32c    33c    34c    35c    36c    37c    38c    39c    40c
Deg.
10       33 0    34      35      36     37      38     39     40      41     42
1002   1002   1003   1003   1003   1003   1003   1003   1003   1003
11       32 6   33 6   34 6   35 6   36 6   37-6  38-6  39-6  40 6   41-6
1002   J002   1002   1002   1002   1002   1002   1002   1003   1003
12       32 2   33 2   34 2   35 2   36 2   37 2   38 2   39 2   40 2   41-2
1001   1001   1002   10(2   1002   1002   1002   1002   1002   1002
13       31-8  32-8  33-8  34-8  35 8   36 8   37-8  38-8  39 8   40 8
1001   1001   1001   1001   1001   1001   1001   1001   1001   1001
14       31-4  32'4   33-4  34-4  35 4   36 4   37-4  38-4  39-4  40 4
1001   1001   1001   1001   1001   1001   1001   1001   1001   1001
15        31      32     33     34      35     36      37     38      39     40
1000   1000   1000   1000   1000   1000   1000   1000   1000   1000
16       30 6   31 6   32-5  33-5  34-5  35-5  36 5   37-5  38 5   39-5
1000   1000    999    999    999    999    999    999    999    999
17       30-2   31-2  32*1   33 1  34-1  35.1   36 1  37 1  38 1   39 1
999    999    999    999    999    999    999    999    999    999
18       29-8  30 8   31-7  32-7  33-7  34.7   35-7  36 7   37-7  38.7
999    999    998    998    998    998    998    998    998    998
19       29-4  30-4  31-3  32'3   33-3  34-3  35 3   36-3  37-3   38 3
998    998    998    998    998    998    998    998    997    997
20        29      30    30-9  31-9  32 9   33 9   34-9  35*9   36-9   37-9
998    998    997    997    997    997    997    997    997    997
21       28 6   29 6   30 5   31 5   32 5   33 5   34-5   35 5   36 5   37 5
997    997    997    997    997    997    997    996    996    996
22       28 -2  29-2  30 1  31-1  32 1   33 1   34 1  35-1   36 1   37-1
997    997    996    996    99       996    996    996    996    996
23       27-8  28 8  29 7  30 7   31 7   32 7   33 7   34 7   35 7   36 7
996    996    996    996    996    996    996    095    995    995
24       27      284   29-3  30 3   31 3   32-3  33 3  34-3   35-3  36-3
996    996    995    995    995    995    995    995    995    994
25        27      28    28 9  29 9  30 9   31-9   32 9   33-9  34 9   35 -9
995    995    995    995    995    994    994    994    994    994
Temperature.
Te'peru.    410    42c    43c    44r    45c    46c    47c    48c    49e    50c
Deg.
10        43      44      45     46    46 9  47 9   489 9 499  50 9   51-8
1003   1004   1004   1004   1004   1004   1004   1004   1004   1004
11       42-6  43 6   44-6  45'6   46'6  47-6  48-6  49-5  50-5   51-5
1003   1003   1003   1003   1003   1003   1003   1003   1003   1003
12       42 2   43-2   44-2  45'2   46-2  47-2  48 2   49 2  50-2   51'1
1002   10 C    1002   1002   1002   1002   1002   1002   1002   1002
13       41 8   42 8   43-8  44-8  45 8  46 8   47-8  48 8  49-8  50 -8
1001   1001   1001   1002   1002   1002   1002   1002   1002   1002
14       41-4  42-4   43'4  44'4   45'4   46-4  47-4  48 4  49-4  50'4
1001   1001   1001   1001   1001   1000   1001   1001   1001   1000
15        41      42      43     44      45     46     47      48     49      50
1000   1000   1000   1000   1000   1000   1000   1000   1000   1000
16       40-6  41 6   42-6  43-6  44-6  4.56   46-6  47-6  48-6  49-6
999    999    999    999    999    999    999    999    999    999




ALCOHOL.                                              27
Alcometrical Table of real Strength, by M. Gay Lussac (continued).
Temperature.  410    42c    43c    44o    45c    46c    47c    48c    49c    50c
C.   _    __                                         _ _
Deg.
17       40-2  41-2  42-2  43-2  44 9   45'2  46-2  47-2  48.2  49-2
999    999    999    998    998    998    998    998    998    998
18       39-8  40 8   41-8  42-8  43 8  44 9   45 9  46 9   47-9  48-9
998    998    998    998    998    998    998    998    998    998
19       39-4   44     44 414   425   43-5  44-5  45*5  4655  475  48-0
997    997    997    997    997    997    997    997    997    997
o          39     40      41    42 1   43 1   44 1   451  46 1   47-2  48'2
997    997    997    997    996    996    996    996    996    996
21        3386   39-6  40 6   41-7  42 7  43-7  44 8  45 8   46 -8  47 8
996    996    996    996    996    996    996    996    995    995
22        38-2  39-2  40 2   41-3  42-3  43-3  44-3  45 3   46-4  47 4
996    995    995    995    995    995    995    995    995    995
23        37 8   388   39 8  40 9   41 -9 42     43 -9  44 9    46            47
995    995    995    994    994    994    994    994    994    994
24        37 4   38 -4  39 -4  40 -5  41-5  42 -5  43 -6  44 -6  45 -6  46 -6
994    994    994    994    994    994    994    994    993    993
25         37     38      39    401   42 1   42- 2   43           2 2  446- 45 2    6.-3
994      994    993    9 93  93 93    993      993    993 3    993
Deg
10       52-8  53-8  54-8  55-8   56-8  57-8  58-8  59-7   60-7   61-7
1004   1004   1004   1004   1004   1004   1004   1004   1004   1004
11       52-5  53-5  54-4  55-4  56-4   57-4  58-4   59-4  60-4   61-4
1003   1003   1003   1003   1003   1003   1003   1003   1003   1003
12       52-1  53-1  54-1   55          56      57     58      59      60     61
1002   1002   1002   1002   1002   1002   1002   1002   1002   1002
13       51.8  52-7  53-7  54-7  55.7  56-7  57-7   58-7  59-7  60-7
1002   1002   1002   1002   1002   1002   1002   1002   1002   1002
14       51-4  52-3  53-3  54-3  55-3  56-3   57-3   58-3  59-3  60-3
1001   1001   1001   1001   1001   1001   1001   1001   1001   1001
15        51      52     53      54     55      56     57      58     59      60
1800   1000   1000   1000   1000   1000   1000   1000   1000   1000
16       50-6  51 -6  52-6   53-6  54-6  55-6  56-6   57-6  58-6  59'6
999    999    999    999    999    999    999    999    999    999
17       50-3  51-3  52-3  53-3  54-3  55-3  56-3   57-3  58-3  59-3
998    998    998    998    998    998    998    998    998    998
18       49-9  50-9  51-9  52-9  53-9  54-9  55-9   56-9  57-9  58-9
998    998    998    998    998    998    998    997    997    997
19       49-5  50-6  51-6  52-6  53-6  54-6  55-6  56-6  57-6   58-6
997    997    997    997    997    997    997    997    997    997
20       49-2  50-2  51-2  52-2  53-2  54-2  55-2  56-2  57-2  58-2
996    996    996    996    996    996    996    996    996    996
21       48'8  49-8  50-8  518  52-9  53-9  54-9   55-9  56-9  57-9
995    995    995    995    995    995    995    995    995    995
22       48-4  49-4  50-4   51-4  52-5  53-5  54-5   55-5  56-5  57-5
995    995    995    994    994    994    994    994    994    994
23        48    49-1  50-1  51'1  52-1  53-1  54-1  55-1  56-1  57-1
994    994    994    994    994    994    994    993    993    993
24       47-6  48-7  49-7  50-7   51-8  52-8  53-8  54-8  55-8  56-8
993    993    993    993    993    993    993    993    993    992
25       47'3  48-3  49-3  50-3   51-4  52-4  53-4  54-4  55-5  56-5
__________  993  993  993  992  992  992  902  992992




28                                    ALCOHOL.
Alcometrical Table of real Strength, by M. Gay Lussac (continued).
Temperature.  61c    62c    63c    64c    65c    66c    67c    68c    69c    70c
C.
Deg.
10       62 7   63 7   64 7   65 7   66 7   67 6   68 6   69 6   70 6   71 6
1004   1004   1004   1004   1004   1004   1004   1004   1004   1004
11       62 4   63 4   64-4  65 4   66 4   67 3   68 3   69 3   70 3   71-3
1003   1003   1003   1003   1003   1003   1003   1004   1004   1004
12        62      63     64      65     66     67      68     69      70     71
1002   1002   1002   1002   1002   1002   1003   1003   1003   1003
13       61.7   62-7  63-7  64-7  65 7   66-7  67-7  68 7   69 6   70-6
1002   1002   1002   1002   1002   1002   1002   1002   1002   1002
14       61-3   62'3   63 3  64-3  65-3  66-3  67-3  68-3  69 3   70-3
1001   1001   1001   1001   1001   1001   1001   1001   1001   1001
15        61      62     63      64     65     66    -67      68      69      70
1000   1000   1000   1000   1000   1000   1000   1000   1000   1000
16       60-6   61'7  62-7  63-7  64-7  65-7  66'7   67 7   68-7  69-7
999    999    999    999    999    999    999    999    999    999
17       60-3   61 3   62-3  63 3   64-3  65-3  66-3  67-3  68-3  69-3
998    998'  998    998    998    998    998    998    998    998
18       59'9    61      62      63     64      65     66      67     68      69
997    997    997    997    997    997    997    997    997    997
19       59-6  60-6  61-6  62-7  63-7  64-7  65 7   66-7  67-7  68-7
997    997    997    997    997    997    997    997    996    596
20       59 2   60 3  61-3  62 3  63 3  64-3  65 4   66 4   67-4   68-4
996    996    996    996    996    996    996    996    996    996
21       58-9  59-9   61        62      63      64     65      66     67    681
995    995    995    995    995    995    995    995    995    995
22       58'5   59 5   60-6  61-6  62-7  63-7  64-7  65-7  66-7  67-8
994    994    994    994    994    994    994    994    994    994
23       58 1  59-2  60-2  61-3  62-3  63-3  64-3   65-4  66-4  67-4
993    993    993    993    993    993    993    993    993    993
24       57-8  58-9  59 9    61         62      63     64      65     66    67-1
992    992    992    992    992    992    992    992    992    992
25       57-5  58-5  59 -5  60-6  61-6  62-6  63-7  64-7  65-7  66-7
992    992    992    991    991    991    991    991    991    991
Temperature.
Temper e.  71o    720    73c    74c    75c    76c    77c    78c    790    80c
Deg. 
10       72-6   73-5  74'5  75-5  76'5  77-5  78-5  79-5   80-5   81-5
1004   1004   1005   1005   1005   1005   1005   1005   1005   1005
11       72 -3   73 2   74-2  75 2   76 2  77-2  78 2  792            0-2   81-2
1004 1004   1004   1004   1004   1004   1004   1004   1004   1004
12        72    72 9   73-9  74 9   75 9  76-9  77-9  78-9  79 9   80-9
1003   1003   1003   1003   1003   1003   1003   1003   1003   1003
13       71-6  72 6   73 6   74-6  75-6  76 6   77 6  78-6  79-6   80 6
1002   1002   1002   1002   1002   1002   1002   1002   1002   1002
14       71 3   72 3   73 -3  74 3   75-3  76 3   77 -3  78 3   79 3   80-3
1001   1001   1001   1001   1001   1001   1001   1001   1001   1001
15        71      72     73      74     75     76      77     78      79     80
1000   1000   1000   1000   1000   1000   1000   1000   1000   1000
16       70'7   71-7  72-7  73-7  74-7  7.57   76-7  77-7   78-7  79*7
999    999    999    999    999    999    999    999    999    999
17       70-3   71-3  72-3  73*3   74-3  75-4  76-4  77-4   78-4  79.4
________ 998  998  998  998  998  998  998  998  998  998




ALCOHOL.                                             29
Alcometrical Table of real Strength, by M. Gay Lussac (continued).
T perature.  71c    72c     73c    74c.   75c    76c    77c    78c    79         80
C.
Deg. 
18        70     71      72     73      74    75 1  76'1  77-1  78-1  79-1
997    997    997    997    997    997    997    997    997    997
19       69-7  70 7  71-7  72 7  73-7  74-7  75 8  76 8   77 8  78-8
996    996    996    996    996    996    996    996    996    996
20       69-4   70-4  71-4  72-4  73*4   74-4  75-5  76 5   77*5  78*5
996    996    995    995    995    995    995    995    995    995
21       69-1  70-1  71'1   72-1  73-1  74-1  75 2  76 2   77 2   78-2
995    995    995    994    994    994    994    994    994  % 994
22       68-8  69 8   70 8   71 8  72 8   73 8   74 -8  75 9   76 9  77 9
994    994    994    994    993    993    993    993    993    993
23       68-4  69 4   70-5  71-5  72-5  73-5  74-5  75 5   76 6  77 6
993    993    993    993    992    992    992    992    992    992
24       68 1  69.1  70-1  71-2  72-2  73 2   74 2  75-2  76 3  77-3
992    992    992    992    992    992    992    991    991    991
25       67*8   68*8   69-8  70-8  71 8   72-8  73 9  74-9   76              77
9 91 991          991     991 991    991    991    991    91    991
Tempat        81c    82      83c    84c    85c    86c    87c    88c    89c    90c
Deg.
10       82 4   83 4  84 4   85 4   86 4   87 4   88 3   S9 3   90 2   91-2
1005   1005   1005   1005   1005   1005   1005   1005   1005   1005
11       82-2  83 1  84.1  85-1  86 1  87-1   88              89     90      91
1004   1004   1004   1004   1004   1004   1004   1004   1004   1004
12       81-9  82-9  83.9  848  85 -8  86-8  s87            88-77  89 7   90 7
1003   1003   1003   1003   1003   1003   1003   1003   1003   1003
13       81.6  82 6  83-6  84-6  85.5   86 5   875   8855  89.5  90.5
1002   1002   1002   1002   1002   1002   1002   1002   1002   1002
14       813   82-3  83-3  84 3  85 3   86 3   87-3  88-2  89-2  90-2
1001   1001   1001   1001   1001   1001   1001   1001   1001   1001
15        81     82      83     84     85      86     87      88     89      90
1000   1000   1000   1000   1000   1000   1000   1000   1000   1000
16       80-7  81 7  82-7  83-7  84 7   85-7  86-7  87 7   88 7   89 7
999    999    999    999    999    999    999    999    999    999
17       80 4   81-4  82*4   83-4  84-4  85-4  86-4  87-4  88-4  89-5
998    998    998    998    998    998    996    998    998    998
18       80-1  81 1  82*1   83*1  84-1  85-2  86-2  87-2  88-2  89-2
997      97    997    997    997    997    997    997    997    997
19       79 8  80-8  81'9   82'9  83 9   84 9  85 9   86 9   87 9   88 9
996    996    996            996    996    996    99 6 99         996
20       79 5   80 5   81-6  82 6  83 6   84 6   85-6  86-6  87-7  88-7
995    995    995    995    995    995    995    995    995    995
21       79-2  80 2  81-3  82 3  83 3   84-3  85 3   86'4  87 4   88-4
994    994    994    994    994    994          9 94     994     994
22       78 9   79 -9   81      82     63      84     85    86 -1  87-1  88-2
993    993    993    993    993    993    993    993    993    993
23       78 6   79 6  80 7  81-7  82 7   83 8   84 8   85 8   86 8   87 9
992    992    992    992    992    992    992    992    992    992
24       78 3   79 3  80 4   81 4  82 4   83 5   84 5   85 5   86 5   87-6
991    991    991    991    991    991    991    991        1    991 991
25        78      79    80 1  81 1  82 1  83-2  84-2  85 2   86 3   87-4
991    991    990    990    990        990     990     990    990    990




30                                 ALCOHOL.
I consider the preceding table, which I have extracted from the longer tables of
M. Gay Lussac, as an important addition to the resources of British dealers and manufacturing chemists.  With the aid of his little instrument, which may be got for a
trifle from its ingenious maker, M. Collardeau, Rue Fauburg St. Martin at Paris, or
constructed by one of the London hydrometer artists, the per centage of real alcohol,
and the real value of any spirituous liquor, may be determined to sufficient nicety for
most purposes, in a far easier manner than by any instruments now used in this country. It has been adopted by the Swedish government, with M. Gay Lussac's tables.
M. Gay Lussac's table gives, by inspection, the true bulk of the spirits as corrected
for temperature; that is their volume, if of the normal temperature of 15~ Cent. (590
Fahr).  Now this is important information; for, if a person buys 1000 gallons of spirits
in hot weather, and pays for them exactly according to their strength corrected for
temperature, he will not have 1000 gallons when the weather is in its mean state. He
may lose, in this way, several gallons, without being aware of it from his hydrometer.
Sometimes, after moist autumns, when damaged grain abounds, the alcohol distilled
from its fermented wash contains a peculiar volatile body. When we apply our nose
to this species of spirits in its hot state, the volatile substance dissolved in it irritates
the eyes and nostrils; it has very nearly the same smell as an alcoholic solution of
cyanogen, as any chemist may discover by standing near the discharge pipe of the
refrigeratory worm of a raw-grain whisky still. Such spirits intoxicate more strongly
than pure spirits of the same strength, and excite, in many persons, even temporary
frenzy. It is a volatile fatty matter, of a very fetid odor, when obtained by itself, as
I have procured it in cold weather at some of the great distilleries in Scotland. It
does not combine with bases. At the end of a few months, it spontaneously decomposes
in the spirits and leaves them in a less nauseous and noxious state. By largely diluting the spirits with water, and distilling at a moderate temperature, the greater part
of this oil may be separated. Part of it comes over with the strongest alcohol, and
part with the latter runnings, which are called by the distillers strong and weak feints.
The intermediate portion is purer spirit. The feints are always more or less opalescent,
or become so on dilution with water, and then throw up an oily pellicle upon their
surface. The charcoals of light wood, such as pine or willow, well calcined, and infused in sufficient quantity with the spirits prior to rectification, will deprive them of
the greater part of that oily contamination. Animal charcoal, well calcined, has also
been found useful; but it must be macerated for some time with the empyreumatic
spirits, before distillation. Another mode of separating that offensive oil is, to agitate
the impure spirits with a quantity of a fat oil, such as olive oil, or oil of almonds, to
decant off the oil, and re-distil the spirits with a little water.
Digestion and agitation with calcined magnesia, for sonfe time, followed by filtration
and distillation, are also good means of improving the flavor of alcohol. The taste
of the oil of grains is best recognized by agitation with water, whereby, on standing,
the diluted spirit throws up a film of oil, visible by reflected light. If the spirit be
mixed with a few drops of nitrate of silver and exposed for some time to sunshine, the
oil will react upon the oxide of silver, and cause a brown tinge; but if there be no oil
present, the spirits will remain limpid. If one part of hydrate of potash, dissolved
in a little water, be mixed with 160 parts of spirits, and if the mixture be well shaken,
then slowly evaporated down to 15 parts and mixed with 15 parts of dilute sulphuric
acid in a phial, to be then corked, there will soon exhale from the mixture a peculiar
offensive odor, characteristic of the quality and origin of the impure spirit, whether
obtained from  raw grain, from  malt, from potatoes, rye, arrack, rum, brandy, &c.
This excellent process may be used also for testing wines. Lime and alkalis always
injure the flavor of ardent spirits of all kinds.
Some foreign chemists direct empyreumatic or rank spirits to be rectified with the
addition of chloride of lime. I have tried this method in every way, and on a considerable scale, but never found the spirits to be improved by it. They were rather
deteriorated. See BRANDY, DISTILLATION, FERMENTATION, GIN, RUM, and WHISKY.
Anhydrous. or absolute alcohol, when swallowed, acts as a mortal poison, not only
by its peculiar stimulus on the nervous system, but by its abstracting the aqueous
particles from the soft tissue of the stomach, with which it comes in contact, so as to
destroy its organization.
The absence of water in alcohol may be tested by sulphate of copper calcined to
whiteness, which imparts a blue tinge to the liquid. 46 parts of absolute alcohol
contain 6 parts of hydrogen; and hence, by being burnt in a tubulated globular receiver connected with a condensing worm, they afford 54 parts of water. If the spirit
was free from oil, the water will be quite pure, as the carbonic acid flies off.
The high price of alcohol in this country, in consequence of the heavy fiscal duties,
and its low price in most other countries, where it is nearly duty free, has led to its
contraband importation under various disguises. Sometimes it is introduced under the




ALGAROVILLA.                                   31
mask of oil of turpentine, from which it can be sufficiently freed by rectification for
the purpose of the gin manufacturers. Sometimes it is disguised with wood naphtha,
or wood vinegar; from the latter of which it may beseparated by distillation in a water
bath; but from the former it is more difficult to extricate it, as alcohol and wood spirit
are nearly equally volatile. It has also been disguised with coal naphtha; but from
this it may be easily separated by distillation, on account of the great difference between the boiling points of the two liquids; besides, coal naphtha will not combine
with water, as alcohol does.
When the object is to discover whether wood spirit contains alcohol, we may proceed as follows:-Add to the suspected liquid a little nitric acid, of specific gravity
1.45. If alcohol be present, in even small proportion, an effervescence will ensue,
from the evolution of etherised nitrous gas, with its characteristic ethereous smell.
On treating the mixture with a nitrous solution of mercury, as in the process for fulminate of mercury, an effervescence will take place, the dense vapor of etherised
mercurial gas will appear, and a certain proportion of fulminate will be formed, corresponding pretty closely to the proportion of alcohol in the wood naphtha mixture.
As the boiling point of wood spirit is only about 145~, while that of alcohol, of like
specific gravity (0-825), is 173~ F., a good criterion of the proportion of the two liquids
present in the mixture may be found in its boiling temperature.
Pure wood spirit, when mixed with the above nitric acid, becomes of a ruby tint,
but remains tranquil. Alcohol continues colorless, but enters into violent ebullition,
and is nearly all dissipated in fumes.
Alcohol diluted with water has a less resultant density than wood spirit of like
strength similarly diluted. While alcohol thus becomes of 0 920, wood spirit becomes
0'926 or 0'927.
If wood spirit be contained in alcohol, it may be detected to the greatest minuteness by the test of caustic potash, a little of which, in powder, causing wood spirit to
become speedily yellow and brown, while it gives no tint to alcohol. Thus 1 per cent.
of wood spirit may be discovered in any sample of spirits of wine. For further details
upon this analytical inquiry, see my pamphlet entitled The Revenue in Jeopardy.
ALDEHYDE; a name compounded out of alcohol dehydrogenated, being a substance
formed by depriving alcohol of its hydrogen. The process is too intricate for description here. It is a limpid liquid, of 0'790 specific gravity, boiling at 21 8~ C., and not
reddening litmus. It has a peculiar ethereous smell: when its vapor is inhaled it
causes suffocation, and even in small quantities a spasmodic-constriction of the thorax.
It is composed 6f 4 atoms of carbon = 24, 4 of hydrogen =4, and 2 of oxygen = 16;
or in 100 of 64-55, 9'09 and 36'36 respectively. It is very inflammable.
ALE. The fermented infusion of pale malted barley, combined with infusion of
hops. See BEER.
ALEMBIC, a STILL; which see.
ALEMBROTH, salt of. The salt of wisdom, of the alchemists; a compound of
bichloride of mercury and sal ammoniac, from which the old white precipitate of
mercury is made.
ALGAROTH, powder of. A compound of oxide and chloride of antimony, being
a precipitate obtained by pouring water into the acidulous chloride of that metal.
ALGAROVILLA. This substance is called by the Spaniards Algaroba, from the
resemblance it bears to the fruit of the Carob (Ceratonia siliqua), which is a native of
Europe, in the southern countries of Spain and Portugal. The substance lately analysed by me is the fruit of a tree which grows in Chili, of which the botanical name
is Prosopis pallida, according to Captain Bagnald, R.N., who first brought a sample
of it to this country in the year 1832. It consists of pods bruised and agglutinated
more or less with the extractive exudation of the seeds and husks. According to a
more recent determination, algarovilla is said to be the product of the tree Juga Marthe of Santa Martha, a province of New Carthagena.
It is an astringent substance replete with tannin, capable, by its infusion in water,
of tanning leather, for which purpose it possesses more than four times the power ot
good oak bark. Its active matter is very soluble in water at a boiling temperature.
The seeds are merely nutritive and demulcent, but contain no astringent property.
This resides in the husks. The seeds in the entire pod constitute about 1-5th of the
weight, and they are three or four in number in each oblong pod. Alcohol of 60 per
cent. over proof dissolves 64 parts in 100 of this substance. The solution consists
chiefly of tannin, with a very little resinous matter. Water dissolves somewhat more
of it, and affords a very styptic-tasted solution, which precipitates solution of isinglass
very copiously, like infusion of galls and catechu. Its solution forms with sulphate of
iron a black precipitate, which is kept floating by means of the gum present, and
thereby constitutes good ink. My report to the merchant was written with a combination thus made, in proportions taken at random; and there is no doubt that by




82                           ALKALIMETER.
using a stronger decoction of the algarovilla, along with a proper proportion of copperas, an excellent black ink might be prepared without any other addition.
I find that a decoction of the algarovilla affords with cotton cloth, mordanted with
tin solution, as also with acetate of alumina liquor, a brilliant yellow dye; the former
being the brighter and fuller of the two.
A tincture of algarovilla might be used as an astringent in medicine; or probably
a decoction of the whole substance would be preferable, on account of the demulcent
quality of the seeds when bruised. As an article of commerce it cannot be rated at a
high price, nor should it pay much duty till its value as an article of manufactures or
medicine be fully ascertained.
ALIZARINE  See MADDER
ALKALI. A class of chemical bodies, distinguished chiefly by their solubility in
water, and their power of neutralizing acids, so as to form saline compounds. The
alkalis of manufacturing importance are, ammonia, potash, and soda. These alkalis
change the purple color of red cabbage and radishes to a green, the reddened tincture of litmus to a purple, and the color of turmeric and many other yellow dyes to
a brown. Even when combined with carbonic acid, the three alkalis exercise this
discoloring power, which the alkaline earths, lime, and barytes, do not. The same
three alkalis have an acrid, and somewhat urinous taste; the first two are energetic
solvents of animal matter; and the three combine with oils so as to form soaps. They
unite with water in every proportion, and also with alcohol; and the three combine
with water after being carbonated.
ALKALI-ORGANIC; OR ORGANIC BASES. Many plants and ingredients of plants
which exercise a powerful specific operation upon the living system of man and other
animals contain peculiar combinations which have in chemistry a decidedly alkaline
reaction; and have hence been called alkaloids. They unite directly with both hydrogen and oxygen acids, and in this respect differ essentially from methyloxide, acthyloxide, and amyloxide. Serturnier was the first discoverer of these bases, having
recognised in opium the alkaloid now called morphia. Soon afterwards Pelletier and
Caventou discovered analogous bases in the strychnos nux vomica, as also in white
hellebore. As these bases possessed in a remarkable degree the peculiar action of
each plant upon the human system, chemists set themselves diligently to search in the
poisonous and narcotic extracts for similar principles. From the discovery, however,
of quinia, cinchonia, piperine, &c., it appeared, that not only the poisonous ingredients
of plants, but others possessed of peculiar medicinal qualities, constituted peculiar alkaloids. These occur in plants always combined with organic acids, which are also
often of a peculiar nature. Thus the base of opium occurs combined with meconic
acid, and the base of chelidonium with chelidonic acid. The acid constituent, however, is often the malic or one of the forms of the tannic.
Wohler first made the discovery that through the decomposition of cyanate of ammonia urea was formed, which possessed the property of combining with several acids,
especially the nitric and oxalic, under like conditions with the bases existing in nature.
Unverdorben extracted from animal empyreumatic oil several basic compounds,
such as odorine, ammoline, &c., and Runge out of coal-tar obtained kyanol and leukol.
Fritszche obtained by the decomposition of anthranilic acid, aniline, whose identity
with kyanol has been since shown by Hofmann. Zinin made the discovery that by
the operation of sulphuretted hydrogen upon nitrobenzide and upon nitronaphtalide,
certain organic bases were formed with separation of sulphur, such as aniline, benzidine, naphtalidine, &c. Laurent discovered lophine and amarine, bases which result
through the operation of ammonia upon oil of bitter almonds.  Thiosinnamine is
formed by the action of ammonia upon the volatile oil of mustard, &c.
Composition of alkaloids or organic bases.-The whole of these bases contain nitrogen combined with carbon and hydrogen, and most of them contain also oxygen.
These alkaloids combine also with hydrogen and oxygen acids, as ammonia does, and
thereby are distinguished essentially from acthyloxide, methyloxide, and amyloxide.
If we reckon ammonia as a hydrogen basis, the organic bases must belong to the same
category. Their oxygen constituent does not correspond to their capacity of saturation, which follows from the fact, that alkaloids exist which are free from oxygen.
The production of the organic bases is different according as they belong to volatile
or non-volatile bodies. The volatile may be obtained when the plants in which they
exist are distilled with a somewhat dilute potash lye. The distilled liquor contains
always besides the organic base a little ammonia. It is to be exactly saturated with
sulphuric acid, then evaporated by gentle heat, and the remainder treated with absolute
alcohol or with ether, in which the sulphuric salt of the organic base dissolves. This
solution is to be mixed with water, the spirit is to be distilled off, the remainder decomposed with potash lye, next agitated with ether, which dissolves out the alkaloid, which
remains after the evaporation of the ether. In this way nicotine is obtained. The non



ALKALIMETRY.                                    38
volatile bases are commonly obtained by extracting the constituents of the plant with
water acidulated with sulphuric or muriatic acid, and from the concentrated solution
precipitating the bases by means of an alkaline substance, such as potash, lime, ammonia, or magnesia.  The precipitate is to be dried and boiled in alcohol, which
dissolves the alkaloid. This may be purified by repeated crystallizations aided by
animal charcoal, &c.
ALKALIMETER.  An instrument for measuring the alkaline force or purity of
any of the alkalis of commerce. It is founded on the principle, that the quantity of
real alkali present in any sample is proportional to the quantity of acid which a
given weight of it can neutralize.
ALKALIMETRY.  Nearly forty years have elapsed since I was led, by peculiar
circumstances, to construct a very simple method of testing alkalis, the principle of
which I soon afterward applied to acids, bleaching powder, dye-stuffs, and most other
chemical substances extensively used in manufactures.* In 1814 and 1815, during the
summer vacation of my Glasgow classes, I was engaged in delivering courses of lectures
on chemistry in the Belfast Academical Institution, and had many of the most eminent members of the Linen Board of that town for my pupils. Being occasionally
consulted upon the qualities of the alkalis, which were used to the value of 200,0001. by
the linen bleachers of Ireland, I saw the importance to them of a simple alkalimetrical
test, both for purchasing and for using their barillas and potashes. The following
extract from the Belfast News Letter, of July 9th, 1816, will show the nature of mv
contrivance:
" This day one of the porters of the Linen Hall, Belfast, was called into the libraryroom at the request of Dr. Ure, who being quite unknown to Dr. Ure, and never
having seen any experiments made with acids and alkalis, he took the instrument at
our desire, which being filled with colored acid, by pouring it slowly on adulterated
alkali, which we had previously prepared, he ascertained exactly the per-centage of
genuine alkali in the mixture. Belfast, 25th June, 1816.
"JOHN S. FERGUSON, Chairman.
JAMES M'DONNEL, M. D.
JOHN M. STOUPE.
S. THOMSON, M. D."
Of these gentlemen, two were leading members of the Linen Board, and the others
the two principal physicians of the town. The publication of the details of my method
of alkalimetry was delayed till arrangements were made for its general introduction,
under the direction of the Linen Board of Dublin, whose professor of chemistry, Mr.
W. Higgins, as well as Dr. Barker, professor of chemistry in Trinity College, granted
certificates of the " accuracy and the national importance" of the instrument. The
alkaline matter then imported into Ireland was often largely contaminated with common
salt, even to the extent of 80 or 90 per cent. During the procrastination of the Board,
I lent my Treatise on Alkalimetry to Dr. Henry, of Manchester, who inadvertently published an account of it, though with reference to me, in the next edition &o his Elements
of Chemistry. Having, in the long interval since, contrived many modifications of the
instrument, and having extended its principle to testing other articles I am induced to
offer it now to the world, in consequence of the recent appearance of a publication upon
the same subject, by two very ingenious chemists of Liebig's school, Drs. R. Fresenius
and H. Will. Of their system of alkalimetry, &c., a copious abstract appeared in the
Annalen der Chimie und Pharmacie for July last, and about the same time a pamphlet
was published by Winter, at Heidelberg, under the title Neue Verfahrungsweisen zur
Bestimmung des Werthes der Pottasche und Soda, der Saluren, und des Braunstein; or
" New Processes for determining the Value of Potash and Soda, of Acids, and Black
Oxide of Manganese."  However accurate these processes may be, and however apt
for a German or French student of chemistry, they are, in my apprehension, not at all
fitted for the familiar use of manufacturers and dealers in any country, and certainly
not for those of the United Kingdom.
Descroizilles was the first person who contrived an instrument, called an alkalimeter, to ascertain the alkaline strength of potash and soda, without much calculation.  His method was described in the.Rnnales de Chimie for 1806, tom. lx.,
and a translation of it appeared in our Philosophical Magazine, vol. xxviii., for July
* Among others to nitrate of potash, nitrate of soda, and to white lead, either in powder or in paint.
My nitrometer enables a person not at all versant in chemistry to ascertain in a quarter of an hour,
out by two distinct processes, the quantity of pure nitrate in either of these salts, to one part in 200~.
The cerussa-metel is equally simple and expeditious.




34                            ALKALIMETRY.
and August of the following year. His apparatus consisted of a glass tube, 8 or 9
inches long, and 7 or 8 lines in diameter, closed at one end, but terminated at the
other in a kind of small funnel (with a beak or spout), connected to the tube by a
narrow  neck, having a calibre of two lines and a half. Upon the shoulder, under
the throat, there was a hole for admitting air to the long tube in the act of being
emptied, by sloping its mouth downward.  This cylindrical vessel was to contain
38 grammes of water, which space was divided into 76 equal parts, which it was
extremely important to proportion accurately. The liquor was prepared by taking
concentrated sulphuric acid, at 66~ Baum6 (1'845 spec. grav.), and diluting it with
nine times its weight of water. The instrument being poised in a balance, he
introduced into it very exactly two grammes of the above test acid, and when the
instrument stood upright, he scratched a line at the level of the liquor, and thus
proceeded by addition of successive grammes to graduate the whole, till 36 were
added, after which he subdivided these spaces by lines into 72 demi-gramme volumes.
He then proceeds to describe eight different subsidiary articles required for his operations:
" dlkalimetrical trials ofpotash.-Weigh exactly one demi-gramme ofpotash, put it into
a glass, and pour upon it about four fifths of a decilitre of water; facilitate the solution of
the potash by stirring it with a small chip of wood, three or four times in an hour and a
half, a minute at each time. When the solution is effected, pour it into the small tin
measure, No. 4, which is to be then filled up with water; pour it back again into the
glass, in which you must still pour a measure full of pure water; stir this new mixture
also three or four times within half an hour, in order to facilitate the precipitation of a
slight sediment, which soon falls down.  This sediment being completely formed,
slope the glass with caution, in order to fill with clear liquor the small measure; then
empty this last into another large glass; after this place round the edges of a plate
drops of syrup of violets; pour also into the alkalimeter test liquor until the line
marks 0; take it afterward with the left hand, inclining it upon the glass which contains the moiety of the clean alkaline solution: the acid liquor will fall into it by hasty
drops, or in a very small thread, which you may moderate at pleasure, by retarding the
entrance of the air at the lateral hole or vent, upon which must be placed the end of
the finger; at the same time, with a small stick or match, assist the mixture and facilitate the development of the carbonic acid which is manifested by effervescence.
When you have emptied the alkalimeter to about the line 40, try if the saturation
approaches, by drawing your_ small stick from the mixture, and resting it upon the
drops of syrup of violets, which should become green, if the potash is not of a very
inferior quality. If, on the contrary, the violet color is not altered, or what would
be worse, if it be changed into red, there would be, in the first case, an indication of
saturation, and in the second a proof of super-saturation. But this is not the case with
good potashes; at that line, the liquor tried can alter the syrup of violets into green
only; or cause to return to the violet, and even to the green, the drops which hadbeen
changed into red at the time of a former trial; we must, therefore, in general add more
acid, which occasions a new effervescence. This addition must always be made with
caution, and we must touch every time a drop of syrup of violets in order to stop.
When at last the latter assumes a red hue, then, after having restored the alkalimeter
to a perpendicular position, in order to see at what line the testing liquor stops, you
must reckon one degree less, in order to compensate the excess of saturation. The
mean term of potashes is 56; this implies that they require for their saturation fifty-five
hundredths of their weight of sulphuric acid."
For the analysis of commercial sodas of all kinds, M. Descroizilles prescribes using
ten and a hlalf deci-grammes of this alkali, instead of the ten deci-grammes for potashes,
and proceeds as above detailed. In his table of results annexed, we find American
potashes called 60~ to 63~.
American pearlashes     -       -      -    500 to 55~
Dantzic potash   -      -       -      -    45  to 55
Alicant soda     -      -              -    20  to 33
It is obvious; from  these statements, that the alkalimeter so made and graduated
denoted comparative, but not absolute, quantities of alkalis present in the commercial samples. The rest of his very long memoir is occupied with what he calls the
graduation of potashes and sodas, the economy of their graduation, the proportions of
carbonic acid in them, the processes of caustification, the presence of potash in all
lime which is burnt by a wood fire, origin of neutral soda, and probable origin of
natrum; without any more explicit instructions. The instrument, as left in this vague
state, never was employed, nor could it come into use, among English manufacturers
and dealers.




AALALIMETRY.                                     35
The next alkalimeter, of which an account has been published, was my own. In constructing this instrument, I availed myself of the lights recently shed on chemical proportions by Dr. Dalton's atomic theory, and I thus made it to represent, not relative, but
absolute measures of the amount of real alkali existing in any commercial sample.
The test-liquor used at that time was sulphuric acid, which is most readily and accurately
diluted to the requisite degree by means of a glass bead, very carefully made, of the
specific gravity that the standard acid should have. In order to make'the test-liquor,
therefore, nothing more is requisite than to put the bead into distilled water, and to
add to it somewhat dilute but pure sulphuric acid, slowly and with agitation, till the
bead rises from the bottom, and floats in the middle of the liquor at the temperature of
600 Fahr. The delicacy of this means of adjustment is so great, that a single degree of
increase of heat will cause the bead to sink to the bottom-a precision which no hydrometer can rival. The test-tube, about 14 inches long, contains generally 1,000 grains
of water, and is graduated into 100 equal parts by means of equal measures of mercury.
The test-liquor is faintly tinged with red cabbage or litmus; so that the change of
color, as it approaches to the saturating pitch, on adding it to 100 grains of the commercial alkali, becomes a sure guide in conducting the experiment to a successful issue.
One hundred measures of this test-liquor neutralize exactly 100 grains of absolute soda
(oxide of sodium), and of course very nearly 150 of potash. A bead may also be adjusted for test-liquors, of which 1,000 grain measures neutralize 100 of potash, and
therefore 661 of soda, as well as other proportions, for special purposes of greater
minuteness of research. One may be so graduated as to indicate clearly a difference of
10 of a grain of ammonia. In making such nice experiments, it is of course requisite
to free the alkaline matter beforehand from sulphurets, sulphites, and hyposulphites, by
igniting it in contact with chlorate of potash, as long since recommended by GayLussac.  With such means in careful hands, all the problems of alkalimetry may be
accurately solved by an ordinary operator.
On the same principle, my Acidimeter is constructed; pure water of ammonia is
made of such a standard strength by an adjusted glass bead, as that 1,000 grain measures of it neutralize exactly a quantity of any one real acid, denoted by its atomic
weight, upon either the hydrogen or oxygen scale or radix; as for example, 40 grains
of sulphuric acid. Hence it becomes a universal acidimeter; after the neutralization
of 10 or 100 grains of any acid, as denoted by the well-defined color in the litmustinted ammonia, the test-tube measures of ammonia expended being multiplied by the
atomic weight of the acid, the product denotes the quantity of it present in 10 or 100
grains. The proportion of any one free acid in any substance may thus be determined with precision, or to one fiftieth of a grain, in the course of five minutes. Like
methods are applied to Chlorometry, and other analytical purposes, with equal facility;
adapting the test-liquor to the particular object in view. Instead of using beads for
preparing the alkalimetric and acidimetric test-liquors, specific gravity bottles, or hydrometers, may of course be employed; but they furnish incomparably more tedious,
and less delicate means of adjustment. To adapt the above methods to the French
weights and measures, now used generally also by the German chemists, we need only
substitute I00 deci-grammesfor 100 grains, and proceed in the graduation, &c., as
already described.
The possession of two reciprocal test-liquids affords ready and rigid means of verification. For microscopic analyses of alkaline and acid matter, a graduated tube of
small bore, mounted in a frame with a valve apparatus at top, so as to let fall drops of
any size, and at any interval, is desirable; and such I have employed for many years.
Of this kind is my ammonia-meter, used in the ultimate analysis of guanos and other
azotized products, in conjunction with a modified apparatus on the principle of that
of Varrentrapp and Will. It may be remarked, that when the crude alkali contains
some hyposulphite, it should not be calcined with chlorate of potash, because one atom
of hyposulphurous acid is thereby converted into two atoms of sulphuric, which
of course saturate double the quantity of alkali, previously in combination with the
hyposulphurous acid. In such cases it is preferable to change the condition of
the sulphurets, sulphites, and hyposulphites, by adding a little neutral chromate of
potash to the alkaline solution, whence result sulphate of chromium, water, and
sulphur, three bodies, which will not affect the accuracy of the above alkalimetrical
process.
In the annals of Philosophy for October, 1817, I described a new instrument for
analyzing the earthy and alkaline carbonates, and for determining the quantity of base
present in them from the volume of carbonic acid, disengaged by their solution in acids,
upon the data of the atomic theory. This method was applied to the analysis of the
carbonates of ammonia, soda, potash, lime, magnesian limestone (dolomite), &c.
" The indications of the above analytical instrument are so minute as to enable us,
by the help of the old and well-known theorem for computing the proportions of two




36                             ALKALIMETRY.
metals from the specific gravity of an alloy to deduce the proportions of the bases from
the volume of gas disengaged by a given weight of a mixed carbonate."*
That small instrument consisted of a bent glass tube, open at one end, and terminated
at the other with an egg-shaped bulb from two to three inches in diameter, and it
required for operating with it, about five pounds of quicksilver. The following glass
apparatus (fig. 6) will be found more generally convenient, and equally exact. A is
a cylinder, 2 inches in diameter, and 14 inches long. It contains 10,000 grains of water in the graduated portion; 0, or zero
6       being at the top. It has a tubulure in the side close to the
bottom, through the cork of which a short tube passes tight, and
is connected to a collar of caoutchouc, E, which serves for a joint
C ^        to the upright tube, B, resting near its open upper end in a
hooked wire. Through the cork in the mouth of the cylinder,
the taper tail of the flask c passes air-tight. The small tube F,
open at both ends, is cemented at bottom into the tail of c, and
rises to the shoulder of the flask. The cork of c is perforated,
and receives air-tight the taper tube r, which can also be closed
with the stopcock.
0 ^a \ \   In operating with this apparatus, proceed as follows:Fill the cylinder with water, and cover its surface with half
an inch of oil. Insert the tail of the flask. Put into the flask
c, 58 6 grains of carbonate of potash, or 45-2 of carbonate of soda,
a<~O| I according as common pearl-ash or soda-ash is to be tested, alone
with as much water as will cover fully the lower end of D, and
s8          |    then introduce this tube. Have a bottle containing about 40
s^\no    \   parts of oil of vitriol, previously mixed with 60 of water, and
cooled. Take of this, in a pouring or dropping glass, 100 water
Ao                grain measures, and suck this quantity gradually up into the tube
n, then shut the stopcock. On opening it slightly the acid will
80               fall into c, and as slowly as may be prudent. The carbonic acid
B     gas, forthwith disengaged, will depress the water in A, cause an
20               overflow of it from the tube B, whieh, being held in the left hand,
must have its swanbeak placed over a basin, and progressively
lowered to the level of the descending water in the cylinder.
9o               When all the sulphuric acid has been introduced by the right
E     hand, the orifice of D is to be corked, and the tube B continually
150       ~pylowered with the left, till the effervescence being finished, the
water in A remains stationary. The number on the centigrade
scale, opposite to the surface of the oil, deducting 100 grain measures for the bulk of dilute acid added, denotes the per-centage of pure carbonate of potash, or ofsoda, in the sample under examination. The above prescribed weights of these
two carbonates, when pure, disengage each by the action of sulphuric acid (used here
in small excess) 10,000 water grain measures of carbonic acid gas, or 100 measures
of the scale on A. The cylinder which I employ contains about 12,000 water grain
measures, so that the bottom of the centigrade scale is fully two inches above the level
of the lower tubulure. This capacity and the graduation into 120 parts, will be found
convenient in certain cases, particularly in analyzing bicarbonates of potash and soda.t
We may estimate 10J0 water grain measures of carbonic acid at 60~ Fahr., to
weigh 18.4 grains, and we thus perceive what a magnified scale we should possess, if
we applied the vernier contrivance here, as we do to barometers. At any rate, he must
be an awkward operator who can not determine the value of an alkaline carbonate, by
the above means, to one part in a thousand.
In operating upon limestones, marles, &c., 42*1 grains should be taken as the
standard weight of assay, because that weight of pure carbonate of lime should give
out on solution in dilute muriatic acid 10,000 water grain measures of carbonic acid
gas. Since 100 water grain measures of liquid hydrochloric acid, specific gravity 1' 14,
will supersaturate the lime in the above weight of carbonates, that quantity may be
used in the experiment. The preceding instrument will be found more convenient ir
experimenting, as also the system of indication, than one on similar principles constructed by the ingenious Dr. Mohr, of Coblenz.
In examining bicarbonates of potash and of soda, the weights to be used in the above
apparatus are 42 grains of the former, and 354 grains of the latter, each of which
Dictionary of Chemistry, 1821.
t For the greatest precision hot acid may he used in the above experiment, by taking in a graduated
test-tube seventy-five grains of water, and filling it up to the line 100 with concentrated sulphuric acid.
This mixture being poured in successive portions into the flask c (represented much too large in pro.
portion to the cylinder A), will ensure the expulsion of all the carbonic acid from c, which may be afterward cooled by wrapping round it a towel dipped in cold water.




ALKALIMETRY.                                     37
quantities, if the salts be perfect, will disengage 10,000 water grain measures of carbonic acid gas, by the action of sulphuric acid. There will be no harm in taking the
formerly prescribed measure of the sulphuric acid though considerably less would
answer the purpose. The centigrade measures of gas obtained in A will indicate the
carbonated state of the two alkalis respectively. Their alkaline force may be most
readily ascertained by my old alkalimeter, with colored test acid. Since the bicarbonates usually sold in our shops, especially that of soda, are far from being exact
atomic compounds, they should be always examined, both for their base and acid,
which may also be well done in the following way, where the quantity of carbonic acid
gas is determined by weight instead of by volume.
For this purpose, a small compact apparatus of the annexed form (fig. 7) will be
found convenient; it is to be used in conjunction with my
B              alkalimeter. A in the dotted line is the phial for receiving
7?                the carbonate to be tested. B, the funnel into which the
test acid is to be poured; c c, an inverted syphon filled
with pieces of chloride of calcium for absorbing the aqueous..l.'. c  vapors exhaled by the carbonic acid. The loss of weight
in the phial above that in the tube of test acid shows the
1i:  l'         b,  quantity of acid gas, and the indication of the alkalimeter
tube, that of alkaline base, from which data the proportion
of neutral carbonate and bicarbonate may be immediately
I{   I ~   deduced. Thus, 100 grains of bicarbonate of soda should
give out 511 grains of carbonic acid, and saturate 37'6 cenI   tirade measures of the test acid, equivalent to 37'6 grains
A  of real soda. But if neutral carbonate of soda be present,
less gas will be given out, and more or less alkali may be
indicated, according to the degree of dryness of the neutral
soda. The amount of water in the bicarbonate may be de-'j  I{    ~termined by igniting 20 grains in a test tube, connected with
I       I       the chlorcalcium inverted syphon; 10; grains of carbonic
cI  acid gas should be expelled, and 2j of water, making a total
loss of 1211 grains, of which 21 will be found as water absorbed by the chlorcalcium. But since a very moderate heat
*am.sss ss  D    suffices to expel the second atom of carbonic acid from the
11   i\           bicarbonate of soda, the readiest mode of estimating its
\, \^  \J        quality is to heat, over a spirit lamp, in a small flask, or
retort, connected air-tight by a tube with the mouth of the
1'".1_.. ~cylinder A, (fig.  6) 701 grains of the supposed bicarbonate. Of the perfect salt this quantity should give out pretty
exactly 10,000 grain measures of gas; and whatever aliquot part of this volume is
evolved will indicate, without calculation. the relative value of the substance as a
bisalt. Thus if 8,500 grain measures of gas are obtained, 85 parts of bicarbonate
of soda are present in 100. The crystalline form of bicarbonate of potash is a tolerably
good criterion of its quality.
The quantity of caustic alkali mixed with carbonate may be readily determined,
with sufficient accuracy, by the expert use of my alkalimeter; because, till the caustic
portion be nearly neutralized, little or no carbonic gas is expelled.  When the
effervescence at length begins, the test measures already expended denote the percentage of caustic alkali. It is not right to disregard the alkali which is present in the
state of sulphuret, because as such it is effective in many processes of the chemical arts;
in the manufacture of yellow soap, crown glass, in the bleaching of linen and cotton
goods, &c. The alkalimeter, directly applied, will show the alkali present in this form,
when compared with that indicated after ignition of the crude alkali with chlorate of
potash, or after its treatment with yellow chromate of potash.*
A few years ago I had the following apparatus made for the ready analysis of carbonates, by ascertaining the loss of weight they suffered from the disengagement of their
carbonic acid gas, during their solution in an acid. A, B (fig. 8) are two globes, of about
two inches in diameter each; A has its inferior neck strangled into a bore nearly capillary; B stands lower, with its centre line on a level with the narrow neck of B. The
tubes of these globes are about one half inch in diameter. c is shut at top with a perforated cork, through which enters, air-tight, a small glass tube, which is bent across to
the mouth of the tube E, and then passes down into it a little below the centre line of
* If the alkaline carbonate contains sulphuret, sulphite, or hyposulphite, a teaspoonful of vellow
chromate of potash may be added to it, wherefrom result sulphate of chromium, water, and bulphur,
which remain in the apparatus without effecting its weight. The mutual action of neutral chromate of
potash, and of sulphuret of potash, &c., has been discussed in an ingenious paper published by Dopping,
in; the Annalen der Chimie for May, 1843, p. 172.




38                             ALKALIMETRY.
the globe B. This globe is rather more than half filled with sulphuric acid, when the
instrument is employed in the analysis of the carbonates. The standard weight of carbonate of soda = 24! grains, or of carbonate of potash =
8       311 grains, is then put into A, having previously laid a, D            minute globe of glass over the lower orifice; the cork,
with its small tube, is now firmly adjusted; and the apparatus is weighed in its upright position, either by suspen~      c         sion with a hook to the end of the beam, or by resting it on
the scale in a light socket of any kind. It is next laid hold
of, and inclined so as to cause a little of the acid in B to pass
over into A. Effervescence ensues with greater or less
vehemence, according to the nature of the carbonate and
quantity of the acid introduced. Should it be too violent,
and threaten an overflow by intumescence, it can be instantly abated to any degree by the slightest slope of the
instrument. Now, this power of control forms the peculiar feature and advantage of this contrivance; whereas
in all other forms of suchapparatus that I know, whether
by sucking over or pouring in, if a little too much acid
comes upon the carbonate, the experiment is effectually
f A    \  marred. The gas disengaged in A must necessarily traverse the sulphuric acid in B, and be stripped of its
moisture before escaping into the air. Having super^  B   >- ^  saturated the alkaline base, and cooled the apparatus,
we weigh it again, and the loss of weight in grains and
tenths denotes the per-centage of soda or potash, provided
their neutral carbonates had been the subjects of experi.
ment. For limestone, on the same plan of computation,
221 grains may be taken. It deserves to be noted, that the
present instrument has only one junction, and needs no
chloride of calcium, a substance so apt by its swelling to burst the glass tubes that
contain it.*
II. ACIDIMETRY.
I have already stated, that water of ammonia of standard strength, faintly tinted
with litmus, affords a most exact and convenient acidimeter, when poured or let fall
from a graduated dropping-tube. Bicarbonate of potash also, when dissolved in water,
so that 1,000 grain measures contain one atom of the salt counted in grains, is a good
test-liquor for the same purpose; for if the centigrade measures expended in effecting
neutralization are multiplied by the atomic weight of the given acid, the product is the
quantity in grains of acid present..cidimetry may be likewise exactly performed by measuring in the cylindric gasmeter (fig. 6) the volumes of carbonic acid gas disengaged from pure bicarbonate ot
potash or soda, by a given weight of any acid, taking care to use a small excess of the
salt. Thus, for example, 16'8 grains of dry and 201 of hydrated sulphuric acid disengage 10,000 water grain measures of gas from bicarbonate of potash. Therefore, if
200 grains of a given sulphuric acid be poured into the flask offig. 6, upon about 50
grains of the bicarbonate, powdered and covered with a little water, it will cause the
evolution of a volume of gas proportioned to its strength. If the acid be pure oil of
vitriol, that weight. of it will disengage 10,000 grain measures of gas; but if it be
weaker, so much less gas-the centigrade measures of which will denote the per-centage value of the acid. If the question be put, how much dry acid is present per cent.
in a given sulphuric acid, then 16*8 grains of the acid under trial must be used; and
the resulting volume of carbonic acid gas read on the scale will denote the per-centage
of dry acid.t
For nitric acid, we should take 22'6 grains; for hydrochloric or muriatic acid, 15*34;
for acetic acid, 21'6; for citric acid, 24-6; for tartaric acid, 28 grains: then in each
case we shall obtain a volume of carbonic acid gas proportioned to the strength and
purity of these acids respectively. The nitric, hydrochloric, and acetic acids are referred to in their anhydrous state; the tartaric and citric in their crystalline. If the
latter two acids be pure, a solution of 24*6 grains of the first and of 28 of the last
* 1,000 water grain measures of sulphuric acid of specific gravity 1'032, or 32 above water, neutralize
32 grains of soda, and, consequently, one atom, on the hydrogen scale, of each of the other.bascs.
reckoned in grains.
Having in the course of many years subjected my tables of sulphuric, nitric, and muriatic acids, as
well as of ammonia, to strict cross-examination, I have found them trustworthy for all alkalimetrical
and acidimetrical purposes.
t The bicarbonate must be free from carbonate, a point easily secured by washing its powder with
cold water, and drying it in the air.




ALKALIMETRY.                                   39
will disengage from 50 grains of bicarbonate of potash 10,000 grain measures of carbonic acid gas.*
Acidimetrical operations may likewise be performed by determining the weight of
carbonic acid gas expelled from the bicarbonate of potash or soda, by a given quantity
of any acid, in the apparatus either fig. 7, or fig. 8.  Here the weights to be taken
are as follows, in reference to
Grains.
Dry Sulphuric acid   -        -     9127
"  Nitric     12-33
"  Hydrochloric    -    -  829
"  Acetic     -                   11-67
Crystallized Tartaric -   -   -    13-31
"     Citric   -              15-13
Each of these quantities of real acid, with 25 or 26 grains of bicarbonate of potash,
will give off 10 grains of carbonic acid gas; and hence whatever weight the apparatus
loses, being reckoned in grains and tenths of a grain, denotes the
9             per-centage of acid in the sample under trial, without the necessity of any arithmetical reduction. Persons accustomed to
the French metrical system  may use deci-grammes instead of
B       grains, and they will arrive at the same per-centage results.
The preceding experiments, in reference to the weight of carbonic acid gas expelled for the purpose of either alkalimetry or
acidimetry, may also be made by means of the ordinary apparatus
represented in fig. 9.  A is a small matrass which contains the
acid or carbonated alkali at its bottom; and conversely the alkali
or acid, for their mutual decomposition in the small test-tube,,   ~ ^j  shown first at b nearly upright and filled, but afterward at a,
horizontal and emptied. B is a bulbous tube filled with fragments of chlorcalcium  for absorbing the aqueous vapor that
rises with the carbonic acid gas, and d c is a small bent tube
which dips into the liquid in the matrass. The weighings, &c.,
may be conducted as already detailed; and when the effervescence is completed, the residuary gas is sucked up through
B, while the atmospheric air enters to replace it at the orifice d
of the bent tube.
The NEW methods which pervade the whole treatise of Drs.
Fresenius and Will are all based on the principle of estimating
alkalinity, acidity, and the oxygen in manganese (or chlorometry) by the weight of carbonic acid gas evolved.  As in
taking these measures the gas must be discharged without
carrying water off with it, an elegant and ingenious little piece
of apparatus has been invented by the authors for effecting that
purpose, and it will do it well. A and B (fig. 10) are two flasks (wide-mouthed
medicine-bottles may be employed). A must have a capacity of from 2 ounces to 2,
10       b       ounces of water; it is advisable that B should be
somewhat smaller, say of a capacity of about I to
11   ounces. Both flasks are closed by means of
J^  e"~            ~ doubly perforated corks. These perforations serve
for the reception of the tubes a, c, and d. c is a
l   tube bent twice at right angles, which enters at
la     its one end just into the flask A, but descends at
its other end, near to the bottom of B. These tubes
are open at both ends when operating; except the
top end b of the tube a, which is closed by means
of a pellet of wax.  The substance to be examined is weighed and put into the flask A, into
which water is then poured to the extent of one
third of its capacity.  B is filled with common
English sulphuric acid to about half its capacity.
B               A       \ Both flasks are then corked (by which they become united by the rectangular tube), and the apparatus is weighed.
\ I|?l  \   j.        The air of the whole apparatus is next rarefied by
applying suction to the tube d: the consequence is,
that the sulphuric acid contained in B ascends into
* The expulsion of the gas may be completed by surrounding the flask with a towel dipped in hot
water.




40                            ALKALIMETRY.
the tube c, and thus a portion of it flows over into B. Immediately upon its coming
into contact with the carbonate contained in A, carbonic acid gas is disengaged, and in
its escape must necessarily traverse the oil of vitriol in B, and therein deposite all its
aqueous vapor before issuing from d. The sulphuric acid in passing over into A heats
the mixture at the same time, and thus promotes the expulsion of the gas. Whenever
this ceases to flow, a little more sulphuric acid must be sent over into A by suction
from d (or rather from a recurved tube attached, pro tempore, to it); an artifice which
may be repeated till no more gas can be expelled, even when the contents of A are
heated, as they must be at the end by the excess of oil of vitriol.
" From the aperture b of the tube a, which has been all the time closed, the bit of
wax is now to be removed, and to the tube connected with d, suction is to be applied,
till all the carbonic acid lodged in the apparatus be replaced by atmospheric air. The
whole is to be then cooled, wiped, and weighed; the loss of weight indicates exactly
the quantity of carbonic acid which existed in the carbonate submitted to experiment.
The process is no less neat than it is simple, and does honor to the ingenuity of its inventors. Their mode of deducing the per-centage of alkali from  the quantity of
carbonic acid discharged in the operation is also quite exact, and suitable for continental chemists familiar with gramme weights and calculations, but certainly not for
persons conversant only with ounces, drains, and scruples, or even with grain subdivisions. The whole book, however excellent, needs, for the British public, transposition, before it can serve in this country the purpose intended by its scientific authors.
Thus, in section 4, where several results of their analyses are given, the statements
have a somewhat mysterious aspect. Should any one ask why the oracular number of
4-83 grammes of carbonate of soda is used as their standard weight for analysis, he
can obtain no response in the book, either in a note or anywhere else. A German or
French student, familiar with chemical computation, will probably be able to discover
that 4'83 grammes of pure carbonate of soda contain, by Berzelius's tables of atomic
weights, 2 grammes of carbonic acid; for 53-47 (1 atom of carbonate): 22*15 (1 of
carbonic acid):: 4-83: 200. Such is the simple solution of this apparent enigma,
and of some other similar puzzles in the book. Indeed, unless the reader is aware of
that proportion, he can not see the grounds of the accordance in the results between
experiment and theory, or why the numbers 2-010, 1.993, and 2-020, are presented as
specimens of great precision. This accordance gives satisfaction when it is known
that these numbers, in experiments 1, 2, and 3, oscillate on one side or other so near to
the theoretical number 2-00. But 4 grammes and 83 centi-grammes, as also 1 gramme
and 995 milli-grammes, are awkward weights for an ordinary English chemist or
apothecary, which would require a month or two's residence in the laboratories of
Giessen and Paris to manipulate with readiness.
Again, in testing carbonate of potash, our authors take 6-29 grammes as their unity of
weight, undoubtedly, because, if pure, it should discharge, by saturation with the sulphuric acid, 2 grammes of carbonic acid. Here, however, they have not stuck so rigidly
as the school of Giessen usually does to Berzelius's atomic numbers; for his atom of
carbonate of potash is 69-42; whence, 2215: 69-42:: 200: 668, hydrogen = 1-00;
or 276-44: 866-33:: 200: 6-268 oxygen = 100.
Admitting the value of the new method in testing neutral carbonates, it can not be
directly applied to the mixed carbonate and bicarbonate of soda, so commonly sold
in this country for bicarbonate; nor is it applicable to the case of a mixture of caustic
and carbonated alkali, without the tedious process of previous treatment with carbonate of ammonia and heat.
The new German method of acidimetry consists in determining how much carbonic
acid gas is disengaged from a standard bicarbonate of soda, by a given weight of any
acid. The twin-flask apparatus (fig. 10) is used. The weighed portion of acid is
put into A, and a sufficient quantity of the soda into a test-tube, which is suspended
upright with a silk thread fastened by the pressure of the cork to the mouth of the
flask. On letting the thread loose, the test-tube falls, and the cork being instantly replaced, the whole gas evolved is forced to pass through the sulphuric acid in B, and
there to deposite its moisture. The experiment is conducted in other respects as already
described for alkalimetry.
The following extract from Drs. Fresenius and Will's New Methods of alkalimetry,
&c., will show the Giessen plan of calculating results:" The amount of anhydrous acid contained in the hydrated acid under examination
is determined from the amount of carbonic acid escaped, as follows:" Two measures of carbonic acid bear the same proportion to one measure of the
anhydrous acid in question, as the amount of carbonic acid expelled does to the amount
sought of anhydrous acid. Thus, let us suppose, for instance, we have examined
dilute sulphuric acid, and obtained 1-5 grammes of carbonic acid, the arrangement
would be:




ALKALIMETRY.                                   41
550 (2 X 275): 501= 1-5: x
x= 1-36.
The amount of sulphuric acid operated upon consequently would  contain 1*36
grammes of anhydrous acid. Let us suppose the weight of this amount to have
been 15 grammes, the sulphuric acid under examination would contain a per-centage
amount of 9'06; for
15: 1-36 = 100: x
x = 9'06."
"SECTION XXIX. Stating the Quantities of the various Acids to be used in their
Examination.-To enable our readers at once, without the trouble of calculation, to
determine from the weight of carbonic acid expelled, the exact'amount of anhydrous
acid contained in those acids which are of most frequent occurrence, we have subjoined
lists of certain quantities to be taken of each acid for experiment, so that the number
of centi-grammes of carbonic acid expelled will directly indicate the per-centage amount
of anhydrous acid in the acid under examination.
"Multiples of those weights may of course be substituted for the numbers given,
according to the degree of dilution of the acid under examination. In such cases the
number of centi-grammes of the carbonic acid expelled must be divided by the same
number, which has served as the multiplier.
" These numbers are obtained by dividing the atomic weight of the acid by 550
(2 X 275, one eq. of carbon),t as follows:"Two eq. of carbonic acid, corresponding to one eq. of the acid to be examined, how much should be taken of the latter to expel 1'00 grammes of carbonic
acid?
"The arrangement of sulphuric acid, for instance, is as follows:550: 501- =  00: x
x = 0-91 (or, more correctly, 0-911).
"When examining acids, it is most advisable to use that multiple of the unity (according to the degree of concentration) which will expel from one to two grammes of
carbonic acid.
I. SULPHURIC ACID.
"Unity 0*91 grammes (or, more correctly, 0-911 grammes).
" Multiples:2 X 0  911 =   1-822 grammes.
3 X 0-911 -  2-733    "
4 X 0-911 =  3-644    "
5 X 0-911 =  4-555    c
6 X 0-911 =-  5466    "
7 X 0-911 =  6-377    "
8 X 0-911 =  7-288    "
9 X 0-911 =  8-199    "
10 X 0911 =  9-110    "
15 X 0-911 = 13-665    "
20 X 0-911 = 18-220    "
30 X 0-911 = 27-330    c &c.
"Thus, knowing that 0-91 of anhydrous sulphuric acid will expel 1P00 of carbonic
acid, it will be easy to determine what multiple ought to be used, according to the degree of concentration of the acid to be examined."t
III. CHLOROMETRY,
J.nd the testing of Black Oxide of Manganese for its available Oxygen.
The value of manganese may be estimated very exactly by measuring the quantity
of chlorine which a given weight of it produces with hydrochloric acid; the chlorine
bcng at the same time estimated by the quantity of solution of green sulphate of iron,
which it will peroxidize. A process of this kind was long ago practised with chloride
of lime (bleaching powder or liquor) by Dr. Dalton; and it has been since improved
by Mr. Waltercrum. As the conversion of two atoms of green sulphate of iron into
red sulphate requires only one atom of oxygen, this change may be effectod by the
reaction of one atom of chlorine in liberating one atom of oxygen, while this appropriates one of hydrogen from the hydrochloric acid.
* New Methoas of Alkalimetry, 4c., pp. 93, 94.
t A typographical error in Mr. Bullock's edition; it should be carbonic acid.
*New Methods of Alkalimetry, 4c., pp. 103-105.




42                             ALKALIMETRY.
The weight of 2 atoms of green sulphate of iron is 278 = (139 X 2), consisting of 2
atoms of protoxide = 72, X 2 of sulphuric acid = 80. X 14 of water = 126; in all = 278;
and this weight is equivalent to 36 of chlorine, to 8 of oxygen, and to 44 of peroxide of
manganese.*  Therefore, if we take a solution of copperas, containing 278 grains in
1,000 water grain measures, that volume of liquid will represent, by the conversion of
its protoxide into peroxide, exactly one atom, either of peroxide of manganese= 44
grains, or 1 atom of chlorine = 36. Hence the following plan of restarch:
Into the flask or phial c of my chlorometric apparatus (fig. 11), put 100 grains of the
manganese to be tested, and into the globes A, B, pour out
of an alkalimetrical tube charged with 1,000 grain measures
of the above equivalent copperas solution, from 200 to 500
grain measures, according to the supposed quality of the
manganese; then introduce through the funnel d, some hydrochloric acid of known specific gravity (suppose 1 1), containing nearly 20 per cent. of chlorine, also from  a charged
alkalimetrical tube, and apply gentle heat to the bottom of
\ the flask by placing it in a capsule of water standing over
a spirit-lamp. The chlorine evolved will rise up through
B           A   J the tuber, which passes merely beyond the cork, and will
enter into the solution in B and A, converting it into red
sulphate. Have ready some dry paper imbued with solution
of red ferrocyanide of potassium  (red prussiate of iron).
Dip a slip of whalebone into the liquor in the globe A,
through the funnel e (represented in the figure rather too
d         high above the globe), and touch the paper with its point.
As long as it forms a blue spot, some of the iron still exists
as black oxide, and the process is to be urged by the addition of a little more hydrochloric acid to the manganese,
~11 ^  +     as long as chlorine gas continues to be disengaged, and while
it maintains the level of the liquor in A above that in B.
Whenever the liquor, by the reaction of the chlorine, ceases
to stain the test-paper blue, more of the solution from  the
graduated tube must be added till it begins to do so. By
the cautious administration of the hydrochloric acid on the
one hand, and of the copperas liquor on the other, the term
C o    of saturation will be arrived at in a few  minutes.  The
manganese has then produced all the chlorine which it can
yield. The number of water grain measures, of the liquor,
or degrees of its alkalimeter scale being multiplied by 44,
will give a product denoting the per-centage of pure manganese present in the sample; or being multiplied by 36, a product which will denote
the quantity of chlorine by weight which 100 grains of it can serve to generate.
Since one atom  of pure manganese (44 grains), in producing 36 grains of chlorine,
consumes 2 atoms = 74 grains of hydrochloric acid, the quantity of this acid expended
from the graduated tubes, beyond the due proportion of chlorine obtained, will show
how much of the acid is unprofitably consumed by foreign substances in the manganese.
In fact, every grain of chlorine should, with pyrolusite, be generated by an expenditure
of little more than 2 grains of real muriatic acid, or 10 grains weight of the dilute acid, =
about 9 grain measures of the graduated tube. Liquid hydrochloric acid of spec. grav.
1*093 contains in 1,000 grain measures exactly 200 grains of real acid. Hence 100 grains
of pure pyrosulite should produce about 82 grains of chlorine, and consume about 169
of real muriatic acid = 845 grain measures of liquid acid, spec. grav. 1-093. Instead
of taking 100 grains of manganese as the testing dose, 10 or 20 grains may be taken,
according to the dimensions of the apparatus and the exactness of the operator.
But if it be wished to obtain direct per-centage of manganese by the graduated tubes
without the trouble of reduction, then for a dose of 10 grains take a solution of fresh green
copperas (free from adhering moisture), containing 632 grains in 10,000 grain measures.
Proceed as above directed. If the manganese be a pure peroxide, 10 grains of it
* Berzelius, in the 4th edition of his Lehrbuch, rates the atom of the green sulphate of iron (ferrous
sulphate) at 129-43, hydrogen = 1, and considers it. after- Mitscherlich, to contain only 6 atoms of water.
I have ascertained, by the most careful experiments, that it contains 7 atoms of water; and that 139
grains of it, or 138-44 (Berzelius) are equivalent to 1 atom of chlorbarium, and to very nearly 40 grains
of peroxide of iron.
This remarkable error has probably arisen from an attempt to measure the proportion of water in the
salt from its loss of weight by desiccation. But I have found it impossible by this means to expel more
than 6 atoms of water without causing partial decomposition of the salt by disengagement of sulphuric
acid. The copperas so dried acquires such an affinity for water, that it absorbs fully one tenth of its
weight of moisture from the atmosphere in the course of an hour.




ALKALIMETRY.                                   43
will generate as much chlorine as will peroxidize exactly 1,000 grain measures, or 300
degrees by the test-tube of the copperas solution.  But if the manganese contain
only 40 or 50 per cent. of peroxide, then 40 or 50 centigrade measures of the said
solution will be equivalent to the chlorine evolved from it by the reaction of hydrochloric acid.
If the object is on the other hand to obtain direct indications as to chlorine, then a
test solution of copperas, containing 772 grains in 10,000 grain measures, will serve
to show, by the peroxidizement of each 10 grain measures, or of one degree of the centestimal scale of the test-tube, the reaction of one grain of chlorine available for
bleaching, &c., in the chloride of lime or of soda, &c. The test solutions of copperas
should be kept in well-corked bottles, containing a little powdered sulphuret of iron at
their bottom, which is to be shaken up occasionally in order to preserve the iron in the
state of protoxide.
The manganese should always be treated with dilute nitric acid before submitting it
to the above-described ordeal; and if it exhibits effervescence, 100 grains of it should
be digested with the acid for a sufficient time to dissolve out all the carbonates present,
then thrown upon a filter, washed and dried before weighing it for the testing operation. The loss of weight thereby sustained denotes the per-centage of carbonates, and
if calcareous it will measure the waste of acid that would ensue from that source alone,
in using that manganese for the production of chlorine.
That manganese is most chlorogenous which contains no carbonates, the least proportion of oxide of iron, and of sesquioxide of manganese.
The plan of testing manganese with oxalic and sulphuric cids was originally practised by M. Berthier and Dr. Thomson, but is lately modified by Drs. Fresenius and
Will, who employ oxalate of potash, as likely to afford more exact results. They prescribe a multiple by 3 of 993 milli-grammes = 2979 grammes, as the quantity of
manganese best adapted to experiment; but this quantity will not be found convenient
by ordinary British operators.
I, therefore, take leave to prescribe the following proportions: Into the vessel A
of my twin-globe apparatus (fig. 8), put 100 grains of the ground manganese under
trial, along with 250 grains of oxalate of potash and a little water; poise the whole in
the scale of a balance; then, by gentle inclination, cause a little of the strong sulphuric
acid to pass from B up into A. The oxygen thereby liberated from the manganese,
reacting in its nascent state upon the oxalic acid, will convert it into carbonic acid gas;
which, in passing through B, will deposite its moisture before escaping into the air.
Whenever the extrication of gas ceases, after such a quantity of oil of vitriol has been
introduced into the globe A, as both to complete the decomposition of the oxalic acid
and to heat the mixture, withdraw the cork for a moment, to replace the carbonic acid
with air, then cool, and weigh the apparatus. The loss of weight, in grains, will
denote the per-centage value of the manganese; that is, the proportion per cent.
of perfect peroxide in the sample. If the manganese be pure no black powder should
remain.
The preceding experiment is founded upon the following principle: One atom of
peroxide of manganese = 44, contains one atom of oxygen separable by sulphuric acid,
and capable of converting one atom of oxalic acid into two atoms of carbonic acid,
also= 44, which fly off; and cause therefore a loss of weight equal to that of the
whole peroxide. To one atom of oxalic acid, which consists of three atoms of oxygen,
and two of carbon-if one atom of oxygen be added, the sum is obviously four atoms
of oxygen and two of carbon = 2 atoms of carbonic acid.
The apparatus (fig. 10) of Drs. Fresenius and Will will answer perfectly well for
making the same experiment, the manganese being put into A, with about two and a
half times its weight of oxalate of potash, and the sulphuric acid being drawn over into
the mixture by suction, as above described.
The economy of any sample of manganese in reference to its consumption of acid, in
generating a given quantity of chlorine, may be ascertained also by the oxalic acid
test: 44 grains of the pure peroxide, with 93 grains of neutral oxalate of potash,
and 98 of oil of vitriol disengage 44 grains of carbonic acid, and afford a complete
neutral solution; because the one half of the sulphuric acid, = 49 grains; goes to forra
an atom of sulphate of manganese, and the other half to form an atom of sulphate of
potash.
The deficiency in the weight of carbonic acid thrown off will show the deficiency of
peroxide of manganese; the quantity of free sulphuric acid may be measured by a test
solution of bicarbonate of potash, and the quantity neutralized, compared to the car
bonic gas produced, will show, by the ratio of 98 to 44, the amount of acid unprofitably
consumed.




44                             ALKALIMETRY.
In fig. 6, the tube, D, may also be graduated, and may contain the quantity of
acid, for the purpose either of alkalimetry or acidimetry: and if the lower orifice be
capillary, it will allow none of its contents to flow out, till the stopcock in the top
orifice is opened.
In fig. 7, such a tube as r (fig.  6, may be substituted with advantage for
the funnel, B; and as that tube, D, may be made of such dimensions as to contain
enough of acid to supersaturate the bases of the carbonates in the phial, A, there will
be no necessity for a separate vessel to hold the decomposing acid. Thus the apparatus
becomes very light, convenient, and may be placed in the small scale of a fine balance;
whereas the twin matrasses of Drs. Fresenius and Will (fig. 10), as furnished by Mr.
Bullock, require a very large pan or scale to stand in. I flatter myself that the instrument, fig. 7, so mounted, will be found an acceptable present to practical chemists, and that it will enable them readily to examine, not only carbonates, but also
manganese and bleaching substances, with great precision, by the weight of carbonic
acid gas disengaged, on the principles above explained.
Into the twin globe apparatus (fig. 8), after the sulphuric acid is poured into
B, a little water should be poured into c, before the carbonate is introduced into the
latter. By this means, the capillary throat of the tube under A will not be apt to get
choked with concrete salt.
The following quotations are from the work of Drs. Fresenius and Will, as edited
by Mr. Bullock for the English reader. An accurate comparison may thus be made
between the relative utility of their methods and mine to th. practice of ordinary
operators:" SECTION XXXIV. Examination of Manganese: having at the same time due regard
to the amount of acid required for its complete Decomposition.-We have stated, at
Section 30, that it is not a matter of indifference, with regard to the amount of acid
employed in the production of chlorine from manganese, what are the minerals which
this substance contains in admixture with the peroxide. The following modification
of our method will give the most correct information on this point:"Sulphuric acid of commerce is taken, and its amount of anhydrous acid determined, as directed at Section 26, or by means of an accurate hydrometer. Of this
sulphuric acid as much is weighed into A (fig. 10), as to give an amount of 5'47
grammes of anhydrous acid.
" The following table will show the amount which ought to be taken, acoording to
the various degree of concentration of the acid:
Per-centage  Amount to               Per-centage  Amount to
Specific weight  amount of  be used for Specific weight  amount of  be used for
found.     anhydrous  the exami-    found.      anhydrous  the examiacid found.  nation.                 acid found.  nation.
1-8485       81-54       6-708       1-8336       76-65       7-136
1-8480       81-13       6-742       1-8313       76-24       7-174
1-8475       80-72       6-776       1-8290       75-83       7-213
1-8467       80-31       6811        1-8261       75-42       7-252
1-8460       79-90       6-846       1-8233       75-02       7-291
1-8449       79'49       6-881       1 8206       74 61       7-331
1-8439       79-09       6-916       1-8179       74-20       7-371
1'8424       78-68       6'951       1-8147       73-79       7-412
1-8410       78-28       6-987       1-8115       73-39       7-453
1-8393       77-84       7'027       1-8079       72-97       7'495
1-8376       77-40       7-067       1'8043       72-57       7-537
1-8356       77-02       7-101
"As much water is then poured into A as will fill the flask to about one fourth;
and, lastly, from 6-5 to 7 grammes of neutral oxalate of potash, or from 5-5 to 6
grammes of neutral oxalate of soda, are added; 2-98 grammes of the (finely-pounded)
manganese to be examined are then weighed (the manganese must have been previously tested for carbonate alkaline earths: compare this section at the end) into a
small glass tube, such as used in acidimetry, and described in Section 25. About the
same quantity of pure pyrolusite,* in powder, is then put into another similar tube.
The tube, with the manganese to be examined, is then suspended in A (fig. 10), as
described at Section 26, and the apparatus prepared, as directed at Section 3. The
* " Any variety of pyrolusite will serve this purpose, provided it be free from other manganese ores.
if it contains heavy spar, it may be employed directly; but should it contain alumina or lime, it must
be treated first with dilute nitric acid, at a gentle heat, until all soluble parts have been dissolved; it
is then washed and dried. Artificially prepared, hydrated peroxide of manganese may be substituted
for pyrolusite."




ALKALIMETRY.                                     45
apparatus is then placed on one scale of a balance, together with the other little tube
containing the pyrosulite, and exactly weighed.
"The cork of A is then somewhat raised to allow the little tube with the manganese
to fall into the flask. The evolution of carbonic acid commences immediately, and
continues until all the manganese is decomposed. When the operation begins to get
on moie slowly, the flask, A, is placed in boiling water, and allowed to remain there
until no more bubbles appear.  The little wax-stopper is then removed* from a, the
flask, A, taken out of the hot water, and suction applied to d, until the sucked air
tastes no longer of carbonic acid. The apparatus, after having been allowed to cool,
is wiped dry, and replaced in the original scale, where the little tube with the pyrolusite still remains; weights are then substituted for the loss of carbonic acid. The
number of centigrammes required, divided by three, directly indicates the per-centage
amount of peroxide of manganese (vide Section 32). The centigrammes substituted
for the loss of carbonic acid are then removed from the balance, and the little tube
with the pyrosulite is thrown into A. (The little wax-stopper must of course previously be replaced on a). If no fresh evolution of carbonic acid takes place, the
manganese examined consists of pure pyrosulite, and the experiment is at an end. But
should a fresh evolution of carbonic acid take place, the operation must be further
conducted, and brought to a close, exactly as just stated (vide supra). The apparatus
is then replaced on the balance, with an additional weight of three grammes on the
same scale. If this is sufficient to restore a perfect equilibrium, no loss of acid has
taken place; the manganese, indeed, contains other matters in admixture, but only
such as do not consume any acid. But if the scale with the apparatus sinks, this is a
certain sign that a portion of the acid has been lost by combining with the oxides which
the manganese under examination contains. The number of centigrammes required
to restore the perfect equilibrium of. the balance, multiplied by 0*6114, immediately
indicates how much anhydrous sulphuric acid has been wasted in the decomposition of
100 parts of the manganese under examination.  The same number, multiplied by
30333, indicates the amount of acid wasted in every 100 parts of sulphuric acid employed for the decomposition of the manganese in question. The same number, multiplied by 0'5552, indicate how much anhydrous hydrochloric acid would be wasted in
the decomposition of 100 parts of the manganese. The same number, multiplied by
0*333, indicates also how much acid would be wasted in every 100 parts of hydrochloric
acid employed for the decomposition of the manganese.
"These figures result from the following equations:"I. 275 (eq. of carbonic acid): 501 (eq. of sulphuric acid) =the carbonic acid obtained minus (in proportion to the sulphuric acid used): x.
x=this carbonic acid X  -5   i... X 1'822.
Thus, the number obtained for x indicates the amount of sulphuric acid corresponding
to the amount of carbonic acid obtained minus.
"II. 2'98 of manganese: 100=x of equation I.: x.
x=x of I. X 1o,i. e. X 0-33557.
"The x of the first equation tells us how much sulphuric acid has been wasted without
contributing to the decomposition of 2-98 grammes of the manganese; the x of the
second equation tells us the same for 100 parts of manganese.
"If, therefore, the amount of carbonic acid obtained minus be directly multiplied by
the product of the quotients of I. and II.,
1-822 and 0-33557,
i. e. with 0-61141 (the number given above), the amount of anhydrous sulphuric acid
wasted in the decomposition of every 100 parts of manganese will immediately be
found.
"III. 5*47 (the amount of sulphuric acid used):
100=the x of I.: x.
x=thex of I. X 1 o     i. e. X 0-18282.
"Of 5-47 of sulphuric acid, the x of I. has been wasted, 100 corresponds to the x
of lI.
"The x of III. is, therefore, found directly by multiplying the amount of carbonic
acid obtained minus with the product of the quotients, 1-822 and 0-18282, i. e.=
0-33301.
"The figures for hydrochloric acid are found in the same manner (4-967 of hydrochloric acid must be taken instead of 5-47 of the sulphuric acid)."t
* " This must of necessity be done while the flask is still standing in the hot water, or else the sulphuric acid will recede upon the apparatus being removed from the hot water."
t New Methods of Alkalimetry, and of determining the Commercial Value of Acids and Manganeae.
By Drs. C. R. Fresenius and H Will. Edited by J Lloyd Bullock: pp. 123-128.




46                                  ALLOY.
ALKANA, is the name of the root and leaves of Lausania inermis, which have been
long employed in the East, to dye the nails, teeth, hair, garments, &c. The leaves,
ground and mixed with a little limewater, serve for dyeing the tails of horses in Persia
and Turkey.
ALKANET, the root of. (.dnchusa tinctoria.)  A species of bugloss, cultivated
chiefly in the neighborhood of Montpellier. It affords a fine red color to alcohol
and oils; but a dirty red to water. Its principal use is for coloring ointments, cheeses,
and pommades.  The spirituous tincture gives to white marble a beautiful deep
stain.
ALLIGATION. An arithmetical formula,'useful, on many occasions, for ascertaining
the proportion of constituents in a mixture, when they have undergone no change of
volume by chemical action. When alcoholic liquors are mixed with water, there is a
condensation of bulk, which renders that arithmetical rule inapplicable. The same thing
holds, in some measure, in the union of metals by fusion. See ALLOY.
ALLOY.  (.lliage, Fr.; Legirung, Germ.)  This term formerly signified a compound
of gold and silver, with some metal of inferior value, but it now means anjr compound
of any two or more metals whatever. Thus, bronze is an alloy of copper and tin; brass,
an alloy of copper and zinc; and type metal, an alloy of lead and antimony. All the
alloys possess metallic lustre, even when cut or broken to pieces; they are opaque; are
excellent conductors of heat and electricity; are frequently susceptible of crystallizing;
are more or less ductile, malleable, elastic, and sonorous. An alloy which consists of
metals differently fusible is usually malleable in the cold, and brittle when hot, as is exemplified with brass and gong metal.
Many alloys consist of definite or equivalent proportions of the simple component
metals, though some alloys seem to form in any proportion, like combinations of salt or
sugar with water. It is probable that peculiar properties belong to the equivalent or
atomic ratio, as is exemplified in the superior quality of brass made in that proportion.
One metal does not alloy indifferently with every other metal, but it is governed in this
respect by peculiar affinities; thus, silver will hardly unite with iron, but it combines
readily with gold, copper, and lead. In comparing the alloys with their constituent
metals, the following differences may be noted; in general, the ductility of the alloy is
less than that of the separate metals, and sometimes in a very remarkable degree; on
the contrary, the alloy is usually harder than the mean hardness of its constituents. The
mercurial alloys or amalgams are, perhaps, exceptions to this rule.
The specific gravity is rarely the mean between that of each of its constituents, but is
sometimes greater and sometimes less, indicating, in the former case, an approximation,
and in the latter, a recedure, of the particles from each other in the act of their
union. The following tables of binary alloys exhibit this circumstance in experimental
detail:Alloys having a density greater than the  Alloys having a density less than the
mean of their constituents.           mean of their constituents.
Gold and zinc                          Gold and silver
Gold and tin                           Gold and iron
Gold and bismuth                       Gold and lead
Gold and antimony                      Gold and copper
Gold and cobalt                        Gold and iridium
Silver and zinc                        Gold and nickel
Silver and lead                       Silver and copper
Silver and tin                         Silver and lead
Silver and bismuth                     Iron and bismuth
Silver and antimony                    Iron and antimony
Copper and zinc                        Iron and lead
Copper and tin                         Tin and lead
Copper and palladium                  Tin and palladium
Copper and bismuth                    Tin and antimony
Lead and antimony                     Nickel and arsenic
Platinum and molybdinum               Zinc and antimony.
Palladium and bismuth,
It would be hardly possible to infer the melting point of an alloy from that of each of,its constituent metals; but, in general, the fusibility is increased by mutual affinity in their state of combination. Of this, a remarkable instance is afforded in the
fusible metal consisting of 8 parts of bismuth, 5 of lead, and 3 of tin, which melts at the
heat of boiling water, or 212~ Fahr., though the melting point deduced from the mean of
its components should be 5140. This alloy may be rendered still more fusible by adding
a very little mercury to it, when it forms an excellent material for certain anatomical injections, and for filling the hollows of carious teeth. Nor do the colors of alloys depend,
in any considerable degree, upon those of the separate metals; thus, the color of copper.




ALLOY.                                     47
instead of being rendered paler by a large addition of zinc, is thereby converted into the
rich-looking pinchbeck metal.
By means of alloys, we multiply, as it were, the numbers of useful metals, and sometimes give usefulness to such as are separately of little value. Since these compounds
can be formed only by fusion, and since many metals are apt to oxydize readily at their
melting temperature, proper precautions must be taken in making alloys to prevent this
occurrence, which is incompatible with their formation. Thus, in combining tin and lead,
rosin or grease is usually put on the surface of the melting metals, the carbon produced
by the decomposition of which protects them, in most cases, sufficiently from oxydizement.
When we wish to combine tin with iron, as in the tinning of cast-iron tea kettles, we
rub sal ammoniac upon the surfaces of the hot metals in contact with each other, and
thus exclude the atmospheric oxygen by means of its fumes. When there is a notable
difference in the specific gravities of the metals which we wish to combine, we often find
great difficulties in obtaining homogeneous alloys; for each metal may tend to assume
the level due to its density, as is remarkably exemplified in alloys of gold and silver
made without adequate stirring of the melting metals. If the mass be large, and slow
of cooling, after it'is cast in an upright cylindrical form, the metals sometimes separate,
to a certain degree, in the order of their densities. Thus, in casting large bells and
cannon s with copper alloys, the bottom of the casting is apt to contain too much copper and
the top too much tin, unless very dexterous manipulation in mixing the fused materials
have been employed immediately before the instant of pouring out the melted mass.
When such inequalities are observed, the objects are broken and re-melted, after which
they form a much more homogeneous alloy. This artifice of a double melting is often
had recourse to, and especially in casting the alloys for the specula of telescopes.
When we wish to alloy three or more metals, we often experience difficulties, either
because one of the metals is more oxydable, or denser, or more fusible, than the others,
or because there is no direct affinity between two of the metals. In the latter predicament, we shall succeed better by combining the three metals, first in pairs, for example,
and then melting the two pairs together. Thus, it is difficult to unite iron with bronze
directly; but if, instead of iron, we use tin plate, we shall immediately succeed, and the
bronze, in this manner, acquires valuable qualities from the iron. Thus, also, to render
brass better adapted for certain purposes, a small quantity of lead ought to be added to
it, but this cannot be done directly with advantage: it is better to melt the lead first
along with the zinc, and then to add this alloy to the melting copper, or the copper to
that alloy, and fuse them together.
We have said that the difference of fusibility was often an obstacle to metallic combination; but this circumstance may also be turned to advantage in decomposing certain
alloys by the process called eliquation. By this means silver may be separated from
copper, if a considerable quantity of lead be first alloyed with the said copper; this
alloy is next exposed to a heat just sufficient to melt the lead, which then sweats out, so
to speak, from the pores of the copper, and carries along with it the greater part of the
silver, for which it has a strong affinity. The lead and the silver are afterwards separated from each other, in virtue of their very different oxydability, by the action of
heat and air.
One of the alloys most useful to the arts is brass; it is more ductile and less easily
oxydized than even its copper constituent, notwithstanding the opposite nature of the
zinc. This alloy may exist in many different proportions, under which it has different
names, as tombac, similor, pinchbeck, &c. Copper and tin form, also, a compound of
remarkable utility, known under the names of hard brass, for the bushes, steps, and
bearings of the axles, arbors, and spindles in machinery; and of bronze, bell-metal, &e.
Gold and silver, in their pure state, are too soft and flexible to form either vessels or
coins of sufficient strength and durability; but when alloyed with a little copper, they acquire the requisite hardness and stiffness for these and other purposes.
When we have occasion to unite several pieces of the same or of different metals, we
employ the process called soldering, which consists in fixing together the surfaces by
means of an interposed alloy, which must be necessarily more fusible than the metal or
metals to be joined. That alloy must also consist of metals which possess a strong
affinity for the substances to be soldered together. Hence each metal would seem to
require a particular kind of solder, which is, to a certain extent, true. Thus, the solder
for gold trinkets and plate is an alloy of gold and silver, or gold and copper; that of
silver trinkets, is an alloy of silver and copper; that of copper is either fine tin, for
pieces that must not be exposed to the fire, or a brassy alloy called hard solder, of which
the zinc forms a considerable proportion. The solder of lead and tinplate is an alloy of
lead and tin, and that of tin is the same alloy with a little bismuth. Tinning, gilding,
and silvering may also be reckoned a species of alloys, since the tin, gold, and silver are
superficially united in these cases to other metals.
Metallic alloys possess usually more tenacity than could be inferred from their con



48                                  ALLOY.
stituents; thus, an alloy of twelve parts of lead with one of zinc has a tenacity double
that of zinc. Metallic alloys are much more easily oxydized than the separate metals, a
phenomenon which may be ascribed to the increase of affinity for oxygen which results
from the tendency of the one of the oxydes to combine with the other. An alloy of tin
and lead heated to redness takes fire, and continues to burn for some time like a piece
of bad turf.
Every alloy is, in reference to the arts and manufactures, a new metal, on account of
its chemical and physical properties. A vast field here remains to be explored. Not above
sixty alloys have been studied by the chemists out of many hundred which may be made;
and of these very few have yet been practically employed. Very slight modifications
often constitute very valuable improvements upon metallic bodies. Thus, the brass most
esteemed by turners at the lathe contains from two to three per cent. of lead; but such
brass does not work well under the hammer; and, reciprocally, the brass which is best
under the hammer is too tough for turning.
That metallic alloys tend to be formed in definite proportions of their constituents is
clear from the circumstance that the native gold of the auriferous sands is an alloy with
silver, in the ratios of 1 atom of silver united to 4, 5, 6, 12 atoms of gold, but never with
a fractional part of an atom. Also, in making an amalgam of 1 part of silver with 12
or 15 of mercury, and afterwards squeezing the mixture through chamois leather, the
amalgam separates into 2 parts: one, containing a small proportion of silver and much
mercury, passes through the skin; and the other, formed of 1 of silver and 8 of mercury,
is a compound in definite proportions, which crystallizes readily, and remains in the knot
of the bag. An analogous' separation takes place in the tinning of mirrors; for on loading them with the weights, a liquid amalgam of tin is squeezed out, while another amalgam remains in a solid form composed of tin and mercury in uniform atomic proportions.
But, as alloys are generally soluble, so to speak, in each other, this definiteness of combination is masked and disappears in most cases.
M. Chaudet has made some experiments on the means of detecting the metals of
alloys by the cupelling furnace, and they promise useful applications. The testing
depends upon the appearances exhibited by the metals and their alloys when heated on a
cupel. Pure tin, when heated this way, fuses, becomes of a grayish black color, fumes
a little, exhibits incandescent points on its surface, and leaves an oxyde, which, when
withdrawn from the fire, is at first lemon-yellow, but when cold, white. Antimony
melts, preserves its brilliancy, fumes, and leaves the vessel colored lemon-yellow when
hot, but colorless when cold, except a few spots of a rose tint. Zinc burns brilliantly,
forming a cone of oxyde; and the oxyde, much increased in volume, is, when hot, greenish, but when cold, perfectly white. Bismuth fumes, becomes covered with a coat of
melted oxyde, part of which sublimes, and the rest enters the pores of the cupel; when
cold, the cupel is of a fine yellow color, with spots of a greenish hue. Lead resembles
bismuth very much; the cold cupel is of a lemon-yellow color. Copper melts, and becomes covered with a coat of black oxyde; sometimes spots of a rose tint remain on the
cupel.
Alloys.-Tin 75, antimony 25, melt, become covered with a coat of black oxyde,
have very few incandescent points; when cold, the oxyde is nearly black, in consequence of the action of the antimony: a  Jo-i  part of antimony may be ascertained in
this way in the alloy. An alloy of antimony, containing tin, leaves oxyde of tin in the
cupel: a Tl0  part of tin may be detected in this way. An alloy of tin and zinc gives an
oxyde which, while hot, is of a green tint, and resembles philosophic wool in appearance.
An alloy containing 99 tin, 1 zinc, did not present the incandescent points of pure tin,
and gave an oxyde of greenish tint when cold. Tin 95, bismuth 5 parts, gave an oxyde
of a gray color. Tin and lead give an oxyde of a rusty brown color. An alloy of lead
and tin, containing only 1 per cent. of the latter metal, when heated, does not expose a
clean surface, like lead, but is covered at times with oxyde of tin. Tin 75, and copper
25, did not melt, gave a black oxyde: if the heat be much elevated, the under part of
the oxyde is white, and is oxyde of tin; the upper is black, and comes from the copper.
The cupel becomes of a rose color. If the tin be impure from iron, the oxyde produced
by it is marked with spots of a rust color.
The degree of affinity between metals may be in some measure estimated by the
greater or less facility with which, when of different degrees of fusibility or volatility,
they unite, or with which they can, after union, be separated by heat. The greater or
less tendency to separate into differently proportioned alloys, by long-continued fusion,
may also give some information upon the subject. Mr. Hatchett remarked, in his
elaborate researches on metallic alloys, that gold made standard with the usual precaul
tions, by silver, copper, lead, antimony, &c., and then cast, after long fusion, into verticabars, was by no means a uniform compound; but that the top of the bar, corresponding
to the metal at the bottom of the crucible, contained the larger proportion of gold.
Hence, for a more thorough combination, two red-hot crucibles should be employed, and
the liquefied metals should be alternately poured from the one into the other. To pre



ALLOY.                                    49
vent unnecessary oxidisement from the air, the crucibles should contain, besides the
metal, a mixture of common salt and pounded charcoal. The metallic alloy should
also be occasionally stirred up with a rod of pottery ware.
The most direct evidence oY a chemical change having been effected in alloys is,
when the compound melts at a lower temperature than the mean of its ingredients.
Iron, which is nearly infusible, acquires almost the fusibility of gold when alloyed with
this precious metal. The analogy is here strong with the increase of solubility which
salts acquire by mixture, as is exemplified in the difficulty of crystallizing residuums
of saline solutions, or mother waters, as they are called.
When there is a strong affinity between the two metals, their alloy is generally
denser than the mean, and vice versd. This is exemplified in the alloys of copper with
zinc and tin on the one hand; and with copper and lead on the other. When one
of the metals is added in excess, there result an atomic compound and an indefinite
combination, as would appear from Muschenbroek's experiments. Thus,
1 of lead with 4 of silver give a density of 10'480.
1      do    2             do           11-032.
1      do    3             do           10'831.
The proportion of the constituents is on this principle estimated in France by the test
qf the ball applied to pewter; in which the weight of the alloyed ball is compared with
that of a ball of pure tin or standard pewter cast in the same mould. Alloys possess
the elasticity belonging to the mean of their constituents, and also the specific caloric.
According to M. Rudberg, while lead solidifies at 325~ C., and tin at 228~, and their
atomic alloy at 187~, which he calls the fixed point, for a compound Pb Sns.
The action of the air is in general less on alloys than on their components; to which,
however, there are remarkable exceptions, as for example, with the alloy of 3 parts of
lead and 1 of tin, which when heated to redness burns briskly into a red oxide. When
two metals, as copper and tin, are combined, which oxidize at different temperatures,
they may be separated by fusion with exposure to the air, an artifice practised on
the church bells in France to procure tin for making cannon metal bronze. Cupellation of the precious metals is a like phenomenon.
An alloy too slowly cooled is often apt to favor the crystallization of one or more
of its components, and thus to render it brittle; and hence an iron mould is preferable to one of sand when there is danger of such a result.
It is not a matter of indifference in what order the metals are melted together in
making an alloy. Thus, if we combine 90 parts of tin and 10 of copper, and to this
alloy add 10 of antimony; or if we combine 10 parts of antimony with 10 of copper,
and add to that alloy 90 parts of tin, we shall have two alloys chemically the same;
and still it will be easy to discover that, in other respects, fusibility, tenacity, &c.,
they totally differ. Whence this result? Obviously from the nature of their combination, dependent upon the order pursued in the preparation, and which continues
after the mixture. In the alloys of lead and antimony also, if the heat be raised in
combining the two metals together much above their fusing points, the alloy becomes
harsh and brittle; probably because some alloy formed at that high temperature is
not soluble in the mass.
In common cases the specific gravity affords a good criterion whereby to judge of the
proportion of two metals in an alloy. But a very fallacious rule has been given in some
respectable works for computing the specific gravity that should result from the alloying
of given quantities of two metals of known densities, supposing no chemical condensation
or expansion of volume to take place. Thus, it has been taught, that if gold and copper
be united in equal weights, the computed specific gravity is merely the arithmetical
mean between the numbers denoting the two specific gravities. Whereas the specific
gravity of any alloy must be computed by dividing the sum of the two weights by the
sum of the two volumes, compared, for convenience sake, to water reckoned unity. Or,
in another form, the rule may be stated thus:-Multiply the sum of the weights into
the products of the two specific-gravity numbers for a numerator; and multiply each
specific gravity-number into the weight of the other body, and add the two products
together for a denominator. The quotient obtained by dividing the said numerator by
the denominator, is the truly computed mean specific gravity of the alloy. On comparing with that density, the density found by experiment, we shall see whether expansion or condensation of volume has attended the metallic combination. Gold having a
specific gravity of 19-36, and copper of 8-87, when they are alloyed in equal weights, give,
by the fallacious rule of the arithmetical mean of the densities 19-36 + 8-87 = 14-11;
2
whereas the rightly computed mean density is only 12-16. It is evident that, on comparing the first result with experiment, we should be led to infer that there had been a
prodigious condensation of volume, though expansion has actually taken place. Let




50                                   ALUM.
W, w be the two weights; P, p the two specific gravities, then M, the mean specific
gravity, is given by the formula
M    (W-w) Pp   2        -(P-P)2  twice
Pw —pW                   p+p
the error of the arithmetical mean; which is therefore always in excess.
Alloys of a somewhat complex character are made by Mr. Alexander Parkes, of
Birmingham, of a white or pale color, by melting together 331 lbs. of foreign zinc, 64
of tin, 14 of iron, and 3 of copper; or 50 zinc, 48 tin, 1 iron, and 3 copper; or any intermediate proportion of zinc and copper may be used. The iron and copper are first
melted together in a crucible, the tin is next introduced, in such quantities at a time
as not to solidify the iron and copper; the zinc is added lastly, and the whole mixed
by stirring. The flux recommended for this alloy is 1 part of lime, 1 part of Cumberland (iron?) ore, and 3 parts of sal ammoniac.
Another of his alloys is composed of 66 lbs. of foreign zinc, 33~ tin, 34 antimony;
or 704 zinc, 195 tin, and 24 antimony; or any intermediate proportions, and with or
without arsenic. He uses black flux. When to be applied to the sheathing of ships,
from 8 to 16 oz. of metallic arsenic are added to every 100 lbs. of alloy. A third class
of alloys consists of equal parts of iron and nickel; the copper is next added, and lastly
the zinc, or the copper and zinc, may be added as an alloy. 100 lbs. may consist of
454 lbs. of iron and nickel (partes cequales), and 101 lbs. of foreign zinc; or 304 lbs. of
alloy of iron and nickel (p. ce.), 46 copper, and 261 zinc; or any intermediate propor.
tions of zinc and copper. He uses also an alloy of 60 lbs. of copper, 20 of zinc, and 20
of silver; or 60 copper, 10 nickel, 10 silver, and 20 zinc; the copper and nickel being
first fused together. His fifth alloy is called by him a non-conductor of heat! It is
made of 25 nickel, 25 iron, and 50 copper; or 15 nickel, 25 iron, and 60 copper; the
last being added after the fusion of the others.
Mr. Parkes also proposes to deposit metals by means of electricity from their iodides,
chlorides, and phosphates, while in fusion by heat, either singly or combined with
compatible haloids.
ALMOND. (Amande, Fr.; Afandel, Germ.) There are two kinds of almond which
do not differ in chemical composition, only that the bitter, by a curious chemical reaction of its constituents, generates in the act of distillation a quantity of a volatile oil,
which contains hydrocyanic acid.  Vogel obtained from bitter almonds 8'5 per cent.
of husks. After pounding the kernels, and heating them to coagulate the albumen, he
procured, by expression, 28 parts of an unctuous oil, which did not contain the smallest
particle of hydrocyanic acid. The whole of the oil could not be extracted in this way.
The expressed mass, treated with boiling water, afforded sugar and gum, and, in consequence of the heat, some of that acid. The sugar constitutes 6'5 per cent. and the gum
3. The vegetable albumen extracted, by means of caustic potash, amounted to 30
parts: the vegetable fibre to only 5. The poisonous aromatic oil, according to Robi
quet and Boutron-Charlard, does not exist ready-formed in the bitter almond, but
seems to be produced under the influence of ebullition with water. These chemists
have shown that bitter almonds deprived of their unctuous oil by the press, when
treated first by alcohol, and then by water, afford to neither of these liquids any volatile oil. But alcohol dissolves out a peculiar white crystalline body, without smell, of
a sweetish taste at first, and afterwards bitter, to which they gave the name of amygdaline. This substance does not seem convertible into volatile oil. See AMYGDALINE.
Sweet almonds, by the analysis of Boullay, consist of 54 parts of the bland almond
oil, 6'of uncrystallizable sugar, 3 of gum, 24 of vegetable albumen, 24 of woody fibre,
5 of husks, 3'5 of water, 0'5 of acetic acid including loss. We thus see that sweet
almonds contain nearly twice as much oil as bitter almonds do.
ALMOND OIL. A bland fixed oil, obtained usually from bitter almonds by the
action of a hydraulic press, either in the cold, or aided by hot iron plates. See OIL.
ALOE.  A series of trials has been made within a few years at Paris to ascertain
the'comparative strength of cables made of hemp and of the aloe from Algiers; and
they are said to have all turned to the advantage of the aloe. Of cables of equal size,
that made of aloe raised a weight of 2000 kilogrammes (2 tons nearly); that made of
hemp, a weight of only 400 kilogrammes. At the exposition of objects of national industry, some years ago, in Brussels, I saw aloe cordage placarded, as being far preferable to hempen; but I believe without just grounds.
ALUDEL. A pear-shaped vessel open at each end, of which a series are joined for
distilling mercury in Spain. See MERCURY.
ALUM. (Alun, Fr.; Alaum, Germ.) A saline body, consisting of the earth of clay,
called alumina by the chemists, combined with sulphuric acid and potash, or sulphuric
acid and ammonia, into a triple compound. It occurs in the crystallized form of octahedrons, has an acerb subacid taste, and reddens the blue color of litmus or red cabbage.




ALUM.                                     51
Alum works existed many centuries ago at Roccha, formerly called Edessa, in Syria,
whence the ancient name of Roch alum given to this salt. It was afterwards made at
Foya Nova, near Smyrna, and in the neighborhood of Constantinople. The Genoese,
and other trading people of Italy, imported alum from these places into western Europe,
for the use of the dyers of red cloth. About the middle of the fifteenth century, alum began
to be manufactured at La Tolfa, Viterbo, and Volaterra, in Italy; after which time the
importation of oriental alum was prohibited by the pope, as detrimental to the interests
of his dominions. The manufacture of this salt was extended to Germany at the beginning of the sixteenth century, and to England at a somewhat later period, by Sir
Thomas Chaloner, in the reign of Elizabeth. In its pure state, it does not seem to have
been known to the ancients; for Pliny, in speaking of something like plumose alum,
says, that it struck a black color with pomegranate juice, which shows that the green
vitriol was not separated from it. The stypteria of Dioscorides, and the alumen of
Pliny, comprehended, apparently, a variety of saline substances, of which sulphate of
iron, as well as alumina, was probably a constituent part. Pliny, indeed, says, that a
substance called in Greek'Yypa, or watery, probably from its very soluble nature, which
was milk-white, was used for dyeing wool of bright colors. This may have been the
mountain butter of the German mineralogists, which is a native sulphate of alumina, of
a soft texture, waxy lustre, and unctuous to the touch.
The only alum manufactories now worked in Great Britain, are those of Whitby, in
England, and of Hurlett and Campsie, near Glasgow, in Scotland; and these derive the
acid and earthy constituents of the salt from a mineral called alum slate. This mineral
has a blueish or greenish-black color, emits sulphurous fumes when heated, and acquires
thereby an aluminous taste.  The alum manufactured in Great Britain contains potash
as its alkaline constituent; that made in France contains, commonly, ammonia, either
alone, or with variable quantities of potash. Alum may in general be examined by water
of ammonia, which separates from its watery solutions its earthy basis, in the form of a
light flocculent precipitate. If the solution be dilute, this precipitate will float long as
an opalescent cloud.
If we dissolve alum in 20 parts of water, and drop this solution slowly into water or
caustic ammonia till this be nearly, but not entirely, saturated, a bulky white precipitate
will fall down, which, when properly washed with water, is pure aluminous earth or
clay, and dried forms 10-82 per cent. of the weight of the alum. If this earth, while
still moist, be dissolved in dilute sulphuric acid, it will constitute, when as neutral
as possible, the sulphate of alumina, which requires only two parts of cold water for its
solution. If we now decompose this solution, by pouring into it water of ammonia,
there appears an insoluble white powder, which is subsulphate of alumina, or basic alum;
and contains three times as much earth as exists in the neutral sulphate. If, however,
we pour into the solution of the neutral sulphate of alumina a solution of sulphate of
potash, a white powder will fall if the solutions be concentrated, which is true alum; but
if the solutions be dilute, by evaporating their mixture, and cooling it, crystals of alum
will be obtained.
When newly precipitated alumina is boiled in a solution of alum, a portion of the
earth enters into combination with the salt, constituting an insoluble compound, which
falls in the form of a white powder. The same combination takes place, if we decompose a boiling hot solution of alum with a solution of potash, till the mixture appears
nearly neutral by litmus paper.  This insoluble or basic alum exists native in the
alum-stone of Tolfa, near Civita Vecchia, and it consists in 100 parts of 19'72 parts of
sulphate of potash, 61-99 basic sulphate of alumina, and 18'29 water.  When this
mineral is treated with a due quantity of sulphuric acid, it dissolves, and is converted
into the crystallizable alum of commerce.
These experimental facts develop the principles of the manufacture of alum, which
is prosecuted under various modifications, for its important uses in the arts. Alum
seldom occurs ready-formed in nature; occasionally, as an efflorescence on stones, and in
certain mineral waters in the East Indies. The alum of European commerce is fabricated
artificially, either from the alum schists or stones, or from clay. The mode of manufacture
differs according to the nature of these earthy compounds. Some of them, such as the
alum-stone, contain all the elements of the salt, but mixed with other matters from
which it must be freed. The schists contain only the elements of two of the constituents,
namely, clay and sulphur, which are convertible into sulphate of alumina, and this may
be then made into alum by adding the alkaline ingredient. To this class belong the
alum-slates, and other analogous schists, containing brown coal.
1. Manufacture of d1lum from the.llum Stone.-The alum-stone is a rare mineral, being
found in moderate quantity at Tolfa, and in larger in Hungary, at Bereghszasz, and Muszag, where it forms entire beds in a hard substance, partly characterized by numerous
cavities, containing drusy crystallizations of alum-stone or basic alum.  The larger
lumps contain more or fewer flints disseminated through them, and are, according to




52                                 ALUM.
their quality, either picked out to make alum, or are thrown away. The sorted pieces
are roasted or calcined, by which operation apparently the hydrate of alumina, associated
with the sulphate of alumina, loses its water, and, as burnt clay, loses its affinity for
alum. It becomes, therefore, free; and during the subsequent exposure to the weather
the stone gets disintegrated, and the alum becomes soluble in water.
The calcination is performed in common lime-kilns in the ordinary way.  In the
regulation of the fire it is requisite, here, as with gypsum, to prevent any fusion or
running together of the stones, or even any disengagement of sulphuric or sulphurous
acids, which would cause a corresponding defalcation in the product of alum. For this
reason the contact of the ignited stones with carbonaceous matter ought to be avoided.
The calcined alum-stones, piled in heaps from 2 to 3 feet high, are to be exposed to
the weather, and meanwhile they must be continually kept moist by sprinkling them
with water. As the water combines with the alum the stones crumble down, and fall,
eventually, into a pasty mass, which must be lixiviated with warm water, and allowed to
settle in a large cistern. The clear supernatant liquor, being drawn off, must be
evaporated, and then crystallized. A second crystallization finishes the process, and furnishes a marketable alum. Thus the Roman alum is made, which is covered with a
fine red film of peroxyde of iron.
2..lum Manufacture from  lMum Schist.-The greater portion of the alum found in
British commerce is made from alum-slate and analogous minerals. This slate contains
more or less iron pyrites, mixed with coaly or bituminous matter, which is occasionally
so abundant as to render them somewhat combustible. In the strata of brown coal and
bituminous wood, where the upper layers lie immediately under clay beds, they consist
of the coaly substance rendered impure with clay and pyrites.  This triple mixture
constitutes the essence of all good alun schists, and it operates spontaneously towards
the production of sulphate of alumina. The coal serves to make the texture open, and
to allow the air and moisture to penetrate freely, and to change the sulphur and iron present into acid and oxyde. When these schists are exposed to a high temperature in
contact with air, the pyrites loses one half of its sulphur, in the form of sublimed
sulphur or sulphurous acid, and becomes a black sulphuret of iron, which speedily
attracts oxygen, and changes to sulphate of iron, or green vitriol. The brown coal schists
contain, commonly, some green vitriol crystals, spontaneously formed in them. The
sulphate of iron transfers its acid to the clay, progressively, as the iron, by the action
of the air with a little elevation of temperature, becomes peroxydized; whereby sulphate
of alumina is produced. A portion of the green vitriol remains, however, undecomposed,
and so much the more as there may happen to be less of other salifiable bases present in
the clay slate.  Should a little magnesia or lime be present, the vitriol gets more
completely decomposed, and a portion of Epsom salt and gypsum is produced.
The manufacture of alum from alum schists may be distributed under the six following
heads:-l. The preparation of the alum slate. 2. The lixiviation of the slate. 3. The
evaporation of the lixivium.  4. The addition of the saline ingredients, or the precipitation of the alum. 5. The washing of the aluminous salts; and, 6. The crystallization.
1. Preparation of the.lum Slate.-Some alum  slates are of such a nature that,
being piled in heaps in the open air, and moistened from time to time, they get spontaneously hot, and by degrees fall into a pulverulent mass, ready to be lixiviated. The
greater part, however, require the process of ustulation, from which they derive many
advantages. The cohesion of the dense slates is thereby so much impaired that their decomposition becomes more rapid; the decomposition of the pyrites is quickened by the
expulsion of a portion of the sulphur; and the ready-formed green vitriol is partly
decomposed by the heat, with a transference of its sulphuric acid to the clay, and
the production of sulphate of alumina.
Such alum-slates as contain too little bitumen or coal for the roasting process must be
interstratified with layers of small coal or brushwood over an extensive surface. At
Whitby the alum rock, broken into small pieces, is laid upon a horizontal bed of fuel,
composed of brushwood; but at Hurlett small coal is chiefly used for the lower bed.
When about four feet of the rock is piled on, fire is set to the bottom in various parts; and
whenever the mass is fairly kindled, more rock is placed over the top. At Whitby this
piling process is continued till the calcining heap is raised to the height of 90 or 100 feet.
The horizontal area is also augmented at the same time till it forms a great bed nearly
200 feet square, having therefore about 100,000 yards of solid measurement. The rapidity of the combustion is tempered by plastering up the crevices with small schist
moistened. When such an immense mass is inflamed, the heat is sure to rise too high,
and an immense waste of sulphur and sulphuric acid must ensue. This evil has been
noticed at the Whitby works. At Hurlett the height to which the heap is piled is only
a few feet, while the horizontal area is expanded; which is a much more judicious arrangement. At Whitby 130 tons of calcined schist produce on an average 1 ton of alum.




ALUM.                                     53
In this humid climate it would be advisable to pile up on the top of the horizontal strata
of brushwood or coal, and schist, a pyramidal mass of schist, which having its surface
plastered smooth, with only a few air-holes, will protect the mass from the rains, and at
the same time prevent the combustion from becoming too vehement. Should heavy rains
supervene, a gutter must be scooped out round the pile for receiving the aluminous lixivium, and conducting it into the reservoir.
It may be observed, that certain alum schists contain abundance of combustible matter,
to keep up a suitable calcining heat after the fire is once kindled; and therefore nothing
is needed but the first layer of brushwood, which, in this case, may be laid over the first
bed of the bituminous schist.
A continual, but very slow heat, with a smothered fire, is most beneficial for the
ustulation of alum slate. When the fire is too brisk, the sulphuret of iron may run
with the earthy matters into a species of slag, or the sulphur will be dissipated in vapor,
by both of which accidents the product of alum will be impaired. Those bituminous
alum schists which have been used as fuel under steam boilers have suffered such a
violent combustion that their ashes yield almost no alum. Even the best regulated
calcining piles are apt to burn too briskly in high winds, and should have their draughtholes carefully stopped under such circumstances. It may be laid down as a general
rule, that the slower the combustion the richer the roasted ore will be in sulphate of
alumina. When the calcination is complete, the heap diminishes to one half its original
bulk; it is covered with a light reddish ash, and is open and porous in the interior, so
that the air can circulate freely throughout the mass. To favor this access of air, the
masses should not be too lofty; and in dry weather a little water should be occasionally
sprinkled on them, which, by dissolving away some of the saline matter, will make the
interior more open to the atmosphere.
When the calcined mineral becomes thoroughly cold, we may proceed to the lixiviation.
But as, from the first construction of the piles or beds till their complete calcination,
many weeks, or even months, may elapse, care ought to be taken to provide a sufficient
number or extent of them, so as to have an adequate supply of material for carrying on
the lixiviating and crystallizing processes during the course of the year, or at least during
the severity of the winter season, when the calcination may be suspended, and the
lixiviation becomes unsatisfactory. The beds are known to be sufficiently decomposed
by the efflorescence of the salt which appears upon the stones, from the strong aluminous
taste of the ashes, and from the appropriate chemical test of lixiviating an aliquot average
portion of the mass, and seeing how much alum it will yield to solution of muriate or
sulphate of potash.
2. The Lixiviation.-The lixiviation is best performed in stone-built cisterns; those of
wood, however strong at first, are soon decomposed, and need repairs. They ought to be
erected in the neighborhood of the calcining heaps, to save the labor of transport, and so arranged that the solutions from the higher cisterns may spontaneously flow into the lower.
In this point of view, a sloping terrace is the best situation for an alum work. In the
lowest part of this terrace, and in the neighborhood of the boiling-house, there ought
to be two or more large deep tanks, for holding the crude lixivium, and they should be
protected from the rain by a proper shed. Upon a somewhat higher level the cisterns
of the clear lixivium may be placed. Into the highest range of cisterns the calcined
mineral is to be put, taking care to lay the largest lumps at the bottom, and to cover
them with lighter ashes. A sufficient quantity of water is now to be run over it, and
allowed to rest for some time. The lixivium may then be drawn off, by a stopcock
connected with a pipe at the bottom of the cistern, and run into another cistern at a
somewhat lower level. Fresh water must now be poured on the partly exhausted
schist, and allowed to remain for a sufficient time. This lixivium, being weak, should
be run off into a separate tank. In some cases a third addition of fresh water may be
requisite, and the weak lixivium which is drawn off may be reserved for a fresh portion
of calcined mineral. In order to save evaporation. it is always requisite to strengthen weak
leys by employing them instead of water for fresh portions of calcined schist. Upon the
ingenious disposition and form of these lixiviating cisterns much of the economy and success of an alum work depend. The hydrometer should be always used to determine the
degree of concentration which the solutions acquire.
The lixiviated stone, being thus exhausted of its soluble ingredients, is to be removed
from the cisterns, and piled up in a heap in any convenient place, where it may be left
either spontaneously to decompose, or, after drying, may be subjected to another calcination.
The density of the solution may be brought, upon an average, up to the sp. gr. of
from 1'09 to 1*15. The latter density may always be obtained by pumping up the weaker solutions upon fresh calcined mine. This strong liquor is then drawn off, when the
sulphate of lime, the oxyde of iron, and the earths are deposited. It is of advantage to
leave the liquor exposed for some time, whereby the green vitriol may pass into a per



54                                   ALUM.
sulphate of iron with the deposition of some oxyde, while the liberated acid may combine
with some of the clay present, so as to increase the quantity of sulphate of alumina.
The manufacture of alum is the more imperfect, as the quantity of sulphate of iron left
undecomposed is greater, and therefore every expedient ought to be tried to convert the
sulphate of iron into sulphate of alumina.
3. The evaporation of the Schist Lixivium.-As the aluminous liquors, however
well settled at first, are apt, on the great scale, to deposite earthy matters in the course
of their concentration by heat, they are best evaporated by a surface fire, such as
that employed at Hurlett and Campsie. A water-tight stone cistern must be built,
having a layer of well rammed clay behind the flags or tiles which line its bottom
and sides. This cistern may be 4 or 6 feet wide, 2 or 3 feet deep, and 30 or 40
feet long, and it is covered in by an arch of stone or brickwork. At one extremity of
this tunnel, or covered canal, a fire-grate is set, and at the other a lofty chimney
is erected. The cistern being filled to the brim with the alum ley, a strong fire is
kindled in the reverberatory grate, and the flame and hot air are forced to sweep along
the surface of the liquor, so as to keep it in constant ebullition, and to carry off the
aqueous parts in vapor. The soot which is condensed in the process falls to the bottom,
and leaves the body of the liquor clear. As the concentration goes on, more of the
rough lixivium is run in from the settling cistern, placed on a somewhat higher level, till
the whole gets charged with a clear liquor of a specific gravity sufficiently high for transferring into the proper lead boilers.
At Whitby, the lead pans are 10 feet long, 4 feet 9 inches wide, 2 feet 2 inches deep
at the one end, and 2 feet 8 inches deep at the other. This increase of depth and corresponding slope facilitates the decantation of the concentrated lixivium by means of
a syphon, applied at the lower end. The bottom of the pan is supported by a series of
parallel iron bars, placed very near each other. In these lead pans the liquor is concentrated, at a brisk boiling heat, by means of the flame of a flue beneath them. Every
morning the pans are emptied into a settling cistern of stone or lead. The specific gravity of the liquor should be about 1'4 or 1'5, being a saturated solution of the saline matters present. The proper degree of density must vary, however, with different kinds of
lixivia, and according to the different views of the manufacturer. For a liquor which
consists of two parts of sulphate of alumina, and one part of sulphate of iron, a specific
gravity of 1'25 may be sufficient; but for a solution which contains two parts of sulphate
of iron to one of sulphate of alumina, so that the green vitriol must be withdrawn first of
all by crystallization, a specific gravity of 1-4 may be requisite.
The construction of an evaporating furnace well adapted to the concentration of aluminous and other crude lixivia, is described under SODA. The liquor basin may be made
of tiles or flags puddled in clay, and secured at the seams with a good hydraulic cement.
A mortar made of quicklime mixed with the exhausted schist in powder, and iron turnings, is said to answer well for this purpose. Sometimes over the reverberatory furnace
a flat pan is laid, instead of the arched top, into which the crude liquor is put for neutralization and partial concentration. In Germany, such a pan is made of copper, because
iron would waste too fast, and lead would be apt to melt. From this preparation basin
the under evaporating trough is gradually supplied with hot liquor. At one side of this
lower trough there is sometimes a door, through which the sediment may be raked out
as it accumulates upon the bottom. Such a contrivance is convenient for this mode of
evaporation, and it permits, also, any repairs to be readily made; but, indeed, an apparatus of this kind, well mounted at first, will serve for many years.
In the course of the final concentration of the liquors, it is customary to add some of
the mother waters of a former process, the quantity of which must be regulated by a
proper analysis and knowledge of their contents. If these mother waters contain much
free sulphuric acid, from the peroxydation of their sulphate of iron, they may prove useful
in dissolving a portion of the alumina of the sediment which is always present in greate
or less quantity.
4. The precipitation of the J.lum by adding alkaline Salts.-As a general rule, it is
most advantageous to separate, first of all, trom the concentrated clear liquors, the alum
in the state of powder or small crystals, by addition of the proper alkaline matter, and
to leave the mingled foreign salts, such as the sulphate of iron or magnesia, in solution,
instead of trying to abstract these salts by a previous crystallization. In this way we
not only simplify and accelerate the manufacture of alum, and leave the mother waters
to be worked up at any convenient season, but we also avoid the risk of withdrawing
any of the sulphate of alumina with the sulphate of iron or magnesia. On this account,
the concentration of the liquor ought not to be pushed so far as that, when it gets cold,
it should throw out crystals, but merely to the verge of this point. This density may be
determined by suitable experiments.
The clear liquor should now be run off into the precipitation cistern, and have the




ALUM.                                     65
proper quantity of sulphate or muriate of potash, or impure sulphate or carbonate of
ammonia added to it. The sulphate of potash, which is the best precipitant, forms 18-34
parts out of 100 of crystallized alum; and therefore that quantity of it, or its equivalent
in muriate of potash, or other potash or ammoniacal salts, must be introduced into the
aluminous liquor. Since sulphate of potash takes 10 parts of cold water to dissolve it,
but is much more soluble in boiling water, and since the precipitation of alum is more
abundant the more concentrated the mingled solutions are, it would be prudent to add
the sulphate solution as hot as may be convenient; but, as muriate of potash is fully
three times more soluble in cold water, it is to be preferred as a precipitant, when it can
be procured at a cheap rate. It has, also, the advantage of decomposing the sulphate of
iron present into a muriate, a salt very difficult of crystallization, and, therefore, less
apt to contaminate the crystals of alum. The quantity of alkaline salts requisite to
precipitate the alum, in a granular powder, from the lixivium, depends on their richness in potash or ammonia, on the one hand, and on the richness of the liquors in
sulphate of alumina on the other; and it must be ascertained, for each large quantity of
product, by a preliminary experiment in a precipitation glass. Here, an aliquot measure
of the aluminous liquor being taken, the liquid precipitant must be added in successive
portions, as long as it causes any cloud, when the quantity added will be indicated by
the graduation of the vessel. A very exact approximation is not practicable upon the
great scale; but, as the mother waters are afterwards mixed together inone cistern, any
excess of the precipitant, at one time, is corrected by excess of aluminous sulphate at
another, and the resulting alum meal is collected at the bottom. When the precipitated saline powder is thoroughly settled and cooled, the supernatant mother water must
be drawn off by a pump, or rather a syphon or stopcock, into a lower cistern. The
more completely this drainage is effected, the more easily and completely will the alum
be purified.
This mother liquor has, generally, a specific gravity of 1'4 at a medium temperature
of the atmosphere, and consists of a saturated solution of sulphate or muriate of black
and red oxyde of iron, with sulphate of magnesia, in certain localities, and muriate of
soda, when the soaper's salt has been used as a precipitant, as also a saturated solution
of sulphate of alumina. By adding some of it, from time to time, to the fresh lixivia, a
portion of that sulphate is converted into alum; but, eventually, the mother water must
be evaporated, so as to obtain from it a crop of ferruginous crystals; after which it becomes capable, once more, of giving up its alum to the alkaline precipitants.
When the aluminous lixivia contain a great deal of sulphate of iron, it may be good
policy to withdraw a portion of it by crystallization before precipitating the alum. With
this view, the liquors must be evaporated to the density of 1'4, and then run off into
crystallizing stone cisterns. After the green vitriol has concreted, the liquor should be
pumped back into the evaporating pan, and again brought to the density of 1-4. On
adding to it, now, the alkaline precipitants, the alum will fall down from this concentrated solution, in a very minute crystalline powder, very easy to wash and purify. But this
method requires more vessels and manipulation than the preceding, and should only be
had recourse to from necessity; since it compels us to carry on the manufacture of both
the valuable alum and the lower priced salts at the same time; moreover, the copperas
extracted at first from the schist liquors carries with it, as we have said, a portion of the
sulphate of alumina, and acquires thereby a dull aspect; whereas the copperas obtained
after the separation of the alum is of a brilliant appearance.
5. The washing, or edulcoration, of the Alum Powder.-This crystalline pulverulent
matter has a brownish color, from  the admixture of the ferruginous liquors; but
it may be freed from it by washing with very cold water, which dissolves not more
than one sixteenth of its weight of alum. After stirring the powder and the water
well together, the former must be allowed to settle, and then the washing must be
drawn off. A second washing will render the alum  nearly pure.  The less water
is employed, and the more effectually it is drained off, the more complete is the
process. The second water may be used in the first washing of another portion of
alum powder, in the place of pure water. These washings may be added to the schist
lixivia.
6. The crystallization.-The washed alum is put into a lead pan, with just enough
water to dissolve it at a boiling heat; fire is applied, and the solution is promoted by
stirring. Whenever it is dissolved in a saturated state, it is run off into the crystallizing
vessels, which are called roching casks. These casks are about five feet high, three feet
wide in the middle, somewhat narrower at the ends; they are made of very strong staves,
nicely fitted to each other, and held together by strong iron hoops, which are driven on
pro tempore, so that they may be easily knocked off again, in order to take the staves
asunder. The concentrated solution, during its slow cooling in these close vessels, forms
large regular crystals, which hang down from the top, and project from the sides, while
a thick layer or cake lines the whole interior of the cask. At the end of eight or ten days




56                                   ALUM.
rmor  or less, acccording to the weather, the hoops and staves are removed, when a cask,
of apparently solid alum is disclosed to view. The workman now pierces this mass with
a pickaxe at the side near the bottom, and allows the mother water of the interior to run
off on the sloping stone floor into a proper cistern, whence it is taken and added to another
quantity of washed powder to be crystallized with it. The alum is next broken into
lumps, exposed in a proper place to dry, and is then put into the finished bing for the
market. There is sometimes a little insoluble basic alum (subsulphate) left at the bottom
of the cask. This being mixed with the former mother liquors, gets sulphuric acid from
them; or, being mixed with a little sulphuric acid, it is equally converted into alum.
When, instead of potash or its salts, the ammoniacal salts are used, or putrid urine,
with the aluminous lixivia, ammoniacal alum is produced, which is perfectly similar to
the potash alum in its appearance and properties. At a gentle heat both lose their water of crystallization, amounting to 451 per cent. for the potash alum, and 48 for the ammoniacal. The quantity of acid is the same in both, as, also, very nearly the quantity of
alumina, as the following analyses will show:Potash alum.                          Ammonia alum.
Sulphate of potash   -    -  18-34      Sulphate of ammonia       -    12-88
Sulphate of alumina   -    - 36*20      Sulphate of alumina       -  38-64
Water                     - -  45-46    Water                           48-48
100-00                                    100-00
Or otherwise, Potash alum.                   Ammonia alum.
1 atom sulphate of potash  - 1089-07    1 atom sulphate of ammonia  - 716-7
1               alumina  - 2149-80      1                  alumina  - 2149-8
24 water                -   2669-52    24 water                       - - -2699-5
5938-39                                    5566-0
Or, Potash alum.                        Ammonia alum.
Alumina          -         -  10-82     Alumina       -    -    -    -  11-90
Potash..   9-94     Ammonia    -    -    -    -   389
Sulphuric acid     -       - 33-77      Sulphuric acid     -    -   - 36-10
Water       -         -       45-47     Water  -      -    -    -    - 48-11
100-00                                   100-00
When heated pretty strongly, the ammoniacal alum loses its sulphuric acid and
ammonia, and only the earth remains. This is a very convenient process for procuring
pure alumina. Ammoniacal alum is easily distinguished from the other by the smell of
ammonia which it exhales when triturated with quicklime. The Roman alum, made
from alum-stone, possesses most of the properties of the schist-made alums, but it has a
few peculiar characters: it crystallizes always in opaque cubes, whereas the common
alum crystallizes in transparent octahedrons. It is probable that Roman alum is a
sulphate of alumina and potash, with a slight excess of the earthly ingredient. It is
permanent when dissolved in cold water; for after a slow evaporation it is recovered in
a cubical form. But when it is dissolved in water heated to 110~ Fahr. and upwards, or
when its solution is heated above this pitch, subsulphate of alumina falls, and on
evaporation octahedral crystals of common alum are obtained. The exact composition
of the Roman alum has not been determined, as far as I know. It probably differs
from the other also in its water of crystallization. The Roman alum contains, according to
MIM. Thenard and Roard, only 21-y  of sulphate of iron, while the common commercial
alums contain ro~1. It may be easily purified by solution, granulation, crystallization, and
washing, as has been already explained.
Alum is made extensively in France from an artificial sulphate of alumina. For this
purpose clays are chosen as free as possible from carbonate of lime and oxyde of iron.
They are calcined in a reverberatory furnace, in order to expel the water, to peroxydize
the iron, and to render the alumina more easily acted on by the acid. The expulsion of
the water renders the clay porous and capable of absorbing the sulphuric acid by
capillary attraction. The peroxydation of the iron renders it less soluble in the
sulphuric acid; and the silica of the clay, by reacting on the alumina, impairs its
aggregation, and makes it more readily attracted by the acid. The clay should, therefore,




ALUM.                                      57
be moderately calcined; but not so as to indurate it like pottery ware, for it would then
suffer a species of silicious combination which would make it resist the action of acids.
The clay is usually calcined in a reverberatory furnace, the flame of which serves
thereafter to heat two evaporating pans an ad a basin for containing a mixture of the
calcined clay and sulphuric acid.. As soon as the clay has become friable in the furnace
it is taken out, reduced to powder, and passed through a fine sieve. With 100 parts of
the pulverized clay, 45 parts of sulphuric acid, of sp. gr. 1'45, are well mixed, in a
stone basin, arched over with brickwork.  The flame and hot air of a reverberatory
furnace are made to play along the mixture, in the same way as described for evaporating
the schist liquors. See SODA. The mixture, being stirred from time to time, is, at the
end of a few days, to be raked out, and to be set aside in a warm place, for the acid 1o
work on the clay, during six or eight weeks. At the end of this time it must be washed,
to extract the sulphate of alumina. With this view, it may be treated like the roasted
alum ores above described. If potash alum is to be formed, this sulphate of alumina is
evaporated to the specific gravity of 1'38; but if ammonia alum, to the specific gravity
of only 124; because the sulphate of ammonia, being soluble in twice its weight of
water, will cause a precipitation of pulverulent alum from a weaker solution of sulphate
of alumina than the less soluble sulphate of potash could do.
The alum  stone, from  which the Roman alum  is made, contains potash.  The
following analysis of alunite, by M. Cordier, places this fact in a clear light:
Sulphate of potasn    -                          18-53
Sulphate of alumina   -                     -    38-50
Hydrate of alumina   -..    42'97
100-00
To transform this compound into alum, it is merely necessary to abstract the hydrate
of alumina. The ordinary alum stone, however, is rarely so pure as the above analysis
would seem to show; for it contains a mixture of other substances; and the above are in
different proportions.
Alum is very extensively employed in the arts, most particularly in dyeing, lake
makn, drin dressing sheep-skins, pasting paper, in clarifying liquors, &c. Its purity for
the dyer may be tested by prussiate of potash, which will give solution of alum  a blue
tint in a few minutes if it contain even a very minute portion of iron. A bit of nut-gall
is also a good test of iron.
Alum liquors.-In the alum  works on the Yorkshire coast, 8 different liquors are
met with.
1st. " Raw Liquor." The calcined alum shale is steeped in water till the liquor
has acquired a specific gravity of 9 or 10 pennyweights, according to the language of the alum-maker.
2d. "Clarified Liquor."  The raw liquor is brought to the boiling point in lead
pans, and suffered to stand in a cistern till it has cleared: it is then called clarified liquor. Its gravity is raised to 10 or 11 pennyweights.
3d. "Concentrated Liquor."  Clarified liquor is boiled down to about 20 pennyweights. This is kept merely as a test of the comparative value of the potash
salts used by the alum-maker.
4th. " Alum Mother Liquor." The alum pans are fed with clarified liquor, which
is boiled down to about 25 or 0S pennyweights, when a proper quantity of
potash salt in solution is mixed with it, and the whole run into coolers to
crystallize.  The liquor pumped from those rough crystals is called "alum
mothers."
5th. " Salts Mothers." The alum mothers are boiled down to a crystallizing point,
and afford a crop of " Rough Epsom," which is a sulphate of magnesia and protoxide of iron.
6th and 7th. "Alum Washings."  The rough crystals of Alum (No. 4) are washed
twice in water, the first washing being about 4 pennyweights, the second
about 21, the difference in gravity being due to mother liquor clinging to the
crystals.
8th. " Tun Liquor." The washed crystals are now dissolved in boiling water, and
run into the "roching tuns" (wood vessels lined with lead) to crystallize. The
mother liquor of the "roch alum" is called "tun liquor;" it is, of course, not
quite so pure as a solution of roch alum in water.
The alum-maker's sp. gr. bottle holds 80 pennyweights of water, and by 10 pennyweights he means 10 more than water, or 90.
The numbers on Twaddle's hydrometer, divided by 2 5, give alum-makers' pennyweights.




58                                   ALUM.
The alum-maker tests his samples of potash salts comparatively by dissolving equal
weights of the different samples in equal measures of alum liquor at 20 pennyweights,
heated up to the boiling-point, and weighing the quantity of alum crystals produced
on cooling.
For the above information I am indebted to my friend, Mr. Maurice Scanlan, who
superintended for some time the Mulgrave alum works.
He informs me that 611 tons of the alum rock at the Mulgrave Works, to the north
of Whitby, yield, after calcination, &c., one ton of alum.
It has been computed that with sulphur at 61. per ton, sulphuric acid of sp. gr, 1'750
can be produced at 31. per ton, including the mere cost of making: this acid contains
2 atoms of water: 174 tons of this acid, and 87~ tons of sulphate of potash, with the
pipe-clay, will form 474 tons of alum; so that the nett cost would be 5221. for the
acid+ 10471. for the sulphate of potash, =15691.  which sum divided by 474, gives a
quotient of 31. 6s. for the nett cost of 1 ton of alum by the direct process.
At the pit I ton of alum-rock or mine, costs 31. 4s.; to which, adding the cost of
the potash salt for 1 ton of alum, 31. 15s., they constitute together an amount of 61. 19s.
From the latter sum 11. 10s. must, however, be deducted for the value of rough Epsom
salt produced, leaving a balance of 51. 9s. for the cost of a ton of mine-alum, prior to
evaporation and crystallization.
A patent was obtained in November, 1839, by Mr. William Wiesman, of Duesburg,
for improvements in the manufacture of alum. He subjects potter's clay to a moderate
red heat, grinds it, and subjects the powder, in leaden pans, to the action of concentrated sulphuric acid (76~ Beaume), taking care to use excess of clay and a moderate
heat. This mixture is to be stirred till it is dry, then treated with boiling water, in
order to dissolve the sulphate of alumina formed. So far the process is old and well
known. The novelty consists in freeing the saline solution from iron by ferrocyanure
of potassium (prussiate of potash). When the iron has been all thrown down in the
form of prussian blue, the liquor is allowed to settle, the supernatant pure sulphate is
drawn off, and evaporated till it forms on cooling a concrete mass, which may be
moulded into the shape of bricks, &c., for the convenience of packing.
Alum, manufacture of.-The manufacture of alum from clay and clay slate, or shale,
is now beginning to assume a considerable aspect in the list of our manufactures, and
several improvements in this way have lately been patented, which promise to extend
largely this branch of industry. One in particular, for the fabrication of alum from the
ash or residue left after the combustion of a kind of coal, called Boghead coal, seems
based on the sound principle of industrial economy which turns every waste prodnct
to profitable account. It was but the other day that this very Boghead ash was a
serious impediment to the sale of the coal, and perceptibly diminished its price in the
market.  Now, however, it constitutes a decided item of value, and powerfully vindicates the right of chemistry to the title of a useful and profitable science. In preparing
alum from clay or shale, it is of infinite importance that so much and no more heat be
applied to the clay or shale, in the first instance, as will just expel the water of combination, without inducing contraction. A temperature of 600~ Fahr. is well adapted
to effect this object, provided it be maintained for a sufficient period. When this has
been carefully done, the silicate of alumina remaining is easily enough acted upon by
sulphui-ic acid, either slightly diluted or of the ordinary commercial strength. The best
form of apparatus is a leaden boiler, divided into two parts by a perforated septum or
partition, also in lead-though on a very large scale, brickwork set in clay might be
employed. Into one of the compartments the roasted clay or shale should be put, and
diluted sulphuric acid being added, the bottom of the other compartment may be exposed to the action of a well-regulated fire, or-what is better-heated by means of
steam through the agency of a coil of leaden pipe. In this way a circulation of the
fluid takes place throughout the mass of shale; and, as the alumina dissolves, the dense
fluid it produces, falling continually towards the bottom of the boiler, is replaced by
dilute acid, which, becoming in its turn saturated, falls like the first; and so on in
succession, until either the whole of the alumina is taken up, or the acid in great part
neutralized. The solution of sulphate of alumina, thus obtained, is sometimes evaporated to dryness, and sold under the name "concentrated alum;" but more generally it
is boiled down until of the specific gravity of about 1'35, then one or other of the carbonates, muriate, or sulphates of potash or ammonia, or a mixture of these, is added to
the boiling fluid; and as soon as the solution is complete, the whole is run out into a
cooler to crystallize. The rough alum thus made is sometimes purified by a subsequent
recrystallization, after which it is "roched" for the market-a process intended merely to give it the ordinary commercial aspect, but of no real value in a chemical point
of view.  Alum not unfrequently contains iron, an impurity which unfits it for many
uses in the arts, and more especially for the purposes of the dyer. The best mode cf




AMBER.                                    59
ascertaining the presence of this impurity, and demonstrating its amount, is that
previously stated in the commencement of this article,-that is, mix a solution of the
suspected alum with tartaric acid, or an alkaline tartrate, and then add an excess of
carbonate of soda; after which, pour in a few drops of hydrosulphate of ammonia, when,
if iron be present, a black precipitate will ensue. If the alum contains lime or magnesia, then the addition of carbonate of soda causes a white precipitate, which must
be removed by filtration before applying the hydrosulphate of ammonia.
Alum manufacture simplified.-The alum shale, or schist, is the material whence the
alum is obtained: this shale is roasted in heaps, in the open air, in order to render
it porous, and more absorbent of the sulphuric acid. To the roasted shale, sulphuric
acid of sp. gr. 1-75 is added, by which means sulphate of alumina is formed. In
order to wash out from the almost dry mass this sulphate of alumina, and at the same
time to supply the equivalent of the sulphate of ammonia necessary to constitute
the formation of the double salt of alumina and ammonia, the boiling hot mother
liquor of a previous operation is employed; and, as this mother liquor, when re
moved from the alum crystallizers, contains free sulphuric acid, the ammonia from a
still, containing the ammoniacal liquor of the gas works, is distilled into it, and the
boiling hot solution of sulphate of ammonia thus formed dissolves out the sulphate
of alumina from the shale. The alum  liquor thus obtained is of such a specific
gravity, that it crystallizes without the necessity of having recourse to evaporation,
and thus a considerable saving in fuel is effected. In order to obtain ammoniacal
salts, such as sulphate and muriate, with the greatest possible economy, a series of
two or more-say, for instance, four-cylindrical boilers are employed, each of which
is placed at such a distance above the other, that the contents of the upper boiler may
be drawn off into the one next below it. The uppermost boiler is provided with an
exit pipe, and has also a supply pipe, connecting the boiler with a reservoir of ammoniacal gas liquor. Into the lowermost vessel of the series passes a pipe conveying
high pressure steam, by means of which the liquor in the boiler soon becomes heated
to the boiling point. The vapor of ammonia and water pass off through an exit pipe
into the boiler placed next above it in the series, the liquor in which also quickly boils,
and vapor of ammonia and water pass off in the same way as before to the next vessel
above it, and so throughout the series. By the time the vapor of ammonia passes off
from the uppermost boiler, it has been so concentrated that, on passing it into sulphuric
or muriatic acid, a concentrated solution of either of those salts is obtained, of sufficient
sp. gr. to crystallize without evaporation, and thus a considerable saving in fuel and
time is effected, and the ammoniacal liquor most thoroughly exhausted. Fresh supplies of ammoniacal liquor are constantly furnished to the uppermost vessel from the
reservoir; the partially exhausted liquors are run from the higher to the lower vessels
in succession, and the exhausted liquors run off to waste, from time to time, from the
lowermost vessel of the series.
ALUMINA. The pure earth of clay, or argillaceous earth. It is the oxide of the
metal aluminum, the basis of the aluminous salts, and the principal constituent of
porcelain, pottery, bricks and tiles.
AMADOU. The French name of the spongy combustible substance called in German zundersehwamm, prepared from a species of agaric, the boletus igniarius, a kind
of mushroom which grows on the trunks of old oaks, ashes, beeches, &c. It must be
plucked in the months of August and September. It is prepared by removing the outer
bark with a knife, and separating carefully the spongy substance of a yellow brown
color, which lies within it, from the ligneous matter below. This substance is cut
into thin slices, and beat with a mallet to soften it, till it can be easily pulled asunder
between the fingers. In this state the boletus is a valuable substance for stopping
oozing hemorrhages, and some other surgical purposes. To convert it into tinder it
must receive a finishing preparation, which consists in boiling it in a strong solution
of nitre; drying it, and beating it anew, and putting it a second time into the solution.
Sometimes, indeed, to render it very inflammable, it is imbued with gunpowder,
whence the distinction of black and brown amadou.
All the puff balls of the lycopodium genus of plants, which have a fleshy or filamentous structure, yield a tinder quite ready for soaking in gunpowder water. The
Hindoos employ a leguminous plant, which they call solu, for the same purpose. Its
thick spongy stem, being reduced to charcoal, takes fire like amadou.
AMALGAM. When mercury is alloyed with any metal, the compound is called an
amalgam of that metal; as, for example, an amalgam of tin, bismuth, &c.
AMALGAMATION,  This is a process used extensively in extracting silver and
gold from certain of their ores, founded on the property which mercury has to dissolve
these metals as disseminated in the minerals, and thus to separate them from the
earthy matters. See MERCURY, METALLURGY, and SILVER.
AMBER. (Succin, Fr.; Bernstein, Germ.) A mineral solid, of a yellow colour




60                                  AMBER.
of various shades, which burns quite away with flame, and consists of carbon, hydrogen,
and oxygen, in nearly the same proportions, and the same state of combination, as vegetable resin. Its specific gravity varies, by my trials, from  1-080 to 1-085. It becomes
negatively and powerfully electrical by friction. When applied to a lighted candle it
takes fire, swells considerably, and exhales a white smoke of a pungent odor; but
does not run into drops. Copal, which resembles it in several respects, differs in being
softer, and in melting into drops at the flame; and mellite, or honey-stone, which is a
mineral of a similar color, becomes white when laid on a red-hot coal.
The texture of amber is resino-vitreous, its fracture conchoidal, and lustre glassy. It
is perfectly homogeneous; sufficiently hard to scratch gypsum, and to take a fine polish.
It is, however, scratched by calcareous spar. When amber is distilled in a retort,
crystalline needles of succinic acid sublime into the dome, and oil of amber drops from
the beak into the receiver. Fossil resins, such as that of Highgate, found in the London clay formation, do not afford succinic acid by heat: nor does copal. Amber is
occasionally found of a whitish and brownish color.
The most interesting fact relative to this vegeto-mineral is its geological position,
which is very characteristic and well determined. It is found almost uniformly in separate nodules, disseminated in the sand, clay, or fragments of lignite of the plastic clay,
and lignite formation, situated between the calcaire grossier (crag limestone) of the
tertiary strata above, and the white chalk below. The size of these nodules varies from
a nut to a man's head; but this magnitude is very rare in true amber. It does not
occur either in continuous beds, like the chalk flints, nor in veins; but it lies at one
time in the earthy or friable strata, which accompany or include the lignites; at another,
entangled in the lignites themselves; and is associated with the minerals which constitute
this formation, principally the pyrites, the most abundant of all. The pieces of amber
fouid in the sands, and other formations evidently alluvial, those met with on the seacoasts of certain countries, and especially Pomerania, come undoubtedly from the above
geological formation; for the organic matters found still adhering to the amber leave
no doubt as to its primitive place. Amber does not, therefore, belong to any postdiluvian or modern soil, since its native bed is covered by three or four series of strata, often
of considerable thickness, and well characterized; proceeding upwards from the plastic
clay which includes the amber: these are, the crag limestone, the bone gypsum, with
its marls, the marly limestone, the upper marl sandstone, which covers it, and, lastly,
the fresh water or lacustrine formation, often so thick, and composed of calcareous and
silicious rocks.
The amber bed is not, however, always covered with all these strata; and it is even
rare to see a great mass of one of them above the ground which contains it; because,
were it buried under such strata, it would be difficult to meet with such circumstances
as would lay it spontaneously open to the day. But by comparing observations made
in diflbreut places, relatively to the patches of these formations, which cover the amber
deposites, we find that no other mineral formations have been ever seen among them
except those above detailed, and thus learn that its geological locality is completely determined.
The proper yellow amber therefore, or the Borussic, from the country where it has been
most abundantly found, belongs to the plastic clay formation, intermediate, in England,
between the chalk and the London clay. It is sometimes interposed in thin plates between
the layers of the lignites, but more towards the bark of the fibrous lignites, which retain
the form of the wood, than towards the middle of the trunk of the tree; a position analogous to that of the resinous matters in our existing ligneous vegetables. The fibrous
lignites which thus contain amber belong to the dicotyledinous woods.  Hence that
substance seems to have been formed during the life of the vegetable upon which it is
now incrusted. It must be remembered that the grounds containing the amber are
often replete with the sulphates of iron, alumina, and lime, or at least with the pyritous
elements of these salts. Some specimens of amber have a surface figured with irregular
meshes, indicating a sort of shrinkage from consolidation, and consequently a matter
that was at one time fluid, viscid, or merely soft.  From  optical examination, Dr.
Brewster has concluded amber to be of vegetable origin.
The different bodies included in the amber, distinguishable from its transparence, demonstrate, indeed, in the most convincing manner, its primitive state of liquidity or softness.
These bodies have long exercised the skill of naturalists. They are generally insects,
or remains of insects, and sometimes leaves, stalks, or other portions of vegetables.
Certain families of insects occur more abundantly than others. Thus the hymenoptera,
or insects with four naked mernbranaceous wings, as the bee and wasp, and the diptera,
or insects with two wings, as gnats, flies, gadflies, &c.; then come the spider tribe;
some coleoptera (insects with crustaceous shells or elytra, which shut together, and form
a longitudinal suture down the back), or beetles, principally those which live on trees;
such as the elaterides, or leapers, and the chrysomelida. The lepidoptera, or insects withI




AMMONIA.                                      61
four membranaceous wings, and pterigostea covered with mail-like scales, are very rare
in amber. We perceive from  this enumeration, which results from  the labors of
Germar, Schweiger, &c., that the insects enveloped in this resinous matter are in
general such as sit on the trunks of trees, or live in the fissures of their bark. Hitherto,
it has not been found possible to refer them to any living species; but it has been observed in general that they resemble more the insects of hot climates than those of the
temperate zones.
The districts where amber occurs in a condition fit for mining operations are not
numerous; but those in which it is met with in small scattered bits are very abundant.
Its principal exploitation is in Eastern Prussia, on the coasts of the Baltic Sea, from
Memel to Dantzick, particularly in the neighborhood of Konigsberg, along the shore
which runs north and south from Grossdirschheim to Pillau, and in several other places
near Dantzick.
It is collected upon this coast in several ways; 1. In the beds of small streams which
run near the villages, and in rounded fragments without bark, or in the sand-banks of
rivers, in pieces thrown back by the sea, and rounded by the waves. 2. If the pieces
thrown up by the waters are not numerous, the fishers, clothed in a leather dress, wade
into the sea up to the neck, seek to discover the amber by looking along its surface, and
seize it with bag nets, hung at the end of very long poles. They conclude that a great
deal of amber has been detached from the cliffs by the sea, when many pieces of lignite
(wood coal) are seen afloat. This mode of collecting amber is not free fiom danger, and
the fishers, therefore, advance in troops, to lend each other aid in case of accident; but
their success, even thus, is most precarious. 3. The third method of searching for amber is a real mining operation: it consists in digging pits upon the borders of the sandy
downs, sometimes to a depth of more than 130 feet. 4. The last mode is by exploring
the precipitous sea cliffs in boats, and detaching masses of loose soil from them with long
poles terminating in iron hooks; a very hazardous employment. They search the cliffs
with great care at the level, where the amber nodules commonly lie, and loosen the seams
with their hooks; in which business the boats are sometimes broken against the precipices, or sunk by an avalanche of rubbish.
Amber occurs in Sicily, disseminated in beds of clay and marl, which lie below the
crag limestone. It is accompanied with bitumen; and, though a scanty deposite, it is
mined for sale.  The pieces are coated with a kind of whitish bark, present a variety
of colors, and include many insects. Amber is found in a great many places in the sandy
districts of Poland, at a very great distance from the sea, where it is mixed with cones
of the pine. In Saxony it is met with in the neighborhood of Pretsch and Wittemberg,
in a bituminous clay mingled with lignite. At the embouchure of the Jenissey, in Siberia, it occurs likewise along with lignite; as also in Greenland.
Fine amber is considerably valued for making ornamental objects, and the coarser
kinds for certain uses in chemistry, medicine, and the arts. The oriental nations prize
more highly than the people of Europe trinkets made of amber; and hence the chief
commerce of the Pomeranian article is with Turkey. The Prussian government is said
to draw an annual revenue of 17,000 dollars from  amber. A  good piece of a pound
weight fetches 50 dollars. A mass weighing 13 pounds was picked up not long since in
Prussia, for which 5000 dollars were offered, and which would bring, in the opinion of
the Armenian merchants, from 30,000 to 40,000 dollars at Constantinople. At one time
it was customary to bake the opaque pieces of amber in sand, at a gentle heat, for several hours, in order to make it transparent, or to digest it in hot rapeseed oil, with the
same view; but how far these processes were advantageous does not appear.
When amber is to be worked into trinkets, it is first split on a leaden plate at a lathe
(see GEMS, Cutting of), and then smoothed ir:lo shape on a Swedish whetstone. It is
polished on the lathe with chalk and water, or vegetable oil, and finished by friction
with flannel. In these processes the amber is apt to become highly electrical, very hot,
and even to fly into fragments. Hence, the artists work the pieces time about, so as to
keep each of them cool, and feebly excited. The men are often seized with nervous
tremors in their wrists and arms from the electricity. Pieces of amber may be neatly
joined by smearing their edges with linseed oil, and pressing them strongly together,
while they are held over a charcoal fire. Solid specimens of amber, reported to have
been altogether fused by a particular application of heat, are now shown in the royal
cabinet of Dresden.
A strong and durable varnish is made by dissolving amber in drying linseed oil. For
this purpose, however, the amber must be previously heated in an iron pot, over a clear
red fire, till it soften and be semi-liquefied. The oil, previously heated, is to be now
poured in, with much stirring, in the proportion of 10 ounces to the pound of amber;
and after the incorporation is complete, and the liquid somewhat cooled, a pound of oil
of turpentine must be added. Some persons prescribe 2 ounces of melted shellac,




62                              AMYGDALINE.
though by this means they are apt to deepen the colour, already rendered too dark
by the roasting. The finest varnish is made with oil of spike.
though by this means they are apt to deepen the color, already rendered too dark by the
roasting.
The fine black varnish of the coachmakers is said to be prepared by melting 16 ounces
of amber in an iron pot, adding to it half a pint of drying linseed oil, boiling hot, of powdered resin and asphaltum 3 ounces each: when the materials are well united, by stirring over the fire, they are to be removed, and, after cooling for some time, a pint of warm
oil of turpentine is to be introduced.
The oil of amber enters into the composition of the old perfume called eau de luce;
and is convertible, by the action of a small quantity of strong nitric acid, into a viscid
mass like shoemakers' rosin, which has a strong odor of musk, and, under the name of
artificial musk, has been prescribed, in acoholic solution, as a remedy against hooping
cough, and other spasmodic diseases.
Acid of amber (succinic acid) is a delicate reagent, in chemistry, for separating red
oxyde of iron from compound metallic solutions.
AMBERGRIS. (./mbregric, Fr.;.Ambra, Germ.)-A morbid secretion of the liver
of the spermaceti whale (physeter macrocephalus), found usually swimming upon the
sea. It occurs upon the coasts of Coromandel, Japan, the Moluccas, and Madagascar,
and has sometimes been extracted from the rectum of whales in the South sea fishery.
It has a gray-white color, often with a black streak, or is marbled, yellow and black;
has a strong but rather agreeable smell, a fatty taste, is lighter than water, melts at 600
C. (140~ F.), dissolves readily in absolute alcohol, in ether, and in both fat and volatile
oils. It contains 85 of the fragrant substance called ambreine. This is extracted from
ambergris by digestion with alcohol of 0'827, filtering the solution, and leaving it to
spontaneous evaporation. It is thus obtained in the form of delicate white tufts:
which are convertible into ambreic acid by the action of nitric acid. Ambergris is used
in perfumery.
AMIANTHUS. A mineral in silky filaments, called also ASBESTUS.
AMMONIA. A chemical compound, called also volatile alkali. This substance, in its
purest state, is a highly pungent gas, possessed of all the mechanical properties of the
air, but very condensable with water. It consists of 3 volumes of hydrogen and 1 of azote
condensed ipto two volumes; and hence its density is 0-591, atmospheric air being 1'000.
By strong compression and refrigeration it may be liquefied into a fluid, whose specific
gravity is 0-76 compared to water 1'000.
Ammonia gas is composed by weight of 82*53 azote and 17'47 hydrogen in 100
parts. It is obtained by mixing muriate of ammonia, commonly called sal ammoniac,
with quicklime, in a retort or still, applying a moderate heat, and receiving the gas either
over mercury for chemical experiments, or in water to make liquid ammonia for the
purposes of medicine and the arts. Woulfe's apparatus is commonly employed for this
condensation.
Ammonia is generated in a great many operations, and especially in the decomposition
of many organic substances, by fire or fermentation. Urine left to itself for a few days is
found to contain much carbonate of ammonia, and hence this substance was at one time
collected in great quantities for the manufacture of certain salts of ammonia, and is still
used for its alkaline properties in making alum, scouring wool, &c. When woollen rags,
horns, bones, and other animal substances are decomposed in close vessels by fire, they
evolve a large quantity of ammonia, which distils over in the form of a carbonate. The
main source of ammonia now in this country, for commercial purposes, is the coal gas
works. A large quantity of watery fluid is condensed in their tar pits, which contains,
chiefly, ammonia combined with sulphureted hydrogen and carbonic acid. When this
water is saturated with muriatic acid and evaporated it yields muriate of ammonia, or
sal ammoniac, somewhat impure, which is afterwards purified by sublimation. See
CARBONATE OF AMMONIA and SAL AMMONIAC.
The soot of chimneys where coal is burned contains both sulphate and carbonate of
ammonia, and was extensively employed, at one time, to manufacture these salts.
In making water of ammonia on the great scale, a cast iron still should be preferred,
and equal weights of quicklime and sal ammoniac should be brought to the consistence
of a pap, with water, before the heat is applied. In this case a refrigeratory worm or
globe should be interposed between the adopter tube of the capital of the still and the
bottles of Woulfe's apparatus. The muriate of lime, or chloride of calcium, which is left
in the still when the whole ammonia is expelled, is of no value. Water is capable of
condensing easily about one third of its weight of ammonia gas, or 460 times its bulk.
The following table of the quantity of ammonia in 100 parts by weight of its aqueous
combinations, at successive densities, is the result of very careful experiments made by
me, and recorded in the Philosophical Magazine for March, 1821.




ANCHOR.                                       63
Table of Water of.mRmonia or Volatile Alkali, by Dr. Ure.
Water  Ammonia       Water      Specific     Mean
of       il         in        gravity by    specific        Equivalent primes.
0'900     100         100     experiment.   gravity.
100     26-500      73-500     0.9000
95     25-175      74-825      0-9045     0-90452                      Wat. Aim.
90     23-850      76-150      0'9090     0'90909         24   76        6 to 1
85     22-525      77-475      0-9133     0-91370
80     21-200      78-800      0-9177     0-91838      21-25   78-75,   7 to 1
75     19-875      80-125      0-9227     0-92308
70     18-550      81-450      0-9275     0-92780       19.1 + 80.9,    8 to 1
55     17-225      82-775      0-9320     0-93264      17-35 + 82-65,   9 to 1
60     15-900      84-100      0-9363     0-93750       15-9 + 84-1,   10 to 1
55     14-575      85-425      0-9410     0-94241      14-66 + 85-34,  11 to 1
50     13-250      86-750      0-9455     0-94737      13-60 - 86-40,  12 to 1
45     11-925      88-075      0.9510     0-95238       11-9 + 88-1,   14 to 1
40     10-600      89-400      0-9564     0-95744       11-2 + 88-8,    15 to 1
35      9-275      90-725      0-9614     0-96256
30      7-950      92-050      0-9662     0-96774       8-63 - 91-37,  20 to 1
25      6-625      93-375      0-9716     0-97297          7 + 93,      25 to 1
20      5-300      94-700      0-9768     0-97826          6 -- 94,     30 to 1
15      3-975     96-025      0-9828    0-98360         45 955,   40 to 1
10      2-650     97-350      0-9887      0.98900         3 t 97,      60 to 1
5      1-325     98-675      0.9945      0-99447 
AMMONIAC, gum-resin. This is the inspissated juice of an umbelliferous plant
(the dorema armeniacum) which grows in Persia.  It comes to us either in small
white tears clustered together, or in brownish lumps, containing many impurities. It
possesses a peculiar smell, somewhat like that of asafcetida, and a bitterish taste. It
is employed in medicine. Its only use in the arts is for forming a cement to join
broken pieces of china and glass, which may be prepared as follows: Take isinglass
1 ounce, distilled water 6 ounces, boil together down to 3 ounces, and add 1' ounce of
strong spirit of wine; boil this mixture for a minute or two; strain it; add, while
hot, first, half an ounce of a milky emulsion of gum ammoniac, and then five drams of
an alcoholic solution of resin mastic. This resembles a substance sold in the London
shops, under the name of diamond cement. The recipe was given me by a respectable
dispensing chemist.
AMORPHOUS.  Without shape. Said of mineral and other substances which occur
in forms not easy to be defined.
AMYGDALINE is a principle of bitter almonds and of bay-laurel berries.  It is
obtained by digesting, in a retort, alcohol of 0-825 at its boiling temperature upon
the meal of bitter almonds, then distilling off the alcohol by the heat of a water-bath
till the residuum assumes the consistence of syrup. To the residuum, diluted with a
little water, some yeast is to be added, and the mixture is to be set aside in a warm
place for some time to ferment. Whenever the fermentation is over, the liquor is to
be filtered and evaporated on the water-bath to a syrupy consistence.  On mixing
this syrup with alcohol of 0-825, the amygdaline falls in a white crystalline powder,
which, after being squeezed between folds of filtering-paper, is to be finally purified,
by repeated crystallizations, with alcohol. Its crystals are silky-looking scales, or
short needles, without smell, but with a slight taste of bitter almonds. When heated,
they exhale the fragrance of hawthorn flowers, and burn into a bulky charcoal. Cold
alcohol hardly dissolves them, but boiling alcohol pretty copiously. They are very
soluble in water, and produce therefrom, by evaporation and cooling, large transparent
prisms, of a silky aspect, which contain 6 atoms, or 10-57 per cent. of water. Their
composition in the dry state is as follows:
40 atoms of carbon       --    52-98 in 100 parts.
27    -    hydrogen    -        -      -       -     5'84
1    -    azote         -      -      -       -     306    -
22    -    oxygen        -      -      -       -    38-12 
1 atom amygdaline (Liebig)    -       -       -   100'00
The purpose of the fermentation above prescribed is to decompose a portion ofsugar,




64                                 ANCHOR.
extracted by the alcohol from the bitter almonds along with the amygdaline, of which
latter they afford from 3 to 4 per cent.
Almonds, both bitter and sweet, contain also another curious principle, called emulsine
by Liebig, and synaptase by Robiquet. It is soluble in water, but is precipitated from it
in flakes by alcohol. It coagulates at the temperature of about 140~ Fahr. like white
of egg. On mixing a solution of 10 parts of amygdaline in 100 parts of water,
with 1 part of synaptase in 10 parts of water, a peculiar decomposition immediately
takes place. The mixture becomes opaline without losing its transparency; it assumes
the odor of bitter almonds, and yields, on distillation, hydrocyanic (prussic) acid, and
the hydrure of benzoil (pure essence of bitter almonds), mixed with vapor of water.
Coagulated synaptase has no perceptible action on amygdaline. These facts explain
a series of puzzling phenomena, which have been long known. Fresh bitter almonds
contain emulsine (synaptase), amygdaline, and an unctuous oil, all in such a state that
the first two cannot react upon each other; and by removing the water by desiccation
their mutual action becomes impossible. On squeezing the almonds the oil is drawn
off, and on treating the cake with boiling alcohol the amygdaline is dissolved out, and
the synaptase is coagulated; but on moistening the bitter almonds with water the
reaction of the two principles becomes instantly effective, as shown by the production
of the smell and taste of hydrocyanic acid and of the essential oil. By throwing the
bitter almond meal into boiling water the synaptase immediately coagulates, and the
above mutual reaction can no longer be obtained, nor the above volatile products.
In order properly to prepare the essence of bitter almonds it is therefore necessary
to mix 1 part of bitter almond meal with 20 parts of lukewarm water, to leave the
mixture to digest for 24 hours, and only then to submit it to distillation. 100 parts
of amygdaline produce 47 parts of the crude essence of bitter almonds, which contain
5-9 parts of hydrocyanic acid.
AMYLOXIDE-HYDRATE. See FUSEL OIL.
ANALYSIS. The art of resolving a compound substance or machine into its constituent parts. Every manufacturer should so study this art, in the proper treatises,
and schools of chemistry or mechanics, as to enable him properly to understand and
regulate his business.
ANCHOR.  (Ancre, Fr.; Anker, Germ.) An iron hook of considerable weight
and strength, for enabling a ship to lay hold of the ground, and fix itself in a certain
situation by means of a rope called the cable. It is an instrument of the greatest importance to the navigator, since upon its taking and keeping hold depends his safety
upon many occasions, especially near a lee shore, where he might be otherwise
stranded or shipwrecked. Anchors are generally made of wrought iron, except among
nations who cannot work this metal well, and who therefore use copper. The mode
in which an anchor operates will be understood from inspection of fig. 12, where from
the direction the strain, it is obvious that the anchor cannot move without ploughing up the ground in which its hook or fluke is sunk. When this, however, unluckily
takes place, from the nature of the ground, from the mode of insertion of the anchor, or
from the violence of the winds or currents, it is called dragging the anchor. When
the hold is good, the cable or the buried arm will soofter break than the ship will
drive. Anchors are of different sizes, and have different names, according to the purposes they serve; thus there are sheet, best bower, small bower, spare, stream, and Hedge
anchors. Ships of the first class have seven anchors, and smaller vessels, such as
brigs and schooners, three.
12




ANCHOR.                                    65
The manufacture of anchors requires great knowledge
lff lof the structure of iron, and skill in the art of working
C )  tit. I shall give, here, a brief notice of the improved system
13                      introduced by Mr. Perring, clerk of the cheque at Plymouth, in which the proportions of the parts are admirably
adapted to the strains they are likely to suffer. In fig. 13
A is the shank; B, the arm or fluke; c, the palm; D, the
A                 blade; E, the square; F, the nut; G, the ring; H,the crown.
Formerly the shank was made of a number of square
iron rods, laid parallel together in a cylindrical form, and
bound by iron hoops. When they were welded into one
bar, the exterior rods could not fail to be partially burned
and wasted by the strong heat. Mr. Perring abated this
I  /y     evil by using bars of the whole breadth of the shank, and
^Do^^ Am^l'placing them right over each other, hooping them  and
welding them together at two heats into one solid mass.
To any one who has seen the working of puddled iron, with
a heavy mill hammer, this operation will not appear difficult.
He formed the crown with bars similarly distributed with those of the shank. His
mode of uniting the flukes to the crown is probably the most valuable part of his
invention. The bars and half the breadth of the anchor are first welded separately, and
then placed side by side, where the upper half is worked into one mass, while the lower
part is left disunited, but has carrier iron bars, or porters, as these prolongation rods
are commonly called, welded to the extremity of each portion. The lower part is now
heated and placed in the clamping machine, which is merely an iron plate firmly bolted
to a mass of timber, and bearing upon its surface four iron pins. One end of the crown
is placed between the first of these pins, and passed under an iron strap; the other end
is brought between the other pins, and is bent by the leverage power of the elongated
rods or porters.
Thus a part of the arm being formed out of the crown gives much greater security
that a true union of fibres is effected, than when the junction was made merely by a short
scarf.
The angular opening upon the side opposite B H, fig. 13, is filled with the chock,
formed of short iron bars placed upright. When this has been firmly welded, the trusspiece is brought over it. This piece is made of plates similar to the above, except that
their edges are here horizontal. The truss-piece is half the breadth of the arm; so that
when united to the crown, it constitutes, with the other parts, the total breadth of the
arms at those places.
The shank is now shut upon the crown; the square is formed, and the nuts welded to
it; the hole is punched out for the ring, and the shank is then fashioned.
The blade is made much in the way above described. In making the palm, an iron
rod is first bent into the approximate form, notching it so that it may more readily take
the desired shape. To one end a porter rod is fastened, by which the palm is carried
and turned round in the fire during the progress of the fabrication. Iron plates are next
laid side by side upon the rod, and the joint at the middle is broken by another plate
laid over it. When the mass is worked, its under side is filled up by similar plates, and
the whole is completely welded; pieces being added to the sides, if necessary, to form the
angles of the palm. The blade is then shut on to the palm, after which the part of the
arm attached to the blade is united to that which constitutes the crown. The smith-work
of the anchor is now finished.
The junction, or shutting on, as the workmen call it, of the several members of an
anchor, is effected by an instrument called a monkey, which is merely a mass of iron
raised to a certain height, between parallel uprights, as in the pile engine or vertical
ram, and let fall upon the metal previously brought to a welding heat.
The monkey and the hercules, both silly, trivial names, are similar instruments, and are
usually worked, like a portable pile engine, by the hands of several laborers, pulling
separate ropes. Many other modes of manufacturing anchors have been devised, in
which mechanical power is more extensively resorted to.
The upper end of the shank F (fig. 13)is squared to receive and hold the stock steadily, and keep it from turning. To prevent it shifting along, there are two knobs or
tenon-like projections. The point of the angle H, between the arms and the shank, is
sometimes called the throat. The arm B C generally makes an angle of 56~ with the
shank A; it is either round or polygonal, and about half the length of the shank.
The stock of the anchor (fig. 12)is made of oak. It consists of two beams which em.
brace the square, and are firmly united by iron bolts and hoops, as shown in the figure.
The stock is usually somewhat longer than the shank, has in the middle a thickness
about one twelfth of its length, but tapers at its under side to nearly one half this thick



66                                ANCHOR.
ness at the extremities. In small anchors the stock is frequently made of iron; but in
this case it does not embrace the anchor, but goes through a hole made in the square,
which is swelled out on purpose.
The weight of anchors for different vessels is proportioned to the tonnage; a good rule
being to make the anchor in hundred weights one twentieth of the number of tons of the
burden. Thus a ship of 1000 tons would require a sheet anchor of 50 cwts. Ships of
war are provided with somewhat heavier anchors.
Several new forms and constructions of anchors were proposed under Mr. Piper's patent of November, 1822, by the adoption of which great advantages as to strength were
anticipated over every other form or construction previously made.
The particular object was to preserve such a disposition of the fibres of the metal as
should afford the greatest possible strength; in doing which the crossing or bending of
the fibres at the junctions of the shank, flukes, and crown, where great strength is required, has been avoided as much as possible, so that the fibres are not disturbed or
injured.
In this respect most anchors are defective; for in connecting the shanks to the crownpieces, the grain of the metal is either crossed, or so much curved, as to strain the fibre,
and consequently induce a weakness where the greatest strength is required. And, further, the very considerable thicknesses of metal which are to be brought into immediate
contact by means of the hammer in forging anchors upon the old construction, render it
highly probable that faulty places may be left within the mass, though they be externally
imperceptible. Mr. Piper's leading principle was, that the fibre of the metal should run
nearly straight in all the parts where strength is particularly required.
[]i            / 14/Fig. 15 shows an anchor with one tumbling fluke, which
14                                                        n
14 X            passes through the forked or branched part of the shank. The
V17    lower part of this anchor, answering to the crown, has a spinJ'      ^      rTdie through it, upon which the fluke turns, and a pin is there
introduced for the purpose of confining the fluke when in a
holding position. This shank is formed of a solid piece of
l A\\  \    wrought iron, the fibres of which run straight, and at the
crown holes are pierced, which merely bulge the metal without
bending the fibres round so as to strain them. The arm and
fluke, also, are formed of one piece punched through without
curling or crossing the fibre, and the spindle which holds the
arm to the crown is likewise straight. This spindle extends some distance on each side
of the anchor, and is intended to answer the purpose of a stock; for when either of the
ends of the spindle comes in contact with the ground, the anchor will be thrown over
into a holding position; or an iron stock may be introduced near the shackle, instead of
these projecting ends. In the descent of the anchor, the fluke will fall over towards
that side which is nearest the ground, and will there be ready to take hold when the
anchor is drawn forward.
6   _l        ^*s Fig. 15 is another anchor upon the same principle, but
6l i  I ~    slightly varied in form from the last. In this the forked part
of the shank is closer than in the former, and there are two
arms or flukes connected to the crown-pieces, one of which falls
into its holding position as the anchor comes to the ground,
and is held at its proper angle by the other fluke stopping
against the shank.
Fig. 16 represents another variation in the form of these
niproved anchors, having two tumbling flukes, which are both
intended to take hold of the ground at the same time. The
shank is here, as before, made without crossing the grain of the iron, and the eyes for
admitting the bolt at the crown and at the shackle are punched out of the solid, not
formed by welding or turning the iron round. In this form a guard is introduced at
the crown, to answer the purpose of a stock, by turning the flukes over into a holding
position. The arms and flukes are made, as before described, of the straight fibre of
ihe iron punched through, and the flukes are fixed to the spindle, which passes through
the crown-piece.
Fig. 17 has a shank without any fork, but formed straight throughout; the guard
here is an elongated frame of iron, for the same purpose as a stock, and is, with the
tumbling flukes, fastened to the spindle, which passes through the crown of the anchor,
and causes the flukes to fall into their holding position.
The principles of these new anchors are considered to consist in shanks which are
made of straight lengths of metal, and finished so that the fibres of the iron shall not be
injured by cross-shuts or uncertain welding; also each arm and palm is made in one
solid piece, and finished in straight lines, so that the fibres will not be altered, and the
shaft-pin or spindle will also be in one straight line; and this is the improvement
claimed. These anchors, being made in separate pieces, give a great advantage to the




ANCHOR.                                     67
workman to execute each part perfectly; for he will not have such heavy weights to lift
when hot, which will render these anchors much stronger, with less weight; and if any
accident should happen to them, any part may be taken separate from the others to be
repaired, and several of those parts of the anchor which may be likely to break may be
carried on board, in case of accident. This anchor is so contrived that one of thirty
hundred weight may be taken to pieces and put together again, by one man, in twenty
minutes; it may also be dismounted, and stowed in any part of the ship, in as little room
as straight bars of iron, and speedily put together again.
The anchor (fig. 18) patented by Mr. Brunton, in February,
18                of r1822, has its stock introduced at the crown p     f  he part, for the purpose
of turning it over into a holding position. The shank is perforated through the solid, in two places, with elliptical apertures, for
the purpose of giving it a greater stability, and more effectually
>3f l^     resisting the strain to which the anchor may be subjected. The
I,^/^\^^    ~stock is a cylindrical iron rod, held at its extremities by lateral
braces, which are bolted to the shank.
Fig. 18 shows the form of the anchor. The shank is seen
upright, with one of the flukes projecting in its front; the horizontal iron stock is at
bottom; and the oblique braces are bolted to both shank and stock. The ends of the
stock, from the shoulder, are formed dove-tailed, and oval in the vertical direction, and
are protruded through apertures in the braces, also oval, but in the horizontal direction,
and counter sunk. When the ends of the
20              stock have been thus introduced through the
holes, the braces are securely bolted to the
rYXnJ   _n~I l         shank, the ends of the stock are then spread,
__I-l~1~ ~     by hammering into the counter-sunk holes
of the braces, and by that means they are
19 1 1  made firm.
An anchor of this description is consider_   y            4 / 2   ed by the patentee to possess considerable
1L        ='' -      l.  advantage, particularly in point of stability,
^-~.  i. i| II over the ordinary construction of anchors,
lj.  I     2111   ^and is economical, inasmuch as a less weight
h-^-  no      2    3  _..of metal will give, upon this plan, an equal
~(oi 23       //        1degree of strength.
V. X  i    r    I J An ingenious form of anchor was made
_       v  7V^   ^the subject of a patent, by Lieutenant Rodg1 a ^  ers, of the Royal Navy, in 1828, and was
i.      I ~                afterwards modified by him in a second paa h,=,22               tent, obtained in August, 1829. The whole,i.=;~ i'IIof the parts of the anchor are to be bound
- together by means of iron bands or hoops,
J.^ a gin place of bolts or pins.
&      ^J LL      ^  anchor, formed  upon  his last improved
^ ^~ij=^   ~construction, and fig. 20, a plan of the
same; fig. 21, an end view of the crown
and flukes, or arms; fig. 22 represents
the two principal iron plates, a, a, of
which the shank is constructed, but so as to form parts of the stump arms to which the
flukes are to be connected.
The crown piece is to be welded to the stump piece, c, c, fig. 22, as well as to the
end I of the centre piece h h, and the scarfs m m are to be cut to receive the arms or
flukes. Previously, however, to uniting the arms or flukes with the stump arms, the
crown and throat of the anchor are to be strengthened, by the application of the crown
slabs n n,fig. 22, which are to be welded upon each side of the crown, overlapping the
end of the pillar h, and the throat or knees of the stump arms and the crown piece. The
stump arms are then to be strengthened in a similar manner, by the thin flat pieces p p,
which are to be welded upon each side. The palms are united to the flukes in the
usual way, and the flukes are also united to the stump arms by means of the long scarfs
m m. When the shank of the anchor has been thus formed, and united with the flukes,
the anchor smith's work may be said to be complete.
Another of the improvements in the construction of anchors, claimed under this
patent, consists in a new method of affixing the stock upon the shank of the anchor,
which is effected in the following manner: in fig. 20, the stock is shown affixed to the
anchor; infig. 23 it is shown detached. It may be made either of one or two pieces




68                              ANNEALING.
of timber, as may be found most convenient. It is, however, to be observed, that the
stock is to be completed before fitting on to the shank. After the stock is shaped, a
hole is to be made through the middle of it, to fit that part of the shank to which it is
to be affixed. Two stock plates are then to be let in, one on each side of the stock,
and made fast by counter sunk nails and straps, or hoops; other straps or hoops of
ironare also to be placed round the stock, as usual.
In place of nuts, formed upon the shank of the anchor, it is proposed to secure the
stock by means of a hoop and a key, shown above and below J, infig. 20. By this
contrivance, the stock is prevented from going nearer to the crown of the anchor than
it ought to do, and the key prevents it from sliding towards the shackle.
Since fitting the stock to the shank of an anchor, by this method, prevents the use
of a ring, as in the ordinary manner, the patentee says that he in all cases substitutes
a shackle for the ring, and which is all that is required for a chain cable; but, when
a hempen cable is to be used, he connects a ring to the usual shackle, by means of a
joining shackle, as infigs. 19 and 20.
Mr. Rodgers proposes under another patent, dated July, 1833, to alter the size and
form of the palms; having found from experience that anchors with small palms will
not only hold better than with large ones, but that the arms of the anchor, even without any palms, have been found to take more secure hold of the ground than anchors
of the old construction, of similar weight and length. He has, accordingly, fixed
upon one-fifth of the length of the arm, as a suitable proportion for the length or
depth of the palm. He makes the palms, also, broader than they are long or deep.
ANILINE. An organic compound, which may be procured in several ways:  1,
when isatine (see INDIGO) is fused with solid hydrate of potash; 2, when to an
alcoholic solution of benzine a little zinc and muriatic acid is added: but it is obtained
best from coal tar, which is to be distilled in a large iron retort, and the successive
products to be separately received, especially the latter and denser ones. This heavy
tar-oil is to be strongly agitated along with muriatic acid in a glass globe. The acid
solution contains the aniline, which, being of an alkaline nature, is called a volatile
base.  It must be subjected to an operose process of purification, with milk of lime,
&c., too complex to be detailed here, as no useful application of it in the arts has
hitherto been made. Dr. Ilofmann has written many elaborate papers upon aniline,
and its saline combinations.
ANIM].  A resin of a pale brown yellow color, transparent and brittle.  It
exudes fiom the courbaril of Cayenne, a tree which grows also in various parts of
South America. It occurs in pieces of various sizes, and it often contains so many
insects belonging to living species, as to have merited its name, as being animated.
It contains about a fifth of one per cent. of a volatile oil, which gives it an agreeable
odor. Alcohol does not dissolve the genuine anim6, as I have ascertained by careful experiments; nor does caoutchoucine, but a mixture of the two, in equal parts,
softens it into a tremulous jelly, though it will not produce a liquid solution. When
reduced to this state, the insects can be easily picked out, without injury to their
most delicate parts.
The specific gravity of the different specimens of anime which I tried varied from
1 054 to 1'057. When exposed to heat, in a glass retort over a spirit flame, it softens,
and, by careful management, it may be brought into liquid fusion, without discolouration.  It then exhales a few white vapors, of an ambrosiacal odor, which being
condensed in water, and the liquid being tested, is found to be succinic acid.
Author.
It is extensively used by the varnish-makers, who fuse it at a pretty high heat, and
in this state combine it with their oils or other varnishes.
ANKER. A liquid measure of Amsterdam, which contains 32 gallons English.
ANNEALING  or NEALING. (Le recuit, Fr.; das anlassen, Germ.) A process
by which glass is rendered less frangible; and metals, which have become brittle,
either in consequence of fusion or long-continued hammering, are again rendered
malleable. When a glass vessel is allowed to cool immediately after being made,
it will often sustain the shock of a pistol-bullet, or any other blunt body falling
into it from a considerable height; while a small splinter of flint, or an angular
fragment of quartz, dropped gently into it, makes it sometimes immediately, sometimes after a few minutes, fly to pieces with great violence. This extreme fragility
is prevented by annealing, or placing the vessels in an oven where they take
several hours or even some days to cool. Similar phenomena are exhibited in a
higher degree by glass-tears, or Prince Rupert's drops. They are procured by letting
drops of melted glass fall into cold water. Their form resembles that of a pear,
rounded at one extremity, and tapering to a very slender tail at the other. If a
part of the tail be broken off, the whole drop flies to pieces with a loud explosion;
and yet the tail of a drop may be cut away by a glass-cutter's wheel, or the thick end




ANNOTTO.                                     69
may be struck smartly with a hammer, without the fear of sustaining any injury. When
heated to redness, and permitted to cool gradually in the open air, they lose these peculiarities, and do not differ sensibly from common glass.
The properties of unannealed glass depend on a peculiar structure, extending uniformly through its whole substance; and the bursting of a glass drop by breaking off
the tail, or of an unannealed. glass vessel, by dropping a piece of flint into it, arises from
a crack being thus beoun, which afterwards extends its ramifications in different directions throughout the glass.
When metals have been extended to a certain degree under the hammer, they become
brittle, and incapable of being further extended without cracking. In this case the
workman restores their malleability by annealing, or heating them  red-hot. The
rationale of this process seems to be, that the hammering and extension of the metal
destroy the kind of arrangement which the particles of the metal had previous to the hammering; and that the annealing, by softening the metal, enables it to recover its original
structure.
Of late years a mode has been discovered of rendering cast iron malleable, without
subjecting it to the action of puddling. The process is somewhat similar to that employed in annealing glass. The metal is kept for several hours at a temperature a little
below its fusing point, and then allowed to cool slowly. In this manner vessels are
made of cast iron which can sustain considerable violence, without being broken. See
STEEL, softening of.
ANNOTTO. (Rocou, or roucou, Fr.; orleans, Germ.) A somewhat dry and hard paste,
brown without, and red within. It is usually imported in cakes of two or three pounds
weight, wrapped up in leaves of large reeds, packed in casks, from America, where it is
prepared from the seeds of a certain tree, the bixa orellana, of Linnaeus.
The pods of the tree being gathered, their seeds are taken out and bruised; they are
then transferred to a vat, which is called the steeper, where they are mixed with as much
water as covers them. Here the substance is left for several weeks, or even months;
it is now squeezed through sieves placed above the steeper, that the water containing
the coloring matter in suspension may return into the vat. The residuum is preserved
under the leaves of the anana (pine-apple) tree, till it becomes hot by fermentation. It
is again subjected to the same operation, and this treatment is continued till no more
color remains.
The substance thus extracted is passed through sieves, in order to separate the
remainder of the seeds, and the color is allowed to subside. The precipitate is boiled
in coppers till it be reduced to a consistent paste; it is then suffered to cool, and dried ir.
the shade.
Instead of this long and painful labor, which occasions diseases by the putrefaction induced, and which affords a spoiled product, Leblond proposes simply to wash the seeds ot
annotto till they be entirely deprived of their color, which lies wholly on their surface;
to precipitate the color by means of vinegar or lemon juice, and to boil it up in the ordinary manner, or to drain it in bags, as is practised with indigo.
The experiments which Vauquelin made on the seeds of annotto imported by Leblond,
confirmed the efficacy of the process which he proposed; and the dyers ascertained that
the annotto obtained in this manner was worth at least four times more than that of commerce; that, moreover, it was more easily employed; that it required less solvent; that
it gave less trouble in the copper, and furnished a purer color.
Annotto dissolves better and more readily in alcohol than in water, when it is introduced into the yellow varnishes for communicating an orange tint.
The decoction of annotto in water has a strong peculiar odor, and a disagreeable
taste. Its color is yellowish-red, and it remains a little turbid. An alkaline solution
renders its orange-yellow clearer and more agreeable, while a small quantity of a whitish
substance is separated from it, which remains suspended in the liquid. If annotto be
boiled in water along with an alkali, it dissolves much better than when alone, and the
liquid has an orange hue.
The acids form with this liquor an orange-colored precipitate, soluble in alkalies,
which communicate to it a deep orange color. The supernatant liquor retains only a
pale yellow hue.
When annotto is used as a dye, it is always mixed with alkali, which facilitates its
solution, and gives it a color inclining less to red. The annotto is cut in pieces, and
boiled for some instants in a copper with its own weight of crude pearl ashes, provided
the shade wanted do not require less alkali. The cloths may be thereafter dyed in this
bath, either by these ingredients alone, or by adding others to modify the color; but annotto is seldom used for woollen, because the colors which it gives are too fugitive, and
may be obtained by more permanent dyes. Hellot employed it to dye a stuff, prepared
with alum and tartar; but the color acquired had little permanence. It is almost solely
used for silks.




70                             ANTHRACITE.
For silks intended to become aurora and orange, it is sufficient to scour them at the
rate of 20 per cent. of soap. When they have been well cleansed, they are immersed
in a bath prepared with water, to which is added a quantity of alkaline solution of annotto, more or less considerable according to the shade that may be wanted. This bath
should have a mean temperature, between that of tepid and boiling water.
When the silk has become uniform, one of the hanks is taken out, washed, and wrung,
to see if the color be sufficiently full; if it be not so, more solution of annotto is added,
and the silk is turned again round the sticks: the solution keeps without alteration.
When the desired shade is obtained, nothing remains but to wash the silk, and give it
two beetlings at the river, in order to free it from the redundant annotto, which would
injure the lustre of the color.
When raw silks are to be dyed, those naturally white are chosen, and dyed in the annotto bath, which should not be more than tepid, or even cold, in order that the alkali
may not attack the gum of the silk, and deprive it of the elasticity which it is desirable
for it to preserve.
What has been now said regards the silks to which the aurora shades are to to be given;
but to make an orange hue, which contains more red than the aurora, it is requisite,
after dyeing with annotto, to redden the silks with vinegar, alum, or lemon juice. The
acid, by saturatino the alkali employed for dissolving the annotto, destroys the shade of
yellow that the alkali had given, and restores it to its natural color, which inclines a
good deal to red.
For the deep shades, the practice at Paris, as Macquer informs us, is to pass the silks
through alum; and if the color be not red enough, they are passed through a faint bath
of brazil wood. At Lyons, the dyers who use carthamus, sometimes employ old baths
of this ingredient for dipping the deep oranges.
When the orange hues have been reddened by alum, they must be washed at the river;
but it is not necessary to beetle them, unless the color turns out too red.
Shades may be obtained also by a single operation, which retain a reddish tint, employing for the annotto bath a less proportion of alkali than has been pointed out.
Guhliche recommends to avoid heat in the preparation of annotto. He directs it to be
placed in a glass vessel, or in a glazed earthen one; to cover it with a solution of pure
alkali; to leave the mixture at rest for 24 hours; to decant the liquor, filter it, and add
water repeatedly to the residuum, leaving the mixture each time at rest for two or three
days, till the water is no longer colored; to mix all these liquors, and preserve the whole
for use in a well-stopped vessel.
He macerates the silk for 12 hours in a solution of alum, at the rate of an eighth of
this salt for one part of silk, or in a water rendered acidulous by the aceto-citric acid
above described; and he wrings it well on its coming out of this bath.
Silk thus prepared is put into the annotto bath quite cold. It is kept in agitation
there till it has taken the shade sought for; or the liquor may be maintained at a heat
far below ebullition. On being taken out of the bath, the silk is to be washed and dried
in the shade.
For lighter hues, a liquor less charged with color is taken; and a little of the acid
liquid which has served for the mordant may be added, or the dyed silk may be passed
through the acidulous water.
We have seen the following preparation employed for cotton velvet:-one part of
quicklime, one of potash, two of soda.
Of these a ley is formed, in which one part of annotto is dissolved; and the mixture
is boiled for an hour and a half. This bath affords the liveliest and most brilliant auroras.  The buff (chamois) fugitive dye is also obtained with this solution. For this purpose only a little is wanted; but we must never forget, that the colors arising from annotto are all fugitive.
Dr. John found in the pulp surrounding the unfermented fresh seeds, which are about
the size of little peas, 28 parts of coloring resinous matter, 26'5 of vegetable gluten, 20
of ligneous fibre, 20 of coloring extractive matter, 4 formed of matters analogous to vege.
table gluten and extractive, and a trace of spicy and acid matters.
The Gloucestershire cheese is colored with annotto, in the proportion of one cwt. to
an ounce of the dye.
When used in calico-printing, it is usually mixed with potash or ammonia and starch.
It is an appropriate substance for tinging varnishes, oils, spirits, &c.
The following statement gives an account of the quantities imported and exported
with the nett revenue, during the following years:1841.    1842.    1843.    1844.
Quantities imported...     wt.  -        2319    3271    3494
Quantities exported...       cwt.            513      229      307
Retained for consumption...    cwt.  -          3197    3347    2689
Nett Revenue....    154                          185     175      144




ANTIMONY.                                     71
ANTHRACITE, from avapar, coal, is a species of coal found in the transition rcQk
formation, and is often called stone coal.  It has a grayish black, or iron black color,
an imperfectly metallic lustre, conchoidal fracture, and a specific gravity of from 1-4 to
1-6, being, therefore, much denser than the coal of the proper coal measures. It consists wholly of carbon, with a small and variable proportion of iron, silica, and alumina.
It is difficult to kindle in separate masses, and burns when in heaps or grates without
smell or smoke, leaving sometimes an earthy residuum. It has been little explored
or worked in the old world; but is extensively used in the United States of America,
and has become of late years a most valuable mineral to that country, where it is burned
in peculiar grates, adapted to its difficult combustion. In Pensylvania, the anthracite
coal formation has been traced through a tract many miles in width, and extending
across the two entire counties of Luzerne and SchuylkilL. At Mauch Chunk, upon
the Lehigh, 800 men were employed so far back as 1825, in digging this coal. In that
year 150,000 bushels were dispatched for Philadelphia.  It is worked there with little
cost or labor, being situated on hills from 300 to 600 feet above the level of the neighboring rivers and canals, and existing in nearly horizontal beds, of from 1 5 to 40 feet in thickness, covered by only a few feet of gravelly loam. At Portsmouth, in Rhode Island,
an extensive stratum of this coal has been worked, with some interruptions, for 20
years; and more recently a mine of anthracite has been opened at Worcester, in Massachusetts, at the head of the Blackstone canal. It has been of late employed in South
Wales for smelting iron, and in a cupola blast furnace.
ANTIGUGGLER.  A small syphon of metal, which is inserted into the mouths of
casks, or large bottles, called carboys, to admit air over the liquor contained in them,
and thus to facilitate their being emptied without agitation or a guggling noise.
ANTIMONY. (Antimoine, Fr.; Spiessglanz, or Spiessglass, Ger.) The only ore of this
metal found in sufficient abundance to be smelted is the sulphuret, formorly called crude
antimony. It occurs generally in masses, consisting of needles closely aggregated, of a
metallic lustre; a lead-gray color, inclining to steel-gray, which is unchanged in the
streak. The needles are extremely brittle, and melt even in the flame of a candle, with
the exhalation of a sulphureous smell. The powder of this sulphuret is very black, and
was employed by women in ancient times to stain their eyebrows and eyelids. This ore
consists in 100 parts of 12-86 metal, and 27'14 sulphur. Specific gravity from 4.13 to 4-6.
The veins of sulphuret of antimony occur associated with gangues of quartz, sulphate
of barytes, and carbonate of lime; those of Allemont occur in the numerous fissures of
a mica schist, evidently primitive. Of late years very productive mines of antimony
have been found in Borneo, which have furnished great importations to this country.
In treating the oar to obtain the metal, the first object is to separate the gangue,
which was formerly done by filling crucibles with the mixed materials, placing them
on the hearth of an oven, and exposing them to a moderate heat. As the sulphuret
easily melts, it ran out through a hole in the bottom of the crucible into a pot placed
beneath, and out of the reach of the fire. But the great loss from breakage of the
crucibles has caused another method to be adopted.  In this the broken ore, being
sorted, is laid on the bottom of a concave reverberatory hearth, wherere it is reduced.
Figs. 24, 25, represent a wind or flame furnace, for the reduction of antimony. The
~.i  25.      hearth is formed ofsand and
24                                                    clay solidly beat together,
and slopes from all sides towards the middle, where it
____ __.  -  ~Iul-iis connected with the orifice
"S~  ~....g    a,which is closedwith dense
coal-ashes; b is the air channel up through the bridge;
c, the door for introducing
the prepared ore, and running off the slags; d, the bridge; e, the grate; f, the fire or fueldoor; g, the chimney. With 2 or 3 cwt. of ore, the smelting process is completed in from
8 to 10 hours. The metal thus obtained is not pure enough, but must be fused under coal
dust, in portions of 20 or 30 pounds, in crucibles placed upon a reverberatory hearth.
To obtain antimony free from iron, it should be fused with some antimonic oxide
in a crucible, whereby the iron is oxidized and separated. The presence of arsenic in
antimony is detected by the garlic smell, emitted by such an alloy when heated at the
blow-pipe; or, better, by igniting it with nitre in a crucible; in which case insoluble
antimonite and antimoniate of potash will be formed along with soluble arseniate.
Water digested upon the mixture, filtered, and then tested with nitrate of silver, will
afford the brown-red precipitate characteristic of arsenic acid.
According to Berthier, the following materials afford, in smelting, an excellent product of antimony: 100 parts of sulphuret; 60 of hammerschlag (protoxide of iron from
the shingling or rolling mills); 45 to 50 of carbonate of soda; and 10 of charcoal powder. From 65 to 70 parts of metallic antimony or regulus should be obtained. Glauber




12                                  ANVIL.
salts may be used advantageously instead of soda. Another formula is 100 parts of
sulphuret of antimony; 42 of metallic iron, and 10 of dry sulphate of soda. The product thence is said to be from 60 to 64 parts of metal.
In the works where antimonial ores are smelted, by means of tartar (argol), the alkaline scoriae, which cover the metallic ingots, are not rejected as useless, for they hold
a certain quantity of antimonial oxide in combination; a property of the potash flux,
which is propitious to the purity of the metal. These scoria, consisting of sulphuret
of potassium and antimonite of potash, being treated with water, undergo a reciprocal
decomposition; the elements of the water act on those of the sulphuret, and the resulting alkaline hydro-sulphuret re-acts on the antimonial solution, so as to form a
species of kermes mineral, which precipitates.  This is dried, and sold at a low price as
a veterinary medicine, under the name of kermes, by the dry way.
Metallic antimony, as obtained by the preceding process, is the antimony of commerce, but is not absolutely pure; containing frequently minute portions of iron, lead,
and even arsenic; the detection and separation of which belong to the sciences of chemistry and pharmacy; but considerable purity may be secured by fusing the metal,
mixed with a little of its sulphuret and some carbonate of soda, repeatedly in a crucible
From 100 parts of the impure metal in this way 94 of pure antimony are obtained.
The addition of sulphuret serves the purpose, making fluid compounds of the sulphurets of iron, arsenic, and copper, with the soda. Wihler purifies antimony completely from arsenic (not from iron and copper), by deflagrating 10 parts of the crude
ore with 12 of nitre and 15 of carbonate of soda; washes away the arsenic salt, and
then smelts the residuary antimoniate of potash with black flux. Lead can be separated only by the humid analysis.
Antimony is a brittle metal, of a silvery white color, with a tinge of blue, a lamellar
texture, and crystalline fracture.  When heated at the blow-pipe, it melts with great
readiness, and diffuses white vapors, possessing somewhat of a garlic smell. If thrown
in this melted state on a sheet of flat paper, the globule sparkles and bursts into a
multitude of small spheroids, which retain their incandescence for a long time, and
run about on the paper, leaving traces of the white oxide produced during the combustion. When this oxide is fused with borax, or other vitrefying matter, it imparts
a yellow color to it. Metallic antimony, treated with hot nitric acid in a concentrated
state, is converted into a powder, called antimonious acid, which is altogether insoluble
in the ordinary acid menstrua; a property by which the chemist can separate that metal
from lead, iron, copper, bismuth, and silver. According to Bergmann,the specific gravity
of antimony is 686; but that of the purest is 6715. The alchemists had conceived the
most brilliant hopes of this metal; the facility with which it is alloyed with gold,
since its fumes alone render this most ductile metal immediately brittle, led them to
assign to it a royal lineage, and distinguish it by the title of regulus, or the little king.
Its chief employment now is in medicine, and in making the alloys called type me4al,
stereotype metal, music plates, and Britannia metal; the first consisting of 6 of lead
and 2 of antimony; the second of 6 of lead and 1 of antimony; the third of lead, tin,
and antimony; and the fourth also of lead, tin, and antimony, with occasionally a
little copper and bismuth.-For Glass of Antimony, see PASTES.
ANTISEPTICS. Substances which counteract the spontaneous decomposition of animal and vegetable substances. These are chiefly culinary salt, nitre, spices, and sugar,
which operate partly by inducing a change in the animal or vegetable fibres, and
partly by combining with and rendering the aqueous constituent unsusceptible of decomposition. See PROVISIONS, CURING OF, and PRESERVED MEATS.
ANVIL. A mass of iron, having a smooth, and nearly flat top surface of steel;
upon which blacksmiths, and various other artificers, forge metals with the hammer.
The common anvil is usually made of seven pieces: 1, the core, or body; 2, 3, 4, 5,
the four corner pieces which serve to enlarge its base; 6, the projecting end, which
has a square hole for the reception of the tail or shank of a chisel on which iron bars
may be cut through; and 7, the beak, or horizontal cone round which rods or slips of
metal may be turned into a circular form, as in making rings. These 6 pieces are welded
separately to the first, or core, and then hammered into a uniform body. In manufacturing large anvils two hearths are needed, in order to bring each of the two pieces
to be welded to a proper heat by itself; and several men are employed in working
them together bliskly in the welding state, by heavy swing hammers. The steel facing
is applied by welding in the same manner. The anvil is then hardened by heating it
to a cherry red, and plunging it into cold water; a running stream being preferable
to a pool or cistern.  The facing should not be too thick a plate, for, when such, it is
apt to crack in the hardening. The face of the anvil is now smoothed upon a grindstone, and finally polished with emery and crocus, for all delicate purposes of art.
The blacksmith, in general, sets his anvil loosely upon a wooden block, and in preference on the root of an oak. But the cutlers and file-makers fasten their anvils to
a large block of stone; which is an advantage, for the more firmly and solidly this




ARABLE LAND.                                     73
tool is connected to the earth, the more efficacious will be the blows of the hammer
on any object placed upon it.
AQUAFORTIS.  Nitric acid, somewhat dilute, was so named by the alchemists on
account of its strong solvent and corrosive operation upon many mineral, vegetable,
and animal substances. See NITRIC ACID.
AQUA REGIA.  The name given by the alchemists to that mixture of nitric and
muriatic acids which was best fitted to dissolve gold, styled by them the king of the
metals.  It is now called nitro-muriatic acid.
AQUA VITTE.  The name very absurdly given to alcohol, when used as an intoxicating beverage. It has been the aqua mortis to myriads of the human race; and
will, probably, ere long, destroy all the native tribes of North America and Australia.
ARABLE LAND may be regarded with Thaer as consisting of one or other of the
following sorts of soils:Clay     Sand    Carb. of   Humus
No. jper                                      per      Lime      per      Value.
Cent.    Cent   per Cent.   Cent.
1  1'74       10        4        115    100
2    First class of strong wheat    81         6        4         8-4      98
3      soils  -    -         -       9        10        4         6-5      96
J                              L    40        22       36         4        90
5 Rich light sand  in natural
grass    -         -    -      14       49        10        27         3
6 Rich barley land  -    -    -   20          67        3        10        78
7 Good wheat land  -         -      58        36        2         4        77
8  Wheat land  -    -    -    -   56          30       12         2       75
9       Do.     -            -      60        38                  2       70
10       Do.    -                    48        50       e          2        65
11       Do.    -          --        68        30           2               60
12 Good barley land -    -           38        60                  2        60
13      Do. Second quality           33        65'  2                    50
14          Do.                      28'0'          2        40
15 Oat land --— 23    75                                              5   30
16    Do.                            18        80                  1        20
Below this are very poor lands.
In all these soils the depth is supposed the same, and the quality uniform  to the
depth of at least 6 inches; the subsoil sound, and neither too wet nor too dry.
Nos. 1, 2, & 3, are alluvial soils; and from the division and intimate union of the
humus, are not so heavy and stiff as the quantity of clay would indicate.
No. 4, is a rich clay loam, such as is found in many parts of England, neither too
heavy nor too loose; a soil easily kept in heart by judicious cultivation.
No. 5, is very light and rich, and best adapted for gardens and orchards, but not for
corn; hence its comparative value can scarcely be given.
Nos. 6, 7, & 8, are good soils. The quantity of carbonate of lime in No. 8 compensates for the smaller portion of humus. This land requires manure, as well as the
others below.  In those from No. 9, downwards, lime or marl would be the greatest
improvement.  Nos. 15 and 16 are poor light soils, requiring clay and much manure;
but even these lands will pay the cost of judicious cultivation, and rise in value.
The last column, of comparative value, is the result of several years' careful valuation of the returns, after labor and seed had been deducted.
Few soils in England contain more than 4 or 5 per cent. of humus, even when in a
very good heart; and 2 per cent., with a good loamy texture, will render a soil fit for
corn with judicious cultivation. The texture is of most importance, as may be seen
by comparing Nos. 7 & 8 with No. 6. If this is of good quality, dung will soon give
the proper supply of humus.
The depth of the soil and the nature of the subsoil greatly affect its value.  However rich it may be, if there is only a thin layer of good soil over a sharp gravel or a
wet clay, it can never be very productive: in the first, it will be parched in dry weather; and in the latter, converted into mud by every continued rain. If the subsoil
be loam or chalk, 6 inches of good soil will be sufficient.  With a foot of good soil, the
subsoil is of little consequence, provided it be dry, and the water can find a ready
outlet. The best alluvial soils are generally deep, the chalky shallow.
The exposure with respect to the sun, and the declivity of the ground, are very
important circumstances, and equivalent to an actual difference in the climate. A
gentle declivity towards the south, and a shelter against cold winds, may make as great
a difference as several degrees of latitude; and in comparing the value of similar lands in
different climates, the average heat and moisture in each must be accurately known. A
YoL I.




74                             ARABLE LAND.
soil very fertile in the south of Europe may be very unproductive in England; and a light
soil of some value in the west of Scotland might be absolutely barren in Italy or Spain.
2. Cultivation of the Soil. The better the soil, the less cultivation it requires to produce tolerable crops; hence, where the land is very rich, we find in general a slovenly
culture; where the ground is less productive, more labor and skill are applied to compensate for the want of natural fertility. The simplest cultivation is that of the spade,
the hoe, and the rake; and, on a small scale, it is the best: but spade husbandry cannot
be carried to a great extent without employing more hands than can be spared from other
occupations. The plough, drawn by oxen or horses, is the chief instrument of tillage, and
has been so in all ages and nations of which we have any records. Its general form is
familiar to every one, and requires no minute description. A plough should as much
as possible imitate the work done with a spade. It should cut a slice from the land
by its coulter vertically, and by the share horizontally lift it up, and turn it quite over
by means of the mould board; and the art of the ploughman consists in doing this
perfectly, and with such a depth and width as suit the soil and the intended purpose.
In rich mellow soils a ploughed field should differ little fiom a garden dug with a spade.
In tenacious soils, the slice will be continued without breaking, especially if bound by
the fibres and roots of plants; the whole surface will be turned over, and the roots
exposed to the air. It is of great consequence that each slice be of the same width,
and thickness, and the sides of it perfectly straight and parallel. The plane of the coulter must be perfectly vertical, and that of the share horizontal, in order that the bottom
of the furrow may be level, without hollows or baulks, which are irregularities produced
by the rising or sinking of the plough, or inclining it to either side. The ancients
were very particular in this respect, and recommended sounding the earth with a
sharp stake, to ascertain whether the ploughman had done his duty. There are various modes of ploughing land, either quite flat, or in lands or stitches, as they are called
in England, and in Scotland riggs; that is, in portions of greater or less width, with a
double furrow between them, somewhat like beds in a garden. Sometimes two ridges
are set up against each other, which is called ridging or bouting. The land, then, is
entirely laid in ridges and deep furrows, by which it is more exposed to the influence
of the atmosphere and kept drier. This is generally done before winter, especially in
stiff wet soils. Sometimes two or more ridges are made on each side, forming narrow
stitches.  When the ground is to be ploughed without being laid in lands or stitches,
and all the ridges inclined one way, the mould board of the plough is shifted at each
turn from one side to the other. The plough which admits of this is called a turn-wrest
plough, and is in general use in Kent and in many parts of the Continent, where the
subsoil is dry and the land not too moist. In most other situations the ground is laid
in lands, and the mould board of the plough is fixed on the right side. When grass
land or stubble is ploughed, care must be taken to bury the grass and weeds completely; and the slice cut off by the plough must be turned over entirely, which is
best done by making the width of the furrow greater than the depth.  When the
grass and weeds are rotten, and the ground is ploughed to pulverize it, a narrow deep
furrow is best. The earth ploughed up is laid against the side of the preceding ridge,
which forms a small furrow between the tops of the ridges, well adapted for the seed
to lodge in, and to be readily covered with the harrows.
Nothing has divided both practical and theoretical agriculturists more than the
question whether the land should be ploughed deep or shallow; but a very slight attention to the purposes for which land is ploughed, and to the nature of the soil, will
readily reconcile these apparently contradictory opinions. A deep, rich, and stiff soil
can never be moved too much nor too deep. Deep ploughing brings up rich earth,
admits the air and water readily, and gives room for the roots to shoot, while the rich
compact soil affords moisture and nourishment. Wherever trees are to be planted,
the ground should be stirred as deep as possible, even in a poor soil. For grass and
corn this is not always prudent; their roots seldom go above 3 or 4 inches deep; and
if they find sufficient moisture and humus, they require little more depth.
Whenever the soil below a certain depth is of an inferior quality, there can be no use
in bringing it up; and where the soil is light and porous, the bottom had much better
not be broken. Norfolk farmers know this well, and are very careful not to break the
pan, as they call it, in their light lands. This pan is formed by the pressure of the sBle
of the plough and the tread of the horses, and opposes a useful bank to the too rapid
filtration of the water. It lies from 5 to 8 inches below the surface. If it is broken,
the manure is washed down into the light subsoil, and the crop suffers, especially when
sheep have been folded,their dung being very soluble. In such soils an artificial pan may
be formed by the land-presser or press-drill. This instrument consists of two very heavy
cast-iron wheels, with angular edges, set on an axle, at a distance from each other equal
to the width of the furrows, and a lighter wheel to keep the instrument vertical.
It is drawn by a horse immediately after the plough, pressing two furrows at once,




ARABLE LAND.                                   75
and going twice over each furrow. It leaves the land in regular drills; and the seed
sown by hand falls into the bottom of the drills, and is covered by the harrows. When
the plants come up, they appear in regular parallel rows.
The great object in ploughing land is to divide it, expose every part of it to the influence of the elements, and destroy every plant or weed but those which are sown in it. To
do this perfectly requires several ploughings, with certain intervals; and during that
time no crop can be upon the land. This is the real use of fallows,and not, as was once supposed, to allow the land to rest; on the contrary, it ought then to have the least repose.
Where the soil is good, with a porous subsoil, the greatest care should be taken not
to go too deep; but where the subsoil is compact and impervious to water, but not
wet for want of outlet or draining, it is useful to stir the soil to a great depth, but
without bringing it to the surface, which may be done by a plough without a mould
board following a common plough in the same furrow. This is an excellent mode of
draining; and at the same time keeping a reservoir of moisture, which in dry weather ascends in vapors through the soil and refreshes the roots.
The mode in which the soil is prepared most perfectly for the reception of the seed
is best shown by following the usual operations on fallows. After the harvest, the
plough is set to work, and the stubble ploughed in. The winter's frost and snow mellow it, while the stubble and weeds rot below. In spring, as soon as the weather
permits, it is ploughed again, the first ridges being turned over as they were before.
This completes the decomposition of the roots and weeds. It is then stirred with
harrows or other instruments, which tear up the roots which remained; and some of
these not being easily destroyed, are carefully gathered and burnt, or put in a heap
to ferment and rot, a portion of quicklime being added. Another ploughing and stirring follows, at some interval, till the whole ground is mellow, pulverized, and free
from weeds; manure is put on if required, and immediately spread and ploughed in;
the land is then prepared for the seed.
There is no method yet found out of ascertaining the comparative state of land
which has been exhausted. It would be a discovery well worth the attention of modern chemists, who have made such progress lately in the analysis of vegetable substances, and would be invaluable to farmers and proprietors of land. In the meantime the nature of the weeds which abound on the land will give some clue to its state;
and an experienced person will collect from various minute appearances in the soil
whether it has been fairly managed or exhausted. It is in general more advantageous
to take a farm in a district with which you are well acquainted. It will be a great
advantage if you have had an opportunity of seeing the land at all times, observing it
in different seasons and states of the weather, and especially of seeing the crops thrashed
out, and ascertaining the quantity of corn which is usually yielded from a certain
quantity of straw, for lands very similar in outward appearance will produce a very
different return when the crops are thrashed. A want of attention to these circumstances is the cause that a man who comes from a distant part of the country, and
hires a farm on his own judgment, seldom succeeds so well as might be expected, even
with a superior knowledge of agriculture. He naturally compares the soil with some
similar soil which he has been acquainted with. If he comes from a district where
the soil is sandy, and where clay is in request, he will give the preference to very stiff
loams; if he comes from a cold wet clay, he will prefer the sandy; and the chances
are, that he is mistaken in his judgment, and finds it out when he has already embaliked his capital in a losing concern. Next to the nature of the soil is to be considered the convenient situation of the farm, the disposition of the fields, and the adaptation of the farm-buildings to the most profitable occupation of the land. The roads,
especially those which lead to the neighboring towns, whence manure may be obtained, are a most important object, and if there is water carriage, it greatly enhances
the value of the farm. The roads to the fields, and the distance of these from the farmyard; the convenience of having good pasture, or land easily laid down to grass, near
the homestead, and especially the situation of the farm-buildings with respect to the
land, and the abundance of good water, are all circumstances which must be well considered, and which greatly influence the probable profits, and consequently the rent
which may be fairly offered. A central situation is no doubt the most advantageous
for the farm-buildings, as greatly diminishing the labor in harvest, and in carrying out
manure. But there may be circumstances which render some spot nearer the extremity of the land more eligible, and it is only when entirely new buildings are to be
erected that there is a choice. The old farm-buildings are generally in low and sheltered situations, but it is a great inconvenience to have to carry the manure, which
is the heaviest thing carted on a farm, up a steep hill. The best situation is on a moderate slope, neither in the lowest nor highest ground. This disposition of the buildings
is of great importance both to the landlord and tenant.
Large straggling buildings are inconvenient, and cost much in repairs. The house
should be neat and comfortable, fit for the residence of a farmer who has a capital




76                              ARABLE LAND.
such as the farm requires. The rooms should be airy and healthy, facing the south,
with a neat garden in front of the house. The farm-yard should be to the north, behind it. Near the house, and the farm-yard, there should be a small paved court,
separated from the yard by a low wall. In this court, which should communicate
with the dairy, utensils may be placed on proper benches, to air and dry in the sun.
The architecture of the buildings may be left to the taste of the proprietor or his architect. The simpler it is, the more appropriate. The yard or yards in a large farm
should be sheltered on the north side by the barns, which need not be so extensive as
used formerly to be thought necessary.  If there is a thrashing machine, a single floor
to thrash the seeds upon, and to employ the men occasionally in winter, is quite sufficient.  Every farm which is so extensive as to require more than one floor to thrash
the corn on, ought always to have a thrashing mill attached to it.
A small yard, distinct from the other, with sheds for the cattle to shelter themselves
under, in wet and stormy weather, is a great advantage, and may be added at a trifling expense to any set of farm-buildings.  The cart-sheds should be in the stack-yard,
which properly occupies a space north of the barn.  There should be a sufficient
number of stands, with proper pillars and frames to build stacks on. Each stack
should be of such a size as to be conveniently taken into the barn to be thrashed out.
The round form, and the square which becomes nearly round when built up, are most
convenient. Nine stone or cast-iron pillars, with caps over them, are placed on brick
foundations, and support a strong frame on which the stack is built.  In the centre of
the stack there is usually a pyramidical open frame, to allow the air to circulate
through the stack, and prevent the heating of the grain. On each side of the yard
should be placed the stables, cow-houses, and feeding-stalls, with a pump of good
water near the last, and convenient places to put hay, straw, and turnips in, with a
machine to cut them.  A great deal of time and labor is saved by a proper arrangement of the different parts of the farm-buildings.  An underground cistern near the
cow-house and stables, into which the urine and washings of the cow-house may run
by means of a sink or drain, is a most useful appendage, which is too little thought
of in England, whereas it is one of the most indispensable parts of a Flemish farm. It
supplies a kind of manure, which can be applied to the land at all times, which invigorates sickly crops, and may often produce an abundant return, where otherwise
there would be a complete failure.
In Scotland it is notorious that rents are much higher than in England, not only for
small occupations, but for extensive farms; and that the tenants have complained less
of the times than their neighbors in the south. It may be worth while to inquire
into the cause of this, for the low price of corn must affect the Scotch farmer equally
with the English. One great difference between the Scotch and the English farmer is,
that the former gets work done at a cheaper rate than the latter. The Scotch laborer
is fully as well fed, and clothed, and lodged, as the English; but he has less money to
spend at the ale-house.  He is paid, not in a certain sum every Saturday, but in comforts, in the keep of a cow, in a certain number of rows of potatoes, a certain quantity
of malt to make his beer, a cottage to live in, and oatmeal to feed his family. His
immediate wants are supplied, and he is comfortable; the consequence is, that he
works willingly. He has no remnant of the last night's debauch at the beer-shop.
He is early at work, and he does his work cheerfully. The horses of a Scotch farmer
are well fed; they are always in good condition. They work 10 and even 12 hours
in a day, at 2 yokings.  The ploughman only thinks how he shall finish his work in
proper time, and unless he makes the horses work as much as they can without distressing them, he knows he shall not get through his work.  All this is worth 25 per
cent. on the whole labor of the farm, as Arthur Young has very judiciously calculated,
when he gives the expense of labor on the farm of a gentleman, compared with that
on the land of a farmer who works with his men. The moral effect of an interest in
the work to be done, when opposed to that of a perfectly distinct and often hostile
interest, will readily account for so great a difference.
But besides this, the Scotch farmer has generally the advantage of a scientific education, and of a thorough knowledge of the principles of his profession; and with the
shrewdness peculiar to his country, he knows how to take advantage of every favorable circumstance.  He has also been taught to calculate, and will soon discover
where there is a profit or a loss.  This has made him turn his attention to cattle and
sheep of late years, more than to the production of corn; and the Scotch have found
that while a very decent profit was made on the cattle, their land produced more corn,
although it sold at a lower price; for the green crops raised for the cattle, and the
manure made by them, enriched the land so much, that the average produce on some
light lands was nearly doubled. All this kept up rents to a much higher level than
in England, where prices were low, and there were no means of diminishing expenses
or increasing produce. Hence rents in Scotland have kept up wonderfully, when we
consider the great fall of rents in England since the peace.




ARCHIL.                                      77
ARCHIL.  A  violet red paste used in dyeing, of which the substance called
cudbear in Scotland (from Cuthbert, its first preparer in that form), is a modification.
Two kinds of archil are distinguished in commerce, the archil plant of the Canaries, and
that of Auvergne. The first is most esteemed: it is prepared from the lichen rocellus,
which grows on rocks adjoining the sea in the Canary and Cape de Verd Islands, in Sardinia, Minorca, &c., as well as on the rocks of Sweden. The second species is prepared
from the lichen parellus, which grows on the basaltic rocks of Auvergne.
There are several other species of lichen which might be employed in producing an
analogous dye, were they prepared, like the preceding, into the substance called archil.
Hellot gives the following method for discovering if they possess this property. A little
of the plant is to be put into a glass vessel; it is to be moistened with ammonia and
lime-water in equal parts; a little muriate of ammonia (sal ammoniac) is added; and
the small vessel is corked. If the plant be of a nature to afford a red dye, after three or
four days, the small portion of liquid, which will run off on inclining the vessel, now
opened, will be tinged of a crimson red, and the plant itself will have assumed this color.
If the liquor or the plant does not take this color, nothing need be hoped for; and it is
useless to attempt its preparation on the great scale. Lewis says, however, that he has
tested in this way a great many mosses, and that most of them afforded him a yellow or
reddish-brown color; but that he obtained from only a small number a liquor of a deep
red, which communicated to cloth merely a yellowish-red color.
Prepared archil gives out its color very readily to water, ammonia, and alcohol. Its
solution in alcohol is used for filling spirit-of-wine thermometers; and when these thermometers are well freed from air, the liquor loses its color in some years, as Abbe
Nollet observed. The contact of air restores the color, which is destroyed anew, in
vacuo, in process of time. The watery infusion loses its color, by the privation of air,
in a few days; a singular phenomenon, which merits new researches.
The infusion of archil is of a crimson bordering on violet. As it contains ammonia,
which has already modified its natural color, the fixed alkalies can produce little change
on it, only deepening the color a little, and making it more violet. Alum forms in it
a precipitate of a brown red; and the supernatant liquid retains a yellowish-red color.
The solution of tin affords a reddish precipitate, which falls down slowly; the supernatant liquid retains a feeble red color. The other metallic salts produce precipitates
which offer nothing remarkable.
The watery solution of archil, applied to cold marble, penetrates it, communicating a
beautiful violet color, or a blue bordering on purple, which resists the air much longer
than the archil colors applied to other substances. Dufay says, that he has seen marble
tinged with this color preserve it without alteration at the end of two years.
To dye with archil, the quantity of this substance deemed necessary, according to the
quantity of wool or stuff to be dyed, and according to the shade to which they are to be
brought, is to be diffused in a bath of water as soon as it begins to grow warm. The bath
is then heated till it be ready to boil, and the wool or stuff is passed through it without
any other preparation, except keeping that longest in, which is to have the deepest shade.
A fine gridelin, bordering upon violet, is thereby obtained; but this color has no permanence. Hence archil is rarely employed with any other view than to modify, heighten, and
give lustre to the other colors. Hellot says, that having employed archil on wool boiled
with tartar and alum, the color resisted the air no more than what had received no
preparation.  But he obtained from herb archil (l'orseille d'herbe) a much more durable
color, by putting in the bath some solution of tin. The archil thereby loses its natural
color, and assumes one approaching more or less to scarlet, according to the quantity
of solution of tin employed. This process must be executed in nearly the same manner
as that of scarlet, except that the dyeing may be performed in a single bath.
Archil is frequently had recourse to for varying the different shades and giving them
lustre; hence it is used for violets, lilachs, mallows, and rosemary flowers. To obtain a
deeper tone, as for the deep s.upes au vin, sometimes a little alkali or milk of lime is
mixed with it. The suites of this browning may also afford agates, rosemary flowers,
and other delicate colors, which cannot be obtained so beautiful by other processes.
Alum cannot be substituted for this purpose; it not only does not give this lustre, but
it degrades the deep colors.
The herb-archil is preferable to the archil of Auvergne, from the greater bloom which
it communicates to the colors, and from the larger quantity of coloring matter. It
has, besides, the advantage of bearing ebullition. The latter, moreover, does not answer
with alum, which destroys the color; but the herb archil has the inconvenience of
dyeing in an irregular manner, unless attention be given to pass the cloth through hot
water as soon as it comes out of the dye.
Archil alone is not used for dyeing silk, unless for lilachs; but silk is frequently
passed through a bath of archil, either before dyeing it in other baths or after it has been
dyed, in order to modify different colors, or to give them  lustre. Examples of this




78                                    ARCHIL.
will be given in treating of the compound colors. It is sufficient here to point out how
white silks are passed through the archil bath. The same process is performed with a
bath more or less charged with this color, for silks already dyed.
Archil, in a quantity proportioned to the color desired, is to be boiled in a copper. The
clear liquid is to be rln off quite hot from the archil bath, leaving the sediment at the
bottom, into a tub of proper size, in which the silks, newly scoured with soap, are to be
turned raund on the skein-sticks with much exactness, till they have attained the wishedfor shade. After this they must receive one beetling at the river.
Archil is in general a very useful ingredient in dyeing; but as it is rich in color, and
communicates an alluring bloom, dyers are often tempted to abuse it, and to exceed the
proportions that can add to the beauty without at the same time injuring in a dangerous
manner the permanence of the colors.  Nevertheless, the color obtained when solution
of tin is employed, is less fugitive than without this addition: it is red, approaching to
scarlet. Tin appears to be the only ingredient which can increase its durability. The
solution of tin may be employed, not only in the dyeing bath, but for the preparation of
the silk. In this case, by mixing the archil with other coloring substances, dyes may be
obtained which have lustre with sufficient durability.
We have spoken of the color of the archil as if it were natural to it; but it is, really,
due to an alkaline combination. The acids make it pass to red, either by saturating the
alkali, or by substituting themselves for the alkali.
The lichen which produces archil is subjected to another preparation, to make turnsole (litmus).  This article is made in Holland. The lichen comes from the Canary
Islands, and also from Sweden.  It is reduced to a fine powder by means of a mill,
and a certain proportion of potash is mixed with it.  The mixture is watered with
urine, and allowed to suffer a species of fermentation.  When this has arrived at a
certain degree, carbonate of lime in powder is added, to give consistence and weight to
the paste, which is afterwards reduced into small parallelopipeds that are carefully
dried.
The latest researches on the lichens, as objects of manufacture, are those of Westring
of Stockholm.  He examined 150 species, among which he found several which might
be rendered useful.  He recommends that the coloring matter should be extracted in
the places where they grow, which would save a vast expense in curing, package, carriage, and waste.  He styles the coloring substance itself cutbear, persio, or turnsole;
and distributes the lichens as follows:-lst. Those which, left to themselves, exposed to
moderate heat and moisture, may be fixed without a mordant upon wool or silk; such
are the L. cinereus, cematonta, ventosus, corallinus, westringii, saxatilis, conspassus, barbatus, plicatus, vulpinus, &c.
2. Those which develop a coloring matter, fixable likewise without mordant, but which
require boiling and a complicated preparation; such are the lichens subcarneus, dillenii,
farinaceus, jubatus, furJfraceus, pulmonareus, cornigalus, cocciferus, digitatus, ancialis, aduncus, &c.  Saltpetre or sea-salt is requisite to improve the lustre and fastness
of the dye given by this group to silk.
3. Those which require a peculiar process to develop their color; such as those
which become purple through the agency of stale urine or ammonia. Westring employed the following mode of testing:-He put three or four drachms of the dried
and powdered lichen into a flask; moistened it with three or four measures of cold
spring water; put the stuff to be dyed into the mixture, and left the flask in a cool
place.  Sometimes he added a little salt, saltpetre, quicklime, or sulphate of copper. If
no color appeared, he then moistened the lichen with water containing one twentieth
of sal ammoniac, and one tenth of quicklime, and set the mixture aside in a cool place
from eight to fourteen days. There appeared in most cases a reddish or violet colored
tint. Thus the lichen cinereus dyed silk a deep carmelite, and wool a light carmelite;
the l. physodes gave a yellowish-gray; the pustulatus, a rose red; sanguinarius, gray;
tartareus, found on the rocks of Norway, Scotland, and England, dyes a crimson-red.
In Jutland, cutbear is made from it, by grinding the dry lichen, sifting it, then setting
it to ferment in a close vessel with ammonia. The lichen must be of the third year's
growth to yield an abundant dye; and that which grows near the sea is the best.  It
loses half its weight by drying. A single person may gather from twenty to thirty
pounds a day in situations where it abounds.  No less than 2,239,685 pounds were
manufactured at Christiansand, Flekkefiort, and Fakrsund, in Norway, in the course of
the six years prior to 1812. Since more solid dyes of the same shade have been
invented, the archil has gone much into disuse.  Federigo, of Florence, who revived
its use at the beginning of the fourteenth century, male such an immense fortune by its
preparation, that his family became one of the grandees of that city, under the name of
Oricellarii, or Rucellarii.  For more than a century Italy possessed the exclusive art of
making archil, obtaining the lichens from the islands of the Mediterranean. According
to an official report of 1831, Teneriffe furnished annually 500 quintals (cwts.) of lichen;




ARROW ROOT.                                                79
the  Canary  Isles, 400; Fuerta Santura, 300; Lancerot,  300: Gomera, 300; Isle  of
Ferro, 800. This business belonged to the crown, and brought in a revenue of 1500
piastres. The farmers paid from 15 to 20 reals for the right to gether each quintal.
At that time the quintal fetched in the London market 41. sterling.
Archil is perhaps too much used in some cloth factories of England, to fhe discredit
of our dyes. It is said, that by its aid one third of the indigo may be saved in the
blue vat; but the color is so much the more perishable. The fine soft tint induced
upon  much  of the black cloth by means of archil is also deceptive.  One half-pound
of cudhear will dye one pound of woolen cloth. A crimson red is obtained by adding
to the decoction of archil a little salt of tin (muriate), and passing the cloth through
the bath, after it has been prepared by a mordant of tin and tartar. It must be afterwards passed through hot water.
The lichens have been of late years subjects of a multitude of interesting but intricate chemical researches, and a number of new compounds have been produced, as
lecanorin, from  lecanora, and variolaria, with which colorless substance a purple red
is formed by the action of ammonia and the air; also erythrine and erythryline from
several sorts of lichens, especially parmeliar ocella and tartarean, which afford, when
digested with ammonia, a bright red dye, but if treated with alcohol only a white
granular precipitate, when the solution is slowly evaporated; orcine and orceine are
somewhat analogous products, also  crystallizable, which may be obtained from  the
variolaria dealbata, by decomposition of the lecanorine. It has a sweet nauseous
taste, and  melts into a colorless fluid, which may be distilled.  It is soluble both  in
water and alcohol.  Orceine by means of ammonia and air forms archil.
Dyeing with archil with the aid of oil has been patented by Mr. Lightfoot, on the
same  principle as has been so long used  in the Turkey red cotton dye.  He has also
recourse to metallic and earthy bases, with what success I have not heard. Aluminated potash is likewise mentioned along with a great variety of other chemicals.
ARDENT  SPIRIT.  Alcohol of moderate strength.
AREOMETER OF BAUME'. This scale is much used by the French authors,
Specific Gravity Numbers corresponding with Baum6's Areometric Degrees.
Liquids denser than Water.                          Less dense than Water.
De-    Specific    De-    Specific    De-   Specific    De-    Specific    De-    Specific
grees.   gravity.   grees.   gravity.   grees.  graviy.   grees.  gravity.   grees.  gravity
0      1 0000      26      1-2063      52      1*5200      10      1-0000      36      0-8488
1      1-0066      27      1-2160      53      1-5353      11      0 9932      37      0.8139
2      1.0133      28      1-2258      54      1-5510      12      0-9865      38      0-8391
3      1-0201      29      1-2358      55      1-5671      13      0 9799      39      0-8343
4      1-0270      30      1-2459      56      1 5833      14      0-9733      40      0.8295
5      1-0340      31      1.2562      57      1e6000      15      09669       41      0 849
6      1-0411      32      1-2667      58      1-6170      16      0-9605      42      0-8202
7      1-0483      33      1-2773      59      1-6344      17      0-9542      43      0-8156
8      1-0556      34      1-2881      60      1-6522      18      0-9480      44      0-8111
9      1-0630      35      1-2992      61      1-6705      19      0-9420      45      0-8066
10      1-0704      36      1 3103      62      1 6889      20      0-9359      46      0-8022
11      1-0780      37      1-3217      63      1-7079      21      0-9300      47      0-7978
12      1-0857      38      1-3333      64      1-7273      22      0-9241      48      0-7935
13      1-0935      39      1-3451      65      1-7471      23      0-9183      49      0-7892
14      1 1014      40      1-3571      66      1-7674      24      0-9125      50      0-7849
15      11095       41      1 3694      67      1-7882      25      0-9068      51      0-7807
16      1-1176      42      1-3818      68      1-8095      26      09012       52      0-7766
17      1-1259      43      1-3945      69      1-8313      27      0-8957      53      0-7725
18      1-1343      44      1-4074      70      1-8537      28      0-8902      54      0 7684
19      1-1428      45      1-4206      71      1-8765      29      0-8848      55      0 7643
20      11515       46      1-4339      72      19000       30      0-8795       56     0-7604
21      1-1603      47      1-4476      73      1-9241      31      0-2  08742  57      0656
22      11692       48      1-4615       74     1-9487      32      0 8690      58      0-7526
23      1-1783      49      1-4758      75      1-9740      33      0-8639      59      0-7487
24      1.1875      50      1-4902      76      2-0000      34      0-8588      60      0-7449
L 25      11968        51      1-4951   135                            0-8538      61      0-7411
ARGILLACEOUS  EARTH. The earth of clay, called in chemistry alumina, because
it is obtained in greatest purity from alum.
ARGOL.  Crude tartar; which see.
ARMS.  Weapons of war.  See FIRE-ARMS for an account of this manufacture.
ARRACK.  A kind of intoxicating beverage made in India, by distilling the fermented juice of the cocoa-nut, the palmyra tree, and rice in the husk.
ARROW   ROOT.  The root of the maranta arundinacea, a plant which grows in the
West Indies, furnishes, by pounding in mortars and elutriation through sieves, a peculiar
species of starch, commonly, but improperly  called  arrow  root.  It is reckoned more




80                             ARROW ROOT.
nourishing than the starch of wheat or potatoes, and is generally also freer from peculiar taste or flavor. The fresh root consists, according to Benzon, of 0'07 of volatile oil; 26 of starch (23 of which are obtained in the form of powder, while the
other 3 must be extracted from the parenchyma in a paste by boiling water); 1 58
of vegetable albumen; 0'6 of a gummy extract; 0'25 of chloride of calcium; 6 of
insoluble fibrine; and 65-6 of water.
This plant has been lately cultivated with great success, and its root manufactured
in a superior manner, upon the Hopewell estate, in the island of St. Vincent. It
grows there to the height of about 3 feet, and it sends down its tap roots from 12 to
18 inches into the ground.  Its maturity is known by the flagging and falling down
of the leaves, an event which takes place when the plant is from 10 to 12 months
old. The roots being dug up with the hoe are transported to the washing-house,
where they are thoroughly freed from all adhering earth, and next taken individually
into the hand, and deprived by a knife of every portion of their skins, while every
unsound part is cut away. This process must be performed with great nicety, for
the cuticle contains a resinous matter, which imparts color and a disagreeable flavor
to the fecula, which no subsequent treatment can remove. The skinned roots are
thrown into a large cistern, with a perforated bottom, and there exposed to the
action of a copious cascade of pure water, till this runs off quite unaltered. The
cleansed roots are next put into the hopper of the mill, and are subjected to the powerful pressure of two pairs of polished rollers of hard brass; the lower pair of rollers
being set much closer together than the upper. (See the accompanying figure.) The
starchy matter.s thus ground into a pulp which falls into the receiver placed beneath, and is thence transferred to large fixed copper cylinders, tinned inside, and
perforated at the bottom with numerous minute orifices, like a kitchen drainer.
Within these cylinders, wooden paddles are made to revolve with great velocity, by
the power of a water-wheel, at the same time that a stream of pure water is admitted from above. The paddle arms beat out the fecula from the fibres and parenchyma
of the pulp, and discharge it in the form of a milk through the perforated bottom of
the cylinder. This starchy water runs along pipes, and then through strainers of
fine muslin into large reservoirs, where, after the fecula has subsided, the supernatant water is drawn off, and fresh water being let on, the whole is agitated and left
again to repose. This process of ablution is repeated till the water no longer acquires any thing from the fecula. Finally, all the deposits of fecula of the day's
work are collected into one cistern, and, being covered and agitated with a fiesh
charge of water, are allowed to settle till next morning. The water being now let
off the deposit is skimmed with palette knives of German silver, to remove any of
the superficial parts, in the slightest degree colored; and only the lower, purer, and
denser portion is prepared by drying for the market.  The drying-house on the
Hopewell estate is constructed like the hothouse of an English garden. But instead
of plants, it contains about 4 dozen of drying pans made of copper, 7 feet by 4L,
and tinned inside. Each pan is supported on a carriage, having iron axles, with
lignum vite wheels, like those of a railway carriage, and they run on rails. Immediately after sunrise, these carriages with their pans, covered with white gauze, to
exclude dust and insects, are run out into the open air, but if rain be apprehended,
they are run back under the glazed roof. In about 4 days the fecula is thoroughly
dry and ready to be packed, with German silver shovels, into tins or American flour
barrels, lined with paper attached with arrow root paste. The packages are never
sent to this country in the hold of the ship, as their contents are easily tainted
by noisome effluvia, of sugar, &c. By such a skilful series of operations, and by
such precautions, the arrow  root thus manufactured may vie with any similar
preparation in the Bermudas or any other part of the world. I have found it, on
analysis and trial, to be pure, powerful, and agreeable, and a most wholesome article
of food.
Fig. 26. Plan of arrow root grinding-mill, and of 2 sets of copper cylinder washing-machines, with the connecting machinery for driving them; the washing agitator
being driven from the connecting shaft with leathern belts. Fig. 27. End elvevation
of arrow root mill, with wheels and pinions, disengaging lever, &c. Fig. 28. End
elevation of copper washing-cylinders, with press-framing, &c. The washing-cylinders are 61 feet long and 31 in diameter. The mill-rollers are 3 feet long and 1 foot
in diameter.




ARROW ROOT.                                    81
Wit                                            / a
28
The uses of arrow root are too well known and acknow-,fA^,        loledged to require recounting here. It is the most elegant
//f,    \\\   and the richest of all the feculas, and being now manui, ^         ^    ~   factured, with the advantage of excellent machinery, and
abundance of pure water, in the fertile island of St. Vincent,
l    ok ^ z   o it may be brought into our market at a much more moderate
price than it has heretofore been supplied from less favored
localities. The Bermuda arrow root is treated necessarily
with rain water collected in tanks, and therefore is occasionally soiled with insects, from which the St. Vincent article is entirely free.




82                                   ARSENIC.
2The presence of potato starch in arrow root may be discovered by the microscope.
Arrow root consists of regular ovoid particles of nearly equal size, whereas potato
starch consists of particles of an irregular ovoid or truncated form, exceedingly irregular in their dimensions, some being so large as 3  of an inch, and others only, I-.
But the most convenient test is dilute nitric acid of 1 10 (about the strength of single
aquafortis), which, when triturated in a mortar with the starch, forms immediately a
transparent very viscid paste orjelly. Flour starch exhibits a like appearance. Arrow
root, however, forms an opaque paste, and takes a much longer time to become viscid.
Arrow root may be distinguished from potato starch, not only by the different size
of its particles, but by the difference of structure. Their surfaces in the arrow root
are smooth, and free from the streaks and furrows seen in the potato particles by a
good microscope. The arrow root, moreover, is destitute of that fetid unwholesome
oil extractable by alcohol from potato starch.
Liebig places the powers of arrow root, as a nutriment to man, in a very remarkable point of view, when he states that 15 pounds of flesh contain no more carbon for
supplying animal heat by its combustion into carbonic acid in the system than 4
pounds of starch; and that if a savage, with one animal and an equal weight of
starch, could maintain life and health for a certain number of days, he would be
compelled, if confined to flesh alone, in order to procure the carbon necessary-for
respiration during the same time, to consume five such animals.
1841.    1842.       1843.    1844.
Quantities imported-        -      - cwt. -          7953        9236    10274
Quantities exported  -      -       - cwt.  -          334        264       200
Retained for consumption   -        - cwt. -         7561        8499    10018
Net revenue                 -       -       1012       737        623       769
ARSENIC.  This metal occurs native, in the state of oxide, and also combined with
sulphur under the improper name of yellow and red arsenic, or orpiment and realgar.
Arsenic is associated with a great many metallic ores; but it is chiefly extracted firom
those of cobalt, by roasting, in which case the white oxide of arsenic, or, more correctly, the arsenious acid is obtained. This acid is introduced occasionally in small
quantities into the materials of flint glass, either before their fusion, or in the melting
pot. It serves to peroxidize the iron oxide in the sand, and thereby to purify the body
of the glass; but an excess of it makes the glass milky.
Scheele's green is a combination of this arsenious acid with oxide of copper, or an
arsenite of copper, and is described under this metal.
Arseniate of potash is prepared, in the small way, by exposing to a moderate heat
in a crucible a mixture of equal parts of white arsenic and nitre in powder. After
fusion the crucible is to be cooled; the contents being dissolved in hot water, and
the solution filtered, will afford regular crystals on cooling.  According to M. Berzelius, they are composed of arsenic acid, 63-87; potash, 26-16; and water, 9'97. It is
an acidulous salt, and is hence usually called the binarseniate, to denote that its composition is 2 atoms of arsenic acid, and I of potash. This article is prepared upon
the great scale, in Saxony, by melting nitre and arsenious acid together in a cylinder
of cast-iron. A neutral arseniate also is readily formed, by saturating the excess of
acid in the above salt with potash; it does not crystallize. The acid arseniate is occasionally used in calico printing, for preventing certain points of the cotton cloth
from taking on the mordant; with which view  it is mixed up with gum water and
pipe clay into a paste, which is applied to such places with a block.




ARSENIC.                                       83
The extraction of arsenic from the cobalt ores, is performed at Altenberg and Reichenstein, in Silesia, with an apparatus, excellently contrived to protect the health of the
smelters from the vapors of this most noxious metallic sublimate.
Figs. 29 to 32 represent the arsenical furnaces at Altenberg.  Fig. 29 is a vertical
section of the poison tower; fig. 30, a longitudinal section of the subliming furnace A,
with the adjoining vault B, and the poison tower in part at n; fig. 31, the transverse
section of the furnace A, of fig. 30; fig. 32, ground plan of the furnace A, where the
left half shows the part above, and the right the part below  the muffle or oblong
retort; B' is the upper view, B" the ground plan of the vault B, of fig. 30; m, n, the
base of the poison tower. In the several figures the same letters denote the same objects;
29
A ii                                        32.a St |[
07 ~n                                                         _4
a is the muffle; b is its mouth for turning over the arsenical schlich, or ground ore;
c c c, fire draughts or flues; d, an aperture for charging the muffle with fiesh schlich;
c, the smoke chimney; f, two channels or flues for the ascent of the arsenious fumes,
which proceed to other two flues g, and then terminate both in h, which conducts the
fumes into the vault B. They issue by the door i, into the conduit k, thence by I into the
spaces m, n, o, p, q, r, of the tower. The incondensable gases escape by the chimney, s.
The cover t, is removed after completion of the process, in order to push down the precipitate into the lower compartments.
The arsenious schlichs, to the amount of 9 or 10 cwt. for one operation (1 roas!-post,
or roasting round), are spread 2 or 3 inches thick upon the bottom  of the muffle, heated
with a brisk fire to redness, then with a gentler heat, in order to oxydize completely,
before subliming, the arsenical ore. With this view the air must have free entrance, and
the front aperture of the muffle must be left quite open. After 11 or 12 hours, the calcined materials are raked out by the mouth of the muffle, and fresh ones are introduced
by the openings indicated above, which are closed during the sublimation.
The arsenious acid found in these passages is not marketable till it be re-sublimed in
large iron pots, surmounted with a series of sheet iron drums or cast-iron cylinders, upon
the sides of which the arsenic is condensed in its compact glassy form. The top cylinder
is furnished with a pipe, which terminates in a condensing chamber.
Figs. 33, 34, represent the arsenic refining furnaces at Reichenstein.  Fig. 33 shows




84                                   ARSENT(.
at A, a vertical section of the furnace,
-_ - - - - - -— " -the kettle, and the surmounting drums
or cylinders; over B it is seen in eleva~ ~ ~g ~ ~ t       tion; fig. 34 is a ground plan of the
four fireplaces.  a is the grate; b, the
ash-pit; c, the openings for firing; d,
the fire-place; e, iron pots or kettles
which are charged with the arsenious
powder; f, the fire-flues proceeding to
1 9 ff      1             the common chimney g; h, iron cyr  si'   Ulinders; i, caps; k, pipes leading to
8 a3  h1         X  the poison vent 1; m, openings in the
pipes  for  introducing  the  probing
wires.
*^E^'^   ^'.' is~l   ^M E*   follThe conduct of the process is as
follows: —The pot is' filled nearly to
its brim  with 3- cwt. of the arsenic
meal, the cylinders are fitted on by
means of their handles, and luted together with a mixture of loam, blood,
and hair; then is applied first a gentle,
/1^   {i ll d "      and after half an hour, a strong fire,
l   11 i 11  I  wA"""~g/     ll 7    whereby the arsenic is raised partly
(     bIrT I  1y ^1             / b |  I z /^  )in the form of a white dust, and partly
I    }l  in crystals; which, by the continaance
or the heat, fuse together into a homogeneous mass.  If the fire be too fee134                           ble, only a sublimate is obtained; but,
if too violent, much of the arsenic is
volatilized into the pipes. The workmen judge by the heat of the cylinders whether the operation be going
on well or not. After 12 hours the
furnace is allowed to cool, provided
the probe wires show  that the sublimation  is over.   The  cylinders are
then lifted off, and the arsenious glass
is detached from their inner surface.
According to the quality of the poisonflour., it yields from 1  to 7 of its weight
of the glass or enamel. Should any dark particles of metallic arsenic be intermixed with
the glass, a fresh sublimation must be had recourse to.
The following is the product in cwts. of arsenious acid, at Altenberg and Reichenstein,
in Silesia, in the years
1825.  1826.  1827.  1828.  1829.  1830.  183.  1832.
White arsenic in a glassy
state-    -    -    -  2632   1703  2686   1900  2070  2961  3337   2730
Sublimed arsenic in powder --   27                              33      31     30     44      69     38
Yellow arsenical glass -   112      11     56    -        86    313      60    219
Red arsenical glass           3     -      -      -       28
ARSENICAL POISON (detection of).-It is well known that fluids mixed with glutinous
matter are very liable to froth up when hydrogen is disengaged in them from the mutual action of zinc and a dilute acid; and that the froth obstructs the due performance of
the experiment of Marsh. It is equally known, that much of the arsenic contained in
the poisonous liquid so tested escapes condensation and eludes measurement. A committee, appointed by the Prussian government, have contrived an ingenious modification of Marsh's apparatus, which I have simplified into the annexed form:- A is a
narrow glass cylinder, open at top, about 10 inches high, and 14 or 1. inch diameter inside; B is a glass tube, about I inch diameter outside, drawn to a point at bottom, and
shut with a cork at top.  Through the centre of this cork, the small tube c passes down
air-tight, and is furnished at top with a stop-cock, into which the bent small tube of
glass (without lead) E is cemented. The bent tube F is joined to the end of B with
a collar of caoutchouc, or a perforated cork, which will be found more convenient.
The manner of using this apparatus is as follows:-Introduce a few  oblong
slips of zinc, free from arsenic, into B, and then insert its air-tight cock with




ARSENIC.                                       85
suspected liquid, acidulated with dilute hy-' drochloric or sulphuric acid (each pure) as
O35!                                i will rise to the top of the cork, after B is
35|                     |,I~ ~full, and immediately shut the stop-cock.
The generated hydrogen will force down
)ID                        F  the liquid out of the lower orifice of B into A,
and raise the level of it above the cork. The
extremity of the tube F being dipped be-' l~-~                          neath the surface of a weak solution of nitrate of silver, and a spirit-flame being plaC                               |ced a little to the left of the letter E, the
stop-cock is then to be slightly opened, so
that the gas which now fills the tube B may
escape so slowly as to pass off in separate
small bubbles through the silver solution.
By this means the whole of the arsenic conA.                                     tained in the arseniuretted hydrogen will be
deposited either in the metallic state upon
the inside of the tube E, or with the silver
into the characteristic black powder.  The
first charge of gas in B being expended, the
((i^~~~~ stop-cock is to be shut, till the liquid be
^~~~~\ \~ lagain expelled from  it by a fresh disengagement of hydrogen.  The ring of metallic arsenic deposited beyond E may be chased onwards by placing a second flame under it,
and thereby formed into an oblong brilliant
a^  __~ —~ m~             steel-like mirror.  It is evident that by the
patient use of this apparatus the whole arsenic in any poisonous liquid may be collected, weighed, and subjected to every
kind of chemical verification. If F be joined to E by means of a perforated cork, it
may readily be turned about, and its taper point raised into a position such as when
the hydrogen issuing from it is kindled, the flame may be made to play upon a surface of glass or porcelain, in order to produce the arsenical mirror.
Or the preceding process may be made supplementary to that of boiling the arsenical foul liquor, acidulated with hydrochloric acid upon slips of clean copper, wherebv
the arsenic is precipitated upon the copper in a metallic film or thin crust more or less
brilliant. If one of the slips of copper thus coated be placed in the tube B of the
above described apparatus, it will give off its arsenic without the annoyance produced by the frothing up of a glutinous mixture.
ARSENIC (detection of)-It is now generally known in this country, that towards
the close of last year Professor Reinsch has proposed an entirely new method of detecting arsenic; which consists in acidulating any suspected fluid with hydrochloric acid,
heating in it a thin plate of bright copper, upon which the arsenic is deposited in the
form of a thin metallic crust, and then separating the arsenic from the copper in the
state of oxide, by subjecting the copper to a low red heat in a glass tube. Organic
fluids and solids, suspected to contain arsenic, may be prepared for this purpose by
boiling them for half an hour with a little hydrychloric acid; solid matters being cut
into small shreds, water being added in sufficient quantity to let the ebullition go on
quietly, and care being taken to continue the boiling until the solids are either dissolved, as generally happens, or are reduced to a state of minute division.
Nothing can be more simple, easy or precise than the method of Reinscb. It is also
exceedingly delicate, more so than is ever likely to be necessary in any medico-legal investigation; for it is adequate to detect a 250,000th part of arsenic in a fluid.  It is
also perfect in another respect: it does not leave any arsenic in the subject of analysis;
none, at least, which can be detected by any other means, even by the most delicate
process yet proposed, that of Mr. Marsh.
Cut the copper, on which the arsenic is deposited, into small chips, so that they may
be easily packed in the bottom of a small glass tube, and apply a low red heat. A
white crystalline powder sublimes; and if this be examined in the sunshine, or with a
candle near it, a magnifier of four or five powers will enable the observer to distinguish
the equilateral triangles composing the facets of the octahedral crystals, which are
formed by arsenious acid when it sublimes.  Sometimes the three equal angles, composing a corner of the Octahedron, may be seen by turning the glass in various directions. If triangular facets cannot be distinguished, owing to the minuteness of the
crystals, then shake out the copper chips, close the open end of the tube with the
finger, and heat the sublimed powder over a very minute spirit lamp flame, chasing it




86                                 ARSENIC.
up and down the tube till crystals of adequate size are formed. Next boil a little distilled water in the tube over the part where the crystalline powder is collected; and
when the solution is cold divide it into three parts, to be tested with ammoniacal
nitrate of silver, ammoniacal sulphate of copper, and sulphuretted hydrogen, either in
the state of gas or dissolved in water.
In boiling organic substances in the weak hydrochloric acid care must be taken to
ascertain that there is a decided excess of acid always present. Two fluidrachms to every
8 oz. of liquid are in general sufficient; but if the organic matter be an animal texture
in a state of decay, a much larger quantity of acid may be necessary, owing to the presence of ammonia, which tends gradually to neutralize the acid as the solution goes on.
Reinsch does not advise filtration of the fluid after the acid has acted sufficiently on the
subject of analysis. But notwithstanding the delay occasioned by filtration, this seems
to me advisable in most instances, otherwise organic particles are apt to attach themselves to the copper, and thus give rise to empyreuma, when the metallic arsenic is
driven off by heat. The most convenient form for using the copper is that of copper
leaf; but ordinary plates of copper may be easily made of any degree of fineness by
immersing them for a time in dilute nitric acid. Where the quantity of arsenic in the
fluid is supposed to be small, nearly half an hour should be allowed to elapse before
the copper is removed. Before applying the sulphuretted hydrogen as a test to the
solution of the sublimed oxide, the solution must be acidulated with hydrochloric or
acetic acid. In every case the whole process should be applied in the first instance
to distilled water, acidulated with the hydrochloric acid to be employed afterwards;
and if the copper be tarnished, a purer acid must be obtained, or the copper must be
subjected to the subsequent steps of the process, in order to ascertain whether the
tarnishing be occasioned by arsenic or not.
ARSEN CAL AND ANTIMONIAL SPOTS (distinguishing reactions of).-If a drop of bromine
is placed on a saucer, and a capsule containing arsenical spots iiverted over it, the spots
take a very bright lemon-yellow tinge in a short time. Antimonial spots, under the same
circumstances, are acted on much more rapidly (in about five seconds at a temperature
of 52~ F.), and assume an orange shade. Both become colorless if exposed to the air,
and are again restored if treated with a strong solution of sulphuretted hydrogen. The
secondary yellow of the arsenical spots, as observed by Lassaigne, disappears on the addition of ammonia, whilst that of antimonial spots remains untouched. A concentrated
solution of iodate of potash turns arsenical spots of a cinnamon-red, and dissolves them
almost immediately. On antimonial spots it has no visible action within 3 or 4 hours.
Solution of the hypochlorites (chlorides) of soda and lime and chlorine water dissolve
arsenical spots instantaneously, leaving those of antimony. A concentrated solution of
the chlorate of potash gradually acts upon arsenical spots, but not upon those of antimony. The nitroprusside of potassium, on the other hand, slowly dissolves antimony,
producing no perceptible effect upon arsenic. The statement of Bischoff, that arsenical
spots were soluble, antimonial insoluble, in a solution of the chloride of sodium, could
not be verified, as, after repeated trials, it was found to leave both not perceptibly
affected. The chloride of barium, the hydrochlorate and the sulphite of ammonia,
afforded likewise no distinguishing action. The nitrate of ammonia dissolves arsenical
more rapidly than antimonial stains.  Of these reactions the most decisive are those
of iodate of potash, hypochlorites of soda and lime, and fresh chlorine water.
ARSENIC, TIN, AND ANTIMONY (qualitative determination of).-Although analytical
chemistry possesses several methods of distinguishing between tin, antimony, and arsenic, I am not acquainted with any process by which these three metals, when they
occur together, can be recognized with the same ease and quickness as in the case of
most other metals. At the same time, the frequent occurrence of these three metals
together renders a quick mode of detecting them highly desirable. The following
may be viewed as a small contribution towards this object.
With regard to the discrimination of tin and antimony, this is founded on the solubility of metallic tin in strong muriatic acid, and the insolubility of antimonial stains,
obtained according to Marsh's method in hypochlorite of soda.
When the muriatic solution of the two metal; is treated with some metallic zinc, they
are both precipitated, the antimony with disengagement of antimoniuretted hydrogen.
When the precipitation is made in a small apparatus for the disengagement of hydrogen,
the antimony is readily detected by the black stains insoluble in hypochlorite of soda,
which it produces upon a piece of porcelain. When subsequently the precipitated
metallic powder of tin and antimony is boiled with strong muriatic acid, only tin dissolves, forming protochloride, which, after subsequent dilution with water, is recognized by the brownish-black precipitate produced by sulphuretted hydrogen. Neither
of these reactions are modified by the presence of arsenic.
The detection of arsenic when antimony is present, is founded upon a remarkable
difference which these two metals exhibit towards nascent hydrogen when the latter is




ARTESIAN WELLS.                                  87
disengaged from an alkaline liquid. When a strong alkaline solution of antimony is
heated with metallic zinc, antimony is precipitated simultaneously with a lively disengagement of pure hydrogen, which does not show the slightest reaction of antimoniuretted hydrogen. If, on the contrary, a substance containing arsenic acid is mixed with
an excess of potash and some finely-divided zinc, the hydrogen given off on the application of heat is abundantly charged with arseniuretted hydrogen. The presence of this
latter is ascertained most simply by holding a strip of paper dipped in nitrate of silver
over the arseniferous mixture of potash and zinc; with the slightest trace of arsenic
the paper is colored distinctly black.
ARTESIAN  WELLS. Under this name is designated a cylindrical perforation,
bored vertically down through one or more of the geological strata of the earth, till it
passes into a porous gravel bed containing water, placed under such incumbent pressure
as to make it mount up through the perforation, either to the surface or to a height convenient for the operation of a pump. In the first case, these wells are called spouting
or overflowing. This property is not directly proportional to the depth, as might at first
sight be supposed, but to the subjacent pressure upon the water. We do not know exactly the period at which the borer or sound was applied to the investigation of subterranean fountains, but we believe the first overflowing wells were made in the ancient
French province of Artois, whence the name of Artesian. These wells, of such importance to agriculture and manufactures, and which cost nothing to keep them in condition,
have been in use, undoubtedly, for several centuries in the northern departments ofFrance,
and the north of Italy; but it is not more than 50 or 60 years since they became known
in England and Germany. There are now a great many such wells in London and its
neighborhood, perforated through the Immensely thick bed of the London clay, and even
through some portions of the subjacent chalk. The boring of such wells has given much
insight into the geological structure of many districts.
The formation of Artesian wells depends on two things, essentially distinct from each
other: 1. On an acquaintance with the physical constitution, or nature, of the mineral
structure of each particular country; and, 2. On the skilful direction of the processes
by which we can reach the water level, and of those by which we can promote its ascent
in the tube. We shall first treat of the best method of making the well, and then offer
some general remarks on the other subjects.
The operations employed for penetrating the soil are entirely similar to those daily
practised by the miner, in boring to find metallic veins; but the well excavator must resort to peculiar expedients to prevent the purer water, which comes from deep strata,
mingling with the cruder waters of the alluvial beds near the surface of the ground, as
also to prevent the small perforation getting eventually filled with rubbish.
The cause of overflowing wells has been ascribed to a variety of circumstances. But,
as it is now generally admitted that the numerous springs which issue from the ground
proceed from the infiltration of the waters progressively condensed in rain, dew, snow,
&c. upon the surface of our globe, the theory of these interior streamlets becomes by no
means intricate; being analogous to that of syphons and water jets, as expounded in the
treatises on physics. The waters are diffused, after condensation, upon the surface of the
soil, and percolate downwards, through the various pores and fissures of the geological
strata, to be again united subterraneously in veins, rills, streamlets, or expanded films,
of greater or less magnitude, or regularity. The beds traversed by numerous disjunctions
will give occasion to numerous interior currents in all directions which cannot be recovered, and brought to the day; but when the ground is composed of strata of sand, or
gravel very permeable to water, separated by other strata nearly impervious to it, reservoirs are formed to our hand, from which an abundant supply of water may be spontaneously raised. In this case, as soon as the upper stratum is perforated, the waters may
rise, in consequence of the hydrostatic pressure upon the lower strata, and even overflow
the surface in a constant stream, provided the level from which they proceed be proportionally higher.
The sheets of water occur principally at the separation of two contiguous formations;
and, if the succession of the geological strata be considered, this distribution of the water
will be seen to be its necessary consequence. In fact, the lower beds are frequently
composed of' compact sandstone or limestone, and the upper beds of clay. In level
countries, the formations being almos alalways in horizontal beds, the waters which feed
the Artesian wells must come from districts somewhat remote, where the strata are more
elevated, as towards the secondary and transition rocks. The copious streams condensed
upon the sides of these colder lands may be therefore regarded as the proper reservoirs of
lur wells.




88                          ARTESIAN WELLS.
Fig. 36 represents the manner in which the condensed water of the heavens distributes itself under the.36                            surface  of  our globe.
o whih te w r r   s in te be of                   Here we have a geolo.
gical  section,  showing
the  succession  of the
A   several formations, and
/~~~~                                    ~~~~and in  ~ the sheets or laminm of
B   water that exist at their
boundaries, aswellas in,,//whence they take                           their sandy beds.  The
D   figure  shows also very
~~~~~some will rem~plainly that the  height
to which the water reascends in the bore of a well depends upon the height of the reservoir which supplies the sheet of water to which the well is perforated. Thus the
well A, having gone down to the aqueous expanse a a, whose waters of supply are derived from the percolation M, will afford rising waters, which will come to the surface;
while in the well B, supplied by the sheet r, the waters will spout above the surface,
and in the well c they will remain short of it. The same figure  shows that these wells
often traverse sheets of water, which rise to different heights. Thus, in the well c there
are five columns of ascending nwaters, which rise to haeihts proportional to the points
whence they take their origin. Several of these will be spouting or overflowing, but
some will remain beneath the surface.
The situation of the intended well being determined upon, a circular hole is generally
dug in the ground, about 6 or 8 feet deep, and 5 or 6 feet wide. In the centre of this
hole the boring is carried on by two workmen below, assisted by a laborer above, as
shown in fig. 37.
The handle (fig. 38) having a female screw in the bottom of its iron shank, with a
wooden bar or rail passing through the socket of the shank, and a ring at top, is the
general agent to which all the boring implements are to be attached.  A  chisel
40  41            46
37
39
48
42
43 44
(fig. 39) is first employed, and connected
to this handle by its screw at top. If the
ground is tolerably soft, the weight of the
~~38          fl~   ~two workmen bearing upon the cross bar, and
8 8 t'occasionally forcing it round, will soon cause
47   Jji  ~ the chisel to penetrate; but if the ground is
hard or strong, the workmen strike the chisel
down with repeated blows, so as to peck their
way, often changing their situation by walking round, which breaks the stones, or other
hard substances, that may happen to obstruct
its progress.
The labor is very considerably reduced
by means of an elastic wooden pole, placed
horizontally over the well, from which a chain is brought down, and attached to the ring




ARTESIAN WELLS.                                    89
of the handle. This pole is usually made fast at one end, as a fulcrum, by being set
into a heap of heavy loose stones; at the other end the laborer above gives it a slight
up and down vibrating motion, corresponding to the beating motion of the workmen
below, by which means the elasticity of the pole in rising lifts the handle and pecker,
and thereby very considerably diminishes the labor of the workmen. See fig. 37.
When the hole has been thus opened by a chisel, as far as its strength would permit,
the chisel is withdrawn, and a sort of cylindrical auger (fig. 40) attached to the handle
(fig. 38), for the purpose of drawing up the dirt or broken stones which have been
disturbed by the chisel. A section of this auger is shown infig. 41, by which the internal valve will be seen. The auger being introduced into the hole and turned round
by the workmen, the dirt or broken stones will pass through the aperture at bottom
(shown at fig. 42), and fill the cylinder, which is then drawn up, and discharged at
the top of the auger, the valve preventing its escape at bottom.
In order to penetrate aeeper into the ground, an iron rod, as a, fig. 43, is now to
be attached to the chisel, fig. 39, by screwing on to its upper end, and the rod is also
fastened to the handle, fig. 38, by screwing into its socket. The chisel having thus
become lengthened by the addition of the rod, it is again introduced into the hole;
and the operation of pecking or forcing it down, is carried on by the workmen as before. When the ground has been thus perforated, as far as the chisel and its rod will
reach, they must be withdrawn, in order again to introduce the auger, fig. 40, to collect and bring up the rubbish; which is done by attaching it to the iron rod, in place
of the chisel. Thus, as the hole becomes deepened, other lengths of iron rods are added,
by connecting them together, as a b are in fig. 44. The necessity of frequently withdrawing the rods from the holes, in order to collect the mud, stones, or rubbish, and
the great friction produced by the rubbing of the tools against its sides, as well as the
lengths of rods augmenting in the progress of the operation, sometimes to the extent of
several hundred feet, render it extremely inconvenient, if not impossible, to raise them
by hand. A  tripedal standard is therefore generally constructed by three scaffolding
poles tied together, over the hole, as shown fig. 37, from the centre of which a wheel
and axle, or a pair of pully blocks is suspended, for the purpose of hauling up the rods,
and from which hangs the fork, fig. 45. This fork is to be brought down under the shoulder, near the top of each rod, and made fast to it by passing a pin through two little
holes in the claws. The rods are thus drawn up, about seven feet at a time, which is
the usual distance between each joint, and at every haul a fork, fig. 46, is laid horizontally over the hole, with the shoulders of the lower rod resting between its claws, by
which means the rods are prevented from sinking down into the hole again, while the
upper length is unscrewed and removed. In attaching and detaching these lengths of
rod, a wrench, fig. 47, is employed, by which they are turned rewind, and the screws forced up to their firm bearing.
The boring is sometimes performed for the first sixty or a hundred feet, by a chisel
of 21 inches wide, and cleared out by a gouge of 21 diameter, and then the hole is
widened by a tool, such as is shown atfig. 48. This is merely a chisel, as fig. 39, four
inches wide, but with a guide, a, put on at its lower part, for the purpose of keeping
it in a perpendicular direction; the lower part is not intended to peck, put to pass
down the hole previously made, while the sides of the chisel operate in enlarging the
hole to four inches. The process, however, is generally performed at one operation, by
a chisel of four inches wide, as fig. 39, and a gouge of three inches and three quarters,
asfig. 40.
It is obvious that placing and displacing the lengths of rod, which is done every time
that the auger is required to be introduced or withdrawn, must, of itself, be extremely
troublesome, independent of the labor of boring, but yet the operation proceeds, when
no unpropitious circumstances attend it, with a facility almost incredible. Sometimes,
however, rocks intercept the way, which require great labor to penetrate; but this is
always effected by pecking, which slowly pulverizes the stone. The most unpleasant
circumstance attendant upon this business is the occasional breaking of a rod into the
hole, which sometimes creates a delay of many days, and an incalculable labor in drawing up the lower portion.
When the water is obtained in such quantities and of such quality as may be required,
the hole is dressed or finished by passing down it a diamond chisel, funnel mouthed,
with a triangular bit in its centre; this makes the sides smooth previous to putting in
the pipe. This chisel is attached to rods, and to the handle, as before described; and,
in its descent, the workmen continually walk round, by which the hole is made smooth
and cylindrical. In the progress of the boring, frequent veins of water are passed
through; but, as these are small streams, and perhaps impregnated with mineral substances, the operation is carried on until an aperture is made into a main spring, which
will flow up to the surface of the earth. This must, of course, depend upon the level of
its source, which, if in a neighboring hill, will frequently cause the water to rise up,
and produce a continued fountain. But if the altitude of the distant spring happens to




90                           ARTESIAN WELLS.
be below the level of the surface of the ground where the boring is effected, it sometimes
happens that a well of considerable capacity is obliged to be dug down to that level, in
order to form a reservoir, into which the water may flow, and whence it must be raised
by a pump; while, in the former instance, a perpetual fountain may be obtained.
Hence, it will always be a matter of doubt, in level countries, whether water can be
procured which would flow near to or over the surface; if this cannot be effected, the
process of boring will be of little or no advantage, except as an experiment to ascertain
the fact.
In order to keep the strata pure and uncontaminated with mineral springs, the hole
is cased, for a considerable depth, with a metallic pipe, about a quarter of an inch
smaller than the bore. This is generally made of tin (though sometimes of copper or
lead) in convenient lengths; and, as each length is let down, it is held by a shoulder
resting in a fork, while another length is soldered to it; by which means a continuous
pipe is carried through the bore, as far as may be found necessary, to exclude land springs,
and to prevent loose earth or sand from falling in, and choking the aperture.
Mr. John Good, of Tottenham, who had been extensively employed in boring the
earth for water, obtained a patent, in Aug. 1823, for certain improved implements contrived by him to facilitate his useful labors; a description of which cannot fail to be in.
teresting.
The figures annexed exhibit these ingenious tools; fig. 49 is an auger, to be connected
52  51  50  49   by the screw-head to the length of rods by which the boring is carried on. This auger is for boring in soft clay or sand; it is cylinI t- I 11 Idrical, and has a slit or opening from end to end, and a bit, or
cutting-piece at bottom. When the earth is loose or wet, an auger
of the same form is to be employed, but the slit or opening reduced
in width, or even without a slit or opening. A similar auger is
used for cutting through chalk; but the point or bit at bottom
should then project lower, and, for that purpose, some of these
cylindrical augers are made with moveable bits, to be attached by
screws, which is extremely desirable in grinding them to cutting
edges. Fig. 50 is a hollow conical auger, for boring loose sandy
soils; it has a spiral cutting edge coiled round it, which, as it
turns, causes the loose soil to ascend up the inclined plane, and
deposite itself in the hollow within. Fig. 51 is a hollow cylinder
or tube, shown in section, with a foot-valve, and a bucket to be
raised by a rod and cord attached at the top; this is a pumping
tool, for the purpose of getting up water and sand that would not
rise by the auger. When this cylinder is lowered to the bottom of the bore, the bucket
is lifted up by the rod and cord, and descends again by its own gravity, having a valve
in the bucket, opening upwards, like other lift pumps; which, at every stroke, raises a
quantity of water and sand in the cylinder equal to the stroke; the ascent and descent ol
the bucket being limited by a guide-piece at the top of the cylinder, and two small knobs
upon the rod which stop against the cross-guide. Fig. 52 is a tool for getting up broken
rods. It consists of a small cylindrical piece at bottom, which the broken rod slips through
when it is lowered, and a small catch with a knife-edge, acted upon by a back-spring.
In rising, the tool takes hold of the broken rod, and thereby enables the workman at
top to draw it up. Another tool for the same purpose, is shown at fig. 53, which is like
a pair of tongs; it is intended to be slidden down the bore, and for the broken rod to pass
between the two catches, which, pressed by back-springs, will, when drawn up, take fast
hold of the broken rod.
Fig. 54 is a tool for widening the hole, to be connected, like all the others, to the end
59   3 54   55               of the length of rods passed
62       66     0                                 down the bore; this tool has
62 1 66~   ^60 1~              A 57     two cutting-pieces extending on
3L1AJf Jt   the sides at bottom, by which,
f     as the tool is turned round in
HeJ^~~  zJL A1 A              1 APr            vJ U the bore, the earth is peeled
away. Fig. 55 is a chisel, or
punch, with a projecting piece
to  be  used  for penetrating
61 al                                            pc through stone; this chisel is,
/A US   ^  2~~Al              0 |by rising and falling, made to
peck the stone, and pulverize
A  I ^I^^^4 (fS,8 8   it; the small middle part break6 \ ^  F U )~    &    ~ U~  ing it away first, and afterwards
~~~~~~63         t J  ) t     the broad part coming into ac65                641   r'tion. Fig. 56 is another chisel,
or punching tool, twi3ted on its
cutting edge, which breaks away
a greater portion of the stone as it beats against it.




ARTESIAN WELLS.                                  91
The manner of forcing down lengths of cast-iron pipe, after the bore is formed, is
shown at fig. 57; the pipe is seen below in the socket, at the end of which a block is
inserted; and from this block a rod extends upwards, upon which a weight at top
slides. To this weight cords are shown to be attached, reaching to the top of the bore;
where the workmen alternately raise the weight and let it fall, which, by striking upon
the block in its middle, beats down the pipe by a succession of strokes; and when one
length of pipe has, by these means, been forced down, another length is introduced into
the socket of the former. Another tool for the same purpose is shown at fig. 58, which
is formed like an acorn; the raised part of the acorn strikes against the edge of the
pipe, and by that means, it is forced down the bore. When it happens that an auger
breaks in the hole, a tool similar to that shown at fig. 59 is introduced; on one side of
this tool a curved piece is attached, for the purpose of a guide, to conduct it past the
cylindrical auger; and at the end of the other side is a hook, which, taking hold of the
bottom edge of the auger, enables it to be drawn up.
Wrought iron, copper, tin, and lead pipes, are occasionally used for lining the bore;
and as these are subject to bends and bruises, it is necessary to introduce tools for the
purpose of straightening their sides. One of these tools is shown at fig. 60, which is a
bow, and is to be passed down the inside of the pipe, in order to press out any dents.
Another tool, for the same purpose, is shown at fig. 61, which is a double bow, and
may be turned round in the pipe for the purpose of straightening it all the way down;
atfig. 62, is a pair of clams, for turning the pipe round in the hole while driving.
When loose stones lie at the bottom of the hole, which are too large to be brought up
by the cylindrical auger, and cannot be conveniently broken, then it is proposed to
introduce a triangular claw, asfig. 63, the internal notches of which take hold of the
stone, and as the tool rises, bring it up. For raising broken rods, a tool likefig. 64
is sometimes employed, which has an angular claw that slips under the shoulder of the
rod, and holds it fast while drawing up.
In raising pipes it is necessary to introduce a tool into the insiCe of the pipe, by
which it will be held fast. Fig. 65 is a pine-apple-tool for this purpose; its surface is
cut like a rasp, which passes easily down into the pipe, but catches as it is drawn up;
and by that means brings the pipe with it. Fig. 66 is a spear for the same purpose,
which easily enters the pipe by springing; at the ends of its prongs there are forks
which stick into the metal as it is drawn up, and thereby raise it.
These are the new implements, for which the patent was granted. In the process of
boring, there does not appear to be anything new proposed; but that these several
tools are to be employed for boring, packing, and otherwise penetrating, raising the
earth, and extracting broken or injured tools. There are also suggestions for employing
long buckets, with valves opening upward in their bottoms, for the purpose of drawing
water from these wells when the water will not flow over the surface; also lift pumps,
with a succession of buckets for the same purpose. But as these suggestions possess
little if any novelty, it cannot be intended to claim them as parts of the patent.
The older geological formations are seldom propitious to the construction of Artesian wells, on account of the compact massiveness of their rocks, of the few fissures
or porous places in them, and of the rarity of filtering strata overlying retentive ones. It
is therefore vain to attempt the formation of an overflowing spring, upon the above principles, in territories of granite, gneiss, mountain limestone, and basalt. Among transition
and secondary formations, such wells will rarely furnish a supply of good water. The
latter strata of alternating clay and variegated sandstone contain so much gypsum and
rock salt as to impregnate therewith the waters derived from them to an unpalatable
degree. It is in the sandy, calcareous, and argillaceous strata of the Jura limestone,
indeed, that borings may most probably be made for brine springs. The hot springs
which burst out of the ground in primitive rocky districts come undoubtedly from a
great depth under the surface, and derive their temperature, and also probably their
waters, from the vapors of deep-seated volcanoes in connexion with the sea. A miniature
representation of such springs is exhibited in the intermitting fountains of fresh water
on the shoulder of Vesuvius. Springs of this kind, which vary with the seasons, may derive a portion of their water from the surface of the earth, from which it may sink through
clefts in the primitive rocks, till meeting in its descent with stony obstructions and ascending steam, it is forced to remount in a heated state to the day, like the Geisers in Iceland.
The most remarkable example of an Artesian well is that recently formed at Grenelle,
a suburb at the southwest of Paris, where there was a great want of water.  It cost
eight years of difficult labor to perforate. The geological strata round the French
capital are all of the tertiary class, and constitute a basin, like that shown in fig. 61
The bottom of this basin is chalk; A A are tertiary strata above the chalk; B B, chalk
or cretaceous carbonate of lime; c c, D D, green sand and clay; E E, oolite and Jura
limestone (muschelkalk); E A, general slope of the surface of the country from Langres
to Paris; M A, the level of the sea. Over a circular space, of which Paris is the centre,.




92                            ARTESIAN WELLS.
and which is bounded by the towns of Laon, Mantes, Blois, Saneerre, Nogent-surSeine, and Epernay, these strata are found upon the surface, concealing the chalk; but
on the other side of these towns, the edge of the basin being passed, the chalk is geneNogentsur- Troyes.     Bar-surParis.     Provins. Seine.    Lusigny. Seine.
Jt,!      g      it Plateau de Langres.
67 
rally the superficial bed. By looking at the order of these tertiary strata, it is easy
to perceive the obstacles that M. Malot, the engineer of the well, had to overcome, and
the difficulty and hazard of his undertaking. The surface at Grenelle consists of gravel, pebbles, and fragments of rock, which have been deposited by the waters at some
period anterior to any historical record.  Below this layer of detritus, it was known
to the engineer, by geological induction, as well as previous experience, that at Grenelle marl and clay would be found, instead of the limestone which generally forms
the immediately subjacent stratum.  He was aware that he had to bore about 440
yards! deep before he should arrive at the sheet of water (see figure) which flows in
the gravel below the limestone, and supplies the wells of St. Ouen, St. Denis, and Stains.
Underneath the marl and the clay, the boring rods had to perforate pure gravel, plastic clay, and finally chalk, which forms the bottom of the general tertiary basin, as we
have seen. No calculation from geological data could determine the thickness of this
stratum of chalk, which, from its powers of resistance, might present an almost insuperable obstacle. The experience acquired in boring the wells of Elbeuf, Rouen, and
Tours, was in this respect but a very imperfect guide. But supposing this obstacle to
be overcome, was he sure of finding a supply of water below this mass of chalk? In
the first place, the strata c D below the chalk possessed, as we shall see, all the necessary conditions for producing Artesian springs, namely, successive layers of clay and
gravel, or of pervious and impervious beds.  M. Malot confidently relied on his former experience of the borings of the wells at Rouen, Elbeuf, and Tours, where abundant supplies of water had been found below the chalk, between similar strata of clay
and gravel.
But one other condition is requisite to insure the rising of the water in an Artesian
well, namely, that the feeding level of infiltration should be higher than the orifice in
the bore above which the water is to ascend. This, however, turned out to be the case
with Grenelle.  M. Arago had shown that the water of the spring here would necessarilv rise to the surface, because in the well at Elbeuf, which is nearly 9 yards above
the level of the sea, the water rises from 27 to 29 yards above the surface of the earth,
and, consequently, from 36 to 38 yards above the ocean level. Now, as the orifice of
the bore at Grenelle is only 34 yards above the same level, it follows that, if the identical spring be met with, the water must rise above the earth's surface at Grenelle.
The necessary works were commenced with boring-rods about 9 yards long, attached
to each other, and which could be raised or lowered by mechanical power, while an
ingenious method was adopted for giving them a rotary motion.  The diameter of
the bore was about 6 inches. The instrument affixed to the end of the lowest boringrod was changed according to the different strata which were successively attacked;
the form suited for passing through the softer materials near the surface being unsuitable for boring through the chalk and flint, a hollow tube was used for the former,
while a chisel-shaped tool was employed to penetrate the latter. The size of the rods
was lessened as the depth increased; and, since the subterraneaean water was not reached
so soon as was expected, it became requisite to enlarge five several times the diameter
of the bore, in order to permit the work to be successfully prosecuted. Accidents occurred which tried the patience of the projectors.  In May, 1837, when the boring had
extended down to a depth of 418 yards, the hollow tube, with nearly 90 yards of the
long rods attached to it, broke and fell to the bottom of the hole, whence it became
necessary to extract the broken parts before any further progress could be made. The
difficulty of accomplishing this task may be conceived; for the different fragments
were not all extracted until after the constant labor of 15 months. Again, in April,
1840, in passing through the chalk, the chisel attached to the boring-rod got detached,




ARTESIAN WELLS.                                    93
and before it could be recovered, several months were spent in digging round about
it. A similar occurrence created an obstacle which impeded the work for 3 months,
but, instead of withdrawing the detached part, it was forcibly driven down among the
stratum of gravel. At length, in February, 1841, after eight years' labor, the rods
suddenly descended several yards, having pierced into the vault of the subterranean
water so long sought after by the indefatigable engineer.  A few hours afterwards he
was rewarded for all his anxious toils; for lo! the water rose to the surface, and discharged itself at the rate of 600,000 gallons per hour!
The depth reached down was 602 yards, or about three times the height of St. Paul's.
The pipe by which the water reaches the surface has been recently carried to a height
nearly level with the source of supply. The portion of the pipe above the ground is
surrounded with a monumental pagoda of ornamental carpentry, and it discharges a
circular cascade of clear water continually into a circular iron reservoir, to be thence
conveyed by a lateral pipe to the ground. The water is well adapted for all domestic
uses, and it will be unfiling, being supplied from the infiltration of a surface of country nearly 200 miles in diameter. The Artesian wells of Elbeuf, Rouen, and Tours,
which were formed many years ago, overflow in never-varying streams; and the ancient Artesian well at Lillers, in the Pas de Calais, has for about seven centuries furnished a constant and equable supply.
The opportunity of ascertaining the temperature of the earth at different depths
was not neglected during the progress of the works at Grenelle.  Thermometers
placed at a depth of 30 yards in the wells of the Paris Observatory invariably stand
at 53~ Fahrenheit.  In the well at Grenelle the thermometer indicated 740 Fahr. at a
depth of 442 yards, and at 550 yards it stood at 79~. At the depth finally arrived at
of 602 yards, the temperature of the water which rose to the surface was 81~, corroborating previous calculations on the subject.  For a descent of 572 yards there is an
increase of temperature equal to 280 F., which is 20-4 yards, or 61-2 feet for each degree of that scale. Now that the skilful labor of so many years is terminated, the
Parisians regret that the subterranean sheet of water had not lain 1000 yards beneath
the surface, that they might have had an overflowing stream of water at 104~, to furnish a cheap supply to their numerous hot-bath establishments.
In boring Artesian wells through stratified formations, several sheets of water are
met with at successive heights; as at St. Ouen there are 5, each capable of rising: one
of these is at 36 metres of depth; a second at 45-m., a third at 511m., a fourth at
59 30m., and a fifth at 66km. At Tours there are 3 sheets susceptible of mounting,
at 95, 102, and 125 metres respectively beneath the surface. Seven large sheets of
fresh water were in like manner observed in boring for coal near Dieppe.  The deepest sheets, having the greatest superincumbent pressure, in general give the highest
hydrostatic level. The quantity of water furnished by such wells seems to be nearly
constant: thus the well of Grenelle, near Paris, continues to deliver 3000 litres per
minute at the surface of the ground; the well of Bages, near Perpignan, 2000 litres;
that at Tours, 1110 at 2 metres above the level of the ground. It is said that some
of the Artesian wells in and round about London do not deliver so much water as
they formerly did; a deficiency ascribed to the vast quantities which have been
drawn up fiom the lower sheets of water by the multitude of steam engines employed
in pumping.  When a copious flow of water from a deep well can be commanded, it
may be used for driving water wheels with great advantage, since, from its elevated
temperature, it is not liable to freeze; and for the same reason it is made to maintain
a mild temperature by circulating in pipes through the interior of factories.
ASHES; said of crude potash, which is in fact obtained from the ashes of plants.
ASHES OF PLANTS; see AGRICULTURE.
ASHES, PEARL AND POT, see POTASH.
ASPARAGINE; a crystallizable product extracted from  asparagus, consisting of
32-35 carbon, 18-73 azote, 6-60 hydrogen, and 42-32 oxygen.  It is most easily procured
from the roots of marsh-mallows.  It is a curious substance, but hitherto has been applied to no use.
ASPHALTIC PAVEMENT; see BITUMEN.
ASPHALTUM.  Native bitumen, so called from the lake Asphaltites.
ASSAY and ASSAYING.  (Coupellation, Fr.; Ahtreiben auf der capelle, Germ.)
This is the process by which the quality of gold and silver bullion, coin, plate, or
trinkets, is ascertained with precision.
The art of assaying gold and silver by the cupel is founded upon the feeble affinity
which these metals have for oxygen, in comparison with copper, tin, and the other
cheaper metals; and on the tendency which the latter metals have to oxidize rapidly
in contact with lead at a high temperature, and sink with it into any porous, earthy
vessel in a thin, glassy, or vitriform state. The porous vessel may be made either of
wood-ashes, freed from their soluble matter by washing with water; or, preferably,
of burned bones reduced to a fine powder.




94                                   ASSAY.
LAlloy,                             A.      Ratio of the Copper to
Lead for I of Alloy.    the Lead.
Silver.            Copper.
1000                   0                                   0
950                  50               3                   1: 60
900                 100               7                   1: 70
800                 200              10                   1: 50
700                 300              12                   1: 40
600                 400              14                   1: 35
500                 500              16 or 17             1: 32
400                 600              16 -17               1: 26'7
300                 700              16 -17               1: 22-9
200                 800              16 - 17              1: 20
100                 900              16- 17               1: 17'8
0                1000              16- 17               1: 16
Bismuth may be used as a substitute for lead in cupellation; two parts of it being
nearly equivalent to three of lead. But its higher prices will prevent its general
introduction among assay masters.
We begin this assay process by weighing, in a delicate balance, a certain weight of
the metallic alloy; a gramme (=15'444 gr.) is usually taken in France, and 12 grains
in this country. This weight is wrapped up in a slip of lead foil or paper, should it
consist of several fragments. This small parcel, thus enveloped, is then laid in a watch
glass or a capsule of copper, and there is added to it the proportion of lead suited to
the quality of alloy to be assayed; there being less lead, the finer the silver is presumed
to be. Those who are much in the habit of cupellation can make good guesses in this
way; though it is still guess work, and often leads to considerable error, for if too
much lead be used for the proportion of baser metal present, a portion of the silver
is wasted; but if too little, then the whole of the copper, &c. is not carried off, and
the button of fine silver remains more or less impure. The most expert and experienced
assayer by the cupel, produces merely a series of approximate conjectural results which
fall short of chemical demonstration and certainty in every instance. The lead must be,
in all cases, entirely free from silver, being such as has been revived from pure litharge;
otherwise errors of the most serious kind would be occasioned in the assays.
The best cupels weigh 121 grammes, or 193 grains. The cupels allow the fused
oxydes to flow through them  as through a fine sieve, but are impermeable to the
particles of metals; and thus the former pass readily down into their substance while
the latter remain upon their surface; a phenomenon owing to the circumstance of the
glassy oxydes moistening, as it were, the bone-ash powder, whereas the metals can
contract no adherence with it. Hence also the liquid metals preserve a hemispherical
shape in the cupels, as quicksilver does in a cup of glass, while the fused oxyde spreads
over, and penetrates their substance like water. A  cupel may be regarded, in some
measure, as a filter permeable only to certain liquids.
If we put into a cupel, therefore, two metals, of which the one is unalterable in the
air, the other susceptible of oxydizement, and of producing a very fusible oxyde, it is
obvious that, by exposing both to a proper degree of heat, we shall succeed in separating
them. We should also succeed, though the oxyde were infusible, by placing it in contact
with another one, which may render it fusible. In both cases, however, the metal from
68   which we wish to part the oxydes must not be volatile; it
should also melt, and form  a button at the heat of cupele    / f        lation; for otherwise it would continue disseminated, attached to the portion of oxyde spread over the cupel, and
incapable of being collected.
s b^rlA               The furnace and implements used for assaying in the. __  j       ~~Royal Mint and the Goldsmiths' Hall, in the city of Lon-.
don, are the following:A A A A,.fig. 68, is a front elevation of an assay furnace;
[griTN^f     a a, a view of one of the two iron rollers on which the furII LJIIInace rests, and by means of which it is moved forward or
-. o   o       o,   backward; b, the ash-pit; c c are the ash-pit dampers,
A  l   b |~~1~   A     which are moved in a horizontal direction towards each
}c9 I       I c I   other for regulating the draught of the furnace; d, the
a     -    --'.       door, or opening, by which the cupels and assays are introduced into the muffle; e, a moveable funnel or chimney
by which the draught of the furnace is increased.




ASSAY.                                     95
B      B B  fig. 69, is a perpendicular section of fig. 68; a a, end view  of the rollers;
69                 b the ash-pit; c one of the ash-pit dampers; d the.1.. I        grate, over which  is the plate upon which the
muffle rests, and which is covered with loam nearly
one inch thick; f the muffle in section representing the situation of the cupels; g the mouth-plate,
B  and upon it are laid pieces of charcoal, which during
1 ^ ^   I       ^Pthe process are ignited, and heat the air that is
allowed to pass over the cupels, as will be more
fully explained in the sequel; h the interior of the
furnace, exhibiting the fuel.
0la Go V Q \     The total height of the furnace is 2 feet 6- inches;
from the bottom to the grate, 6 inches; the grate,
muffle, plate, and bed of loam, with which it is
B   II     b       Do         covered, 3 inches; from the upper surface of the
B        grate to the commencement of the funnel e, fig. 68,
_ ()a   -  -?     21-  inches; the funnel e, 6 inches.  The square
of the furnace which receives the muffle and fuel
is 114 inches by 15 inches. The external sides of the furnace are made of plates of
wrought iron, and are lined with a 2-inch fire-brick.
c c c c, fig. 70, is a horizontal section of the furnace over the grates showing the width
T0                                        of the mouth-piece, or plate
c                         i id  is~71              of wrought iron, which  is
i~:-::::  6 inches, and the opening which
i     I                         receives the muffle-plate.
1l1    I S   C   \ff )r        Fi tg.'1, represents the mufl}__  {li1 —— 11 J____fle or pot, which is 12 inches
long, 6 inches broad inside;
in the clear 6: In height 4&
C "        YC                                  inside measure, and nearly 5t
in the clear.
Fig. 72, the muffle-plate, which is of the same size as the bottom of the muffle.
Fig. 73, is a representation of the sliding-door of the mouth-plate, as shown at d, in
fig. 68.'76'C) <    A    t   i~l69
78                                                I
R12ES4
222i 3  724 (23
Fig.'75, a                                    16 17 11  2 0   
Fig. 74, a front view of the mouth-plate or piece, d, fig. 58.
Fig. S5, a representation of the mode of making, or shutting up with pieces of charcoal, the mouth of the furnace.
Fig. 76, the teaser for cleaning the grate.
Fig. 77, a larger teaser, which is introduced at the top of the furnace, for keeping a
complete supply of charcoal around the muffle.
Fig. 78, the tongs used for charging the assays into the cups.
Fig. 79, represents a board of wood used as a register, and is divided into 45 equal
compartments, upon which the assays are placed previously to their being introduced
into the furnace. When the operation is performed, the cupels are placed in the furnace
in situations corresponding to these assays on the board. By these means all confusion
is avoided, and without this regularity it would be impossible to preserve the accuracy
which the delicate operations of the assayer require.
I shall now proceed to a description of a small assay furnace, invented by Messrs.
Anfrye and d'Arcet, of Paris. They term it, Le Petit Fourneau d Coupelle. Fig. 80
represents this furnace, and it is composed of a chimney or pipe of wrought iron a, and
of the furnace B. It is 171 inches high, and 74 inches wide. The furnace is formed
of three pieces; of a dome A; the body of the furnace B; and the ash-pit c, which is




96                                    ASSAY.
used as the base of the furnace, figs. 80 and 81. The principal piece, or body of the
furnace, B, has the form of a hollow tower, or of a hollow cylinder, flattened equally at
the two opposite sides parallel to the axis, in such a manner that the horizontal section
is elliptical. The foot which supports it is a hollow truncated cone flattened in like
manner upon the two opposite sides, and having consequently for its basis two ellipses
80               of  different diame80              ters; the  smallest
81                                         ought to be equal to
that of the furnace,
82         ff                 so that the bottom of
the latter may dxactly
0.                     ^  ^'^fit it.   The  dome,
or@^=^~~ /^1  {which forms an arch
above  the furnace,
9   s            has also its base ellipw@^~~ ^   @  D^ ~ "tical, while that of
the  superior orifice
84 71_1       by which the smoke
884            =                goes out preserves the:.           ^     o              cylindrical form. The''          X*~'             tube of wrought iron
e                          I _           ~is 18 inches long and
m ~ ^ 85 -^A  d~  Je    2' inches diameter,
a little enlarged, and
_                  /^~  A~  i |' NA  slightly conical, that
/   it may  be  exactly
m I             En^    1 I'      _~       \.b  fitted or jointed upon
^. *         11-9890  88 W         1 i s                 the  upper part of
9 i  V\   I   El s 9 7 89          / \             the furnace dome d,
^W/^^   ^\~Is. (  ^         fig. 80. Attheunion
"' a  S          w                    W W g 91 k S of the conical and
""^^ ^    ____     ~          k  a^.       B  cylindrical parts of
the  tube, there  is
placed a small galtX^  I^ "    ~'I@~ \~ 11b   lery of iron, e,fig. 80,
y^   f  C   W      j92/ c /9               \           81. See also a plan
I  L......I  ^?^      ^of it, fig. 82. This
gallery is both  ingenious and useful.
Upon it are placed the cupels, which are thus annealed during the ordinary work of
the furnace, that they may be introduced into the muffle, when it is brought into its
proper degree of heat. A little above this gallery is a doorf, by which, if thought
proper, the charcoal could be introduced into the furnace; above that there is placed at
g a throttle valve, which is used for regulating the draught of the furnace at pleasure.
Messrs. Anfrye and d'Arcet say, that, to give the furnace the necessary degree of heat
so as to work the assays of gold, the tube must be about 18 inches above the gallery,
for annealing or heating the cupels. The circular opening h, in the dome, fig. 80, and
as seen in the section, fig. 81, is used to introduce the charcoal into the furnace: it is
also used to inspect the interior of the furnace, and to arrange the charcoal round the
muffle. This opening is kept shut during the working of the furnace, with the mouthpiece, of which the face is seen at n,fig. 81.
The section of the furnace, figg 81, presents several openings, the principal of which is
that of the muffle; it is placed at i; it is shut with the semicircular door m, fig. 80, and
seen in the section m, fig. 81. In front of this opening, is the table or shelf, upon
which the door of the muffle is made to advance or recede; the letter q, fig. 81, shows
the face, side, and cross section of the shelf, which makes part of the furnace. Immediately under the shelf, is a horizontal slit, 1, which is pierced at the level of the upper
part of the grate, and used for the introduction of a slender rod of iron, that the grate
may be easily kept clean. This opening is shut at pleasure, by the wedge represented
at k,figs. 80, and 81.
Upon the back of the furnace is a horizontal slit p, fig. 81, which supports the firebrick, s, and upon which the end of the muffle, if necessary, may rest; u,fig. 81, is the
opening in the furnace where the muffle is placed.
The plan of the grate of the furnace is an ellipse: fig. 83, is a horizontal view of it.
The dimensions of that ellipsis determine the general form of the furnace, and thickness
of the grate. To give strength and solidity to the grate, it is encircled by a bar or hoop of




ASSAY.                                     97
iron. There is a groove in which the hoop of iron is fixed. The holes of the grate are
truncated cones, having the greater base below, that the ashes may more easily fall into the ash-pit. The letter v, fig. 81, shows the form of these holes. The grate is supported by a small bank or shelf, making part of the furnace, as seen at a, fig. 81.
The ash-pit, c, has an opening y in front,fig. 81; and is shut when necessary by the
mouth-piece, r, figs. 80 and 81.
To give strength and solidity to the furnace, it is bound with hoops of iron, at b, b,
b, b, fig. 80.
Figs. 84,, 8 6, are views of the muffle.
Fig. 87, is a view of a crucible for annealing gold.
Figs. 88, 89, 90, are cupels of various sizes, to be used in the furnace. They are the
same as those used by assayers in their ordinary furnaces.
Figs. 91 and 92 are views of the hand-shovels, used for filling the furnace with
charcoal; they should be made of such size and form as to fit the opening h, in figs.
80 and 81.
The smaller pincers or tongs, by which the assays are charged into the cupels, and by
which the latter are withdrawn from the furnace, as well as the teaser for cleaning the
grate of the furnace, are similar to those used in the British Mint.
In the furnace of the Mint above described, the number of assays that can be made at
one time is 45. The same number of cupels are put into the muffle. The furnace is
then filled with charcoal to the top, and upon this are laid a few pieces already ignited.
In the course of three hours, a little more or less, according to circumstances, the whole
ts ignited; during which period, the muffle, which is made of fire-clay, is gradually
heated to redness, and is prevented from cracking; which a less regular or more sudden
increase of temperature would not fail to do: the cupels, also, become properly annealed. All moisture being dispelled, they are in a fit state to receive the piece of silver or
gold to be assayed.
The greater care that is exercised in this operation, the less liable is the assayer to accidents from the breaking of the muffle; which is both expensive and troublesome to fit
properly into the furnace.
The cupels used in the assay process, are made of the ashes of burnt bones (phosphate
of lime). In the Royal Mint, the cores of ox-horn are selected for this purpose; and the
aashes produced are about four times the expense of the bone-ash, used in the process of
cupellation upon a large scale. So much depends upon the accuracy of an assay of
gold or silver, where a mass of 151bs. troy in the first, and 601bs troy in the second
instance is determined by the analysis of a portion not exceeding 20 troy grains, that
every precaution which the longest experience has suggested, is used to obtain an accurate result. Hence the attention paid to the selection of the most proper materials for
making the cupels.
The cupels are formed in a circular mould made of cast steel, very nicely turned, by
which means they are easily freed from the mould when struck. The bone-ash is used
moistened with a quantity of water, sufficient to make the particles adhere firmly together. The circular mould is filled, and pressed level with its surface; after which, a pestle
or rammer, having its end nicely turned, of a globular or convex shape, and of a size
equal to the degree of concavity wished to be made in the cupel for the reception of the
assay, is placed upon the ashes in the mould, and struck with a hammer until the cupel
is properly formed. These cupels are allowed to dry in the air for some time before they
are used. If the weather is fine, a fortnight will be sufficient.
An assay may prove defective for several reasons. Sometimes the button or bead
sends forth crystalline vegetations on its surface with such force, as to make one suppose
a portion of the silver may be thrown out of the cupel. When the surface of the bead
is dull and flat, the assay is considered to have been too hot, and it indicates a loss of
silver in fumes. When the tint of the bead is not uniform, when its inferior surface is
bubbly, when yellow  scales of oxyde of lead remain on the bottom of the cupel, and
the bead adheres strongly to it, by these signs it is judged that the assay has been too cold,
and that the silver retains some lead.
Lastly, the assay is thought to be good if the bead is of a round form, if its upper surface is brilliant, if its lower surface is granular and of a dead white, and if it separates
readily from the cupel.
After the lead is put into the cupel, it gets immediately covered with a coat of oxyde,
which resists the admission of the silver to be assayed into the melted metal; so that the
alloy cannot form. When a bit of silver is laid on a lead bath in this predicament, we
see it swim about for a long time without dissolving. In order to avoid this result, the
silver is wrapped up in a bit of paper; and the carbureted hydrogen generated by its
combustion reduces the film of the lead oxyde, gives the bath immediately a bright metallic lustre, and enables the two metals readily to combine.
As the heat rises, the oxyde of lead flows round about over the surface, till it is ab



98                                     ASSAY.
sorbed by the cupel. When the lead is wasted to a certain degree, a very thin film of it
only remains on the silver, which causes the iridiscent appearance, like the colors of
soap-bubbles; a phenomenon, called by the old chemists, fulguration.
When the cupel cools in the progress of the assay, the oxygenation of the lead ceases;
and, instead of a very liquid vitreous oxyde, an imperfectly melted oxyde is formed, which
the cupel cannot absorb. To correct a cold assay, the temperature of the furnace ought
to be raised, and pieces of paper ought to be put into the cupel, till the oxyde of lead
which adheres to it be reduced. On keeping up the heat, the assay will resume its ordinary train.
Pure silver almost always vegetates. Some traces of copper destroy this property,
which is obviously due to the oxygen which the silver can absorb while it is in fusion,
and which is disengaged the moment it solidifies. An excess of lead, by removing all the
copper at an early stage, tends to cause the vegetation.
The brightening is caused by the heat evolved, when the button passes from the liquid
to the solid state. Many other substances present the same phenomenon.
In the above operation it is necessary to employ lead which is very pure, or at least free
from silver. That kind is called poor lead.
It has been observed at all times, that the oxyde of lead carries off with it, into the cupel, a little silver in the state of an oxyde. This effect becomes less, or even disappears,
when there is some copper remaining; and the more copper, the less chance there is of
any silver being lost. The loss of silver increases, on the other hand, with the dose of
lead. Hence the reason why it is so important to proportion the lead with a precision
which, at first sight, would appear to be superfluous. Hence, also, the reason of the attempts which have, of late years, been made to change the whole system of silver assays,
and to have recourse to a method exempt from the above causes of error.
M. d'Arcet, charged by the Commission of the Mint in Paris, to examine into the justice of the reclamations made by the French silversmiths against the public assays, ascertained that they were well founded; and that the results of cupellation gave for the
alloys betwen 897 and 903 thousandths (the limits of their standard coin) an inferior
standard, by from 4 to 5 thousandth parts, from the standard or title which should result
from the absolute or actual alloy.
The mode of assay shows, in fact, that an ingot, experimentally composed of 900
thousandths of fine silver, and 100 thousandths of copper, appears, by cupellation, to be
only, at the utmost, 896 or 897 thousandths; whereas fine silver, of 1000 thousandths,
comes out nearly of its real standard. Consequently a director of the Mint, who should
compound his alloy with fine silver, would be obliged to employ 903 or 904 thousandths,
in order that, by the assay in the laboratory of the Mint, it should appear to have the
standard of 900 thousandths. These 3 or 4 thousandths would be lost to him, since they
would be disguised by the mode of assay, the definitive criterion of the quantity of silver,
of which the government keeps count from the coiner of the money.
From the experiments subsequently made by M. d'Arcet, it appears that silver assays
always suffer a loss of the precious metal, which varies, however, with the standard of
the alloy. It is 1 thousandth for fine silver,
4'3 thousandths for silver of 900 thousandths,
4-9     -      for  -   of 800
4'2     -      for  -   of 500 
and diminishes thereafter, progressively, till the alloy contains only 100 thousandths of
silver, at which point the loss is only 0'4.
Assays requested by the Commission of the Paris Mint, from the assayers of the principal Royal Mints in Europe, to which the same alloys, synthetically compounded, were
sent, afforded the results inscribed in the following table.
Cities where they Standards found for the Mathematical Alloys
Names of the Assaiers.         reside
Names of the Assr.  resde.  90 ml.    900 mill.    800 mill.
F. de Castenhole, Mint Assayer      Vienna        94620       89840       795-10
A. R. Vervaez,       ditto    -     Madrid        944-40      893-70      789-20
D. M. Cabrera, Assayer in
Spain-    -    -        -         Ditto         944-40      893-70      788-60
Assayer-    -...   Amsterdam        947-00      895-00      795-00
Mr. Bingley, Assay Master  -       London         946-25      89625       794-25
Mr. Johnson, Assayer  -    -         Ditto        933-33      88350       783-33
Inspector of the Mint  -    -       Utrecht       945-00      896-50      799-00
Assayer of the Mint    -    -       Naples        9450         900 891700 787
Assayer of Trade -    -    -         Ditto        945-00      891-00      787-00
Assayer of the Mint    -          Hamburgh        946- 3      897 —4      79841
Ditto   -.-               Altona        942 ^       894700      790
L                                                 _  _ _  _ _ _  _ _  _ _ _  _




ASSAY.                                     99
These results, as well as those in still greater numbers, obtained from  the ablest
Parisian assayers, upon identical alloys of silver and copper, prove that the mode of
assay applied to them brings out the standard too low; and further, that the quantity
of silver masked or disguised, is not uniform for these different eminent assay masters.
An alloy, for example, at the standard of 900 thousandths is judged at
M.
the Mint of Paris to have a standard of 895'6
At that of Vienna        -           898-4
Madrid         -           893-7
Naples           -           891'0
The fact thus so clearly made out of a loss in the standard of silver bullion and coin,
merits the most serious attention; and it will appear astonishing, perhaps, that a thing
recurring every day, should have remained for so long a time in the dark. In reality,
however, the fact is not new; as the very numerous and well-made experiments of
Tillet, from  1760 to 1763, which are related in the memoirs of the Academy of
Sciences, show, in the silver assays, a loss still greater than that which was experienced
lately in the laboratory of the Commission of the French Mint. But he thought that,
as the error was common to the nations in general, it was not worth while or prudent
to introduce any innovation.
A mode of assaying, to give, with certainty, the standard cf silver bullion, should be
entirely independent of the variable circumstances of temperature, and the unknown
proportions of copper, so difficult to regulate by the mere judgment of the senses. The
process by the humid way, recommended by me to the Royal Mint in 1829, and exhibited as to its principles before the Right Honorable John Herries, then Master, in
1830, has all the precision and certainty we could wish. It is founded on the well-known
property which silver has, when dissolved in nitric acid, to be precipitated in a chloride of
silver quite insoluble, by a solution of sea salt, or by muriatic acid; but, instead of determining the weight of the chloride of silver, which would be somewhat uncertain and
rather tedious, on account of the difficulty of drying it, we take the quantity of the
solution of sea salt which has been necessary for the precipitation of the silver. To
put the process in execution, a liquor is prepared, composed of water and sea salt in such
proportions that 1000 measures of this liquor may precipitate, completely, 12 grains of
silver, perfectly pure, or of the standard 1000, previously dissolved in nitric acid. The
liquor thus prepared, gives, immediately, the true standard of any alloy whatever, of
silver and copper, by the weight of it which may be necessary to precipitate 12 grains
of this alloy  If, for example, 905 measures have been required to precipitate the 12
grains of alloy, its standard would be 905 thousandths.
The process by the humid way is, so to speak, independent of the operator. The
manipulations are so easy; and the term of the operation is very distinctly announced by
the absence of any sensible nebulosities on the affusion of sea salt into the silver solution,
while there remains in it 1 thousandth of metal. The process is not tedious, and in
experienced hands it may rival the cupel in rapidity; it has the advantage over the
cupel of being more within the reach of ordinary operators, and of not requiring a long
apprenticeship. It is particularly useful to such assayers as have only a few assays to
make daily, as it will cost them very little time and expense.
By agitating briskly during two minutes, or thereby, the liquid rendered milky by
the precipitation of the chloride of silver, it may be sufficiently clarified to enable us to
appreciate, after a few moments of repose, the disturbance that can be produced in it by
the addition of 1000 of a gram of silver. Filtration is more efficacious than agitation,
especially when it is employed afterwards; it may be sometimes used; but agitation,
which is much more prompt, is generally sufficient. The presence of lead and copper,
or any other metal, except mercury, has n perceptible influence on the quantity of sea
salt necessary to precipitate the silver; that is to say, the same quantity of silver, pure
or alloyed, requires for its precipitation a constant quantity of the solution of sea salt.
Supposing that we operate upon a gramme of pure silver, the solution of sea salt
ought to be such that 100 centimetres cube may precipitate exactly the whole silver.
The standard of an alloy is given by the number of thousandths of solution of sea salt
necessary to precipitate the silver contained in a gramme of the alloy.
When any mercury is accidentally present, which is, however, a rare occurrence, it
is made obvious by the precipitated chloride remaining white when exposed to daylight,
whereas when there is no mercury present, it becomes speedily first gray and then
purple. Silver so contaminated must be strongly ignited in fusion before being assayed,
and its loss of weight noted. In this case, a cupel assay must be had recourse to.
Preparation of the Normal Solution of Sea Salt, when it is measured by Weight.-Supposing the sea salt pure as well as the water, we have only to take these two bodies in
the proportion of 0-5427 k. of salt to 99-4573 k. of water, to have 100 k. of solution,




100                               ASSAY.
of which 100 grammes will precipitate exactly one gramme of silver. But instead of
pure salt, which is to be procured with difficulty, and which besides may be altered
readily by absorbing the humidity of the air, a concentrated solution of the sea salt of
commerce is to be preferred, of which a large quantity may be prepared at a time, to be
kept in reserve for use, as it is wanted. Instruction de Gay Lussac.
Preparation of the Normal Solution of Sea Salt, when measured by Volume.-The
measure by weight has the advantage of being independent of temperature, of having
the same degree of precision as the balance, and of standing in need of no correction.
The measure by volume has not all these advantages; but, by giving it sufficient
precision, it is more rapid, and is quite sufficient for the numerous daily assays of the
mint. This normal solution is so made, that a volume equal to that of 100 grammes
of water, or 100 centimetres cube, at a determinate temperature, may precipitate exactly
one gramme of silver. The solution may be kept at a constant temperature, and in
this case the assay stands in want of no correction; or if its temperature be variable,
the assay must be corrected according to its influence. These two circumstances make
no change in the principle of the process, but they are sufficiently important to occasion
some modifications in the apparatus. Experience has decided the preference in favor
of applying a correction to a variable temperature.
We readily obtain a volume of 100 cubic centimetres by means of a pipette, fig. 93,
so gauged that when filled with water up to the
95 9  93    mark a, b, and well dried at its point, it will run
r                      out, at a continuous efflux, 100 grammes of water
L  -L                 at the temperature of 15 C. (59 Fah.). We say
d  purposely at one efflux, because after the cessation
L v {_  11      of the jet, the pipette may still furnish two or
1)   a id 11    a   b  three drops of liquid, which must not be counted
IR'^  /r^> ov    or reckoned upon. The weight of the volume of
KaQ                         the normal solution, taken in this manner with
-D    i    s          suitable precautions, will be uniform from  one
extreme to another, upon two centimetres and a
N                     half, at most, or to a quarter of a thousandth, and
the difference from the mean will be obviously
twice less, or one half. Let us indicate the most
Q    /^       \  \            simple manner of taking a measure of the normal
solution of sea salt.
After having immersed the beak c of the pipette
in the solution, we apply suction by the mouth,
to the upper orifice, and thereby raise the liquid to
T          _. _ l  ^d, above the circular line a b. We next apply
neatly the forefinger of one hand to this orifice,
(  cV  Jremove the pipette from the liquid, and seize it
Ic\~ ~      as represented in fig. 94. The mark a b being
placed at the level of the eye, we make the surface of the solution become exactly a tangent to
the plane a b. At the instant it becomes a tangent, we leave the beak c of the pipette
open, by taking away the finger that had been applied to it, and without changing
anything else in the position of the hands, we empty it into the bottle which should
receive the solution, taking care to remove it whenever the efflux has run out.
If, after filling the pipette by suction, any one should find a difficulty in applying the
forefinger fast enough to the upper orifice, without letting the liquid run down below
the mark a b, he should remove the pipette from the solution with its top still closed
with his tongue, then apply the middle finger of one of his hands to the lower orifice;
after which he may withdraw his tongue, and apply the forefinger of the other hand to
the orifice previously wiped. This mode of obtaining a measure of normal solution of
sea salt is very sirnple, and requires no complex apparatus: but we shall indicate another
manipulation still easier, and also more exact.
In this new process the pipette is filled from the top like a bottle, instead of being
filled by suction, and it is moreover'fixed. Fig. 95 represents the apparatus. D and
D' are two sockets separated by a stop-cock R. The upper one, tapped interiorly,
receives, by means of a cork stopper L, the tube T, which admits the solution of sea
salt. The lower socket is cemented on to the pipette; it bears a smal. air-cock R', and
a screw plug v, which regulates a minute opening intended to let the air enter very
slowly into the pipette. Below the stop-cock R', a silver tube N, of narrow diameter,
soldered to the socket, leads the solution into the pipette, by allowing the air, which it
displaces, to escape by the stop-cock R'. The screw plug, with the milled head v',
replaces the ordinary screw by which the key of the stop-cock may be made to press,
with more or less force, upon its conical seat.




ASSAY.                                  101
Fig. 96 represents, in a side view, the apparatus just described. We here remark an
air-cock R, and an opening m. At the extremity Q of the same figure, the conical pipe
T enters, with friction. It is by this pipe that the air is sucked into the pipette when it
is to be filled from its beak.
The pipette is supported by two horizontal arms H K (fig. 97) moveable about a
common axis A A, and capable of being drawn
99             97                 out or shortened by the aid of two longituj /  R  Ac  dinal slits.  They are fixed steadily by two
- Adi, i\    e A^      screw nuts e i, and their distance may be varied
by means of round bits of wood or cork interposed, or even by opposite screw nuts o 6. The
upper arm H is pierced with a hole, in which
T?     *         r "   Fis fixed, by the pressure of a wooden screw v,
^&@ IR~ ~          the socket of the pipette. The corresponding
hole of the lower arm is larger; and the beak
of the pipette is supported in it by a cork stopper L. The apparatus is fixed by its tail-piece
P, by means of a screw, to the corner of a wall,
or any other prop.
The manner of filling the pipette is very simple. We begin by applying the fore-finger of
the left hand to the lower aperture c; we then
B s   v~         X ~ ^~ open the two stop-cocks R and t'. Whenever
_-   I - X  i o     the liquor approaches the neck of the pipette, we
must temper its influx, and when it has arrived
at some millimetres above the mark a b, we close
the two stop-cocks, and remove our fore-finger.
We have now nothing more to do than to regulate the pipette; for which purpose the liquid
must touch the line a b, and must simply adhere
externally to the beak of the pipette.
This last circumstance is easily adjusted.
After taking away the finger which closed the aperture c of the pipette, we apply to this
orifice a moist sponge m, fig. 88, wrapped up in a linen rag, to absorb the superfluous
liquor as it drops out. This sponge
98             is called the handkerchief (mouchoir), by M. Gay Lussac. The
~0Jtc                          pipette is said to be wiped when
t^Y^^t~~ m  |          there is no liquor adhering to its
point exteriorly.
For the convenience of operating, the handkerchief is fixed by
jl~~  F       friction in a tube of tin plate, terTURX  i^~s ~~~__~  ~minated by a cup, open at bottom
to let the droppings flow off into
V"''  C\^      Du\b  the cistern c, to which the tube is
~R   \ \ ~ —.   \     9 "^^    ^\^ soldered.  It may be easily removed for the purpose of washing
it; and, if necessary, a little wedge
of wood, o, can raise it toward the pipette.
To complete the adjustment of the pipette, the liquid must be made merely to descend
to the mark a, b. With this view, and while the handkerchief is applied to the beak
o the pipette, the air must be allowed to enter very slowly by unscrewing the plug v,
fig. 95; and at the moment of the contact the handkerchief must be removed, and the
bottle F, destined to receive the solution, must be placed below the orifice of the pipette,
fig. 98. As the motion must be made rapidly, and without hesitation, the bottle is
placed m. a cylinder of tin-plate, of a diameter somewhat greater, and forming one body
with the cistern and the handkerchief. The whole of this apparatus has for a basis a
plate of tinned iron, moveable between two wooden rulers R R, one of which bears a
groove, under which the edge of the plate slips. Its traverses are fixed by two abutments
b b, placed so that when it is stopped by one of them, the beak of the pipette corresponds
to the centre of the neck of the bottle, or is a tangent to the handkerchief. This
arrangement, very convenient for wiping the pipette and emptying it, gives the apparatus
sufficient solidity, and allows of its being taken away and replaced without deranging
anything. It is obvious that it is of advantage, when once the entry of the air into
the pipette has been regulated by the screw v, to leave it constantly open, because the




102                                 ASSAY.
motion from the handkerchief to the bottle is performed with sufficient rapidity to prevent
a drop of the solution from collecting and falling down.
Temperature of the Solution.-After having described the manner of measuring by
volume the normal solution of the sea salt, we shall indicate the most convenient means
of taking the temperature. The thermometer is placed in a tube of glass T, fig. 89,
which the solution traverses to arrive at the pipette. It is suspended in it by a piece of
cork, grooved on the four sides to afford passage to the liquid. The scale is engraved
upon the tube itself, and is repeated at the opposite side, to fix the eye by the coincidence
of this double division at the level of the thermometric column. The tube is joined
below to another narrower one, through which it is attached by means of a cork stopper
B, in the socket of the stop-cock of the pipette. At its upper part it is cemented into a
brass socket, screw-tapped in the inside, which is connected in its turn by a cock, with
the extremity, also tapped, of the tube above T, belonging to the reservoir of the normal
solution.  The corks employed here as connecting links between the parts of the
apparatus, give them a certain flexibility, and allow of their being dismounted and remounted in a very short time; but it is indispensable to make them be traversed by a
hollow tube of glass or metal, which will hinder them from being crushed by the pressure
they are exposed to. If the precaution be taken to grease them with a little suet, and to
fill their pores, they will suffer no leakage.
Preservation of the Normal Solution of Sea Salt in metallic Vessels.-M. Gay Lussac
uses for this purpose a cylindrical vessel or drum of copper, of a capacity of about 110
litres, having its inside covered with a rosin and wax cement.
Preparation of the Normal Solution of Sea Salt, measuring it by Volume.-If the drum
contains 110 litres, we should put only 105 into it, in order that sufficient space may be
left for agitating the liquor without throwing it out. According to the principle that
100 centimetres cube, or -- of a litre of the solution should contain enough of sea salt to
precipitate a gramme of pure silver; and, admitting, moreover, 13'516 for the prime equivalent of silver, and 7 335. for that of sea salt, we shall find the quantity of pure salt that
should be dissolved in the 105 litres of water, and which corresponds to 105 X 10 = 1050
grammes of silver, to be by the following proportion:13-516: 7-335:: 1050 gramm.: x=569-83 gr.
And as the solution of the sea salt of commerce, formerly mentioned, contains approximately 250 grammes per kilogramme, we must take 2279-3 grammes of this solution to
have 569-83 gram. of salt. The mixture being perfectly made, the tubes and the pipette
must be several times washed by running the solution through them, and putting it into
the drum. The standard of the solution must be determined after it has been well agitated, supposing the temperature to remain uniform.
To arrive more conveniently at this result, we begin by preparing two decimes solutions; one of silver, and another of sea salt.
The decime solution of silver is obtained by dissolving 1 gramme of silver in nitric acid,
and diluting the solution with water till its volume becomes a litre.
The decime solution of sea salt may be obtained by dissolving 0-543 grammes of pure
sea salt in water, so that the solution shall occupy a litre; but we shall prepare it even
with the normal solution which we wish to test, by mixing a-measure of it with 9 measures of water; it being understood that this solution is not rigorously equivalent to that
of silver, and that it will become so, only when the normal solution employed for its preparation shall be finally of the true standard. Lastly, we prepare beforehand several
stoppered vials, in each of which we dissolve 1 gramme of silver in 8 or 10 grammes of
nitric acid. For brevity's sake we shall call these tests.
Now to investigate the standard of the normal solution, we must transfer a pipette of
it into one of these test vials; and we must agitate the liquors briskly to clarify them.
After some instants of repose, we must pour in 2 thousandths of the decime solution o!
sea salt, which, we suppose, will produce a precipitate. The normal liquor is consequently too feeble; and we should expect this, since the sea salt employed was not perfectly pure. We agitate and add 2 fresh thousandths, which will also produce a precipitate. We continue thus by successive additions of 2 thousandths, till the last produces
no precipitation. Suppose that we have added 16 thousandths: the last two should not
be reckoned, as they produced no precipitate; the preceding two were necessary, but
only in part; that is to say, the useful thousandths added are above 12 and below 14, or
otherwise they are on an average equal to 13.
Thus, in the condition of the normal solution, we require 1013 parts of it to precipitate one gramme of silver, while we should require only 1000. We shall find the
quantity of concentrated solution of sea salt that we should add, by noting that the
quantity of solution of sea salt, at first employed, viz. 2279-3 grammes, produced a
standard of only 987 thousandths=100-13; and by using the following proportion:
987: 2279-3:3:  x=30'02 grammes.




ASSAY.                                   103
This quantity of the strong solution of salt, mixed with the normal soedtion in the
drum, will correct its standard, and we shall now see by how much.
After having washed the tubes and the pipette with the new  solution, we must
repeat the experiment upon a fresh gramme of silver. We shall find, for example, in
proceeding only by a thousandth at a time, that the first causes a precipitate, but not the
second. The standard of the solution is still too weak, and is comprised between 1000
and 1001; that is to say, it may be equal to 1000-, but we must make a closer approximation.
We pour into the test bottle 2 thousandths of the decime solution of silver, which will
destroy, perceptibly, two thousandths of sea salt, and the operation will have retrograded
by two thousandths; that is to say, it will be brought back to the point at which it was
first of all. If, after having cleared up the liquor, we add half a thousandth of the decime solution, there will necessarily be a precipitate, as we knew beforehand, but a second will cause no turbidity. The standard of the normal liquor will be consequently
comprehended between 1000 and 1000-, or equal to 1000-.
We should rest content with this standard, but if we wish to correct it, we may
remark that the two quantities of solution of salt added, viz. 2279-3 gr. +- 30-02 gr.=
2309-32 gr. have produced only 999-75 thousandths, and that we must add a new
quantity of it corresponding to - of a thousandth. We make, therefore, the proportion
999-75: 2309-32:: 0-25: x.
But since the first term  differs very little from  1000, we may content ourselves to
have x by taking the o_    of 2309-32, and we shall find 0'577 gr. for the quantity of
solution of sea salt to be added to the normal solution.
It is not convenient to take exactly so small a quantity of solution of sea salt by the
balance, but we shall succeed easily by the following process. We weigh 50 grammes
of this solution, and we dilute it with water; so that it occupies exactly half a litre, or
500 centimetres cube. A pipette of this solution, one centimetre cube in volume, will
give a decigramme of the primitive solution, and as such a small pipette is divided into
twenty drops, each drop, for example, will represent 5 milligrammes of the solution. We
should arrive at quantities smaller still by diluting the solution with a proper quantity
of water; but greater precision would be entirely needless.
The testing of the normal liquor just described, is, in reality, less tedious than might
be supposed. It deserves also to be remarked, that liquor has been prepared for more
than 1000 assays; and that, in preparing a fresh quantity, we shall obtain directly its true
standard, or nearly so, if we bear in mind the quantities of water and solution of salt
which had been employed.
Correction of the Standard of the Normal Solution of Sea Salt, when the Temperature
changes.-We have supposed, in determining the standard of the normal solution of sea
salt, that the temperature remained uniform. The assays made in such circumstances,
have no need of correction; but if  the temperature should change, the same measure of
the solution will not contain the same quantity of sea salt. Supposing that we have
tested the solution of the salt at the temperature of 15~ C.; if, at the time of making the
experiment, the temperature is 18~ C., for example, the solution will be too weak on account of its expansion, and the pipette will contain less of it by weight; if, on the contrary, the temperature has fallen to 120, the solution will be thereby concentrated and
will prove too strong. It is therefore proper to determine the correction necessary to be
made, for any variation of temperature.
To ascertain this point, the temperature of the solution of sea salt was made successively to be 0~, 5~, 100, 15~, 20~, 25~, and 30~ C.; and three pipettes of the solution were
weighed exactly at each of these temperatures. The third of these weighings gave the
mean weight of a pipette. The corresponding weights of a pipette of the solution, were
afterwards graphically interpolated from degree to degree. These weights form the second column of the following table, entitled, Table of Correctionfor the Variations in the
Temperature of the Normal Solution of the Sea Salt. They enable us to correct any temperature between 0 and 30 degrees centigrade (32~ and 86~ Fahr.) when the solution of
sea salt has been prepared in the same limits.
Let us suppose, for example, that the solution has been made standard at 15~, and
that, at the time of using it, the temperature has become 18~. We see by the second
column of the table, that the weight of a measure of the solution is 100*099 gr. at 15~,
and 100-065 at 18~; the difference 0-034 gr., is the quantity of solution less which has
been really taken; and of course we must add it to the normal measure, in order to
make it equal to one thousand milliemes. If the temperature of the solution had fallen
to 10 degrees, the difference of the weight of a measure from 10 to 15 degrees would be
0-019 gr., which we must on the contrary deduct from the measure, since it had been taken
too large. These differences of weight of a measure of solution at 15~, from that of a;




104                                 ASSAY.
measure at any other temperature, form the column 15~ of the table, where they are
expressed in thousandths; they are inscribed on the same horizontal lines as the tem.
peratures to which each of them relates, with the sign + plus, when they must be added,
and with the sign - minus, when they must be subtracted. The columns 50, 10~, 20~,
25~, 35~, have been calculated in the same manner for the cases in which the normal
solution may have been graduated to each of these temperatures. Thus, to calculate the
column 10, the number 100'118 has been taken of the column of weights for a term of
departure, and its difference from  all the numbers of the same column has been
sought.
Table of Correction for the Variations in the Temperature of the Normal Solution of
the Sea Salt.
Temperature.  Weight.     50       100      15~      20~       25~      300
gram.     mill.    mill.     mill.    mill.    mill.     mill.
4      100,109       0-0   -0-1          1       0-77 -    1-7   + 2-7
5       100,113      0-0   0-  1       0-71              - 17   + 2-8
6      100,115       0-0      0-0    - 0-2    40-8    - 1-7   + 2-8
7      110,118   4-0-1        0-0     -0-2       0-8      1-7        -8
8      100,120       0-1      0-0   — 02         0'8    -1-8    -2-8
9      100,120      0-1       0-0      0-2      00'8        1-8   +2-8
10      100,118       0-1      0-0 _0-2   +-0            - 1-7   +-2-8
I1      100,116      0-0       0-0   — 02    -0-8   -1-7   — 28
12      100,114       0-0      0-0      0-2   + 0-8       - 17       2-8
13      100,110       0-0      0 — 0      -1- 1   0-7     - 1-7       2-7
14      100,106      0'1   -- 01         0-1      0-7        1-6   +2-7
15      100,099      -01   — 0-2  — 0-0          00-6       1-6      2-6
16      100,090   - 0-2   - 03          0-1       0-5      1-5      2*5
17      100,078   - 0-4            -- 02   +0-4              1-3      2-4
18      100,065   - 0-5   - 05   -0-3   +0-3                 1-2   + 2-3
19      100,053   - 0-6   - 0-7   -05   +            0-1    -1-1   +  -22
20      100,039   — 0-7   - 0-8   -0-6            0-0   -1-0          2-0
21      100,021   - 0-9    - 1-0   -   -8          0-2   - 0-8       19
22      100,001   - 11   -  1-2   -  10   -0*4             0-6     - 1-7
23       99,983   - 13   — 14   -  1-2   -0*6              0-4   + 1-5
24       99,964   -1-5   -15    -  1-4   -0*8   - 02                 1-3
25       99,944   -1-7 - 1-7   -1-6               1-0 00             1-1
26       99,924   -1-9   -1-9   -1-8   -1-22   -02                   0-9
27       99,902   - 2-1   -2*2   - 20   -1*4   -0-4                 0-7
28       99,879   - 2-3   - 24   -  2-2           1-6   - 0-7        0-4
29       99,858   - 26   -2-6   -2-4              1-8   -0-9   +0-2
30       99,836   - 2-8       2-8   -2-6         2-0   - 11          0-0
Several expedients have been employed to facilitate and abridge the manipulations. In
the first place, the vials for testing or assaying the specimens of silver should all be of
the same height and of the same diameter. They should be numbered at their top, as well
as on their stoppers, in the order 1, 2, 3, &c. They may be ranged successively in tens;
the stoppers of the same series being placed on a support in their proper order. Each two
vials should, in their turn, be placed in a japanned tin case (fig. 100), with ten compartments duly numbered. These compartments are cut out anteriorly to about half their
height, to allow the bottoms of the bottles to be seen. When each vial has received its
portion of alloy, through a wide-beaked funnel, there must be poured into it about 10
grammes of nitric acid, of specific gravity 1-28, with a pipette, containing that quantity;
it is then exposed to the heat of a water bath, in order to facilitate the solution of the
alloy. The water bath is an oblong vessel made of tin plate, intended to receive the
vials. It has a moveable double bottom, pierced with small holes, for the purpose of preventing the vials being broken, as it insulates them from the bottom to which the heat is
applied. The solution is rapid; and, since it emits nitrous vapors in abundance, it ought
to be carried on under a chimney.
The agitator.-Fig. 101 gives a sufficiently exact idea of it, and may dispense with a
lengthened description. It has ten cylindrical compartments, numbered from 1 to 10.
The vials, after the solution of the alloy, are arranged in it in the order of their numbers. The agitator is then placed within reach of the pipette, intended to measure out
the normal solution of sea salt, and a pipette full of this solution is put in each vial.
Each is then closed with its glass stopper, previously dipped in pure water. They are
fixed in the cells of the agitator by wooden wedges. The agitator is then suspended




ASSAY.                                   105
to a spring R, and, seizing it with the two hands, the operator gives an alternating
rapid movement, which agitates the solution, and makes it, in less than a minute, as
101                           limpid as water.  This movement
R                             is promoted by a spiral spring, B,
fixed to the agitator and the ground,
but this is seldom  made use of, because it is convenient to be able to
transport the agitator from one place
to another. When the agitation is
finished, the wedges are to be taken
out, and the vials are placed in order
upon a table furnished with round
cells destined to receive them, and to
screen them from too free a light.
When we place the vials upon this
table, we must give them a brisk circular motion, to collect the chloride
of silver scattered round their sides;
we must lift out their stoppers, and
suspend them in wire rings, or pincers.
c. =  I _ _ _    We next pour a thousandth of the
decime solution into each vial; and
100 C   "             ilbefore this operation is terminated,
-t _ ll  g   there is formed in the first vials,
l,~ II~~  ~            when there should be a precipitate, a
nebulous stratum, very well marked,
_  ^ > _  Mof about a centimetre in thickness.
~ /B           At the back of the table there is a
black  board divided into compartments numbered from 1 to 10, upon
1 ll-l  each of which we mark, with chalk,:~ - ~  IIthe thousandths of the decime liquor
put into the correspondent vial. The
_i _  JT    ^thousandths of sea salt, which indicate
an augmentation of standard, are preceded by the sign +, and the thousandths of nitrate of silver by the sign -.
When the assays are finished, the liquor of each vial is to be poured into a large
vessel, in which a slight excess of sea salt is kept; and when it is fill, the supernatant
clear liquid must be run off with a syphon.
The chloride of silver may be reduced without any perceptible loss. After having
washed it well, we immerse pieces of iron or zinc into it, and add sulphuric acid in sufficient quantity to keep up a feeble disengagement of hydrogen gas. The mass must not
be touched. In a few days the silver is completely reduced. This is easily recognised
by the color and nature of the product; or by treating a small quantity of it with
water of ammonia, we shall see whether there be any chloride unreduced; for it will
be dissolved by the ammonia, and will afterwards appear upon saturating the ammonia
with an acid. The chlorine remains associated with the iron or the zinc in a state
of solution. The first washings of the reduced silver must be made with an acidulous
water, to dissolve the oxyde of iron which may have been formed, and the other washings
with common water. After decanting the water of the last washing, we dry the mass,
and add a little powdered borax to it. It must be now fused. The silver being in a
bulky powder, is to be put in successive portions into a crucible as it sinks down. The
heat should be at first moderate; but towards the end of the operation it must be pretty
strong to bring into complete fusion the silver and the scoriae, and to effect their
complete separation. In case it should be supposed that the whole of the silver had
not been reduced by the iron or zinc, a little carbonate of potash should be added to the
borax. The silver may also be reduced by exposing the chloride to a strong heat, in
contact with chalk and charcoal.
The following remarks by M. Gay Lussac, the author of the above method, upon the
effect of a little mercury in the humid assay, are important:It is well known that chloride of silver blackens the more readily as it is exposed
to an intense light, and that even in the diffused light of a room, it becomes soon
sensibly colored. If it contains four to five thousandths of mercury, it does not blacken;
it remains of a dead white: with three thousandths of mercury, there is no marked
discoloring in diffused light; with two thousandths it is slight; with one it is much
more marked, but still it is much less intense than with pure chloride. With half a




106                                 ASSAY.
thousandth of mercury the difference of color is not remarkable, and is perceived only
in a very moderate light.
But when the quantity of mercury is so small that it cannot be detected by the
difference of color in the chloride of silver, it may be rendered quite evident by a very
simple process of concentration. Dissolve one gramme of the silver supposed to contain
- of a thousandth of mercury, and let only - of it be precipitated, by adding only l  of
the common salt necessary to precipitate it entirely. In thus operating, the ^ thousandth of mercury is concentrated in a quantity of chloride of silver four times smaller:
it is as if the silver having been entirely precipitated, four times as much mercury,
equal to two thousandths, had been precipitated with it.
In taking two grammes of silver, and precipitating only - by common salt, the
precipitate would be, with respect to the chloride of silver, as if it amounted to four
thousandths. By this process, which occupies only five minutes, because exact weighing
is not necessary, iL of a thousandth of mercury may be detected in silver.
It is not useless to observe, that in making those experiments the most exact manner
of introducing small quantities of mercury into a solution of silver, is to weigh a minute
globule of mercury, and to dissolve it in nitric acid, diluting the solution so that it
may contain as many cubic centimetres as the globule weighs of centigrammes. Each
cubic centimetre, taken by means of a pipette, will contain one milligramme of
mercury.
If the ingot of silver to be assayed is found to contain a greater quantity of mercury,
one thousandth for example, the humid process ought either to be given up in this
case, or to be compared with cupellation.
When the silver contains mercury, the solution from which the mixed chlorides are
precipitated does not readily become clear.
Silver containing mercury, put into a small crucible and mixed with lamp-black,
to prevent the volatilization of the silver, was heated for three quarters of an hour
in a muffle, but the silver increased sensibly in weight. This process for separating the
mercury, therefore, failed. It is to be observed, that mercury is the only metal which
has thus the power of disturbing the analysis by the humid way.
ASSAYING OF GOLD.-In estimating or expressing the fineness of gold, the whole
mass spoken of is supposed to weigh 24 carats of 12 grains each, either real, or merely
proportional, like the assayer's weights; and the pure gold is called fine. Thus, if
gold be said to be 23 carats fine, it is to be understood, that in a mass, weighing
24 carats, the quantity of pure gold amounts to 23 carats.
In such small work as cannot be assayed by scraping off a part and cupelling it,
the assayers endeavor to ascertain its fineness or quality by the touch. This is a
method of comparing the color and other properties, of a minute portion of the
metal, with those of small bars, the composition of which is known. These bars are
called touch needles, and they are rubbed upon a smooth piece of black basaltes or
pottery, which, for this reason, is called the touchstone. Black flint slate will serve
the same purpose. Sets of gold needles may consist of pure gold; of pure gold, 23A
Carats with 2 carat of silver; 23 carats of gold with one carat of silver; 221 carats of
gold with 11 carat of silver; and so on, till the silver amounts to four carats; after
which the additions may proceed by whole carats. Other needles may be made in the
same manner, with copper instead of silver; and other sets may have the addition,
consisting either of equal parts of silver and copper, or of such proportions as the
occasions of business require. The examination by the touch may be advantageously
employed previous to quartation, to indicate the quantity of silver necessary to be
added.
In foreign countries, where trinkets and small work are required to be submitted to
the assay of the touch, a variety of needles is necessary; but they are not much used
in England. They afford, however, a degree of information which is more considerable
than might at first be expected. The attentive assayer compares not only the color of
the stroke made upon the touchstone by the metal under examination, with that produced
by his needle, but will likewise attend to the sensation of roughness, dryness, smoothness, or greasiness, which the texture of the rubbed metal excites, when abraded by the
stone. When two strokes perfectly alike in color are made upon the stone, he may
then wet them with aquafortis, which will affect them very differently. if they be not
similar compositions; or the stone itself may be made red-hot by the fire, or by the blowpipe, if thin black pottery be used; in which case the phenomena of oxydation will differ
according to the nature and quantity of the alloy. Six principal circumstances appear
to affect the operation of parting; namely, the quantity of acid used in parting, or in
the first boiling; the concentration of this acid; the time employed in its application;
the quantity of acid made use of in the reprise, or second operation; its concentration;
and the time during which it is applied. From experiment it has been shown, that
each of these unfavorable circumstances might easily occasion a loss of from the half of




ASSAY.                                      107
a thirty-second part of a carat, to two thirty-second parts. The assayers explain their
technical language by observing, that in the whole mass consisting of twenty-four carats,
this thirty-second part denotes 1-768th part of the mass. It may easily be conceived,
therefore, that if the whole six circumstances were to exist, and be productive of errors,
falling the same way, the loss would be very considerable.
It is therefore indispensably necessary, that one uniform process should be followed
in the assays of gold; and it is a matter of astonishment, that such an accurate process
should not have been prescribed by government for assayers, in an operation of such
great commercial importance, instead of every one being left to follow  his own
judgment.  The process recommended in the old French official report is as follows:
twelve grains of the gold intended to be assayed must be mixed with thirty grains of
fine silver, and cupelled with 108 grains of lead. The cupellation must be carefully
attended to, and all the imperfect buttons rejected. When the cupellation is ended, the
Dutton must be reduced, by lamination, into a plate of 1  inches, or rather more, in
length, and four or five lines in breadth.  This must be rolled up upon a quill, and
placed in a matrass capable of holding about three ounces of liquid, when filled up to
its narrow  part.  Two ounces and a half of very pure aquafortis, of the strength of 20
degrees of Baume's areometer, must then be poured upon it; and the matrass being
placed upon hot ashes, or sand, the acid must be kept gently boiling for a quarter of an
hour: the acid must then be cautiously decanted, and an additional quantity of 12
ounces must be poured upon the metal, and slightly boiled for twelve minutes.  This
being likewise carefully decanted, the small spiral piece of metal must be washed with
filtered river water, or distilled water, by filling the matrass with this fluid. The
vessel is then to be reversed, by applying the extremity of its neck against the bottom
of a crucible of fine earth, the internal surface of which is very smooth. The annealing
must now be made, after having separated the portion of water which had fallen into
the crucible; and, lastly, the annealed gold must be weighed.  For the certainty of
this operation, two assays must be made in the same manner, together with a third assay upon gold of twenty-four carats, or upon gold the fineness of which is perfectly and
generally known.
No conclusion must be drawn from this assay, unless the latter gold should prove to
be of the fineness of twenty-four carats exactly, or of its known degree of fineness; for,
if there he either loss or surplus, it may be inferred that the other two assays, having
undergone the same operation, must be subject to the same error. The operation being
made according to this process by several assayers, in circumstances of importance, such
as those which relate to large fabrications, the fineness of the gold must not be depended
upon, nor considered as accurately known, unless all the assayers have obtained a uniform result, without communication with each other. This identity must be considered as
referring to the accuracy of half the thirty-second part of a carat. For, notwithstanding
every possible precaution or uniformity, it very seldom happens that an absolute agreement is obtained between the different assays of one and the same ingot; because the
ingot itself may differ in its fineness in different parts of its mass.
The phenomena of the cupellation of gold are the same as of silver, only the operation is less delicate, for no gold is lost by evaporation or penetration into the boneash, and therefore it bears safely the highest heat of the assay furnace. The button
of gold never vegetates, and need not therefore be drawn out to the front of the muffle,
but may be left at the further end till the assay is complete. Copper is retained more
strongly by gold than it is by silver; so that with it 16 parts of lead are requisite to
sweat out 1 of copper; or, in general, twice as much lead must be taken for the copper
alloys of gold, as for those of silver.  When the copper is alloyed with very small quantities of gold, cupellation would afford very uncertain results; we must then have recourse to liquid analysis.
M. Vauquelin recommends to boil 60 parts of nitric acid at 22~ Baume, on the spiral
slip or cornet of gold and silver alloy, for twenty-five minutes, and replace the liquid
afterwards by acid of 32~, which must be boiled on it for eight minutes. This process
is free from uncertainty when the assay is performed upon an alloy containing a considerable quantity of copper. But this is not the case in assaying finer gold; for then
a little silver always remains in the gold. The surcharge which occurs here is 2 or 3
thousandths; this is too much, and it is an intolerable error when it becomes greater,
which often happens.  This evil may be completely avoided by employing the following
process of M. Chaudet. He takes 0'500 of the fine gold to be assayed; cupels it with
1-500 of silver, and 1-000 of lead; forms, with the button from the cupel, a riband or
strip three inches long, which he rolls into a cornet. He puts this into a matrass with
acid at 22~ B., which he boils for 3 or 4 minutes. He replaces this by acid of 32~ B., and
boils for ten minutes; then decants off, and boils again with acid of 320, which must be
finally boiled for 8 or 10 minutes.
Gold thus treated is very pure. He washes the cornet, and puts it entire into a small




108                              AUTOMATIC.
crucible permeable to water; heats the crucible to dull redness under the muffle, when
the gold assumes the metallic lustre, and the cornet becomes solid. It is now taken out
of the crucible and weighed.
When the alloy contains platinum, the assay presents greater difficulties. In general,
to separate the platinum from the gold with accuracy, we must avail ourselves of a peculiar property of platinum; when alloyed with silver, it becomes soluble in nitric acid.
Therefore, by a proper quartation of the alloy by cupellation, and boiling the button with
nitric acid, we may get a residuum of pure gold. If we were to treat the button with
sulphuric acid, however, we should dissolve nothing but the silver. The copper is easily
removed by cupellation. Hence, supposing that we have a quaternary compound of cop.
per, silver, platinum, and gold, we first cupel it, and weigh the button obtained; the loss
denotes the copper. This button, treated by sulphuric acid, will suffer a loss of weight
equal to the amount of silver present. The residuum, by quartation with silver and boiling with nitric acid, will part with its platinum, and the gold will remain pure. For
more detailed explanations, see PLATINUM.
ATOMIC WEIGHTS OR ATOMS, are the primal quantities in which the different
objects of chemistry, simple or compound, combine with each other, referred to a common
body, taken as unity. Oxygen is assumed by some philosophers, and hydrogen by others,
as the standard of comparison. Every chemical manufacturer should be thoroughly acquainted with the combining ratios, which are, for the same two substances, not only definite, but multiple; two great truths, upon which are founded not merely the rationale of
his operations, but also the means of modifying them to useful purposes. The discussion of the doctrine of atomic weights, or prime equivalents, belongs to pure chemistry;
but several of its happiest applications are to be found in the processes of art, as pursued
upon the greatest scale. For many instructive examples of this proposition, the various
chemical manufactures may be consulted in this Dictionary.
ATROPIA; a vegetable alkali extracted from  the Atropa belladonna, or deadly
night-shade. It is composed of about 70'98 carbon, 7'83 hydrogen, 4-83 azote, and
16'36 oxygen in 100 parts.  It is prepared by treating the expressed juice of the fresh
plant, or watery extract of the dry, with caustic soda unto slight alkaline reaction, and
then agitating the mixture with one and a half times its volume of ether. The atropia
is taken up by the ether, but again deposited from it when the ethereous solution is
left at rest for some time. The treatment with ether is repeated upon the first precipitate, till the atropia becomes pure. Other processes are prescribed.
ATTAR OF ROSES. See OILS, VOLATILE, and PERFUMERY.
AURUM MUSIVUM. Mosaic gold, a preparation of tin; which see.
AUTOMATIC, a term which I have employed to designate such economic arts as
are carried on by self-acting machinery.  The word "manufacture," in its etymological sense, means any system or objects of industry executed by the hands; but in
the vicissitude of language, it has now come to signify every extensive product of
art which is made by machinery, with little or no aid of the human hand, so that the
most perfect manufacture is that which dispenses entirely with manual labor.* It is
in our modern cotton and flax mills that automatic operations are displayed to most
advantage; for there the elemental powers have been made to animate millions of
complex organs, imparting to forms of wood, iron and brass, an intelligent agency.
And as the philosophy of the fine arts, poetry, painting, and music, may be best studied in their individual masterpieces, so may the philosophy of manufactures in these
its noblest creations.t.
The constant aim and effect of these automatic improvements in the arts are philanthropic, as they tend to relieve the workman either from niceties of adjustment, which
exhaust his mind and fatigue his eyes, or from painful repetition of effort, which distort
and wear out his frame. A well arranged power-mill combines the operation of many
work-people, adult and young, in tending with assiduous skill a system of productive
machines continuously impelled by a central force.  How vastly conducive to the
commercial greatness of a nation, and the comforts of mankind, human industry can
become, when no longer proportioned in its results to muscular effort, which is by its
nature fitful and capricious, but when made to consist in the task of guiding the work
of mechanical fingers and arms regularly impelled, with equal precision and velocity,
by some indefatigable physical agent, is apparent to every visitor of our cotton, flax,
silk, wool, and machine factories. This great era in the useful arts is mainly due to
the genius of Arkwright. Prior to the introduction of his system, manufactures were
every where feeble and fluctuating in their development, shooting forth luxuriantly for
a season, and again withering almost to the roots like annual plants. Their perennial
growth then began, and attracted capital, in copious streams, to irrigate the rich domains
* Philosophy of Manufactures, p. 1.        t Ibid., p. 2.




AUTOMATON.                                   109
of industry.  When this new career commenced, about the year 1V70, the annual
consumption of cotton in British manufactures was under four millions of pounds'
weight, and that of the whole of Christendom was probably not more than ten millions.
In 1850 the consumption in Great Britain and Ireland was about five hundred and
eighty-eight millions of pounds, and that of Europe and the United States together one
thousand and ninety-two millions. In our spacious factory apartments the benignant
power of steam summons around him his myriads of willing menials, and assigns to each
the regulated task, substituting for painful muscular effort upon their part, the energies
of his own gigantic arm, and demanding in return, only attention and dexterity to correct such little aberrations as casually occur in his workmanship. Under his auspices
and in obedience to Arkwright's polity, magnificent edifices, surpassing far in number,
value, usefulness, and ingenuity of construction, the boasted monuments of Asiatic,
Egyptian, and Roman despotism, have, within the short period of fifty years, risen up
in this kingdom, to show to what extent capital, industry, and science, may augment
the resources of a state, while they meliorate the condition of its citizens. Such is the
automatic system, replete with prodigies in mechanics and political economy, which
promises, in its future growth, to become the great minister of civilization to the terraqueous globe, enabling this country, as its heart, to diffuse, along with its commerce,
the life-blood of knowledge and religion to myriads of people still lying " in the region
and shadow of death."*  Of these truths, the present work affords decisive evidence in
almost every page.
AUTOMATON. In the etymological sense, this word (self-working) signifies every
mechanical construction which, by virtue of a latent intrinsic force, not obvious to common eyes, can carry on, for some time, certain movements more or less resembling the
results of animal exertion, without the aid of external impulse. In this respect, all kinds
of clocks and watches, planetariums, common and smoke jacks, with a vast number of the
machines now employed in our cotton, silk, flax, and wool factories, as well as in our
dyeing and calico printing works, may be denominated automatic. But the term, automaton, is, in common language, appropriated to that class of mechanical artifices in which
the purposely concealed power is made to imitate the arbitrary or voluntary motions of
living beings. Human figures, of this kind, are sometimes styled.ndroides, from the
Greek term, like a man.
Although, from what we have said, clock-work is not properly placed under the
head automaton, it cannot be doubted that the art of making clocks, in its progressive
improvement and extension, has given rise to the production of automata. The most
of these, in their interior structure, as well as in the mode of applying the moving
power, have a distinct analogy with clocks; and these automata are frequently mounted
in connexion with watch work. Towards the end of the 13th century, several tower
clocks, such as those at Strasburg, Lubec, Prague, Olmutz, had curious mechanisms
attached to them. The most careful historical inquiry proves that automata, properly
speaking, are certainly not older than wheel-clocks; and that the more perfect structures of this kind are subsequent to the general introduction of spring-clocks. Many
accounts of ancient automata, such as the flying doves of Archytas of Tarentum.
Regiomontanus's iron flies, the eagle which flew towards the emperor Maximilian, in
Nuremburg, in the year 1470, were deceptions, or exaggerated statements; for, three such
masterpieces of art would form now, with every aid of our improved mechanisms, the
most difficult of problems. The imitation of flying creatures is extremely difficult, for
several reasons. There is very little space for the moving power, and the only material possessed of requisite strength being metal, must have considerable weight. Two
automata, of the celebrated French mechanician, Vaucauson, first exhibited in the year
1738, have been greatly admired; namely, a flute-player, five and a half feet high, with
its cubical pedestal, which played several airs upon the German flute; and that, not by
any interior tube-work, but through the actual blowing of air into the flute, the motion
of the tongue, and the skilful stopping of the holes with the fingers; as also a duck,
which imitated many motions of a natural kind in the most extraordinary manner.
This artist has had many imitators, of whom the brothers Droz of Chaux de Fonds
were the most distinguished. Several very beautiful clock mechanisms of theirs are
known. One of them with a figure which draws; another playing on the piano; a third
which writes, besides numerous other combined automata. Frederick Von Knauss
completed a writing machine at Vienna, in the year 1760. It is now in the model
cabinet of the Polytechnic Institute, and consists of a globe 2 feet in diameter, containing the mechanism, upon which a figure 7 inches high sits, and writes upon a sheet
of paper fixed to a frame, whatever has been placed beforehand upon a regulating cylinder. At the end of every line, it rises and moves its hand sideways, in order to begin
a new line.
Very complete automata have not been made of late years, because they are very
* Philosophy of Manufactures, p. 18




110                              AUTOMATON.
expensive; and by soon satisfying curiosity, they cease to interest. Ingenious mechanicians find themselves better rewarded by directing their talents to the self-acting
machinery of modern manufactures.  We may notice here, however, the mechanical
trumpeter of Malzl, at Vienna, and a similar work of Kauffmann, at Dresden.  In
French Switzerland some artists continue to make minute automata which excite no
little wonder; such as singing canary birds, with various movements of a natural kind;
also little birds, sometimes hardly three-quarters of an inch long, in snuff-boxes and
watches of enamelled gold. Certain artificial figures which have been denominated
automata, hardly deserve the name; since trick and confederacy are more or less concerned in their operation. To this head belong a number of figures apparently speaking
by mechanism; a clock which begins to strike, or to play, when a person makes a
sign of holding up his finger; this effect being probably produced by a concealed
green-finch, or other little bird, instructed to set off the detente of the wheel-work at a
signal. It is likely, also, that the chess player of Von Kempelen, which excited so much
wonder in the last century, had a concealed confederate. Likewise, the very ingenious
little figures of Tendler, father and son, which imitated English horsemen and rope-dancers, constructed at Eisenerz, in Styria, are probably no more true automata than the
fantoccini, or figures of puppets which are exhibited in great perfection in many towns of
Italy, especially at Rome.
The moving power of almost all automata is a wound-up steel spring; because in comparison with other means of giving motion, it takes up the smallest room, is easiest concealed, and set a-going. Weights are seldom employed, and only in a partial way. The
employment of other moving powers is more limited; sometimes fine sand is made to fall
on the circumference of a wheel, by which the rest of the mechanism is moved. For the
same purpose water has been employed; and, when it is made to fall into an air-chamber,
it causes sufficient wind to excite musical sounds in pipes. In particular cases quicksilver has been used, as, for example, in the Chinese tumblers, which is only a physical ap
paratus to illustrate the doctrine of the centre of gravity.
Figures are frequently constructed for playthings which move by wheels hardly visible.
An example of this simplest kind of automaton which may be introduced here, as illustrating the self-acting principles of manufactures, is shown in the figure.
Fig. 102 exhibits the outlines of an automaton, representing a swan, with suitably
combined movements. The mechanism  may be described, for the sake of clearness
of explanation, under distinct heads. The first relates
to the motion of the whole
figure. By means of this
1^1~102  ~part it swims upon the water,
^11~~102 -in directions changed from
time to time without exterior
agency. Another construclj[hill~~ ntion gives to the figure the
faculty of bending its neck on
/l  Q;l AT~    i'\                     several occasions, and  to
/HS/JI  ((fhi ^such an extent that it can
1,,  l   plunge the bill and a portion
of the head under water.
Lastly, it is made to move
~\^Qin /y*/ ij Gl  >its head and neck  slowly
=/e  ~         ifrom side to side.
On the barrel of the spring,
exterior to the usual ratchet
wheel, there is a main-wheel, marked 1, which works into the pinion of the wheel 2.
The. wheel 2 moves a smaller one, shown merely in dotted lines, and on the long axis
of the latter, at either end there is a rudder, or water-wheel, the paddles of which are
denoted by the letter a. Both of these rudder-wheels extend through an oblong
opening in the bottom of the figure down into the water. They turn in the direction
of the arrow, and impart a straight-forward movement to the swan. The chamber,
in which these wheels revolve, is made water tight, to prevent moisture being thrown
upon the rest of the machinery. By the wheel 4, motion is conveyed to the fly-pinion 5;
the fly itself 6, serves to regulate the working of the whole apparatus, and it is provided
with a stop bar not shown in the engraving, to bring it to rest, or set it a-going at
pleasure. Here, as we may imagine, the path pursued is rectilinear, when the rudderwheels are made to work in a square direction. An oblique bar, seen only in section
at b, moveable about its middle point, carries at each end a web foot c, so that the direction of the bar b, and of both feet towards the rudder wheels, determines the form of
the path which the figure will describe. The change of direction of that oblique bar




AUTOMATON.                                     111
is effected without other agency. For this purpose, the wheel 1 takes into the pinion 7,
and this carries round the crown-wheel 8, which is fixed, with an eccentric disc 9, upon
a common axis.  While the crown-wheel moves in the direction of the arrow, it turns
the smaller eccentric portion of the elliptic disc towards the lever m, which, pressed
upon incessantly by its spring, assumes, by degrees, the position corresponding with the
middle line of the figure, and afterwards an oblique position; then it goes back again,
and reaches its first situation; consequently through the reciprocal turning of the bar h,
and the swim-foot, is determined and varied the path which the swan must pursue.
This construction is available with all automata, which work by wheels; and it is obvious, that we may, by different forms of the disc 9, modify, at pleasure, the direction
and the velocity of the turnings. If the disc is a circle, for instance, then the changes
will take place less suddenly; if the disc has an outward and inward curvature, upon
whose edge the end of the lever presses with a roller, the movement will take place in a
serpentine line.
The neck is the part which requires the most careful workmanship. Its outward case
must be flexible, and the neck itself should therefore be made of a tube of spiral wire,
covered with leather, or with a feathered bird-skin. The double line in the interior,
where we see the triangles e, e, e, denotes a steel spring made fast to the plate 10, which
forms the bottom of the neck; it stands loose, and needs to be merely so strong as to
keep the neck straight, or to bend it a little backwards. It should not be equally
thick in all points, but it should be weaker where the first graceful bend is to be made;
and, in general, its stiffness ought to correspond to the curvature of the neck of this bird.
The triangles e are made fast at their base to the front surface of the spring; in the
points of each there is a slit, in the middle of which a moveable roller is set, formed of a
smoothly turned steel rod. A thin catgut string f, runs from  the upper end of the
spring, where it is fixed over all these rollers, and passes through an aperture pierced
in the middle of 10, into the inside of the rump.  If the catgut be drawn straight
back towards f, the spring, and consequently  the neck, must obviously be bent,
and so much the more, the more tightly f is pulled, and is shortened in the hollow of
the neck. How this is accomplished by the wheel-work will presently be shown. The
wheel 11 receives its motion from  the pinion s, connected with the main-wheel 1.
Upon 11 there is, moreover, the disc 12, to whose circumference a slender chain is
fastened.  When the wheel 11 turns in the direction of the arrow, the chain will be so
much pulled onwarjs through the corresponding advance at the point at 12, till this
point has come to the place opposite to its present situation, and, consequently, 11 must
have performed half a revolution. The other end of the chain is hung in the groove
of a very moveable roller 14; and this will be turned immediately by the unwinding of
the chain upon its axis. There turns, in connexion with it, however, the large roller 13,
to which the catgut f is fastened; and as this is pulled in the direction of the arrow,
the neck will be bent until the wheel 11 has made a half revolution. Then the drag
ceases again to act upon the chain and the catgut; the spring in the neck comes into
play: it becomes straight, erects the neck of the animal, and turns the rollers 13 and
14, back into their first position.
The roller 13 is of considerable size, in order that through the slight motion of the
roller 14, a sufficient length of the catgut may be wound off, and the requisite shortening of the neck may be effected; which results from the proportion of the diameters
of the rollers 11, 13, and 14. This part of the mechanism is attached as near to the
side of the hollow body as possible, to make room for the interior parts, but particularly
for the paddle-wheels.  Since the catgut,f, must pass downwards on the middle from
10, it is necessary to incline it sideways and outwards towards 13, by means of some
small rollers.
The head, constituting one piece with the neck, will be depressed by the complete
flexure of this; and the bill, being turned downwards in front of the breast, will touch
the surface of the water. The head will not be motionless; but it is joined on both
sides by a very moveable hinge, with the light ring, which forms the upper part of the
clothing of the neck. A weak spring, g, also fastened to the end of the neck, tends to
turn the head backwards; but in the present position it cannot do so, because a chain
at g, whose other end is attached to the plate 10, keeps it on the stretch. On the bending
of the neck, this chain becomes slack; the spring g comes into operation, and throws
the head so far back, that, in its natural position, it will reach the water.
Finally, to render the turning of the head and the neck practicable, the latter is not
closely connected with the rump, while the plate 10 can turn in a cylindrical manner
upon its axis, but cannot become loose outwardly. Moreover, there is upon the axis of
the wheel 1, and behind it (shown merely as a circle in the engraving) a bevel wheel,
which works into a second similar wheel, 15, so as to turn it in a horizontal direction.
The pin 16, of the last wheel, works upon a two-armed lever 19, moveable round the
point h, and this lever moves the neck by means of the pin 17. The shorter arm of the




112                            AUTOMATON.
lever 19 has an oval aperture in which the pin 16 stands. As soon as this, in eonsequence of the movement of the bevel-wheel 15, comes into the dotted position, it pushes the oval ring outwayds on its smaller diameter, and thereby turns the lever upon the
point h, into the oblique direction shown by the dotted lines. The pin 16, having come
on its way right opposite to its present position, sets the lever again straight. Then the
lever, by the further progress of the pin in its circular path, is directed outwards to the
opposite side; and, at last, when 15 has made an entire revolution, it is quite straight.
The longer arm of the lever follows, of course, these alternating movements, so that
it turns the neck upon its plate 10, by means of the pin 17; and, as 18 denotes the bill,
this comes into the dotted position. It may be remarked in conclusion, that the
drawing of fig. 102 represents about half the size of which the automaton may be
constructed, and that the body may be formed of thin sheet-copper or brass.
Fig. 103, 104, 105, show the plan of a third automaton; a horse which moves its feet
~~~~103  /   I   \ ~~~105
Q -
~~~~104   (lese                                 o..
in a natural way, and draws a carriage with two figures sitting in it. The man appears
to drive the horse with a whip; the woman bends forward from him in front. The
four wheels of the carriage have no connexion with the moving mechanism. In fig. 105,
some parts are represented upon a larger scale. The wheel 1, in fig. 103, operates
through the two carrier wheels upon the wheels marked 4 and 5. By means of the axis
of these two wheels, the feet are set in motion. The left fore-foot, a, then the right
hinder foot, move themselves backwards, and take hold of the ground with small tacks
in their hoofs, while the two other legs are bent and raised, but no motion of the body
takes place. The carriage, however, with which the horse is connected, advances upon
its wheels. By studying the mechanism of the foot, a, and the parts connected with it,
we can readily understand the principles of the movement. The axis of wheel 4 is
crank-shaped on both sides, where it has to operate directly on the fore feet; but for
each foot, it is bent in an opposite direction, as is obvious in the front view fig.104.
This crank, or properly its part furthest from the axis, serves instead of the pin 16, in
the swan, and moves like it in an oval spot, p, fig. 103, a two-armed lever, which gives
motion through tooth-work, but not as in the swan, by means of a second pin. This wheelwork renders the motion smoother. The above lever has its fulcrum at n,fig. 103, about
which it turns alternately, to the one and the other side, by virtue of the rotation of the
wheel 4. The toothed arch, or the half-wheel on the under side, lays hold of a shorter
lever, in a similar arch, upon the upper joint of the foot, which is moved forward and
backward upon the pivot m. In virtue of the motions in the direction of the arrow,
the foot a will move itself first obliquely backwards, without bending, and the body
will thereby bend itself forward. When the right hand foot makes the same motion,
both the other feet are raised and bent. The joints of the foot at d and e are formed
of hinges, which are so constructed that they can yield no farther than is necessary at
every oblique position of the foot. With the continued rotation of the wheel 4, the
lever turns itself about a, in an inverted direction inwards, and impels the uppermost
foot-joint forward, so that it forms an acute angle with the body in front. The foot is
now twice bent upon its joints. This takes place by the traction of the chain t, which
is led over rollers (as the drawing shows) to the foot, and is there fastened. As its
upper end has its fixed point in the interior of the body, it is therefore drawn by
the eccentric pin r standing in the vicinity of m, and thus bends the foot at the
hinges. If there was space for it, a roller would answer better than a pin. By




AVENTURINE.                                  113
the recedure of the uppermost joint into the first position, the tension of the chain t
ceases again of itself, while the pin r removes from it, and the foot is again extended
in a straight line by the small springs operating upon its two under parts, which were
previously bent stiffly by the chain. By the aid of the figures with this explanation,
it will be apparent that all the fore feet have a similar construction, that the proper
succession of motions will be effected through toothed arcs, and the position of the
cranks on the axis of the wheels 4 and 5, and hence the advance of the figure must
follow. The wheel 6 puts the fly 7 in motion, by means of the small wheel marked 1;
on the fixed points of the 4 chains, by means of a ratchet-wheel and a catch, the necessary tension will again be produced when the chains have been drawn out a little.
There is sufficient room for a mechanism which could give motion to the head and
ears, were it thought necessary.
The proper cause of the motions may now be explained. In fig. 105, a, is a wheel
connected with the wound-up spring, by which the motion of the two human figures,
and also, if desired, that of the horse may be effected. The axis of the wheel b carries
a disc with pins, which operate upon the two-armed lever with its fulcrum e, and thus
causes the bending of the upper part of one of the figures, which has a hinge atf.
On the axis of that wheel there is a second disc c, for giving motion to the other
figure; which, for the sake of clearness, is shown separate, although it should sit
alongside of its fellow. On the upper end of the double-armed lever d, there is a
cord whose other end is connected with the moving arm, in the situation i, and raises
it whenever a pin in the disc presses the under part of the lever. A spring h brings
the arm back into the original position, when a pin has passed from the lever, and has
left it behind. The pins at c and d may be set at different distances from the middle
of the disc, whereby the motions of the figures by every contact of another pin, are
varied, and are therefore not so uniform, and consequently more natural.
For the connection of both mechanisms, namely, the carriage with the horse, various arrangements may be adopted. Two separate traction springs should be employed; one at a, fig. 105, in the coach-seat; the other in the body of the horse. In the
coach-seat at b, the fly with its pinion, as well as a ratchet-wheel, is necessary. Bymeans
of the shaft, the horse is placed in connection with the wagon. It may, however,
receive its motion from the spring in the carriage, in which case one spring will be sufficient. Upon the latter plan the following construction may be adopted:-To the
axis of b, fig. 105, a bevel wheel is to be attached, and from this the motion is to be
transmitted to the bottom of the carriage with the help of a second bevel wheel s,
connected with a third bevel wheel t. This again turns the wheel u, whose long
axis v goes to the middle of the horse's body, in an oblique direction, through the hollow shaft. This axis carries an endless screw 9, fig. 103, with very oblique threads,
which works into the little wheel 8, corresponding to the wheel 1, through an opening in the side of the horse, and in this way sets the mechanism of the horse a-going.
With this construction of fig. 105, a spring of considerable strength is necessary, or
if the height of the carriage-seat does not afford sufficient room, its breadth will answer for placing two weaker springs alongside of each other upon a common barrel.
AVENTURINE.  According to Wohler's examination, aventurine glass owes its
golden iridescence to a crystalline separation of metallic copper from the mass colored brown by the peroxide of iron.
In the aventurine glaze for porcelain a crystalline separation of green oxide of
chromium from  the brown ferruginous mass of the glaze produces a similar effect.
This glaze is prepared as follows:
31 parts of fine lixiviated dry porcelain earth from Halle,
43      do.       do.    dry quartz sand,
14      do.       do.    gypsum,
12      do.      do.   fragments of porcelain,
are stirred up with 300 parts of water, and by repeated straining through a linen sieve
uniformly suspended in it, and intimately mixed. To this paste is added, under constant agitation and one after the other, aqueous solutions of
19 parts bichromate of potash,
100  "   protosulphate of iron,
47"   acetate of lead,
and then so much solution of ammonia that the iron is completely separated. The
salts of potash and ammonia are removed by frequent decantation with spring water.
The baked porcelain vessels are dipped into the pasty mixture obtained as above
described in the same manner as with other glazes, and then fired in the porcelain
furnace. After this they appear covered with a brown glaze, which in reflected light
appears to be filled with a countless number of light gold spangles.
VOL. I.




114                              BALANCE.
A thin fragment of the glass appears, under the microscope, by transmitted light, as
a clear brownish glass, in which numerous transparent green six-sided prisms of oxide
of chromium, and some brownish crystals, probably of oxide of chromium and peroxide of iron, are suspended. The oxide of chromium therefore separates, on the slow
cooling of the glaze in the porcelain furnace, from the substance of the glaze-a silicate of potash, lime, and alumina-saturated with the peroxide of iron, and shines
through the brownish mass with a golden color. When the aventurine glaze is
mixed with an equal amount of colorless porcelain glaze, the glassy mass no longer
has a brown color after the burning, but a light greenish-gray, and the eliminated
crystalline spangles likewise exhibit in reflected light their natural green color.
AXE. A tool much used by carpenters for cleaving, and roughly fashioning, blocks
of wood. It is a flat iron wedge, with an oblong steel edge, parallel to which, in the
short base, is a hole for receiving and holding fast the end of a strong wooden handle.
In the cooper's adze, the oblong edge is at right angles to the handle, and is slightly
curved up, or inflected towards it.
AXLES, of carriages.-See WHEEL CARRIAGES.
AXUNGE. Hog's lard; see FAT and OILS.
AZOBENZOIDE, and AZOBENZOYLE, products of the action of pure water
of ammonia upon oil of bitter almonds, by making the ammonia pass down through a
wide tube filled with the almond pap. The operation must be continued for weeks.
AZOTIZED, said of certain vegetable substances, which, as containing azote, were
supposed at one time to partake, in some measure, of the animal nature; most animal
bodies being characterized by the presence of much azote in their composition. The vegetable products, indigo, cafeine, gluten, and many others, contain abundance of azote.
AZURE, the fine blue pigment, commonly called smalt, is a glass, colored with oxide of cobalt, and ground to an impalpable powder.
The manufacture of azure, or smalt, has been lately improved in Sweden, by the
adoption of the following process: —
The cobalt ore is first roasted till the greater part of the arsenic is driven off. The
residuary impure black oxide is mixed with as much sulphuric acid (concentrated) as
will make it into a paste, which is exposed at first to a moderate heat, then to a
cherry-red ignition for an hour. The sulphate thus obtained is reduced to powder,
and dissolved in water. To the solution, carbonate of potash is gradually added, in
order to separate the remaining portion of oxide of iron; the quantity of which depends upon the previous degree of calcination. If it be not enough oxidized, the
iron is difficult to be got rid of.
When, from the color of the precipitate, we find that the potash separates merely
carbonate of cobalt, it is allowed to settle, the supernatant liquor is decanted, and
precipitated, by means of a solution of silicate of potash, prepared as follows:Ten parts of potash are carefully mixed with fifteen parts of finely ground flints or
sand, and one part of pounded charcoal. This mixture is melted in a crucible of brick
clay, an operation which requires steady ignition during 5 or 6 hours. The mass,
when melted and pulverized, may be easily dissolved in boiling water, adding to it, by
little at a time, the glass previously ground. The filtered solution is colorless, and
keeps well in the air, if it contains one part of glass for 5 or 6 of water. The silicate
of cobalt which precipitates upon mixing the two solutions, is the preparation of cobalt most suitable for painting upon porcelain, and for the manufacture of blue glass.
See COBALT.
B.
BABLAH. The rind or shell which surrounds the fruit of the mimosa cineraria;
it comes from the East Indies, as also from Senegal, under the name of Neb-neb. It
contains gallic acid, tannin, a red coloring matter, and an azotized substance; but
the proportion of tannin is smaller than in sumach, galls, and knoppern (gall-nuts of
the common oak) in reference to that of gallic acid, which is considerable in the bablah. It has been used, in dying cotton, for producing various shades of drab; as a
substitute for the more expensive astringent dye-stuffs.
BAGASSE. The sugar-cane, in its dry, crushed state, as delivered from the sugarmill. It is much employed for fuel in the colonial sugar-houses.
BAKING. (Cuire, Fr. Backen, Germ.) The exposure of any body to such a heat
as will dry and consolidate its parts without wasting them. Thus wood, pottery, and
porcelain, are baked, as well as bread.
BALANCE.-To conduct arts, manufacturers, and mines, withjudgment and success,
recourse must be had, at almost every step, to a balance. Experience proves that all
material bodies, existing upon the surface of the earth, are constantly solicited by a
force which tends to bring them to its centre, and that they actually fall towards it




BALANCE.                                    115
when they are free to move.  This force is called gravity.  Though the bodies be
not free, thk effort of gravity is still sensible, and the resultant of all the actions
which it exercises upon their material points constitutes what is popularly called
their weight. These weights are, therefore, forces which may be compared together,
and by means of machines may be made to correspond or be counterpoised.
To discover whether two weights be equal, we must oppose them to each other in a
machine where they act in a similar manner, and then see if they maintain an equilibrium; for example, we fulfil this condition if we suspend them at the two extremities
of a lever, supported at its centre, and whose arms are equal. Such is the general idea
of a balance. The beam of a good balance ought to be a bar of well-tempered steel, of
such form as to secure perfect inflexibility under any load which may be fitly applied
to its extremities. Its arms should be quite equal in weight and length upon each side
of its point of suspension; and this point should be placed in a vertical line over the
centre of gravity; and the less distant it is from it, the more delicate will be the balance.
Were it placed exactly in that centre, the beam would not spontaneously recover the
horizontal position when it was once removed from it. To render its indications more
readily commensurable, a slender rod or needle is fixed to it, at right angles, in the line
passing through its centres of gravity and suspension. The point, or rather edge of
suspension, is made of perfectly hard steel, and turns upon a bed of the same. For
common uses the arms of a balance can be made sufficiently equal to give satisfactory
results; but, for the more refined purposes of science, that equality should never be
presumed nor trusted to; and, fortunately, exact weighing is quite independent of that
equality. To weigh a body is to determine how many times the weight of that body
contains another species of known weight, as of grains or pounds, for example. In
order to find it out, let us place the substance, suppose a piece of gold, in the left hand
scale of the balance; counterpoise it with sand or shot in the other, till the index
needle be truly vertical, or stand in the middle of the scale, proving the beam to be
horizontal.  Now remove gently the piece of gold, and substitute in its place standard
multiple weights of any graduation, English or French, till the needle again resumes the
vertical position, or till iis oscillations upon either side of the zero point are equal.
These weights will represent precisely the weight of the gold, since they are placed in
the same circumstances precisely with it, and make the same equilibrium with the weight
laid in the other scale.
This method of weighing is obviously independent of the unequal length as well as
the unequal weight of the arms of the beam. For its perfection two requisites only are
indispensable. The first is that the points of suspension should be rigorously the same
in the two operations; for the power of a given weight to turn the beam being unequal,
according as we place it at different distances from the centre of suspension, did that
point vary in the two consecutive weighings, we would require to employ, in the second,
a different weight from that of the piece of gold, in order to form an equilibrium with
the sand or shot originally put in the opposite scale; and as there is nothing to indicate
such inequality in the states of the beam, great errors would result from it. The best
mode of securing against such inequality is to suspend the cords of the scales from
sharp-edged rings, upon knife edges, at the ends of the beam, both made of steel sc
hard tempered as to be incapable of indentation. The second condition is, that the
balance should be very sensible, that is, when in equilibrium and loaded, it may be
disturbed, and its needle may oscillate, by the smallest weight put into either of the
scales. This sensibility depends solely upon the centre or nail of suspension; and it
will be the more perfect the less friction there is between that knife-edge surface and
the plane which supports it. Both should therefore be as hard and highly polished as
possible; and should not be suffered to press against each other, except at the time of
weighing.  Every delicate balance of moderate size, moreover, should be suspended
within a glass case, to protect it from the agitations of the air, and the corroding
influence of the weather.  In some balances a ball is placed upon the index or needle
(whether that index stand above or below the beam), which may be made to approach
or recede from  the beam  by a fine-threaded screw, with the effect of varying the
centre of gravity relatively to the point of suspension, and thereby increasing, at will,
either the sensibility, or the stability of the balance. The greater the length of the arms,
the less distant the centre of gravity is beneath the centre of suspension, the better
polished its central knife-edge of 30~, the lighter the whole balance, and the less it is
loaded, the greater will be its sensibility.  In all cases the arms must be quite inflexible. A balance made by Ramsden for the Royal Society is capable of weighing
ten pounds, and turns with one hundredth of a grain, which is the seven-millionth
part of the weight. In pointing out this balance to me one evening, Dr. Wollaston
told me it was so delicate, that Mr. Pond, then astronomer royal, when making some
observations with it, found its indications affected by his relative position before it,
although it was inclosed in a glass case. When he stood opposite the right arm, that




116                 BALANCE FOR WEIGHING COIN.
end of the beam preponderated, in consequence of its becoming expanded by the radiation of heat from his body; and when he stood opposite the left arm, he made this
preponderate in its turn. It is probable that Mr. Pond had previously adjusted the
centres of gravity and suspension so near to each other as to give the balance its maximum sensibility, consistent with stability. Were these centres made to coincide, the
beam, when the weights are equal, would rest in any position, and the addition of the
smallest weight would overset the balance, and place the beam in a vertical position,
from which it would have no tendency to return. The sensibility in this case would
be the greatest possible; but the other two requisites of level and stability would be
entirely lost. The case would be even worse if the centre of gravity were higher than
the centre of suspension, as the balance When deranged, if free, would make a revolution
of no less than a semi-circle. Abalance maybe made by a fraudulent dealer to weigh
falsely though its arms be equal, provided the suspension be as low as the centre of
gravity, for he has only to toss his tea, for instance, forcibly into one scale to cause 15
ounces of it, or thereby, to counterpoise a pound weight in the other. Inspectors of
weights, &c., are not aufait to this fruitful source of fraud among hucksters.
BALANCE FOR WEIGHING  COIN  at the Bank of England, invented by
William Cotton, Esq., Governor of the Bank.
The new coinage first arrives at the Bank from the Mint in what are called "journies,"
a single journey weighing 15 lbs," and containing 701 sovereigns. The officers of the
Mint are allowed 12 grains plus in every pound weight of metal, for the irregularities
incidental to working it into coin; but they usually work to within one half of that
allowance, which is technically called " the remedy."
There was coined for the Bank in the spring of 1843, 8,000,000 of sovereigns, and
the greatest variation from the weight allowed was only 60 grains, or one third of the
remedy. Each sovereign should contain a portion of this remedy, to allow for wear in
public use; and this extraordinary subdivision of metal is invariably obtained. The
usual delivery of new coinage at the Bank contains 100journies, which is counted by
weight only, that is, 200 sovereigns are counted into one scale, and the rest of the dellvery is weighed in parcels which balance these 200, and this is all the counting the
new coinage receives. The regularity and precision of the manipulations at the Mint
obviate the necessity of any further examination, either as regards the gross amount
or the weight of an individual piece.
When the currency returns to the Bank from the public, it becomes necessary to
ascertain if it has been reduced below the standard weight, and this imposes an arduous
duty on the officers of the Bank. The amount of gold paid daily over the Bank counter
varies considerably, but 30,000 may be taken as a rough average; and hence arises a
tedious, irksome, and expensive process in weighing so large a number of pieces singly,
and in quick succession, separating at the same time the light from the standard coin.
The mode of weighing coins by hand requires much dexterity, practice and attention;
but, in spite of all these, errors were inevitable, and it was to obviate these that the
machine was invented by Mr. Cotton, the Governor of the Bank of England; it was
constructed from his plans by Mr. Napier, and is thus described:Its exterior presents a plain brass case, with a small hopper tube on the top plate,
about 4J inches from which there is an opening in the top plate. In this opening is
seen a platform in the form of a quadrant. This platform is suspended above one end
of the beam, and is to receive the coin to be weighed. On one side of the case is a till
to receive the sovereigns as they are weighed, partitioned so that one division is left for
standard coin, and the other for such as are light. There is a sliding door to each division, for removing the coins at pleasure.  The machine may be worked like a clock,
with a weight, or by any simple application of power.
Its visible action is as follows:-The hopper being filled with gold, upon setting the
machine in motion, it immediately places a sovereign on the little platform, which
serves, as already stated, in place of a scale plan; and if it is of standard weight a small
tongue comes rapidly forward and pushes the sovereign into that side of the till allotted
to such coin; if light, another, and similar tongue to the first, pushes the sovereign into
the other side of the till. The action of these tongues is at right angles to each other.
While a sovereign is being weighed, a succeeding one is on its way from the hopper
to the platform, and the moment the preceding sovereign is disposed of, according to its
value, another is placed in its stead. To keep the hopper supplied with gold, and
remove it from the till as it is filled, is all the attendance necessary. The more minute
parts of the mechanical arrangement of the machine, such as the fulcrum, the forceps,
&c., are described in detail; and the following statement by Mr. Miller is given as a
comparison with the old method of weighing:" With the bullion-scales 4,000 may be stated as the number a person can weigh in
six hours. As the sovereigns now tendered at the Bank counter are most of them new,
the scale dips quickly in weighing, and one person can weigh 5,000 in six hours; but a




BALANCE FOR WEIGHING COIN.                               117
short time ago, before the issue of the new coinage, the same person could weigh only
3,000, as it took a longer time for the scales to indicate.
" The bullion scales cannot indicate nearer than 4-100ths of a grain, at the above
rate.
"The machine is perfectly free from the sources of error to which the scales are
subject, and weighs as quickly, whether the sovereigns are new and of full weight,
or old and doubtful; it can weigh 10,000 in six hours, and divide coin varying only
one-fiftieth of a grain."
The paper is illustrated by two drawings of the internal arrangement of the machine,
and a model, showing the action of the tongues and platform.
Mr. Oldham exhibited, at the Institute of Civil Engineers, the automaton balance at
work, weighing coin, and after describing, with the aid of a diagram and model, the
action of ~ome of the more delicate parts of the machine, he observed, that in seeking
to obtain extraordinary performances by machinery, mechanical propriety of construction was too often overlooked, and premature deterioration, in the action of many
parts, was the result.
The automaton balance was peculiarly worthy of notice, from the judgment exercised
in its relative proportions, as was proved by the fact that after being at work for several
months, it had become more delicate in detecting slight variations between standard
and light coin, than when it was first constructed. Mr. Cotton's object in this invention
should be well understood. Public convenience demanded great accuracy in weighing
the currency: by the ordinary mode of weighing gold with the bullion scales, although
it was due to the banktellers to state that they gave the utmost attention to their monotonous duty, it was nearly impossible to guard against the various difficulties detailed
in the paper. The injury sustained by the optic nerve, from constantly watching the
indicator of the scales, was a serious inconvenience to the operative, which, coupled
with the incidental sources of error referred to, created even greater absence of delicacy than the papers stated.  Errors to the amount of one-third, or even half a grain,
were not unfrequent.
By the " automaton balance," the number weighed in a given time was increased,
and undeviating accuracy obtained. The delicacy of the instrument was such, that
from thirty to thirty-five coins per minute could be passed through the machine, detecting a difference of only one-fifth of a grain.
It should be mentioned, that iuch greater delicacy could be accomplished; that is,
to the one-hundredth of a grain, out not at the same rate; because it would be understood that a slow action of the beam was necessary for very small variations, and that
must regulate the speed of working; but such delicacy was beyond all useful purposes
in those transactions which it was intended to improve.
Mr. Cotton said that his attention had been attracted to the point by the inconveniences to which the " tellers" were subjected in weighing gold for the public; with
balances so delicately constructed as the bullion-scales, the agitation of the air, by the
sudden opening of a door, or even by the breathing of those around, sufficed to cause
errors.  It was possible, also, by pressing the fulcrum against the bridle, to produce
such a degree of friction as materially to interfere with accuracy; and the tellers confessed that after weighing two or three thousand coins, the sight was injured, and they
no longer observed with the same degree of correctness. He therefore imagined that
a machine might be contrived, which, being defended from external influence, might
weigh coins as fast as by hand, and within one-fourth of a grain; but he certainly did
not contemplate attaining such perfection as the machine now possessed. His first
idea was, that the light coins should be taken off by forceps, and that those of average
weight should be pushed off by the succeeding ones; but it was found that the slightest
inaccuracy in the milled edges sufficed to give them a wrong direction; therefore when
he had made the first rough sketch, and consulted with his friend, the late Mr. Ewart,
he recommended that Mr. Napier, of York Road, Lambeth, should be employed to
make the machine, and to him was due the suggestion of the two alternately advancing
-tongues, as well as several other arrangements of the machinery, which he had so
successfully constructed.
When the first machine was tried, out of 1000 sovereigns 160 were found to be
light. They were given to a teller to be verified, and he returned several of them as
being of the proper weight; but, on again weighing them more carefully, the results
given by the machine were found to be correct. As an instance of how many circumstances should be taken into consideration in delicate machines, he might mention, that
after being used for a time, the machine varied in its results, and, on examination, it
was discovered, that the end of the lever which traversed the pendant had become
magnetic, and thus affected the balance. An ivory end was substituted, and ever since
that period its accuracy had been maintained.
Mr. W. Miller observed that the efficiency of any scales must be determined, in a
great degree, by the fineness of the edge of the fulcrum of the beam; and it would be




118                                BALSAMS.
easily imagined that the friction, to which the edge in a pair of bullion scales was
subjected, whilst weighing 5000 or 6000 sovereigns per day, must soon impair its
delicacy, and consequently the efficiency of the whole apparatus; for, whether the
sovereigns were light or heavy, the beam must turn upon its fulcrum.  Such was not
the case with Mr. Cotton's machine; its beam did not act at all, unless a light sovereign was placed upon the platform; so that, among 1000 sovereigns, if only 100
were light, the beam  of the machine would only move 100 times, while that of the
ordinary scales would oscillate 1000 times.  An immense advantage was thus given
to the machine in point of durability.
All weighing was but an approach to correctness, and the nearest point to which the
best kind of common scales were sensible, might be stated as  3 ~ths of a grain, and
ith of a grain would hardly cover their errors; but the machine was sensible to v — ths
of a grain, and -l  ths would fully cover its errors, which were not a twentieth part
so numerous as those of the scales.
BALSAMS (Baumes, Fr. Balsame, Germ.) are native compounds of ethereal or
essential oils, with resin, and frequently benzoic acid.'Most of them have the consistence of honey; but a few are solid, or become so by keeping. They flow either
spontaneously, or by incisions made from trees and shrubs in tropical climates. They
possess peculiar powerful smells, aromatic hot tastes, but lose their odoriferous properties by long exposure to the air. They are insoluble in water; soluble, to a considerable degree, in ether; and completely in alcohol. When distilled with water,
ethereal oil comes over, and resin remains in the retort.
1. BALSAMS WITH BENZOIC ACID:Balsam of Peru is extracted from the myroxylon peruiferum, a tree which grows in
Peru, Mexico, &c.; sometimes by incision, and sometimes by evaporating the decoction
of the bark and branches of the tree. The former kind is very rare, and is imported
in the husk of the cocoa-nut, whence it is called balsam en coque. It is brown, transparent only in thin layers, of the consistence of thick turpentine; an agreeable smell,
an acrid and bitter taste; formed of two matters, the one liquid, the other granular,
and somewhat crystalline. In 100 parts, it contains 12 of benzoic acid, 88 of resin,
with traces of a volatile oil.
The second sort, the black balsam  of Peru, is much more common than the pieceding, translucent, of the consistence of well-boiled sirup, very deep red-brown
color, an almost intolerably acrid and bitter taste, and a stronger smell than the other
balsam. Stoltze regards it as formed of 69 parts of a peculiar oil, 20*7 of a resin, little
soluble in alcohol, of 6'4 of benzoic acid, of 0'6 of extractive matter, and 0-9 of
water.
From  its high price, balsam of Peru is often adulterated with copaiba, oil of turpentine, and olive oil.  One thousand parts of good balsam  should, by its benzoic
acid, saturate 75 parts of crystallized carbonate of soda. It is employed as a perfume
for pomatums, tinctures, lozenges, sealing-wax, and for chocolate and liqueurs, instead
of vanilla, when this happens to be very dear
Liquid amber, Storax or Styrax, flows from the leaves and trunk of the liquid amber
styracifua, a tree which grows in Virginia, Louisiana, and Mexico. It is brownish
ash-gray, of the consistence of turpentine, dries up readily, smells agreeably, like benzoin, has a bitterish, sharp, burning taste; is soluble in 4 parts of alcohol, and contains
only 1-4 per cent. of benzoic acid.
Balsam of Tolu flows from the trunk of the myroxylon toluiferum, a tree which grows in
South America; it is, when fresh, of the consistence of turpentine, is brownish-red,
dries into a yellowish or reddish brittle resinous mass, of a smell like benzoin; is soluble
in alcohol and ether; affords, with water, benzoic acid.
Chinese varnish flows from the bark of the Jugia sinensis; it is a greenish yellow
turpentine-like substance, smells aromatic, tastes strong and rather astringent, in thin
layers dries soon into a smooth shining lac, and consists of resin, ethereous oil, and benzoic acid. It is soluble in alcohol and ether; and has been employed, immemorially,
in China, for lackering and varnishing surfaces, either alone or colored.
BALSAMS WITHOUT BENZOIC ACID:Copaiva balsam, balsam of copahu or capivi, is obtained from incisions made in the
trunk of the Copaifera officinalis, a tree which grows in Brazil and Cayenne. It is pale
yellow, middling liquid, clear transparent, has a bitter, sharp, hot taste; a penetrating
disagreeable smell; a specific gravity of from 0-950 to 0'996. It dissolves in absolute
alcohol, partially in spirit of wine, forms with alkalis, crystalline compounds. It consists of 45'59 ethereous oil, 52'75 of a yellow brittle resin, and 1'66 of a brown viscid
resin.  The oil contains no oxygen, has a composition like oil of turpentine, dissolves
caoutchouc (according to Durand), but becomes oxydized in the air, into a peculiar
species of resin. This balsam is used for making paper transparent, for certain lackers,
and in medicine.




BANDANNA.                                       119
This substance, which is extensively used in medicine, is often adulterated. Formerly some unctuous oil was mixed with it, but as this is easily discovered by its
insolubility in alcohol, castor oil has since been used. The presence of this cheaper oil
may be detected, 1, by agitating the balsam  with a solution of caustic soda, and
setting the mixture aside to repose; when the balsam will come to float clear on the
top, and leave a soapy thick magma of the oil below; 2, when the balsam is boiled
with water, in a thin film, for some hours, it will become a brittle resin on cooling, but
it will remain viscid if mixed with castor oil; 3, if a drop of the oil on white paper be
held over a lamp, at a proper distance, its volatile oil will evaporate and leave the
brittle resin, without causing any stain around, which the presence of oil will produce;
4, when three drops of the balsam are poured into a watch-glass, alongside of one
drop of sulphuric acid, it becomes yellow at the point of contact, and altogether of a
saffron hue when stirred about with a glass rod, but if sophisticated with castor oil,
the mixture soon becomes nearly colorless like white honey, though after some time
the acid blackens the whole in either case; 5, if 3 parts in bulk of the balsam be
mixed with 1 of good water of ammonia (of 0'970 sp. grav.) in a glass tube, it will
form a transparent solution, if it be pure, but will form a white liniment if it contains castor oil; 6, if the balsam be triturated with a little of the common magnesia
alba, it will form a clear solution, from which acids dissolve out the magnesia, and
leave the oil transparent, if it be pure, but opaque if it be adulterated. When turpentine is employed to falsify the balsam, the fraud is detected by the smell on heating the compound.
Mecca balsam, or opobalsam, is obtained both by incisions of, and by boiling, the
branches and leaves of the Balsamodendron Gileadense, a shrub which grows in Arabia
Felix, Lesser Asia, and Egypt. When fresh it is turbid, whitish, becomes, by degrees,
transparent; yellow, thickish, and eventually solid. It smells peculiar, but agreeable;
tastes bitter and spicy; does not dissolve completely in hot spirit of wine, and contains
10 per cent. of ethereous oil, of the specific gravity 0-876.
Japan lac varnish flows from incisions in the trunk of the Rhus Vernix (Melanorrhea
usitata) which is cultivated in Japan, and grows wild in North America. The juice
becomes black in the air; when purified, dissolves in very little oil; and, mixed with
coloring matter, it constitutes the celebrated varnish of the Japanese.
For Benzoin and Turpentine, see these articles in their alphabetical places.
BANDANNA. A  style of calico printing, in which white or brightly colored
spots are produced upon a red or dark ground. It seems to have been practised from
time immemorial in India, by binding up firmly with thread, those points of the cloth
which were to remain white or yellow, while the rest of the surface was freely subjected
to the dyeing operations.
The European imitations have now far surpassed, in the beauty and precision of
the design, the oriental patterns; having called into action the refined resources of
mechanical and chemical science. The general principles of producing bright figures
upon dark grounds, are explained in the article CALICO-PRINTING; but the peculiarities
of the Bandanna printing may be conveniently introduced here. In Brande's Journal
for July, 1823, I described the Bandanna gallery of Messrs. Monteith at Glasgow,
which, when in full action some years ago, might be reckoned the most magnificent and
profitable printing apartment in the world. The white spots were produced by a solution of chlorine, made to percolate down through the Turkey red cotton cloth, in
certain points defined and circumscribed by the pressure of hollow lead types in plates,
in a hydraulic press. Fig. 106 is an elevation of one press; A, the top or entablature;
B B, the cheeks or pillars; C, the upper block for fastening the upper lead perforated
pattern to; D, the lower block to which the fellow pattern is affixed, and which moves
up and down with the piston of the press; E, the piston or ram; F, the sole or
base; G, the water-trough, for the discharged or spotted calico to fall into; H, the
small cistern, for the aqueous chlorine or liquor-meter, with glass tubes for indicating
the height of liquor inside of the cistern; e e, glass stopcocks, for admitting the liquor
into that cistern from the general reservoir; f f, stopcocks for admitting water to wash
out the chlorine; g g, the pattern lead-plates, with screws for setting the patterns parallel
to each other; m m, projecting angular pieces at each corner, perforated with a half-inch
hole to receive the four guide-pins rising from the lower plate, which serve to secure
accuracy of adjustment between the two faces of the lead pattern plates; h h, two rollers
which seize and pull through the discharged pieces, and deliver them into the watertrough. To the left of D there is a stopcock for filling the trough with water; 1, is the
waste tube for chlorine liquor and water of washing. The contrivance for blowing a
stream of air across the cloth, through the pattern tubes, is not represented in the figure.




120                                BANDANNA.
Sixteen engines similar to the above, each possessing the power of pressing with
several hundred tons, are arranged in one line, in subdivisions of four; the spaces
106
B       B,B
between each subdivision serving as passages to allow  the workmen to go readily
from the front to the back of the presses. Each occupies twenty-five feet, so that the
total length of the apartment is 100 feet.
To each press is attached a pair of patterns in lead, (or plates, as they are called,) the
manner of forming which will be described in the sequel.  One of these plates is fixed
to the upper block of the press. This block is so contrived, that it rests upon a kind of
universal joint, which enables this plate to apply more exactly to the under fellowplate.  The latter sits on the moveable part of the press, commonly called the sill.
When this is forced up, the two patterns close on each other very nicely, by means of
the guide-pins at the corners, which are fitted with the utmost care.
The power which impels this great hydrostatic range is placed in a separate apartment, called the machinery room. This machinery consists of two press cylinders
of a peculiar construction, having solid rams accurately fitted to them.  To each of
these cylinders, three little force-pumps, worked by a steam-engine, are connected.
The piston of the large cylinder is eight inches in diameter, and is loaded with a
top-weight of five tons.  This piston can be made to rise about two feet through a
leather stuffing or collar. The other cylinder has a piston of only one inch in diameter,
which is also loaded with a top-weight of five tons. It is capable, like the other, of
being raised two feet through its collar.
Supposing the pistons to be a their lowest point, four of the six small force-pumps
are put in action by the steam-engine, two of them to raise the large piston, and two
the little one. In a short time, so much water is injected into the cylinders, that
the loaded pistons have arrived at their highest points.  They are now  ready for
working the hydrostatic discharge-presses, the water pressure being conveyed from
the one apartment to the other, under ground, through strong copper tubes, of small
calibre.
Two valves are attached to each press, one opening a communication between the large




BANDANNA.                                     121
driving-cylinder and the cylinder of' the press, the other between the small driving-cylinder and the press. The function of the first is simply to lift the under-block of the press
into contact with the upper-block; that of the second, is to give the requisite compression
to the cloth. A third valve is attached to the press, for the purpose of discharging the
water from its cylinder, when the press is to be relaxed, in order. to remove or draw
through the cloth.
From twelve to fourteen pieces of cloth, previously dyed Turkey-red, are stretched
over each other, as parallel as possible, by a particular machine. These parallel layers are
then rolled round a wooden cylinder, called by the workmen, a drum. This cylinder is
now placed in its proper situation at the back of the press. A portion of the fourteen layers of cloth, equal to the area of the plates, is next drawn through between them, by hooks
attached to the two corners of the webs. On opening the valve connected with the eightinch driving-cylinder, the water enters the cylinder of the press, and instantly lifts its lower
block, so as to apply the under plate with its cloth, close to the upper one. This valve is
then shut, and the other is opened. The pressure of five tons in the one inch prime-cylinder, is now brought to bear on the piston of the press, which is eight inches in diameter.
The effective force here will, therefore, be 5 tons X 82=320 tons; the areas of cylinders
being to each other, as the squares of their respective diameters. The cloth is thus condensed between the leaden pattern-plates with a pressure of 320 tons, in a couple of
seconds; -a splendid example of automatic art.
The next step, is to admit the blanching or discharging liquor (aqueous chlorine, obtained by adding sulphuric acid to solution of chloride of lime) to the cloth. This liquor
is contained in a large cistern, in an adjoining house, from which it is run at pleasure into
small lead cisterns H attached to the presses; which cisterns have graduated index tubes,
for regulating the quantity of liquor according to the pattern of discharge. The stopcocks
on the pipes and cisterns containing this liquor, are all made of glass.
From the measure-cistern H, the liquor is allowed to flow into the hollows in the upper
lead-plate, whence it descends on the cloth, and percolates through it, extracting in its passage the Turkey-red dye. The liquor is finally conveyed into the waste pipe, from a groove
in the under block. As soon as the chlorine liquor has passed through, water is admitted in a similar manner, to wash away the chlorine; otherwise, upon relaxing the pressure, the outline of the figure discharged would become ragged. The passage of the discharge liquor, as well as of the water through the cloth, is occasionally aided by a pneumatic apparatus, or blowing machine; consisting of a large gasometer, from which air
subjected to a moderate pressure may be allowed to issue, and act in the direction of the
liquid upon the folds of the cloth. By an occasional twist of the air stopcock, the workman also can ensure the equal distribution of the discharging liquor, over the whole excavations in the upper plate. When the demand for goods is very brisk, the air apparatus is much employed, as it enables the workman to double his product.
The time requisite for completing the discharging process in the first press is sufficient to enable the other three workmen to put the remaining fifteen presses in play. The
discharger proceeds now from press to press, admits the liquor, the air, and the water;
ani is followed at a proper interval by the assistants, who relax the press, move forwards
another square of the cloth, and then restore the pressure. Whenever the sixteenth press
has been liquored, &c., it is time to open the first press. In this routine, about ten minutes are employed; that is, 224 handkerchiefs (16+14) are discharged every ten minutes.
The whole cloth is drawn successively forward, to be successively treated in the above
method.
When the cloth escapes from the press, it is passed between the two rollers in front; from
which it falls into a trough of water placed below. It is finally carried off to the washing and bleaching department, where the lustre of both the white and the red is considerably brightened.
By the above arrangement of presses, 1600 pieces, consisting of 12 yards each- 19,200
yards, are converted into Bandannas in the space of ten hours, by the labor of four
workmen.
The patterns, or plates, which are put into the presses to determine the white figures
on the cloth, are made of lead in the following way. A trellis frame of cast-iron, one
inch thick, with turned-up edges, forming a trough rather larger than the intended lead
pattern, is used as the solid ground-work. Into this trough, a lead plate about one half
inch thick, is firmly fixed by screw nails passing up from below. To the edges of this lead
plate, the borders of the piece of sheet-lead are soldered, which covers the whole outer
surface of the iron frame. Thus a strong trough is formed, one inch deep. The upright
border gives at once great strength to the plate, and serves to confine the liquor. A thin
sheet of lead is now laid on the thick lead-plate, in the manner of a veneer on toilettables, and is soldered to it round the edges. Both sheets must be made very smooth
beforehand, by hammering them on a smooth stone table, and then finishing with a plane:
the surface of the thin sheet (now attached) is to be covered with drawing paper, pasted




122                                 BARYTA.
on, and upon this the pattern is drawn. It is now ready for the cutter. The first
thing which he does is to fix down with brass pins all the parts of the pattern which
are to be left solid.  He now proceeds with the little tools generally used by blockcutters, which are fitted to the different curvatures of the pattern, and he cuts perpendicularly quite through the thin sheet. The pieces thus detached are easily lifted
out; and thus the channels are formed which design the white figures on the red cloth.
At the bottom of the channels, a sufficient number of small perforations are made
through the thicker sheet of lead, so that the discharging liquor may have free ingress
and egress.  Thus, one plate is finished, from which an impression is to be taken by
n-eans of printers' ink, on the paper pasted upon another plate. The impression is taken
in the hydrostatic press. Each pair of plates constitutes a set, which may be put into
the presses, and removed at pleasure.
BARBERRY.  The root of this plant contains a yellow coloring matter, which is
soluble in water and alcohol, and is rendered brown by alkalis. The solution is employed in the manufacture of Morocco leather.
BARILLA.  A crude soda, procured by the incineration of the salsola soda, a plant
cultivated for this purpose in Spain, Sicily, Sardinia, &c. Good barilla usually contains, according to my analysis, 20 per cent. of real alkali, associated with muriates
and sulphates, chiefly of soda, some lime, and alumina, with very little sulphur.
Caustic leys made from it were used in the finishing process of the hard soap manufacture.
The quantity of barilla and alkali imported in 1850 amounted to 34,880 cwts., and
in 1851 to 45,740 cwts. The quantity of soda exported in 1850 was 827,403 cwts.,
and in 1851, 839,183 cwt.; the declared value being respectively 375,3511., and 360,5651.
There is no duty on barilla.
BARIUM.  The metallic basis of Baryta.
BARK, the outer rind of plants.  Many varieties of barks are known to commerce,
but the term is commonly used to express either Peruvian or Jesuits' bark, a most valuable pharmaceutical remedy, or Oak bark, which is very extensively used by tanners and
dyers. The quantity of this article imported for the use of the latter amounted in 1850 to
380,674 cwts., and in 1851 to 460,895 cwts. The duty on bark has been repealed.
BARLEY.  (Orge, Fr.; Gerste, Germ.) English barley is that with two-rowed ears,
or the hordeum vulgare distichon of the botanists; the Scotch beer or bigg is the hordeun
vulgare hexastichon.  The latter has two rows of ears, but 3 corns come from the same
point, so that it seems to be six-eared. The grains of bigg are smaller than those of
barley, and the husks thinner.  The specific gravity of English barley varies from 1 25
to 1'33; of bigg from 1-227 to 1-265; the weight of the husk of barley is one-sixth, that
of bigg two-ninths. 1000 parts of barley flour contain, according to Einhof, 720 of starch,
56 sugar, 50 mucilage, 36-6 gluten, 12-3 vegetable albumen, 100 water, 2-5 phosphate of
lime, 68 fibrous or ligneous matter. Sp. gravity of barley is 1-235 by my trials.
BARM. The yeasty top of fermenting beer. See BEER, DISTILLATION, FERMENTATION.
BARYTA or BARYTES, one of the simple earths.  It may be obtained most easily
by dissolving the native carbonate of barytes (Witherite) in nitric acid, evaporating
the neutral nitrate till crystals be formed, draining and then calcining these, by successive portions, in a covered platina crucible, at a bright red heat. A less pure baryta
may be obtained by igniting strongly a mixture of the carbonate and charcoal, both in
fine powder and moistened. It is a grayish white earthy looking substance, fusible only
at the jet of the oxy-hydrogen blowpipe, has a sharp caustic taste, corrodes the tongue
and all animal matter, is poisonous even in small quantities, has a very powerful alkaline
reaction; a specific gravity of 4'0; becomes hot, and slakes violently when sprinkled
with water, falling into a fine white powder, called the hydrate of baryta, which contains
10- per cent. of water, and dissolves in 10 parts of boiling water. This solution lets fall
abundant columnar crystals of hydrate of baryta as it cools; but it still retains one-lwen
tieth its weight of baryta, and is called baryta water. The above crystals contain 61 per
cent. of water, of which, by drying, they lose 50 parts. This hydrate may be fused at a
red heat without losing any more water. Of all the bases, baryta has the strongest affinity for sulphuric acid, and is hence employed either in the state of the above water, or
in that of one of its neutral salts, as the nitrate or muriate, to detect the presence and
determine the quantity of that acid present in any soluble compound. Its prime equivalent is 7 66, hydrogen being 1,000. Native sulphate of baryta, or heavy spar, is fraudulently used to adulterate white lead by the English dealers to a shameful extent.
BASSORINE.  A constituent part of a species of gum which comes from Bassora,
as also of gum tragacanth, and of some gum resins. It is semi-transparent, difficult
to pulverize, swells considerably in cold or boiling water, and forms a thick mucilage
without dissolving.  Treated with ten times its weight of nitric acid, it affords nearly
23 per cent. of its weight of mucic acid, being much more than is obtainable from gum
arabic or cherry-tree gum. Bassorine is very soluble in water slightly acidulated
with nitric or muriatic acid. This principle is procured by soaking gum Bassora in a
great quantity of cold water, and in removing, by a filter, all the soluble parts.




BATHS.                                 123
BATHS.  (Bains, Fr.; Baden, Germ.) Warm baths have lately come into very
general use, and they are justly considered as indispensably necessary in all modern
houses of any magnitude, as also in club-houses, hotels, and hospitals. But the mode
of constructing these baths, and of obtaining the necessary supplies of hot and cold
water, does not appear to have undergone an improvement equal to the extension of
their employment.
The several points in regard to warm baths, are,
1. The materials of which they are constructed.
2. Their situation.
3. The supply of cold water.
4. The supply of hot water.
5. Minor comforts and conveniences.
1. As to the materials of which they are constructed.-Of these the best are slabs
of polished marble, properly bedded with good water-tight cement, in a seasoned
wooden case, and neatly and carefully united at their respective edges. These, when
originally well constructed, form a durable, pleasant, and agreeable-looking bath;
but the expense is often objectionable, and, in upper chambers, the weight may prove
inconvenient. If of white or veined marble, they are also apt to get yellow or discolored by frequent use, and cannot easily be cleansed; so that large Dutch tiles, as
they are called, or square pieces of white earthenware, are sometimes substituted;
which, however, are difficultly kept water-tight; so that, upon the whole, marble is
preferable. Welsh slate has now superseded marble to a great extent.
Where there are reasons for excluding marble, copper, tinned, or galvanized iron is
the usual material resorted to. The first is most expensive in the outfit, but far more
durable than the latter, which are, moreover, liable to leakage at the joints, unless
most carefully made. Either the one or the other should be well covered outside and
inside with several coats of paint, which may then be marbled or otherwise ornamented.
Wooden tubs, square or oblong, and oval, are sometimes used for warm baths; and
are cheap and convenient, but neither elegant nor cleanly. The wood always contracts a mouldy smell; and the difficulty and nuisance of keeping them water-tight,
and preventing shrinkage, are such as to exclude them from all except extemporaneous application.
2. As to the situation of the bath, or the part of the house in which it is to be
placed.-In hotels and club-houses this is a question easily determined: several baths
are usually here required, and each should have annexed to it a properly warmed
dressing-room. Whether they are up stairs or down stairs is a question of convenience, but the basement story, in which they are sometimes placed, should always be
avoided: there is a coldness and dampness belonging to it, in almost all weathers,
which is neither agreeable nor salubrious.
In hospitals, there should be at least two or three baths on each side of the house
(the men's and women's), and the supply of hot water should be ready at a moment's
notice. The rooms in which the baths are placed should be light, and comparatively
large and airy; and such conveniences for getting into and out of the baths should be
adopted as the sick are well known to require. The dimensions of these baths should
also be larger than usual.
In private houses, the fittest places for warm baths are dressing-rooms annexed to
the principal bed-rooms; or, where such convenience cannot be obtained, a separate
bath-room, connected with the.dressing-room, and always upon the bed-room floor.
All newly-built houses should be properly arranged for this purpose, and due attention
should be paid to the warming of the bath-room, which ought also to be properly ventilated. A temperature of 70~ may be easily kept up in it, and sufficient ventilation
is absolutely requisite to prevent the deposition of moisture upon the walls and furniture.
The objection which formerly prevailed, in respect to the difficulty of obtaining adequate supplies of water, in the upper rooms, has been entirely obviated by having cisterns at or near the top of the house; and we would just hint that these should be so
contrived as to be placed out of the reach of frost; a provision of the utmost importance in every point of view, and very easily effected in a newly-built house, though it
unfortunately happens that architects usually regard these matters as trifles, and treat
them with neglect,as indeed they do the warming and ventilation of buildings generally.
3. The supply of water of proper quality and quantity is a very important point,
as connected with the present subject. The water should be soft, clean, and pure, and
as free as possible fiom all substances mechanically suspended in it. In many cases
it answers to dig a well for the exclusive supply of a large house with water. In most
parts of London this may effectually be accomplished at a comparatively moderate expense; and, if the well be deep enough, the water will be abundant, soft, and pellucid.
ihe labor of forcing it by a pump to the top of the house is the only drawback; this,




124                                   BATHS.
however, is very easily done by a horse-engine, or there are people enough about
town glad to under'take it at a shilling a day. I am led to these remarks by observing
the filthy state of the water usually supplied, at very extravagant rates, by the water
companies. It deposits its nastiness in the pipes connected with warm baths, and
throws down a slippery deposit upon the bottom of the vessel itself, to such an extent
as often to preclude its being used, at least as a luxury, which a clear and clean bath
really is. This inconvenience may, in some measure, be avoided by suffering the
water to throw  down its extraneous matters upon the bottom  of the cistern, and
drawing our supplies from pipes a little above it; there will, however, always be more
or less deposit in the pipes themselves, and every time the water runs into the cistern
the grouts are stirred up and diffused through its mass.
4. and 5.-In public bathing establishments, where numerous and constant baths
are required, the simplest and most effective means of obtaining hot water for their
supply consists in drawing it directly into the baths from a large boiler, placed somewhere above their level. This boiler should be supplied with proper feeding-pipes
and gauges; and, above all things, its dimensions should be ample; it should be of
wrought iron or copper. The hot water should enter the bath by a pipe at least an
inch and a half in diameter; and the cold water by one of the same dimensions, or
somewhat larger, so that the bath may not be long in filling. The relative proportions of the hot and cold water are, of course, to be adjusted by a thermometer, and
every bath should have a two-inch waste-pipe, opening about two inches from the top
of the bath, and suffering the excess of water fieely to run off; so that when a person
is immersed in the bath, or when the supplies of water are accidentally left open, there
may be no danger of an overflow.
When there is a laundry in the upper story of the house, or other convenient place
for erecting a copper and its appurtenances, a plan similar to the above may often be
conveniently adopted in private houses, for the supply of a bath upon the principal
bed-room floor. An attempt is sometimes made to place boilers behind the fires of
dressing-rooms, or otherwise to erect them in the room itself, for the purpose of supplying warm water; but this plan is always objectionable fiom the complexity of the
means by which the supply of water is furnished to the boiler, and often dangerous
from the flues becoming choked with soot and taking fire. Steam is also apt, in such
eases, to. escape in quantities into the room; so that it becomes necessary to search for
other methods of heating the bath; one or two of the least objectionable of which I
shall describe.
(1.) A contrivance of some ingenuity consists in suffering the water for the supply
of the bath to flow from a cistern above it, through a leaden pipe of about one inch
diameter, which is conducted into the kitchen or other convenient place, where a large
boiler for the supply of hot water is required. The bath-pipe is immersed in this boiler,
in which it makes many convolutions, and, again emerging, ascends to the bath. The
operation is simply this:-the cold water passing through the convolutions of that
part of the pipe which is immersed in the boiling water, receives there sufficient heat
for the purpose required, and is delivered in that state by the ascending pipe into the
bath, which is also supplied with cold water and waste-pipes as usual. The pipe may
be of lead, as far as the descending and ascending parts are concerned, but the portion forming the worm or convolutions immersed in the boiler should be copper, in
order that the water within it may receive heat without impediment.
This plan is economical only where a large boiler is constantly kept at work in the
lower part of the house; otherwise the trouble and expense of heating such a boiler,
for the mere purpose of the bath, render it unavailable. The worm-pipe is also apt to
become furred upon the outside by the deposition of the earthy impurities of the water
in which it is immersed; it then becomes a bad conductor of heat, is cleansed with
difficulty, and the plan is rendered ineffective. This system, however, has been adopted,
in some particular cases, with satisfaction.
(2.) A much more simple, economical, and independent mode of heating a warm
bath, by a fire placed at a distance from it, is the following, which is found to answer
perfectly in private houses, as well as upon a more extended scale in large establishments. It is certainly open to some objections, but these are overbalanced by its advantages. A wagon-shaped boiler, holding about six gallons of water, is properly
placed over a small furnace in any convenient and safe part of the house, as the kitchen,
scullery, servants' hall, or wash-house. The bath itself, of the usual dimensions and
construction, is placed where it is wanted, with a due supply of cold water from above.
Two pipes issue from within an inch of the bottom of the bath at its opposite estremities; one at the head of the bath, about one inch, and the other at the foot, an inch
and one-eighth in diameter. These tubes descend to the boiler, the smaller one entering it at the bottom, and the larger one issuing from its top.
Under these circumstances, supposing the pipes and boiler everywhere perfectly
tight, when the bath is filled, the water will descend into and expel the air from the




BATHS.                                      125
boiler, and completely fill it. Now upon making a gentle fire under the boiler, an
ascending current of warm water will necessarily pass upwards through the larger
pipe which issues forn its top, and cold water will descend by the pipe which enters
at the bottom; and thus, by the establishment of currents, the whole mass of water
in the bath will become heated to the desired point; or, if above it, the temperature
may easily be lowered by the admixture of cold water.
The advantages of this form of bath are numerous. The shorter the pipes of communication the better, but they may extend forty or fifty feet without any inconvenience beyond that of expense; so that there is no obstacle to the bath being near the
bed-room while the boiler is on the basement story. There is but little time required
for heating the bath; the water in which may, if requisite, be raised to about 1000 in
about half an hour fiom the time of lighting the fire.  The consumption of fuel is also
trifling.
The following are the chief disadvantages attendant upon this plan, and the means
of obviating them:It is necessary, when the water has acquired its proper temperature, to arrest the
circulation of the water by means of a stopcock or valve adjoining the boiler; the next
resource is to withdraw the fire from the boiler, or not to use the bath immediately,
as it may go on acquiring some heat from the boiler, so that we may become inconveniently hot in the bath. When, therefore, this bath is used, we may proceed as follows:-Heat the water in it an hour before it is wanted, to about 100~, and then extinguish the fire. The water will retain its temperature, or nearly so, for three or
four hours, especially if the bath be shut up with a cover; so that when about to use
it, cold water may be admitted till the temperature is lowered to the required point,
and thus all the above inconveniences are avoided.
Another disadvantage of this bath arises from  too fierce a fire being made under
the boiler, so as to occasion the water to boil within it, a circumstance which ought always to be carefully avoided.  In that case, the steam rising in the upper part of the
boiler, and into the top pipe, condenses there, and occasions violent concussions, the
noise of which often alarms the whole house, and leads to apprehensions of explosion,
which, however, is very unlikely to occur; but the concussions thus produced injure
the pipes, and may render them leaky; so that in regard to these, and all other baths,
&c., we may remark, that the pipes should pass up and down in such parts of the house
as will not be injured if some leakage takes place; and under the bath itself should
be a sufficiently large leaden tray with a waste-pipe, to receive and carry off any accidental drippings, which might injure the ceilings of the rooms below.  In all newlybuilt houses, two or three flues should be left in proper places for the passage of ascending and descending water-pipes; and these flues should in some way receive at
their lower part a little warm air in winter, to prevent the pipes freezing; the same
attention should also be paid to the situation of the cisterns of water in houses, which
should be kept within the house, and always supplied with a very ample waste-pipe,
to prevent the danger of overflow. Cisterns thus properly placed, and carefully constructed, should be supplied from the water-mains by pipes kept under ground, till
they enter the house, and not carried across the area, or immediately under the pavement, where they are liable to freeze.
(8.) Baths are sometimes heated by steam,which has several advantages; it may either
be condensed directly into the water of the bath, or, if the bath be of copper or tinned
iron, it may be conducted into a casing upon its outside, usually called a jacket; in
the latter case there must be a proper vent for the condensed water, and for the escape
of air and waste steam. Steam is also sometimes passed through a serpentine pipe,
placed at the bottom of the bath. But none of these methods are to be recommended
for adoption in private houses, and are only advisable in hospitals, or establishments
where steam boilers are worked' for other purposes than the mere heating of baths.
The French make much more use of hot baths than we do, both as respects health
and cleanliness, a fact well illustrated by the following statistics.  In the year 1780 the
whole public bathing establishments in Paris contained only 250 separate baths; in
1813 they contained 300; in 1832 there were 78 houses fitted up with 2374 fixed baths,
and 1059 movable ones for transporting to private houses; and at present new bathing
establishments are being mounted from day to day in the several quarters of the capital.
Galvanized iron is now preferred even to copper for making baths, being equally
durable and greatly cheaper. Sulphureous baths are made of sheet zinc, for the alkaline sulphurets act very little upon that metal.  The form of the baths is usually
made ovoid, because this shape requires less water for immersing the human body than
the rectangular.
Many copper and tin baths have been lately constructed in London, with a little
furnace attached to one end, and surrounded with a case or jacket, into which the water
flows and circulates backwards and forwards till the whole mass in the bath gets
heated to the due degree. One of the best of these is that constructed by Mr. Benham,




126                                  BEER.
of Wigmore street. The bath must be placed near the fire-grate, and the smoke-pipe
of the attached furnace be conducted up the chimney a certain way to secure a sufficient
draught to maintain combustion. The above bath, well managed, heats the water from
50~ to 98~ in about 20 or 25 minutes, as I have experimentally proved. When the
proper temperature is attained, the fire must of course be extinguished.
BDELLIUM.  A  gum  resin, produced  by an unknown plant which grows in
Persia and Arabia. It comes to us in yellowish or reddish pieces, smells faintly,
like myrrh, and consists of 59 resin, 9-2 gum, 30'6 bassorine, and 1-2 ethereous oil.
BEER. (Biere, Fr.; Bier, Germ.) The fermented infusion of malted barley, flavored
with hops, constitutes the best species of beer; but there are many beverages of inferior
quality to which this name is given, such as spruce beer, ginger beer, molasses beer, &c.;
all of which consist of a saccharine liquor, partially advanced into the vinous fermentation,
and flavored with peculiar substances.
The ancients were acquainted with beer, and the Romans gave it the appropriate
name of Cerevisia (quasi Ceresas), as being the product of corn, the gift of Ceres. The
most celebrated liquor of this kind in the old time, was the Pelusian potation, so called
from the town where it was prepared at the mouth of the Nile. Aristotle speaks of the
intoxication caused by beer; and Theophrastus very justly denominated it the wine of
barley. We may, indeed, infer from the notices found in historians, that drinks analogous to our beer were in use among the ancient Gauls, Germans, and in fact almost every
people of our temperate zone; and they are still the universal beverage in every land
where the vine is not an object of rustic husbandry.
The manufacture of beer, or the art of brewing, may be conveniently considered under
five heads:
1. An examination of the natural productions which enter into its composition; or of
barley and hops.
2. The changes which barley must undergo to fit it for making beer; or the processes
of malting and mashing.
3. The formation of a proper wort from the mashed malt and hops.
4. The fermentation of that wort; and,
5. The lining, ripening, and preservation of the beer.
I. Of the materials.
1. Barley, wheat, maize, and several other kinds of corn are capable of undergoing those
fermentative changes, by which beer may be made; but the first substance is by far the
fittest. There are two species of barley, the hordeum vulgare or common barley, having
two seeds arranged in a row on its spikes; and the hordeum hexastichon, in which three
seeds spring from one point, so that its double row has apparently six seeds. The former
is the proper barley, and is much the larger sized grain; the latter is little known in
England, but is much cultivated in Scotland under the name of bear or bigg; being a
hardy plant adapted to a colder country. The finer the climate in which barley grows,
the denser and larger its seed, and the thinner its husk; thus the Norfolk and Suffolk
barley is distinguished in these respects from that of Aberdeenshire. Bigg is aless compact grain than barley; the weight of a Winchester bushel (2150-42 cubic inches) of
the former is only about 47 lbs., while that of a bushel of the latter is nearly 51 lbs.
Their constituents, however, bear much the same proportion to each other.
The quality of barley is proved not only by its density when dry, but by the increase
of volume which it acquires when steeped in water. Thus,
100 measures of average English barley thereby swell into 124.
100   -     of -       Scotch ditto,    -    -    -    121.
100   -     of -         -   bigg or bear,        -    118.
Nay, 100 of very fine Suffolk barley have swollen into  -    183.
While 100 of an inferior Scotch bigg became no more than   -    109.
This circumstance indicates so nearly the probable yield of malt, that it is carefully
attended to by the officers of excise, who gauge the steep cistern, and levy their duty in
conformity with the largest volume. 100 pounds of good barley become almost one half
heavier by the absorption of moisture; and weigh upon an average 147 pounds; thebest
of course taking up most water.
By chemical analysis barley flour seems to consist of 67*18 parts of hordeine, or starch
and gluten intimately combined, 7'29 of vegetable fibre, 1-15 of coagulated albumen,
3-52 parts of gluten, 5-21 of sugar, 4-62 of gum, 0-24 of phosphate of lime, and 9-37 of
water. The loss amounted to 1-42. To these principles should be added a peculiar
volatile oil of a concrete nature, which is obtained during the process of distilling fe:mented malt wash. (See WHISKEY.)  It may also be extracted from barley flour, by the
solvent action of alcohol; and never amounts to more than a few parts in the thousand.
The husk also contains some of that fetid oil. Proust thought that he had discovered in
barley a peculiar principle, to which he gave the name of hordeine; and which he separated from starch by the action of both cold and boiling water. He found that by treat



BEER.                                     127
ing barley meal successively with water, he obtained from 89 to 90 parts of a farinaceous
substance, composed of from 32 to 33 of starch, and from 57 to 58 of hordeine. Einhof
obtained from barley seeds, 70-05 of flour, 18-75 of husks or bran, and 11-20 of water.
According to Proust, hordeine is a yellowish powder, not unlike fine saw-dust. It
contains no azote, for it affords no ammonia by distillation, and is therefore very dissimilar to gluten. In the germination of barley, which constitutes the process of malting,
the proportion of hordeine is greatly diminished by its conversion into sugar and starch.
Other chemists suppose that the hordeine of Proust is merely a mixture of the bran of
the barley with starch and gluten. It is obvious that the subject stands in need of new
chemical researches. In barley the husk constitutes from one fourth to one fifth of the
whole weight; in oats it constitutes one third; and in wheat one tenth. From the analysis of barley flour recently made, it appears to consist in 1000 parts: of water, 100; albumen, 22-3; sugar, 56; gum  or mucilage, 50; gluten, 37-6; starch, 720; phosphate
of lime, 2-5.
2. The hop, humulus lupulus, the female flowers of the plant. Ives first directed attention
to a yellow pulverulent substance which invests the scales of the catkins, amounting to
about one eighth of their weight; and referred to it the valuable properties which hops impart to beer. We may obtain this substance by drying the hops at a temperature of 86~
F., introducing them into a coarse canvass bag, and shaking it so that the yellow powder
shall pass through the pores of the canvass. This powder bears some resemblance to lycopodium.  Of the 13 parts in 100 of this powder, 4 parts are foreign matters, derived from
the scales of the cones; leaving 9 parts of a peculiar granular substance. When distilled
with water, this substance affords two per cent. of its weight (2 for 100 times the
weight of hops) of a volatile colorless oil, to which the plant owes its peculiar aroma.
This oil dissolves in water in considerable quantity. It appears to contain sulphur (for
it blackens solutions of silver), and also acetate of ammonia. No less than 65 per cent.
of the yellow dust is soluble in alcohol. This solution, treated with water and distilled,
leaves a resin, which amounts to 52'5 per cent. It has no bitter taste, and is soluble in
alcohol and ether. The watery solution from which the resin was separated contains the
bitter substance which has been called lupuline by Payen and Chevallier, mixed with a
little tannin and malic acid. To obtain this in a state of purity, the free acid must be
saturated with lime, the solution evaporated to dryness, and the residuum must be treated
with ether, which removes a little resin; after which the lupuline is dissolved out by alcohol, which leaves the malate of lime. On evaporating away the alcohol, the lupuline
remains, weighing from  8-3 to 12-5 per cent. It is sometimes white, or slightly yellowish, and opaque, sometimes orange yellow and transparent. At ordinary temperatures it is inodorous, but when heated strongly it emits the smell of hops. It possesses
the characteristic taste and bitterness of the hop. Water dissolves it only in the proportion of 5 per cent., but it thereby acquires a pale yellow color. Lupuline is neither
acid nor alkaline; it is an;ted upon neither by the dilute acids nor alkalis, nor by the
solutions of the metallic salts; it is quite soluble in alcohol, but hardly in ether. It
contains apparently no azote, for it affords no ammnonia by destructive distillation; but
only an empyreumatic oil.
The yellow dust of hops contains, moreover, traces of a fatty matter, gum, a
small quantity of an azotized substance, and several saline combinations in minute
quantity. Boiling water dissolves from 19 to 31 per cent. of the contents of the dust, of
which a large proportion is resin. Ives thought that the scales of the catkins of hops, when
freed from the yellow powder, contained no principles analogous to it; but Payen and
Chevallier have proved the contrary. The cones of hop give up to boiling alcohol 36
per cent. of soluble matter; while the same cones, stripped of their yellow powder, yield
only 26 per cent.; and further, these chemists found the same principles in the different
parts of the hop, but in different proportions.
The packing of the hop catkins or cones is one of the most important operations
towards the preservation of this plant; and is probably the cause of the enormous difference in value between the English and French hops after a few years keeping. The
former, at the end of six years, possess still great value, and may be sold as an article
only two or three years old; while the latter have lost the greater part of their value in
three years, and are no more saleable at the end of four. In France, it is packed merely
by tramping it with the feet in sacks. Under this slight pressure, large interstitial
spaces are left amid the mass of the hops, through which the air freely circulates, carrying off the essential oil, and oxygenating some of the other proximate principles, so as
to render them inert. By the English method, on the contrary, the hops, after being
well rammed into strong sacks hung in frames, are next subjected to the action of a
hydraulic press. The valuable yellow powder thus enclosed on every side by innumerable compact scales, is completely screened from the contact of the atmosphere, and
from all its vicissitudes of humidity. Its essential oil, in particular, the basis of its flavor,
is preserved without decay.




128                                   BEER.
According to the experiments of Chevallier and Payen upon the hops of England,
Flanders, the Netherlands, and the department of the Vosges, those of the county of Kent
afforded the largest cones, and were most productive in useful secreted and soluble matters. Next to them were the hops of Alost.
The best hops have a golden yellow color, large cones, an agreeable aroma: when rub.
bed between the hands, they leave yellow traces, powerfully odoriferous, without any
broken portions of the plant, such as leaves, stems, and scaly fragments. When alcohol
is digested on good hops, from 9 to 12 per cent. of soluble yellow matter may be obtained
by evaporating it to dryness. This is a good test of their quality.
The best-flavored and palest hops are packed in sacks of fine canvass, which are called pockets, and weigh about 1x cwt. each. These are bought by the ale brewer. The
stronger-flavored and darker-colored hops are packed in bags of a very coarse texture
like door-mats, called hop bags: these contain generally about 3 cwt., and are sold to the
porter and beer brewers. After the end of a year or two, hops are reckoned to have lost
much of their marketable value, and are then sold to the second-rate porter brewers, under the name of old hops. The finest hops are grown in the neighborhood of Canterbury;
but those of Worcester have an agreeable mildness of flavor, greatly admired by many
ale drinkers.  When the bitter and aromatic principles disappear, the hops are no better
than so much chaff; therefore, an accurate chemical criterion of their principles would
be a great benefit to the brewer.
II. Malting.-This process consists of three successive operations; the steeping; the
couching, sweating, and flooring; and the kiln-drying.
The steeping is performed in large cisterns made of wood or stone, which being filled
with clear water up to a certain height, a quantity of barley is shot into them, and well
stirred about with rakes. The good grain is heavy, and subsides; the lighter grains,
which float on the surface, are damaged, and should be skimmed off; for they would injure the quality of the malt, and the flavor of the beer made with it. They seldom amount
to more than two per cent. More barley is successively emptied into the steep cistern,
till the water stands only a few inches, about five, above its surface; when this is levelled
very carefully, and every light seed is removed. The steep lasts from forty to sixty hours,
according to circumstances; new barley requiring a longer period than old, and bigg requiring much less time than barley.
During this steep, some carbonic acid is evolved from the grains, and combines with
the water, which, at the same time, acquires a yellowish tinge, and a strawy smell, from
dissolving some of the extractive matter of the barley husks. The grain imbibes about
one half its weight of water, and increases in size by about one fifth. By losing this extract, the husk becomes about one seventieth lighter in weight, and paler in color.
The duration of the steep depends, in some measure, upon the temperature of the air,
and is shorter in summer than in winter.  In general from  40 to 48 hours will be
found sufficient for sound dry grain.  Steeping has for its object to expand the farina
of the barley with humidity, and thus prepare the seed for.germination, in the same way
as the moisture of the earth prepares for the growth of the radicle and plumula in seed
sown in it. Too long continuance in the steep is injurious; because it prevents the
germination at the proper time, and thereby exhausts a portion of the vegetative power:
it causes also an abstraction of saccharine matter by the water. The maceration is known
to be complete when the grain may be easily transfixed with a needle, and is swollen
to its full size. The following is reckoned a good test:-If a barley-corn, when pressed
between the thumb and fingers, continues entire in its husk, it is not sufficiently steeped;
but if it sheds its flour upon the fingers, it is ready. When the substance exudes in the
form of a milky juice, the steep has been too long continued, and the barley is spoiled for
germination.
In warm weather it sometimes happens that the water becomes acescent before the
grain is thoroughly swelled. This accident, which is manifest to the taste and smell,
must be immediately obviated by drawing off the foul water through the tap at the bottom
of the cistern, and replacing it with fresh cold water. It does no harm to renew it two
or three times at one steep.
The couch.-The water being drawn off, and occasionally a fresh quantity passed
through, to wash away any slimy matter which may have been generated in warm
weather, the barley is now laid upon the couch floor of stone flags, in square heaps from
12 to 16 inches high, and left in that position for 24 hours. At this period, the bulk
of the grain being the greatest, it may be gauged by the revenue officers if they think
fit. The moisture now leaves the surface of the barley so completely, that it imparts
no dampness to the hand. By degrees, however, it becomes warm; the temperature
rising 10~ above the atmosphere, while an agreeable fruity smell is evolved. At this time,
if the hand be thrust into the heap, it not only feels warm, but it gets bedewed with
moisture.  At this sweating stage, the germination begins; the fibrils of the radicle
first sprout forth from the tip of every grain, and a white elevation appears, that soon




BEER.                                    129
separates into three or more radicles, which grow rapidly larger. About a day after this
appearance, the plumula peeps forth at the same point, proceeding thence beneath the
husk to the other end of the seed, in the form of a green leaflet.
The greatest heat of the couch is usually about 96 hours after the barley has been
taken out of the steep. In consequence, the radicles tend to increase in length with
very great rapidity, and must be checked by artificial means, which constitute the
chief art of the maltster. He now begins to spread the barley thinner on the floor,
and turns it over several times in the course of a day, bringing the portions of the
interior into the exterior surface. The depth, which was originally 15 or 16 inches,
is lowered a little at every turning over, till it be brought eventually down to three
or four inches. Two turnings a day are generally required. At this period of spreading or flooring, the temperature in England is about 620, and in Scotland 5 or 6 degrees
lower.
About a day after the radicles appear, the rudiments of the stem, or of the plumula,
sprout forth, called by the English maltsters the acrospire. It issues from the same end
of the seed as the radicle, but turns round, and proceeds within the husk towards the other
end, and would there come forth as a green leaf, were its progress not arrested. The
malting, however, is complete before the acrospire becomes a leaf.
The barley couch absorbs oxygen and emits carbonic acid, just as animals do in breathing, but to a very limited extent; for the grain loses only three per cent. of its weight
upon the malt floor, and a part of this loss is due to waste particles. As the acrospire
creeps along the surface of the seed, the farina within undergoes a remarkable alteration. The gluten and mucilage disappear, in a great measure, the color becomes whiter.
and the substance becomes so friable that it crumbles into meal between the fingers.
This is the great purpose of malting, and it is known to be accomplished when the plumula or acrospire has approached the end of the seed. Now the further growth must
be completely stopped. Fourteen days may be reckoned the usual duration of the
germinating stage of the malting operations in England; but in Scotland, where the
temperature of the couch is lower, eighteen days, or even twenty-one, are sometimes required. The shorter the period within the above limiits, the more advantageous is the
process to the maltster, as he can turn over his capital the sooner, and his malt is also
somewhat the better. Bigg is more rapid in its germination than barley, and requires to
be still more carefully watched. In dry weather it is sometimes necessary to water the
barley upon the couch.
Occasionally the odor disengaged from the couch is offensive, resembling that of
rotten apples. This is a bad prognostic, indicating either that the barley was of bad
quality, or that the workmen, through careless shovelling, have crushed a number of the
grains in turning them over. Hence when the weather causes too quick germination, it
is better to check it by spreading the heap out thinner than by turning it too frequently
over. On comparing different samples of barley, we shall find that the best develop the
germ or acrospire quicker than the radicles, and thus occasion a greater production of
the saccharine principle; this conversion advances along with the acrospire, and keeps
pace with it, so that the portion of the seed to which it has not reached is still in its unaltered starchy state. It is never complete for any single barleycorn till the acrospire
has come to the end opposite to that from which it sprung; hence one part of the corn
may be sugary, while the other is still insipid. If the grain were allowed to vegetate
beyond this term, the radicles being fully one third of an inch long, the future stem would
become visibly green in the exterior; it would shoot forth rapidly, the interior of the
grain would become milky, with a complete exhaustion of all its useful constituents,
and nothing but the husk would remain.
In France, the brewers, who generally malt their barley themselves, seldom leave it on
the couch more than 8 or 10 days, which, even taking into account the warmer climate
of their country, is certainly too short a period, and hence they make inferior wort to the
English brewer, from the same quantity of malt.
At the end of the germination, the radicles have become 1 longer than the barley,
and are contorted so that the corns hook into one another, but the acrospire is just
beginning to push through. A moderate temperature of the air is best adapted to malt.
ing; therefore it cannot be carried on well during the heat of summer or the colds of
winter.  Malt-floors should be placed in substantial thick-walled buildings, without
access of the sun, so that a uniform temperature of 59~ or 60~ may prevail inside.
Some recommend them to be sunk a little under the surface of the ground, if the
situation be dry.
During germination a remarkable change has taken place in the substance of the
grain. The glutinous constituent has almost entirely disappeared, and is supposed to
have passed into the matter of the radicles, while a portion of the starch is converted
into sugar and mucilage. The change is similar to what starch undergoes when
dissolved in water, and digested in a heat of about 1600 F. along with a little gluten.




130                                  BEER.
The thick paste becomes gradually liquid, transparent, and sweet tasted, and the solution
contains now, sugar and gum, mixed with some unaltered starch. The gluten suffers a
change at the same time, and becomes acescent, so that only a certain quantity of starch
can be thus converted by a quantity of gluten. By the artificial growth upon the maltfloor, all the gluten and albumen present in barley is not decomposed, and only about
one half of the starch is converted into sugar; the other half, by a continuance of the
germination, would only go to the growth of the roots and stems of the plant; but it receives its nearly complete conversion into sugar without any notable waste of substance
in the brewer's operation of mashing.
The kiln-drying.-When the malt has become perceptibly dry to the hand upon
the floor, it is taken to the kiln, and dried hard with artificial heat, to stop all further
growth, and enable it to be kept, without change, for future use, at any time. The
malt-kiln, which is particularly described in the next page, is a round or a square
chamber, covered with perforated plates of cast iron, whose area is heated by a stove or
furnace, so that not merely the plates on which the malt is laid are warmed, but the air
which passes up through the stratum of malt itself, with the effect of carrying off very
rapidly the moisture from the grains. The layer of malt should be about 3 or 4 inches
thick, and evenly spread, and its heat should be steadily kept at from the 90th to the
100th degree of Fahrenheit's scale, till the moisture be mostly exhaled from it. During
this time the malt must be turned over at first frequently, and latterly every three or
four hours. When it is nearly dry, its temperature should be raised to from 145~ to
165~ F., and it must be kept at this heat till it has assumed the desired shade of color,
which is commonly a brownish-yellow or a yellowish-brown. The fire is now allowed
to die out, and the malt is left on the plates till it has become completely cool; a result
promoted by the stream of cool air, which now rises up through the bars of the grate;
or the thoroughly dry browned malt may, by damping the fire, be taken hot from the
plates, and cooled upon the floor of an adjoining apartment. The prepared malt must
be kept in a dry loft, where it can be occasionally turned over till it is used. The
period of kiln-drying should not be hurried. Many persons employ two days in this
operation.
According to the color and the degree of drying, malt is distributed into three sorts;
pale, yellow, and brown. The first is produced when the highest heat to which it has
been subjected is from 90~ to 100~ F.; the amber yellow, when it has suffered a heat
of 122~; and the brown when it has been treated as above described. The black malt
used by the porter brewer to color his beer, has suffered a much higher heat, and is
partially charred. The temperature of the kiln should, in all cases, be most gradually
raised, and most equably maintained. If the heat be too great at the beginning, the
husk gets hard dried, and hinders the evaporation of the water from the interior substance; and should the interior be dried by a stronger heat, the husk will probably split,
and the farina become of a horny texture, very refractory in the mash-tun. In general,
it is preferable to brown malt, rather by a long-continued moderate heat, than by a more
violent heat of shorter duration, which is apt to carbonize a portion of the mucilaginous
sugar, and to damage the article. In this way, the sweet is sometimes converted into a
bitter principle.
During the kiln-drying, the roots and acrospire of the barley become brittle, and fall
off; and are separated by a wire sieve whose meshes are too small to allow the malt
itself to pass through.
A quantity of good barley, which weighs 100 pounds, being judiciously malted, will
weigh, after drying and sifting, 80 pounds. Since the raw grain, dried by itself at the
same temperature as the malt, would lose 12 per cent. of its weight in water, the malt
process dissipates out of these remaining 88 pounds, only 8 pounds, or 8 per cent. of the
raw barley. This loss consists of1t per cent. dissolved out in the steep water,
3   -      dissipated in the kiln,
3   -      by the falling of the fibrils,
-       of waste.
The bulk of good malt exceeds that of the barley from which it was made, by about 8
or 9 per cent.
The operation of kiln-drying is not confined to the mere expulsion of the moisture
from the germinated seeds; but it serves to convert into sugar a portion of the starch
which remained unchanged, and that in a twofold way; first, by the action of the
gluten upon the fecula at an elevated temperature, as also by the species of roasting
which the starch undergoes, and which renders it of a gummy nature. (See STARCH.)
We shall have a proof of this explanation, if we dry one portion of the malt in a
naturally dry atmosphere, and another in a moderately warm kiln; the former will
yield less saccharine extract than the latter. Moreover, the kiln-dried malt has a peculiar, agreeable, and faintly burned taste, probably from a small portion of empy



BEER.                                    131
reumatic oil formed in the husk, and which not only imparts its flavor to the beer, but
also contributes to its preservation. It is therefore obvious, that the skilful preparation
of the malt must have the greatest influence both on the quantity and quality of the worts
to be made from it. If the germination be pushed too far, a part of the extractible matter is wasted; if it has not advanced far enough, the malt will be too raw, and too much
of its substance will remain as an insoluble starch; if it is too highly kiln-dried, a portion
of its sugar will be caramelized, and become bitter; and if the sweating was imperfect
or irregular, much of the barley may be rendered lumpy and useless. Good malt is distmguishable by the following characters:The grain is round and full, breaks freely between the teeth, and has a sweetish taste,
an agreeable smell, and is full of a soft flour from end to end. It affords no unpleasant
flavor on being chewed; it is not hard, so that when drawn along an oaken table across
the fibres, it leaves a white streak, like chalk. It swims upon water, while unmalted
barley sinks in it. Since the quality of the malt depends much on that of the barley, the
same sort only should be used for one malting. New  barley germinates quicker than
old, which is more dried up; a couch of a mixture of the two would be irregular, and
difficult to regulate.
Description of the malt-kiln.-Figs. 107,108,109,110, exhibit the construction of a wellcontrived malt-kiln.  Fig. 107,is the ground plan: fig. 108,is the vertical section; and
figs.109,and 110, a horizontal and vertical section in the line of the malt-plates. The same
letters denote the same parts in each of the figures. A cast-iron cupola-shaped oven is
108
J    e     d                                   ot 
/                                      @~t rM'         O
109                                110
supported in the middle, upon a wall of brickwork four feet high; and beneath it, are the
grate and its ash-pit. The smoke passes off through two equi-distant pipes into the chimney. The oven is surrounded with four pillars, on whose top a stone lintel is laid: a is
the grate, 9 inches below the sole of the oven b; c c c c are the four nine-inch strong
pillars of brickwork which bear the lintel m; d d d d d d are strong nine-inch pillars,
which support the girder and joists upon which perforated plates repose; e denotes a
vaulted arch on each of the four sides of the oven; f is the space between the kiln
and the side arch, into which a workman may enter, to inspect and clean the kiln; g g,
the walls on either side of the kiln, upon which the arches rest; h, the space for the ashes
to fall; k, the fire-door of the kiln; 1 1, junction-pieces to connect the pipes r r with
the kiln; the mode of attaching them  is shown in fig. 109. These smoke-pipes lie
about three feet under the iron plates, and at the same distance from the side walls:
they are supported upon iron props, which are made fast to the arches. In fig. 108, u




132                                  BEER.
shows their section; at s s, fig. 109, they enter the chimney, which is provided with two
register or damper plates, to regulate the draught through the pipes. These registers
are represented by t t, fig. 110, which shows a perpendicular section of the chimney.
m, fig. 108,is the lintel which causes the heated air to spread laterally instead of
ascending in one mass in the middle, and prevents any combustible particles from falling
upon the iron cupola. n n are the main girders of iron for the iron beams o o, upon
which the perforated plates p lie; q,fig. 108,is the vapor pipe in the middle of the roof,
which allows the steam of the drying malt to escape. The kiln may be heated either
with coal or wood.
The size of this kiln is about 20 feet square; but it may be made proportionally either
smaller or greater. The perforated floor should be large enough to receive the contents
of one steep or couch.
The perforated plate might be conveniently heated by steam pipes, laid zig-zag, or in
parallel lines under it; or a wire-gauze web might be stretched upon such pipes. The
wooden joists of a common floor would answer perfectly to support this steam-range, and
the heat of the pipes would cause an abundant circulation of air. For drying the pale
malt of the ale brewer, this plan is particularly well adapted.
The kiln-dried malt is sometimes ground between stones in a common corn mill, like
oatmeal; but it is more generally crushed between iron rollers, at least for the purposes
of the London brewers.
The crushing mill.-The cylinder malt-mill is constructed as shown infigs. 111, 112.
I is the sloping-trough, by which the malt is let down from its bin or floor to the
('. r \i"'f __            _____hopper A  of the mill, whence
lll  *    ~      ~ 1        112  _\    it is progressively  shaken  in
I o e l   II* r _'         - v  _  between the rollers B D. The
A          rollers are of iron, truly cylindrical, and their ends rest in
a ~1\1                   \,i4Y, /      bearers of hard brass, fitted into
a^^^1Z ftl\,LE Athe side frames of iron. A screw
E  goes through the  upright,
^ ^^         r-.... Anu b 1 d  and serves to force the bearer
EP   g>liLlelk  "': t~.  c,of the one roller towards that of
*    D    *  _ I  H   the other, so as to bring them
closer together when the crushing effect is to be increased. G
l A if            ^        is the square end of the axis,
by which  one  of the rollers. _~* \  L     may be turned  either by the. r   ___    *     ba         ~\___ ___  --   hand or by power; the other
derives its rotatory motion from a pair of equal-toothed wheels H, which are fitted to
the other end of the axes of the rollers. d is a catch which works into the teeth of
a ratchet-wheel on the end of one of the rollers (not shown in this view.) The lever
c strikes the trough b at the bottom of the hopper, and gives it the shaking motion for
discharging the malt between the rollers, from the slide sluice a.  e e, fig. 111, are
scraper-plates of sheet iron, the edges of which press by a weight against the surfaces
of the rollers, and keep them clean.
Instead of the cylinders, some employ a crushing mill of a conical-grooved form like a
coffee-mill, upon a large scale. (See the general plan, infrc.)
The mashing and boiling.-Mashing is the operation by which the wort is extracted,
or eliminated from the malt, and whereby a saccharo-mucilaginous extract is made
from it. The malt should not in general be ground into a fine meal, for in that case
it would be apt to form a cohesive paste with hot water, or to set, as it is called, and to
be difficult to drain. In crushed malt, the husk remains nearly entire, and thus helps
to keep the farinaceous particles open and porous to the action of the water. The bulk
of the crushed malt is about one fifth greater than that of the whole, or one bushel of
malt gives a bushel and a quarter of crushed malt. This is frequently allowed to lie
a few days in a cool place, in order that it may attract moisture from the air, which it
does very readily by its hygrometric power. Thus, the farinaceous substance which had
been indurated in the kiln, becomes soft, spongy, and fit for the ensuing process of watery
extraction.
Mashing has not for its object merely to dissolve the sugar and gum already present
in the malt, but also to convert into a sweet mucilage the starch which had remained
unchanged during the germination. We have already stated that starch, mixed with
gluten, and digested for some time with hot water, becomes a species of sugar. This
conversion takes place in the mash-tun. The malted barley contains not only a portion
of gluten, but diastase more than sufficient to convert the starch contained in it, by this
means, into sugar.




BEER.                                   133
The researches of Payen and Persoz show, that the mucilage formed by the reaction
of malt upon starch, may either be converted into sugar, or be made into permanent
gum, according to the temperature of the water in which the materials are digested.
We take of pale barley malt, ground fine, from 6 to 10 parts, and 100 parts of starch; we
heat, by means of a water-bath, 400 parts of water in a copper, to about 80~ F.; we
then stir in the malt, and increase the heat to 140~ F., when we add the starch,
and stir well together.  We next raise the temperature to 158~, and endeavor to
maintain it constantly at that point, or at least to keep it within the limits of 167~ on
the one side, and 158~ on the other. At the end of 20 or 30 minutes, the original milky
and pasty solution becomes thinner, and soon after as fluid nearly as water. This is the
moment in which the starch is converted into gum, or into that substance which the
French chemists call dextrine, from its power of polarizing light to the right hand, whereas
common gum does it to the left. If this merely mucilaginous solution, which seems to
be a mixture of gum with a little liquid starch and sugar, be suitably evaporated, it may
serve for various purposes in the arts to which gum is applied, but with this view, it
must be quickly raised to the boiling point, to prevent the farther operation of the malt
upon it. If we wish, on the contrary, however, to promote the saccharine fermentation,
for the formation of beer, we must maintain the temperature at between 158~ and 167~
for three or four hours, when the greatest part of the gum will have passed into sugar,
and by evaporation of the liquid at the same temperature, a starch sirup may be obtained
like that procured by the action of sulphuric acid upon starch. The substance, which operates in the formation of sugar, or is the peculiar ferment of the sugar fermentation, may
be considered as a residuum  of the gluten or vegetable albumen in the germinating
grain: it is reckoned by Payen and Persoz, a new proximate principle called diastase,
which is formed during malting, in the grains of barley, oats, and wheat, and may be
separated in a pure state, if we moisten the malt flour for a few minutes in cold water,
press it but strongly, filter the solution, and heat the clear liquid in a water bath, to the
temperature of 158~. The greater part of that albuminous azotized substance is thus
coagulated, and is to be separated by a fresh filtration; after which, the clear liquid is
to be treated with alcohol, when a flocky precipitate appears, which is diastase. To purify it still further, especially from the azotized matter, we should dissolve it in
water, and precipitate again with alcohol. When dried at a low temperature, it appears
as a solid white substance, which contains no azote; is insoluble in alcohol, but dissolves
in water and proof spirit. Its solution is neutral and tasteless; when left to itself, it
changes with greater or less rapidity according to the temperature, and becomes sour at
a temperature of from 149~ to 167~. It has the property of converting starch into gum
(dextrine) and sugar, and indeed, when sufficiently pure, with such energy that one
part of it disposes 2000 parts of dry starch to that change, but it operates the quicker the
greater its quantity.  Whenever the solution of diastase with starch or with dextrine is
heated to the boiling point, it loses the sugar-fermenting property. One hundred parts
of well-malted starch appear to contain about one part of this substance.
We can now understand the theory of malting, and the limits between which the
temperature of the liquor ought to be maintained in this operation; namely, the range
between 157~ and 160~ F. It has been ascertained as a principle in mashing, that
the best and soundest extract of the malt is to be obtained, first of all, by beginning to
work with water at the lowest of these heats, and to conclude the mash with water at
the highest. Secondly, not to operate the extraction at once with the whole of the wafer
that is to be employed; but with separate portions and by degrees. The first portion is
added with the view of penetrating equally the crushed malt, an  of extracting the
already formed sugar; the next for effecting the sugar fermentation by the action of the
diastase. By this means, also, the starch is not allowed to run into a cohesive paste, and
the extract is more easily drained from the poorer mass, and comes off in the form of a
nearly limpid wort. The thicker, moreover, or the less diluted the mash is, so much the
easier is the wort fined in the boiler or copper by the coagulation of the albuminous
matter: these principles illustrate, in every condition, the true mode of conducting
the mashing process; but different kinds of malt require a different treatment. Pale
and slightly kilned malt requires a somewhat lower heat than malt highly kilned, because
the former has more undecomposed starch, and is more ready to become pasty. The
former also, for the same reason, needs a more leisurely infusion than the latter, for its
conversion into mucilaginous sugar. The more sugar the malt contains, the more is its
saccharine fermentation accelerated by the action of the diastase. What has been here
said of pale malt, is still more applicable to the case of a mixture of raw grain with malt,
for it requires still gentler heats, and more cautious treatment.
III. The mash-tun is a large circular tub with a double bottom; the uppermost of
which is called a false bottom, and is pierced with many holes. There is a space of about
2 or 3 inches between the two, into which the stopcocks enter, for letting m the water
and drawing off the wort. The holes of the false bottom should be burned, and not bored,




134                                  BEER.
to prevent the chance of their filling up by the swelling of the wood, which would
obstruct the drainage: the holes should be conical, and largest below, being about A of
an inch there, and ~ at the upper surface. The perforated bottom must be fitted truly
at the sides of the mash-tun, so that no grains may pass through. The mashed liquor is
let off into a large back, from which it is pumped into the wort coppers. The mash-tun
is provided with a peculiar rotatory apparatus for agitating the crushed grains and water
together, which we shall presently describe. The size of the wort copper is proportional
to the amount of the brewing, and it must, in general, be at least so large as to
operate upon the whole quantity of wort made from one mashing; that is, for every
quarter of malt mashed, the copper should contain 140 gallons. The mash-tun ought to
be at least a third larger, and of a conical form, somewhat wider below than above.
The quantity of water to be employed for mashing, or the extraction of the wort, depends upon the greater or less strength to be given to the beer. The seeds of the crushed
malt, after the wort is drawn off, retain still about 32 gallons of water for every quarter
of malt. In the boiling, and evaporation from the coolers, 40 gallons of water are dissipated from one quarter of malt; constituting 72 gallons in all. If 13 quarters of barley
be taken to make 1500 gallons of beer, 2400 gallons of water must therefore be required
for the mashing. This example will give an idea of the proportions for an ordinary
quality of beer.
When the mash is to begin, the copper must be filled with water, and heated. As soon
as the water has attained the heat of 145~ m summer, or 167~ in winter, 600 gallons of it
are to be run off into the mash-tun, and the 13 quarters of crushed malt are to be gradually thrown in and well intermixed by proper agitation, so that it may be uniformly
moistened, and no lumps may remain. After continuing the agitation in this way for one
half or three quarters of an hour, the water in the copper will have approached to its
boiling point, when 450 gallons at the temperature of about 200~ are to be run into the
mash-tun, and the agitation is to be renewed till the whole assumes an equally fluid
state: the tun is now to be well covered for the preservation of its heat, and to be
allowed to remain at rest for an hour, or an hour and a half. The mean temperature of
this mash may be reckoned at about 145~. The time which is necessary for the transmuting heat of the remaining starch into sugar depends on the quality of the malt.
Brown malt requires less time than pale malt, and still less than a mixture with raw
grain, as already explained. After the mash has rested the proper time, the tap of the
tun is opened, and the clear wort is to be drawn out into the under back. If the wort
that first flows is turbid, it must be returned into the tun, till it runs clear. The amount
of this first wort may be about 675 gallons. Seven hundred and fifty gallons of water,
at the temperature of 200~, are now to be introduced up through the drained malt, into
the tun, and the mixture is to be agitated till it becomes uniform, as before. The mashtun is then to be covered, and allowed to remain at rest for an hour. The temperature
of this mash is from 167~ to 174~. While the second mash is making, the worts of the
first are to be pumped into the wort copper, and set a-boiling as speedily as possible.
The wort of the second mash is to be drawn off at the proper time, and added to the
copper as fast as it will receive it, without causing the ebullition to stop.
A third quantity of water amounting to 600 gallons, at 200~, is to be introduced into
the mash-tun, and after half an hour is to be drawn off, and either pumped into the wort
copper, or reserved for mashing fresh malt, as the brewer may think fit.
The quantity of extract, per barrel weight, which a quarter of malt yields to wort,
amounts to about 84 lbs. The wort of the first extract is the strongest; the second contains, commonly, one half the extract of the first; and the third, one half of the second;
according to circumstances.
To measure the degrees of concentration of the worts drawn off from the tun, a particular form of hydrometer, called a saccharometer, is employed, which indicates the
number of pounds weight of liquid contained in a barrel of 36 gallons imperial measure.
Now, as the barrel of water weighs 360 lbs., the indication of the instrument, when
placed in any wort, shows by how many pounds a barrel of that wort is heavier than a
barrel of water; thus, if the instrument sinks with its poise till the mark 10 is upon a
line with the surface of the liquid, it indicates that a barrel of that wort weighs ten
pounds more than a barrel of water. See SACCHAROMETER.
Or, supposing the barrel of wort weighs 396 lbs., to convert that number into specific
gravity, we have the following simple rule:360: 396:: 100: 1*100;
at which density, by my experiments, the wort contains 25 per cent. of solid extract.
Having been employed to make experiments on the density of worts, and the fermentative changes which they undergo, for the information of a committee of the House of
Commons, which tat in July and August, 1830, I shall here introduce a short abstract of
that part of my evidence which bears upon the present subject.
My first object was to clear up the difficulties which, to common apprehension, hung




BEER.                                     135
over the matter, from the difference in the scales of the saccharometers mn use among the
brewers and distillers of England and Scotland. I found that one quarter of good malt
would yield to the porter-brewer a barrel Imperial measure of wort, at the concentrated
specific gravity of 1'234. Now, if the decimal part of this number be multiplied by
360, being the number of pounds weight of water in the barrel, the product will denote
the excess in pounds, of the weight of a barrel of such concentrated wort, over that of
a barrel of water; and that product is, in the present case, 84*24 pounds.
Mr. Martineau, jun., of the house of Messrs. Whitbread and Company, and a gentleman connected with another great London brewery, had the kindness to inform me that
their average product from a quarter of malt was a barrel of 84 lbs. gravity. It is obvious, therefore, that by taking the mean operation of two such great establishments, I
must have arrived very nearly at the truth.
It ought to be remarked that such a high density of wort as 1'234 is not the result of
any direct experiment in the brewery, for infusion of malt is never drawn off so strong;
that density is deduced by computation from the quantity and quality of several successive infusions; thus, supposing a first infusion of the quarter of malt to yield a barrel of
specific gravity 1-112, a second to yield a barrel at 1'091, and a third a barrel at 1-031,
we shall have three barrels at the mean of these three numbers, or one barrel at their
sum, equal to 1*234.
I may here observe that the arithmetical mean or sum is not the true mean or sum of
the two specific gravities; but this difference is either not known or disregarded by the
brewers. At low densities this difference is inconsiderable, but at high densities it would
lead to serious errors.  At specific gravity 1-231, wort or sirup contains one half of its
weight of solid pure saccharum, and at 1'1045 it contains one fourth of its weight; but
the brewer's rule, when here applied, gives for the mean specific gravity 11155=
1'231 -- 1-000. The contents in solid saccharine matter at that density are however 272
per cent., showing the rule to be 21 lbs. wrong in excess on 100 lbs., or 9 lbs. per barrel.
The specific gravity of the solid dry extract of malt wort is 1-264; it was taken in oil
of turpentine, and the result reduced to distilled water as unity. Its specific volume is
0'7911, that is, 10 lbs. of it will occupy the volume of 7-911 lbs. of water.  The mean
specific gravity, by computation of a solution of that extract in its own weight of water,
is 1*1166; but by experiment, the specific gravity of that solution is 1-216, showing
considerable condensation of volume in the act of combination with water.
The following Table shows the relation between the specific gravities of solutions of
malt extract, and the per-centage of solid extract they contain:
Extr Malt.         Water.      Malt Extract in 100.   Sugar in 100. Specific gravity.
600       +        600               50-00           47-00          1'2160
600                900                40-0           37-00          1'1670
600               1200                33-3           31-50          1-1350
600               1500               28-57           26-75          1'1130
600        -      1800               25-00           24-00          1'1000
The extract of malt was evaporated to dryness, at a temperature of about 250~ F.,
without the slightest injury to its quality, or any empyreumatic smell. Bate's tables
have been constructed on solutions of sugar, and not with solutions of extract of malt,
or they agree sufficiently well with the former, but differ materially from the latter.
Allan's tables give the amount of a certain form of solid saccharine matter extracted
from malt, and dried at 175~ F., in correspondence to the specific gravity of the solution;
but I have found it impossible to make a solid extract from infusions of malt, except at
much higher temperatures than 175~ F.  Indeed, the numbers on Allan's saccharometer
scale clearly show that his extract was by no means dry: thus, at 1-100 of gravity he
assigns 29-669 per cent. of solid saccharine matter; whereas there is at that density of
solid extract only 25 per cent. Again, at 1-135, Allan gives 40 parts per cent. of solid
extract, whereas there are only 331 present.
By the triple mashing operations above described, the malt is so much exhausted that
it can yield no further extract useful for strong beer or porter.  A weaker wort might
no doubt still be drawn off for small beer, or for contributing a little to the strength of
the next mashing of fresh malt. But this I believe is seldom practised by respectable
brewers, as it impoverishes the grains which they dispose of for feeding cattle.
The wort should be transferred into the copper, and made to boil as soon as possible,
for if it remains long in the under-back it is apt to become acescent. The steam moreover raised from it in the act of boiling serves to screen it from the oxygenating or acidifying influence of the atmosphere. Until it begins to boil, the air should be excluded
by some kind of a cover.




136                                   BEER.
Sometimes the first wort is brewed by itself into strong ale, the second by itself into an
intermediate quality; and the third into small beer; but this practice is not much followed in this country.
We shall now treat of the boiling in of the hops. The wort drawn from the mashtun, whenever it is pumped into the copper, must receive its allowance of hops. Besides
evaporating off a portion of the water, and thereby concentrating the wort, boiling has a
twofold object. In the first place, it coagulates the albuminous matter, partly by the
heat, and partly by the principles in the hops, and thereby causes a general clarification
of the whole mass, with the effect of separating the muddy matters in a flocculent form.
Secondly, during the ebullition, the residuary starch and hordeine of the malt are converted into a limpid sweetish mucilage, the dextrine above described; while some of the
glutinous stringy matter is rendered insoluble by the tannin principle of the hops, which
favors still further the clearing of the wort. By both operations the keeping quality
of the beer is improved. This boil must be continued during several hours; a longer
time for the stronger, and a shorter for the weaker beers. There is usually one seventh
or one sixth part of the water dissipated in the boiling copper. This process is known
to have continued a sufficient time, if the separation of the albuminous flocks is distinct,
and if these are found, by means of a proof gauge suddenly dipped to the bottom, to be
collected there, while the supernatant liquor has become limpid. Two or three hours'
boil is deemed long enough in many well-conducted breweries; but in some of those in
Belgium, the boiling is continued from 10 to 15 hours, a period certainly detrimental to
the aroma derived from the hop.
Many prefer adding the hops when the wort has just come to the boiling point.
Their effect is to repress the further progress of fermentation, and especially the passage
into the acetous stage, which would otherwise inevitably ensue in a few days. In this
respect, no other vegetable production hitherto discovered can be a substitute for the
hop. The odorant principle is not so readily volatilized as would at first be imagined;
for when hop is mixed with strong beer wort and boiled for many hours, it can still
impart a very considerable degree of its flavor to weaker beer. By mere infusion in
hot beer or water, without boiling, the hop loses very little of its soluble principles.
The tannin of the hop combines, as we have said, with the vegetable albumen of the
barley, and helps to clarify the liquor. Should there be a deficiency of albumen and
gluten, in consequence of the mashing having been done at such a heat as to have coagulated them beforehand, the defect may be remedied by the addition of a little gelatine to
the wort copper, either in the form of calf's foot, or of a little isinglass. If the hops be
boiled in the wort for a longer period than 5 or 6 hours, they lose a portion of their fine
flavor; but if their natural flavor be rank, a little extra boiling improves it. Many brewers throw the hops in upon the surface of the boiling wort, and allow them to swim there
for some time, that the steam may penetrate them, and open their pores for a complete solution of their principles when they are pushed down into the liquor. It is proper to add
the hops in considerable masses, because, in tearing them asunder, some of the lupuline
powder is apt to be lost.
The quantity of hop to be added to the wort varies according to the strength of the
beer, the length of time it is to be kept, or the heat of the climate where it is intended
to be sent. For strong beer, 4- lbs. of hops are required to a quarter of malt, when it
is to be highly aromatic and remarkably clear. For the stronger kinds of ale and
porter, the rule, in England, is to take a pound of hops for every bushel of malt, or 8 lbs.
to a quarter. Common beer has seldom more than a quarter of a pound of hops to the
bushel of malt.
It has been attempted to form an extract of hops by boiling in covered vessels, so as
not to lose the oil, and to add this instead of the hop itself to the beer. On the great
scale this method has no practical advantage, because the extraction of the hop is perfectly accomplished during the necessary boiling of the wort, and because the hop operates very beneficially, as we have explained, in clarifying the beer. Such an extract,
moreover, could be easily adulterated.
Of the Coolers.-The contents of the copper are run into what is called the hopback, on the upper part of which is fixed a drainer, to keep back the hops. The
pump is placed in the hop-back, for the purpose of raising the wort to the coolers,
usually placed in an airy situation upon the top of the brewery. Two coolers are
indispensable when we make two kinds of beer from the same brewing, and even in
single brewings, called gyles, if small beer is to be made. One of these coolers ought
to be placed above the level of the other. As it is of great consequence to cool the
worts down to the fermenting pitch as fast as possible, various contrivances have been
made for effecting this purpose. The common cooler is a square wooden cistern, about
6 inches deep, and of such an extent of surface that the whole of one boil may only
occupy 2 inches, or thereabouts, of depth in it. For a quantity of wort equal to about
1500 gallons its area should be at least 54 feet long and 20 feet wide. The seams of




BEER.                                    137
the cooler must be made perfectly water-tight and smooth, so that no liquor may lodge in
them when they are emptied. The utmost cleanliness is required, and an occasional
sweetening with lime-water.
The hot wort reaches the cooler at a temperature of from 200~ to 208~, according to
the power of the pump. Here it should be cooled to the proper temperature for the
fermenting tun, which may vary from 54~ to 64~, acctrding to circumstances. The
refrigeration is accomplished by the evaporation of a porion of the liquor: it is more
rapid in proportion to the extent of the surface, to the low temperature, and the dryness
of the atmosphere surrounding the cooler. The renewal of a body of cool dry air by
the agency of a fan, may be employed with great advantage. The cooler itself must
be so placed that its surface shall be freely exposed to the prevailing wind of the district,
and be as free as possible from the eddy of surrounding buildings. It is thought by many
that the agitation of the wort during its cooling is hurtful. Were the roof made moveable, so that the wort could be readily exposed, in a clear night, to the aspect of the sky,
it would cool rapidly by evaporation, on the principles explained by Dr. Wells, in his
"Essay on Dew."
When the cooling is effected by evaporation alone, the temperature falls very slowly,
even in cold air, if it be loaded with moisture. But when the air is dry, the evaporation
is vigorous, and the moisture exhaled does not remain incumbent on the liquor, as in
damp weather, but is diffused widely in space. Hence we can understand how wort
cools so rapidly in the spring and autumn, when the air is generally dry, and even more
quickly than in winter, when the air is cooler, but loaded with moisture. In fact, the
cooling process goes on better when the atmosphere is from 50~ to 55~, than when it falls
to the freezing point, because in this case, if the air be still, the vapors generated remain
on the surface of the liquor, and prevent further evaporation. In summer the cooling
can take place only during the night.
In consequence of the evaporation during this cooling process, the bulk of the worts
is considerably reduced; thus, if the temperature at the beginning was 208~, and if it
be at the end 64~, the quantity of water necessary to be evaporated to produce this
refrigeration would be nearly - of the whole, putting radiation and conduction of heat
out of the question. The effect of this will be a proportional concentration of the
beer.
The period of refrigeration in a well-constructed cooler, amounts to 6 or 7 hours in
favorable weather, but to 12 or 15 in other circumstances. The quality of the beer is
much improved by shortening this period; because, in consequence of the great surface
which the wort exposes to the air, it readily absorbs oxgyen, and passes into the acetous
fermentation with the production of various mouldy spots; an evil to which ill-hopped
beer is particularly liable. Various schemes have been contrived to cool wort, by transmitting it through the convolutions of a pipe immersed in cold water. The best plan
is to expose the hot wort for some hours freely to the atmosphere and the cooler, when
the loss of heat is most rapid by evaporation and other means, and when the temperature falls to 1000, or thereby, to transmit the liquor through a zig-zag pipe, laid almost
horizontally in a trough of cold water. The various methods described under Refrigerator are more complex, but they may be practised in many situations with considerable advantage.
Whilst the wort reposes in the cooler, it lets fall a slight sediment, which consists
partly of fine flocks of coagulated albumen combined with tannin, and partly of starch,
which had been dissolved at the high temperature, and separates at the lower. The wort
should be perfectly limpid, for a muddy liquor never produces transparent beer. Such
beer contains, besides mucilaginous sugar and gum, usually some starch, which even remains after the fermentation, and hinders its clarifying, and gives it a tendency to sour.
The wort contains more starch the hotter it has been mashed, the less hops have been
added, and the shorter time it has been boiled. The presence of starch in the wort may
be made manifest by adding a little solution of iodine in alcohol to it, when it will become immediately blue. We thus see that the tranquil cooling of wort in a proper vessel has an advantage over cooling it rapidly by a refrigeratory apparatus. When the
wort is sufficiently cool, it is let down into the fermenting tun. In this transfer the cooling might be carried several degres lower, were the wort made to pass down through a
tube enclosed in another tube, along which a stream of cold water is flowing in the opposite direction, as we have described in the sequel of ACETIC ACID. These fermenting tuns
are commonly called gyle-tuns, or working tuns, and are either square or circular, the
latter being preferable on many accounts.
IV. Of the Fermentation.-In the great London breweries, the size of these fermenting
tuns is such that they contain from  1200 to 1500 barrels. The quantity of wort
introduced at a time must, however, be considerably less than the capacity of the vessel,
to allow room for the head of yeast which rises during the process; if the vessel be
cylindrical, this head is proportional to the depth of the worts. In certain kinds of




138                                     BEER.
fermentation, it may rise to a third of that depth. In general, the fermentation proceeds
more uniformly and constantly in large masses, because they are little influenced by vicissitudes of temperature; smaller vessels, on the other hand, are more easily handled.
The general view of fermentation will be found under that title; I shall here make a
few remarks on what is peculiar lo beer. During the fermentation of wort, a portion
of its saccharine matter is converted into alcohol, and wort thus changed is beer. It is
necessary that this conversion of the sugar be only partial, for beer which contains no
undecomposed sugar would soon turn sour, and even in the casks its alcohol undergoes
a slow fermentation into vinegar.  The amount of this excess of sugar is greater in
proportion to the strength of the wort, since a certain quantity of alcohol, already
formed, prevents the operation of the ferment on the remaining'vort. Temperature has
the greatest influence upon the fermentation of wort. A temperature of from 55~ to 600
of the liquor, when that of the atmosphere is     i5~, is most advantageous for the
commencement.  The warmth of the wort as it comes into the gyle-tun must be modified by that of the air in the apartment. In winter, when this apartment is cold, the
wort should not be cooled under 64~ or 60~, as in that case the fermentation would be
tedious or interrupted, and the wort liable to spoil or become sour. In summer, when
the temperature of the place rises to above 75~, the wort should be cooled, if possible,
down to 55~, for which purpose it should be let in by the system of double pipes, above
mentioned.  The higher the temperature of the wort, the sooner will the fermentation
begin and end, and the less is it in our power to regulate its progress. The expert
brewer must steer a middle course between these two extremes, which threaten to destroy his labors. In some breweries a convoluted pipe is made to traverse or go round
the sides of the gyle-tun, through which warm water is allowed to flow in winter, and
cold in summer, so as to modify the temperature of the mass to the proper fermenting
pitch. If there be no contrivance of this kind, the apartment may be cooled in summer,
by suspending wet canvass opposite the windows in warm weather, and kindling a small
stove within it in cold.
When the wort is discharged into the gyle-tun, it must receive its dose of yeast, which
has been previously mixed with a quantity of the wort, and left in a warm place till it
has begun to ferment. This mixture, called lobb, is then to be put into the tun, and stirred well through the mass. The yeast should be taken from similar beer. Its quantity
must depend upon the temperature, strength, and quantity of the wort.  In general, one
gallon of yeast is sufficient to set 100 gallons of wort in complete fermentation. An excess of yeast is to be avoided, lest the fermentation should be too violent, and be finished
in less than the proper period of 6 or 8 days. More yeast is required in winter than in
summer; for, at a temperature of 50~, a double quantity may be used to that at 68~.
Six or eight hours after adding the yeast, the tun being meanwhile covered, the fermentation becomes active: a white milky-looking froth appears, first on the middle, and
spreads gradually over the whole surface; but continues highest in the middle, forming
a frothy elevation, the height of which increases with the progress of the fermentation,
and whose color gradually changes to a bright brown, the result, apparently, of the oxydation of the extractive contained in this yeasty top. This covering screens the wort
fiom the contact of the atmospherical air.  During this time, there is a perpetual disengagement of carbonic acid gas, which is proportional to the quantity of sugar converted
into alcohol. The warmth of the fermenting liquid increases at the same time, and is at
a maximum when the fermentation has come to its highest point. This increase of
temperature amounts to from 9~ to 14~ or upwards, and is the greater the more rapid the
fermentation. But in general, the fermentation is not allowed to proceed so far in the
gyle-tun, for after it is advanced a little way, the beer is cleansed, that is, drawn off into
other vessels, which are large barrels set on end, with large openings in their top, furnished with a sloping tray for discharging an excess of yeast into the wooden trough, in
which the stillions stand. These stillions are placed in communication with a store-tub,
which keeps them  always full, by hydrostatic pressure, so that the head of yeast may
spontaneously flow over, and keep the body of liquor in the cask clean. This apparatus
will be explained in describing the brewery plant.  See the figures, infra.
It must be observed, that the quantity of yeast, and the heat of fermentation, differ
for every different quality of beer. For mild ale, when the fermentation has reached 75~
its first flavor begins; at 80~ the flavor increases; at 85~ it approaches the high
flavor; at 90~ it is high; but it may be carried to 100~ and upwards, for particular
purposes.  A wort of 301bs. per barrel (sp. gr. 1'088), ought to increase about 15~,
so that in order to arrive at 80~, it should be set at 65~. The quantity of yeast for such
an ale should be from 2 to 3 lbs. per barrel. The higher the heat, the less yeast is necessary. If the heat of the fermentation should at any time fall, it must be raised by a
supply of fresh yeast, well stirred in; but this practice is not advisable in general,
because rousing the worts in the gyle-tun is apt to communicate a rank flavor of yeast
to the ale.  It is the practice of many experienced brewers to look every 2 hours into the




BEER.                                      139
gyle-tun, chiefly with the view of observing the progress of the heat, which is low at
first, but afterwards often increases half a degree per hour, and subsequently declines, as
the fermentation approaches its conclusion, till at length the heat becomes uniform, or
sometimes decreases, before the fermentation is finished, especially where the quantity
operated upon is small.
Some brewers recommend, when the fermentation is carried to its utmost period, to add
about 7 lbs. of wheat or bean flour to a gyle-tun of 25 or 30 barrels, at the time of cleansing, so as to quicken the discharge of the yeast, by disengagement of more carbonic acid.
The flour should be whisked up in a pail, with some of the beer, till the lumps are broken, and then poured in. By early cleansing, the yeast is preserved longer in a state
proper for a perfect fermentation than by a contrary practice.
For old ale, which is to be long kept, the heat of the fermentation should not exceed
750, but a longer time is required to complete the fermentation and ensure the future
good flavor of the ale.
For porter, the general practice is, to use from 4 to 4- lbs. of hops per barrel for keeping; though what is termed mild or mixing porter, has not more than 3 or 31 lbs. The
heat of fermentation must not exceed 70~, and begin about 60~. If the heat tend to increase much above that pitch in the gyle-tun, the porter should be cleansed, by means of
the stillions. At this period of the fermentation, care should be taken that the sweetness
of the malt be removed, for which purpose more yeast may be used than with any other
beer of the same strength. The quantity is from 3 to 4 lbs. per barrel, rousing the wort
in the gyle-tun every 2 hours in the day-time.
When the plan of cleansing casks is not employed, the yeast is removed from the
surface of the fermenting tun by a skimmer, and the clear beer beneath is then drawn
off into the ripening tuns, called store-vats, in which it is mixed up with different brewings, to suit the taste of the customers. This transfer must take place whenever the
extrication of carbonic acid has nearly ceased; lest the alcohol formed should dissolve
some of the floating yeast, acquire thereby a disagreeable taste, and pass partially into
the acetous state.
In this process, during the formation of vinous spirit at the expense of the sugar, the
albumen and gluten diffused through the beer, being acted upon by the alcohol, become
insoluble; one portion of them is buoyed to the top with the carbonic acid gas, to form
the frothy yeast; and another portion falls to form the bottom  barm.  The former consists of the same materials as the wort, with a large proportion of gluten, which forms
its active constituent; the latter is a peculiar deposite, consisting of the same gluten mixed
with the various dense impurities of the wort, and may be also used as a ferment, but is
cruder than the floating yeast. The amount of yeast is proportional to the activity of the
fermentation, or extrication of carbonic acid gas, as also to the heat of the mashing process, and the quantity of starch or flour unaltered by germination. Pale malt affords,
usually, more yeast than malt highly kilned. When the yeast becomes excessive, from
too violent fermentation, it should be skimmed off from time to time, which will tend to
cool the liquor and moderate the intestine changes.
After the beer is let down into the close store-tuns in the cellar, an obscure fermentation goes on, for a considerable period, in its body, which increases its splrituous strength,
and keeps up in it a constant impregnation of carbonic acid gas, so as to render it lively
and agreeable to the taste, when it is casked off for sale. It would appear that beer is
never stationary in quality, while it is contained in the tuns; for the moment when it
ceases to improve by the decomposition of its residuary sugar, it begins to degenerate
into vinegar. This result may be produced either by the exhaustion of the saccharine,
or by the fermentative matter. The store cellar should therefore be under ground, free
from alternations of temperature, vibrations of carriages, and as cool as possible. In the
great London breweries the fermentation is rendered very complete in the cleansing
butts; so that a slow and steady ripening is ensured in the great store-tuns. The gyletuns are too capacious to permit the fermentation to be finished, with either safety or
sufficient despatch in them.
V. OF RIPENING DIFFERENT RINDS OF BEER.-The varieties of beer depend either upon
the difference of their materials, or from a different management of the brewing processes.
With regard to the materials, beers differ in the proportion of their malt, hops, and
water; and if the different kinds of malt or other grain. To the class of table or
small beers, all those sorts may be referred whose specific gravity does not exceed 1'025,
which contain about 5 per cent. of malt extract, or nearly 18 pounds per barrel. Beers
of middling strength may be reckoned those between the density of 1'025 and 1'040;
which contain at the average 7 per cent. or 25 pounds per barrel.  The latter may
be made with 400 quarters of malt to 1500 barrels of beer. Stronger beers have a
specific gravity of from 1'050 to 1*080, and take from 45 to 75 quarters of malt to
the same quantity of beer. The strongest beer found in the market is some of the
English and Scotch ales, for which from 18 to 27 quarters of malt arc taken for 1500




140                                  BEER.
gallons of beer. Good porter requires from 16 to 18 quarters for that quantity. Beers
are sometimes made with the addition of other farinaceous matter to the malt; but
when the latter constitutes the main portion of the grain, the malting of the other
kinds of corn becomes unnecessary, for the diastase of the barley-malt changes the
starch into sugar during the mashing operation. Even with entirely raw grain, beer
is made in some parts of the Continent, the brewers trusting the conversion of the
starch into sugar to the action of the gluten alone, at a low mashing temperature, on
the principle of Saussure's and Kirchoff's researches.
The color of the beer depends upon the color of the malt, and the duration of the
boil in the copper. The pale ale is made, as we have stated, from steam or sun-dried'malt, and the young shoots of the hop; the deep yellow ale from a mixture of pale
yellow and brown malt; and the dark brown beer from well-kilned and partly carbonized malt, mixed with a good deal of the pale, to give body. The longer and more
strongly heated the malt has been in the kiln, the less weight of extract, ceteris paribus,
does it afford. In making the fine mild ales, high temperatures ought to be avoided,
and the yeast ought to be skimmed off, or allowed to flow very readily from its top, by
means of the cleansing butt system, so that little ferment being left in it to decompose
the rest of the sugar, the sweetness may remain unimpaired. With regard to porter,
in certain breweries, each of the three kinds of malt employed for it is separately
mashed, after which the first and the half of the second wort is boiled along with the
whole of the hops, and thence cooled and set to ferment in the gyle-tun. The third
drawn wort, with the remaining half of the second, is then boiled with the same hops,
saved by the drainer, and, after cooling, added to the former in the gyle-tun, when the
two must be well roused together.
It is obvious, from the preceding development of principles, that all amylaceous and
saccharine materials, such as potatoes, beans, turnips, as well as cane and starch sirup,
molasses, &c., may be used in brewing beer. When, however, a superior quality of
brown beer is desired, malted barley is indispensable, and even with these substitutes
a mixture of it is most advantageous. The washed roots of the common carrot, of the
red and yellow beet, or of the potato, must be first boiled in water, and then mashed
into a pulp. This pulp must be mixed with water in the copper, along with wheaten
or oat meal, and the proper quantity of hops, then boiled during 8 or 9 hours. This
wort is to be cooled in the usual way, and fermented, with the addition of yeast.
A much better process is that now practised, on a considerable scale, at Strasbourg, in
making the ale, for which that city is celebrated. The mashed potatoes are mixed with
from a twentieth to a tenth of their weight of finely ground barley malt, and some
water. The mixture is exposed, in a water-bath, to a heat of 160~ F. for four hours,
whereby it passes into a saccharine state, and may then be boiled with hops, cooled, and
properly fermented into good beer.
Maize, or Indian corn, has also been employed to make beer; but its malting is
somewhat difficult on account of the rapidity and vigor with which its radicals and
plumula sprout forth. The proper mode of causing it to germinate is to cover it, a few
inches deep, with common soil, in a garden or field, and to leave it there till the bed is
covered with green shoots of the plant. The corn must be then lifted, washed, and
exposed to the kiln.
The Difference of the Fermentation.-The greater or less rapidity with which the
worts are made to ferment has a remarkable influence upon the quality of the beer,
especially in reference to its fitness for keeping. The wort is a mucilaginous solution
in which the yeasty principles, eliminated by the fermentation, will, if favored by
regular and slow intestine movements, completely rise to the surface, or sink to the
bottom, so as to leave the body fine. But, when the action is too violent, these barmy
glutinous matters get comminuted and dispersed through the liquor, and can never afterwards be thoroughly separated. A portion of the sa'me feculent matter becomes, moreover,
permanently dissolved, during this furious commotion, by the alcohol that is generated.
Thus the beer loses not merely its agreeable flavor and limpidity, but is apt to spoil
from the slightest causes. The slower, more regularly progressive, and less interrupted,
therefore, the fermentation is, so much better will the product be.
Beer, in its perfect condition, is an excellent and healthful beverage, combining, in
some measure, the virtues of water, of wine, and of food, as it quenches thirst, stimulates,
cheers, and strengthens. The vinous portion of it is the alcohol, proceeding from the
fermentation of the malt sugar. Its amount, in common strong ale or beer, is about
4 per cent., or four measures of spirits, specific gravity 0'825 in 100 measures of the
liquor. The best brown stout porter contains 6 per cent., the strongest ale even 8 per
cent.; but common beer only one. The nutritive part of the beer is the undecomposed
gum-sugar, and the starch-gum, not changed into sugar. Its quantity is very variable,
according to the original starch of the wort, the length of the fermentation, and the age
of the beer.




BEER.                                    141
The main feature of good beer is fine color and transparency; the production of
which is an object of great interest to the brewer. Attempts to clarify it in the cask
seldom fail to do it harm. The only thing that can be used with advantage for fining
foul or muddy beer, is isinglass. For porter, as commonly brewed, it is frequently had
recourse to.'A pound of good isinglass will make about 12 gallons of finings. It is
cut into slender shreds, and put into a tub with as much vinegar or hard beer as will
cover it, in order that it may swell and dissolve. In proportion as the solution proceeds,
more beer must be poured upon it, but it need not be so acidulous as the first, because,
when once well softened by the vinegar, it readily dissolves. The mixture should be
frequently agitated with a bundle of rods, till it acquires the uniform consistence of thin
treacle, when it must be equalized still more by passing through a tammy cloth, or a
sieve. It may now be made up with beer to the proper measure of dilution. The
quantity generally used is from a pint to a quart perbarrel, more or less, according to
the foulness of the beer. But before putting it into the butt, it should be diffused
through a considerable volume of the beer with a whisk, till a frothy head be raised
upon it. It is in this state to be poured into the cask, briskly stirred about; after
which the cask must be bunged down for at least 24 hours, when the liquor should be
limpid. Sometimes the beer will not be improved by this treatment; but this should
be ascertained beforehand, by drawing off some of the beer into a cylindric jar or vial,
and adding to it a little of the finings. After shaking and setting down the glass, we
shall observe whether the feculencies begin to collect in flocky parcels, which slowly
subside; or whether the isinglass falls to the bottom without making any impression
upon the beer. This is always the case when the fermentation is incomplete, or a secondary decomposition has begun. Mr. Jackson has accounted for this clarifying effect
of isinglass in the following way.
The isinglass, he thinks, is first of all rather diffused mechanically, than chemically
dissolved, in the sour beer or vinegar, so that when the finings are put into the foul beer,
the gelatinous fibres, being set free in the liquor, attract and unite with the floating feculencies, which before this union were of the same specific gravity with the beer, and
therefore could not subside alone; but having now acquired additional weight by the
coating of fish glue, precipitate as a flocculent magma. This is Mr. Jackson's explanation; to which I would add, that if there be the slightest disengagement of carbonie
acid gas, it will keep up an obscure locomotion in the particles, which will prevent the said
light impurities, either alone or when coated with isinglass, from subsiding. The beer
is then properly enough called stubborn by the coopers. But the true theory of the action
of isinglass is, that the tannin of the hops combines with the fluid gelatine, and forms a
flocculent mass, which envelopes the muddy particles of the beer, and carries them to the
bottom as it falls, and forms a sediment. When, after the finings are poured in, no
proper precipitate ensues, it may be made to appear by the addition of a little decoction
of hop.
Mr. Richardson, the author of the well-known brewer's saccharometer, gives the
following as the densities of different kinds of beer:Beer.                 Pounds per Barrel.      Specific Gravity.
Burton ale, 1st sort  -    -           40 to 43             1-111 to 1-120
2d ditto -        -          35 to 40            1-097 to 1-111
3d ditto   -    -            28 to 33            1-077 to 1-092
Common ale  -      -                   25 to 27             1-070 to 1-073
Ditto ditto -   -    -    -    -          21                1-058
Porter, common sort    -     -            18                1-050
Ditto, double   -    -20                                    1.055
Ditto, brown stout     -                  23                1-064
Ditto, best brown stout    -    -         26                1-072
Common small beer-    -                    6                1-014
Good table beer                        12 to 14             1-033 to 1-039'Of Returns or Malt Residuums.- When small beer is brewed after ale or porter, only
one mash is to be made; but where this is not done, there may be two mashes, in order
to economize malt to the utmost. We may let on the water at 160~ or 165% in any
convenient quantity, infuse for an hour or thereby, then run it off, and pump into the
copper, putting some hops into it, and causing it to boil for an instant; when it may be
transferred to the cooler. A second mash or return may be made in the same manner,
but at a heat 5~ lower; and then disposed of in the boiler with some hops, which may
remain in the copper during the night at a scalding heat, and may be discharged into
the cooler in the morning. These two returns are to be let down into the underback immediately before the next brewing, and thence heated in the copper for the next




142                                  BEER.
mashing of fresh malt, instead of hot water, commonly called liquor, in the breweries.
But allowance must be made, in the calculation of the worts, for the quantity of fermentable matter in these two returns. The nett aggregate saving is estimated from the
gravity of the return taken when cold in the cooler. A slight economy is also made in
the extra boiling of the used hops. The lapse of a day or two between the consecutive
brewings is no objection to the method of returns, because they are too weak in saccharine matter to run any risk of fermentation.
In conclusion, it may be remarked that Mr. Richardson somewhat underrates the
gravity of porter, which is now seldom under 201bs. per barrel. The criterion for transferring from the gyle-tun to the cleansing butts is the attenuation caused by the production of alcohol in the beer: when that has fallen to 10lbs. or 1 llbs., which it usually does
in 48 hours, the cleansing process is commenced. The heat is at this time generally 75~,
if it was pitched at 65~; for the heat and the attenuation go hand in hand.
About thirty years ago, it was customary for the London brewers of porter to keep
immense stocks of it for eighteen months or two years, with the view of improving its
quality. The beer was pumped from the cleansing butts into store-vats, holding from
twenty to twenty-five gyles or brewings of several hundred barrels each. The store-vats
had commonly a capacity of 5000 or 6000 barrels; and a few were double, and one was
treble, this size. The porter, during its long repose in these vats, became fine, and by
obscure fermentation its saccharine mucilage was nearly all converted into vinous liquor,
and dissipated in carbonic acid. Its hop-bitter was also in a great degree decomposed.
Good hard beer was the boast of the day. This was sometimes softened by the publican,
by the addition of some mild new-brewed beer. Of late years, the taste of the metropolis has undergone such a complete revolution in this respect, that nothing but the
mildest porter will now go down. Hence, six weeks is a long period for beer to be kept
in London; and much of it is drunk when only a fortnight old. Ale is for the same reason come greatly into vogue; and the two greatest porter houses, Messrs. Barclay,
Perkins, & Co., and Truman, Hanbury, & Co., have become extensive and successful
brewers of mild ale, to please the changed palate of their customers.
We shall add a few observations upon the brewing of Scotch ale. This beverage is
characterized by its pale amber color, and its mild balsamic flavor. The bitterness of
the hop is so mellowed with the malt as not to predominate. The ale of Preston Pans
is, in fact, the best substitute for wine which barley has hitherto produced. The low
temperature at which the Scotch brewer pitches his fermenting tun restricts his labors
to the colder months of the year. He does nothing during four of the summer months.
He is extremely nice in selecting his malt and hops; the former being made from the best
English barley, and the latter being the growth of Farnham or East Kent. The yeast is
carefully looked after, and measured into the fermenting tun in the proportion of one
gallon to 240 gallons of wort.
Only one mash is made by the Scotch ale brewer, and that pretty strong; but the
malt is exhausted by eight or ten successive sprinklings of liquor (hot water) over the
goods (malt), which are termed in the vernacular tongue, sparges.  These waterings
percolate through the malt on the mash-tun bottom, and extract as much of the saccharine
matter as may be sufficient for the brewing. By this simple method much higher specific
gravities may be obtained than would be practicable by a second mash. With malt, the
infusion or saccharine fermentation of the diastase is finished with the first mash; and
nothing remains but to wash away from the goods the matter which that process has
rendered soluble. It will be found on trial that 20 barrels of wort drawn from a certain
quantity of malt, by two successive mashings, will not be so rich in fermentable matter
as 20 barrels extracted by ten successive sparges of two barrels each. The grains
always remain soaked with wort like that just drawn off, and the total residual quantity
is three fourths of a barrel for every quarter of malt. The gravity of this residual wort
will on the first plan be equal to that of the second mash; but on the second plan, it
will be equal only to that of the tenth sparge, and will be more attenuated in a very high
geometrical ratio. The only serious objection to the sparging system is the loss of time
by the successive drainages. A mash-tun with a steam jacket promises to suit the
sparging system well; as it would keep up a uniform temperature in the goods, without
requiring them to be sparged with very hot liquor.
The first part of the Scotch process seems of doubtful economy; for the mash liquor is
heated so high as 180~. After mashing for about half an hour, or till every particle of
the malt is thoroughly drenched, the tun is covered, and the mixture left to infuse about
three hours; it is then drained off into the under-back, or preferably into the wort
copper.
After this wort is run off, a quantity of liquor (water), at 180~ of heat, is sprinkled
uniformly over the surface of the malt; being first dashed on a perforated circular
board, suspended horizontally over the mash-tun, wherefrom it descends like a shower




BEER.                                    143
upon the whole of the goods. The percolating wort is allowed to flow off, by three or
more small stopcocks round the circumference of the mash-tun, to ensure the equal diffusion of the liquor.
The first sparge being run off in the course of twenty minutes, another similar one
is affused; and thus in succession till the whole of the drainage, when mixed with the
first mash-wort, constitutes the density adapted to the quality of the ale. Thus, the
strong worts are prepared, and the malt is exhausted either for table beer, or for a
return, as pointed out above. The last sparges are made 5~ or 6~ cooler than the
first.
The quantity of hops seldom exceeds four pounds to the quarter of malt. The manner
of boiling the worts is the same as that above described; but the conduct of the fermentation is peculiar. The heat is pitched at 50~, and the fermentation continues from
a fortnight to three weeks. Were three brewings made in the week, seven or eight
working tuns would thus be in constant action; and, as they are usua2ly in one room,
and some of them at an elevation of temperature of 15~, the apartment must be propitious to fermentation, however low its heat may be at the commencement. No mort:
yeast is used than is indispensable; if a little more be needed, it is made effective by
rousing up the tuns twice a day from the bottom.
When the progress of the attenuation becomes so slack as not to exceed half a pound
in the day, it is prudent to cleanse, otherwise the top-barm might re-enter the body of the
beer, and it would become yeast-bitten. When the ale is cleansed, the head, which has
not been disturbed for some days, is allowed to float on the surface till the whole of the
then pure ale is drawn off into the casks. This top is regarded as a sufficient preservative
against the contact of the atmosphere. The Scotch do not skim their tuns, as the London ale brewers commonly do. The Scotch ale, when so cleansed, does not require to
be set upon close stillions. It throws off little or no yeast, because the fermentation
was nearly finished in the tun. The strength of the best Scotch ale ranges between 32
and 44 pounds to the barrel; or it has a specific gravity of from 1-088 to 1'122, according
to the price at which it is sold. In a good fermentation, seldom more than a fourth of
the original gravity of the wort remains at the period of the cleansing. Between one
third and one fourth is the usual degree of attenuation. Scotch ale soon becomes fine,
and is seldom racked for the home market. The following table will show the progress
of fermentation in a brewing of good Scotch ale:
20 barrels of mash-worts of 42^ pounds gravity = 860-6
20           returns       6-1-               =122
12) 982'6
pounds weight of extract per quarter of malt =  81
Fermentation:March 24. pitched the tun at 51~: yeast 4 gallons.
Temp.          Gravity.
25.             52~             41 pounds.
28.             56~             39
30.             60~             34
April  1.             62~             32
4.            65~              29 added 1 lb. of yeast.
5.             66~             25
6.            67~              23
7.             67~             20
8.            66~              18
9.             66~             15
10.            64~             14-5 cleansed. *
The following table shows the origin and the result of fermentation, in a number of
practical experiments:Oliginal Gravity of Lbs. per Barrel of Specific Gravity of Lbs. per Barrel of Attenuation, or Sacthe Worts.   Saccharine Matter.   the Ale.    Saccharine Matter. charum decomposed.
1'0950         88-75           1'0500           40-25           0-478
1-0918         85-62           1-0420           38-42           0-552
1-0829         78-125          1-0205           16-87           0-787
1-0862         80-625          1-0236           20-00           0-757
1-0780         73-75           1-0280           24-25           0-698
1-0700         65-00           1-0285           25-00           0-615
1-1002         93-75           1-0400           36-25           0-613
* BREWINo (Society for diffusing Useful Knowledge), p. 156.




144                                    BEER.
Fermentation Table- continued.
Original Gravity of Lbs. per Barrel of Specific Gravity of Lbs. per Barrel of Attenuation, or Sacthe Worts.    Saccharine Matter.    the Ale.    Saccharine Matter. charum decomposed.
1-1025          9593             1-0420           38-42            0-600
1-0978          9156             1-0307           27-00            0-705
1-0956          89-37            1-0358           32-19            0-640
1-1130         105-82            10352            31-87            0-661
1-1092         102-187           1-0302           26-75            0-605
1-1171         110-00            1-0400           36-25            0-669
1-1030          96-40            1-0271           23-42            0-757
1_0660          61-25            10214            17-80            0-709
The second column here does not represent, I believe, the solid extract, but the pasty
extract obtained as the basis of Mr. Allen's saccharometer, and therefore each of its
numbers is somewhat too high. The last column, also, must be in some measure erroneous, on account of the quantity of acohol dissipated during the process of fermentation. It must be likewise incorrect, because the density due to the saccharine matter
will be partly counteracted, by the effect of the alcohol present in the fermented liquor.
In fact, the attenuation does not correspond to the strength of the wort; being greatest
in the third brewing, and smallest in the first. The quantity of yeast for the above ale
brewings in the table was, upon an average, one gallon for 108 gallons; but it varied
with its quality, and with the state of the weather, which, when warm, permits much
less to be used with propriety.
The good quality of the malt, and the right management of the mashing, may be tested
by the quantity of saccharine matter contained in the successively drawn worts. With
this view, an aliquot portion of each of them should be evaporated by a safety-bath heat
to a nearly concrete consistence, and then mixed with twice its volume of strong spirit
of wine. The truly saccharine substance will be dissolved, while the starch and other
matters will be separated; after which the proportions of each may be determined by
filtration and evaporation. Or an equally correct, and much more expeditious method of
arriving at the same result would be, after agitating the viscid extract with the alcohol
in a tall glass cylinder, to allow the insoluble fecula to subside, and then to determine
the specific gravity of the supernatant liquid by a hydrometer.  The additional density
which the alcohol has acquired will indicate the quantity of malt sugar which it has
received. The following table, constructed by me, at the request of Henry Warburton,
Esq., M. P., chairman of the Molasses Committee of the House of Commons in 1830,
will show the brewer the principle of this important inquiry. It exhibits the quantity in
grains weight of sugar requisite to raise the specific gravity of a gallon of spirit of different densities to the gravity of water = 1-000:
Specific Gravity of       Grains; Weight of Sugar in the
Spirit.                     Gallon Imperial.
0-995                           980
0-990                          1-890
0-985                         2-800
0-980                          3-710
0-975                         4-690
0-970                         5-600
0-965                         6-650
0-960                         7-070
0-955                         8-400
0-950                          9-310
The immediate purpose of this table was to show the effect of saccharine matter in
disguising the presence or amount of alcohol in the weak feints of the distiller. But
a similar table might easily be constructed, in which, taking a uniform quantity of alcohol of 0-825, for example, the quantity of sugar in any wort-extract would be shown by
the increase of specific gravity which the alcohol received from agitation with a certain
weight of the wort, inspissated to a nearly solid consistence by a safety-pan, made on
the principle of my patent sugar-pan.  (See SUGAR.)  Thus, the normal quantities
being 1000 grain measures of alcohol, and 100 grains by weight of inspissated mashextract, the hydrometer would at once indicate, by help of the table, first, the quantity
per cent. of truly saccharine matter, and next, by subtraction, that of farinaceous matter
present in it.
Plan, Machinery, and Utensils of a great Brewery.-Figs. 113 and 114 represent the
arrangement of the utensils and machinery in a porter brewery on the largest scale; in
which. however, it must be observed that the elevation fig. 113 is in a great degree imaginary as to the plane upon which it is taken; but the different vessels are arranged so as




BEER.                                   145;o explain their uses most readily, and at the same time to preserve, as nearly as possible,
the relative positions which are usually assigned to each in works of this nature.
The malt for the supply of the brewery is stored in vast granaries or malt-lofts, usually
situated in the upper part of the buildings. Of these, I have been able to represent
only one, at A, fig. 113: the others, which are supposed to be on each side of it, cannot




146                                    BEER.
be seen in this view. Immediately beneath the granary A, on the ground floor, is the
mill; in the upper story above it, are two pairs of rollers, figs. 111, 112, and 113, under
a, a, for bruising or crushing the grains of the malt. In the floor beneath the rollers are
the mill-stones b, b, where the malt is sometimes ground, instead of being merely bruised
by passing between the rollers, under a, a.
The malt, when prepared, is conveyed by a trough into a chest d, to the right of b,
from which it can be elevated by the action of a spiral screw, fig. 115, enclosed in the
sloping tube e, into the large chest or bin B, for holding ground malt, situated immediately over the mash-tun D. The malt is reserved in this bin till wanted, and it is
then let down into the mashing-tun, where the extract is obtained by hot water supplied
from the copper G, seen to the right of B.
The water for the service of the brewery is obtained from the well E, seen beneath the
mill to the left, by a lifting pump worked by the steam engine; and the forcing-pipe f
of this pump conveys the water up to the large reservoir or water-back F, placed at the
top of the engine-house. From this cistern, iron pipes are laid to the copper G (on the
right-hand side of the figure), as also to every part of the establishment where cold water
can be wanted for cleaning and washing the vessels.  The copper G can be filled with
cold water by merely turning a cock; and the water, when boiled therein, is conveyed
by the pipe g into the bottom of the mash-tun D. It is introduced beneath a false bottom, upon which the malt lies, and, rising up through the holes in the false bottom, it
extracts the saccharine matter from the malt; a greater or less time being allowed for the
infusion, according to circumstances. The instant the water is drawn off from the copper,
fresh water must be let into it, in order to be ready for boiling the second mashing; because the copper must not be left empty for a moment, otherwise the intense heat of the
fire would destroy its bottom. For the convenience of thus letting down at once as much
liquor as will fill the lower part of the copper, a pan or second boiler is placed over the
top of the copper, as seen in fig. 113; and the steam rising from the copper communicates a considerable degree of heat to the contents of the pan, without any expense of
fuel. This will be more minutely explained hereafter.  (Seefig. 117.)
During the process of mashing, the malt is agitated in the mash-tun so as to expose
every part to the action of the water. This is done by a mechanism contained within
the mash-tun, which is put in motion by a horizontal shaft above it, H, leading from the
mill. The mash machine is shown separately in fig. 116. When the operation of mashing is finished, the wort or extract is drained down from the malt into the vessel i, called
the under-back, immediately below the mash-tun, of like dimensions, and situated always
on a lower level, for which reason it has received this name. Here the wort does not remain longer than is necessary to drain off the whole of it from the tun above. It is then
pumped up by the three-barrelled pump k, into the pan upon the top of the copper, by a
pipe which cannot be seen in this section. The wort remains in the pan until the water
for the succeeding mashes is discharged from  the copper.  But this delay is no loss of
time, because the heat of the copper, and the steam arising from it, prepare the wort,
which had become cooler, for boiling. The instant the copper is emptied, the first wort
is let down from the pan into the copper, and the second wort is pumped up from the
under-back into the upper pan. The proper proportion of hops is thrown into the copper through the near hole, and then the door is shut down, and screwed fast, to keep in
the steam, and cause it to rise up through pipes into the pan. It is thus forced to blow
up through the wort in the pan, and communicates so much heat to it, or water, called liqcuor by the brewers, that either is brought near to the boiling point. The different worts
succeed each other through all the different vessels with the greatest regularity, so that
there is no loss of time, but every part of the apparatus is constantly employed. When
the ebullition has continued a sufficient period to coagulate the grosser part of the extract,
and to evaporate part of the water, the contents of the copper are run off through a large
cock into the jack-back K, below G, which is a vessel of sufficient dimensions to contain
it, and provided with a bottom of cast-iron plates, perforated with small holes, through
which the wort drains and leaves the hops. The hot wort is drawn off from the jackback through the pipe h by the three-barrelled pump, which throws it up to the coolers
L, L, L; this pump being made with different pipes and cocks of communication, to serve
all the purposes of the brewery except that of raising the cold water from the well. The
coolers L, L, L, are very shallow vessels, built over one another in several stages: and that
part of the building in which they are contained is built with lattice-work or shutter flaps,
on all sides, to admit free currents of air. When the wort is sufficiently cooled to be put to
the first fermentation, it is conducted in pipes from all the different coolers to the large
fermenting vessel or gyle-tun M, which, with another similar vessel behind it, is of sufficient capacity to contain all the beer of one day's brewings.
Whenever the first fermentation is concluded, the beer is drawn off from the great fermenting vessel M, into the small fermenting casks or cleansing vessels N, of which there
are a great number in the brewery. They are placed four together, and to each four a com



BEER.                                   147
mon spout is provided to carry off the yeast, and conduct it into the troughs u, placed
beneath. In these cleansing vessels the beer remains till the fermentation is completed;
and it is then put into the store-vats, which are casks or tuns of an immense size, where
it is kept till wanted, and  is
>    finally drawn  off into  barrels,
a  nd sent away from the brewery.
The store-vats are not represented
I=               t'E. l p E ^ W ^.^1~ sin the figure: they are of a conical
$I ^  ~ ~- ~ ~Zlllll i   l   gishape, and of different dimenI       \  l                      sions, from fifteen to twenty feet
diameter, and usually from fifteen
I =J^ -                    I1!111111. i  to twenty feet in depth.   The,.  ~   _ ^ ^ - ^^         ^    steam-engine which puts all the
machine in  motion is exhibited
-   in its place, on the left side of
the figure.  On the axis of the
\N//.   \     large fly-wheel is a bevelled spurwheel, which  turns another si--  \ =  __1111 1     milar wheel upon the end of a
horizontal shaft, which  extends
f  - -j - l -         from  the  engine-house  to  the
/  l l   great horse-wheel, set in motion
= ="  by means of a spur-wheel. The
— L=  -  -l^ I g]               ^o|e\ |     l horse-wheel drives all the pinions
for the mill-stones b b, and also
O m   i   1i~  ^1 ^X   I     the horizontal axis which works
1  x  the three-barrelled pump Ik. The
rollers a, a, are turned by a bevel;' \'x~4'~'~,       i wheel upon the upper end of the
axis of the horse-wheel, which is.        3"'.......                          prolonged for that purpose; and,z -\@=1  {ll   {      l ~ i ~x1 ~    the horizontal shaft H, for the
-1    111\T^  "'li  ____~0               W    pmashing engine, is driven by a
pair of bevel wheels. There is
likewise a sack-tackle, which is
not represented. It is a machine
~^  _ ~     1  |   | for drawing up the sacks of malt
_    from the court-yard to the highest.    part of the building, whence the
1 l  sacks are wheeled on a truck to
the malt-loft A, and the contents...... ~1:111:1. ~iJ Y    l^l^of the sacks are discharged.
1_m I _   -  "                           The horse-wheel is intended to
be driven by horses occasionally,'    if the steam-engine should fail;
~//  11111?           bu1  t    these engines are now brought
_f___  ~ ^3^^   ^^   ^^1   to such perfection that it is very
f    1  ^~  1 1}1  1 11  nseldom any recourse of this kind is
needed.
_____  ~[xx               F {, { ]~,ig. 114 is a representation
1yXt I   of the fermen/ing house at the
brewery  of Messrs. Whitbread
___~_ | ^^U~~~~~y                          oand Company, Chiswell Street,
l  London, which is one of the most
complete  in its arrangement in
the world: it was erected after the
I F\F- IS  111 1 1- 1  ^^  plan of Mr. Richardson, who conducts the brewing at those works.
The whole of fig. 114 is to be
~,I, lii    |    considered as devoted to the same
=~^  d 5i  1   object as the large vessel M  and
===llIIII-il --        the casks N, fig. 113. In fig. 114
r r is the pipe which leads from
~   the different coolers to  convey
the wort to the great fermenting
vessels or squares M, of which there are two, one behind the other; ff represents a part of
the great pipe which conveys all the water from the well E, fig. 113, up to the water cistern




148                                    BEER.
F. This pipe is conducted purposely up the wall of the fermenting-house,fig. 114) and
has a cock in it, near r, to stop the passage. Just beneath this passage a branch-pipe p
proceeds, and enters a large pipe x x, which has the former pipe r withinside of it.
From the end of the pipe x, nearest to the squares M, another branch n n proceeds, and
returns to the original pipef, with a cock to regulate it. The object of this arrangement
is to make all, or any part, of the cold water flow through the pipe x x, which surrounds
the pipe r, formed only of thin copper, and thus cool the wort passing through the pipe
r, until it is found by the thermometer to have the exact temperature which is desirable
before it is put to ferment in the great square M. By means of the cocks at n and p, the
quantity of cold water passing over the surface of the pipe r can be regulated at pleasure,
whereby the heat of the wort, when it enters into the square, may be adjusted within half
a degree.
When the first fermentation in the squares M M is finished, the beer is drawn off from
them by pipes marked v, and conducted by its branches w w w, to the different rows of
fermenting-tuns, marked N N, which occupy the greater part of the building. In the
hollow between every two rows are placed large troughs, to contain the yeast which
they throw off. The figure shows that the small tuns are all placed on a lower level
than the bottom of the great vessels M, so that the beer will flow into them, and, by hydrostatic equilibrium, will fill them to the same level. When they are filled, the communication-cock is shut; but, as the working off the yeast diminishes the quantity of
beer in each vessel, it is necessary to replenish them  from  time to time.  For this
purpose, the two large vats o o are filled from the great squares M M, before any beer
is drawn off into the small casks N, and this quantity of beer is reserved at the highei
level for filling up. The two vessels o o are, in reality, situated between the two squares
M M; but I have been obliged to place them  thus in the section, in order that they
may be seen. Near each filling-up tun o is a small cistern t communicating with the
tun o by a pipe, which is closed by a float-valve. The small cisterns t are always in
communication with the pipes which lead to the small fermenting vessels N; and therefore the surface of the beer in all the tuns, and in the cisterns, will always be at the same
level; and as this level subsides by the working off of the yeast from the tuns, the float
sinks and opens the valve, so as to admit a sufficiency of beer from the filling-up tuns
o, to restore the surfaces of the beer in all the tuns, and also in the cistern t, to the
original level. In order to carry off the yeast which is produced by the fermentation of
the beer in the tuns o o, a conical iron dish or funnel is made to float upon the surface of
the beer which they contain; and from the centre of this funnel a pipe, o, descends, and
passes through the bottom of the tun, being packed with a collar of leather, so as to be
water-tight; at the same time that it is at liberty to slide down, as the surface of the beer
descends in the tun. The yeast flows over the edge of this funnel-shaped dish, and is
conveyed down the pipe to a trough beneath.
Beneath the fermenting-house are large arched vaults, r, built with stone, and lined
with stucco. Into these the beer is let down in casks when sufficiently fermented, and
is kept in store till wanted. These vaults are used at Mr. Whitbread's brewery, instead
of the great store-vats of which we have before spoken, and are in some respects preferable, because they preserve a great equality of temperature, being beneath the surface
of the earth.
The malt-rollers, or machines for bruising the grains of the malt, figs. 111, 112, have
been already described.  The malt is shot down from A, fig. 113, the malt-loft, into the
hopper; and from this It is let out gradually through a sluice or sliding shuttle, a, fig. 113,
and falls between the rollers.
Fig. 115, is the screw by which the ground or bruised malt is raised up, or conveyed
from one part of the brewery to another. K is an inclined box or trough, in the centre
of which the axis of the screw H is placed; the spiral iron plate or worm, which is
fixed projecting from  the axis, a.d which forms the screw, is made very nearly to
fill the inside of the box. By this means, when the screw  is turned round by the
wheels E F, or by any other means, it raises up the malt from the box d, and delivers it
at the spout G.
This screw is equally applicable for conveying the malt horizontally in the trough K,
as slantingly; and similar machines are employed in various parts of breweries for conveying the malt wherever the situation of the works requires.
Fig. 116, is the mashing-fiachine.  a a is the tun, made of wood staves, hooped together. In the centre of it rises a perpendicular shaft, b, which is turned slowly round
by means of the bevelled wheels t u at the top.  c c are two arms, projecting from
that axis, and supporting the short vertical axis d of the spur-wheel x, which is
turned by the spur-wheel w; so that, when the central axis b is made to revolve, it
will carry the thick short axle d round the tun in a circle. That axle d is furnished
with a number of arms, e e, which have blades placed obliquely to the plane of their




BEER.                                  149
motion. When the axis is turned round, these arms agitate the malt m the tun, and give
it a constant tendency to rise upward from the bottom.
The motion of the axle d is produced by a wheel, x, on the upper end of it, which is
115
turned by a wheel, w, fastened on the middle of the tube b, which turns freely round
upon its central axis. Upon a higher point of the same tube b is a bevel wheel, o,
receiving motion from a bevel wheel, q, fixed upon the end of the horizontal axis n n,
116
which gives motion to the whole machine. This same axis has a pinion, p, upon
it, which gives motion to the wheel r, fixed near the middle of a horizontal axle,
which, at its left hand end, has a bevel pinion, t, working the wheel u, before mentioned.
By these means, the rotation of the central axis b will be very slow compared with the
motion of the axle d; for the latter will make seventeen or eighteen revolutions on its
own axis in the same space of time that it will be carried once round the tun by the
motion of the shaft b. At the beginning of the operation of mashing, the machine is
made to turn with a slow motion; but, after having wetted all the malt by one revolution, it is driven quicker. For this purpose, the ascending shaft f g, which gives




150                                  BEER.
motion to the machine, has two level wheels, h i, fixed upon a tube, f g, which is, fitted
upon a central shaft. These wheels actuate the wheels m and o, upon the end of the
horizontal shaft n n; but the distance between the two wheels h and i is such. that they
cannot be engaged both at once with the wheels m and o; but the tube f g, to which
they are fixed, is capable of sliding up and down on its central axis sufficiently to bring
either wheel h or i into gear with its corresponding wheel o or m, upon the horizontal
shaft; and as the diameters of n o, and i m, are of very different proportions, the velocity
of the motion of the machine can be varied at pleasure, by using one or other. k and
k are two levers, which are forked at their extremities, and embrace collars at the ends
of the tube f g. These levers being united by a rod, I, the handle k gives the means of
moving the tube f g, and its wheels h i, up or down, to throw either the one or the other
wheel into gear.
The object of boiling the wort is not merely evaporation and concentration, but extraction, coagulation, and, finally, combination with the hops; purposes which are better accomplished in a deep confined copper, by a moderate heat, than in an open shallow pan
with a quick fire. The copper, being incased above in brickwork, retains its digesting
temperature much longer than the pan could do. The waste steam of the close kettle,
moreover, can be economically employed in communicating heat to water or weak worts;
whereas the exhalations from an open pan would prove a nuisance, and would need to be
carried off by a hood. The boiling has a four-fold effect: 1. it concentrates the wort; 2.
during the earlier stages of heating, it converts the starch into sugar, dextrine, and gum,
by means of the diastase; 3. it extracts the substance of the hops diffused through the
wort; 4. it coagulates the albuminous matter present in the grain, or precipitates it by
means of the tannin of the hops.
The degree of evaporation is regulated by the nature of the wort, and the quality of
the beer. Strong ale and stout for keeping, require more boiling than ordinary porter
or table-beer brewed for immediate use. The proportion of the water carried off by
evaporation is usually from a seventh to a sixth of the volume. The hops are introduced
during the progress of the ebullition. They serve to give the beer not only a bitter
aromatic taste, but also a keeping quality, or they counteract its natural tendency to
become sour; an effect partly due to the precipitation of the albumen and starch, by
their resinous and tanning constituents, and partly to the antifermentable properties of
their lupuline, bitter principle, ethereous oil, and resin. In these respects, there is none
of the bitter plants which can be substituted for hops with advantage.  For strong beer,
powerful fresh hops should be selected; for weaker beer, an older and weaker article
will suffice.
The hops are either boiled with the whole body of the wort, or extracted with a
portion of it; and this concentrated extract added to the rest. The stronger the hops
ale, the longer time they require for extraction of their virtues; for strong hops, an hour
and a half or two hours boiling may be proper; for a weaker sort, half an hour or an
hour may be sufficient; but it is never advisable to push this process too far, lest a disagreeable bitterness, without aroma, be imparted to the beer. In our breweries, it is the
practice to boil the hops with a part of the wort, and to filter the decoction through a
drainer, called the jack hop-back. The proportion of hops to malt is very various; but, in
general, from a pound and a quarter to a pound and a half of the former are taken for
100 lbs. of the latter in making good table-beer. For porter and strong ale, 2 pounds of
hops are used, or even more; for instance, one pound of hops to a bushel of malt, if the
beer be destined for the consumption of India.
During the boiling of the two ingredients, much coagulated albuminous matter, in
various states of combination, makes its appearance in the liquid, constituting what is
called the breaking or curdling of the wort, when numerous minute flocks are seen floating
in it. The resinous, bitter, and oily-ethereous principles of the hops combine with the
sugar and gum, or dextrine of the wort; but for this effect they require time and heat;
showing that the boil is not a process of mere evaporation, but one of chemical reaction.
A. yellowish-green pellicle of hop-oil and resin appears upon the surface of the boiling
wort, in a somewhat frothy form: when this disappears, the boiling is presumed to be
completed, and the beer is strained off into the cooler. The residuary hops may be
pressed and used for an inferior quality of beet; or they may be boiled with fresh wort,
and be added to the next brewing charge.
Figs. 117,118, represent the copper of a London brewery. Fig. 117 is a vertical section;
fig. 118, a ground-plan of the fire-grate and flue, upon a smaller scale: a is the close copper kettle, having its bottom convex within; b is the open pan placed upon its top. From
the upper part of the copper, a wide tube, c, ascends, to carry off the steam  generated
during the ebullition of the wort, which is conducted through four downwards-slanting
tubes, d d (two only are visible in this section), into the liquor of the pan b, in order to
warm its contents. A vertical iron shaft or spindle, e, passes down through the tube c,
nearly to the bottom of the copper, and is there mounted with an iron arm, called a




BEER.                                    151
rouser, which carries round a chain hung in loops, to prevent the hops from adhering to
the bottom of the boiler. Three bent stays,f, are stretched across the interior, to support
the shaft by a collet at their middle junction. The shaft carries at its upper end a bevel
118                      117 
o'       j!
wheel, g, working into a bevel pinion upon the axis h, which may be turned either by
power or by hand. The rouser shaft may be lifted by means of the chain i, which, going
over two pulleys, has its end passed round the wheel and axle k, and is turned by a
winch: I is a tube for conveying the waste steam into the chimney m.
The heat is applied as follows:-For heating the colossal coppers of the London
breweries, two separate fires are required, which are separated by a narrow wall of
brickwork, n, figs. 117, 118. The dotted circle a' a' indicates the largest circumference of
the copper, and b' b' its bottom; o o are the grates upon which the coals are thrown,
not through folding doors (as of old), but through a short slanting iron hopper, shown at
p,fig. 117, built in the wall, and kept constantly filled with the fuel, in order to exclude
the air. Thus the lower stratum of coals gets ignited before it reaches the grate. Above
the hopper p, a narrow channel is provided for the admission of atmospherical air, in
such quantity merely as may be requisite to complete the combustion of the smoke of
the coals. Behind each grate there is a fire-bridge, r, which reflects the flame upwards,
and causes it to play upon the bottom of the copper. The burnt air then passes round
the copper in a semicircular flue, s s, from which it flows off into the chimney m, on
whose under end a sliding damper-plate, t, is placed for tempering the draught. When
cold air is admitted at this orifice, the combustion of the fuel is immediately checked.
There is, besides, another slide-plate at the entrance of the slanting flue into the vertical
chimney, for regulating the play of the flame under and around the copper. If the plate
t be opened, and the other plate shut, the power of the fire is suspended, as it ought to
be, at the time of emptying the copper. Immediately over the grate is a brick arch, u, to
protect the front edge of the copper from the first impulsion of the flame. The chimney is supported upon iron pillars, wv; w is a cavity closed with a slide-plate, through
which the ashes may be taken out from behind, by means of a long iron hook.
Fig. 119 represents one of the sluice-cocks, which are used to make the communications of the pipes with the pumps, or other parts of the brewery. n B represents
the pipe in which the cock is placed. The two parts of this pipe are screwed to the
side of a box, c c, in which a slider, A, rises and falls, and intercepts, at pleasure, the
passage of the pipe. The slider is moved by the rod a. This passes through a stuffing



152                                  BEER.
box, in the top of the box which contains the slider, and has the rack b fastened to it.
The rack is moved by a pinion fixed upon the axis of a handle e, and the rack and
pinion are contained in a frame d which is supported by two pillars. The frame
contains a small roller behind the rack, which bears it up towards the pinion, and keeps
its teeth up to the teeth of the pinion. The slider A is made to fit accurately against
the internal surface of the box c, and to bear against this surface by the pressure of
a spring, so as to make a perfectly close fitting.
Fig. 120 is a small cock to be placed in the side of the great store vats, for the
purpose of drawing off a small quantity of beer to taste and try its quality. A is a
120
7<
C a aE  I a E
part of the stave or thickness of tne great store vat; into this the tube B of the cock
is fitted, and is held tight in its place by a nut, a, a, screwed on withinside.  At the
other end of the tube B, a plug, c, is fitted, by grinding it into a cone, and it is kept
in by a screw. This plug has a hole up the centre of it, and from this a hole proceeds side-wise, and corresponds with a hole made through the side of the tube when
the cock is open; but when the plug c is turned round, the hole will not coincide, and
then the cock will be shut. D is the handle or key of the cock, by which its plug is
turned to open or shut it: this handle is put up the bore of the tube (the cover E
being first unscrewed and removed), and the end of it is adapted to fit the end of the
plug of the cock. The handle has a tube or passage bored up it, to convey the beer
away from the cock when it is opened, and from this the passage f, through the handle, leads, to draw the beer into a glass or tumbler. The hole in the side of the plug
is so arranged, that, when the handle is turned into a perpendicular direction, with
the passagef downwards, the cock will be open. The intention of this contrivance is,
that there shall be no considerable projection beyond the surface of the tun; because
it sometimes happens that a great hoop of the tun breaks, and, falling down, its great
weight would strike out any, cock which had a projection; and, if this happened in
the night, much beer might be lost before it was discovered. The cock above described, being almost wholly withinside, and having scarcely any projection beyond
the outside surface of the tun, is secure from this accident.
Fig. 121 is a small contrivance of a vent peg, to be screwed into the head of a common
cask when the beer is to be drawn off from it, and it is necessary to admit some air to
121   allow the beer to flow. A A represents a portion of the head
of the cask into which the tube B is screwed. The top of
oC   ECm this tube is surrounded by a small cup, from which project
the two small handles c c, by which the peg is turned round
to screw it into the cask. The cup round the other part of
the tube is filled with water; into this a small cup, D, is inverted; in consequence, the air can gain admission into the
B           cask when the pressure within is so far diminished, that the
air will bubble up through the water, and enter beneath the small cup D.
The most efficient substance for fining beer hitherto discovered is isinglass, which is
prepared by solution in vinegar or old stale beer, and this solution is afterwards reduced
with thin mild beer generally brewed for the purpose, in all large establishments, from
a raw or return wort.  It must next be passed through a fine hair sieve, by means ot
rubbing it down with a hard hair-brush, and brought to the proper consistency by thin
mild beer. If properly made, it will be clear, transparent, and free from feculencies.
Finings serve excellently to remove any extraneop matter that may be found floating
in the beer, and thus changes it from bright to brfliant. The common quantity used
is from a pint to a quart per barrel, according to the nature of the beer.
To ascertain whether the beer is in a fit state for fining, put it into a long glas;
cylindric vessel, and add to it a teaspoonful, or thereby, of the fining; then give the
mixture a good shake, by turning the vessel up and down, after closing its mouth with




BEER.                                        153
the palm of the hand. If the beer has been well brewed, its aptitude to become bright
will be soon shown by the mixture getting thick and curdy; a bright portion will generally show itself at the bottom or middle; after which the finings will gradually mount to
the top, taking up all the impurities along with them, till the whole becomes brilliant.
Some have said that the finings should carry the impurities down to the bottom; but
this, according to Mr. Black,* takes place only with stubborn beer, which would not become thoroughly bright with any quantity of finingswhich could be introduced. Finings
have usually a specific gravity of from 1l010 to 1*016, and, when added to beer in a fit
condition for fining, invariably go to the top, and not to the bottom. In fining beer in
a barrel laid on its side, if the finings do not make their appearance at the bung-hole,
the beer will not become bright. The isinglass must not be dissolved with heat, nor in
hot water.
Beer brewed from imperfectly malted grain, or from a mixture of malt and raw corn,
gives a fermentation quite different in flavor from that of beer from sound malt. The
nose is, in fact, the best guide to the experienced brewer for ascertaining whether his
process is going on well or ill.
Ropiness is a morbid state of beer, which is best remedied, according to Mr. Black, by
putting the beer into a vat with a false bottom, and adding, per barrel, 4 or 5 pounds of
hops, taken gradually away after the first boilings of the worts; and to them  may be
added about half a pound per barrel of mustard-seed. Rouse the beer as the hops are
gradually introduced, and, in some months, the ropiness will be perfectly cured. The
beer should be drawn off from below the false bottom.
For theoretical views, see FERMENTATION; and for wort-cooling apparatus, see REFRIGERATOR.
The quantity of beer and ale exported from the United Kingdom amounted in 1850
to 182,480 barrels, and in 1851 to 191,639; the declared value being respectively
558,7941., and 577,8741.
BEER (BAVARIAN). The Germans from time immemorial have been habitually beer
drinkers, and have exercised much of their technical and scientific skill in the production of beer of many different kinds, some of which are little known to our nation,
while one at least, called Bavarian, possesses excellent qualities, entitling it to the attention of all brewers and consumers of this beverage. The peculiarities in the manufacture of Bavarian beer have recently attracted the attention of the most eminent
chemists in Germany, especially of Professor Liebig, and much new light has thereby
been thrown upon this curious portion of vegetable chemistry, which I shall endeavor to reflect upon the present article.
The following is a list of the principal beers at present brewed in Germany.
1. Brown beer of Merseburg; of pure barley malt.
2.    -                               barley malt and beet-root sugar.
3.    -          barley malt, potatoes, and beet-root syrup.
4.    -          refined beet-root syrup alone.
5. Covent or thin beer.
6. Berlin white beer, or the Champagne of the north.
7. Broyhan, a famous Hanoverian beer.
8. Double beer of Griintbal.
9. Bavarian beer; 1. Summer beer; 2. Winter beer.
10. - Bock-beer.
11. Wheat Lager-beer (slowly fermented).
12. White bitter beer of Erlangen.
Considerable interest among men of science, in favor of the Bavarian beer process,
has been excited ever since the appearance of Liebig's Organic Chemistry, first published about twelve years ago. In the introduction to this admirable work, he says,
"The beers of England and France, and the most parts of those of Germany, become
gradually sour by contact of air. This defect does not belong to the beers of Bavaria,
which may be preserved at pleasure in half-full casks, as well as full ones, without alteration in the air. This precious quality must be ascribed to a peculiar process
employed for fermenting the wort, called in German untergdhrung, or fermentation
from below; which has solved one of the finest theoretical problems.
" Wort is proportionally richer in soluble gluten than in sugar. t  When it is set to
ferment by the ordinary process, it evolves a large quantity of yeast, in the state of a
thick froth, with bubbles of carbonic acid gas attached to it, whereby it is floated to the
surface of the liquid. This phenomenon is easily explained. In the body of the wort
along side of particles of sugar decomposing, there are particles of gluten being oxidized
* Treatise on Brewing, 8vo. p. 68.
t It does not surely contain more gluten than it does sugar; at' least no experiments, known to mo,
prove this proposition.




154                          BEER, BAVARIAN.
at the same time, and enveloping as it were the former particles, whence the carbonic
acid of the sugar and the insoluble ferment from the gluten being simultaneously produced, should mutually adhere. When the metamorphosis of the sugar is completed,
there remains still a large quantity of gluten dissolved in the fermented liquor, which
gluten, in virtue of its tendency to appropriate oxygen, and to get decomposed, induces
also the transformation of the alcohol into acetic acid (vinegar). But were all the
matters susceptible of oxidizement as well as this vinegar ferment removed, the beer
would thereby lose its faculty of becoming sour. These conditions are duly fulfilled in
the process followed in Bavaria.
" In that country the malt-wort is set to ferment in open backs, with an extensive surface, and placed in cool cellars, having an atmospheric temperature not exceeding 8~ or
10~ centigrade (46-? or 50~ F.). The operation lasts from 3 to 4 weeks; the carbonic
acid is disengaged, not in large bubbles that burst on the surface of the liquid, but in
very small vesicles, like those of a mineral water, or of a liquor saturated with carbonic
acid, when the pressure is removed. The surface of the fermenting wort is always in
contact with the oxygen of the atmosphere, as it is hardly covered with froth, and as
all the yeast is deposited at the bottom of the back under the form of a very viscid
sediment, called in German unterhefe.
"' In order to form an exact idea of the difference between the two processes of fermentation, it must be borne in mind that the metamorphosis of gluten and of azotized
bodies in general is accomplished successively in two principal periods, and that it is in
the first that the gluten is transformed in the interior of the liquid into an insoluble
ferment, and that it separates alongside of the carbonic acid proceeding from the sugar.
This separation is the consequence of an absorption of oxygen. It is, however, hardly
possible to decide if this oxygen comes from the sugar, from the water, or even from
an intestine change of the gluten itself, or, in other words, whether the oxygen combines directly with the gluten, to give it a higher degree of oxidation, or whether it lays
hold of its hydrogen to form water.
" This oxidation of the gluten, from whichever cause, and the transformation of the
sugar into carbonic acid and alcohol, are two actions so correlated, that by an exclusion
of the one, the other is immediately stopped."
The superficial ferment (oberhefe in German) which covers the surface of the fermenting works is gluten oxidized in a state of putrefaction; and the ferment of deposite
is the gluten oxidized in a state of eremacausie.
The surface yeast, or barm, excites in liquids containing sugar and gluten the same
alteration which itself is undergoing, whereby the sugar and the gluten suffer a rapid
and tumultuous metamorphosis. We may form an exact idea of the different states of
these two kinds of yeast by comparing the superficial to vegetable matters putrefying
at the bottom  of a marsh, and the bottom yeast to the rotting of wood in a state of
eremacausie, that is, of slow combustion. The peculiar condition of the elements of the
sediment ferment causes them to act upon the elements of the sugar in an extremely
slow manner, and excites the change into alcohol and carbonic acid, without that of the
dissolved gluten.
Sugar, which at ordinary temperatures has no tendency to combine with oxygen,
enters in the above predicament into fermentation; but the action is rendered much
slower by the low temperature, while the affinity of the dissolved gluten for the oxygen
of the air is aided by the contact of the sediment. The superficial yeast may be
removed without stopping the fermentation, but the under yeast can not be removed
without arresting all the phenomena of disoxidation of the second period. These would
immediately cease; and if the temperature were now raised, they would be succeeded
by the phenomena of the first period. The deposite does not excite the phenomena of
tumultuous fermentation, for which reason it is totally unfit for panification (breadbaking), while the superficial yeast alone is suitable to this purpose.
If to wort at a temperature of from 461~ to 50~ F. the top yeast be added, a quiet
slow fermentation is produced, but one accompanied with a rising up of the mass, while
yeast collects both at the surface and bottom of the backs. If this deposite be removed
to make use of it in other operations, it requires by little and little the characters of the
unterhefe, and becomes incapable of exciting the phenomena of the first fermenting
period, causing only, of 59~ F., those of the second; namely, sedimentary fermentation.
It must be carefully observed that the right unterhefe is not the precipitate which falls
to the bottom of backs in the ordinary fermentation of beer, but is a matter entirely
different. Peculiar pains must be taken to get it genuine, and in a proper condition at
the commencement. Hence the brewers of Hessia and Prussia, who wished to make
Bavarian beer, found it more to their interest to send for the article to Wurtzburg, or
Bamberg, in Bavaria, than to prepare it themselves. When once the due primary fermentation has been established and well regulated in a brewery, abundance of the true
unterhefe may be obtained for all future operations.




BEER, BAVARIAN.                                 155
In a wort made to ferment at a low temperature with deposite only, the presence of
the unterhefe is the first condition essential to the metamorphosis of the saccharum,
but it is not competent to bring about the oxidation of the gluten dissolved in the wort,
and its transformation into an insoluble state. This change must be accomplished at
the cost of the atmospherical oxygen.
In the tendency of soluble gluten to absorb oxygen, and in the free access of the
air, all the conditions necessary for its eremacausis, or slow combustion, are to be found.
It is known that the presence of oxygen and soluble gluten are also the conditions of
acetification (vinegar-making), but they are not the only ones; for this process requires
a temperature of a certain elevation for the alcohol to experience this slow combustion.
Hence, by excluding that temperature, the combustion (oxidation) of alcohol is obstructed, while the gluten alone combines with the oxygen of the air. This property
does not belong to alcohol at a low temperature, so that during the oxidation in this
case of the gluten, the alcohol exists alongside of it, in the same condition as the gluten
alongside of sulphurous acid in the muted wines. In wines not impregnated with the
fumes of burning sulphur, the oxygen which would have combined at the same time
with the gluten and the alcohol does not seize either of them in wines which have been
subjected to mutism, but it unites itself to the sulphurous acid to convert it into the
sulphuric. The action called sedimentary fermentation is therefore merely a simultaneous metamorphosis of putrefaction and slow combustion; the sugar and the unterhefe
putrefy, and the soluble gluten gets oxidized, not at the expense of the oxygen of the
water and the sugar, but of the oxygen of the air, and the gluten then falls in the insoluble state. The process of Appert for the preservation of provisions is founded
upon the same principle as the Bavarian process of fermentation  in which all the putrescible matters are separated by the intervention of the air at a temperature too low
for the alcohol to become oxidized. By removing them in this way, the tendency of
the beer to grow sour, or to suffer a further change, is prevented. Appert's method
consists in placing in presence of vegetables or meat which we wish to preserve the
oxygen at a high temperature, so as to produce slow combustion, but without putrefaction or even fermentation. By removing the residuary oxygen after the combustion
is finished, all the causes of an ulterior change are removed. In the sedimentary fermentation of beer, we remove the matter which experiences the combustion; whereas,
on the contrary, in the method of Appert, we remove that which produces it.
It is uncertain whether the dissolved gluten, in being converted into insoluble yeast
by the action of the oxygen, combines directly with the oxygen; that is to say, whether
the yeast differs from the soluble gluten merely by having absorbed an additional quantity of oxygen. This question is in fact very difficult to solve by analysis. If the gluten
be regarded as a hydrogenated combination, it is obvious that in the fermentation of
wine-must, and malt-wort, the hydrogen will be carried off by the oxygen, and the
action will then be the same as the transformation of alcohol into aldehyde. When the
contact of the atmosphere is excluded, this oxygen can not evidently be derived from the
elements of the air, or from those of the water; for it can not be supposed that oxygen
will take hydrogen from the water, in order to recompose water with the hydrogen of
the gluten. The elements of the saccharum must therefore furnish this oxygen; or in
the course of the formation of the yeast, a portion of the sugar will be decomposed; but
thts decomposition is not of the same kind as that which results from the immediate
metamorphosis of the sugar into carbonic acid and alcohol; hence a certain portion of
the sugar will afford neither alcohol nor carbonic acid, but it will yield less oxgenated
products from its elements. These products occasion the great difference in the qualities of fermented liquors, and particularly in their alcoholic strength. In the ordinary
fermentation of grape-juice and worts, these liquids do not furnish a quantity of alcohol
equivalent to the sugar which they contain, because a certain portion of the sugar serves
for the oxidation of the gluten, and is not transformed like the rest. But whenever the
liquor has arrived at the second period, the product in alcohol ought to be equivalent to
the quantity of sugar present, as happens in all fermentations which are not accompanied with a formation, but a disappearance of the yeast. It is well ascertained that
worts furnish in the Bavarian breweries 10 or 20 per cent. more alcohol than they do
by the ordinary process of fermentation. It is also a well-established fact that in the
manufacture of spirits from potatoes, where no yeast is produced, or merely a quantity
corresponding to the proportion of barley-malt added to the potato-wort, a quantity of
alcohol may be produced, as also of carbonic acid, corresponding exactly to the quan.
tity of carbon in the fecula employed. But, on the contrary, in the fermentation of
beet-root juice, it is hardly possible to determine precisely, from the quantity of car.
bonic acid evolved, the quantity of sugar contained in the beets, for there is always
less carbonic acid than the juice of the fresh root would furnish. In equal volumes,
the beer made by the unterhefe process contains more alcohol, and is therefore more
heady than that formed by the ordinary process.




156                           BEER, BAVARIAN
The temperature at which fermentation is carried on has a very marked influence
upon the quantity of alcohol produced. It is known that the juice of beets set to
ferment between 86~ and 95 Fahr. does not yield alcohol, and its sugar is replaced by
a less oxygenated substance, mannite, and lactic acid, resulting from the mucilage.
In proportion as the temperature is lowered the mannite fermentation diminishes.
As to azotized juices, however, it is hardly possible to define the conditions under
which the transformation of the sugar will take place, without being accompanied with
another decomposition which modifies its products.  The fermentation of beer by
deposite demonstrates that by the simultaneous action of the oxygen of the air and a
low temperature, the metamorphosis of sugar is effected in a complete manner; for
the vessels in which the operation is carried on are so disposed that the oxygen of the
air may act upon a surface great enough to transform all the gluten into insoluble
yeast, and thus to present to the sugar a matter constantly undergoing decomposition.
The oxidizement of the dissolved gluten goes on, but that of the alcohol requires a
higher temperature; whence it can not suffer eremacausis, that is, acetification, or
conversion into vinegar.
At the beginning of the fermentation of must and wort, the quantity of matter
undergoing change is obviously the largest. All the phenomena which accompany it,
the disengagement of gas and the rise of temperature, are most active at this period,
and in proportion as the decomposition advances, the external signs of it become less
perceptible, without, however, disappearing completely before the transformation has
reached its limit. The slow and continuous decomposition which succeeds to the
rapid and violent disengagement of gases is denominated the after or complementary
fermentation. For wine and beer it lasts till all the sugar has disappeared, so that the
specific gravity of the liquors progressively diminishes during several months. This
slow fermentation is in most cases a truly depositary fermentation; for by the pro.
gressive decomposition of the less, the sugar still in solution gets completely trans.
formed; but when the air is excluded, that decomposition does not occasion the complete separation of the azotized matters in an insoluble shape.
In several states of the German confederation, the favorable influence of a rational
process of fermentation upon the quality of the beers has been fully recognised. In
the Grand Dutchy of Hesse considerable premiums were proposed for the brewing of
beer according to the process pursued in Bavaria, which were decreed to those brewers
who were able to prove that their product (neither strong nor highly hopped) had kept
six months in the casks without becoming at all sour. When the first trials were being
made several thousand barrels were spoiled, till eventually experience led to the dis.
covery of the true practical conditions which theory had foreseen and prescribed.
Neither the richness in alcohol, nor in hops, nor both combined, can hinder ordinary
beer from getting tart. In England, says Liebig, an immense capital is sacrificed
to preserve the better sorts of ale and porter from souring, by leaving them for several
years in enormous tuns quite full, and very well closed, while their tops are covered
with sand. This treatment is identical with that applied to wines to make them
deposite the wine-stone. A slight transpiration of air goes on in this case through
the pores of the wood; but the quantity of azotized matter contained in the beer is so
great, relatively to the proportion of oxygen admitted, that this element can not act
upon the alcohol. And yet the beer thus managed will not keep sweet more than
two months in smaller casks to which air has access. The grand secret of the Munich
brewers is to conduct the fermentation of the wort at too low a temperature to permit
of the acetification of the alcohol, and to cause all the azotized matters to be completely separated by the intervention of the oxygen of the air, and not by the sacrifice
of the sugar, It is only in March and October that the good store beer is begun to be
made in Bavaria.
In our ordinary breweries, the copious disengagement of carbonic acid from the
frothy top of the fermenting tuns and gyles prevents the contact of oxygen from the
worts; so that, as the gluten can not be oxidized by the air, it attracts oxygen from
the sugar, and thus gives rise to several adventitious hydrogenated products, just as
the fetid oil is generated in the rapid fermentation of spirit-wash by the distillers. In
this case no inconsiderable portion of the gluten remains undecomposed in the beer,
which, by its extreme proneness to corruption, afterward attracts oxygen greedily from
the air, and, at temperature above 520, imparts this contact action to the alcohol, and, by
a species of infection, changes it into vinegar. Indeed, in most of the rapid fermentations a portion of vinegar is formed, which itself serves as an acetous ferment to the rest
of the alcohol; whereas the result of the bottom fermentation is a beer free from vinegar,
and certainly hardly a trace of gluten; so that it does not possess the conditions requisite
to intestine change or deterioration. This perfection is, however, in my opinion, rarely
attained.  In my several journeys into Germany I have met with much spurious or
ill-made Bavarian beer. The best contains, when brought to England, a little acid,




BEER, BAVARIAN.                                 157
but no perceptible gluten on the addition of ammonia in excess. Most of our beers,
ales, &c., deposite more or less gluten when thus treated.
The following table exhibits the results of the chemical examinations of the undermentioned kinds of beer:Quantity in 100 parts by weight
Name of the Beer.         Water.  Malt extr. Alcohol. Carb. acid. Analyst
Augustine double beer-          88 86      8.0       3.6      0.14  Kaiser.
Munich    - 
Salvator beer-do. -             87-62      80       4-2       0-18    Do.
Bock-beer, from the Royal i 8864 7.          2       4-0      0.16    Do.
brewery - do.   -
Schenk (pot) beer, from a Ba- )
varian country brewery; a     92-94      4-0 2'9            0-16    Do.
kind of small beer  -
Bock-beer of Brunswick, of     8850        6.50      50          -Balhorn.
the Bavarian kind  -
Lager (store) beer, of Bruns-    91        54        350         -  Otto.
wick, of the Bavarian kind
Brunswick sweet small beer      84-70     14-0 1'30   -              Do.
Brunswick mum       -      -    59-2      39-0       1.80     0-1   Kaiser.
Malting in Munich.-The barley is steeped till the acrospire, embryo, or seed-germ,
seems to be quickened; a circumstance denoted by a swelling at the end of that ear
which was attached to the foot-stalk, as also when, on pressing a pile between two
fingers against the thumb-nail, a slight projection of the embryo is perceptible. As
long, however, as the seed-germ sticks too firm to the husk, it has not been steeped
enough for exposure on the underground malt-floor. Nor can deficient steeping be
safely made up for afterward by sprinkling the malt-couch with a watering-can, which
is apt to render the malting irregular. The steep-water should be changed repeatedly,
according to the degree of foulness and hardness of the barley; first, six hours after
immersion, having previously stirred the whole mass several times; afterward, in
winter, every twenty-four hours, but in summer every twelve hours. It loses none of
its substance in this way, whatever vulgar prejudice may think to the contrary. After
letting off the last water from the stone cistern, the Bavarians leave the barley to drain
in it during four or six hours. It is now taken out, and laid on the couch floor, in a
square heap, eight or ten inches high, and it is turned over, morning and evening, with
dexterity, so as to throw the middle portion upon the top and bottom of the new-made
couch. When the acrospire has become as long as the grain itself, the malt is carried
to the withering (welkboden) or drying-floor, in the open air, where it is exposed (in
dry weather) during from eight to fourteen days, being daily turned over three times
with a winnowing shovel. It is next dried on a well-constructed cylinder or flueheated malt-kin, at a gentle clear heat, without being browned in the slightest degree,
while it turns friable into a fine white meal. Smoked malt is entirely rejected by the
best Bavarian brewers. Their malt is dried on a series of wove wire horizontal shelves,
placed over each other; up through whose interstices or perforations streams of air,
heated to only 122~ Fahr., rise from the surfaces of rows of hot sheet-iron pipe-flues,
arranged a little way below the shelves. Into these pipes the smoke and burned air
of a little furnace on the ground are admitted. The whole is enclosed in a vaulted
chamber, from whose top a large wooden pipe issues, for conveying away the steam
from the drying malt. Each charge of malt may be completely dried on this kiln in the
space of from eighteen to twenty-four hours, by a gentle uniform heat, which does not
injure the diastase, or discolor the farina.*
The malt for store-beer should be kept three months at least before using it, and be
freed by rubbing and sifting from the acrospires before being sent to the mill, where
it should be crushed pretty fine. The barley employed is the best distichon or common
kind, styled hordeum vulgare.
The hops are of the best and freshest growth of Bavaria, called the fine spalter, or
saatser Bohemian townhops, and are twice as dear as the best ordinary hops of the rest
of Germany. They are in suc(h esteem as to be exported even into France.
The Bavarians are so much attached to the beer beverage, which they have enjoyed
from their remotest ancestry, that they regard the use of distilled spirits, even in
moderation, as so immoral a practice, as to disqualify dram-drinkers for decent society.
* I have a set of designs of the Bavarian kiln, but I believe the above description will make its construction sufficiently intelligible.




158                            BEER, BAVARIAN.
Their government has taken great pains to improve this national beverage, by encouraging the growth of the best qualities of hops and barley. The vaults in which
the beer is fermented, ripened, and kept, are aH underground, and mostly in stony excavations, called felsenkeller or rock-cellars. The beer is divided into two sorts, called
summer and winter. The latter is light, and, being intended for immediate retail in
tankards, is termed schankbier. The other, or the lagerbier, very sensibly increases in
vinous strength in proportion as it decreases in sweetness, by the judicious management of the nachgihrung, or fermentation in the casks. In several parts of Germany
a keeping quality is communicated to beers by burning sulphur in the casks before
filling them, or by the introduction of sulphite of lime. But the flavor thus imparted is disliked in Munich, Bayreuth, Regensburg, Nurnberg, Hof, and the other
chief towns of Bavaria; instead of which a preservative virtue is sought for in an
aromatic mineral or Tyrol pitch, with which the insides of the casks are carefully coated,
and in which the ripe beer is kept and exported. In December and January, after the
casks are charged with the summer or store-beer, the double doors of the cellars are
closed, and lumps of ice are piled up against them, to prevent all access of warm air.
The cellar is not opened till next August, in order to take out the beer for consumption.  In these circumstances the beer becomes transparent like champagne wine;
and, since but little carbonic acid gas has been disengaged, little or none of the additionally generated alcohol is lost by evaporation.
The winter or schank (pot) beer is brewed in the months of October, November,
March, and April; but the summer or store-beer in December, January, and February, or the period of the coldest weather. For the former beer, the hopped worts
are cooled down only to from 51~ to 55~, but for the latter to from 410 to 42g~ Fahr.
The winter beer is also a little weaker than the summer beer, being intended to be
sooner consumed; since four bushels* (Berlin measure) of fine, dry, sifted malt, of
large heavy hordeum vulgare distichon, affords seven eimers of winter beer, but not more
than from five and a half to six of summer beer.t  At the second infusion of the worts,
small beer is obtained to the amount of twenty quarts from the above quantity of malt.
For the above quantity of winter beer, six pounds of middling hops are reckoned
sufficient; but for the summer beer, from seven to eight pounds of the finest hops.
The winter beer may be sent out to the publicans in barrels five days after the fermentation has been completed in the tuns, and, though not quite clear, it will become
so in the course of six days; yet they generally do not serve it out in pots for two or
three weeks.  But the summer beer must be perfectly bright and still before it is
racked off into casks for sale.
Statement of the Products of a Brewing of Bavarian Beer.-The quantity brewed is
41 Munich eimers (64 maass) = 85  Berlin quarts; and 60 Berlin quarts = 1 eimer;
or 24 Munich barrels (of 100 Berlin quarts each); 1 Munich eimer =15 gallons
imperial. The beer contains from 50 to 60 parts by weight, of dry saccharum in 1,000
parts.
Expenditure.                      Thaler. Slbg.
24 Berlin bushels of white kiln-dried barley, rather finely crushed,
weighing from 12 to 13 cwts.      -      -24   0
36 pounds of new fine spalter (parted) hops at 46 thalers the cwt.   -  16  17
i pound of Carageen moss, for clarifying                    -       - 0   3
1 quart of yeast.
1 quart of Tyrol pitch  -      -      -       -      -       -      -11   0
Mash-tax (in Bavaria and Prussia) upon 12 cwts. malt, at the
rate of 20 silbergroschen = 2s., the cwt.   -   -       -      - 8   0
Cost of crushing       -      -       -      -       -      -1   0
Fuel   -                                                                4   0
Wages of labor, in the brewhouse and vault           -                  6   0
Do.    Do. for cooper in pitching the casks        -      -       -   3   0
Sundry small expenses.       -      -      -       -      -       -   2  10
Or 11. 8s.                                                    76   0
1 thaler = 30 silbergroschen = 3 shillings
Deduct for the grains of 12 cwts. of malt, at 10 silbergroschen, or Is.
per cwt. = 4 thalers, and for the value in yeast produced= 2
thalers more -                                                        6   0
Total neat expenditure = 101. 10s.                                  -  70   0
* An English quarter of grain is equal to 5 bushels (scheffel) and nearly one third Prussian measure.
t 1 Eimer Prussian = 15 English imperial gallons; one Munich scheffel is equal to four Berlin scheffels;
I Lib. Munich = 1-235 Eng. lbs. Avoird.: 1 Lib. Berlin = 1-031 lbs. Avoird.




BEER, BAVARIAN.                                 159
This cost for 42 eimers (1 eimer = 141 galls. Imp.)= 6191 gallons = 17'2 London
porter barrels, amounts to 4d. per n, r gallon, or 12. 2d. per barrel. By the above
reckoning, a good profit accrues to the brewer, after allowing a liberal sum for the
rent of premises, interest of capital, &c.
He has less profit from the summer beer. For a brewing of 33 eimers = 505 gallons
Imp., containing from 60 to 65 pounds of saccharum in 1,000 pounds of the beer, by
Hermstaedt's saccharometer.
Expenditure.
Thaler. Slbg.
24 Berlin scheffels of white kiln-dried barley-malt, weighing from
12 to 13 centners* -                                  -      -24  0
48 Berlin pounds of fresh Bavarian fine hops, at 46 thaler per centner   20  0
I pound of Carageen moss      -              -      -                  0  3
1 quart setting yeast (unterhefe).
I centner pitch        -       -      -      -      -      -       -  11  0
Malt tax on 12 centners        -                                       8  0
Crushing the malt              -..     -      -      -              0
Fuel          --                                                       4  0
Wages, 6 thalers; coopers' do., 3 thalers; and sundries, 3 th. 27 sq.    12 27
81  0
Deduct for grains 4 thalers, and yeast 2 thalers    -      -           6  0
Neat cost          -         -              -                         75  0
This cost of Ill. 5s. for 505 gallons amounts to fully 5.d. per gallon, and 16s. 6d.
the barrel.
The cost at Munich is 2- thalers the eimer, and 4 thalers the barrel. The eimer of
the summer beer, or lagerbier, is sold for 4 thalers. The publicans there, as in London, are known to add more or less water to their beer before retailing it.
The yeast (unterhefe) is carefully freed by a scraper from the portions of light top
yeast that may have fallen to the bottom; the true unterhefe is then carefully sliced off
from the slimy sediment on the wood.
In Munich the malt is moistened slightly 12 or 16 hours before crushing it, with from
2 to 3 maast of water for every bushel; the malt being well dried, and several months
old. The mash-tun into which the malt is immediately conveyed is, in middle-sized
breweries, a round oaken tub, about 4j feet deep, 10 feet in diameter at bottom and
9 at top, outside measure, containing about 6,000 Berlin quarts. Into this tun cold
water is admitted late in the evening, to the amount of 25 quarts for each scheffel, or
600 quarts for the 24 scheffels of the ground malt, which are then shot in and stirred
about and worked well about with the oars and rakes, till a uniform pasty is formed
without lumps. It is left thus for three or four houss; 3,000 quarts of water being
put into the copper, and made to boil; and 1,800 quarts are gradually run down into
the mash-tun, and worked about in it, producing a mean temperature of 142-5~ Fahr.
After an hour's interval, during which the copper has been kept full, 1,800 additional
quarts of water are run into the tun, with suitable mashing. The copper being now
emptied of water, the mash-mixture from the tun is transferred into it, and brought
quickly to the boiling point, with careful stirring to prevent its setting on the bottom
and getting burned, and it is kept at that temperature for half an hour. When the mash
rises by the ebullition, it needs no more stirring. This process is called, in Bavaria,
boiling the thick mash, dickmaisch kochen. The mash is next returned to the tun, and
well worked about in it. A few barrels of a thin mash-wort are kept ready to be put
into the copper the moment it is emptied of the thick mash. After a quarter of an
hour's repose the portion of liquid filtered through the sieve-part of the bottom of the
tun into the wort-cistern is put into the copper, thrown back boiling hot into the mash
i the tun, which is once more worked thoroughly.
The copper is next cleared out, filled up with water, which is made to boil for the
after or small-beer brewing. After two hours settling in the open tun, the worts are
drawn off clear.
Into the copper, filled up one foot high with the wort, the hops are introduced, and
the mixture is made to boil during a quarter of an hour. This is called roasting the
hops. The rest of the wort is now put into the copper, and boiled along with the hops
during at least an hour or an hour and a half. The mixture is then laded out through
the hop-filter into the cooling-cistern, where it stands three or four inches deep, and is
exposed upon an extensive surface to natural or artificial currents of cold air, so as to
* 1 Centner = 110 Prussian pounds = 113-44 Ibs. Avoird.
t A Bavarian maas-= 1 quarts English measure.




160                          BEER, BAVARIAN.
be quickly cooled. For every 20 barrels of lagerbier, there are allowed 10 of small
beer; so that 30 barrels of wort are made in all.
For the winter or pot-beer the worts are brought down to about 590 Fahr. in the
cooler, and the beer is to be transferred into the fermenting-tuns at from 54.5~ to 59~
Fahr.; for the summer or lagerbier, the worts must be brought down in the cooler to
from 43~ to 450~, and put into the fermenting-tuns at to from 41~ to 43~ Fahr.
A few hours beforehand, while the wort is still at the temperature of 63~0 Fahr., a
quantity of lobb must be made, called vorstellen (fore-selting) in German, by mixing the
proportion of ounterhefe (yeast) intended for the whole brewing with a barrel or a
barrel and a half of the worts, in a small tub called the gahr-tiene, stirring them well
together, so that they may immediately run into fermentation. This lobb is in this
state to be added to the worts. The lobb is known to be ready when it is covered with
a white froth from one quarter to one half an inch thick; during which it must be well
covered up. The large fermenting-tun must in like manner be kept covered, even
in the vault. The colder the worts, the more yeast must be used. For the above
quantity, at
From 57~ to 59~ Fahr., 6 maas of unterhefe.
53~ to 55       8        -
48~ to 50~     10 
41~ to 33~     12 
Some recommend that wort for this kind of fermentation (the untergdhrung) should be
set with the yeast at from 48~ to 57~; but the general practice at Munich is to set the
summer lager beer at from 41~ to 43~ F.
By following the preceding directions, the wort in the tun should, in the course of
from twelve to twenty-four hours, exhibit a white froth round the rim, and even a slight
whiteness in the middle. After another twelve or twenty-four hours, the froth should
appear in curls; and, in a third like period, these curls should be changed into a still
higher frothy brownish mass. In from twenty-four to forty-eight hours more, the barm
should have fallen down in portions through the beer, so as to allow it to be seen in certain points. In this case it may be turned over into the smaller ripening tuns in the
course of other five or six days. But when the worts have been set to ferment at from
41~ to 43~ Fahr., they require from eight to nine days. The beer is transferred, after
being freed from the top yeast by a skimmer, by means of the stopcock near the bottom
of the large tun. It is either first run into an intermediate vessel, in order that the top
and bottom portions may be well mixed, or into each of the lager casks, in a numbered
series, like quantities of the top and bottom portions are introduced. In the ripening
cellars the temperature can not be too low. The best keeping beer can never be
brewed unless the temperature of the worts at setting, and of course the fermentingvault, be as low as 50~ F. In Bavaria, where this manufacture is carried on under
government inspectors, a brewing period is prescribed by law, which is, for the under
fermenting lager beer, from Michaelmas (29th September) to St. George (23d April).
From the latter to the former period the ordinary top-harm beer alone is to be made.
The ripening-casks must not be quite full, and they are to be closed merely with a
loose bung, in order to allow of the working over of the ferment. But should the fermentation appear too languid, after six or eight days, a little briskly fermenting lager
beer may be introduced. The store lager beer-tuns are not to be quite filled, so as to
prevent all the yeasty particles from being discharged in the ripening fermentation;
but the pot lager beer-tuns must be made quite full, as this beverage is intended for
speedy sale within a few weeks of its being made.
As soon as the summer beer-vaults are charged with their ripening-casks, and with
ice-cold air, they are closed air-tight with triple doors, having small intervals between,
so that one may be entered and shut again, before the next is opened. These vaults
are sometimes made in ranges radiating from a centre, and at others in rooms set off
at right angles to a main gallery; so that in either case, when the external opening is
well secured, with triple air-tight doors, it may be entered at any time, in order to
inspect the interior, without the admission of warm air to the beer-barrels. The
wooden bungs for loosely stopping them must be coated with the proper pitch, to
prevent the possibility of their imparting any acetous ferment. In the Beer Brewer*
of A. F. Zimmermann, teacher of theoretical and practical brewing, who has devoted
thirty-five years to this business, it is stated, that a ripened tun of lager or store-beer
must be racked off all at once, for when it is left half full it becomes flat (schaal); and
that the tun of pot lager beer must, if possible, be all drunk off in the same day it is
tapped; because on the following day the beer gets an unpleasant taste, even when
the bung has not been taken out, but only a small hole has been made, which is
opened only at the time of drawing the beer, and is immediately closed again with a
* Der Bicr-Brauer, als Meister in seinem fache, &c., illustrates with many plates, Berlin. 1842.




BEER, BAVARIAN.                                 161
spigot. He ascribes this change to the loss of the carbonic acid gas, with which the
beer has got strongly impregnated during the latter period of its ripening, while
being kept in tightly-bunged casks. The residuums in these casks are, however,
bottled up in Bavaria, whereby the beer, after some time, recovers its brisk and
pungent taste. But the beer-topers in Bavaria, who are professedly very numerous,
indulge so delicate and fastidious a palate, that when assembled in their favorite pothouse, they wait impatiently for the tapping of a fresh cask, and cease for a while to
tipple whenever it is half empty, puffing the time away with their pipes till another
fresh tap be made. In the well-frequented beer-shops of Munich a common-sized cask
of lager beer is thus drank off in an hour. A reputation for superior brewing is there
the readiest road to fortune.
Bock-Beer of Bavaria.-This is a favorite double strong beverage, of the best lager
description, which is so named from  causing its consumers to prance and tumble about
like a buck or a goat; for the German word bock has both these meanings. It is
merely a beer having a specific gravity one third greater, and is therefore made with
a third greater proportion of malt, but with the same proportion of hops, and flavored
with a few coriander-seeds. It has a somewhat darker color than the general lager
beer, occasionally brownish, taste less bitter on account of the predominating malt,
and somewhat aromatic. It is an eminently intoxicating beverage. It is brewed in
December and January, and takes a long time to ferment and ripen; but still it contains too large a quantity of unchanged saccharum and dextrine for its hops, so that it
tastes too luscious for habitual topers, and is drunk only from the beginning of May
till the end of July, when the fashion and appetite for it are over for the year.
Statement of a Brewing of Bavarian Bock-Beer.
For 41 Bavarian eimers of 64 maass each (about 15 gallons Imperial) per eimer, or
615 gallons, nearly 17 barrels English in all:Expenditure.
Thaler. Slbg.
32 Berlin scheffels of the best pale malt freed from its acrospires,
weighing 17^ centners, at 1 thaler per centner     -      -    32   0
48 lbs. (Berlin) of the best Bavarian hops        -      -       -    20   0
I lb. Carageen moss for clarifying        -      -      -       -     0   3
1 lb. Coriander-seeds      -       -      -      -              -     0   1
1 Quart setting yeast.
1 Centner Tyrolese pitch    -      -      -                    -    11   0
Malt-tax           -      -      -      -       -      -      -     11  20
Malt-crushing, fuel, wages, coopering, &c.         -       -    16   51
Thalers of 3s. each     -       -    91   0
Deduct for the value of grains and yeast       -       -      -     7   0
Thalers of neat cost      -      -      -       -      -      -    84   0
This statement makes the eimer of the Bavarian bock-beer amount to about 2 tha.
lers, or 6 shillings; being at the rate of nearly 5 pence per gallon; though without
counting rent, interest of capital, or profit. It is, in fact, a malt or barley sweet wine
or liqueur; but a very cheap one, as we see by this computation.
The chief difference in the process for making bock-beer lies in the mash-worts,
and in the hops being boiled a shorter time, to preserve more of the aroma, and acquire
less of the bitterness of the hop. The coriander-seeds are coarsely bruised, and added
along with the hops and Carageen moss, to the boiling mash-worts, about twenty
or thirty minutes before they are laded or drawn off into the mash-tun. Sometimes
the hops are boiled apart in a little clear wort, as formerly described. The bock-beer
is retailed in Munich at 3 silver groschen, about 3~d. the seidel, or pot, which is one
English pint. The 25 gallon cask (toane) is sold at 10 thalers, or 30 shillings. The
publicans, therefore, have a very remunerating profit per pot, even supposing that they
do not reduce the beer with water like our London craftsmen.
Zimmermann assumes the merit of having introduced Carageen moss as a clarifier
into the beer manufacture. I do not know whether it may not have been used in this
country for the same purpose, or in Ireland, where this fucus (Chondra crispa) grows
abundantly. He says that 1 ounce of it is sufficient for 25 gallons of beer; and that
it operates, not only in the act of boiling with the hops, but in that of cooling, as also
in the squares and backs before the fermentation is begun. Whenever this change,
however, takes places the commixture throws up the gluten and moss to the surface of
the liquid in a black scum, which is to be skimmed off, so that the proper yeast may




162                           BEER, BAVARIAN.
not be soiled with it. It occasions the separation of much of the vegetable slime, or
mucilage, called by the German brewers pech (pitch).
On the Clarifying or Clearing of Beers.-Clarifiers act either chemically-by being
soluble in the beer, and by forming an insoluble compound with the vegetable gluten,
and other viscid vegetable extracts; gelatine and albumen, under one shape or other,
have been most used; the former for beer, the latter, as white of egg, for wineor mechanically, by being diffused in fine particles through the turbid liquor, and, in
their precipitation, carrying down with them the floating vegetable matters. To this
class belong sand, bone-black (in some measure, but not entirely), and other such
articles. The latter means are very imperfect, and can take down only such matters
as exist already in an insoluble state; of the former class, milk, blood, glue, calf's-foot
jelly, hartshorn-shavings, and isinglass, have been chiefly recommended. Calve's-foot
jelly is much used in many parts of Germany, where veal forms so common a kind of
butcher-meat; but in summer it is apt to acquire a putrid taint, and to impart the
same to the beer. In these islands, isinglass swollen and partly dissolved in vinegar,
or sour beer, is almost the sole clarifier, called finings, employed. It is costly, when
the best article is used; but an inferior kind of isinglass is imported for the brewers.
The solvent or medium through or with which it is administered is eminently injudicious, as it never fails to infect the beer with an acetous ferment. In Germany
their tart wine has been used hitherto for dissolving the isinglass; and this has also the
same bad property. Mr. Zimmermann professes to have discovered an unexceptionable solvent in tartaric acid, one pound of which dissolved in 24 quarts of water is
capable of dissolving two pounds of ordinary isinglass; forming finings which may be
afterward diluted with pure water at pleasure. Such isinglass imported from Petersburg into Berlin costs there only 3s. per lb. These finings are best added, as already
mentioned, to the worts prior to fermentation, as soon as they are let in to the setting.
back or tun, immediately after adding the yeast to it. They are best administered by
mixing them in a small tub with thrice their volume of wort, raising the mixture into a
froth with a whisk (twig-besom, in German), and then stirring it into the worts. The
clarification becomes manifest in the course of a few hours, and when the fermentation
is completed, the beer will be as brilliant as can be wished; the test of which with the
German topers is when they can read a newspaper while a tall glass beaker of beer is
placed between the paper and the candle. One quart of finings of the above strength
will be generally found adequate to the clearing of 100 gallons of well-brewed lagerbeer, though it will be surer to use double that proportion of finings. The Carageen
moss, as finings, is to be cut in fine shreds, thrown into the boiling thin wort, when
the flocks begin to separate, and before adding the hops; after which the boiling is
continued for an hour and a half or two hours, as need be. The clarifying with this
kind of finings takes place in the cooler, so that a limpid wort may be drawn off into
the fermenting back.
Berlin tVhite or Pale Beer (Weiss-bier).-This is the truly patriotic beverage of
Prussia Proper, and he is not deemed a friend to his Valerland who does not swig it.
It is brewed from 1 part of barley-malt and 5 parts of wheat-malt, mingled, moistened,
and coarsely crushed between rollers. This mixture is worked up first with water at
95~ Fahr., in the proportion of 30 quarts per scheffel of the malt, to which pasty
mixture 70 quarts of boiling water are forthwith added, and the whole is mashed in the
tan. After it has been left here a little to settle, a portion of the thin liquor is drawn
off by the tap, transferred to the copper, and then for each bushel of malt there is added
to it a decoction of half a pound of  lltmark hops separately prepared. This hopped
wort, after half an hour's boiling, is turned back with the hops into the mash-tun, of
which the temperature should now be 1621- Fahr., but not more. In half an hour
the wort is to be drawn off from the grains, and pumped into the cooler. The grains
are afterward mashed with from 40 to 50 quarts of boiling water per scheffel of malt,
and this infusion is drawn off and added to the former worts. The whole mixture
is set at 66~ Fahr., with a due proportion of top yeast or ordinary barm, and very
moderately fermented. According to Zimmermann, a very competent judge, this his
native beer is very apt to turn sour, and therefore it must be very speedily consumed.
This proneness to acetification is the character of all wheat-malt beers. He recommends, what he himself has made for many years, a substitution of potato-starch sugar
for this sort of malt, and as much tartaric acid as to give the degree of tartness peculiar
to the pale Berlin beer, even in its best state. This acid moreover prevents the beer
from running into the acetous fermentation.
Potato-Beer.-The potatoes being well washed are to be rubbed down to a pulp by
such a grating cylinder-machine as is represented infig. 122, where a is the hopper for
receiving the roots (whether potato or beet, as in the French sugar-factories; b is the
crushing and grinding-drum; c, the handle for turning the spur-wheel d, which drives
the pinion e, and the fly-wheelf; g, h, is the frame. The dotted lines above c, are the




BEER, BAVARIAN.                               163
[liil                  g
cullender through which the pulp passes. Fig. 123 is the stopcock used in Bavaria for
bottling beer. For every scheffel of potatoes 80 quarts of water are to be put with
them into the copper, and made to boil.
123
Crushed malt, to the amount of 12 scheffels, is to be well worked about in the Inashtun with 360 quarts, or 90 gallons (English) of cold water, to a thick pap, and then
840 additional quarts, or about 6 barrels (English) of cold water are to be successively
introduced with constant stirring, and left to stand an hour at rest.
The potatoes having been meanwhile boiled to a fine starch paste, the whole maltmash, thin and thick, is to be speedily laded into the copper, and the mixture in it is
to be well stirred for an hour, taking care to keep the temperature at from 144~ to
156~ Fahr. all the time, in order that the diastase of the malt may convert the starch
present in the two substances into sugar and dextrine. This transformation is made
manifest by the white pasty liquid becoming transparent and thin. Whenever this




164:                           BEER, BAVARIAN.
happens the fire is to be raised, to make the mash boil, and to keep it at this heat for 10
minutes.  The fire is then withdrawn, the contents of the copper are to be transferred
into the mash, worked well there, and left to settle for half an hour; during which
time the copper is to be washed out, and quickly charged once more with boiling
water.
The clear wort is to be drawn off from the top of the tun, as usual, and boiled as
soon as possible with the due proportion of hops; and the boiling water may be added
in any desired quantity to the drained mash, for the second mashing. Wort made in
this way is said to have no flavor whatever of the potato, and to clarify more easily
than malt-wort, from its containing a smaller proportion of gluten relatively to that of
saccharum.
A scheffel of good mealy potatoes affords from 26 to 271 lbs. of thick, well-boiled
syrup, of the density of 360 Baume (see AREOMETER); and 26 lbs. of such syrup are
equivalent to a scheffel of malt in saccharine strength.  Zimmermann thinks beer
so brewed from potatoes quite equal, at least, if not superior, to pure malt beer, both in
appearance and quality.
Professor Leo, of Munich, has given the following analysis of two kinds of Munich
beer:Bock-bier.    HeiligerVater.
Specific gravity   - - -       1-020         1-030
Alcohol - - - - - -            4000          5.000
Extract  ------                8'200        13-500
Carbonic acid     - -   -      0085          0 077
Water ----- -                 87 393        81 923
_  100-000  100-000
Carl states the alcohol in the Bavarian beer of Bamberg at only 2-840 in 100. Extract, 6 349.
The following analyses of other German beers are also by Leo:Lichtenhain.  WTUpper    Ilmenau.     Jena.   Double Jena.
Alcohol- - - --           3-168       2'567       3-096       3 018       2'080
Albumen  - - - -          0 048       0'020       0'079       0-045      0-028
Extract-    ---           4-485       7'316       7 072       6-144      7'153
Water - ----    92'299               90'097      89'753      90'793     90'739
100'000    100'000    100'000    100000    100-000
Under the term extract, in these analyses, is meant a mixture of starch, sugar, dextrine, lactic acid, various salts, certain extractive and aromatic parts of the hop, gluten,
and fatty matter.
The following statement is from some of the published analyses of other beers:Alcohol.
English ale         -                    - 8-5 in 100
Burton   -          -               -       62
Scotch    -    -                            5-8
Common London ale-    -                     5 0
Brown stout   -    -                  -    50
London porter -     -       -               4-0
To the above I add the following analyses of certain ales made lately by myself, as
follows:1. After exposing a portion of the liquor in a wine glass till the bubbles of carbonic
acid were disengaged, I took the specific gravity in a globe with a capillary bored
stopper.
2. I then saturated 5000 grain measures of the ale with a test solution of pure carbonate of soda, to determine the quantity of acid present, after which I added an excess of the alkali to precipitate the gluten; which, however, being but small in amount,
I did not separate by a filter, dry, and weigh.
3. I subjected the supersaturated liquid to distillation, by the heat of 2300 F. in a
chlor-zinc bath till I drew off all its alcohol, of which I noted the quantity in watergrain measures and the specific gravity.




BEER  (BITTER).                               165
4. I evaporated to dryness 500 water-grain measures slowly in a porcelain capsule,
to determine the extract.
Bavarian.   Do. Bock.    Allsop's.  Bass's.
Specific gravity  ------    1-004                 1-013       1'010       1'006
Alcohol - - - - - - - - -    400                  450         6 00       7'00
Extract ---              -    -      4'50         6 40        5'00        4'80
Acetic acid-              - - -    0-20           0'20        0'20        0'18
Water-  ---------   91-30                        88 90       88-80      88-02
100-00     100-00      100-00      100.00
The Bavarian beers had been recently imported from Germany in casks lined with
pitch.  The two samples of English ale are those made chiefly for the Indian market,
but, being highly hopped, and comparatively clean, as the brewers say, have been
recommended as a tonic beverage by the faculty. Hodgson's bitter beer was the original of this quality.
The above Bavarian beers afford no precipitate of gluten with carbonate of potash;
the two English ales become mottled thereby, and yield a small portion of gluten,
which had been held in solution by the acid, which is here estimated as the acetic.
Common vinegar, excise strength, contains 5 per cent. of such acid as is stated in the
above analysis, indicating from 3 to 4 per cent. of table vinegar in the above varieties
of beer.
ALE, PALE OR BITTER; brewed chiefly for the Indian market and for other tropical countries.-It is a light beverage, with much aroma, and, in consequence of the regulations
regarding the malt duty, is commonly brewed from a wort of specific gravity 1-055 or
upwards; for no drawback is allowed by the excise on the exportation of beer brewed
friom worts of a lower gravity than 1 054. This impolitic interference with the operations of trade compels the manufacturer of bitter beer to employ wort of a much greater
density than he otherwise would do; for beer made from wort of the specific gravity
1-042 is not only better calculated to resist secondary fermentation and the other effects
of a hot climate, but is also more pleasant and salubrious to the consumer. Under present circumstances the law expects the brewer of bitter beer to obtain 4 barrels of
marketable beer from every quarter of malt he uses, which is just barely possible when
the best malt of a good barley year is employed. With every quarter of such malt
16 lbs of the best hops are used; so that, if we assume the cost of malt at 60s. per
quarter, and the best hops at 2s. per lb., we shall have, for the prime cost of each barrel
of bitter beer, in malt 15s., in hops 8s., and together 23s.; fiom which, on exportation,
we must deduct the drawback of 5s. per barrel allowed by the excise, which brings
the prime cost down to 18s. per barrel, exclusive of the expense of manufacture, wear
and tear of apparatus, capital invested in barrels, cooperage, &c., which constitute
altogether a very formidable outlay.  As, however, this ale is sold as high as from
50s. to 65s. per barrel, there can be no doubt that the bitter ale trade has long been,
and still continues, an exceedingly profitable speculation, though somewhat hazardous, from the liability of the article to undergo decomposition ere it finds a market.
The English ale-bibbers were recently horrified by a public report, apparently well
authenticated, that French chemistry* was largely engaged in preparing immense
quantities of that most deadly poison strychnine, for the purpose of drugging the pale
bitter ale, in such great vogue at present in Great Britain and its colonies.  The fable would have been made more piquant, by suggesting that it was a project of the
Prince President of France to indemnify his country for the miseries of Waterloo. It
is surprising that such a tale should have been told by any gossip, and almost incredible that it should have been entertained gravely by any chemist of reputation, for
the following plain reasons: 1. Strychnine is an exceedingly costly article; 2. It has
a most unpleasant metallic bitter taste; 3. It is a notorious poison, and by its use in
any brewery would ruin the reputation of the brewer; 4. It cannot be introduced
into ordinary beer brewed with hops, because it is entirely precipitated by infusions
of that wholesome fragrant herb.  In fact, the quercitannic acid of hops is incompatible with strychnia and all its kindred alkaloids. Hence hopped beer becomes in this
respect a sanatory beverage; refusing to take up a particle of strychnia, and other
noxious drugs of like character. Had the two chemists employed by Messrs. Allsopp
to disprove the above calumny in respect to their bitter ale taken the trouble to
consult Berzelius, Anthony Todd Thompson, and other writers on strychnia, they
might have saved themselves the vain attempt to dissolve strychnia in the said beer;
for it all remains at the bottom in combination with the quercitannic acid so abun
dantly present.  Were the nux vonmica powder, from which strychnia is extracted,




166                       BERRIES OF AVIGNON.
even stealthily thrown into the mash tun, its dangerous principle would be all infallibly thrown down with the grounds in the subsequent hop-boil.
The Board of Excise or Inland Revenue having a few years ago, with delusive liberality, permitted the legislature to grant leave to use sugar in the place of barley
malt in breweries, an extensive sugar merchant in London, hoping, under this pretended boon, to acquire a new and wealthy class of customers, employed me to ascertain by experiment the relative values of malt and sugar for the manufacture of beer.
Ten samples of muscovado sugar of several qualities were examined, and were found
to vary very slightly in the proportions of alcohol they could furnish by fermentation
in a brewer's tun; the average being 12 gallons of proof spirit for 112 lbs. of the sugar; whereas an equal quantity of proof spirit could be obtained from 4'8 bushels of
malt. One pound of malt yields i of a lb of extract, capable of making as much beer
as that weight of sugar. On comparing the actual prices of sugar and malt, we shall
see how ruinous a business it would be to use sugar instead of malt in a brewery, and
hence the delusiveness of the excise generosity towards the beer trade.
BEET-ROOT SUGAR. See SUGAR.
BELL METAL, an alloy of copper and tin. See COPPER
BELLOWS. See METALLURGY.
BEN OIL. See OIL OF BEN.
BENGAL STRIPES.  Ginghams; a kind of cotton cloth woven with colored
stripes.
BENJAMIN or BENZOIN. (Benjoin, Fr.; Benz6e, Germ.)  A species of resin used
chiefly in perfumery. It is extracted by incision from the trunk and branches of the
styrax benzoin, which grows in Java, Sumatra, Santa Fe, and in the kingdom of Siam.
The plant belongs to the decandria monogynia of Linneus, and the natural family of
the ebenaceie. It hardens readily in the air, and comes to us in brittle masses, whose
fracture presents a mixture of red, brown, and white grains of various sizes, which,
when white, and of a certain shape, have been called anygdaloid, from their resemblance to almonds. The sorted benzoin is, on the other hand, very impure.
The fracture of benzoin is conchoidal, and its lustre greasy: its specific gravity varies from 1-063 to 1-092. It has an agreeable smell, somewhat like vanilla, which is
most manifest when it is ground. It enters into fusion at a gentle heat, and then exhales a white smoke, which may be condensed into the acicular crystals of benzoic
acid, of which it contains 18 parts in the hundred. Stoltze recommends the following process for extracting the acid: The resin is to be dissolved in 3 parts of alcohol,
the solution is to be introduced into a retort, and a solution of carbonate of soda dissolved in dilute alcohol is to be gradually added to it, till the free acid be neutralized;
and then a bulk of water equal to double the weight of the benzoin is to be poured
in. The alcohol being drawn off by distillation, the remaining liquor contains the
acid, and the resin floating upon it may be skimmed off and washed, when its weight
will be found to amount to about 80 per cent. of the raw material. The benzoin contains traces of a volatile oil, and a substance soluble in water, at least through the
agency of carbonate of potash. Ether does not dissolve benzoin completely. The
fat and volatile oils dissolve very little of it.
Unverdorben has found in benzoin, besides benzoic acid, and a little volatile oil, no
less than three different kinds of resin, none of which has, however, been turned as
yet to any use in the arts.
Benzoin is of great use in perfumery, as it enters into a number of preparations;
among which may be mentioned fumigating pastilles, fumigating cloves (called also
nails), poudre dt la marechale, &c. The alcoholic tincture, mixed with water, forms
virginal milk. Benzoin enters also into the composition of certain varnishes employed
for snuff-boxes and walking-sticks, in order to give these objects an agreeable smell
when they become heated in the hand. It is likewise added to the spirituous solution
of isinglass, with which the best court-plaster is made.
BERLIN BLUE. Prussian blue, which see.
BERRIES OF AVIGNON, andPersian Berries. (Graines a Avignon, Fr.; Gelbbeeren,
Germ.) A yellowish dye-drug, the fruit of the rhamnus infectorius, a plant cultivated
in Provence, Languedoc, and Dauphine, for the sake of its berries, which are plucked
before they are ripe, while they have a greenish hue. Another variety comes from
Persia, whence its trivial name: it is larger than the French kind, and has superior
properties. The principal substances contained in these berries are: 1. A coloring
matter, which is united with a matter insoluble in ether, little soluble in concentrated
alcohol, and very soluble in water: it appears to be volatile. 2. A matter remarkable
for its bitterness, which is soluble in water and alcohol. 3. A third principle in small
quantity. A decoction of one part of the Avignon or Persian berry in ten of water
affords a brown-yellow liquor, bordering upon green, having the smell of a vegetable
extract, and a slightly bitter taste.




BIRDLIME.                                   167
With gelatine that decoction gives, after some time, a slight precipitate,- alkalis                  -       -a yellow hue,
-   acids          -                       -       a slight muddiness,
-   lime-water    --                       -       a greenish-yellow tint,
-   alum           -       -       -       -       a yellow color,
-   red sulphate of iron    -      -       -       an olive-green color,
sulphate of copper,    -        -       -       an olive color,
-   proto-muriate of tin   -       -       -       a greenish yellow with a slight
precipitate.   (See  CALICO
PRINTING).
BERYL.  A beautiful mineral or gem, of moderate price, usually of a green color
of various shades, passing into honey-yellow and sky blue.
BEZOAR.  The name of certain concretions found in the stomachs of animals, to
which many fanciful virtues were formerly ascribed. They are interesting only to the
chemical pathologist.
BICARBONATE  OF POTASH  AND  OF SODA.  These salts, so much used
in medicine, may, according to M. Behrens, be very readily prepared by gradually
adding acetic acid to a strong solution of their carbonates; that of soda being hot.
The carbonic acid, at the moment of its disengagement, by the stronger affinity of the
acetic for the alkalis, combines with a portion of them to form bicarbonates, which
fall to the bottom  of the vessel in which the mixture is made. The supernatant
acetate being separated by decantation, the residuary bicarbonate is to be pressed in
linen washed with ice-cold water, and dried. This process may be practised by the
chamber chemist, but will not afford the bicarbonates at so cheap a rate as the ordinary
modes of manufacture. But a far better method of forming these two salts is by exposing each of them in chambers on extensive surfaces, perforated with small holes, to
an atmosphere of carbonic acid, generated by the combustion of coke, and purified by
being passed through cold water, by the action of an air-pump worked by a steamengine.
BILE.  (Bile, Fr.; Galle, Germ.) The secreted liquor of the liver in animals. For
an account of the uses of animal bile in the arts, see GALL.
Bile (ox's) is composed, according to Berzelius,
1.  Of biline, fellinic acid, and fat of gall   -      -       -         8 00
2. Mucus           -      -      -       -      -       -      -         030
3.  Of alkali combined with biline, &c.  -          -      -    0'41
4. Muriate of soda, extractive matter           -       -      -         074
5. Phosphate of soda: do. of lime, &c.  -          -      -    -         0.11
6. Water           -      -       -      -                              90-44
100-00
Thenard's analysis gives:1. Resin of bile and picromel (acid gallenate of soda)   -     -       1054
2.  Coloring matter       -      -       -      -      -       -        050
3. Soda            -......        0'50
4. Phosphate of soda          -..         0'25
5. Muriate of soda               -       -      -      -       -         040
6. Sulphate of soda           -          -      ---                      0'10
7.           of lime                     -      -       -      -         0'15
8. Traces of oxide of iron                      - -     - 
9.  Water          -      -      -       -      -      -       -        87 56
100-00
A substance may be tested for bile by dropping into it two-thirds of its bulk of oil
of vitriol very slowly, so that the heat does not exceed 122~ Fahr., adding a few drops
of syrup, and shaking the mixture; when it should assume a deep violet hue.
BIRDLIME.  (Glu, Fr.; Vogelleim, Germ.) The best birdlime may be made from
the middle bark of the holly, boiled seven or eight hours in water, till it is soft and
tender, then laid by heaps in pits under ground, covered with stones after the water
is drained from it. There it must be left during two or three weeks, to ferment in the
summer season, and watered, if necessary, till it passes into a mucilaginous state. It
is then to be pounded in a mortar to a paste, washed in running water, and kneaded
till it be free from extraneous matters. It is next left for four or five davs in earthen
vessels to ferment and purify itself, when it is fit for use. Birdlime may be made by
the same process from the mistletoe (viburnum lantana), young shoots of elder, and
the barks of other vegetables, as well as from most parasite plants.
Good birdlime is of a greenish color, and sour flavor, somewhat resembling that of
linseed oil; gluey, stringy, and tenacious. By drying in the air it becomes brittle and




168                               BISCUITS.
may be powdered; but its viscosity may be restored by moistening it. It has an
acid reaction with litmus paper. It contains resin, mucilage, a little free acid, coloring and extractive matter. The resin has been called VISCINE.
All the parts of the mistletoe contain a peculiar viscid gluey substance, which they
yield by decoction, particularly of the bark and green portions; as also from the expressed juice of the bark or berries, when it is kneaded with the fingers under water.
The birdlime is thus obtained in the form of a white opaque mass, sticking to the
fingers. It may also be extracted from the berries of the mistletoe by means of ether,
repeatedly applied, digested with them. It dissolves at first a mixture of green wax
and birdlime, but afterwards birdlime alone. By distilling off the ether, the birdlime
remains colorless and pure.  Birdlime may be considered as a kind of viscid resin
which does not dry, and resembling in this respect an ointment of oil or lard and
rosin melted together-the old basilicon of the surgeon. Alcohol, even boiling hot,
dissolves hardly any birdlime; but merely its waxy impurities, which it deposits in
flocks on cooling. It is soluble in the oils of rosemary and turpentine, as also in
petroleum.  Heated with the ley of caustic potash, it forms a compound soluble in
alcohol. Nitric acid converts it into oxalic acid, and into a fat which solidifies.
Macaire has examined a substance which exudes from the receptacle and involucro
of the atractylis gummifera, and describes it as the pure matter of birdlime, which he
styles viscine. It is said to be composed in 100 parts of 75-6 carbon, 9-2 hydrogen,
and 15-2 oxygen.  Common birdlime may be regarded as a mixture of viscine, vegetable mucilage, and vinegar. The young shoots of the ficus elastica afford a milky
juice, which is viscine, while the old branches afford a juice rich in caoutchouc.
BISCUITS.  For the following account of the mechanical system of baking biscuits
for the royal navy, I am indebted to the ingenious inventor, Thomas Grant, Esq.
Ships' biscuits are now made by machinery; and one of the reasons for this has
been that the manual preparation of them was too slow and too costly during the last
war. A landsman knows very little of the true value of a biscuit: with a seaman,
biscuit is the only bread that he eats for months together. There are many reasons
why common loaves of bread could not be used during a long voyage; because, containing a fermenting principle, they would soon become musty and unfit for food, if
made previous to the voyage; while the preparation of them on board ship is subject
to insuperable objections. Biscuits contain no leaven, and, when well baked throughout, they suffer little change during a long voyage.
The allowance of biscuit to each seaman on board a queen's ship is a pound per day
(averaging six biscuits to the pound). The supply of a man-of-war for several months
is, consequently, very large; and it often happened during the last war that the difficulty of making biscuits fast enough was so great, that at Portsmouth wagon loads
were unpacked in the streets and conveyed on board ships.
We shall now describe the mode of making biscuits by hand; and afterwards speak
of the improved method. The bakehouse at Gosport contained nine ovens, and to each
was attached a gang of five men-the "turner," the "mate," the "driver," the "breakman," and the "idleman."  The requisite proportions of flour and water were put into
a large trough, and the "driver," with his naked arms, mixed the whole up together
into the form of dough-a very laborious operation. The dough was then taken from
the trough and put on a wooden platform called the break: on this platform worked
a lever called the break-staff, five or six inches in diameter, and seven feet long; one
end of this was loosely attached by a kind of staple to the wall, and the breakman,
riding or sitting on the other end, worked this lever to and fro over the dough, by an
uncouth jumping or shuffling movement. When the dough had become kneaded by
this barbarous method into a thin sheet, it was removed to the moulding-board, and
cut into slips by means of an enormous knife; these slips were then broken into pieces,
each large enough for one biscuit, and then worked into a circular form by the hand.
As each biscuit was shaped it was handed to a second workman, who stamped the
king's mark, the number of the oven, &c., on the biscuit. The biscuit was then
docked, that is, pierced with holes by an instrument adapted to the purpose. The
finishing part of the process was one in which remarkable dexterity was displayed.
A man stood before the open door of the oven, having in his hand the handle of a long'
shovel called a peel, the other end of which was lying flat in the oven. Another
man took the biscuits as fast as they were formed and stamped, and jerked or threw
them into the oven with such undeviating accuracy that they should always fall on
the peel. The man with the peel then arranged the biscuits side by side over the
whole floor of the oven. Nothing could exceed (in manual labor alone) the regularity with which this was all done. Seventy biscuits were thrown into the oven and
regularly arranged in one minute; the attention of each man being vigorously directed
to his own department; for a delay of a single second on the part of any one man
would have disturbed the whole gang. The biscuits do not require many minutes'




BISCUITS.                                 169
baring; and as the oven is kept open during the time that it is being filled, the biscuits
first thrown in would be overbaked were not some precaution taken to prevent it.
The moulder therefore made those which were to be first thrown into the oven larger
than the subsequent ones, and diminished the size by a nice gradation.
The mode in which, since about the year 1831, ships' biscuits have been made by
machinery invented by T. T. Grant, Esq., of the Royal Clarence yard, is this: the
meal or flour is conveyed into a hollow cylinder four or five feet long and about
three feet in diameter, and the water, the quantity of which is regulated by a gauge
admitted to it; a shaft, armed with long knifes, works rapidly round in the cylinder,
with such astonishing effect that, in the short space of three minutes, 340 pounds
of dough are produced, infinitely better made than that mixed by the naked arms of
a man. The dough is removed from the cylinder and placed under the breakingrollers; these latter, which perform the office of kneading, are two in number, and
weigh 15 cwt. each; they are rolled to and fro over the surface of the dough by
means of machinery, and in five minutes the dough is perfectly kneaded. The sheet
of dough, which is about two inches thick, is then cut into pieces half a yard square,
which pass under a second set of rollers, by which each piece is extended to the
size of six feet by three, and reduced to the proper thickness for biscuits. The
sheet of dough is now to be cut up into biscuits, and no part of the operation is
more beautiful than the mode by which this is accomplished. The dough is brought
under a stamping or cutting-out press, similar in effect, but not in detail, to that by
which circular pieces for coins are cut out of a sheet of metal. A series of sharp
knives are so arranged that, by one movement, they cut out of a piece of dough a
yard square about sixty hexagonal biscuits. The reason for a hexagonal (six-sided)
shape is, that not a particle of waste is thereby occasioned, as the sides of the hexagonals accurately fit into those of the adjoining biscuits; whereas circular pieces
cut out of a large surface always leave vacant spaces between. That a flat sheet can
be divided into hexagonal pieces without any waste of material is obvious.
Each biscuit is stamped with the queen's mark, as well as punctured with holes
by the same movement which cuts it out of the piece of dough. The hexagonal
cutters do not sever the biscuits completely asunder; so that a whole sheet of them
can be put into the oven at once on a large peel or shovel adapted for the purpose.
About fifteen minutes are sufficient to bake them; they are then withdrawn and
broken asunder by the hand.
The corn for the biscuits is purchased at the markets, and cleaned, ground, and
dressed; at the government mills; in quality it is a mixture of fine flour and middlings, the bran and pollard being removed. The ovens for baking are formed of
fire-brick and tile, with an area of about 160 feet. About 112 lbs. weight of biscuits
are put into the ovens at once. This is called a suit, and is reduced to about 110 lbs.
by the baking. From twelve to sixteen suits can be baked in each oven every day, or
after the rate of 224 lbs. per hour. The men engaged are dressed in clean check
shirts and white linen trowsers, apron, and cap; and every endeavor is made to
observe the most scrupulous cleanliness.
We may now make a few remarks on the comparative merits of the hand and the
machine processes. If the meal and the water with which the biscuits are made be
not thoroughly mixed up, there will be some parts moister than others. Now, it was
formerly found that the dough was not well mixed by the arms of the workman; the
consequence of which was that the dry parts became burnt up, or else that the moist
parts acquired a peculiar kind of hardness which the sailors called " flint:" these defects
are now removed by the thorough mixing and kneading which the ingredients receive
by the machine.
We have seen that 450 lbs. of dough may be mixed by the machine in four minutes,
and kneaded in five or six minutes; we need hardly say how much quicker this is than
men's hands could effect it. The biscuits are cut out and stamped sixty at a time,
instead of singly: besides the time thus saved, the biscuits become more equally
baked, by the oven being more speedily filled. The nine ovens at Gosport used to
employ 45 men to produce about 1,500 lbs. of biscuit per hour; 16 men and boys will
now produce, by the same number of ovens, 2,240 lbs. of biscuits (one ton) per hour.
The comparative expense is thus stated: Under the old system, wages, and wear
and tear of utensils, cost about is. 6d. per cwt. of bis cuit: under the new system, the
cost is 5d.
The bakehouses at Deptford, Gosport, and Plymouth, could produce 7,000 or 8,000
tons of biscuits annually, at a saving of 12,0001. per annum from the cost under the
old system. The advantages of machine-made over hand-made biscuits, therefore, are
many: quality, cleanliness, expedition, cheapness, and independence of government
contractors.
Fig. 124 represents the biscuit machinery, as executed beautifully by Messrs. Rennie,
VOL. L




170                                BISMUTH.
engineers. a, is the breaking roller, table and roller; b, the finishing roller, table and
roller; c, c, docking machines for stamping out the biscuits; d, mixing machine for
1241
_ rw]            l^^l^.( 11-i "
J           7
I f 
making the dough; e, spur pinion to engine shaft; f, spur wheel; g, g, bevel mitrewheels to give the upright motion; h, h, bevel-wheels for working the mixing machine;
i, i, i, ditto for communicating motion to the rolling machines; j, j, k, the crank shaft;
1, I, connecting rods; m, m, pendulums for giving motion to rollers; n, n, clutches for
connecting either half of the machinery to the other.
BISMUTH.  (Bismuth, Fr.; Wismuth, Germ.)  Called also marcasite and tin-glass.
It was shown to be a metal somewhat different from lead, by G. Agricola, in 1546; Stahl
and Dufay proved its peculiarity; but it was more minutely distinguished by Pott and
Geoffroy about the middle of the last century.  It is a rare substance, occurring native,
as an oxide, under the name of bismuth ochre; as a sulphuret, called bismuth glance; as
a sulphuret with copper, called copper bismuth ore; as also with copper and lead, called
needle ore. It is found associated likewise with selenium and tellurium. The native
metal occurs in various forms and colors, as white, reddish, and variegated; in primitive and floetz formations, along with the ores of cobalt, nickel, copper, silver and
bismuth ochre; at the Saxon Erzegebirge, near Schneeberg, and Joh. Georgenstadt; also
in Bohemia, Baden, Wurtemberg, Hessia, Sweden, Norway, England, and France.
The production of this metal is but a limited object of the smelting-works, of the
Saxon Erzegebirge at Schneeberg. It there occurs, mixed with cobalt speiss, in the
proportion of about 7 per cent. upon the average, and is procured by means of a peculiar furnace of liquation, which is the most economical method, both as to saving
fuel, and oxidizement of the bismuth.
The bismuth eliquation furnace at Schneeberg is represented in figs. 125,126, and 127,
of which the first is a view from above, the second a view in front, and the third a transverse section in the dotted line A B of fig. 125. a, is the ash-pit; b, the fire-place; c, the
eliquation pipes; d, the grate of masonry or brickwork, upon which the fuel is thrown
through the fire-door e e. The anterior deeper lying orifice of the eliquation pipes is closed
with the clay-platef; which has beneath a small circular groove, through which the
liquefied metal flows off. g is a wall extending from the hearth-sole nearly to the anterior
orifices of the liquation pipes, in which wall there are as many fire-holes, h, as there are
pipes in the furnace: i are iron pans, which receive the fluid metal; h, a wooden water



BISMUTH.                                     171
trough, in which the bismuth is granulated and cooled; I, the posterior and higher lying
apertures of the eliquation pipes, shut merely with a sheet-iron cover. The granulations
of bismuth drained from the posterior openings fall upon the flat surfaces m, and then
125
127
iii            I 0O
into the water-trough. n n are draught-holes in the vault between the two pipes, which
serve for increasing or diminishing the heat at pleasure.
The ores to be eliquated (sweated) are sorted by hana from the gangue, broken into
pieces about the size of a hazel nut, and introduced into the ignited pipes; one charge
consisting of about 2 cwt.; so that the pipes are filled to half their diameter, and three
fourths of their length. The sheet-iron door is shut, and the fire strongly urged, whereby
the bismuth begins to flow in ten minutes, and falls through the holes in the clay-plates
into hot pans containing some coal-dust. Whenever it runs slowly, the ore is stirred
round in the pipes, at intervals during half an hour, in which time the liquation is usually
finished. The residuum, called bismuth barley (graupen), is scooped out with iron rakes
into a water trough; the pipes are charged afresh; the pans, when full, have their contents cast into moulds, forming bars of from 25 to 50 pounds weight. About 20 cwt. of
ore are smelted in 8 hours, with a consumption of 63 Leipzic cubic feet of wood. The
total production of Shneeberg, in 1830, was 9800 lbs. The bismuth thus procured by
liquation upon the great scale, contains no small admixture of arsenic, iron, and some
other metals, from which it may be freed by solution in nitric acid, precipitation by water,
and reduction of the subnitrated oxyde by black flux. By exposing the crude bismuth
for some time to a dull red heat, under charcoal, arsenic is expelled.
Bismuth is white, and resembles antimony, but has a reddish tint; whereas the latter
metal has a blueish cast. It is brilliant, crystallizes readily in small cubical facets, is
very brittle, and may be easily reduced to powder. Its specific gravity is 9'83; and by
hammering it with care, the density may be increased to 9-8827. It melts at 480~ Fahr.,
and may be cooled 6 or 7 degrees below this point without fixing; but the moment it begins to solidify, the temperature rises to 4800, and continues stationary till the whole
mass is congealed. When heated from 32~ to 212~, it expands  a6 in length. When
pure it affords a very valuable means of adjusting the scale of high-ranged thermometers.
At strong heats bismuth volatilizes, may be distilled in close vessels, and is thus obtained
in crystalline laminae.
The alloy of bismuth and lead in equal parts has a density of 10-709, being greater
than the mean of the constituents; it has a foliated texture, is brittle, and of the same
color as bismuth. Bismuth, with tin, forms a compound more elastic and sonorous than
the tin itself, and is therefore frequently added to it by the pewterers. With 1 of bismuth and 24 of tin, the alloy is somewhat malleable; with more bismuth, it is brittle.
When much bismuth is present, it may be easily parted by strong muriatic acid, which
dissolves the tin, and leaves the bismuth in a black powder. It has been said, that an
alloy of tin, bismuth, nickel, and silver hinders iron from rusting. (Erdmann's Journal.)
The alloy of bismuth with tin and lead was first examined by Sir I. Newton, and has
been called ever since fusible metal. Eight parts of bismuth, 5 of lead, and 3 of tin, melt
at the moderate temperature of 202~ F.; but 2 of bismuth, 1 of lead, and 1 of tin, melt
at 200-75~ F. according to Rose. A small addition of mercury of course aids the fusibility. Such alloys serve to take casts of anatomical preparations. An alloy of 1 bismuth, 2 tin, and 1 lead, is employed as a soft solder by the pewterers; and the same
has been proposed as a bath for tempering steel instruments. Cake-moulds, for the
manufacturers of toilet soaps, are made of the same metal; as also excellent clich6s for
stereotype, of 3 lead, 2 tin, and 5 bismuth; an alloy which melts at 199~ F. This compound should be allowed to cool upon a piece of pasteboard, till it becomes of a doughy
consistence, before it is applied to the mould, to receive the impress of the stamp.




172                                BITUMEN.
The employment of plates of fusible metal as safety rondelles, to apertures in the tops
of steam boilers, has been proposed in France, because they would melt and give way at
elevations of temperature under those which would endanger the bursting of the vessel;
the fusibility of the alloy being proportioned to the quality of steam required for the engine. It has been found, however, that boilers, apparently secured in this way, burst,
while the safety discs remained entire; the expansive force of the steam causing explosion so suddenly, that the fusible alloy had not time to melt or give way.
There are two, perhaps three, oxydes of bismuth; the first and the third, or the suboxyde and super-oxyde, are merely objects of chemical curiosity. The oxyde proper occurs
native, and may be readily formed by exposing the metal to a red-white heat in a muffle,
when it takes fire, burns with a faint blue flame, and sends off fumes which condense into
a yellow pulverulent oxyde. But an easier process than that now  mentioned is to
dissolve the bismuth in nitric acid, precipitate with water, and expose the precipitate to
a red heat. The oxyde thus obtained has a straw yellow color, and fuses at a high
heat into an opaque glass of a dark-brown or black color; but which becomes less
opaque and yellow after it has cooled. Its specific gravity is so high as 8'211. It consists of 89-87 of metal and 10-13 oxygen in 100 parts. The above precipitate, which
is a sub-nitrate of bismuth, is called pearl-white, and is employed as a flux for certain
enamels; as it augments their fusibility without imparting any color to them. Hence,
it is used sometimes as a vehicle of the colors of other metallic oxydes. When well
washed, it is employed in gilding porcelain; being added in the proportion of one
fifteenth to the gold. But pearl-white is most used by ladies as a cosmetic for giving a
brilliant tint to a faded complexion. It is called blanc de fard, by the French. If it contains, as bismuth often does, a little silver, it becomes gray or dingy colored on exposure
to light. When the oxyde is prepared, by dropping the nitric solution into an alkaline
ley in excess, if this precipitate is well washed and dried, it forms an excellent medicine;
and is given, mixed with gum tragacanth, for the relief of cardialgia, or burning and
spasmodic pains of the stomach.
Another sort of pearl-powder is prepared by adding a very dilute solution of common
salt to the above nitric solution of bismuth, whereby a pulverulent sub-chloride of the
metal is obtained in a light flocculent form. A similar powder of a mother-of-pearl
aspect may be formed by dropping dilute muriatic acid into the solution of nitrate of
bismuth. The arsenic always present in the bismuth of commerce is converted by nitric
acid into arsenic acid, which, forming an insoluble arseniate of bismuth, separates from
the solution, unless there be such an excess of nitric acid as to re-dissolve it. Hence the
medicinal oxyde, prepared from a rightly-made nitrate, can contain no arsenic. If we
write with a pen dipped in that solution, the dry invisible traces will become legible on
plunging the paper in water.
It has been proposed to substitute bismuth for lead in assaying silver, as a smaller
quantity of it answers the purpose, and, as its oxyde is more fluent, can therefore
penetrate the cupel more readily, and give a more rapid result. But, independently
of the objection from its high price, bismuth has the disadvantage of boiling up, as
well as of rocking or vegetating, with the silver, when the cupellation requires a high
heat. In extracting the silver from the galena found in the copper-mine of Yahlun,
it has happened sometimes that the silver concreted towards the end of the operation,
and produced a cauliflower excrescence, which had to be cupelled again with a fresh
dose of lead. It was observed that, in this case, a portion of the silver had passed into
the cupel. Berzelius detected in a sample of silver thus concreted the presence of
bismuth.
The nitrate of bismuth, mixed with solution of tin and tartar, has been employed as a
mordant for dyeing lilach and violet in calico printing.
BISTRE.  (Bistre, Fr.; bister, Germ.) A brown color which is used in water colors,
in the same way as China ink. It is prepared from wood-soot, that of beech being preferred. The most compact and best burned parcels of soot are collected from the chimney, pulverized, and passed through a silk sieve. This powder is infused in pure water,
and stirred frequently with a glass ruler, then allowed to settle, when the water is decanted. If the salts are not all washed away, the process may be repeated with warm water.
The paste is now to be poured into a long narrow vessel filled with water, stirred well,
and left to settle for a few minutes, in order to let the grosser parts subside. The supernatant part is then to be poured off into a similar vessel. This process may be repeated
twice or thrice, to obtain a very good bistre. At last the settled deposite is sufficiently
fine, and when freed from its supernatant water, it is mixed with gum-water, moulded
into proper cakes, and dried. It is not used in oil painting, but has the same effect in
water-colors as brown pink has in oil.




BITUMEN.                                   173
BITTER PRINCIPLE. (Amere, Fr.; Bitterstof, Germ.)  This principle has not
been insulated hitherto by the chemist from the other proximate principles of plants,
but its existence is sufficiently recognized by the taste.  The following list contains
the principal bitter substances, many of which have been used in the arts and in
medicine.
Name.            Part employed.        Country.           Observations.
Quassia                Wood              Surinam, E. Indies  Powerfully bitter
Wormwood               Herb              Great Britain        Ditto
Aloe                  Inspissated juice  South Africa         Ditto
Angustura              Bark              South America        Ditto
Orange                Unripe Fruit       South of Europe        omati bitter
Ditto                 Peel               Ditto
Acorns                 Root              Ditto                Ditto
Carduus Benedictus   Herb                Greek Archipelago
Cascarilla            Bark               Jamaica              Ditto
Centaury              Herb               Great Britain
Camomile               Flowers
Colocynth             Fruit              Levant               Intolerably bitter
Colombo                Root              East Africa          Very bitter
Fumitory               Herb              Great Britain
Gentiana lutea        Root               Switzerland          Very bitter
Ground Ivy            Herb               Great Britain
Walnut                 Peels                                  With tannin
Island moss                                                   With starch
Scales of the feHops                     male flowers   Great Briltin         Aromatic bitters
Milfoil                Herb flowers      Great Britain
Large-leavedSatyrion  Herb               Great Britain
Rhubarb                Root              China                Disagreable odor
Rue                    Herb              Great Britain        Bitter and sharp
Tansy                 Herb flowers       Ditto                Bitter and offensive
Bitter trefoil         Herb              Ditto
Simarouba              Bark              Guiana
Bryony                 Root              Great Britain          Sharp, bitter,nau(  seous
Coffee                 Seeds             Arabia             I
BITUMEN, or ASPHALTUM.  (Bitume, Fr.; Erdpech, Germ.)  A black substance found in the earth, externally not dissimilar to pit-coal. It is composed of
carbon, hydrogen, and oxygen, like organic bodies; but its origin is unknown. It
has not been observed among the primitive or older strata, but only in the secondary
and alluvial formations. It constitutes sometimes considerable beds, as in the Isle of
Trinidad, where it occurs over an extensive district, in scattered masses. The greater
part of the asphaltum to be met with in commerce comes from the Dead Sea, on whose
shores it is cast up and gathered; whence it has got the name of Jewish bitumen. In
its black color and fracture it resembles ordinary pitch. By friction it affords negative electricity. Its average density is 1'16. It melts at the temperature of boiling
water, kindles very readily at the flame, burns brightly with a thick smoke and
leaves little ashes. Distilled by itself, it yields a peculiar bituminous oil, very little
water, some combustible gases, and traces of ammonia. It leaves about one-third of
its weight of charcoal after combustion, and ashes, containing silica, alumina, oxide of
iron, sometimes a little lime, and oxide of manganese. According to John, asphaltum
may be decomposed, by different solvents, into three distinct substances. Water dissolves nothing; alcohol (anhydrous) dissolves out a yellow resin equal to 5 per cent. of
the weight of the asphaltum; that resin is soluble in dilute alcohol and in ether. The
portion not soluble in the alcohol gives up a brown resin to ether, amounting to 70 per
cent. of the weight of the asphaltum. On evaporating off the ether, the resin remains
of a brownish-black colour, which dissolves readily in the volatile oils and in the oil
of petrolium. The portion of asphaltum which does not dissolve in ether is very
soluble in oil of turpentine, and in oil of petroleum; but less so in oil of lavender.
These three resinous principles dissolve all together by digestion in the oils of anise,
rosemary, turpentine, olive, hemp-seed, nut, and linseed. Caustic potash dissolves a
notable quantity of asphaltum; but carbonate of potash has no effect upon it.
Asphaltum enters into the composition of hydraulic cements, and into that of black
varnishes called japans, for coating iron trays, &c. A similar varnish may be prepared by dissolving 12 parts of fused amber, 2 parts of rosin, and 2 parts of asphaltum,
in 6 parts of linseed oil varnish, to which 12 parts of oil of turpentine have been added.




174                              BITUMEN.
There is a kind of bitumen found at Aniches, in France, in the department of the
North, which is black, very fusible and soft. It burns with flame. Alcohol, ether, and oil
of turpentine extract from it a fatty substance, which may be saponified with alkalis.
The bitumen of Murindb, near Choco, in Columbia, is of a brownish-black color,
soft, and has an earthy fracture. It has an acrid taste, burns with a smell of vanilla,
and is said to contain a large quantity of benzoic acid. It appears to be the result of
the decomposition of trees containing benzoin.
Asphaltum occurs abundantly at the surface of the salt lake Asphaltites, in Judea,
produced from springs in the neighborhood; it is floated down, gathers consistence,
and accumulates upon the surface of the lake; the winds drive it on the shores, and
the inhabitants collect it for sale. Its inspissation diffuses a disagreable smell in the
air of that region, which is supposed by the natives to be powerful enough to kill birds
when they attempt to fly across the lake.
But probaby the most remarkable locality of asphaltum in the world is the entire
basin or rather plain of it, in the island of Trinidad, called the Tar Lake. It lies on the
highest land in the island, and emits a strong smell, sensible at ten miles' distance. Its
first appearance is that of a lake of water, but when viewed more nearly it seems to be
a surface of glass. In hot weather its surface liquifies to the depth of an inch, and it
cannot then be walked upon. It is of a circular form, about three miles in circumference, and of a depth not ascertained. Large fissures frequently open and close up in
it, whence the pitch has been supposed to float upon a body of water. The soil for a
considerable distance round it, consists of cinders and burnt earth, and presents in
many points indications of convulsions by subterranean fire. In several parts of the
neighboring woods, there are round holes and fissures in the ground, containing liquid
bitumen to the depth of two inches.
Mr. Hatchett examined some specimens from Trinidad, and concluded that what had'
been heretofore supposed to be a pure mineral pitch was in reality only a porous stone
of the argillaceous kind, much impregnated with bitumen.
These various bitumens belong exclusively to the secondary and tertiary geological formations, and are not found among primitive rocks, except very rarely in veins.
They occur most generally in calcareous, argillaceous and sandy strata, and also in
volcanic districts. Petroleum  frequently floats on the waters which issue from the
volcanic mountains, or which lie at their base; even the sea is at times covered with
it near the volcanic islands of Cape de Verd. Mr. Breislack observed a petroleum
spring rising from the bottom of the sea near the south base of Vesuvius.
The substance with which bitumen seems to have the most constant and most remarkable relations is sea-salt; so that almost all the countries most abundant in petroleum, as Italy, Transylvania, Persia, the environs of Babylon, the region of the
Dead Sea, &c., contain salt mines, or lakes, or exhibit saline efflorescences  Iron pyrites is often impregnated with petroleum, or contains a bituminous nucleus.
The origin of bitumen is as little known as that of most of the productions of nature.
Some regard it as an empyreumatic oil, a matter analogous to liquid resin or essential
oil, resulting from the destruction of that astonishing multitude of animals and vegetables buried in the earth, whose solid remains are daily brought to view in mineral
researches.  It has been also supposed that naptha and petroleum are the product of
coals decomposed either by the fire of volcanoes, by the subterranean combustion of
coal itself, or by the decomposition of pyrites. The latter opinion is not supported
by any direct evidence, but the two former are sufficiently probable.
Elastic Bitumen is a rare substance, found hitherto only near Castleton, in Derbyshire, in fissures of slaty clay.
Bituminous mastic, or cement, has been of late extensively employed in France for
covering roofs and terraces, and lining water-cisterns. The mineral bitumen used for
the composition of this mastic is procured chiefly from the Obsann (Bas-Rhin), from
the Pare (department de l'Ain), and from the Puy-de-la-Poix (department of'uy-deDome). But boiled coal tar answers pretty well.  In the neighborhood of those
localities, there is a limestone impregnated with bitumen which suits for giving con
sistence to the cement. This is well dried, ground to powder, sifted, and stirred while
hot, in about one fifth its weight of melted asphaltum, contained in a cast iron boiler.
Dry chalk or bricks, ground and sifted, will suit equally well. As soon as this paste is
made quite homogeneous, it is lifted out with an iron shovel or spoon, and spread in
rectangular moulds, secured with pegs at the joints, fastened to a kind of platform of
smoothed planks, covered with strong sheet-iron. The sides of these moulds should be
previously smeared over with a thin coat of loam-paste, to prevent their adhesion to
the mastic. Whenever the cake is cold, the frame is taken asunder, and it is removed
from the iron plate by an oblong shovel, or strong spatula of iron. These cakes or
bricks are usually 18 inches long, 12 broad and 4 thick, and weigh about 70 lbs.
It is a very remarkable fact, in the history of the useful arts, that asphalt, which




BITUMEN.                                    175
was so generally employed as a solid and durable cement in the earliest constructions
upon record, as in the walls of Babylon, should for so many thousand years have
fallen well nigh into disuse among civilized nations. For there is certainly no class
of mineral substance so well fitted as the bituminous by their plasticity, fusibility,
tenacity, adhesiveness to surfaces, impenetrability by water, and unchangeableness
in the atmosphere, to enter into the composition of terraces, foot-pavements, roofs,
and every kind of hydraulic work. Bitumen, combined with calcareous earth, forms
a compact, semi-elastic solid, which is not liable to suffer injury by the greatest alternations of frost and thaw, which often disintegrate in a few years the hardest stone,
nor can it be ground to dust and worn away by the attrition of the feet of men and
animals, as sandstone, flags, and even blocks of granite are. An asphalt pavement,
rightly tempered in tenacity, solidity, and elasticity, seems to be incapable of suffering
abrasion in the most crowded thoroughfares; a fact exemplified of late in a few places
in London, but much more extensively, and for a much longer time in Paris.
The great Place de la Concorde (formerly Place Louis Quinze) is covered with a
beautiful mosaic pavement of asphalt; many of the promenades on the Boulevards,
formerly so filthy in wet weather, are now covered with a thin bed of bituminous
mastic, free alike from dust and mud; the foot-paths of the Pont Royal and Pont
Carousel, and the areas of the great public slaughter-houses, have been for several
years paved in a similai manner with perfect success. It is much to be regretted that
the asphalt companies of London made the ill-judged, and nearly abortive attempt,
to pave the carriage-way near the east end of Oxford street, and especially at a moist
season, most unpropitious to the laying of bituminous mastich. Being formed of
blocks not more than three or four inches thick, many of which contained much
siliceous sand, such a pavement could not possibly resist the crash and vibration of
many thousand heavy drays, wagons, and omnibuses, daily rolling over it.*  This
failure can afford, however, no argument against rightly-constructed foot-pavements
and terraces of asphalt. Numerous experiments and observations have led me to
conclude that fossil bitumen possesses far more valuable properties, for making a
durable mastich, than the solid pitch obtained by boiling wood or coal tar. The latter,
when inspissated to a proper degree of hardness, becomes brittle, and may be readily
crushed into powder; while the former, in like circumstances, retains sufficient tenacity to resist abrasion. Factitious tar and pitch being generated by the force of fire,
seem to have a propensity to decompose by the joint agency of water and air, whereas
mineral pitch has been known to remain for ages without alteration.
Bitumen alone is not so well adapted for making a substantial mastich as the native
compound of bitumen and calcareous earth, which has been properly called asphaltic
rock, of which the richest and most extensive mine is unquestionably that of the
Val-de-Travers, in the canton of Neufchatel. This interesting mineral deposite occurs
in the Jurassic limestone formation, the equivalent of the English oolite. The mine
is very accessible, and may be readily excavated by blasting with gunpowder. The
stone is massive, of irregular fracture, of a liver-brown color, and is interspersed with
a few minute spangles of calcareous spar. Though it may be scratched with the nail,
it is difficult to break by the hammer. When exposed to a very moderate heat it exhales a fragrant ambrosial smell, a property which at once distinguishes it from all
compounds of factitious bitumen. Its specific gravity is 2'114, water being 1,000,
being nearly the density of bricks. It may be most conveniently analyzed by digesting
it in successive portions of hot oil of turpentine, whereby it affords 80 parts of a white
pulverulent carbonic of lime, and 20 parts of bitumen in 100. The asphalt rock of
Val-de-Travers seems therefore to be far richer than that of Pyrimont, which, according to the statement in the specification of Claridge's patent, of November, 1837,
contains " carbonate of lime and bitumen in about the proportion of 90 parts of carbonate
of lime to about 10 parts of bitumen."
The calcareous matter is so intimately combined and penetrated with the bitumen,
as to resist the action not only of air and water for any length of time, but even of
muriatic acid; a circumstance partly due to the total absence of moisture in the
mineral, but chiefly to the vast incumbent pressure under which the two materials
have been incorporated in the bowels of the earth. It would indeed be a difficult
matter to combine, by artificial methods, calcareous earth thus intimately with bitumen, and for this reason the mastichs made in this way are found to*be much more
perishable. Many of the factitious asphalt cements contain a considerable quantity
of siliceous sand, from which they derive the property of cracking and crumbling down
when trodden upon.  In fact, there seems to be so little attraction between siliceous
matter and bitumen, that their parts separate from each other by a very small disruptive force.
Since the asphalt rock of Val-de-Travers is naturally rich enough in concrete bitu* See the conclusion of this article.




176                              BITUMEN.
men, it may be converted into a plastic workable mastic of excellent quality for foot
pavements and hydraulic works at very little expense, merely by the addition of a
very small quantity of mineral or coal tar, amounting to not more than 6 or 8 per
cent. The union between these materials may be effected in an iron cauldron, by the
application of a very moderate heat, as the asphalt bitumen readily coalesces with
the tar into a tenacious solid.
The mode adopted for making the beautiful asphalt pavement at the Place de la
Concorde in Paris was as follows.:-The ground was made uniformly smooth, either
in a horizontal plane or with a gentle slope to carry off the water; the curb-stones
were then laid round the margin by the mason about 4 inches above the level of the
ground. This hollow space was filled to a depth of 3 inches with concrete, containing
about a sixth part of hydraulic lime, well pressed upon its bed. The surface was
next smoothed with a thin coat of mortar. When the whole mass had become perfectly dry, the mosaic pattern was set out on the surface, the moulds being formed
of flat iron bars, rings, &c. about half an inch thick, into which the fluid mastic was
poured by ladles from a cauldron, and spread evenly over.
The mastic was made in the following way:-The asphalt rock was first of all
roasted in an oven, about 10 feet long and 3 broad in order to render it friable.
The bottom  of the oven was sheet iron, heated below by a brisk fire. A volatile
matter exhaled, probably of the nature of naptha, to the amount of one-fortieth the
weight of asphalt; after roasting, the asphalt became so friable, as to be easily reduced
to powder, and passed through a sieve, having meshes about one-fourth of an inch square.
The bitumen destined to render the asphalt fusible and plastic was melted in small
quantities at a time, in an iron cauldron, and then the asphalt in powder was gradually
stirred in to the amount of 12 or 13 times the weight of bitumen. When the mixture became fluid, nearly a bucketful of very small, clean gravel, previously heated
apart, was stirred into it; and, as soon as the whole began to simmer with a treacley
consistence, it was fit for use. It was transported in buckets, and poured into the
moulds.
For the reasons above assigned, I consider this addition of rounded, polished, siliceous
stones to be very injudicious. If anything of the kind be wanted to give solidity to the
pavement, it should be a granitic or hard calcareous sand, whose angular form will
secure the cohesion of the mass. I conceive, also, that tar, in moderate quantity,
should be used to give toughness to the asphaltic combination, and prevent its being
pulverized and abraded by friction.
In the able report of the Bastenne and Gaujac Bitumen company, drawn up by
Messrs. Goldsmid and Russell, these gentlemen have made an interesting comparison
between the properties of mineral tar and vegetable tar: the bitumen composed of the
latter substance, including various modifications, extracted from coal and gas, have, so
far as they were able to ascertain, entirely failed. This bitumen, owing to the qualities and defects of vegetable tar, becomes soft at 115~ of Fahrenheit's scale, and is brittle
at the freezing point; while the bitumen, into which mineral tar enters, will sustain
170~ of heat, without injury. In the course of the winter, 1837-'38, when the cold
was at i 4-O below zero, C., the bitumeA of Bastenne and Gaujac, with which one side of
the Pont Neuf at Paris is paved, was not at all impaired, and would, apparently, have
resisted any degree of cold; while that in some parts of the Boulevard, which was
composed of vegetable tar, cracked and opened in white fissures. The French government, instructed by these experiments, has required, when any of the vegetable
bitumens are laid, that the pavement should be an inch and a quarter thick; whereas,
where the bitumen composed of mineral tar is used, a thickness of three quarters of
an inch is deemed sufficient. The pavement of the bonding warehouse at Bordeaux
has been laid upward of 15 years by the Bastenne company, and is now in a condition
as perfect as when first formed. The reservoirs constructed to contain the waters of
the Seine at Batignolles, near Paris, have been mounted 6 years, and, notwithstanding
the intense cold of the winter of 1837, which froze the whole of their contents into one
solid mass, and the perpetual water pressure to which they are exposed, they have not
betrayed the slightest imperfection in any point. The repairs done to the ancient fortifications at Bayonne, have answered so well, that the government, 2 years ago,
entered into a very large contract with the company for additional works, while the
whole of the asches of the St. Germain and St. Cloud railways, and the pavements and
floorings necessary for these works, are being laid with the Bastenne bitumen.
The mineral tar in the mines of Bastenne and Gaujac is easily separated from the
earthy matter with which it is naturally mixed by the process of boiling, and is then
transported in barrels to Paris or London, being laid down in the latter place to the
company at 171. per ton, in virtue of a monopoly of the article purchased by the company at a sum, it is said, of 8,0001.
Mr. Harvey, the able superintendent of the Bastenne company, was good enough
to supply me with various samples of mineral tar, bitumen, and asphaltic rock, for




BITUMEN.                                   177
analysis. The tar of Bastenne is an exceedingly viscid mass, without any earthy impurity.  It has the consistence of bakers' dough at 60~ of Fahrenheit; at 80~ it yields
to the slightest pressure of the finger; at 150~ it resembles a soft extract; and at 212~
it has the fluidity of molasses. It is admirably adapted to give plasticity to the calcareous asphalts.
A specimen of Egyptian asphalt which he brought me, gave by analysis the very
same composition as the Val de Travers, namely, 80 per cent. of pure carbonate of
lime, and 20 of bitumen. A specimen to mastic, prepared in France, was found to
consist, in 100 parts, of 29 of bitumen, 52 of carbonate of lime, and 19 of silicious sand.
A portion of stone called the natural Bastenne rock afforded me 80 parts of gritty
silicious matter and 20 of thick tar. The Trinidad bitumen contains a considerable
portion of foreign earthy matter; one specimen yielded me 25 per cent. of silicious
sand; a second, 28; a third, 20; and a fourth, 30: the remainder was pure pitch. One
specimen of Egyptian bitumen, specific gravity 1'2, was found to be perfectly pure,
for it dissolved in oil of turpentine without leaving any appreciable residuum.
Robinson's Parisian Bitumen company use a mastich made with the pitch obtained
from boiling coal-tar mixed with chalk. One piece laid down by this company at
Knightsbridge and another at Brighton, are said to have gone to pieces. The portion of
pavement laid down by them in Oxford street, next Charles street, has been taken up.
Claridge's company have laid down their mastich under the archway of the HorseGuards, and in the carriage-entrance at the Ordnance Office; the latter has cracked at
the junction with the old pavement of Yorkshire curb-stone. The foot-pavement laid
down by Claridge's company at Whitehall has stood well. The Bastenne company
has exhibited the best specimen of asphalt pavement in Oxford street; they have laid
down an excellent piece of foot-pavement near Northumberland House; a piece, 40
feet by 7, on Blackfriars' Bridge; they have made a substantial job in paving 830
superficial feet in front of the guard-room at Woolwich, which, though much traversed
by foot-passengers, and beat by the guard in grounding arms, remains sound; lastly,
the floor of the stalls belonging to the cavalry barracks of the Blues at Knightsbridge,
is probably the best example of asphaltic pavement laid down in this country, as it has
received no injury from the beating of the horses' feet.
As the specific gravity of properly-made mastich is nearly double that of water, a
cubic foot of it will weigh from 125 to 130 lbs.; and a square foot, three quarters of
an inch thick, will weigh very nearly eight pounds. A ton of it will therefore cover
280 square feet. The prices at which the Bastenne Bitumen company sell their products is as follows:
Pure Mineral tar, 241. per ton, or 28s. per cwt.
Mastich 81. 8s. per ton, or 10s. per cwt.
Side Pavement.            Roofs and Terraces.
From  50 to 100 feet, Is. 3d. per foot.    -    Is. 6d. per foot.
100   250      Is. ld.     -       -    Is. 4d.
250   500         lid.     -       -    Is. ld.
500   750        10d.      -      -    Is. Od.
750   1000         9d.     -       -      lid.
1000  2000          8d.     -      -       10d.
2000  5000          7d.     -       -       9d.
Where the work exceeds 5,000 feet, contracts may be entered into.
For filling up joints of brickwork, &c., from ld. to lId. per foot, run according tc
quantity.
These prices are calculated for half an inch thickness, at which rate a ton will cover
420 square feet.
As the Val-de-Travers company engage to lay down their rich asphaltic rock in
London at 51. per ton; and as the mineral tar equal to that of Seissel may probably be
had in England at one fourth the price of that foreign article, they may afford to lay
their mastich three quarters of an inch thick per the thousand feet, including a substratum of concrete, at a rate of fivepence per square foot, instead of fifteenpence, being
the rate charged under that condition by the Bastenne company.
These charges are for London and its immediate vicinity.
Report of the experimental Pavements laid down in Oxford street, from Charles street to
Tottenham Court Road, January, 1839.
1. Robinson's Parisian bitumen, laid in blocks 12 inches square and 5 inches deep;
the substance is a compound of bitumen, lime, &c., and five granite stones are inserted
in the top of each block; the work is laid in straight courses, the joints cemented with
hot bitumen. The quantity of this is 97 square yards, the length is 20 feet, and the
price, if adopted, 9s. per square yard.
2. Same as 1, but the courses laid diagonally. The quantity is 97 square yards, the
length is 20 feet.




178                              BLACK DYE.
3. Granite paving, 9 inches deep, joined with Clarige's asphalt, the work laid in
straight courses. The cost to the parish has been II s. 7 d. per yard superficial for the
stone and laying, &c., no charge being made by Claridge's Company for the asphalt.
The quantity is 240 yards, the length 54 feet.
4. Granite paving, 4- inches deep, jointed with Claridge's asphalt, the work laid in
diagonal courses.  Cost to the parish 9s. 6d. per square yard.  No charge made for
the asphalt. The quantity is 88 square yards, the length 20 feet.
5. The Bastenne Bitumen Company.  The blocks are 12 inches long, 64 wide, and
34 deep with bevelled joints, close at bottom, and - inch open at top; the joints
cemented with hot bitumen; the substance is bituminous, with a very large proportion of granite imbedded in each block; the price, if adopted, 13s. 6d. per square
yard; the length in straight courses, 20 feet.
6. Same as 5, but the courses laid diagonally. The length 40 feet; the total quantity in 5 and 6 is 274 square yards.
7. Aberdeen granite paving, 9 inches deep; laid on a concrete bottom, formed of
gravel and lime, the joints of the pavement run with hot lime grout, in straight courses.
The length is 69 feet; cost, 16s. 5d. per square yard.
8. Same as 7, but the courses laid diagonally; length 38 feet.
9. Aberdeen granite paving, 9 inches deep, in straight courses, without a concrete
bottom; joints filled with fine gravel; cost, 12s. 5d. per yard; length, 24 feet.
10. The Scotch Asphaltum company.  The work is laid in blocks of divers length,
9 inches wide, and 6- deep; the side joints are straight, the end joints are bevelled
alternately. The work is laid in straight courses, and jointed in Roman cement; the
substance is, apparently, a bituminous matter mixed with fine gravel. The length is
50 feet; the number of square yards, 210; the price, per yard, if adopted, 13s. 6d.
11. The wood-paving.  The blocks are sexagon on the plan, and (with the exception of a few courses that are only 8 inches), 12 inches deep. The work is laid endwise of the grain; the blocks are mostly 8 inches diameter-a few  courses are 7
inches.  The material is Norway fir; there is no prepared bottom-the blocks are
laid on the plain ground, a small layer of gravel being spread to bed them in. From
the west end, 22 rows of courses of blocks are of wood in its natural state; 31 rows
have been Kyanised; 9 rows at the eastern end have been dipped in Claridge's asphalt; 6 rows have been dipped in a solution prepared by the patentee; the remainder are of wood in the natural state. The length of this piece is 60 feet: the number
of yards, 230; price per yard, if approved, 10s. 6d.
12. Val-de-Travers company.  Blocks in straight courses, 12 inches square, 5 inches
deep, with square joints. The substance of the blocks is bituminous, with a very large
proportion of granite imbedded in each block, the joints cemented with hot bitumen.
The length is 25 feet; number of square yards 94; the work is performed gratuitously.
13. The same company.  A layer of clean chippings and hot asphalt poured thereon.
The face up, with hot asphalt and broken stone imbedded therein.  The length is 25
feet: number of yards, 94; the work is gratuitous.
14. Same as 9. The length 47 feet.
By order of the Committee,
H. KENSETT, Chairman.
Statement of the number of carriages passing through Oxford street at the undernamed
times and places.
ao C~I           ho <
Date.          Time.              Place.         |                        
1839.                                              -  S  E   
C          ed;Z
Jan. 16. 6 in the morning till 12 at by the Pantheon. 347  935 890 621 752 91 372 1507 5515
18.        do.    [night. by Stratford place. 254  603 1213 401 728 89 472  993 4753
22.        do.           byNewmanstreet. 339 1241 1015 584 1288 85 958 1382 6992
26.        do.  [morning. by Stratford place. 371  766 1337 542 762 92 881 1292 5943
26. 12 at night till 6 in the   do.       -     4   1  82 139 2  38  58 324
The asphalt pavements were, in my judgment, so imperfectly constructed with coal
tar, ill boiled and aqueous, as to have a crumbling property when exposed to vicissitudes of weather.  Native bitumen makes a far better and more durable cement.
BLACK DYE.  (Teinte noire, Fr.; Schwartze farbe, Germ.)  For 1 cwt. of cloth
there are put into a boiler of middle size 18lbs. of logwood with as much Aleppo galls
in powder, and the whole, being enclosed in a bag, is boiled in a sufficient quantity of
water for 12 hours. One-third of this bath is transferred into another boiler with two




BLACK DYE.                                   179
pounds of verdigris; and the stuff is passed through this solution, stirring it continually during two hours, taking care to keep the bath very hot without boiling. The
stuff is then lifted out, another third of the bath is added to the boiler, along with 8
pounds of sulphate of iron or green vitriol. The fire is to be lowered while the sulphate dissolves, and the bath is allowed to cool for half an hour, after which the stuff
is introduced, and well moved about for an hour, and then it is taken out to air. Lastly,
the remaining third of the bath is added to the other two, taking care to squeeze the
bag well. 18 or 22 lbs. of sumach are thrown in; the whole is just brought to a boil,
and then refreshed with a little cold water; 2 pounds more of sulphate of iron are
added, after which the stuff is turned through for an hour. It is next washed, aired,
and put again into the bath, stirring it continually for an hour. After this, it is carried to the river, washed well, and then fulled. Whenever the water runs off clear, a
bath is prepared with weld, which is made to boil for an instant; and after refreshing
the bath the stuff is turned in to soften, and to render the black more fast. In this
manner, a very beautiful black is obtained without rendering the cloth too harsh.
Commonly more simple processes are employed. Thus the blue cloth is simply
turned through a bath of gall-nuts, where it is boiled for two hours. It is next
passed through a bath of logwood and sulphate of iron for two hours, without boiling, after which it is washed and fulled. But in all cases the cloth, after passing
through the blue vat, should be thoroughly washed, because the least remains of its
alkalinity would injure the tone to be given in the black copper.
Hellot has found that the dyeing might be performed in the following manner:For 20 yards of dark blue cloth, a bath is made of 2 lbs. of fustic (morus tinctoria),
44 lbs. logwood, and 11 lbs of sumach. After boiling the cloth in it for three hours
it is lifted out, 11 lbs. of sulphate of iron are thrown into the boiler, and the cloth is
then passed through it during two hours. It is now aired, and put again in the bath
for an hour. It is, lastly, washed and scoured. The black is less velvety than that by
the preceding process. Experience convinced him that the maddering prescribed in
the ancient regulations only gives a reddish cast to the black, which is obtained finer
and more velvety without madder.
A black may be dyed likewise without having given a blue ground. This method
is employed for cloths of little value. In this case they are rooted; that is to say,
they receive a dun ground with walnut husks, or the root of the walnut tree, and
are afterwards made black in the manner above described, or in some other way; for
it is obvious that a black may be obtained by several processes.
According to Lewis, the proportions which the English dyers most generally adopt
are, for 112 lbs. of woollen cloth previously dyed of a dark blue, about 5 lbs. of sulphate
of iron, as much gall-nuts, and 30 lbs. of logwood. They begin by galling the cloth,
they then pass it through the decoction of logwood, to which the sulphate of iron has
been added.
When the cloth is completely dyed, it is washed in the river, and passed through
the fulling-mill till the water runs off clear and colorless. Some persons recommend,
for fine cloths, to full them with soap water. This operation requires an expert workman, who can free the cloth thoroughly from the soap. Several recommend at its
coming from the fulling to pass the cloth through a bath of weld, with the view of
giving softness and solidity to the black. Lewis says, that passing the cloth through
weld, after it has been treated with soap, is absolutely useless, although it may be
beneficial when this operation has been neglected.
The following German process is cheap and good. 100 lbs of cloth or wool are put
into the copper with sufficient water and 15 lbs. of Salzburg vitriol (potash-sulphate of
iron) and 5 lbs. of argol, heating the bath gradually to boiling, while the goods are
well worked about for two hours, taking them out, and laying them in a cool place
for twenty-four hours. They are then to be put in a lukewarm bath of from 25 lbs. to
30 lbs. of logwood, and 10 lbs. of fustic, and to be worked therein while it is made to
boil during two hours. The goods are now removed, and there is put into the copper
14 lbs. of verdigris, dissolved in vinegar; the goods are restored into the improved
bath, and turned in it for half an hour, after which they are rinsed and dried.
The process for dyeing merinos black is for 100 lbs. of them to put 10 lbs. of copperas
into the bath of pure water, and to work therein for a quarter of an hour, as soon as
it is tepid, one-third of the goods; then to replace that portion by the second, and
after another quarter of an hour, to put in the last third. Each portion is to be laid
aside to air in the cold. The bath being next heated to 140~ F., the merinos are to be
treated as above piecemeal; but the third time it is to be passed through the bath at
a boiling heat. Being now well mordanted, the goods are laid aside to air till the
following day. The copper being charged with water, 50 lbs. of ground logwood and
2 lbs. of argol, and heated, the goods are to be passed through while boiling for half
an hour. They are then rinsed.




180                                BLACK DYE.
Different operations may be distinguished in dyeing silk black; the boiling of the silk,
its galling, the preparation of the bath, the operation of dyeing, the softening of the
black.
Silk naturally contains a substance called gum, which gives it the stiffness and elasticity peculiar to it in its native state; but this adds nothing to the strength of the silk,
which is then styled raw; it rather renders it, indeed, more apt to wear out by the stiffness which it communicates; and although raw silk more readily takes a black color, yet
the black is not so perfect in intensity, nor does it so well resist the re-agents capable of
dissolving the coloring particles, as silk which is scoured or deprived of its gum.
To cleanse silk intended for black, it is usually boiled four or five hours with one fifth
of its weight of white soap, after which it is carefully beetled and washed.
For the galling, nut-galls equal nearly to three fourths of the weight of the silk are
boiled during three or four hours; but on account of the price of Aleppo galls, more or
less of the white gall-nuts, or of even an inferior kind called galon, berry or apple galls,
are used. The proportion commonly employed at Paris is two parts of Aleppo galls to
from  eight to ten parts of galon. After the boiling, the galls are allowed to settle for
about two hours. The silk is then plunged into the bath, and left in it from twelve to
thirty-six hours, after which it is taken out and washed in the river.
Silk is capable of combining with quantities, more or less considerable, of the astringent principle; whence results a considerable increase of weight, not only from the weight
of the astringent principle, but also from that of the coloring particles, which subsequently fix themselves in proportion to the quantity of the astringent principle which had entered into combination. Consequently the processes are varied according to the degree
of weight which it is wished to communicate to the silk; a circumstance requiring some
illustration.
The commerce of silk goods is carried on in two ways; they are sold either by the
weight, or by the surface, that is, by measure. Thus the trade of Tours was formerly
distinguished from that of Lyons; the silks of the former being sold by weight, those of
the latter, by measure. It was therefore their interest to surcharge the weight at Tours,
and, on the contrary, to be sparing of the dyeing ingredients at Lyons; whence came the
distinction of light black and heavy black. At present, both methods of dyeing are practised at Lyons, the two modes of sale having been adopted there.
Silk loses nearly a fourth of its weight by a thorough boiling, and it resumes, in the
light black dye, one half of this loss; but in the heavy black dye, it takes sometimes upwards of a fifth more than its primitive weight; a surcharge injurious to the beauty of
the black, and the durability of the stuff. The surcharged kind is denominated English
black, because it is pretended that it was first practised in England. Since silk dyed with
a great surcharge has not a beautiful black, it is usually destined for weft, and is blended
with a warp dyed of a fine black.
The peculiarity of the process for obtaining the heavy black consists in leaving the
silk longer in the gall liquor, in repeating the galling, in passing the silk a greater number of times through the dye, and even letting it lie in it for some time.  The first galling is usually made with galls which have served for a preceding operation, and fresh
gall-nuts are employed for the second. But these methods would not be sufficient for
giving a great surcharge, such as is found in what is called the English black. To give
it this weight, the silk is galled without being ungummed; and, on coming out of the
galls, it is rendered supple by being worked on the jack and pin.
The silk-dyers keep a black vat, and its very complex composition varies in different
dye-houses. These vats are commonly established for many years: and when their black
dye is exhausted it is renovated by what is called in France a brevet. When the deposite
which has accumulated in it is too great, it is taken out, so that at the end of a certain
time nothing remains of the several ingredients which composed the primitive bath, but
which are not employed in the brevet.
For the dyeing of raw silk black, it is galled in the cold, with the bath of galls which
has already served for the black of boiled silk. For this purpose, silk, in its native
yellow color, is made choice of. It should be remarked, that when it is desired to
preserve a portion of the gum of the silk, which is afterwards made flexible, the galling
is given with the hot bath of gall-nuts in the ordinary manner. But here, where the
whole gum of the silk, and its concomitant elasticity, are to be preserved, the galling
is made in the cold. If the infusion of galls be weak, the silk is left in it for several
days.
Silk thus prepared and washed takes very easily the black dye, and the rinsing in a
little water, to which sulphate of iron may be added, is sufficient to give it. The dye is
made in the cold; but, according to the greater or less strength of the rinsings, it requires more or less time. Occasionally three or four days are necessary; after which
it is washed, it is beetled once or twice, and it is then dried without wringing, to avoid
softening it.




BLACK DYE.                                    181
Raw silk may be more quickly dyed, by shaking it round the rods in the cold bath
after the galling, airing it, and repeating these manipulations several times, after
which it is washed and dried as above.
lacquer describes a more simple process for the black by which velvet is dyed at
Genoa; and he says that this process, rendered still simpler, has had complete success
at Tours. The following is his description.
For 1 cwt. (50 kilogrammes) silk, 22 lbs. (11 kilogrammes) ofAleppo galls, in powder,
are boiled for an hour in a sufficient quantity of water. The bath is allowed to settle till
the galls have fallen to the bottom of the boiler, from which they are withdrawn; after
which 32 lbs. of English vitriol (or copperas) are introduced, with 13 lbs. of iron-filings,
and 22 lbs of country gum, put into a kind of two-handled cullender, pierced every
where with holes. This kettle is suspended by two rods in the boiler, so as not to
reach the bottom.  The gum is left to dissolve for about an hour, stirring it from time
to time. If, after this time, some gum remains in the kettle, it is a proof that the bath,
which contains two hogsheads, has taken as much of it as is necessary. If, on the contrary, the whole gum is dissolved, from 1 to 4 lbs. more may be added. This cullender is left constantly suspended in the boiler, from which it is removed only when the
dyeing is going on; and afterwards it is replaced. During all these operations the boiler
must be kept hot, but without boiling. The galling of the silk is performed with one
third of Aleppo galls. The silk is left in it for six hours the first time, then for twelve
hours. The rest, secundum artem.
Lewis states that he has repeated this process in the small way; and that by adding
sulphate of iron progressively, and repeating the immersions of the silk a great number
offtimes, he eventually obtained a fine black.
Astringents differ from one another as to the quantity of the principle which enters into
combination with the oxyde of iron. Hence, the proportion of the sulphate, or of any
other salt of iron, and that of the astringents, should vary according to the astringents
made use of, and according to their respective quantities.  Gall-nut is the substance
which contains most astringent; sumach, which seems second to it in this respect, throws
down (decomposes), however, only half as much sulphate of iron.
The most suitable proportion of sulphate of iron appears to be that which corresponds
to the quantity of the astringent matter, so that the whole iron precipitable by the astringent may be thrown down, and the whole astringent may be taken up in combination
with the iron. As it is not possible, however, to arrive at such precision, it is better
that the sulphate of iron should predominate, because the astringent, when in excess,
counteracts the precipitation of the black coloring particles, and has the property of even
dissolving them.
This action of the astringent is such that, if a pattern of black cloth be boiled with gallnuts, it is reducible to gray. An observation of Lewis may thence be explained. If cloth
be turned several times through the coloring bath, after it has taken a good black color,
instead of acquiring more body, it is weakened, and becomes brownish. Too considerable a quantity of the ingredients produces the same effect; to which the sulphuric acid,
set at liberty by the precipitation of the oxyde of iron, contributes.
It is merely the highly oxydized sulphate which is decomposed by the astringent;
whence it appears, that the sulphate will produce a different effect according to its state
of oxydizement, and call for other proportions. Some advise, therefore, to follow the
method of Proust, employing it in the oxydized state; but in this case it is only partially
decomposed, and another part is brought, by the action of the astringent, into the lower
degree of oxydizement.
The particles precipitated by the mixture of an astringent and sulphate of iron have
not at first a deep color; but they pass to a black by contact of air while they are
moist.
Under dyeing I shall show that the black dye is only a very condensed color, and that
it assumes more intensity from the mixture of different colors likewise deep. It is for
this reason advantageous to unite several astringents, each combination of which produces a different shade. But blue appears the color most conducive to this effect, and it
corrects the tendency to dun, which is remarked in the black produced on stuffs by the
other astringents.
On this property is founded the practice of giving a blue ground to black cloths, which
acquire more beauty and solidity the deeper the blue. Another advantage of this practice is to diminish the quantity of sulphuric acid which is necessarily disengaged by the
precipitation of the black particles, and which would not only counteract their fixation,
but would further weaken the stuff, and give it harshness.
For common stuffs, a portion of the effect of the blue ground is produced by the
rooting.
The mixture of logwood with astringents contributes to the beauty of the black in a
twofold way.  It produces molecules of a hue different from what the astringents do,




182                            BLACK PIGMENT.
and particularly blue molecules, with the oxide of copper, commonly employed in the
black dyes; which appears to be more useful the more acetate the verdigris made use
of contains.
The boil of weld, by which the dye of black cloth is frequently finished, may also
contribute to its beauty, by the shade peculiar to its combination. It has, moreover,
the advantage of giving softness to the stuffs.
The processes that are employed for wool yield, according to the observation of
Lewis, only a rusty black to silk; and cotton is hardly dyed by the process propel
for wool and silk. Let us endeavor to ascertain the conditions which these three varieties of dyeing demand.
Wool has a great tendency to combine with coloring substances; but its physical
nature requires its combinations to be made in general at a high temperature. The
combination of the black molecules may therefore be directly effected in a bath, in
proportion as they form; and if the operation be prolonged by subdividing it, it is
only with the view of changing the necessary oxidizement of the sulphate, and augmenting that of the coloring particles themselves.
Silk has little disposition to unite with the black particles. It seems tobe merely by
the agency of the tannin, with which it is previously impregnated, that these particles
can fix themselves on it, especially after it has been scoured. For this reason, silk baths
should be old, and have the coloring particles accumulated in them, but so feebly suspended as to yield to a weak affinity. Their precipitation is counteracted by the addition of gum, or other mucilaginous substances. The obstacles which might arise from
the sulphuric acid set at liberty is destroyed by iron filings, or other basis. Thus,
baths of a very different composition, but with the essential condition of age, may be
proper for this dye. For cotton black dye, see CALICO PRINTING.
Blue-black dye.-The mordant much employed in some parts of Germany for this
dye, with logwood, galls, sumach, &c., is iron-alum, so called on account of its having
the crystalline form of alum, though it contains no alumina. It is prepared by dissolving 78 pounds of red oxide of iron in 117 pounds of sulphuric acid, diluting this compound with water, adding to the mixture 87 pounds of sulphate of potash, evaporating
the solution to the crystallizing point. This potash sulphate of iron has a fine amethyst
color when recently prepared; and though it gets coated in the air with a yellowish
crust, it is none the worse on this account.  As a mordant, a solution of this salt, in
from 6 to 60 parts of water, serves to communicate and fix a great variety of uniform
ground colors, from light gray to brown, blue, or jet black, with quercitron, galls, logwood, sumach, &c., separate or combined.  The above solution may be usefully modified by adding to every 10 pounds of the iron-alumi, dissolved in 8 gallons (80 pounds)
of warm water, 10 pounds of acetate (sugar) of lead, and leaving the mixture, after
careful stirring, to settle. Sulphate of lead falls, and the oxide of iron remains combined with the acetic acid and the potash. After passing through the above mordant,
the cotton goods should be quickly dried.
BLACK  PIGMENT. The finest light black is prepared principally for the manufacturing of printers' ink. In Messrs. Martin and Grafton's patent process, the black
is obtained by burning common coal-tar, which should, however, be previously divested, as much as possible, of the ammoniacal liquor and acid mixed with it in
the tank.
For this purpose, it is proposed that four casks should be employed, each capable of
holding 130 gallons, and into every one of them are to be put about 60 gallons of the
rough impure tar, to which an equal quantity of lime-water is to be added, and then
agitated by machinery or manual labor until the lime-water is completely mixed with
the tar. The vessels should next be suffered to rest for about six hours, by which time
the tar will settle at the bottom of the casks, and the water may be drawn off. The
casks containing the tar should now be filled with hot water, which may be supplied
from the boiler oP a steam engine, and the whole again agitated as before. This process
may be repeated three times, suffering the tar to subside between each; and twelve
hours should be allowed for settling from the last water, so that the whole of the tar and
water may become separated, the water rising to the top of the cask, and the tar being
left at the bottom in a pure state.
But, as some of the water will yet remain mechanically combined with the tar, it is
proposed that the tar should be subjected to the -process of distillation. For this
purpose, a still, capable of holding 120 gallons, may be employed, in which about
50 gallons at one time may be operated upon; when, by a gentle heat, the water, and
other impurities which the tar may have retained, will be driven off. As soon as the
water appears to have evaporated, and the spirit runs fine and clear, the process of
distillation should be stopped; and, when cold, the pure tar may be drawn off, and set
apart for the purpose of being employed as contemplated in the patent.
The tar thus purified may be now converted into black, or it may be subjected to
further rectification to divest it of the mineral pitch, or asphaltum, which is combined




BLACK PIGMENT.                                  183
with the oil and spirit: the latter is to be preferred, because the mineral pitch, or
asphaltum, is only inflammable at a high temperature, which renders it more troublesome to use in the process here contemplated, and also would cause the apparatus to
require frequent cleaning from the carbonized pitch deposited. In order, therefore, to
get rid of the mineral pitch, or asphaltum, forty gallons of the tar are to be introduced
into a still, as before; and, instead of stopping the operation, as soon as the spirit begins
to come over, the distillation is continued with a strong heat, so as to force over the
whole of the oil and spirit, leaving the residuum of asphaltum in the still; this process,
however, is known to every chemist, and need not be further explained.
In fig. 128, is exhibited a rude representation of the apparatus employed in preparing
and collecting the fine light spirit black, produced by the combustion of the oil and
128
i   i                      ii
129
spirit of coal-tar after it has been purified as above described. a is the brickwork
which supports a number of burners issuing from a tube, b, within, and here shown by
dots, as passing along its whole length.  Fig. 129. is a section of the brickwork, with
the tube burner, and receiver, as will be described hereafter. The tube may be called
the tar main, as it is intended to be filled with tar: it is constructed of cast iron, and
from  it issue several (in this figure twenty-four) jets or burners, c. c, c; any other
number may be employed.  d is a furnace under the tar main, the flue of which
extends along, for the purpose of heating the tar to the boiling point, in order to
facilitate the process. Erom the main, b, the tar flows into the jets c; wicks are
introduced into the jets, and, when set fire to by a red-hot stick, will burn and emit a
very considerable quantity of smoke; which it is the object of this apparatus to conduct through many passages, for the purpose of collecting its sooty particles.
There are a number of hoods, e, e, e, or bonnets, as they are termed, all of which,
through their pipes, have communication with or lead into, a main chimney, f, f. Into
these hoods or bonnets the smoke of the burners ascends, and from thence passes into
the main chimney.f, and thence through the smoke tubes into the box g; here the
heaviest particles of th.e black deposit themselves; but, as the smoke passes on through
the farthest pipes, a deposit of the second, or finer, particles of black takes place in the
box, h. From hence the smoke proceeds through other pipes into aseries of canvas
bags, i, i, which are proposed to be about 18 feet long, and 3 in diameter. These bags
are connected together at top and bottom alternately, and through the whole series
the smoke passes up one bag and down the next, depositing fine black, called spirit
black, upon the sides of the convas. After the jets have continued burning for
several days, the bags are to be beaten with a stick, so that the black may fall to the
bottom; and when a sufficient quantity has accumulated, the bags may be emptied
and swept out. Thus seventy or eighty bags may be employed; so that the smoke should
pass through a length of about 400 yards, the farthest of which will be found to contain the finest black. The last bag should be left open, in order to allow the vapor
to escape into the open air.
The main tar tube will require to be emptied every four or five days, in order to
clear it from the pitchy matter that may have subsided from the burners, and they
also will require to be frequently poked with a wire, to clear off the black which
forms upon the edges, and to drive down the carbonized tar which attaches itself to
the upper part of the jets.
A fine lamp-black is obtained by the combustion of a thick torch of coal-gas, sup



184                                   BLEACHING.
plied with a quantity of air adequate to burn only its hydrogen. In this case, the
whole of its carbon is deposited in the form of a very fine black powder of extreme
lightness. This black is used in making the better qualities of printers' ink.
BLACKING FOR SHOES.  (Cirage des bottes, Fr.; Schuhschwarze.)
The following prescription for making liquid and paste blacking is given by William  Bryant and Edward James, under the title of a patent, dated December, 1836.
Their improvement consists in the introduction of caoutchouc, with the view, possibly,
of making the blacking waterproof:18 ounces of caoutchouc are to be dissolved in about 9 pounds of hot rape oil. To
this solution 60 pounds of fine ivory black, and 45 pounds of molasses, are to be added,
along with I pound of finely ground gum arabic, previously dissolved in 20 gallons of
vinegar, of strength No. 24. These mixed ingredients are to be finely triturated in a
paint mill till the mixture becomes perfectly smooth.  To this varnish 12 pounds of
sulphuric acid are to be now added in small successive quantities, with powerful stirring for half an hour.  The blacking thus compounded is allowed to stand for 14
days, it being stirred half an hour daily; at the end of which time, 3 pounds of finely-ground gum arabic are added; after which the stirring is repeated half an hour
every day for 14 days longer, when the liquid blacking is ready for use.
In making the paste blacking, the patentees prescribe the above quantity of India
rubber oil, ivory black, molasses, and gum arabic, the latter being dissolved in only
12 pounds of vinegar.  These ingredients are to be well mixed, and then ground together in a mill till they form a perfectly smooth paste. To this paste 12 pounds of
sulphuric acid are to be added in small quantities at a time, with powerful stirring,
which is to be continued for half an hour after the last portion of the acid has been
introduced. This paste will be found fit for use in about 7 days.
BLACK SILK DYEING.  In dyeing silk, " the hat-black color," it has been usual
to employ nitrate of iron as a mordant, and oak bark as the dye stuff, but Mr. Le Leivre has found that alder bark is preferable; in the next process fustic has been employed, but equal parts of fustic and citron bark are to be preferred; and the patentee proposes to finish the process with a lather of olive oil, soap and logwood.
In stretching silk so dyed he does it in an atmosphere of steam, by placing a perforated tube connected with a steam boiler close under the silk while being stretched.
BLEACHING (Blanchiment, Fr.; Bleichen, Germ.) is the process by which the textile filaments, cotton, flax, hemp, wool, silk, and the cloths made of them, as well as various vegetable and animal substances, are deprived of their natural color, and rendered
nearly or altogether white. The term bleaching comes from the French verb blanchir, to
whiten. The word blanch, which has the same origin, is applied to the whitening of
living plants by making them grow in the dark, as when the stems of celery are covered
over with mould.
The operations which the bleacher has recourse to differ according to the nature of
the bleaching means, the property of the stuff to be bleached, and local customs or circumstances; and the result is also obtained with more or less rapidity, certainty,
economy, and perfection.  The destruction of the coloring matters attached to the bodies
to be bleached is effected either by the action of the air and light, of chlorine, or sulphurous acid; which may be considered the three bleaching powers employed for manufacturing purposes.
Bleaching by the influence of air and sunshine is the most ancient, and still the most
common, method in several civilized countries; it is also supposed by many to be the
least injurious to the texture of yarn and cloth. The operations it involves are very
simple, consisting in the exposure of the goods upon a grass-plat to the sky, with their
occasional aspersion with moisture if necessary, in addition to the rain and dew. The
atmospheric air effects the bleaching by means of its oxygenous constituent, which combines with the coloring matter, or its elements carbon and hydrogen, and either makes it
nearly white, or converts it into a substance easily soluble in water and alkaline solutions.
This natural process is too slow to suit the modern demands of the cotton and linen
manufacturers. Fortunately for them, a new bleaching agent, unknown to our forefathers,
has been discovered in chlorine, formerly called oxymuriatic acid, an agent modified by
chemistry so as to give an astonishing degree of rapidity, economy, and perfection, to this
important art. It is, however, not a little surprising, that the science which has so greatly
advanced its practical part should have left its theory far from complete, and should afford
no satisfactory answers to the two following questions.-What is the action of the solar
rays upon the coloring matter?  How do air and chlorine operate upon this principle?
Some suppose that light predisposes the coloring matter to combine with oxygen; others
fancy that it acts merely in the manner of a high temperature, so as to determine a
reaction between the elements of that substance, and to cause a new  combination
possessed of peculiar properties. It is generally admitted at the present day, that a
portion of the oxygen of the air passes into the coloring matter, and changes its con



BLEACHING.                                     185
stitution. This is, however, probably not the part which oxygen plays, nor is it the only
principle in the atmosphere which exercises a bleaching influence. Neither is the action
of chlorine such as has been commonly represented in our chemical systems.
But if authors offer us only vague hypotheses concerning the three principal agents,
light, oxygen, chlorine, they afford no information whatever concerning the phenomena
due to greasy spots so frequently found upon cotton cloth, and so very troublesome to
the bleacher.  It has indeed been sometimes said in bleach-works, that fatty substances are no longer soluble in alkalis, when they are combined with oxygen. The
very reverse of this statement is probably nearer the truth.
The object of bleaching is to separate from the textile fibre, by suitable operations, all
the substances which mask its intrinsic whiteness: or which, in the course of ulterior
dyeing operations, may produce injurious effects. In this latter respect, cotton deserves
especial consideration. This substance is covered with a resinous matter, which obstructs
its absorption of moisture, and with a yellow coloring matter in very small quantity,
often so inconsiderable in some cottons, that it would be unnecessary to bleach them,
before submitting them to the dyer, were it not that the manipulations which they
undergo introduce certain impurities which are more or less injurious, and must be
removed. It is in fact a circumstance well known in the factories, that unbleached
cottons may be dyed any dark color, provided they are deprived of that matter which
makes them difficult to moisten.  The substances present in cotton goods are the
following:1. The resinous matter natural to the cotton filaments.
2. The proper coloring matter of this vegetable.
3. The paste of the weaver.
4. A fat matter.
5. A cupreous soap.
6. A calcareous soap.
7. The filth of the hands.
8. Iron, and some earthy substances.
1. The matter which prevents the moistening of cotton wool may be separated by
means of alcohol, which, when evaporated, leaves thin yellowish scales, soluble in alkalis,
in acids, and even in a large quantity of boiling water.  For a long time the bleaching
process commenced with the removal of this resinous stuff, by passing the cloth or the
yarn through an alkaline ley. This was called scouring; it is now nearly laid aside.
2. The coloring matter of cotton seems to be superficial, and to have no influence
on the strength of the fibres; for the yarn is found to be as strong after it has been
stripped by caustic soda of its resinous and coloring matters, as it was before. The
coloring matter is slightly soluble in water, and perfectly in alkaline leys. When gray
calico is boiled in lime-water, it,comes out with a tint darker than it had before; whence
it might be supposed that the coloring matter was not dissolved out, even in part.
This, however, is not the case; for if we filter the liquor, and neutralize it with an acid,
we shall perceive light flocks, formed of the resinous substance, united with the coloring
matter. The dark color of the cloth is to be ascribed solely to the property which lime
possesses of browning certain vegetable colors. This action is here exercised upon the
remaining color of the cloth.
It may be laid down as a principle, that the coloring matter is not directly soluble
by the alkalis; but that it becomes so only after having been for some time exposed to
the joint action of air and light, or after having been in contact with chlorine. What
change does it thereby experience, which gives it this solubility? Experiments made
upon pieces of cloth placed in humid oxygen, in dry oxygen, in moist chlorine, and in dry
chlorine, tend to show that hydrogen is abstracted by the atmosphere; for in these
experiments proofs of dis-hydrogenation appeared, and of the production of carbonic acid.
In all cases of bleaching by chlorine, this principle combines immediately with the
hydrogen of the coloring matter, and forms muriatic acid, while the carbon is eliminated. Undoubtedly water has an influence upon this phenomenon, since the bleaching
process is quicker with the humid chlorine than with the dry; but this liquid seems to
act here only mechanically, in condensing the particles of the gas into a solution.  We
should also take into account the great affinity of muriatic acid for water.
3. The weaver's dressing is composed of farinaceous matters, which are usually allowed
to sour before they are employed.  It may contain glue, starch, gluten; which last is
very soluble in lime-water.
4. When the dressing gets dry, the hand-weaver occasionally renders his warp-threads
more pliant by rubbing some cheap kind of grease upon them. Hence it happens, that
the cloth which has not been completely freed from this fatty matter will not readily
imbibe water in the different bleaching operations; and hence, in the subsequent dyeing
or dunging, these greasy spots, under peculiar circumstances, somewhat like lithographic
stones, strongly attract the aluminous and iron mordants, as well as the dye-stuffs, and




186                              BLEACHING.
occasion stains which it is almost impossible to discharge. The acids act differently
upon the fatty matters, and thence remarkable anomalies in bleaching take place. When
oil is treated with the acetic or muriatic acid, or with aqueous chlorine, it evolves no
gas, as it does with the sulphuric and nitric acids, but it combines with these substances
so as to form a compound which cannot be dissolved by a strong boiling ley of caustic
soda. Carbonic acid acts in the same way with oil. On the other hand, when the oils
and fats are sufficiently exposed to the air, they seize a portion of its oxygen, and
become thereby capable of sapon:fication, that is, very soluble in the alkalis.
5. When the hand-weaver's grease continues in contact for a night with the copper
dents of his reed, a kind of cupreous soap is formed, which is sometimes very difficult to
remove fiom the web. Lime-water does not dissolve it; but dilute sulphuric acid carries
off the metallic oxyde, and liberates the margaric acid, in a state ready to be acted on by
alkalis.
6. When cloth is boiled with milk of lime, the grease which is uncombined unites
with that alkaline earth; and forms a calcareous soap, pretty soluble in a great excess of
lime-water, and still more so in caustic soda. But all fats and oils, as well as the soaps
of copper and lime, cease to be soluble in alkaline leys, when they have remained a considerable time upon the goods, and have been in contact with acetic, carbonic, muriatic
acids, or chlorine. These results have been verified by experiment.
7. Cotton goods are sometimes much soiled, from being sewed or tamboured with dirty
hands; but they may be easily cleansed from this filth by hot water.
8. Any ferruginous or earthy matters which get attached to the goods in the course of
bleaching, are readily removable.
We are now prepared to understand the true principles of bleaching cotton goods, for
the most delicate operations of the calico printer.
1. The first process is steeping, or rather boiling, the goods in water, in order to remove all the substances soluble in that liquid.
2. The next step is to wash or scour the goods by the dash-wheel or the stocks. This
is of great importance in the course of bleaching, and must be repeated several times; so
much so, that in winter, when the water of the dash-wheel is cold, the bleaching is
more tedious and difficult. Yarn and very open fabrics do not much need the dashwheel.
By these first two operations, the woven goods lose about sixteen per cent. of their
weight, while they lose only two parts out of five hundred in all the rest of the
bleaching.
3. In the third place the calicoes are boiled with milk of lime, whereby they are
stripped of their gluten, and acquire a portion of calcareous soap. Formerly, and still
in many bleach-works, the gluten was got rid of by a species of fermentation of the
farinaceous dressing; but this method is liable to several objections in reference to the
calico printer. 1. The fermentative action extends sometimes to the goods and weakens
their texture, especially when they are piled up in a great heap without being previously
washed.  2. The spots of grease, or of the insoluble soaps, become thereby capable of
resisting the caustic alkalis, and are rendered in some measure indelible; an effect due
to the acetic and carbonic acids generated during fermentation, and which will be easily
understood from what has been said concerning the action of acids on fatty substances.
It is not, therefore, without good reason that many practical men throw some spent leys
into the fermenting vats, to neutralize the acids which are formed. Were it not for the
presence of fat, fermentation, skilfully conducted, would be an excellent means of carrying off the gluten; and the steep is therefore applicable to power-loom goods, which
are not polluted with grease.
4. The goods are now subjected to a caustic soda ley, which dissolves out the soaps
of lime and copper, as well as that portion of the coloring matter wl.ich is sufficiently
dis-hydrogenated to be capable of combining with it.  This bucking with ley, which is
repeated several times upon the goods, in order to purge them completely from the fatty
matter present in the hand-loom webs, and also partially introduced in the spinning, is
almost the only operation to which yarns for Turkey red are subjected.  After being
boiled in a caustic soda ley, they are passed through solutions of chloride of lime, and
afterwards through the acid steep.
5. When the goods are sufficiently bucked in the leys, they are eitler exposed to
chlorine, or laid out on the grass; sometimes both are had recourse to for delicate work.
These different modes of action have the same influence on the coloring matter, but
they give rise to different effects in reference to greasy stains.
The goods are dipped in a solution of chloride of lime, which should be kept tepid
by means of steam. Alongside of the chlorine cistern, there is another filled with dilute
sulphuric or muriatic acid. When the goods are taken out of the chlorine, they are
drained on the top of its cistern till no more liquid ruirs off them, and they are then
plunged into the sour. The action of the acid in the present case may be easily ex



BLEACHING.                                   187
plained. In proportion as a salt of lime is formed, this base quits the chlorine, and allows
it to act freely upon the coloring matter. Thus we prevent the development of too great
a quantity of chlorine at once, which would be apt to injure the fibres; and we pursue
both a prudent and economical plan.  Only so much chlorine as is strictly necessary is
called forth, and hence it excites no smell in the apartment.
The chlorine serves to acidify the coloring matter, by abstracting a portion of its hydrogen; but we must take the greatest care that there is no grease upon the goods before
immersion in it, for the consequence would be, as above shown, very troublesome spots.
When the cloth is laid out upon the grass, it is the oxygen of the air which acidifies the
coloring matter; for which reason, the dew, which contains much air rich in oxygen, singularly accelerates the bleaching process. It is likewise, by absorbing oxygen from the
atmosphere, that fats or oils pass to the state of margaric and oleic acids, and become
most easily saponified. Should the goods, however, be left too long on the grass, the fats
absorb carbonic acid, and become insoluble in leys.
6. The goods must now receive a new soda ley, to dissolve out that portion of the
coloring matter which has been dis-hydrogenated in the chlorine of the air, as well as
the grease, if any perchance remained in the soluble state. These last two operations
are to be several times repeated, because the coloring matter should be removed only by
degrees, for fear of injuring the texture of the goods, by subjecting them to too much
chlorine at a time.
7. We finish with the dilute sulphuric acid, which should be very weak and tepid. It
dissolves out the iron, and some earthy matters occasionally found upon cotton. The
goods must be most carefully washed at the dash-wheel, or in a stream of water on quitting the sour bath, for if the acid were allowed to dry in them, it would infallibly injure
their texture by its concentration. In winter, if the goods are allowed to get frozen with
the acid upon them, they may likewise be damaged.
We may here observe, that when the goods are not to remain white, their bleaching
may be completed with a ley; for though it leaves a faint yellow tint, this is no inconvenience to the dyer. But when they are to be finished with a starching after the last
ley, they must have another dip of the chlorine to render the white more perfect. An
immersion in the dilute acid has nearly the same effect.
The principles expounded above lead to this important consequence, that when we
wish to bleach goods that are free from greasy stains, as is the case generally with the
better kinds of muslins, or when we wish to bleach even greasy goods for the starch
finish, we may content ourselves with the following operations:1. Boiling in water.
2. Scouring by the stocks or the dash-wheel.
3. Bucking with milk of lime.
4. Passing through chlorine, or exposure on the grass.
5. Bucking, or bouking with milk of lime. These two latter operations require to be
alternated several times, till the whole of the coloring matter be removed.
6. Souring.
The bleaching of goods, which are never laid down on the green, and which are not
dried between two operations, may be completed in a couple of days. They answer as
well for the printer as the others, and they are as white. Cotton fibres or yarns suffer
no diminution of their strength, when the cloth has been properly treated in the above
described processes.
Accurate experiments have demonstrated that their strength is not impaired by being
boiled in milk of lisme for two hours at the ordinary pressure, provided they be constantly
kept covered with liquid during the whole ebullition, and that they be well washed immediately afterwards; or, by being boiled in pure water under the pressure of ten atmospheres of steam; or by being boiled under the same pressure in a caustic soda ley, marking 3~ of Tweedale, or specific gravity 1'015, though it has increased to double the density
in the course of the boil, by the escape of the steam; or by being boiled under the atmospheric pressure at 14~ of Tweedale, or specific gravity of 1-070; or by being immersed
for eight hours in chloride of lime, capable of decoloring three times its bulk, of test solution of indigo (See CHLORINE); and by being afterwards dipped in sulphuric acid of
specific gravity 1'067, Tweedale 14~; or by being steeped for eighteen hours in sulphuric or muriatic acid of specific gravity 1*035, 7~ Tweedale.
In other well-conducted bleach-works the following is the train of operations:
1. Cleansing out the weaver's dressing by steeping the cloth for twelve hours in cold
water, and then washing it at the stocks or the dash-wheel. 2. Boiling in milk of lime,
of a strength suited to the quality of the goods, but for a shorter time than with the
soda ley; two short operations with the lime, with intermediate washing, being preferable to one of greater duration. 3 and 4. Two consecutive leys of ten or twelve hours'
boiling, with about two pounds of soda chrystals for I cwt. of cloth. 5. Exposure to
the air for six or eight days, or the application of the chloride of lime and the sulphuric




188                               BLEACHING.
acid. 6. A ley of caustic soda, like the former, sometimes with less alkali.  7. Exposure
to the air for six or eight days, or chlorine and the sour, as above. 8. Caustic soda ley,
as before.  9. Chlorine and the sour.  10. Rinsing in hot water, or scouring at the
dash-wheel.
If the numoer of vessels to be heated exceeds four or five, there is an economy in
using steam as the medium of heat; but under this number there is an advantage in
the direct application of fire to a boiling or bucking apparatus; since when only two
vessels are in activity, there is a waste of fuel by the extra steam power. It deserves to
be remarked, also, that the increase of the bulk of the liquid by the condensation of the
steam, does not permit the spent white ley to be turned to use for the green goods, on account of its excessive dilution. With the milk of lime boil, however, this dilution
would be rather an advantage.
It has been found that the introduction of bran into the fermenting steep (when this is
used) endangers the texture of the goods, by causing a putrefactive fermentation in some
places.
When in the milk of lime boil there is too much of this caustic earth, or when it is
poured in on the top of the goods, they are apt to suffer damage. The milk of lime should
be introduced from beneath into the under compartment of the bucking apparatus. For
the same reason, after the caustic soda ley, the vessel should be filled up with water, if
the goods be not immediately transferred to the dash-wheel. When they are allowed to
become partially dry on the top, they are easily injured.  The copper of the bucking apparatus ought to be of a size proportioned to that of the surmounting crib or vat; for
when it is too small, the liquid is too long of being brought into proper circulation, and
the goods may be meanwhile injured.  In a bucking apparatus, which requires five or six
hours to be brought into full play, those goods are very apt to be injured, which lie immediately under the overflow pipe.
When the chloride of lime steep is too strong, sometimes small round holes are made
in the calico, just as if they had been cut out by a punch, especially in the borders or
thicker parts of the goods. This accident is owing to the presence of bubbles of chlorine.
From the saturated state of the liquid, they remain gaseous a sufficient length of time for
corroding the parts of the cloth with which they are in contact. These will be obviously
the denser parts, for they confine the gas most completely, or prevent its diffusion through
the mass.  This evil is prevented by diluting the chloride steep to the proper degree, and
moving the goods through it.
The greasy spots, described above, show themselves in the maddering by attracting the
dye-stuff more copiously than the pure parts of the cloth, so as to mottle it; they are also
recognised in the white goods by being somewhat repulsive of moisture. When the combination of fatty matters with chlorine takes place at the surface of cotton goods, it is of
a nature to resist the action of alkalis. It is the stearine, or the principle of suet, particularly, which, by this means, acquires such a strong affinity for cottons; the elaine, or
the principle of oils, has no such remarkable affinity. Lime, in some circumstances,
seems to act as a mordant to greasy matters, and to fix them fast. Hence the weaver
should be prohibited, in all cases, from allowing candle-grease to touch his web. Goods
soiled with it should never be allowed to lie by in the ware-house, but be immediately
cleansed before the air has fixed the stearine by converting it into margaric acid. Lime
should, in these cases, be prudently employed; chlorine should never be used till the greasy
stains are thoroughly removed; and the bleacher should never warrant his pieces for the
printer till he has verified some of them by the water test.
I shall conclude this general analysis of the principles of bleaching by a few
precepts. Avoid lime, at the first ley, for goods which contain greasy spots; but use
it freely after one or two soda leys, and apply two soda leys after it. Do not apply
chlorine between these leys, but reserve it for the final operation. By this plan the
goods will be well bleached and very little worn. Use the souring steeps freely,
giving them after each ley, whether of lime or soda, since the calcareous base, with
which the greasy spots get charged merely from hard water, is an obstacle to the further
action of the leys.
I shall now give some practical instructions concerning the several steps of the bleaching process, as applied to cotton, linen, silk, and wool.
The first thing which the cotton bleacher does, is to mark the pieces with the initials
of the owner, by means of a stamp imbued with coal tar.  The linen bleacher marks
with nitrate of silver, a far more expensive substance, but one which resists better the
severer treatment which his goods are destined to undergo.
The cotton goods are generally singed before they are sent to the bleacher, and this is
done either by passing them rapidly over a red-hot semi-cylinder of iron, or over a row
of gas flames, by Mr. Hall's ingenious contrivance. (See SINGEING.) Each piece is next
creased together lengthwise like a rope, folded into a bundle, and fixed by a noose at the
end. In this open state it is easily penetrated by the water of the soaking cistern into
which it is thrown. It is then scoured by the dash or wash-wheel. It is now ready foi




BLEACHING.                                    189
the bucking or steaming apparatus, where it is treated with milk of lime. The steam
chamber resembles the bucking vessel, without its bottom copper; that is to say, a few
inches below the grated bottom of the bucking tub, there is a close iron sole, through
the centre of which the steam is admitted by several small apertures, for the purpose of
diffusing it throughout the goods, and causing a liquid circulation by its pressure, as
the steam does in the proper bucking boiler. One pound of lime previously made into
a cream consistenced mixture, and passed through a sieve, is used for every thirty or forty
pounds of cloth, according to its color and texture; and this cream mixed with more water
is interstratified with the pieces, as they are laid regularly in the vessel. Whenever this
is stocked with goods, all their interstices are filled up with water. After the lime
bucking, the cloth is transferred to the dash-wheel.
A  pound of cloth requires for its whitening about half a pound of good average
chloride of lime or bleaching powder, as it is commonly called, and this ought to be
dissolved in about three gallons of water.  Mr. Crum  of Thorniebank, near Glasgow,
an extensive and excellent bleacher, has so modified Dr. Dalton's ingenious plan of
testing the power of bleaching liquors by green sulphate of iron, as to give it much
greater precision for the bleacher's use, than the discoloration of indigo originally proposed by Berthollet. Mr. Crum dissolves four ounces of fresh green vitriol in hot water,
and then adds the solution of bleaching powder by small quantities at a time, till the
iron becomes wholly peroxydized, when the smell of chlorine will become perceptible.
When the bleacher has once found by trial the proper blanching power which his chlorine
steep ought to have, he can verify its standard, by seeing how much of it must be added
to an ounce, or any given weight of fresh copperas, dissolved in hot water, to cause the
peroxydizement and the exhalation of the peculiar odor. M. Gay Lussac's new method
by arsenious acid will be described under chlorine.  From the experiments which I
made some years ago,* upon indigo, it will be seen that this dye stuff is so variable in
its quantity of coloring matter, that no two chemists operating with it independently,
as a test for chloride of lime, could arrive at the same result.  They must provide
themselves with absolute indigo, by an expensive and troublesome process, not suited to
the busy bleacher.  The vitriolage, as the French term it, or the souring of the English
bleacher, consists in immersing the goods for four hours in dilute sulphuric acid, containing one gallon of oil of vitriol to from 25 to 30 of water, thoroughly intermixed by
stirring; for the density of the acid is an obstacle to its equal distribution through the
water.  This dilute acid will have a density of from 1-047 to 1-040, and will contain
from 7 to 61 per cent. by weight of the oil of vitriol.
The goods are now washed, and then boiled for eight or nine hours in an alkaline
ley, containing about two pounds of crystals of soda, or their equivalent in soda ash or
pearl-ash, for every 100 lbs. of cloth.  The ley must be made previously caustic by
quick lime. A washing in the wheel follows this boil; and then a chlorine steep for
five hours in a liquor two thirds of the strength of the former. It is next soured in the
dilute sulphuric acid, for two, three, or four hours, according to the color and quality
of the cotton, and then thoroughly washed.
The cloth is now bleached white, but cannot be presented in the market till it
undergoes certain finishing processes. The piece is elongated from the folds which it
contracts during the rotation of the dash-wheel by being thrown into a stream of water
in a cistern, terminated by the squeezing rollers, which take in the end of the piece, and
run it through between them, with the effect of making it nearly dry.  Two pieces of
cloth pass simultaneously through the rollers, and are disentangled spontaneously, so to
speak, without the help of hands.
The squeezing rollers or squeezers, for discharging the greater part of the water from
the yarns and goods in the process of bleaching, are represented in figs. 130, 131, the
130  Qrr    o                               131
&air  Jun o  cec 130  0eaue n  h   rtvl i.p
* QuarLerly Journal of Science, Literature, and the Arts, vol. vii. p. 160




190                              BLEACHING.
former being a side-view, to show how the roller gudgeons lie in the slots of the frame,
and how the shaft of the upper roller is pressed downward by a weighted lever, through
a vertical junction rod, jointed at the bottom to a nearly horizontal bar, on whose end
the proper weight is hung. In fig. 118, these rollers of birch-wood are shown in face;
the under one receiving motion through the toothed wheel on its shaft, from any suitable
power of water or steam. Upon the shaft of the latter, between the toothed wheel and
the roller, the lever and pulley for putting the machine into and out of gear are visible.
The under roller makes about 25 revolutions in the minute, in which time three pieces
of goods, stitched endwise, measuring 28 yards each, may be run through the machine,
from a water trough on one side, to a wooden grating upon the other.
When the goods are run through, they are carried off upon a grated wheelbarrow, in
a nearly dry state, and transferred to the spreading machine, called at Manchester a
candroy. In many bleach-works, however, the creased pieces are pulled straight by the
hands of women, and are then strongly beat against a wooden stock to smooth out the
edges. This being done, a number of pieces are stitched endwise together, preparatory
to being mangled.
Calender.-Fig. 132 is a cross section of this machine, and figs. 133, 134, are front
views broken off. The goods are first rolled upon the wooden cylinder a, near the
132                        133                          134
d                                                d ci
ground; by the tension roller b, upon the same cylinder, the goods receive a proper
degree of stretching in the winding off. They then pass over the spreading bars c c c,
by which they are still more distended; next round the hollow iron cylinder d, 16 inches
diameter, and the paper cylinder e, of like dimensions; thence they proceed under the
second massive iron cylinder f, of 8 inches diameter, to be finally wound about the projecting wooden roller g. This is set in motion by the pulleys h,fig. 121, and i,fig. 120,
and receives its proper tension from the hanging roller k; I is a press cylinder, of 14
inches diameter, made of plane-tree wood. By its means we can at all times secure an
equal degree of pressure, which would be hardly possible did the weighted lever press
immediately upon two points of the calender rollers. The compression exercised by
the cylinders may be increased at pleasure by the bent lever m, weights being applied
to it at n. The upper branch of the lever o is made fast by screws and bolts at p, to
the upper press-cylinder. The junction leg q is attached to the intermediate piece r, by
left and right-handed screws, so that according as that piece is turned round to the right
or the left, the pressure of the weighted roller will be either increased or diminished. By
turning it still more, the piece will get detached, the whole pressure will be removed, and
the press-roller may be taken off; which is a main object of this mechanism.
The unequable movement of the cylinders is produced by the wheels s t u, of which
the undermost has 69, the uppermost has 20, and the carrier-wheel t, either 33, 32, or 20
teeth, according to the difference of speed required. The carrier-wheel is bolted on at
v, and adjusted in its proper place by means of a slot. To the undermost iron cylinder,
the first motion is communicated by any power, for which purpose either a rigger
(driving pulley) is applied to its shaft at u, or a crank motion. If it be desired to




BLEACHING.                                    191
operate with a heated calender, the undermost hollow cylinder may be filled with hot
steam, admitted through a stuffing-box at one end, and discharged through a stuffing-box
at the other, or by a red-hot iron roller.
Pure starch would be too expensive a dressing for common calico shirtings, and therefore an extemporaneous starch is made by mixing one pound of flour with one gallon of
water, and allowing the mixture to ferment in a warm place for twenty-four hours. In
this way, a portion of lactic acid is formed, which dissolves the gluten, or separates it
from the starch; so that when the whole is thrown upon a sieve, a liquid paste passes
through, which, being boiled, answers well for stiffening the goods, without giving them
a gray tinge. The paste is thinned with water to the desired degree, and faintly tinged
with solution of indigo. The starch, which is sometimes thickened with porcelain clay,
Paris plaster, or Spanish white, is put into a trough, and is evenly imparted to the cloth as
this is drawn down through it, by the traction of rollers. There is a roller near the
bottom of the trough, round which the cloth is made to run, to secure its full impregnation; while the upper rollers serve to expel its excess of the starch, and throw it back
into the cistern. See STARCHING APPARATUS.
The goods are next dried in an apartment heated by two, three, or more flues, running
along the floor, and covered usually with fire-tiles. At first the heat is moderate, but it
is gradually raised to upwards of 110~ F.
The goods must now be passed again through the calender, in order to receive their
final smoothness and lustre. They are, in the first place, damped with a peculiar machine, furnished with a circular brush, whose points revolve in contact with water in a
trough placed beneath them, and sprinkle drops of water upon the goods as they are
drawn forward by a pair of cylinders. They are then subjected to the powerful pressure
of the calender rollers.
The calendered pieces are neatly folded into compact parcels, and stamped with the
marks of each particular manufacturer, or various devices to suit the markets for which
they are designed. They are finally piled on the sole of an hydraulic press, with a sheet
of pasteboard between each piece; but with occasional plates of iron to secure uniformity
of pressure throughout. When sufficiently condensed by the press, they are taken out,
and despatched to their respective manufacturers in a state ready for sale.
There are no less than 25 steps in the bleaching of calicoes, many of them effected
with expensive machinery; yet the whole do not produce to the bleacher more than 10
pence per piece of 24 yards.
The following system was pursued, a few years back, by a skilful bleacher of muslins
near Glasgow:"In fermenting muslin goods, we surround them with our spent leys, from  the temperature of 100~ to 150~ F., according to the weather, and allow them to ferment for
36 hours. In boiling 112 lbs. =  112 pieces of yard-wide muslin, we use 6 or 7 lbs. of
pearl-ashes, and 2 lbs. of soft soap, with 360 gallons of water, and allow them to boil for
6 hours; then wash them, and boil them  again with 5 lbs. of pearl-ashes and 2 lbs. of
soft soap, and allow them to boil 3 hours; then wash them with water, and immerse
them into the solution of oxymuriate of lime, at 5 on the test-tube, and allow them to
remain from 6 to 12 hours; next wash them, and immerse them into dilute sulphuric acid
at the specific gravity of 3- on Tweedale's hydrometer =  1'0175, and allow them to
remain an hour. They are now well washed, and boiled with 24 lbs. of pearl-ashes, and
2 lbs. of soft soap for half an hour; afterwards washed and immersed into the oxymuriate of lime as before, at the strength of 3 on the test-tube, which is stronger than the
former, and allowed to remain for 6 hours. They are again washed, and immersed in
diluted sulphuric acid at the specific gravity of 3 on Tweedale's hydrometer =  1'015.
If the goods be strong, they will require another boil, steep, and sour. At any rate, the
sulphuric acid must be well washed out before they receive the finishing operation with
starch.
" With regard to the lime, which some use instead of alkali immediately after fermenting, the same weight of it is employed as of pearl-ashes. The goods are allowed to boil
in it for 15 minutes, but no longer, otherwise the lime will injure the fabric."
More recently the plan adopted is as follows; by which the purest whites are produced for the London market.
" Lime is seldom used for our finer muslin goods, as it is found to injure their fabric,
and the colors do not keep for any length of time.
" An alkaline ley is made by boiling equal weights of lime and soda together for an
hour: this alkali is used for boiling goods the same as potash, but without soap.
"In finishing jaconets or muslins, after washing them  from the sour, they are run
through spring-water containing a little fine smalts, which give them a clear shade;
if of a coarse fabric, a little well-boiled starch is added to the water. From this they
are wrung or pressed, and taken up by the selvage for the breadthing frame, and are
run off it upon a tin cylinder heated by steam, by which the piece is completely dried




192                              BLEACHING.
in 15 minutes: it is then stripped from the cylinder, neatly folded and pressed, which
finishes the piece for the market. From 6d. to 9d. per piece of 12 yards is obtained for
the bleaching and finishing of those goods.
" Book muslins, after being washed from the sour, are wrung or pressed; then they are
hung up to dry in a heated stove, previous to being put into starch, prepared by boiling
3 lbs. of it to every 5 gallons of water, with 20 ounces of smalts: they are wrung out of
this starch, and taken to a room heated to 110~ F.; the starch is wrought into the piece
till clear, then taken into a cold room, and the selvages dressed or set, before being put
on the breadthing frame in the heated stove, where the piece is stretched to its length,
while three or four persons at each selvage keep the piece to its breadth. If a stiff finish
is wanted, they keep exactly opposite each other; but in breadthing the piece of elastic,
they cross the piece in breadthing, which gives it a springy elastic finish. From 9d. to
15d. per piece of 12 yards is obtained for the bleaching and finishing of these goods.
"Sewed trimmings, flounces, and dresses are run through spring water containing fine
smalts with a little well-boiled starch. They are then taken to the drying-stove, where
they are stented till dry, which finishes the piece for the market. From 6d. to 8d. per
piece is obtained for trimmings and flounces, and from 9d. to Is. for dresses, bleaching
and finishing."
In the bleaching of cotton cloth, where fixed colors are previously dyed in the yarn
before it is woven into cloth, such as the Turkey or Adrianople red, and its compounds
of lilach or purple, by the addition of iron bases, various shades of blue from indigo, together
with buff and gold color, tinged with the oxydes of iron, great care is necessary.
The comnmon process of bleaching pulicates, into which permanent colors are woven,
is, to wash the dressing or starch well out in cold water; to boil them gently in soap,
and, after again washing, to immerse them in a moderately strong solution of the oxymuriate of potash; and this process is followed until the white is good: they are then
soured in dilute sulphuric acid. If the goods are attended to in a proper manner, the
colors, in place of being impaired, will be found greatly improved, and to have acquired
a delicacy of tint which no other process can impart to them.
Pulicates, or ginghams, which have been woven along with yarn which has been previously bleached, are first freed by washing from the starch or dressing: they are then
washed, or slightly boiled with soap. After which, they are completely rinsed in pure
spring water, and then soured.
Besides these common processes for bleaching, another was some time ago introduced,
which consisted in immersing the cotton or linen goods in pretty strong solution of caustic alkali, and afterwards exposing them to the action of steam in a close vessel. It is
now generally abandoned.
The cotton or linen goods, having been previously cleaned by steeping and washing,
were, after being well drained, steeped in a solution of caustic alkali of the specific gravity
of 1020. After the superfluous alkaline ley had been drained from them, they were arranged on a grating in a receiver. The cover was then placed on the vessel, and firmly
screwed down; and the steam was admitted by turning the stopcock of the pipe which
communicated with a steam boiler of the common construction.
The stains which come out upon maddered goods, in consequence of defective bleaching, are called in this country spangs. Their origin is such as I have described above,
as the following statement of facts will show. The weaver of calicoes receives frequently
a fine warp so tender from bad spinning or bad staple in the cotton, that it will not bear
the ordinary strain of the heddles, or friction of the shuttle and reed, and he is obliged
to throw in as much weft as will compensate for the weakness or thinness of the warp,
and make a good marketable cloth. He of course tries to gain his end at the least
expense of time and labor. Hence, when his paste dressing becomes dry and stiff, he has
recourse to such greasy lubricants as he can most cheaply procure; which are commonly
either tallow or butter in a rancid state, but the former, being the lowest priced, is preferred. Accordingly, the weaver, having heated a lump of iron, applies it to a piece of
tallow held over the warp in the loom, and causes the melted fat to drop in patches upon
the yarns, which he afterwards spreads more evenly by his brush. It is obvious, however,
that the grease must be very irregularly applied in this way, and be particularly thick on
certain spots. This irregularity seldom fails to appear when the goods are bleached or
dyed by the common routine of work. Printed calicoes examined by a skilful eye will
be often seen to be stained with large blotches evidently occasioned by this vile practice
of the weaver. The ordinary workmen call these copper stains, believing them  to be
communicated in the dyeing copper. Such stains on the cloth are extremely injurious in
dyeing with the indigo vat. The following plan is adopted by some Scotch bleachers,
with the effect, it is said, of effectually counteracting spangs from grease.
The goods having been singed and steeped in pure water, as is customary in common
bleaching, they are passed through a pair of rollers to press out the impurities which
have been loosened by the steeping. It must here, however, be observed, that where the




BLEACHING.                                     193
expense of one extra drying can be afforded, the process might be very much improved
by steeping the brown calicoes for thirty or forty hours before singeing, because this would
separate much of that impurity which usually becomes fixed in the stuff on its being passed over the hot cylinders.  When the pieces have been thus singed, steeped, and pressed,
they are boiled four times, ten or twelve hours at each time, in a solution of caustic potash, of the specific gravity of from 1-0127 to 1-0156, washing them carefully and thoroughly in pure water between each of these boilings.  They are then immersed in a solution
of the chloride of potash, originally of the strength of 1'0625, and afterwards reduced
with twenty-four times its measure with water.
When the preparation is good, these proportions will whiten cotton goods completely in
eight hours. In this steep they are, however, generally suffered to remain twelve hours.
It has been supposed that the common bleaching liquor (chloride of lime) cannot, without
injury, be substituted for chloride of potash, but I believe this to be a mistake.
Some printers take the pieces from this solution, and, while wet, lay them upon the
grass, and there expose them to the sun and weather for two or three days. They arc
thence removed to the sours, made of the specific gravity of about 1-0254 at the temperature of 110~ of Fahrenheit. In bleaching common goods, and such as are not designed
for the best printing, the specific gravity of the sours is varied from that of 1'0146 to that
of 1-0238, if weighed when they become of the temperature of the atmosphere. In these
they are suffered to lie for five or six hours, after which they are taken to the dash-wheel
and washed thoroughly. When this operation is finished, they are submitted to four more
boilings as before, with a solution of caustic potash; taking care to wash well between
each of these boilings. Sometimes pearl-ash, made caustic, is used for the last of these
boilings, lest the sulphur, which always exists in the potashes of commerce, should impair
the whites. They are next immersed in the diluted chloride of potash, of the strength
before mentioned; after which they are well washed in pure water, and then winched
for half an hour in common sours. The last process is that of careful washing in plenty
of clean water, after which they are not put into the stove, but are immediately hung up
in the airing sheds to dry gradually. The water must be good, and abundant.
The number of operations, as here described, is great; but I know of no other mode
of procedure by which perfect bleaching is so likely to be effected at all times and in all
seasons, without disappointment. It must here be remarked, that, for the best purposes
of printing, it would not be sufficient to take goods which have been bleached in the
common way and finish these by the better process; because the sulphate of lime deposited in the cloth by that operation will be apt to spoil them for madder colors; at least,
a printer who is curious in his business would hesitate to work up such cloth.
Bucking or Bowking. —This is one of the most important operations in the bleaching
of both cotton and linen goods. There are several methods whereby this process is carried on; but of these we shall select only two, distinguishing them as the old and new
method of bucking. In the former way, the cloths have been steeped in the alkaline ley,
as before described, and afterwards well washed, are regularly arranged in a large wooden
vat, or kieve; a boiler of sufficient capacity is then filled with caustic alkaline ley,
which is heated to the temperature of blood. The boiler is then emptied by a stop-cock
upon the linens in the kieve, until they are covered with the liquor. After having
remained on the cloth for some time, it is run off by a stop-cock, at the bottom of the
kieve, into an iron boiler sunk in the ground, from whence it is raised into the boiler
by a pump. The heat is now elevated to a higher temperature, and the ley again run
upon the goods in the kieve; from whence it is returned into the boiler, as before
described: and these operations are continued, always increasing the heat, until the
alkaline ley is completely saturated with the coloring matter taken from the cloth,
which is known by its having acquired a completely offensive smell, and losing its
causticity.
When we consider the effect which heated liquids have upon colored vegetable
matter, we shall see the propriety of the temperature of the alkaline ley being gradually
increased. Thus, when vegetable substances are hastily plunged into boiling liquids,
the coloring matter, in place of being extracted, is, by this higher temperature, fixed
into them. It is on this principle that a cook acts in the culinary art, when the green
color of vegetables is intended to be preserved: in place of putting them into water when
cold, they are kept back until the water is boiling; because it is well known that, irn
the former case, the green color would be entirely extracted, whereas, when the vegetables are not infused until the water is boiling, the color is completely preserved or fixed.
On the same principle, when the temperature of the alkaline ley is gradually raised, the
extractive and coloring matter is more effectually taken from the cloth; and the case is
reversed when the ley is applied at the boiling temperature: so much so, that linen
which has been so unfortunate as to meet with this treatment, can never be brought to a
good white.
When the alkaline ley is saturated with coloring matter, it is run off as unfit for




194                             BLEACHING.
further use in this operation; but, were the goods to be instantly taken out of the
kieve, and carried to be washed in the dash-wheel while hot, a certain portion of the
coloring matter would be again fixed into them, which is extremely difficult to
eradicate. In order to prevent this, the most approved bleachers run warm water upon
the cloth as soon as the impure ley is run off: this combines with and carries off part
of the remaining impurities. A stream of water is then allowed to run upon the cloth
in the kieve, until it comes off almost transparent. The goods are now to be taken
to the wash stocks, or to the dash-wheel, to be further cleaned, with the greatest
efficacy.
The improved mode of bowking was the invention of Mr. John Laurie, a native of
Glasgow. It is now practised by many bleachers in Lancashire, some on more perfect
plans than others; but we shall give the description of the kind of apparatus approved
of by those whose experience and skill have rendered them the most competent
judges.
In fig. 135, A B C D is the wooden kieve, or kier, containing the cloth; c E F D
represents the cast-iron boiler; G G, the
G    pump; g K, the pipe of communication
135.....between the kieve and the boiler. This
pipe has a valve on each of its extremities;
that on the upper extremity, when shut,
QA,) NI    prevents the ley from running into the
3B      O        M         A          boiler, and is regulated by the attendant,A         by means of the rod and handle g B.
The valve at K admits the ley; but, opening inwards, it prevents the steam from
escaping through the pipe g K.  The
boiler has a steam-tight iron cover, g L;
and at c D, in the kieve, is a wooden
grating, a small distance above the cover
of the boiler.
\\  \   X   I  e   At M o is a broad plate of metal, in
order to spread the ley over the cloth.
\L                 It is hardly necessary to say that the
X                             boiler has a furnace, as usual, for similar
purposes.
While the ley is at a low temperature,
z~-~~___ —-~ e= E                  the pump is worked by the mill or steamengine. When it is sufficiently heated, the elasticity of the steam forces it up through
the valves of the pump, in which case it is disjoined from the moving power.
N P is a copper spout, which is removed at the time of taking the cloth out of the
kieve.
The boilers A, fig. 136, used in bleaching, are of the common form, having a stopcock, H G, at bottom, for running off the waste ley.
D       E    136  D         They are commonly made of cast-iron, and are ca— ~B R  pable of containing from 300 to 600 gallons of water,
according to the extent of the business done. In
order that the capacity of the boilers may be enlarged,
B   they are formed so as to admit of a crib of wood,
strongly hooped, or, what is preferable, of cast-iron,
\             A  to be fixed to the upper rim or edge of it. To keep
the goods from the bottom, where the heat acts most
forcibly, a strong iron ring, covered with netting
made of stout rope, c, is allowed to rest six or eight
inches above the bottom  of the boiler.  Four
double ropes are attached to the ring E, for withdIt         cl\ ldl o      loo I    Z g I drawing the goods when sufficiently boiled, which
have each an eye for admitting hooks from  the
running tackle of a crane.  Where more boilers
than one are employed, the crane is so placed,
that, in the range of its sweep, it may withdraw the goods from any of them. For this
purpose, the crane turns on pivots at top and bottom; and the goods are raised or lowered at pleasure, with double pulleys and sheaves, by means of a cylinder moved by castiron wheels. The lid is secured by the screw  bolts D D, and rings B B. F is a safety
valve.
The efficacy of Laurie's bowking apparatus is remarkable. While the heat is
gradually rising, a current of fresh ley is constantly presented to the different surfaces
for saturating the goods, so as to increase its detersive powers. Besides, the manner in




BLEACHING.                                    195
which the apparatus is worked, first by the water-wheel or steam-engine, and then by its
intrinsic operation, puts it completely out of the power of servants to slight the work;
not to speak of the great saving of alkali, which, in many cases, has been found to
amount to 25 per cent.
A simple modification of the bowking apparatus is shown in figs. 137, 138, 139; the
first being a vertical section, the
second, a horizontal section in the
line x of the first. It consists of
two parts: the upper wide part,
a a, serves for the reception of the
itcc^~  ggoods, and the lower or pot, b, for
a!  d  d )     137g    holding the ley; c c is an iron
grating, shown apart in fig. 139.
The grating has numerous square
apertures in the middle of the
disc, to which the rising pipe d is
*   - [L                         screwed fast. The upper cylinder
is formed of cast iron, or of sheet
^~ I  [             ~b  J h   iron well riveted at the edges; or
_  a. h l.    A*  I Q c ___     sometimes of wood, this being
l l  secured at its under edge into a
groove in the top edge of the leypot. The mouth of the cylinder
is constructed usually of sheet
iron. e e is the fire-grate, whose. \\\R\2\ 2g_ _   2       \\upper surface is shown infig. 138;
it is made of cast iron, in thiee
pieces. The flame is parted atf, and passes through
the two apertures g g, into the flues h h, so as to play
138   round the pot, as is visible in fig. 138; and escapes by
/               \        two outlets into the chimney. The apertures ii
serve for occasionally sleaning out the flues h h, and
/  /    1.  \   are, at other times, shut with an iron plate. In the
/  / X   \  partitionf, which separates the two openings g g,
I /J1j   \\   \ and the flues h h, running round the pot, there is a
1 i [  11h1t l 1lIli}^ A ~ +    circular space at the point marked with k, fig. 138, in
AI  II     l 111  I  which the large pipe for discharging the waste ley is
\  [    / - ~  lodged. The upper large cylinder should be incased
in wood, with an intermediate space filled with saw"\ x^  r" I..   /  dust, to confine the heat. The action of this apparatus is exactly the same as of that already explained.'~\^~                  ~ / ~ Besides the boiling, bucking, and other apparatus above described, the machinery and utensils
used in bleaching are various, according to the
3^^S'~^   ~     business done by the bleacher. When linen or
/(\Sil F?/>\  139 heavy cotton cloths are whitened, and the business
/^\    UU //5\  is carried on to a considerable extent, the machines
/ow  f h  d   \     ^are both complicated and expensive. They consist chiefly of a water-wheel, sufficiently powerful'[D3 d      i C Q        for giving motion to the wash-stocks, dash-wheels,
squeezers, &c., with any other operations where
~\"^;UU  /     Ppower is required.
\Figs. 140, 141, represent a pair of Wash-stocks.
l 8                 ^ p^ A A are called the stocks, or feet. They are suspended on iron pivots at B, and receive their motion from wipers on the revolving shaft c. The
cloth is laid in at D, and by the alternate strokes of the feet, and the curved form of
the turnhead E, the cloth is washed and gradually turned. At the same time, an
abundant stream of water rushes on the cloth throughout holes in the upper part ot
the turnhead. Wash-stocks are much used in Scotland and in Ireland. In the latter
country they are often made with double feet, suspended above and below two turnheads,
and wrought with cranks instead of wipers. Wash-stocks, properly constructed, make
from 24 to 30 strokes per minute.
This mode of washing is now entirely given up in Lancashire, where a preference is
given to what are called dash-wheels and squeezers. The dash are small water-wheels,
the inside of which is divided into four compartments, and closed up, leaving only a hole
in each compartment for putting in the cloth.




196                              BLEACHING.
There are, besides, smaller openings for the free admission and egrets of the water employed in cleansing. The cloth, by the motion of the wheel, is raised up in one part of
140                L
141
the revolution of the wheel; while, by its own weight, it falls in another. This kind of
motion is very effectual in wrashing the cloth, while, at the same time, it does not injure
its strength. The plan, however, where economy of water is of any importance, is very
objectionable; because the wheel must move at by far too great a velocity to act to advantage as a water-wheel.
The wash or dash-wheel, now  driven by power in all good bleach and printworks, is represented in
142 _fig. 142, upon the left side
in a back view, and upon,,0T~ 0" ~c^ ^  ~      the right side in a front
A ~o h"'S. ~-Q~view  (the  sketch  being
^"~o _^~ V^~ ~halved).  Fig. 143 is a
ground plan.
a a is the washing-wheel;
A1~ f ^~ ^5 ^ ^11^',"b b its shaft-ends; c c their
If.~.a ^11, ^..:^   v^       ~ brass bearings or plummerAk     ~ It                       r. _  l  a       blocks, supported upon the
* i"                  -:':' ~ 9^    Il' a  iron pillars d d. The frame
is made of strong beams of
U  \  v 8  *;  wood, e e, bound together
-\  h \<^  \  w ff  11    by cross bars with mortises.
f f, two of the circular
j Q ^^o  Ul^~ l~ l~ X~          apertures, each leading to
_~ ~ ~-~~           a quadrantal compartment
I~-~__ _~     within the dash-wheel. In
the back view (the left-hand half of the figure) the brass grating g g, of a curvilinear
form, is seen, through which the jets of water are admitted into the cavity of the
wheel; h h, are the round
I ^ ^ ~\ ~rc'^^i^^ ~ "m~\ ~orifices, through which the
1e- e~       lfm; Hi       __       1'  n   foul water runs off, as each
" "~'  ~   &   - "'  quadrant passes the lower
l~__t______t~___ ~ f_              part of its revolution; i, a
water-pipe, with a stop-cock
for regulating the washing}   v;  l&~           j   ~jets; kk, the lever for throwo        ing the driving-crab 1, or
________  coupling-box, into or out
of gear with the shaft of the
wheel. This machine is so
f~~. ~ ^ _] \       _____    -. |    constructed, that the waterL    I_    r_ |r.~IN    cock is opened or shut by
i*~'  I:  eZ..'  "  the same leverage which
k    143    k  l,,athrows the wheel into or
"143     ~Inll      Un "                     out of gear. m, a wheel,
fixed upon the round extremity of the shaft of the dash-wheel, which works into the toothed piniou connected




BLEACHING.                                  197
with the prime mover. When the end of the lever k, whose fork embraces the couplings
box upon the square part of the shaft, is pushed forwards or backwards, it shifts the clutch
into or out of gear with the toothed wheel m. In the latter case, this wheel turns with
its pinion without affecting the dash-wheel. n n, holdfasts fixed upon the wooden frame,
to which the boards o o are attached, for preventing the water fiom being thrown about
by the centrifugal force.
The dash-wheel is generally from 6 to 7 feet in diameter, about 30 inches wide, and requires the power of about two horses to drive it.
From one to two pieces of calico may be done at once in each quadrantal compartment,
in the course of 8 or 10 minutes; hence, in a day of 13 hours, with two such wheels
1200 pieces of yard-wide goods may be washed.
After the process of washing by the dash-wheel, the water is expressed from the cloth
by means of the squeezers already described.
Bleaching of Linen.-Linen contains much more coloring matter than cotton. The
former loses nearly a third of its weight, while the latter loses not more than a twentieth.
The fibres of flax possess, in the natural condition, a light gray, yellow, or blond color.
By the operation of rotting, or, as it is commonly called, water-retting, which is employed
to enable the textile filaments to be separated from the boon, or woody matter, the color
becomes darker, and, in consequence probably of the putrefaction of the green matter of
the bark, the coloring substance appears. Hence, flax prepared without rotting is much
paler, and its coloring matter may be in a great measure removed by washing with
soap, leaving the filaments nearly white. Mr. James Lee obtained a patent in 1812, as
having discovered that the process of steeping and dew-retting is unnecessary, and that
flax and hemp will not only dress, but will produce an equal if not greater quantity of
more durable fibre, when cleaned in the dry way. Mr. Lee stated that, when hemp or
flax plants are ripe, the farmer has nothing more to do than to pull, spread, and dry
them in the sun, and then to break them by proper machinery. This promising improvement has apparently come to naught, having been many years abandoned by the
patentee himself, though he was favored with a special act of parliament, which permitted the specification of his patent to remain sealed up for seven years, contrary to the
general practice in such cases.
The substance which gives steeped flax its peculiar tint is insoluble in boiling water,
in acids, and in alkalis; but it possesses the property of dissolving in caustic or carbonated
alkaline leys, when it has possessed the means of dehydrogenation by previous exposure
to oxygen. Hemp is, in this respect, analogous to flax. The bleaching of both depends
upon this action of oxygen, and upon the removal of the acidified dye, by means of an
alkali. This process is effected generally by the influence of air in combination with
light and moisture acting on the linen cloth laid upon the grass: but chlorine will effect
the same object more expeditiously. In no case, however, is it possible to acidify the
color completely at once, but there must be many alternate exposures to oxygen or chlorine, and alkali, before the flax becomes white. It is this circumstance alone which renders the bleaching of linen an apparently complicated business.
Having made these preliminary observations with regard to the method of applying the
alkaline leys used in bleaching linen cloth, I shall now bring the whole into one point of
view, by detailing the connexion of these processes, as carried on at a bleach-field, which
has uniformly been successful in returning the cloth of a good white, and has otherwise
given satisfaction to its employers; and I shall only remark, that I by no means hold it
up as the best process which may be employed, as every experienced bleacher knows that
processes must be varied, not only according to existing circumstances, but also acccrding
to the nature of the linens operated upon.
In order to avoid repetition, where washing is mentioned, it must always be understood that the linen is taken to the wash-stocks or dash-wheel, and washed well in them
for some hours. This part of the work can never be overdone; and on its being properly
executed between every part of the bucking, boiling, steeping in the chloride of lime
solution, and souring, not a little of the success of bleaching depends. By exposure is
meant, that the linen cloth is taken and spread upon the bleach-green for four, six, or
eight days, according as the routine of business calls for the return of the cloth, in order
to undergo further operations.
A parcel of goods consists of 360 pieces of those linens which are called Britannias.
Each piece is 35 yards long; and they weigh, on an average, 10 lbs. each: the weight of
the parcel is, in consequence, about 3600 lbs. avoirdupois weight. The linens are first
washed, and then steeped in waste alkaline ley, as formerly described under these processes; they then undergo the following operations:1st, Bucked with 60 lbs. pearl-ashes, washed, exposed on the field.
2d,  Ditto       80        ditto    ditto   ditto        ditto.
3d,  Ditto       90     potashes    ditto  ditto         ditto.
4th, Ditto       80        ditto     ditto   ditto       ditto.




198                              BLEACHING.
5th, Bucked with 80 lbs. pearl-ashes, washed, exposed on the field.
6th, Ditto       50       ditto     ditto    ditto        ditto.
7th, Ditto       70       ditto      ditto    ditto       ditto.
8th, Ditto       70       ditto     ditto    ditto        ditto.
9th, Soured one night in dilute sulphuric acid, washed.
10th, Bucked with 50 lbs. pearl-ashes, washed, exposed on the field.
11th, Immersed in the chloride of potash or lime 12 hours.
12th, Boiled with 30 lbs. pearl-ashes, washed, exposed on the field.
13th, Ditto     30        ditto     ditto    ditto       ditto.
14th, Soured, washed.
The linens are then taken to the rubbing-board, and well rubbed with a strong lather
of black soap, after which they are well washed in pure spring water. At this period
they are carefully examined, and those which are fully bleached are laid aside to be
blued, and made up for the market; while those which are not fully white are returned
to be boiled, and steeped in the chloride of lime or potash; then soured, until they are
fully white.
By the above process, 690 lbs. weight of alkali is taken to bleach 360 pieces of linen,
each piece consisting of 35 yards in length; so that the expenditure of alkali would be
somewhat less than 2 lbs. for each piece, were it not that some parts of the linens are
not fully whitened, as above noted. Two pounds of alkali may therefore be stated as the
average quantity employed for bleaching each piece of goods.
The method of bleaching linens in Ireland is similar to the foregoing; any alteration in
the process depending upon the judgment of the bleacher in increasing or diminishing the
quantity of alkali used. But it is common, at most bleach-fields, to steep the linens in the
chloride of lime or potash at an early stage of the process, or after the goods have undergone the fifth or sixth operation of bucking. By this means those parts of the flax which
are most difficult to bleach are more easily acted upon by the alkali; and, as before noticed,
souring early in very dilute sulphuric acid, assists greatly in forwarding the whitening of
the linens. Mr. Grimshaw, calico-printer, near Belfast, was the first who recommended
early souring, which has since been very generally adopted.
The bleaching of Silk.-Silk in its raw state, as spun by the worm, is either white or
yellow of various shades, and is covered with a varnish, which gives it stiffness and a
degree of elasticity. For the greater number of purposes to which silk is applied, it
must be deprived of this native covering, which was long considered to be a sort of gum.
The operation by which this coloring matter is removed is called scouring, cleansing,
or boiling. A great many different processes have been proposed for freeing the silk
fibres from all foreign impurities, and for giving it the utmost whiteness, lustre, and
pliancy; but none of the new plans has superseded, with any advantage, the one practised of old, which consists essentially in steeping the silk in a warm solution of soap; a
circumstance placed beyond all doubt by the interesting experiments of M. Roard.
The alkalis, or alkaline salts, act in a marked manner upon the varnish of silk, and effect
its complete solution; the prolonged agency of boiling water, alone answers the same
purpose; but nothing agrees so well with the nature of silk, and preserves its brilliancy
and suppleness so perfectly, as a rapid boil with soap-water. It would appear, however,
that the Chinese do not employ this method, but something that is preferable. Probably
the superior beauty of their white silk may be owing to the superiority of the raw material.
The most ancient method of scouring silk consists of three operations. For the first,
or the ungumming, thirty per cent. of soap is first of all dissolved in clean river water by
a boiling heat; then the temperature is lowered by the addition of a little cold water,
by withdrawing the fire, or at least by damping it. The hanks of silk, suspended
upon horizontal poles over the boiler, are now plunged into the soapy solution, kept at
a heat somewhat under ebullition, which is an essential point; for if hotter, the soap
would attack the substance of the silk, and not only dissolve a portion of it, but deprive
the whole of its lustre. The portions of the hanks plunged in the bath get scoured by
degrees; the varnish and the coloring matter come away, and the silk assumes its proper
whiteness and pliancy. Whenever this point is attained, the hanks are turned round upon
the poles, so that the portion formerly in the air may be also subjected to the bath. As
soon as the whole is completely ungummed, they are taken out, wrung by the peg, and
shaken out; after which, the next step, called the boil, is commenced. Into bags of coarse
canvass, called pockets, about 25 lbs. or 35 lbs. of ungummed silk are enclosed, and put
into a similar bath with the preceding, but with a smaller proportion of soap, which may
therefore be raised to the boiling point without any danger of destroying the silk. The
ebullition is to be kept up for an hour and a half, during which time the bags must be
frequently stirred, lest those near the bottom should suffer an undue degree of heat. The
silk experiences in these two operations a loss of about 25 per cent. of its weight.
The third and last scouring operation is intended to give the silk a slight tinge, which




BLEACHING.                                    199
renders the white more agreeable, and better adapted to its various uses in trade. In
this way we distinguish the China white, which has a faint cast of red, the silver white,
the azure white, and the thread white. To produce these different shades, we begin by
preparing a soap-water so strong as to lather by agitation; we then add to it, for the
China white, a little annotto, mixing it carefully in; and then passing the silk properly
through it, till it has acquired the wished for tint. As to the other shades, we need only
azure them more or less with a fine indigo, which has been previously washed several
times in hot water, and reduced to powder in a mortar. It is then diffused through
boiling water, allowed to settle for a few minutes, and the supernatant liquid, which
contains only the finer particles, is added to the soap bath in such proportion as may be
requisite. The silk, on being taken out of this bath, must be wrung well, and stretched
upon perches to dry; after which it is introduced into the sulphuring chamber, if it is
to be made use of in the white state. At Lyons, however, no soap is employed at the
third operation: after the boil, the silk is washed, sulphured, and azured, by passing
through very clear river water properly blued.
The silks intended for the manufacture of blonds and gauzes are not subjected to the
ordinary scouring process, because it is essential, in these cases, for them to preserve their
natural stiffness. We must therefore select the raw silk of China, or the whitest raw
silks of other countries; steep them, rinse them in a bath of pure water, or in one containing a little soap; wring them, expose them to the vapor of sulphur, and then pass
them through the azure water.  Sometimes this process is repeated.
Before the memoir of M. Roard appeared, extremely vague ideas were entertained
about the composition of the native varnish of silk. He has shown that this substance,
so far from being of a gummy nature, as had been believed, may be rather compared to
bees' wax, with a species of oil, and a coloring matter, which exists only in raw silks.
It is contained in them to the amount of from 23 to 24 per cent., and forms the portion
of weight which is lost in the ungumming.  It possesses, however, some of the properties
of vegetable gums, though it differs essentially as to others. In a dry mass, it is friable
and has a vitreous fracture; it is soluble in water, and affords a solution which lathers
like soap; but when thrown upon burning coals, it does not soften like gum, but burns
with the exhalation of a fetid odor. Its solution, when left exposed to the open air, at
first of a golden yellow, becomes soon greenish, and ere long putrefies, as a solution of
animal matter would do in similar circumstances. M. Roard assures us that the city of
Lyons alone could furnish several thousand quintals of this substance per annum, were it
applicable to any useful purpose.
The yellow varnish is of a resinous nature, altogether insoluble in water, very soluble
in alcohol, and contains a little volatile oil, which gives it a rank smell. The color of
this resin is easily dissipated, either by exposure to the sun or by the action of chlorine:
it forms about one fifty-fifth of its weight.
Bees' wax exists also in all the sorts of silk, even in that of China; but the whiter the
filaments, the less wax do they contain.
M. Roard has observed that, if the silk be exposed to the soap baths for some time after
it has been stripped of its foreign matters, it begins to lose body, and has its valuable
qualities impaired. It becomes dull, stiff, and colored in consequence of the solution
more or less considerable of its substance; a solution which takes place in all liquids,
and even in boiling water. It is for this reason that silks cannot be alumed with heat;
and that they lose some of their lustre in being dyed brown, a color which requires a
boiling hot bath. The best mode, therefore, of avoiding these inconveniences, is to boil
the silks in the soap-bath no longer than is absolutely necessary for the scouring process,
and to expose them in the various dyeing operations to as moderate temperature as may
be requisite to communicate the color.  When silks are to be dyed, much less soap
should be used in the cleansing, and very little for the dark colors. According to M.
Roard, raw silks, white or yellow, may be completely scoured in one hour, with 15 lbs.
of water for one of silk, and a suitable proportion of soap. The soap and the silk should
be put into the bath half an hour before its ebullition, and the latter should be turned
about frequently. The dull silks, in which the varnish has already undergone some alteration, never acquire a fine white until they are exposed to sulphureous acid gas. Exposure to light has also a very good effect in whitening silks, and is had recourse to, it is
said, with advantage by the Chinese.
Carbonate of soda has been proposed to be used instead of soap in scouring silk,
but it has never come into use.  The Abbe Collomb, in 1785, scoured silk by eight
hours' boiling in simple water, and he found the silks bleached in this way to be
stronger than by soap, but they are not nearly so white. A patent has been taken out
in England for bleaching them  by steam, of which an account will be found under the
article SILK.
It appears that the Chinese do not use soap in producing those fine white silks which
are imported into Europe. Michel de Grubbens, who resided long at Canton, saw and




200                               BLEACHING.
practised himself the operation there, which he published in the Memoirs of the
Academy of Stockholm  in 1803. It consists in preparing the silk with a species of
white beans, smaller than the Turkey beans, with some wheat flour, common salt, and
water. The proportions are 5 parts of beans, 5 of salt, 6 of flour, and 25 of water, to
form this vegetable bath. The beans must be previously washed. It is difficult to discover what chemical action can occur between that decoction and the varnish of raw
silk; possibly some acid may be developed, which may soften the gummy matter, and
facilitate its separation.
Baume contrived a process which does not appear to have received the sanction of
experience, but which may put us in the right way. He macerates the yellow raw silk
in a mixture of alcohol at 36~ (sp. gr. 0837) and one thirty-second part of pure muriatie
acid. At the end of forty-eight hours, it is as white as possible, and the more so, the
better the quality of the silk. The loss which it suffers in this menstruum is only one
fortieth; showing that nothing but the coloring matter is abstracted. The expense of
this menstruum is the great obstacle to Baume's process. The alcohol, however, might
be in a very great measure recovered, by saturating the acid with chalk, and redistillation.
Bleaching of Wool.-Wool, like the preceding fibrous matter, is covered with a peculiar varnish, which impairs its qualities, and prevents it from being employed in the
raw state for the purposes to which it is well adapted when it is scoured. The English
give the name yolk, and the French suint, to that native coat: it is a fatty unctuous matter, of a strong smell, which apparently has its chief origin in the cutaneous perspiration
of the sheep; but which, by the agency of external bodies, may have undergone some
changes which modify its constitution. It results from the experiments of M. Vauquelin, that the yolk is composed of several substances; namely, 1, a soap with basis of
potash, which constitutes the greater part of it; 2, of a notable quantity of acetate of
potash; 3, of a small quantity of carbonate, and a trace of muriate, of potash; 4, of a
little lime in an unknown state of combination; 5, of a species of sebaceous matter,
and an animal substance to which the odor is due. There are several other accidental
matters present on sheeps' wool.
The proportion of yolk is variable in different kinds of wool, but in general it is more
abundant the finer the staple; the loss by scouring being 45 per cent. for the finest wools,
and 35 per cent. for the coarse.
The yolk, on account of its soapy nature, dissolves readily in water, with the exception of a little free fatty matter, which easily separates from the filaments, and remains floating in the liquor. It would thence appear sufficient to expose the wools to
simple washing in a stream of water; yet experience shows that this method never answers so well as that usually adopted, which consists in steeping the wool for some time
in simple warm water, or in warm water mixed with a fourth of stale urine. From 15
to 20 minutes of contact are sufficient in this case, if we heat the bath as warm as the
hand can bear it, and stir it well with a rod. At the end of this time the wool may be
taken out, set to drain, then placed in large baskets, in order to be completely rinsed in
a stream of water.
It is generally supposed that putrid urine acts on the wool by the ammonia which it
contains, and that this serves to saponify the remainder of the fatty matter not combined
with the potash. M. Vauquelin is not of this opinion, because he found that wool steeped
in water, with sal ammoniac and quick lime, is not better scoured than an equal quantity
of wool treated with mere water. He was hence led to conclude that the good effects of
putrefied urine might be ascribed to anything else besides the ammonia, and probably to
the urea. Fresh urine contains a free acid, which, by decomposing the potash soap of
the yolk, counteracts the scouring operation.
If wools are better scoured in a small quantity of water than in a great stream, we
can conceive that this circumstance must depend upon the nature of the yolk, which, in
a concentrated solution, acts like a saponaceous compound, and thus contributes to remove the free fatty particles which adhere to the filaments. It should also be observed
that too long a continuance of the wool in the yolk water, hurts its quality very much,
by weakening its cohesion, causing the filaments to swell, and even to split. It is said
then to have lost its nerve. Another circumstance in the scouring of wool, that should
always be attended to, is never to work the filaments together to such a degree as to occasion their felting; but in agitating we must merely push them slowly round in the
vessel, or press them gently under the feet. Were it at all felted, it would neither card
nor spin well
As the heat of boiling water is apt to decompose woollen fibres, we should be careful
never to raise the temperature of the scouring bath to near this point, nor, in fact, to exceed 140~ F.  Some authors recommend the use of alkaline or soapy baths for scouring
wool, but practical people do not deviate from the method above described.
When the washing is completed, all the wool which is to be sent white into the mar



BLEACHING OF PAPER.                                201
ket, must be exposed to the action of sulphurous acid, either in a liquid' or a gaseous
state. In the latter case, sulphur is burned in a close chamber, in which the wools are
hung up or spread out; in the former, the wools are plunged into water, moderately
impregnated with the acid. (See SULPHURING.) Exposure on the grass may also contribute to the bleaching of wool. Some fraudulent dealers are accused of dipping wools
in butter-milk, or chalk and water, in order to whiten them and increase their weight.
Wool is sometimes whitened in the fleece, and sometimes in the state of yarn; the
latter affording the best means of operating. It has been observed that the wool cut
from certain parts of the sheep, especially from the groins, never bleaches well.
After sulphuring, the wool has a harsh crispy feel, which may be removed by a weak
soap bath. To this also the wool comber has recourse when he wishes to cleanse and
whiten his wools to the utmost. He generally uses a soft or potash soap, and after the
wool is well soaked in the warm soap bath, with gentle pressure he wrings it well with
the help of a hook, fixed at the end of his washing tub, and hangs it up to dry.
Bleaching of rags, and paste for paper making. - After the rags are reduced to what is
called half stuff, they should have the greater part of the floating water run off, leaving
just enough to form a stir-about mass. Into this a clear solution of chloride of lime
should be poured, of such a strength as is suited to the color of the rags, which should
have been previously sorted; and the engine is kept going so as to churn the rags
with the bleaching agent. After an hour, the water may be returned upon the engine,
and the washing of the paper resumed. From two to four pounds of good chloride of
lime are reckoned sufficient to bleach one hundred weight of rags.
When the rags consist of dyed or printed cottons, after being well washed and reduced to half stuff, they should be put into a large cask or butt, supported horizontally
by iron axles upon cradle bearings, so that it may be made to revolve like a barrelchurn. For each hundred weight of the colored rags, take a solution containing from
four to eight pounds of chloride of lime; add it to the liquid mixture in the butt along
with half a pound of sulphuric acid for every pound of the chloride; and after inserting
the bung, or rather the square valve, set the vessel in slow revolution backwards and forwards. In a short time the rags will be colorless. The rags and paper paste ought
to be very well washed, to expel all the chlorine, and perhaps a little muriatic acid
might be used with advantage to dissolve out all the calcareous matter, a portion of
which is apt to remain in the paper, and to operate injuriously upon both the pens and
the ink. Some of the French paper manufacturers bleach the paste with chlorine gas.
Paper prepared from such paste, well washed, is not apt to give a brown tint to maps, as
that carelessly bleached with chloride of lime is known to do.
BLEACHING OF PAPER. The following are the proportions of liquid chloride of
lime, at 10~ of Gay Lussac's Chlorometre, employed for the different sorts of rags, consisting of two piles, or 200 pounds French.
Cotton.                                                          litres.
No. 1. Fine cotton rags    --                    -             -10
2. Clean calicoes      -      -       -      -      -      -12
3.                                           -      -      -  14
4. White dirty calico, coarse cotton   -     -      -      -16
5. Coarse cotton              -       -      -      -      -18
6. Grey, No.-          -      -       -      -      -      -  20
No. 2-         -       -      -      -             - 22
Saxon gray  -      -      -.-24
-No. 2   -       -      -       -      -      - 26
Pale white and half-white shades  -      -      -         28
Saxon blues; pale pink, dark blue, velvet -     -      -32
It is considered to be much better to bleach the fine rags with liquid chloride of lime,
and not with chlorine gas, because they are less injured by the former, and afford a
paper of more nerve, less apt to break, and more easily sized. But the coarse or gray
rags are much more economically bleached with the gaseous chlorine, without any risk
of weakening the fibre too much. Bleaching by the gas is performed always upon the
sorted rags, which have been boiled in an alkaline ley, and torn into the fibrous state.
They are subjected to the press, in order to form them into damp cakes, which are broken in pieces and placed in large rectangular wooden cisterns. The chlorine gas is introduced by tabes in tile lid of the cistern, which falls down by its superior gravity,
acting always more strongly upon the rags at the bottom than those above.
When the chlorine, disengaged from 150 kilogrammes (330 lbs.) of manganese and
500 kilos. of muriatic acid, is made to act upon 2,500 kilos. of the stuff (supposed dry),
it will have completed its effect in the course of a few hours. The quantity of gaseous
chlorine is equal to what is contained in the quantity of chloride of lime requisite to produce a like bleaching result. The bleached stuff should be forthwith carefully washed,




202                        BLOCK MANUFACTURE.
to remove all the muriatic acid produced from the chlorine; for if any of this remain
in the paper, it destroys lithographic stones and weakens common ink.
BLENDE. (Fr. and Germ.) Sulphuret of zinc, so named from the German blenden,
to dazzle, on account of its glistening aspect. It is called black jack from its usual
color. Its lustre is pearly adamantine. Spec. gravity from 3'7 to 4-2. It contains
frequently iron, copper, arsenic, cadmium and silver, all associated with sulphur.  It is
worked up partly into metallic zinc, and partly into the sulphate of zinc, or white
vitriol. It consists of 66'72 zinc, and 83328 sulphur; being nearly by weight as two
to one. See ZINC.
BLOCK MANUFACTURE. Though the making of ships' blocks belongs rather
to a dictionary of engineering than of manufactures, it may be expected that I should
give some account of the automatic machinery for making blocks, so admirably devised
and mounted by M. I. Brunel Esq., for the British navy, in the dockyard of Portsmouth.
The series of machines and operations are as follows:1. The straight cross cutting saw.-The log is plated horizontally on a very low
bench, which is continued through the window of the mill into the yard. The saw is
exactly over the place where the log is to be divided. It is let down, and suffered to rest
with its teeth upon the log, the back still being in the cleft of the guide. The crank
being set in motion, the saw reciprocates backwards and forwards with exactly the same
motion as if worked by a carpenter, and quickly cuts through the tree.  When it first
begins to cut, its back is in the cleft in the guide, and this causes it to move in a straight
line; but before it gets out of the guide, it is so deep in the wood as to guide itself; for
in cutting across the grain of the wood, it has no tendency to be diverted from its true
line by the irregular grain.  When the saw has descended through the tree, its handle
is caught in a fixed stop, to prevent its cutting the bench. The machine is thrown
out of gear, the attendant lifts up the saw by a rope, removes the block cut off, and
advances the tree to receive a fresh cut.
2. ITe circular cross cutting saw.-This saw possesses universal motion; but the axis
is always parallel to itself, and the saw in the same plane. It can be readily raised or
lowered, by inclining the upper frame on its axis; and to move it sidewise, the saw
frame must swing sidewise on its joints, which connect it with the upper frame. These
movements are effected by two winches, each furnished with a pair of equal pinions,
working a pair of racks fixed upon two long poles. The spindles of these winches are
fixed in two vertical posts, which support the axis of the upper frame. One of these pairs
of poles isjointed to the extreme end of the upper frame; therefore by turning the handle belonging to them, the frame and saw is elevated or depressed; in like manner, the
other pair is attached to the lower part of the saw frame, so that the saw can be moved
sidewise by means of their handles, which then swing the saw from its vertical position.
These two handles give the attendant a complete command of the saw, which we
suppose to be in rapid motion, the tree being brought forward and properly fixed. By
oue handle, he draws the saw against one side of the tree, which is thus cut into (perhaps half through); now, by the other handle, he raises the saw up, and by the firstmentioned handle he draws it across the top of the tree, and cuts it half through from
the upper side; he then depresses the saw and cuts half through from the next side 
and lastly a trifling cut of the saw, at the lower side, completely divides the tree,
which is then advanced to take another cut.
The great reciprocating saw is on the same principle as the saw mill in common use
in America.
3. The circular ripping saw is a thin circular plate of steel, with teeth similar to those
of a pit saw, formed in its periphery.  It is fixed to a spindle placed horizontally, at a
small distance beneath the surface of abench or table, so that the saw projects through
a crevice a few inches above the bench. The spindle being supported in proper collars,
has a rapid rotatory motion communicated to it by a pulley on the opposite end, round
which an endless strap is passed from a drum placed overhead in the mill. The block
cut by the preceding machine from the end of the tree, is placed with one of the sides
flat upon the bench, and thus slides forward against the revolving saw which cuts the
wood with a rapidity incredible to any one who has not seen these or similar machines.
4. Boring machine.-The blocks, prepared by the foregoing saws, are placed in the
machine represented infig. 144. This machine has an iron frame, A A, with three legs,
beneath which the block is introduced, and the screw near B being forced down upon it,
confines it precisely in the proper spot to receive the borers D and. This spot is determined by a piece of metal fixed perpendicularlyjust beneath the point of the borer E,
shown separately on the ground at x; this piece of metal adjusts the position for the
borer D, and its height is regulated by resting on the head of the screw x. which fastens
the piece x down to the frame. The sides of the block are kept in a parallel position, by
being applied against the heads of three screws tapped into the double leg of the frame
A. The borer D is adapted to bore the hole for the centre pin in a direction exactly per



BLOCK MANUFACTURE.                                   203
144                                                           145
LL                                            L
pendicular to the surface resting against the three screws; the other, at E, perforates the
holes for the commencement of the sheave holes. Both borers are constructed in nearly
the same manner; they are screwed upon the ends of small mandrels, mounted in frames
similar to a lathe. These frames, G and H, are fitted with sliders upon the angular edges
of the flat broad bars, I and K. The former of these is screwed fast to the frame; the
latter is fixed upon a frame of its own, moving on the centre screws, at L L, beneath the
principal frame of the machine. By this means the borer E can be moved within certain
limits, so as to bore holes in different positions. These limits are determined by two
screws, one of which is seen at a; the other, being on the opposite side, is invisible. They
are tapped through fixed pieces projecting up from the frame. A projecting piece of
metal, from the under side of the slider K of the borer E, stops against the ends of these
screws, to limit the excursion of the borer. The frames for both borers are brought up
towards the block by means of levers M and N. These are centred on a pin, at the opposite sides of the frame of:he machine, and have oblong grooves through them, which
receive screw pins, fixed into the frames G and H, beneath the pulleys P P, which give
motion to the spindles.
5. The mortising machine is a beautiful piece of mechanism, but too complicated for
description within the limits prescribed to this article.
6. The corner saw, fig. 145, consists of a mandrel, mounted in a frame A, and carrying a circular saw L upon the extreme end of it. This mandrel and its frame being
exactly similar to those at G and H, fig. 144, does not require a separate view, although
it is hid behind the saw, except the end of the screw, marked A. This frame is screwed
down upon the frame B B of the machine, which is supported upon four columns.  c c,
D D, is an inclined bench, or a kind of trough, in which a block is laid, as at E, being
supported on its edge by the plane c c of this bench, and its end kept up to its position
by the other part of the bench D D.
By sliding the block along this bench, it is applied to the saw, which cuts off its
angles, as is evident from the figure, and prepares it for the shaping engine. All the
four angles are cut off in succession, by applying its different sides to the trough, or
bench.  In the figure, two of them are drawn as being cut, and the third is just marked
by the saw. This machine is readily adapted to different sizes of blocks, by the simple
expedient of laying pieces of wood of different thickness against the plane D D, so as to




204                     BLOCK MANUFACTURE.
fill it up, and keep the block nearer to or farther from the saw; for all the blocks are
required to be cut at the same angle, though, of course, a larger piece is to be cut
from large than from small blocks. The
4c6l,_i~~ Iblock reduced to the state of E is now
taken to
II1G      X Q      7. The shaping machine.-A  great
deal of the apparent complication of this
*F1Z~ (:;r 1ViB             4  figure arises from the iron cage, which
is provided to defend the workmen, lest
the blocks, which are revolving in the
I  circles, or chuck, with  an  immense
16 r   L      f^  ^^   l   lh        velocity, should be loosened by the action of the tool, and fly out by their
J   a  o II Xcentrifugal force. Without this provision, the consequences of such an accident would be dreadful, as the blocks
would be projected in all directions, with
i~  - %   L \ Jr m  ^ /       an inconceivable force.
~' ca t^            ^'8. The scoring engine receives two
blocks, as they come from the shaping
l"" 1engine, and forms the groove round
M                     their longest diameters for the reception
of their ropes or straps, as represented
in the two snatch blocks and double
block, under figs. 144, 145.
A B,  fig. 146, represent the above
two blocks, each held between two smaP
pillars a (the other pillar is hid behind
^^V^ l^J^  lthe block), fixed in a strong plate D, and
pressed against the pillars by a screw b,
which acts on a clamp d. Over the
blocks a pair of circular planes or cutters, E E, are situated, both being fixed on the same spindle, which is turned by a pulley
in the middle of it.  The spindle is fitted in a frame F F, moving in centres at e e, so
as to rise and fall when moved by a handler. This brings the cutters down upon the
blocks; and the depth to which they can cut is regulated by a curved shape g, fixed by
screws upon the plate D, between the blocks. Upon this rests a curved piece of metal
h, fixed to the frame F, and enclosing, but not touching, the pulley. To admit the cutters to traverse the whole length of the blocks, the plate D (or rather a frame beneath
it) is sustained between the points of two centres. Screws are seen at I, on these centres. The frame inclines when the handle L is depressed. At M is a lever, with a weight
at the end of it, counterbalancing the weight of the blocks, and plate D, all which are
above the centre on which they move. The frame F is also provided with a counterpoise
to balance the cutters, &c. The cutters E E are circular wheels of brass, with round
edges. Each has two notches in its circumference, at opposite sides; and in these notches
chisels are fixed by screws, to project beyond the rim of the wheel, in the manner of a
plane iron before its face.
This machine is used as follows:-In order to fix the block, it is pressed between
the two pins (only one of which at a, can be seen in this view), and the clamp d, screwed
up against it, so as just to hold the block, but no more. The clamp has two claws,
as is seen in the figure, each furnished with a ring entering the double prints previously
made, in the end of the block.  These rings are partly cut away, leaving only
such a segment of each as will just retain the block, and the metal between them is
taken out to admit the cutter to operate between them, or nearly so. In putting the
blocks into this machine, the workman applies the double prints to the ends of the
claws of the clamps, but takes care that the blocks are higher between the pins a than
they should be: he then takes the handle f, and by it presses the cutters E E (which
we suppose are standing still) down upon the blocks, depressing them between their
pins at the same time, till the descent of the cutters is stopped by the piece h resting
on the shape g. He now turns the screws b b, to fix the blocks tight. The cutters
being put in motion cut the scores, which will be plainly seen by the mode of adjustment just described, to be of no depth at the pin-hole; but by depressing the handle L,
so as to incline the blocks, and keeping the cutters down upon their shape g, by the
handle f, they will cut any depth towards the ends of the blocks, which the shape g
admits.
By this means one quarter of the score is formed; the other is done by turning both
blocks together half round in this manner. The centres I are not fitted into the plate D




BLOCK MANUFACTURE.                                  205
itself, but into a frame seen at R beneath the plate, which is connected with it by a
centre pin, exactly midway between the two blocks A B. A spring catch, the end of
which is seen at r, confines them together; when this catch is pressed back, the plate D
can be turned about upon its centre pin, so as to change the blocks, end for end, and
bring the unscored quarters (i. e. over the clamps) beneath the cutters; the workman
taking the handles f and L, one in each hand, and pressing them down, cuts out the
second quarter. This might have been effected by simply lifting up the handle L; but
in that case the cutter would have struck against the grain of the wood, so as to cut
rather roughly; but by this ingenious device of reversing the blocks, it always cuts
clean and smooth, in the direction of the grain. The third and fourth quarters of the
score are cut by turning the other sides of the blocks upwards, and repeating the above
operation. The shape g can be removed, and another put in its place, for different sizes
and curves of block; but the same pins a, and holding clamps d, will suit many different
sizes.
By these machines the shells of the blocks are completely formed, and they are next
polished and finished by hand labor; but as this is performed by tools and methods which
are well known, it is needless to enter into any explanation: the finishing required being
only a smoothing of the surfaces. The machines cut so perfectly true as to require no
wood to be removed in the finishing; but as they cut without regard to the irregularity
of the grain, knots, &c., it happens that many parts are not so smooth as might be wish.
ed, and for this purpose manual labor alone can be employed.
The lignum vitee for the sheaves of the blocks, is cut across the grain of the woo(. by
two cross-cutting saws, a circular and straight saw, as before mentioned. These ma.
chines do not essentially differ in their principle from the great cross-cutting saws we
have described, except that the wood revolves while it is cutting, so that a small saw will
reach the centre of a large tree, and at the same time cut it truly flat. The limits prescribed for our plates will not admit of giving drawings of these machines, and the idea
which could be derived from a verbal description would not be materially different from
the cross-cutting saws before mentioned. These machines cut off their plates for the end
of the tree, which are exactly the thickness for the intended sheave. These pieces are
of an irregular figure, and must be rounded and centred in the crown saw.
9. The crown saw is represented in fig. 147, where A is a pulley revolving by
means of an endless strap. It has the crown or trepan saw a fixed to it, by a screw cut
within the piece, upon which the saw is fixed, and which gives the ring or hoop of the
saw sufficient stability to perform its office. Both the pulleys and saw revolve together
upon a truly cylindrical tube b, which is stationary, being attached by a flaunch c to a.F   _       fixed puppet B, and on this tube as an axis
A-     3           i  the saw and pulley turn, and may be slid
\    _iendwise by a collar fitted round the centreT  cL\  I) )     Ppiece of the pulley, and having two iron
^Df sX \ r1rods (only one of which can be seen at d
in the figure), passing through holes made
through the flaunch and puppet B. When
the saw is drawn back upon its central tube,
the end of the latter projects beyond the
teeth of the saw. It is by means of this fixed
h_^  C-"""""""^~~ I _ring or tube within the saw, that the piece
of wood e is supported during the operation
of sawing, being pressed forcibly against it
by a screw D, acting through a puppet fixed
147   to the frame of the machine. At the end of
this screw is a cup or basin which applies
itself to the piece of wood, so as to form a
kind of vice, one side being the end of the
fixed tube, the other the cup at the end of
the screw D. Within the tube b is a collar
for supporting a central axis, which is perfectly cylindrical. The other end of this axis,
(seen at f,) turns in a collar of the fixed puppet E. The central axis has a pulley r,
fixed on it, and giving it motion by a strap similar to the other. Close to the latter
pulley a collar g is fitted on the centre piece of the pulley, so as to slip round freely,
but at the same time confined to move endways with the pulley and its collar. This collar receives the ends of the two iron rods d. The opposite ends of these rods are, as
above mentioned, connected by a similar collar, with the pulley A of the saw a. By this
connexion, both the centre bit, which is screwed into the end of the central axis f, and
the saw sliding upon the fixed tube b, are brought forward to the wood at the same time,
both being in rapid motion by their respective pulleys.
10. The Coaking Engine.-This ingenious piece of machinery is used to cut the three




206                                 BLUE DYES.
semicircular holes which surround the hole bored by the crown saw, so as to produce a
cavity in the centre of the disc.
11. Face-turning Lathe.-The sheave is fixed against a flat chuck at the end of a
mandrel, by a universal chuck, similar to that in the coaking engine, except that the
centre pin, instead of having a nut, is tapped into the flat chuck, and turned by a screwdriver.
BLOOD.  (Sang, Fr.; Blut, Germ.)  The liquid which circulates in the arteries and
veins of animals; bright red in the former and purple in the latter, among all the tribes
whose temperature is considerably higher than that of the atmosphere. It consists, 1. of
a colorless transparent solution of several substances in water; and, 2. of red, undissolved
particles diffused through that solution. Its specific gravity varies with the nature and
health of the animal; being from 1'0527 to 1-0570 at 60~ F. It has a saline sub-nauseous
taste, and a smell peculiar to each animal. When fresh drawn from the vessels, it rapidly
coagulates into a gelatinous mass, called the clot, cruor, or crassamentum, from which,
after some time, a pale yellow fluid, passing into yellowish green, oozes forth, called the
serum.  If the warm blood be stirred with a bundle of twigs, as it flows from the veins,
the fibrine concretes, and forms long fibres and knots, while it retains its usual appearance in other respects. The clot contains fibrine and coloring matter in various proportions. Berzelius found in 100 parts of the dried clot of blood, 35 parts of fibrine;
58 of coloring matter; 1'3 of carbonate of soda; 4 of an animal matter soluble in water,
along with some salts and fat. The specific gravity of the serum varies from 1'027 to
1*029. It forms about three fourths of the weight of the blood, has an alkaline reaction,
coagulates at 167~ F. into a gelatinous mass, and has for its leading constituent albumen
to the amount of 8 per cent., besides fat, potash, soda, and salts of these bases. Blood
does not seem to contain any gelatine.
The red coloring matter called hematine, may be obtained from the cruor by washing
with cold water and filtering.
Blood was at one time largely employed for clarifying sirup, but it is very sparingly
used by the sugar refiners in Great Britain of the present day. It may be dried by evaporation at a heat of 130~ or 140~, and in this state has been transported to the colonies for
purifying cane juice. It is an ingredient in certain adhesive cements, coarse pigments for
protecting walls from the weather, for making animal charcoal in the Prussian blue works,
and by an after process, a decoloring carbon. It is used in some Turkey red dye-works.
Blood is a powerful manure.
BLOWING MACHINE.  See IRON, METALLURGY, VENTILATION.
BLOWPIPE.  (Chalumeau, Fr.; Lothrohre, Germ.)  Jewellers, mineialogists, chemists, enamellers, &c., make frequent use of a tube, usually bent near the end, terminated
with a finely pointed nozzle, for blowing through the flame of a lamp, candle, or gas-jet,
and producing thereby a small conical flame possessing a very intense heat. Modifications of blow pipes are made with jets of hydrogen, oxygen, or the two gases mixed in
due proportions.
BLUE DYES.  (Teint, Germ. See ENAMEL.)  The materials employed for this purpose are indigo, Prussian blue, logwood, bilberry, (vaccinium myrtillus,) elder berries,
(sambucus nigra,) mulberries, privet berries, (ligustrum vulgare,) and some other berries
whose juice becomes blue by the addition of a small portion of alkali, or of the salts of
copper. For dyeing with the first three articles, see them in their alphabetical places. I
shall here describe the other or minor blue dyes.
To dye blue with such berries as the above, we boil one pound of them in water, adding one ounce of alum, of copperas, and of blue vitriol, to the decoction, or in their stead
equal parts of verdigris and tartar, and pass the stuffs a sufficient time through the liquor.
When an iron mordant alone is employed, a steel blue tint is obtained; and when a tin
one, a blue with a violet cast. The privet berries which have been employed as sap
colors by the card painters, may be extensively used in the dyeing of silk. The berries
of th e African night-shade (solanum guineense) have been of late years considerably applied to silk on the continent in producing various shades of blue, violet, red, brown, &c.,
but particularly violet. With alkalis and acids these berries have the same habitudes as
bilberries; the former turning them green, the latter red. They usually come from
Italy compressed in a dry cake, and are infused in hot water. The infusion is merely
filtered, and then employed without any mordant, for dyeing silk, being kept at a warm
temperature by surrounding the bath vessel with hot water. The goods must be winced
for six hours through it in order to be saturated with color; then they are to be rinsed
in running water and dried. One pound of silk requires a pound and a half of the berry,
cake.  In the residuary bath, other tints of blue may be given. Sometimes the dyed
silk is finished by running it through a weak alum water. A color approaching to indigo in permanence, but which differs from it in being soluble in alkalis, though incapable of similar disoxydizement, is the gardenia genipa and aculeata of South America,
whose colorless juice becomes dark blue with contact of air; and dyes stuffs, the skin,




BOILERS.                                   207
and nails of an unchangeable deep blue color, but the juice must be applied in the colorless state. See INDIGO and PRUSSIAN BLUE.
BLUE PIGMENTS.  Several metallic compounds possess a blue color; especially
those of iron, cobalt, and molybdenum. The metallic pigments, little if at all employed,
but which may be found useful in particular cases, are the molybdate of mercury, the
hydro-sulphuret of tungsten, the prussiate of tungsten, the molybdate of tin, the oxide of
copper darkened with ammonia, the silicate of copper, and a fine violet color formed
from manganese and molybdenum. The blues of vegetable origin, in common use, are indigo, litmus, and blue cakes. The blue pigments of a metallic nature found in commerce are the following; Prussian blue; mountain blue, a carbonate of copper mixed with
more or less earthy matter; Bremen blue or verditer, a greenish blue color obtained
from copper mixed with chalk or lime; iron blue, phosphate of iron, little employed;
cobalt blue, a color obtained by calcining a salt of cobalt with alumina or oxide of tin;
smalt, a glass colored with cobalt and ground to a fine powder; charcoal blue, a deep
shade obtained by triturating carbonized vine stalks with an equal weight of potash in
a crucible till the mixture ceases to swell, then pouring it upon a slab, putting it into
water, and saturating the alkali with sulphuric acid. The liquor becomes blue, and
lets fall a dark blue precipitate, which becomes of a brilliant blue color when heated.
Molybdenum blue is a combination of this metal, and oxide of tin, or phosphate of
lime. It is employed both as a paint, and an enamel color. A blue may also be obtained by putting into molybdic acid (made by digesting sulphuret of molybdenum
with nitric acid) some filings of tin and a little muriatic acid. The tin deoxidizes
the molybdic acid to a certain degree, and converts it into the molybdous, which,
when evaporated and heated with alumina recently precipitated, forms this blue pigment.  Ultramarine is a beautiful blue pigment, which see.
BLUE.  Turnbull's and Chinese are both double cyanides of iron.
BLUE VITRIOL; sulphate of copper.
BOILERS (construction of).-The modifications of the steam  engine which have
been adopted since its introduction by Watt, three quarters of a century ago, have been
very numerous and varied; and although the progression in its applications and improvements has been most rapid and wonderful, we are still undecided as to the best form of
its construction. Sound principles scientifically applied, and the gradually increasing excellence of our mechanical workshops, have enabled us to attain the great perfection
which characterizes the working parts of the modern steam engine. The steam engine
itself may be regarded as a comparatively perfect machine, and therefore we shall confine
our observations almost exclusively to that very important and necessary adjunct-the
Boiler-which is the source of its power.  With this limitation, a very wide field of inquiry is opened out, and in the earliest steps of the investigation we become perplexed
with the endless variety of forms and constructions which at different periods have been
adopted by engineers, and which have never, unfortunately, received the same judicious
attention that was paid, as I have already remarked, to the steam engine. This is an anomalous and much to be regretted fact, for the boiler, being the source of the motive power, is undoubtedly one of the most important parts of the whole machine. Upon its
proper proportions and arrangements for the generation of steam, depend the economy
and regularity with which the engine can be worked, and upon its strength and excellence of workmanship depends the safety of the lives and property of those who come in
contact with it.  Regarding the steam engine as one of the most active agents in the
extension of our prosperity, and in the civilization of the world, and seeing how it is
mixed up with the daily duties and working of society, the safety and efficiency of
every part, and more especially the boiler, are subjects of national importance; and
it is of great consequence to introduce here such knowledge and experience on this
subject of deep interest as has been offered by William Fairbairn, Esq.
"The boiler may be considered in its construction, management, security, and economy.  1st. As to the construction.  Here I shall have to go a little into detail, in
order to show, in construction, the absolute necessity there exists for adhering to form
and other considerations essential in the practice of mechanical engineers, so as to
effect the maximum of strength, with the minimum of material. In boilers this is the
more important, as any increase in the thickness of the plates obstructs the transmission of heat, and exposes the rivets as well as the plates to injury on the side exposed
to the action of the furnace.
"It has generally been supposed that the rolling of boiler plate iron gives to the
sheets greater tenacity in the direction of their length than in that of their breadth;
this is, however, not correct; as a series of experiments which Mr. Fairbairn made
some years since fully proves that there is no difference in the tensile strength of
boiler plates whether torn asunder in the direction of the fibre, or across it.  From
five different sorts of iron the following results were obtained:



208                                 BOILERS.
Mean Breaking weight    Mean Breaking weight
Description of Iron.         in tons, in the direc-   in tons across the
tion of the fibre.          fibre.
Yorkshire plates      -    -    - 25-77  -    - -           2749
Yorkshire plates      -    -    - 2276  -    -    -         26'37
Derbyshire plates     -    -    - 21-68  -    -    -        1865
Shropshire plates     -    -    - 22-82  -    -    -        2200
Staffordshire plates   -    -    - 1956  -    -    -        2101
Mean                                  5 -     - 2    -      23-10
"From this it appears that we may safely use iron plates in the construction of
boilers, in whatever direction may best suit the convenience of the maker.  Next to
the tenacity of the plates comes the question of riveting, or the best and surest means
of securing them together.  On this part of the subject we have been widely astray,
and it requires some skill, and no inconsiderable attention, in conducting the experiments, to convince the unreflecting portion of the public, and even some of our boiler
makers, that the riveted joints were not stronger than the plate itself. At first sight
this would appear the case, but a moment's reflection will soon convince us to the
contrary, as, in punching holes along the edge of a plate, it is obvious that the plate
must be weakened to the extent of the sectional areas punched out, and that it is
next to impossible, under the circumstances, to retain the same strength in the material after such diminution has been effected, as existed in the previously solid plate.
This was clearly demonstrated by a series of experiments, which took place some
years since, and in which the strength of almost every description of riveted joints
was determined by tearing them directly asunder. The results obtained from these
experiments were conclusive, as regards the relative strength of riveted joints and the
solid plates. In two different kinds of joints-double and single riveted-the strength
was found to be, in the ratio of the plate, as the numbers 100, 70 and 56.
"Assuming the strength of the plate to be      -         -              100
The strength of a double riveted joint would be, after allowing for
the adhesion of the surfaces of the plate    -  -    -     -          70
And the strength of a single riveted joint   -    -    -    -           56
"These proportions of the relative strengths of plates and joints may, therefore, in
practice be safely taken as the standard value, in the construction of vessels required
to be steam and water tight, and subjected to pressure varying from 10 lbs to 100 lbs.
on the square inch.
"In the construction of boilers, exposed to severe internal pressure, it is desirable to
establish such forms, and so to dispose the material as to apply the greatest strength in
the direction of the greatest strain; and in order to accomplish this, it will be necessary
to consider whether the same arrangement be required for all diameters, or whether the
form as well as the disposition of the plates should not be changed. To determine
these questions in cylindrical boilers, recourse must be had to experiment, or such deduction as may apply to any given case, and such as is founded upon unerring data,
derived from experimental research. On this head I am fortunate in having before
me the calculations of Professor W. R. Johnson, of the Franklin Institute of America,
whose inquiries into the strength of cylindrical boilers are of great value, and from
which the following short abstract may be useful.
" 1st. To know the force which tends to burst a cylindrical vessel in the longitudinal direction, or, in other words, to separate the head from the curved sides, we have
only to consider the actual area of the head, and to multiply the units of surface by
the number of units of force applied to each superficial unit. This will give the total
divellent force in that direction.
"To counteract this, we have, or may be conceived to have, the tenacity of as
many longitudinal bars as there are lineal units in the circumference of the cylinder.
The united strength of these bars constitutes the total retaining or quiescent force,
and at the moment when rupture is about to take place the divellent and the quiescent forces must obviously be equal.
" 2d. To ascertain the amount of force which tends to rupture the cylinder along the
curved side, or rather along the opposite sides, we may regard the pressure as applied,
through the whole breadth of the cylinder, upon each lineal unit of the diameter.
Hence the total amount of force which would tend to divide the cylinder in halves, by
separating it along two lines, on opposite sides, would be represented by multiplying
the diameter by the force exerted on each unit of surface, and this product by the length
of the cylinder. But even without regarding the length, we may consider the force
requisite to rupture a single band in the direction now supposed, and of one lineal unit




BOILERS.                                  209
in breadth; since it obviously makes no difference whether the cylinder be long or
short, in respect to the ease or difficulty of separating the sides. The divellent force in
this direction is, therefore, truly represented by the diameter multiplied by the pressure per unit of surface. The retaining or quiescent force, in the same direction, is
only the strength or tenacity of the two opposite sides of the supposed bond. Here
also, at the moment when a rupture is about to occur, the divellent force must exactly
equal the quiescent force.
" Mr. Johnson then goes on to show that, as the diameter is increased, the product
of the diameter, and the force or pressure per unit of surface, are increased in the same
ratio. This truth I shall endeavor to prove; as, also, that, as the diameter of any
cylindrical vessel is increased, the thickness of the metal must also be increased in the
exact ratio of the increase of the diameter: the pressure, or as Mr. Johnson calls it, the
divellent force, being the same when the diameter of a boiler is increased, it must be
borne in mind that the area of the ends is also increased, not in the ratio of the diameter
but in the ratio of the square of the diameter: and it will be seen that instead of the
force being doubled, as is the case in the direction of the diameter and circumference,
it is quadrupled upon the ends, or, what is the same thing, a cylinder double the diameter of another cylinder has to sustain four times the pressure in the' longitudinal
direction.  The retaining force of the thickness of the metal of a cylindrical boiler does
not, however, increase in the same ratio as the area of the circle, but simply in the
ratio of the diameter; consequently, the thickness of the metal will require to be increased in the same ratio as the diameter is increased.  From this it appears, that the
tendency to rupture by blowing out the ends of a cylindrical boiler will not be greater
in this direction than it is in any other direction; we may therefore safely conclude,
since we have seen that the tendency to rupture increases in both directions in the
ratio of the diameter, that any deviation from that law, as regards the thickness of
the plates, would not increase the strength of the boiler.
" I have been led to these inquiries from the circumstance that Mr. Johnson appears
to reason on the supposition that there are no joints in the plates, and that the tenacity of the iron is equal to 60,000 lbs.-rather more than 26 tons to the square inch.
Now, we have shown by the results of the experiments already adduced, that ordinary
boiler plates will not bear more than 23 tons to the square inch; and, as nearly one
third of the material is punched out for the reception of the rivets, we must still
further reduce the strength, and take 15 tons or about 34,000 lbs.* on the square inch
as the tenacity of the material or the pressure at which a boiler would burst.
"This I should consider in practice as the maximum power of resistance of boiler
plates in their riveted state, and I will now endeavor to show you in a very concise,
and I trust not uninteresting investigation, the bearing power of boilers, and the
pressure at which they can be worked with safety. It has been stated that the strength
of cylindrical boilers, when taken in the direction of their circumference, is in the ratio
of their diameters, and when taken in the direction of the ends, as the squares of the
diameters,-a proposition which it will not be difficult to demonstrate, as applicable to every description of boiler of the cylindrical form. It will be seen, however, that
the strain is not exactly the same in every direction, and that there is actually less
upon the material in the longitudinal direction than there is upon the circumference.
For example, let us take two boilers, one three feet diameter and the other six feet, and
suppose each to be subject to a pressure of 40lbs. on the square inch.  In this condition, it is evident that the area or number of square inches in the end of a three-feet
boiler is, to that of the area of the six-feet boiler, as 1 to 4; and, by a common process
of arithmetic, it will be found that the edges of the plates forming the cylindrical part
of the three-feet boiler are subject (at 40 lbs. on the square inch) to a pressure of
40,7121 bs., upwards of 18 tons: whereas the plates of the six-feet boiler have to sustain a pressure of 162,848 lbs., or 72 tons, which is quadruple the force to which the
boiler only one half the diameter is exposed; and the circumference being only as 2'
to 1, there is necessarily double the strain upon the cylindrical plates of the large boiler;.
Now this is not the case with the other parts of the boiler, as the circumference of a,
cylinder increases only in the ratio of the diameter; consequently, the pressure, inr
stead of being increased in the ratio of the square of the diameter, as shown in the
ends, is only doubled, the circumference of the six-feet boiler being twice that of the
three-feet boiler.
"Let us for the sake of illustration, suppose the two cylindrical boilers, such as-we
have described, to be divided into a series of hoops of one inch in width; and, taking
one of these hoops in the three-feet boiler, we shall find it exposed, at a pressure of 40 lbs.
on the square inch, to a force of 1,440 lbs., acting on each side of a line drawn through
* By experiment it is found that the strength of the riveted joints of boilers is only about one-half the
strength of the plate itself; but taking into consideration the crossing of the joints, 34,000 lbs. may reasoaably be taken as the tenacity of the riveted plates, or the bursting pressure of a cylindrical boiler.
VOL. 1.




210                                 BOILERS.
the axis of a cylinder 36 inches diameter and 1 inch in depth, and which line forms the
diameter of the circle.  Now, this force causes a strain upon the points a a in the
148  a        direction of the arrows in the annexed diagram of the three-feet circle,
of 720 lbs., and, assuming the pressure to be increased till the force becomes equal to the tenacity or retaining powers of the iron at a a, it
i,     is evident, in this state of the equilibrium of the two forces, that the
least preponderance on the side of the internal pressure would insure
fracture.  And suppose we take the plates of which the boiler is
composed at one quarter of an inch thick, and the ultimate strength at
a       34,000 lbs. on the square inch, we shall have 84-0'    472 per square
inch, as the bursting pressure of the boiler. Again, as the forces in this direction
are not as the squares, but simply as the diameters, it is clear that at 40 lbs. on the
square inch we have in a hoop an inch in depth, or that portion of a cylinder whose
diameter is six feet, exactly double the force applied to the points b b, which was acting
149                       on the points a a, in the diameter of three feet.  Now, asb             suming the plates to be a qmuarter of an inch thick, as in the
three-feet boiler, it follows, if the forces at the same pressure
/^       ^\      h~be doubled in the large cylinder, that the thickness of the
~/ \~ ~           plates must also be doubled in order to sustain the same
/                     \  pressure with equal security; or what is the same thing,'      o f. >           the six-feet boiler must be worked at half the pressure,
- tp >.  in order to insure the same degree of safety as attained in
\                       fthe three-feet boiler at double the pressure.  From  these
~~~~\           /  facts it may be useful to know, that boilers having increased
~\        ~~/ ~   dimensions should also have increased strength in the ratio
of their diameters; or, in other words, the plates of a sixfeet boiler should be double the thickness of the plates of
b              a three-feet boiler, and so on in proportion as the diameter
is increased.
"The relative power of force applied to cylinders of different diameters becomes more
strikingly apparent when we reduce them to their equivalents of strain per square inch,
as applied to the ends and circumference of the boiler respectively. In the three-feet
boiler, working at 40 lbs. pressure, we have a force equal to 7201bs. upon an inch
width of plate, and one quarter of an inch thick, or 720 by 4   2,880 lbs., the force
per square inch upon every point of the circumference of the boiler.  Let us now compare this with the actual strength of the riveted plates themselves, which, taken as
before, at 34,000 bs. on the square inch, we arrive at the ratio of pressure as applied to the strength of the circumference, as 2,880 to 34,000, nearly as I to 12, or 472 lbs.
per square inch, as the ultimate strength of the riveted plates.
" These deductions appear to be true in every case as regards the resisting powers
of cylindrical boilers to a force radiating in every direction from the axis towards the
circumference; but the same reasoning is, however, not maintained when applied to
the ends, or, to speak technically, to the angle iron and riveting, where the ends are
attached to the circumference.  Now, to prove this, let us take the three-feet boiler,
where we have 113 inches in the circumference; and upon this circular line of connection we have, at 40lbs. to the square inch. to sustain a pressure of 18 tons, which is
equal to a strain of 360 lbs., acting longitudinally upon every inch of the circumference. Apply the same force to a six-feet boiler, with a circumference or line of connection equal to 226 inches, and we shall find it exposed to exactly four times the
force, or 72 tons; but, in this case, it must be borne in mind, that the circumference
is doubled, and consequently the strain, instead of being in the quadruple ratio, is
only doubled, or a force equal to 720 lbs. acting longitudinally, as before, upon every
inch of the circumference of the boiler. From these facts we come to the conclusion,
that the strength of cylindrical boilers is in the ratio of their diameters if taken in the
line of curvature, and as the squares of the diameters as applied to the ends or their
sectional area; and that all descriptions of cylindrical tubes, to bear the same pressure, must be increased in strength in the direction of their circumference simply as
their diameters, and in the direction of the ends as the squares of the diameters.
"Again, if we refer to the comparative merits of the plates composing cylindrical
vessels subjected to internal pressure, they will be found in this anomalous condition,
that the strength in their longitudinal direction is twice that of the plates in the curvilinear direction. This appears by a comparison of the two forces, wherein we have
shown that the ends of the three-feet boiler, at 40 lbs. internal pressure, sustain 360 lbs.
of longitudinal strain upon each inch of a plate a quarter of an inch thick; whereas the
same thickness of plates has to bear in the curvilinear direction a strain of 720 lbs.
Thib Jifferencc of strain is a difficulty not easily overcome; and all that we can accom



BOILERS.                                      211
plish in this case will be to exercise a sound judgment in crossing the joints, in the
quality of the workmanship, and the distribution of the material. For the attainment of these objects, the following table, which exhibits the proportionate strength of
cylindrical boilers from three to eight feet in diameter, may be useful.
"Table of equal Strengths in Cylindrical Boilers from  3 to 8 feet diameter, showing the
thickness of metal in each respectively, at a pressure of 450 lbs. to the square inch.
Bursting Pressure equivalent to the  Thickness of the
Diameter of  ultimate strength of the riveted Joints,   Plates in
Boilers.   as deduced from experiment, 34,000 lbs. Decimal parts
to the square inch.        of an Inch.
Ft. Inch.
3    0                 450 lbs.'250
3    6                    --                      291
4    0                    --                      333
4     6                   -'376
5    0'416
5    6                    -'458
6    0                    -'500
6    6                    -'541
7    -0                   -'583
1    6                    -'625
8    0                    -'666
"Boilers of the simple form, and without internal flues, are subjected only to one
species of strain; but those constructed with internal flues are exposed to the same tensile force which pervades the simple form; and, further, to the force of compression
which tends to collapse or crush the material of the internal flues. In the cylindrical
boiler with round flues, the forces are diverging from the central axis as regards the
outer shell, and converging as applied to every separate flue which the boiler contains.
"These two forces in a steam boiler are in constant operation; the tendency of the
one being to tear up the external plates and force out the ends, and the other to destroy
the form and to force the material into the central area of the flues. These two forces
operate widely different upon the resisting powers of the boiler, which, taken in the direction of its exterior envelope, has to resist a tensile strain operating in every direction
from within, and the internal flues acting as an arch offer a powerful resistance to compression from without. It might be instructive as well as interesting to exhibit the
nature of these powers, and determine the law by which vessels of this description are
retained in shape, but this can only be done by experiment; and as these experiments
would have to be conducted upon a large scale, and with great accuracy, in order to
arrive at satisfactory results, we must abandon the idea for the present, and content
ourselves with such information as we already possess.'At some future period I may
possibly devote my attention to this subject. It is one of great importance; and a
series of well-conducted experiments would, I make no doubt, supply valuable data
in the varied requirements of boiler construction, and their comparative powers of
resistance to the united force of tension and compression.'-(Mr. Fairbairn's Lecture.)
" From the existing state of our knowledge, we must rest satisfied with the fact, that
the resisting powers of cylindrical flues to compression will be directly as their diameters; and we may therefore conclude that a circular flue 18 inches in diameter will
resist double the pressure of one 3 feet in diameter. Hence it follows that the resistance of wrought iron plates of the circular form is to the force of compression as their
diameters-the same, but with greatly diminished powers, as compared with the resistance of wrought iron cylindrical plates to tension.
"To show the amount of strain upon a high-pressure boiler 30 feet long, 6 feet diameter, having two centre flues, each 2 feet 3 inches diameter, working at a pressure of
50 lbs. on the square inch, we have only to multiply the number of square feet of sur
face, 1,030, exposed to pressure, by 321, and we have the force of 3,319 tons, which a
boiler of these dimensions has to sustain.  I mention this to show that the statistics of
pressure when worked out are not only curious in themselves, but instructive as regards
a knowledge of the retaining powers of vessels so extensively used, and on which the
bread of thousands depends. To pursue the subject a little further, let us suppose the
pressure to be at 450 lbs. on the square inch, which a well-constructed boiler of this
description will bear before it bursts, and we have the enormous force of 29,871, or
nearly 30,000 tons, bottled up within a cylinder 30 feet long and 6 feet diameter.
"This is, however, inconsiderable when compared with the locomotive and some




212                                 BOILERS.
marine boilers, which, from the number of tubes, present a much larger extent of sur.
face to pressure. Locomotive engines are usually worked at 80 to 100 lbs. on the inch,
and, taking one of the usual construction, we shall find, at 100 lbs. on the inch, that it
rushes forward on the rail with a pent-up force within its interior of nearly 60,000
tons, which is rather increased than diminished at an accelerated speed.
" In a stationary boiler charged with steam at a given pressure, it is evident that the
forces are in perfect equilibrium, and, the strain being the same in all directions, there
will be no tendency to motion. Supposing, however, this equilibrium to be destroyed
by accumulative pressure till rupture ensues, it then follows that, the forces in one direction having ceased, the other in an opposite direction, being active, would project
the boiler from its seat with a force equal to that which is discharged through the orifice of rupture. The direction of motion would depend upon the position of the ruptured part.  If in the line of the centre of gravity, motion would ensue in that direction; if out of that line, an oblique or rotatory motion round the centre of gravity
would be the result.
" The velocity or quantity of motion produced in one direction would be equal to the
intensity or quantity lost; and the velocity with which the body would move would
be in the ratio of the impulsive force, or the quantity lost. Therefore, the quantity
of motion gained by an exploded boiler in one direction will be as its weight and the
quantity lost in that direction. These definitions are, however, more in the province
of the mathematician, and may easily be computed from well-known formulae on the
laws of motion.
"We now come to the rectangular forms, or flat surfaces, which are not so well calculated to resist pressure.  Of these we may instance the fire-box of the locomotive
boiler, the sides and flues of marine boilers-the latter of which, by the by, are now
superseded by those of the tubular form-and the flat ends of the cylindrical boilers,
and others of weaker construction.
"The locomotive boiler is frequently worked up to a pressure of 120 lbs. on the square
inch, and at times, when rising steep gradients, I have known the steam nearly as high
as 200 Ibs. on the inch. In a locomotive boiler subject to such an enormous working
pressure, it requires the utmost care and attention on the part of the engineer to satisfy
himself that the flat surfaces of the fire-box are capable of resisting that pressure, and
that every part of the boiler is so nearly balanced in its powers of resistance, as that,
when one part is at the point of rupture, every other part is on the point of yielding
to the same uniform force.  This appears to be an important consideration in mechanical constructions of every kind, as any material applied for the security of one part
of a vessel subject to uniform pressure, whilst another part is left weak, is so much
material thrown away; and in stationary boilers, or in moving bodies, such as locomotive engines and steam vessels, it is absolutely injurious, at least so far as the parts
are disproportionate to each other, and the extra weight when maintained in motion
becomes an expensive and unwieldy encumbrance.  A knowledge of the strength of
materials used, judicious care, and the exercise of sound judgment in its distribution,
are therefore some of the most essential qualifications of the practical engineer. Our
limited knowledge and defective principles of construction are manifest from the numerous abortions which exist, and, although I am free to communicate all that I know
on the subject, I nevertheless find myself deficient in many of the requirements necessary for the attainment of sound principles of construction.
" Reverting to the question more immediately under consideration, it is, however,
essential to give the requisite security to those parts which, if left unsupported, would
involve the public as well as ourselves in the greatest jeopardy.
" The greater portion of the fire-boxes of locomotive boilers, as before noticed, have
the rectangular form, and, in order to economize heat and give space for the furnace,
it becomes necessary to have an interior and exterior shell.
" That which contains the furnace is generally made of copper, firmly united by rivets,
and the exterior shell, which covers the fire-box, is made of iron and united by rivets
in the same way as the copper fire-box. Now these plates would of themselves be totally inadequate, unless supported by riveted stays to sustain the pressure. In fact,
with one-tenth the strain, the copper fire-box would be forced inwards upon the furnace
and the external shell bulged outwards, and with every change of force these two flat
surfaces would move backwards and forwards, like the sides of an inflated bladder,
at the point of rupture. To prevent this, and give the large flat surfaces an approximate degree of strength with the other parts of the boiler, wrought iron or copper
stays, one inch thick, are introduced; they are first screwed into the iron and copper on both sides to prevent leakage, and then firmly riveted to the interior and exterior plates These stays are about six inches asunder, forming a series of squares,
and each of them will resist a strain of about fifteen tons before it breaks.
" Let us now suppose the greatest pressure contained in the boiler to be 200 lbs. on the




BOILERS.                                      213
square inch, and we have 6 x 6 x 200 = 7,200 lbs., or 31 tons, the force applied to a
square of 36 inches. Now as these squares are supported by four stays, each capable
of sustaining fifteen tons, we have 4 x 15 = 60 tons as the resisting powers of the
stays, but the pressure is not divided amongst all the four, but each stay has to sustain
that pressure; consequently the ratio of strength to the pressure will be as 43 to 1
nearly, which is a very fair proportion for the resisting power of that part.
" We have treated of the sides, but the top of the fire-box and the ends have also to be
protected, and there being no plate but the circular top of the boiler from which to attach stays, it has been found more convenient and equally advantageous to secure those
parts by a series of strong wtought-iron bars, from which the roof of the fire-box is suspended, and which effectually prevent it firom being forced down upon the fire. It will
not be necessary to go into the calculations of those parts; they are, when riveted to the
domo or roof, of sufficient strength to resist a pressure of 300 to 400 lbs. on the square
inch.  This is, however, generally speaking, the weakest part of the boiler, with the
exception, probably, of the flat end above the tubes in the smoke-box, if not carefully
stayed.
" In the flat ends of cylindrical boilers, and those of the marine principle, the same
rule applies as regards construction, and a due proportion of the parts, as in those of
the locomotive boilers, must be closely adhered to. Every description of boiler used
in manufactories, or on board of steamers, should in my opinion be constructed to a
bursting pressure of 400 to 500 lbs. on the square inch; and locomotive engine boilers,
which are subjected to a much severer duty, to a bursting pressure of 600 to 700 lbs.
"It now only remains for me to state that internal flues, such as contain the furnace
in the interior of the boiler, should be kept as near as possible to the cylindrical form,
and as wrought-iron will yield to a force tending to crush it about one half of what would
tear it asunder, the flues should in no case exceed one half the diameter of the boiler;
and with the same thickness of plates they may be considered equally safe with the
other parts.  But the force of compression is so different from that of tension, that I
should advise the diameter of the internal flues to be in the ratio of 1 to 2J instead of
I to 2 of the diameter of the boiler.
"I will not trouble you with a description of the haycock, hemispherical, and wagonshape boilers; they are all bad as respects their powers of resistance, and ought to be
entirely disused: I shall congratulate the public when they disappear from the list of
those constructions having the confidence of the public, and the consideration of the
man of science or the practical engineer.
" In conclusion, I have to recommend attention to a few simple rules, which, if carefully observed, will lead to the most satisfactory results. To construct boilers as nearly
as possible, of maximum strength, I have already observed they should be of the cylindrical form; and where flat ends are used, they should be composed of plates one
half thicker than those which form the circumference. The flues, if two in number,
to be of the same thickness as the exterior shell; and the flat ends to be carefully stayed
with gussets of triangular plates and angle iron, firmly connecting them with the circumference, as per annexed sketch.
"The use of gussets I earnestly recommend, as being infinitely superior to. and
more certain in their action and retaining pow150                   ers, than stay rods. Gussets, when used, should
__________ ____  be placed in lines diverging from the centre of
w the boilers, and made as long as the position.l.... contrt of the flues and other circumstances in the
construction will admit.  They are of great.-as imprt e ad -t e__frms-L -     value in retaining the ends in shape, and may
safely be relied upon as imparting an equality of strength to every part of the structure.
With these observations, I would direct atten_  tion to the facts I have endeavored to inculcate.  You will, I am persuaded, find them
M e o te I     t                      useful; and I trust the object contemplated
by the committee of your valuable Institution
will be fully attained, in the acquisition of
greater security and a more perfect principle of construction."*
BOILERS(Explosions of).-" In a former lecture I endeavored to explain the principles on which boilers should be constructed, and the laws which govern the strength
and other properties of these important vessels. The subject of construction is one of
vast importance, and those forms which give the greatest security with the least quantity of material, may be considered as the safest examples for imitation —the true elements
* Lecture at Leeds Mechanics' Institution, by William Fairbairn, Esq., C. E. F. R. S. and Corresp.
Member of the Institute of France.




214                                 BOILERS.
of construction. Boilers, of all other vessels, require, in the variety of their conditions,
shapes, and dimensions, the study of the philosopher as well as the hands of the mechanic. They contain, within comparatively narrow bounds, a force which, if properly governed, will propel the largest and most stately vessel against wind and tide;
perform the work of a thousand hands, and drive a hundred cars loaded with hundreds
of tons, at the speed of the swiftest race horse, from one extremity of the kingdom to
the other. They do all this and more; they impart heat and comfort to our dwellings,
-are essential for the requirements of our domestic arrangements,-and under the
control of judicious management, will advance the interests of commerce, and contribute to the enjoyments of civilized existence.
"Reverse the picture, and entrust the construction and management to the hands of
incapacity and ignorance, or the reckless folly and hardihood of fancied security, and
death and destruction follow as a result. When the mischief is done, we then begin
to guess at the causes, and to lament the inconsiderate confidence which led to the
employment of incompetency, and all those errors of judgment which invariably present themselves, not before, but after the event. How often do we hear of the most
lamentable accidents terminating in the destruction of life and property, and how
often do we lament (when too late) the causes which led to those frightful catastrophes! All these accidents might be prevented, and, instead of using steam, which we
now do in our manufactories, at a pressure of 5 to 20 lbs. on the square inch, we might
with equal safety use it, and enjoy the advantage of its superior economy, at 60 lbs. on
the inch. It shall be my duty to point out how this may be accomplished, and I hope
in these endeavors to have the support of every well wisher for increased security to
the public, and enlarged economy in the varied requirements of the use of steam.
"Before I attempt a solution of this difficult question, I would first direct attention
to a few facts which bear more directly upon the question now at issue.' Various notions are entertained as to the causes of boiler explosions, and scientific
men are not always agreed as to whether they arise from excessive pressure due to the
accumulation of heat, or to some other cause, such as the explosion of hydrogen gas,
generated by the decomposition of water suddenly thrown on heated plates, of which
we have an exceedingly indefinite conception. That of the decomposition of water is, I
believe, a somewhat prevalent opinion, but I apprehend it cannot be the invariable
cause, inasmuch as in that case we must assume the boiler to be nearly empty of water,
and the plates over the furnace red hot.
" It is not unreasonable to suppose that a force of such sudden origin, and so immediate and destructive in its effects, should suggest the presence-of an explosive mixture; but I think it will be difficult, if not impossible, to account for the accumulation
of a sufficient quantity of hydrogen, without the presence of oxygen and other gases,
in their due proportions, to form an explosive compound. Now as these equivalents
cannot be generated all at once by the simple decomposition of water (admitting, for
the moment, that the water is decomposed), we must look for some other cause for the
fatal and destructive accidents which of late years have become so prevalent.'" In treating of this subject, I hope to show not only what are the probable causes of
explosions, but, what appears equally important, what are not the causes. So many
theories (some of them exceedingly problematical) have been brought forward on the
occasion of disastrous explosions, that it requires the utmost care and attention to circumstances before they are generally admitted. To acquire satisfactory evidence as
to the precise condition of the boiler and furnace before an explosion, is next to impossible, as most frequently the parties in charge, and from whose mismanagement and
neglect we may, in many cases, date the origin of the occurrence, are the first to become the victims of their own indiscretion, and we can only judge from the havoc and
devastation that ensues as to the immediate cause of the event.
"From this it follows that, in many of the explosions on record, few, if any, of the
real circumstances of the case are made known, and we are left to draw conclusions
from the appearances of the ruptured parts, and the terrific consequences which too
frequently follow as a result. This want of evidence as to the precise condition of
a boiler, with all its valves and mountings, preceding an explosion, is much to be regretted, as it causes a degree of mystery to surround the whole transaction; and the
vague and sometimes inaccurate testimony of witnesses but too often baffles all attempts
at research, and creates additional cause of alarm to all those exposed to the occurrence of similar dangers.
"In the discussion of this subject I shall, however, endeavor to trace, from a number
of examples in which I have been personally engaged, and from others which have come
to my knowledge, the causes which have led to those disastrous effects; and provided
I am successful in the discovery of the true origin of the majority of those occurrences, we shall have less difficulty in devising and applying the necessary remedies for
their prevention.




BOILERS.                                   215
"In my attempts to ascertain facts by a course of reasoning which I shall have to
follow in this investigation, I wish it to be understood that it is not my intention to
raise doubts and fears, in the public mind, calculated to arrest the progress of commercial enterprise, or to cripple the energies of mechanical skill. On the contrary, I am
most anxious to promote the advancement of the useful arts, to increase our confidence in the application of increased pressure, and to secure within moderate bounds
the economical and useful employment of one of the most powerful agents ever known
ill the history of practical science. My object in this inquiry will, therefore, be to
enlarge our sphere of action by a more comprehensive knowledge of the subject on
which it treats; to induce greater caution along with improved construction; and to
insure confidence in all those requirements essential to the public security.
"For the full consideration of this subject, it will be necessary to divide it into the
following heads;" 1st. Boiler explosions arising from accumulated internal pressure.
" 2d. Explosions from deficiency of water.
" 3d. Explosions produced from collapse.
" 4th. Explosions from defective construction.
" 5th. Explosions arising from mismanagement or ignorance; and
" 6th. The remedies applicable for the prevention of these accidents.
"1st. Boiler explosions arising from  accumulated internal pressure.
"In nine cases out of ten a continuous increasing pressure of steam, without the
means of escape, is probably the immediate cause of explosion; in some instances it
arises from deficiency of water, but accidents of this kind are comparatively few in
number, as we often find, in tracing the causes, that they have their origin in undue
pressure, emanating from progressive accumulation of steam of great force and density.
Let us take an example, and we shall find that a boiler under the influence of a furnace in active combustion will generate an immense quantity of steam; and unless this
is carried off by the safety-valve or the usual channels when so generated, the greatest
danger may be apprehended by the continuous increase of pressure that is taking place
within the boiler.  Suppose that, from some cause, the steam thus accumulated does
not escape with the same rapidity with which it is generated,-that the safety-valves
are either inadequate to the full discharge of the surplus steam, or that they are entirely inoperative, which is sometimes the case,-and we have at once the clue to the
injurious consequences which, as a matter of fact, are sure to follow.  The event may
be procrastinated, and repeated trials of the antagonistic forces from within, and the resistance of the plates from without, may occur without any apparent danger, but these
experiments often repeated will at length injure the resisting powers of the material,
and the ultimatum will be the arrival of the fatal moment when the balance of the two
forces is destroyed, and explosion ensues. How very often do we find this to be the
true cause of accidents arising from extreme internal pressure, and how very easily
these accidents might be avoided by the attachment of proper safety-valves, to allow
the steam to escape and relieve the boiler of those severe trials which ultimately lead
to destruction! If a boiler whose generative power is equal to 100, be worked at a
pressure of 10 lbs. on the square inch, the area of the safety-valves should also be equal
to 100, in order to prevent a continuous increase of pressure; or, in case of the adhesion
of any of the valves, it is desirable that their areas should, collectively, be equal to 100.
If two or more valves are used, 100 or 120 would then be the measure of outlet.*  Under these precautions, and with a boiler so constructed, the risk of accident is greatly
diminished; and, provided one of the valves is kept in working order beyond the
reach of interference by the engineer, or any other person, we may venture to assume
that the means of escape are at hand, irrespective of the temporary stoppage of the
usual channels for carrying off the steam.
" So many accidents have occurred from this cause-the defective state of the safetyvalves-that I must request attention whilst I enumerate a few of the most prominent
cases that have come before me. In the year 1845 a tremendous explosion took place at
a cotton millin Bolton. The boilers, three in number, were situated under the mill, and,
from the unequal capacity and imperfect state of the safety-valves (as they were probably fast), a terrible explosion of the weakest boiler took place, which tore up the plates
along the bottom, and, the steam having no outlet at the top, not only burst out the end
next the furnace, demolishing the building in that direction, but, tearing up the top on
the opposite side, the boiler was projected upwards in an oblique direction, carrying
the floors, walls, and every other obstruction before it; ultimately it lodged itself across
the railway at some distance from the building.  Looking at the disastrous consequences of this accident, and the number of persons (from 16 to 18) who lost their lives on
the occasion, it became a subject of deep interest to the community that a close investigation should immediately be instituted, and a recommendation followed that every
*This may be stated in other words, viz., that the generative powers of a boiler being equal to a given
number of square inches of area, say 50, the area of the safety-valve should also be 50.




216                                  BOILERS.
precaution should be used in the construction as well as the management of boilers.
"The next fatal occurrence on record in this district was a boiler at Ashton-underLyne, which exploded under similar circumstances, namely, from excessive interior
pressure, when four or five lives were lost; and again at Hyde, where a similar accident occurred from the same cause, which was afterwards traced to the insane act of
the stoker or engineer, who prevented all means for the steam to escape by tying down
the safety-valve.
"There was a boiler explosion at Malaga, in Spain, some years since, and my reason
for noticing it in this place is to show that explosions may be apprehended from other
causes than those enumerated in the divisions of this inquiry, and one of these is incrustation. Dr. Ritterbrandt says, in a paper read before the Institution of Civil Engineers by an eminent chemist, Mr. West-' That a sudden evolution of steam under
circumstances of incrustation is no uncommon occurrence.' In several instances I have
known this to be the case, particularly in marine boilers, where the incrustation from
salt water becomes a serious grievance, either as regards the duration of the boiler,
or the economy of fuel.
" If it were supposed, as Dr. Ritterbrandt observes, that the boiler was incrusted to
the extent of half an inch, it would at once be seen that nothing was more easy than to
heat the boiler strongly, even to a red heat, without the immediate contact of water.
Under these circumstances, the hardened deposits, being firmly attached to the plates,
and forming an imperfect conductor of heat, would tend greatly to increase the temperature of the iron; and the difference of temperature, thus induced between the iron and
the incrustation, and the greater expansibility of the iron, would cause the incrustation
to separate from the plates, and the water rushing in between them would generate a
considerable charge of highly elastic steam, and thus endanger the security of the boilers.
"These phenomena were singularly exemplified in the Malaga explosion, which in
thus described by Mr. Hick;-' I have ascertained that a very thick incrustation of
salt was formed on the lower part of the boiler, immediately over the fire, and so far as
it extended the plates appear to have been red hot, being thereby much weakened,
and hence the explosion. The ordinary working pressure of the boiler is 130 lbs. per
square inch, and perhaps at the time of the explosion very much above that pressure,
as there was only one small safety-valve of two and a-half inches diameter. The
boiler was only two feet six inches diameter, and twenty feet long.'
" Incrustation, exclusive of being dangerous, is attended with great expense and
injury to the boiler by its removal. In the case of the transatlantic, oriental, or other
long sea-going vessels, even after the use of brine-pumps, blowing out, &c., a very
large amount of incrustation is formed, and considerable sums of money are expended
each voyage to remove it.
" Other explosions of a more recent date are those which occurred at Bradford and
Halifax. They are still fresh in the recollection of the public mind, and are so well
known as not to require notice in this place.
"I cannot, however, leave this part of the subject without reverting to an accident
which occurred on the Lancashire and Yorkshire Railway, whichhad its origin in the
same cause-excessive internal pressure. This accident is the more peculiar as it led
to a long mathematical disquisition as to the nature of the forces which produced results
at once curious and interesting. The conclusions which I arrived at, although practically right, were, however, considered by some mathematically wrong, as they were firmly combated by several eminent mathematicians; but notwithstanding the.number of
algebraic formulas and the learned discussions of my friends on that occasion, I have
been unable to change the opinions I then formed, for others more conclusive.
"The accident here alluded to occurred to the' Irk' locomotive engine, which, in
February, 1745, blew up and killed the driver, the stoker, and another person who was
standing near the spot at the time. A great difference of opinion as to the cause of this
accident was prevalent in the minds of those who witnessed the explosion, some attributing it to a crack in the copper fire-box, and others to the weakness of the stays over
the top.  Neither of these opinions was, however, correct, as it was afterwards demonstrated that the material was not only entirely free from cracks and flaws, but the stays
were proved sufficient to resist a pressure of 150 to 200 lbs. on the square inch. The true
cause was afterwards ascertained to arise from the fastening down of the safety-valve of
the engine (an active fire being in operation under the boiler at the time), which was
under the shed, with the steam up, ready to start with the early morning train. The effect of this was the forcing down of the top of the copper fire-box upon the blazing embers of the furnace, which, acting upon the principle of the rocket, elevated the boiler
and engine of 20 tons weight to a height of 30 feet, which, in its ascent made a summerset
in the air, passed through the roof of the shed, and ultimately landed at a distance of 60
yards from its original position. The question which excited most interest, was the absolute force required to fracture the fire-box, its peculiar properties when once liberated,




BOILERS.                                  217
and the elastic or continuous powers in operation which forced the engine from its place
to an elevation of 30 feet from the position in which it stood. An elaborate mathematical discussion ensued relative to the nature of these forces, which ended in the
opinion that a pressure sufficient to rupture the fire-box, was, by its continuous action,
suffici6nt to elevate the boiler and produce the results which followed. Another reason was assigned, namely, that an accumulated force of elastic vapor, at a high temperature, with no outlet through the valves, having suddenly burst upon the glowing
embers of the furnace, would charge the products of combustion with their equivalents
of oxygen, and hence explosion followed. Whether one or both of these two causes
were in operation is probably difficult to determine; at all events, we have in many
instances precisely the same results produced from similar causes, and unless greater
precaution is used in the prevention of excessive pressure, we may naturally expect
a repetition of the same fatal consequences.
"The preventives against accidents of this kind are, well-constructed boilers of the
strongest form, and duly proportioned safety valves; one under the immediate control of the engineer, and the other, as a reserve under the keeping of some competent
authority.
" 2d. Explosions by deficiency of water.
"This division of the subject requires the utmost care and attention, as the circumstance of boilers being short of water is no unusual occurrence. Imminent danger
frequently arises from this cause; and it cannot be too forcibly impressed upon the
minds of engineers, that there is no part of the apparatus constituting the mountings
of a boiler which require greater attention-probably the safety-valves not excepted
-tlan that which supplies it with water. A well-constructed pump, and self-acting
feeders, when boilers are worked at a low pressure, are indispensable; and where the
latter cannot be applied, the glass tubular gauge, steam, and water cocks must have
more than ordinary attention.
" In a properly constructed boiler every part of the metal exposed to the direct action
of the fire should be in immediate contact with the water, and, when proper provision
is made to maintain the water at a sufficient height above the part of the plates so
exposed, accidents can never occur from this cause.
"Should the water, however, get low from defects in the pump, or any stoppage of
the regulating feed valves, and the plates over the furnace become red hot, we then
risk the bursting of the boiler, even at the ordinary working pressure. We have no
occasion, under such circumstances, to search for another cause, from the fact that the
material when raised to a red-heat has lost about five-sixths of its strength, and a force
of less than one-sixth will be found amply sufficient to bear down the plates direct upon
the fire, or to burst the boiler.
" When a boiler becomes short of water, the first, and perhaps the most natural,
action is to run to the feed valve, and pull it wide open. This certainly remedies the
deficiency, but increases the danger, by suddenly pouring upon the incandescent plates
a large body of water, which, coming in contact with a reservoir of intense heat, is
calculated to produce highly elastic steam. This has been hitherto controverted by
several eminent chemists and philosophers; but I make no doubt such is the case,
unless the pressure has forced the plates into a concave shape, which for a time would
retard the evaporization of the water when suddenly thrown upon themi. Some
curious experimental facts have been elicited on this subject, and those of M. Boutigny,
and Professor Bowman, of King's College, London, show that a small quantity of water
projected upon a hot plate does not touch it; that it forms itself into a globule surrounded with a thin film, and rolls about upon the plate without the least appearance
of evaporation. A repulsive action takes place, and these phenomena are explained
uponthe supposition that the spheroid has a perfectly reflecting surface, and consequently the heat of the incandescent plate is reflected back upon it.  What is, however, the most extraordinary in these experiments, is the fact that the globule, whilst
rolling upon a red hot plate, never exceeds a temperature of about 204~ of Fahr.; and
in order to produce ebullition, it is necessary to cool the plate until the water begins
to boil, when it is rapidly dissipated in steam.
"The experiments by the committee of the Franklin Institute on this subject, give
some interesting and useful results.  That committee found that the temperature at
which clean iron vaporized drops of water was 334~ of Fahr. The development of a
repulsive force which I have endeavored to describe was, however, so rapid above that
temperature, that drops which required but one second of time to disappear at the
temperature of maximum evaporation, required 152 seconds when the metal was heated
to 395~ of Fahr. The committee go on to state that-' One ounce of water introduced
into an iron bowl three-sixteenths of an inch thick, and supplied with heat by an oilbath, at the temperattire of 546~, was vaporized in fifteen seconds, while, at the initial
temperature of 507~, that of the most rapid evaporization was thirteen seconds.'




218                                BOILERS.
"The cooling effect of the metal is here strikingly exemplified by the increased
rapidity of the evaporization, which at a reduced temperature of 38~ is effected in
thirteen instead of fifteen seconds.
"This does not, however, hold good in every case, as an increased quantity of water,
say from one-eighth of an ounce to two ounces, thrown upon heated plates, raised the
temperature of vaporization from 4600 to 600~ Fahr.; thus clearly showing that the
time required for the generation of explosive steam under these circumstances is attended with danger; and it may be doubted whether the ordinary safety valves may
not be wholly inadequate for its escape.
"Numerous examples may be quoted to show that explosions from deficiency of
water, although less frequent than those arising from undue pressure, are by no means
uncommon. They are nevertheless comparatively few in number, and the preventives are good pumps, self-acting feeders (when they can be applied), and all those
conveniences, such as water-cocks, water-gauges, floats, alarms, and other indicators
of the loss and reduction of water in the boiler.
"3d. Explosions producedfrom collapse.
"Accidents from this cause can scarcely be called explosions, as they arise, not from
internal force which bursts the boiler, but from the sudden action of a vacuum within
it. In high pressure boilers, from their superior strength and circular form, these
accidents seldom occur, and the low pressure boiler is effectually guarded against it by
a valve which opens inwards by the pressure of the atmosphere whenever a vacuum
occurs. In some cases a collapse of the internal flues of boilers has been known to
take place, from a partial vacuum within, which, united to the pressure of the steam,
has forced down the top and sides of the flue, and with fatal effect discharged the contents of the boiler into the ash-pit, and destroyed and scalded every thing before it. A
circumstance of this kind occurred on the Thames on board the steamer Victoria, some
years since, when a number of persons lost their lives, and serious injury was sustained
in all parts of the vessel within reach of the steam. This accident could not, however,
be called an explosion, but a collapse of the internal flues, which were of large dimensions, and the consequent discharge of large quantities of steam and water into the
space occupied by the engines.
" One or two cases which bear more directly on this point, are, however, on record,
and one of them, which took place in the Mold mines in Flintshire, was attended with
explosion. The particulars, as given by Mr. John Taylor, will be found circumstantially recorded in the first volume of the Philosophical Magazine.  This occurrence
seems to prove that rarefaction produced in the flues of a high pressure boiler may determine an explosion. The boiler which exploded belonged to a set of three feeding the
same engine; the fuel used was bituminous coal. The furnace doors of all three of
the boilers had been opened, and the dampers of two had been closed, when a gust
of flame was seen to issue from the mouth of the furnace of these latter, and was immediately followed by an explosion. The interior flue of this boiler was flattened from
the sides, the flue and shell of the boiler remaining in their places, and the safety-valve
upon the latter not being injured.
"Other similar cases of collapse might be stated, but as most of them have been attended by a defective supply of water in the boiler, the plates over the fire having become heated, they can scarcely be included in the category of this class of accidents,
and more properly belong to those of which we have just treated,-explosions from a
deficiency of water in the boiler.
" It is, nevertheless, necessary to observe, that cases of collapse should be carefully
guarded against, as the great source of danger is in the escape of hot water, which,
with the steam generated by it produces death in one of its worst and most painful
forms.
"The remedies for these accidents will be found in the vacuum valve, and careful
construction in the form and strength of the flues.
"4th. Explosions from defective construction.
"This is, perhaps, one of the most important divisions that can possibly engage our
attention, and on which it shall be my duty to enlarge. In a previous inquiry I have
already shown the nature of the strain and the ultimate resistance which the material
used in the construction of boilers is able to bear. We have not, however, in all cases
shown the distribution and position in which that material should be placed in order
to attain the maximum of strength, and afford to the public greater security in the resisting powers of vessels subject to severe and sometimes ruinous pressure.  This is a
subject of such importance that I shall be under the necessity of trespassing upon your
time, in endeavoring to point out the advantages peculiar to form, and the use of a
sound and perfect system of construction.
"For a number of years the haycock, hemispherical, and wagon-shaped boilers
were those generally m use; and it was not until high pressure steam was first intro



)ILERS.                                 219
duced into Cornwall, that the cylindrical form with hemispherical ends, and the furnace
under the boiler, came into use. Subsequently this gave way to the introduction of a
large internal flue extending the whole length of the boiler, and in this the furnace
was placed. For many years this was the best and most economical boiler in Cornwall, and its introduction into this country has effected great improvements in the
economy of fuel as well as the strength of the boiler. Several attempts have been
made to improve this boiler by cutting away one half of the end, in order to admit a
larger furnace. This was first done by the Butterley Company, and it since has gone
by the name of the Butterley boiler.  This construction has the same defects as the 
haycock or hemispherical and wagon-shaped boilers: it is weak over the fire-place, and
cannot well be strengthened without injury to the part A,fig. 151, of the boiler, from
151                          152
the vast number of stays necessary to suspend the part which forms the canopy of the
furnace.  Of late years a much greater improvement has, however, been effected by the
double flue, B B,fig. 152, and double furnace boiler, which is now in general use, and has
nearly superseded all the other, constructions.  It consists of the cylindrical form, varying from five to seven feet in diameter, with two flues which extend the whole length of
the boiler; they are perfectly cylindrical, and of sufficient magnitude to admit a furnace
in each. This boiler is the simplest, and probably the most effective, that has yet been
constructed. It presents a large flue surface as the recipient of heat, and the double flues,
when riveted to the flat ends, add greatly to the security and strength of those parts.
It, moreover, admits of the new process of alternate firing, so highly conducive to perfect combustion, and the prevention of the nuisance of smoke.-Fairbairn and Hetherington's patent of April 30, 1844.
"Another boiler, into which a number of small tubes are introduced, exhibits a powerful generator of steam, from the extent of its flue surface, and the facility with which
the repairs can be effected.  It does not present any greater security against explosion
than the boiler with two flues, but its construction on the tubular system  effects a
great saving in space, and is otherwise productive of all the advantages of economy in
the consumption of fuel and the prevention of smoke. This boiler is constructed with
a large internal flue, divided in the middle, which admits of two fire-places and alternate firing. In the space which I call the mixing chamber, the products of combustion
amalgamate, and are thus ignited before they enter the tubes, and from which they
issue into the end flues, and from thence to the chimney in the usual way. In this
latter construction it will be observed that the boiler is of the same form as the last,
and contains the same elements of strength as the double-flue boiler, the only difference
being a combination of the locomotive and marine tubular system, which contains a
large absorbent heating surface in a small space.
" It will not be necessary to multiply examples of construction, as I have already described those which I consider best calculated to sustain severe pressure. At the same
time, when the parts are judiciously and skilfully arranged, with a grate-bar surface
well proportioned to the amount of flue-surface as the recipient, we may reasonably
conclude that we are not far from the maximum of strength, including other important
elements in the material and the consumption of fuel.
"The means necessary to be employed for the prevention of accidents in this department of the inquiry, are a knowledge of the principles of construction, and an acquaint
ance with the strength and properties of the materials used for that purpose.
"5th. Explosions arising from mismanagement or ignorance.
"To mismanagement, ignorance, and the misapplication of a few leading principles
in connection with the use and application of steam, may be traced the great majority
of accidents which from time to time occur. Many of these accidents, so fruitful of the
destruction of property and human life, might be prevented if we had well constructed
vessels, judiciously united to skill and competency in the management. To convey a
few practical instructions to engineers, stokers, and engine-men, would be an undertaking of no great difficulty. A young man of ordinary capacity would learn all that is
necessary in a few months; and if placed under competent instructors, he might be
made acquainted with the properties of steam-its elastic force at different degrees of
pressure-the advantages peculiar to sensitive and easy working safety valves-the




220                                 BOILERS.
necessity of cleanliness and keeping them in good working condition-the use of water
gauges, fusion plugs, indicators, signals, &c., &c., connected with the supply and height
of water in the boiler-the dangers to be apprehended from a scarcity of water-the
danger of explosion when the engine is standing, or when the usual channels for relieving the boiler of its surplus steam are stoppod. All these are parts of elementary instruction which the stoker, as well as the engineer, should be acquainted with; and no
proprietor of a mill, captain of a steamship, or superintendent of locomotives should
give employment to any persons unless they can produce certificates of good behavior,
and a knowledge of the elementary principles of their profession.
"If these precautions were adopted, greater care observed in the selection of men
of skill and responsibility in the construction of boilers, and a more strict and rigid
code of laws in the management, we might look forward with greater certainty to
a considerable diminution, if not a prevention, of those calamitous events which so
frequently plunge whole families into mourning by unexpected and instantaneous
death.
"As an individual, I would cheerfully lend my best assistance to the development
of a principle of instruction calculated to relieve the country of the ignorance which
pervades that part of the community on which the lives of so many depend. A resolution on the part of those who employ persons of this description, and whose interests
are so much at stake, to take only those whose knowledge and character come up to
the requisite standard, and pay for it, would soon cause, from the economy of the
management, and the increased security of their property, a very important change in
all the requirements of the economy, as well as the application, of steam. How often
do we find implements of danger, and vessels containing the elements of destruction,
in the hands of the most ignorant and reckless practitioners, whose insensibility to danger, and total incompetency to judge of its presence, render them above all others the
most unfit to be employed. And why? Because they are the very persons, from their
defective knowledge, to increase the danger and aggravate the evils they were selected
to prevent. It is not the first time that engineers, to secure (if I may use the expression)
an insane pressure, have fastened the safety valves, and screwed down the steam valve,
closing every outlet, without ever thinking of the fire that was blazing under the boiler.
Under such circumstances what could be expected but a blow up? A madman rushing with a lighted match into a powder magazine could not act with greater insanity.
Such, however, has been the case, and all arising from want of thought, or, what is
worse, from the total absence of knowledge, which it was the duty of his employer as
well as himself to have possessed.
"I have on former occasions stated that I am not an advocate for legislative interference either in the construction or management of boilers; but, seeing the dangerous
tendency of these vessels when placed under the control of ignorance and incapacity, I
would forego many considerations to encourage a more judicious and intelligent class
of men than has hitherto been employed in the care and management of steam and the
steam engine.  The reforms necessary to be introduced may be made by the owners of
steam engines, steamboats, railways, and others engaged in the use and application of
this important element. A desire to enforce more judicious and stringent regulations, to
remunerate talent, and to employ only those whose good conduct and superior knowledge entitle them to confidence, is the only sure guarantee of public safety and the prosperity of the employer.
" Lastly, The remedies applicable for the prevention of accidents arising from explosions.
"Having noticed in the foregoing remarks most of the causes incident to boiler explosions, it now only remains to draw such inferences as will point out the circumstances
which it is desirable to cultivate, and others which it is desirable to avoid.  These
circumstances I have endeavored to class in such a way as to bring the subject prominently forward, and to point out under each head, first, the causes which lead to accident; and, secondly, the means necessary to be observed in avoiding it.  In a general
summary, it may not be inexpedient briefly to recapitulate these statements, in order to impress more forcibly upon the mind of those concerned the necessity for
care and consideration in the use of one of the most powerful agents ever placed
at our disposal.
"One of the most scientific nations of Europe places the greatest confidence, as a
means of safety, on the use of a fusible metal plate over the furnace. These plates are alloys of tin and lead, with a small portion of bismuth, in such proportions as will ensure
fusion at a temperature something below that of molten lead. In France the greatest
importance is attached to these alloys, and, in order to ensure certainty as to the definite
proportions, the plates are prepared at the royal mint, where they may be purchased
duly prepared for use  In this country these alloys are not generally in use, but in
this respect I think we are wrong, as boiler explosions are not so frequent in France as




BOILERS.                                      22]
in this country, and high-pressure steam, from its superior economy, is more extensively
used in France than in England. In my own practice I invariably insert a lead rivet,
one inch in diameter, immediately over the fireplace, and as common lead melts at 620~,
I have invariably found these metallic plugs a great security in the event of a scarcity ol
water in the boiler. I am persuaded many dangerous explosions may be avoided by the
use of this simple and effective precaution; and as pure lead melts at 610~, we may infer
from this circumstance that notice will be given and relief obtained before the internal
pressure of the steam exceeds that of the resisting powers of the heated plates. As this
simple precaution is so easily accomplished, I would advise its general adoption. It
can do no harm to the boiler, and may be the means of averting explosions and the
destruction of many valuable lives.
"The fusible metal plates, as used in France, are generally covered by a perforated
metallic disc, which protects the alloy of which the plate is composed, and allows it to
ooze through as soon as the steam has attained the temperature necessary to insure the
fusion of the plate. The nature of the alloy is, however, somewhat curious, as the different equivalents have different degrees of fluidity, and the portion which is the first to
melt is found out by the pressure of the steam causing the adhesion of the less fusible
parts, but in a most imperfect state, and incapable of resisting the internal force of the
steam. The result of these compounds is the fusion of one portion of the alloy and the
fracture of the other, which is generally burst by pressure.
"This latter description of fusible plates is different from the lead plug over the fire,
which is fused at 600~ by the heat of the furnace, and the other, by the temperature
of the steam, when raised to the fusible point of the alloy, which varies from 280~ to
350~.
"Another method is the bursting plate, fixed in a frame and attached to some convenient part of the upper side of the boiler; this plate is to be of such thickness and of
such ductility as to cause rupture whenever the pressure exceeds that of the weight on
the safety valve.  There can be no doubt that such an apparatus, if made with a sufficiently large opening, would relieve the boiler; but the objections to this and several
other devices are the frequent bursting of those plates, and the effect every change of
pressure has upon the material in reducing its powers of resistance, and thus increasing
uncertainty as to the amount of pressure in the boiler, as well as the constant renewal
of the plates.
"It has already been noticed that one of the most important securities against explosions is a duly proportioned boiler, well constructed; and to this must be added
ample means for the escape of the steam on every occasion when the usual channels have
been suddenly stopped. The only legitimate outlets under these circumstances appear
to me to be the safety-valves, which, connected with this inquiry, are indispensable to
security. Every boiler should, therefore, have two safety-valves, of sufficient capacity
to carry off the quantity of steam generated by the boiler. One of these valves should
be of the common construction, and the other beyond the reach of the engineer or any
other person.
" Fig. 153 is a sketch of a lock-up safety-valve, as constructed by Mr. Fairbairn.  A is
the valve. B is a shell of thin brass, opening on an hinge and secured by a padlock; it
is of such a diameter as to allow the waste steam to escape in the direction of the arrows.
163                                             c is the weight, which may be
SB        fixed at any part of the lever
<a.        to give the desired amount of
X                I eJ,        pressure, but which cannot be
oV 05 >1    fixed  or altered unless the
boiler is opened to allow  a
man to get inside.   D is a
SE w_ ithandle, having a long slot, by
which the valve may be re-;_ Ad___-_-__________X mlieved or tried at any time, to
obviate the liability of its cordicu en=g  Abv           roding or being jammed; the
engineer cannot, however, put
any  additional weight upon......_ _______ _______ _______ ____ __  the  valve  by  this  handle.
-     "Whilst tracing the causes
of explosions from a deficiency
of water in the boiler, I have recommended as the usual precautions, good pumps, selfacting feeders, water cocks, glass gauges, floats, alarms, and other indicators which
mark the changes and variations in the height of the water. To these may be added
the steam whistle, but chiefly the constant inspection of a careful, sober, and judicious engineer.  Above all other means however ingeniously devised, this is the most




222                                 BOILERS.
essential to security, for on that official depends, not only the security of the property
under his charge, but also the interests of his family, and the lives of all those within
the immediate influence of his operations. One of the most important considerations
in this and every other department of management is cleanliness and the careful attention of a good sober engineer.
" Explosions produced fiom collapse have their origin in different causes to those
arising from a deficiency of water, and the only remedy that can be applied is the
vacuum valve and the cylindrical or spheroidal form of boiler.
"Defective construction is unquestionably one of the greatest sources of the frightful
accidents which we are so frequently called upon to witness. No man should be allowed
unlimited exercise of judgment on a question of such vital importance as the construction of a boiler, unless duly qualified by matured experience in the theoretical and
practical knowledge of form, strength of materials, and other requirements requisite
to insure the maximum  of sound construction.  It appears to me equally important
that we should have the same proofs and acknowledged system of operations in the
construction of boilers, as we have in the strength and proportions of ordnance. In
both cases we have to deal with a powerful and dangerous element; and I have yet
to learn why the same security should not be given to the general public as we find
so liberally extended to an important branch of the public service. In the ordnance
department at Woolwich (with which I have been more or less connected for some
years) the utmost care and precision is observed in the manufacture of guns; and the
proofs are so carefully made under the superintendence of competent officers, as to
render every gun perfectly safe to the extent of 1000 to 1200 rounds of shot.
"Boilers and artillery are equally exposed to fracture, and it appears to me of little
moment whether the one is burst by the discharge of gunpowder, or the other by the
elastic force of steam.
":Taking into consideration all the circumstances connected with the bursting of
boilers and the bursting of guns, and looking at the active competition which exists,
and is likely to be extended, in manufactories, railway traffic, and steam navigation,
rendering it every day more desirable to reduce the cost by an extended use of steam
at a much higher pressure, it surely becomes a desideratum to secure the public safety
by the introduction of some generally acknowledged system of construction that will
bear the test of experience, and involve a maximum power of resistance. The most
elaborate disquisitions have taken place, by the most distinguished men of all ages
since the invention of gunpowder, to discover the strength and form of guns of every
aescription.  Surely boilers are equally if not more important, as the sacrifice of human
life appears to me much greater in the one case than the other.  It is therefore a subject of paramount importance to the public to know that the facts of scientific inquiry,
and the knowledge of practical skill, have combined to give undeniable security as well
as confidence, that boilers are properly constructed, and capable of bearing at least six
times their working pressure.
" On the question of explosions arising from mismanagement and ignorance, we have
little further to add; and it now only remains to state, that the subject of security from
boiler explosions is of such importance as to call for more able exponents than myself.
I have endeavored to trace the causes of these lamentable occurrences, and to draw
such deductions therefrom as I trust may be useful in at least mitigating, if not almost
entirely averting, the danger.
"I repeat the means of prevention and the precautions necessary to be observed in
the construction and management of boilers.
"1st. To avoid explosions from internal pressure, cylindrical boilers of maximum
forms and strength must be used, including all the necessary appendages of safety-valves,
&c.
"2d. Explosions arising from deficiency of water may be prevented by the fusible
alloys, bursting plates, good feed pumps, water gauges, alarms and other marks of indication; but above all, the experienced eye and careful attention of the engineer is the
greatest security.
" 3d. Explosions from collapse are generally produced from imperfect construction,
wvhich can only be remedied by adopting the cylindrical form of boiler, and a valve to
prevent the formation of vacuum in the boiler.
"4th. Explosions from defective construction admit of only one simple remedy, and
that is, the adoption of those forms which embody the maximum powers of resistance to
internal pressure, and such as we have already recommended for general use.
" Lastly. Good and efficient management, a respectable and considerate engineer, and
the introduction of such improvements, precautions, and securities as we have been able
to recommend, will not only ensure confidence, but create a better system of management in all the requirements necessary to be observed for the prevention of steam boiler
explosions.  (Fairbairn, in Lecture at Leeds.)




BONES.                                    228
BOMBAZINE. A worsted stuff, sometimes mixed with silk.
BONES.  (Os, Fr.; Knochen, Germ.)  They form the frame work of animal bodies,
commonly called the skeleton; upon which the soft parts are suspended, or in which they
are enclosed. Bones are invested with a membrane styled the periosteum, which is
composed of a dense tissue affording glue; whence it is convertible into jelly, by
ebullition with water. Bones are not equally compact throughout their whole substance; the long ones fiave tubes in their centres lined with a kind of periosteum, of
more importance to the life of the bones than even their external coat. The flat, as
well as the short and thick bones, exhibit upon their surface an osseous mass of a
dense nature, while their interior presents a cavity divided into small cellules by their
bony partitions.
In reference to the composition of bones, we have to consider two principal constituents; the living portion or the osseous cartilage, and the inorganic or the earthy salts of
the bones.
The osseous cartilage is obtained by suspending bones in a large vessel full of dilute
muriatic acid, and leaving it in a cool place at about 50~ Fahr. for example. The acid
dissolves the earthy salts of the bones without perceptibly attacking the cartilage, which,
at the end of a short time, becomes soft and translucid, retaining the shape of the bones;
whenever the acid is saturated, before it has dissolved all the earthy salts it should be
renewed. The cartilage is to be next suspended in cold water, which is to be frequently
changed till it has removed all the acidity. By drying, the cartilage shrinks a little,
and assumes a darker hue, but without losing its translucency.  It becomes, at the
same time, hard and susceptible of breaking when bent, but it possesses great
strength.
This cartilage is composed entirely of a tissue passing into gelatine. By boiling with
water, it is very readily convertible into a glue, which passes clear and colorless through
the filter, leaving only a small portion of fibrous matter insoluble by further boiling.
This matter is produced by the vessels which penetrate the cartilage, and carry nourishment to the bone. We may observe all these phenomena in a very instructive manner,
by macerating a bone in dilute muriatic acid, till it has lost about the half of its salts;
then washing it with cold water, next pouring boiling water upon it, leaving the
whole in repose for 24 hours, at a temperature a few degrees below 212~ Fahr.
The cartilage, which has been stripped of its earthy salts, dissolves, but the small
vessels which issue from the undecomposed portion of the bone remain under the form
of white plumes, if the water has received no movement capable of crushing or breaking
them. We may then easily recognise them with a lens, but the slightest touch tears
them, and makes them fall to the bottom of the vessel in the form of a precipitate; if
we digest bones with strong hot muriatic acid so as to accelerate their decomposition, a
portion of the cartilage dissolves in the acid with a manifest disengagement of carbonic
acid gas, which breaks the interior mass, and causes the half-softened bone to begin to
split into fibrous plates, separable in the direction of their length. According to Marx,
these plates, when sufficiently thin, possess, like scales of mica, the property of polarizing light, a phenomenon which becomes more beautiful still when we soak them with
the essential oil of the bark of the Laurus Cassia. The osseous cartilage is formed
before the earthy part. The long bones are then solid, and they become hollow only in
proportion as the earthy salts appear. In the new-born infant, a large portion of the
bones is but partially filled with these salts, their deposition in cartilage takes place
under certain invariable points of ossification, and begins at a certain period after conception, so that we may calculate the age of the foetus according to the progress which
ossification has made.
The earthy parts of bones are composed principally of the phosphate and carbonate
of lime in various proportions, variable in different animals, and mixed with small
quantities, equally variable, of phosphate of magnesia and fluate of lime. The easiest
means of procuring the earthy salts of bones consists in burning them to whiteness, but
the earthy residuum procured in this manner, contains substances which did not exist
beforehand in the bones, and which did not form a part of their earthy salts; as, for
example, sulphate of soda, produced at the expense of the sulphur of tne bones and the
alkaline carbonate, proceeding from the cartilage with which it was combined. On the
other hand, the greater part of the lime has lost its carbonic acid. As the sulphuric
acid is the product of combustion, it is obvious that an acidulous solution of a fresh bone
can afford no precipitate with muriate of barytes. The phosphate of lime contained in
the bone-salts is a subphosphate, consisting, according to Berzelius, of three prime
equivalents of the acid, and eight of the base; or of 2,677 parts of the formrr, and 2,818
of the latter. It is always obtained when we precipitate the phosphate of lime by an
excess of ammonia. When calcined bones are distilled in a retort with their own weight
of sulphuric acid, a little fluoric acid is disengaged, and it acts on the surface of the
glass.  The following analyses of the bones of men and horned cattle, are given by Berzelius. They were dried after being stripped of their fat and periosteum till they lost
no more weight.




224                                  BONES.
Human bone.  Ox bone.
Cartilage completely soluble in water    -    -    -    -    3217 
Vessels-                                                      1-113      33
Subphosphate with a little fluate of lime  -    -  53-04                 57-35
Carbonate of lime -       113                                             385
Phosphate of magnesia  -    -  116                                        2'05
Soda with very little muriate of soda   -    - -              1-20        3.45
100-00      100-00
The most essential difference in the composition of these bones is that those of man
contain three times as much carbonate of lime as those of the ox; and that the latter
are richer in phosphate of lime and magnesia in the same proportion. Fernandez de
Barros has established a comparison between the phosphate and carbonate of lime in
the bones of different animals. He found in 100 parts of earthy salt of the bones of the
following animals:Phosphate oflime Carb. lime.
Lion-    -                   -    -    -    -    -    -       95-0        2-5
PSheep..-                                                     80'0  19-3
Hen      -   -   -    -    -                                  88-9       10-4
Frog....-                                                    95-2  2-4
Fish..-        -.-                                   91-9        5-3
The bones of fish are divided into those which contain earthy salts and those which
have none, called cartilaginous fishes.  The enamel of the teeth is composed as
follows:Human enamel. Ox enamel.
Phosphate of lime with fluate of lime                         88-5       85-0
Carbonate of lime- -                     -       -             8-0        7'1
Phosphate of magnesia  - -                                     1.5  3'      0
Soda -                                                         0-0 1'4
Brown membranes attached to the tooth, alkali, water    -      2-0        3-5
100'0      100-0
In the arts, the bones are employed by turners, cutlers, manufacturers of animal charcoal, and, when calcined, by assayers for making cupels. In agriculture, they are
employed as a manure, for which purpose they should be ground in a mill, and the powder sowed along with the seeds in a drill. It is supposed, in many cases, to increase the
crop in weight of grain and straw together, by from 40 to 50 per cent. In France, soup
is extensively made by dissolving bones-in a steam-heat of two or three days' continuance. The shavings of hartshorn, which is a species of bone, afford an elegant jelly:
the shavings of calves' bones may be used in their stead.
Living bones acquire a red tinge when the animals receive madder with their food;
but they lose it when the madder is discontinued for some time.
The following analysis of the middle part of the thigh-bone of a man of 30 years of
age by Marchand, merits confidence:1. Cartilage insoluble in muriatic acid..  27-23
2.  Do.   soluble in       do......  5-02
3. Blood-vessels and nerves..                            1-01
4. Subphosphate of lime.....    5226
5. Fluoride of calcium......           1'00
6. Carbonate of lime......    10-21
7. Phosphate of magnesia.....                  105
8. Soda.........                                 0-92
9. Chlorsodium......0.25
10. Oxides of iron and manganese, and loss...      1.05
100-00
The human bones contain much more carbonate of lime than those of oxen; which
are, however, richer in phosphate of lime and magnesia. The proportion of cartilaginous matter in bones is not uniform, but varies in the same species of animal with
age, sex, and pasture. The quantity of bones imported in 1850 amounted to 27,198
tons, and in 1851 to 31,956 tons.




BONE BLACK.                                  225
BONE BLACK (Noir d'os, Fr.; Klochenschwartz, Germ.), or Animal charcoal, as
it is less correctly called, is the black carbonaceous substance into which bones are
converted by calcination in close vessels. This kind of charcaol has two principal
applications: to deprive various solutions, particularly sirups, of their coloring matters,
and to furnish a black pigment. The latter subject will be treated of under IVORY
BLACK.
The discovery of the antiputrescent and decoloring properties of charcoal in general,
is due lo Lowitz, of Petersburg; but their modifications have occupied the attention of
many chemists since his time. Kels published, in 1798, some essays on the discoloring
of indigo, saffron, madder, sirup, &c. by means of charcoal, but he committed a mistake
in supposing bone black to have less power than the charcoal of wood. The first
useful application of charcoal to the purification of raw colonial sugar was made by
M. Guillon, who brought into the French markets considerable quantities of fine sirups,
which he discolored by ground wood charcoal, and sold them to great advantage, as
much superior to the cassonades of that time. In 1811, M. Figuier, an apothecary at
Montpehier, published a note about animal charcoal, showing that it blanched vinegars
and wines with much more energy than vegetable charcoal; and, lastly, in 1812,
M. Derosnes proposed to employ animal charcoal in the purification of sirups and
sugar refining. The quantities of bone black left in the retorts employed by MM.
Payen, for producing crude carbonate of ammonia, furnished abundant materials for
making the most satisfactory experiments, and enabled these gentlemen soon to ob.
tain ten per cent. more of refined sugar from the raw article than had been formerly
extracted, and to improve, at the same time, the characters of the lumps, bastards,
treacle, &c.
The calcination of bones is effected by two different systems of apparatus; by heating
them in a retort similar to that in which coal is decomposed in the gas works, or in
small pots piled up in a kiln.  For the description of the former, see GAS-LIGHT.
On the second plan, the bones, broken into pieces, are put into small cast-iron pots
of the form shown in fig. 154, about three eighths of an inch thick, two of which are
dexterously placed with their mouths in contact, and then luted together with loam.
The lip of the upper pot is made to slip inside of the under one. These double vessels,
containing together about fifty pounds of bones, are arranged alongside, and over each
other, in an oven, like a potter's kiln, till it be filled. The oven or kiln may be either
oblong or upright. The latter is represented in figs. 155, 156, 157. A is the fireplace
or grate for the fuel; c c are the openings in the dome of the furnace through which
the flame flows; the divisions of these orifices are shown in fig. 157. B is the wall of
brick-work. D the space in which the pots are distributed. E is the door by which the
workman carries in the pots, which is afterwards built up with fire-bricks, and plastered
over with loam. This door is seen in fig. 155. r F are the lateral flues for conveying
the disengaged gases into the air.
15   158
154                  M                     5
-               A
Fig. 158 is a longitudinal section, and fig. 159, a ground plan of a horizontal kiln for
calcining bones, a is the fire-chamber, lying upon a level with the sole of the kiln; it
is separated by a pillar b, from the calcining hearth c. In the pillar or wall, several
rows of:holes d, are left at different heights; e is the entrance door; f, the outlet vents
for the gases, vapors, and smoke, into the chimney g; h, a sliding damper-plate for regulating the admission of the air into the fire in the space a.
By this arrangement the offensive emanations are partly consumed, and partly carried
off with the smoke. To destroy the smell completely, the smoke should be made to pass
through a second small furnace.
The number of pots that may be put into a kiln of this kind depends, of course, upon
its dimensions; but, in general, from 100 to 150 are piled up over each other, in columns,




226                              BONE BLACK.
at once; the greatest heat being nearest the roof of the kiln; which resembles, in many
respects, that used for baking pottery ware.
In bQth kilns the interior walls are built of fire-bricks. In the oblong one, the
fiercest heat is near the vaulted roof; in the upright one, near the sole; and the pots,
containing the larger lumps of bones, should be placed accordingly near the top of the
former, and the bottom of the latter.  Such a kiln may receive about seventy double
pots, containing in the whole thirty-five cwt. of bones.
After the earth is filled with the pots, and the entrance door is shut, the fire is
applied at first moderately, but afterwards it must be raised and maintained, at a brisk
heat, for eight or ten hours.  The door of the ash-pit and the damper may now be
nearly closed, to moderate the draught, and to keep up a steady ignition for six or eight
hours longer, without additional firing; after which the doors must be all opened to
cool the furnace. When this is done, the brick-work of the entrance door must be
taken down, the kiln must be emptied, and immediately filled again with a set of pots
previously filled with bones, and luted together; the pots which have been ignited may,
in the course of a short time, be opened, and the contents put into the magazine. But
in operating with the large decomposing cylinder retort, the bones being raked out hot,
must be instantly tossed into a receiver, which can be covered in air-tight till they are cool.
The bones lose upon the average about one half of their weight in the calcination.
In reference to the quality of the black, experience has shown that it is so much more
powerful as a discoloring agent, as the bones from which it was made have been freer
from adhering fatty, fleshy, and tendinous matters.
The charcoal is ground in a mill, either to a fine powder and sifted, or into a coarse
granular state, like gunpowder, for the preparation of which two sieves are required, one
with moderately fine meshes, to allow the small dust to pass through, and one with large
meshes, to separate the proper-sized grains from the coarser lumps. Either a corn-mill,
an edgestone mill, or a steel cylinder mill, may be employed for grinding bone-black, and
it is generally damped in the operation to keep down the fine dust.
Bone-black, as found in commerce, is very variable in its discoloring power, which
arises from its having been exposed either to too great a heat which has glazed its carbon, or too low a heat which has left its albumen imperfectly decomposed. A steady
ignition of due continuance is the proper decomposing temperature. Its composition is
generally as follows:Phosphate of lime, with carbonate of lime, and a little sulphuret of iron, or oxyde of
iron, 88 parts; iron in the state of a silicated carburet, 2 parts; charcoal containing
about one fifteenth of azote, 10 parts. None of the substances present, except the charcoal, possesses separately any discoloring power.
The quality may be tested by a solution of brown sugar, or molasses, or of indigo in
sulphuric acid. The last is generally preferred by the French chemists, who have occupied themselves most with this subject, and it contains usually one thousandth part
of its weight of this dye-drug of the best quality. Other animal substances yield a
charcoal, possessed of very considerable discoloring properties. The following table by
M. Bussy exhibits an interesting comparison of almost every kind of charcoal in this
point of view.
Table of the discoloring powers of different charcoals.
JIndigo test  Molasses test Blanching by  Power by
Species of Charcoal.  Weight.  consumed.   consumed.   indigo.       molasses.
Gramme.    Litres.
Blood calcined with potash   1         1-60       0'18        50          20
Ditto with chalk -  -  1              0'57         0'10        18          11
Ditto with phosphate lime     1       038        0-09         12         10
Gelatine ditto with potash   1         1-15       0-14        36           15-5
Albumen ditto ditto  - -      1        1-08       0-14        34          15*5
Starch ditto ditto -         I-  1    0-34        0'08        10-6          8-8
Charcoal from acet. potash   1        0'18        0-04         5-6         4'4
Ditto from carb. soda by
phosphorus  - - - -         1        0-38        0'08        12           8-8
Calcined lamp black --       1        0-128       0O03         4           3-3
Ditto ditto potash - -  -     1       0'55        0'09        15-2        10-6
Bone black treated with
mur. acid and potash -     1        1'45        0'18        45          20
Bone black ditto with mur.
acid          - - - -      1        0-06        0-015        1-87        1-6
Oil calcined with phosph.
of lime        -    - -  -  1       0-064       0-017        2           1'9
Crude bone black - - -       1        0-032       0'009        1           1,   -......... ~~~ ~~~ ~~~ ~~~ ~~~ ~~~ ~~~ ~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~




BONE BLACK.                                  227
With regard to the mode of operation of bone black on colored liquids, M. Payen
showed in his prize essay, 1. That' the decoloring power of charcoal depends in
general upon its state of division; 2. That in the various charcoals, the ciubonaceous
matter acts only upon the coloring matters, combining with and precipitating them; 3.
That in the application of charcoal to the refining of sugar, it acts also upon the gluten,
for it singularly promotes crystallization; 4. That according to the above principles, the
decoloring action of charcoals may be so modified, as to make the most inert become
the most active; 5. That the distinction between animal and vegetable charcoals is improper, and that we may substitute for it that of dull and brilliant charcoals; 6. That
of the substances present in charcoal besides carbon, and particularly animal charcoal,
those which favor the decoloring action, have an influence relative only to the carbon;
they serve as auxiliaries to it, by insulating its particles, and presenting them more
freely to the action of the coloring matter; 7. That animal charcoal, besiles its decoloring power, has the valuable property of taking lime in solution from water and
sirup; 8. That neither vegetable, nor other charcoals, besides the animal, have this
power of abstracting lime; 9. That by the aid of the decolorimeter, or graduated tube
charged with test solution of indigo or molasses, it is easy to appreciate exactly the de
coloring properties of all kinds of charcoal.
Different varieties of lignite (fossilized wood) or even pit coal, when well carbonized
in close vessels, afford a decoloring charcoal of considerable value. By reducing 100
parts of clay into a thin paste with water, kneading into it 20 parts of tar, and 500 of
finely-ground pit coal, drying the mixed mass, and calcining it out of contact of air, a
charcoally matter may be obtained not much inferior to bone-black in whitening sirups.
The restoration of animal charcoal from burnt bones, for the purpose of sugar refining, has been long practised in France. Mr. W. Parker has lately made the following
process the subject of a patent. The charcoal, when taken from the vessel in which it
has been employed for the purposes of clarifying the sugar, is to be thoroughly washed
with the purest water that can be obtained, in order to remove all the saccharine matter
adhering to it. When the washing process has been completed, the charcoal is laid out
to dry, either in the open air or in a suitable stove, and when perfectly free from moisture, it is to be separated into small pieces and sifted through a sieve, the wires or meshes
of which are placed at distances of about two and a half in every inch. This sifting
will not only divide the charcoal into small pieces, but will cause any bits of wood or
other improper matters to be separated from it.
The charcoal, thus prepared, is then to be packed lightly in cylindrical vessels called
crucibles, with some small quantity of bones, oil, or other animal matter mixed with it.
The crucibles are then to be closed by covers, and luted at the joints, leaving no other
opening but one small hole in the centre of the cover, through which any gas, generated
within the vessel when placed in the oven or furnace, may be allowed to escape.
The crucibles are now to be ranged round the oven, and placed, one upon another, in
vertical positions; and when the oven is properly heated, gas will be generated within
each crucible, and issue out from the central hole. The gas thus emitted, being of an
inflammable quality, will take fire, and assist in heating the crucibles; and the operation
being carried on until the crucibles become of a red heat, the
160   j c                1 6161 1  c    c        oven is then to be closed, and allowed to cool; after which the
crucibles are to  be removed,
{1  II  I.,I    when the charcoal will be found
to have become perfectly reno-^                 ^ H i    X  rvated, and fit for use as before.
" a                 >7 b IIBONE BLACK, or animal charcoal
__Y__i_/./ ____ I~      restored. A process for this pur~1.  * i  pose was made the subject of a
patent by Messrs. Bancroft and
~It ~,,iIn        jj>~ ^     MacInnes of Liverpool, which
d                     i                   consists in washing the granular....'Xi'i -.i' In                  charcoal, or digesting it when
E  X  m l   l     finely ground, with a weak soluX'f -^, e~T   1 ^1      tion of potash or soda, of specific
gravity 1-06. The bone black
9 5 g    which has been used in sugar rei, I I-'''i'               I. I' lq  X  fining may thus be restored, but
-~"  ~'" i,',t1. HI,    it should be first cleared from all',, l,',in,',r %  ~      Mthe soluble filth by means ofwater.
~~'   r''.'', L'~  IHI            Mr. F. Parker's method, patenti\\i////' ii////~.,,i  J~ ^.............~  ed in June, 1839, for effecting a./ /,(,/,~, 2 L.................... like purpose, is by a fresh calcination as follows:




228                              BOOKBINDING.
Fig. 160 represents a front section of the furnace and retort; andfig. 161 is a transverse vertical section of the same. a is a retort, surrounded by the flues of the furnace
b; c is a hopper or chamber, to which a constant fresh supply of the black is furnished,
as the preceding portion has been withdrawn, from the lower part of a. d is the cooling vessel, which is connected to the lower part of the retort a by a sand joint e. The
cooler dis made of thin sheet iron, and is large; its bottom is closed with a slide plate,
f. The black after passing slowly through the retort a into the vessel d, gets so much
cooled by the time it reachesf, that a portion of it may be safely withdrawn, so as to
allow more to fall progressively down; g is the charcoal meter, with a slide door.
BOOKBINDING, is the art of sewing together the sheets of a book, and securing
them with a back and side boards.
Bookbinding, according to the present mode, is performed in the following manner:
-The sheets are first folded into a certain number of leaves, according to the form in
which the book is to appear; viz., two leaves for folios, four for quartos, eight for
octavos, twelve for duodecimos, &c. This is done with a slip of ivory or boxwood,
called a folding-stick; and in the arrangement of the sheets the workmen are directed
by the catch-words and signatures at the bottom of the pages. When the leaves are thus
folded and arranged in proper order, they are usually beaten upon a stone with a heavy
hammer, to make them solid and smooth, and are then condensed in a press. After
this preparation they are sewed in a sewing press, upon cords or packthreads called
bands, which are kept at a proper distance from each other, by drawing a thread through
the middle of each sheet, and turning it round each band, beginning with the first and
proceeding to the last. The number of bands is generally six for folios, and five for
quartos, or any smaller size. The backs are now glued, and the ends of the bands are
opened, and scraped with a knife, that they may be more conveniently fixed to the pasteboard sides; after which the back is turned with a hammer, the book being fixed in a
press between boards, called backing boards, in order to make a groove for admitting the
pasteboard sides. When these sides are applied, holes are made in them for drawing
the bands through, the superfluous ends are cut off, and the parts are hammered
smooth. The book is next pressed for cutting; which is done by a particular machine
called the plough, to which is attached a knife. See the figures and descriptions itfra.
It is then put into a press called the cutting press, betwixt two boards, one of which
lies even with the press, for the knife to run upon; and the other above for the knife
to cut against. After this the pasteboards are cut square with a pair of iron shears;
and last of all, the colors are sprinkled on the edges of the leaves, with a brush made
of hog's bristles; the brush being held in the one hand, and the hair moved with the
other.
A patent was obtained in 1799 by Messrs. John and Joseph Williams, stationers in
London, for an improved method of binding books of every description. The improvement consists of a back, in any curved form, turned a little at the edges, and made of
iron, steel, copper, brass, tin, or of ivory, bone, wood, vellum, or, in short, any material
of sufficient firmness. This back is put on the book before it is bound, so as just to
cover without pressing the edges; and the advantage of it is that it prevents the book,
when opened, from spreading on either side, and causes it to rise in any part to nearly a
level surface. In this method of binding the sheets are prepared in the usual manner,
then sewed on vellum slips, glued, cut, clothed, and boarded, or half boarded; the firm
back is then fastened to the sides by vellum drawn through holes, or secured by enclosing
it in vellum or ferret wrappers, or other materials pasted down upon the boards, or drawn
through them.
A patent was likewise obtained in 1800 by Mr. Ebenezer Palmer, a London stationer,
for an improved way of binding books, particularly merchants' account-books. This improvement has been described as follows:-let several small bars of metal be provided,
about the thickness of a shilling or more, according to the size and thickness of the
book; the length of each bar being from half an inch to several inches, in proportion to
the strength required in the back of the book. At each end of every bar let a pivot be
made of different lengths, to correspond to the thickness of two links which they are to
receive. Each link must be made in an oval form, and contain two holes proportioned
to the size of the pivots, these links to be the same metal as the hinge, and each of
them nearly equal in length to the width of two bars. The links are then to be riveted
on the pivots, each pivot receiving two of them, and thus holding the hinge together,
on the principle of a link-chain or hinge. There must be two holes or more of different
sizes, as may be required, on each bar of the hinge or chain; by means of these holes
each section of the book is strongly fastened to the hinge which operates with the back
of the book. when bound, in such a manner as to make the different sections parallel
with each other, and thus admit writing without inconvenience on the ruled lines, close
to the back.
The leather used in covering books is prepared ad  applied as follows: being first




BOOKBINDING.                                 229
moistened in water, it is cut to the size of the book, and the thickness of the edge is
paired off on a marble stone. It is next smeared over with paste made of wheat flour,
stretched over the pasteboard on the outside, and doubled over the edges within. The
book is then corded, that is, bound firmly betwixt two boards, to make the cover stick
strongly to the pasteboard and the back; on the exact performance of which the neatness of the book in a great measure depends. The back is then warmed at the fire to
soften the glue, and the leather is rubbed down with a bodkin or folding stick, to set and
fix it close to the back of the book. It is now set to dry, and when dry, the boards are
removed; the book is then washed or sprinkled over with a little paste and water, the
edges and squares blacked with ink, and then sprinkled fine with a brush, by striking it
against the hand or a stick; or with large spots, by being mixed with solution of green
vitriol, which is called marbling. Two blank leaves are then pasted down to the cover,
and the leaves, when dry, are burnished in the press, and the cover rolled on the edges.
The cover is now glazed twice with the white of an egg, filleted, and, last of all, polished,
by passing a hot iron over the glazed color.
The employment in bookbinding of a rolling press for smoothing and condensing the
leaves, instead of the hammering which books have usually received, is an improvement
introduced several years ago into the trade by Mr. W. Burn. His press consists of two
iron cylinders about a foot in diameter, adjustable in the usual way, by means of a screw,
and put in motion by the power of one man or of two, if need be, applied to one or two
winch-handles. In front of the press sits a boy who gathers the sheets into packets, by
placing two, three, or four, upon a piece of tin plate of the same size, and covering them
with another piece of tin plate. and thus proceeding by alternating tin plates and bundles
of sheets till a sufficient quantity have been put together, which will depend on the stiffness and thickness of the paper. The packet is then passed between the rollers and received by the man who turns the winch, and who has time to lay the sheets on one side,
and to hand over the tin plates by the time that the boy has prepared a second packet.
A  minion Bible may be passed through the press in one minute, whereas the time
necessary to beat it would be twenty minutes. It is not, however, merely a saving of
time that is gained by the use of the rolling-press; the paper is made smoother than it
would have been by beating, and the compression is
162                 so much greater, that a rolled book will be reduced
to about five sixths of the thickness of the same book
l ~ 6. so muchI g if beaten. A shelf, therefore, that will hold fifty
E t    -           7~  ~ ~51  books bound in the usual way would hold nearly
Ir                   I r    sixty of those bound in this manner, a circumstance
l    P p      I      of no small importance, when it is considered how
large a space even a moderate library occupies, and
that book-cases are an expensive article of furniture.
A -         _             A     The rolling-press is now substituted for the hammer
177  -v y  ~         by several considerable bookbinders.
lii, ~ ~ ~ ~l~          Fig. 162 represents the sewing-press, as it stands
I  A  13     upon the table, before which the bookbinder sits.
iL I  l' Fig. 163 is a ground plan, without the parts a and
{ (If) -      -        n in the former figure. A is the base-board, supported upon the cross bars m n, marked with dotted
lines in fig. 163. Upon the screw rods r r,fig. 162, the nuts t d serve to fix the flat upper
bar n, at any desired distance from the base. That bar has a slit along its middle, through
which the hooks below z z pass down for receiving the ends of the sewing cords p p,
X, oIl "fixed at y y, and stretched by the thumb-screws z z.
-c:.- LI   ~               The bar y y is let into an oblong space cut out of the
t                          front edge of the base-board, and fixed there by a
moveable pin a, and a fixed pin at its other end, round
which it turns.
Fig. 164 is the bookbinder's cutting-press, which is
16~l4               -set upright upon a sort of chest for the reception of
the paper parings; and consists of three sides, being
open above and to the left hand of the workman.
The pressbar, or beam a, has two holes n n upon its
p~        o~0           under surface, for securing it to two pegs standing on
(~tqS~g.l 3-           the top of the chest. The screw rods t t pass through.s(    ~   two tapped holes in the bar, marked with b c at its
upper end; their heads r r being held by the shoulders o o. The heads are pierced with
holes into which lever pins are thrust for screwing the rods hard up. The heavy beam
a remains immoveable, while the parallel bar with the book is brought home towards it
by the two screws. The two rulers s s serve as guides to preserve the motions truly




230                               BOOKBINDING.
parallel; and the two parallel lath bars b c guide between them the end bar e, of the
plough, whose knife is shown at i, with its clamping screw z.
Mr. Oldham, printing engineer of the Bank of England, distinguished for mechanical
ingenuity, has contrived a convenient machine for cutting the edges of books, banknotes,
&c., either truly square or polygonal, with mathematical precision. Fig. 165, represents
an end elevation of the machine. Fig. 166, a side view of the same, the letters of
reference indicating the same parts of the machine in each of the figures.
a, is the top cross bar with rectangular grooves b b; c c, are side posts; d d, cross feet
to the same, with strengthening brackets; e e, a square box, in which the press stands,
for holding waste cuttings. Fig. 167, is a cross section of the upright posts, c c, taken
horizontally. There are rectangular grooves in the upright posts, for the projecting ends
of the cast iron cross bracketf, to slide up and down in. In the middle of the under-side
of this piece f, there is a boss, within which is a round recess, to receive the top of the
screw g, which works in the cast iron cross piece h, similarly made with the former, but
bolted firmly to the posts c c. Upon the screw g, there is a circular handle or ring i, for
166
170                      1                         1
partially turning the screw, and immediately over it cross holes for tightening the press
by means of a lever bar. Upon the cross piece f, is bolted the board j, and upon each
169
168
1710                                                174r 
P ~l~           2  173    r                              m
Across the middle of this board, and parallel to the pieces k k, the tongue piece m is
made fast, which fits into a groove in the bottom of board 1. A horizontal representation
of this is seen at fig. 168, and immediately under this view is also seen an end view of I
and f, connected together, and a side view off by itself. In the middle of the board I,
is a pin for a circular board h,, to turn upon, and upon this letter board is placed the
"material to be cut," with a saving piece between it, and the circular piece which is to
be divided upon its edge into any number of parts required, with a stationary index on
the board 1, to point to each.
It will now be understood that the " material to be cut," may be turned round upon'. centre pin of the board n, and also that both it and the board can be shifted back



BOOKBINDING.                                  231
ward and forward under the top cross piece a, and between the side slide slips k k, the
surfaces of which should also be divided into inches and tenths.
The plough, fig. 169, shown in several positions, is made to receive two knives or
cutters as the " material to be cut" may require, and which are situated in the plough
as I now describe. The plough is composed of three principal parts, namely, the top,
and its two sides. The top o, is made the breadth of the cross piece a, and with a
handle made fast thereon. The sides p p, are bolted thereto, with bolts and nuts through
corresponding holes in the top and sides. The figures below give inside views, and
cross sections of the details of the manner in which the cutters and adjustments are
mounted. A groove is cut down each cheek or side, in which are placed screws that
are held at top and bottom from moving up and down, but by turning th   c       they cause the
nuts upon them to do so; they are shown at q q. These nuts have each a pin projecting
inwards, that go into plain holes made in the top ends of cutters r r. The 169th and
following figs. are \ in scale.
The cutters, and the work for causing them to go up and down, are sunk into the
cheeks, so as to be quite level with their inner surfaces. Fig. 170 shows one of those
screws apart, how fixed, and with moveable nut and projecting pin. The top of each
screw terminates with a round split down, and above it a pinion wheel and boss thereon,
also similarly split. This pinion fits upon the split pin. Above, there is a cross section
of a hollow coupling cap with steel tongue across, that fits into both the cuts of the screw
pin and pinion boss, so that when lowered upon each other, they must all turn together.
In the middle and on the top of the upper piece o, the larger wheel s, runs loose upon its
centre, and works into the two pinion-wheels t t. The wheel s has a fly-nut with wings
mounted upon it.
It will now be seen, when the plough is in its place as at fig. 171, that if it be pushed
to and fro by the right hand, and the nut occasionally turned by the left, the knives or
cutters will be protruded downwards at the same time, and these either will or will not
advance as the coupling caps u u are on or off. The ribs v v, run in the grooves b b,
fig. 165, and keep the cutters to their duty, working steadily. The top cross bar a, is the
exact breadth of a bank-note, by which means both knives are made to cut at the same
time. The paper is cut uniformly to one length, and accurately square.
By the use of this machine, the air-pump paper-wetting apparatus, and appendant
press, the paper of 45,000 notes is fully prepared in one hour and a half by one person,
and may then be printed. It is not so much injured by this process as by the ordinary
method of clipping by hand, soaking it, &c., which more or less opens and weakens the
fabric, especially of bank-note paper.
One of the greatest improvements ever made in the art of bookbinding is, apparently,
that for which Mr. William Hancock has very recently obtained a patent.  After
folding the sheets in double leaves, he places them vertically, with the edges forming the
back of the book downwards in a concave mould, of such rounded or semi-cylindrical
shape as the back of the book is intended to have. The mould for this purpose consists
of two parallel upright boards, set apart upon a cradle frame, each having a portion or
portions cut out vertically, somewhat deeper than the breadth of the book, but of a width
nearly equal to its thickness before it is pressed. One of these upright boards may be
slidden nearer to or farther from its fellow, by means of a guide bar, attached to the sole
of the cradle. Thus the distance between the concave bed of the two vertical slots in
which the book rests, may be varied according to the length of the leaves. In all cases
about one fourth of the length of the book at each end projects beyond the board, so
that one half rests between the two boards. Two or three packthreads are now botuid
round the leaves thus arranged, from top to bottom of the page in different lines, in
order to preserve the form given to the back of the mould in which it lay. The book is
next subjected to the action of the press. The back, which is left projecting very slightly
in front, is then smeared carefully by the fingers with a solution of caoutchouc, whereby
each paper-edge receives a small portion of the cement. In a few hours it is sufficiently
dry to take another coat of a somewhat stronger caoutchouc solution. In 48 hours, 4 applications of the caoutchouc may be made and dried. The back and the adjoining part
of the sides are next covered with the usual band or fillet of cloth, glued on with caoutchouc; after which the book is ready to have the boards attached, and to be covered with
leather or parchment as may be desired.
We thus see that Mr. Hancock dispenses entirely with the operations of stitching,
sewing, sawing-in, hammering the back, or the use of paste and glue. Instead of leaves
attached by thread stitches at 2 or 3 points, we have them agglutinated securely along
their whole length. Books bound in this way open so perfectly flat upon a table
without strain or resilience, that they are equally comfortable to the student, the musician,




232                      BORACIC ACID LAGOONS.
and the merchant. The caoutchouc cement moreover being repulsive to insects, and
not affected by humidity, gives this mode of binding a great superiority over the old
method with paste or glue, which attracted the ravages of the moth, and in damp situations allowed the book to fall to pieces. For engravings, atlasses, and ledgers, this binding is admirably adapted, because it allows the pages to be displayed most freely without the risk of dislocating the volume; but for security, 3 or 4 stitches should be made.
The leaves of music books bound with caoutchouc, when turned over lie flat at their
whole extent, as if in loose sheets, and do not torment the musician like the leaves of
the ordinary books, which are so ready to spring back again. Manuscripts and collections of letters which happen to have little or no margin left at the back for stitching
them by, may be bound by Mr. Hancock's plan without the least encroachment upon the
writing. The thickest ledgers thus bound, open as easily as paper in quire, and may be
written on up to the innermost margin of the book without the least inconvenience.
BOOKBINDING, Mechanical.-An ingenious invention, for which Mr. Thomas Richards
of Liverpool, bookbinder, obtained a patent in April 1842.  He employs, first a
mechanism  to sew, weave, or bind a number of sheets together to form a book, instead of stitching them by hand; 2dly, a table which slides to and fro to feed or supply
each sheet of paper separately into his machine; also needle bars, or holders, to present
needles with the requisite threads, for stiching such sheets as they are supplied with
in succession. He has, moreover, a series of holding fingers, or pincers, suitably provided with motions, to enable them to advance and clasp the needles, draw them
through the sheets of paper, and return them into their respective holders, after threading orstitching the sheet; lastly, there are arms or levers for delivering each sheet
regularly upon the top of the preceding sheets, in order to form a collection or book
of such sheets, ready for boarding or finishing. A minute description of the whole
apparatus, with plates, is given in Newton's Journal, C. S. xxiii. 157.
BORACIC ACID.                                 41.  15. s42.   1843.   1834.
Quantities imported.          cwts. -      7,833   14,986  15,060
Quantities exported.        cwts. -         1      22      620
Retained for consumption..  cwts.  -  7,245  13,T17  15,953
Nett revenue..             8,193    798    361    422
The duty was repealed in 1845.:
BORACIC ACID LAGOONS. Before the discovery of this acid in the time of the
Grand Duke Leopold I., by the chemist Haefer, the fetid odor developed by the sulphuretted hydrogen gas, and the disruptions of therground occasioned by the appearance of new Sofioni or vents of vapor, had made the natives regard them as a diabolical scourge, which they sought to remove by priestly exorcisms; but since science
has explained the phenomena, the fumachi have become a source of public prosperity,
and, were they to cease would be prayed to return. The vapors which issue from
these lakes keep the waters always at a boiling temperature; hence, after impregnation
for 20 or 30 hours by the steams of the highest lake, they draw off the waters into a
second lake to suffer a fresh impregnation. Thence they are drawn into a third, and
so on till, they reach the lowest receptacle. In this passage, they get charged with
one-half per cent. of boracic acid. They are then concentrated in leaden reservoirs,
by the heat of the vapors themselves.
The liquid, after having filled the first compartment, is diffused very gradually into
the second, then into the third, and successively to the last, where it reaches such a state
of concentration that it deposits the crystallized acid; the workmen remove it immediately by means of wooden scrapers. This mode of gradual concentration is very ingenious, and requires so few hands that it may almost be said that the acid is obtained
without expense. From 1818 to 1845 the quantity of acid manufactured was 33,349,095
Tuscan pounds. From 1839 to 1845 the mean quantity has been 2,500,000 pounds.
Thus in estimating the product at 7,500 pounds per day, the quantity of saturated
water upon which they operate is 1,500,000 lbs. daily, and annually 547,500,000 lbs.
This labor brings to Tuscany ten millions of francs: it is surprising that it should
have remained unproductive for so many ages, and that it should have been reserved
for the skill of M. Dardarel, now Count of Mote Corboli,-before 1818 a simple
wandering merchant, entirely unacquainted with scientific researches, to discover the
nature of the fugitive vapors, and render them a source of inexhaustible wealth.
The violence with which the scalding vapors escape gives rise to muddy explosions
when a lake has been drained by turning its waters into another lake. The mud is
then thrown out, as solid matters are ejected from volcanoes, and there is formed in the
bottom of the lake a crowd of those little cones of eruption, whose activity and play
are generally from 120~ to 145~ Centigrade, and the clouds which they form in the
lagoons constitute true natural barometers, whose greater or less density rarely disappoints the predictions that they announce.




BORAX.                                     233
BORAX.  A native saline compound of boracic acid and soda, found abundantly in
Thibet and in South America. The crude product from the former locality was imported
into Europe under the name of tincal, and was purified from some adhering fatty matter
by a process kept a long time secret by the Venetians and the Dutch, and which consisted
chiefly in boiling the substance in water with a little quicklime.
Gmelin found borax, in prismatic crystals, to contain 46'6 per cent. of water; and
Arvredson, in the calcined state, to consist of 68-9 of acid and 31'1 soda, in 100 parts.
M. Payen describes an octahedral borax, which contains only 30'64 per cent. of water,
and is therefore preferred by the brasiers in their soldering processes.
Borax has a sweetish, somewhat lixivial taste, and affects vegetable colors like an alkali; it is soluble in 12 parts of cold and 2 of boiling water. It effloresces and becomes
opaque in a dry atmosphere, and appears luminous, by friction, in the dark. It melts at
a heat a little above that of boiling water, and gives out its water of crystallization, after
which it forms a spongy mass, called calcined borax. The octahedral borax, which is
prepared by crystallization, in a solution of 1-256 sp. gr., kept up at 145~ F., is not
efflorescent. When borax is ignited, it fuses into a glassy-looking substance.
The following is the improved mode of purifying borax. The crude crystals are to
be broken into small lumps, and spread upon a filter lined with a lead grating, under
which a piece of cloth is stretched upon a wooden frame. The lumps are piled up to
the height of 12 inches, and washed with small quantities of a caustic soda ley of 5~ B.
(sp. gr. 1'033) until the liquor comes off nearly colorless; they are then drained, and put
into a large copper of boiling water, in such quantities that the resulting solution stands
20~ B. (sp. gr. 1 160.)  Carbonate of soda, equivalent to 12 per cent. of the borax,
must now be added; the mixed solution is allowed to settle, and the clear liquid syphoned
off into crystallizing vessels.  Whenever the mother waters get foul, they must be
evaporated to dryness in cast-iron pots, and roasted, to burn away the viscid coloring
matter.
Borax is sometimes adulterated with alum and common salt; the former addition may
be readily detected by a few drops of water of ammonia, which will throw down its alumina; and the latter by nitrate of silver, which will give with it a precipitate insoluble
in nitric acid.
The native boracic acid obtained from the lakes of Tuscany, which has been mannfactured in France into borax, has greatly lowered the price of this article of commerce.
When MM. Payen and Cartier first began the business, they sold the crystals at the
same price as the Dutch, viz., 7 francs the kilogramme (2J lbs. avoird.); but, in a few
years, they could obtain only 2 francs and 60 centimes, in consequence of the market
getting overstocked. The annual consumption of France in 1823 was 25,000 kilos., and
the quantity produced in M. Paven's works was 50,000. The mode of making borax
from the acid is as follows:-The lake water is evaporated in graduation houses, and
then concentrated in boilers till it crystallizes. In that state it is carried to Marseilles. About 500 kilogrammes of water are made to boil in a copper, and 600 kilogrammes of crystallized carbonate of soda are dissolved in it by successive additions
of 20 kilogrammes. The solution being maintained at nearly the boiling point, 500
kilogrammes of the crystallized boracic acid of Tuscany are introduced, in successive
portions. At each addition of about 10 kilogrammes, a lively effervescence ensues,
on which account the copper should be of much greater capacity than is sufficient to
contain the liquors. When the whole acid has been added, the fire must be damped
by being covered up with moist ashes, and the copper mrust be covered with a tight lid
and blankets, to preserve the temperature uniform. The whole is left in this state
during 30 hours; the clear liquor is then drawn off into shallow crystallizing vessels of
lead, in which it should stand no higher than 10 or 12 inches, to favor its rapid cooling.
At the end of three days in winter, and four in summer, the crystallization is usually
finished.  The mother water is drawn off, and employed, instead of simple water,
for the purpose of dissolving fresh crystals of soda. The above crystals are carefully
detached with chisels, redissolved in boiling water, adding for each 100 kilos., 10 kilos.
of carbonate of soda. This solution marks 20~ B. (sp. gr. 1'160); and, at least, one ton
(1000 kilos.) of borax should be dissolved at once, in order to obtain crystals of a
marketable size. Whenever this solution has become boiling hot, it must be run off into
large crystallizing lead chests of the form of inverted truncated pyramids, furnlshed with
lids, enclosed in wooden frames, and surrounded with mats to confine the heat. For a
continuous business, there should be at least 18 vessels of this kind; as the solution
takes a long time to complete its crystallization, by cooling to 30~ C. (86~ F.) The borax crystals are taken out with chisels, after the liquor has been drawn off, and the whole
has become cold.
One hundred parts of the purest acid, usually extracted from the lakes of Tuscany, contain only fifty parts of the real boracic acid, and yield no more, at the utmost, than 140
or 150 of good borax.




234                                  BORAX.
According to Wittstein, the commercial boracic acid is composed as follows:Sulphate of manganese   -      — A trace
iron  0 —           -      -       -      -      -      -   365
alumina      -      -      -       -      -      -      - 0320
lime  -                    -       -      -      -      - 1018
magnesia    -       -              -                    - 2632
ammonia    -        -      -      --                    - 8'508
soda  0 —           -      -      -       -      -      -   917
potash       -      -      -      -       -      -      - 0369
salammonia  -       -      -      -       -      -         0-298
silica (in solution)   -   -      -       -      -      - 1-200
sulphuric acid (combined with the boracic) -     -      - 1322
crystallizable boracic acid   -   -       -      -      - 76494
Water           6 —            -      -      -      --'557
100-000
Dry borax acts on the metallic oxides at a high temperature, in a very remarkable
manner, melting and vitrifying them into beautiful colored glasses. On this account
it is a most useful reagent for the blowpipe. Oxide of chrome tinges it of an emerald
green; oxide of cobalt, an intense blue; oxide of copper, a pale green; oxide of tin,
opal; oxide of iron, bottle green and yellow; oxide of manganese, violet; oxide of
nickel, pale emerald green. The white oxides impart no color to it by themselves.
In the fusion of metals borax protects their surface from oxidizement, and even dissolves away any oxides formed upon them; by which twofold agency it becomes an
excellent flux, invaluable to the goldsmith in soldering the precious metals, and to
the brazier in soldering copper and iron.
Borax absorbs muriatic and sulphureous acid gases, but no others, whereby it becomes, in this respect, a useful means of analysis.
The strength or purity of borax may be tested by the quantity of sulphuric acid
requisite to neutralize a given weight of it, as indicated by tincture of litmus.
When mixed with shellac in the proportion of one part to five, borax renders that
resinous body soluble in water, and forms with it a species of varnish.
Boracic acid is a compound of 31'19 of boron and 68'81 oxygen, in 100 parts. Its
prime equivalent referred to oxygen 100, is 871'96.
The following process for refining the native Indian borax, or tincal, has been published by MM. Robiquet and Marchand:It is put into large tubs, covered with water for 3 or 4 inches above its surface, and
stirred through it several times during six hours. For 400 lbs. of the tincal there
must now be added 1 lb. of quicklime diffused through two quarts of water.  Next
day the whole is thrown upon a sieve, to drain off the water with the impurities,
consisting, in some measure, of the fatty matter combined with the lime, as an insoluble soap. The borax, so far purified, is to be dissolved in 21 times its weight of
boiling water, and 8 lbs. of muriate of lime are to be added for the above quantity of
borax. The liquor is now filtered, evaporated to the density of 18~ or 200 B. (1'14 to
1'16 sp. gray.), and set to crystallize in vessels shaped like inverted pyramids, and
lined with lead. At the end of a few days, the crystallization being completed, the
mother waters are drawn off, and the crystals are detached and dried. The loss of
weight in this operation is about 20 per cent.
1841.   1842.    1848.    1844.
Quantities imported  - -           - cwts.            3581      841      1427
Quantities exported  -             - cwts.   -        2435     2940      3637
Retained for consumption -   -   - cwts.              7798      889       349
Nett revenue   -     -         -~   866                161         5        4 
The duty on borax has been repealed.
BORAX, DRY. A considerable saving of expense in manufacturing borax, and a more
ready application of the borax to use, are proposed by Saulter, as follows:-Take
about 38 parts of pure crystallized boracic acid, pounded and sifted; mix them well
with 45 parts of crystals of carbonate of soda in powder; expose the mixture upon
wooden shelves to heat in a stove room; and rake it up from time to time. The boracic acid and the alkali thus get combined, while the carbonic cid and water are expelled; and a perfect dry borax is obtained.




BOUGIE.                                   235
176                                        BOTTLE MANUFACTURE. The fol.
m q:;,.'       __._P     lowing  mechanism  for moulding bottles
-A ~I = 11., "l ~    forms the subject of a patent obtained by
mi ( a  _          _ e  e   Henry Rickets of Bristol, in 1822. Fig. 176
X 71      ~~~n    X    is a section of the apparatus, consisting of
q        m       a square frame, a a, of iron or wood; this
is fixed in a pit formed in the floor; b b
o C    is the base of the frame, with an aperjj k p.   -- _k                    to ture for knocking up the bottom of the
bottle; c c are four legs secured to the,.1^~ JX frame.floor b, upon which the mould is
X I~~~,w I         X supported. The platform or stand of the
mould d d has an opening in its centre for;  /~ lll 1       X          the introduction  of the bottom  of the
-.; l1,  I  mould, which is raised against the bottom
"^llzo' M l"  g                  of the bottle by the knocker-up; e e are
HI |  9~    g  ~7  1'.P^  IIIthe sides of the mould; and ff is the top
of the mould in two pieces, turning over
m1 e          wl l   PO upon the joints at g g, so as to form the
neck of the bottle; h h are levers or arms
for raising and depressing the top pieces;
I|~ |I-~ 1i i  is a horizontal shaft or axle, turning in
bearings at each end, from which shaft two
C        C         vcl  levers, k k, extend; these levers are conA  _        a/1^nected by upright rods, 1 1, to the levers or
I    arms, h h, of the top pieces ff.
The weight of the arms h h, and rods 11, will, by their gravity, cause the top pieces
to open, as shown by the dotted lines; in this situation of the mould, the melted glass
is to be introduced by a tube as usual. The workman then steps with one foot upon
the knob mn, which forces down the rod n, and by means of a short lever o, extending from
the shaft i, forces down the top pieces f, and closes the mould, as seen in the figure; the
glass is then made to extend itself to the shape of the mould, by blowing as usual, so as
to form the bottle, and the workman at this time putting his other foot upon the knob p,
depresses the rod q, and hence raises the bottom of the mould by means of the knockerup, r, so as to form the bottom of the bottle.
At the bottom of the mould a ring is introduced of any required thickness, for the
purpose of regulating the capacity of the bottle; upon which ring it is proposed to
raise letters and figures, as a mould to imprint the maker's name and the size of the
bottle. These moulds can be removed and changed at pleasure. Under the knob p,
a collar or washer is to be introduced, of any required thickness, to regulate the
knocking up of the bottom, by which a perfect symmetry of form is presented. In
order to make bottles of different sizes or forms, the mould is intended to be removed,
and its place supplied by another mould of different dimensions and figure; the lower
parts of all the moulds being made to fit the same frame. Such a mould ought to be
prescribed by legislative enactment, with an excise stamp to define the capacity of every
bottle, and thereby put an end to the interminable frauds committed in the measure of
wine and all other liquors sold by the bottle.
BOUGIE. A smooth, flexible, elastic, slender cylinder, introduced into the urethra,
rectum, or esophagus, for opening or dilating it, in cases of stricture and other diseases.
The invention of this instiument is claimed by Aldereto, a Portuguese physician, but its
form  and uses were first described by his pupil Amatus, in the year 1554. Some are
solid, and some hollow; some corrosive, and some mollifying. They generally owe their
elasticity to linseed oil, inspissated by long boiling, and rendered drying by litharge.
This viscid matter is spread upon a very fine cord or tubular web of cotton, flax, or silk,
which is rolled upon a slab when it becomes nearly solid by drying, and is finally polished
in the same way.
Pickel, a French professor of medicine, published the following recipe for the composition of bougies. Take 3 parts of boiled linseed oil, one part of amber, and one
of oil of turpentine; melt and mix these ingredients well together, and spread the
compound at three successive intervals upon a silk cord or web. Place the pieces
so coated in a stove heated to 150~ F.; leave them in it for 12 hours, adding 15
or 16 fresh layers in succession, till the instruments have acquired the proper size.
Polish them first with pumice-stone, and finally smooth with tripoli and oil. This process is the one still employed in Paris, with some slight modifications; the chief of
which is dissolving in the oil one twentieth of its weight of caoutchouc to render the
substance more solid. For this purpose the caoutchouc must be cut into slender
shreds, and added gradually to the hot oil. The silk tissue must be fine and open, to




236                           BRAIDING MACHINE.
admit of the composition entering freely among its filaments. Each successive layer
ought to be dried first in a stove, and then in the open air, before another is applied.
This process takes two months for its completion, in forming the best bougies called
elastic; which ought to bear twisting round the finger without cracking or scaling, and
extension without giving way, but retracting when let go. When the bougies are to be
hollow, a nandril of iron wire, properly bent with a ring at one end, is introduced into
the axis of the silk tissue. Some bougies are made with a hollow axis of tin foil rolled
into a slender tube. Bougies are also made entirely of caoutchouc, by the intervention
of a solution of this substance in sulphuric ether, a menstruum sufficiently cheap in
France, on account of the low duty upon alcohol. There are medicated bougies, thecomposition of which belongs to surgical pharmacy. The manufacture of these instruments of various kinds forms a separate and no inconsiderable branch of industry at
Paris.  MM. Feburger and Lamotte are eminent in this line.
BRACES.  (Bretelles, Fr.; Hosentrager, Germ.)  Narrow fillets or bands of leather
or textile fabric, which pass over the shoulders, and are attached behind and before to
the -waistbands of pantaloons and trousers, in the act of wearing them, for supporting
their weight, and bracing them up to the body. It is a useful modern invention, superseding the necessity of girding the belly with a tight girdle, as in former times.
BRAIDING MACHINE. (Machine a lacets, Fr.; Bortenwerkerstuhl, Germ.)  This
being employed not only to manufacture stay-laces, braid, and upholsterers' cord, but
to cover the threads of caoutchouc for weaving brace-bands, deserves a description in
this work.  Three threads at least are required to make such a knitted lace, but 11, 13,
or 17, and even 29 threads are often employed, the first three numbers being preferred.
They are made by means of a frame of a very ingenious construction, which moves by
a continuous rotation.  We shall describe a frame with 13 threads, from  which the
structure of the others may be readily conceived. The basis of the machine consists of
N
3D oD   O
I,J   1. - -7 i'..'
I IIE IJM ~,
four strong wooden uprights, A, figs. 177, 178, 179, occupying the four angles of a
rectangle, of which one side is 14 inches long, the other 18 inches, and the height of the
rectangle about 40 inches. Fig. 177 is a section in a horizontal plane, passing through
the line a b offig. 178, which is a vertical section in a plane passing through the centre of
the machine c, according to the line c d,fig. 177. The side x is supposed to be the front
of the frame; and the opposite side, Y, the back. B, six spindles or skewers, numbered,
from 1 to 6, placed in a vertical position upon the circumference of a circle, whose centre
coincides with that of the machine at the point c. These six spindles are composed,
1. Of so many iron shafts or axes i, supported in brass collets E (fig. 178), and ex.
tended downwards within six inches of the ground, where they rest in brass steps fixed
upon a horizontal beam.  2. Wooden heads, made of horn-beam or nut-tree, placed, the
first upon the upper end of each spindle, opposite the cut-out beam F, and the second
opposite the second beam  G.  3. Wooden-toothed wheels, H, reciprocally working
together, placed between the beam G and the collet-beam E. The toothed wheels and
the lower heads for each spindle are in one piece.
The heads and shafts of the spindles No. 1 and 6, are one fifth stronger than those of
the other spindles; their heads have five semicircular grooves, and wheels of 60 teeth,
while the heads of the others have only four grooves, and wheels of 48 teeth; so that
the number of the grooves in the six spindles ir 26, one half of which is occupied with
the stems of the puppets r, which carry the 13 threads from No. 1 to 13. The toothed
wheels, which give all the spindles a simultaneous movement, but in different directions,




BRAN.                                    237
are so disposed as to bring their grooves opposite to each other in the course of
rotation.
K, the middle winglet, triple at bottom and quintuple at top, which serves to guide the
puppets in the direction they ought to pursue.
L, three winglets, single at top and bottom, placed exteriorly, which serve a like
purpose.
hI, two winglets, triple at bottom and single at top, placed likewise exteriorly, and
which serve the same purposes as the preceding; m are iron pins inserted in the cut-out
beam G, which serve as stops or limits to the oscillations of the exterior winglets.
Now, if by any moving power (a man can drive a pair) rotation be impressed upon
the large spindle No. I, in the direction of the arrow, all the other spindles will necessarily pursue the rotatory movement indicated by the respective arrows. In this case,
the 13 puppets working in the grooves of the heads of the spindles will be carried round
simultaneously, and will proceed each in its turn, from  one extremity of the machine to
the opposite point, crossing those which have a retrograde movement. The 13 threads
united at the point N, situated above the centre of the machine, will form at that point
the braid, which, after having passed over the pulley o, comes between the
e       a1 Ma    two rollers P Q, and is squeezed together, as in a flatting-mill, where the
braid is calendered at the same time that it is delivered. It is obvious
that the roller P receives its motion from the toothed wheel of the spindle
No. 3, and from the intermediate wheels R, s, T, as well as from the endless
screw z, which drives at proper speed the wheel w, fixed upon the shaft
of the roller P.
The braid is denser in proportion as the point N is less elevated above
g  the tops of the puppets; but in this case, the eccentric motion of these
puppets is much more sensible in reference to that point towards which
b   1,  all the threads converge than when it is elevated. The threads, which
must be always kept equally stretched by means of a weight, as we shall
presently see, are considerably strained by the traction, occasioned by the
constantly eccentric movement of the puppets. From this cause, braiding machines must be worked at a moderate velocity. In general, for
fine work, 30 turns of the large spindle per minute are the utmost that can
safely be made.
The puppet or spindle of this machine, being the most important
piece, I have represented it in section, upon a scale one fourth of its actual size, fig. 179. It is formed of a tube, a, of strong sheet iron well
brazed; b is a disc, likewise of sheet iron, from which a narrow fillet, c,
rises vertically as high as the tube, where both are pierced with holes,
d e, through which the thread f is passed, as it comes from the bobbin,
a   g, which turns freely upon the tube a. The top of this bobbin is conical
and toothed. A  small catch or detent, h, moveable in a vertical direction round i, falls by its own weight into the teeth of the crown of
the bobbin, in which case this cannot revolve; but when the detent is
raised so far as to disengage the teeth, and at the same time to pull the
thread, the bobbin turns, and lets out thread till the detent falls back into
179         these same teeth.
A skewer of iron wire, k, is loaded with a small weight, 1, melted upon
it. The top of this skewer has an eye in it, and the bottom is recurved as is shown in
fig. 179, so that supposing the thread comes to break, this skewer falls into the actual
position in the figure, where we see its lower end extending beyond the tube a, by
about - of an inch; but as long as the thread is unbroken, the skewer k, which serves
to keep it always tense, during the eccentric movement of the puppet, does not pass out
below the tube.
This disposition has naturally furnished the means of causing the machine to stop,
whenever one of the threads breaks. This inferior protrusion of the skewer pushes in
its progress a detent, which instantly causes the band to slide from the driving pulley to
the loose pulley. Thus the machine cannot operate unless all the threads be entire. It
is the business of the operative, who has 3 or 4 under her charge, to mend the threads
as they break, and to substitute full bobbins for empty ones, whenever the machine is
stopped.
The braiding frame, though it does not move quickly, makes a great deal of noise, and
would make still more, were the toothed wheels made of metal instead of wood. For
them to act well, they should be made with the greatest precision, by means of appropriate tools for forming the teeth of the wheels, and the other peculiar parts.
BRAN. (Son, Fr.; Kleie, Germ.)  The husky portion of ground wheat, separated by
the bolter from the flour. It is advantageously employed by the calico printers, in the
clearing process, in which, by boiling in bran-water, the coloring matters adhering to the




238                                 BRANDY.
non-mordanted parts of maddered goods, as well as the dun matters which cloud the mordanted portions, are removed. A valuable series of researches concerning the operation
of bran in such cases was made a few years ago by that distinguished chemist and calico
printer, M. Daniel Kcechlin-Schouch, and published in the ninth number of the Bulletin
de la Societ6 Industrielle de Mulhausen. Nine sets of experiments are recorded, which
justified the following conclusions.
1. The dose of two bushels of bran for 10 pieces of calico is the best, the ebullition
being kept up for an hour. A boil for the same time in pure water had no effect in clearing either the grounds or the figures.
2. Fifteen minutes boiling are sufficient when the principal object is to clear white
grounds, but in certain cases thirty minutes are requisite to brighten the dyed parts. If,
by increasing the charge of bran, the time of the ebullition could be shortened, it would
be in some places, as Alsace, an economy; because for the passage of ten pieces through
a copper or vat heated with steam, 1 cwt. of coal is consumed in fuel which costs from
2- to 3 francs, while two bushels of bran are to be bought for one franc.
3. By increasing the quantity of water from 12 to 24 hectolitres with two bushels of
bran, the clearing effect upon the ten pieces was impaired. It is therefore advantageous
not to use too much water.
4. Many experiments concur to prove that flour is altogether useless for the clearing
boil, and that finer bran is inferior for this purpose to the coarser.
5. The white ground of the calicoes boiled with wheat bran, are distinguishable by
their superior brightness from that of those boiled with rye bran, and especially with
barley bran; the latter having hardly any effect.
6. There is no advantage in adding soap to the bran boil; though a little potash or soda
may be properly introduced when the water is calcareous.
7. The pellicle of the bran is the most powerful part, the flour and the starch are of
no use in clearing goods, but the mucilage which forms one third of the weight of the
bran has considerable efficacy, and seems to act in the following way. In proportion as
the mucilaginous substance dissolves the coloring and tawny matters upon the cloth, the
husky surface attracts and fixes upon itself the greater part of them. Accordingly, when
used bran is digested in a weak alkaline bath, it gives up the color which it had absorbed
from the cloth.
The following chemical examination of bran is interesting. A pound of it was boiled
at successive times with water; the decoctions, being filtered, let fall in cooling a grayish
deposite, which was separated by decantation. The clear liquor afforded by evaporation
to dryness four ounces of a brownish, brittle matter, composed chiefly of mucilage, a
little gluten, and starch. The gray deposite of the above filtered liquor amounted to half
an ounce. Nine ounces of the cortical portion of the bran were obtained. The loss
amounted to 24  ounces, being in some measure the hygrometric water of the bran
itselfl
When boiled with distilled water, goods are cleared pretty well without bran. Certain delicate dyes must be boiled only a few minutes in a strong decoction of bran previously made.
BRANDY. The name given in this country to ardent spirits distilled from wine,
and possessed of a peculiar taste and flavor, due to a minute portion of a peculiar
volatile oil. Each variety of alcohol has an aroma characteristic of the fermented substance from which it is procured; whether it be the grape, cherries, sugar-cane, rice,
corn, or potatoes; and it may be distinguished even as procured from different growths
of the vine.  The brandies of Languedoc, Bordeaux, Armagnac, Cognac, Aunis,
Saintonge, Rochelle, Orleans, Barcelona, Naples, &c. being each readily recognisable by
an experienced dealer.
Aubergier showed, by experiments, that the disagreeable taste of the spirits distilled
from the marc of the grape is owing to an essential oil, contained in the skin of the
grape; and found that the oil, when insulated, is so energetic that a few drops are sufficient to taint a pipe of 600 litres of fine flavored spirit.
The most celebrated of the French brandies, those of Cognac and Armagnac, are slight.
ly rectified to only from 0-935 to 0-922; they contain more than half their weight of water, and come over therefore highly charged with the fragrant essential oil of the husk of
the grape. When, to save expense of carriage, the spirit is rectified to a much higher
degree, the dealer, on receiving it at Paris, reduces it to the market proof by the addition
of a little highly-flavored weak brandy and water; but he cannot in this way produce so
finely-flavored a spirit, as the weaker product of distillation of the Cognac wine. If the
best Cognac brandy be carefully distilled at a low heat, and the strong spirit be diluted
with water, it will be found to have suffered much in its flavor.
Genuine French brandy evinces an acid reaction with litmus paper, owing to a minute
portion of vinegar; it contains, besides, some acetic ether, and, when long kept in oak




BRASS.                                     239
casks, a little astringent matter. The following formula may be proposed for converting
a silent or flavorless corn spirit, into a factitious brandy. Dilute the pure alcohol to the
proof pitch, add to every hundred pounds weight of it from half a pound to a pound of
argol (crude winestone) dissolved in water, a little acetic ether, and French wine-vinegar,
some bruised French plums, and flavor-stuff from Cognac; then distil the mixture with a
gentle fire, in an alembic furnished with an agitator.
The spirit which comes over may be colored with nicely burned sugar (caramel) to
the desired tint, and roughened in taste with a few drops of tincture of catechu or oakbark.
The above recipe will afford a spirit free from the deleterious drugs too often used to
disguise and increase the intoxicating power of British brandies; one which may be reckoned as wholesome as alcohol, in any shape, can ever be.
BRASS.  (Laiton, cuivre jaune, Fr.; Messing, Germ.)  An alloy of copper and
zinc. It was formerly manufactured by cementing granulated copper, called bean-shot, or
copper clippings, with calcined calamine (native carbonate of zinc) and charcoal, in a
crucible, and exposing them to bright ignition. Three parts of copper were used for
three of calamine and two of charcoal. The zinc reduced to the metallic state by the
agency of the charcoal, combined with the copper, into an alloy which formed, on cooling, a lump at the bottom of the crucible. Several of these, being remelted and cast
into moulds, constituted ingots of brass for the market. James Emerson obtained a patent, in 1781, for making brass by the direct fusion of its two metallic elements, and it
is now usually manufactured in this way.
It appears that the best proportion of the constituents to form fine brass is one prime
equivalent of copper=63+-one of zinc=32'3; or very nearly 2 parts of copper to I of
zinc. The bright gold colored alloy, called Prince's, or Prince Rupert's metal, in this
country, consists apparently of two primes of zinc to one of copper, or of nearly equal
parts of each. Brass, or hard solder, consists of two parts of brass and one of zinc
melted together, to which a little tin is occasionally added; but when the solder must
be very strong, as for brass tubes that are to undergo drawing, two thirds of a part of
zinc are used for two parts of brass. Mosaic gold, according to the specification of
Parker and Hamilton's patent, consists of 100 parts of copper, and from 52 to 55 of zinc;
which is no atomic proportion. Bath metal is said to consist of 32 parts of brass and 9
parts of zinc.
The button manufacturers of Birmingham make their platin with 8 parts of brass and
5 of zinc; but their cheap buttons with an alloy of copper, tin, zinc, and lead.
Red brass, the Tombak of some, (not of the Chinese, for this is white copper,)
consists of more copper and less zinc than go to the composition of brass; being from
2, to 8 or 10 of the former to 1 of the latter. At the famous brass works of Hegermuhl, to be presently described, 11 parts of copper are alloyed with 2 of zinc into a red
brass, from which plates are made that are afterwards rolled into sheets. From such
an alloy the Dutch foil, as it is called, is manufactured at Nfirnberg; Pinchbeck, Similor,
Mannheim gold, are merely different names of alloy similar to Prince's metal. The last
consists of 3 of copper and 1 of zinc, separately melted, and suddenly incorporated by
stirring.- Wiegleb.
In the process of alloying two metals of such different fusibilities as copper and zinc,
a considerable waste of the latter metal by the combustion, to which it is so prone,
might be expected; but, in reality, their mutual affinities seem to prevent the loss, in
a great measure, by the speedy absorption of the zinc into the substance of the copper.
Indeed, copper plates and rods are often brassed externally by exposure, at a high
temperature, to the fumes of zinc, and aftewards laminated or drawn. The spurious
gold wire of Lyons is made from such rods. Copper vessels may be superficially converted into brass by boiling them in dilute muriatic acid containing some wine-stone and zinc
amalgum.
The first step in making brass is to plunge slips of copper into melted zinc till an alloy
of somewhat difficult fusion be formed, to raise the heat, and add the remaining proportion of the copper.
The brass of the first fusion is broken to pieces, and melted with a fresh quantity of
zinc, to obtain the finished brass. Each melting takes about 8 or 9 hours. The metal
is now cast into plates, about 40 inches long by 26 inches broad, and from one third to
one hal inch thick. The moulds are, in this case also, slabs of granite mounted in an iron
frame.  Granite appears to be preferred to every thing else as a mould, because it preserves the heat long, and by the asperities of its surface, it keeps hold of the clay lute
applied to secure the joinings.
The cast plates are most usually rolled into sheets. For this purpose they are cut
into ribands of various breadths, commonly about 61 inches. The cylinders of the
brass rolling-press are generally 46 inches long, and 18 inches in diameter. The




240                                  BRASS.
rbands are first of all passed cold through the cylinders; but the brass soon becomes
too hard to laminate. It is then annealed in a furnace, and, after cooling, is passed
afresh through a rolling press. After paring off the chipped edges, the sheets are
laminated two at a time: and if they are to be made very thin, even eight plates are
passed through together. The brass in these operations must be annealed 7 or 8 times
before the sheet arrives at the required thinness. These successive heatings are very
expensive; and hence they have led the manufacturers to try various plans of economy. The annealing furnaces are of two forms, according to the size of the sheets
of brass. The smaller are about 12 feet long, with a fire-place at each end, and about
13 inches wide. The arch of the furnace has a cylindrical shape, whose axis is
parallel to its small side. The hearth is horizontal, and is made of bricks set on edge.
In the front of the furnace there is a large door, which is raised by a lever, or chain,
and counterweight, and slides in a frame between two cheeks of cast iron. This furnace
has, in general, no chimney, except a vent slightly raised above the door, to prevent the
workmen being incommoded by the smoke. Sometimes the arch is perforated with a number of holes. The sheets of brass are placed above each other, but separated by parings,
to allow the hot air to circulate among them, the lowest sheet resting upon two bars of
cast iron placed lengthwise.
The large furnaces are usually 32 feet long, by 68 feet wide, in the body, and 3 feet
at the hearth. A grate, 13 inches broad, extends along each side of the hearth,
through its whole length, and is divided from it by a small wall, 2 or 3 inches high.
The vault of the furnace has a small curvature, and is pierced with 6 or 8 openings,
which allow the smoke to pass off into a low bell-chimney above. At each end of the
furnace there is a cast-iron door, which slides up and down in an iron frame, and
is poised by a counterweight. On the hearth there is a kind of railway, composed of
two iron bars, on the grooves of which the carriage moves with its loads of sheets of
brass.
These sheets, being often 24 feet long, could not be easily moved in and out of the
furnace; but as brass laminates well in the cold state, they are all introduced and
moved out together. With this view, an iron carriage is framed with four bars, which
rest on four wheels. Upon this carriage, of a length nearly equal to that of the furnace,
the sheets are laid, with brass parings between them. The carriage is then raised by a
crane to a level with the furnace, and entered upon the grooved bars which lie upon the
hearth. That no heat may be lost, two carriages are provided, the one being ready to
put in as the other is taken out; the furnace is meanwhile uniformly kept hot. This
method, however convenient for moving the sheets in and out, wastes a good deal of fuel
in heating the iron carriage.
The principal places in which brass is manufactured on the great scale in England, are
Bristol, Birmingham, and Holywell, in North Wales.
The French writers affirm, that a brass, containing 2 per cent. of lead, works more
freely in the turning lathe, but does not hammer so well as a mere alloy of copper and
zinc.
At the brass manufactory of Hegermiihl, upon the Finon canal near Potsdam, the following are the materials of one charge; 41 pounds of old brass, 55 pounds refined copper (gahrkupfer) granulated; and 24 pounds of zinc. This mixture, weighing 120 pounds,
is distributed into four crucibles, and fused in a wind furnace with pitcoal fuel. The
waste varies from 21 to 4 pounds upon the whole.
Fig. 180 represents the furnace as it was formerly worked there with charcoal; a, the
laboratory in which the crucibles were
7, 180        1           182           placed. It was walled with fire-bricks.
E~  3        I a"///The foundations, and the filling-in walls
/ill    111    1, I /   / / were formed of stone rubbish, as being bad
"  lll:| i:~  \\ /    I    conductors of heat; sand and ashes may be
also used; b, cast iron circular grating
/^-^g   W    W \  ///  plates pierced with 12 holes (see fig. 181),
~_l'_-~'____  IHjI AX\\    J{  over them a sole of loam, c, is beat down,
iil yalllllj^  ^        vand perforated with holes, corresponding
(7: //,,,  a~  to those in the iron discs; d, the ash pit;
e, the bock, a draught flue which con"  ducts the air requisite to the combustion, from a sunk tunnel, in communica181               /tion with several melting furnaces. The
To^              I/   \\  \\  terrace or crown of the furnace, f, lies on
0o o                            a level with the foundery floor, h h, and is
0OO}            f 0           \2  shut with a tile of fire-clay, g, which may
\pir ~O   7      ^   ^be moved in any direction by means of
hooks and eyes in its binding iron ring.




BRASS.                                      241
Fig. 182, the tongs for putting in and taking out the charges, as viewed from  above
and from the side.
Figs. 183, 184, represent the furnaces constructed more recently for the use of
pitcoal fuel; fig. 183 being an upright section, and fig. 184, the ground plan. In
this furnace the crucibles are not surrounded with the fuel, but they receive the
requisite mnelting heat from the flame proceeding from the grate upon which it is
burned. The crucibles stand upon seven binding arches, a, which unite in the middle at
the keystone b, fig. 186; between the arches are spaces through which the flame rises
183                    184          fiom the grate c; d is the fire door;
vy~~-7 in /////M'////::/M/z //M\ e, a sliding tile or damper for regulattaken ^//         il 1J^ //77 /1     ing or shutting off the air-draught;
/1e.. i/z c e  o/v/   f, an inclined plane, for carrying off
/,~.,     /;il     /l                 the cinders that fall through  the'" ~,       grate, along the draught tunnel g, so
E/ight c ia p         etsthat the air in entering below may
not be heated by them.
The crucibles are 16 inches deep,
/9/  wide at the mouth, 6a at the
oea/n   In from             bottom; with a thickness in the sides
of 1 inch and 1  below; they stand from 40 to 50 meltings.  The old brass, which
fills their whole capacity, is first put in and melted down; the crucibles are now
taken out and are charged with the half of the zinc in pieces of from I to 3 cubic
inches in size, covered over with coal ashes; then one-half of the copper charge is introduced, again coal-dust; and thus the layers of zinc and copper are distributed alternately with coal-ashes betwixt them, till the whole charge gets finally fused. Over
all, a thicker layer of carbonaceous matter is laid, to prevent oxidizement of the brass.
Eight crucibles filled in this way are put into the furnace between the 11 holes of the
grate shelf; and over them two empty crucibles are laid to be heated for the casting
operation.  In from 3f  to 4 hours the brass is ready to be poured out.  Fifteen English bushels of coals are consumed in one operation; of which six are used at the
introduction of the crucibles, and four gradually afterwards.
When sheet brass is to be made the following process is pursued:An empty crucible, called a caster (giesser), is taken out of the furnace through the
crown with a pair of tongs, and is kept red hot by placing it in a hollow hearth (mundal)
surrounded with burning coals; into this crucible the contents of four of the melting
pots are poured; the dross being raked out with an iron scraper. As soon as the melting pot is emptied, it is immediately re-charged in the manner above described, and replaced in the furnace. The surface of the melted brass in the caster is swept with the
stump of a broom, then stirred about with the iron rake, to bring up any light foreign
matter to the surface, which is then skimmed with a little scraper; the crucible is now
seized with the casting tongs, and emptied in the following way:The mould or form for casting sheet brass consists of two slabs of granite, a a, figs.
185, 186. They are 51 feet long; 3 feet broad, 1 foot thick, and for greater security,
girt with iron bands, b b, 2 inches broad, 11 thick, and joined at the four corners with
bolts and nuts. The mould rests upon an oaken block, c, 31 feet long, 2' broad, and 11
thick, which is suspended at each end upon gudgeons, in bearing blocks, placed under the
foundry floor, dd, in the casting pit, e e. This is lined with bricks; and is 61 feet long,
5j broad, and 2 deep; upon the two long side walls of the pit, the bearing blocks are
laid which support the gudgeons. The swing-blocks are 10 inches long, 18 inches
broad, 15 inches thick, and are somewhat rounded upon their back edge, so that the
casting frame may slope a little to the horizon. To these blocks two cross wooden arms,
185       M                      186              i      l.
/      L                     o
/hll ///  / k~   c01... f........
VZ1111A /, W, 7A




242                                 BRASS.
ff, are mortised, upon which the underslab rests freely, but so as to project about 5 inches backwards over the block, to secure an equipoise in the act of casting.  g g are bars,
placed at both of the long sides, and one of the ends, between the slabs, tg determine the
thickness of the brass-plate. Upon the other slab the gate h is fastened, a sheet of
iron 6 inches broad, which has nearly the shape of a parallel trapezium (lozenge), and
slopes a little towards the horizon. It serves for setting the casting pot upon in the act
of pouring out, and renders its emptying more convenient. That gate (steinmaul)
is coated with a mixture of loam and hair. The upper slab is secured to the under one
in its slanting position by an armor or binding. This consists of the tension bars of
wood, i k I m, of the iron bars n, (3 to 3- inches broad, 1  inch thick, see the top view,
fig. 186,) of a rod with holes and pins at its upper end, and of the iron screw spindle o.
The mode in which these parts act may be understood from inspection of the figure. In
order to lift the upper slab from the under one, which is effected by turning it round its
edge, a chain is employed, suspending two others, connected with the slab. The former
passes over a pully, and may be pulled up and down by means of a wheel and axle, or
with the aid of a counterweight. Upon each of the two long sides of the slab there
are two iron rings, to which the ends of the chains may be hooked. The casting faces
of the slab must be coated with a layer of finely ground loam; the thinner the better.
When calamine is employed, I cwt. of copper, j cwt. of calamine, and * the volume
of both of charcoal mixed, are put into seven crucibles, and exposed to heat during
11 or 12 hours; the product being from 70 to 72 lbs. of brass.
Brass-Plate Rolling.-At Hegermiihl there are two re-heating or annealing furnaces, one larger, 18 feet long, and another smaller, 8; the hot chamber is separated
from the fire place by iron beams, in such a way that the brass castings are played
upon by the flames on both their sides. After each passage through the laminating
press (rolls) they are heated anew, then cooled and laminated afresh, till they have
reached the proper length. The plates are besmeared with grease before rolling.
ward an       4;  x7x d7-' thto e,
188
Is;7:! ij
Fig. 187 shows the ground plan of the furnace and its railway;fig. 188 the cross section; and fig. 189 the section lengthwise; a a, the iron way bars or rails upon the floor
of the foundry, for enabling the wheels of the wagon-frame to move readily backwards and forwards; b b, the two grates; c c, the ash pits; d d, the fire beams; e e e,
vents in the roof of the hot chamberf; g g, two plates for shutting the hot chamber;
h, the flue; i, the chimney. After the rolling, the sheets covered with a black oxide
of copper, are plunged into a mother water of the alum works for a few minutes, then
washed in clean water, and lastly, smeared with oil, and scraped with a blunt knife.
In rough brass and brass wares, no less than 16,240 cwts. were manufactured in
the Prussian States in the year 1832.
For musical purposes, the brass wire made in Berlin, has acquired great and merited celebrity; but that of Birmingham is now preferred even by foreigners.
BRASS COLOR, for staining glass, is prepared by exposing for several days thin plates
of brass upon tiles in the leer or annealing arch of the glass-house, till it be oxidized




BRASS.                                      243
into a black powder, aggregated in lumps.  This being pulverized and sifted, is to be
again well calcined for several days more, till no particles remain in the metallic state;
when it will form a fine powder of a russet brown colour. A third calcination must now
be given, with a carefully regulated heat; its quality being tested from time to time by
fusion with some glass. If it makes the glass swell, and intumesce, it is properly prepared; if not, it must be still farther calcined. Such a powder communicates to glass
greens of various tints, passing into turquoise.
When thin narrow strips of brass are stratified with sulphur in a crucible, and calcined
at a red heat, they become friable, and may be reduced to powder. This being sifted
and exposed upon tiles in a reverberatory furnace for ten or twelve days becomes fit for
use, and is capable of imparting a chalcedony, red or yellow tinge to glass by fusion,
according to the mode and proportion of using it.
The glass-maker's red colour may be prepared by exposing small plates of brass to a
moderate heat in a reverberatory furnace, till they are thoroughly calcined, when the
substance becomes pulverulent, and assumes a red colour.  It is then ready for
immediate use.
BRAss COLOUR, as employed by the colourmen to imitate brass, is of two tints, the
red or bronze, and the yellow like gilt brass. Copper filings mixed with red ochre
or bole, constitute the former; a powdered brass imported from Germany is used for
the latter. Both must be worked up with varnish after being dried with heat, and then
spread with a flat camel-hair brush evenly upon the surface of the object. The best
varnish is composed of 20 ounces of spirits of wine, 2 ounces of shellac, and 2 ounces of
sandarach, properly dissolved.  (See VARNISH.)  Only so much of the brass powder
and varnish should be mixed at a time as is wanted for immediate use.  (See BRONZE
POWDER.)
BRASS FOIL   Dutch leaf, called Knitter or Rauschgold in Germany, is made from
a very thin sheet brass, beat out under a hammer worked by water power, which gives
300 or 400 strokes per minute; from 40 to 80 leaves being laid over each other. By
this treatment it acquires its characteristic solidity and lustre. See above, the process
for converting the copper superficially into brass by the fumes of zinc.
BRASS, YELLOW. The following table exhibits the composition of several varieties
of this species of brass. No. 1. is a cast brass of uncertain origin; 2. the brass
of Jemappes; 3. the sheet brass of Stolberg, near Aix-la-Chapelle; 4. and 5. the
brass for gilding, according to D'Arcet; 6. the sheet brass of Romilly; 7. English
brass wire; 8. Augsburg brass wire; 9. brass wire of Neustadt-Eberswald, in the
neighbourhood of Berlin.
1.     2.      3.      4.      5.     6.      7.      8.      9.
Copper  -      -  61-6   64-6     4      670 64'8    6 45   70-1   7029   7189   70-16
Zinc     -    -  35-3   33'7   32'8   3355   32-44   29'9 29-26   27-63   27-45
Lead     -     -   29      1-4    2-0    0-25    2-86  -   -   028  -   -   020
Tin      -     -   0-2    0-2    0-4    250    0-25  -   -    017    0-85    0-79
_loo 0  9_9 9 i 0   10000   100-0  -   - 10000  100-37  9860
The mean proportion of the metals in yellow brass is 30 zinc to 70 copper.
Tombak, or Red Brass, in the cast state, is an alloy of copper and zinc, containing
not more than 20 per cent. of the latter constituent.  The following varieties are
distinguished:-1, 2, 3. tombak for making gilt articles; 4. French tombak for swordhandles, &c.; 4. tombak of the Okar, near Goslar, in the Hartz; 5. yellow tombak of
Paris for gilt ornaments; 6. tombak for the same purpose from a factory in Hanover;
8. chrysochalk; 9. red tombak from Paris; 10. red tombak of Vienna.
1.     2.      3.      4.     5.      6.      7.      8.     9.     10.
Copper   -  820    82      82-3    80       85     85-3    86     900      92   97 - -
Zinc -   -  18-0    18      175     17      15     14-7    14      79       8    2-2
Lead - - 15 3-1-6
Tin  -   -   3'0     1      0.2      3    trace.
104-5   104    1000    100    100  1 1000   100       995      00   100o0
Pinchbeck is made of 2 parts copper and 1 yellow brass:
Prince's metal...  3.1 Z.inc.
Mannheim gold (semilor), 28 copper,'12 yellow brass, 3 tin.
Cast white metal buttons are made of an alloy of 32 parts brass (yellow), 4 parts
zinc, and 2 tin.
The specific gravity of brass is greater than the mean density of its constituents,




244                             BRAZIL-WOOD.
varying from'782 to 8'73, according to the proportion of zinc to copper. Sheet brass
varies from  8'52 to 8-62; brass wire from  8-49 to 8-73. Brass heated and quickly
cooled becomes somewhat less dense.  The specific gravity of sheet tombak (81'25
copper +  18-75 zinc) is 8-788; of tombak wire (87'5 copper +  12'5 zinc) has been
found so great as 9'00.
BRASS, MALLEABLE. It is known that common brass containing from 27'4 to 31'8 per
cent. of zinc, and from 71-9 to 65'8 per cent. of copper, is not malleable while hot,
but that articles of it must be made by casting. As it would be of great advantage in
many branches of industry to have an alloy of this kind that could be worked while
hot, like malleable iron, the information that such an alloy exists must be welcome to
artists.
By melting together 33 parts of copper, and 25 parts of zinc, there was a loss of three
parts; thus making 60 per cent. copper, and 40 per cent. zinc. It differs from the
English specimens by containing a larger proportion of zinc, and possesses, according to
M. Machts, the precious property of malleability in a higher degree than the English
specimens.
A piece of "yellow metal," similar in colour to this alloy, was found, on analysis, to
contain 60'16 copper, and 39-71 zinc, which is the composition of malleable brass. It
also showed great density or solidity.
An alloy was prepared by melting together 60 parts copper and 40 parts zinc, which
had the following properties:-The colour was between that of brass and tombak, it
had a strong metallic lustre, a fine, close grained fracture, and great solidity (density).
Its specific gravity at the temperature of 10~ Cent. was 8-44; by calculation it ought
only to have been 8'08; thus showing that in the formation of the alloy a condensation
must have taken place.  Calculation shows that the alloy may be considered as a determinate chemical combination, for the results of the analysis very nearly accord with
the assumption that it may be considered as composed of 3 atoms by weight of copper,
and 2 atoms by weight of zinc (3 Cu + 2 Zn). The hardness of the alloy is the same
as that of fluor spar; it can be scratched by apatite (glass), consequently its hardness
is =4.  The alloy is harder than copper, very tough, and is, in a properly managed fire,
malleable; so much so that a key was forged out of a cast rod.
These important properties of this alloy warrant an expectation of its application to
many purposes in the arts, and it would appear that they depend on its definite chemical
proportions. Agreeably to the directions of M. Feyerabind, care must be taken in
melting together the metals, not to permit too great a loss of zinc to take place, lest the
proportions between the metals should be altered, which might not be without effect on
the important properties of the alloy. With this view, it might be advantageous in
practice, in place of zinc, to add, in melting, a proportionate mixture of brass to the
proper proportions of copper. An alloy prepared in this way gave, on analysis, 61'44
copper, and 38'15 zinc. It is very probable that malleable brass will hereafter, in many
cases, be made use of instead of the higher priced copper.
BRAZING.  (Braser, Fr.; Messing-lothung, Germ.)  The soldering together of
edges of iron, copper, brass, &c., with an alloy consisting of brass and zinc, sometimes
with a little tin or silver.  The surfaces to be thus united must be filed perfectly
bright, and not be soiled with the fingers or in any other way. The granular or nearly
pulverulent alloy is usually wetted with a paste of ground borax and water, applied in
this state, dried, and then exposed carefully to bright ignition at a clear forge fire.
Some workmen enclose the part to be soldered in a clay lute, but others prefer leaving
it uncovered, that they may see when the solder has flowed freely, and entered into all
the seams.
BRAZIL-WOOD.  (Bois de Fernambouc, Fr.; Brasilienholz, Germ.)  This dye-wood
derives its name from the part of America whence it was first imported. It has also
the names Fernambuca, wood of Saint Martha, and of Sapan, according to the places
which produce it.  Linnaeus distinguishes the tree which furnishes the Brazil-wood
by the name of Caesa!pinia crista. It commonly grows in dry places among rocks. Its
trunk is very large, crooked, and full of knots. It is very hard, susceptible of a fine
polish, and sinks in water. It is pale when newly cleft, but becomes red on exposure to
the air.
It has different shades of red and orange. Its goodness is determined particularly by
its density. When chewed, a saccharine taste is perceived. It may be distinguished
from red saunders wood, as the latter does not yield its color to water.
Boiling water extracts the whole coloring matter of Brazil-wood. If the ebullition be
long enough continued, it assumes a fine red color. The residuum appears black. In
this case, an alkali may still extract much coloring matter. The solution in alcohol or
ammonia is still deeper than the preceding.
The decoction of Brazil-wood, called juice of Brazil, is observed to be less fit for
dyeing when recent, than when old or even fermented. By age, it takes a yellowish



BRAZIL-WOOD.                                  245
red color. For making this decoction, Hellot recommends to use the hardest water; but
it should be remarked, that this water deepens the color in proportion to the earthy salts
which it contains. After boiling this wood reduced to chips, or, what is preferable, to
powder, for three hours, this first decoction is poured into a cask. Fresh water is poured
on the wood, which is then made to boil for three hours, and mixed with the former.
When Brazil-wood is employed in a dyeing bath, it is proper to enclose it in a thin linen
bag, as well as all the dye-woods in general.
Wool immersed in the juice of Brazil takes but a feeble tint, which is speedily destroyed. It must receive some preparations.
The wool is to be boiled in a solution of alum, to which a fourth or even less of tartar
is added, for a larger proportion of tartar would make the color yellowish. The wool is
kept impregnated with it for at least eight days, in a cool place. After this, it is dyed in
the Brazil juice with a slight boiling. But the first coloring particles that are deposited,
afford a less beautiful color; hence it is proper to pass a coarser stuff previously through
the bath. In this manner a lively red is procured, which resists pretty well the action
of the air.
Brazil-wood is made use of for dyeing silk what is called false crimson, to distinguish
it from the crimson made by means of cochineal, which is much more permanent.
The silk should be boiled at the rate of 20 parts of soap per cent., and then alumed.
The aluming need not be so strong as for the fine crimson. The silk is refreshed at the
river, and passed through a bath more or less charged with Brazil juice, according to the
shade to be given. When M ater free from earthy salts is employed, the color is too red
to imitate crimson; this quality is given it by passing the silk through a slight alkaline
solution, or by adding a little alkali to the bath. It might, indeed, be washed in a hard
water till it had taken the desired shade..To make deeper false crimsons of a dark red, juice of logwood is put into the Brazil
bath after the silk has been impregnated with it. A little alkali may be added, according
to the shade that is wanted.
To imitate poppy or flame color, an annotto ground is given to the silk, deeper even
than when it is dyed with carthamus. It is washed, alumed, and dyed with juice of Brazil, to which a little soap water is usually added.
The coloring particles of Brazil-wood are easily affected, and made yellow by the action
of acids.
They thus become permanent colors. But what distinguishes them from madder and
Kermes, and approximates them to cochineal, is their reappearing in their natural color,
when they are thrown down in a state of combination with alumina, or with oxyde of tin.
These two combinations seem to be the fittest for rendering them durable. It is requisite,
therefore, to inquire what circumstances are best calcualted to promote the formation of
these combinations, according to the nature of the stuff.
The astringent principle, likewise, seems to contribute to the permanence of the coloring matter of Brazil-wood; but it deepens its hue, and can only be employed for light
shades.
The coloring particles of Brazil-wood are very sensible to the action of alkalis
which give them a purple hue; and there are several processes in which the alkalis,
either fixed or volatile, are used for forming violets and purples. But the colors obtained by these methods, which may be easily varied according to the purpose, are
perishable, and possess but a transient bloom.   The alkalis appear not to injure
the colors derived from  madder, but they accelerate the destruction of most other
colors.
In England and Holland the dye-woods are reduced to powder by means of mills erected
for the purpose.
The bright fugitive red, called fancy red, is given to cotton by Nicaragua, or peachwood, a cheap kind of Brazil-wood.
The cotton being scoured and bleached, is boiled with sumach. It is then impregnated with a solution of tin (at 50 Baume, according to Vitalis). It should now be washed
slightly in a weak bath of the dyeing wood, and, lastly, worked in a somewhat stale infusion of the peach or Brazil wood. When the temperature of this is lukewarm, the dye is
said to take better. Sometimes two successive immersions in the bath'are given. It is
now wrung out, aired, washed in water, and dried.
M. Vitalis says, that his solution of tin is prepared with two ounces of tin and a pound
of aqua regia made with two parts of nitric acid at 240 Baume, and three parts of muriatic acid at 22~.
For a rose color, the cotton is alumed as usual, and washed from the alum. It then
gets the tin mordant, and is again washed. It is now turned through the dye-bath, an
operation which is repeated if necessary.
For purple, a little alum is added to the Brazil bath.
1. For amaranth, the cotton is strongly galled, dried, and washed.




246                                  BREAD.
2. It is passed through the black cask (tonne au noir,) see BLACK DYE, till it has takep
a strong gray shade.
3. It receives a bath of lime-water
4. Mordant of tin.
5. Dyeing in the Brazil-wood bath.
6. The two last operations are repeated.
Dingier has endeavored to separate the coloring matter of the different sorts of Brazilwood, so as to obtain the same tint from the coarser as from the best Pernambuco. His
process consists in treating the wood with hot water or steam, in concentrating the decoction so as to obtain 14 or 15 pounds of it from 4 pounds of wood, allowing it to cool,
and pouring into it two pounds of skim milk; agitating, then boiling for a few minutes,
and filtering. The dun coloring matters are precipitated by the coagulation of the
caseous substance. For dyeing, the decoctions must be diluted with water; for printing
they must be concentrated, so that 4 pounds of wood shall furnish only 5 or 6 pounds of
decoction, and the liquor may be thickened in the ordinary way. These decoctions may
be employed immediately, as by this treatment they have acquired the same property as
they otherwise could get only by being long kept. A slight fermentation is said to improve the color of these decoctions; some ground woo.'s put into the decoction to favor
this process.
As gelatine produces no precipitate with these decoctions, they consequently contain
no tannin. Gall-nuts, however, sumach, the bark of birch or alder, render the color of
Brazil-wood more durable, upon alumed linen and cotton goods, but the shade is a little
darker.
In dyeing wool with Pernambuco, the temperature of the bath should never be above
150~ Fahr., since higher heats impair the color.
According to Dingler and Kurrer, bright and fast scarlet reds may be obtained upon
wool, by preparing a decoction of 50 pounds of Brazil-wood in three successive boils,
and setting the decoction aside for 3 or 4 weeks in a cool place; 100 pounds of the wool
are then alumed in a bath of 22 pounds of alum and 11 pounds of tartar, and afterwards
rinsed in cold water. Meanwhile we fill two thirds with water, a copper containing 30
pails, and heated to the temperature of 150~ or 1600 F. We pour in 3 pailfuls of the decoction, heat to the same point again, and introduce 30 pounds of wool, which does not
take a scarlet, but rather a crimson tint. This being removed, 2 pails of decoction are
put in, and 30 pounds of wool, which becomes scarlet, but not so fine as at the third dip.
If the dyer strengthens the color a little at the first dip, a little more at the second, and
adds at the third and fourth the quantity of decoction merely necessary, he will obtain a
uniform scarlet tint. With 50 pounds of Pernambuco 1000 pounds of wool may be dyed
scarlet in this way, and with the deposites another 100 may be dyed of a tile color. An
addition of weld renders the color faster but less brilliant.
Karkutsch says the dye may be improved by adding some ox-gall to the bath.
In dyeing cotton the tannin and gallic acid are two necessary mordants, and the color
is particularly bright and durable, when the cloth has been prepared with the oily process
of Turkey red.
It is said that stale urine heightens the color of the Brazil dye when the ground wood
is moistened with it.
The qpantity of Brazil or Nicaragua wood imported into the United Kingdom in 1835,
was 6,242 tons, whereof 1,811 were exported; of Brazilietto 230 tons. The duty upon
the first article is 5s. per ton.
BREAD  (Pain, Fr.; Brod, Germ.) is the spongy mass produced by baking the
leavened or fermented dough of wheat or rye flour, at a proper heat. It is the principal
food of highly civilized nations. The skilful preparation of this indispensable article constitutes the art of the Baker. Dough baked without being fermented constitutes cakes
or biscuits; but not bread strictly speaking.
Pliny informs us, that barley was the only species of corn at first used for food; and
even after the method of reducing it to flour had been discovered, it was long before
mankind learned the art of converting it into cakes.
Ovens were first invented in the East. Their construction was understood by the
Jews, the Greeks,.and the Asiatics, among whom baking was practised as a distinct profession. In this art, the Cappadocians, Lydians, and Phoenicians, are said to have particularly excelled. It was not till about 580 years after the foundation of Rome, that
these artisans passed into Europe. The Roman armies, on their return from Macedonia,
brought Grecian bakers with them into Italy. As these bakers had handmills beside
their ovens, they still continued to be called pistores, from the ancient practice of bruising the corn in a mortar; and their bakehouses were denominated pistorice. In the time
of Augustus there were no fewer than 329 public bakehouses in Rome; almost the whole
of which were in the hands of Greeks, who long continued the only persons in that city
acquainted with the art of baking good bread.
12




BREAD.                                    247
In nothing, perhaps, is the wise and cautious policy of the Roman government more
remarkably displayed, than in the regulations which it imposed on the bakers within
the city. To the foreign bakers who came to Rome with the army from Macedonia, a
number of freedmen were associated, forming together an incorporation from which
neither they nor their children could separate, and- of which even those who married the
daughters of bakers were obliged to become members.  To this incorporation were intrusted all the mills, utensils, slaves, animals, every thing, in short, which belonged to
the former bakehouses. In addition to these, they received considerable portions of land;
and nothing was withheld, which could assist them in pursuing, to the best advantage,
their highly prized labors and trade. The practice of condemning criminals and slaves,
for petty offences, to work in the bakehouse, was still continued; and even the judges of
Africa were bound to send thither, every five years, such persons as had incurred that
kind of chastisement. The bakehouses were distributed throughout the fourteen divisions
of the city, and no baker could pass from one into another without special permission.
The public granaries were committed to their care; they paid nothing for the corn employed in baking bread that was to be given in largess to the citizens; and the price of
the rest was regulated by the magistrates. No corn was given out of these granaries except for the bakehouses, and for the private use of the prince. The bakers had besides
private granaries, in which they deposited the grain, which they had taken from the publie granaries for immediate use; and if any of them happened to be convicted of having
diverted any portion of the grain to another purpose, he was condemned to a ruinous fine
of five hundred pounds weight of gold.
Most of these regulations were soon introduced among the Gauls; but it was long before they found their way into the more northern countries of Europe. Borrichius informs
us that in Sweden and Norway, the only bread known, so late as the middle of the 16th
century, was unleavened cakes kneaded by the women. At what period in our own history the art of baking became a separate profession, we have not been able to ascertain;
but this profession is now common to all the countries in Europe, and the process of
baking is also nearly the same.
The French, who particularly excel in the art of baking, have a great many different
kinds of bread. Their pain bis, or brown bread, is the coarsest kind of all, and is made
of coarse groats mixed with a portion of white flour. The pain bis blanc, is a kind of
bread between white and brown, made of white flour and fine groats. The pain blanc,
or white bread, is made of white flour, shaken through a sieve after the finest flour has
been separated. The pain mollet, or soft bread, is made of the purest flour without any
admixture. The pain chaland, or customers' bread, is a very white kind of bread, made
of pounded paste. Pain chapele, is a small kind of bread, with a well-beaten and very
light paste, seasoned with butter or milk. This name is also given to a small bread, from
which the thickest crust has been removed by a knife. Pain cornu, is a name given by
the French bakers to a kind of bread made with four corners, and sometimes more. Of
all the kinds of small bread, this has the strongest and firmest paste. Pain a la reine,
queen's bread, pain ci la Sigovie, pain chapele, and pain cornu, are all small kinds of bread,
differing only in the lightness or thickness of the paste. Pain gruau is a small very
white bread made now in Paris, from the flour separated after a slight grinding from the
best wheat. Such flour is in hard granular particles.
In this country we have fewer varieties of bread, and these differ chiefly in their degrees of purity. Our white or fine bread is made of the purest flour; our wheaten
bread, of flour with a mixture of the finest bran; and our household bread, of the whole
substance of the grain without the separation either of the fine flour or coarse bran. We
have also symnel bread, manchet or roll bread, and French bread, which are all made of
the purest flour from the finest wheat; the roll bread being improved by the addition of
milk, and the French bread by the addition of eggs and butter. To these may be added
gingerbread, a cake made of flour, with almonds, liquorice, aniseed, rose-water, and sugar
or treacle; and mastlin bread, made of wheat and rye, or sometimes of wheat and barley.
We have various kinds of small bread, having various names, according to their various
forms. They are, in general, extremely light, and are sweetened with sugar, currants,
and other palatable ingredients. In Scotland there is a cake called short bread, made
from a pretty thick dough, enriched with butter, sweetened with sugar, and seasoned with
orange peel, or other kinds of spices.
The process of making bread is nearly the same in all the countries of modern Europe;
though the materials of which it is composed vary with the farinaceous productions of
different climates and soils. The flour of wheat is most generally employed for this pur.
pose, wherever that vegetable can be reared. This flour is composed of a small portion
of mucilaginous saccharine matter, soluble in cold water, from which it may be separated
by evaporation; of a great quantity of starch, which is scarcely soluble in cold water, but
capable of combining with that fluid by means of heat; and an adhesive gray substance
called gluten, insoluble in water, ardent spirit, oil, or ether, and resembling an animal




248                                   BREAD.
substance in many of its properties. Flour kneaded with water, forms a tough and rather
indigestible paste containing all the constituent parts which we have enumerated. Heat
produces a considerable change on the glutinous part of this compound, and renders it
more easy of mastication and digestion. Still, however, it continues heavy and tough,
compared with bread which is raised by leaven or yeast. Leaven is nothing more than a
piece of dough, kept in a warm place till it undergoes a process of fermentation; swelling,
becoming spongy, or full of air bubbles, at length disengaging an acidulo-spirituous vapor, and contracting a sour taste. When this leaven is mingled in proper proportions
with fresh-made dough, it makes it rise more readily and effectually than it would do
alone, and gives it at the same time a greater degree of firmness. Upon the quality of
the leaven employed, the quality of the bread materially depends.
The principal improvement which has been made on bread in miern times, is the
substitution of yeast or barm in place of common leaven. This yeast is the viscid froth
that rises to the surface of beer, in the first stage of its fermentation. When mixed with
the dough, it makes it rise much more speedily and effectually than ordinary leaven,
and the bread is of course much lighter, and freer from that sour and disagreeable taste
which may often be perceived in bread raised with leaven, either because too much is
mingled with the paste, or because it has been allowed to advance too far in.he process
of fermentation.
Bread properly raised and baked differs materially from unleavened cakes, not only in
being less compact and heavy, and more agreeable to the taste, but in losing its tenacious and glutinous qualities, and thus becoming more salutary and digestible.
Wt possess several analyses of wheat flour. Ordinary wheat (triticum  hybernum
mixed with triticum turgidum) contains, according to the analyses made by Vauquelin
of several species of wheat flour, the following substances:Water
Species of Wheat.    Water. Gluten. Starch. Sugar.  Gum. Bran.  Total.  of dough
French wheat flour -     10 0   10-96  71-49  4-72   3-32    -   100-49   50-3
Hard wheat of Odessa
flour-          - -    12-0  14-55  56-50  8-48   4-90   2-3   98-73   51'2
Soft wheat of Odessa
flour- --- -    10-0  12-00  62-00  7-56   5-80   1-2   98-42   54-8
Same sort of flour - -   8-0  12-10  70-84  4-90   4-60    -   100-41   37.4
Same sort of flour - -  12-0    7-30  72-00  5-42   3-30    -   100-02   37-2
Wheat of the French
bakers --          -  10-0  10-20  7280  4-20   2-80    -   100-00   40-6
Flour of the Paris hospitals (2d quality)  -   8-0  10-30  7120  4-80   3-60    -    97-90   37-8
Ditto (3d quality) -  -  12-0    9-02  67-78  4-80   4-60   2-0  100-21   37-8
The following table of analyses merits also a place here.
Species of Flour.    Water. Gluten. Starch. Sugar. Gummigluten. Albumen.  Bran.
Flour of the triticum spelta    1    22-    74    5-50      1'        150
Ditto triticum hybernum      1    24      68-     5.0       1         1-50
Ditto common wheat - -    -    12-5   74-5   12             2Ditto  wheat  and  rye
mixed (mastlin)  - -    6        9-80  75-501  4-22       3'28       -       1*2
The first two of the above analyses were made by Vogel, the third by Proust, and the
fourth by Vauquelin.
Analyses of the flour of some other corns.
Species of Flour.   Starch. Mucilage. Gluten. Albumen. Sugar.   Husk.  Hordein.
Of a fat oil,
Whtte oatmeal  - - -  5900    25             -      430    8-25  2
Of resin,
Barley meal -    -     32-00    9*           3        -       2        -       55
The first analysis is by Vogel, the second by Proust.
It deserves to be remarked, that the flour of Odessa contains a much greater quantity
of sugar than the French flour. The substance indicated in the preceding table by the
name of gluten, is the gluten of Beccaria; that is to say, a mixture of gluten and vegetable




BREAD.                                   249
albumen. The gum of wheat is not quite identical with ordinary gum. It is a browr
azotized substance, which, when treated by nitric acid, affords no mucic acid, but oxalic
acid and the bitter principle of Welter. It contains besides superphosphate of lime.
The last column of the first table exhibits the quantity of water necessary to convert
the flour into dough of the ordinary consistence, and it is usually proportional to the
quantity of gluten. The hard wheat of Odessa forms an exception in this respect; the
reason of the difference being that the starch contained in this flour is not as in ordinary flour in a fine powder, but in small transparent grains, which resemble pounded
gum, and absorb less water than pulverulent starch.
The triticum monococcon, according to Zenneck, contains in its unsifted flour, 16-334
of gluten and vegetable albumen; 64-838 of starch; 11-347 of gum, sugar, and extractive;
7-481 of husks. The sifted flour affords 15-536 of gluten and vegetable albumen;
76-459 of starch; 7-198 of sugar, gum, and extractive; 0-807 of husky matter. It is
difficult to conceive how such great quantities of gluten, albumen, and extractive matter
could disappear in the sifting. The triticum spelta contains in 100 parts of the finest
flour, 22-5 of a soft and humid gluten, mixed with vegetable albumen; 74 of starch, and
5*5 of sugar. Here we have an excess of 2 parts in the 100.
Wheat furnishes very little ashes by incineration, not more than 0-15 per cent. of the
weight; containing superphosphates of soda, lime, and magnesia.
The object of baking is to combine the gluten and starch of the flour into a homogeneous substance, and to excite such a vinous fermentative action, by means of its
saccharine matter, as shall disengage abundance of carbonic acid gas in it for making
an agreeable, soft, succulent, spongy, and easily digestible bread. The two evils to be
avoided in baking are hardness on the one hand, and pastiness on the other. Well-made
bread is a chemical compound, in which the gluten and starch cannot be recognised
or separated, as before, by a stream of water. When flour is kneaded into a dough,
and spread into a cake, this cake, when baked, will be horny if it be thin, or if thick,
will be tough and clammy; whence we see the value of that fermentative process, which
generates thousands of little cells in the mass or crumb, each of them dry, yet tender
and succulent, through the intimate combination of the moisture. By this constitution
it becomes easily soluble in the juices of the stomach, or, in other words, light of digestion. It is moreover much less liable to turn sour than cakes made from unfermented
dough.
Rye, which also forms a true spongy bread, though inferior to that of wheat, consists
of similar ingredients; namely, 61-07 of starch; 9-48 of gluten; 3-28 of vegetable
albumen; 3-28 of uncrystallizable sugar; 11-09 of gum; 6-38 of vegetable fibre; the
loss upon the 100 parts amounted to 5-62, including an acid whose nature the analyst,
M. Einhof, did not determine. Rye flour contains also several salts, principally the
phosphates of lime and magnesia. This kind of grain forms a dark-colored bread
reckoned very wholesome; comparatively little used in this country, but very much in
France, Germany, and Belgium.
Dough fermented with the aid either of leaven or yeast, contains little or none of the
saccharine matter of the flour, but in its stead a certain portion, nearly half its weight,
of spirit, which imparts to it a vinous smell, and is volatilized in the oven; whence it
might be condensed into a crude weak alcohol, on the plan of Mr. Hick's patent, were it
worth while. But the increased complexity of the baking apparatus will probably prove
an effectual obstacle to the commercial success of this project, upon which already upwards of ~20,000 sterling have been squandered.
That the sugar of the flour is the true element of the fermentation preposterously
called panary, which dough undergoes, and that the starch and gluten have nothing to
do with it, may be proved by decisive experiments. The vinous fermentation continues
till the whole sugar is decomposed, and no longer; when, if the process be not checked
by the heat of baking, the acetous fermentation will supervene. Therefore, if a little
sugar be added to a flour which contains little or none, its dough will become susceptible
of fermenting, with extrication of gas, so as to make spongy succulent bread. But since
this sponginess is produced solely by the extrication of gas, and its expansion in the heat
of the oven, any substance capable of emitting gas, or of being converted into it under
these circumstances, will answer the same purpose. Were a solution of bicarbonate ot
ammonia obtained by exposing the common sesqui-carbonate in powder for a day to the
air, incorporated with the dough, in the subsequent firing it will be converted into
vapor, and in its extrication render the bread very porous. Nay, if water highly
impregnated with carbonic acid gas be used for kneading the dough, the resulting bread
will be somewhat spongy.  Could a light article of food be prepared in this way, then
as the sugar would remain undecomposed, the bread would be so much the sweeter, and
the more nourishing. How far a change propitious to digestion takes place in the
constitution of the starch and gluten, during the fermentative action of the dough, has
sot been  hitherto ascertained by precise experiments. Medical practitioners, who




250                                  BREAD.
derive an enormous revenue from dysi epsia, should take some pains to investigate this
subject.
Dr. Colquhoun, in his able essay upon the art of making bread, has shown that its texture,
when prepared by a sudden formation and disengagement of elastic fluid generated within
the oven, differs remarkably from that of a loaf which has been made after the preparatory fermentation with yeast. Bread which has been raised with the common carbonate
of ammonia, as used by the pastry-cooks, is porous no doubt, but not spongy with vesicular spaces, like that made in the ordinary way. The former kind of bread never presents
that air-cell stratification which is the boast of the Parisian baker, but which is ahnost unknown in London. I have found it, moreover, very difficult to expel by the oven the last
portion of the ammonia, which gives both a tinge and a-.taste to the bread. I believe,
however, that the bicarbonate would be nearly free from this objection, which operates
so much against the sesqui-carbonate of the shops.
In opposition to Mr. Edlln's account of the excellent quality of bread made by impregnating dough with carbonic acid gas,* Dr. Colquhoun adduces Vogel's experiments,
which show that such dough, when baked, after having been kept in a warm situation
during the usual time, afforded nothing better than a.ard cake, which had no resemblance to common bread.  Vogel further states, as illustrative of the general necessity
of providing a sufficient supply of disengaged elastic fluid within the dough, before
baking it at all, that when he made various attempts to form a well-raised vesicular loaf,
within the oven, by mixing flour with carbonate of magnesia, or with zinc filings, and
then kneading it into a paste by means of water, acidulated with sulphuric acid, he always met with complete failure and disappointment. Dr. Colquhoun performed a series
of well-devised experiments on this subject, which fully confirmed Vogel's results, and
prove that a proper spongy bread cannot be made by the agency of either carbonic acid
water, or of mixtures of sesqui-carbonate of soda, and tartaric acid. The bread proved
doughy and dense in every case, though less so with the latter mixture than the former.
No loaf bread can, indeed, be well made by any of these two extemporaneous systems,
because they are inconsistent with the thorough kneading of the dough. It is this pro.
cess which renders dough at once elastic enough to expand when carbonic acid gas is
generated within it, and cohesive enough to confine the gas when it is generated. The
whole gas of the loaf is disengaged in its interior by a continuous fermentation, after all
the processes of kneading have been finished; for the loaf, after being kneaded, weighed
out, and shaped, is set aside till it expands gradually to double its bulk, before it is put
into the oven. But when a dough containing sesqui-carbonate of soda is mixed with one
containing muriatic acid, in due proportions to form the just dose of culinary salt, the gas
escapes during the necessary incorporation of the two, and the bread formed from it is
dense and hard. Dr. Whiting has, however, made this old chemical process the subject
of a new patent for baking bread.
When the baker prepares his dough, he takes a portion of the water needed for
the batch, having raised its temperature to from 70~ to 100~ F., dissolves a certain
proportion of his salt in it, then adds the yeast, and a certain quantity of his flour.
This mixture, called the sponge, is next covered up in the small kneading-trough,
alongside of the large one, and let alone for setting in a warm situation. In about an
hour, signs of vinous fermentation appear, by the swelling and heaving up of the sponge,
in consequence of the generation of carbonic acid; and if it be of a semi-liquid consistence, large air bubbles will force their way to the surface, break, and disappear in
rapid succession. But when the sponge has the consistence of thin dough, it confines the
gas, becomes thereby equably and progressively inflated to double its original volume;
when no longer capable of containing the pent-up air, it bursts and subsides. This
process of rising and falling alternately might be carried on during twenty-four hours,
but the baker has learned by experience to guard against allowing full scope to the fermentative principle. He generally interferes- after the first, or at furthest after the
second or third dropping of the sponge; for were he not to do so, the bread formed with
such dough would be invariably found sour to the taste and the smell. Therefore he
adds at this stage to the sponge the reserved proportions of flour, salt, and water, which
are requisite to make the dough of the desired consistence and size; and next incorporates the whole together by a long and laborious course of kneading. When this
operation has been continued till the fermenting and the fresh dough have been intimately
blended, and till the glutinous matter of both is worked into such union and consistence
that the mass becomes so tough and elastic as to receive the smart pressure of the
hand without adhering to it, the kneading is suspended for some time. The dough is
now abandoned to itself for a few hours, during which it continues in a state of active
fermentation throughout its entire mass. Then it is subjected to a second but much
less laborious kneading, in order to distribute the generated gas as evenly as possible
* Treatise on the Art of Bread Making, p. 56.




BREAD.                                   251
among its parts, so that they may all partake equally of the vesicular structure. Aftel
this second kneading, the dough is weighed out into the portions suitable to the size of
bread desired; which are of course shaped into the proper forms, and once more set
aside in a warm situation. The continuance of the fermentation soon disengages a fresh
quantity of carbonic acid gas, and expands the lumps to about double their pristine volume.
These are now ready for the oven, and when they finally quit it in the baked state, are
about twice the size they were when they went in. The generation of the due quantity
of gas should be complete before the lumps are transferred to the oven; because whenever
they encounter its heat, the process of fermentation is arrested; for it is only the previously existing air which gets expanded throughout every part of the loaf, swells out its
volume, and gives it the piled and vesicular texture. Thus the well-baked loaf is composed of an infinite number of ceilules filled with carbonic acid gas, and apparently lined
with a glutinous membrane of a silky softness. It is this which gives the light, elastic,
porous constitution to bread.
After suffering the fermentative process to exhaust itself in a mass of dough, and the
dough to be brought into that state in which the addition of neither yeast, nor starch, nor
gluten will produce any effect in restoring that action, if we mix in 4 per cent. of saccharine matter, of any kind, with a little yeast, the process of fermentation will immediately
re-commence, and pursue a course as active and lengthened as at first, and cease about
the same period.*
This experiment, taken in connexion with the facts formerly stated, proves that what
was called panary fermentation, is nothing but the ancient and well-known process of the
vinous fermentation of sugar, which generates alcohol. There seems to be but one objection to the adoption of this theory. After the loaf is baked, there is found in its composition nearly as much saccharine matter as existed in the flour before fermentation.
M. Vogel states that in the baked bread there remains 3*6 parts of sugar, out of the
5 parts which it originally contained. Thus, in 100 parts of loaf bread prepared with
wheaten flour, distilled water, and yeast without the admixture of any common salt, he
found the following ingredients:
Sugar      -       -      -         36
Torrefied or gummy starch     -    18'0
Starch     -      -       -        53-5
Gluten, combined with a little starch, 20-75
Exclusive of carbonic acid, muriate of lime, phosphate of lime, &c.
It must be borne in mind that in every loaf the process of fermentation has been prematurely checked by the baker's oven, and therefore the saccharine constituent can never
be wholly decomposed. It seems certain, also, that by the action of gluten upon the
starch in the early stage of the firing, a quantity of sugar will be formed by the saccharine fermentation; which we have explained in treating of BEER.
Several masses of dough were prepared by Dr. Colquhoun in which pure wheat starch
was mixed with common flour, in various proportions. In some of the lumps this starch
had been gelatinized, with the minimum of hot water, before it was added to the flour.
After introducing the usual dose of salt, the dough was thoroughly kneaded, set apart for
the proper period, allowed to ferment in the accustomed way, and then baked in the oven.
In outward appearance, increase of bulk, and vesicular texture, none of them differed
materially from a common loaf, baked along with them for the sake of comparison;
except that when the starch considerably exceeded the proportion of flour in the lump,
the loaf, though whiter, had not risen so well, being somewhat less vesicular. But, on
tasting the bread of each loaf, those which contained most gelatinized starch were unexpectedly found to be the sweetest. The other loaves, into which smaller quantities of
the gelatinized starch had been introduced, or only some dry starch, had no sweetish
taste whatever to distinguish them from ordinary bread. These facts seem to establish
the conclusion, that the presence of gelatinous starch in bread put into the oven, is a
means of forming a certain portion of saccharine matter within the loaf, during the baking process. Now it is more than probable that gelatinized starch does exist, more or
less, in all loaves which have been fermented by our usual methods, and hence a certain
quantity of sugar will necessarily be generated at its expense, by the action of heat.
Thus the difficulty started by M. Vogel is sufficiently solved; and there remains no doubt
that, in the saccharine principle of flour, the fermentation has its origin and end, while dough
is under fermentation.
The source of the sourness which supervenes in bread, under careless or unskilful
hands, had been formerly ascribed to each of all the constituents of flour; to its gluten,
its starch, and its sugar; but erroneously, as we now see: for it is merely the result of
the second fermentation which always succeeds the vinous, when pushed improperly too
far. It has been universally taken for granted by authors, that the acid thus generated
* Dr. Colquhoun, in Annals of Philosophy for 1826, vol. xii. p. 171




252                                  BREAD.
in dough is the acetic. But there appear good grounds to believe that it is frequently
a less volatile acid, probably the lactic, particularly when the process has been tardy,
from the imperfection of the yeast or the bad quality of the flour. The experiments of
Vogel, Braconnot, and others, prove that the latter acid is generated very readily, and in
considerable quantity during the spontaneous decomposition of a great many vegetable
substances, when in a state of humidity. The presence of lactic acid would account
for the curious fact, that the acidity of unbaked dough is much more perceptible to the
taste than to the smell; while the sourness of the same piece of bread, after coming out
of the oven, is, on the contrary, much more obvious to the olfactory organs than to the
palate. But this is exactly what ought to happen, if the lactic acid contributes, in conjunction with the acetic, to produce the acescence of the dough. At the ordinary temperature of a bakehouse, the former acid, though very perceptible in the mouth, is not
distinguishable by the nostrils; but as it is easily decomposed by heat, no sooner is it exposed to the high temperature of the oven, than it is resolved, in a great measure, into
acetic acid,* and thus becomes more manifest to the sense of smell, and less to that of
taste. This theory seems to explain satisfactorily all the phenomena accompanying the
progress of fermentation in baker's dough, and also some of its results in the process of
baking which do not easily admit of any other solution.
There are extremely simple and effectual methods for enabiing the baker to adopt
measures either to prevent or correct the evil of acescence, and these are to neutralize
the acid by the due exhibition of an alkali, such as soda; or an alkaline earth, such as
magnesia or chalk. And it affords a striking proof of how much the artisan has been
accustomed to plod, uninquiring and uninformed, over the same ground, that a remedy
so safe and so economical, should remain at this day unthought of and unemployed by
most of the manufacturers of bread in the United Kingdom. The introduction of a
small portion of carbonate of soda will rectify any occasional error in the result of the
so called panary fermentation, and will, in fact, restore the dough to its pristine sweetness. The quantity of acetate of soda, which will be thus present in the bread, will be
altogether inconsiderable; and as it has no disagreeable taste, and is merely aperient to
the bowels in a very mild degree, it can form no objection in the eye of the public
police. The restoration of dough thus tainted with acid, and its conversion into
pleasant and wholesome bread, has been sufficiently verified by experiment. But,
according to Mr. Edmund Davy, carbonate of magnesia may be used with still greater
advantage, as during the slow action of the acid upon it, the carbonic acid evolved
serves to open up and lighten bread which would otherwise be dense and doughy from
the indifferent quality of the flour. Here, however, the dangerous temptation lies with
a sordid baker to use cheap or damaged flour, and to rectify the bread made of it by
chemical agents, innocent in themselves, but injurious as masks of a bad raw material.
When sour yeast must be used, as sometimes happens with the country bakers, or in
private houses at a distance from beer breweries, there can be no harm, but, on the
contrary, much propriety, in correcting its acidity, by the addition of as much carbonate
of soda to it as will effect its neutralization, but nothing more. When sour yeast has
been thus corrected, it has been found, in practice, to possess its fermentative power unimpaired, and to be equally efficacious with fresh formed yeast, in making good palatable loaves.
We have seen that, in baking, about one fourth of the starch is converted into a
matter possessing the properties of British gum (see STARCH), and also that the gluten,
though not decomposed, has its particles disunited, and is not so tough and adhesive as
it is in the flour. This principle is also, as we have said, useful in cementing all the
particles of the dough into a tenacious mass, capable of confining the elastic fluid generated by the vinous fermentation of the sugar. Starch is the main constituent, the basis
of nourishment in bread, as well as in all farinaceous articles of food. The albumen also of the wheat, being coagulated by the heat of the oven, contributes to the setting of
the bread into a consistent elastic body.
In the mills in the neighborhood of London, no less than seven distinct sorts of flour
are ground out of one quantity of wheat. These are for one quarterFine flour    -.       5 bushels 3 pecks.
Seconds                                 0         2
Fine middlings     -         -      -   0         1
Coarse middlings        -          -    0         0'5
Bran  -     -...3                     0
Twenty-penny-   -.          3         0
Pollard  -  -   -                        2
14       2*5
* Berzelius.




BREAD.                                    253
So that we have nearly a double bulk of flour, or 14 bushels and 24 pecks from 8 bushelr
of wheat. In the sifting of the flour through the bolter, there is a fine white angular meal
obtained called sharps, which forms the central part of the grain. It is consumed partly
by the fine biscuit bakers. The bakers of this country were formerly bound by law to bake
three kinds of bread, the wheaten, standard wheaten, and the household; marked respectively with a W, S W, and H, and if they omitted to make these marks on their bread
they were liable to a penalty. The size of the loaves were usually peck, half-peck,
quartern, and half-quartern; the weights of which, within 48 hours of their being baked,
should have been respectively 17 lbs. 6 oz.; 8 lbs. 11 oz.; 4 lbs. 5 oz. 8 dr.; and 4 lbs.
2 oz. 14 dr. In general they weigh about one seventh more before they enter the oven,
or they lose one seventh of their weight in baking. The French bread loses fully one
sixth in the oven, owing chiefly to its more oblong thin shape, as compared to the
cubical shape of the English bread. But this loss of weight is very variable, being dependant upon the quality of the wheaten flour, and the circumstances of baking. The
present law in England defines the quartern loaf at 4 lbs., and subjects the baker to a
penalty if the bread be one ounce lighter than the standard. Hence it leaves the baker,
in self-defence, to leave it in rather a damp and doughy state. But there is much light
bread sold in London. I have met with quartern loaves of 3 lbs. 10 oz. A sack of flour
weighing 280 lbs. was presumed by the framers of our former parliamentary acts, for the
assize of bread, to be capable of being baked into 80 loaves. If this proportion had been
correct, one fifth part of our quartern loaf must consist of water and salt, and four fifths
of flour. But in general, of good wheaten flour, three parts will take up one part of
water; so that the sack of flour should have turned out, and actually did turn out, more
than 80 loaves. At present with 4 lb. bread it may well yield 92 loaves.
The following statement of the system of bakiag at Paris, I received in 1835 from a
very competent judge of the business.
1,000 kilogrammes of wheat=5 quarters English, cost 200 fr., and yield 800 kilos.
of flour of the best white quality, equivalent to 5-1- sacks French. Hence the sack of
flour costs 40 francs at the mill, and including the carriage to Paris, it costs 45 or 46
francs.
The profit of the flour dealer is about 34 francs, and the sale price becomes from 43 to
50 francs.
Bread manufacturedfrom the above.
~  s.  d.    ~  s. d.
One day's work of an ordinary baker, who makes four batches
in a day, consists of 3 sacks at 50 francs, or 21. sterling each       6  0  0
Salt 21 lbs. at 2d. per lb.-                             -               0 0 51
Yeast or leaven 3 lbs. at 5d.  -     -                                   0  1  3
Total cost of materials    -..-                                  6  1  88
Expenses of Baking.
Three workmen at different rates of wages, 15 francs  -   - 0  12 0
Fire-wood 0, as the charcoal produced pays for it -    -    -
General expenses, such as rent, taxes, interest of capital, &c.  0  12 0
1  40=  1  40
7  5  81
For this sum 315 loaves are made, being 105 for every sack
of flour weighing 156-66 kilos. or 3441 lbs. avoird. One
loaf contains therefore 3 46- 66 = 3'282 lbs., and as 100 lbs.
of flour in Parisian  baking  are reckoned  to produce
127 lbs. of bread, each loaf will weigh 4'168 lbs., avoird.,
and will cost 71. 5s. 8dd. divided by 315 =  54d. very
nearly. The value of 315 loaves at the sale price of 6d.
willbe      -      -      -                                           717 5
Upon this day's work the clear profit is therefore    -  -               0 11 61
A  new  baking  establishment has been recently formed at the Royal Clarence
Victualling Establishment at Weevil, near Portsmouth, upon a scale of magnitude nearly sufficient to supply the whole royal navy with biscuits, and that of a very superior
description. The following account of it is taken from the United Service Journal.
" It having been discovered that the flour supplied to government by contract, had in
many instances been most shamefully adulterated, the corn is ground at mills comprised
within the establishment, by which means the introduction of improper ingredients is
prevented, and precisely the proportion of bran which is requisite in the composition of
good sea-biscuit is retained, and no more. The flour-mill is furnished with ten pairs of




254                                 BREAD.
stones, by which 40 bushels of flour may be ground and dressed ready for baking, in an
hour. The baking establishment consists of 9 ovens, each 13 feet long by 11 feet wide,
and 171 inches in height. These are each heated by separate furnaces, so constructed
that a blast of hot air and fire sweeps through them, and gives to the interior the
requisite dose of heat in an incredible short space of time. The first operation in
making the biscuits consists in mixing the flour, or rather meal and water; 13 gallons of
water are first introduced into a trough, and then a sack of the meal, weighing 280 lbs.
When the whole has been poured in by a channel communicating with an upper room,
a bell rings, and the trough is closed. An apparatus consisting of two sets of what are
called knives, each set ten in number, are then made to revolve amongst the flour and
water by means of machinery. This mixing operation lasts one minute and a half,
during which time the double set of knives or stirrers makes twenty-six revolutions. The
next process is to cast the lumps of dough under what are called the breaking-rollers,huge cylinders of iron, weighing 14 cwt. each, and moved horizontally by the machinery
along stout tables. The dough is thus formed into large rude masses 6 feet long by 3
feet broad, and several inches thick. At this stage of the business, the kneading is still
very imperfect, and traces of dry flour may still be detected. These great masses of
dough are now drawn out, and cut into a number of smaller masses about a font and a
half long by a foot wide, and again thrust under the rollers, which is repeated until the
mixture is so complete that not the slightest trace of any inequahry is discoverable in any
part of the mass. It should have been stated that two workmen stand one at each side
of the rollers, and as the dough is flattened out they fold it up, or double one part upon
another, so that the roller at its next passage squeezes these parts together, and forces
them to mix. The dough is next cut into small portions, and being placed upon large
flat boards, is, by the agency of machinery, conveyed from the centre to the extremity of
the baking-room. Here it is received by a workman, who places it under what is
called the sheet roller, but which, for size, color, and thickness, more nearly resembles
a blanket. The kneading is thus complete, and the dough only requires to be cut into
biscuits before it is committed to the oven. The cutting is effected by what is called
the cutting-plate, consisting of a net-work of 52 sharp-edged hexagonal frames, each as
large as a biscuit. This frame is moved slowly up and down by machinery, and the
workman, watching his opportunity, slides under it the above-described blanket of
dough, which is about the size of a leaf of a dining-table; and the cutting-frame in its
descent indents the sheet, but does not actually cut it through, but leaves sufficient
substance to enable the workman at the mouth of the oven to jerk the whole mass of
biscuits unbroken into it. The dough is prevented sticking to the cutting-frame by
the following ingenious device: between each of the cutter-frames is a small flat open
frame, moveable up and down, and loaded with an iron ball, weighing several ounces.
When the great frame comes down upon the dough, and cuts out 52 biscuits, each of
these minor frames yields to the pressure, and is raised up; but as soon as the great
frame rises, the weight of the balls, acting upon the little frames, thrusts the whole
blanket off, and allows the workmen to pull it out. One quarter of an hour is sufficient.o bake the biscuit, which is afterwards placed for three days in a drying room, heated
to 85~ or 900, which completes the process."  The following statement of the performance of the machinery is taken from actual experiment; in 116 days, during 68 of
which the work was continued for only 71 hours; and during 48, for only 51 hours
each day, in all 769 working hours, equal to 77 days of 10 hours each; the following
quantity of biscuit was baked in the 9 ovens, viz.: 12,307 cwt. = 1,378,400 lbs. The
wages of the men employed in baking this quantity amounted to 2731. 10s. 9-d.; if it
had been made by hand, the wages would have been 9331. 9s. 10d.; saving in the wages
cf labor, 6591. 7s. Od. In this, is not included any part of the interest of the sum laid
out upon the machine, or expended in keeping it in order. But in a very few years, at
such an immense rate of saving, the cost of the engine and other machinery will be
repaid. This admirable apparatus is the invention of T. T. Grant, Esq., storekeeper of
the Royal Clarence Victualling Establishment, who, we believe, has been properly
rewarded, by a grant of 2,0001. from government.
The labor of incorporating the ingredients of bread, viz., flour, water, and salt, or
kneading dough, is so great as to have led to the contrivance of various mechanical modes
of producing the same effect. One of the most ingenious is that for which a patent was
obtained in August, 1830, by Mr. Edwin Clayton. It consists of a rotatory kneading
trough, or rather barrel, mounted in bearings with a hollow axle, and of an interior
frame of cast iron made to revolve by a solid axle which passes through the hollow one;
in the frame there are cutters diagonally placed for kneading the dough. The revolving
frame and its barrel are made to turn in contrary directions, so as greatly to save time
and equalise the operation. This double action represents kneading by the two hands,
in which the dough is inverted from time to time, torn asunder, and reunited in every
different form. The mechanism will be readily understood from the following description,




BREAD.                                   255
Fig. 190 exhibits a front elevation of a rotatory kneading trough, constructed according
to improvements specified by the patentee, the barrel being shown in section; a is the
barrel, into which the several ingredients, consisting of flour, water, and yeast, are put,
which barrel is mounted in the frame-work b, with hollow axles c and d, which hollow
axles turn in suitable bearings at e; f is the revolving frame which is mounted in the
interior of the barrel a, by axles g and h. The ends of this revolving frame are fastened, or braced together by means of the oblique cutters or braces i, which act upon the
dough when the machine is put in motion, and thus cause the operation of kneading.
Either the barrel may be made to revolve without the rotatory frame, or the rotatory
frame without the barrel, or both may be made to revolve together, but in opposite ways.
These several motions may be obtained by means of the gear-work, shown at k, 1, and
m, as will be presently described.
If it be desired to have the revolving motion of the barrel and rotatory frame together,
but in contrary directions, that motion may be obtained by fastening the hollow axle of
the wheel m, by means of a screw n, to the axle h, of the rotatory frame f, tight, so as
they will revolve together, the other wheels k and I being used for the purpose of reversing the motion of the barrel. It will then be found that by turning the handle o,
the two motions will be obtained.
If it be desired to put the rotatory frame f, only, into motion, that action will be obtained by loosening the screw n, upon the axle of the wheel m, when it will be found that
the axle h will be made to revolve freely by means of the winch o, without giving motion
to the wheels k, 1, and m, and thus the barrel will remain stationary. If the rotatory
action of the barrel be wanted, it will be obtained by turning the handle p, at the reverse
end of the machine, which, although it puts the gear at the opposite end of the barrel
into motion, yet as the hollow axle of the wheel m is not fastened to the axle h, by the
screw n, these wheels will revolve without carrying round the frame f.
M. Kuhlmann, Professor of Chemistry at Lille, having been called upon several times
by the courts of justice to examine by chemical processes bread suspected of containing
substances injurious to health, collected some interesting facts upon the subject, which
were published under the direction of the central council of salubrity of the department
du Nord.
For some time public attention had been drawn to an odious fraud committed by a
great many bakers in the north of France and in Belgium-the introduction of a certain
quantity of sulphate of copper into their bread. When the flour was made from bad
grain this adulteration was very generally practised, as was proved by many convictions
and confessions of the guilty persons. When the dough does not rise well in the fermentation (le pain pousse plat), this inconvenience was found to be obviated by the addition of blue vitriol, which was supposed also to cause the flour to retain more water.
The quantity of blue water added is extremely small, and it is never done in presence of
strangers, because it is reckoned a valuable secret. It occasions no economy of yeast,
but rather the reverse. In a litre (about a quart) of water, an ounce of sulphate of
copper is dissolved; and of this solution a wine-glass full is mixed with the water necessary for 50 quartern or 4 pound loaves.
M. Kuhlmann justly observes, that there can be no safety whatever to the public when
such a practice is permitted, because ignorance and avarice are always apt to increase the
quantity of the poisonous water. In analyses made by him and his colleagues, portions
of bread were several times found so impregnated with the above salt that they had acquired a blue color, and presented occasionally even small crystals of the sulphate. By
acting on the poisoned bread with distilled water, and testing the water with ferro-cyanate (prussiate) of potash, the reddish brown precipitate or tint characteristic of copper
will appear even with small quantities. Should the noxious impregnation be still more
minute, the bread should be treated with a very dilute nitric acid, either directly or after
incineration in a platinum capsule, and the solution, when concentrated by evaporation,
should be tested by the ferro-cyanate of potash. In this way, a one seventy thousandth
part of sulphate of copper may be detected.




256                                BREAD.
M. Kuhlmann deduces, from a series of experiments on baking with various small
quantities of sulphate of copper, that this salt exercises an extremely energetic action
upon the fermentation and rising of the dough, even when not above one seventy thousandth part of the weight of the bread is employed; or one grain of sulphate for ten pounds
of bread. The proportion of the salt which makes the bread rise best is one twenty thousandth, or one grain in three pounds of bread. If much more of the sulphate be added,
the bread becomes moist, less white, and acquires a peculiar disagreeable smell like that
of leaven. The increase of weight by increased moisture may amount to one sixteenth
without the bread appearing softer, in consequence of the solidifying quality of the copper; for the acid does not seem to have any influence; as neither sulphate of soda, sulphate of iron, nor sulphuric acid have any analogous power. Alum operates like blue
vitriol on bread, but larger quantities of it are required. It keeps water, and raises well,
to use the bakers' terms.
When alum is present in bread it may be detected by treating the bread with listilled
water, filtering the water first through calico, and next through filtering paper, till it becomes clear; then dividing it into two portions, and into the one pouring a few drops
of nitrate or muriate of barytes, and into the other a few drops of water of ammonia. In
the former a heavy white precipitate indicating sulphuric acid will appear, and in the
latter a light precipitate of alumina, redissoluble by a few drops of solution of caustic
potash.
When chalk or Paris plaster is used to sophisticate flour, they may be best detected by
incinerating the bread made of it, and examining the ashes with nitric acid, which will
dissolve the chalk with effervescence, and the Paris plaster without. In both cases the
calcareous matter may be demonstrated in the solution, by oxalic acid, or better by oxalate of ammonia.
In baking puff-paste the dough is first kneaded along with a certain quantity of butter,
then rolled out into a thin layer, which is coated over with butter, and folded face-wise
many times together, the upper and under surfaces being made to correspond. This
stratified mass is again rolled out into a thin layer, its surface is besmeared with butter,
and then it is folded face-wise as before. When this process is repeated ten or a dozen
times, the dough will consist of many hundred parallel laminae, with butter interposed
between each pair of plates. When a moderately thick mass of this is put into the oven,
the elastic vapor disengaged from the water and the butter, diffuses itself between each
of the thin laminae, and causes them to swell into what is properly called puff-paste, being an assemblage of thin membranes, each dense in itself, but more or less distinct from
the other, and therefore forming apparently, but not really, light bread.
One of the most curious branches of the baker's craft is the manufacture of gingerbread, which contains such a proportion of molasses, that it cannot be fermented by
means of yeast. Its ingredients are flour, molasses or treacle, butter, common potashes,
and alum. After the butter is melted, and the potashes and alum are dissolved in a
little hot water, these three ingredients, along with the treacle, are poured among the
flour, which is to form the body of the bread. The whole is then incorporated by
mixture and kneading into a stiff dough.  Of these five constituents the alum is
thought to be the least essential, although it makes the bread lighter and crisper, and
renders the process more rapid; for gingerbread dough requires to stand over several
days, sometimes 8 or 10, before it acquires that state of porosity which qualifies it for
the oven. The action of the treacle and alum on the potashes in evolving carbonic acid,
seems to be the gasefying principle of gingerbread; for if the carbonate of potash is
withheld from the mixture, the bread, when baked, resembles in hardness a piece of
wood.
Treacle is always acidulous. Carbonate of magnesia and soda may be used as substitutes for the potashes. Dr. Colquhoun has found that carbonate of magnesia and
tartaric acid may replace the potashes and the alum with great advantage, affording a
gingerbread fully more agreeable to the taste, and much more wholesome than the
common kind, which contains a notable quantity of potashes. His proportions are one
pound of flour, a quarter of an ounce of carbonate of magnesia, and one eighth of an
ounce of tartaric acid; in addition to the treacle, butter, and aromatics, as at present
used. The acid and alkaline earth must be well diffused through the whole dough.
The magnesia should, in fact, be first of all mixed with the flour. Pour the melted
butter, the treacle, and the acid dissolved in a little water all at once among the flour,
and knead into a consistent dough, which being set aside for half an hour or an hour will
be ready for the oven, and should never be kept unbaked more than 2 or 3 hours. The
following more complete recipe is given by Dr. Colquhoun, for making thin ginger.
bread cakes:
Flour           1 lb.
Treacle       o0
Raw sugar      0^




BREAD.                                   257
Butter            2 oz.
Carbon. magnesia 0^
Tartaric acid    0o
Ginger          O0
Cinnamon        0O
Nutmeg           1
This compound has rather more butter than common thin gingerbread.
I shall here insert a passage from my Dictionary of Chemistry, as published in 1821 
as it may prove interesting to many of my present readers.
" Under Process of Baking, in the Supplement to the Encyclopedia Britannica, we
have the following statement:-' An ounce of alum is then dissolved over the fire in a
tin pot, and the solution poured into a large tub, called by the bakers the seasoningtub. Four pounds and a half of salt are likewise put into the tub, and a pailful of hot
water.'-Foot note on this passage.-' In London, where the goodness of bread is estimated ennrely by its whiteness, it is usual with those bakers who employ flour of an inferior quality, to add as much alum as common salt to the dough; or, in other words,
the quantity of salt added is diminished one half, and the deficiency supplied by an equal
weight of alum. This improves the look of the bread very much, rendering it much
whiter and firmer.' "
In a passage which we shall presently quote, our author represents the bakers of
London in a conspiracy to supply the citizens with bad bread. We may hence infer
that the full allowance he assigns of 2- pounds of alum for every 2- pounds of salt, will
be adopted in converting the sack of flour into loaves. But as a sack of flour weighs 280
pounds, and furnishes on an average 80 quartern loaves, we have 21 pounds divided by
80, or 15750 rains = 197 grains, for the quantity present, by this writer, in a London
80
quartern loaf. Yet in the very same page (39th of vol. ii.) we have the following
passage: C Alum is not added by all bakers. The writer of this article has been assured
by several bakers of respectability, both in Edinburgh and Glasgow, on whose testimony
he relies, and who made excellent bread, that they never employed any alum. The reason for adding it given by the London bakers is, that it renders the bread whiter, and enables them to separate readily the loaves from each other. This addition has been alleged
by medical men, and is considered by the community at large, as injurious to the health,
by occasioning constipation. But if we consider the small quantity of this salt added by
the baker, not quite 51 grains to a quartern loaf, we will not readily admit these allegations. Suppose an individual to eat the seventh part of a quartern loaf a day, he would
only swallow eight tenths of a grain of alum, or, in reality, not quite so much as half a
grain; for one half of this salt consists of water. It seems absurd to suppose that half a
grain of alum, swallowed at different times during the course of a day, should occasion
constipation."  Is it not more absurd to state 2- pounds or 36 ounces, as the alum adulteration of a sack of flour by the London bakers, and within a few periods to reduce the
adulteration to one ounce?
That this voluntary abstraction of -3 of the alum, and substitution of superior and
more expensive flour, is not expected by him from the London bakers, is sufficiently evident from the following story. It would appear that one of his friends had invented a
new yeast for fermenting dough, by mixing a quart of beer barm with a paste made of
ten pounds of flour and two gallons of boiling water, and keeping this mixture warm for
six or eight hours.
"Yeast made in this way," says he, " answers the purposes of the baker much better
than brewers' yeast, because it is clearer, and free from the hop mixture which sometimes
injures the yeast of the brewer. Some years ago the bakers of London, sensible of the
superiority of this artificial yeast, invited a company of manufacturers from Glasgow
to establish a manufactory of it in London, and promised to use no other. About
5,0001. accordingly was laid out on buildings and materials, and the manufactory was
begun on a considerable scale. The ale-brewers, finding their yeast, for which they had
drawn a good price, lie heavy on their hands, invited all the journeymen bakers to their
cellars, gave them their full of ale, and promised to regale them in that manner every
day, provided they would force their masters to take all their yeast from the ale-brewers.
The journeymen accordingly declared, in a body, that they would work no more for their
masters unless they gave up taking any more yeast from the manufactory. The masters
were obliged to comply; the new manufactory was stopped, and the inhabitants of London were obliged to continue to eat worse bread, because it was the interest of the alebrewers to sell the yeast. Such is the influence of journeymen bakers in the metropolis
of England!"
This doleful diatribe seems rather extravagant; for surely beer yeast can derive
nothing noxious to a porter drinking people, from a slight impregnation of hops; while
it must form probably a more energetic ferment than the fermented paste of the new
company, which at any rate could be prepared in six or eight hours by any baker who




258                                 BREAD.
found it to answer his purpose of making a pleasant eating bread. But it is a very serious
thing for a lady or gentleman of sedentary habits, or infirm constitution, to have their digestive process daily vitiated by damaged flour, whitened with 197 grains of alum pei
quartern loaf. Acidity of stomach, indigestion, flatulence, headaches, palpitation, costiveness, and urinary calculi may be the probable consequences of the habitual introduction
of so much acidulous and acescent matter.
I have made many experiments upon bread, and have found the proportion of alum very
variable. Its quantity seems to be proportional to the badness of the flour; and hence
when the best flour is used no alum need be introduced. That alum is not necessary for
giving bread its utmost beauty, sponginess, and agreeableness of taste, is undoubted; since
the bread baked at a very extensive establishment in Glasgow, in which about 20 tons of
flour were regularly converted into loaves in the course of a week, united every quality
of appearance with an absolute freedom from that acido-astringent drug. Six pounds of
salt were used for every sack of flour; which, from its good quality, generally afforded
83 or 84 quartern loaves of the legal weight of four pounds five ounces and a half each.
The loaves lost nine ounces in the oven.
Every baker ought to be able to analyze his flour. He may proceed as follows:-A ductile paste is to be made with a pound of the flour and a sufficient quantity of water, and
left at rest for an hour; then having tied across a bowl a piece of silken sieve-stuff, a
little below the surface of the water in the bowl, the paste is to be laid upon the sieve on
a level with the water, and kneaded tenderly with the hand, so as merely to wash the
starchy particles out of it. This'portion of the flour gets immediately diffused through
the water, some of the other constituents dissolve, and the gluten alone remains upon the
filter. The water must be several times renewed till it ceases to become milky. The
last washings of the gluten are made out of the sieve.
The whole of the turbid washings are to be put into a tall conical glass or stoneware
vessel, and allowed to remain at rest, in a cool place, till they deposite the starch. The
clear supernatant liquor is then decanted off. The deposite consists of starch, with a
little gluten. It must be washed till the water settles over it quite clear, and then it is
to be dried.
The filtered waters being evaporated at a boiling heat, discover flocks floating through
them, which have been supposed by some to be albumen, and by others gluten. At last,
phosphate of lime precipitates. When the residuum has assumed a sirupy consistence in
the cold, it is to be mixed with alcohol, in order to dissolve out its sugar. Cold water
being added to what remains, effects a solution of the mucilage, and leaves the insoluble
azotized matter with the p,,sphate of lime.
By this mode of analysis a minute portion of resin may remain in the gluten and in the
washing water; the gluten retains also a small proportion of a fixed oil, and a volatile
principle, which may be renoved by alcohol. If we wish to procure the resin alone, we
must first of all treat the flour, well dried, with alcohol.
When corn flour, poor in gluten, is to be analyzed, the dough must be enclosed in a
linen bag, kneaded with water, and washed in that state.
In analyzing barley-meal by the above process, hordeine, mixed with common starch, is
obtained: they may be separated by boiling water, which dissolves the starch, and leaves
the hordeine under the aspect of saw-dust.
Fig. 191 is the plan of a London baker's oven, fired with coal fuel.
Fig. 192 is the longitudinal section.,  191     
~
1l1V   I l   l  4  1  I
a, the body of the oven; b, the door; c, the fire-grate and furnace; d, the smoke
flue; e, the flue above the door, to carry off the steam and hot air, when taking out the
bread; f, recess below the door, for receiving the dust; g, damper plate to shut off the
steam flue; h, damper plate to shut off smoke flue, after the oven has come to its proper




BREAD.                                   259
ldI     193               heat; i, a small ircn pan over the fire-place c;! i                       for heating water; k, ash-pit below the fur
nace.
-mN~"~......'-Fig. 193 is the front view; the same letters ret i -! -z"~ —-,       -      fer to the same objects in all the figures.
" o'f 1~.fl T_. ~    _ -The flame and burnt air of the fire at c, sweep
LLL'  _  I.IL     c   along the bottom  of the oven by the right hand
side, are reflected from the back to the left hand
side, and thence escape by the flue d; (see plan
f             k     J/ig. 193.) Whenever the oven has acquired the
proper degree of heat, the fire is withdrawn, the
EU  ____~_    __~   i    flues are closed by the damper plates, and the lumps
AME$~~~~.. ~ \\\ Aof fermented douch are introduced.
I believe it may be safely asserted that the art of baking bread, pastry, and confectionery, is carried in Paris to a pitch of refinement which it has never reached in
London. I have never seen here any bread which, in flavour, colour and texture,
rivalled the French pain de gruau. In fact, our corn monopoly laws, till they were
of late happily repealed, prevented us from getting the proper wheat for preparing, at
a moderate price, the genuine semoule out of which that bread is baked. Hence, the
plebeian bourgeois can daily grace his table with a more beautiful piece of bread than
the most affluent English nobleman. The French process of baking has been recently
described, with some minuteness, by their distinguished chemist, Mi. Dumas*, and it
merits to be known in this country.
At each operation, the workman (petrisseur) pours into the kneading trough the
residuary leaven of a former kneading, adding the proportion of water which practice
enjoins, and diffuses the leaven through it with his hands. He then introduces into
the liquid mass the quantity of flour destined to form the sponge (pate). This flour
is let down from a chamber above, through a linen hose (manche), which may be shut
by folding it up at the end.
The workman now introduces the rest of the flour by degrees, diffusing and
mingling it, in a direction from the right to the left end of the trough. When he has
thus treated the whole mass successively, he repeats the same manipulation from left
to right. These operations require no little art for their dextrous performance; hence
they have the proper name assigned respectively to each, of frasage and contrefrasage. The workman next subjects the dough to three different kinds of movement,
m  the kneading process. He malaxates it; that is, works it with his hands and
fingers, in order to mix very exactly its component parts, while he adds the requisite
quantity of flour. He divides it into six or seven lumps (patons), each of which he
works successively in the same manner. Then he seizes portions of each, to draw
them out, taking only as much as he can readily grasp in his hands. When he has
thus kneaded the different lumps, he unites them into one mass, which he extends and
folds repeatedly back upon itself. He then lifts up the whole at several times, and
dashes it forcibly against the kneading trough, collecting it finally at its left end.
The object of these qperations is to effect an intimate mixture of the flour, the water,
and the leaven. No dry powdery spots called marrons, should be left in any part of
the dough.
The kneader has now completed his work; and after leaving the dough for some
time at rest, he turns it upside down. He lays the lumps, of a proper weight, upon a
table, rolls them out, and dusts them with a little flour. He next turns over each
lump, and puts it in its panneton, where he leaves it to swell. If the flour be of good
quality, the dough be well made, and the temperature be suitable, the lumps will
swell much and uniformly.  If after the surface has risen, it falls to a considerable
extent, the flour must be bad, or it must contain other substances, as potato starch,
bean meal, &c.
Whenever the oven is hot enough, and the dough sufficiently fermented, it is subjected to the baking process. Ovens, as at present constructed, are not equally
heated throughout, and are particularly liable to be chilled near the door, in consequence of its being occasionally opened and shut. To this cause M. Dumas ascribes
many of the defects of ordinary bread; but he adds, that by adopting the patent
invention of M. Mouchot these may be obviated. This is called the improved bakery,
boulangerie perfectionnee.
Fig. 194. is a ground plan of the aerothermal bake-house, the granaries being in the
upper stories, and not shown here. b b are the ovens; c, the kneading machine; d,
the place where the machinery is mounted for hoisting up the bread into the store
* Traite de Chimie appliquee aux Arts, vi. p. 400.
2L2




260                                BREAD.
room above; e, a space common to the two ovens, into which the hot air passes; f, the
place of a wheel driven by dogs, for giving motion to the kneading machine.
194
I  mi
Fig. 195. is a longitudinal section of the oven; A, the grate where coke or even pit,
coals may be burned; B, B, void spaces which, becoming heated, serve for warming
small pieces of dough in; c, c are flues for conducting the smoke, &c., from the fireplace; D, seen in fig. 196., is the chimney for carrying off the smoke transmitted by the
flues; E, E, void spaces immediately over the flues, and beneath the sole, F, F, of the
oven. By this arrangement the air, previously heated, which arrives from the void
spaces B through the flues, c, c, gets the benefit of the heat of the flame which circulates in these flues, and, after getting more heated in the spaces E, E, ascends through
channels into the oven F, F, upon the sole of which the loaves to be baked are laid.
\       \         E
1Z1\\\    \\    \\
A              13
The hot air is admitted into it through the passages a, a, being drawn from the reservoirs B, B, B, and also by the passage d, d, drawn from the reservoirs E, E. The
sole is likewise heated by contact with the hot air contained in the space E, E, placed
immediately below it. The hot air, loaded with moisture, issues by the passage b, b,
and returns directly into the reservoir B, B. G, G, an enclosed space directly over




BREAD.                                  261
the oven, to obstruct the dissipation of its heat; g, vault of the fire-place. Fig. 196., a
transverse section through the middle of the oven. Fig. 197., the kneading machine, a
longitudinal section passing through its axis; P, P, the contour of the machine, made
196
F A
]1tll__ll___ _____                         _ I~IJ
of wood, and divided into three compartments for the reception of the dough. The
wooden bars, o, o, are so placed in the interior of the compartments, as to divide the
dough whenever the cylinder is made to revolve. One portion, D, of the cylinder may
be opened and laid over upon the other by means of a hinge joint, when the dough and
flour are introduced. A, B, C, the three compartments of the machine, two for making
the dough, and one for preparing the sponge, called levain, or leaven, by the French. a, a,
is the pulley which receives its motion from the engine, and transmits it to the cylinder
through the pinion b, and the spur-wheel e; d d, the fly-wheel to regulate the motion;
g, a brake to act upon the fly d, by means of a lever h; i, the pillar of the fly-wheel
There is a ratchet wheel counter for numbering the turns of the kneading machine,
but it cannot be shown in this view; n, cross bars of wood, which are easily removed
when the cylinder is opened; they divide the dough.
Each of the three compartments of the kneader (fig. 197.) is furnished at pleasure
with two bars fixed crosswise, but which may be easily removed, whenever the
cylinder is opened. These bars ck nstitute the sole agents for drawing out the dough.
p              197                   a
P                    ^             P
125 kilogrammes of ordinary leaven or yeast.
The person in charge of the mechanical kneader shuts down its lid, and sets it
67    -                            flour.
33ih                               water.
In all   225 kilogrammes.
The person in charge of the mechanical kneader shuts down its lid, and sets it




262                               BREAD.
a-going. At the end of about seven minutes he hears the bell of the counter sound,
announcing that the number of revolutions has been sufficient to call for an inspection
of the sponge, in regard to its consistence. The cylinder is therefore opened, and
after verifying the right state of the leaven, and adding water to soften, or flour to
stiffen it, he closes the lid, and sets the machine once more in motion. In ten minutes
more the counter sounds again, and the kneading is completed. The 450 kilogrammes of leaven obtained from  the two compartments are adequate to prepare
dough enough to supply alternately each of the two ovens. For this purpose 75
kilogrammes of leaven are taken from each of the two compartments A and A', and
placed in the intermediate compartment B. The whole leaven is then 75+75=150
kilogrammes; to which are added 100 kilogs. of flour and 50 of water=150, so that
the chest contains 300 kilogrammes. There is now replaced in each of the cavities A
and A' the primitive quantity, by adding 50 kilogrammes of flour and 25 of
water= 75.
The cylinder is again set a-going; and from  the nature of the apparatus, it is
obvious that the kneading takes place at once on the leavens A and A' and on the
paste B; which last is examined after 7 minutes, and completed in 10 more=17, at
the second sound of the counter-bell.
The kneader is opened, the paste on the side and on the bars is gathered to the
bottom by means of a scraper. The whole paste of the chest B being removed, 150
kilogs. of the leaven are taken, to which 150 kilogs. of flour and water are added to
prepare the 300 kilogs. of paste destined for the supply of the oven No. 2. These
75 kilogs. of leaven from each compartment are replaced as before, and so on in succession.
The water used in this operation is raised to the proper temperature, viz. 25~ or
30~ C. (77~ or 86~ F.) in cold weather, and to about 68~ F. in the hot season, by
mixing common cold water with the due proportion of water maintained at the temperature of about 160~ F., in the basin F placed above the ovens.
Through the water poured at each operation upon the flour in the compartment B,
there is previously diffused from 200 to 250 grammes of fresh leaven, as obtained from
the brewery, after being drained and pressed (German yeast). This quantity is
sufficient to raise properly 300 kilogs. of dough. As soon as this dough is taken out
of the kneader, as stated above, and while the machine goes on to work, the quantity
re.uisite for each loaf is weighed, turned about on the table D, to give it its round or
oblong form, And there is impressed upon it with the fore-arm or roller, the cavity
which characterizes cleft loaves. All the lots of dough of the size of one kilog.,
called cleft loaves (pains fendus) are placed upon a cloth a fold of which is raised
between two loaves, the cloth being first spread upon a board; which thus charged
with 10 or 15 loaves is transferred to the wooden shelves G G in front of the oven.
The whole of them rise easily under the influence of the gentle temperature of this antechamber or fournl, Whenever the dough loaves are sufficiently raised here, they are
put into the oven, a process called enfournement in France; which consists in setting
each loaf on a wooden shovel dusted with coarse flour, and placing it thereby on the
sole of the oven, close to its fellow, without touching it. This operation is made easy, in
consequence of the introduction of a long jointed gas-pipe and burner into the interior
of the oven, by the light of which all parts of it may be minutely examined. The oven,is first kept moderately hot, by shutting the dampers; but whenever the thermometer
attached to it indicates a temperature of from 300~ to 2900 C. (5720 to 554~ F.),
the dampers or registers are opened, to restore the heat to its original degree, by
allowing of the circulation of the hot air, which rises from the lower cavities around
the fire-place into the interior of the oven. When the baking is completed, the gaslight, which had been withdrawn, is again introduced into the oven, and the bread is
taken out; called the process of defourqzemnent. If the temperature have been maintained at about 3000 C., the 300 kilogs. of dough divided into loaves of one kilog.
(21 lbs. avoirdupois) will be baked in 27 minutes. The charging having lasted 10
minutes, and the discharging as long, the baking of each batch will take up 47 minutes.
But on account of accidental interruptions, an hour may be assigned for each charge
of 260 loaves of 1 kilog. each; being at the rate of 6240 kilogs. (or 6-75 tons) of bread
in 24 hours.
Although the outer parts of the loaves be exposed to the radiation of the walls,
heated to 280~ or 300~ C., and undergo therefore that kind of caramelization (charring)
which produces the colour, the taste, and the other special characters of the crust, yet
the inner substance of the loaves, or the crumb, never attains to nearly so high a temperature; for a thermometer, whose bulb is inserted into the heart of a loaf, does not
indicate more than 100~ C. (212~ F.).
The theory of panification (bread-baking) is easy of comprehension.  The flour
owes this valuable quality to the gluten, which it contains in greater abundance than




BREAD.                                   263
any of the other cerealia (kinds of corn). This substance does not constitute, as had
been heretofore imagined, the membranes of the tissue of the perisperm of the wheat;
but is enclosed ii cells of that tissue under the epidermic coats, even to the centre of
the grain. In this respect the gluten lies in a situation analogous to that of the starch,
and of most of the immediate principles of vegetables. The other immediate principles
which play a part in panification are particularly the starch and the sugar; and they
all operate as follows:The diffusion of the flour through the water, hydrates the starch and dissolves the
sugar, the albumen, and some other soluble matters. The kneading of the dough, by
completing these reactions through a more intimate union, favors also the fermentation of the sugar, by bringing its particles into close contact' with those of the
leaven or yeast; and the drawing out and malaxating the dough softens and stratifies it,
introducing at the same time oxygen to aid the fermentation. The dough, when
distributed and formed into loaves, is kept some time in a gentle warmth, in the folds
of the cloth, pans, &c., a circumstance propitious to the development of their volume
by fermentation. The dimensions of all the lumps of dough now gradually enlarge,
from the disengagement of carbonic acid in the decomposition of the sugar; which gas
is imprisoned by the glutinous paste. Were these phenomena to continue too long,
the dough would become too vesicular; they must, therefore, be stopped at the proper
point of sponginess, by placing the loaf lumps in the oven. Though this causes a
sudden expansion of the enclosed gaseous globules, it puts an end to the fermentation,
and to their growth; as also evaporates a portion of the water.
The fermentation of a small dose of sugar is, therefore, essential to true breadbaking; but the quantity actually fermented is so small as to be almost inappreciable.
It seems probable that in well-made dough the whole carbonic acid that is generated
remains in it; amounting to one half the volume of the loaf itself at its baking temperature, or 212~. It thence results that less than one hundredth part of the weight of the
flour is all the sugar requisite to produce well-raised bread. What egregious folly was
it, therefore, to mount the bakery in Chelsea, twelve years ago, at an expense of 20,0001.,
for the purpose of catching the volatile spirits in their escape from the loaves in the
oven-or, as it was vulgarly termed, " taking the gin out of the bread!" whereas it was
nothing but taking the cash out of the pockets of the pseudo-chemical visionaries who
swarm in this metropolis.
The richness or nutritive powers of sound flour and also of bread are proportional to
the quantity of gluten they contain. It is of great importance to determine this point,
for both of these objects are of enormous value and consumption; and it may be accomplished most easily and exactly by digesting in a water-bath, at the temperature of 167'
F., 1,000 grains of bread (or flour) with 1,000 grains of bruised barley-malt, in 5,000
grains, or in a little more than half a pint, of water. When this mixture ceases to take
a blue color from iodine (that is, when all the starch is converted into soluble dextrine)
the gluten left unchanged may be collected on a filter cloth, washed, dried at a heat of
212~, and weighed. The color, texture, and taste of the gluten, ought also to be examined, in forming a judgment of good flour, or bread.
Independently of the skill of the baker, bread varies in quality according to the
quantity of water and gluten it contains. A patent of German or French origin was
obtained here a few years ago, for manufacturing loaf-bread by using thin boiled flour.
paste instead of water for setting the sponge, that is, for the preliminary dough fermentation. By this artifice, 104 loaves of 4 lbs. each could be made out of a sack of flour,
instead of 94, as in ordinary baking; because the boiled paste gave a water-keeping
faculty to the bread in that proportion.  But this hydrated bread was apt to spoil in
warm weather, and became an unprofitable speculation to all concerned.
Bread and flour are often adulterated in France with potato starch, but almost never,
I believe, in this country. The sophistication is easily detected by the microscope, on
account of the peculiar ovoid shape and the large size of the particles of the potato
fecula. Horse-bean flour gives to wheaten bread a pinkish tint. In spoiled flour
(such as is too often used, partially at least, by our inferior bakers) the gluten sometimes disappears altogether, and is replaced by ammoniacal salts.* In this case quicklime separates ammonia from the flour without heat; in flour slightly damaged, or
ground from damaged wheat, the gluten present is deprived of its elasticity, and is
softer than in the natural state. On this account the gluten test of M. Boland is
valuable. It consists in putting some gluten into the bottom of a copper tube, and
heating that tube in an oven, or in oil at a temperature of 284~ F. The length to
which the cylinder of gluten expands is proportional to and indicates its quality.
It appears that a French sack of flour, which weighs 159 kilogrammes, affords from
102 to 106 loaves of 2 kilogrammes each: and therefore,
159: 52-0:: 280: 91-6; that is, if 159 kilogs. or lbs. afford 52 loaves of 4 kilogs.
or lbs., 280 lbs., a sack English, should afford 91 6 loaves of 4 lbs. each; but our
* Dumas, Chimie Appliquee, vi. 425.




264                                BREWING.
bakers usually make out 94 loaves, which are rated at 4 pounds, though they seldom
weigh so much. The loaves of a baker in my neighbourhood, who supplied my family
with bread for some time, were found on trial to be from 6 to 8 oz. deficient in weight:
when challenged for this fraud, he had the effrontery to palliate it by alleging that all
his neighbour bakers did the same. It must be borne in mind that a Paris loaf of 2 lbs.
or 2 kilogs. contains more dry farina than a London loaf of like weight; for it contains,
from its form and texture, more crust. The crumb is to the crust in the Paris long
loaves, as 25 to 75, or 1 to 3; in our quartern loaves it is as 18 or 20 to 100.
M. Dumas gives the following Table:
Weight of a    Number of   Weight of the   Increase of  Ratio of dry Flour
Sack of Flour.    Loaves.      Bread.    Weight of Flour. — 1. to Bread.
159 Kilogs.      102       202 Kilogs.      1-283
159  do.         104       208  do.         1 300         1: 1-60
159  do.         106       212  do.         1-333
Thus it would appear that the mean yield would correspond to 130 kilogs. of bread
for 100 of the flour employed: and admitting that common flour contains 0'17 of
water, the product would be equivalent to 150 of bread for 100 of flour absolutely dry.
The whole loaf contains 66 per cent. of dry substance, and the crumb only 44.
BRECCIA, an Italian term, used by mineralogists and architects to designate such
compound stony masses, natural or artificial, as consist of hard rocky fragments of
considerable size, united by a common cement. When these masses are formed of
small rounded pebbles, the conglomerate is called a pudding-stone, from a fancied
resemblance to plum pudding.
Concrete, now so much used for the foundation of large buildings, is a factitious
breccia, or pudding-stone. See CONCRETE.
BREWING.  (Brasser, Fr.; Brauen, Germ.)' The art of making BEER, which see.
The peculiar properties contained in wort, do not exist ready formed in malt, but are
the result of the direct action of heat and water upon that substance. Hence it follows
that the composition of beer-wort depends more upon the process of mashing than upon
the malt employed,-for it would be quite practicable to obtain from 1 part of malt
and 8 parts of barley, a wort precisely similar to that procured from 9 parts of
pure malt alone. But, of course, this could not be done without modifying considerably the process of mashing; and it happens, unfortunately, that the practice of the
present day, amongst brewers, is to maintain, as closely as possible, one uniform system
of mashing, whatever may be the nature or quality of the malt employed. Thus a
difference in the malt is made to produce a difference in the wort, and all the energy
and skill of the practical brewer are sometimes insufficient to compensate for the alterations which this difference induces in the subsequent working of the beer.  With a
regular and certain composition, as to the constituents of his wort, the operations of
the brewer would assume a fixed and definite character, which, at present, they are very
far indeed from possessing; and by which he not unfrequently suffers the most severe
pecuniary loss and mental anxiety. With the exception of a trifling quantity of vegetable albumen, the only solid ingredients of beer-wort are dextrine and sugar; the
latter of which ferments with great ease and rapidity, whilst the dextrine, though
capable of fermentation, enters into the process only with difficulty, and requires, for
its successful termination, not only much more yeast, but also a much higher temperature
in the fermenting fat. At the same time, it is this very sluggishness in the fermentative
quality of dextrine which is essential to the production of good beer; for, with sugar
alone, the fermentation cannot be checked at ordinary temperatures, until the full
measure of its decomposition has taken place, and it has become either a vapid admixture
of alcohol and water, or, by the absorption of oxygen, is resolved into vinegar. It is
indeed a notorious fact, that beer made with sugar will not keep so well as that made
from malt; though, for rapid consumption, the use of sugar is, under some circumstances,
to be commended, more especially on the small scale and in cold weather. The peculiarity of dextrine is, however, as we have stated, to undergo fermentation only with
difficulty and by slow degrees; hence its decomposition spreads over a long space of
time, and, in very cold weather, amounts to nothing; so that for months, or even years,
after all the sugar of the wort has been destroyed, the evolution of carbonic acid gas
from the still fermenting dextrine, keeps up a briskness and vitality in the beer; and,
by excluding oxygen, all chance of acidification is shut off. A perfect beer-wort should
therefore have reference to the period of its consumption: if this be speedy and pressing,
the proportion of sugar ought to be large; if remote, the dextrine should greatly predominate.  Under the first condition, the attenuation would proceed quickly, and,
provided the temperature of the fermenting vat was not allowed to exceed 78~, the beer
would soon cleanse and become ripe and bright; under the second, the attenuation in




BREWING.                                     265
the vat would be slow and trifling, and require, perhaps, several years for its completion
in the cask. Nevertheless, if the attenuation in the vat had gone on to the complete
destruction of all the sugar, this kind of beer would prove in the end both the better and
more healthy beverage of the two; for by the mode of its formation the presence of
ananthic ether or fusel oil is avoided. The importance therefore of placing in the
hands of the brewer a means of determining the relative amounts of sugar and dextrine
in his wort is sufficiently obvious. Now, this may be done in two ways; either by
ascertaining, in wort of a determinate strength, the proportion of the one or the other of
these substances. The dextrine is easier of calculation than the sugar, in a rough or
approximate way; but the sugar can be determined with much more minute accuracy
than the dextrine. Yet, in practice, the former plan is preferable, from its simplicity,
as we shall proceed to show. If, to a certain volume of strong wort (say of 30 lbs. per
barrel), we add an equal amount of alcohol or spirits of wine, the whole of the dextrine
will precipitate as a dense coagulum; and by examining the bulk of this deposit in the
tnbe, its weight may be inferred pretty nearly if the tube has been previously graduated
so as to indicate, from actual experiment, the weight of the different measures of the
coagulated dextrine. With weaker wort, more alcohol must be used, and with a denser
wort, less alcohol,-the relations of which to each other may easily be kept recorded on
a small card or scale affixed to the tube. This instrument is very easy of application,
and has been found extremely useful to more than one practical brewer of the present
day; and the accompanying record of brewing operations has reference to this mode of
analysing wort. The determination of sugar in wort is best effected by boiling 100 grs.
of it with about half a pint of the following solution, and collecting and weighing the
red-coloured precipitate which ensues,-every three grains of which indicate one grain
of grape-sugar in the wort.
Grape-sugar Test Solution.
Sulphate of copper in crystals    -      -      -       -    100 grains
Bitartrate of potash      -       -                          200  do
Carbonate of soda in crystals-                  -       -    800  do
Boiling water, one pint, or      -       -      -      -   8750  do
First dissolve the sulphate of copper, then the bitartrate of potash, after which add
the carbonate of soda, and filter if necessary. This solution is not affected when boiled
with cane-sugar, dextrine, gum, or starch.
We now proceed to lay before our readers the result of two brewings taken from one
mash at two different periods, and analyzed to determine their relative contents of dextrine and sugar, according to the tube or alcohol process:-March 28th, 1851, proceeded
to mash for experimental brewings; weather clear and open; thermometer outside at 510,
-in fermenting room 58~; difference between wet and dry bulb 5 7500; barometer
39.4 inches.  Composition of the malt:-Moisture 6'1; insoluble matter 27; extract
66'9. Quantity of malt employed 70 bushels; of water at 180~ F., 700 gallons;
made the mixture with a common mashing-oar, and finished in fifteen minutes. One hour
afterwards, drew off 200 gallons of wort; and three hours from commencing to mash,
drew off 200 gallons more,-continuing the mash for table-beer-wort.  The first-drawn
wort contained 7-5 parts of dextrine to 1 of sugar; the second, 6-3 parts of dextrine
2'2 of sugar;-their densities were, respectively, 30 and 36'5 lbs. per barrel.  They
were each boiled separately, with relative amount of hop,-the first having 30 and the
second 36~ lbs. added; and the boiling in each case was kept up for three hours. At
the end of this time both were cooled and diluted with water to a gravity of 271 lbs. per
barrel, and 250 gallons of each let down into separate fermenting-vats placed side by
side; after which, they both received three quarts of good yeast,-the temperature
being at 68~ F. Two hours afterwards, the following observations commenced:-No.
1. being the wort containing 7'5 parts of dextrine to I of sugar, and No. 2. the wort
having 6-3 of dextrine to 2'2 of sugar.
1851.                          No. 1.                           Temp.
March 28. 5 P. M. No action                                      67'5
" " 10 P. M. Light thin cream   -               -      -    67-5
"   29. 9 A. M. White head         -       -      -       -    70
"  6 P. M. Fine white head   -          -           -       71'
"   30. 9 A. M. Thick tough head  -        -      -       -    74
"  6 P. M. Tough brown head -                        -    75'
"   31. 2 P. M. Ferment well roused up   -        -       -    75
Deg.
Attenuation of No. 1.     -      -      -     8
April 2. 2 P. M. (Skimmed off yeast)  -              -           10
11. 2 P..                        -       -      -      -     15
"   13. 2..        "        "      -      -       -      -    15
VOL. 1.                               2 M




266                               BREWING.
No. 2.                          Deg.
No action            -      -       --                 68Fine white head       -      -      -             - -0
Thick yellow head    -       -      -      -      -   74
Fine tough brown head        -      -      -      - 77
High roused up rocky head           -      -      -   77In rapid fermentation -     -       -        -'76'5
Throws up much yeast (skimmed off yeast)  -       -     6
Ditto of No. 2.      -      -      -       -      -    127
-      -      -      -      -      -    15'5.-         -. -         -      -.17 5
"      "                  -       -      -.-    18-2
The temperature of both had now fallen to 690 F., though each had been roused re.
peatedly; the yeast was, therefore, again skimmed off, and the beer run into barrels, and
filled up with reserved wort three times a day as it worked over. On April the 18th
the barrels were closed, having then lost, by attenuation,-No. 1. 16-2 lbs., and No. 2.
19'6 lbs. Six weeks afterwards these ales were examined;-No 1. was found muddy
and unpleasant; whilst No. 2. had a fine fragrant aroma, a brisk, lively appearance, and
was perfectly bright. On January 2nd, 1852, the casks were again examined; No. 1.
had now lost 17-9 lbs., and was bright, rich, and fine flavoured; whilst N. 2., though
bright and pleasant, had contracted a little acidity, and was becoming flat; it had lost,
in all, 21~ lbs.
Two similar experiments, made about the same time in another quarter, gave almost
exactly the same results; and, consequently, there can be little doubt that, where a quick
sale and rapid consumption of beer can be ensured, the great object of the brewer should
be to convert as much of the dextrine of his wort into sugar as is proportional to the
rapidity of that consumption; whereas, for beer intended to keep, the opposite practice
should be followed.
The conversion of any given amount of the dextrine wort into sugar may be effected
either by keeping up the temperature of the mash-tun, and prolonging the operation of
mashing: or, which is better and simpler, by merely preserving the wort for a few hours
at a heat of 170~ F., either in the underback or any other convenient vessel. We have
found from experiment that a wort which when run out from the mash-tun had only 3
parts of sugar to 16 of dextrine, became by 10 hours' exposure to a heat of 165~ converted almost altogether into sugar,-the proportions then being 17-8 of sugar to 1'2
of dextrine.
A very important part of the duty of a brewer should therefore be, first, the determination of the relative amounts of dextrine and sugar required to suit the taste of his
customers, or the circumstances of the market, and next, the continued careful examination of his wort, so as to insure that these proportions are regularly maintained; for
by no other plan is it possible to insure that certainty of result, and uniformity of quality
which are essential to the proper conducting of an expensive business like brewing. It
seems to us that far too little attention has hitherto been given to the fluctuating qualities of beer-wort. In warm weather, this wort should probably contain at least twice as
much dextrine as in winter; yet this is the very period when from the increased temperature of the air and materials, the largest quantity of sugar must be formed by those
who mash upon a fixed and unvarying principle. Hence the proneness of the wort to
ferment violently in summer is still further increased by the presence of an extra proportion of sugar;-whereas prudence would suggest, under such circumstances, a predominance of dextrine, and seek to effect this purpose by a low temperature in the
mash-tun, and by shortening the period of mashing. We are not, however, aware that
this custom prevails, except in one or two solitary instances, in the north of England,
where it is well appreciated. As a general rule, in the management of wort, more
sugar is requisite where small quantities are brewed at a time, than where large operations are conducted, for the loss of heat is relatively larger in small masses than in
large ones; and, from what has been stated, it must be apparent, that, as the fermentation of dextrine is more easily checked by cold than that of sugar, the beer brewed
in trifling quantities could not preserve a fermentative temperature, but would become
chilled and dead from the excessive radiation of caloric, unless a principle existed in it
capable of fermentation at the most ordinary temperatures of this country. If, therefore, beer-wort consisting chiefly of dextrine be fermented in very cold weather, or with
an insufficiency of yeast, or if the temperature happen to rise too high, so as to destroy
or impair the fermentative power of the yeast, then a dull languid action will ensue,
accompanied by what has been called the viscous fermentation, and the beer becomes
permanently ropy, and is spoiled.
Although, clearly, it would be impossible to lay down any specific rule for the proper
proportion of dextrine and sugar in beer-wort, yet there could be no difficulty in each




BREWING.                                   267
brewer determining for himself, and for the conditions of size, time of sale, time of year,
and other contingencies, the requisite ratio to be established in his own case; and, as we
have shown, nothing can be simpler than the means proposed for ascertaining the composition of wort.
The advance of the arts is gradually assuming a character which will no longer
permit any manufacturer to neglect the assistance of science; and those who first take
advantage of the power of knowledge, will assuredly leave their fellow-labourers behind.
From being an uncertain and hazardous operation, brewing must ere long become a
fixed and definite principle based upon facts well understood, and capable of perpetual repetition and reproduction at will. To sum up briefly the general details of ale brewing,
we may state, that, for most kinds of ale, the attenuation in the first instance should be
finished in from 6 to 21 days, according to the strength of the wort; that this attenuation should approach to two-thirds of the whole weight; and that after tunning and
cleansing, the ale itself should weigh about one-fourth of the original gravity of the
wort. Thus, if the fermenting tun be set with wort of 27 lbs., then the attenuation
should bring it down to 9 or 10 lbs., and the subsequent operations produce an ale
weighing from 6 to 7 lbs. When these conditions are fulfilled, without much extra
trouble or attention, the ale is pretty certain to turn out well, though, in some localities,
ale is never attenuated to more than one-half its original gravity; this kind of ale is,
however, very apt to become sour in hot weather and ropy in cold.
We will now proceed to describe the brewing of porter, which differs from that of
ale both in the nature of the materials used and in the mode of finishing the fermentation. Porter owes its peculiar colour and flavour to burnt saccharine or starchy matter; and this was formerly obtained by burning sugar until it exhaled the odour called
by French writers "caramel." At present, however, nothing but highly-torrefied malt
is used; and of this there are several kinds, as brown malt, imperial malt, and black
malt; all of which are used by some brewers, whilst others employ only the brown and
black, and a few the black alone, for giving colour and flavour. The fermentative
quality is saccharine, is, however, the same as that of ale, and is derived from pale or
amber malt. As a general rule, the ratio of the colouring and flavouring malts are to
the saccharine, as about 1 to 5, or 1 to 4; but where black malt only is used, the proportion does not exceed 1 to 10.
The employment of these burnt malts permits a singular act of injustice on the part
of the Excise, as regards the drawback dn exportation. By the Excise regulations, it
is assumed that a quarter of malt will produce four barrels of ale brewed from wort of
the sp. gr. 1-054, or 19'4 lbs. per barrel; but, although this is hopeless even with pale
malt, yet with an admixture of brown and black malt the assumption becomes absurd
in the extreme. Admitting that, by good management, on the average, four barrels of
wort, weighing 20 lbs., can be obtained from one quarter of fine pale malt, yet in the
operations of cooling, fermenting, tunning, skimming, and cleansing, a loss of fully 10
per cent. occurs under the most vigilant superintendence; and, taking the great bulk
of our metropolitan breweries, it would be nearer the truth to estimate this loss at 12
per cent. In plain words, 100 gallons of wort will not, by any management, produce
more than about 88 gallons of saleable beer, though no allowance is made for this by
the Excise; and the brewer who has paid duty upon 100 gallons gets a drawback upon
but 88. This, however, is the most favourable view of the case; and we solicit attention to the force with which the argument returns in the instance of porter.
If a quarter of pale malt be assumed at 84 lbs. of saccharine strength, then such an
admixture of brown and black malt as is usually employed by brewers of porter, will not
give more than about 24 lbs.; and as this constitutes at least one-fifth of the whole bulk
used in porter brewing, we see that a quarter of such mixed malt can never give more
than 70 lbs.; that is to say, 80 parts of pale malt, mixed with 20 of brown and black,
instead of giving at the rate of 84 lbs., as pale malt alone does, would give but 70 lbs.,
or produce a difference between the actual return and that taken for granted by the Excise authorities, of no less than 16'6 per cent; to which, if we add the loss previously
mentioned as arising from fermentation, yeast, &c., and which we have called 12 per
cent., a total difference ensues of 28-6 per cent. between the duty paid by the brewer
and the drawback allowed by act of parliament. But the grievance does not stop here;
for the only return allowed by act of parliament is based upon the malt duty, and
nothing whatever is said of the duty on hops. This, however, is at the rate of 19s. 7d.
per cwt.; and since hops yield only about 35 per cent. of their weight of soluble matter, it would require 168 lbs. of hops to produce a barrel of fluid or wort weighing 19'4
lbs., or having the requisite parliamentary specific gravity of 1'054. Upon this barrel,
when exported, the drawback is 5s.; but as may easily be seen, on calculation, the duty
paid by the brewer has been 29s. 3d. In fact, upon every 168 lbs. of hops consumed
by the export brewer,. he suffers a dead loss of 24s. 3d., independently of the waste
incidental to his various processes. These things may seem startling, yet I challenge
2M2




268                                BREWING.
the whole Board and Staff of the Excise to prove that they are in the least over-estimated. At the same time the intelligent reader will gather that the profits of brewing
are not by any means so large as a cursory glance at the subject might warrant; and
we say this rather as having reference to schemes now in progress for reducing the
price of beer, than from its connection with our general arrangements. No doubt the
brewing business has been of late singularly prosperous; and if the price of malt continues as low this year as it was last, the public have a right to look for some reduction
in the price of ale and porter; but it must not be forgotten that the capital required is
large, and invested in very perishable materials, such as casks and other wooden utensils, the wear and tear upon which is a very large item; nor again, as we have shown,
must a speculator begin by assuming, with the Excise authorities, that a quarter ot
malt will produce four barrels of beer, for he will be much nearer the truth if he estimates his saleable produce at three barrels. As, however, it forms no part of our
present task to enter into the financial statistics of brewing, we return to the object
more immediately in view, merely throwing out, en passant, the above hints for the
benefit of those whom they may concern.
If the analyses of malt and malt-wort are requisite to enable the brewer to perform
his operations with safety and success, the analysis of beer is not less indispensable to
qualify him for the harassing labour of competition with his neighbours, and for the
protection of his interest against Excise confiscation. Although beer may have been
brewed of the requisite gravity for justifying a drawback on exportation, yet this is
very far indeed from ensuring a return of the malt duty, even to the limited extent
awarded by law. The question is, how are the Excise officials to know the real weight
of the wort from which the beer was brewed. This may be ascertained by the following method, which should take the place of the present indefinite system:-Having agitated a portion of the ale or beer, so as to dissipate its carbonicacid gas, measure out
exactly 3600 grain measures of it, and pour these into a retort; then distil, with great
care, into a receiver, surrounded by ice-cold water, about one-third of the whole fluid,
or rather more than this if the ale or beer is known to be highly alcoholic.  Next weigh
the distilled fluid, and then ascertain its specific gravity; from whence, by any of the
proper tables of alcohol (which see), the total quantity of absolute alcohol in the distilled fluid may be known. This alcohol is to be converted, by calculation, into its
equivalent of sugar, at the rate of 171 parts of sugar for every 92 of alcohol found;
after which, this sugar must be brought into pounds per barrel, by the rule given in our
article BEER, which is 52~ lbs. of sugar for every 20 lbs. of gravity. The amount of
vinegar is next to be determined, by any of the known forms of alkalimetry. (See
ACETIC ACID.) This vinegar or acetic acid must, like the alcohol, be also converted into
its representative of sugar, by assigning 171 of sugar to every 102 of anhydrous acetic
acid present in the beer,-this sugar being, as before, converted into pounds per barrel
To the beer remaining in the retort, sufficient distilled water is then to be added, that
the entire bulk of fluid may once more be equal to 3600 grain measures; and the temperature of the mixture having fallen to 60~ Fahr., its specific gravity must be determined in the usual way, and this reduced to pounds per barrel, by multiplying the excess above 1000 by 360, and dividing the product by 1000. The whole of these weights,
added together, gives the original weight of the wort. Thus, for example, we will suppose that 3600 grs. of a particular beer have given 1300 gr. of a dilute alcohol, of
specific gravity'9731, and consequently containing about 17~ per cent., by weight, of
alcohol; again, that the same quantity of beer, when tested by ammonia, has indicated 30 grs. of acetic acid; and, lastly, that the spent wash, when filled up with
distilled water to its primary bulk, has, at 60~, a specific gravity of 1-016;-then the
total alcohol would be in 360 grs., or the representative of a barrel, 221 grs., and the
acetic acid in the same quantity, 3 grs.: hence we have the following results: -
Grs. of sugar. Brewer's libs.
Alcohol, 221 grs., equal to     -       -                   42-2  or  16Acetic acid, 3 grs.      -      -       -       -       -   5           1'9
Spent wash, of sp. gray. 1'016  -       -       -       -              576
Total weight   -       -      23-66
It might be thought that the proper kind of sugar to select in this instance, as the
representative of alcohol and acetic acid, should be grape sugar, whose atomic weight
is 180; but it has long ago been shown by Dr. Ure, that the kind of sugar actually
employed in the construction of our saccharometer tables must have been cane sugar,
the atom of which is 171; and hence the reason why it must be employed in this
calculation.
We may now turn our attention to the business of the distiller, which is a kind of




BREWING.                                       269
supplementary operation to that of the brewer. There are, however, some important
differences, both in mashing and fermenting, between these two methods of producing
alcohol; for the principal object of the brewer is to secure flavour and transparency
to the fermented product, whilst the sole care of the distiller is to ensure the complete
alcoholisation of all the saccharine and gummy constituents of this wort. We have
seen that to the brewer the presence of dextrine was essential; whereas, in distillation,
the more purely saccharine the wort the better. On this account, although malt is
much dearer than raw grain, many eminent distillers continue to employ it alone, from
the simple circumstance that its relatively large contents of diastase furnishes, in the
limited period assigned for mashing, an infinitely more saccharine wort than can be
produced in the same space of time from a mixture of one part of malt and seven or
eight of barley meal. Nevertheless by maintaining the wort from the latter at a
sufficient temperature for a few hours, as indicated with respect to beer-wort, the
diastase in it would exert its specific action upon the dextrine, and, in the end, give as
saccharine a wort from mixed grain as from pure malt. This subject is peculiarly
worthy of the attention of distillers; for the sluggish fermentative qualities of dextrine
are such, that very frequently a considerable quantity of this substance remains in the
wash unacted on, and passes away with the residue as a waste product. It is, indeed,
customary for the distiller to seek a remedy for this, in the employment of large and
frequently repeated additions of yeast; and there can be no doubt as to the propriety
of this measure. Still, however, the true solution of this difficulty must be referred
to a period anterior to fermentation, and it is in the under-back where it should be
grappled with and vanquished.
If we examine with care the catalytic effect of diastase upon starch, we shall find
that the time employed by the distiller is far too short to achieve the object which
it is his interest to bring about. In the case of the brewer, many conditions, as
we have pointed out, require to be foreseen and provided for; and hence a uniform
system of mashing is to be condemned in brewing; but the distiller has only one single
circumstance to bear in mind, and that is, if possible, the total conversion of all the
hordeine, starch, dextrine, and other constituents of his grain and wort into sugar.
In fact, he can scarcely by any chance mash too long or keep his wort at 170~ for
too many hours;-at all events, the following observations demonstrate that the time
now  employed is barely one-fourth of that necessary for success, under'the most
favourable circumstances:-A mixture, composed of 1 part of very fine malt and'7 parts of barley-meal, was mashed with great care in a vessel capable of having its
temperature kept at any required degree for many consecutive hours. The heat of the
water was 180~; and it was found, after thorough mixing, that this had fallen to 168~, at
which point it was accordingly decided to maintain it, and a series of experimental
essays were made upon each sample of the wort, with the view of illustrating the progressive formation of sugar. The results were as follows:Sugar.    Dextrine.
2 hours after mashing.        -                 1 - 3     18-7
3  ditto       ditto     -       -      -       - 4'1        l9
4  ditto       ditto     -       -      -       -  63        137
5  ditto       ditto     -       -       -      -  8-        126  ditto       ditto     -       -       -      -9-2         10'8
7  ditto       ditto     -       -       -      -107          9'3
8  ditto       ditto     -       -       -      -12- 8'
9  ditto       ditto     -       -      -       -13-3         6'7
10  ditto       ditto     -       -       -      -14-5         5-5
11  ditto       ditto     -       -       -      -157          4-3
12  ditto       ditto     -       -      -       -16-9         3-1
Hence, instead of three hours, which is the period commonly used for mashing, the
distiller would be warranted in continuing this operation for twelve hours. In reality,
however, it is only the wort which requires this treatment; for, after the third hour, all
the starch and nearly the whole of the hordeine have become soluble, and nothing but
continued heat is required to complete the saccharification of the wort. The working
of the mash-tun need not therefore be varied, as it will suffice to maintain the underback for 6 or 8 hours at a temperature of 170~. The advantage of converting all the
dextrine into sugar is not limited to the mere saving of material, or the production of
more  alcohol, for there is another and most important object gained.  Sugar
ferments more freely and at a lower temperature than dextrine, consequently the heat
of the fermenting vat need never rise so high, nor require the large quantity of yeast
now  employed for the purpose of forcing a rapid and hot fermentation.  Thus the
tendency to generate fusel oil would be destroyed, as there is not the slightest doubt
that the formation of this oil is due to an excess of temperature in the fermenting-vat,




270                                 BRICK.
and constantly bears a relation to the amount of dextrine in the wort; for this, as we
have before stated, necessitates the employment of a higher fermenting heat than sugtr,
by which the elements of the decomposing materials take on new and unusual arrangenents. The presence of fusel oil in spirit is a serious impediment to the distiller, and
either retards the sale of his produce, or diminishes its value in the market.
As usual, the Excise regulations interfere much with the progress of this, as of every
other manufacture under fiscal superintendence. Careful to prevent fraud, they cripple
industry, and seek, as it were, to secure the honesty of the labourer by cutting off his
hand:-ignorant or careless, meanwhile, of the permanent mischief which they inflict.
Yet, we know of no more fitting subject for fiscal burdens, than the manufacture of
ardent spirits; and had Excise interference been limited to this branch of industry, we
should have deemed it a matter for congratulation, rather than otherwise. Nevertheless, consistency is a kind of virtue in politics; and we cannot imagine why the quasi
superior, moral, and intellectual status of Ireland is continually tempted to err, by a low
duty of but 2s. 8d. per gallon, whilst nearly three times this amount is needed to repress
thebad habits of the people of England. The duty now charged is, for England 7s. lOd.,
for Scotland 3s. 8d., and for Ireland 2s. 8d. per gallon of proof spirits: but on what
principle this graduated scale of temptation to drunkenness has been so fixed, we are
quite unable to conceive. To return, however, to the question of distillation, the duty
can be charged the distiller in any one of three ways,viz. according to the gravity of the
wort he uses: the attenuation of that wort by fermentation; or lastly, the actual quantity of spirit which he produces; the latter being, of course, the only just mode of charge.
The restrictions and penalties are excessive, as our courts of law too frequently testify;
and the notorious prevalence of smuggling seems to prove that the present rates of duty
are too high, and offer a premium for fraud greater than the terror of a temporary imprisonment. The greatest improvement in modern times, as regards distillation, is that
brought about by the invention of the apparatus, now well known under the name of
"Coffey's still."  It would be foreign to our task to give a minute description of this
contrivance here (see STILL); its principle is similar to that of the "cascade chimique" of Clement Desormes. The wort, or other fluid to be distilled, is made to flow
over a very extensive surface in contact with a current of steam passing in an opposite
direction; by which means the steam is condensed, and giving up its latent heat to the
more volatile spirit, this latter is driven on into the condenser in a state of great
purity; whilst the residuary wort and the condensed steam flow out of the vessel from
beneath in a continual stream. Mr. Coffey had many impediments to contend with,
from the opposition of the Excise authorities, in his first attempt to introduce this ingenious invention into public use; but prejudice and ignorance have at length given
way, and the Coffey's still may be now seen in operation at almost every large distillery
in the kingdom. After the distiller has paid duty on the spirit which he has manufactured, it is transmitted to the rectifier, whose premises must be at a considerable distance
from the distillery, according to act of parliament. The business of the rectifier is to
purify the spirit by separating its fusel oil; and this he commonly effects through the
agency of caustic potash. The impure spirit being mixed with a portion of potash,
and carbonate of potash, is carefully distilled or rectified, until it ceases to possess any
disagreeable odour, when it is again distilled in contact with certain aromatic substances,
to give it the requisite qualities of the particular spirit or liquor desired. There is, however, too much reason to fear that the necessary measures of purification are neglected
in the case of common gin,-the defect being merely covered or concealed beneath
more powerful odours. This practice cannot be too strongly reprobated; for experiments made purposely on dogs have convinced us that fusel oil is a highly poisonous
substance, and possesses acro-narcotic powers of no ordinary energy. Its removal from
an article of universal consumption, like spirits, ought therefore to be deemed an important subject.for sanitary legislation, and not left to the casual skill or dubious
honesty of any class of manufacturers whatever. There is more or less fusel oil in all
the gin we have examined.
BRICK. (Brique, Fr.; Backsteine, ziegelsteine, Germ.) A solid, commonly rectangular, composed of clay hardened by heat, and intended for building purposes. The
natural mixture of clay and sand, called loam, as well as marl, which consists of lime
and clay, with little or no sand, constitutes also a good material for making bricks.
The poorer the marl is in lime, the worse adapted it is for agricultural purposes, and
the better for the brick manufacturer, being less liable to fuse in his kiln. When a
natural compound of silica and clay can be got nearly free from lime and magnesia, it
forms a kind of bricks very refractory in the furnace, hence termed fire-bricks. Such a
material is the slate-clay, schieferthon, of our coal measures, found abundantly, and of
excellent quality, at Stourbridge, and in the neighbourhood of Newcastle and Glasgow.
The London brick-makers add to the clay about one-third of coal ashes obtained from
the kitchen dust-holes; so that when the bricks are put into the kiln, the quantity of




BRICK.                                   271
coaly matter attached to their surface serves to economise fuel, and makes them less
apt to shrink in the fire; though they are less compact, and probably less durable than
the bricks made in the coal districts of England.
The general process of brick-making consists in digging up the clay in autumn;
exposing it, during the whole winter, to the frost, and the action of the air, turning it
repeatedly, and working it with the spade; breaking down the clay lumps in spring,
throwing them into shallow pits, to be watered and soaked for several days. The next
step is to temper the clay, which is generally done by the treading of men or oxen.
In the neighbourhood of London, however, this process is performed in a horse-mill.
The kneading of the clay is, in fact, the most laborious but indispensable part of the
whole business; and that on which, in a great measure, the quality of the bricks
depends. All the stones, particularly the ferruginous, calcareous, and pyritous kinds,
should be removed, and the clay worked into a homogeneous paste with as little water
as possible.
The earth, being sufficiently kneaded, is brought to the bench of the moulder, who
works the clay into a mould made of wood or iron, and strikes off the superfluous
matter. The bricks are next delivered from the mould, and ranged on the ground;
and when they have acquired sufficient firmness to bear handling, they are dressed with
a knife, and staked or built up in long dwarf walls, thatched over, and left to dry. An
able workman will make, by hand, 5000 bricks in a day.
The different kinds of bricks made in England are principally place bricks, gray and
red stocks, marl facing bricks, and cutting bricks. The place bricks and stocks are used
in common walling. The marls are made in the neighbourhood of London, and used
in the outside of buildings; they are very beautiful bricks, of a fine yellow colour,
hard, and well burnt, and, in every respect, superior to the stocks. The finest kind of
marl and red bricks, called cutting bricks, are used in the arches over windows and
doors, being rubbed to a centre, and gauged to a height.
In France attempts were long ago made to substitute animals and machines for the
treading of men's feet in the clay kneading pit; but it was found that their schemes
could not replace, with advantage, human labour where it is so cheap, particularly for
separating the stones and heterogeneous matter from the loam. The more it is worked,
the denser, more uniform, and more durable, the bricks which are made of it. A good
French workman, in a day's labour of 12 or 13 hours, it has been said, is able to mould
from 9000 to 10,000 bricks, 9 inches long, 4~ inches broad,'and 2~ thick; but he must
nave good assistants under him. In many brickworks near Paris, screw-presses are
now used for consolidating the bricks and paving tiles in their moulds. M. Mollerat
employed the hydraulic press for the purpose of condensing pulverized clay, which,
after baking, formed beautiful bricks; but the process was too tedious and costly. An
ingenious contrivance for moulding bricks mechanically, is said to be employed near
Washington, in America. This machine moulds 30,000 in a day's work of 12 hours,
with the help of one horse, yoked to a gin wheel, and the bricks are so dry when
discharged from their moulds, as to be ready for immediate burning. The machine is
described, with figures, in the Bulletin de la Sociiet d'Encouragement for 1819, p. 361.
See further on, an account of our recent patents.
Bricks, in this country, are generally baked either in a clamp or in a kiln. The
latter is the preferable method, as less waste arises, less fuel is consumed, and the bricks
are sooner burnt. The kiln is usually 13 feet long, by 10- feet wide, and about 12 feet
in height. The walls are one foot two inches thick, carried up a little out of the
perpendicular, inclining towards each other at the top. The bricks are placed on flat
arches, having holes left in them resembling lattice-work; the kiln is then covered
with pieces of tiles and bricks, and some wood put in, to dry them with a gentle fire.
This continues two or three days before they are ready for burning, which is known by
the smoke turning from a darkish color to transparent. The mouth or mouths of the
kiln are now dammed up with a shinlog, which consists of pieces of bricks piled one
upon another, and closed with wet brick earth, leaving above it just room sufficient to
receive a fagot.  The fagots are made of furze, heath, brake, fern, &c., and the kiln
is supplied with these until its arches look white, and the fire appears at the top; upon
which the fire is slackened for an hour, and the kiln allowed gradually to cool. This
heating and cooling is repeated until the bricks be thoroughly burnt, which is generally
done in 48 hours. One of these kilns will hold about 20,000 bricks.
Clamps are also in common use. They are made of the bricks themselves, and
generally of an oblong form.  The foundation is laid with place brick, or the driest of
those just made, and then the bricks to be burnt are built up, tier upon tier, as high as
the clamp is meant to be, with two or three inches of breeze or cinders strewed between
each layer of bricks, and the whole covered with a thick stratum of breeze. The fireplace is perpendicular, about three feet high, and generally placed at the west end; and
the flues are formed by gathering or arching the bricks over, so as to leave a space




272                                 BRICK.
between each of nearly a brick wide. The flues run straight through the clamp, and
are filled with wood, coals, and breeze, pressed closely together. If the bricks are to
be burnt off quickly, which may be done in 20 or 30 days, according as the weather
may suit, the flues should be only at about six feet distance; but if there be no
immediate hurry, they may be placed nine feet asunder, and the clamp left to burn
off slowly.
Floating bricks are a very ancient invention: they are so light as to swim in water;
and Pliny tells us, that they were made at Marseilles; at Colento, in Spain; and at
Pittane, in Asia. This invention, however, was completely lost, until M. Fabbroni
published a discovery of a method to imitate the floating bricks of the ancients.
According to Posidonius, these bricks are made of a kind of argillaceous earth, which
was employed to clean silver plate. But as it could not be our tripoli, which is too
heavy to float in water, M. Fabbroni tried several experiments with mineral argaric,
guhr, lac-lune, and fossil meal, which last was found to be the very substance of which
he was in search. This earth is abundant in Tuscany, and is found near Casteldelpiano,
in the territories of Sienna. According to the analysis of M. Fabbroni, it consists of
55 parts of silicious earth, 15 of magnesia, 14 of water, 12 of alumina, 3 of lime, and 1 of
iron. It exhales an argillaceous odor, and, when sprinkled with water, throws out a
light whitish smoke. It is infusible in the fire; and, though it loses about an eighth
part of its weight, its bulk is scarcely diminished. Bricks composed of this substance,
either baked or unbaked, float in water; and a twentieth part of clay may be added to
their composition without taking away their property of swimming.  These bricks
resist water, unite perfectly with lime, are subject to no alteration from heat or cold,
and the baked differ from the unbaked only in the sonorous quality which they have
acquired from the fire. Their strength is little inferior to that of common bricks, but
much greater in proportion to their weight; for M. Fabbroni found, that a floating
brick, measuring 7 inches in length, 4x in breadth, and one inch eight lines in thickness, weighed only 14- ounces; whereas a common brick weighed 5 pounds 6- ounces.
The use of these bricks may be very important in the construction of powder magazines
and reverberatory furnaces, as they are such bad conductors of heat, that one end may
be made red hot while the other is held in the hand. They may also be employed for
buildings that require to be light; such as cooking-places in ships, and floating batteries,
the parapets of which would be proof against red-hot bullets.
The following plan of a furnace or kiln for burning tiles has been found very convenient:
Fig. 198., front view, A A, B B, the solid walls of the furnace; a a a, openings to the
ash-pit, and the draught hole; b b b, openings for the supply of fuel, furnished with a
sheet-iron door. Fig. 199. Plan of the ash-pits and air channels c c c. The principal
UC~~~~~~~~~! U111 
198                        199
branch of the ash-pit D D D, is also the opening for taking out the tiles, after removing
the grate; i, the smoke flue. _Fg. 200. Plan of the kiln seen from above. The
grates H H R. The tiles to be fired are arranged upon the
spaces ffff.
Fig. 201. is the plan and section of one of the grates upon
a much larger scale than in the preceding figures.
6f         Y        f Mechanical brick moulding.-Messrs. Lyne and Stainford obtained in August, 1825, a patent for a machine for making a
considerable number of bricks at one operation. It consists, in
the first place, of a cylindrical pug-mill of the kind usually employed for comminuting clay for bricks and tiles, furnished with
rotatory knives, or cutters, for breaking the lumps and mixing
the clay with the other materials of which bricks are commonly
made. Secondly, of two movable moulds, in each of which
201  fifteen bricks are made at once; these moulds being made to
SMggREffiXQ \travel to and fro in the machine for the purpose of being alternately brought under the pug-mill to be fitted with the clay,




BRICK.                                273
and then removed to situations where plungers are enabled to act upon them. Thirdly,
in a contrivance by which the plungers are made to descend, for the purpose of compressing the material and discharging it from the mould in the form of bricks.
Fourthly, in the method of constructing and working trucks which carry the receiving
boards, and conduct the bricks away as they are formed.
Fig. 202. exhibits the general construction of the apparatus; both ends of which
being exactly similar, little more than half of the machine is represented.  a is the
cylindrical pug-mill, shown partly in section, which is supplied with the clay and other
202
Iii        R       II   IJ IIi
4                                 14                            Jo>
materials from a hopper above; b b, are the rotatory knives or cutters, which are attached to the vertical shaft, and, being placed obliquely, press the clay down towards the
bottom of the cylinder, in the act of breaking and mixing it as the shaft revolves. The
lower part of the cylinder is open; and immediately under it the mould is placed in
which the bricks are to be formed. These moulds run to and fro upon ledges in the
side frames of the machine; one of the moulds only can be shown by dots in the figure,
the side rail intervening; they are situated at c c, and are formed of bars of iron
crossing each other, and encompassed with a frame. The mould resembles an ordinary
sash window in its form, being divided into rectangular compartments (fifteen are proposed in each) of the dimensions of the intended bricks, but sufficiently deep to allow
the material, after being considerably pressed in the mould, to leave it, when discharged, of the usual thickness of a common brick.
The mould being open at top and bottom, the material is allowed to pass into it,
when situated exactly under the cylinder; and the lower side of the mould, when so
laced, is to be closed by a flat board d, supported by the trunk e, which is raised by a
lever and roller beneath, running upon a plane rail with inclined ends.
The central shaft, f, is kept in continual rotatory motion, by the revolution of the
upper horizontal wheel g, of which it is the axis; and this wheel may be turned by a
horse yoked to a radiating arm, or by any other means. A part of the circumference
of the wheel g, has teeth which are intended at certain periods of its revolution to take
into a toothed pinion, fixed upon the top of a vertical shaft h h. At the lower part of,
this vertical shaft, there is a pulley i, over which a chain is passed that is connected to
the two moulds c, and to the frame in which the trucks are supported; by the rotation
of the vertical shaft, the pulley winds a chain, and draws the moulds and truck frames
along.
The clay and other material having been forced down from the cylinder into the
mould, the teeth of the horizontal wheel g now come into geer with the pinion upon
VOL. L                          2 N




274                                  BRICK.
h, and turn it and the shaft and pulley i, by which the chain is wound, and the mould
at the right hand of the machine brought into the situation shown in the figure; a
scraper or edge-bar under the pug-mill having levelled the upper face of the clay in the
mould, and the board d, supported by the truck e, formed the flat under side.
The mould being brought into this position, it is now necessary to compress the materials, which is done by the descent of the plungers k k. A friction-roller I, pendant
from the under side of the horizontal wheel, as that wheel revolves, comes in contact
with an inclined plane, at the top of the shaft of the plungers; and, as the frictionroller passes over this inclined plane, the plungers are made to descend into the mould,
and to compress the material; the resistance of the board beneath causing the clay to
be squeezed into a compact state. When this has been effectually accomplished, the
further descent of the plungers brings a pin m, against the upper end of a quadrant
catch-lever n, and, by depressing this quadrant, causes the balance-lever upon which the
truck is now supported to rise at that end, and to allow the truck with the board d to
descend, as shown by dots; the plungers at the same time forcing out the bricks from
the moulds, whereby they are deposited upon the board d; when, by drawing the truck
forward out of the machine, the board with the bricks may be removed and replaced by
another board.  The truck may then be again introduced into the machine, ready to
receive the next parcel of bricks.
By the time that the discharge of the bricks from this mould has been effected, the
other mould under the pug cylinder has become filled with the clay, when the teeth of
the horizontal wheel coming round, take into a pinion upon the top of a vertical shaft,
exactly similar to that at h, but at the reverse end of the machine, and cause the
moulds and the frame supporting the trucks to be slidden to the left end of the machine;
the upper surface of the mould being scraped level in its progress, in the way already
described.  This movement brings the friction-wheel o, up the inclined plane, and
thereby raises the truck, with the board to the under side of the mould, ready to receive
another supply of clay; and the mould at the left hand side of the machine being now
in its proper situation under the plungers, the clay becomes compressed, and the bricks
discharged from the mould in the way described in the former instance; when this truck
being drawn out, the bricks are removed to be dried and baked, and another board
is placed in the same situation. There are boxes, p, upon each side of the pug cylinder
containing sand, at the lower parts of which small sliders are to be opened (by contrivances not shown in the figure) as the mould passes under them, for the purpose of
scattering sand upon the clay in the mould to prevent its adhering to the plungers.
There is also a rack and toothed sector, with a balance-weight connected to the inclined
plane at the top of the plunger-rods, for the purpose of raising the plunger after the
friction-roller has passed over it. And there is a spring acting against the back of the
quadrant-catch for the purpose of throwing it into its former situation, after the pin of
the plunger has risen.
One of the latest, and apparently most effective machines for brick-making, is that
patented by Mr. EdFward Jones, of Birmingham, in August, 1835. His improvements
are described under four heads; the first applies to a machine for moulding the earth
into bricks in a circular frame-plate horizontally, containing a series of moulds or rectangular boxes, standing radially round the circumference of the circular frame, into
which boxes successively the clay is expressed from a stationary hopper as the frame
revolves, and after being so formed, the bricks are successively pushed out of their boxes,
each by a piston, acted upon by an inclined plane below. The second head of the specification describes a rectangular horizontal frame, having a series of moulding boxes
placed in a straight range, which are acted upon for pressing the clay by a corresponding
range of pistons fixed in a horizontal frame, worked up and down by rods extending
from a rotatory crank shaft, the moulding boxes being allowed to rise for the purpose of
enabling the pistons to force out the bricks when moulded, and leave them upon the bed
or board below. The third head applies particularly to the making of tiles, for the
flooring of kilns in which malt or grain is to be dried. There is in this contrivance a
rectangular mould, with pointed pieces standing up for the purpose of producing airholes through the tiles as they are moulded, which is done by pressing the clay into the
moulds upon the points, and scraping off the superfluous matter at top by hand. The
fourth or last head applies to moulding chimney pots in double moulds, which take
to pieces for the purpose of withdrawing the pot when the edges of the slabs or sides are
sufficiently brought into contact.
" The drawing which accompanies the specification very nimperfectly represents some
parts of the apparatus, and the description is still more defective; but as we are acquainted with the machinery, we will endeavor to give it an intelligible form, and quote
those parts of the specification which point the particular features of novelty proposed to
be claimed by the patentee as his invention, under the several heads." *
* Mr Newton, in his London Journal, February, 1837.




BRICK.                                   275
Fig. 203 represents, in elevation, the first-mentioned machine for moulding bricks. The
^203 o  moulds are formed in the face
^ "  J203.i  of a circular plate or wheel,
a a, a portion of the upper surI....  IIlllll  __        IIIIII I-        face of which is represented in
i g   the horizontal view, fig. 204.
Any convenient number of these...                   litllmoulds are set radially in the
l ifll t I, I[.   wheel, which is mounted upon
roSI/II/  /^~IllI             a  central pivot, supported by
the masonry b b. There is a
SlHlillll   1 1     11  111 11    rm  of teeth round the outer
~~~~~~~204  ~edge of the wheel a a, which
I2 04 J-O,^         C,!i~  ~take into a pinion c, on a shaft,  o — "  _' ^  connected to the first mover;!\^^^^^~ \ ~  /^ \ / _   S         and by these means the wheel
L9 A \  \ I    \ Mll a, with the moulding boxes, is
~\t///W,/,\^    / /  ^    t ~made  to revolve horizontally,
~\//B///  / /    />&&         /.     guided by arms with anti-friction
rollers, which run round a horizontal plate a a, fixed upoa the
masonry.
A  hopper, e, filled with the
^ ~-~2^"""^~  ~         brick earth shown with one of the
moulding boxes in section, is fixed
above the face of the wheel in such a way that the earth may descend from the hopper
into the several moulding boxes as the wheel passes round under it; the earth being
pressed into the moulds, and its surface scraped off smooth by a conical rollerf, in the
bottom of the hopper.
Through the bottom of each moulding box there is a hole for the passage of a piston
rod g, the upper end of which rod carries a piston with a wooden pallet upon it, acting
within the moulding box; and the lower end of this rod has a small anti-friction roller,
which, as the wheel a revolves, runs round upon the face of an oblique ring or inclined
way, h h, fixed upon the masonry.
The clay is introduced into the moulding boxes from the hopper, fixed over the lowest
part of the inclined way h, and it will be perceived that as the wheel revolves, the piston
rods g, in passing up the inclined way, will cause the pistons to force the new-moulded
bricks, with their pallet or board under them, severally up the mould, into the situation
shown at i, in fig. 203, from whence they are to be removed by hand. Fresh pallets
being then placed upon the several pistons, they, with the moulds, will be ready for
moulding fresh bricks, when, by the rotation of the wheel a, they are severally brought
under the hopper, the pistons having sunk to the bottoms of their boxes, as the piston
rods passed down the other side of the inclined way h.
The patentee says, after having described the first head of his invention, he would
have it understood that the same may be varied without departing from the main object
of the invention; viz., that of arranging a series of moulds when worked by means of an
inclined track, and in such manner that bricks, tiles, or other articles made of brick
earth, may be capable of being formed in a mould with pallets or boards laid within
the moulds, and constituting the bottom thereof, the bricks being removed from out of
the moulds, with the pallets or boards under them, as above described. "I do not, therefore, confine myself to the precise arrangement of the machine here shown, though it is
the best with which I am acquainted for the purpose."
The second head of the invention is another construction of apparatus for moulding
bricks, in this instance, in a rectangular frame. Fig. 205 is a front elevation of the machine; fig. 206, a section of the same taken transversely. a a is the standard frame-work
and bed on which the bricks are to be moulded. Near the corners of this standard
frame-work, four vertical pillars b b are erected, upon which pillars the frame of the
moulding boxes c, slides up and down, and also the bar d. carrying the rods of the pistons e e e. These pistons are for the purpose of compressing the clay in the moulding
box, and therefore must stand exactly over and correspond with the respective moulds
in the frame c beneath.
The sliding frame c, constituting the sides and ends of the moulding boxes, is supported at each end by an upright sliding rod f, which rods pass through guides fixed to
the sides of the standard frame a a, and at the lower end of each there is a roller, bearing
upon the levers g, on each side of the machine, but seen only in fig. 181, which levers




276                              BRICKS.
when depressed, allow the moulding boxes to descend, and rest upon the bed or table of
tc machine h h.
205'...'06
In this position of the machine resting upon the bed or table, the brick-earth is to be
placed upon, and spread over, the top of the frame c, by the hands of workmen, when
the descent of the plunger or pistons e e e, will cause the earth to be forced into the
moulds, and the bricks to be formed therein. To effect this, rotatory power is to be
applied to the toothed wheel i, fixed on the end of the main driving crank shaft k k,
which on revolving will, by means of the crank rods I l, bring down the bar a, with the
pistons or plungers e e e, and compress the earth compactly into the moulds, and thereby
form the bricks.
When this has been done, the bricks are to be released from the moulds by the
moulding frame c rising up from the bed, as shown infig. 205., the pistons still remaining depressed, and bearing upon the upper surfaces of the bricks. The moulding frame
is raised by means of cams m, upon the crank shaft, which at this part of the operation
are brought under the leversg, for the purpose of raising the cams and the sliding rods
f, into the position shown in fig. 206.
The bricks having been thus formed and released from their moulds, they are to be
removed from the bed of the machine by pushing forward, on the front side, fresh
boards or pallets, which of course will drive the bricks out upon the other side, whence
they are to be removed by hand.
There is to be a small hole in the centre of each pallet, and also in the bed, for the
purpose of allowing any superfluous earth to be pressed through the moulding boxes
when the pistons descend. And in order to cut off the projecting piece of clay which
would be thus formed on the bottom of the brick, a knife-edge is in some way connected
to the bed of the machine; and as the brick slides over it, the knife separates the protuberant lump; but the particular construction of this part of the apparatus is considered to be of little importance; and the manner of effecting the object is not clearly
stated in the specification.
The patentee proposes a variation in this construction, which he describes in these
words: "It will be evident that in place of having the moulds to rise, they may, by
suitable arrangements, be made to descend below the bricks. In this case, in place ol
the boards, stationary blocks to receive the pallets must be fixed on the bed of the
machine, and these blocks must be shaped in such a manner as to allow of the mould,
passing over them: and then it will be desirable to use the first part of my improvements, that of having the pallets within the moulds at the time of moulding the bricks;
or in case of working with exceedingly stiff brick-earth, the pallets may be dispensed
with." In 1849, 1,503,961,106 bricks paid duty in the United Kingdom; the revenue
from which was 461,5821. 6s. Id.
BRICKS. Mr. F. W. Simms, C. E., communicated to the Institution of Civil Engineers, in April and May, 1843, an account of the process of brick-making for the
Dover railway. The plan adopted is called slop-moulding, because the mould is dipped
into water before receiving the clay, instead of being sanded as in making sand-stock
bricks. The workman throws the proper lump of clay with some force into the mould,
presses it down with his hands to fill the cavities, and then strikes off the surplus clay
with a stick. An attendant boy, who has previously placed another mould in a water
trough by the side of the moulding table, takes the mould just filled, and carries it to
the floor, where he carefully drops the brick from the mould on its flat side, and leaves
it to dry; by the time he has returned to the moulding table, and deposited the empty




BRICKS.                                    277
mould in the water trough, the brickmaker will have filled the other mould, for the
boy to convey to the floor, where they are allowed to.dry, and are then stacked in readiness for being burned in clamps or kilns. The average product is shown in the fol
lowing table:Force employed.   Area of land.  Duration of season.| Produce per week. [Produce per season.
Roods.  Perches.    Weeks.           Bricks.         Bricks.
I moulder    -
1 temperer   -
1 wheeler    -      2     14.           22            16,100          354,200
I carrier boy -
I picker boy -
It appears that while the produce in sand-stock bricks is to that of slop-bricks in the
same time as 30 to 16, the amount of labor is as 7 to 4; while the quantity of land,
and the cost of labor per thousand, is nearly the same in both processes. The quantity of coal consumed in the kiln was at the rate of 10 cwt. 81bs. per thousand bricks.
The cost of the bricks was 21. Is. 6d. per thousand.  The slop-made bricks are
fully 1 pound heavier than the sand-stock. Mr. Bennett stated to the meeting, that
at his brick-field at Cowley, the average number of sand-stock bricks moulded was
32,000; but that frequently so many as 37,000, or even 50,000, were formed. The
total amount in the shrinkage of his bricks was l 3 of an inch upon 10 inches in length;
but this differed with the different clays. Mr. Simms objected to the use of machinery
in brick-making, because it caused economy only in the moulding, which constituted no
more than about one eighth of the total expense.
The principal varieties of bricks are called malm,paviors, stocks, grizzles, places, and
shuffs. For the first and best kind, the clay was washed and selected with care;
stocks were good enough for ordinary building purposes; the rest are inferior. The
difference in price between malms, paviors, and stocks, was 15s. or 20s. per 1,000; between stocks and places, 10s.  The average weight of a sand-stock brick is fully 5
pounds, that of a slop is 1 pound more.
I believe that the siliceous sand on the surface of the sand-stocks is useful in favoring adhesion of mortar, by the production of a silicate of lime. To smooth aluminous
bricks, mortar sometimes forms no stony adhesion.
Mr. Prosser, of Birmingham, makes bricks by pressure. The clay is first ground
upon a slip Ailn, as if for making pottery, then ground to a fine powder, and in that
dry state it is subjected to the heavy pressure of about 250 tons, in strong metal
moulds, by which means it is reduced to about one third of its original thickness.
The clay seems to have retained sufficient moisture to give it cohesion, and the tiles
are perfectly sharp at the edges. They being then baked within seggars by the heat of
a kiln, seldom crack in the baking. The brrcks thus formed are denser than usual, and
weigh 6 lbs., with a specific gravity of 2'5.
Fig. 207., represents Mr. Hunt's brick-making machine.  The principal working
207
parts consist of 2 cylinders, each covered by an endless web, and so placed as to form
the front and back of a hopper, the two sides being iron plates, placed so that when
the hopper is filled with tempered clay from the pug-mill, the lower part of the
hopper, and consequently the mass of clay within it, has exactly the dimensions of
a brick. Beneath the hopper an endless chain traverses simultaneously with the
movement of the cylinders. The pallet-boards are laid at given intervals upon the
chain, and being thus placed under the hopper, while the clay is brought down with
a slight pressure, a frame with a wire stretched across it is projected throng the




278                                BRICKS.
mass of clay, cutting off exactly the thickness of the brick, which is removed at the
same moment by the forward movement of the endless chain. This operation is
repeated each time that a pallet-board comes under the hopper.
The chief object of this machine, which is worked by hand, is to produce good
square compact bricks of uniform quality, using only a slight pressure. It has been
found to be very difficult to dry bricks made by machinery, where a considerable pressure has been employed, because, before the evaporation from the centre of the clay is
completed, the surfaces have become hard and peel off. The present machine is in
operation in several parts of England, producing usually about 1200 bricks per hour,
while each machine requires only 2 men and 3 boys to tend it, and to take off the
bricks.  The clot-moulders are dispensed with, and the workmen are common
labourers, so that professed brick-makers at higher wages are not needed.
Fig. 208. shows Mr. Hunt's machine for making tiles, and it is on the same principle.
It consists of two iron cylinders, round which webs or bands of cloth revolve, whereby
the clay is pressed into a slab of uniform thickness, without adhering to the cylinders.
It is then carried over a covered wheel, curved on the rim, which gives the tile the
semi-cylindrical or other required form; after which the tiles are polished and finished
208
by passing through three iron moulds of a horse-shoe form, as shown in the centre of
the cut, while they are at the same time moistened from a water cylinder placed above
them. The tiles are next cut off to such lengths as are wanted, and carried away by
an endless web, whence they are transferred by boys to the drying shelves.
Flat tiles, for sole pieces to draining tiles, are formed in nearly the same manner,
being divided into two portions while passing through the moulds; the quantity of clay
used for one draining tile being as much as for two soles.
The method of making bricks in the vicinity of London differed from that of almost
all other places, because the material there employed is not pure clay, but a loam of
a slightly cohesive nature, which will not admit of its being used in the natural
state and burned in close kilns with coal; but with an admixture of ashes it becomes
sufficiently tenacious to be formed into bricks, by inducing a slight semi-fusion. But
the coal-ashes are also of advantage in the process of burning, because they enable the
fire to spread gradually from the lower tiers, through the whole mass in the kiln or
clamp, and thus obviate the effect of an intense partial heat, where distinct coal fires
are trusted to alone, whereby the bricks nearest it get vitrified and glazed.
The brick kilns and clamps round London, and other large cities, which are fired
with the breeze-rubbish collected from dust holes, that contain the refuse of kitchens,
&c., emit, in consequence, most unpleasant effluvia; but brick-kilns fired with clean
coke or coals, give out no gases of a more noxious nature than common household fires.
The consideration of this subject was closely pressed upon my attention on being consulted concerning an injunction issued by the chancellor against a brick clamp in the
Isle of Wight, fired with clean coke cinders from the steam-engine furnace at Portsmouth Dock Yard. The bricks being of the description called sand-stock, were of
course made in moulds very slightly dusted with sand, to make them fall freely out.
The sand was brought from Portsmouth harbor, and on being subjected to a degree
of heat, more intense certainly than it would suffer in the clamp, was discovered by two
chemical witnesses to give out traces of hydrochloric acid. Not content with this
trivial indication, the said chemists, in their evidence before the courts of law, paraded
a train of goblin gases, as the probable products of the pre-adjudicated clamp.
As it is well known to the chemist that common salt strongly ignited in contact with
moist sand will emit hydrochloric acid, there was nothing remarkable in the above




BRITANNIA TUBULAR BRIDGE.                                279
observation, but I ascertained that the sand with which the moulds were strewed would
give out no hydrochloric acid, at a heat equal at least to what the bricks were exposed
to in a clamp 10 or 12 feet high, and fired at its bottom only with a layer of cinders
3 or 4 inches thick. But I further demonstrated that the entire substance of the brick
with its scanty film of sand, on being exposed to ignition in a suitable apparatus, gave
out-not hydrochloric or any other corrosive acid, but ammonia gas.  Hence, the
allegations that the clamp set forth a host of acid gases to blight the neighbouring
trees, were shown to be utterly groundless; on the contrary, the ammonia evolved from
the heated clay would act beneficially upon vegetation, while it was too small in quantity
to annoy any human being. A few yards to leeward of a similar clamp, in full activity,
I could perceive no offensive odour. All ferruginous clay, when exposed to the atmosphere, absorbs ammonia from it, and of course emits it again on being gently ignited.
It is a reproach to science when, as in the above case, it lends itself to judicial
prejudice and oppression.
Messrs. Whalley and Lighloller have patented apparatus for manufacturing bricks
and tiles, which combines the pug mill, pressing cylinder, screens and die-plate all
in one machine; thereby effecting great economy in time and labour, and also in
the cost of the machinery itself. The combination alone is claimed.
BRIMSTONE. (Soufre, Fr.; Schwefel, Germ.) Sulphur, which see.
BRITANNIA TUBULAR BRIDGE (opening of the). The opening of this magnificent structure, looked forward to with so much interest, came off on the 5th of March,
1849, at dawn with the grandest success. At precisely seven o'clock, the adventurous
convoy, progressing at a speed of seven miles an hour, was lost sight of in the recess of the
vast iron corridor. Instead of being driven through with a dispatch indicative of a
desire on the part of those who manned it to get in and out with the utmost expedition,
the locomotives were propelled at a slow and stately pace, with a view of boldly proving
by means of a dead weight the calibre of the bridge at every hazard. The total weight
of the locomotives was 90 tons. The appearance of the interior of the tube during the
experiment was of a novel and remarkable character. The locomotives were brought
to a standstill in the centre of each of the great spans, without causing the slightest
strain or deflection. The first process, that of going through the tube and returning,
occupied altogether 10 minutes. The second experimental convoy that went through
consisted of 24 heavily laden waggons filled with huge blocks of Brymbo coal, in all,
engines included, an aggregate weight of 300 tons. This was drawn deliberately
through, at the rate of from eight to ten miles an hour, the steam working at quarter
power. During the passage of this experimental train through the tube, a breathless
silence prevailed until the train rushed out exultingly, and with colours flying, on
the other side of the tube, when loud acclamations arose, followed at intervals by the
rattle of artillery down the Straits. Upon the return, which occupied about seven
minutes, similar demonstrations ensued, and during the progress of the train those who
stood upon its top to ascertain any possible vibration, reported they could detect no
sensible deflection. An ordeal stronger still was then resorted to; a train of 200 tons
of coals was allowed to rest with all its weight for two hours in the centre of the
Carmarthenshire tube, and at the end of the time, on the load being removed, it was
found to have caused a deflection of only four-tenths of an inch. It is remarkable that
this amount of deflection is not so much as one half hour of sunshine would produce
upon the structure, it being moreover calculated with confidence that the whole bridge
might with safety, and without injury to itself, be deflected to the extent of 13 inches.
These loads, it is most material to remember, are immensely more than the bridge
will ever be called on to bear in the ordinary run of traffic, though the engineers are
of opinion that it would support with ease, and without much show of deflection, a dead
weight on its centre of 1,000 tons. Twelve miles an hour is the limit of speed at which
Mr. Stephenson intends that trains shall at first go through, more particularly as there
are sharp curves at the termini of the tube.
The effect of the recent hurricane on the calibre of the tube has proved that its
lateral surface strength is sufficient, and far more than sufficient, to resist the strongest
wind. It is calculated that, taking the force of the wind at 50 lbs. on the square foot,
an excessive supposition, the resistance offered by the bridge would be 300 tons X 2 =
600 tons, which is not two thirds of its own weight.  The wind going at 80 miles an
hour, the rush of a hurricane would only press in the ratio of 128 tons on the side. It
is intended, when both tubes are up, to brace them together with stays, so as to counteract
any possible oscillation.
The great work has now been four years in hand, and is nearly complete, while
Telford's suspension bridge took eight years.
The floating and actual transference of the tubes have occupied since June last, a short
period, when the bulk of the fabric is taken into consideration. Great fears were




280                                BRONZE.
entertained for its safety during the late gales, from the recollection in this part of
the country of the damage done to Telford's suspension bridge.
BRITISH GUM. The trivial name given to starch, altered by a slight calcination
in an oven, whereby it assumes the appearance and acquires the properties of gum,
being soluble in cold water, and forming in that state a paste well adapted to thicken
the colours of the calico printer. See DEXTRINE and STARCH.
BROMINE, one of the archieal elements, which being developed from its combinations
at the positive pole of the voltaic circuit, has been therefore deemed to be idio-electropositive like oxygen and chlorine.  It derives its name from its nauseous smell, Bpjoos,
fcrtor. It occurs in various saline springs on the continent of Europe, in those of Ashby
de la Zouche, and some others in England; in the lake Asphaltites, in sponges, in some
marine plants, in an ore of zinc, and in the cadmium of Silesia. At ordinary temperatures it is liquid, of a dark brown colour in mass, but of a hyacinth-red in thin layers.
Its smell is rank and disagreeable, somewhat like that of chlorine. It has a very caustic
taste. Its specific gravity is 2-966. Applied to the skin it colours it deep yellow and
corrodes it. One drop put within the bill of a bird suffices to kill it. It combines with
oxygen with feeble affinity, forming bromic acid. Its attraction for hydrogen being far
more energetic, it forms therewith a strong acid, the hydrobromic.
Bromine dissolves very sparingly in water, but it is very soluble'in alcohol and ether.
It combines with carbon, phosphorus, sulphur, and chlorine, as well as with most of the
metals. From its scarcity it has not hitherto been applied to any purpose in the arts,
except photography; but it is supposed to possess powerful discutient effects upon
scrofulous and other glandular tumours, whence the waters containing it are prescribed as an internal and external remedy in such forms of disease.
BRONZE. A compound metal consisting of copper and tin, to which sometimes a
little zinc and lead are added.  This alloy is much harder than copper, and was
employed by the ancients to make swords, hatchets, &c., before the method of working
iron was generally understood. The art of casting bronze statues may be traced to the
most remote antiquity, but it was first brought to a certain degree of refinement by
Theodoros and Roecus of Samos, about 700 years before the Christian era, to whom the
invention of modelling is ascribed by Pliny. The ancients were well aware that by
alloying copper with tin, a more fusible metal was obtained, that the process of casting
was therefore rendered easier, and that the statue was harder and more durable; and
yet they frequently made them of copper nearly pure, because they possessed no means
of determining the proportions of their alloys, and because by their mode of managing
the fire, the copper became refined in the course of melting, as has happened to many
founders in our own days. It was during the reign of Alexander that bronze statuary
received its greatest extension, when the celebrated artist Lysippus succeeded by new
processes of moulding and melting to multiply groups of statues to such a degree that
Pliny called him the mob of Alexander.  Soon afterwards enormous bronze colossuses
were made, to the height of towers, of which the isle of Rhodes possessed no less than one
hundred. The Roman consul Mutianus found 3,000 bronze statues at Athens, 3,000 at
Rhodes, as many at Olympia and at Delphi, although a great number had been previously
carried off from the last town.
In forming such statues, the alloy should be capable of flowing readily into all the
parts of the mould, however minute; it should be hard, in order to resist accidental
blows, be proof against the influence of the weather, and be of such a nature as to
acquire that greenish oxidized coat upon the surface which is so much admired in the
antique bronzes called patina antiqua. The chemical composition of the bronze alloy
is a matter therefore of the first moment. The brothers Keller, celebrated founders in
the time of Louis XIV., whose chefs-d'ouvre are well known, directed their attention
towards this point, to which too little importance is attached at the present day. The
statue of Desaix in the place Dauphine, and the column in the Place Vendome, are
noted specimens of most defective workmanship from mismanagement of the alloys of
which they are composed. On analysing separately specimens taken from the basreliefs of the pedestal of this column, from the shaft, and from the capital, it was found
that the first contained only 6 per cent. of alloy, and 94 of copper, the second much
less, and the third only 0'21. It was therefore obvious that the founder, unskilful in the
melting of bronze, had gone on progressively refining his alloy, by the oxidizement of
the tin, till he had exhausted the copper, and that he had then worked up the refuse
scorise in the upper part of the column. The cannons which the government furnished
him for casting the monument consisted ofCopper  -       -      - 89-360
Tin     -          -   - 10040
Lead    -       -      -   0102
Silver, zinc, iron, and loss  0-498
100-000




BRONZE.                                     281
The moulding of the several bas-reliefs was so ill-executed, that the chiselers employed
to repair the faults removed no less than 70 tons of bronze, which was given them,
besides 300,000 francs for their work.  The statues made by the Kellers at Versailles
were found on chemical analysis to consist ofNo. 1.     No. 2.     No. 3.     The mean.
Copper       91-30       91-68       91-22      91-40
Tin            1-00       2-32        1'78        1'70
Zinc          6-09        4-93        5-57        5-53
Lead          1-61        1-07        1-43        1-37
100'00     100-00      100-00      100-00
The analysis of the bronze of the statue of Louis XV. was as follows:Copper  82-45  Its specific gravity was 8-482.
Zinc     10-30
Tin       4-10
Lead      3-15
100-00
The alloy most proper for bronze medals which are to be afterward struck, is composed
of from 8 to 12 parts of tin, and from 92 to 88 of copper; to which if two or three parts
in the hundred of zinc be added, they will make it assume a finer bronze tint. The alloy
of the Kellers is famous for this effect. The medal should be subjected to three or four
successive stamps of the press, and be softened between each blow by being heated and
plunged into cold water.
The bronze of bells or bell metal is composed in 100 parts of copper 78, tin 22. This
alloy has a fine compact grain, is very fusible and sonorous. The other metals sometimes
added are rather prejudicial, and merely increase the profit of the founders. Some of the
English bells consist of 80 copper, 10.1 tin, 5-6 zinc, and 4'3 lead; the latter metal when
in such large quantity is apt to cause insolated drops, hurtful to the uniformity of the
alloy.
The tam-tams and cymbals of bronze.-The Chinese make use of bronze instruments
forged by the hammer, which are very thin, and raised up in the middle; they are called
gongs, from the word tshoung, which signifies a bell. Klaproth has shown that they contain nothing but copper and tin; in the proportions of 78 of the former metal and 22 of
the latter. Their specific gravity is 8*815. This alloy when newly cast is as brittle as
glass, but by being plunged at a cherry-red heat into cold water, and confined between
two discs of iron to keep it in shape, it becomes tough and malleable. The cymbals
consist of 80 parts copper and 20 tin.
Bronze vessels naturally brittle may be made tenacious by the same ingenious process,
for which the world is indebted to M. Darcet.  Bronze mortars for pounding have their
hps tempered in the same way. Ancient warlike weapons of bronze were variously compounded; swords were formed of 87} copper, and 12   tin in 100 parts; the springs of
balistee consisted of 97 copper, and 3 tin.
Cannon metal consists of about 90 or 91 copper, and 10 or 9 of tin. From the experiments of Papacino-d'Antony, made at Turin. in 1770, it appears that the most proper
alloy for great guns is from 12 to 14 parts of tin to 100 of copper; but the Comte Lamar
tilliere concluded from his experiments made at Douay, in 1786, that never less than 8,
nor more than 11 of tin should be employed in 100 parts of bronze.
Gilt ornaments of bronze.-This kind of bronze should be easy of fusion, and take
perfectly the impression of the mould. The alloy of copper and zinc is when fused of a
pasty consistence, does not make a sharp cast, is apt to absorb too much amalgam, is
liable to crack in cooling, and is too tough or too soft for the chaser or the turner. Were
the quantity of zinc increased to make the metal harder, it would lose the yellow color
suitable to the gilder. A fourfold combination of copper, zinc, tin, and lead is preferable
for making such ornamental bronze articles; and the following proportions are probably
the best, as they unite closeness of grain with the other good qualities. Copper 82, zinc
18, tin 3 or 1, lead 12 or 3.  In the alloy which contains most lead, the tenacity is diminished and the density is increased, which is preferable for pieces of small dimensions
Another alloy, which is said to require for its gilding only two thirds of the ordinary quantity of gold, has the following composition: copper, 82-257; zinc, 17-481; tin, 0'238;
lead, 0-024.
The antique bronze color is given to figures and other objects made from these alloys by
the following process:-Two drachms of sal-ammoniac, and half a drachm of salt of sorrel
(binoxalate of potash) are to be dissolved in fourteen ounce measures (English) of color
less vinegar. A hair pencil being dipped into this solution, and pressed gently between
VOL. 1.                             2 0




282                                  BRONZE.
the fingers, is to be rubbed equally over the clean surface of the object, slightly warmed
in the sun or at a stove; and the operation is to be repeated till the wished-for shade is
obtained. (See GILDING.)
The bronze founder ought to melt his metals rapidly, in order to prevent the loss of tin,
zinc, and lead, by their oxydizement. Reverberatory furnaces have been long used for
this operation; the best being of an elliptical form. The furnaces with dome tops are
employed by the bell-founders, because their alloy being more fusible, they do not require
so intense a heat; but they also would find their advantage in using the most rapid mode
of fusion. The surface of the melting metals should be covered with small charcoal, 01
coke; and when the zinc is added, it should be dexterously thrust to the bottom of the
melted copper. Immediately after stirring the melted mass so as to incorporate its ingredients, it should be poured out into the moulds. In general, the metals most easily altered by the fire, as the tin, should be put in last. The cooling should be as quick as
possible in the moulds, to prevent the risk of the metals separating from each other in
the order of their density, as they are very apt to do. The addition of a little iron, in the
form of tin-plate, to bronze, is reckoned to be advantageous.
One part of tin, and two parts of copper (nearly one atom of tin and four of copper, or
more exactly, 100 parts of tin, and 215 copper), form the ordinary speculum metal of reflecting telescopes, which is of all the alloys the whitest, the most brilliant, the hardest,
and the most brittle. The alloy of 1 part of tin, and 10 of copper (or nearly one atom
of the former to eighteen of the latter), is the strongest of the whole series.
Ornamental objects of bronze, after being cast, are commonly laid upon red-hot coals
till they take a dull red heat, and are then exposed for some time to the air. The surface is thereby freed from any greasy matter, some portion of the zinc is dissipated, the
alloy assumes more of a coppery hue, which prepares for the subsequent gilding. The
black tinge which it sometimes gets from the fire may be removed by washing it with a
weak acid.  It may be made very clean by acting upon it with nitric acid, of specific
gravity 1 324, to which a little common salt and soot have been added, the latter being
of doubtful utility; after which it must be well washed in water, and dried with rags or
saw-dust.
BRONZING is the art of giving to objects of wood, plaster, &c., such a surface as makes
them appear as if made of bronze. The term is sometimes extended to signify the production of a metallic appearance of any kind upon such objects. They ought first to be
smeared over smoothly with a coat of size or oil varnish, and when nearly dry, the metallic powder made from Dutch foil, gold leaf, mosaic gold, or precipitated copper, is to
be applied with a dusting bag, and then rubbed over the surface with a linen pad; or the
metallic powders may be mixed with the drying oil beforehand, and then applied with a
brush. Sometimes fine copper, or brass filings, or mosaic gold, are mixed previously with
some pulverized bone-ash, and then applied in either way. A mixture of these powders
with mucilage of gum arabic is used to give paper or wood a bronze appearance. The
surface must be afterward burnished. Copper powder precipitated by clean plates of iron,
from a solution of nitrate of copper, after being well washed and dried, has been employed in this way, either alone or mixed with pulverized bone-ash. A finish is given to
works of this nature by a coat of spirit varnish.
A white metallic appearance is given to plaster figures by rubbing over them an amalgam of equal parts of mercury, bismuth, and tin, and applying a coat of varnish over it.
The iron-colored bronzing is given by black lead or plumbago, finely pulverized and
washed.  Busts and other objects made of cast iron acquire a bronze aspect by being
well cleaned and plunged in solution of sulphate of copper, whereby a thin film of this
metal is left upon the iron.
Copper acquires by a certain treatment a reddish or yellowish hue, in consequence of
a little oxide being formed upon its surface. Coins and medals may be handsomely
bronzed as follows: 2 parts of verdigris and 1 part of sal ammoniac are to be dissolved in vinegar; the solution is to be boiled, skimmed, and diluted with water till it has
only a weak metallic taste, and upon further dilution lets fall no white precipitate. This
solution is made to boil briskly, and is poured upon the objects to be bronzed, which are
previously made quite clean, particularly free from grease, and set in another copper pan.
This pan is to be put upon the fire, that the boiling may be renewed. The pieces under
operation must be so laid that the solution has free access to every point of their surface.
The copper hereby acquires an agreeable reddish brown hue, without losing its lustre.
But if the process be too long continued, the coat of oxide becomes thick, and makes the
objects appear scaly and dull. Hence they must be inspected every five minutes, and
be taken out of the solution the moment their colour arrives at the desired shade. If
the solution be too strong, the bronzing comes off with friction, or the copper gets covered
with a white powder, which becomes green by exposure to air, and the labour is consequently lost. The bronzed pieces are to be washed with many repeated waters, and
carefully dried, otherwise they would infallibly turn green. To give fresh-made bronze




BRONZE.                                     283
objects an antique appearance, three quarters of an ounce of sal ammoniac, and a drachm
and a half of binoxalate of potash (salt of sorrel) are to be dissolved in a quart of vinegar,
and a soft rag or brush moistened with this solution is to be rubbed over the clean bright
metal, till its surface becomes entirely dry by the friction. This process must be repeated several times to produce the full effect; and the object should be kept a litle warm.
Copper acquires very readily a brown color by rubbing it with a solution of the common
liver of sulphur, or sulphuret of potash.
The Chinese are said to bronze their copper vessels by taking 2 ounces of verdigris, 2 ounces of cinnabar, 5 ounces of sal ammoniac, and 5 ounces of alum, all in
powder, making them into a paste with vinegar, and spreading this pretty thick like a
pigment on the surfaces previously brightened.  The piece is then to be held a little
while over a fire, till it becomes uniformly heated. It is next cooled, washed, and dried;
after which it is treated in the same way once and again till the wished for color is
obtained. An addition of sulphate of copper makes the color incline more to chestnut
brown, and of borax more to yellow. It is obvious that the cinnabar produces a thin coat
of sulphuret of copper upon the surface of the vessel, and might probably be used with
advantage by itself.
To give the appearance of antique bronze to modern articles, we should dissolve I
part of sal ammoniac, 3 parts of cream  of tartar, and 6 parts of common salt in
12 parts of hot water, and mix with the solution 8 parts of a solution of nitrate
of copper of specific gravity 1-160. This compound, when applied repeatedly in a
moderately damp place to bronze, gives it in a short time a durable green coat,
which becomes by degrees very beautiful.  More salt gives it a yellowish tinge, less
salt a blueish cast. A large addition of sal ammoniac accelerates the operation of the
mordant.
BRONZE PowDERs, an article much used of late in the decorative painting of houses, &c.
They are prepared of every various shade, from that of bright gold to orange, dark
copper, emerald green, &c. Pale gold is produced from an alloy of 13: of copper, and
21 of zinc: crimson metallic lustre-from copper: do. paler, copper and a very little
zinc: green bronze with a proportion of verdigris: another fine orange by 14~ copper
and 11 zinc: another do. 13 copper and 21 zinc: a beautiful pale gold from an alloy
of the two metals in atomic proportions.  See ATOMIC WEIGHTS.
The alloy is laminated into very fine leaves with careful annealing, and these are
levigated into impalpable powders along with a film of fine oil to prevent oxidizement,
and to favour the levigation.  This Nuremberg manufacture has been successfully
introduced here by Mr. Bessemer.
BROWNING of gun-barrels and other arms.-By this process, the surface of several
articles of iron acquires a shining brown color. This preparation, which protects the
iron from rust, and also improves its appearance, is chiefly employed for the barrels of
fowling-pieces and soldiers' rifles, to conceal the fire-arms from the game and the enemy.
The finest kind of browning is the Damascus, in which dark and bright lines run through
the brown ground.
This operation consists in producing a very thin uniform film of oxyde or rust upon the
iron, and giving a gloss to its surface by rubbing wax over it, or coating it with a shellac varnish.
Several means may be employed to produce this rust speedily and well. The effect
may be obtained by enclosing the barrels in a space filled with the vapor of muriatic
acid.  Moistening their surface with dilute muriatic or nitric acid, will answer the same
purpose.  But the most common material used for browning, is the butter or chloride
of antimony, which, on account of its being subservient to this parpose, has been called
bronzing salt.  It is mixed uniformly with olive oil, and rubbed upon the iron slightly
heated; which is afterwards exposed to the air, till the wished-for degree of browning is
produced. A little aquafortis is rubbed on after the antimony, to quicken its operation.
The brown barrel must be then carefully cleaned, washed with water, dried, and finally
polished, either by the steel burnisher, or rubbed with white wax, or varnished with a
solution of 2 ounces of shellac, and three drachms of dragon's blood, in 2 quarts of spirit
of wine.
The following process may also be recommended: Make a solution with half an
ounce of aquafortis, half an ounce of sweet spirit of nitre, 1 ounce of spirit of wine,
2 ounces of sulphate of copper, and 1 ounce of tincture of iron, in so much water as
will fill altogether a quart measure. The gun barrel to be browned must first of all be
filed and polished bright, and then rubbed with unslaked lime and water to clear away
all the grease. Its two ends must now be stopped with wooden rods, which may serve
as handles, and the touch-hole must be filled with wax. The barrel is then to be rubbed
with that solution, applied to linen rags or a sponge, till the whole surface be equally
moistened; it is allowed to stand 24 hours, and is then scrubbed with a stiff brush.
The application of the liquid and the brushing may be repeated twice or oftener,
202




284                               BRONZE.
till the iron acquires a fine brown colour. After the last brushing, the barrel must be
washed with plenty of boiling water, containing a little potash; then washed with clean
water, dried, rubbed with polishing hard wood, and coated with shell-lac varnish, for
which purpose the barrel must be heated to the boiling point of water. It is finally
polished with a piece of hard wood.
Storch recommends to make a browning solution with 1 part of sulphate of copper,
one third of a part of sulphuric ether, and 4 parts of distilled water.
To give the damask appearance, the barrel must be rubbed over first with very dilute
aquafortis and vinegar, mixed with a solution of blue vitriol; washed and dried, and
rubbed with a hard brush to remove any scales of copper which may be precipitated
upon it from the sulphate.
Statues, vases, bas-reliefs, and other objects made of gypsum, may be durably bronzed,
and bear exposure to the weather better than after the ordinary oil-varnish, by the
following process:-Prepare a soap from linseed oil, boiled with caustic soda ley,
to which add a solution of common salt, and concentrate it by boiling, till it becomes
somewhat granular upon the surface. It is then thrown upon a piece of linen cloth,
and strained with moderate pressure. What passes through is to be diluted with
boiling water, and again filtered. On the other hand, 4 parts of blue vitriol and 1
part of copperas are to be dissolved separately in hot water. This solution is to be
poured slowly into the solution of soap, as long as it occasions any precipitate. This
fiocculent matter is a mixture of cupreous soap and ferruginous soap, that is, a combination of the oxides of copper and iron with the margaric acid of the soda soap. The
copper soap is green, the iron soap is reddish brown, and both together resemble that
green rust which is characteristic of the antique bronzes. When the precipitate is completely separated, a fresh portion of the vitriol solution is to be poured upon it in a
copper pan, and is made to boil, in order to wash it. After some time, the liquid part
must be decanted, and replaced by warm water for the purpose of washing the metallic
soaps. They are finally treated with cold water, pressed in a linen bag, drained and
dried. In this state the compound is ready for use in the following way:Three pounds of pure linseed oil are to be boiled with 12 ounces of finely-powdered
litharge, then strained through a coarse canvass cloth, and allowed to stand in a
warm place till the soap turns clear. Fifteen ounces of this soap-varnish, mixed with
12 ounces of the above metallic soaps, and 5 ounces of fine white wax, are to be melted
together at a gentle heat in a porcelain basin, by means of a water bath.  The mixture
must be kept for some time in a melted state, to expel any moisture which it may contain.
It must be then applied, by means of a painter's brush, to the surface of the gypsum previously heated to the temperature of about 200~ F. By skilful management of the heat
the colour may be evenly and smoothly laid on without filling up the minute lineaments
of the butts. When after remaining in the cool air for a few days, the smell of the pigment has gone off, the surface is to be rubbed with cotton wool, or a fine linen rag, and
variegated with a few streaks of metal powder or shell gold. Small objects may be
dipped in the melted mixture, and then exposed to the heat of a fire till they are
thoroughly penetrated and evenly coated with it.
The patina antica (iErugo nobilis) of the Italian antiquaries is said to be imitated by
plunging the copper medals in a boiling-hot solution of 2 parts of verdigris and 1 of
sal ammoniac, so much diluted as to be nearly tasteless. They are allowed to remain
in the solution till they take an agreeable reddish or yellowish brown colour, when the
fluid is to be poured off, and the medals washed and dried.
BRONZE POWDER consists of a metallic alloy reduced to thin laminae by beating
between skins or membranes in the ordinary way, and then triturated into fine powder
along with oil, to prevent oxidation by the atmosphere. The leaves are put first into
an iron wire sieve of ten meshes to the inch; olive oil is then allowed to flow freely
from a stopcock over the centre of the sieve on to the leaf metal, which is briskly moved
over the surface of the sieve with a wire brush, until the whole is forced through into
a vessel below. This mixture of metal and oil is then introduced through a funnel
hopper of the triturating machine, and spreading among the rods is caused by their
rotation to approach the periphery of the steel bed beneath, and escape into a circular
trough, whence they are conducted by a spout into another vessel. In this progress the
metal is acted upon by polished hemispherical bottom ends of upright rods, as they
ascend and descend the corrugated surface of the steel bed, and which, by a tearing and
burnishing operation, separate the coarse pieces of leaf into a multitude of polished
particles. By being passed three times through the machine, the metal is reduced to
the quality of a coarse bronze powder; and is then subjected to a similar machine containing smaller rods, tossed up and down by the revolution of the corrugated angular
bed on which they rapidly dance till the requisite fineness be produced. The contents
of the vessel, which are usually 10 pounds of metal and 10 pounds of oil, are then put
into a strong bag, made of three thicknesses of fustian, with their respective seams at
different parts of the circumference, so as to prevent the metallic particles from passing




BROWN DYE.                                   285
through. This bag is subjected to the action of a hydraulic press, of about 300 tons
upon a bag of one foot diameter, nearly all the oil is expelled. The empty bag is filled
with boiling water, and again squeezed; and after two or three repetitions of this washing,
all the oil comes out in the form of an emulsion. The bag now contains only a dense
lump of bright metallic particles of nearly the gravity of the original metal. This lump
is cut with a knife into slices about half an inch thick, and exposed to the air of a warm
room, where the moisture evaporates, and the slices may then be crumbled into powder.
(Newton's Journal, xxiv. 321.)
BRONZING (of Objects in Imitation of Metallic Bronze). Plaster of Paris, paper,
wood, and pasteboard, may be made to resemble pretty closely the appearance of articles
of real bronze, modern or antique. The simplest way of giving a brilliant aspect of
this kind is with a varnish made of the waste gold leaf of the beater, ground up on a
porphyry slab with honey or gum-water. A coat of drying linseed-oil should be first
applied, and then the metallic powder is put on with a linen dossil. Mosaic gold
ground up with six parts of bone-ashes has been used in the same way. When it is
to be put on paper, it should be ground up alone with white of eggs or spirit varnish,
applied with a brush, and burnished when dry. When a plate of iron is plunged into
a hot solution of sulphate of copper, it throws down fine scales of copper. which being
repeatedly washed with water, and ground along with six times its weight of boneashes, forms a tolerable bronzing.
Powdered and sifted tin may be mixed with a clear solution of isinglass, applied
with a brush, and burnished or not, according as a bright or dead surface is desired.
Gypsum casts are commonly bronzed by rubbing brilliant black-lead, graphite, upon
them with a cloth or brush. Real bronze long exposed to the air gets covered with a
thin film of carbonate of copper, called by virtuosi antique cerugo (patine antique, Fr.).
This may be imitated in a certain degree by several applications skilfully made. The
new bronze being turned or filed into a bright surface, and rubbed over with dilute
aquafortis by a linen rag or brush, will become at first greyish, and afterwards take a
greenish blue tint; or we may pass repeatedly over the surface a liquor composed of
1 part of sal ammoniac, 3 parts of carbonate of potash, and 6 of sea-salt dissolved in
12 parts of boiling water, to which' 8 parts of nitrate of copper are to be added; the
tint thereby produced is at first unequal and crude, but it becomes more uniform and
softer by time. A fine green-blue bronze may be obtained with very strong water of
ammonia alone, rubbing it at intervals several times upon the metal.
The base of most of the secret compositions for giving the antique appearance is
vinegar with sal ammoniac. Skilful workmen use a solution of 2 ounces of that salt in
an English quart of French vinegar. Another compound which gives good results is
made with an ounce of sal ammoniac, and a quarter of an ounce of salt of sorrel (binoxalate of potash) dissolved in vinegar. One eminent Parisian sculptor makes use of a mixture of half an ounce of sal ammoniac, half an ounce of common salt, an ounce of spirits
of hartshorn, and an English quart of vinegar. A good result will also be obtained by
adding half an ounce of sal ammoniac, instead of the spirits of hartshorn. The piece
of metal being well cleaned, is to be rubbed with one of these solutions, and then dried
by friction with a fresh brush. If the hue be found too pale at the end of two or
three days, the operation may be repeated. It is found to be more advantageous to
operate in the sunshine than in the shade.
BROWN DYE. Upon this subject some general views are given in the article
DYEING, explanatory of the nature of this colour, to which I may in the first place refer.
This dye presents a vast variety of tints, from yellow and red to black brown, and is
produced either by mixtures of red, yellow, and blue with each other, or of yellow or
red with black, or by substantive colours, such as catechu or oxide of manganese,
alone. We shall here notice only the principal shades; leaving their modifications to
the caprice or skill of the dyer.
1. Brown from mixture of other colours.
Wool and woollen cloths must be boiled with one eighth their weight of alum and
sulpho-tartrate of iron (see this article); afterwards washed, and winced through the
madder bath, which dyes the portion of the stuff imbued with the alum red, and that
with the salt of iron black; the tint depending upon the proportion of each, and the
duration of the madder bath.
A similar brown is produced by boiling every pound of the stuff with two ounces of
alum, and one ounce of common salt, and then dyeing it in a bath of logwood containing either sulphotartrate, acetate, or sulphate of iron. Or the stuff may be boiled with
alum and tartar, dyed up in a madder bath, and then run through a black bath of iron
mordant and galls or sumach. Here the black tint is added to the red till the proper hue
be hit. The brown may be produced also by adding some iron liquor to the madder bath,
after the stuff has been dyed up in it with alum and tartar. A better brown of this
kind is obtained by boiling every pound of wool with 2 ounces of alum, dyeing it up in
coehineal, then changing the crimson thus given into brown, by turning the stuff through




286                             BROWN DYE.
the bath after acetate of iron has been added to it. Instead of the cochineal, archil, or
cutbear, with a little galls or sumach, may be used.
Wool or silk may also receive a light blue ground from the indigo vat, then be morlanted with alum, washed, and turned through a madder bath till the wished-for brown
be brought out. For the deeper shades, galls or sumach may be added to the paler Brazilwood, with more or less iron mordant. Instead of the indigo vat, Saxon blue may be
employed to ground the stuff before dyeing it with madder, or 5 pounds of madder, with
1 pound of alum, a solution of one tenth of a pound of indigo in sulphuric acid, may be
used with the proper quantity of water for 20 pounds of wool; for dark shades, some iron
mordant may be added. Or we may combine a bath of cochineal or cutbear, fustic,
and galls, and add to it sulphate of iron and sulphate of indigo, blunted with a little
potash.
If we boil woollen cloth with alum and tartar, then pass it through a madder bath, and
afterward through one of weld or fustic, containing more or less iron mordant, we obtain
shades variable, according to the proportions of the materials, from mordore and cinnamon
to chestnut brown.
After the same manner, bronze colors may be obtained from the union of olive dyes
with red. For 25 pounds of cloth, we take 4 pounds of fustic chips, boil them for 2 hours,
turn the cloth in this bath for an hour, and drain it; then add to the bath from 4 to 6
ounces of sulphate of iron, and 1 pound of ordinary madder, or 2 pounds of sandal-wood;
put the cloth again in this compound bath, and turn it through, till the desired shade be
obtained. By changing the proportions, and adding an iron mordant, other tints may be
produced.
This mode of dyeing is suitable for silk, but with three different baths; one of logwood,
one of Brazil-wood, and one of fustic. The silk, after being boiled with soap, is to be
alumed, and then dyed up in a bath compounded of these three decoctions, mixed in the
requisite proportions. By the addition of walnut peels, sulphate of copper, and a little
sulphate of iron, or by passing the silk through a bath of annotto, a variety of brown
shades may be had.
Or the silk may receive an annotto ground, and then be passed through a bath of logwood or Brazil-wood. For 10 pounds of silk, 6 ounces of annotto are to be taken, and
dissolved with 18 ounces of potashes in boiling water. The silk must be winced through
this solution for 2 hours, then wrung out, dried, next alumed, passed through a bath of
Brazil-wood, and finally through a bath of logwood, containing some sulphate of iron.
It is to be wrung out and dried.
Brown of different shades is imparted to cotton and linen, by impregnating them with
a mixed mordant of acetates of alumina and iron, and then dyeing them up, either with
madder alone, or with madder and fustic. When the aluminous mordant predominates,
the madder gives an amaranth tint. For horse-chestnut brown, the cotton must be galled,
plunged into a black bath, then into a bath of sulphate of copper, next dyed up in a decoction of fustic, wrung out, passed through a strong madder bath, then through the sulphate of copper solution, and finished with a soap boil. Different shades of cinnamon
are obtained, when cottons first dyed up with madderget an olive cast with iron liquor in
a fustic bath.
These cinnamon and mordor6 shades are also produced by dyeing them first in a bath
of weld and verdigris, passing them through a solution of sulphate of iron, wringing and
drying them; next putting them through a bath containing 1 pound of galls for 10 pounds
of stuff, again drying, next aluming, and maddering. They must be brightened by a boil
in soap water.
A superior brown is produced by like means upon cotton goods, which have undergone
the oiling process of the Turkey red dye. Such stuffs must be galled, mordanted with
alum (see MADDER), sulphate of iron, and acetate of lead (equal to ~ of the alum); after
washing and drying, dyed in a madder bath, and cleared with a soap boil. The tint of
brown varies with the proportion of alum and sulphate of iron.
We perceive from these examples, in how many ways the browning of dyes may be
modified, upon what principles they are founded, and how we have it in cur power to turn
the shade more or less toward red, black, yellow, blue, &c.
Brown may be produced by direct dyes. The decoction of oak bark dyes wool a fast
brown of different shades, according to the concentration of the bath. The color is more
lively with the addition of alum.
The decoction of bastard marjoram (Origanum vulgare) dyes cotton and linen a reddish brown, with acetate of alumina. Wool takes from it a dark brown.
The bark of the mangrove tree (Rizophora mangle) affords to wool boiled with alum
and tartar a fine red brown colour, which, with the addition of sulphate of iron, passes
into a fast chocolate.
The Bablah, the pods of the East Indian Mimosa cineraria, and the African Mimosa
nilotica, gives cotton a brown with acetate or sulphate of copper.
The root of the white sea rose (Nymphcea alba) gives to cotton and wool beautiful




BUTTER.                                   287
shades of brown. A mordant of sulphate of iron and zinc is first given, and then the
wool is turned through the decoction of the root, till the wished-for shade is obtained.
The cotton must be mordanted with a mixture of the acetates of iron and zinc.
Walnut peels (Juglans regia), when ripe, contain a dark brown dye stuff, which communicates a permanent color to wool. The older the infusion or decoction of the peels,
the better dye does it make. The stuff is dyed in the lukewarm bath, and needs no
mordant, though it becomes brighter with alum. Or this dye may be combined with the
madder or fustic bath, to give varieties of shade. For dyeing silk, this bath should be
hardly lukewarm, for fear of causing inequality of color.
The peelings of horse-chestnuts may be used for the same purpose. With muriate of
tin they give a bronze color, and with acetate of lead a reddish brown.
Catechu gives cotton a permanent brown dye, as also a bronze, and mordore, when its
solution in hot water is combined with acetate or sulphate of copper, or when the stuff
is previously mordanted with the acetates of copper and alumina mixed, sometimes with
a little iron liquor, rinsed, dried, and dyed up, the bath being at a boiling heat.
Ferrocyanate of copper gives a yellow brown or a bronze to cotton and silk.
The brown color called carmelite by the French is produced by one pound of catechu
to four ounces of verdigris, with five ounces of muriate of ammonia. The bronze
(solitaire) is given by passing the stuff through a solution of muriate or sulphate of
manganese, with a little tartaric acid, drying, passing through a potash ley at 4~ Baume,
brightening and fixing with solution of chloride of lime.
BRUSHES. (Brosses, Fr.; Biersten, Germ.)  Mr. T. Mason obtained a patent in
October, 1830, for an improvement in the manufacture of this article. It consists in a
firmer mode of fixing the knots or small bundles of hair into the stock or the handle of
the brush. This is done by forming grooves in the stocks of the brushes, for the purpose
of receiving the ends of the knots of hair, instead of the holes drilled into the wood, as
in brushes of the common constructions. These grooves are to be formed like a dovetail,
or wider at the bottom than the top; and when the ends of the knots of hair have been
dipped into cement, they are to be placed in the grooves and compressed into an oval form,
by which the ends of the hair will be pressed outwards into the recess or wider part of
the dovetailed groove, or the grooves may be formed with threads or teeth on the sides,
instead of being dovetailed; and the cement and hairs being pressed into the teeth or
threads, will cause them to adhere firmly to the stock or handle of the brush.
A metal ferrule may be placed on the outside of the stock of the brush, if necessary,
and secured by pins or rivets, or in any other convenient manner, which ferrule may
209   c    also form  one side of the outer groove. Fig. 209 is
a plan view of the stock of a round brush; fig. 210
is a section of the same; a a are the dovetailed grooves,
which are turned out of the wood; b is the metal fer/210,rule; c c are knots or small bundles of hair, to form
t^'2u           i?  ^\ the brush. After a number of the knots of hair are
prepared, the ends are to be dipped into proper cement,
(/         /////  I / and then placed into the grooves, when their ends are
to be squeezed by a pair of pliers, or other means, which'a.-!will compress them into the oval shape, as shown in
fig. 211 and cause the ends of the hairs to extend out} ) l   * 7,  ib  " ward under the dovetailed part of the recess.
The knots of hair are to be successively placed in the
^211 a11         grooves, and forced up by a tool against the last knot
put in, and soon, until the grooves are filled; fig. 211 is
a section taken through a brush with teeth or threads of a screw formed upon the sides
of the groove; into these teeth or threads the cement and hairs will be forced by the
compression, by which means they will be held firmly in the stock of the brush.
BUTTER. (Beurre, Fr.; Butter, Germ.) Milk contains a fatty matter of more
or less consistency, modified very much according to the nature of the animals which
afford it. This substance is butter, held suspended in the milk by means of the caseous
matter and whey, with which it is intimately blended. Milk is a true emulsion
resulting from the mixture of these three ingredients, owing its opacity and white
color to the diffusion through it of that butyraceous oil. When any circumstance
dissolves this union, each component becomes insulated, and manifests its peculiar
properties. Milk, even left to itself, at a temperature of from 50~ to 60~ F., separates
spontaneously into several products. A layer of a fatter, more consistent, but lighter
nature floats on its surface, while the subjacent liquid forms a white magma, which
retains among its curdy flocks all the whey of the milk. The upper layer or cream
contains nearly the whole of the butter; but a portion remains entangled with the curd
and whey below.




288                      BUTTON MANUFACTURE.
It belongs to a work on husbandry or rural economy to treat fully of the operations
of the dairy: one of the principal of which is the extraction of butter from milk.
The Tartars and French have been long in the habit of preserving butter, by melting
it with a moderate heat, whereby are coagulated the albuminous and curdy matters
remaining in it, which are very putrescible. This fusion should be made by a heat of
a water bath, about 176~ F., continued for some time to effect the more complete
purification of the butter. If in this settled liquefied state it be carefully decanted,
strained through a tammy cloth, and slightly salted, it may be kept for a long time
nearly fresh, without becoming in any degree rancid, more especially if it be put up in
small jars closely covered.
Butter is the fatty matter of milk, usually of that of the cow. Milk is composed of butter, caseine, sugar of milk, several salts, and water. The butter exists in
the form of very small globules of nearly uniform size, quite transparent, and strongly
refractive of light. Milk left in repose throws up the lighter particles of butter to the
surface as cream. It was imagined that the butter was separated in the process of
churning, in consequence of the milk becoming sour; but this is not the case, for milk
rendered alkaline by bicarbonate of potash affords its butter fully more readily than
acidulous milk. The best temperature for churning milk or cream is 53~ F.; that of
60~ is too high; and under 50~ it is too low. By the churning action the heat rises from
3 to 4 degrees F. All the particles of butter are never separated by churning; many
remain diffused through the butter-milk, and are easily discoverable by the microscope.
These are more numerous in proportion to the bulk of the liquid; and hence it is more
economical to churn cream than the whole milk which affords it. It is computed that
a cow which gives 1800 quarts (old English) of milk per annum eats in that time 8000
lbs. of hay, and produces 140 lbs. of butter.* Analysis shows that this weight
of hay contains 168 pounds of fat. The finest flavoured butter is obtained from milk
churned not long after it is drawn; but the largest proportion is derived from the
cream thrown up by milk after standing 24 hours, in a temperature of about 50~ F.
The butter-milk, which contains the very fermentable substance, caseine, should be well
separated from the butter by washing with cold water, and by beating with the hands,
or preferably, without water, for the sake of fine flavour, by the action of a press.
The French purify their butter by melting it in pots, plunged into water heated to
200' or 212~; and sometimes they mix a pure brine with the melting butter, whereby
they favour the subsidence of the coagulated caseine and other impurities. The supernatant clear butter should be drawn or poured off, and rapidly cooled, to prevent the
crystallization of its stearine and separation of its oleine, which injure its flavour and
appearance.
BUTTER OF CACAO. See CACAO, CHOCOLATE, and OILS.
BUTTON  MANUFACTURE.  This art is divided into several branches, constituting so many distinct trades. Horn, leather, bone, and wood, are the substances
frequently employed for buttons, which are either plain, or covered with silk, mohair,
thread, or other ornamental materials. The most durable and ornamental buttons are
made of various metals, polished, or covered with an exceedingly thin wash, as it is
termed, some more valuable metal, chiefly tin, silver, and gold.
Those buttons intended to be covered with silk, &c., are termed in general moulds.
They are small circles, perforated in the centre, and made from those refise chips of
bone which are too small for other purposes.  These chips, which for the large and
coarser buttons, are pieces of hard wood, are sawn into thin flakes, of an equal thickness;
from which, by a machine, the button moulds are cut out at two operations.
The shavings, sawdust and more minute fragments are used by manufacturers of
cutlery and iron toys, in the operations of case-hardening; so that not the smallest
waste takes place.
Metal buttons are formed of an inferior kind of brass, pewter, and other metallic
compositions: the shanks are made of brass or iron-wire, the formation of which is a
distinct trade. The buttons are made by casting them  round the shank. For this
purpose the workman has a pattern of metal, consisting of a great number of circular
buttons, connected together in one plane by very small bars from one to the next; and
the pattern contains from four to twelve dozen of buttons of the same size. An
impression from this pattern is taken in sand in the usual manner; and shanks are
pressed into the sand in the centre of each impression, the part which is to enter the
metal being left projecting above the surface of the sand. The buttons are now cast
from a mixture of brass and tin; sometimes a small proportion of zinc is added, which
is found useful in causing the metal to flow freely into the mould, and makes a sharp
casting. When the buttons are cast, they are cleaned from the sand by brushing;
they are then broken asunder, and carried to a second workman at the lathe, who
inserts the shank of a button into a chuck of a proper figure, in which it is retained by
* Two pounds and a quarter of hay correspond to one quart of good milk; and a cow which eats
16.500 lbs. of hay will produce 300 lbs. of butter Der annum.




BUTTON MANUFACTURE.                                  289
the back centre of the lathe being pressed against the button with a spring. The
circumference is now, by filing it as it turns around, reduced to a true circle; and the
button is instantly released by the workman's holding back the centre, and is replaced
by another. A third workman now turns the back of the button smooth, in a chuck
lathe, and makes the projecting part round the shank true; and a fourth renders
the face of the button smooth, by placing it in a chuck, and applying the edge of a
square bar of steel across its centre.
Gilt buttons are stamped out from copper (having sometimes a small alloy of zinc),
laminated in the flatting mill to the proper thickness. The stamp is urged by a flypress, which cuts them out at one stroke. These circular pieces, called blanks, are
annealed in a furnace to soften them; and the maker's name, &c. is struck on the back
by a monkey, which is a machine very similar to a pile engine. This stamp also renders
the face very slightly convex, that the buttons may not stick together in the gilding
process. The shanks are next soldered on.  The burnishing is performed by a
piece of hematites or blood-stone, fixed into a handle, and applied to the button as it
revolves by the motion of the lathe.
A great number of the buttons, thus prepared for gilding, are put into an earthen
pan, with the proper quantity of gold to cover them,* amalgamated with mercury in
the following manner: —The gold is put into an iron ladle, and a small quantity
of mercury added to it; the ladle is held over the fire, till the gold and mercury are
perfectly united. This amalgam being put into the pan with the buttons, as much
aquafortis, diluted with water, as will wet them all over, is thrown in, and they are
stirred up with a brush, till the acid, by its affinity to the copper, carries the amalgam
to every part of its surface, covering it with the appearance of silver. When this is
perfected, the acid is washed away with clean water. This process by the workman
is called quicking.
The old process in gilding buttons, called the drying off, was exceedingly pernicious
to the operator, as he inhaled the vapour of the mercury, which is well known to be a
violent poison. In order to obviate this, the following plan of apparatus has been employed with success. The vapour, as it rises from the pan of buttons heated by a charcoal
fire, is conducted into an oblong iron flue or gallery, gently sloped downwards, having at
its end a small vertical tube dipping into a water cistern, for condensing the mercury,
and a large vertical pipe for promoting the draught of the products of the combustion.
Plated buttons are stamped by the fly-press, out of copper-plate, covered on one side
with silver at the flatting mill. The copper side is placed upwards in stamping, and
the die or hole through which they are stamped, is rather chamfered at its edge, to
make the silver turn over the edge of the button. The backs are stamped in the same
manner as the gilt buttons. The shanks are soldered on with silver solder, and heated
one by one in the flame of a lamp, with a blow-pipe urged by bellows. The edges are
now filed smooth in the lathe, care being taken not to remove any of the silver which
is turned over the edge. They are next dipped in acid, to clean the backs, and boiled
in cream of tartar and silver, to whiten them; after which they are burnished, the
backs being first brushed clean by a brush held against them as they revolve in the
lathe. The mode of burnishing is the same as for gilt buttons.
Button shanks are made by hand from brass or iron wire, bent and cut by the following means: -
The wire is lapped spirally round a piece of steel bar. The steel is turned round
by screwing it into the end of the spindle of a lathe, and the wire by this means lapped
close round it till it is covered. The coil of wire thus formed is slipped off, and a
wire fork or staple with parallel legs put into it. It is now laid upon an anvil, and by
a punch the coil of wire is struck down between the two prongs of the fork, so as to
form a figure 8, a little open in the middle. The punch has an edge which marks the
middle of the 8, and the coil being cut open by a pair of shears along this mark,
divides each turn of the coil into two perfect button shanks or eyes.
Mr. Holmes, of Birmingham, obtained in May, 1833, a patent for an improved construction of buttons. Fig. 212. represents the outside appearance of one of his improved shanks, as raised or formed out of the disc of metal which is to constitute the
back of the button; fig. 213, an edge view, looking through the shank or loop; fig.
214. is another edge view, looking at the raised shank or loop endways; fig. 215. is a
section taken through the shank and disc in the direction of the dotted line A B, in fig.
212.; and fig. 216. another section taken in the direction of the dotted line c D, in fig.
212. All these figures of his improved shanks, as well as those hereinafter described,
together with the tools used to form the same, are drawn at about half the real size, to
show the parts more distinctly. It will be seen that the shanks or loops a a are formed
* By act of parliament 5 grains of gold are allotted for the purpose of gilding 144 buttons, though they
may be tolerably well gilt by half that quantity. In this last case, the thickness would be about the
214,000th part of an inch.
VOL. 1.                            2P




290                     BUTTON MANUFACTURE.
by partially cutting and raising, or forcing up a portion of the metal disc or back b, and
are compressed or formed by the action of the tools, or punches and dies, so as to have
c~                       A212   213
n X 2 2 4 3  2g' Xlz       b215'
221 220 219 
a~ft                                                            a, 225,2,      222
__I0,,  K^"'~l         2327                 227
236                 220
~8 6I ^r231
L L          i Q235 Q233
a rounded figure on the inside of the top part of the shank, as at c, the edges of the
metal being turned so as to prevent them cutting the threads by which the button is
fastened to the cloth or garment. It will be observed that, there being but one passage
or way through which the thread can be passed to sew on the button, and that opening
being rounded on all edges, will cause the threads to keep in the centre of the shanks,
the form of the shank allowing a much neater attachment to the garment, and keeping
the threads from the edges of the metal. The ends of the shank or portions e e, which
rise up from the disc or back b, are made nearly circular, in order to avoid presenting
any edges of the metal to the sides of the button-hole; and when the shank is sewed on
the cloth, it forms, in conjunction with the threads, a round attachment, thereby preventing the shank from cutting or wearing the button-hole: the threads, when the shank is
properly sewed to the garment, nearly filling up the opening through the shank, and completing that portion of the circle which has been taken out of the shank by the dies in
forming the crescented parts of the loop. It will be therefore understood that the intention is, that the inside edges of the shank should be turned as much as possible away from
the threads by which the button is sewed on the cloth, and that the outside of the shank
should be formed so as to present rounded surfaces to the button-hole, and that the
thread should fill up the opening through the shank, so as to produce a round attachment
to the garment. It should here be observed, that the backs of the buttons shown in these
figures are of the shape generally used for buttons covered with Florentine or other fabric,
or faced with plates of thin metal, and are intended to have the edges of a disc, or what is
termed a shell, forming the face, to be closed in upon the inclined or bevelled edges of
the backs. Having now described the peculiar form of the improved shanks which he
prefers, for buttons to be covered with Florentine or other fabric, or shells of thin metal
plate, he proceeds to describe some of the different variations from the same.
Fig. 217. is a representation of a shank, the cut through the disc or back being effected
by a parallel rib on the die, and corresponding groove in the shaping punch, instead of the
semi-circular or crescented cut shown in fig. 212.; fig. 218. is a view of another shank, the
separation of the sides of the loop being performed by straight edges in both punch and
die. He prefers finishing this shaped shank (that is, giving it the rounded form, to prevent its cutting the threads), by detached punches, and dies, or pincers, as will be hereinafter described. Fig. 219. is a representation of one of the improved shanks, which has
merely portions, ff, of the back of the button connected to its ends. This shank may be
used for buttons which have a metal shell to be closed in upon the bevelled edges of the
ends, or the shank piece may be otherwise connected to the face part of the button. Fig.
220. is a representation of a shank raised out of a small disc of metal gg, intended to be
soldered to the disc of metal forming the button, or it may be otherwise fixed to the
back; fig. 221. is a representation of another shank for the same purpose, having only




BUTTON MANUFACTURE.                               291
portions of metal h h, for soldering or otherwise attaching it to the back of the button,
as by placing a ring or annular piece over it forming the back, which shall be confined
to the face, as before described; fig. 222. is a representation of a shank raised upon a dish
or bevelled piece of met&l, and is intended to be used for buttons made from pearl-shell,
horn, wood, paper, or other substances. The back part of the button has a dovetailed
recess formed in it to receive the dish-shaped back, which is pressed into the recess, the
edges of the dish being expanded in the dovetailed parts of the recess by the ordinary
means, and thereby firmly fixing it to the button, as shown infig. 223.
Having now explained the peculiar form of his improved shanks,he proceeds to describe
the tools,or punches and dies,by which he cuts the disc or back from out of a sheet of metal,
and at the same operation produces and forms the shank complete. Fig. 224. is a longitudinal section taken through a pair of dies and punches when separated; fig.225. is a similar
section, taken when they are put together, and in the act of forming a shank after cutting
out the disc or back of the button from a sheet of metal; fig. 226. is a face view of the
punch; andfig. 227. is a similar representation of the counter die,with the tools complete;
a is the puncher or cutter, and b the counter bed, by the circular edges of which the disc
of metal is cut out of the sheet; c is a die, fixed in the cutter a, (upon which the name of
the button maker may be engraved.) Fig. 228. is a face view of this die when removed
out of the punch; d is the counter die to the die c. It will be perceived that these dies
c and d, together with the punch and bed, compress the disc of metal into the form
required for the back of the button; that shown in the figures, as before stated, is of the
shape used for buttons to be covered with Florentine or thin plate metal, in a round
shell closed in upon the inclined or bevelled edge of the back; e is the cutting and
shaping punch of the shank, which is fixed within the counter die; this punch cuts
through the metal of the disc, and forms the shank as the dies approach nearer together,
by raising or forcing it up into the recess or opening in the die c, where it is met by the
end of another shaping punch f, fixed in the punch a, which compresses the upper part
of the shank into the recess g, in the end of the punch e, thereby giving the shank its
rounded figure, and at the same time forming the other part of the shank into the required shape, as described atfigs. 212. to 216. The ends of these shaping punches fit into
and over each other, as will be seen by the detached figures of the punches designed for
forming the shank first described. Fig. 229. is a representation of the punches when apart
and removed out of the dies: fig. 230. is a longitudinal section of the same; fig. 231. is
another view of the punches as seen on the top. The sharp edge of the recess h, in the
punch e, comes in contact with the cutting edges of the projecting rib i, of the die c, and
thereby cuts through so much of the metal as is required. The edge k of this die keeps
the outside ends of the shank of a spherical figure, as before explained,while the punches
force up the metal, and form the elevated loop or shank: u u are holes made through the
counter die d, for the passage of clearing pins, which force out the shank or back piece
from the counter die when finished; the operation of which will be shown when describing the machinery hereafter. There are adjusting screws at the back of the punches and
dies, by which they can be regulated and brought to their proper position one to the other.
Although he has shown the punches which form his improved shanks, fixed into and
working in conjunction with the punch and dies which cut out and shape the discs of
metal for the back of the button, yet he does not intend to confine himself to that mode
of using them, as flat blanks or discs for the backs of buttons may be cut out in a
separate stamping press, and afterwards shaped in the same press or in another, and then
brought under the operation of the punches which form his improved shanks, fixed in
any suitable press. This last-mentioned mode of producing button shanks and backs
he prefers when such metals are employed as require annealing between the operations
of shaping the backs and forming the shank. Fig. 232. is a section taken through a
pair of dies, in which the operation only of forming the shank is to be performed, the
backs being previously shaped in another press. In this instance the punches e andf
are mounted in guide-pieces m and n, which keep them in the proper position towards
each other, the die c being mounted in the piece n, and acting against the face of the
guide m. The blanks or backs of the buttons may be fed into these dies by hand or
any other means; and after the shank is formed, the finished back can be pushed out
of the lower die by clearing rods passed through the holes u u, and removed by hand,
or in any convenient manner.
When his improved shanks are formed out of iron or other metal which is too brittle
to allow of the shank being forced up and finished at one operation in the dies and
punches, he prefers cutting out and shaping the blank or back of the button first, and
after annealing it, to raise or force up the portion of metal to form the shank into the
shape shown infig. 233., that is, without the edges of the metal being turned to prevent
their cutting the threads, and after again annealing it, to bend or turn the edges into the
shape shown in fig. 218. by means of suitable punches in another press, or by a pair of
pincers and punch as shown infig. 234, which is a side view of a small apparatus to be
2P2




292                                BUTTON.
used for turning the edges of the shank by hand, with a partly formed shank seen under
operation. a, is the upper jaw of a pair of pincers, this jaw being fixed on to the head
of the standard b; the under jaw c, is formed by the end of the lever or handle d, which
has its fulcrum in the standard b. e, is a small punch, passed through a guide hole in
the head of the standard, one end projecting into the jaws of the pincers, the other
against a piecef, attached by a joint to the lever d, and working through a slot in the
head of the standard; this piece f, has an inclined plane on the side next the end of
the punch, which, in its descent, projects the punch forward against the top of the
loop of the shank, (placed at g,) as the pincers are closed by forcing down the lever d,
and, in conjunction with the jaws of the pincers, compresses the shank into the required
form, as shown at h, and in the enlargedfig. 218. A spring, i, acts against a pin fixed
into the punch e, for the purpose of bringing it back as the jaws open after forming a
shank. Figs. 235. and 236. represent the face and section of the dies mentioned before,
for cutting the slits in the discs, as atfig. 217.
Having explained the peculiar forms of his improved metallic shanks for buttons,
and the tools employed in making the same, he proceeds to describe the machinery or
apparatus by which he intends to carry his invention into effect. He proposes to take
a sheet of metal, say about 30 or 40 feet long, and of the proper width and thickness,
which thin sheet is to be wound upon a roller, and placed above the machine, so that it
can be easily drawn down into the machine as required for feeding the punches and
dies. Fig. 237. is a plan view of a machine, intended to work any convenient number
of sets of punches and dies placed in rows.  Eleven sets of punches and dies are re-.-... ~   presented, each set being...Iiiii  ~ ~..... Tll~ll  constructed as described
under figs. 224. to 231.;
I_='1  _ _ = 1   ~fg. 238. is a side view,
-     andfig. 239. a longitudinal section, taken through
the machine; figs. 240.
and 241. are transverse
G  R  ""'""""1  "7"' i e  i     i      sections taken  through
nil    1'I the machine between the;    I  Di7 Apunches  and  counter
dies, fig. 240. representing its appearance at the
it lgltlll~~~FI  c ~face of the punches, and
fig. 241. the opposite view
of the counter dies. a a,
are the punches; b b,
the counter dies; each,.~_   I    r       - ~'._'WE -a;.....   I   -W  _  being mounted in rows
in the steel plates c c,
i-.' -C~F  X  rfixed upon two strong
bars d and e, by countersunk screws and nuts,
— k   _^jJ=   LE               ^ ^          \ dthe  punches and dies
l      ^          e _ }11g)1 \ being retained in their
ABA  ~-        -I \      d I   Vproper position by the
plates, which are screwed
on to the front of the
steel plates, and press
238      a, \ ~~against the collars of the
I~238 In.punches and dies. The
bars d and e are both
mounted on the guidepins g g, fixed in the
h hbynutrheads h h of the frame,
which  guide-pins  pass'1          C                        -,1 othrough  the bosses on
^^^J n   l-'fthe ends of the bars.!    The bar d is stationary
upon  the  guide-pins,
being fixed to the heads
h h, by nuts and screws
r I T 2PB9                  passed through ears cast
on their bosses. The bar
e slides freely upon the
guide-pins g g, as it is




BUTTON.                                   293
moved backwards and forwards by the crank i i, and connecting-rods j j, as the crank
shaft revolves. The sheet of thin iron to be operated upon is placed, as before stated,
above the machine; its end being brought down as at a a, and passed between the
guide-rod and clearing plate k, and between the pair of feeding-rollers  1, which, by
revolving, draw down a further portion of the sheet of metal between the punches and
dies, after each operation of the punches.
As the counter dies advance towards the punches, they first come in contact with
the sheet of metal to be operated upon; and after having produced the pressure which
cuts out the discs, the perforations of the sheet are pushed on to the ends of the punches
by the counter dies; and in order that the sheet may be allowed to advance, the carriage which supports the axles of the feeding-rollers, with the guide-rod and clearingplate, are made to slide by means of the pin m, which works in a slot in the slidingpiece n, bearing the axis of the feeding-roller 1 l, the slide n being kept in its place on
the framework by dovetailed guides, shown in fig. 241.
When the counter dies have advanced near to the sheet of metal, the pin m, comes
in contact with that end of the slot in the piece n, which is next to the punches, and
forces the carriage with feed-rollers and clearing plate, and also the sheet of metal, onwards, as the dies are advanced by the reaction of the cranks; and after they have cut
out the discs, and raised the shanks, the sheet of metal will remain upon the punches;
and when the bar e returns, the finished backs and shanks are forced out of the counter dies, by the clearing-pins and rods o o, which project through the bar e, and through
the holes before mentioned in the counter dies; these clearing-pins being stationary between the bars p p, mounted upon the standard q q, on the cross bar of the frame, as
shown in figs. 237. 239. 240. Immediately after this is done, the pins m come in contact with the other ends of the slots in the pieces n, and draw back the feeding-rollers
11, together with the clearing-plate k, and the sheet of metal, away from the punches
into the position represented in the figures.
At this time the feeding of the metal into the machine is effected by a crank-pin r,
on the end of the crank-shafts coming in contact with the bent end of the sliding-bar s,
supported in standards t t; and as the crank-shaft revolves, this pin r forces the bar s
forward, and causes the tooth or pall u, on its reverse end, to drive the racket-wheel v,
one or more teeth; and as the racket-wheel v is fixed on to the end of the axle of one
of the rollers I, it'will cause that roller to revolve; and by means of the pair of spurpinions on the other ends of the axles of the feeding-rollers, they will both revolve
simultaneously, and thereby draw down the sheet of metal into the machine. It will
be perceived that the standards which support the clearing-plate and guide-bar are carried by the axles of the feeding-rollers, and partake of their sliding motion: also that
the clearing-pins o, are made adjustable between the bars p, to correspond with the
counter dies. There is an adjustable sliding-stop x upon the bar s, which comes in
contact with the back standard t, and prevents the bar s sliding back too far, and consequently regulates the quantity of sheet metal to be fed into the machine by the pall
and ratchet-wheel, in order to suit different sizes of punches and dies. In case the
weight of the bar c, carrying the counter dies, should wear upon its beaAngs, the
guide-pins g g, have small friction-rollers y y, shown under the bosses of this bar, which
friction-rollers run upon adjustable beds or planes z z, by which ineans the guide-pins
may be partially relieved from the weight of the bar c, and the friction consequently
diminished.
BuTTros OF HORN.-Mr. Thomas Harris obtained in April, 1841, a patent for improvements in the manufacture of horn buttons, and in their dies. His invention
relates, first, to a mode of applying flexible shanks to horn buttons; secondly, to a mode
of ornamenting horn buttons, by inlaying the front surface thereof; thirdly to a mode
of ornamenting what are called horn buttons, by gilding or silvering their surfaces;
fourthly, to a mode of constructing dies, by applying separate boundary circles to each
engraved surface of a die, by which the process of engraving, as well as the forming
of accurate dies, will be facilitated; fifthly, to a mode of constructing dies, used in the




294                                 BUTTON.
manufacture of horn buttons, whereby the horn or hoof employed will not be permitted to be expressed beyond the circumference of the button.
Fig. 242. represents, in section, a pair of dies, A and B, used in producing the
242                245                 250           254        257
(~)  251
252                        258
244 (0)   249 A_2563                                              259
29.
244 Q~8                                                           0' i2
T  248^  2
improved horn buttons, according to the first improvement; the upper die A is made
to produce the back surfaces of the buttons, and the recess or groove for receiving the
flexible shank. Fig. 243. shows, in section and back view, the form of a button produced by the dies.
Buttons thus formed are now ready to receive flexible shanks; and if the buttons
are to have plain smooth front surfaces, then, in fixing the flexible shanks, the same
kind of under die B may be used; but if the front surface of the button is to be embossed or ornamented, then, in place of that die a similar one having engraved or
suitably ornamented surfaces, is to be used. When fixing the shanks to buttons, the
lower or face die, containing the previously formed buttons, is to be heated till a drop
of water will nearly boil upon it.
The shank is applied as follows:-a metal shell or collet a (see fig. 244.) is placed
over the flexible shank b, and a plate of metal c is laid under the shank; these are
placed in the groove or recess of the button, which had been previously heated
in the lower die; the upper die A, fig. 245., is then to be placed on the lower die B, and
the two submitted to pressure, until they become cool, when the shank will be firmly
attached, as shown at fig. 246., and the bottom maybe finished in the usual way.
The second part of the invention, which relates to a mode of ornamenting horn buttons, by inlaying the front surface thereof,is performed in a manner similar to what has
been above described, for fixing flexible shanks, and consists in first forming the front
face or surface of a button, in suitable dies, for providing a recess; and then, by a
second pressure in dies, to fix the ornamental surface; and, when desired, the surrounding front surface of the button may be embossed. Fig. 247. is a longitudinal section of a
pair of dies, for forming a recess in the face of a button. Fig. 248. shows, in front view
and section, a horn button, produced by these dies. Fig. 249. shows a metal ornament,
to be inlaid or fixed in the front surface of the button, but it should be stated that the
ornamenting surface, to be fixed in the front surface of the button may be of pearl or
other material; and the size and device varied according to taste. Fig. 250. shows in
section a'pair of dies, for giving the second pressure for affixing the ornamental surface;
and, if desired, the remaining front surface of the button maybe ornamented, by having
the lower die engraved, or otherwise suitably ornamented. Fig. 251. shows in front
view and section a button made according to this part of the invention.
The third part of the invention relates to a mode of ornamenting horn buttons, by
gilding or silvering their surfaces. This is effected by applying a suitable cementing
or adhesive material with a soft brush to the button, in order that gold or silver leaf
may be attached to its surface. The cementing or adhesive material preferred to be
used is dressing varnish rendered sufficiently liquid by essence of turpentine; and when
the varnish is nearly dry, gold or silver leaf is applied thereto, and pressed in the same
manner as practised when gilding and silvering other surfaces; by thus treating horn
buttons, a very novel manufacture of that description of buttons may be produced.
The fourth part of this invention relates to the construction of dies used in the
manufacture of horn buttons. Fig. 252. is a section of a die, constructed according to




BUTTON.                                    295
this part of the invention; andfig. 253. is a section showing the die without the bounding circles, which confine the pattern; f is the die engraved at the parts g, g; around
each of which engraved surfaces are circular grooves or recesses to receive the bounding
circles, h, h, which fit accurately. By the after insertion of these circles, the workman
is not confined to move his graver within the bounding line, as that line is not present
when engraving the plate; and the graver may pass beyond, and the grooves and the
bounding circles may readily be made with great accuracy to each of the engraved
surfaces.
The fifth part of the invention also relates to a mode of constructing dies, for the
manufacture of horn buttons, and consists in forming the dies, so that the bounding
circle shall be of a sufficient depth for the counter die to slide within it, and fit accurately in order that the circumference of each button shall be smoothly and accurately
formed. Fig. 254. represents in section two dies, and one counter die, made according
to this part of the invention; fig. 255. shows one of the dies, in plan and section; and
fig. 256. a plan and section of a counter die, suitable for flexible shank buttons.  h, h,
are the dies, having the engraved surfaces i, i, on separate circular discs of metal, such
as have heretofore been used; j, is a counter die, and k, a tube, within which the
counter die is held, the object of this tube being to guide the projecting edges I, l, of
the dies as shown, and thus keep the dies and counter dies correct to each other. Fig 257.
is a section of two dies h, and a counter die j; but in this case the tube k is dispensed
with, the dies being deeper sunk, and thus guiding the counter die correctly. By the
use of these dies, the edges of horn buttons will be more accurately formed, and consequently require less finishing. This description of dies may be made according to
the mode described in the fourth part of this invention; that is, by forming the boundary
circle separately, as will be understood by referring tofig. 258., which is a side section of
a die complete, with its boundary circle formed in a similar manner to that described
above.  Fig. 259. represents, in plan and section, a variation in the means of affixing a
separate bounding circle to each engraved surface; and it is suitable for working without the tube.  In using these dies they are to be heated but slightly, whether for
buttons with metal shanks, or to receive flexible shanks, and are to be pressed as heretofore. The patentee claims, firstly, the mode of manufacturing horn buttons with
flexible shanks, by first forming buttons by pressure and heat, and then by a second
pressure in dies, to affix flexible shanks thereto, as above described.  Secondly, the
mode of ornamenting horn buttons, by causing suitable surfaces to be affixed in the
front surfaces, by pressing the buttons with the ornaments in dies, as above described.
Thirdly, the mode of ornamenting horn buttons by gilding and silvering their surfaces
as described. Fourthly, the mode of constructing dies used in the manufacture of horn
buttons, by applying separate bounding circles to each engraved surface for a button;
and fifthly, the mode of manufacturing horn buttons in dies, wherein the horn or hoof
is prevented from being expressed at the circumference of the buttons as described.
BUTTONS, COVERED.  Mr. Joseph Parkes obtained, in 1840, a patent for improvements in the manufacture of covered buttons made by dies and pressure, by the
application of horn as a covering material. The process resorted to by the patentees
for carrying out this invention, is very similar to that pursued in manufacturing
Florentine buttons; such modifications being applied as are rendered necessary
for adapting such process to the peculiar nature of the material employed for covering
the face of each button. a, fig. 260. shows a plan of a disc of iron plate, with four
projecting points, which is formed by suitable dies in a fly-press, as is well understood; the points are then turned down, and the disc a, is sunk into the shape
shown at fig. 261., and two such sunk discs are applied to the internal core of the
button-board of each button; b, fig. 262., shows a plan and edge view of a circular dise
of button-board, suitable for forming the internal core of a button.
The dies being placed in suitable presses, as is well understood in using similar
dies in manufacturing Florentine or other covered buttons, one of the sunk dies a
is placed in the under die, with the points upwards, having a disc of button-board
placed on the points, as shown at fig. 263.; the upper die or punch is then caused to
descend and press the button board b into the shape shown at fig. 264.; which, when
thus formed, is to have a die a, applied on the other side, as shown at fig. 265. The
disc a, to be next fixed to the button-board, is placed in a suitable die, the disc which
has already been fixed being upwards; the die or punch is now to be pressed down,
which will produce the button-board, with the discs a a on either side, into the shape
shown at fig. 266.; and it will be seen, that one of the discs will, by the shape of the die,
be sunk concave, whilst the other disc a, on the other side, will be formed convex, or
according to the figure of the face of the intended button.
The core of button-board, fig. 266., is now ready for being inserted into the fabric
which is to become the flexible shank of the button, and which flexible shank is formed
by sinking a portion of fabric in suitable dies, as is well understood when making




296                                BUTTON.
similar shanks for Florentine or other covered buttons; and the shank being so sunk,
the button-board or core, fig. 266., is to be placed thereon, with the concave surface
260 lgT       M          IA                                              274
260                                             63 b  267
261  2;              - 2687
262 ()   265'    269Xv
2660/                           2 
272               s     s2
towards the protruding shank; and the edges of the fabric are then to be pressed over
the core, (as is well understood,) which will produce the partly formed button, fig. 267,
which is a side view, and consists of the shank containing the core, which is next
inserted into the metal shell c, fig. 268., and these parts being placed in a suitable die,
are pressed together, and the partly manufactured button, fig. 269., will be produced,
consisting of the shank containing the core, covered on the front surface with the metal
shell c, which, by the die, has its edges bent down on the fabric of the flexible shank.
The button, thus far formed, is now in a condition to be covered with a thin plate of
horn, which is performed in the following manner:-d, fig. 270., shows a disc of horn,
cut out by suitable dies, the circumference being scolloped, in order that in folding
over the mould, fig. 269., the horn may not be puckered. e e, fig. 271., shows a collet,
for affixing the covering of horn to the button, the collet being similar to that used in
what is called "Sandar's plan of making Florentine and other covered buttons."
The method of covering the mould of the button with horn is described as follows:
Fig. 272. represents, in section, a lower covering die, and also a proper punch for pressing
the parts into the lower die; these dies being in a suitable press, as is well understood.
The lower die is to be kept heated to such an extent that the workman can just bear
his hand to rest, for a very short time, on the upper surface of the die; the heating is
preferred to be accomplished by means of a flame of gas below the die; and it will be
seen that there are holes f, f, in the die, through which the heat of the flame may pass;
and g is an opening, to allow of atmospheric air flowing under the lower die. The disc
of horn d is placed in the lower die g. The shape or mould, fig. 269., is then placed on
the horn, and the punch or die H, is caused to descend, and press the parts into the die
g; the punch h is then raised, in order to allow of the introduction of the parts shown
at figs. 273 and 274., which consist of the tube i, and the punch or die j. The lower
edge of the tube i is made bell-mouthed, so as to cause the scolloped edges to be
pressed on the back of the buttons, and the die or punch j is to cause the collet to be
forced through the horn in the button; and, in using these parts, the collet is placed in
the tube i, which with its punch is inserted into the die s, as shown at fig. 275., which
figure represents the die g, and punch h, in the condition just described, after having
forced the parts into the die G; and this figure also shows the tube i, with a collet d
and the punch or die J, placed in the tube i; and all things are in a condition to receive
the pressure of the punch H. In order to prevent the pressure coming on the punch or
die J, before the horn has been folded down by the tube i, the hollow block K is placed
over the die or punch J; consequently when the punch H is caused to descend, it will
force down the tube i, and cause it to gather the edges of the horn, and press them on
the back of the mould of the button, when the punch H will be raised again, and the
block x removed, which will leave all things in the position shown at fig. 276.; and then
again, the bringing down of the punch i will cause the die or punch J to descend and
force the collet into the button, the die J being retained in the tube I by means of the
pin z, passing through a slit formed therein, which allows of the die J rising and falling
in the tube i, but prevents its coming out of that tube. The button, thus far formed,
is now in a condition to be completed in the finishing dies, fig. 277.; the lower dies being
kept heated in a similar manner to the die e. The dies being fixed in a suitable press
the button to be finished is inserted into the die L, (which may be ornamented or plain,)




CABLE.                                   297
with the shank upwards, and the punch or die M is caused to descend and press the
button into shape.
When the front of the button' is to be plain, the disc of horn should be polished before
being used for covering; but when used to cover a button, and finished by an engraved
or ornamented die, the polishing is not necessary. The button being thus made is to
be finished by placing it in a lathe to be " edged," as is commonly practised in finishing
horn buttons.
The patentee does not claim the means of making the mould or shape shown atfig. 269.,
nor the dies employed when separately considered, very similar dies having been before
used in the manufacture of other covered buttons; nor does he confine himself thereto,
so long as the peculiar character and essence of the invention be retained; viz. that of
manufacturing covered buttons, made by dies and pressure by the application of thin
sheet horn as the covering material. He claims the mode herein described, of manufacturing covered buttons by the application of horn as a covering material, as above described.
C.
CABLE. (Cable, Fr.; Ankertau, Germ.) A strong rope or chain connecting the
ship with the anchor for the purpose of mooring it to the ground.  The sheet
anchor cable is the strongest, and is used at sea; the stream cable is more slender,
being used chiefly in rivers. A cable's length is 120 fathoms. The greatest improvement in mooring vessels has been the introduction of the chain cable, which, when
duly let out, affords in the weight of its long catenary curve, an elastic tension and play
to the ship under the pressure of the wind. The dead strain upon the anchor is thus
greatly reduced, and the sudden pull by which the flukes or arms are readily snapped
is in a great measure obviated. The best iron cables are chains made of links, bound
and braced by rods across their middle. Experience has taught that the ends of these
links wear out much sooner than the sides. To remedy this evil, Mr. Hawkes, iron
manufacturer, obtained a patent in July, 1828, for constructing these anchor chains
with links considerably stouter at the ends than in the middle. With this view
he forms the short rods of iron, of which the links are to be made, with swells or protuberances about one-third of their length from each of their ends, so that when these
are welded together, the slenderer parts are at the sides, and the thicker at the ends of
the elliptical links. Such rods as the above are formed at once by rolling, swagging, or
any other means. When the link is welded, it may be strengthened, by a brace or
stretcher fixed across the middle.
The first avowed proposal to substitute iron cables for cordage in the sea service was
made by Mr. Slater, surgeon of the navy, who obtained a patent for the plan in 1808,
though he does not seem to have had the means of carrying it into effect; a very general
misfortune with ingenious projectors.  It was Captain Brown, of the West India
merchant service, who, in 1811, first employed chain cables in the vessel Penelope, of
400 tons burden, of which he was captain. He made a voyage in this ship from England
to Martinique and Guadaloupe and home again, in the course of four months, having
anchored many times in every variety of ground without any accident. He multiplied
his trials, and acquired certain proofs that iron might be substituted for hemp in making
cables, not only for mooring vessels, but for the standing rigging. Since this period
chain cables have been universally introduced into all the ships of the royal navy, but
the twisted links employed at first by Brown have been replaced by straight ones, stayed
in the middle with a cross rod, the contrivance of Mr. Brunton, which was secured by
patent in this country and in France; but the latter patent was suffered to fall from not
being acted upon within the two years specified by law.
The first thing to be considered in the manufacture of iron cable is, to procure a
material of the best quality, and, in using it, always to keep in view the direction of the
strain, in order to oppose the maximum strength of the iron to it. The best form of
the links may be deduced from the following investigation.
278 RM            Let A B, fig. 278., be a circular link or ring, of one inch rod iron, the
outer circumference of the ring being 15 inches, and the inner 9.
C/ \\ \   It equal opposite forces be applied to the two points of the link
]E   )  1 1CD, pulling c towards E, and D towards F, the result will be, when
the forces are sufficiently intense, that the circular form of the link
will be changed into another form with two round ends and two
P ^~       parallel sides, as seen in Jig. 279. The ratio of the exterior to the
279            interior periphery, which was originally as 15 to 9, or 5 to 3, is no:lo  -nglonger the same in fig. 279. Hence there will be a derangement in
( =       g  )the relative position of the component particles, and consequently
~ their cohesion will be progressively impaired, and eventually de]     ~  stroyed. Infig. 278. the segment M N of the outside periphery being
VoL. I.                              2Q.




298                                  CABLE.
*qual to 3 inches, the corresponding inside segment will be 3 of it, or 15 inches. If
his portion of the link, in consequence of the stretching force, comes to be extended
into a straight line, as shown in fig. 279, the corresponding segments, interior and
exterior, must both be reduced to an equal length. The matter contained in the 3
inches of the outside periphery must therefore be either compressed, that is, condensed
into 15 inches, or the inside periphery, which is only I  inches already, must be extended to
3 inches; that is to say, the exterior condensation and the interior expansion must take
place in a reciprocal proportion. But, in every case, it is impossible to effect this contraction of one side of the rod, and extension of the other, without disrupture of the link.
Let us imagine the outside periphery divided into an infinity of points, upon each of
which equal opposite forces act to straighten the curvature: they must undoubtedly occasion the rupture of the corresponding part of the internal periphery. This is not the
sole injury which must result; others will occur, as we shall perceive in considering what
passes in the portion of the link which surrounds c D, fig. 279, whose length is 4~ inches
outside, and 2-1 inside. The segments M P and N o, fig. 278 are actually reduced to
semi-circumferences, which are inside no more than half an inch, and outside as before.
There is thus contraction in the interior, with a quicker curvature or one of shorter
radius in the exterior. The derangement of the particles takes place here, in an order
inverse to that of the preceding case, but it no less tends to diminish the strength of that
portion of the link; whence we may certainly conclude that the circular form of cable
links is an extremely faulty one.
Leaving matters as we have supposed in fig. 278, but suppose that G is a rod introduced
into the mail, ^-ndering its two opposite points A B from approximating. This circum280           stance makes a remarkable change in the results. The link pulled as
above described, must assume the quadrilateral form shown in fig. 280.
f/A< >>sA  It offers more resistance to deformation than before; but as it may still
suffer change of shape, it will lose strength in so doing, and cannot
 \/     therefore be recommended for the construction of cables which are to be
exposed to very severe strains.
Supposing still the link to be circular, if the ends of the stay comprehended a larger
portion of the internal periphery, so as to leave merely the space necessary for the plan
of the next link, there can be no doubt of its opposing more effectively the change of
form, and thus rendering the chain stronger. But, notwithstanding, the circular portions
which remain between the points of application of the strain and the stay, would tend
always to be straightened, and of consequence to be destroyed. Besides, though we
could construct circular links of sufficient strength to bear all strains, we ought still to
reject them, because they would consume more materials than links of a more suitable
f.rm, as we shall presently see.
The effect of two opposite forces applied to the links of a chain, is, as we have seen,
to reduce to a straight line or a straight plane every curved part which is not stayed:
whence it is obvious that twisted links, such as Brown first employed, even with a stay
in their middle, must of necessity be straightened out, because there is no resistance in
the direction opposed to the twist. A cable formed of twisted links, for a vessel of 400
tons, stretches 30 feet, when put to the trial strain, and draws back only 10 feet. This
elongation of 20 feet proceeds evidently from the straightening of the twist in each link,
which can take place only by impairing the strength of the cable.
From the preceding remarks, it appears that the strongest links are such as present, in
their original form, straight portions between the points of tension; whence it is clear
that links with parallel sides and round ends would be preferable to all others, did not
a good cable require to be able to resist a lateral force, as well as one in the direction
of its length.
Let us suppose that by some accident the linkfig. 279. should have its two extremities
281 -A        pulled towards Y and z, whilst an obstacle x, placed right opposite to
"/,\~  its middle, resisted the effort. The side of the link which touches x
z/,4 ^     would be bent inwards; but if, as infig. 281., there is a stay AG B, the
( U) </J~ )two sides would be bent at the same time; the link would notwithstanding assume a faulty shape.
In thus rejecting all the vicious forms, we are naturally directed to that which deserves
the preference. It is shown in fig. 282. This link has a cast-iron stay with large ends;
it presents in all directions a great resistance to every
t"  ~'change of form; for let it be pulled in the direction a b,
{~^ (e~   ~,~-)' against an obstacle c, it is evident that the portions d e
and d f, which are supported by the parts g e and g f
283  8 2  cannot get deformed or be broken without the whole link
283            C   282giving way. As the matter composing g e and gf cannot
be shortened, or that which composes d e and df be lengthened, these four sides will




CABLE.                                   299
remain necessarily in their relative positions, by virtue of the large-ended stay h,
whose profile is shown infig. 283.
We have examined the strength of a link in every di\    rection, except that perpendicular to its plane. Fig. 284.
// \  \\   represents the assemblage of three links in the above
A              Ip Pr edicament; but we ought to observe, that the ob\  \   J    V 9o~   1stacle c, placed between the links A B, must be necessarily very small, and could not therefore resist the
\^'/  284  \"/ pressure or impact of the two lateral links.
Process of manufacturing iron cables.-The implements and operations are arranged in the following order:1. A reverberatory furnace (see IRON), in which a number of rods or round bars of
the best possible wrought-iron and of proper dimensions, are heated to bright ignition.
2. The cutting by a machine of these bars, in equal lengths, but with opposite bevels,
to allow of the requisite crossing and slicing of the ends in the act of welding.
3. The bending of each of these pieces by a machine, so as to form the links; the
last two operations are done rapidly while the iron is red-hot.
4. The welding of the links at small forge fires, fitted with tools for this express pur
pose, and the immediate introduction of the stay, by means of a compound lever press
5. Proving the strength of the cables by an hydraulic press, worked by two mei
turning a winch furnished with a fly wheel.        *
The furnace is like those used in the sheet-iron works, but somewhat larger, and
needs no particular description here.
Figs.285. and 286. are a plan and elevation of the shears with which the rods are cut into
285
equal pieces for forming each a link. It is moved at Mr. Brunton's factory by a smaequal pieces for forming each a link. It is moved at Mr. Brunton's factory by a sma2
steam engine, but, for the sake of simplicity, it is here represented worked by foul
or more labourers, as it may be in any establishment. These must be relieved however
frequently by others, for I believe each shears' machine is calculated to require nearly
one horse in steam power. It is portable and must be placed in the neighbourhood of
both the furnace and bending machine.
A and B are the two cast-iron limbs of the shears. The first is fixed and th-' Mconc
286    -
2Q2




300                                  CABLE.
is moveable by means of a crank shaft c, driven by a heavy fly-wheel weighing 7 or 8
cwt.
The cutting jaws G are mounted with pieces of steel which are made fast by bolts,
and may be changed at pleasure.
E, the bar of iron to be cut. It is subjected, immediately upon being taken out of
the fire, to the shears, under a determinate uniform angle, care being taken not to let
it turn round upon its axis, lest the planes of the successive incisions should become
unequal.
F is a stop which serves to determine, for the same kind of chain, the equality of
length in the link pieces.
Figs. 287, 288, 289, plan and elevations of the machine for bending the links into an
elliptic form. It is represented at the moment when a link is getting bent upon it.
287
289
288
A is an elliptic mandrel of cast-iron; it is fixed upon the top of a wooden pillar
B, solidly supported in the ground. c is the jaw of the vice, pressed by a squareheaded screw against the mandrel A.
D part of the mandrel comprehended between x and Y, formed as an inclined plane,
so as to preserve an interval equal to the diameter of the rod between the two
surfaces that are to be welded together.
E rectangular slots (shears) passing through the centre of the nut of the mandrel, in
which each of the pins F may be freely slidden.
G horizontal lever of wrought-iron six feet long. It carries at H a pulley or frictionroller of steel, whose position may be altered according to the diameter of the links.
It is obvious that as many mandrels are required as there are sizes and shapes of links.
The piece of iron intended to form a link being cut, is carried, while red-hot, to the
bending machine, where it is seized with the jaw of the vice c, by one of its ends, the
slant of the cut being turned upwards; this piece of iron has now the horizontal direction m n; on pushing the lever G in the line of the arrow, the roller H will force m n to
be applied successively in the elliptic groove of the mandrel: thus finally the two faces
that are to be welded together will be placed right opposite each other.
The length of the small diameter of the ellipse ought to exceed by a little the length
of the stay-piece, to allow of this being readi y introduced. The difference between
the points F, E, is equal to the difference of the radii vectores of the ellipse.  Hence it
will be always easy to find the eccentricity of the ellipse.
Fig. 290 is a lever press for squeezing the links upon their stays, after the links are
290                                   g         >         =
welded. This machine consists of a strong cast-iron piece A, in the form of a square,
of which one of the branches is laid horizontally, and fixed to a solid bed by means of
bolts; the other branch, composed of two cheeks, leaving between them a space of two




CABLE.                                   301
inenes, stands upright. These two cheeks are united at top, and on the back of their
plane by a cross piece B. c, a rectangular staple, placed to the right and left of the cheeks
through which is passed the mandrel D, which represents and keeps the place of the following link. E, is a press lever, 6 feet long. F, clamp and counterclamp, between which
the link is pressed at the moment when the stay is properly placed. There are other
clamps, as well as staples c, for changing with each changed dimension of links.
The links bent, as we have seen, are carried to the forge hearth to be welded, and to receive their stay; two operations performed at one heating. Whenever the welding is
finished, while the iron is still red-hot, the link is placed upright between the clamps
F; then a workman introduces into the staple the mandrel D, and now applies the stay
with a pair of tongs or pincers, while another workman strikes down the lever E forcibly
upon it. This mechanical compression first of all joins perfectly the sides of the link
against the concave ends of the stay, and afterwards the retraction of the iron on cooling
increases still more this compression.
If each link be made with the same care, the cable must be sound throughout. It
is not delivered for use, however, till it be proved by the hydraulic press, at a draw-bench
made on purpose.  The press is a horizontal one, having the axis of its ram in the
middle line of the draw-bench, which is about 60 feet long, and is secured to the body of
the press by strong bolts.
The portion of chain under trial, being attached at the one end to the end of the ram
of the press, and at the other to a cross-bar at the extremity of the draw-bench, two
men put the press in action, by turning the winch, which works by a triple crank three
forcing pumps alternately; the action being equalized by means of a heavy fly-wheel.
As long as the resistance does not exceed the force of two men, the whole three pumps
are kept in play. After a while one pump is thrown out of gear and next another,
only one being worked towards the conclusion. The velocity of the ram being retarded
first one third and next two thirds, gives the men a proportional increase of mechanical
power.
The strength of two average men thus applied being computed, enables us to know at
every instant the resistance opposed by the chain to the pressure of the ram. The strain
usually applied to the stronger cables is about 500 tons.
The side beams of the draw-bench are of cast-iron, 6 inches in diameter; the different pieces composing it are adjusted to each other endwise by turned joints. Props
also of cast-iron support the beams two feet asunder, and at the height of 30 inches
above the ground. The space between them is filled with an oak plank on which the
trial chain is laid.
Strengtn of iron cables compared to hemp cables:Iron Cables.       Hemp Cables.        Resistance.
Diameter of Iron Rod. Circumference of Rope.
Inches.            Inches.             Tons.
0O-              9                     12
1                10                   18
1I               11                   26
1l               12                   32
1i~              13                   35
1               14 to 15             38
14               16                   44
1               17                   52
1f               18                   60
1       -        20                   70
2                22 to 24              80
It would be imprudent to put hemp cables to severer strains than those indicated in
the preceding table, drawn up from Brunton's experiments; but the iron cables of the
above sizes will support a double strain without breaking. They ought never in common cases, however, to be exposed to a greater stress. A cable destined for ships of a
certain tonnage, should not be employed in those of greater burden. Thus treated it
may be always trusted to do its duty, and will last longer than the ship to which it belongs. A considerable part of this decided superiority which iron cables have over hemp
ones, is undoubtedly due to the admirable form  contrived by Brunton. Repeated
experiments have proved that his cables possess double the strength of the iron rods
with which they are made -a fact which demonstrates that no stronger form can be
devised or is in fact possible.
One of the most valuable qualities of iron cables is their resisting lateral as well as
longitudinal strains, as explained underfigs. 219 and 221.
Vessels furnished with such cables have been saved by them from the most imminent




302                                CADMIUM.
peril. The Henry, sent out with army stores during the peninsular war, was caught
on the northern coast of Spain in a furious storm. She run for shelter into the Bay of
Biscay among the rocks, where she was exposed for three days to the hurricane.  She
possessed fortunately one of Brunton's 70 fathom chain cables, which held good all the
time, but it was found afterwards to have had the links of its lower portion polished
bright by attrition against the rocky bottom. A hemp cable would have been speedily
torn to pieces in such a predicament.
In the contracts of the Admiralty for chain cables for the British navy, it is stipulated
that " the iron shall have been manufactured in the best manner from pig iron, smelted
from iron-stone only, and selected of the best quality for the purpose, and shall not have
received, in any process whatever subsequent to the smelting, the admixture of either the
cinder or oxydes produced in the manufacture of iron; and shall also have been puddled
in the best manner upon iron bottoms, and at least three times sufficiently drawn out at
three distinct welding heats, and at least twice properly fagoted."
The following is a table of the breaking proof of chain cables, and of the iron for the
purpose of making them, also of the proofs required by her majesty's navy for chains.
Size of Bolt.       Proof of Bolt.        Proof of Chain.    Navy Proof of Chain.
Inches.           Tons.  Cwt.            Tons.  Cwt.              Tons.
4S ^5                   7                8    11                 41
A                8      7              13      4                 54
4           12      1              19      5                107
-l               16     4               26     5                134
1                21      8               34     5                18
1-               27      2               48    15                224
1l               33    10                53    11                284
1~               40    10                65     0                34
14               48      4               77      0               401
1               56    11                90    10                474
14               65    12               105     0                551
1                75      6              120    10                634
2                 85    14              137      0               72
21                96    15              155     0                811
In Brunton's cable the matter in the link is thrown very much into one plane; the
link being of an oval form, and provided with a stay. As there are emergencies in which
the cable must be severed, this is accomplished in those of iron by means of a bolt and
sheckle (shackle), at every fathom or two fathoms; so that by striking out this bolt or
pin, this cable is parted with more ease than a hempen one can be cut.
CACAO, BUTTER OF. See CocoA, and OILS, UNCTUOUS.
CADMIUM  is a metal discovered about the beginning of the year 1818. It occurs
chiefly in Silesia in several ores of zinc; and may be readily recognised by means of
the blowpipe; for at the first impression of the reducing or smoky part of the flame, the
ores containing cadmium stain the charcoal all round them with a reddish yellow circle
of oxyde of cadmium.  The Silesian native oxyde of zinc contains from  14 to 11 per
cent. of cadmium.
The cadmium  may be extracted by dissolving the ore in sulphuric acid, leaving
the solution acidulous, and diluting it with water, then transmitting through it a
stream  of sulphureted hydrogen, till the  yellow  precipitate ceases to fall. This
powder, which is sulphuret of cadmium, is to be dissolved in concentrated muriatic acid, the excess of which is to be expelled by evaporation; and the muriatic
salt being dissolved in water, carbonate of ammonia is to be added in excess, whereby
the cadmium  separates as a carbonate, while the small portion of adhering copper
or zinc is retained in solution by the ammonia. Herapath has shown, that in distilling
zinc per descensum (see ZINC), the first portions of gaseous metal which are disengaged
burn with a brown flame and deposite the brown oxyde of cadmium.
Cadmium  has the color and lustre of tin, and is susceptible of a fine polish. Its
fracture is fibrous; it crystallizes readily in regular octahedrons, and when it suddenly
solidifies, its surface gets covered with fine mossy vegetations. It is soft, easily bent,
filed, and cut, soils like lead any surface rubbed with it. It is harder and more tenacious than tin, and emits a creaking sound when bent, like that metal. It is very ductile,
and may be drawn out into  fine wire, and hammered into  thin  leaves without
cracking at the edges. Its specific gravity, after being merely melted, is 8.604; and
8'6944 after it has been hammered. It is very fusible, melting at a heat much under
redness; indeed, at a temperature little exceeding that of boiling mercury, it boils and
distils over in drops. Its vapors have no smell. It is but slightly altered by exposure




CALCIUM.                                   303
to air. When heated in the atmosphere, it readily takes fire, and burns with a brownish
yellow smoke which is destitute of smell. In strong acids it dissolves with disengagement of hydrogen, and forms colourless solutions. Chromate of potash causes no precipitate in them, unless zinc or lead be present.
There is only one oxide of cadmium, the brown above mentioned. Its specific gravity is 8-183. It is neither fusible nor volatile at a very high temperature.  When in
the state of a hydrate it is white. The oxide of cadmium consists of 87-45 parts of
metal, and 12-55 oxygen in 100 parts. Berzelius states its atomic weight to be 55'833
to hydrogen 1'000. Its sulphuret has a fine orange yellow colour, and would form a
beautiful pigment, could the metal be found in sufficient quantity for the purposes of
art. The sulphate is applied to the eyes by surgeons for removing specks of the cornea.
CAFFEINE. A chemical principle discovered in coffee, remarkable for containing
much azote. See COFFEE.
According to Robiquet the proportion of caffeine in 1000 of coffee is as follows:
Martinique 6-4, Alexandrian 4-4, Java 4-4, Mocha 4, Cayenne 3-8, St. Domingo 3-2.
It is probable that 0'64 per cent. is an ordinary proportion. According to Liebig, the
proportions are per lb., Martinique 32 gr., Alexandrian 22, Java 22, Mocha 20,
Cayenne 19, St. Domingo 16. H. J. Versman of Lubeck mixes 10 lbs. of bruised raw
coffee with 2 of caustic lime, made previously into hydrate; treats the mixture in a
displacement apparatus with alcohol of 80~ till the fluid which passes through no
longer furnishes evidence of the presence of caffeine. The coffee is then roughly ground
and brought nearly to the state of a powder, and the refuse of the once digested mixture from the displacement apparatus, dried and ground again, and mixed with hydrate
of lime, is once more macerated. The grinding is more easily effected after the coffee
has been subjected to the operation of alcohol, having lost its horny quality, and the
caffeine is thus more certainly extracted. The clear alcoholic liquid thus obtained is then
to be distilled, and the refuse in the retort to be washed with warm water, to separate
the oil. The fluid is now evaporated into a crystalline mass, filtered and expressed.
The impure caffeine is freed from oil by pressure between folds of blotting paper,
purified by solution in water with animal charcoal, and is thus obtained in shining
white silky crystals. In general not more than 3 drams were procured from 5 pounds
of coffee, from 10 pounds 7 drams, and from 100 pounds the largest quantity, viz. 6
ounces and 4 scruples of caffeine; a proof that a large quantity must be operated upon,
if in a quantitative respect a satisfactory result is to be obtained. Thus it is seen that
good Brazilian coffee contains 0'57 per cent. of caffeine. At the same time it may be
observed that it contains about 10 per cent. of a green liquid oil, and 2 per cent. of a
yellow solid fat.
CAJEPUT OIL is obtained from the leaves of the tree called MIelaleuca Leucadendron by Linneus, which grows upon the mountains of Amboyna, and in other of
the Molucca islands. It is procured by distillation of the dried leaves along with
water, is prepared in great quantities in the island of Banda, and sent to Holland
in copper flasks. Hence as it comes to us, it has a green colour. It is very limpid,
lighter than water, of a strong smell resembling camphor, and pungent taste like
cardamoms. When rectified the copper remains in the retort, and the oil comes over
colourless. It is used in medicine as a stimulant. See OILS, ETIEREOUS.
CALAMANCO.  A sort of woollen stuff of a shining appearance, chequered in
the warp, so that the checks are seen only upon one side.
CALAMINE. A native carbonate of zinc. See ZINC.
CALCAREOUS  EARTH.  (Terre calcaire, Fr.; Kalkerde, Germ.)  Commonly
denotes lime, in any form; but, properly speaking, it is pure lime.
CALCAREOUS SPAR.  Crystallized native carbonate of lime.
CALCEDONY. A hard mineral of the siliceous family, often cut into seals. Under
it may be grouped common calcedony, heliotrope, chrysoprase, plasma, onyx, sardonyx,
and sard.
CALCHANTUM. The ancient name of native copperas or sulphate of iron.
CALCINATION, is the chemical process of subjecting metallic bodies to heat with
access of air, whereby they are converted into a pulverulent matter, somewhat like
lime in appearance, called calx in Latin. The term calcination, however, is no, used
when any substance whatever is exposed to a roasting heat.
CALCIUM. The metallic basis of lime. See LIME.
The atomic weight of this element being an important point, both as to pure
chemistry and the chemical arts, has been the subject of innumerable researches.
Very lately Berzelius, in the Annalen der Chemie zud Pharrmacie, XLVI. p. 241., has
collated the most recent results of the analysis of other philosophers with his own; and
while Dumas, Marchand, and Erdmann estimate the weight at 20, that of hydrogen = 1,
or 250 oxygen = 100, he finds it ought to be, as compared with the latter, 2519; and
to the former, 20,152.




304                                 CALENDER.
CALC-SINTER.  The incrustations of carbonate of lime upon the ground, or the
pendulous conical pieces called stalactites, attached to the roofs of caverns, ar so called.
CALC-TUFF.  A  semi-hard, irregular deposite of carbonate of lime, formed from
the waters of calcareous springs.
CALCULUS.  The stony-looking morbid concretion, occasionally formed in  the
bladder of urine, gall-bladder, cystic duct, kidneys, and other parts of living animals,
Its examination belongs to medical chemistry.
CALENDER  (Calandre, Fr.; Kalander, Germ.), a word derived from  the Greek
kalindros (cylinder), is the name of a machine, consisting of two or more cylinders, revolving
so nearly in contact with each other that cloth passed through between them is smoothed,
and even glazed, by their powerful pressure. It is employed either to finish goods for the
market, or to prepare cotton and linen webs for the calico-printer, by rendering their surfaces level, compact, and uniform. This condensation and polish, or satinage, as the French
call it, differ in degree according to the object in view, and may be arranged into three
distinct series. 1. For goods which are to receive the first impression by the block,
a very strong pressure is required; for, upon the uniformity of the polish, the neatness
and regularity of the printing, and the correspondence of its members, depend. In
many establishments the calico is passed twice through the calender before being sent
to the tables.  2. The pieces already dyed up at the madder bath, or otherwise, and
which remain to be filled in with other colors, or grounded-in, as it is technically styled,
must receive a much less considerable gloss. This is a principle everywhere admitted
and acted upon, because the outline of the figured design being deranged by the
washing, and sometimes in consequence of the peculiar texture of the cloth, the printer,
in order to apply his grounding blocks properly, and to fit them to the contours of the
figures already impressed, is obliged to stretch the piece sometimes in the direction of
the warp, and sometimes of the weft, which would be impossible if they had been hard
glazed by the calender. 3. The degree of glazing given to finished goods depends upon
the taste of purchasers, and the nature of the article; but it is, in general, much less
than for the first course of block-printing.
The most complete calender probably in' existence is that used by some of the
eminent calico-printers of Alsace, as contrived by M. Charles Dollfus, and constructed
by MM. Witz, Blech, and Co. 1. It passes two pieces at once, and thus does double the
work of any ordinary machine. 2. It supersedes the necessity of having a workman to
fold up the goods, as they emerge from the calender, with the aid of a self-acting folder.
3. It receives, at pleasure, the finished pieces upon a roller, instead of laying them in
folds; and, by a very simple arrangement, it hinders the hands of the workmen from
being caught by the rollers.
Calenders, in consequence of the irregular demand for foreign orders and shipments,
are worked very irregularly, being sometimes overloaded with duty, and at others altogether unemployed.  A machine which can, when required, turn out a double quantity
of goods, must, therefore, be a desirable possession. For the first course of the printers,
where high calendering is necessary, the goods are usually passed twice through between two paper cylinders, to give that equality of surface which could not be obtained by
one passage, however strong the pressure; and therefore the simplification of this calender will prove no economy. Besides, in order to increase the pressure to the requisite degree, the cylinders would need to be made bulging at their middle part, and with such
cylinders common smoothing could not be given; for the pieces would be glazed in the
central line, and rough towards the edges. For pieces already printed in part, and requiring only to be grounded-in for other colors, the system of double effect has fewer objections, as a single passage through the excellent calender described under BLEACHING,
page 140, is found to answer very well.
The mcat remarkable feature of M. Dollfus's machine is its being managed by a single
workman. Sx or eight pieces are coiled upon the feed-roller, and they are neither pasted
nor stitched together, but the ends are merely overlapped half a yard or so. The
workman is careful not to enter the second piece till one third or one half of the first
one has passed through on the other side, to prevent his being engrossed with two ends
at a time. He must, no doubt, go sometimes to the one side, and sometimes to the
other of the machine, to see that no folds or creases occur, and to be ready for supplying
a freshipiece as the preceding one has gone through. The mechanism of the folder in
the Alsace machine is truly ingenious: it performs extremely well, really saves the
attendance of an extra workman, and is worthy the attention of manufacturers intent
upon economizing hand labor.  The lapping-roller works by friction, and does its duty
fully better than similar machines guided by the hand.
The numerous accidents which have happened to the hands of workmen engaged in
calenders should direct the attention towards its effective contrivance for preventing such
misfortunes. These various improvements in the Alsace machine may be easily adapted'o the ordinary calenders of almost every construction.




CALENDER.                                      305
The folder is a kind of cage, in the shape of an inverted pyramid, shut on the tour
sides, and open at top and bottom; the top orifice is about five inches, the bottom one
an inch and a half; the front and the back, which are about four feet broad, are made of
tin-plate or smooth pasteboard, and the two sides are made of strong sheet-iron; the whole
being bolted together by small bars of iron. Upon the sheet-iron of the sides, iron up.
rights are fixed, perforated with holes, through which the whole cage is supported freely
by means of studs that enter into them. One of the uprights is longer than the other,
and bears a slot with a small knob, which, by means of the iron piece, joins the guide to
the crank of the cylinder, and thereby communicates to the cage a seesaw movement;
at the bottom extremity of the great upright, there is a piece of iron in the shape of an
anchor, which may be raised, or lowered, or made fast, by screws.
At the ends of this anchor are friction-rollers, which may be drawn out or pushed
back and fixed by screws; these rollers lift alternately two levers made of wood, and fixed
to a wooden shaft.
The paws are also made of wood: they serve to lay down alternately the plies of the
cloth which passes upon the cage, and is folded zigzag upon the floor, or upon a board
set below the cage; a motion imparted by the seesaw motion of the cage itself. See
STRETCHING MACHINE.
To protect the fingers of the workmen, above the small plate of the spreading-board
or bar, there is another bar, which forms with the former an angle of about 75~; they
come sufficiently near together for the opening at the summit of the angle to allow the
cloth to pass through, but not the fingers. See Bulletin de la Soci&et Industrielle de
Mulhausen, No. 18.
I shall now describe, more minutely, the structure of the powerful but less complicated
calender mechanisms employed in the British manufactories.
A front elevation of a four-rollered calender (five rollers are often introduced) for giazing goods is given infig. 293. d I are two pasteboard or paper cylinders, each 20 inches
nicag   293             291                                 292               
0i V-                        I P.                      \'ro 
Lfi
in diameter, whose structure will be presently described: f is a cast-iron cylinder turned
perfectly smooth (its fellow is often placed between e and d): it is eight inches in diameter outside, four inches inside, with two inches thickness of metal. e is another pasteboard cylinder, fourteen inches in diameter: the strong cast-iron frame contains the bushes in which the journals of the rollers turn. op, is one of the pair of levers for communicating a graduated pressure according to the quality of the goods. Figs. 292, 293, are end
views of the same machine to show  the working gear.  The wheel s, on the end of the
upper iron cylinder, is ten inches in diameter; that on the end of the fellow iron cylinder
below (when it is present) is thirteen inches; both are connected by the larger carrier
wheel t.  The lower wheel u is one third larger than the upper wheel, and therefore
receives from the carrier wheel t, a proportionally slower motion, which it imparts to the
central pasteboard roller e, lying upon it, causing it to move one third more slowly than
the upper pasteboard roller. Thus a sort of sliding motion is produced, which, by rubbing
their surfaces, glazes the goods.
The iron rollers are made hollow for the purpose of admitting either a hot roller of




306                               CALENDER.
iron, or steam when hot calendering is required. The other cylinders used formerly to be
made of wood, but it was liable to many defects. The advantage of the paper roller
consists in its being devoid of any tendency to split, crack, or warp, especially when
exposed to a considerable heat from the contact and pressure of the hot iron rollers.
The paper, moreover, takes a vastly finer polish, and, being of an elastic nature, presses
into every pore of the cloth, and smooths its surface more effectually than any wooden
cylinder, however truly turned, could possibly do.
The paper cylinder is constructed as follows:-The axis of the cylinder is a strong
square bar of the best wrought iron, cut to the proper length. Upon this bar a strong
round plate of cast iron is first put, somewhat less in diameter than the cylinder when
finished. A quantity of thick stout pasteboard is then procured, and cut into round
pieces an inch larger in diameter than the iron plate. In the centre of the plates, and
of every piece of the pasteboard, a square hole must be cut to receive the axis; and, the
circle being divided into six equal parts, a hole must also be cut at each of the divisions,
an inch or two within the rim. These pieces of pasteboard being successively put
upon the axis, a long bolt of malleable iron, with a head at one end, and screwed at the
other, is also introduced through each of the holes near the rim; and this is continued
until a sufficient number of pasteboards are thus placed to form a cylinder of the
length required, proper allowance being made for the compression which the pasteboard
is afterwards to undergo. Another round plate is then applied, and, nuts being put
upon the screws, the whole are screwed tight, and a cylinder formed. This cylinder is
now to be placed in a stove, exposed to a strong heat, and must be kept there for at least
several days; and, as the pasteboard shrinks by exposure to the heat, the screws must
be frequently tightened until the whole mass has been compressed as much as possible.
When the cylinder is thus brought to a sufficient degree of density, it is removed from
the stove; and, when allowed to cool, the pasteboard forms a substance almost incon.
ceivably dense and hard. Nothing now remains but to turn the cylinder; and this is an
operation of no slight labor and patience. The motion in turning must be slow, not
exceeding about forty revolutions in a minute; the substance being now so hard and
tough that tools of a very small size must be used to cut, or rather scrape it, until it is
true.  Three men are generally employed for the turning, even when the motion of
the cylinder is effected by mechanical power, two being necessary to sharpen tools for
the third, who turns, as quickly as he blunts them.
Let us suppose it to be a five-rollered machine: when a person stands in front of
the calender, the cloth coming from behind above the uppermost cylinder 1, passes between 1 and 2: proceeding behind 2, it again comes to the front between 2 and 3:
between 3 and 4 it is once more carried behind, and, lastly, brought in front between
4 and 5, where it is received, and smoothly folded on a clean board, or in a box, by a
person placed there for the purpose. In folding the cloth at this time, care must be
taken that it may be loosely done, so that no mark may appear until it be again folded
in the precise length and form into which the piece is to be made up. The folding may
be done either by two persons or by one, with the aid of two sharp polished spikes
placed at a proper distance, to ascertain the length of the fold, and to make the whole
equal. When folded into lengths, it is again folded across upon a smooth clean table,
according to the shape intended, which varies with the different kinds of goods, or the
particular market for which the goods are designed.
When the pieces have received the proper fold, the last operation previous to packing
them is the pressing. This is commonly performed by placing a certain number of pieces,
divided by thin smooth boards of wood, in a common screw press, similar to those used
by printers for taking out the impression left by the types in the printing-press. Besides the wooden boards, a piece of glazed pasteboard is placed above and below every
piece of cloth, that the outer folds may be as smooth and glossy as possible. The
operation of the common screw press being found tedious and laborious, the hydraulic press is now in all well-mounted establishments had recourse to. See HYDRAULIC
PRESS.
No improvements that have taken place in calendering can exceed the power and facility of the water press: one of these presses may be worked by two men, who can
with great ease produce a pressure of 400 tons; but, in considerable establishments, the
presses are worked by power. See BANDANNA.
The appearance and finish of the goods, in consequence of such an immense weight
acting on them, are materially improved.
The press is also used for the purpose of packing; whereby the bale is rendered much
more compact than formerly. It is commonly roped, &c., while in this compressed
state; the dimensions are therefore greatly diminished from what they would otherwise
be by any other method. For instance, the same quantity of goods packed in a bale
are from one third to one half less bulky than if they were packed in a box with the
utmost force of the hands.




CALICO-PRINTING.                                307
For lawns and muslins of a light texture, the operation of smoothing rwires a dit.
ferent process in some respects than close heavy fabrics. They only require to be slightly
smoothed to remove any marks which they may have received at the bleaching; and as
their beauty depends rather on their transparency than their closeness, the more the cy
lyndrical form of the yarn is preserved the better. They are therefore put through a
small machine, consisting of three rollers or cylinders; and as the power required to
move this is small, the person who attends it generally drives it by a small winch; or
the same effect may be produced by passing the muslins between only two or three rollers
of the above calender, lightly loaded.
In the thick fabrics of cloth, including those kinds which are used for many parts ot
household furniture, as also those for female dress, the operation of glazing is used both
to add to the original beauty of the cloth, and to render it more impervious to dust or
smoke. The glazing operation is performed entirely by the friction of any smooth
substance upon the cloth; and, to render the gloss brighter, a small quantity of bleached
wax is previously rubbed over the surface. The operation of glazing by the common
plan is very laborious, but the apparatus is of the most simple kind. A table is mounted
with a thick stout cover of level and well-smoothed wood, forming an inclined plane;
that side where the operator stands at work being the lowest. The table is generally
placed near a wall, both for convenience in suspending the glazing apparatus, and for
the sake of light." A long piece of wood is suspended in a groove formed between two
longitudinal beams, placed parallel to the wall, and fixed to it. The groove resembles
exactly the aperture between the shears of a common turning lathe. The lever, of which
the groove may be supposed to be the centre or fulcrum, is faced at the bottom with a
semi-cylindrical piece of finely polished flint, which gives the friction to the cloth stretched
upon the table below. Above the flint are two cross handles, of which the operator
lays hold, and moves them backward and forward with his hands, keeping the flint pressing slightly upon the cloth. When he has glazed a portion equal to the breadth of the
flint, he moves his lever between the shears sidewise, and glazes a fresh part: thus he
proceeds from one side or selvage of the cloth to the other; and when all which is upon
the table is sufficiently glazed, he draws it over, and exposes a new portion to the same
operation. To preserve the cloth at a proper tension, it may be wound smoothly upon
a roller or beam, which being set so as to revolve upon its own axis behind the table,
another roller to receive the cloth may be placed before, both being secured by a catch,
acting in a ratchet wheel. Of late years, however, a great part of the labor employed
in glazing cloth has been saved, as the common four or five bowl calender has been
altered to fit this purpose by direct pressure.
As a matter of accommodation, the different processes of packing, cording of boxes,
sheeting of trunks, and, in general, all the arrangements preparatory to shipments, and
also the intimations and surveys necessary for obtaining drawbacks, debentures, or
bounties, according to the excise laws, are generally conducted at the calender houses
where goods are finished. These operations sufficiently account for the general meaning
attached to the word.
CALICO-PRINTING  (Impression d'lndiennes, Fr.; Zeugdruckerei, Germ.) is the
art of impressing cotton cloth with topical dyes of more or less permanence. Of late
years, silk and woollen fabrics have been made the subjects of a similar style of
dyeing. Linens were formerly stained with various colored designs, but since the
modern improvements in the manufacture of cotton cloth, they are seldom printed, as
they are both dearer, and produce less beautiful work, because flax possesses less affinity
than cotton for coloring matters.
This art is of very ancient date in -India, and takes its English name from Calicut, a
district where it has been practised with great success from time immemorial. The
Egyptians, also, appear from Pliny's testimony to have practised at a remote era some of
the most refined processes of topical dyeing.'' Robes and white veils," says he, "are
painted in Egypt in a wonderful way. They are first imbued, not with dyes, but with
dye-absorbing drugs, by which, though they seem to be unaltered, yet, when immersed
for a little while in a caldron of the boiling dye-liquor, they are found to become
painted. Yet, as there is only one color in the caldron, it is marvellous to see many
colors imparted to the robe, in consequence of the influence of the excipient drug. Nor
can the dye be washed out. A caldron, which would of itself merely confuse the colors
of cloths previously dyed, is thus made to impart several pigments from a single dyestuff, painting as it boils."  The last expression, pingitque dum coquit, is perfectly graphic
and descriptive of calico-printing.
The cotton chints counterpanes of great size, called pallampoors, which have been
manufactured in Madras from the earliest ages, have in like manner peculiar dye-absorbing drugs applied to them with the pencil, as also wax, to protect certain parts of the
surface from the action of the dye, and are afterwards immersed in a staining liquor, which,
when wax is applied, is usually the cold indigo-vat, but without the wax is a hot liquor
similar to the Egyptian. M. Koechlin Roder, of Mulhouse, brought home lately from




308                          CALICO-PRINTING.
India a rich collection of cloths in this state of preparation, which I saw in the
cabinet of the Sociiet Industrielle of that interesting emporium of calico-printing.
The native implements for applying the wax and coloring bases are placed alongside of the cloths, and form  a curious picture of primeval art. There is among
other samples an ancient pallampoor, five French yards long, and two and a half broad,
said to be the labor of Hindoo princesses, which must have taken a lifetime to execute.
The printing machinery of great Britain has begun to supersede, for these styles of
work, the cheapest hand labor of India.
Calico-printing has been for several hundred years practised by the oriental methods
in Asia Minor and the Levant; but it was unknown as an English art till 1696,
when a small print-ground was formed upon the banks of the Thames, near Richmond,
by a Frenchman-probably a refugee from his own country, in consequence of the
revocation of the edict of Nantes. Some time afterwards, a considerable printing
work was established at Bromley Hall, in Essex, and several others sprung up success
sively in Surrey, to supply the London shops with chintses, their import from India
having been prohibited by act of parliament in 1700. The silk and woollen weavers,
indeed, had all along manifested the keenest hostility to the use of printed calicoes,
whether brought from the East or made at home. In the year 1680 they mobbed the
India House in revenge for some large importations then made of the chintses of
Malabar. They next induced the government, by incessant clamors, to exclude altogether the beautiful robes of Calicut from the British market. But the printed goods,
imported by the Engiish and Dutch East India companies, found their way into this
country, in spite of the excessive penalties annexed to smuggling, and raised a new alarm
among the manufacturing population of Spitalfields. The sapient legislators of that day,
intimidated, as would appear, by the East London mobs, enacted in 1720 an absurd
sumptuary law, prohibiting the wearing of all printed calicoes whatsoever, either offoreign
or domestic origin. This disgraceful enactment, worthy of the meridian of Cairo or
Algiers, proved not only a death-blow to rising industry in this ingenious department
of the arts, but prevented the British ladies from attiring themselves in the becoming
drapery of Hindostan. After an oppressive operation of ten years, this act was repealed
by a partially enlightened set of senators, who were then pleased to permit what they
called British calicoes, if made of linen warp, with merely weft of the hated cotton, to be
printed and worn, upon paying a duty of no less than sixpence the square yard. Under
this burden, English calico-printing could not be expected to make a rapid progress.
Accordingly, even so lately as the year 1750, no more than 50,000 pieces of mixed
stuff were printed in Great Britain, and that chiefly in the neighborhood of London;
whereas a single manufacturer, Mr. Coates of Manchester, now-a-days will turn off
nearly twenty times that quantity, and there are very many others who manufacture
several hundred thousand pieces per annum. It was not till about 1766 that this art
migrated into Larcashire, where it has since taken such extraordinary development;
but it was only after 1774 that it began to be founded upon right principles, in consequence of the repeal of that part of the act of 1730 which required the warp to be made
of linen yarn. Henceforth the printer, though still saddled with a heavy duty of 3d. the
square yard, was allowed to apply his colors to a homogeneous web, instead of the mixed
fabric of linen and cotton substances, which differ in their affinities for dyes.
France pursued for some time a similar false policy with regard to calico-printing, but
she emerged sooner from the mists of manufacturing monopoly than England. Her
avowed motive was to cherish the manufacture of flax, a native product, instead of that
of cotton, a raw material, for which prejudice urged that money had to be exported.
Her intelligent statesmen of that day, fully seventy years ago, replied that the money
expended in the purchase of cotton was the produce of French industry, beneficially
employed, and they therefore took immediate measures to put the cotton fabrics upon a
footing of equality. Meanwhile the popular prejudicec became irritated to such a degree,
by the project of permitting the free manufacture and sale of printed cottons, that every
French town possessed of a chamber of commerce made the strongest remonstrances
against it. The Rouen deputies declared to the government, " that the intended measure would throw its inhabitants into despair, and make a desert of the surrounding
country:" those of Lyons said, "the news had spread terror through all its workshops:"
Tours "foresaw a commotion likely to convulse the body of the state:" Amiens said,
" that the new law would be the grave of the manufacturing industry of France;" and
Paris declared that " her merchants came forward to bathe the throne with their tears
upon that inauspicious occasion."
The government persisted in carrying its truly enlightened principles into effect, and
with so manifest advantage to the nation, as to warrant the inspector-general of manu
factures to make, soon afterwards, the following appeal to those prejudiced bodies: —
" Will any of you now deny that the fabrication of printed cottons has occasioned a vast
extension of the industry of France, by giving profitable employment to a great many




CALICO-PRINTING.                                309
hands in spinning, weaving, bleaching, and printing the colors? Look only at the dyeing
department, and say whether it has not done more good to France in a few years than
many of your other manufactures have in a century?"
The despair of Rouen has been replaced by the most signal prosperity in the cotton
trade, and especially in printed calicoes, for the manufacture of which it possesses 70
different establishments, producing upwards of a million of pieces of greater average size
and price than the English. In the district of the Lower Seine, round that town, there
are 500 cotton factories of different kinds, which give employment to 118,000 operatives
of all orders, and thus procure a comfortable livelihood to probably not less than half a
million of people.
The repeal, in 1831, of the consolidated duty of 31d. per square yard upon printed
calicoes in Great Britain is one of the most judicious acts of modern legislation. By
the improvements in calico-printing, due to the modern discoveries and inventions in
chem:try and mechanics, the trade had become so vast as to yield in 1830 a revenue of
2,280,0001. levied upon 8,596,000 pieces, of which, however, about.hree fourths were
exported, with a drawback of 1,579,0001. 2,281,512 pieces were consumed in that year
at home. When the expenses of collection were deducted, only 350,0001. found their
way into the exchequer, for which pitiful sum thousands of frauds and obstructions were
committed against the honest manufacturer. This reduction of duty enables the consumer to get this extensive article of clothing from 50 to 80 per cent. cheaper than
before, and thus places a becoming dress within the reach of thousands of handsome
females in the humbler ranks of life. Printed goods, which in 1795 were sold for two
shillings and three-pence the yard, may be bought at present for eight-pence. In fact, a
woman may now purchase the materials of a pretty gown for two shillings. The repeal
of the tax has been no less beneficial to the fair dealers, by putting an end to the contraband trade, formerly pursued to an extent equally injurious to them and the revenue.
It has, moreover, emancipated a manufacture, eminently dependant upon taste, science,
and dexterity, from the venal curiosity of petty excisemen, by whom private improvements, of great value to the inventor, were in perpetual jeopardy of being pirated and
sold to any sordid rival. The manufacturer has now become a free agent, a master of
his time, his workmen, and his apparatus; and can print at whatever hour he may receive an order; whereas he was formerly obliged to wait the convenience of the excise
officer, whose province it was to measure and stamp the cloth before it could be packed,
-an operation fraught with no little annoyance and delay. Under the patronage of parliament, it was easy for needy adventurers to buy printed calicoes, because they could
raise such a sum by drawbacks upon the export of one lot as would go far to pay for
another, and thus carry on a fraudulent system of credit, which sooner or later merged
in a disastrous bankruptcy.  Meanwhile the goods thus obtained were pushed off to
some foreign markets, for which they were possibly not suited, or where they produced,
by their forced sales, a depreciation of all similar merchandise, ruinous to the man who
meant to pay for his wares.
The principles of calico-printing have been very profoundly studied by many of the
French manufacturers, who generally keep a chemist, who has been educated in the Parisian
schools of science, constantly at work, making experiments upon colors in a well-mounted
laboratory. In that belonging to M. Daniel Kcechlin, of Mulhausen, there are upwards
of 3000 labelled vials, filled with chemical reagents, and specimens subservient to dyeing.
The great disadvantage under which the French printers labor is the higher price they
pay for cotton fabrics above that paid by the English printers. It is this circumstance
alone which prevents them from becoming very formidable rivals to us in the markets of
the world. M. Barbet, deputy and mayor of Rouen, in his replies to the ministerial
commission of inquiry, rates the disadvantage proceeding from that cause at 2 francs per
piece, or about 5 per cent. in value. In the annual report of the Societi Industrielle of
Mulhausen, made in December, 1833, the number of pieces printed that year in Alsace
is rated at 720,000, to which if we add 1,000,000 for the produce of the department of
the Lower Seine, and 280,000 for that of St. Quentin, Lille, and the rest of France, we
shall have for the total amount of this manufacture 2,000,000 of pieces, equivalent to
nearly 2,400,000 pieces English; for the French piece usually measures 331 aunes,
= 41 yards nearly; and it is also considerably broader than the English pieces upon
an average. It is therefore probable that the home consumption of France in printed
goods is equal in quantity, and superior in value, to that of England. With regard to
the comparative skill of the workmen in the two countries, M. Nicholas Koechlin, deputy
of the Upper Rhine, says, that one of his foremen, who worked for a year in a printfield in Lancashire, found little or no difference between them in that respect. The
English wages are considerably higher than the French. The machines for multiplying
production, which for some time gave us a decided advantage, are now getting into very
general use among our neighbors. In my recent visit to Mulhausen, Rouen, and their
environs, I had an opportunity of seeing many printing establishments mounted with all
the resources of the most refined mechanisms.




310                         CALICO-PRINTING.
The calico-printing of this country still labors under the burden of considerable taxes
upon madder and gallipoli oil, which have counteracted the prosperity of our Turkey red
styles of work, and caused them to flourish at Elberfeldt, and some other places on the
continent whither a good deal of the English yarns are sent to be dyed, then brought
back, and manufactured into ginghams, checks, &c., or forwarded directly thence to our
Russian customers. This fact places our fiscal laws in the same odious light as the facility of pirating printers' patterns with impunity does our chancery laws.
Before cloth can receive good figured impressions its surface must be freed from fibrous
down by SINGEING, and be rendered smooth by the CALENDER. See these articles. They
are next bleached, with the exception of those destined for Turkey red. See BLEACHING
and MADDER. After they are bleached, dried, singed, and calendered, they are lapped
round in great lengths of several pieces, stitched endwise together, by means of an apparatus called in Manchester a candroy, which bears on its front edge a rounded iron bar,
transversely grooved to the right and left from the centre, so as to spread out the web as
it is drawn over it by the rotation of the lapping roller. See a figure of this bar subservient to the cylinder printing-machine.
Four different methods are in use for imprinting figures upon calicoes: the first is by
small wooden blocks, on whose face the design is cut, which are worked by hand; the second
is by larger wood-cut blocks, placed in either two or three planes, standing at right angles
to each other, called a Perrotine, from the name of its inventor; the third is by flat copper
plates, a method now almost obsolete; and the fourth is by a system of copper cylinders,
mounted in a frame of great elegance, but no little complexity, by which two, three, four,
or even five colors may be printed on in rapid succession by the mere rotation of the machine driven by the agency of steam or water. The productive powers of this printing
automaton are very great, amounting for some styles to a piece in the minute, or a mile
of cloth in the hour. The fifth color is commonly communicated by means of what is
called a surface cylinder, covered with wooden figures in bass-relief, which, by rotation,
are applied to a plane of cloth imbued with the thickened mordants.
The hand blocks are made of sycamore or pear-tree wood, or of deal faced with these
woods, and are from two to three inches thick, nine or ten inches long, and five broad,
with a strong box handle on the back for seizing them by. The face of the block is either
carved in relief into the desired design, like an ordinary wood-cut, or the figure is formed
by the insertion edgewise into the wood of narrow slips of flattened copper wire. These
tiny fillets, being filed level on the one edge, are cut or bent into the proper shape, and
forced into the wood by the taps of a hammer at the traced lines of the configuration.
Their upper surfaces are now filed flat, and polished into one horizontal plane, for the
sake of equality of impression. As the slips are of equal thickness in th.ir whole depth,
from having been made by running the wire through between the steel cylinders of a
flatting mill, the lines of the figure, however much they get worn by use, are always
equally broad as at first; an advantage which does not belong to wood-cutting. The
interstices between the ridges thus formed are filled up with felt-stuff. Sometimes a
delicate part of the design is made by the wood-cutter, and the rest by the insertion of
copper slips.
The coloring matter, properly thickened, is spread with a flat brush, by a child, upon
fine woollen cloth, stretched in a frame over the wax cloth head of a wooden drum or
sieve, which floats inverted in a tubful of old paste, to give it elastic buoyancy. The inverted sieve drum should fit the paste tub pretty closely. The printer presses the face
of the block on the drum head, so as to take up the requisite quantity of color, applies
it to the surface of the calico, extended upon a flat table covered with a blanket, and
then strikes the back of the block with a wooden mallet, in order to transfer the impression fully to the cloth. This is a delicate operation, requiring equal dexterity and diligence. To print a piece of cloth 25 yards long and 30 inches broad, no less than 672
applications of a block, 9 inches long and 5 inches broad, are requisite for each color;
so that if there are three colors, or three hands as the French term it, no less than
2016 applications will be necessary. The blocks have pin-points fixed into their corners,
by means of which they are adjusted to their positions upon the cloth, so as to join the
different parts of the design with precision. Each printer has a color-tub placed
within reach of his right hand; and for every different color he must have a separate
sieve. Many manufacturers cause their blocks to be made of three layers of wood, two
of them being deal with the grain crossed to prevent warping, and the third sycamore for
engraving.
The printing shop is an oblong apartment, lighted with numerous windows at each
side, and having a solid table opposite to each window. The table B,fig. 231, is formed
of a strong plank of well-seasoned hard wood, mahogany, or marble, with a surface truly
plane. Its length is about 6 feet, its breadth 2 feet, and its thickness 3, 4, or 5 inches.
It stands on strong feet, with its top about 36 inches above the floor. At one of its
ends there are two brackets c for supporting the axles of the roller E, which carries the




CALICO-PRINTING                                  311
white calico to be printed. The hanging rollers E are laid across joists fixed near the roof
of the apartment above the printing shop, the ceiling and floor between them being open
bar work, at least in the middle of the room. Their use is to facilitate the exposure,
and, consequently, the drying of the printed pieces, and to prevent one figure being daubed
by another. Should they come to be all filled, the remainder of the goods must be folded
lightly upon the stool D.
295                           t if   E.9~......"i.........
o. r"'dI^ 
in [ -==l   Ix eI"
2,
The printer stretches a length of the piece upon his table A B, taking care to place
the selvage towards himself, and one inch from the edge. He presents the block
towards the end, to determine the width of its impression, and marks this line A B, by
means of his square and tracing point. The spreader now besmears the cloth with the
color, at the commencement, upon both sides of the sieve head; because, if not uniformly
applied, the block will take it up unequally. The printer seizes the block in his right
hand, and daubs it twice in different directions upon the sieve cloth, then he transfers it
to the calico in the line A B, as indicated by the four points a b c d, corresponding to
the four pins in the corners of the block. Having done so, he takes another daub of
the color, and makes the points a b fall on c d, so as to have at the second stamp
a' b', covering a b and c' d'; and so on, through the rest, as denoted by the accented letters. When one table length is finished, he draws the cloth along, so as to bring a new
length in its place.
The grounding-in, or re-entering (rentrage), of the other colors is the next process.
The blocks used for this purpose are furnished with pin-points, so adjusted that, when
they are made to coincide with the pin-points of the former block, the design will be correct; that is to say, the new color will be applied in its due place upon the flower or other
figure. The points should net be allowed to touch the white cloth, but should be made to
fall upon the stem of a leaf, or some other dark spot. These rentrages are of four sorts:
1. One for the mordants, as above; 2. one for topical colors; 3. one for the application of
reds; and, 4. one for the application of resist pastes or reserves. These styles have
superseded the old practice of pencilling.
The Perrotine is a machine for executing block-printing by mechanical power; and
it performs as much work, it is said, as 20 expert hands. I have seen its operation, in
many factories in France and Belgium, in a very satisfactory manner; but I have
reason to believe that there are none of them as yet in this country. Three wooden
blocks, from 2~ to 3 feet long, according to the breadth of the cloth, and from 2 to 5
inches broad, faced with pear-tree wood, engraved in relief, are mounted in a powerful
cast-iron frame work, with their planes at right angles to each other, so that each
of them may, in succession, be brought to bear upon the face, top, and back of a
square prism of iron covered with cloth, and fitted to revolve upon an axis between the
said blocks. The calico passes between the prism  and the engraved blocks, and
receives successive impressions from them as it is successively drawn through by a
winding cylinder. The blocks are pressed against the calico through the agency of
springs, which imitate the elastic pressure of the workman's hand. Each block receives
a coat of colored paste from a woollen surface, smeared after every contact with a
mechanical brush. One man, with one or two children for superintending the colorgiving surfaces, can turn off about 30 pieces English per day, in three colors, which
is the work of fully 20 men and 20 children in block printing by hand. It executes
some styles of work to which the cylinder machine, without the surface roller, is
inadequate.




312                           CALICO-PRINTING.
The copper-plate printing of calico is almost exactly the same as that used fot printing
engravings on paper from flat plates, and being nearly superseded by the next machine,
need not be described.
The cylinder printing machine consists, as its name imports, of an engraved copper
cylinder, so mounted as to revolve against another cylinder lapped in woollen cloth, and
imbued with a colored paste, from  which it derives the means of communicating
colored impressions to pieces of calico passed over it.  Fig. 296
d          296  a   will give the reader a general idea of this elegant and expeditious plan of printing. The pattern is engraved upon the
surface of a hollow  cylinder of copper, or sometimes gun
metal, and the cylinder is forced by pressure upon a strong
iron mandrel, which serves as its turning shaft. To facilitate
the transfer of the impression from the engraving to the cotton
cloth, the latter is lapped round another large cylinder, rendered
elastic by rolls of woollen cloth, and the engraved cylinder
t,<\Wllo   presses the calico against this elastic cushion, and thereby prints
it as it revolves. Let A be the engraved cylinder mounted upon
its mandrel, which receives rotatory motion by wheels on its
_fC 8  _  end, connected with the steam  or water power of the factory.
-~>=~      / 3B is a large iron drum or roller, turning in bearings of the end
frames of the machine. Against that drum the engraved cylinder A is pressed by weights or screws; the weights acting steadily,
by levers, upon its brass bearings.  Round the drum B the endless web of felt or blanket stuff a a, travels in the direction of the arrow, being carried round along with the
drum B, which again is turned by the friction of contact with the cylinder A. c represents a clothed wooden roller, partly plunged into the thickened color of the trough ) D.
That roller is also made to bear, with a moderate force, against A, and thus receives, by
friction, in some cases, a movement of rotation. But it is preferable to drive the roller e
from the cylinder A, by means of a system of toothed wheels attached to their ends, so that
the surface speed of the wooden or paste roller shall be somewhat greater than that of
the printing cylinder, whereby the color will be rubbed, as it were, into the engraved
parts of the latter.
As the cylinder A is pressed upwards against B, it is obvious that the bearers of the
trough and its roller must be attached to the bearings of the cylinder A, in order to
preserve its contact with the color-roller c. b is a sharp-edged ruler of gun-metal or
steel, called the color doctor, screwed between two gun-metal stiffening bars; the edge
of which wiper is slightly pressed as a tangent upon the engraved roller A. This ruler
vibrates with a slow motion from side to side, or right to left, so as to exercise a delicate
shaving action upon the engraved surface, as this revolves in the direction of the arrow.
c is another similar sharp-edged ruler, called the lint doctor, whose office it is to remove
any fibres which may have come off the calico in the act of printing, and which, if left
on the engraved cylinder, would be apt to occupy some of the lines, or at least to prevent
the color from filling them all. This lint doctor is pressed very slightly upon the cylinder
A, and has no transverse motion.
What was stated with regard to the bearers of the color trough D, namely, that they
are connected, and moved up and down together with the bearings of the cylinder A, may
also be said of the bearers of the two doctors.
The working of this beautiful mechanism  may now be easily comprehended. The
web of calico, indicated in the figure by the letter d, is introduced or carried in along
with the blanket stuff a a, in the direction of the arrow, and is moved onward by the
pressure of the revolving cylinder A, so as to receive the impression of the pattern engraved on that cylinder.
Before proceeding to describe the more complex calico-machine which prints upon
cloth 3, 4, or 5 colors at one operation, by the rotation of so many cylinders, I shall
explain the modern methods of engraving the cylinder, which I am enabled to do by the
courtesy of Mr. Locket, of Manchester, an artist of great ingenuity in this department, who
politely allowed me to inspect the admirable apparatus and arrangements of his factory.
To engrave a copper cylinder 3 or 4 inches in diameter, and from 30 to 36 inches long,
with the multitude of minute figures which exist in many patterns, would be a very:aborious and expensive operation.  The happy invention made by Mr. Jacob Perkins,
m America, for transferring engravings from one surface to another by means of steel
roller dies, was with great judgment applied by Mr. Locket to calico-printing, so long
ago as the year 1808, before the first inventor came to Europe with the plan. The
pattern is first drawn upon a scale of about 3 inches square, so that this size of figure
being repeated a definite number of times, will cover the cylinder. This pattern is next
engraved in intaglio upon a roller of softened steel, about 1 inch in diameter, and 3 inches
long, so that it will exactly occupy its surface. The engraver aids his eye with a




CALICO-PRINTING.                                  313
lens, when employed at this delicate work. This roller is hardened by heating it to a
cherry-red in an iron case containing pounded bone-ash, and then plunging it into cold
water; its surface being protected from oxydizement by a chalky paste. This hardened
roller is put into a press of a peculiar construction, where, by a rotatory pressure, it trans
fers its design to a similar roller in the soft state; and as the former was in intaglio, th.
latter must be in relievo.  This second roller being hardened, and placed in an appro
priate volutory press, is employed to engrave by indentation upon the full-sized copper
cylinder the whole of its intended pattern. The first roller engraved by hand is called
the die; the second, obtained from it by a process like that of a milling tool, is called the
mill. By this indentation and multiplication system, an engraved cylinder may be had fol
seven pounds, which engraved by hand would cost fifty or upwards. The restoration of
a worn-out cylinder becomes extremely easy in this way; the mill being preserved, need
merely be properly rolled over the copper surface again.
At other times, the hard roller die is placed in the upper bed of a screw press, not unlike that for coining, while the horizontal bed below is made to move upon strong rollers
mounted in a rectangular iron frame. In the middle of that bed a smooth cake or flat
disc of very soft iron, about 1 inch thick, and 3 or 4 inches in diameter, is made fast
by four horizontal adjusting screws, that work in studs of the bed frame. The die being
now  brought down by a powerful screw, worked by toothed wheel-work, and made to
press with force upon the iron cake, the bed is moved backwards and forwards, causing
the roller to revolve on its axles by friction, and to impart its design to the cake. This
iron disc is now case-hardened by being ignited amidst horn shavings in a box, and then
suddenly quenched in water, when it becomes itself a die in relievo.  This disc die is
fixed in the upper part of a screw press with its engraved face downwards, yet so as to be
moveable horizontally by traverse screws. Beneath this inverted bed, sustained at its
upper surface by friction-rollers, a copper cylinder 30 inches long, or thereby, is mounted
horizontally upon a strong iron mandrel, furnished with toothed wheels at one of its
ends, to communicate to it a movement upon its axis through any aliquot arcs of the
circle.  The disc die being now brought down to bear upon the copper cylinder, this is
turned round through an arc corresponding in length to the length of the die; and thus,
by the steady downward pressure of the screw, combined with the revolution of the cylinder, the transfer of the engraving is made in intaglio. This is, I believe, the most convenient process for engraving, by transfer, the copper of a one-cylinder machine. But
when 2, 3, or 4 cylinders are to be engraved with the same pattern for a two, three, or
four-colored machine, the die and the mill roller plan of transfer is adopted. In this
case, the hardened roller die is mounted in the upper bed of the transfer press, in such a
way as to be capable of rotation round its axis, and a similar roller of softened steel
is similarly placed in the under bed. The rollers are now made to bear on each other by
the action of the upper screw, and while in hard contact, the lower one is caused to revolve, which, carrying round the upper by friction, receives from it the figured impression
in relief. When cylinders for a three-colored machine are wanted, three such mills are
made fac-similes of each other; and the prominent parts of the figure which belong to
the other two copper cylinders are filed off in each one respectively. Thus three differently figured mills are very readily formed, each adapted to engrave its particular figure
upon a distinct copper cylinder.
Some copper cylinders for peculiar styles are not graved by indentation, as just described, but etched by a diamond point, which is moved by mechanism in the most curious
variety of configurations, while the cylinder slowly revolves in a horizontal line beneath it.
The result is extremely beautiful, but it would require a very elaborate set of drawings to
represent the machinery by which Mr. Locket produces it. The copper is covered by a resist varnish while being heated by the transmission of steam through its axis. After being
etched, it is suspended horizontally by the ends, for about five minutes, in an oblong trough
charged with dilute nitric acid.
With regard to the two and three-colored machines, we must observe, that as the calico
in passing between the cylinders is stretched laterally from the central line of the web, the
figures engraved upon the cylinders must be proportionally shortened, in their lateral dimensions especially, for the first and second cylinder.
Cylinder printing, though a Scotch invention, has received its wonderful development in England, and does the greatest honor to this country.  The economy of
labor introduced by these machines is truly marvellous; one of them, under the
guidance of a man to regulate the rollers, and the service of a boy, to supply the
color troughs, being capable of printing as many pieces as nearly 200 men and boys
could do with blocks. The perfection of the engraving is most honorable to our
artisans. The French,with all their ingenuity and neat-handedness, can produce nothing
approaching in excellence to the engraved cylinders of Manchester,-a painful admission,
universally made to me by every eminent manufacturer in Alsace, whom I visited in my
late tour.




314                            CALICO-PRINTING.
Another modification of cylinder printing is that writh wooden rollers cut in relief; it
is called surface printing, probably because the thickened color is applied to a tense sur
face of woollen cloth, from which the roller takes it up by revolving in contact with the
cloth. When the copper cylinders and the wooden ones are combined in one apparatus.
it has got the appropriate name of the union printing machine.
In mounting three or more cylinders in one frame, many more adjustments become necessary than those described above. The first and most important is that which ensures
the correspondence between the parts of the figures in the successive printing rollers, for
unless those of the second and subsequent engraved cylinders be accurately inserted into
their respective places, a confused pattern would be produced upon the cloth as it advances round the pressure cylinder B, figs. 233, 234.
Each cylinder must have a forward adjustment in the direction of rotation round its
axis, so as to bring the patterns into correspondence with each other in the length of the
piece; and also a lateral or traverse adjustment in the line of its axis, to effect the correspondence of the figures across the piece; and thus, by both together, each cylinder may
be made to work symmetrically with its fellows.
Fig. 297 is a cross section of a four-color cylinder machine, by which the working
parts are clearly illustrated.
A A A is a part of the two strong iron frames or cheeks, in which the various rollers
are mounted. They are bound together by the rods and bolts a a a a.
B is the large iron pressure cylinder, which rests with its gudgeons in bearings or bushes, which can be shifted up and down in slots of the side cheeks A A. These bushes are
suspended from powerful screws b, which turn in brass nuts, made fast to the top of the
frame A, as is plainly shown in the figure. These screws serve to counteract the strong
pressure applied beneath that cylinder, by the engraved cylinders D E.
c D E F are the four printing cylinders, named in the order of their operation. They
consist of strong tubes of copper or gun-metal, forcibly thrust by a screw press upon the
iron mandrels, round which as shafts they revolve.
The first and last cylinder c and F are mounted in brass bearings, which may be shifted
in horizontal slots of the frame A. The pressure roller B, against whose surface they
bear with a very little obliquity downwards, may be nicely adjusted to that pressure by its
elevating and depressing screws. By this means c and F can be adjusted to B with geometrical precision, and made to press it in truly opposite directions.
The bearings of the cylinders D and E are lodged also in slots of the frame A, which
point obliquely upwards, towards the centre of B. The pressure of these two print cylinders c and F is produced by two screws c and d, which work in brass nuts, made fast
to the frame and very visible in the figure. The frame-work in which these bearings and
screws are placed, has a curvilinear form, in order to permit the cylinders to be readily
removed and replaced; and also to introduce a certain degree of elasticity. Hence the
pressure applied to the cylinders c and F, partakes of the nature of a spring; a circumstance essential to their working smoothly, on account of the occasional inequalities in the
thickness of the felt web and the calico.
The pressure upon the other two print cylinders D and E is produced by weights acting
with levers against the bearings. The bearings of D are, at each of their ends, acted
upon by cylindrical rods, which slide in long tubular bosses of the frame, and press with
their nuts g at their under end upon the small arms of two strong levers G, which lie on
each side of the machine, and whose fulcrum is at h (in the lower corner at the left hand).
The long arms of these levers G, are loaded with weights H, whereby they are made to
press up against the bearings of the roller D, with any degree of force, by screwing up
the nut g, and hanging on the requisite weights.
The manner in which the cylinder E is pressed up against B, is by a similar construction to that just described. With each of its bearings, there is connected by the link k,
a curved lever I, whose fulcrum or centre of motion is at the bolt 1. To the outer end
of this lever, a screw, m, is attached, which presses downwards upon the link n, connected with the small arm of the strong lever k, whose centre of motion is at o. By turning
therefore the screw m, the weight L, laid upon the end of the long arm of the lever K (of
which there is one upon each side of the machine), may be made to act or not at pleasure
upon the bearings of the cylinder E.
In tracing the operation of this exquisite printing machine, we shall begin with the
first engraved cylinder c. Its bearings or bushes shift, as was already stated, in slots of
the frame A. Each of them consists of a round piece of iron, to which the end of the
screw c is joined, in the same way as at d, in the opposite side. In each of these iron
bearings, a concave brass is inserted to support the collar of the shaft, and in a dovetailed slit of this brass, a sliding piece is fitted, upon which a set or adjusting screw in
the iron bearing acts, and which, being forced against the copper cylinder c, serves to
adjust the line of its axis, and to keep it steady between its bearings, and true in its
rotatory motion. Upon the iron bearing a plate is screwed, provided with two fliage.,
15




CALICO-PRINTING.                                  315
which support the color trough q, and the color roller M. This trough, as well as the
others to be mentioned presently, is made of sheet copper in the sides and bottom, and
297
alt 3  6 9 o            I           Ia       3
0                                  a
fixed upon a board; but its ends are made of plates of cast copper or gun-metal to serve
as bearings to the color roller M. The trough and its roller may be shifted both together
into contact with the printing cylinder c, by means of the screw r. Near s, seen above
the roller, c, and t below it, are sections of the two doctors, which keep the engraved
cylinders in sound working condition; the former being the colour doctor, and the latter
the lint doctor. Their ends lie in brasses, which may be adjusted by the screws X and v,
working in the respective brackets, which carry their brasses, and are made fast to the,;;                d dtl
iron bearings of the cylinder.
The pressure of the color doctor is produced by two weights w, (see high up on the
frame work,) which act on a pair of small levers x, (one on each side of the machine,)
and thus, by means of the chains, tend to lift the arms y, attached to the end axles of the
doctor. The pressure of the lint doctor upon the cylinder c, is performed by the screw
z, pressing upon an arm which projects downwards, and is attached to the axle of that
doctor.
The bearings of the second printing cylinder D, consist at each end of a mass of iron
(removed in the drawing to show the mechanism below it), which shifts in the slanting
slot of the frame A. In each of these masses there is another piece of iron, which slides
in the transverse direction, and may be shifted by the adjusting screw a' fixed to it, and
working in a nut cast upon the principal bearing above described. To the inner bearings, which carry the brasses in which the shaft lies, are screwed the two curved arms
bV V, to which are attached the bearings &c., for the color trough and the doctors. In
these brasses there are also dovetailed pieces, which slide and are pressed by set screws
furnished with square heads in the iron secondary bearings, which serve, as before said, to
adjust the printing cylinder in the line of its axis, while other screws adjust the distance
of the cloth upon which the second color is printed, and the line of contact with the
cylinder B.
N, is the color roller of D, and d' the color trough, which rests by its board upon the
lever e'; whose centres of motionf', are made fast to the curved arms b', fixed at the
A/          GF
fixed upon a board; but its ends are made of plates of east copper or gun-metal to serve
as bearings to the color roller M. The trough and its roller may be shifted both together
into contact with the printing cylinder c, by means of the screw r. Near s, seen above
the roller, c, and t below  it, are sections of the two doctors, which keep the engraved
cylinders in sound working condition; the former being the colour doctor, and the latter
the lint doctor. Their ends lie in brasses, which may be adjusted by the screws u and v,
working in the respective brackets, which carry their brasses, and are made fast to the
iron bearings of the cylinder.
The pressure of the color doctor is produced by two weights w, (see high up on the
frame work,) which act on a pair of small levers x, (one on each side of the machine,)
and thus, by means of the chains, tend to lift the arms y, attached to the end axles of' the
doctor. The pressure of the lint doctor upon the cylinder c, is performed by the screw:, pressing upon an arm whiqh projects downwards, and is attached to the axle of that
doctor.
The bearings of the second printing cylinder D, consist at each end of a mass of iron
(removed in the drawing to show the mechanism below it), which shifts in the slanting
slot of the frame A. In each of these masses there is another piece of iron, which slides
in the transverse direction, and may be shifted by the adjusting screw a' fixed to it, and
working in a nut cast upon the principal bearing above described. To the inner bearings, which carry the brasses in which the shaft lies, are screwed the two curved arms
b' b' to which are attached the bearings &e., for the color trough and the doctors. In
these brasses there are also dovetailed pieces, which slide and are pressed by set screws
furnished with square heads in the iron secondary bearings, which serve, as before said, to
adjust the printing cylinder in the line of its axis, while other screws adjust the distance
of the cloth upon which the second color is printed, and the line of contact with the
cylinder is.
x, is the color roller of D, and d' the color trough, which rests by its board upon the
lever e'j whose centres of motionf', are made fast to the curved arms bY, fixed at the




316                            CALICO-PRINTING.
bearings of the cylinder, and whose ends are suspended by screws g'; whereby the color
roller N, may be pressed with greater or less force to the cylinder D. h' and i' are the
two doctors of this cylinder; the former being the color, the latter the lint doctor.
They rest, as was said of the cylinder c, in brasses which are adjustable by means of
screws, that work in the studs or brackets by which the brasses are supported. These
brackets must of course be screwed to the secondary bearing-pieces, in order that they
may keep their position, into whatever direction the bearings may be shifted. k' and 1'
are these set screws for the color and lint doctors. The pressure of the former upon the
cylinder D, is produced by weights m', acting upon levers n', and pressing by rods or links
o', upon arms attached to each end of the axis of the doctar. (See the left hand side of
the figure near the bottom.) The lint-doctor i' is pressed in a similar way at the other
side upon the cylinder D, by the weights acting upon levers p', and by rods q' upon arms
fixed at each end of the axis of the doctor.
The bearings of the third printing cylinder E, are of exactly the same construction as
that above described, and therefore require no particular detail. The lint doctor s, is
here pressed upon the engraved cylinder by screws t', working in the ends of studs or
arms fixed upon each end of the axis of the doctor, and pressing upon flanges cast upon
the brackets in which the brasses of the doctor's axis lie, which are made fast to the bearings of the cylinder E.
The bearings of the fourth copper cylinder F, are also constructed in a similar way,
Each consists of a first bearing, to which is joined the end of the screw d, by which it
is made to slide in a slot of the frame. Another bearing, which contains the brass for
the shaft of the cylinder, can be shifted up and down in a transverse direction by a screw
z', of the second bearing, working in a nut cast upon the first bearing. To this secondary
bearing, plates are made fast by the screws v' v' to the inside, to carry the studs or
brackets of the doctors x' and y'. In the brasses of the cylinder shaft, dovetailed pieces
are made to slide, being pressed by set screws w', against the engraved cylinder F, similar
to what has been described for adjusting the cylinders to one another. This cylinder has
no separate color roller, nor trough, properly speaking, but the color doctor y' is made
concave to serve the purpose of a trough in supplying the engraved lines of the cylinder
with color. With this view the top plate of the doctor is curved to contain the colored
paste, and it is shut up at the ends by pieces of wood made to fit the curvature of the doctor.
Its pressure against the engraved surface is produced by weights a", acting at the ends
of arms b", attached to the ends of the axis of the doctor. The pressure of the lint
doctor x' is given by screws c", working in arms attached to the ends of the axis of the
doctor, and pressing upon the flanges d", cast upon the brackets which carry the brasses
for the axis of the doctor. These brasses are themselves adjustable, like those of all the
other cylinders, by set screws in the brackets, which work in the nuts formed in the
brasses.
e" e", is the endless web of felt stuff which goes round the cylinder B, and constitutes
the soft elastic surface upon which the printing cylinders c, D, E, and F exercise their
pressure. This endless felt is passed over a set of rollers at a certain distance from the
machine, to give opportunity for the drying up of any coloring paste which it may
have imbibed from the calico in the course of the impressions. In its return to the machine in the direction of the arrow, it is led over a guide roller o, which is thereby made
to revolve. Upon the two ends of this, and outside of the bearings which are fixed upon
the tops of the frame A, are two eccentrics, one of which serves to give a vibratory traverse movement to the color doctors s', h', and r' of the three cylinders, c, D, and E,
whilst the other causes the color doctor y' of the cylinder F, to make lateral vibrations.
Q is one of a pair of cast-iron brackets, screwed on at the back of the side-frames or
cheeks A A, to carry the roller filled with white calico a, ready for the printing operations.
Upon the end of the shaft whereon the calico is coiled, a pulley is fixed, over which a
rope passes suspending a weight in order to produce friction, and thereby resistance to
the action which tends to unwind the calico. In winding it upon that and similar
rollers, the calico is smoothed and expanded in breadth by being passed over one or
more grooved rods, or over a wooden bar s, fig. 298, the surface
of which is covered with wire, so as to have the appearance of a
united right and left-handed screw. By this device, the calico,
folded or creased at any part, is stretched laterally from  the
298      S             centre, and made level.  It then passes over the guide-roller
o, where it comes upon the surface of the felt e" e", and thence proceeds under its guidance to the series of printing cylinders.
Three and four-color machines, similar to the above, are now at work in many establishrents in Lancashire, which will turn off a piece of 28 yards per minute, each of
the three or four cylinders applying its peculiar part of the pattern to the cloth as it
passes along, by ceaseless rotation of the unwearied wheels. At this rate, the astonishing




CALICO-PRINTING                                  317
length of one mile of many-colored web is printed witn elegant flowers and other
figures in an hour. When we call to mind how much knowledge and skill are involved
in this process, we may fairly consider it as the greatest achievement of chemical and
mechanical science.
Before entering upon the different styles of work which constitute calico-printing, I
shall treat, in the first place, of what is common to them all, namely, the thickening of
the mordants and colors. This is an operation of the greatest importance towards the
successful practice of the art. Several circumstances may require the consistence of the
thickening to be varied; such as the nature of the mordant, its density, and its acidity.
A strong acid mordant cannot be easily thickened with starch; but it may be by roasted
starch, vulgarly called British gum, and by gum  arabic or senegal. Some mordants
which seem sufficiently inspissated with starch, liquefy in the course of a few days, and,
being apt to run in the printing-on, make blotted work. In France, this evil is readily
obviated by adding one ounce of spirits of wine to half a gallon of color-a remedy
which the English excise duties render too costly.
The very same mordant, when inspissated to different degrees, produces different tints
in the dye-copper-a difference due to the increased bulk from the thickening substance;
thus, the same mordant, thickened with starch, furnishes a darker shade than when
thickened with gum. Yet there are circumstances in which the latter is preferred, because it communicates more transparency to the dyes, and because, in spite of the wash.
ing, more or less of the starch always sticks to the mordant. The gum  has the
inconvenience, however, of drying too speedily, and of also increasing too much the
volume of the mordants; by both of which causes it obstructs their combination with the
stuff, and the tints become thin or scratchy.
The substances generally employed as thickeners are the following:1. Wheat starch.
2. Flour.
3. Roasted starch.
4. Gum senegal.
5. Gum tragacanth.
6. Salep.
7. Pipe-clay, mixed with gum senegal.
8. Sulphate of lead.
9. Sugar.
10. Molasses.
11. Glue.
After thickening with gum, we ought to avoid adding metallic solutions in the liquid
state; such as nitrate of iron, of copper, solutions of tin, of subacetate of lead, &c.;
as they possess the property of coagulating gum. I shall take care to specify the nature
and' proportion of thickening to be employed for each color; a most important matter,
hitherto neglected by English writers upon calico-printing.
The atmosphere of the printing shops should never be allowed to cool under 65~ or
70~ F.; and it should be heated by proper stoves in cold weather, but not rendered too
dry. The temperature and moisture should therefore both be regulated with the aid oi
thermometers and hydrometers, as they exercise a great influence upon all the printing
processes, and especially upon the combination of the mordant with the cloth. In the
course of the desiccation, a portion of the acetic acid evaporates with the water, and subacetates are formed, which combine with the stuff in proportion as the solvent principle
escapes; the water, as it evaporates, carries off acetic acid with it, and thereby aids the
fixation of bases. These remarks are peculiarly appropriate to delicate impressions by
the cylinder machine, where the printing and drying are both rapidly effected. In the
lapis lazuli style, the strong mordants are apt to produce patches, being thickened with
pipe-clay and gum, which obstruct the evaporation of the acids. They are therefore apt
to remain, and to dissolve a portion of the mordants at their immersion in the blue vat,
or at any rate in the dung bath. In such a case, a hot and humid air is indispensable,
after the application of the mordants, and sometimes the stuffs so impregnated must be
suspended in a damp chamber. To prevent the resist pastes becoming rapidly crusty,
substances apparently useless are mixed with them, but which act beneficially by their
hygrometric qualities, in retarding the desiccation. Oil also is sometimes added with
that view.
It is often observed that goods printed upon the same day, and with the same mordant,
exhibit inequalities in their tints. Sometimes the color is strong and decided in one
part of the piece, while it is dull and meager in another. The latter has been printed
in too dry an atmosphere. In such circumstances a neutral mordant answers best, especially if the goods be dried in a hot flue, through which humid vapors are in constant
circulation.
In padding, where the whole surface of the calico is imbued with mordant, the drying




318                           CALICO-PRINTING.
apartment mi flue, in which a great many pieces are exposed at once, should be so constructed as to afford a ready outlet to the aqueous and acid exhalations. The cloth ought
to be introduced into it in a distended state; because the acetic acid may accumulate in
the foldings, and dissolve out the earthy or metallic base of the mordant, causing white
and gray spots in such parts of the printed goods. Fans may be employed with great advantage, combined with HOT FLUES.  (See this article.)
In the color laboratory, all the decoctions requisite for the print work should be ready
prepared. They are best made by a steam heat, by means of copper boilers of a cylinr
dric form, rounded at the bottom, and incased within a cast-iron cylinder, the steam being
supplied to the space between the two vessels, and the dye-stuff and water being introduced into the interior one, which for some delicate purposes may be made of tin, or copper tinned inside. A range of such steam apparatus should be placed either along one of
the side walls, or in the middle line of the laboratory. Proper tables, drawers, vials,
with chemical reagents, measures, balances, &c., should also be provided. The most useful dye-extracts are the following:Decoction of logwood, of Brazil-wood, of Persian berries, of quercitron bark, of nut.
galls, of old fustic, of archil or cutbear, of cochineal, of cochineal with ammonia, of
catechu.
The following mordants should also be kept ready prepared:1. Aluminous mordant.
Take 50 gallons of boiling water.
100 lbs. of alum.
10 lbs. of soda crystals.
75 lbs. of acetate of lead.
The soda should be added slowly to the solution of the alum in the water, and when
the effervescence is finished, the pulverized acetate of lead is put in and well stirred about
till it be all dissolved and decomposed. During the cooling, the mixture should be raked
up a few times, and then allowed to settle. The supernatant liquor is the mordant; it has
a density of 11~ or 11' Baum6. It serves for reds and pinks, and enters into the composition of puce and lilach.
2. Aluminous mordant.
Take 50 gallons of water.
100 lbs. of alum.
10 lbs. of soda crystals.
100 lbs. of acetate of lead;-operate as above directed.
The supernatant liquor here has a density of 12' Baume; it is employed for lapis resists
or reserves, and the cylinder printing of madder reds.
3. Aluminous mordant.
Take 50 gallons of water.
100 lbs of alum.
6 lbs. of soda crystals.
50 lbs. of acetate of lead;-operate as above directed.
This mordant is employed for uniform yellow grounds.
4. Aluminous mordant.
This is made by adding potash to a solution of alum, till its earth begins to be separated, then boiling the mixture to precipitate the subsulphate of alumina, which is to be
strained upon a filter, and dissolved in acetic acid of moderate strength with the aid of
heat. This mordant is very rich in alumina, and marks 20~ B.
5. Aluminous mordant.
Take 121 gallons of water.
100 lbs. of alum.
150 lbs. of liquid pyrolignite of lime at 111~ Baume.
This mordant is made with heat like the first; after cooling, some alum crystallizes,
and it marks only 12-1 B.
A mordant is made by solution of alum in potash, commonly called6. Aluminate of potash. The caustic ley is prepared by boiling together for an hour
100 ga-ions of water, 200 lbs. of potash, and 80 lbs. of quicklime; the mixture is then
allowed to settle, the supernatant liquor is decanted, and evaporated till its density be 35~
B. In 30 gallons of that ley at a boiling heat, 100 lbs. of ground alum are to be dissolved.
On cooling, crystals of sulphate of potash separate. The clear liquor is to be decanted off,
and the crystals being washed with a little water, this is to be added to the ley. About
33 gallons of mordant should be obtained.
Mordant for Black.
The pyrolignite of iron, called iron liquor in this country, is the only mordant used in
calico-printing for black, violet, puce, and brown colors. The acetate of alumina, prepared from pyroligneous acid, is much used by the calico-printers under the name of red or
yellow liquor, being employed for these dyes.




CALICO-PRINTING.                                 319
We may observe that a strong mordant, like No. 2, does not keep so well as one of
mean density, such as No. 1. Too much mordant relatively to the demands of the works
should therefore not be made at a time.
There are eight different styles of calico-printing, each requiring different methods of
manipulation, and peculiar processes.
1. The madder style, to which the best chintses belong, in which the mordants are applied to the white cloth with many precautions, and the colors are afterwards brought up
in the dye-bath. These constitute permanent prints.
2. The padding orplaquage style, in which the whole surface of the calico is imbued with
a mordant, upon which afterwards different colored figures may be raised, by the topical
application of other mordants joined to the action of the dye-bath.
3. The reserve style, where the white cloth is impressed with figures in resist paste,
and is afterward subjected first to a cold dye, as the indigo vat, and then to a hot dye.
bath, with the effect of producing white or colored spots upon a blue ground.
4. The discharge or rongeant style, in which thickened acidulous matter, either pure or
mixed with mordants, is imprinted in certain points upon the cloth, which is afterwards
padded with a dark-colored mordant, and then dyed, with the effect of showing bright
figures on a darkish ground.
5. China blues; a style resembling blue stone-ware, which requires very peculiar
treatment.
6. The decoloring or enlevage style; by the topical application of chlorine or chromic
acid to dyed goods. This is sometimes called a discharge.
7. Steam colors; a style in which a mixture of dye extracts and mordants is topically applied to calico, while the chemical reaction which fixes the colors to the fibre is pro.
duced by steam.
8. Spirit colors; produced by a mixture of dye extracts, and solution of tin, vulgarly
called spirit by dyers. These colors are brilliant but fugitive.
I. The madder style; called by some dip colors. The true chints patterns belong to it;
they have from 5 to 7 colors, several of which are grounded-in after the first dye has
been given in the madder bath.
In dyeing with madder, sumach, fustic, or quercitron, is sometimes added to the bath,
in order to produce a variety of tints with the various mordants at one operation.
i. Suppose we wish to produce flowers or figures of any kind containing red, purple,
and black colors, we may apply the three mordants at once, by the three-color cylinder
machine, putting into the first trough acetate of alumina thickened; into the second, acetate of iron; and into the third, a mixture of the two; then drying in the air for a few
days to fix the iron, dunging and dyeing up in a bath of madder and sumach. If we wish
to procure the finest madder reds and pinks, besides the purple and black, we must apply
at first only the acetate of alumina of two densities, by two cylinders, dry, dung, and dye
up, in a madder bath. The mordants of iron liquor for the black, and of iron liquor
mixed with the aluminous for purple, must be now grounded-in by blocks, taking care to
insert these mordants into their precise spots: the goods being then dried with airing for
several days, and next dunged, are dyed up in a bath of madder and sumach. They must
be afterwards cleared by branning. See BRAN, DUNGING, and MADDER.
2. Suppose we wish to produce yellow with red, pink, purple, and black; in this case
the second dye-bath should contain quercitron or fustic, and the spots intended to be yellow should receive the acetate of alumina mordant.
3. The mordant for a full red may be acetate of alumina, of spec. grav. 1'055, thickened
with starch, and tinged with Brazil-wood; that for a pale red or pink, the same at spec.
gravity 1-014, thickened with gum; that for a middling red, the same at spec. gravity
1'027, thickened with British gum; and for distinction's sake, it may be tinged yellow
with Persian berries. The mordant for black is a pyroligneous acetate of iron, of specific
gravity 1'04; for purple the same, diluted with six times its volume of water; for
chocolate, that iron liquor mixed with acetate of alumina, in various proportions according to the shade wanted. Sumach is mixed with the madder for all these colors except for
the purple. The quantity of madder required varies according to the body of color to be
put upon the cloth, being from one pound per piece to three or even four. The goods
must be entered when the copper is cool, be gradually heated during two or three hours,
up to ebullition, and sometimes boiled for a quarter of an hour; the pieces being all the
while turned with a wince from the one side of the copper to the other.  (See WINCE.)
They are then washed and boiled in bran and water for ten or fifteen minutes. Whea
there is much white ground in the chints, they must be branned a second or even a third
time, with alternate washing in the dash-wheel. To complete the purification of the white,
they are spread upon the grass for a few days; or what is more expeditious, and equally
good if delicately managed, they are winced for a few minutes in a weak solution of
chloride of lime.
4. In the grounding-in for yellows after madder reds, the aluminous mordant being




820                           CALICO-PRINTING.
applied, &c., the piece is dyed, for about an hour, with one pound of quercitron bark,
the infusion being gradually heated to 150~ or 160~, but not higher.
5. A yellow is sometimes applied in chints work after the other colors are dyed, by
means of a decoction of Persian berries mixed with the aluminous mordant, thickened
with flour or gum, and printed-on with the block; the piece, when dry, is passed
through a weak carbonated alkaline water, or lime water, then washed and dried for
the market.
6. Black mordant.-Take half a gallon of acetate of iron, of spec. grav. 1'04, 4 ounces
of starch, and 4 ounces of flour. The starch must first be moistened with the acetate,
then the flour must be added, the rest of the acetate well mixed with both, and the
whole made to boil over a brisk fire for five minutes, stirring meanwhile to prevent adhesion to the bottom of the pot. The color must be poured into an earthen pipkin, and
well mixed with half an ounce of gallipoli oil. In general, all the mordants, thickened
with starch and flour, must be boiled for a few minutes. With British gum or common
gum, they must be heated to 160~ F., or thereby, for the purpose merely of dissolving
them. The latter should be passed through a sieve to separate the impurities often
present in common gum.
7. Puce mordant.-Take a quart of acetate of alumina and acetate of iron, each of
spec. grav. 1-04, mixed and thickened like the black, No. 6. To give the puce a reddish
tinge, the acetate of alumina should have a specific gravity of 1'048, and the iron liquor
only 1-007.
Red mordants are thickened with British gum, and are sufficiently colored with the
addition of any tinging decoction.
8. Violet mordants.-These consist either of a very weak solution of acetate of iron,
of specific gravity 1-007, for example; or of a little of the stronger acetate of 1'04,
mixed with acetate of alumina, and a little acetate of copper, thickened with starch or
British gum. The shades may be indefinitely varied by varying the proportions of the
acetates.
When black is one of the colors wanted, its mordant is very commonly printed-on
first, and the goods are then hung upon poles in the drying-room, where they are aired
for a few days, in order to fix the iron by its peroxydizement; the mordants for red,
violet, &c., are then grounded in, and the pieces are dyed up, after dunging and
washing, in the madder bath, into which, for certain shades, sumach, galls, or fustic is
added. The goods are brightened with a boil in soap water; occasionally also in a
bath, containing a small quantity of solution of tin or common salt. The following
mode of brightening is much extolled by the French, who are famous for their reds
and roses.
1. A soap boil of forty minutes, at the rate of 1 pound for every 2 pieces. Rinse in
clear water.
2. Pass through chloride of soda solution of such strength that two parts of it decolor
one part of Gay Lussac's test liquor. See CHLORIDE OF LIME and INDIGo. Wince the
pieces through it for 40 minutes. Rinse again.
2. Pass it agaLn through the soap bath, No. 1.
4. Brighten it in a large bath of boiling water, containing 4 pounds of soap, and
I pound of a cream-consistenced salt of tin, containing nearly half its weight of the
muriate of tin, combined with as much nitric acid of spec. gray. 1'288. This strong
nitro-muriate having been diluted with a little water, is to be slowly poured into the bath
of soap water, and well r ixed by stirring. The pieces are now put in, and winced
through it for one half or t'rne quarters of an hour.
5. Repeat the soap boil, No. 1. Rinse and dry.
9. Grounding-in of Indigo blue.
Take half a gallon of water of 120~ F., 8 ounces of ground indigo, and 8 ounces
of red sulphuret of arsenic (orpiment), 8 ounces of quicklime, mix together, and heat
the mixture to the boiling point; withdraw from the fire, and add, when it is lukewarm,
6 ounces of carbonate of soda, stir and leave the whole at rest till the next day. Then
decant the clear liquor, and thicken every quart of it with half a pound of gum. This
color ought to be green, and be preserved in a close vessel. When used, it is put into a
pot with a narrow orifice, the pencil is dipped into it, wiped on the edge of the pot, and
immediately applied by hand. This plan is tedious, and is nearly superseded by the following grounding blue.
Take half a gallon of caustic soda ley of spec. gray. 1-15, heated to 120~ F.
12 ounces of hydrate of protoxyde of tin, obtained by precipitating it from the muriate
of tin by solution of potash.
8 ounces of ground indigo; heat these mixed ingredients   ththe boiling point, then
move the pot off and on the fire two or three times in succession, and finally thicken
with 3 pounds of raw sugar. In order to apply this by the block, the following apparatus is employed, called the canvass frame; figs. 299, 300. It is formed of a copper




CALICO-PRINTING.                                321
-~~\    299                             300
CK a2
case or box A, in which is laid a frame B, filled with pretty stout canvass  The box
communicates by a tube with the cistern c, mounted with a stop-cock D. Fig. 300
represents the apparatus in plan: A, the box; B, the canvass, with its edges a a a a,
fixed by pin points to the sides. The color is teared (tire), or spread even, with a
wooden scraper as broad as the canvass. In working with this apparatus, the color
being contained in the vessel c is drawn off into the case A, by opening the stop-cock D,
till it rises to the level of the canvass. The instant before the printer daubs the block
upon the canvass, the tearer (tireur), boy or girl, runs the scraper across it to renew its
surface; and the printer immediately transfers the color to the cloth. In this kind of
printing great skill is required to give evenly impressions. As the blue is usually applied
to somewhat large designs, it is very apt to run; an inconvenience counteracted by dusting fine dry sand upon the cloth as soon as it is blocked. The goods must be washed
within 24 hours after being printed.
10. Topical grounding blue for the cylinder press.
Take 31 gallons of caustic soda ley of spec. gray. 1 15.
3o lbs. of ground indigo.
5 lbs. of precipitated protoxyde of tin (as above).
Boil the mixed ingredients for ten minutes, take them from the fire, and add, first,
3 lbs. of Venice turpentine; then 11 lbs. of gum.
Put this mixture into the color trough, print with it, and after two days wash in the
dash-wheel; then pass it through a soap-bath, along with a little soda, to brighten the
blue, and to take off its grayish tint.
The use of the turpentine is easily explained; it serves to exclude the atmospherical
oxygen, and prevent the regeneration of the indigo blue, before it is spread upon the
cloth.
After the application to white calico of a similar blue, into which a little acid muriate
of tin has been put, the goods are dipped for ten minutes in thin milk of lime, shaking
the frame all the time. They are then washed, and cleared with a soap boil. The following color remains long in the deoxydized state fiom its containing 8 ounces of indigo,
10 ounces of hydrated protoxyde of tin, and 1  pounds of solution of muriate of tin, to 2
quarts of soda ley of 1'15, thickened with 2- pounds of gum. This blue may be applied
by either the block or the cylinder.
11. Topical Prussian blue for grounding.
2 quarts of water with 8 ounces of starch are to be mixed and boiled; add 21 ounces
of a liquid Prussian blue color, prepared by triturating three quarters of an ounce of that
pigment with as much muriatic acid, leaving the ingredients to react upon each other for
24 hours, and then adding three quarters of an ounce of water.
Adl 4 ounces of liquid perchloride of tin (oxymuriate).
Mix all together, and pass through a searce. This color is not very fast; cloth printed
with it will bear only rinsing.
12. Prussian blue figures are impressed as follows:Dissolve 8 ounces of sulphate of iron, and as much acetate of lead, separately in 2
quarts of boiling water; mix well, and settle. Take one quart of this clear liquor reduced to spec. grav. 1-02, one quart of mucilage containing 3 pounds of gum, colored with
a little prussiate of potash, mix into a mordant, and print it on with the cylinder. Two
days afterwards wash in tepid water containing a little chalk, and then pass the cloth
through a solution of prussiate of potash in water, sharpened with a little muriatic acid,
till it takes the desired hue. Finally rinse.
II. The padding or plaquage style, calledfoulard also by the French. See PADDING.
Any mordant whatever, such as the acetates of alumina, or of iron, or their mixture,
may be applied to the piece by the padding machine, after which it is dried in the HOT
PLUE, washed, dunged, dyed, washed, and brightened.
Colors from metallic oxydes are very elegantly applied by the padding process. Thus
Aie iron buff, the manganese bronze, and the chrome yellows and greens are given.
1. Iron buff or chamois.
Take 50 gallons of boiling water;
150 pounds of sulphate of iron; dissolve along with
10 pounds of alum; which partly saturate by the gradual addition of
5 pounds of crystals of soda; and in this mixture dissolve




322                          CALICO-PRINTING.
50 pounds of pyroligneous acetate of lead. Allow the whole to settle, and draw off the
clear supernatant liquid.
For furniture prints this bath should have the spec. grav. 1'07.
The calico being padded in it, is to be dried in the hot-flue; and after 48 hours suspension is to be washed in water at 170~ containing some chalk, by the wince apparatus. It
is then washed, by the same apparatus, in hot water, containing a pailful of soda ley of
sPe'. grav. 1'04.
For light tints the padding liquor should be reduced to the spec. grav. 1'01. The
dye in either case may be brightened by wincing through a weak solution of chloride of
lime.
Nitrate of iron diffused through a body of water may be also used for padding, with
alternate washings in water, and a final wincing in a weak alkaline ley.
With a stronger solution, similar to the first, the boot-top color is given.
2. The bronze or solitaire.
The goods are to be padded in a solution of the sulphate or muriate of manganese, of
a strength proportional to the shade desired, dried in the hot-flue, and then raised by
wincing them in a boiling-hot caustic ley, of spec. grav. 1'08, and next through a weak
solution of chloride of lime, or soda. They are afterwards rinsed. Instead of passing
them through the chloride, they may be merely exposed to the air till.he manganese attracts oxygen, then rinsed and dried.
When the manganese solution has the density of 1'027, it gives a light shade; at the
density of 1.06, a shade of moderate depth, and at 1'12 a dark tint.
The texture of the stuff is apt to be injured during the oxydation of the manganese.
3. Carmelite is obtained by padding in a mixture of muriate or sulphate of manganese
and acetate of iron, then proceeding as above.
4. Copper green is given by padding in a mixed solution of sulphate and acetate of
copper with a little glue, drying in the hot-flue, and next day padding in a caustic ley of
spec. grav. 1'05. The goods are then rinsed, and padded through a solution made with 8
ounces of arsenious acid combined with 4 ounces of potash diluted wfth 2 gallons of water. They are finally rinsed and dried.
5. Olive and cinnamon colors are given by padding through mixed solutions of the
acetate of iron and sulphate of copper; drying, and padding in a caustic ley of spec
grav. 1 05.
6. Green and solitaire form a pleasing umber, or hellebore shade, which may be obtained by padding through a mixed solution of manganese and aceto-sulphate of copper.
and raising the shades as above prescribed.
7. Chrome yellow.
Pad in a solution of bichromate of potash containing 8 ounces of it to the gallon of water; then dry with moderate heat, and pad in a solution of acetate or nitrate of lead, containing 6 or 8 ounces in the gallon of water; wash, and dry. Or we may pad first in a
solution of acetate of lead containing a little glue; dry, and pad in solution of bichromate of potash. Then rinse. The last process is apt to occasion cloudiness. To obtain
a light lemon tint, we must pad in a solution of acetate of lead of double the above
strength, or 16 ounces to the gallon, then wince the pieces through weak milk of lime,
rinse, pad through bichromate of potash, rinse and dry.
8. Chrome orange.
Pad through a mixed solution of the subacetate and acetate of lead, three times in sue
cession, and dry in the hot-flue; then wince for ten minutes through weak milk of lime;
rinse; wince for a quarter of an hour in a warm solution of bichromate of potash; and
finally raise the color by wincing the goods through hot lime-water.
9. Prussian blue.
Pad in the preceding chamois liquor of the spec. grav. 1'007; dry in the hot-flue;
wince well in chalky water at 160~ F., and then dye by wincing in the following
liquor:Dissolve 5 ounces of prussiate of potash, in 25 gallons of water heated to 90~ or 100~,
adding 2 ounces of sulphuric acid; afterwards rinse, and brighten in a very dilute sulphuric acid.
10. Green is given by padding goods, previously dyed in the indigo vat, in a solution of
acetate of lead containing a little glue; and then padding them in a warm solution of
bichromate of potash; finally rinsing and drying.
III. Resist pastes or reserves; these are subservient to the cold indigo vat, and they
may be distributed under four heads; 1. fat reserves; 2. reserves with bases of metallic
salts; 3. colored reserves capable of assuming different tints in the dyeing; 4. reserves
with mordants, for the cloth to be afterwards subjected to a dyeing bath, whereby variously
colored figures are brought up on a blue ground, so as to resemble the mineral called
lazulite; whence the name lapis or lapis lazuli.
1. The fatty resists are employed in the printing of silk; which see infra.




CALICO-PRINTING.                                  323
2. With regard to reserves the following general observations may be made. After
printing-on the paste, the goods must be hung up in a chamber, rather humid than too dry,
and left there for a certain time, more or less, according to the nature of the reserve. In
dipping them into the blue vat, if the reserve be too dry, it is apt to swell, scale off, and
vitiate the pattern. This accident is liable to happen also when the vat is deficient in
lime, especially with deep blues.
1. Simple white resist paste for a full body of blue.
Take 1 gallon of water, in which are to be dissolved,
1 pound of binacetate of copper (distilled verdigris), and 3 lbs. of sulphate ot
copper.
This solution is to be thickened with
2 lbs. of gum senegal, 1 lb. of British gum, and 4 lbs. of pipe-clay; adding after,
wards, 2 ounces of nitrate of copper-as a deliquescent substance.
2. White reserve for light blues.
Take 1 gallon of water, in which dissolve
4 ounces of binacetate of copper,
1 lb. of sulphate of copper; and thicken this solution with
2 lbs. of gum senegal, 1 lb. of British gum, and 4 lbs. of pipe-clay.
3. White reserve for the cylinder machine.
Take 1  gallons of water; in which dissolve
24 lbs. of binacetate of copper,
10 lbs. of sulphate of copper; and add to the solution
6 lbs. of acetate of lead; then thicken with
10 lbs. of gum; adding afterwards 10 lbs. of sulphate of lead,
After printing-on this reserve, the goods are to be hung up for two days, then dipped
till the proper blue tint be obtained. Finally they must be winced through dilute sulphuric acid to clear up the white, by removing the cupreous tinge.
3. Colored reserves.
1. Chamois reserve.
Take 1 gallon of the chamois bath (No. 1, page 232, at bottom); to which add
8 ounces of nitrate of copper,
24 ditto of muriate of zinc; thicken with
6 pounds of pipe-clay, and 3 pounds of gum senegal.
After printing-on this paste, the goods must be hung up for five or-six days in a somewhat damp room. Then after having dipped them in the vat, they are to be steeped in
water for half an hour, and slightly washed. Next wince for half an hour, through water
at 100~ F. containing 2 pounds of soda crystals per 30 gallons. Rinse and dry.
2. Chrome yellow reserve.
Take 1 gallon of water; in which dissolve
3 lbs. of nitrate of lead,
1 lb. of binacetate of copper; to the solution, add
1 lb. of subacetate of lead; and thicken the mixed solution with
3 lbs. of gum.
6 lbs. of pipe-clay. Grind all the ingredients together, and pass through a searce.
After treating the goods as in No. 1, they must be winced for half an hour in a solution
containing 5 ounces of bichromate of potash, per piece of calico, and also in a dilute
muriatic bath, till the chrome yellow becomes sufficiently bright.
A chrome orange reserve may be made by introducing a larger proportion of subacetate
of lead, and passing the reserve printed goods through weak milk of lime, as already prescribed for producing an orange by chrome.
The basis of the resist pastes used at Manchester is sometimes of more complex composition than the above; since, according to the private information I received from an
extensive calico printer, they contain china clay (instead of pipe-clay, which often contains iron), strong solution of sulphate of copper, oil, tallow, and soap; the whole incorporated by trituration with heat.
In the Lancashire print-works, a little tartaric acid is added to the nitrate of lead,
which prevents the color from taking a dingy cast.
4. Reserves with mordants, or the lazulite style.
1. Black upon a blue ground.
At Manchester the black pattern is printed-on with a mixture of iron liquor and extract
of logwood, and the resist paste by the cylinder machine; in France the black is given
by the following recipe:Take 1 gallon of decoction of galls of spec. grav. 104, mixed and boiled into a paste with
14 ounces of flour; into the paste, when nearly cold, there are added,
8 ounces of an acetated peroxyde of iron, made by adding 1 lb. acetate of lead to 3
lbs. of nitrate of iron, spec. grav. 1*56.
3 ounce of gallipoli oil.




324                        CALICO-PRINTING.
This topical black forms a fast color, and resists the fine blue vat, weak potash ley,
bichromate of potash, boiling milk of lime, dunging, and maddering.
The preceding answers best for the block; the following for the cylinder,2. Take 1 gallon decoction of galls of spec. gray. 1'056.
18 ounces of flour, mix, boil into a paste, to which, when cool, add
8 ounces of the aceto-nitrate ofiron of the preceding formula, and
1 quart of iron liquor of spec. grav. 1-110.
In Lancashire a little prussiate of potash is sometimes added to nitrate of iron and
decoction of logwood; and the goods are after washing, &c. finished by passing through
a weak solution of bichromate of potash. The chromic acid gives depth and permanence
to the black dye, being supposed to impart oxygen to the iron, while it does not affect
any of the other colors that may happen to be impressed upon the cloth, as solution of
chloride of lime would be apt to do. The solution of the bichromate deepens the spirit
purples into blacks, and therefore with such delicate dyes becomes a very valuable application.  This interesting fact was communicated to me by an eminent calico-printer in
Lancashire.
Having premised the composition of the topical black dye, we are now prepared to
apply it in the lazulite style.
1. Black resist.
Take 1 gallon of the above black without the flour,
2 ounces of sulphate of copper,
1 ounce of muriate of ammonia, dissolve and thicken with
4 pounds of pipe-clay and 2 pounds of gum.
Another good formula is the following:Take 1 gallon of iron liquor of 1 056 spec. grav.; dissolve in it,
2 ounces of binacetate of copper,
8 ounces of sulphate of copper; and thicken as just described.
2. Puce reserve paste, contains acetate of alumina mixed with the iron liquor.
3. Full red reserve.
Take 1 gallon of acetate of alumina, (made with 50 gallons water, 100 lbs. alum, 10 lbs.
soda crystals, and 100 lbs. acetate of lead; the supernatant liquid being of spec.
grav. 1'085;) dissolve in it
4 ounces of corrosive sublimate; thicken with
2 pounds of gum senegal,
4 pounds of pipe-clay, and mix in 8 ounces of gallipoli oil.
4. Reserve pastefor a light red.
Take 1 gallon of the weaker sulpho-acetate of alumina formerly prescribed; dissolve in it
4 ounces of corrosive sublimate; and thicken with
4 pounds of pipe-clay, and 2 pounds of gum; adding to the mixture
8 ounces of oil.
5. Neutral resist paste.
Take 1 gallon of water; in which dissolve,
34 lbs. of binarseniate of potash, and
12 ounces of corrosive sublimate; thicken with
3 lbs. of gum, and 6 lbs. of pipe-clay, adding to the paste 16 ounces of oil.
6. Carmelite reserve paste.
Take 1 half gallon of acetate of alumina, spec. grav. 1'014; (see second aluminous mordant, p. 230.)
1 half gallon iron liquor of spec. grav. 1-027; dissolve in them
4 ounces of sulphate of copper, 4 ounces of verdigris, and 1 ounce of nitrate of copper; thicken with
2 lbs. of gum,
4 lbs. of pipe-clay.
7. Neutral reserve paste.
Take 1 gallon of water; dissolve in it,
44 ounces of binarseniate of potash, and
12 ounces of corrosive sublimate; thicken with
3 lbs. of gum,
6 lbs. of pipe-clay,
16 oz. of oil.
To explain fully the manipulation of the lazulite style, we shall suppose that the feb
coes are printed with the following reserves, taken in their order:1. Black reserve,    No. 1. above.
2. Full red reserve,  No. 3.
3. Light red reserve, No. 4.
4. Neutral reserve,   No. 7.
Four days after printing-on these reserves, the goods must be twice dipped in the blue




CALICO-PRINTIN..                                325
vat, ten minutes in and ten minutes out each time; but more dips may be given accord.
ing to the desired depth of the shade. The cloth must be afterwards rinsed in running
water for half an hour. The next process is to remove the paste; which is done by wincing the goods in a bran bath, lowered to 150~, during twenty minutes. They are then
winced for five minutes in a bath of water slightly sharpened with vinegar. When well
cleansed they are ready for the madder bath. The lapis goods are finally cleared in a
bran bath, by exposure on the grass, and a soap boil.
The lazulite style is susceptible of many modifications.
8. Deep blue ground, with light blue, carmelite, and white figures.
1. Print-on the white reserve, No. 1.
2. Dip in the strongest blue vat; rinse and dry.
3. Ground-in with the block, the carmelite reserve (containing the mixed acetates
of iron and alumina.)
4. Ground-in the neutral reserve.
a. Dip for the light blue; rinse.
6. Dung, dye, and clear, as above.
By varying the proportions of the reserve mordants, and the dye-stuffs, as madder,
quercitron, &c. a great variety of effects may be produced.
9. Deep green ground, with buff and white figures.
1. Print-on the white reserve.
2. Dip in the blue vat; rinse and dry.
3. Pad in the buff liquor, as formerly prescribed.
4. Ground in upon the buff spots, the discharge No. 2, presently to be described.
5. Wash away the paste in chalky water.
6. Wince through a boiling alkaline ley, to raise the buff iron color.
IV. The Discharge style; first, of simple discharges.
1. Discharge for block printing.
Take 1 gallon of lemon or lime-juice, of spec. grav. 1-09, in which dissolve
1 pound of tartaric acid,
1 pound of oxalic acid, and thicken the solution with
4 pounds of pipe or china clay, and 2 pounds of pulverized gum; as soon as the
gum is dissolved, the mixture must be put through a searce.
2. Another discharge is made of half the above acid strength.
3. A third with one half of the solid acids of the second.
4. Take 1 gallon of water, in which dissolve with heat
I pound of cream of tartar, adding, to facilitate the solution,
I pound of warm sulphuric acid of spec. grav. 1*7674; after 24 hours mix
4 lbs. of pipe or China clay, and three lbs. of gum, with the decanted clear liquoi.
In some cases British gum is used alone, as a thickener.
5. Discharge for the cylinder machine.
Take 1 gallon of lime-juice, of spec. grav. 1'085; dissolve in it
3 pounds of tartaric acid, and one pound of oxalic acid; thicken with
6 pounds of gum senegal, or 5 pounds of British gum.
6, 7. A stronger and weaker discharge is made of the same materials; and one is made
without the tartaric acid.
Second; combination of discharges with mordants.
1. Black, red, lilach, and white figures upon an olive ground.
The olive being given in a madder bath, and the ground well whitened (see MADDER),
the cloth is padded in a weak buff mordant; and upon the parts that are to remain white,
the weakest simple discharge No. 3 is printed-on by the cylinder; (in some works the discharge paste is applied and made dry before padding through the iron liquor;) the goods
are cleared of the paste in a tepid chalky water, then dyed in a quercitron bath, containing a little glue, and cleared in a bran bath.
Discharge mordants upon mordants may be regarded as a beautiful modification of the
preceding style. Example..d violet ground or impression, with red and white.
1. Pad with an acetate of iron of 1'004; or print-on with the cylinder, iron liquor of
1'027 thickened with British gum.
2. Print-on a red mordant, strongly acidulated with lime-juice of 1'226.
3. Ground in the discharge No. 2; dry.
4. Clear off the paste in chalky water.
5. Dung, madder, and brighten.
6. Ground-in the topical colors at pleasure.
V. China blues.
Take 16 pounds of coarsely ground indigo, and
4 pounds of sulphuret of arsenic; dissolve 22 pounds of sulphate of iron in 6
gallons of water; introduce these three matters into the indigo mill, and grind them for




326                          CALICO-PRINTING.
three days. If it be wished to have a thickened blue, this mixture must have pounde
gum added to it; but if not, 5 gallons of water are added. This color may be called
blue No. 1.
The following table exhibits the different gradations of China blue:Course.      Quantity by measure of Quantity by measure of
Course.    No. 1.         water or mucilage.
No.1                    1                  0
2                 11                    1
3                 10                   2
4                  8                   4
5                  6                   6
6                  4                   8
7                  2                  10
8                  2                  12
9                  2                  14
10                  2                  16
11                  2                  18
12                  2                  20
I shall now give examples of working this style by the block and cylinder:Impression of a single blue with small dots.
For the block, blue No. 5, thickened with starch.
For the cylinder, No. 4, thickened with gum.
Impression of two different blues with the block.
First blue, No. 4, with starch.
Second blue, No. 9, with gum.
Impression of three blues with the block.
First blue, No. 5, with starch.
Second blue, No. 7, with starch.
Third blue, No. 10, with gum.
After printing-on the blues, the pieces are hung up for two days, in a dry and airy
place, but not too dry; then they are dipped as follows:-Three vats are mounted, which
may be distinguished by the numbers 1, 2, 3.
No. 1. 300 pounds of lime to 1,800 gallons of water.
No. 2. Solution of sulphate of iron of spec. grav. 1-048.
3. Solution of caustic soda of spec. grav. 1'055; made from soda crystals, quicklime,
and water, as usual.
The pieces being suspended on the frames, are to be dipped in the first vat, and left
in it ten minutes; then withdrawn, drained for five minutes; next plunged into the
second vat for ten minutes, and drained also for five, &c. These operations will be
most intelligible when put into the form of a table:Dip in the 1st vat.   During 10 minutes.    Drain during 5 minutes.
2
1                 -
3                 -
2
1                 -
2                 -
1                -_
3                 - 
In the dipping of China blues, care should be taken to swing the frames during the
operation; and when the last dip is given, the piece is to be plunged upon its frame into
a fourth vat, containing dilute sulphuric acid of spec. grav. 1'027. This immersion is
for the purpose of removing the oxyde of iron, deposited upon the calico in the alternate
passages through the sulphate of iron and lime vats. They are then rinsed an hour in
running water, and finally brightened in the above dilute sulphuric acid, slightly tepid.
Sometimes they are subjected to a soap bath, at the temperature of 120~. By the
addition of nitrate of lead to the indigo vat, the blue becomes more lively. Some use
the roller dyeing apparatus for running the pieces through the respective baths instead
of the square frames. (See WINCING.) But the frame-dip gives the most evenly dyes,
and preserves the vats in good condition for a much longer time.




CALICO-PRINTINGZ                                327
The various phenomena which occur in the dipping of China blues are not difficult of
explanation with the lights of modern chemistry. We have, on the one hand, indigo
and sulphate of iron alternately applied to the cloth; by dipping it into the lime, the
blue is deoxydized, because a film of the sulphate of iron is decomposed, and protoxyde
of iron comes forth to seize the oxygen of the indigo, to make it yellow-green, and
soluble, at the same time, in lime-water. Then, it penetrates into the heart of the
fibres, and, on exposure to air, absorbs oxygen, so as to become insoluble and fixed
within their pores. On dipping the calico into the second vat of sulphate of iron, a
layer of oxyde is formed upon its whole surface, which oxyde exercises an action only
upon those parts that are covered with indigo, and deoxydizes a portion of it; thus
rendering a second dose soluble by the intervention of the second dip in the lime-bath.
Hence we see that while these alternate transitions go on, the same series of deoxydizement, solution, and re-oxydizement recurs; causing a progressively increasing fixation
of indigo within the fibres of the cotton. A deposite of sulphate of lime and oxyde of
iron necessarily falls upon the cloth, for which reason the frame should be-shaken in tLe
lime-water vat, to detach the sulphate; but, on the contrary, it should be held motionless
in the copperas bath, to favor the deposition of as much protoxyde upon it as possible.
These circumstances serve to account for the various accidents which sometimes befall
the China blue process. Thus the blues sometimes scale off, which may proceed from one
of two causes:-1. If the goods are too dry before being dipped, the color swells, and
comes off in the vats, carrying along with it more or less of indigo. 2. If the quantity
of sulphate of lime formed upon the cloth be considerable, the crust will fall off, and
take with it more or less of the blue; whence arise inequalities in the impression. The
influence of temperature is important; when it falls too low, the colors take a gray cast.
In this case it should be raised with steam.
VI. The decoloring or enlevage style; not by the removal of the mordant, but the
destruction of the dye. The acid, which is here mixed with the discharge paste, is
intended to combine with the base of the chloride, and set the chlorine free to act upon
the color. Among the topical colors for this style are the following:1. Black.-Take one gallon of iron liquor of spec. grav. 1-086.
One pound of starch; boil together, and while the paste is hot, dissolve in it
One pound of tartaric acid in powder; and when cold, add
Two pounds of Prussian blue, prepared with muriatic acid, see p. 232.
Two ounces of lamp black, with four ounces of oil.
2. White discharge.-Take one gallon of water, in which dissolve
One pound and a half of oxalic acid,
Three pounds of tartaric acid; add
One gallon of lime-juice of spec. grav. 1*22; and thicken with
Twelve pounds of pipe clay, and six pounds of gum.
3. Clh >me-green discharge.Take one gallon of water, thicken with 18 ounces of starch;
boil and dissolve in the hot paste;
Two pounds and a half of powdered nitrate of lead,
One pound and a half of tartaric acid,
Two pounds of Prussian blue, as above.
4. Blue discharge.-Take one gallon of water, thicken with
18 ounces of gum; while the boiled paste is hot, dissolve in it
Two pounds of tartaric acid, and mix one pound of Prussian blue.
5. Chrome-yellow discharge.-This is the same as the chrome-green given above, but
without the Prussian blue.
6. d white discharge on a blue ground requires the above white discharge to be strengtl
ened with 8 ounces of strong sulphuric acid, per gallon.
7. White discharge for Turkey red needs to be very strong.
Take one gallon of lime-juice of sp. grav. 1'086; dissolve in it
Five pounds of tartaric acid; thicken with
Eight pounds of pipe-clay, four pounds of gum; then dissolve in the mixture
Three pounds of muriate of tin in crystals; and add, finally,
Twenty-four ounces of sulphuric acid.
8. Yellow discharge for Turkey red.Take one gallon of lime-juice of spec. grav. 1P086; in which dissolve
Four pounds of tartaric acid,
Four pounds of nitrate of lead; thicken the solution with
Six pounds of pipe-clay, and three pounds of gum.
Y. For green discharge, add to the preceding 24 ounces of Prussian Nue, as above.
The decoloring or chlorine bath is usualiy formed of wood lined with lead, and
has an area of about 5 feet square, with a depth of 6 feet. A square frame, mounted
with a hcrizontal series of rollers at top and bottom, may be let down by cords, at




328                         CALICO-PRINTING.
pleaslue, into the cistern. The pieces are introduced and guided in a serpentine path,
round the upper and lower rollers alternately, by a cord.
This bath is filled with a solution of chloride of lime, of the spec. grav. 1*045, whose
decoloring strength is 65~ by Gay Lussac's indigo chlorometer. It ought to be made
turbid by stirring before putting in the goods, which should occupy three minutes in
their passage. The piece is drawn through by a pair of squeezer cylinders at the end of
the trough, opposite to that at which the piece enters. With black, white, and blue
impressions of all shades, the goods are floated in a stream of water for an hour; then
rinsed and dried. When there is yellow or green, the pieces must be steeped in water,
then merely washed by the wince, and passed through solution of bichromate of potash,
containing from 3 to 5 ounces of the salt per piece. Here the pieces are winced during
15 or 20 minutes, rinsed, and next passed through dilute muriatic acid to clear the
ground; then rinsed and dried.
Discharge by the intervention of the chromic acid.
After having dipped the pieces to the desired shade, they are padded in a solution of
bichromate of potash; dried in the shade without heat; and then printed with the
following mordant:Take I gallon of water; dissolve in it
2 pounds of oxalic and I pound of tartaric acid; thicken with
6 pounds of pipe-clay, and 3 pounds of gum; lastly, add
8 ounces of muriatic acid.
After the impression, the pieces are winced in chalky water, at 1200 F., then washed,
and passed through a dilute sulphuric acid.
M. Daniel Kcechlin, of Mulhausen, the author of this very ingenious process, considers the action of the bichromate here as being analogous to that of the alkaline chlo.
rides. At the moment that the block applies the preceding discharge to the bichromate
dye, there is a sudden decoloration, and a production of a peculiar odor.
The pieces padded with the bichromate must be dried at a moderate temperature, and
in the shade. Whenever watery solutions of chromate of potash and tartaric acid are
mixed, an effervescence takes place, during which the mixture possesses the power of
destroying vegetable colors. This property lasts no longer than the effervescence.
VII. Steam  colors.-This style combines a degree of brilliancy with solidity of
color, which can hardly be obtained in any other way except by the chints dyes.
The steam apparatus employed for fixing colors upon goods, may be distributed under
five heads:-1. the column; 2. the lantern; 3. the cask; 4. the steam-chest; and,
5. the chamber.
The column is what is most generally used in this country. It is a hollow cylinder of copper, from three to five inches in diameter, and about 44 inches long, perforated over its whole surface with holes of about one sixteenth of an inch, placed
about a quarter of an inch asunder. A circular plate, about 9 inches diameter, is
soldered to the lower end of the column, destined to prevent the coil of cloth from
sliding down off the cylinder. The lower end of the column terminates in a pipe,
mounted with a stop-cock for regulating the admission of steam from the main steamboiler of the factory. In some cases, the pipe fixed to the lower surface of the disc is
made tapering, and fits into a conical socket, in a strong iron or copper box, fixed to a
solid pedestal; the steam pipe enters into one side of that box, and is provided, of
course, with a stop-cock. The condensed water of the column falls down into that
chest, and may be let off by a descending tube and a stop-cock. In other forms of the
column, the conical junction pipe is at its top, and fits there into an inverted socket
connected with a steam chest, while the bottom has a very small tubular outlet, so that
the steam may be exposed to i certain pressure in the column, when it is incased
with cloth.
The pieces, after being printed with the topical colors presently to be described, and
dried, are lapped round this column, but not in immediate contact with it; for the copper
cylinder is first enveloped in a few coils of blanket stuff; then with several coils of
white calico; next with the several pieces of the printed goods, stitched endwise; and
lastly, with an outward mantle of white calico. In the course of the lapping and
unlapping of such a length of webs, the cylinder is laid in a horizontal frame, in which
it is made to revolve. In the act of steaming, however, it is fixed upright, by one ol
the methods above described. The steaming lasts for 20 or 30 minutes, according to
the nature of the dyes; those which contain much solution of tin admit of less steaming.
Whenever the steam is shut off, the goods must be immediately uncoiled, to prevent the
chance of any aqueous condensation. I was much surprised, at first, on finding the
unrolled pieces to be free from damp, and requiring only to be exposed for a few minutes
in the air, to appear perfectly dry. Were water condensed during the process, it would
be apt to make the colors run.
Steam ctlors are ail topical, though, for many of them, the pieces are previously




CALICO-PRINTING.                                329
padded with mordants of various kinds. Some manufacturers run the goods before
printing them through a weak solution of the perchloride of tin, with the view of brightening all the colors subsequently applied or raised upon them. I shall now illustrate
steam calico-printing by some examples, kindly furnished me by a practical printer near
Manchester, who conducts a great business with remarkable success.
Steam blue.-Prussiate of potash, tartaric acid, and a little sulphuric acid, are dissolved in water, and thickened with starch; then applied by the cylinder, dried at a
moderate heat, and steamed for 25 minutes. They are rinsed and dried after the
iteaming. The tartaric acid, at a high temperature, decomposes here a portion of the
terrocyanic acid, and fixes the remaining ferrocyanate of iron (Prussian blue) in the fibre
of the cloth. The ground may have been previously padded and dyed; the acids will
remove the mordant from the points to which the above paste has been applied, and
bring out a bright blue upon them.
Steam purple.-This topical color is made by digesting acetate of alumina upon ground
logwood with heat; straining, thickening with gum senegal, and applying the paste by
the cylinder machine.
Steam pink.-A decoction of Brazil-wood with a small quantity of the solution of
muriate of tin, called, at Manchester, new tin crystals,* and a little nitrate of copper to
assist in fixing the color; properly thickened, dried, and steamed for not more than 20
minutes, on account of the corrosive action of muriate of tin when the heat is too strong.
Cochineal pink.-Acetate of alumina is mixed with decoction of cochineal, a little tartaric acid and solution of tin; then thickened with starch, dried, and steamed.
Steam  brown.-A mixed infusion of logwood, cochineal, and Persian berries, with
cream of tartar, alum (or acetate of alumina), and a little tartaric acid, thickened, dried,
and steamed.
Green, blue, chocolate, with white ground, by steam.-Prussiate of potash and tartaric
acid, thickened, for the blue; the same mixture with berry-liquor and acetate of alumina,
thickened, for the green; extract of logwood with acetate of alumina and cream of
tartar, thickened, for the chocolate. These three topical colors are applied at once by
the three-color cylinder machine; dried and steamed. Though greens are fixed by the
steam, their color is much improved by passing the cloth through solution of bichromate
of potash.
In France, solution of tin is much used for steam colors.
VIII. Spirit or fancy colors.-These all owe their vivacity, as well as the moderate
degree of permanency they possess, to their tin mordant. After printing-on the topical
color, the goods must be dried at a gentle heat, and passed merely through the rinsing
machine. Purple, brown, or chocolate, red, green, yellow, blue, and white discharge;
any five of these are printed on at once by the five-color cylinder machine. See RINSING
MACHINE.
Chocolate is given by extract of Brazil-wood, extract of logwood, nitro-muriate of tin,
with a little nitrate of copper: all mixed, thickened, and merely printed-on.
Red, by extract of Brazil-wood and tin, with a little nitrate of copper.
Green, by prussiate of potash, with muriate of tin and acetate of lead, dissolved,
thickened, and printed-on.
The goods after rinsing must be passed through solution of bichromate of potash, to
convert the Prussian blue color into green, by the formation of chrome yellow upon it.
Blue.-Prussian blue ground up with solution (nitromuriate) of tin; thickened, &c.
Yellow.-Nitrate of lead dissolved in solution of tartaric acid, thickened, tenderly
dried, passed through the bichromate vat or padding machine, washed and dried.
This yellow is pretty fast; though topical, it can hardly, therefore, be called a fancy
color.
When purple is to be inserted instead of the above blue, extract of logwood with tin
is used in the place of the Prussian blue. Tartaric acid is a useful addition to tin in
brightening fancy colors.
Chocolate.-A good topical chocolate is made by digesting logwood with liquid acetate
of alumina, adding a little cream of tartar to the infusion; thickening, applying by the
cylinder, drying, washing, then passing through solution of bichromate of potash, which
serves to darken and fix the color.
I shall conclude my account of the printing of cotton goods with some miscellaneous
formulae, which were given me by skilful calico-printers in Lancashire.
Prussian blue is prepared for topical printing by grinding it in a handmill, like that for
grinding pepper or coffee, and triturating the powder with solution of muriate of tin.
Green.-The deoxydized indigo vat liquor is mixed with a little pearlash, and
thickened with gum. This is applied by the cylinder or block to goods previously
* This preparation is made by adding 3 lbs. of sal ammoniac to 1 gallon of solution of tin (see SCARLET
DYE, and TIN), evaporating, and crystallizing. The sal ammoniac seems to counteract the separation ol
the tin by peroxydizement.




330                           CALICO-PRINTING.
padded with nitrate of lead; the goods, after being dried, are passed through milky limes
water, rinsed, and then winced or padded through the bichromate of potash bath.
Another green.-Nitrate of lead, prussiate of potash, and tartaric acid, dissolved, and
mixed with a little sulphate, nitrate, and muriate of iron; this mixture is either thickened
for cylinder printing, or used in its liquid state in the padding trough. The goods subjected to one of these two processes are dried, padded in weak solution of carbonate of
potash, which serves to precipitate the oxyde of lead from the nitrate; they are finally
padded with bichromate of potash, which induces a yellow upon the blue, constituting a
green color of any desired tint, according to the proportion of the materials.
Chocolate and black, with white discharge; a fast color.-The cloth is padded with acetate of alumina, and dried in the hot-flue; it is then passed through a two-color machine,
the one cylinder of which prints-on lime-juice discharge, thickened with gum senegal;
the other a black topical dye (made with logwood extract and iron liquor). The cloths
are now hung up to be aired during a week, after which they are dunged, and dyed up
with madder, fistic, and quercitron bark, heated with steam in the bath.
Blue, white, and olive or chocolate.-l. Pad with the aluminous mordant; 2. Apply
thickened lemon-juice for discharge by the cylinder; 3. Dung the goods after they
are thoroughly dried; 4. Pass them through the bath of madder, fustic, and quercitron,
which dye a brown ground, and leave the discharge points white; then print-on a reserve
paste of China clay and gum with sulphate of copper; dry, dip in the blue vat, which
will communicate an olive tint to the brown ground; or a chocolate, if madder alone had
been used.
When a black ground is desired, with white figures, the acid discharge paste should be
printed-on by the cylinder, and dried before the piece is padded in the iron liquor. By
following this plan the whites are much purer than when the iron is first applied.
Green, black, white.-The black is first printed-on by a mixture of iron liquor, and infusion (not decoction) of logwood; then resist or reserve paste is applied by the block,
and dried; after which the goods are blued in the indigo vat, rinsed, dried, passed through
solution of acetate of lead; next, through milky lime-water; lastly, through a very strong
solution of bichromate of potash.
Turkey red, black, yellow.-Upon Turkey red cloth, print with a strong solution of tartaric acid, mixed with solution of nitrate of lead, thickened with gum; dry. The cloth
is now passed through the chloride of lime bath, washed, and chromed. Lastly, the black
is printed-on by the block as above, with iron liquor and logwood.
Black ground dotted white, with red or pink and black figures.-l. Print-on the
lime-juice discharge-paste by the cylinder; dry; 2. Then pad with iron liquor, containing a little acetate of alumina, and hang up the goods for a few days to fix
the iron; 3. Dye in a logwood bath to which a little madder has been added; clear
with bran. The red or pink is now put in by the block, with a mixture of extract of
Brazil-wood, nitromuriate of tin, and nitrate of copper, as prescribed in a preceding
formula.
Orange or brown; black; white; pink.-The black is topical, as above; it is printedon, as also the lemon-juice discharge and red mordant, with muriate of tin (both
thickened), by the three-color machine. Then, after drying the cloth, a single-cylinder
machine is made to apply in diagonal lines to it a mixture of acetate of iron and alumina.
The cloth, being dried and dunged, is next dyed in a bath of quercitron, madder, and
fustic.
Here the orange is the result of the mordant of tin and alumina; the brown, of the
alumina and iron; white, of the citric acid discharge. The tin mordant, wherever it has
been applied, resists the weaker mordant impressed in the diagonal lines. The pink is
blocked-on at the and.
Orange brown, or aventurine; black and white.-The topical black (as above) and
discharge lemon-juice, are printed-on by the two-color machine; then the cloth is subjected to the diagonal line cylinder, supplied with the alumino-iron mordant. The cloth
is dried, dunged, and dyed in a bath of bark, madder, and fustic.
The manganese or solitaire ground admits of a great variety of figures being easily
brought upon it, because almost every acidulous mordant will dissolve the oxyde of
manganese from the spot to which it is applied, and insert its own base in its place; and
of course, by dyeing such mordanted goods in various baths, any variety of colored designs may be produced. Thus, if the paste of nitrate of lead and tartaric acid solution
be applied, and the goods after drying be passed first through lime-water, and then
through a chrome bath, bright yellow spots will be made to appear upon the bronze
ground.
Manganese bronze, buff  and green; all metallic colors.-Pad-on the manganese
solution, and dry; apply the aceto-sulphate of iron, of spec. gray. 1*02, and Scheele's
green (both properly thickened), by the two-color machine. The goods are next to
be dried, and padded through a cold caustic ley of spec. gray. 1-086. They are then
16




CALICO-PRINTING.                                 331
rinsed, and passed through a weak solution of chloride of lime, to raise the bronze, again
rinsed, and passed through a solution of arsenious acid to raise the green.
Sclleele's green for the calico-printer is made as follows:Take 1 gallon of water, in which dissolve with heat,
5 pounds of sulphate of copper, and 1 pound of verdigris. When the two salts are dissolved, remove the kettle from the fire, and put into it 1 quart of solution of nitrate of
copper, and 6 pounds of acetate of lead. Stir the mixture to facilitate the decomposition,
and allow the pigment to subside.
It must be thickened with 2- lbs. of gum per gallon, for pencilling; or 12 oz. of starch
for the block. The goods printed with this paste are to be winced through a caustic ley,
till a fine sky-blue be produced; then washed well and rinsed. They are now to be
passed through water, containing from half an ounce to an ounce of white arsenic per
piece; 4 turns are sufficient; if it be too long immersed it will take a yellow tint.
Catechu has been considerably employed by calico-printers of late years, as it affords a
fine permanent substantive brown, of the shade called carmelite by the French. The following formula will exemplify its mode of application:Take 1 gallon of water;
1 pound of catechu in fine powder; reduce by boiling to half a gallon, pass the decoction through a fine sieve, and dissolve in it 4 ounces of verdigris; allow it then to cool,
and thicken the solution with 5 ounces of starch; while the paste is hot, dissolve in it 5
ounces of pulverized muriate of ammonia.
Print-on this paste, dry, and wash. It is a fast color.
I shall subjoin the prescriptions for two fancy cochineal printing colors..dmaranth by cochineal.-Pad the pieces in the aluminous mordant of spec. grav. 1'027,
page 230.
Dry in the hot flue; and after hanging up the goods during 3 days, wince well through
chalky water, and then dye, as follows:For each piece of 28 or 30 yards, 8 ounces of cochineal are to be made into a decoction of 2 gallons in bulk, which is to be poured into a kettle with a decoction of 3 ounces
of galls, and with two ounces of bran. The pieces are to be entered and winced as in
the madder bath, during two hours and a half; then washed in the dash wheel. On mixing with the amaranth bath a certain quantity of logwood, very beautiful lilachs and violets may be obtained.
Mixture of quercitron and cochineal.-Pad in the aluminous mordant, and dye with 2
lbs. of quercitron, and 4 ounces of cochineal, when a capuchin color will be obtained. If
we pad with the following mordant, viz., 1 gallon of acetate of alumina of 1'056 spec.
grav., and 1 of iron liquor of 1'02 spec. grav., and dye with 1 pound of quercitron, and
1 ounce of cochineal, we shall obtain a shade like boot-tops, of extreme vivacity.
Two ounces of cochineal will print a long piece of calico with rich pink figures, having
acetate of alumina for a mordant. As the ground is hardly tinged by the dye, it neither
needs nor admits of much clearing.
I have already mentioned that goods are sometimes padded with solution of perchloride
of tin before printing-on them the steam colors, whereby they acquire both permanence
and vivacity. I have also stated that the salts of tin at a high temperature are apt to
corrode the fibre of the stuff, and therefore must be used with discretion. This danger
is greatly lessened by adding to the perchloride of tin a sufficient quantity of caustic
potash ley to form a stannate of potash. The goods are padded through this substance,
diluted with water, dried with a moderate heat, and then immersed in very dilute sulphuric acid, which saturates the potash, and precipitates the tin oxyde within the pores of
the cloth. Calico thus prepared affords brilliant and permanent colors by the steam pro
cess, above described.
Printing of silks or woollen stuffs, such as merinoes and mousselin de laine, as also of mixed stuffs of silk and wool, such as chalys.-All these prints are applied, not by the cylinder but the block, and are fixed by the application of steam in one of four ways; 1. By
the lantern; 2. By the cask; 3. By the chest; or, 4. By the chamber.
1. By the lantern.-In this mode of exposure to steam, the goods are stretched upon
a frame; and therefore the apparatus may be described under two heads; the lantern and
the frame. The former is made of copper, in the shape of a box A B c D E, fig. 301, open
below, and with a sloping roof above, to facilitate the trickling down of the water condensed upon the walls. The sides B C D. are 4- feet high, 6 feet long, and 4 feet wide.
The distance of the point A from the line E B is 2 feet. At F is a brass socket, which
may be stopped with a cork; and there is a similar one at the other side. This kind
of penthouse may be raised by means of a pulley with cords fixed to the four angles
of the roof E B; and it rests upon the table G H, a little larger than the area of the box,
which stands upon the four feet I i. Round the borders of the table there is a
triangular groove a b, for receiving the lower edges of the box, and it is stuffed steamtight with lists of cloth. Through the centre of the table, the two-inch steam pipe N




332                          CALICO-PRINTING.
passes; it is surmounted with a hemispherical rose pierced with numerous holes for
the equal distribution of the steam. Right above it, a disc N is placed upon four feet.
The tube L communicates with a box P, which has a syphon Q
301 SAX              to let off the condensed water. At the upper part of this box
the tube L terminates which brings the steam. The little table
E  - /   r  -n G H slopes towards the part G, where the syphon R is placed
0f,  O        \  for drawing off the water.
The frame has such dimensions, that it may stand in the four
corners of the table at s s, as pointed out by the dotted lines.
The second part embraces an open square frame, which is
formed by spars of wood 2 inches square, mortised together;
and is 3 feet 8 inches wide, 5 feet 8 inches long, and 4 feet 3
inches high; it is strengthened with cross bars. Upon the two
JN            sides of its breadth, two rows of round brass hooks are placed,
D   L2 ff            about half an inch apart; they are soldered to a copper plate
/ ~  =...o. f  fixed to uprights by means of screws.
/    1.\\.^.1R 0L -,   Before hanging up the goods, a piece of cloth 3 feet 8 inches
P/=f\ 9IO'~ I -  /   long, and 4 feet wide, is placed upon the row of hooks; and 3
feet of it are left hanging out.
One foot within, the hooks pass through the cloth. A similar one is fitted to the other
side. This cloth is intended to cover the goods hung upon the hooks; and it is kept
straight by resting upon strings. The pieces are attached zig-zag from one hook to
another. When the frame is filled, the bag is put within the cloths; it has the same rectangular shape as the frame. The pieces are in this way all incased in the lclkh; a bit
of it being also put beneath to prevent moisture affecting that part.
When shawls are framed, they are attached with pins; and if they be too large, they
are doubled back to back, with the fringes at top.
These arrangements being made, the frame is set upon the table, the penthouse is placed over it, and the steam is admitted during from 35 to 45 minutes, according to circumstances. The orifice F is opened at first to let the air escape, and when it begins to discharge steam it is stopped. The frame is taken out at the proper time, the bag is removed, the cloths are lifted off, and the goods are spread out for airing. Three frames
and six bags are required for a constant succession of work. The above apparatus is particularly suitable for silks.
2. The drum.-This is the most simple mode of steaming. The apparatus is a drum
of white wood, 2 inches thick, fig. 302; the bottom is pierced with a hole which admits
the steam-pipe F, terminating in a perforated rose. Four inches from the bottom there
is a canvass partition E, intended to stop any drops of water projected from the tube F,
and also to separate the condensed water from the body of the apparatus. The drum is
covered in by a wooden head H, under which the goods are placed. It is made fast either
by bolts, or by hooks, G G, thus m, to which weighted cords are
hung. The frame 1, fig. 302, rests upon a hoop, a a, a few inches
303 \    1         from the edge. The goods are hung upon the frame in the ordinary way, and then wrapped round with flannel. The frame is
_Bom ~~   studded with pin points, like that of the indigo vat, fixed about
5 inches asunder. From 20 to 30 minutes suffice for one steam{   I ^\   ing operation. The upper part of the frame must be covered
also with flannels to prevent the deposition of moisture upon it.
G  302         G   At the bottom of the drum there is a stopcock to let off the conn    r- H     )  densed water. According to the size of the figure, which is 3 feet
A                 B  2 inches, 50 yards may be hung up single; but they may be doubled'~   ~ bll    on occasion.
A    M      24 241       B      3. The box.-This steaming
apparatus is convenient from the
large quantity of goods admisIE                   C  sible at a time: it answers best
for woollen stuffs. From 12 to
_. -                                    w     n s. F    1_     t.  16 pieces, of 36 yards each, may
E _. ___________X_   be operated upon at once; and. I^             *........."' -, from 240 to 260 shawls. It is
I______________'' formed of a deal box, A B c D, fig.
______            X,_C                    D      304, 4 feet wide, 6 long, and 3
high; the wood being 4 inches thick. It is closed by a cover of the same substance, I,
which is made steam-tight at the edges by a list of felt. The lid is fastened down by 5
cross bars of iron, a a a a a, which are secured by screws, c c c c c, fig. 305. The ends of
these cross bars are let into the notches, b b b b b, on the edge of the box. The safety
valve fa,ig. 304, is placed upon the lid. For taking off the lid, there are rings at the four




CALICO-PRINTING.                                333
corners, d d d d, bearing cords, F r F F. These join at the centre into one, which passes
over a pulley. Eight inches from the bottom of the box there is a horizontal canvass par
A,    b  b  B
o06  ii  305 to
(Y'''_
tition, beneath which the steam is discharged from the pipe L, fig. 306. There are two
ledges, E F G H, at the sides for receiving the bobbins. Th-i tube L runs round the box, as
1_iii~i. _ ij i       shown by the letters d a e b: the end d is shut;
307    but the side and top are perforated with many.jj i'  ~i.holes in the direction towards the centre of the box.
~i.ij   j~ -        Fig. 305 shows the arrangement of the lower set.   i,               of bobbins: that of the upper set is shown by the.   i j.i;         dotted lines: it is seen to be in an alternate position, one lying between two others. They are
r x,  FT-If FX_       Iformed of pieces of deal 4 inches broad, 1 inch
thick, and of a length equal to the width of the.  -  d    c.       _         box. They are first wrapped round with 5 or 6
E  -. X. -aturns of doubled flannel or calico: the piece of
goods is laid over it upon a table, and then
wrapped round. At the end of the piece, several
folds of the covering must be put, as also a roll
of flannel. The two ends must be slightly tied
with packthread. When these flat bobbins are
arranged in a box, the steam is let on them, and
continued about 45 minutes; it is then shut off,
the lid is removed, and the pieces are unrolled.
4. The chamber.-The interior height of the
chamber, A B C D, fig. 308, is nine feet, the length
12 feet, and the breadth 9 feet. The steam is inI~   _o              l l       troduced into it by two pipes, a b c, d ef. Their
}   *  308   l l^^  two ends, d c, are shut; but their sides are all
along perforated with small holes. The frames
E F G H, E F G H, are moveable, and run upon
a~ J            R          rollers: they are taken out by front doors, which
are made of strong planks, shut by sliding in
C'~' ~ "     ~H^^^Ta   slots, and are secured by strong iron bars and
pressure screws. The cross rods, E F G H, are provided with hooks for hanging up the
pieces. There is a safety-valve in the top of this large chamber. The dimensions of the
frame are ten feet long, 3 feet wide, and 7 high. Three feet and a half from the upper
part of the frame, a row of hooks is fixed for hanging on a double row of pieces, as shown
in the figure. Over the frame, woollen blankets are laid to protect it from drops of water that might fall from the roof of the chamber. When the hooks are two thirds of an
inch apart, 24 pieces, of 28 yards each, may be suspended at once. The period of steaming is from 45 to 60 minutes.
Muslins and silks do not require so high a temperature as woollen goods. When the
stuffs are padded with color, like merinoes and chalys, they must not be folded together, for
fear of stains, which are sometimes occasioned by the column in steam calico-printing,
where the end which receives the first impression of the steam is seldom of the same
shade as the rest of the roll of goods. The duration of the steaming depends upon the
quantity of acid in the mordant, and of saline solution in the topical color; the more of
which are present the shorter should be the steaming period. A dry vapor is requisite in
all cases; for when it becomes moist, from a feeble supply or external condensation, the
goods become streaky or stained by the spreading of the colors.
1. Black figures are given by decoction of logwood thickened with starch, to which
a little oxalic acid is added while hot, and, after it is cold, neutralized solution of nitrate
of iron.
2. Dark blue for a ground.-Decoction of logwood, and archil thickened w:th starch I
to which, while the paste is hot, a little soluble Prussian blue is added; and, when it is
cold, neutralized nitrate of iron; see supra.




334                          CALICO-PRINTING.
3. Deep poppy or ponceau color.-Cochineal boiled in starch water, with oxalic acid
(or tartaric), and perchloride of tin.
4. Rose.-Cochineal infusion; oxalic acid; perchloride of tin; thickened with gum.
5. Dark amaranth.-Decoctions of archil and cochineal, thickened with starch: to
the paste, alum and perchloride of tin are added.
6. Capuchin color.-Quercitron and cochineal thickened with starch; to the paste add
oxalic acid and perchloride of tin.
7. dnnnotto orange.-Dissolve the annotto in soda ley, of spec. grav. 1'07, at a boiling
heat; add aluminate of soda, and thicken with gum.
8. Golden yellow.-Decoction of Persian berries thickened with starch; to which some
alum and muriate of tin are added, with a little perchloride of tin and oxalic acid.
9. Lemon yellow.-Persian berries; starch; alum.
10. An ammoniacal solution of cochineal is used for making many violet and mallow
colors. It is prepared by infusing cochineal in water of ammonia for 24 hours; then
diluting with water, heating to ebullition, and straining.
11. Fine violet is given by ammoniacal cochineal, with alum and oxalic acid; to which
a little aceto-sulphate of indigo is added, and gum for thickening. The following blue
may be used instead of the solution of indigo. The mallow tint is given by adding a
little perchloride of tin to the above formula, and leaving out the blue.
12. Dark blue.-Soluble Prussian blue; tartaric acid; alum; thicken with gum.
13. Emerald green.-One quart of decoction, equivalent to 1 pound of Persian berries; 1 quart of infusion of quercitron, of spec. grav. 1'027; in which dissolve 12 ounces
of alum in powder; and add 6 ounces of the following blue bath fcx greens; thicken
with 20 ounces of gum.
14. Blue bath for greens. Half a gallon of water at 140~ F., one pound of soluble
Prussian blue, 3 ounces of tartaric acid, and 2 ounces of alum.
I. Printing of Silks.-1. Of the madder style. This is one of the most difficult to execute, requiring both much skill and experience. The first step is the removal of the gum.
A copper being nearly filled with water, the pieces, tied up in a linen bag, are put into
it, with a quarter of a pound of soap for every pound of silk, and are boiled for 3 hours.
If the silk be Indian, half an ounce of soda crystals must be added. When the goods
are taken out, they are rinsed in the river, then passed through water at 140~ F., holding
8 ounces of crystallized soda in solution, as a scourer. They are next rinsed in cold
water, and steeped in water very faintly acidulated with sulphuric acid, during 4 hours,
then rinsed, and dried.
Preparation of Mordants. —1 gallon of boiling water; 2 pounds of alum; dissolve:
1 pound of acetate of lead; 4 ounces of sal-ammoniac; 1 of chalk; mix well together;
after decomposition and subsidence, draw off clear.
1. Red.-1 gallon of the above mordant, thickened with 14 ounces of starch, and
tinged with decoction of Brazil-wood. If dark red be wanted, dissolve, in a gallon of
the above red, 4 ounces of sulphate of copper.
2. Black. —1 gallon of iron liquor, of 1-056 spec. grav.; thicken with 14 ounces of
starch; and dissolve in the hot paste 2 ounces of sulphate of copper.
3. Violet.-Take 1 gallon of iron liquor of 104 spec. grav.;
2 ounces of cream of tartar; 2 ounces of nitre; 2 ounces of copperas;
I ounce of alum: dissolve, and mix the solution with
1 gallon of gum water, containing 6 lbs. of gum.
4. Puce.-Half a gallon of red mordant; half a gallon of iron liquor of 1'07;
7 ounces of starch for thickening; color with logwood.
Manipulation of the above colors.-Print-on the black, then the puce, next the violet,
and lastly the red. Dry in the hot flue, and 48 hours after the impression, wash away
the paste. The copper employed for dyeing is of a square form: a boil is given with
bran, at the rate of 4 lbs. per piece of the foulards: cold water is added to lower the
temperature to 130~ F. The pieces must be entered with the printed surface undermost, and winced for half an hour, taking care to keep them expanded and well covered
with the liquor: they are then taken out and rinsed. When grounds are to be made on
the foulards, 2 ounces of sumach must be added per piece.
Maddering.-Suppose 48 pieces are to be grounded with madder.  12 pounds of madder must be put into the copper, 1 pound of sumach, and 6 pounds of bran; the bath
must be tepid when the pieces are entered: it must be heated to 104~ F. in 20 minutes,
and to the boiling point in an hour and a half. The goods must be briskly winced all
the time, and finally turned out into cold water.
When they come out of the madder bath they are much loaded with color. They are
cleared by a boil of half an hour in bran, then turned out into cold water, and rinsed. A
copper must be now mounted with 3 pounds of soap, 1 ounce of solution of tin, and 2
pailsful of bran, in which the goods are to be boiled for half an hour, then rinsed, and
passed through a very dilute sulphuric acid bath. Then rinse, and dry. By following
this process, a light salmon ground is obtained.




CALICO-PRINTING.                                   335
II. Steam colors upon silk.-The same plan of operations may be adopted here as is
described for calico-printing; the main difference being in the method of mordanting the
stuffs. After boiling in soap water, in the proportion of 4 ounces per pound of silk, the
goods are washed in cold water, and then in hot water at 140~; they are next rinsed,
passed through weak sulphuric acid, rinsed, squeezed between rollers, and afterwards
steeped in a bath containing 8 ounces of alum per gallon, where they remain for four
hours, with occasionally w incing. They are now  rinsed and dried. The subsequent
treatment resembles that of steam-color printed cottons..lack.-Take a gallon of decoction, made with 4 lbs. of logwood, with which
14 ounces of starch are to be combined ~ mix in
2 ounces of powdered nut-galls: boil, and pour the color into a pipkin containing
2 ounces of tartaric acid; 2 ounces of oxalic, both in powder, and
2 ounces of olive oil. Stir the color till it is cold, and add
8 ounces of nitrate of iron, and 4 ounces of nitrate of copper.
The red, violet, lilach, yellow colors, &c. are the same as for steam colors upon cotton.
Topical colors are also applied without mordanting the silk beforehand. In this case a
little muriate of tin is introduced. Thus, for
Yellow.-Take 1 gallon of a decoction, made with 4 lbs. of Persian bellies: dissolve
in it 8 ounces of salt of tin (muriate), and 4 ounces of the nitro-muriatic
solution of tin. Thicken with 2 pounds of gum.
Printing offoulard pieces. The tables which serve for the impression of silk goods are
so constructed as to receive them in their full breadth. Towards the part between the
color or sieve tub and the table, the roller is mounted upon which the piece is wound.
309    B B    This roller, A B, fig. 309, has a groove, c, cut out parallel
to its axis. Into this a bar is pressed, which fixes the end
^~ — ~     -~1^'  of the piece. The head, B, of the roller is pierced with
310             several holes, in which an iron pin passes for stopping its.A """""""""""    rotation at any point, as is shown at B. At the other end
~A'L~'a... 3 ~of the table there is placed a comb, fig. 310, which is
supported by pivots A B at its ends. The teeth of the comb are on a level with the
cloth.
The piece is arranged for printing as follows:-It is unwound, and its end is brought
upon the teeth of the comb, and made to pass into them by slight taps with a brush.
It is now  stretched, by turning round the roller, and fixing it by the pin-handle.
After tracing the outline, the printing blocks are applied. Care should be taken, in
the course of printing, always to fix the teeth of the comb in the middle line between
two handkerchiefs. The operation of grounding-in is much facilitated by this plan of
extension.
The pieces are washed in running water, and must be rapidly dried. The subsequent
dressing is given by gum tragacanth: they are dried upon a stretching frame, and then
folded up for the market.
III. Mandarining of silk stuffs and chalys.-This style ot printing depends upon the
property which nitric acid possesses of giving to silk and woollen stuffs a yellow color.
The first step is the scouring with a soap boil, as already described.
The designs are printed-on as also above described.
The swimming or color tub is usually double, and serves for two tables; instead of
being placed, therefore; at the end of the table, it is put between two, and, conse^                    l]        quently, behind the printer. It is formed of a
copper chest, fig. 311, A B c D, in which steam
3*!:" — iimay circulate, introduced by the pipe I; the excJJa   K    |    ~e -- --- I — r cess being allowed to escape by the tube J, as also
^1^O    I (I"      I... the water of condensation.  The frame is placed
*  I  —.  311 in the hollow box K K. Between two such frames
_r'_r                          there is a plate of copper,,, which closes the box;
it serves for laying the plates in order to keep them
hot. At E and H are prolongations of the box, in which are set the vessels F G for holding the reserve paste.
Preparation of the reserve or resist paste.-Melt in a kettle 21 lbs. of rosin; 1
b. of suet; mix well, and, put it into the basins F  G'.  By means of steam the
reserve is kept melted, as well as the false color upon which the sieve floats. The
piece of silk being laid upon the table, and the reserve spread upon the frame, the
printer heats his block, which should be mounted with lead, if the pattern will permit, upon the little table L. He takes up the color from  the frame, and transfers
it instantly to the piece. He must strike the block lightly, and then lift it, lest, by its
cooling, it might stick to the silk.  When the table pattern is completed, he dusts it
over with sand, and proceeds to another portion of the silk.  The piece must not be




336                           CALICO-PRINTING.
taken out of the stretch till it is quite dry, which requires usually 6 hours. Let us con.
sider first the most common case, that of a white upon an orange ground. We shaL
afterwards describe the other styles, which may be obtained by this process. The piece,
being printed and dry, must next be subjected to the mandarining operation.
312              The apparatus here employed consists of a sandstone trough
I.              A B C D, fig. 312. Upon the two sides, A c, B D, of this trough
are fixed two wooden planks, pierced with a hole an inch from
the bottom to receive the roller E, under which the piece passes.
In this trough the acid mixture is put. That trough is put into a wooden or copper trough, F G H I. Into the latter, water
is put, which is heated by means of steam, or a convenient fur.
l l l E  lenace. Before and behind are placed two winces, or reels, K L;
one serves to guide the piece in entering into the trough, and
the other in its leaving it. The piece falls immediately into a
stream of cold water, or, failing that, into a large back, conC     D  I      taining a mixture of chalk and water. The two winces are
moved by handles: the velocity is proportioned to the action of
U      JI      the acid. The wince L ought to be higher than K, to allow the
acid to drain off. Fig. 313 shows a section of the apparatus.
R      813 </         The temperature of the acid mixture ought to be maintained. K,,L.       I between 950 and 100~ F.; for if it be raised higher, the resist
1;            [[~\ n  would run the risk of melting, and the impression would beJ:I * /   come irregular and blotty.
t& 2' The proportions of the acid mixture are the following:1 gallon of water; and 1 gallon of nitric acid, of spec. grav.
1'288, which may be increased with the strength of the silk. It should be a little weaker
for chalys. For the strong greens it may be 2 measures of acid of 1-288 to 1 measure of
water. The duration of the passage through the acid should be 1 minute at most.
Mixture of orange color, and clearing away of the resist.-The goods, on coming out
of the mandarining apparatus, are rinsed in running water; then boiled in soap water,
quickened with a little soda, at the rate of 2 lbs. of the former and 4 oz. of the latter
for a piece of 30 yards. They must be worked by the wince for half an hour. They
are now rinsed in cold water, then passed through hot, again rinsed, and dried. I shall
give some examples of the mode of manufacture, which is undoubtedly one of the most
curious applications of chemical ingenuity.
1. Orange ground with white figures.
(1.) Print-on the fat reserve; (2.) mandarine; (3.) brighten the orange, and clear.
2. Orange ground with blue figures.
(1.) Dip in the indigo vat as for calico; (2.) print-on the fat resist to preserve the
blue; (3.) mandarine; (4.) clear, and brighten the orange by the boil.
3. Orange ground, with blue and white figures.
(1.) Print-on the resist to preserve the white; (2.) dip in the vat, rinse, and dry; (3.)
ground-in the fat resist to preserve the blue; (4.) mandarine; (5.) cleanse, and brighten.
4. Full green ground, and white figures.
(1.) Print-on the resist; (2.) mandarine, and rinse without drying; (3.) dip in the blue
vat; (4.) cleanse, and brighten.
5. Full green ground, and blue figures.
(1.) Dip a pale blue, rinse, and dry; (2.) print-on the fat resist; (3.) mandarine, wash
and dry; (4.) dip full blue; (5.) clean, and brighten.
6. Full green ground, with white and blue figures.
(1.) Print on the resist; (2.) dip a pale blue, and dry; (3.) ground-in the fat resist;
(4.) mandarine and rinse; (5.) dip a full blue; (6.) clean, and brighten.
7. Full green ground, with while, blue, and orange figures.
(1.) Print-on the fat reserve; (2.) dip a pale blue, and dry; (3.) ground-in the re
serve; (4.) mandarine, rinse, and dry; (5.) ground-in the reserve; (6.) dip a full
blue; (7.) clean, and brighten.
If blue grounds with white figures be wanted, the resist must be applied, and then
the goods must be dipped in the blue vat: the resist is afterwards removed by a boil in
soap-water.
The above processes are applicable to chalys.
The property which nitric acid possesses of staining animal matters yellow, such as
%he skin, wool, and silk, is here applied to a very elegant purpose.
Of the bronze or solitaire style by mandarining.-The mandarining mixture is
1 gallon of nitric acid, of 1'17 spec. grav.; mixed with 3 pints of solution of nitrate
of iron, of spec. grav. 16F5. If the quantity of nitrate of iron be increased, a darker
tint will be obtained. The temperature of the mixture should be 94~ F. The pieces,
after mandarining, are let fall into water, and steeped for an hour.




CALICO-PRINTING.                                 337
In order to raise the bronze, and clear away the fat resist, the goods mut be boiled in
a bath of soap and soda, as described for orange.
1. Bronze ground, with white figures.
(1.) Print-on the fat resist; (2.) dip in the blue vat, and dry; (3.) pad in a decoction
of logwood, of 4 lbs. per gallon; dry, taking care to turn over the selvages;'(4.) mandarine, and steep in water for an hour; (5.) cleanse, and pass through soap.
2. Bronze ground, with blue figures.
(1.) Dip in the blue vat, and dry; (2.) print-on the fat resist; (3.) pad in the above
decoction of logwood, and dry; (4.) mandarine, and steep an hour; (5.) cleanse, and
brighten.
3. Bronze ground, with white and blue.
(1.) Print-on the fat resist; (2.) dip in the blue vat, and dry; (3.) ground-in the fat resist; (4.) pad in the logwood liquor, and dry; (5.) mandarine, and steep for an hour;
(6.) cleanse, and give the brightening boil with soap.
This style of manufacture may be executed on chalys; and is capable of producing
beautiful effects, which will in vain be sought for by other means.
With silks, advantage may be derived from various metallic solutions which possess
the property of staining animal substances; among which are nitrate of silver, nitrate of
mercury, and muriate of iron. The solutions of these salts may be thickened with gum,
and printed-on..dn orange upon an indigo vat ground.-After the blue ground has been dyed, orange
figures may be produced by printing-on the following discharge paste:1 gallon of water, made into a paste with 1 pound of starch; when cold, add to it from
16 to 24 ounces of nitric acid, of spec. gray. 1'288. After fixing the color by steam,
the orange is brightened with a soap boil.
u.n orange upon a Prussian-blue ground.-The dye is first given by Prussian blue in
the ordinary way, and then the following discharge is printed-on:A  caustic ley being prepared, of 1'086 specific gravity, dissolve in a gallon of it 2
pounds of annotto, and thicken with 3 pounds and a quarter of gum. Two days after
the impression of this paste, pass the goods through steam, and wash them in running
water.  With these two designs, the logwood and gall-black, formerly described, may be
associated, to produce a rich effect.
To the preceding practical instructions for printing calicoes, silks, woollens, and mixed
fabrics, made of the two latter, a few annotations may be added.
When a uniform color is to be applied to both sides of the cloth, the padding process is
employed; but, when only one side is to be thus colored, diagonal lines are cut very closely to each other upon the cylinder, which transfer so much color from the trough to the
cloth passed under it as to make the surface appear uniformly stained. This process is
called mattage by the French. Mordants or topical dyes, to be applied in this way,
should not be-much thickened.
The doubler is the piece of felt or blanket stuff placed between the cloth to be printed,
and the block printing-table, or the cylinders. It should be kept very clean; because,
were it soiled with acetate of iron, it would spoil all the light shades made with acetate
of alumina.
Filters for the color shop of a print-house are best made of wool, formed into a substantial conical cap by felting. A filter ought to be set apart for each different dye-stuff.
When the goods after dyeing are washed, by being held by the selvage, dipped, and
shaken in a stream of water, the process is called giving a list by the French (donner une
lisiere). The piece is transferred alternately from one hand to another.
Stains. When we observe stains produced by mordants upon spots where no color is
to come, we must, before dunging the goods, apply a little of the lime-juice, or tartarooxalic acid discharge paste, to the place. If, on the contrary, the stains are not perceived
till after the maddering, we must then apply to it first a strong solution of chloride of lime
with a pencil, next a solution of oxalic acid mixed with a little muriatic with another
pencil, and immediately afterward wash with water. Every madder stain will be effaced
by this means.
Rust stains are removeable by a mixture of oxalic and muriatic acids.
Indigo stains by the combined action of chloride of lime and muriatic acid.
Topical yellow stains, or yellow dyes, by the same combination.
Metallic greens and Scheele's green by the acid alone.
Chrome green, and Prussian blue.  The blue may be taken out by a caustic alkali;
after which the goods must be washed: the residuary rust stain may be removed by the
mixture of oxalic and muriatic acids. The above methods refer to cotton and linen.
The stains on silk and woollen stuffs should be removed before fixing the colors by the
soap boil; which may generally be done by scratching with the finger, with the aid of a
little water.
For a direct calico green, see oxyde of CHROME.
VOL. 1.                             2 X




338                           CALICO PRINTING.
Mr. Hudson, of Gale, near Rochdale, obtained a patent, in December, 1834, for a mechanism which furnishes a continual and regular supply of color to the sieve or tear
(tire, Fr.), into which the printer has to dip his block, for the purpose of receiving the
color about to be transferred to the fabric in the operations of printing calicoes or paper
hangings. The contrivance consists in a travelling endless web, moved by power, which,
by passing progressively from the color vat over the diaphragm, brings forward continuously an equable supply of the colored paste for the workman's block.
31-4     d                               Fig. 314 represents the
construction of this ingenious  apparatus,  shown
e             \    " *__                     partly in section.  a a is a
vessel of iron, supported
upon wooden standards b b,
over the upper surface of
which  vessel a sheet or
diaphragm, c c, of oiled
cloth, or  other  suitable
elastic  material,  is  dis-     tended  and  made fast at
its  edges by being bent
over a flange, and packed
or cemented to render the joints water-tight. A vertical pipe d is intended to conduct
water to the interior of the vessel a, and, by a small elevation of the column, to create
such upward pressure as shall give to the diaphragm a slight bulge like the swimming
tub.
An endless web, e e e, passing over the surface of the diaphragm, is distended over three
rollers,f g h, the lower of which,f, is in contact with the color-roller i in the colortrough K. On the axle of the roller i a pulley wheel is fixed, which allows the roller to
be turned by a band from any first mover; or the roller may receive rotatory motion by a
winch fixed on its axle. On this said axle there is also a toothed wheel, taking into a
another toothed wheel on the axle of the rollerf; hence, the rotation of the color-roller
i in the one direction will cause the roller f to revolve in the opposite, and to carry forward the endless web e e e, over the elastic diaphragm, the web taking with it a stratum
of color received from the roller i, evenly distributed over its surface, and ready for the
printer to dip his block into.
The axles of the rollers f and g turn in stationary bearings; but the axle of h is mounted
in sliding nuts, which may be moved by turning the screws m, for the purpose of tightening the endless web. The axle of the color-roller i turns in mortises, and may be raised by screws n in order to bring its surface into contact with the endless web. To prevent too great a quantity of color being taken up, the endless web passes through a long
slit, or parallel aperture, in a frame o, which acts as a scraper or doctor, and is adjustable by a screw p, to regulate the quantity of color carried up. The contents of the vessel
a, and of the color-trough k, may be discharged when required by a cock in the bottom
of each. See PAPER HANGINGS, for the Fondu style.
The outside working gear of the four-colour calico printing machine, is shown in fig.
315., where A, A is a part of the two strong iron frames or cheeks in which the various
rollers are mounted. They are bound together by the rods and bolts a, a, a. B is the
large iron pressure cylinder, which rests with its gudgeons in bearings or bushes, which
can be shifted up and down in slots of the side cheeks A, A.  These bushes are
suspended from powerful screws, b, which turn in brass nuts, made fast to the top of the
frame A, as is plainly shown in the figure. These screws serve to counteract the strong
pressure applied beneath that cylinder by the engraved cylinders D, E.
c, D, E, F, (seefig. 297.) are four printing cylinders, named in the order of their operation. They consist of strong tubes of copper or gun metal, forcibly thrust by a screw
press upon the iron mandrels, round which, as shafts, they revolve.  The first and last cylinders, c and F, are mounted in brass bearings, which may be shifted in horizontal slots
of the frame A. The pressure roller B, against whose surface they bear with a very
little obliquity downwards, may be nicely adjusted to that pressure by its elevating and
depressing screws. By this means c and F can be adjusted to B with geometrical
precision, and made to press it in truly opposite directions.
The bearings of the cylinders D and E are lodged also in slots of the frame A,
which point obliquely upwards towards the centre of B. The pressure of these two
print cylinders, c and F, is produced by two screws, c and d, which work in brass nuts
made fast to the frame, and very visible in the figure. The framework in which these
bearings and screws are placed has a curvilinear form, in order to permit the cylinders
to be readily removed and replaced, and also to introduce a certain degree of elasticity.
Hence the pressure applied to the cylinders c and F partakes of the nature of a spring,




CALICO PRINTING.                                      339
11ill~ ~ ~           315
(o."'                    ~~~~                         ~               j
T Scale      a            A                                 A                feet
a circumstance essential to their working smoothly, notwithstanding the occasional
inequalities in the thickness of the felt web and the calico.
The pressure upon the other two print cylinders, D and E, is produced by weights
acting with levers against the bearings. The bearings of D are, at each of their ends,
acted upon by cylindrical rods, which slide in long tubular bosses of the frame, and
press with their nuts g, at their under end upon the smaller arms of two strong levers
G, which lie on each side of the machine, and whose fulcrum is at h (in the lower
corner at the left hand). The longer arms of these levers, G, are loaded with weights,
i, whereby they are made to press up against the bearings of the roller D, with any
desired degree of force, by  screwing up the nut g, and hanging on the requisite
weights.
The manner in which the cylinder E is pressed up against B is by a similar construction to that just described. With each of its bearings there is connected, by
the link k, a curved lever i, whose fulcrum or centre of motion is at o.  By turning,
therefore, the screw mn, the weight L, laid upon the end of the longer arm of the lever I
(of which there is one on each side of the machine), may be made to act or not at pleasure upon the bearings of the cylinder E. The operation of this exquisite machine
is minutely described in pp. 315, 316.
A patent was obtained in August, 1829, by Mr. J. C. Miller of Manchester, for certain improvements in printing calicoes, consisting of a modified mechanism, by which
the same effect can be produced as by block printing.
Figs. 316, 317, 318, are several views of this machine, calculated to print two pieces,
or two different patterns (on the same block) of calico, side by side, or four pieces, the
carriage printing both ways, the intended device consisting of four colours to be printed
from blocks.
Fig. 316. represents a side elevation, fig. 317. a front view, and fig. 318. a transverse section, taken nearly through the middle of the machine.
The side or main framing is shown at a, a, supporting the colour boxes b, b, b, with
their doctors; the furnishing tables or beds, c, c, c, (substitutes for the sieves in ordinary
2X2




340                         CALICO PRINTING.
block printing); the printing table, d, d; and the feeding, drying, and colouring
rollers, f, f, g, g, h, h.
1316   6t
The machine is also provided with a carriage, i, i, for the printing blocks, j, j, j.
This carriage, i, i, travels in and out at suitable ihtervals upon rails, k, k, attached to
the main framing.
The operation of the machine is effected by passing a driving strap, 1, round the
driving pulley m, fixed at the extremity of the main driving shaft, n, n. At the other
end of this shaft, the bevil pinion, o, is keyed, gearing at suitable intervals with the bevil
wheel p,which is mounted upon the end of the cross shaft q; at about the middle of
this shaft, the mitre wheels r, r, driving the upright shaft s, s, and mitre wheels t, t,
above, actuate, by means of the spur pinions u, u, the feeding rollersf, f, and thus draw
the pieces of goods into the machine.
Simultaneously with the progress of the cloth, the mitre wheels v, v, at the other
end of the cross shaft q,. drive the furnishing rollers w, w, w, by means of the spur gearing x, x, x. The furnishing rollers, revolving in their respective color-boxes, spread or
apply the colors upon the travelling endless blankets, y, y, y, which pass round the top
roller and the furnishing tables or beds, c, c, c, in order to supply the colors to the
surfaces of the printing blocks, j, j, j. Either beds or the backs of the printing blocks
may be made slightly elastic, to insure the perfect taking up of the colors.
Supposing the carriage, i, i, to be run out upon its railways, at the farthest point from
the beds c, c, it is drawn inward toward the furnishing beds c, c, by means of the
spur-wheel x, upon the driving-shaft a, taking into a small pinion, I (shown by dots
in fig. 17), upon the shaft, 2. On the end of this shaft is also keyed the mangle
pinion, 3, gearing in the mangle wheel, 4, which is keyed upon the end of the shaft, 5
This shaft drives the spur-wheel, 6, in gear with the pinion, 7, made fast to the shaft, s
(seefig. 19).
Upon either end of the shaft, 5, is a rack pinion, 9, taking into the horizontal rack 10,
made fast to the carriage-frame, i, i; and thus the blocks j, are presented to the furnishing blankets y, y, y, and take a supply of colour ready for printing. The travellingcarriage and blocks now retire, by the agency of the mangle-wheel and pinion, 3 and 4,
the pinion being fixed upon the end of the shaft, 2, and the wheel upon the other shaft
in a line with the shaft 2. At this time another operation of the machine takes
place.




CALICO  PRINTING.                             341
Upon the reverse end of the shaft 5, is a pinion, 11, gearing with the spur-wheel
12; and by means of the spur gearing, 6 and 13, and counter-shaft, 14, the pinion 16,
317                                          - _
Nn                         T. in      i
ra        --- IU
rX    S9 11 9
drives the spur-wheel, 16, which corresponds to the wheel, 12, on the other side of the
machine. To one of these spur-wheels are attached by bolts two quadrant levers, 17, 17;
and as these wheels revolve by means of the gearing just described, the levers, 17, 17,
draw down the chains, 18, 18, actuate the levers, 19 and 20, and thus elevate the whole
series of printing blocks in the parallel grooves, 21, 21; at the same time pressing or
closing them into one mass or block by expanding the springs, 22, 22; and at the nest
of the carriage caused at a proper interval by the agency of the mangle-wheel, the
blocks are made to impress the patterns upon the surface of the goods at once, in four
or more different colours, and in one, two, or more widths of cloth at one operation.
The cloth is now drawn forward for the space of the exact width of one of the blocks,
or sketch of the design, by means of the spur-wheels and pinions, 23, 23, and passed
around heated cylinders, g g, if necessary, and between the delivering rollers out of the
machine. These operations are to be repeated by the continuous rotation of the main
driving-shaft, until the printing is completed; the colours making a single advance
ul)poni the pattern at every presentation of the blocks, until the whole number of blocks
has been presented to the same space or portion of the goods successively.'The steam pipes, 24, are to be in connection with the printing table and drying
cylinders, in order to supply a degree of heat during the operation, which may be
regulated at pleasure.
To give suitable intervals of rest and motion to the various parts of the drivinggear, an ordinary clutched box, 25 (shown infig. 318.). and regulated by suitable stops
fixed to the travelling carriage, is used for throwing the wheel p, in and out of gear
with the pinion, o; this is to prevent clots of colour from being dragged upon the
blocks or cloth.-Newton's Journal, xxi. C. S. p. 242.
General Observations.-The cotton of Pernambuco takes a more lively Turkey red
dye than that of Georgia, and both are preferable to the Macedonian cotton. Goods
woven of dead wool cannot be well dyed. Cloth of mixed cotton and wool yarns require a peculiar treatment from the calico printer. Blues do not take well on cotton.
Indigotine, carthamine, curcumine, oxide of iron, oxide of chrome, arseniuret of sulphur and of antimony, are all substantive colours, and need no mordant to fix them;




342                         CALICO PRINTING.
but they must be presented to the stuff in a soluble state, or rendered so by some solvent. This proposition is well illustrated in the indigo dye.
318
The ferruginous mordants for good dyes, applied by the plate, have almost always a
little of a copper salt added to facilitate the peroxidation of the iron, and its combination with the stuff. The empyreumatical oil of pyrolignous acid has the power of
retarding the oxidation, and preventing the corrosive action of the ferric acid upon the
fibres. The arsenious acid is employed for the violets and lilacs; it combines with the
iron-oxide in its normal state, and stops its peroxidation. The chlor-zinc used in the
black mordant has no tinctorial operation, but it counteracts the tendency of the starch
thickeners to coagulate. Sal-ammoniac and nitre are also in many cases of great service in mordants; as well as the muriates of potash and soda. When pyrolignite of
iron alone is used, the dyes are not so rich as when some purer acetate of iron is added
to it; to favour the more ready oxidizement of the metal, which should be always introduced into the stuff in the state of black oxide. The basic pyrophosphate of iron being
soluble in alkalis makes thus an excellent mordant, especially with ammonia, which
may be dyed immediately after impression. When a solution of sulphate of iron is
mixed with one of pyrophosphate of soda, the whitish precipitate may be dissolved
(after being washed) in water of ammonia. Such a mordant serves well for a madder
bath, and also for many others.
Tin crystals (chloretin) dissolved in the sulphuric acid of Nordhausen to saturation,
have at first the consistence of syrup, but become afterwards solid; and being kept out
of contact of air, make the best of all tin mordants. For some purposes, however, the
peroxide of tin is preferable.
Generalities of Calico Printing.-I. Of the colours fixed in the humid way, or in the
water-bath, and with concourse of mordants; the simple genera are derived from the
application of indigo, carthamus, curcuma, catechu, andthe oxides of iron and chrome;
the peroxides of manganese, and lead; with the sulphide of antimony.
1. From indigo, there are the following species:(1.) The blue vat or blue ground; such as pencil blue, china blue, blue of solid application. Indigo is reduced into a soluble state by grinding in the moist condition and
mixing 100 parts of it with from 75 to 95 parts of green sulphate of iron, and 100 of
quicklime, in the vat along with 8000 parts of water, and stirring vigorously from time
to time. The vat is best heated by transmitting steam into it through pipes. By this
means the indigo vat may be prepared for action in the course of 12 hours. The liquid




CALICO PRINTING.                                343
should be transparent and of a fine yellow hue; and should have a coppery looking
pellicle on its surface.
To insure complete oxidizement to the indigo in the substance of the stuff, it may be
padded through a weak solution of sulphate of copper, mixed with a little boiled starch
and glue. See INDIGO.
Resist pastes for indigo may consist of solutions of the copper salts, which act on chemical principles by furnishing oxygen to the indigo and thus rendering it insoluble and
incapable of entering the fibres of the stuff; or they are composed of pipe clay, sulphate
of lead, and such articles as act mechanically. A resist paste with sulphate of zinc and
alum answers well for brief immersions in the vat, and it washes easily away. The
arseniates and phosphates are sometimes used along with the salts of copper to prevent
the fixation of this metal reduced upon the cloth.
The following are some receipts for reserve pastes.
No. 1. For deep blues. In 9 quarts of water dissolve,
12 pounds of sulphate of copper
5    -      acetate of copper
6    -     nitrate of copper, at 15~ B.
5    -      gum arabic
2    -      pipe clay; the latter two being thickeners.
No. 2. In 9 quarts of water dissolve,
8 pounds of sulphate of copper
4    -      acetate of copper
61 -       nitrate of copper, at 550 B. thickened with
4    -     gum arabic
8           pipe clay
No. 3. For cravats. In 9 quarts of water dissolve
8 pounds of sulphate of copper
4    -      acetate of copper
4    -      nitrate of copper, at 55~ B., thickened with
4    -      of gum arabic
8    -      of pipe clay.
In other formulae, a little alum is used; in others, verdigris dissolved in vinegar is
added to the mixture; in some a little cream of tartar is introduced, also a very small
quantity of sulphuric acid for handkerchiefs to be printed on both sides. In 9 quarts
of water, 3 pounds of sulphate of copper, i pound acetate, to be thickened with 1
pound of starch and 7 pounds of gum, 6~ pounds of pipe clay; the whole being coloured
with 1 pound of acetate of indigo.
By another formula a resist paste is made by dissolving in 8 pints of water, 20 pounds
of sulphate of zinc, incorporated with
41 pounds of pipe clay
5    -     of soft soap
--    of lard
1~ -       olive oil
-     oil of turpentine
12    -      of mucilage at 2 pounds per quart.
All the above pastes should not be thicker than what is absolutely necessary, and the
cloth to be printed should be highly calendered; in printing with blocks the workmen
should strike them with their hand and not with a mallet. It is advisable to dip the
frame with its stretched piece of cloth in milk of lime before plunging it in the vat; in
which it should receive 4 or more immersions, with airing intervals for the oxidizement
of the indigo.
Pencil blue, as applied by hand.-To 35 quarts of water, add 12 pounds of carbonate of potash, 10 of quicklime, 10 of indigo, 12 of realgar. This mixture is to be
boiled for 2 hours, then poured into a tub to settle, when the clear part is to be
thickened with gum arabic in the proportion of 1 pound to 4. The insoluble matter
is treated with a fresh quantity of water, and boiled repeatedly till it be quite exhausted,
and it then serves ulterior purposes. For this prescription may be substituted with
advantage a solution of the realgar in caustic potash, so as to avoid the annoyance introduced by the lime. This pencil blue has been of late successfully applied by the cylinder
press, working in an atmosphere of coal gas, to prevent the oxidizement by the atmospheric oxygen, till the web was all uniformly printed.
Of the styles of colour derived from Carthamus (safflower).-Safflower being washed in
pure water, is to be immersed in solution of carbonate of soda, of which the weight




344                         CALICO PRINTING.
should in no case exceed that of the safflower; for an excess of it, or too long digestion
or at too high a temperature, must be avoided. The alkaline compound, called carthamate of soda, is to be poured into an oval tub, having a discharge pipe at its bottom,
and two supports at each end of the tub, for bearing the pivots of the reel round which
the cloth is coiled, and which is turned by means of a handle. The liquid being slightly
super-saturated with lemon juice, passes from orange to a lively pink hue, and becoming
carthamine is ready to be deposited upon the cloth as it revolves in the tub. Silks,
which have been sulphured, are to be previously passed through a soda bath. But
brighter colours are obtained upon cotton.
Of the styles of colour derived from  curcuma (turmeric). This drug is employed
chiefly to modify the tints produced by other dyes: into a decoction of it any kind of
goods, cotton, silk, wool, or linen, being immersed, take a yellow stain without any
mordant. This substance has been associated with Brazil-wood for printing certain
kinds of silk handkerchiefs with a mordant of iron and alumina.
The colours derivedfrom annotto.-To dye cloth with annotto, an alkaline decoction is
to be made of it, along with a solution of dextrine, into which the cloth is to be plunged.
It needs no mordant, and affords an orange brown dye, after the alkali has been neutralized by an acid bath. A solution of peroxide of tin brightens the dye.
Of the styles of printing by means of catechu.-l. This dye stuff, combined with the
blue vat, produces very fine blacks. Catechu is prepared for dyeing by dissolving in 9
quarts of water, 7% pounds of it. along with 1 pound of acetate of copper, 2 pounds of
sal ammoniac, and 10 pounds of gum arabic.
2. To 9 quarts of pyrolignous acid, put three pounds of catechu in fine powder, which
has been steeped in 12 quarts of water. The mixture is to be evaporated at a gentle
heat, till it be reduced by one tenth, allowed to settle, and set aside for use.
To 9 quarts of the above prepared catechu, there are to be added 2~ pounds of sal
ammoniac, 4 of gum arabic, 5 of pipe clay, and 1 of nitrate of copper.
Introducing into this preparation salts which promote oxidation, the shade may be
modified, and other colours produced. Thus, in adding to 6 quarts of the above 6
quarts of acetate of protoxide of iron, at 120 B. and 9 pounds of gum arabic; or adding
to 9 quarts of the above catechu preparation, 14 quarts of water, 18 of mucilage, containing 2 pounds of gum per quart, and 9 of protacetate of iron of 9~ B.
This colour, which is employed for cylinder printing, may be extensively modified;
the acetate of iron may be replaced by a mixture of acetate and sulphate, or even by
the nitrate, if the proportions of the other soluble matters be changed. If the preparations are to be rendered more oxidable, a little corrosive sublimate or chloride of tin
may be added.
Catechu with manganese (acetate of) either alone, or with acetate of copper, forms
an excellent dye. Catechu is also united with alkalis, and with sulphate of chrome, or
tartaro-acetate of copper; chlor-calcium and acetate of lime are likewise introduced
into the formulae by some printers, for the purpose of keeping the mordants moist, as
the colours of catechu are thereby rendered richer.
After having exposed the goods printed with one or other of the mixtures for some
days to a humid atmosphere, from a hazel nut tint they become of a marron hue. The
colours are then fixed by steaming, or by means of a chromate or of lime, as a milk or
water.
Alkaline catechu gives a brown red impression. 9 quarts of the decoction of catechu,
at i pound per quart, are to be thickened with 2+ pounds of flour, and when it is
boiled, 4+ quarts of solution of caustic soda at a density of 100 B. By varying the
proportion of catechu without changing the ratios which exist among the other substances, stronger or fainter shades may be obtained, but only after several days' digestion. Lime is used for fixing such colours.
Of the colours derived from the application of the peroxide of iron.-One of the ferruginous preparations here employed is the nitro-sulphate of iron (protoxide). It is made
by adding to 10 quarts of nitric acid, about three times its weight of sulphate of iron by
very slow degrees in a large vitriol bottle; and by the mutual action of these ingredients
a portion of ammonia is formed. Six days are required to complete this compound.
Towards the conclusion the sulphate must be added very slowly, otherwise frothing will
ensue in the thickening liquor. It is liquid at the temperature of 59~ Fahr. and has a
density of 560 to 57~ B. When cooled below that point it has a tendency to crystallize.
It should always be diluted to a strength of from 180 to 22~ B. before being used.
To dye with this preparation it is to be diluted to the desired degree, and put into the
padding trough, where it serves to impregnate the goods uniformly. They are then
transferred to the stove, where they are to be dried, but not to hardness, for fear of
corroding the fibres by the red oxide of iron; they are next passed through a peculiar
padding machine containing a weak solution of carbonate of soda mixed with a little
quicklime. In proportion as the cloth is passed through the bath, and its alkaline matter




CALICO PRINTING.                                  345
gets neutralized, it must be refreshed with fresh solution of soda. The cloth may be
supplied by a soap-bath; and lastly by the dash-wheel. If the iron orange tint is not
sufficiently deep by one operation, it may be increased by another, and also rendered
more uniform. A mixture of red muriate of iron and sal ammonia gives a good iron
dye, and with perfect safety; or one of red sulphate and sal ammoniac. Goods padded
in iron liquor, dried, and then padded in a solution of chlorine containing a little freelime, acquire a good rust ground. The following prescriptions serve as resist pastes
for these dyes. In 9 quarts of hot water dissolve 5 lbs. of the biarsenate of potash, and
add to the solution as much carbonate of potash as to give it a slight alkaline reaction.
Dividing this liquor into two equal parts, there is to be incorporated with the first, 10
lbs. of pipe-clay, and to be dissolved in the second 41 lbs. of gum senegal, with I of a
pound of soft soap; the two are to be united. This resist is to a certain degree of a
mechanical quality, for the ferruginous preparation cannot touch it, without setting
the fat acid of the soap at liberty and preventing the entrance of the liquor into the
pores of the web.
White resists on rust grounds are also made with a mixture of tartaric and oxalic
acids; as also of lime juice. When the iron oxide is fixed, as in the genus avanturine,
muriate of tin is a preferable discharge; as for example:
In 9 quarts of water diffuse 31 lbs. of flour, 1 lb. of starch, and boil into a paste;
and add to 2 lbs. of this paste, 2 lbs. of acid muriate of tin at 65~ B. (solution of salt
of tin in muriatic acid.) This for printing with the block. For printing on the discharge paste by the cylinder, to 2 lbs. of the paste are to be added 4 lbs. of the acid
muriate of tin at 65~ B. In these preparations the combined action of the muriatic
acid and muriate of tin is sufficient to displace the oxide of iron; but the paste must
not be left long exposed to the air, otherwise the iron may become fixed by peroxidizement.  White discharge upon chamois (a faint rust colour) is produced by 11 lbs.
of gum arabic, 2~ lbs. of oxalic acid, 2 lbs. of tartaric acid, J lb. of oil of vitriol. After
applying this discharge the goods should not be exposed to a high heat to dry them.
The first of these two receipts tends to crystallize, the second to deliquesce. It deserves
to be remarked, that when soda is employed to precipitate rust of iron upon goods,
the tint is much deeper than it is by lime.
Of the colours produced by the oxide of chrome.-A preparation for this purpose is
made by boiling together 2 lbs. of bichromate of potash, and 4 lbs. of muriatic acid.
The muriatic acid excess is to be evaporated off. For obtaining deeper shades, arsenic
acid is introduced in determinate proportions; as for example:
To 9 quarts of water, there are added 9 lbs. of bichromate of potash, 12 of arsenious
acid, and 20 or 22 lbs. of muriatic acid, in order to destroy all the chromic acid, and
that the chlorine set at liberty in contact with the water and the arsenious acid may
transform the last into arsenic acid by the oxygen of the decomposed water. When
the reaction has ceased, a fine green liquor results, which is to be evaporated to the
density of 60~ or 65~ B. to dissipate the free acid; care should be taken to get rid of
the acid excess either by a regulated heat or by soda. Many pieces of calico are dyed
a fine green by the oxide of chrome, and are very fast.
The solution of muriate of chrome, just described, at a density of 45~ B., is to be
thickened slightly with gum, poured into a padding machine, then dried carefully to aid
the fixation of the colour, and finally passed through a weak bath of soda: to complete
the deposition of the oxide of chrome, ammonia may be substituted for the carbonate
of soda. The colours thus produced are pale green, or grey, but may be deepened by
passing the cloth through a weak bath of sulphate of copper; it may be deepened also
by mixing with arsenic acid, and after some days' repose, precipitating the arseniate
of chrome on the stuff by passing it through a bath of carbonate of soda.
Of the simple genera derived from oxide of manganese.-This colour is generally known
by the name of solitaire bistre, and sometimes turks-head. By impregnating the cloth
with a neutral solution of acetate of manganese, then precipitating the oxide with an
alkali, exposing the goods to the air to favour the oxidation, or passing them through
a bath of chlorite of lime, the process of the manganese dye may be executed. After
passing the goods through the manganese bath over 8 rollers, to secure uniformity of
impression, they should be dried immediately in a stove. The dye-bath should contain
a small quantity of.mucilage of gum arabic. The alkali for precipitating the oxide of
manganese in the padding machine should be caustic, strong, and heated by a steam pipe
to the boiling point. The strength of the alkaline solution should in all cases be 14~
B.: and for some purposes even 22~ B. This alkaline strength is requisite to seize the
fibre the instant of the tissue entering the alkaline bath, and to force, by the contraction
which it causes, the oxide of manganese to remain within it till the oxidation is completed. It is obvious that the bath must be kept up by fresh alkali. The two last
cylinders of the frame should be heavily loaded, so as to render the goods as dry as possible. A passage through solution of chlorine is in general advantageous to complete the
VOL..                                2 Y




346                         CALICO PRINTING.
oxidation of the manganese. A more economical process would be to add an equivalent of sal ammoniac to an equivalent of chlormanganese, and to make the solution
alkaline with a little ammonia. The goods padded in this liquor might be dried without risk of injury, and be then finished in the baths, first, of milk of lime, and next of
chlorine: or at once in a mixture of the two.
The shades with a foundation of manganese are often modified in various ways; as
by adding to the mixture a certain quantity of acetate of lead, whence results chlorlead;
while in passing into the solution of chlorlime, the lead is transformed into peroxide,
whose brownish yellow added to the tint of the manganese produces a yellowish cast
and a velvety aspect. Sometimes some salts of iron are added, which decomposed and
peroxidized along with the salts of manganese give shades which resemble aventurine,
the more closely the larger the proportion of iron.
Prussian blue.-Its white discharge is effected upon calico, by preparing a rust
ground of a proper tint for producing with acidulated ferrocyanure of potash the desired
blue shade. Into either the mordant or into the ferrocyanide put the quantity of muriate
of tin necessary to give the blue its purest tint. The discharge is performed usually at
two operations, by the first the ferrocyanure is decomposed by a powerful base (potash),
which forms a yellow cyanure, and liberates the iron oxide; by the second, we remove
the iron, by the intervention of an acid. But the success of this second operation depends
on the energy of the first, and especially upon the washings which follow it, and which
ought to have carried off the whole of the ferrocyanure; otherwise the presence of the
acid would regenerate the blue upon the points which should remain clear of it. The
pieces, after being dried and calendered, receive an impression with caustic potash ley
(thickened with gum), and which in every case should mark at least 140 B., in order to
make the texture contract or shrink suitably, and furnish a precise or sharp print. It
is then to be rinsed and washed in the dash-wheel so as to clear away every thing but
the oxide of iron from the cloth upon all points touched by the alkali. The piece is
then immersed in water acidulated with muriatic or sulphuric acid, till the oxide of
iron has entirely disappeared. By adding to the potash a little tartrate of potash, the
oxide of iron from the Prussian blue enters into combination with the tartaric acid,
and goes off in a great measure with the subsequent washings.
This style may also be executed upon silk and woollen goods, but great precaution
must be used to avoid injuring the texture by the strong alkaline ley. Silk handkerchiefs are first passed for about thirty minutes through a bath of nitrate of iron of 4~ B.,
then through running water, next through the dash-wheels. They are next put in a bath
of clear and cold lime water, in order to decompose the salt of iron, and to fix the oxide
upon the stuff. It is now rinsed, and sent through the dash-wheel before proceeding
to dye it; which is done by passing it through a tub sharpened with a little sulphuric
acid, and containing a small quantity of ferrocyanure of potash. After working the
cloth fifteen or twenty minutes in this bath, a little more acid and ferrocyanure are introduced, and the passage of the cloth is resumed during fifteen minutes more, which
time is usually sufficient to produce the desired tint. It might be better to decompose
previously in a separate vessel the ferrocyanure by adding to one equivalent of it in solution two equivalents of sulphuric acid. The mixture of sulphate of potash and ferrocyanic acid thence resulting, should be poured by degrees into the dyeing bath, till
the due tint is produced, or the oxide of iron on the cloth becomes saturated. When
the ground has been thus dyed, the discharge-printing may be proceeded with as already
directed. Muriate of tin may sometimes be substituted for acid, for acidifying the
ferrocyanure of potash in the act of dyeing.
By substituting oxide of copper for oxide of iron, a crimson colour is obtained with
the ferrocyanure.
Saxon blue; solution of indigo in sulphuric acid.
This blue dye is given by passing the cloth mordanted with base of alumina through
the indigo solution of a proper degree of strength. It enters also as an ingredient in
certain pistachio green dyes.
The genera of styles derived from. madder are numerous.
There are, 1. Plain grounds upon ordinary cloth; albuminous mordant.
2.              do.; iron mordant,
3.              do.; mordant of alumina and iron,
4.              do.; mordant of chrome,
5. Plain printing; white reserve with mordants of alumina, iron, or
chrome,
6.       do.       white discharge upon common madder dye.
7.       do.       white discharge on oiled cloth, with madder dye;
mordants of iron (violet and lilac) upon the cylinder.




CALICO PRINTING.                                   347
White ground; printing with alumina mordant for red and pink upon the cylinder
White ground; printing on mordants of alumina and iron.
tWhite ground; printing on mordants; for red, violet, puce, black; a binary, threefold, and fourfold union of these colours.
White ground; printing on mordants, for red, violet, or puce; separate or combined;
by the block or Perrotine. Plain ground upon oiled mordanted cloth: with alumina
or iron. Turkey red, or violet oiled.
White ground; printing with mordant of iron and alumina upon oiled cloth.
The colours obtained directly by madder are red and its gradations, pale red and pink,
which have always an aluminous mordant for their base; black and its gradations: deep
violet, light violet, and lilac, of which the base is pyrolignite of iron, or the common
acetate; red and deep puce, whose mordant is a mixture of aluminous and iron liquors;
lastly, the ventre de biche fixed by means of the oxide of chrome.
In every print wort, three principal mordants are prepared beforehand in a certain
state of concentration, which are diluted when wanted with water, but more frequently
with gum-water, and vinegar.
A. Mordant for red is made with 100 quarts of boiling water in which are dissolved
150 pounds of alum; and then 150 pounds of pyrolignite of lead added.
B. Mordant for red,
100 quarts of water, in which are dissolved,
70 pounds of alum, 48 pounds of acetate or pyrolignite of lead, 2- pounds of carbonate of soda (crystals), 4 pounds of muriate of soda.
C. Mordant for red.
In 100 quarts of boiling water are to be dissolved,
66 pounds of alum; and then to be added,
56 pounds of pyrolignite of lime, and
5 pounds of soda carbonate in crystals.
Red Mordant.
To 66 quarts of decoction of logwood, add 100 quarts of boiling water; and dissolve
in this mixture 67 pounds of alum, 56 pounds of pyrolignite of lead, and 6 pounds of
soda:
Other mordants are made of like quantity in which decoction of quercitron is put
along with chlorzinc; some into which an admixture of chalk is made, others with an
admixture of acetate of lead, and some chalk.
The blacks are made by strong mordants, with some salt of copper.
Cochineal is used much in the same way as for the madder printing and discharges,
and the mordants are much the same; Brazil wood printing is of like nature: as also
logwood dyes. The styles of printing derived from mixed colours are innumerable; but
all proceed on the principles already laid down.
Calico Printing by Steam.-All textile fibres do not attract colouring matters to them
with an equal power, but they may be rendered capable of acting with more or less force
by adventitious aids, of which the use of steam conjoined with the salts or oxides of tin
forms two of the most remarkable. The muriate or chloride of tin is decomposed by the
action of water into muriatic acid and oxide of tin, the first of which is expelled by the
heat of steam, or it may be neutralized by the intervention of a saturating substance;
while the second is never set at liberty in presence of cloth without making such a body
with it, as to resist all the means of discharge employed for the removal of the other
substances, and without fixing at the same time on the fibres the colouring matter previously mixed with it. The same reasoning may be applied to the muriate of alumina.
Oxalic acid fulfils at once the functions of these two saline compounds. It is an agent
employed to remove the oxides or the mordants; and this application is based upon the
affinity which it has for alumina and iron. When deposited upon a mordanted cloth,
it may either make the whole of the oxide disappear, if used in sufficient quantity, or it
may restore it in whole or in part eventually, if the contact be prolonged at the ordinary
temperature, or immediately when exposed to steam. It is thereby easy to explain
certain phenomena, since by its energetically dissolving the oxides, it preserves them
in solution during the whole period of printing them, and then quits them under the influence of a steam heat; and leaves them on the cloth in all their properties when alone.
It is to this peculiar property of the oxalic acid that we must ascribe the solidity of
certain topical blacks, for which it has been long employed.
The tartrates and tartaric acid concur also to the same end; but the affinity of this
acid for the bases, and the force with which it masks them, render its application more
limited than the oxalic acid. It is useful for effecting displacements, and for preserving
oxides in solution, so as to insure homogeneity to colours.
Acetic acid enters also as an ingredient into steam printing; possessing a solvent
2Y2




348                               CALOMEL.
power different from the other acids, and being applicable in a state of concentration
without corroding the tissues, it is applied in circumstances where substances of a
more or less resinous nature need to be kept in solution in order to being printed on;
whilst quitting under the influence of heat the bases with which it is associated, it allows
them to contract an intimate union with the stuffs. The salts of copper and chromate
of potash are employed to perform the oxidizing power of the absent air.
The colours fixable by steam, after having been suitably thickened, are to be printed
with the nicety appropriate to each, and the goods covered with them should be previously exposed for some time to a damp atmosphere. In the steaming process, the goods
are coiled round a perforated hollow cylinder charged with steam by a central pipe, or
they are exposed on frames in single pieces without mutual contact in wooden cases filled
with steam. Care must be had to prevent the dropping down of condensed steam upon
the goods. When rolled up in a cylindrical form, they are wrapped in blanket stuff. Of
late years contrivances have been made to keep the cloth moving in the steam so as to
receive the equal benefit of its action. A great variety of other forms of this steam-bath
are in use, according to the fancy of the operators. But in all cases there should be a
redundance of highly elastic steam, of vesicular quality, which is secured by causing
it to bubble up through a stratum of water lying on the bottom of the case.
CALOMEL.  (Chlorure de Mercure, Fr.; Versusstes Quecksilber, Germ.)  The
mild protochloride of mercury. The manufacture of this substance upon the great scale
may be performed in two ways. The cheapest and most direct consists in mixing
1  part of pure quicksilver with 1 part of pure nitric acid, of sp. grav. from
1-2 to 1-25; and in digesting the mixture till no more metal can be dissolved, or till
the liquid has assumed a yellow colour. At the same time a solution of 1 part of
common salt is made in 32 parts of distilled water, to which a little muriatic acid is
added: and, when heated to nearly the boiling point, it is mixed with the mercurial solution. The two salts exchange bases, and a protochloride of mercury precipitates in a
white powder, which after being digested for some time in the acidulous supernatant
liquor, is to be washed with the greatest care in boiling water. The circumstances which
may injure the process are the following:-1. When less mercury is employed than the
acid can dissolve, there is formed a deuto-nitrate of mercury, which forms some corrosive
sublimate with the common salt, and causes a proportional defalcation of calomel. 2. If
the liquors are perfectly neutral at the moment of mixing them, some subnitrate of mercury is thrown down, which cannot be removed by washing, and which gives a noxious
contamination to the bland calomel. The acid prescribed in the above formula obviates this danger.
The second manner of manufacturing calomel is to grind very carefully 4 parts of
corrosive sublimate (bichloride of mercury) with 3 parts of quicksilver, adding a little
water or spirits to repress the noxious dust during the trituration. The mass is then
introduced into a glass globe, and sublimed at a temperature gradually raised. The
quicksilver combines with the deutochloride, and converts it into the protochloride, or
calomel. The following formula, upon the same principle, was recommended to the
chemical manufacturer in Brande's Journal, for July, 1818:" Prepare an oxysulphate of mercury, by boiling 25 pounds of mercury with 35 pounds
of sulphuric acid to dryness. Triturate 31 pounds of this dry salt with 20 pounds 4
ounces of mercury, until the globules disappear, and then add 17 pounds of common
salt. The whole is to be thoroughly mixed, and sublimed in earthen vessels. Between
46 and 48 pounds of pure calomel are thus produced: it is to be washed and levigated
in the usual way." The above is the process used at Apothecaries' Hall, London. The
oxysulphate is made in an iron pot; and the sublimation is performed in earthen vessels. The crystalline crust or cake of calomel should be separated from the accompanying grey powder, which is nearest the glass, and consists of mercury mixed with corrosive sublimate.
An ingenious modification of the latter process, for which a patent, now expired, was
obtained by Mr. Jewell, consists in conducting the sublimed vapours over an extensive
surface of water contained in a covered cistern. The calomel thus obtained is a superior article, in an impalpable powder, propitious to its medical efficacy.
The presence of corrosive sublimate in calomel is easily detected by digesting alcohol
upon it, and testing the decanted alcohol with a drop of caustic potash, when the characteristic brick-coloured precipitate will fall, if any of the poisonous salt be present.
To detect subnitrate of mercury in calomel, digest dilute nitric acid on it, and test the
acid with potash, when a precipitate will fall in case of that contamination. As it is
a medicine so extensively administered to children at a very tender age, its purity ought
to be scrupulously watched.
118 parts of calomel contain 100 of quicksilver
A patent was obtained in September, 1841, by Anthony Todd Thomson, M. D.,




CALORIFERE OF WATER.                                 349
for an improved method of manufacturing calomel and corrosive sublimate, as
follows:
This invention consists in combining chlorine in the state of gas with the vapour of
mercury or quicksilver, in order to produce calomel and corrosive sublimate.
The apparatus employed consists of a glass, earthenware, or other suitable vessel,
mounted in brick-work, and communicating at one end with a large air-tight chamber,
and at the other end, by means of a bent tube, with an alembic, such as is generally
used in generating chlorine gas. The alembic is charged with a mixture of common
salt, binoxide of manganese and sulphuric acid, or of binoxide of manganese and muriatic acid, in order to produce chlorine gas.
The mode of operating with this apparatus is as follows:-A quantity of mercury
or quicksilver is placed in the glass vessel, and the temperature of the same is raised to
between 350~ and 660~ Fahr., by means of an open fire beneath. The chlorine gas, as
it is generated, passes from the alembic through the bent tube into the glass vessel, and
there combining with the vapour of the mercury, forms either corrosive sublimate or
calomel, according to the quantity of chlorine gas employed.
The product is found at the bottom of the air-tight chamber, and may be removed
from the same through a door, when the operation is finished.
According to the patent of Mr. Josiah Jewell, the vapour of calomel was to be
transmitted into a vessel containing water, in order to condense it at once into an
impalpable powder. But this process was beset with many difficulties.  The vapour
of the calomel was afterwards introduced into a large receiver, into which steam was
simultaneously admitted; but this plan has also been found to be precarious in the
execution. The best way is to sublime the calomel into a very large chamber from an
iron pot, in the same way as the flowers of sulphur are formed. The great body of cool
air serves to cause the precipitation of the calomel in a finely comminuted state. It is
afterwards washed with water, till this is no longer coloured by sulphuretted hydrogen.
CALORIC. The chemical name of the power or matter of heat.
CALORIFERE  OF WATER.  (Calorifere d'eau, Fr.; Wasser-Heitzung, Germ.)
In the Dictionnaire Technologique, vol. iv., published in 1823, we find the following description of this apparatus, of late years so much employed in Great Britain for heating
conservatories, &c., by hot water circulating in pipes:"This mode of heating is analogous to that by stove-pipes: it is effected by the circulation of water, which, like air, is a bad conductor, but may serve as a carrier of caloric
by its mobility. We may readily form an idea of the apparatus which has been employed
for this purpose. We adapt to the upper part of either a close kettle, or of an ordinary
cylindric boiler A, fig. 319, a tube B, which rises to a certain
height, then descends, making several sinuosities with a gentle
\ 319       slope till it reaches the level of the bottom of the boiler, to whose
lowest part, as that which is least heated, it is fitted at c.
At the highest point of the tube F we adapt a vertical pipe, des.
tined to serve as an outlet to the steam which may be formed if
the temperature be too much raised: it serves also for the escape of the air expelled from the water by the heat: and it permits the boiler to be replenished from time to time as the water
is dissipated by evaporation; lastly, it is a tube of safety.
"The apparatus being thus arranged, and all the tubes as
well as the boiler filled with water, if we kindle fire in the grate
l A        I      )D, the first portions of water heated, having become specifically
lighter, will tend to rise: they will actually mount into the upi D   //r            Sper part of the boiler, and, of course, enter the tube B F: at
the same time an equivalent quantity of water will re-enter the
boiler by the other extremity c of the tube. We perceive that
these simultaneous movements will determine a circulation in
the whole mass of the liquid, which will continue as long as heat is generated in the fireplace; and if we suppose that the tubes, throughout their different windings, are applied
against the walls of a chamber, or a stove-room, the air will get warmed by contact with
the hot surfaces; and we may accelerate the warming by multiplying these contacts in
the mode indicated.
"This calorifere cannot be employed so usefully as those with heated air, when
It is wished to heat large apartments. In fact, the passage of heat through metallic
plates is in the ratio of the difference of temperature and quantity of the heating surfaces.
In the present case, the temperature of the water, without pressure, in the tubes, must be
always under 100~ C. (212~ F.), even in those points where it is most heated, and less
still in all the other points, while the temperature of the flues in air stoves, heated directly
by the products of combustion, may be greatly higher. In these stoves, also, the pipes




350                               CALOTYPE.
may without inconvenience have a large diameter, and present consequently a large heating surface; whereas, with the water calorifere, the pressure exercised by liquid upon
the sides of the tubes being in the ratio of the surfaces, we are obliged, in order to avoid
too great pressure, to employ a multitude of small tubes, which is expensive. Lastly, if
the hot-water circulation is to be carried high, as may be often necessary in lofty buildings, the pressure resulting from the great elevation would call for proportional thickness
in the tubes and the boiler: for these reasons, and others which we shall state in treating
of heating by steam, it appears that water cannot be advantageously substituted for air
or steam in the applications above stated; yet this mode of heating presents very decided
advantages where it is useful to raise the temperature a small number of degrees in a
uniform manner."  See INCUBATION, ARTIFICIAL.
"M. Bonnemain applied, with much success, these ingenious processes of heating
by the circulation of water, to maintain a very equal temperature in hot-houses (serreschaudes), in stoves adapted to artificial incubation, and in preserving or quickening vegetation within hot-houses, or outside of their walls, during seasons unpropitious to horticulture.
" Since the capacity of water for heat is very great, if the mass of it in a circulationapparatus be very considerable, and the circulation be accelerated by proper arrangements,
as by cooling the descending tube exterior to the stove-room, we may easily obtain by such
means a moderately high and uniform temperature, provided the heat generated in the
fire-place be tolerably regular.  We may easily secure this essential point by the aid of
the fire-regulator, an instrument invented by M. Bonnemain, and which is described under the article INCUBATION, because there its use seems to be indispensable."
From the above quotation, and, more especially, from the evidence adduced in the article INCUBATION, we see how little claim the Marquis de Chabannes, or any of his followers, can have to invention in their arrangements for heating apartments by the calorific
motions of the particles of water, enclosed in pipes of any kind.
CALOTYPE is the name given by Mr. Fox Talbot to the art invented by him, of
making pictures on paper or other such surfaces by the agency of light. It is merely
a modified kind of photography. The processs is as follows:-Dissolve 100 grains
of crystallized nitrate of silver in 6 ounces of distilled water, and brush over the paper
(Whatman's sized post answers well) with a soft brush on one side only with this
solution, and mark the side. When nearly dry, dip it into the solution of iodide of
potassium (for only a few minutes), containing 500 grains of that salt dissolved in a
pint of water. As soon as the paper is completely imbued with this solution, it should
be immediately washed in distilled water, drained, and hung up to dry. This paper is
to be kept for subsequent use in a portfolio, and carefully secluded from light.
Next dissolve 100 grains of silver-nitrate in 2 ounces of distilled water, and add to
the solution one-sixth of its volume of strong acetic acid. Keep this solution in the
dark. Make a saturated solution of gallic acid in distilled water.  When it is required to make a calotype picture, the two liquids last described are to be mixed in
equal quantities, but only so much as is needed for the operation.  With this gallonitrate of silver a sheet of the silver iodide paper is to be washed over upon its marked
side with a soft brush, an operation to be performed by candle-light. After half a
minute, the paper being dipped in water, and dried lightly by pressure between folds
of blotting paper, becomes so exceedingly sensitive to light as to take a pictorial impression in the camera in a space varying from one second to five minutes, according
to the brightness of illumination.  The camera should be mounted with a meniscus
lens, in an adjustable tube, so as to throw the image of the object to be calotyped upon
a vertical plate of roughened glass, in the posterior side or wall of the wooden box.
Whenever the focus is correctly adjusted, the glass is withdrawn, and replaced by
sliding in a groove a frame with the prepared sheet of paper fixed flat upon it, the prepared side towards the lens, but screened from light by a card or thin board. The
telescope, which has been invented for calotype purposes, by Dr. Petzval and M.
Voigtlander, of Vienna, is recommended, in preference to all others, by Mr. Talbot,
especially for taking portraits.
The paper, after exposure for the due time in the camera, is to be again covered
from the light, taken out, and subjected to another process; for as yet it has no pictorial appearance. To bring out this effect, it must be washed with the gallo-nitrate of
silver, and then be gently warmed. In a few seconds the portions of the paper upon
which the light has acted will begin to darken, and eventually grow quite black,
while the rest of the paper retains its original hue. Even though the pictorial impression be very faint, it may be brought out by a second application of the same solution. The operator should watch the gradual development of the tints; and when
it is sufficient, he should fix them by dipping the paper in water, drying it slightly
with blotting paper, then washing it over with a solution of bromide of potassium




CAMPHOR.                                   351
containing 100 grains of that salt, dissolved in 8 or 10 ounces of water. Strong brine
will also answer, but not so well. Similar calotype pictures may be made by using
the bright light emitted from lime ignited by the oxy-hydrogen flame; as is practised
in making the Daguerreotype portraits at night.
In all the photographic pictures the lights and shades of the object are reversed;
but they may be made conformable to nature by rendering the paper transparent with
white wax scraped upon its back, melting this in by rubbing it with a hot smoothingiron, after it is placed between two sheets of common paper, then laying it upon paper
imbued with bromide of potassium, and exposing it to sunshine.  Portraits are best
taken by means of a lens, whose focal length is 3 or 4 times only greater than the
diameter of the aperture. (See PHOTOGRAPHY.)
CAMBRIC. (Batiste, Fr.; Kammertuch, Germ.) A sort of very fine and rather
thin linen fabric, first made at Cambray. An excellent imitation of this fabric is made
in Lancashire, woven from fine cotton yarn hard twisted. Linen cambric of a good
quality is also now manufactured in the United Kingdom from power-spun flax.
CAMLET, or CAMBLET.  A light stuff, much used for female apparel.  It is
made of long wool hard spun, sometimes mixed in the loom with cotton or linen yarn.
CAMPHOR, OR CAMPHIRE. This immediate product of vegetation was known to
the Arabs under the names of kamphur and kaphur, whence the Greek and Latin name
camphora. It is found in a great many plants, and is secreted, in purity, by several laurels; it occurs combined with the essential oils of many of the labiac e; but it is extracted, for manufacturing purposes only, from the Laurus camphora, which abounds in China
and Japan, as well as from a tree which grows in Sumatra and Borneo, called, in the
country, Kapour barros, from the name of the place where it is most common. The camphor exists, ready formed, in these vegetables, between the wood and the bark; but it
does not exude spontaneously. On cleaving the tree Laurus sumatrensis, masses of pure
camphor are found in the pith.
The wood of the laurus is cut into small pieces, and put, with plenty of water, into
large iron boilers, which are covered with an earthen capital or dome, lined within with
rice straw. As the water boils, the camphor rises with the steam, and attaches itself as
a sublimate to the stalks, under the form of granulations of a gray color. In this state,
it is picked off the straw, and packed up for exportation to Europe.
Formerly Venice held the monopoly of refining camphor, but now France, England,
Holland, and Germany refine it for their own markets. All the purifying processes proceed on the principle that camphor is volatile at the temperature of 400~ F. The substance is mixed, as intimately as possible, with 2 per cent. of quicklime, and the mixture
is introduced into a large bottle made of thin uniform glass, sunk in a sand bath. The
fire is slowly raised till the whole vessel becomes heated, and then its upper part is gradually laid bare in proportion as the sublimation goes on. Much attention and experience
are required to make this operation succeed. If the temperature be raised too slowly,
the neck of the bottle might be filled with camphor before the heat had acquired the
proper subliming pitch; and, if too quickly, the whole contents might be exploded. If
the operation be carried on languidly, and the heat of the upper part of the bottle be
somewhat under the melting point of camphor, that is to say, a little under 350~ F., the
condensed camphor would be snowy, and not sufficiently compact and transparent to be
saleable. Occasionally, sudden alternations of temperature cause little jets to be thrown
up out of the liquid camphor at the bottom upon the cake formed above, which soil it,
and render its re-sublimation necessary.
If, to the mixture of 100 parts of crude camphor and 2 of quicklime, 2 parts of boneblack, in fine powder, be added, the small quantity of coloring matter in the camphor
will be retained at the bottom, and whiter cakes will be produced. A spiral slip of platina foil immersed in the liquid may tend to equalize its ebullition.
By exposing some volatile oils to spontaneous evaporation, at the heat of about 700 F.,
Proust obtained a residuum of camphor; from oil of lavender, 25 per cent. of its weight;
from oil of sage, 12-; from oil of marjoram, 10.
Refined camphor is a white translucid solid, possessing a peculiar taste and smell.
It may be obtained, from the slow cooling of its alcoholic solution, in octahedral
crystals. It may be scratched by the nail, is very flexible, and can be reduced into powder merely by mixing it with a few drops of alcohol. Its specific gravity varies from
0'985 to 0'996. Mixed and distilled with six times its weight of clay, it is decomposed,
and yields a golden yellow aromatic oil, which has a flavour analogous to that of a
mixture of thyme and rosemary: along with a small quantity of acidulous watel
tinged with that oil, charcoal remains in the retort. In the air, camphor takes fire on
contact of an ignited body, and burns all away with a bright fuliginous flame.
Camphor is little soluble in water; one part being capable of communicating smell
and taste to 1000 of the fluid. 100 parts of alcohol, spec. gray. 0'806, dissolve 120
parts of camphor, at ordinary temperatures.  It is separated, in a pulverulent state, by
water. Ether and oils, both expressed and volatile, also dissolve it.




352                                 CANDLES.
When distilled with eight parts of aquafortis, camphor is converted into camphoric acid.
Camphor absorbs 144 times its volume of muriatic acid ga~, and is transformed into a colorless transparent liquid, which becomes solid in the air, because the acid attracts humidity, which precipitates the camphor. One part of strong acetic acid dissolves two
parts of camphor. By my analysis, camphor consists of 77-38 carbon, 11,'4 hydrogen,
and 11-48 oxygen. Berzelius's numbers are certainly erroneous.
CAMWOOD. An article imported from Sierra Leone, which seems to possess similar
dyeing powers with Brazil or Nicaragua wood.
CANDLE.  (Chandelle, Fr.; Kerze, Licht, Germ.)  I shall first briefly describe the
ordinary manufacture of candles.  They are either dipped or moulded. But the first
part of the process is the sorting of the tallow. Mutton suet with a proportion of oxtallow is selected for mould candles, because it gives them gloss and consistence. Coarser
tallow is reserved for the dipped candles. After being sorted, it is cut into small pieces,
preparatory to being melted or rendered; and the sooner this is done after the fat is
taken from the carcass the better, because the fibrous and fleshy matters mixed with it
promote its putrefaction. Tallow is too commonly melted by a naked fire applied to
the bottom of the vessel, whereas it should be done either in a cold set pan, where the
flame plays only round the sides a little way above the bottom, or in a steam-cased pan.
After being fused a considerable time, the membraneous matters collect at the surface,
constituting the cracklings used sometimes for feeding dogs, after the fat has been
squeezed out of it by a press. The liquid tallow is strained through a sieve into another
copper, where it is treated with water at a boiling temperature in order to wash it. After a while, when the foul water has settled to the bottom, the purified tallow is lifted out,
by means of tinned iron buckets, into tubs of a moderate size, where it concretes, and is
ready for use.
It is a remarkable circumstance, that the wicks for the best candles are still cotton
rovings imported from Turkey, notwithstanding the vast extension and perfection of
cotton-spinning in this country. Four or'more of these Turkey skeins, according to the
intended thickness of the wick, are wound off at once into bottoms or clews, and afterward cut by a simple machine into lengths corresponding to those of the candles to be
made. Mr. Colebank obtained a patent, in June, 1822, for a machine for cutting, twisting, and spreading wicks, which, though convenient, does not seem to have come into
general use. The operations are performed upon a series of threads at once. The apparatus is placed in a box, in front of which the operator sits. A reel extends across
the box, at the hinder part, upon which the cotton threads have been previously wound:
from this reel they are drawn off in proper lengths, doubled, and cut by an ingenious mechanism. By dipping the wicks into the melted tallow, rubbing them between the palms
of the hands, and allowing the tallow which adheres to harden, they may be arranged
with facility upon the broaches for the purpose of dipping. The dipping-room is furnished with a boiler for melting the tallow, the dipping-mould, or cistern, and a large
wheel for supporting the broaches. From the ceiling of the workshop a long balanceshaped beam is suspended, to one end of which a wooden frame is attached for holding
the broaches with the wicks arranged at proper distances. The opposite arm is loaded
with a weight to counterbalance the wooden frame, and to enable the workman to ascer.
tain the proper size of the candles. The end of the lever which supports the fiame is
placed immediately above the dipping-cistern; and the whole machine is so balanced that
by a gentle pressure of the hand, the wicks are let down into the melted tallow as oftes
as may be required.
The following convenient apparatus for dipping candles has been long in use at Edin
burgh. In the centre of the dipping-room a strong upright post A A, fig. 320, is erected,
with turning iron pivots at its two ends. Near its middle, six mortises are cut at smal
distances from one another, into each of which is inserted a long bar of wood Ba, which
moves vertically upon an iron pin, also passing through the middle of the shaft. The
whole presents the appearance of a large horizontal wheel with twelve arms. A complete
view of two of them only is given in the figure. From the extremity of each arm is
suspended a frame, or port, as the workmen call it, containing 6 rods, on each of which
are hung 18 wicks, making the whole number of wicks upon the wheel 1296. The
machine, though apparently heavy, turns round by the smallest effort of the workman;
and each port, as it comes in succession over the dipping-mould, is gently pressed downwards, by which means the wicks are regularly immersed in melted tallow.  As the
arms of the lever are all of the same length, and as each is loaded with nearly the same
weight, it is obvious that they will all naturally assume a horizontal position.  In
order, however, to prevent any oscillation of the machine in turning round, the
levers are kept in a horizontal position by means of small chains a a, one end of which
is fixed to the top of the upright shaft, and the other terminates in a small square piece
of wood, b, which exactly fills the notch c in the lever. As one end of the lever
must be depressed at each dip, the square piece of wood is thrown out of the notch




CANDLES.                                   353
by the workmen pressing down the handle D, which communicates with the small lever e,
inserted into a groove in the bar B. In order that the square piece of wood fixed in one
extremity of the chain may recover its
position upon the workman's raising
the port, a small cord is attached
320      a/  \   to it, which passes over a pulley inserted in a groove near c, and comd ^  i A.i \            municates with another pulley and. /d/ D I y~  \         weight, which draws it forward to
the notch. In this way the operation
of dipping may be conducted by a.I'     single workman  with  perfect ease
and regularity, and  even dispatch.'Wt ~c ~ ~~11             No time is lost, and no unnecessary
labour expended, in  removing  the
C    ^                                      abor e         d ports  after each dip; and, besides,
the process of cooling is much accelecW                      l  i z ^ _ _  D  3rated by the candles being kept in
constant motion through the air. The
number of revolutions which the wheel
must make, in order to complete one
operation, must obviously depend upon
the state of the weather and the size
of the candles; but it is said that, in
moderately cold weather, not more than two hours are necessary for a single person
to finish one wheel of candles of a common size. Upon the supposition, therefore,
that six wheels are completed in one day, no less a number than 7776 candles will be
manufactured in that space of time by one workman.
I shall next describe the process of moulding, which, if possible, is even less corn
plicated in its details than that of dipping. The moulds are made of some metallic
substance, usually pewter, and consist of two parts. The shaft or great body of the
mould is a hollow cylinder, finely polished in the inside, and open at both extremities.
The top of the mould is a small metallic cup, having a moulding within-side, and a hole
to admit the wick. The two parts are soldered together, and when united, as will readily be imagined, have the shape of a moulded candle. A third piece, called the foot, is
sometimes added: it is a kind of small funnel, through which the liquid tallow runs into
the mould, and, being screwed to the opposite extremity of the shaft, is removeable at
pleasure. This additional piece may certainly be useful in very mild weather, since, by
removing it, the candles may be drawn more easily from the moulds; but, in general, it
may be dispensed with.
Eight or twelve of these moulds, according to their size, are fixed in a frame, which
bears a great resemblance to a wooden stool, the upper surface of which forms a kind of
trough. The top of the moulds points downwards, and the other extremity, which is
open, is inserted into the bottom trough or top of the stool, and made quite level with its
upper surface. In order to introduce the wicks into the mould, the workman lays the
frame upon its side on an adjoining table, and holding in his left hand a quantity of wicks,
previously cut to the proper length, he introduces into the mould a long wire with a
hooked point. As soon as the hook of the wire appears through the hole in the top of
the mould, he attaches to it the looped end of the wick, and, immediately drawing back
the wire, carries the wick along with it. In this manner each mould in succession is
furnished with a wick. Another workman now follows, and passes a small wire through
the loop of each wick. This wire is obviously intended to keep the wick stretched, and
to prevent it from falling back into the mould upon the frame being placed in the propel
position for filling. The frame is then handed to the person that fills the moulds, who
previously arranges the small wires in such a manner that each wick may be exactly
in the axis of the mould.
The moulds are filled by running tallow into each of them, or into the trough, from a
cistern furnished with a cock, and which is regularly supplied with tallow of the proper
temperature from an adjoining boiler. When the workman observes that the moulds are
nearlyhalf filled he turns the cock, and laying hold of that portion of the wick which hangs
out of the moulds, pulls it tight, and thus prevents any curling of the wick, which might
injure the candles: he then opens the cock, and completes the process of filling. The frame
is now set aside to cool; and when the tallow has acquired a proper consistence, which the
workman easily discovers by a snapping noise emitted by the candles upon pressing his
thumb against the bottom of the moulds, he first withdraws the small wires which kept
the wicks tense, and then, scraping off the loose tallow from the top of the frame with
& small wooden spade, he introduces a bodkin into the loop of the wick, and thus
VOL. 1                               2Z




354                                CANDLES.
draws each candle in succession from its mould. The candles are now laid upon a
table for the inspection of the exciseman, and afterwards removed to the storehouse.
Previous to storing them up, some candle-makers bleach their candles, by exposing
them to the air and dews for several days. This additional labour can be necessary
only when the dealer is obliged to have early sales; for if the candles are kept for
some months, as they ought to be, before they are brought to market, they become
sufficiently whitened by age.
Wax candles.-Next to tallow, the substance most employed in the manufacture
of candles is wax. Wax candles are made either by the hand or with a ladle. In the
former case, the wax, being kept soft in hot water, is applied bit by bit to the wick,
which is hung from a hook in the wall; in the latter, the wicks are hung round an iron
circle, placed immediately over a large copper-tinned basin full of melted wax, which is
poured upon their tops, one after another, by means of a large ladle. When the candles
have by either process acquired the proper size, they are taken from the hooks, and
rolled upon a table, usually of walnut-tree, with a long square instrument of box, smooth
at the bottom.
A few years ago I made a set of experiments upon the relative intensities of light, and
duration of different candles, the results of which are contained in the following
table.
Duration of a  Weiht in  Consump    roportion  Economy   Candles
gper hour in                  eqo
Number in a pound.    de.       grain.    per hour in  of light.  of light.  ealone
grains.                      Argand.
A. h.
10 mould-      -   5   9         682         132       124       68       5-7
10 dipped- -  -   4  36          672         150        13       65^      5-25
8 mould- - -   6  31             856        132        10-       591     6-6
6 ditto  - --   7   2`         1160         163       142       66       5'0
4 ditto  - -  -   9  3'6        1707        186       201        80       3-5
Argand oil flame                             512       69-4      100
A Scotch mutchkin, or I of a gallon of good seal oil, weighs 6010 gr., or 13J1 oz.,
avoirdupois, and lasts in a bright Argand lamp 11 hours 44 minutes. The weight of
oil it consumes per honr is equal to 4 times the weight of tallow in candles 8 to the
pound, and I the weigh of tallow in candles 6 to the pound. But, its light being equal
to that of 5 of the latter candles, it appears from the above table that 2 pounds weight of
oil, value 9d. in an Argand, are equivalent in illuminating power to 3 pounds of tallow
candles, which cost about two shillings. The larger the flame in the above candles the
greater the economy of light.
In June, 1825, M. Gay Lussac obtained a patent in England for making candles from
margaric and stearic acids, improperly called stearine, by converting tallow into the above
fat acids by the following process:-Tallow consists, by Chevreul's researches, of stearine,
a solid fat, and elaine, a liquid fat; the former being in much the larger proportion.
When tallow is treated with an alkaline body, such as potash, soda, or lime, it is saponified;
that is, its stearine and elaine become respectively stearic and elaic acids, and, as such,
form compounds with these bases. When by the action of an acid, such as the sulphuric
or muriatic, these combinations are decomposed, the fats reappear in the altered form of
stearic and elaic acids; the former body being harder than tallow, and of a texture
somewhat like spermaceti, the latter body being fluid, like oil. " The decomposition of the
soap should be made," says the patentee, " in a large quantity of water, kept well stirred
during the operation, and warmed by steam introduced in any convenient way. When
the mixture has been allowed to stand, the acid of the tallow or fat will rise to the
surface, and the water being drawn off will carry. the alkaline or saline matters with it;
but if the acids of the tallow should retain any portion of the salts, fresh water may be
thrown upon it, and the whole well agitated, until the acids have become perfectly free
from the alkaline matters; and when allowed to cool, the acids will be formed into a
solid mass. This mass is now to be submitted to considerable pressure in such an apparatus as is employed in expressing oil from seeds; when the liquid acid will run off in the
form of a substance resembling oil, leaving a solid matter, similar, in every respect, to
spermaceti, which is fit for making candles."
The wick to be used in the manufacture of these improved candles, and which forms
one of the features of this invention, is to be made of cotton yarn, twisted rather hard,
and laid in. the same manner as wire is sometimes coiled round bass strings of
musical instruments. For this purpose straight rods or wires are to be procured, of
suitable lengths and diameters, according to the intended size of the candles about to be
made: and these wires, having been covered with cotton coiled round them as described,
are to be inserted in the candle moulds as the common wicks are; and when the candle




CANDLES.                                  355
is made, and perfectly hard, the wire is to be withdrawn, leaving a hollow cylindrical
aperture entirely through the middle of the candle. See STEARINE
CANDLES.  Messrs. Hempel and Blundell have given a very minute account of
the process for making palm-oil, stearic and margaric acids, in the specification of their
patent for this mode of manufacturing candles:
1. Their first process is called crystallization, which consists in pouring the melted
palm-oil into iron pans, and allowing it to cool slowly, whereby, at about 75~ F., the
elaine separates from the crystalline stearine and margarine.
2. The concreted oil is subjected to the action of an hydraulic press, in order to separate the elaine from the solid fats.
3. This process is called oxidation. To 104 lbs. of the stearine and margarine,
melted in an iron pan, about 12 lbs. of slaked and sifted quicklime are added, with
diligent stirring, during which the temperature is to be slowly raised to 240~ F., and
so maintained for about three hours, till a perfect chemical combination takes place.
This is shown by the mass becoming thin, transparent, and assuming a glassy appearance when it cools. The fire being now withdrawn, cold water is added very gradually
at first, with brisk stirring till the whole mass falls into a state of powdery granulation,
when it is passed through a wire sieve to break down any lumps that may remain.
4. Separation of the stearic and margaric acids from the lime. For this prpose, as
much muriate of lime (chlorcalcium) is taken as will, with its equivalent quaitity of
sulphuric acid (8 lbs. of dry chlorcalcium require 7 abs. of the strongest sulphuric
acid), produce as much muriatic acid as will dissolve the lime combined with the fat
acids; and therefore that quantity of muriate of lime dissolved in water must be
treated with as much sulphuric acid as will saturate its lime and throw it down in the
state of sulphate of lime. Add the supernatant solution of muriatic acid in such proportion to the stearate and margarate of lime as will rather more than saturate the
lime. Three pounds of muriatic acid diluted with 9 lbs. of water are stated as enough
for 1 lb. of lime. This mixture is to be let alone for 3 or 4 days, in order to insure the
complete separation of the lime from the fat acids; and then the mixture is heated so
as to melt and cause them to separate in a stratum on the top of the liquid. The resulting muriate of lime is drawn off into another tub, and decomposed by its dose of
sulphuric acid, so as to liberate its muriatic acid for a fresh operation.
5. The fat acids, being well washed by agitation with hot water, are then set to cool
and crystallize, in which state they are subjected to the action of the hydraulic press,
at a temperature of 75~ F., whereat the margaric acid runs off from the solid stearic
acid.
6. Bleaching. The stearic acid is taken from the press, and exposed upon water in
large shallow vessels placed in the open air, where it is kept at the melting temperature from 8 to 12 hours, stirring meanwhile, in order to promote the blanching action
of the atmosphere. The margaric acid is bleached in a similar manner in separate
vessels.
7. Refining process. The fat is warmed again, and poured in a liquid state into an
agitating tub; where, for every 1,000 lbs. of the stearic acid, about 24 lbs. of common
black oxide of manganese, and 40 lbs. of concentrated sulphuric acid, diluted with
200 Ibs. of pure water, are to be used. This solution (" mixture"), while warm from
the heat evolved in diluting the acid, is placed in a suitable vessel above the agitating
tub. The stearic acid being at the melting point, in the vessel below, agitation is to
be given with a revolving shaft, while the mixed manganese and acid are run slowly
down into it, till the whole be well mixed, which generally requires about two hours.
The mass is allowed to lie in this state for 48 hours; after which it may be boiled by
stean for 2 or 3 hours, when it will be sufficiently refined. The sulphuric acid, which
is at the bottom, is now run off, and the stearic acid which remains is well washed with
pure water. It is then put into large conical vessels of stoneware, enclosed in a box
or jacket, kept warm by steam-heat, and lined with conical bags of suitable strong
filtering paper, through which, being warm, it finds its way; and when the stearic acid
has been thus filtered, it is run into blocks, when it will be found to be a beautiful
stearic acid or palm-wax, and is ready to be made into candles in the usual way.
On the above process with manganese and diluted sulphuric acid, it may be observed,
that no solution or chemical action takes place between them, and their joint use seems
therefore most problematical. The patentees proceed to describe other processes of
refining, in which sulphate of manganese, with common salt, phosphoric acid (highly
concentrated), and oxalic acid, are used, and in my opinion either ignorantly or for the
purpose of mystification; for, as prescribed, they can serve no possible purpose of
purifying the stearnine.
The chief solid constituent of palm-oil is margaric acid. This they direct to be
melted with tallow, in the proportion of from 10 to 20 lbs. of the former to 100 lbs. of
the latter. See Newton's Journal, C. S., xi. 207.
2Z 2




356                                CANDLES.
I was told by M. Runge, at Berlin, that he was the inventor of the process for
making white margaric acid from palm-oil, and that Hempel had got it somehow
from him, but most imperfectly, as it would appear. Hempel died here in the midst
of the above patent operations; but the specification is, no doubt, a specimen of his
manufacture of Runge's margaric acid.  He gave me a splendid pearly-looking sample.
Mr. Wilson of Belmont, Vauxhall, obtained in August, 1844, a patent for improvements in treating fats for making candles. If distilled fats are used in making composite candles, they are bleached and hardened in that operation.  When paln-oil is the
material, it is first saponified; then distilled, granulated by fusion and slow cooling, and
cold-pressed; by which means stearic acid and a light coloured oil are obtained; which
may be mixed with the stearine of cocoa-nut oil, or other stearine.  A cheaper article
may be had by mixing the entire product of the above distillation with half its weight
of distilled and cold-pressed stearic acid of tallow. Tallow is deprived of its oleine by
pressure, accompanied by artificial cold if necessary; this being added to the other hard
matter, the mixture is converted into fatty acids, and distilled, and the entire product of
distillation is employed for making candles; or itmay be pressed to make them harder.
As distilled stearic acid is more crystalline than undistilled, 2 or 4 per cent. of wax may
be added to assist the combination of the fatty acid with the stearine.-Newton's Journal, xxvi. 165.
Candles consisting of alternate layers of tallow and stearine have been made by dipping
their wicks alternately in them two fatty bodies in a fluid state. Mr. W. Sykes has
gone to the expense of a patent on the contrivance.  The wicks are impregnated with
a solution of bismuth or borax.
New patent candle manuzfacture.-Vegetable tallow melts at a degree of heat somewhat
above that of animal tallow, but considerably below that of vegetable wax. Mr. Wilson
of Belmont, Vauxhall, treats his tallow by putting 6 tons of it into an iron still capable
of holding 9 tons, heats it gradually to 350~ Fahr., and then adds gradually 1440 lbs.
of sulphuric acid of 1-8 sp. gr. At the expiration of about 2 hours, the tallow is
pumped into a vessel, containing water slightly acidulated with sulphuric acid; and is
therein agitated by free steam passing through it for 2 hours. The materials are then
left to repose for 6 hours; both this vessel and the former should be provided with a
cover and a means of conveying the gases which may be evolved into a chimney.
The vegetable tallow is next distilled in such a manner that the atmosphere is excluded.
This is best effected by the use of steam highly heated, which he introduces into the still,
in numerous jets below the tallow. The distilled products are received into condensers,
and they may be used alone, or they may be mixed with other matters for making the
best class of candles.  The patentee improves paraffine by a like process.  He makes
candles with 2 or 3 wicks, by mixing palm-oil pressed with tallow, or the above distilled
fat, for burning in candle lamps. —Newton's Journal, xxxv. 108.
The following is one of his later processes. Candles and night-lights are manufactured
by 3Mr. Wilson of Vauxhall, by combining palm-oil which has been bleached by the
atmosphere with distilled fatty acids, with or without other fats.  By combining one
part of crude cocoa-nut oil, one part of cold pressed atmospherically bleached palm-oil,
and one part of unpressed palm-oil, acidified by sulphuric acid and distilled, an excellent
product is obtained; and other distilled fatty acids may be used, pressed or unpressed.
This distillation is effected by transmitting through the fat contained in an iron still,
steam at about 600~ or 700~ Fahr., heated by passing through iron pipes laid in a fire.
The steam is transmitted till the oily matter is heated to about 350; the vapours
produced being carried into a high shaft by a pipe from the cover of the iron vessel.
The hot oily matter is then run into another vessel made of brick lined with lead, and sunk
in the ground, for the purpose of supporting the brick-work under or against the internal
pressure of the fluid. It has a wooden cover lined with lead, directly beneath which, and
extending across the vessel, is a leaden pipe, 1 inch in diameter, having a small hole in
each side, at every six inches of its length; and through this pipe is introduced a mixture
of 1000 lbs. of sulphuric acid, sp. gr. 18., and the same weight of water. The introduction of the mixture which falls in divided jets into the heated fat, produces violent ebullition; and by this means the acid and fat are perfectly incorporated before the action of
the acid becomes apparent by any considerable discoloration of the fat. As the ebullition ceases, the fat gradually blackens; and the matter is allowed to remain for 6 hours
after the violent ebullition has ceased. The offensive fumes produced are carried off by
a large pipe, which rises from the top of the vessel, then descends, and afterwards rises
again into a high chimney. At the downward part of this pipe a small jet of water is
kept playing, to condense such parts of the vapours as are condensable. At the end of
the 6 hours above mentioned, the operation is complete, and the product is then pumped
into another close vessel and washed by being boiled up (by means of free steam) with
half its bulk of water. The water is drained off, and the washing repeated, except that
in the second washing the water is acidulated with 100 lbs. of sulphuric acid. The




CAOUTCHOUC.                                   357
ultimate product is allowed to settle for 24 hours; after which it is distilled in an atmosphere of steam, once or oftener, until well purified; and the product of distillation is
again washed, and after being pressed in the solid state, is applied to the manufacture
of candles.-Newton's London Journal, xxvi. and xxxv.
CANE-MILL.  See MILL and SUGAR.
CANNON.  For the composition of these implements of destruction, see BRONZE.
CANVASS.  (Canevas, Fr.; Segeltuch, Germ.)  It has been found that sails of ships
made with the selvages and seams of the canvass running down parallel to their edges,
are very apt to bag, and become torn in the middle, from the strain to which they are subjected by the pressure of the wind. To obviate this inconvenience, a mode of making
sails, with the seams and selvages running diagonally, was proposed by Admiral Brookihg,
and a patent granted to him for the same on the 4th of September, 1828. The invention
of Messrs. Ramsay and Orr, which we are about to describe, has a similar object, viz.,
that of giving additional strength to sails by a peculiar manner of weaving the canvass
of which they are made.
The improvement proposed under their patent of March, 1830, consists in weaving the
canvass with diagonal threads; that is, placing the weft yarn, or shoot, in weaving, at an
oblique angle to the warp yarns, instead of making the decussation of the warp, or weft
threads, or yarns, at right angles to each other, as in the ordinary mode of weaving.
To accomplish this object, the loom must be peculiarly constructed; that is, its warp
and work beams must stand at an oblique angle with the sides of the loom, and the batten
and slay must be hung in a peculiar manner, in order to beat up the weft, or shoot, in
lines ranging diagonally with the warp. No drawing is shown of the method by which
this arrangement of the loom is to be made, but it is presumed that any weaver would
know how to accomplish it: the invention consisting solely in producing sail-cloth with
the threads or yarns of the weft ranging diagonally at any desired angle with the direc
tion of the warp thread.
CAOUTCHOUC, GUM-ELASTIC, OR INDIAN-RUBBER (Federharz, Germ.), occurs as a milky juice in several plants, such as the siphonia cahuca, called also hevea guianensis, cautschuc, jatropha elastica, castilleja elastica, cecropia pellata, ficus religiosa
and undica, urceolaria elastica, &c. It is, however, extracted chiefly from the first plant,
which grows in South America and Java.  The tree has incisions made into it through
the bark in many places, and it discharges the milky juice, which is spread upon clay
moulds, and dried in the sun, or with the smoke of a fire, which blackens it.
The juice itself has been of late years imported. It is of a pale yellow color, and has
the consistence of cream. It becomes covered, in the bottles containing it, with a pellicle
of concrete caoutchouc. Its spec. grav. is 1-012. When it is dried, it loses 55 per cent.
of its weight: the residuary 45 is elastic gum. When the juice is heated, it immediately
coagulates, in virtue of its albumen, and the elastic gum rises to the surface. It mixes
with water in any proportion; and, when thus diluted, it coagulates with heat and alcohol as before.
The specific gravity of caoutchouc is 0-925, and it is not permanently increased by
any degree of pressure. By cold or long quiescence, it becomes hard and stiff. When
the milky juice has become once coherent, no means hitherto known can restore it to
the emulsive state.  By long boiling in water it softens, swells, and becomes more
readily soluble in its peculiar menst'ua; but when exposed to the air, it speedily resumes
its pristine consistence and voluire. It is quite insoluble in alcohol; but in ether, deprived of alcohol by washing with water, it readily dissolves, and affords a colorless
solution. When the ether is evaporated, the caoutchouc becomes again solid, but is
somewhat clammy for a while. When treated with hot naphtha, distilled from native
petroleum, or from coal tar, it swells to 30 times its former bulk; and if then triturated
with a pestle, and pressed through a sieve, it affords a homogeneous varnish, which being
applied by a flat edge of metal or wood to cloth, prepares it for forming the patent
water-proof cloth of Mackintosh.  Two surfaces of cloth, to which several coats of the
above varnish have been applied, are, when partially dried, brought evenly in contact, and
then passed between rollers, in order to condense and smooth them together. This double
cloth is afterwards suspended in a stove-room to dry, and to discharge the disagreeable
odour of the naphtha.
Caoutchouc dissolves in the fixed oils, such as linseed oil, but the varnish has not the
property of becoming concrete upon exposure to air.
It has been lately asserted that caoutchouc is soluble in the oils of lavender and sassafras.
It melts at 248~ F., and stands afterwards a much higher heat without undergoing
any further change. When the melted caoutchouc is exposed to the air, it becomes
hard on the surface in the course of a year.  When kindled it burns with a bright
flame and a great deal of smoke.
Neither chlorine, sulphurous acid gas, muriatic acid gas, ammonia, nor fluosilicic acid




358                              CAOUTCHOUC.
gas affects it, whence it forms very valuable flexible tubes for pneumatic chemistry. Cold
sulphuric acid does not readily decompose it, nor does nitric acid, unless it be somewhat
strong. The strongest caustic potash ley does not dissolve it even at a boiling heat.
Caoutchouc, according to my experiments, which have been confirmed by those of Mr.
Faraday, contains no oxygen, as almost all other solid vegetable products do, but is a
mere compound of carbon and hydrogen, in the proportion, by my results, of 90 carbon to
10 hydrogen, being three atoms of the former to two of the latter. Mr. Faraday obtained only 87-2 carbon, from which I would infer that some of the carbon, which in this
substance is difficult to acidify by peroxyde of copper, had escaped its action. It is obvious that too little carbonic acid gas may be obtained, but certainly not more than corresponds to the carbon in the body. No carbon can be created in the process of ultimate
analysis by pure peroxyde of copper such as I employed; and I repeated the ignition
after attrition of the mixture used in the experiment. Melted caoutchouc forms a
very excellent chemical lute, as it adheres very readily to glass vessels, and withstands
the corrosive action of acid vapors. This substance is much used for effacing the traces
of plumbago pencils, whence it derived the name of Indian-rubber. It has been lately
employed very extensively for making elastic bands or braces. The caoutchouc bottles
are skilfully cut into long spiral slips, which are stretched, and kept extended till nearly
deprived of their elasticity, and till they form a thread of moderate fineness. This thread
is put into a braid machine, and covered with a sheath of cotton, silk, linen, or worsted.
The clothed caoutchouc is then laid as warp in a loom, and woven into an elegant riband.
When woven, it is exposed upon a table to the action of a hot smoothing iron, which restoring to the caoutchouc all its primitive elasticity, the riband retracts considerably in
length, and the braiding corrugates equally upon the caoutchouc cores. Such bands possess a remarkable elasticity, combined with any desired degree of softness. Sometimes
cloth is made of these braided strands of caoutchouc used both as warp and as weft, which
is therefore elastic in all directions. When a light fabric is required, the strands of caoutchouc, either naked or braided, are alternated with common warp yarns. For this mixed
fabric a patent has been obtained. The original manufacturer of these elastic webs is a
major in the Austrian service, who has erected a great factory for them at St. Denys,
near Paris. See ELASTIC BANDS.
Mr. William Henry Barnard, in the course of some experiments upon the impregnation
of ropes with caoutchouc, at the factory of Messrs. Enderby, at Greenwich, discovered that
_-,~^M~~ ~                 when this substance was exposed to
2^~~j~~O^~  ~a heat of about 600~ F. it resolved
E^=/ W                       ~~itself into  a vapor, which, by
proper refrigeratory methods, was
condensable into a liquid possessing
very  remarkable  properties,  to
which the name caoutchoucine has
been  given.  For this invention
" of a solvent not hitherto used in
the arts" Mr. Barnard obtained a
patent, in  August,  1833.  His
321                  process for preparing it is described
in his specification as follows:-I
take a mass of the said caoutchouc,
^111   A    ll 111111~^ 1~or Indian rubber, as imported, and
having  cut it into small lumps,
containing about two cubic inches
each (which I prefer), I throw these
lumps into a cast-iron still (which
I find adapted for the purpose, and
/,I /~     i  a diagram  of which is annexed to,
and forms part of, this my specification), with a woim attached; fig. 321, A is the still, B the cover ground to a metallic
fit, to admit of a thermometer to take the temperature; c the fire-place, D the ash-pit,
E the worm-tub and worm, F the brick-work of the still, G a roller and carriage, in conjunction with a crane, or other means, to raise the cover to take out the residue, and to
charge the same; H the chain.
" I then apply heat to the still in the usual manner, which heat is increased until the
thermometer ranges at 600 degrees of Fahrenheit, or thereabouts. And, as the thermometer ranges progressively upwards to 600 degrees of Fahrenheit, a dark-coloured
oil or liquid is distilled over, which I claim as my said invention, such liquid being a
solvent of caoutchouc, and other resinous and oleaginous substances. When the thermometer reaches 600 degrees, or thereabouts, nothing is left in the still but dirt and
charcoal.




CAOUTCHOUC.                                      359
I have found the operation of distillation to be facilitated by the addition of a portion
ef this oil, either previous or subsequent to rectification, as hereinafter mentioned, in the
proportion of one third of oil to two thirds of caoutchouc.
I afterwards subject the dark-colored liquid thus distilled to the ordinary process of
rectification, and thereby obtain fluids varying in specific gravity, of which the lightest
hitherto has not been under 670, taking distilled water at 1000, which fluids I also claim
as my said invention.
At each rectification the color of the liquid becomes more bright and transparent, until,
at the specific gravity of 680, or thereabouts, it is colorless and highly volatile.
In the process of rectification (for the purpose of obtaining a larger product of the oil
colorless) I put about one third of water into the still.  In each and every state the
liquid is a solvent of caoutchouc, and several resinous and oleaginous substances, nd
also of other substances (such as copal), in combination with very strong alcohol.
Having experienced much difficulty in removing the dirt which adheres to the bottom
of the still, I throw into the still lead and tin in a state of alloy (commonly called solder),
to the depth of about half an inch, and, as this becomes fused, the dirt which lies on the
surface of it is more easily removed.
Objections have been made to the smell of this liquid: I have found such smell removed by mixing and shaking up the liquid with nitro-muriatic acid, or chlorine, in the
proportion of a quarter of a pint of the acid (of the usual commercial strength) to a
gallon of the liquid.
The discovery of the chemical solvent, which forms the subject of the patent above
described, has excited considerable interest in the philosophic world, not only from its
probable usefulness as a new article of commerce, but also from two very extraordinary
characteristics which it is found to possess, viz., that, in a liquid state, it has less specific
gravity than any other liquid known to chemists, being considerably lighter than sulphuric ether, and, in a state of vapor, is heavier than the most ponderous of the gases.
Its elementary constituents are,
Carbon -                   -             6 -812    -    -  8 proportions.
Hydrogen                         1.- 1000    - -    -    7 ditto.
This new material (when mixed with alcohol) is a solvent of all the resins, and particularly of copal, which it dissolves, without artificial heat, at the ordinary temperature of
the atmosphere; a property possessed by no other solvent known; and hence it is peculiarly useful for making varnishes in general. It also mixes readily with oils, and will
be found to be a valuable and cheap menstruum for liquefying oil-paints; and, without in
the slightest degree affecting the most delicate colors, will, from  its ready evaporation,
cause the paint to dry almost instantly.
Cocoa-nut oil, at the common temperature of the atmosphere, always assumes a concrete form; but a portion of this caoutchoucine mixed with it will cause the oil to become
fluid, and to retain sufficient fluidity to burn in a common lamp with extraordinary
brilliancy.
Caoutchoucine is extremely volatile; and yet its vapor is so exceedingly heavy, that
it may be poured, without the liquor, from one vessel into another like water.
Hitherto the greater part of the caoutchouc has been imported into Europe from
South America, and the best from  Para; but of late years a considerable quantity
has been brought from  Java, Penang, Sincapore, and Assam. About twelve years
ago, Mr. William  Griffith published an interesting report upon the Ficus elastica,
the caoutchouc tree of Assam, which he drew up at the request of Captain Jenkins,
agent in that country to the Governor-General of India.  This remarkable species
of fig-tree is either solitary, or in twofold or threefold groups.  It is larger and
more umbrageous than any of the other trees in the extensive forest where it abounds
and may be distinguished from  the other trees, at a distance of several miles, by
the picturesque appearance produced by its dense, huge, and lofty crown. The main
trunk of one was carefully measured, and was found to have a circumference of no less
than 74 feet; while the girth of the main trunk along with the supports immediately
round it, was 120 feet.  The area covered by the expanded branches had a circumference of 610 feet. The height of the central tree was 100 feet.
It has been estimated, after an accurate survey, that there are 43,240 such noble
nrees within a length of 30 miles, and breadth of 8 miles of forest near Ferozepoor, in
the district of Chardwar, in Assam.
Lieutenant Veitch has since discovered that the Ficus elastica is equally abundant in
the district of Naudwar.  Its geographical range in Assam  seems to be between 25
deg. 10 min. and 27 deg. 20 min. of north latitude, and between 90 deg. 40 min. and
95 deg. 30 min. of east longitude. It occurs on the slopes of the hills, up to an elevation of probably 22,500 feet. This tree is of the banyan tribe, famed for its pillared




360                           CAOUTCHOUC.
shade, "whose daughters grow about the mother tree," which has furnished the motto,
tot rami, quot arbores, to the Royal Asiatic Society. Species of this genus afford grateful shade, however, in the tropical regions of America, as well as Asia.
Many species of other trees yield a milky tenacious juice, of which birdlime has
been frequently made; as Artocarpus integrifolia, and Lakoocha, Ficus indica and
religiosa, also F. Tsiela, Roxburghii, glomerata, and oppositsfolia. From some of these
an inferior kind of caoutchouc has been obtained.
The juice of the Ficus elastica of Chardwar is better when drawn from the old than
from the young trees, and richer in the cold season than in the hot. It is extracted by
making incisions a foot apart, across the bark down to the wood, all round the trunk,
and also the large branches, up to the very top of the tree; the quantity which exudes
increasing with the height of the incision. The bleeding may be safely repeated once
every fortnight. The fluid, as fresh drawn, is nearly of the consistence of cream, and
pure white. Somewhat more than half a maund (42 lbs.) is reckoned to be the average produce of each bleeding of one tree; or 20,000 trees will yield about 12,000
maunds of juice: which is composed in 10 parts, of from 4 to 6 parts of water, and,
of course, from 6 to 4 parts of caoutchouc. The bleeding should be confined to the
cold months, so as not to interfere with or obstruct the vigorous vegetation of the tree
in the hot months.
Mr. Griffith says, that the richest juice is obtained from transverse incisions made
into the wood of the larger reflex roots, which are half exposed above ground, and that
it proceeds from the bark alone. Beneath the line of incisions, the natives of Assam
scoop out a hole in the earth, in which they place a leaf of the Phrynitum capitatum
Linn., rudely folded up into the shape of a cup. He observes that the various species
of Tetranthera, upon which the Mloonga silkworm feeds, as also the castor oil plant,
which is the chief food of the Eria silkworm, do not afford a milky caoutchouc juice.
Hence it would appear that Dr. Royle's notion of caoutchouc forming a necessary
ingredient in the food of silkworms, and being "in some way employed in giving
tenacity to their silk," seems to be unfounded. If Botany discountenances this idea,
Chemistry would seem to scout it altogether; for silk contains 11'33 per cent. of azote,
and caoutchouc contains none at all; being simply a solid hydro-carburet, and therefore widely dissimilar in constitution to silk, which consists of oxygen 34'04, azote
11'33, carbon 50-69, and hydrogen 3-94 in 100 parts.
This hydro-carburet emulsion is of common occurrence in the ORDERS Eupphorbiacea
and Tulicea, which may be looked on as the main sources of caoutchouc. The American caoutchouc is said to be furnished by the Siphonia elastica, or the HJevea guianensis of Aublet, a tree which grows in Brazil, and also in Surinam.
Dr. Royle sent models of cylinders, of 1i to 24 inches in diameter, and 4 or 5 inches
in length, to both the Asiatic and Agricultural Societies of Bengal, to serve as patterns
for the natives to mould their caoutchouc by. Mr. Griffith says that this plan of
forming the caoutchouc into tumblers or bottles, as recommended by the committee of
the London Joint Stock Caoutchouc Company, is, in his opinion, the worst that can
possibly be offered; being tedious, laborious, causing the caoutchouc to be blackened
in the drying, and not obviating the viscidity of the juice when it is exposed to the
sun. He recommends, as afar better mode of treating the juice, to work it up with
the hands, to blanch it in water, and then subject it to pressure. I shall presently
describe a still better method which has recently occurred to me, in experimenting
upon the caoutchouc juice. This fluid, with certain precautions, chiefly exclusion
from air and much warmth, may be kept in the state of a creamy emulsion for a very
long time.
NEW EXPERIMENTAL RESEARCHES ON CAOUTCHOUC.
The specific gravity of the best compact Para caoutchouc,
taken in dilute alcohol, is  -                       0941567
The specific gravity of the best Assam is    -   -   -   0942972,,,,           Sincapore   -   -   -   0.936650,,,,           Penang      -   -   -   0919178
Having been favoured by Mr. Sievier, formerly managing director of the Joint-Stock
Caoutchouc Company, and by Mr. Beale, engineer, with two different samples of caoutchouc juice, I have subjected each to chemical examination.
That of Mr. Sievier is greyish brown, that of Mr. Beale is of a milky grey colour;
the deviation from whiteness in each case being due to the presence of aloetic matter,
which accompanies the caoutchouc in the secretion by the tree. The former juice is of
the consistence of thin cream, has a specific gravity of 1'04125, and yields, by exposure
upon a porcelain capsule, in a thin layer, for a few days, or by boiling for a few minutes with a little water, 20 per cent. of solid caoutchouc. The latter, though it has the




CAOUTCHOUC.                                    361
consistence of pretty rich cream, has a specific gravity of only 1'0175. It yields no
less than 37 per cent. of white, solid, and very elastic caoutchouc.
It is interesting to observe how readily and compactly the separate little cloths or
threads of caoutchouc coalesce into one spongy mass in the progress of the ebullition,
particularly if the emulsive mixture be stirred; but the addition of water is necessary
to prevent the coagulated caoutchouc from sticking to the sides or bottom of the vessel
and becoming burnt.  In order to convert the spongy mass thus formed into good
caoutchouc, nothing more is requisite than to expose it to moderate pressure between
the folds of a towel. By this process the whole of the aloetic extract, and other vegetable matters, which concrete into the substance of the balls and junks of caoutchouc
prepared in Assam and Java, and contaminate it, are entirely separated, and an article
nearly white and inodorous is obtained. Some of the cakes of American caoutchouc
exhale when cut the fcetor of rotten cheese; a smell which adheres to the threads made
of it, after every process of purification.
In the interior of many of the balls which come from both the Brazils and East Indies, spots are frequently found of a viscid tarry-looking matter, which, when exposed
to the air, act in some manner as a ferment, and decompose the whole mass into a soft
substance, which is good for nothing. Were the plan of boiling the fresh juice along
with its own bulk of water, or a little more, adopted, a much purer article would be
obtained, and with comparatively less trouble and delay, than has been hitherto brought
into the market.
I find that neither of the above two samples of caoutchouc juice affords any appearance of coagulum when mixed in any proportions with alcohol of 0'825 specific gravity;
and, therefore, I infer that albumen is not a necessary constituent of the juice, as Mr.
Faraday inferred from his experiments published in the 21st vol. of the Journal of the
Royal Institution.
The odour of Mr. Sievier's sample is slightly acescent, that of Mr. Beale's, which is
by far the richer and purer, has no disagreeable smell whatever. The taste of the
latter is at first bland and very slight, but eventually very bitter, from the aloetic impression upon the tongue.  The taste of the former is bitter from the first, in consequence of the great excess of aloes which it contains. When the brown solution which
remains in the capsule, after the caoutchouc has been separated in a spongy state by
ebullition, from 100 grains of the richer juice, is passed through a filter and evaporated,
it leaves 4 grains of concrete aloes.
Both of these emulsive juices mix readily with water, alcohol, and pyroxilic spirit,
though they do not become at all clearer; they will not mix with caoutchoucine (the
distilled spirit of caoutchouc), or with petroleum-naphtha, but remain at the bottom of
these liquids as distinct as mercury does from water. Soda caustic lye does not dissolve the juice; nitric acid (double aquafortis) converts it into a red curdy magma.
The filtered aloetic liquid is not affected by the nitrates of baryta and silver; it affords
with oxalate of ammonia minute traces of lime.
I. CAOUTCHOUC MANUFACTURE.
This department of operative industry has, within a few years, acquired an importance
equal to that of some of the older arts, and promises, ere long, to rival even the ancient
textile fabrics in the variety of its designs and applications.  The manufacture of
caoutchouc has, at present, three principal branches:-1. The condensation of the crude
lumps or shreds of caoutchouc, as imported from South America, India, &c., into compact homogeneous blocks, and the cutting of these blocks into cakes or sheets for the
stationer, surgeon, shoemaker, &c. 2. The filature of either the India-rubber bottles,
or the artificial sheet caoutchouc, into tapes and threads of any requisite length and
fineness, which being clothed with silk, cotton, linen, or woollen yarns, form the basis
of elastic tissues of every kind.  3. The conversion of the refuse cuttings and coarser
qualities of caoutchouc into a viscid varnish, which, being applied between two surfaces of cloth, constitute the well-known double fabrics, impervious to water and air.
I. The caoutchouc, as imported in skinny shreds, fibrous balls, twisted concretions,
cheese-like cakes, and irregular masses, is, more or less, impure, and sometimes fraudulently interstratified with earthy matter. It is cleansed by being cut into small pieces,
and washed in warm water. It is now dried on iron trays, heated with steam, while being
carefully stirred about to separate any remaining dirt, and is then passed through, be
tween a pair of iron rolls, under a stream of water, whereby it gets a second washing,
and becomes at the same time equalized by the separate pieces being blended together
The shreds and cuttings thus laminated, if still foul or heterogeneous, are thrown back
into a kind of hopper over the rolls, set one-sixteenth of an inch apart, and passed several times through between them. The above method of preparation is that practised
by Messrs. Keene and Co., of Lambeth, in their excellent manufactory, under a patent
granted in October, 1836, to Mr. Christopher Nickels, a partner in the firm.
VOL. I.                               3A




362                            CAOUTCHOUC.
In the great establishment of the Joint-Stock Caoutchouc Company, at Tottenham,
originally under the direction of Mr. Sievier, a gentleman distinguished no less by his
genius and taste as a sculptor, than by his constructive talents, the preparatory rinsing
and lamination are superseded by a process of washing practised in Mr. Nickels's second
operation, commonly called the grinding, or, as it should more properly be styled, the
kneading. The mill employed for agglutinating or incorporating the separate fragments
and shreds of caoutchouc into homogeneous elastic ball, is a cylindrical box or drum
of cast iron, 8 or 9 inches in diameter, set on its side, and traversed in the line of its
horizontal axis (also 8 or 9 inches long) by a shaft of wrought iron, furnished with 3
rows of projecting bars, or kneading arms, placed at angles of 120 deg. to each other.
These act by rotation against 5 chisel-shaped teeth, which stand obliquely up from the
front part of the bottom of the drum.  The drum itself consists of 2 semi-cylinders;
the under of which is made fast to a strong iron framing, and the upper is hinged to the
under one behind, but bolted to it before, so as to form a cover or lid, which may be
opened or laid back at pleasure, in order to examine the caoutchouc from time to time,
and take it out when fully kneaded. In the centre of the lid a funnel is made fast, by
which the cuttings and shreds of the India rubber are introduced, and a stream of
water is made to trickle in, for washing away the foul matter often embedded in it.
The power required to turn the axis of one of these mills, as the drums or boxes are
called, may be judged of from the fact, that if it be only 2 inches in diameter, it is
readily twisted asunder, and requires to be 3 inches to withstand every strain produced
by the fixed teeth holding the caoutchouc against the revolving arms.  Five pounds
constitute a charge of the material.
One of the most remarkable phenomena of the kneading operation, is the prodigious
heat disengaged in the alternate condensation and expansion of the caoutchouc. Though
the water be cold as it trickles in, it soon becomes boiling hot, and emits copious vapours. When no water is admitted, the temperature rises much higher, so that the
elastic lump, though a bad conductor of heat, cannot be safely touched with the hand.
As we shall presently find that caoutchouc suffers no considerable or permanent diminution of its volume by the greatest pressure which can be applied, we must ascribe
the heat evolved in the kneading process to the violent intestine movements excited
throughout all the particles of the elastic mass.
During the steaming much muddy water runs off through apertures in the bottom
of the drum.  In the course of half an hour's trituration the various pieces become
agglutinated into a soft, elastic, ovoid ball, of a reddish brown colour. This ball is
now transferred into another similar iron drum, where it is exposed to the pricking and
kneading action of 3 sets of chisel points, 5 in each set, that project from the revolving
shaft at angles of 120 deg. to each other, and which encounter the resistance occasioned
by five stationary chisel teeth, standing obliquely upwards from the bottom of the
drum. Here the caoutchouc is kneaded dry along with a little quicklime.  It soon
gets very hot; discharges in steam through the punctures, the water and air which it
had imbibed in the preceding washing operation; becomes in  onsequence more compact; and in about an hour assumes the dark brown colour of stationers' rubber.
During all this time frequent explosions take place, from the expansion and sudden
extrication of the imprisoned air and steam.
From the second set of drums the ball is transferred into a third set, whose revolving
shaft being furnished both with fiat pressing bars, and parallel sharp chisels, perpendicular to it, exercises the twofold operation of pricking and kneading the mass, so as
to condense the caoutchouc into a homogeneous solid. Seven of these finished balls,
weighing as above stated, 5 pounds each, are then introduced into a much larger iron
drum of similar construction, but of much greater strength, whose shaft is studded all
round with a formidable array of blunt chisels. Here the separate balls become perfectly incorporated into one mass, free from honeycomb cells or pores, and therefore fit
for being squeezed into a rectangular or cylindrical form in a suitable cast-iron mould,
by the action of a screw-press. When condensed to the utmost in this box, the lid is
secured in its place by screw-bolts, and the mould is set aside for several days. It is a
curious fact, that Mr. Sievier has tried to give this moulding force, by the hydraulic
press, without effect, as the cake of caoutchouc, after being so condensed, resiles much
more considerably than after the compressing action of the screw. The cake form
generally preferred for the recomposed, ground, or milled caoutchouc, is a rectangular
mass, about 18 inches long, 9 inches broad, and 5 inches thick.
This is sliced into cakes for the stationer, and into sheets for making tapes and threads
of caoutchouc, by an ingenious self-acting machine, in which a straight steel blade with
its edge slanting downwards, is made to vibrate most rapidly to and fro in a horizontal
plane; while the cake of caoutchouc clamped or embraced at each side between two
strong iron bars, is slowly advanced against the blade by screw-work like that of the
slide-rest of a lathe. In cutting caoutchouc by knives of every form, it is essential that




CAOUTCHOUC.                                    363
either the blade or the incision be constantly moistened with water; for otherwise the
tool would immediately stick fast. As the above straight vibrating knife slants obliquely
downwards, the sheet which it cuts off spontaneously turns up over the blade in proportion as it is detached from the bottom mass of the cake. The thicker slices are afterwards cut by hand, with a wetted knife, into small parallelopipeds for the stationer,
the sections being guided rectangularly by saw lines in a wooden frame. The wholesale price of these is now reduced to 2s. per pound. Slices may be cut off to almost any
desired degree of thinness, by means of an adjusting screw-a mechanism that acts
against a board which supports the bottom of the cake, and raises it by any aliquot
part of an inch, the cutting blade being caused to vibrate always in the same horizontal
plane. These thin slices constitute what is called sheet caoutchouc, and they serve
tolerably for making tubes for pneumatic apparatus, and sheaths of every kind; since,
if their two edges be cut obliquely with clean scissors, they may be made to coalesce,
by gentle pressure, so intimately that the line of junction cannot be discovered either
by the eye, or by inflation of a bag or tube thus formed.
The mode of recomposing the cuttings, shreds, and coarse lumps of caoutchouc, into
a homogeneous elastic cake, specified by Mr. Nickels, for his patent, sealed October 24,
1836, is not essentially different from that above described.  The cylinders of his mill
are more capacious, are open at the sides like a cage, and do not require the washing
apparatus, as the caoutchouc has been cleansed by previous lamination and rinsing.
He completes the kneading operation, in this open cylinder, within the space of about
two hours, and afterwards squeezes the large ball so formed into the cheese form, in a
mould subjected to the action of an hydraulic press. As he succeeds perfectly in making
compact cakes in this way, his caoutchouc must differ somewhat in its physical constitution from that recomposed by Mr. Sievier's process. He uses a press of the power of
70 tons; such pressure, however, must not be applied suddenly, but progressively, at
intervals of two or three minutes between each stroke; and when the pressing is complete, he suffers the caoutchouc to remain under pressure till it is cold, when he
thrusts it out of the mould entirely, or, placing his mould in the slide-rest mechanism,
he gradually raises the caoutchouc out of it, while the vibrating knife cuts it into slices
in the manner already described. The elegant machine by which these sheets are now
so easily and accurately sliced, was, I believe, originally contrived and constructed by
Mr. Beale, engineer, Church-lane, Whitechapel.
IL FILATURE OF CAOUTCHOUC FOR MAKING ELASTIC FABRICS.
Messrs. Rattier and Guibal mounted in their factory at St. Denys, so long ago as the
year 1826 or 1827, a machine for cutting a disc of caoutchouc into a continuous fillet
spirally, from its circumference towards its centre. This flat disc was made by pressing
the bottom part of a bottle of India-rubber in an iron mould. I have described this
machine under the article ELASTIC BANDS. A machine on the same principle was made
the subject of a patent by Mr. Joshua Proctor Westhead, of Manchester, February 16,
1836; and, being constructed with the well-known precision of Manchester workmaniship, it has been found to act perfectly well in cutting a disc of caoutchouc, from the
circumference towards the centre spirally, into one continuous length of tape. For
the service of this machine, the bottom of a bottle of India-rubber of good quality
being selected, is cut off and flattened by heat and pressure into a nearly round
cake of uniform thickness. This cake is made fast at its centre by a screw nut and
washer to the end of a horizontal shaft, which may be made to revolve with any
desired velocity by means of appropriate pulleys and bands, at the same time that the
edge of the disc of caoutchouc is acted on by a circular knife of cast steel, made to
revolve 3000 times per minute, in a plane at right angles to that of the disc, and to
advance upon its axis progressively, so as to pare off a continuous uniform tape or fillet
from the circumference of the cake. During this cutting operation, the knife and
caoutchouc are kept constantly moist with a slender stream of water. A succession
of threads of any desired fineness is afterwards cut out of this fillet, by drawing it in a
moist state through a guide slit, against the sharp edge of a revolving steel disc. This
operation is dexterously performed by the hands of young girls. MM. Rattier and
Guibal employed, at the above-mentioned period, a mechanism consisting of a series
of circular steel knives, fixed parallel to each other at minute distances, regulated by
interposed washers upon a revolving shaft; which series of knives acted against another
similar series, placed upon a parallel adjoining shaft, with the effect of cutting the tape
throughout its length into eight or more threads at once. An improved modification
of that apparatus is described and figured in the specification of Mr. Nickels's patent
of October, 1836. He employs it for cutting into threads the tapes made from the
recomposed caoutchouc.
The body of the bottle of India-rubber, and in general any hollow cylinder of
caoutchouc, is cut into tapes, by being first forced upon a mandril of soft wood of such
3A2




364                             CAOUTCHOUC.
dimensions as to keep it equally distended. This mandril is then secured to the shaft
of a lathe, which has one end formed into a fine-threaded screw, that works in a fixed
nut, so as to traverse from right to left by its rotation. A circular disc of steel, kept
moist, revolves upon a shaft parallel to the preceding, at such a distance from it as to
cut through the caoutchouc, so that, by the traverse movement of the mandril shaft,
the hollow cylinder is cut spirally into a continuous fillet of a breadth equal to the
thickness of the side of the cylinder. Mr. Nickels has described two methods of forming hollow cylinders of recomposed caoutchouc, for the purpose of being cut into fillets
by such a machine.
It is probable that the threads formed from the best India-rubber bottles, as imported
from Para, are considerably stronger than those made from recomposed caoutchouc,
and therefore much better adapted for making Mr. Sievier's patent elastic cordage.
When, however, the kneading operation has been skilfully performed, I find that the
threads of the ground caoutchouc, as it is incorrectly called by the workmen, answer
well for every ordinary purpose of elastic fabrics, and are, of course, greatly more
economical, from the much lower price of the material.
Threads of caoutchouc are readily pieced by paring the broken ends obliquely with
scissors, and then pressing them  together with clean fingers, taking care to admit no
grease or moisture within the junction line. These threads must be deprived of their
elasticity before they can be made subservient to any torsile or textile manufacture.
Each thread is inelasticated individually in the act of reeling, by the tenter boy or girl
pressing it between the moist thumb and finger, so as to stretch it to at least eight times
its natural length, while it is drawn rapidly through between them by the rotation of
the power-driven reel. This extension is accompanied with condensation of the caoutchouc, and with very considerable disengagement of heat, as pointed out in Nicholson's Journal upwards of 30 years ago, by Mr. Gough, the blind philosopher of KendaL  I attempted to stretch the thread, in the act of reeling, but found the sensation
of heat too painful for my unseasoned fingers. The reels, after being completely filled
with the thread, are laid aside for some days, more or fewer, according to the quality
of the caoutchouc, the recomposed requiring a longer period than the bottle material.
When thus rendered inelastic, it is wound off upon bobbins of various sizes, adapted
to various sizes of braiding, or other machines, where it is to be clothed with cotton
or other yarn.
In the process of making the ELASTIC TISSUES, the threads of caoutchouc being first
of all deprived of their elasticity, are prepared for receiving a sheath upon the braiding
machine. For this purpose they are stretched by hand, in the act of winding upon the
reel, to 7 or 8 times their natural length, and left two or three weeks in that state of
tension upon the reels. Thread thus inelasticated has a specific gravity of no less than
0-948732; but when it has its elasticity restored, and its length reduced to its pristine
state, by rubbing between the warm palms of the hands, the specific gravity of the
same piece of thread is reduced to 0'925939. This phenomenon is akin to that exhibited
in the process of wire-drawing, where the iron or brass gets condensed, hard, and brittle, while it disengages much heat; which the caoutchouc thread also does in a degree
intolerable to unpractised fingers, as above mentioned.
The thread of the Joint-Stock Caoutchouc Company is numbered from  1 to 8.
No. 1. is the finest, and has about 5000 yards in a pound weight; No. 4. has 2000 in
the pound weight; and No. 8. 700, being a very powerful thread.  The finest is used
for the finer elastic tissues, as for ladies' gold and silver elastic bracelets and bands.
The ropes made by Mr. Sievier with the strongest of the above threads, clothed with
hemp and worked in his gigantic braiding machine, possess, after they are re-elasticated
by heat, an extraordinary strength and elasticity; and, from the nearly rectilinear
direction of all the strands, can stand, it is said, double the strain of the best patent
cordage of like diameter.
In treating of the manufacture of elastic fabrics, I have great pleasure in adverting
to the ribbon looms at Holloway, which display to great advantage the mechanical
genius of the patentee, Mr. Sievier. Their productive powers may be inferred from
the following statement:-5000 yards of 1-inch braces are woven weekly in one 18
ribbon loom, whereby the female operative, who has nothing to do but watch its automatic movements, earns 10s. a-week; 3000 yards of 2-inch braces are woven upon a
similar loom in the same time. But one of Mr. Sievier's most curious patent inventions is, that of producing, by the shrinking of the caoutchouc threads in the foundation or warp of the stuff, the appearance of raised figures, closely resembling coachlace, in the weft. Thus, by a simple physical operation, there is produced, at an
expense of one penny, an effect which could not be effected by mechanical means foe
ess than one shilling.




CAOUTCHOUC.                                   365
II. OF THE WATER-PROOF DOUBLE FABRICS.
The parings, the waste of the kneading operations above described, and the coarsest
qualities of imported caoutchouc, such as the inelastic lumps from Para, are worked up
into varnish, wherewith two surfaces of cloth are cemented, so as to form a compound
fabric, impervious to air and water. The caoutchouc is dissolved either in petroleum
(coal-tar), naphtha, or oil of turpentine, by being triturated with either of the solvents in
a close cast-iron vessel, with a stirring apparatus, moved by mechanical power. The heat
generated during the attrition of the caoutchouc, is sufficient to favour the solution,
without the application of fuel in any way. These triturating cylinders have been called
pug-mills by the workmen, because they are furnished with obliquely pressing and revolving arms, but in other respects they differ in construction. They are 4 feet in
diameter and depth, receive 13 cwt. at a time, have a vertical revolving shaft of wrought
iron 4 inches in diameter, and make one turn in a second. Three days are required to
complete the solution of one charge of the varnish materials. The proportion of the
solvent oils varies with the object in view, being always much less in weight than the
caoutchouc.
When the varnish is to be applied to very nice purposes, as bookbinding, &c., it
must be rubbed into a homogeneous smooth paste, by putting it in a hopper, and
letting it fall between a couple of parallel iron rolls, set almost in contact.
The wooden frame-work of the gallery in which the water-proof cloth is manufactured,
should be at least 50 yards long, to give ample room for extending, airing, and drying
the pieces; it should be 2 yards wide, and not less than 5 high. It is formed of upright standards of wood, bound with three or four horizontal rails at the sides of the
ends. At the end of the gallery, where the varnish is applied, the web which is to be
smeared must be wound upon a beam, resembling in size and situation the cloth beam
of the weaver's loom. This piece is thence drawn up and stretched in a horizontal
direction over a bar, like the breast beam of a loom, whence it is extended in a somewhat slanting direction downwards, and passed over the edge of a horizontal bar.
Above this bar, and parallel to it, a steel-armed edge of wood is adjusted, so closely as
to leave but a narrow slit for the passage of the varnish and the cloth. This horizontal
slit may be widened or narrowed at pleasure by thumb-screws, which lower or raise
the movable upper board. The caoutchouc paste being plastered thickly with a long
spatula of wood upon the down-sloped part of the web, which lies between the breastbeam and the above described slit, the cloth is then drawn through the slit by means of
cords in a horizontal direction along the lowest rails of the gallery, whereby it gets
uniformly besmeared. As soon as the whole web, consisting of about 40 yards, is thus
coated with the viscid varnish, it is extended horizontally upon rollers, in the upper
part of the gallery, and left for a day or two to dry. A second and third coat are then
applied in succession. Two such webs, or pieces, are next cemented face to face, by
passing them, at the instant of their being brought into contact, through between a
pair of wooden rollers, care being taken by the operator to prevent the formation of any
creases, or twisting of the twofold web. The under one of the two pieces being intended
for the lining, should be a couple of inches broader than the upper one, to insure the
uniform covering of the latter, which is destined to form the outside of the garment.
The double cloth is finally suspended in a well-ventilated stove-room, till it becomes
ory, and nearly free from smell. The parings cut from the broader edges of the under
piece, are reserved for cementing the seams of cloaks and other articles of dress. The
tape-like shreds of the double cloth are in great request among gardeners, for nailing
up the twigs of wall shrubs.
Mr. Walton, of Sowerby-bridge, has recently substituted sheet India-rubber for
leather, in the construction of fillet cards for the cotton and tow manufactures. The
superior elasticity of this article is said to prove advantageous in several respects.
Mr. Charles Keene, proprietor of the extensive and well-organized India-rubber
factory in Lambeth, obtained a patent in March, 1840, for applying a coat of
caoutchouc to the outer surface of flexible leather.  The varnish of caoutchouc,
made with oil of turpentine, has so much lampblack incorporated with it, as to bring
it to the consistence of dough.  The edge of the doe-skin, buck-skin, and washleather, being introduced between a pair of wetted iron rollers, as much of the Indiarubber compound, softened by a gentle heat, and rolled into a proper length as will
cover the leather, is laid in the hollow between the leather and the moist cylinders.
By their rotation, the coating is evenly effected. When the surface has become dry, it
may be embossed or gilt, and varnished over with a solution of shellac, with a little
Venice turpentine, in alcohol. After two or three applications of this kind, the leather
is passed through a pair of iron rollers, either smooth or embossed. When made up
articles, such as shoes or portmanteaus, &c., are to be covered, the India-rubber varnish
is used in a thinner state.-Newton's Journal, xxiii. 357.




366                            CAOUTCHOUC.
Caoutchouc sulphured. — Mr. Burke in describing his patented process for vulcanizing
India-rubber, says, that he avoids two principal defects of the usual article, viz. its
efflorescence of sulphur with an offensive odour, and its consequent decomposition and
becoming rotten. He employs crude antimony (the sulphuret of that metal in fine
powder), and converts it by boiling in water with soda or potash (carbonates) into the
orange sulphuret of that metal (Kermes mineral) by the addition of hydrochloric acid
to the fluid in slight excess. He combines this compound (after being well washed)
with caoutchouc or gutta percha, either together or separately, according to the degree
of elasticity which he wishes to obtain. This mixture is afterwards subjected to a heat
of from 250~ to 280~ Fahr.  He masticates the caoutchouc in the usual iron box, by
means of the kneading fluted revolving rollers, subjecting the whole to heat. The
antimonial compound is then added in quantities varying from 5 to 15 lbs., according to
the strength and elasticity required in the compound. At the end of from one to two
hours' trituration, the block is removed from the box, and while in a warm state it is
strongly compressed in an iron mould; and after being under pressure for a day or two
is subjected to a steam heat for a couple of hours. The block thus prepared may now
be cut into sheets, and afterwards divided into threads, or formed into such other articles
as are desired.
The patentee also mixes the flock of silk, cotton or wool, with liquefied caoutchouc,
and applies this compound for waterproofing cloth, previously coated with the ordinary
water-proof composition. He also proposes to strengthen the gutta percha bands for
driving-pulleys by affixing strips of leather to their edges; and to apply metal tips or
shields to the gutta percha heels and soles of boots and shoes.
The clamminess of Caoutchouc is removed by Mr. Hancock in the following
manner: 10 pounds of it are rolled out into a thin sheet between iron cylinders, and
at the same time 20 pounds of French-chalk (silicate of magnesia) are sifted on and
incorporated with it, by means of the usual kneading apparatus.  When very thin films
are required (like sheets of paper) the caoutchouc, made plastic with a little naphtha,
is spread upon cloth previously saturated with size, and when dry is stripped off. Mixtures of caoutchouc so softened may be made with asphalt, with pigments of various
kinds, plumbago, sulphur, &c.
The improvements patented in January, 1849, by Mr. Christopher Nickels, consist1. In a modification of the grinding, kneading or masticating machine, by furnishing
its roller with flanges at its two ends to prevent the rubber from coming against the
ends of the cylinder. When sulphur is to be kneaded into it in the process of vulcanizing the rubber, as it is called, he covers in the trough, but not otherwise. He
has also given an excentric action to his roller.
He kneads with his rubber flowers of sulphur, or compounds thereof, in the proportion
of 10 pounds of sulphur to 60 pounds of caoutchouc, and he subjects the compound to
pressure in moulds. He prefers to treat the caoutchouc with the fumes of sulphur, or
gases containing sulphur, in order to make a combination in the kneading cylinder.
He uses a retort to distil the vapour of sulphur upon the rubber in the cylinder heated
in a steam jacket. He also occasionally introduces hydrogen or phosphorus along with
it. The compound mass thus obtained is to be subjected to hydraulic pressure, in the
moulds, heated to about 220~ or 250~ Fahr. He causes the blocks to undergo a rolling
motion under heavy pressure by machinery; the effect of which motion is to equalize
the sulphur diffused in the blocks. Even thread of the ordinary India-rubber, when
agitated in a box with flowers of sulphur, is said to be glazed and improved thereby.
-Newton's Journal, xxxv. 21.
The porosity of caoutchouc explains the readiness with which it is permeated
by different liquids which have no chemical action upon it. Thin sections of dry
caoutchouc of the best kinds absorb fiom 18 to 26 per cent. of water in the course
of a month, and become white from having been brown. The best solvent is a mixture
of 100 parts of sulphuret of carbon with from 6 to 8 parts of anhydrous alcohol. If
the alcohol be mixed with a little water a dough is obtained, from which the caoutchouc
may be drawn out into threads and spun. By Gerard's process, gutta percha is also
soluble in the above mixtures of sulphuret of carbon and alcohol.
The sulphuration of caoutchouc, a valuable invention, is due to Mr. Charles Goodyear
of New York. The process of cold sulphuring of Mr. Parkes consists in plunging the
sheets or tubes of caoutchouc in a mixture of 100 parts of sulphuret of carbon, and 2parts of protochloride of sulphur, for a minute or two, and then immersing them in
cold water. Thus supersulphuration is prevented in consequence of decomposing the
chloride of sulphur on the surface by this immersion, while the rest of the sulphur
passes into the interior by absorption. Mr. Parkes prescribes another, and perhaps a
preferable process, which consists in immersing the caoutchouc in a closed vessel for
3 hours, containing a solution of polysulphuret of potassium indicating a density of
25~ Beaume, at the temperature of 248~ Fahr., then washing in an alkaline solution,
and lastly in pure water. A uniform impregnation is thus obtained.




CAPSTAN.                                   367
The caper shrub grows in the driest situations, even upon walls, and does not disdain
any soil; but it loves a hot and sheltered exposure. It is multiplied by grafts made in
autumn, as also by slips of the roots taken off in spring.
CAPSTAN. (Cabestan, Fr.; Spille, Germ.) A machine whereon the cable is wound
successively in weighing the anchor of a vessel. It is a species of wheel and axle; the
axle being vertical, and pierced with holes near its top for the insertion of the ends of
horizontal levers, called handspikes, which represent the wheel. These are turned by
the force of men moving in a circle. The power applied to the lever is to the resistance
to be overcome (the weight of the anchor, for example), when the forces are in equilibrio,
as the radius of the cylinder round which the cable is coiled is to the circumference described by the power.
It is manifest that the radius of the axle must be augmented in this computation by
half the diameter of the cable, which is supposed to lie always one coil thick upon it.
The force of a man, thus applied, has been commonly estimated as equal to the traction
of 27 pounds hanging over a pulley.
Friction being so variable a quantity in capstans, renders the exact calculation of it,
mechanical effect somewhat uncertain.
A stout man, stationed near the bottom of the axle, holds fast the loose part of the
cable, which has already made two or three turns; and, being aided by its friction upon
the wood, he both prevents it from slipping backwards, and uncoils each turn as it is progressively made.
Mr. Hindmarsh, master mariner of Newcastle, obtained a patent, in February, 1827,
for a contrivance to enable a capstan or windlass to be occasionally worked with increased
mechanical advantage. With this view, he placed toothed wheel-work, partly in the
drum-head of the capstan, and partly in the upper part of the barrel, upon which the
cable is coiled and uncoiled in successive portions.
The drum-head, and also the barrel, turn loosely upon a central spindle, independent
of each other, and are connected together either by the toothed gear, or by bolts. On
raising or withdrawing the connecting pinion from the toothed wheels, and then locking
the drum-head and barrel together, the capstan works with a power equal only to that
exerted by the men at the capstan-bars, as an ordinary capstan; but on lowering the
pinion into gear with the wheeT-work, and withdrawing the bolts which locked the drumhead to the barrel, the power exerted by the men becomes increased in proportion to the
diameter and numbers of teeth in the wheels and pinions.
Fig. 322 is the external appearance of this capstan. Fig. 323 a horizontal view of the
toothed gear at the top of the barrel. The barrel, with the whelps a a, turns loosely
323              o324 c         _upon a vertical spindle fixed
32    ^~^^ 4 ^ = ha           b          into the deck of the vessel.
^^^^^ro       (^   1y/// i i r  z/The drum-head b also turns
/i~?',                   loosely upon the same spindle.
tt-~-4 yiyl 11/11I     ___     The circular frame c c, in fig.
\^~is~ \L~ a  I~~ III            *     323, in which the axes of the
toothed wheels d d d are
h~ Ylljt1^i\       mounted, is fixed to the cen322              l,                           tral spindle. The rim e e e,
( r  I. X l  with internal teeth, is made
Z, ^i'(9.'        I                    "    I' ~  fast to the top of the barrel;
{i'i~^i]L                       m i  a ~  _1 — and the pinionf, which slides
LJU    hI IJ^  J                              upon the spindle, is connected
III  e   1i 11       325                          to the drum-head.
When  it is intended to
%p   -  -i po l    M*work the capstan with ordi1 a //  Ur \\U                           nary power, the pinion f is
-I \ \\1 JfS Draised up into the recess of
(  the drum-head, by means of
a screw g, fig. 322, which
^~^n ~ itr —^~ IT~^~ ~throws it out of gear with the
toothed wheels, and it is then
locked up by a pin z: the
bolts h h are now introduced, for the purpose of fastening the drum-head and barrel together, when it becomes an ordinary capstan.
But when it is required that the same number of men shall exert a greater power, the
bolts h are withdrawn, and the pinion f lowered into gear with the toothed wheels.
The rotation of the drum-head, then carrying the pinion round, causes it to drive the
toothed wheels d d d; and these working into the toothed rim e e, attached to the barrel,
cause the barrel to revolve with an increased power.
Thus, under particular circumstances, a smaller number of men at the capstan or




368                                CARBON.
windlass (which is to be constructed upon the same principle) will be enabled to han.
in the cable and anchor, or warp off the vessel, which is an important object to be
effected.
In 1819, Captain Phillips obtained a patent for certain improvements in capstans, a
part of which invention is precisely the same as this in principle, though slightly varied
in its adaptation.
James Brown, ship-rigger, in his capstan, patented in 1833, instead of applying the
moving power by handspikes, having fixed two rims of teeth round the top of the capstan, acts upon them by a rotatory worm, or pinions turned by a winch.
Fig. 324 is an elevation of this capstan, andfig. 258 is a horizontal top view: a is an
upright.shaft, fixed firmly to the deck, serving as an axle round which the body of the
capstan revolves. A frame c, fixed to the top of a stationary shaft a, above the body of
the.capstan, carries the driving apparatus.
The upper part of the body of the capstan has a ring of oblique teeth d formed round
its edge; and above this, on the top of the capstan, is a ring of bevel teeth e. A horizontal shaftf, mounted in the top frame c, has a worm or endless screw, which takes into
the teeth of the ring d; and a short axle g, having its bearings in the central shaft a,
and in the frame c, carries a bevel pinion, which takes into the bevel teeth of the ring e.
The bearings of the shaft f, in the top frame, are in long slots, with angular returns,
something like the fastening of a bayonet, which is for the purpose of enabling the shaft
to be readily lifted in and out of gear with the teeth of the ring d: the outer bearing of
the axle g of the bevel pinion is also supported in the frame c, in a similar way, in order
to put it in and out of gear with the teeth of the bevel ring e. A mode of shifting these
is essential; because the two toothed rings, and their driving worm and pinion, give
different speeds, and, of course, cannot be both in operation at the same time.
The worm of the shaft f, being placed in gear with the teeth of the ring d, on applying rotatory power thereto, by means of winches attached to the ends of the shaft, the
barrel or body of the capstan will be made to revolve with a slow motion, but with great
power; and thus two men at the winches will do the same work as many men with capstan bars in the ordinary way.
If a quicker movement than that of the endless screw is desired, then the driving power
may be applied by a winch to the axle g of the bevel pinion, that pinion being put into
gear with the bevel ring e, and the endless screw withdrawn. It should, however, be
here remarked, that the patentee proposes to employ two short axles g, placed opposite
to each other, with bevel pinions acting in the bevel-toothed ring, though only one is
shown in the figure, to avoid confusion. He also contemplates a modification of the
same contrivance, in which four short axles g, placed at right angles, with pinions
taking into a bevel ring, may be employed, and made effective in giving rotatory motion
to the barrel of a capstan by means of winches applied to the outer ends of the axle, and
turned by the labor of four men.
CARAT, OR CARACT, is a weight used by goldsmiths and jewellers. See ASSAY
and DIAMOND.
CARBON  (Carbone, Fr.; Kohlenstoff, Germ.), in a perfectly pure state, constitutes
diamond. Carbonaceous substances are usually more or less compound, containing hydrogen, or sometimes oxygen, and azote, along with earthy and metallic matters. Carbon,
tolerably pure, abounds in the mineral kingdom; and, in a combined state, it forms a
main constituent of vegetable and animal bodies. Anthracite is a mineral charcoal,
differing from common pit-coal in containing no bitumen, and therefore burning without flame or smoke. Coke is the carbonaceous mass which remains after pit-coal has
been exposed to ignition for some time out of contact of air; its volatile parts having
been dissipated by the heat. It is a spongy substance, of an iron-black color, a somewhat metallic lustre, and does not easily burn unless several pieces are kindled together.
With a good draught, however, it produces a most intense heat. Wood charcoal is obtained by the calcination of wood in close vessels, as described under the article ACETIC
ACID, or in piles of various shapes, covered with loam, to screen it from the free action
of the atmosphere, which would otherwise consume it entirely. See CHARCOAL. Such
carbon is a solid, without smell or taste, and bears the strongest heats of our furnaces
without suffering any change, provided air be excluded: it is a bad conductor of heat,
but conducts electricity very well. When burned, it unites with oxygen, and forms carbonic acid, the fixed air of Dr. Black, the choke-damp of the miner. When this carbonic acid is made to traverse red hot charcoal it dissolves a portion of it, and becomes
carbonic oxyde, which contains only one half of its volume of oxygen; whereas carbonic acid consists of one volume of oxygen combined with one volume of the vapor
of carbon, the two being condensed into one volume. If the specific gravity of oxygen,
= 1-1025, be deducted from that of carbonic acid, = 1-5245, the difference, = 0*422,
will be the specific gravity of the vapor of carbon; as well as the proportion present in
that weight of the acid.




CARBON.                                     369
Charcoal obtained by the action of a rapid fire in close vessels is not so solid and so
good a fuel as that which is made in the ancient way by the slow calcination of pyramidal
piles covered with earth. One of the most economical ovens for making wood charcoal
is that invented by M. Foucauld, which he calls a shroud, or abri. To construct one of
these, 30 feet in diameter at the base, 10 feet at its summit, and from 8 to 9 feet high, he
forms, with wood 2 inches square, a frame 12 feet long, 3 feet broad at one end, and one
foot at the other. The figure will explain the construction. The uprights, A B and
C D, of this frame are furnished with three wooden handles a a a, and a' a' a', by means
of which they can be joined together, by passing through two contiguous handles a
wooden fork, the frame being previously provided with props, as shown in fig. 326, and
covered with loam mixed with grass. A flat cover of 10 feet diameter, made of planks
well joined, and secured by four cross bars, is mounted with two trap doors, M N,fig.
328, for giving egress to the smoke at the commencement of the operation; a triangular
C    B       327
"  Q   R  329
a jlja        a|               x 
a  d    aZ                            328
hole P, cut out in the cover, receives the end of a conduit Q R S, (figs. 329 and 328,)
af wood formed of three deals, destined to convey the gases and  condensed liquids
into the casks F G H. Lastly, a door T, which may be opened and shut at pleasure,
permits the operator to inspect the state of the fire. The charcoal calcined by this abri,
has been found to be of superior quality.
When it is wished to change the place where the abri is erected, and to transport it to
a store of new-felled timber, the frame is taken down, after beating off the clay which
covers it, the joints are then cut by a saw, as well as the ends of the forks which fixed
the frames to one another. This process is economical in use, simple and cheap in
construction; since all the pieces of the apparatus are easily moved about, and may be
readily mounted in the forests. For obtaining a compact charcoal, for the use of artisans,
this mixed process of Foucauld is said to be preferable to either the close iron cylinder
or the pile.
For making gunpowder-charcoal the lighter woods, such as the willow, dogwood, and
alder answer best; and in their carbonization care should be taken to let the vapors freely escape, especially towards the end of the operation, for when they are re-absorbed,
they greatly impair the combustibility of the charcoal.
By the common process of the forests, about 18 per cent. of the weight of the wood is
obtained; by the process of Foucauld about 24 per cent. are obtained, with 20 of crude
pyroligneous acid of 10 degrees Baume. By the process described under ACETIC ACID,
27 of charcoal, and 18 of acid at 6 degrees, are procured from 100 parts of wood, besides
the tar. These quantities were the results of careful experimenting, and are greater than
can be reckoned upon in ordinary hands.
Charcoal for chemical purposes may be extemporaneously prepared by calcining pieces
of wood covered with sand in a crucible, till no more volatile matter exhales.
The charcoal of some woods contains silica, and is therefore useful for polishing metals.
Being a bad conductor of heat, charcoal is employed sometimes in powder to incase
small furnaces and steam-pipes. It is not affected by water; and hence the extremities
of stakes driven into moist ground are not liable to decomposition. In like manner casks
when charred inside preserve water much better than common casks, because they furnish
no soluble matter for fermentation or for food to animalcules.
Lowitz discovered that wood charcoal removes offensive smells from animal and vege.
table substances, and counteracts their putrefaction.  He found the odor of succinie




370                                  CARBON.
and benzolc acids, of bugs, of empyreumatic oils, of infusions of valerian, essence of
wormwood, spirits distilled from bad grain, and sulphureous substances were all absorb.
able by freshly calcined charcoal properly applied. A very ingenious filter has been constructed for purifying water, by passing it through strata of charcoal of different fineness.
When charcoal is burned, one third of the heat is discharged by radiation, and two
thirds by conduction.
The following table of the quantity of charcoal yielded by different woods was published by Mr. Mushet, as the result of experiments carefully made upon the small scale.
He says, the woods before being charred were thoroughly dried, and pieces of each kind
were selected as nearly alike in every respect as possible. One hundred parts of each
sort were taken, and they produced as under: —
Lignum Vitee afforded 26.0 of charcoal of a grayish color, resembling coke.
Mahogany-           - -25-4 tinged with brown, spongy and porous.
Laburnum       -    - 24'5 velvet black, compact, very hard.
Chestnut -    -    - 23*2 glossy black, compact, firm.
Oak     -    -    - 22'6 black, close, very firm.
Walnut  -    -    - 20'6 dull black, close, firm.
Holly     -    -    - 19-9 dull black, loose and bulky.
Beech    -    -    - 19'9 dull black, spongy, firm.
Sycamore -    -    - 19-7 fine black, bulky, moderately firm.
Elm -    -    -    - 19-5 fine black, moderately firm.
Norway Pine   -    - 19-2 shining black, bulky, very soft.
Sallow    -    -    - 18-4 velvet black, bulky, loose and soft.
Ash -          -    - 17'9 shining black, spongy, firm.
Birch     -    -    - 17-4 velvet black, bulky, firm.
Scottish Pine   -    - 16'4 tinged with brown, moderately firm.
Messrs. Allen and Pepys, from 100 parts of the following woods, obtained the quanti.
Ues of charcoal as under:Beech    -    -    - 15-00            Oak       -    -    -17-40
Mahogany       -      15-75           Fir -      - 18-17
Lignum Vitae      - -17-25            Box       -    -    - 20-25
It is observable that the quantities obtained by Messrs. Allen and Pepys are in general
less than those given by Mr. Mushet, which may be owing to Mr. Mushet not having
applied sufficient heat, or operated long enough, to dissipate the aqueous matter of the
gaseous products.
To those persons who buy charcoal by weight, it is important to purchase it as soon
after it is made as possible, as it quickly absorbs a considerable portion of water from
the atmosphere. Different woods, however, differ in this respect. Messrs. Allen and
FPzps found, that by a week's exposure to the air, the charcoal of
Lignum Vitze gained  -   9-6 per cent.
Fir -    -    -    -  13-0  ditto.
Box  -    -    -    -  14-0  ditto.
Beech-    -    -    -  16-3  ditto.
Oak  -    -    -    -  16-5  ditto.
Mahogany -           -  18-0  ditto.
The following is a tabular view of the volumes of the different gases which were
absorbed in the course of 24 hours, by one volume of charcoal, in the experiments of
M. Theodore de Saussure, which were conducted in a way likely to produce correct
results. Each portion of charcoal was heated afresh to a red heat, and allowed to cool
under mercury. When taken from the mercury, it was instantly plunged into the vessel
of gas:
Ammoniacal gas   -    - 90              Bicarbureted hydrogen - 35-00
Muriatic acid gas  -    - 85            Carbonic oxyde   -    -   9-42
Sulphurous acid   -    - 65             Oxygen gas    -    -   9-25
Sulphureted hydrogen   -  55            Nitrogen    -    -    -   750
Nitrous oxyde -        -  40            Carbureted hydrogen   -   5-00
Carbonic acid gas -    - 35             Hydrogen gas    -    -   175
Neumann, who made many experiments on charcoal, informs us, that for the reduction
of the metallic oxydes, the charcoal of the heavier woods, as that of the oak and the
beech, is preferable, and that, for common fuel, such charcoal gives the greatest heat, and
requires the most plentiful supply of air to keep it burning; while those of the lighter
woods preserve a glowing heat with a much less draught of air; and that for purposes
where it is desirable to have a steady and a still fire, charcoal should be employed which




CARBONATE OF AMMONIA.                                371
has been made from wood previously divested of its bark, sinze it is the cortical pan
which crackles and flies off in sparks during combustion, while the coal of the wood
itself seldom does.
For making crayons of charcoal, the willow is the best wood that can be employed, as
the softness is uniform in all its parts. Its durability may be seen in several of our old
churchyards, where the letters made with lamp-black are still perfect, though the white
lead with which the body of the stones was painted is entirely destroyed.
This property of carbon is shown, however, in a more striking manner by the writings
that were found in the ruins of Herculaneum, which have retained their original blackness for two thousand years. The ancients wrote with ink made from ground charcoal.
If it be required to purify any carbonaceous matter, to render it fitter for delicate pigments, this may be done by first calcining it in a close vessel, and then lixiviating it in
water slightly acidulated by nitric acid.
The incorruptibility of charcoal was well known to the ancients, and they availed
themselves of this property upon all important occasions.
About sixty years ago a quantity of oak stakes were found in the bed of the Thames,
in the very spot where Tacitus says that the Britons fixed a vast number of such stakes
to prevent the passage of Julius Caesar and his army. These stakes were charred to a
considerable depth, had retained their form completely, and were firm at the heart.
Most of the houses in Venice stand upon piles of wood, which have all been previously
charred for their preservation. In this country, estates were formerly marked out by
charred stakes driven to a considerable depth into the ground. See BONE-BLACK,
CHARCOAL, and GRAPHITE.
CARBONATED WATER is water either pure, or holding various saline matters in
solution, impregnated with carbonic acid gas. For general sale in this country, the
water usually contains a little soda, which being charged with the gas, is called Soda
water; see this article for a description of an excellent machine for the manufacture of
this fashionable beverage.
CARBONATES. Saline compounds in definite proportions of carbonic acid, with alkalis, earths, and the ordinary metallic oxydes.
The carbonates principally used in the arts and manufactures are those of ammonia,
copper, iron, lead, lime, magnesia, potash, soda. Native carbonate of copper is the beautiful green mineral called Malachite.
Carbonates are easily analyzed by estimating either by weight or measure the quantity
of carbonic acid which they evolve under the decomposing action of somewhat dilute
sulphuric, nitric, or muriatic acid; for as they are all compounds of acid, and base in
equivalent proportions, the quantity of acid will indicate the quantity of base. Thus,
as pure limestone consists of 56 of lime and 44 of acid, in 100 parts, if upon examining
a sample of limestone we find it to give out only 22 per cent. of carbonic acid gas, during its slow solution in muriatic acid, we are sure that there are only 28 parts of lime
present. I have described, in the Annals of Philosophy for October, 1817, a simple form
of apparatus for analyzing the carbonates with equal readiness and precision. The simple rule by measure to which I was led, may be thus stated: From the bulk of evolved
gas, expressed in cubic inches and tenths, deduct-L, the remainder will express the proportion of real limestone present in the grains employed. Pure magnesian limestone yields
very nearly a cubic inch of the gas for every grain in weight.
CARBONATE  OF AMMONIA. A salt called in modern chemistry sesqui-carbonate, to denote its being composed of one and a half equivalent primes of carbonic
acid, and one of ammonia. It consists by my analysis of 55-89 carbonic acid, 28-86
ammonia, and 15'25 water, in 100 parts. It is generally prepared by mixing from 1l to
1I parts of well-washed dry chalk, with 1 of sal-ammoniac, introducing the mixture into
an earthen or cast-iron retort, or subliming pot, and exposing it to a heat gradually raised
to redness. By double decomposition, the ammonia is volatilized in combination with the
carbonic acid of the chalk, and the vapors are received in a condensing receiver made
either of glass, stone ware, or lead. The chlorine of the sal-ammoniac remains in the
retort, associated with the basis of the chalk in the state of chloride )f calcium. Some
ammonia gas escapes during the process.
The saline mass thus sublimed is purified by a second sublimation in glass or saltglazed earthen vessels. The salt may be obtained, by the above method carefully conducted, in rhomboidal octahedrons, but it is generally made for the market in a compvct
simi-crystalline white cake. It has a pungent ammoniacal smell; a hot, pungent, alkaline taste; a strong alkaline reaction, and dissolves in two parts of cold water. It must
be kept in well-closed vessels, as by exposure to the air a portion of its ammonia exhales,
and it passes into the state of the scentless bi-carbonate. It is employed much in medicine, chemical analysis, and by the pastry-cooks to give sponginess to their cakes, in consequence of its volatilization from their dough in the oven. See SAL-AMMONIAC.
For the other carbonates used in the arts, see their respective bases; copper, lead,
lime, &c.




372                      CARBURET OF SULPHUR.
CARBONIC ACID (.cide carbonique, Fr.; Kohlensaure, Germ.) consists of 1 pnme
equivalent of carbon=6'125+2 of oxygen=16'026, whose joint sum=22 151, represents
the atomic weight or combining ratio of this acid, in the neutral or protocarbonate
salts. Its composition by volume is stated under CARBON. Its natural form is a gas,
whose specific gravity is 1'5245, compared to atmospheric air 1-000; and being so
dense, it may be poured out of one vessel into another. Hence it was called at first
aerial acid. From its existing copiously, in a solid state, in limestones and the mild
alkalis, it was styled fixed air by its proper discoverer, Dr. Black. About one volume
of it exists in 1000 volumes of common atmospheric air, which may be made manifest
Ay the crust of carbonate it occasions upon the surface of lime water. Carbonic acid
gas is found accumulated in many caverns of volcanic districts, and particularly in
the grotto dei cani at Pausilippo, near Puzzuoli; being disengaged in such circumstances
by the action of subterranean fire, and, possibly, of certain acids, upon the limestone
strata.  It often issues from  fountains in copious currents, as at Franzensbrunn,
near Eger, in Polterbrunnen; near Trier; and Byrreshorn. This acid gas occurs
also frequently in mines and wells, being called choke damp, from  its suffocating
quality. Its presence may, at all times, be detected, by letting down a lighted candle,
suspended from a string, into the places suspected of containing this mephitic air. It
exists, in considerable quantities, in the water of every pump well, and gives it a fresh
and pleasant taste. Water, exposed some time to the air, loses these aerial particles, and
becomes vapid. Many springs are highly impregnated with carbonic acid gas, and
form a sparkling beverage; such as the Selterswasser, from Selters upon the Lahn, in
the grand dutchy of Nassau; of which no less than two millions and a half of bottles
are sold every year. A  prodigious quantity of a similar water is also artificially
prepared in Great Britain, and many other countries, under the name of aerated or
soda water.
Carbonic acid occurs in nature, combined with many salifiable bases; as in the
carbonates of soda, baryta, strontia, magnesia; the oxydes of iron, manganese, zinc,
copper, lead, &c. From these substances it may be separated, generally speaking, by
strong ignition, or, more readily, by the superior affinity of muriatic, sulphuric, or
nitric acid, for the earth or metallic oxyde. It is formed whenever vegetable or animal
substances are burned with free access of air, from the union of their carbonaceous
principle with atmospheric oxygen. It is also formed in all cases of the spontaneous
decomposition of organic substances, particularly in the process of fermentation; and
constitutes the pungent, noxious, heavy gas thrown off, in vast volumes, from beer vats.
See DISTILLATION and FERMENTATION. Carbonic acid is also generated in the breathing
of animals; from 4 to 5 per cent., in volume, of the inhaled oxygen being converted, at
each expiration, into this gas, which contaminates the air of crowded apartments, and
renders ventilation essential to health, and even to life; witness the horrible catastrophe
of the Black-hole at Calcutta.
Carbonic acid gas is destitute of color, has a sourish, suffocating smell, an acidulous
pungent taste, imparts to moist, but not dry, litmus paper, a transient reddish tint, and
weighs per 100 cubic inches, 462 grains; and per cubic foot, 803. grains; a little more
than 31 oz. avoirdupoise. A cubic foot of air weighs about two thirds of that quantity,
or 527 grains. It may be condensed into the liquid state by a pressure of 40 atmospheres, and this liquid may be then solidified by its own sudden spontaneous evaporation. If air contain more than 15 per cent. in bulk of this gas, it becomes unfit
for respiration and combustion, animal life and candles being speedily extinguished
by it.
Before a person ventures into a deep well, or vault containing fermenting materials,
he should introduce a lighted candle into the space, and observe how it burns. Carbonic acid, being so much denser than common air, may be drawn out of cellars or
fermenting tubs, by a pump furnished with a leather hose, which reaches to the bottom.
Quicklime, mixed with water, may be used also to purify the air of a sunk apartment, by
its affinity for, or power of, absorbing this aerial acid. See MINERAL WATERS and SODA
WATER.
CARBONIC OXYDE. See the article CARBON.
CARBUNCLE. A gem highly prized by the ancients; most probably a variety of the
noble garnet of modern mineralogists.
CARBURET  OF SULPHUR, called also sulphuret of carbon, and alcohol of
sulphur, is a limpid volatile liquid possessing a penetrating fetid smell, and an acrid
burning taste. Its specific gravity is 1'265; and its boiling point is about 1120 Fahr. It
evaporates so readily, and absorbs so much heat in the vaporous state, that if a tube containing quicksilver, surrounded with lint dipped in this liquid, be suspended in the re
ceiver of an air-pump on making the vacuum, the quicksilver will be congealed. It con
sists of 15-8 carbon and 84-2 sulphur, in 100 parts; being two equivalent primes of the
latter to one of the former.




CARD CUTTING.                                   373
CARBURETED  HYDROGEN.  A compound of carbon and hydrogen, of which
lhere are several species-such as oil-gas, coal-gas, olefiant gas, oil of lemons, otto of
roses, oil of turpentine, petroleum, naptha, napthaline, oil of wine, caoutchoucine, and
caoutchouc.
CARDS, PLAYING. (Cartes a jouer, Fr.; Karten, Germ.)  Mr. de la Rue obtained,
in February, 1832, a patent for certain improvements in the manufacture of playing
cards, which he distributed under three heads; first, printing the pips, and also the picture
or court cards, in oil colors by means of types or blocks; secondly, effecting the same ir
oil colors by means of lithography; and thirdly, gilding or silvering borders, and other
parts of the characters, by the printing process, either by types, blocks, or lithography.
In the ordinary mode of manufacturing playing cards, their devices are partly produced
by copperplate printing, and they are filled up with water colors by the means called
stencilling.
The patentee does not propose any material alteration in the devices or forms upon the
cards, but only to produce them with oil colors; and, to effect this, he follows precisely
the same mode as that practised by calico printers.
A set of blocks or types properly devised, are produced for printing the different pips
of hearts, diamonds, spades, and clubs, or they are drawn, as other subjects, in the usual
way upon stone. The ink or color, whether black or red, is to be prepared from the
best French lamp-black, or the best Chinese vermilion ground in oil, and laid on the
types and blocks, or on the stone, in the same way as printers' ink, and the impressions
taken-on to thick drawing paper by means of a suitable press in the ordinary manner of
printing.
The picture or court-cards are to be produced by a series of impressions in different
colors, fitting into each other exactly in the same way as in printing paper hangings, or
silks and calicoes, observing that all the colors are to be prepared with oil.
For this purpose a series of blocks or types are to be provided for each subject, and
which, when put together, will form the whole device. These blocks are to be used separately, that is, all the yellow parts of the picture, for instance, are to be printed at one
impression, then all the red parts, next all the flesh color, then the blue portions, and so
on, finishing with the black outlines, which complete the picture.
If the same is to be done by lithography, there must be as many stones as there are
to be colors, each to print its portion only; and the impression, or part of the picture
given by one stone, must be exactly fitted into by the impression given from the next stone,
and so on until the whole subject is complete.
A superior kind of card is proposed to be made, with gold or silver devices in parts
of the pictures, or gold or silver borders round the pips. This is to be effected by
printing the lines which are to appear as gold or silver, with gilders' size, in place of
ink or color; and immediately after the impression has been given, the face of the card
is to be powdered over with gold dust, silver, or bronze, by means of a soft cotton or
wool dabber, by which the gold, silver, or bronze will be made to adhere to the picture,
and the superfluous portions of the metal will wipe off by a very slight rubbing. When
the prints are perfectly dry, the face of the card may be polished by means of a soft
brush.
If it should be desirable to make these improved cards to resemble ivory, that may be
done by preparing the face of the paper in the first instance with a composition of size
and fine French white, and a drying oil, mixed together to about the consistency of cream;
this is to be washed over the paper, and dried before printing, and when the cards are
finished they will exactly resemble ivory.
The only thing remaining to be described, is the means by which the successive impressions of the types, blocks, or stones, forming the parts of the pictures, are to be brought
exactly to join each othe-, so as to form a perfect whole design when complete; this is by
printers called registering, and is to be effected much in the usual way, by points in the
tympan of the press, or by marks upon the stones.
The parts of the subject having been all accurately cut or drawn to fit, small holes are
to be made with a fine awl through a quire or more of the paper at once, by placing
upon the paper a gauge-plate, having marks or guide-holes, and by observing these, the
same sheet laid on several times, and always made to correspond with the points or
marks, the several parts of the picture must inevitably register, and produce a perfect
subject.
CARD CUTTING. Mr. Dickinson's patent machine for cutting cards, consists of
a pair of rollers with circular revolving cutters, the edges of which are intended to act
against each other as circular shears, and the pasteboards in passing between these
rollers are cut by the circular shears into cards of the desired dimensions. These rollers
are mounted in suitable standards, with proper adjustments, and are made to revolve by




374                                   CARDS.
a band and pulley connected to the axle of a crank, or by any other convenient
means.
Fig. 330 is a front view of
"331                  _f _... L a.   this machine; a a and b b
C are the  two  rollers, the
upper  one  turning  upon
an extended axle, bearing
in tile standards, the lower
one upon  pivots.  These
rollers are formed  by  a
series of circular blocks,
between  a series of cir332   h a'      I i~1(    cular steel cutters, which
are  slidden  on  to  iron
330                   shafts, and  held  together
upon  their axle by nuts
FL  lf  ______e    ___        S screwed up at their ends.
333^  \LF     \  If/    - l        The  accurate  adjustment
8333;                                   \           y of the cutters is of the
{~~/9 en~^\~~           ~first importance  to  their
I~o 0e)              l                                 correct performance; it is
therefore  found  necessary
to introduce spiral springs....... I  within the blocks, in order
to press the cutters up to
their proper bearings. A section of one of the blocks is shown at fig. 332, and an end
view of the same at fig. 333, with the spiral springs inserted.
At the outer extremity of the axle of the roller a, a rigger c, is attached, whence a band
passes to a pulley d, on the crank shaft e, to which a fly-wheel f, is affixed, for the purpose
of rendering the action uniform. Rotatory motion being given to the crank shaft, the
upper roller is turned, the lower roller moving at the same time by the friction against the
edges of the cutters.
Fig. 331 is an end view of the rollers, showing the manner in which the pasteboards
are guided and conducted between the cutters. In the front of the machine a moveable
frame g, is to be placed, for the purpose of receiving the pasteboards, preparatory to cutting them into cards, and a stop is screwed to this frame for the edge of the pasteboard to
bear against, which stop is adjustable to suit different sizes. From the back part of this
frame an arm h, extends, the extremity of which acts against the periphery of a ratchet
wheel i, fixed at the end of the roller b, and hence, as the roller goes round, the frame is
made to rise and fall upon its pivots, for the purpose of guiding the pasteboard up to the
cutters; at the same time a rod k, hanging in arms from the sides of the standards (shown
by dots in fig. 330), falling upon the pasteboard, confines it, while the cutters take hold,
and racks corresponding with the indentations of the rollers are placed as at 11, by means
of whlih the cards, when cut, are pushed out of the grooves.
As 7arious widths of cards will require to be cut by this machine, the patentee proposes to have several pairs of rollers ready adjusted to act together, when mounted in the
standards, in preference to shifting the circular cutters, and introducing blocks of greater
or less width.
The second part of the invention is a machine for pasting the papers, and pressing
the sheets together to make pasteboard. This machine consists of several reels (we
suppose rollers are intended) on which the paper is to be wound, along with a paste
trough, and rotatory brushes. The several parts of this machine, and their operations in
making pasteboard, are described in the specification, but the patentee having omitted
the letters of reference in the drawing which he has enrolled, it becomes difficult to
explain it.
As far as we are enabled to understand the machine, it appears, that damped paper is
to be wound upon two rollers, and conducted from thence over two other rollers; that two
fluted rollers revolving in the paste trough are to supply paste to two circular brushes,
and that by those brushes the papers are to be pasted upon one side, and then pressed together, to make the pasteboard; after this, the pasteboard is to be drawn on to a table,
and to remain there until sufficiently dry to be wound upon other rollers. By comparing
this description with the figure, perhaps the intended operations of the machine may be
discovered: it is the best explanation we are enabled to give.
CARDS (Cardes, Fr.; Karden, Germ.) are instruments which serve to disentangle
the fibres of wool, cotton, or other analogous bodies, to arrange them in an orderly lap
or fleece, and thereby prepare them for being spun into uniform threads. The fineness
and the levelness of the yarn, as well as the beauty of the cloth into which it enters.




CARDS.                                     375
depend as much upon the regularity and perfection of the carding, as upon any subsequent
operations of the factory. The quality of the carding depends more upon that of the
cards than upon any attention or skill in the operative; since it is now nearly an automa
tic process, conducted by young women called card-tenters.
Cards are formed of a sheet or fillet of leather pierced with a multitude of small holes,
in which are implanted small staples of wire with bent projecting ends called teeth.
Thus every piece of wire is double toothed. The leather is afterwards applied to a flat
or cylindrical surface of wood or metal, and the co-operation of two or more such surfaces constitutes a card. The teeth of cards are made thicker or slenderer, according as
the filaments to be carded are coarser or finer, stiffer or more pliant, more valuable or
cheaper. It is obviously of great importance that the teeth should be all alike, equably
distributed, and equally inclined over the surface of the leather, a degree of precision
which is scarcely possible with handwork.  To judge of the difficulty of this manipulation we need only inspect the annexed figures. The wire must first be bent at right
angles in c and d, fig. 335, then each branch must receive a second bend in a and b at a
determinate obtuse angle, invariable for each system of cards. It is indispensable that
the two angles ca e and d bf be mathematically equal, not only as to the twin teeth of one
staple, but through the whole series; for it is easy to see that if one of the teeth be more
or less sloped than its fellow, it will lay hold of more or less wool than it, and render the
carding irregular. But though the perfect regularity of the teeth be important, it is not
the sole condition towards making a good card. It must be always kept in view that these
teeth are to be implanted by pairs in a piece of leather, and kept in it by the cross part
c d. The leather must therefore be pierced with twin holes at the distance c d; and pierce
ed in such a manner, that the slope of the holes, in reference to the plane of the leather,
be invariably the same; for otherwise the length of the teeth would vary with this angle
of inclination, and the card would be irregular.
A third condition essential towards producing perfect regularity, is that the leather
ought to be of the same thickness throughout its whole surface, otherwise the teeth,
though of the same length and fixed at the same angle, would be rendered unequal by the
different thicknesses of the leather, and the operation of carding would be in consequence
335
extremely defective. Fig. 334 shows the card teeth acting against each other, as indicated by the arrows in two opposite directions; in fig. 336 they work one way.
Of late years very complex but complete and well-acting machines have been constructed for splitting the leather or equalizing it by shaving, for bending and cutting the
wires, and implanting them in the leather, into holes pierced with perfect regularity.
Card machines which fashion the teeth with great precision and rapidity, and pierce the
leather, have been for a considerable time in use at Halifax, in Yorkshire, a town famous
for the excellence of its card-cloth, as also at Leeds, Glasgow, and several other places.
The wires and the leather thus prepared are given out by the manufacturer to women and
children, who put them together.
1. The simplest machine for equalizing the leather which can be employed, is that
which I saw operating in MM. Scrive's automatic card factory at Lille, the most magnificent I believe in the world, where the leather was drawn forwards by a roller over a solid
horizontal table, or bed, and passed under a nicely adjusted vertical blade, which shaved
it by a scraping motion to a perfectly uniform thickness. About one half the weight of
the leather is lost in this process, and in the subsequent squaring and trimming.
The machine for making cards, invented I believe by a Mr. Ellis of the United States,
for which a first patent was obtained in this country by Joseph Cheeseborough Dyer, Esq.
of Man:hester, in 1811, and a second and third with further improvements in 1814,
atl 1824, is one of the most elegant automatons ever applied to productive industry.
It is, however, necessarily so complicated with different mechanisms as to render its
representation impracticable in such engravings as are compatible with the scope of this
dictionary. I must therefore content myself with the following general description of its
constituent parts.
The first thing to be done after having, as above, prepared the long sheets or fillets of
leather of suitable length, breadth, and thickness, for making the cards, is to stretch the
leather, and hold it firmly; which is accomplished by winding the fillet of leather upon
the roller or drum, like the warp roller of a loom, and then conducting it upwards between
guide rollers, to a receiving or work roller at top of the machine, where the fillet is held
fast by a cramp, by which means the leather is kept stretched.
Secondly, the holes are pierced in the leather to receive the wire staples or teeth of the




376                                 CARMINE.
ard. by means of a sliding fork, the points of which are presented to the face of ihe
leather; while the fork is made to advance and recede continually, by the agency of
levers worked by rotatory cams upon a revolving main shaft.
The points of the fork being thus made to.penetrate into the leather, the holes fol
receiving the staples are pierced at regular distances, and in correct order, by shifting the
leather fillet so as to bring different parts of its surface opposite to the points of the
sliding fork. This is done by cams, or indented wheels and gear, which shift the guide
rollers and confining drums laterally, as they revolve, and consequently move the fillet of
leather at intervals a short distance, so as to present to the points of the fork or piercer,
at every movement, a different part of the surface of the leather.
Thirdly, the wire of which the teeth or points of the card are to be made, is supplied
from a coil on the side of the machine, and is brought forward at intervals by a pair
of sliding pincers, which are slidden to and fro through the agency of levers actuated by
rotatory cams upon the main shaft. The pincers having advanced a distance equal to
the length of wire intended to form one staple or two points, this length of wire is
pressed upon exactly in the middle by a square piece of steel, and being there confined,
a cutter is brought forward, which cuts it off from that part of the wire held in the pincers.
The length of wire thus separated and confined is now, by a movement of the machine,
bent up along the sides of the square steel holder, and shaped to three edges of the square,
that is, formed as a staple; and in the same way, by the continued movements of thq
machine, a succession of pieces of wire are cut off, and bent into staples for making the
teeth of the card as long as the mechanism is kept in action.
Fourthly, the wire staple thus formed is held with its points or ends outwards, closely
contiguous to the forked piercer described above, and by another movement of the mechanism, the staple is protruded forward, its end entering into the two holes Omde previously in the leather by the sliding of the fork.
While the wire staple is being thus introduced into the leather, its legs or points are
to be bent, that is, formed with a knee or angle, which is the fifth object to be effected.
This is done by means of a small apparatus consisting of a bar or bed, which bears up
against the under side of the wire staple when it has been passed half way into the
holes in the leather, and another bar above it, which, being brought down behind the
staple, bends it over the resisting bar to the angle required; that is, forms the knee in
each leg. A pusher now acts behind the staple, and drives it home into the leather,
which completes the operation.
The leather being thus conducted, and its position shifted before the piercer progressively, a succession of the above described operations of cutting the wire, forming the
staple, passing it into the leather, and bending its legs to the angular form, produces
a sheet of card of the kind usually employed for carding or combing wool, cotton, and
other fibrous materials. It may be necessary to add, that as these wire staples are required to be set in the leathers sometimes in lines crossing the sheet, which is called
ribbed, and at other times in oblique lines, called twilled, these variations are produced
by the positions of the notches or steps upon the edge or periphery of the cam or indented wheel, which shifts the guide rollers that hold the fillet or sheet of leather as
already described.
CARMINE (Eng. and Fr.; Karminstoff, Germ.) is, according to Pelletier and Caventon, a triple compound of the coloring substance, and an animal matter contained in
cochineal, combined with an acid added to effect the precipitation. The preparation of this
article is still a mystery, because, upon the one hand, its consumption being very limited,
few persons are engaged in its manufacture, and upon the other, the raw material being
costly, extensive experiments on it cannot be conveniently made. Success in this business is said to depend not a little upon dexterity of manipulation, and upon knowing the
instant for arresting the further action of heat upon the materials.
There is sold at the shops different kinds of carmine, distinguished by numbers, and
possessed of a corresponding value. This difference depends upon two causes; either
upon the proportion of alumina added in the precipitation, or of a certain quantity of
vermilion put in to dilute the color. In the first case the shade is paler, in the second it
has not the same lustre. It is always easy to discover the proportion of the adulteration.
By availing ourselves of the property of pure carmine to dissolve in water of ammonia,
the whole foreign matter remains untouched, and we may estimate its amount by drying
the residuum.
To make Ordinary Carmine.
Take 1 pound of cochineal in powder;
3 drachms and a half of carbonate of potash;
8 drachms of alum in powder;
3 drachms and a half of fish-glue.
The cochineal must be boiled along with the potash in a copper containing five pailsfal of water (60 pints); the ebullition being allayed with cold water. After boiling a




CARMINE.                                    377
few minutes the copper must be taken from the fire, and placed on a table at such an
angle as that the liquor may be conveniently transvased. The pounded alum is then
thrown in, and the decoction is stirred; it changes color immediately, and inclines to a
more brilliant tint. At the end of fifteen minutes the cochineal is deposited at the
bottom, and the bath becomes as clear as if it had been filtered. It contains the coloring matter, and probably a little alum in suspension. We decant it then into a copper of
equal capacity, and place it over the fire, adding the fish-glue dissolved in a great deal of
water, and passed through a searce. At the moment of ebullition, the carmine is perceived to rise up to the surface of the bath, and a coagulum is formed, like what takes
place in clarifications with white of egg. The copper must be immediately taken from
the fire, and its contents be stirred with a spatula. In the course of fifteen or twenty
minutes the carmine is deposited. The supernatant liquor is decanted, and the deposite
must be drained upon a filter of fine canvass or linen. If the operation has been well
conducted, the carmine, when dry, crushes readily under the fingers. What remains after
the precipitation of the carmine is still much loaded with color, and may be employed
very advantageously for carminated lakes. See LAKE.
By the old German process, carmine is prepared by means of alum without any other
addition. As soon as the water boils, the powdered cochineal is thrown into it, stirred
well, and then boiled for six minutes; a little ground alum is added, and the boiling is
continued for three minutes more; the vessel is removed from the fire, the liquor is filtered and left for three days in porcelain vessels, in the course of which time a red matter falls down, which must be separated and dried in the shade. This is carmine, which
is sometimes previously purified by washing. The liquor after three days Lore lets fall
an inferior kind of carmine, but the residuary coloring matter may also be separated by
the muriate of tin.
The proportions for the above process are 580 parts of clear river water, 16 parts of
cochineal, and I part of alum; there is obtained from 1 to 2 parts of carmine.
Another carmine wilh tartar.-To the boiling water the cochineal is added, and after
some time a little cream of tartar; in eight minutes more we add a little alum, and con
tinue the boiling for a minute or two longer. Then take it from the fire and pour it
into glass or porcelain vessels, filter, and let it repose quietly till the carmine falls down.
We then decant and dry in the shade. The proportions are 8 pounds of water, 8 oz.
of cochineal, I oz. of cream of tartar, I oz. of alum, and the product is an ounce of
carmine.
The process of.xon or Langlois.-Boil two pails and a half of river water (30 pints),
throw into it, a little afterwards, a pound of cochineal, add a filtered solution of six
drachms of carbonate of soda and a pound of water, and let the mixture boil for half an
hour; remove the copper from the fire, and let it cool, inclining it to one side. Add
six drachms of pulverized alum, stir with a brush to quicken the solution of the salt, and
let the whole rest 20 minutes. The liquor, which has a fine scarlet color, is to be carefully decanted into another vessel, and there is to be put into it the whites of two eggs
well beat up with half a pound of water. Stir again with a brush. The copper is replaced on the fire, the alumina becomes concrete, and carries down the coloring matter
with it. The copper is to be taken from the fire, and left at rest for 25 or 30 minutes to
allow the carmine to fall down. When the supernatant liquor is drawn off, the deposite is placed upon filter cloth stretched upon a frame to drain. When the carmine
has the consistence of cream cheese, it is taken from the filter with a silver or ivory
knife and set to dry upon plates covered with paper, to screen it from dust. A pound of
cochineal gives in this way an ounce and a half of carmine.
Process of Madame Cenette, of Amsterdam, with salt of sorrel.-Into six pails of river
water boiling hot throw  two pounds of the finest cochineal in powder, continue the
ebullition for two hours, and then add 3 oz. of refined saltpetre, and after a few minutes
4 oz. of salt of sorrel. In ten minutes more take the copper from the fire and let it
settle for four hours; then draw off the liquor with a syphon into flat plates and leave it
there for three weeks.  Afterwards there is formed upon the surface a pretty thick mouldiness, which is to be removed dexterously in one pellicle by a slip of whalebone. Should
the film tear and fragments of it fall down, they must be removed with the utmost care.
Decant the supernatant water with a syphon, the end of which may touch the bottom of
the vessel, because the layer of carmine is very firm. Whatever water remains must be
sucked away by a pipette. The carmine is dried in the shade, and has an extraordinary
lustre.
Carmine by the salt of tin, or the Carmine of China.-Boil the cochineal in river water,
adding some Roman alum, then pass through a fine cloth to remove the cochineal, and
set the liquor aside. It becomes brighter on keeping. After having heated this liquor,
pour into it, drop by drop, solution of tin till the carmine be precipitated. The proportions are one pailful of water, 20 oz. of cochineal, and 60 grains of alum, with a solu.
don of tin containing 4 oz. of the metal.
VOL. 1.                             3 C




378                                  CARPET.
To revive or brighten carmine.-We may brighten ordinary carmine, and obtain a very
ine and clear pigment, by dissolving it in water of ammonia. For this purpose we leave
ammonia upon carmine in the heat of the sun, till all its color be extracted, and the liquor
has got a fine red tinge. It must be then drawn off and precipitated, by acetic acid and
alchohol, next washed with alcohol, and dried. Carmine dissolved in ammonia has been
long employed by painters, under the name of liquid carmine.
Carmine is the finest red color which the painter possesses. It is principally employed
in miniature painting, water colors, and to tint artificial flowers, because it is more transparent than the other colors. For Carminium, see COCHINEAL.
This valuable pigment is often adulterated with starch.  Water of ammonia enables
us to detect this fraud by dissolving the pure carmine, and leaving the starchy matter,
as well as most other sophisticating substances. Such debased carmine is apt to spoil
with damp.
CARPET.  (Tapis, Fr.; Teppich, Germ.)  A  thick woollen fabric of variegated
colors, for covering the floors of the better sort of apartments. This luxurious manufacture took its origin in Persia and Turkey, whence the most beautiful patterns were wont
to come into Europe; but they have been for some time surpassed by the workmanship of
France, Great Britain, and Belgium. To form a just conception of the elegant and ingenious processes by which carpets are made, we should visit the royal establishment of
the Gobelins at Paris, where we would see the celebrated carpet manufactory of the
Savounerie, which has been transported thither.  A detailed set of engravings of this art
is given by Roland de la Platiere in the first and second volumes of the Encyclopedie
Methodique, to which I must refer my readers, as a due exposition.' its machines and
operations would far exceed the scope of the present volume.
The warp, says M. Roland, being the foundation of the fabric, ought to be of fine
wool, equally but firmly spun, and consist of three yarns twisted into one thread. The
yarns that are to form the velvety surface of the carpet, ought also to be of the best
quality, but soft and downy in their texture, so that the dye may penetrate every filament. Hemp, or linen yarns, are likewise employed in this manufacture, as a woof, to
bind the warp firmly together after each shoot of the velvety threads. Thus we see
that good carpeting consists essentially of two distinct webs woven at the same time,
and firmly decussated together by the woof threads. Hence the form of the pattern is
the same upon the two sides of the cloth, only the colors are reversed, so that what was
green upon one side becomes red or black upon the other, and vice versa. The smaller
the figures the more frequent the dccussations of the two planes, and the firmer and
more durable the fabric.
The carpet manufacture, as now generally practised, may be distributed into two systems-that of double fabrics, and that cut in imitation of velvet.  Of late years the
Jacquard loom  has been much used in weaving carpets, the nature of which will be
found fully explained under that title.
For the sake of illustration, if we suppose the double carpets to be composed of only
two colors, the principle of weaving will be easily understood; for it is only necessary
to raise the warp of each web alternately for the passage of the shuttle, the upper web
being entirely above when the under web is being woven, or decussated, and vice versa.
In a Brussels carpet the worsted yarn raised to form the pile, and make the figure, is
not cut; in the Wilton the pile is cut to give it a velvety aspect and softness. In the
imperial Brussels carpet the figure is raised above the ground, and its pile is cut,
but the ground is uncut; and in the royal Wilton, the pile is both raised higher
than in the common Wilton, and it is cut, whereby it has a rich cushion-like appearance.  The cloth of all these superior carpets consists of woollen and linen, or
hemp; the latter being put upon a beam, and brought, of course, through heddles and a
reed; but as its only purpose is to bind together the worsted fabric, it should not be
visible upon the upper face of the carpet. The worsted yarn is wound upon small bobbins or pirns, with a weight affixed to each, for giving proper tension to the threads.
Their number varies, for one web, from  1300 to 1800, according as the carpet is to
be 27 or 36 inches wide; and they are placed, in frames, behind the loom, filled with
differently colored yarn, to correspond with the figure. This worsted warp is then drawn
through the harness, heddles, and reed, to be associated with the linen yarn in the compound fabric.
In Kidderminster carpeting, both warp and weft appear upon the face of the cloth,
whereas, in the Brussels style, only the warp is seen, its binding weft being fine hempen
or linen threads.  The three-ply imperial carpet, called the Scotch, is coming very
much into vogue, and is reckoned by many to be little inferior in texture, look, and
wear to the Brussels. Kilmarnock has acquired merited distinction by this ingenious
industry. In this fabric, as well as in the two-ply Kidderminster, the weft predominates,
and displays the design; but in the French carpets, the worsted warp of the web shows
the figure. Plain Venetian carpets, as used for stairs and passages, are woven in simple
looms, provided merely- with the common heddles and reed. The warp should be a




CARPET.                                     379
substance of worsted yarn, so heavy as to cover in the weft completely from the view.
Figured Venetian carpets are woven in the two-ply Kidderminster looms, and are
provided with a mechanism to raise the pattern upon the worsted warp. The weft is an
alternate shoot of worsted and linen yarn, and must be concealed.
The following figure and description will explain the construction of the three-ply
imperial Scotch and two-ply Kidderminster carpet-loom, which is merely a modification
of the Jacquard metier.  The Brussels carpet-loom, on the contrary, is a draw-boy loom
337                    on the damask plan, and requires the
5'     _ F                 weaver to have an assistant. Fig. 337,
rod...i.  ri        A A A, is the frame of the loom, consisting of four upright posts, with caps
and cross rails to bind them together.
The posts are about six feet high.  c c,
HAi-~II IIF L__.~             \the cloth-beam, is a wooden cylinder,
six inches or thereby in diameter, of
sufficient length to traverse the loom,
with iron gudgeons in the two ends,
I  Dl SSS  l \    I  On one end of this beam  is a ratchet
wheel, with a teeth to keep it from
j    ~ ^^ l;~~oi i  E             turning round backwards by the tension
of the wetb. D, the lay, with its reed,
its under and upper shell, its two lateral
rulers or swords, and rocking-tree above.
There are grooves in the upper and
X1~~ Q  1 13 -1  11/   i under shell, into which the reed is fitted.
E, the heddles, or harness, with a double'~'lilll~- in~neck attached to each of the tower or card
"^:__  - i ^^^ U I                1lmechanisms F F, of the Jacquard loom.
God^c ~_z_ "^^sJ  ~           The heddles are connected and work with
the treddles B B, by means of cords, as shown in the figure.  G G are wooden boxes for
the cards.  H, the yarn or warp-beam.
In draw-looms of every kind, there is no sinking of any portion of the warp, as in
plain cloth-weaving; but the plane of the warp is placed low, and the threads under
which the shuttle is to pass are raised, while all the rest remains stationary.  The
harness part of this carpet-loom is moved by an assistant boy or girl, who thus allows
the weft to be properly decussated, while the weaver attends to working the front
mounting or heddles.  Fig. 338, A repre338                                         sents the frame of a carpet draw-loom;....  B    i    B is a box or frame of pulleys, over
-'j:il  IiTj         which the cords of the harness pass, and
are then made fast to a piece of wood,
seen at E, which the weavers call a table.
____ /I\\  A  From the tail of the harness the simples
11111*   descend, and to the end of each is at111111  I /IIMM\^\      II      tached a small handle G, called a bob.
These handles being  disposed in pairs,
and their regularity preserved by means,, =.^).    i    ^of a perforated board c, it is merely nei   lljlllljlIlll ttj 11  cessary to pull every handle in succession; the weaver, at the same time,
working his treddles with his feet, as in
any other loom. The treddles are four
in number, the fabric being that of plain or alternate cloth, and two treddles allotted  for each web. The harness part of the carpet draw-loom  is furnished  with
mails, or metallic eyes, to save friction; two thisads being drawn through each eye.
The design or pattern of a carpet is drawn upolh cross-rule paper, exactly in the
same way as every other kind of fancy-loom work, and is transferred from  the paper
to the mounting by the rules for damask weaving. Suppose that a double web is so
mounted that every alternate thread of the one may be raised, so as to form a sufficient shed-way for the shuttle, without depressing the other in the least. Then suppose
another web placed above the former, at such a distance that it will exactly touch the
convexity of those threads of the former which are raised. Then, if the threads of
the latter web are sunk while the others are raised, the two would be entirely incorporated.  But if this be only partially done, that is, at particular places, only those
parts immediately operated upon will be affected by the action of the apparatus.
If the carpet is a two-colored pattern, as black and red, and if upon the upper sur3C 2




380                                CARPET.
face, as extended in the loom, red flowers are to be represented upon a black ground,
then all those species of design paper which are colored may be supposed to represent
the red, and those which are vacant the black. Then counting the spaces upon the
paper, omit those which are vacant, and cord those which are colored, and the effect
will be produced. But as the two webs are to be raised alternately, whatever is corded
for the first handle must be passed by for the second, and vice versa; so that the one will
form the flower, and the other the ground.
The board by which the simples are regulated appears at F. D shows the weights.
CARPET-NEW  PATENT.  Mr. Simcox, of Kidderminster, has  patented  an
invention for an improved manufacture of carpets, in which, by dispensing with the
Jacquard loom, as well as the iron wires and tags usually employed to produce terry
fabrics, such as Brussels carpets and coach-lace, he can work his machinery at greater
speed and more economically. His second improvement relates to the manufacture of
fabrics with cut pile, such as Wilton or Axminster carpets. He makes a ribbed fabric,
greatly resembling the Brussels carpet, by a combination of woollen and linen warp and
weft, arranged in such a manner that the woollen warp, in the form of a ribbed surface,
may constitute the face of the fabric, while the linen warp forms the ground or back of the
fabric. The plan he prefers, as most resembling the Brussels, consists in weaving the
fabric as nearly as possible in the ordinary way, except that, instead of inserting a tag
or wire to form the rib or terry, the patentee throws in a thick shoot or weft of woollen
or cotton, over which the woollen warp is drawn, and forms a rib; the woollen warp
being afterwards bound down with a linen shoot or weft in the ordinary way. The
woollen warp employed being all of one colour, the fabric produced will be plain or
unornamented, with a looped or terry pile; and upon this fabric any design may be
printed from blocks.
The looms differ from the former chiefly in the employment of two separate shuttles,
one for the woollen and one for the linen weft. These shuttles are both thrown by the
same pickers and the same picking-sticks, and consequently the shuttle boxes must be
moved up and down as may be required, in order to allow the picker to throw the
proper shuttle. It will also be necessary to work the healds in a suitable manner to
form the proper shreds, in order that the woollen face may be properly bound to the
linen ground.
Figures illustrating the construction of his loom are given by the patentee.
The second part of his invention relates to the production of fabrics with a cut pile,
like the Axminster or Wilton rugs or carpets. The ordinary mode of making some of
these fabrics is to weave the pattern in by means of a Jacquard apparatus, and pass the
woollen warp over a rod or tag, which is afterwards cut by passing a suitable knife
along it, thereby producing the cut pile. The patentee produces the design and surface
of the fabric from the weft in place of the warp as heretofore. For this purpose the
weft is made to consist of thick woollen shoots, which must be painted or stained with
suitable colours, precisely as the woollen warps have been heretofore done; and the
woollen shoot, when thrown in, is, by means of suitably formed hooks, pulled up and
turned into loops, which, when they are properly secured to the foundation or ground
of the fabric, are afterwards cut by means of knives or cutting instruments, with which
the hooks are furnished, for the purpose of releasing them from the loops, and producing
the cut pile. The patentee observes, that cotton and other cheap materials may be employed with great advantage in the production of some of these fabrics. —ewton's
Journal, xxxiv. 167.
Another invention of improvements in manufacturing figured fabrics, principally designed for the production of carpeting, patented by Mr. James Templeton, of
Glasgow, consists in producing the pattern either on one or both sides of the fabric, by
means of printed weft; also in the use of printed parti-coloured fur or weft, in the manufacture of Axminster carpet, and other similar fabrics. This invention is also applicable
to the production of figured chenille weft for the manufacture of chenille shawls.-,ewton's Journal, xxxvii. 148.
CARPETS, PRINTED. Mr. Wood has taken a patent for weaving and printing carpets,
using an ordinary Brussels carpet loom.  After putting in the wire, or otherwise
forming the loop, he throws in the usual linen shoot, on the face, to bind it; and then,
for the back shoot, he throws in a thick soft weft. Or, to make a better edge and more
elastic back, he employs the ordinary two linen shoots,-one on the face and the other
in the back,-and then (or before throwing in the second linen shoot) he draws down
only one-half of the lower portion of the linen warp (being one-quarter of the whole),
and throws in the thick shoot, which is driven up by the batten or lay, so as to cover the
second linen shoot, which is then inside the fabric: from the thick shoot being bound
only by each alternate yarn of the warp, it will be more elastic than if bound more
closely by using every yarn; whilst the second linen shoot, having half the warp over
it, holds down the face or first shoot; and any inequality in the taking up of the linen




CARTHAMUS.                                    381
warp, by one portion of it binding in a greater substance than the other, is remedied
by drawing down the different portions in succession.
In printing Brussels and other pile carpets, the patentee first provides a table, long
enough to receive the entire length or piece of the carpet to be printed; at each end of
the table there is a frame of the same height or level, sufficiently long to receive the
cylinder printing machine when off the fabric; and on the surface of the table the
printing blanket is laid between two rails or guides, which are fixed at exactly the same
distance apart as the carpet is wide, so as to keep it in one position, and to form the
guides for the printing cylinders. The carpet is fastened to one end of the table, and
is then laid on the top of the same, and drawn tight at the other end by a roller, which
is furnished with a ratchet wheel and click. The printing cylinders are mounted in a
movable frame, containing a corresponding number of colour cans and feeding rollers,
to supply them with colour. This printing apparatus is passed over the table, and
between the guide rails (the patterns on the cylinder being coloured, and bearing upon
the carpet), to the frame at the other end of the table, and then back again; and this
process is repeated until the fabric is sufficiently coloured. In order to insure each
part of the pattern or printing surface coming again and again on the same place,
toothed wheels are affixed on the axis of the printing cylinders, which geer into racks
fixed on the sides of the table; so that, however frequently the printing apparatus
passes over the fabric, every part of the pattern will fall on the same place. Instead
of the printing apparatus being passed back again over same table, it may, by the application of movable frames at the end of the table, be moved sideways on to another
table, and so successivelv.-Newton's Journal, xxxiv. 250.
CARTHAMUS, or safflower (carthamus tinctorius), (Carthame, Fr.; F rber distel,
Germ.), the flower of which alone is used in dyeing, is an annual plant cultivated in
Spain, Egypt, and the Levant. There are two varieties of it —one which has large
leaves, and the other smaller ones. It is the last which is cultivated in Egypt, where it
forms a considerable article of commerce.
Carthamus contains two coloring matters, one yellow and the other red. The first
alone is soluble in water; its solution is always turbid: with re-agents it exhibits the
characters usually remarked in yellow coloring matters. The acids render it lighter,
the alkalis deepen it, giving it more of an orange hue: both produce a small dun precipitate, in consequence of which it becomes clearer. Alum forms a precipitate of a deep
yellow, in small quantity. The solution of tin and the other metallic solutions cause precipitates which have nothing remarkable in them.
The yellow matter of carthamus is not employed; but in order to extract this portion,
the carthamus is put into a bag, which is trodden under water, till no more color can
be pressed out. The flowers, which were yellow, become reddish, and lose in this opera
tion nearly one half of their weight. In this state they are used.
For extracting the red part of carthamus, and thereafter applying it to stuff, the property which alkalis possess of dissolving it is had recourse to, and it is afterwards precipitated by an acid.
The process of dyeing consists, therefore, in extracting the coloring matter by means oA
an alkali, and precipitating it on the stuff by means of an acid. It is this fecula which
serves for making the rouge employed by ladies.
As to this rouge, the solution of carthamus is prepared with crystallized carbonate of
soda, and it is precipitated by lemon juice. It has been remarked that lemons, beginning to spoil, were fitter for this operation than those which were less ripe, whose juice
retained much mucilage. After squeezing out the lemon juice, it is left to settle for some
days. The precipitate of carthamus is dried at a gentle heat upon plates of stone-ware;
from which it is detached and very carefully ground with talc, which has been reduced
so a very subtile powder, by means of the leaves of shave-grass (presle), and successively
passed through sieves of increasing fineness. It is the fineness of the talc, and the greater
or less proportion which it bears to the carthamus precipitate, which constitute the difference between the high and low priced rouges.
Carthamus is used for dyeing silk, poppy, nacarat (a bright orange-red), cherry, rose
color, and flesh color. The process differs according to the intensity of the color, and
the greater or less tendency to flame color that is wanted. But the carthamus bath,
whose application may be varied, is prepared as follows:
The carthamus, from which the yellow matter has been extracted, and whose lumps
have been broken down, is put into a trough. It is repeatedly sprinkled with cendres
gravelees (crude pearlashes), or soda (barilla) well powdered and sifted at the rate of
6 pounds for 120 lbs. of carthamus; but soda is preferred, mixing carefully as the alkali
is introduced. This operation is called amestrer. The amestred carthamus is put into
a small trough with a grated bottom, first lining this trough with a closely woven cloth.
When it is about half filled, it is placed over the large trough, and cold water is poured
into the upper one, till the lower becomes full. The carthamus is then set over another




382                            CASE-HARDENING.
trough, till the water comes from it almost colorless. A little more alkali is now mixed
with it, and fresh water is passed through it. These operations are repeated till the carthamus be exhausted, when it turns yellow.
After distributing the silk in hanks upon the rods, lemon juice, brought in casks from
Provence, is poured into the bath till it becomes of a fine cherry color; this is called
turning the bath (virer le bain). It is well stirred, and the silk is immersed and turned
round the skein-sticks in the bath, as long as it is perceived to take up the color. For
ponceau (poppy color), it is withdrawn, the liquor is run out of it upon the peg, and it
is turned through a new bath, where it is treated as in the first. After this it is dried
and passed through fresh baths, continuing to wash and dry it between each operation,
till it has acquired the depth of color that is desired. When it has reached the proper
point, a brightening is given it by turning it round the sticks seven or eight times in a bath
of hot water, to which about half a pint of lemon juice for each pailful of water has been
added.
When silk is to be dyed ponceau or flame color, it must be previously boiled as for
white; it must then receive a slight foundation of annotto, as explained in treating o(
this substance. The silk should not be alumed.
The nacarats, and the deep cherry colors, are given precisely like the ponceaux, only
they receive no annotto ground; and baths may be employed wVnch have served for the
ponceau, so as to complete their exhaustion.  Fresh baths are not made for the latter
colors, unless there be no occasion for the poppy.
With regard to the lighter cherry-reds, rose color of all shades and flesh colors, they
are made with the second and last runnings of the carthamus, which are weaker. The
deepest shades are passed through first.
The lightest of all these shades, which is an extremely delicate flesh color, requires a
little soap to be put into the bath. This soap lightens the color, and prevents it from
taking too speedily, and becoming uneven. The silk is then washed, and a little brightening is given it, in a bath which has served for the deeper colors
All these baths are employed the moment they are made, or as speedily as possible,
because they lose much of their color upon keeping, by which they are even entirely
destroyed at the end of a certain time. They are, moreover, used cold, to prevent the
color from being injured. It must have been remarked in the experiments just described,
that the caustic alkalis attack the extremely delicate color of carthamus, making it pass
to yellow.  This is the reason why crystals of soda are preferred to the other alkaline matters.
In order to diminish the expense of the carthamus, it is the practice in preparing the
deeper shades to mingle with the first and the second bath about one fifth of the bath of
archil.
Dobereiner regards the red coloring matter of carthamus as an acid, and the yellow as
a base. His carthamic acid forms, with the alkalis, colorless salts, decomposed by the
tartaric and acetic acids, which precipitate the acid of a bright rose-red. Heat has a remarkable influence upon carthamus, rendering its red color yellow and dull. Hence, the
colder the water is by which it is extraeted, the finer is the color. Light destroys the
color very rapidly, and hitherto no means have been found of counteracting this
effect. For this reason this brilliant color must be dried in the shade, its dye must be
given in a shady place, and the silk stuffs dyed with it must be preserved as much as
possible from the light. Age is nearly as injurious as light, especially upon the dye in a
damp state. The color is very dear, because a thousand parts of carthamus contain only
five of it.
In preparing the finest rouge, the yellow coloring matter being separated by washing
with water, the red is then dissolved by the aid of alkali, and is thrown down on linen
or cotton rags by saturating the solution with vegetable acid. The color is rinsed out of
these rags, dissolved anew in alkalis, and once more precipitated by lemon juice. The
nest and freshest carthamus must be selected. It is put into linen bags, which are placed
in a stream of water, and kneaded till the water runs off colorless. The bags are then
put into water soured with a little vinegar, kneaded till the color is all expelled, and
finally rinsed in running water. By this treatment the carthamus loses nearly half its
weight.  6633 cwts. of safflower were imported into the United Kingdom  in 1835, of
which 2930 cwts. were retained for internal consumption.
CASE-HARDENING is the name of the process by which iron tools, keys, &c., have
their surfaces converted into steel.
Steel when very hard is brittle, and iron alone is for many purposes, as for fine keys,
far too soft.  It is therefore an important desideratum  to combine the hardness of a
steely surface with the toughness of an iron body. These requisites are united by the
process of case-hardening, which does not differ from the making of steel, except in the
shorter duration of the process. Tools, utensils, or ornaments, intended to be polished,
are first manufactured in iron and nearly finished, after which they are put into an iron




CASHMERE.                                   383
box, together with vegetable or animal charcoal in powder, and cemented for a certain
time. This treatment converts the external part into a coating of steel, which is usually
very thin, because the time allowed for the cementation is much shorter than when the
whole substance is intended to be converted. Immersion of the heated pieces into water
hardens the surface, which is afterwards polished by the usual methods. Moxon, in his
Mechanic Exercises, p. 56, gives the following receipt for case-hardening:-" Cow's horn
or hoof is to be baked or thoroughly dried and pulverized. To this add an equal
quantity of bay salt; mix them with stale chamber-ley or white wine vinegar: cover
the iron with this mixture, and bed it with the same in loam, or enclose it in an iron box;
lay it on the hearth of the forge to dry and harden: then put it into the fire, and blow
till the lump have a blood-red heat, and no higher, lest the mixture be burnt too much.
Take the iron out, and immerse it in water to harden."  I consider the vinegar to be
quite superfluous.
I shall now describe the recent application of prussiate (ferrocyanate) of potash to this
purpose. The piece of iron, after being polished, is to be made brightly red-hot, and
then rubbed or sprinkled over with the above salt in fine powder, upon the part intended
to be hardened. The prussiate being decomposed, and apparently dissipated, the iron ig
to be quenched in cold water. If the process has been well managed, the surface of the
metal will have become so hard as to resist the file. Others propose to smear over
the surface of the iron with loam made into a thin paste with a strong solution of
the prussiate, to dry it slowly, then expose the whole to a nearly white heat, and
finally plunge the iron into cold water, when the heat has fallen to dull redness. See
STEEI.
CASHMERE or CACHEMERE, a peculiar textile fabric first imported from the
kingdom of Cashmere, and now well imitated in France and Great Britain. The
material of the Cashmere shawls is the downy wool found about the roots of the hair of
the Thibet goat. The year 1819 is remarkable in the history of French husbandry for
the acquisition of this breed of goats, imported from the East under the auspices of their
government, by the indefatigable courage and zeal of M. Jaubert, who encountered every
fatigue and danger to enrich his country with these vahable animals, aided by the
patriotism of M. Ternaux, who first planned this importation, and furnished funds for
executing it at his own expense and responsibility. He placed a portion of the flock
brought by M. Jaubert, at his villa of Saint Ouen, near Paris, where the climate seemed
to be very favorable to them, since for several successive years after their introduction
M. Ternaux was enabled to sell a great number of both male and female goats. The
quantity of fine fleece or down afforded by each animal annually, is from a pound and a
half to two pounds.
The wool imported into Europe comes by the way of Casan, the capital of a government of the Russian empire upon the eastern bank of the Wolga; it has naturally a
grayish color, but is easily bleached. Its price a few years back at Paris was 17 francs
per kilogramme; that is, about 6 shillings the pound avoirdupois. The waste in picking,
carding, and spinning, amounts to about one third of its weight.
The mills for spinning Cachemere wool have multiplied very much of late years in
France, as appears from the premiums distributed at the exposition of 1834, and the
prices of the yarn have fallen from 25 to 30 per cent. notwithstanding their improved
fineness and quality. There is a fabric made with a mixture of Cachemere down and
spun silk, which is becoming very general. One of the manufacturers, M. Hindenlang,
exhibited samples of Cachemere cloth woven with yarn so fine as No. 130 for warp, and
No. 228 for weft.
Messrs. Pollino, brothers, of Paris, produced an assortment of Cachemere pieces from
22 to 100 francs the yard, dyed of every fancy shade. Their establishment at Ferte-Bernard occupies 700 operatives, with an hydraulic wheel of 60 horse power.
The oriental Cashmere shawls are woven by processes extremely slow and consequently
costly; whence their prices are very high. They are still sold in Paris at from 4,000 to
10,000 francs a piece; and from 100 to 400 pounds sterling in London. It became
necessary, therefore, either to rest satisfied with work which should have merely a surface
appearance, or contrive economical methods of weaving, to produce the real Cachemere
style with much less labor. By the aid of the draw-loom, and still better of the Jacquard
loom, M. Ternaux first succeeded in weaving Cachemere shawls perfectly similar to the
oriental in external aspect, which became fashionable under the name of French Cachemere. But to construct shawls altogether identical on both sides with the eastern, was
a more difficult task, which was accomplished only at a later period by M. Bauson of
Paris.
In both modes of manufacture, the piece is mounted by reeding-in the warp for the
different leaves of the heddles, as is commonly practised for warps in the Jacquard looms.
The weaving of imitation shawls is executed, as usual, by as many shuttles as there are
colors in the design, and which are thrown across the warp in the order established by




384                                  CASK.
the reeder. The greater number of these weft yarns- being introduced only at intervals
into the web, when the composition of the pattern requires it, they remain floating loose
at the back of the piece, and are cut afterwards, without affecting in the least the quality
of the texture; but there is a considerable waste of stuff in the weaving, which is worked
up into carpets.
The weaving of the imitation of real Cachemere shawls is different from the above.
The yarns intended to form the weft are not only equal in number to that of the colors
of the pattern to be imitated, but besides this, as many little shuttles or pirns (like those
used by embroiderers) are filled with these yarns, as there are to be colors repeated in
the breadth of the piece; which renders their number considerable when the pattern is
somewhat complicated and loaded with colors. Each of these small bobbins or shuttles
passes through only that portion of the flower in which the color of its yarn is to appear,
and stops at the one side and the other of the cloth exactly at its limit; it then returns
upon itself after having crossed the thread of the adjoining shuttle. From this reciprocal intertexture of all the yarns of the shuttles, it results, that although the weft is
composed of a great many different threads, they no less constitute a continuous line in'the whole breadth of the web, upon which the lay or batten acts in the ordinary way
We see, therefore, that the whole art of manufacturing this Cachemere cloth consists in
avoiding the confusion of the shuttles, and in not striking up the lay till all have fulfilled
their function. The labor does not exceed the strength of a woman, even though she has
to direct the loom and work the treddles. Seated on her bench at the end opposite to
the middle of the beam, she has for aids in weaving shawls from 45 to 52 inches wide,
two girl apprentices, whom she directs and instructs in their tasks. About four hundred
days of work are required for a Cachemere shawl of that breadth. For the construction
of the loom, see JACQUARD.
In the oriental process, all the figures in relief are made simply with a slender pirn
without the shuttle used in European weaving. By the Indians the flower and its
ground are made with the pirn, by means of an intertwisting, which renders them in
some measure independent of the warp. In the Lyons imitation of this style, the leaves
of the heddles lift the yarns of the warp, the needles embroider as in lappet weaving,
and the flower is united to the warp by the weft thrown across the piece. Thus a great
deal of labor is saved, the eye is pleased with an illusion of the loom, and the shawls cost
little more than those made by the common fly shuttle.
Considered in reference to their materials, the French shawls present three distinct
classes, which characterize the three fabrics of Paris, Lyons, and Nimes.
Paris manufactures the French Cachemere; properly so called, of which both the warp
and the weft are the yarn of pure Cachemere down. This web represents with fidelity
the figures and the shades of color of the Indian shawl, which it copies; the deception
would be complete if the reverse of the piece did not show the cut ends. The Hindoo
shawl, also woven at Paris, has its warp in spun silk, which reduces its price without
impairing its beauty much.
Lyons, however, has made the greatest progress in the manufacture of shawls. It excels particularly in the texture of its Thibet shawls, the weft of which is yarn spun with
a mixture of wool and spun silk.
Nimes is remarkable for the low price of its shawls, in which spun silk, Thibet down,
and cotton, are all worked up together.
The value of shawls exported from France in the following years was1831.              1832.               1833.
Francs.            Francs.             Francs.
Woollen - -  -           1,863,147           2,070,926           4,319,601
Cachemere down - -         433,410             655,200             609,900
Spun silk- - -  - -.       401,856             351,152             408,824
It appears that M. J. Girard at Sevres, near Paris, has succeeded best in producing
Cachemere shawls equal in stuff and style of work to the oriental, and at a lower price.
They have this advantage over the Indian shawls, that they are woven without seams, in
a single piece, and exhibit all the variety and the raised effect of the eastern colors.
Women and children alone are employed in his factory.
CASK  (Tonneau, Fr.; Fass, Germ.), manufacture of by mechanical power.  Mr.
Samuel Brown obtained a patent in November, 1825, for certain improvements in
machinery for making casks, which seems to be ingenious and worthy of record. His
mechanism consists in the first place of a circular saw attached to a bench, with a sliding
rest, upon which rest each piece of wood intended to form a stave of a cask is fixed;
and the rest being then slidden forward in a curved direction, by the assistance of an
adjustable guide, brings the piece of wood against the edge of the rotatory saw, and causes
it to be cut into the curved shape required for the edge of the stave. The second feature
is an apparatus with cutters attached to a standard, and traversing round with their




CASSAVA.                                    385
carrier upon a centre, by means of which the upper and lower edges of the cask are cut
round and grooved, called chining, for the purpose of receiving the heads. Thirdly, an
apparatus not very dissimilar to the last, by which the straight pieces of wood designed
for the heads of the cask are held together, and cut to the circular figure required, and
also the bevelled edges produced. And fourthly, a machine in which the cask is
made to revolve upon an axis, and a cutting tool to traverse for the purpose of shaving
the external part of the cask, and bringing it to a smooth surface.
The pieces of wood intended to form the staves of the cask, having been cut to their
required length and breadth, are placed upon the slide-rest of the first mentioned machine,
and confined by cramps; and the guide, which is a flexible bar, having been previously
bent to the intended curve of the stave and fixed in that form, the rest is then slidden
forward upon the bench by the hand of the workman, which as it advances (moving
in a curved direction) brings the piece of wood against the edge of the revolving
circular saw, by which it is cut to the curved shape desired.
The guide is a.long bar held by a series of movable blocks fitted to the bench by
screws, and is bent to any desired curve by shifting the screws: the edge of the slide-rests
which holds the piece of wood about to be cut, runs against the long guide bar, and of
consequence is conducted in a corresponding curved course. The circular saw receives
a rapid rotatory motion by means of a band or rigger from any first mover; and the piece
of wood may be shifted laterally by means of racks and pinions on the side-rest, by the
workman turning a handle, which is occasionally necessary in order to bring the piece
of wood up to, or away from, the saw.
The necessary number of staves being provided, they are then set round within a
confining hoop at bottom, and brought into the form of a cask in the usual way, and
braced by temporary hoops. The barrel part of the cask being thus prepared, in order
to effect the chining, it is placed in a frame upon a platform, which is raised up by a
treddle lever, that the end of the barrel may meet the cutters in a sort of lathe above: the
cutters are then made to traverse round within the head of the barrel, and, as they proceed, occasionally to expand, by which means the bevels and grooves are cut on the
upper edge of the barrel, which is called chining. The barrel being now reversed, the
same apparatus is brought to act against the other end, which becomes chined in like
manner.
The pieces of wood intended to form the heads of the cask are now to be cut straight
by a circular saw in a machine, similar to the first described; but in the present instance
the slide-rest is to move forward in a straight course.  After their straight edges are
thus produced, they are to be placed side by side, and confined, when a scribing cutter
is made to traverse round, and cut the pieces collectively into the circular form desired
for heading the cask.
The cask having now been made up, and headed by hand as usual, it is rFaced between
centres, or upon an axle in a machine, and turned round by a rigger or band with a
shaving cutter, sliding along a bar above it, which cutter, being made to advance and
recede as it slides along, shaves the outer part of the cask to a smooth surface.
CASSAVA.  Cassava bread, conaque,  -c., are different names given to the starch
of the root of the Manioc (Jatropha Manihot, Linn.), prepared in the following manner
in the West Indies, the tropical regions of America, and upon the African coast. The
tree belongs to the natural family of the euphorbiacee.
The roots are washed, and reduced to a pulp by means of a rasp or grater. The pulp
is put into coarse strong canvass bags, and thus submitted to the action of a powerful
press, by which it parts with most of its noxious juice (used by the Indians for poisoning
the barbs of their arrows.)  As the active principle of this juice is volatile, it is easily
dissipated by baking the squeezed cakes of pulp upon a plate of hot iron. Fifty pounds
of the fresh juice, when distilled, afford, at first, three ounces of a poisonous water, possessing an intolerably offensive smell; of which, 35 drops being administered to a slave
convicted of the crime of poisoning, caused his death in the course of six minutes, amid
horrible convulsions.*
The pulp dried in the manner above described concretes into lumps, which become
hard and friable as they cool. They are then broken into pieces, and laid out in the sun
to dry. In this state they afford a wholesome nutriment, and are habitually used as such
by the negroes, as also by many white people.  These cakes constitute the only provisions laid in by the natives, in their voyages upon the Amazons. Boiled in water with
a little beef or mutton they form a kind of soup similar to that of rice.
The cassava cakes sent to Europe (which I have eaten with pleasure) are composed
almost entirely of starch, along with a few fibres of the ligneous matter.  It may be
purified by diffusion through warm water, passing the milky mixture through a linen
cloth, evaporating the strained liquid over the fire, with constant agitation. The starch
* Memoir of Dr. Fermin, communicated to the Academy of Berlin concerning experiments made at Cayenne upon the juice of the Manioc.
VOL. L                                 3 D




386                      CASTING OF METALS.
dissolved by the heat, thickens as the water evaporates, but on being stirred, it becomes
granulated, and must be finally dried in a proper stove.  Its specific gravity is 1*530that of the other species of starch.
The product obtained by this treatment is known in commerce under the name of tapioca; and being starch very nearly pure, is often prescribed by physicians as an aliment
of easy digestion.  A tolerably good imitation of it is made by heating, stirring, and
drying potato starch in a similar way.
The expressed juice of the root of manioc contains in suspension avery fine fecula, which
it deposites slowly upon the bottom of the vessels. When freed by decantation from the supernatant liquor, washed several times and dried, it forms a beautiful starch, which
creaks on pressure with the fingers.  It is called cipipa, in French Guyana; it is
employed for many delicate articles of cookery, especially pastry, as also for hair powder,
starching linen, &c.
Cassava flour, as imported, may be distinguished from arrow-root and other kinds
of starch, by the appearance of its particles viewed in a microscope.  They are
spherical, all about 1-1000th of an inch in diameter, and associated in groups; those of
potato starch are irregular ellipsoids, varying in size from 1-300th to 1-3000th of ar
inch; those of arrow-root have the same shape nearly, but vary in size from 1-500tll to
1-800th of an inch; those of wheat are separate spheres 1-1000th of an inch.
CASSIS, the black currant (ribes nigra, Linn.), which was formerly celebrated for its
medicinal properties with very little reason.
The only technical use to which it is now applied is in preparing the agreeable liqueur
called ratafia, by the following French recipe: —Stone, and crush three pounds of
black currants, adding to the magma one drachm  of cloves, two of cinnamon, four
quarts of spirit of wine, at 98~ Baum6 (see AREOMi0TRE OF BAUME), and 2~ pounds of
sugar.  Put the mixture into a bottle which is to be well corked; let it digest for a
fortnight, shaking the bottle once daily during the first eight days; then strain
through a linen cloth, and finally pass through filtering paper.
CASSIUS, purple powder of. A preparation used in the arts as a colour, chiefly for
stained glass and porcelain.  It is also employed in medicine by some French physicians,
and has been prepared by the following prescription:-10 parts of acid chloride of gold
are dissolved in 2.000 parts of water.  In another vessel, 10 parts of pure tin are dissolved in 10 parts of nitric acid mixed with 20 parts of hydrochloric, and this solution
is diluted with 1000 parts of distilled water. The solution of tin is added by degrees
to that of the acid chloride of gold, as long as any precipitate results which is allowed
to subside; it is then washed, filtered, and then dried at a very gentle heat. The tin salt
above used contains both the protoxide and binoxide in certain proportions. The
double compound of chloride of tin with sal ammoniac, called the pink salt of tin, is
the preferable form; as it is not altered by the atmosphere, is of definite composition,
and when boiled with metallic tin it takes up just so much as will form the protochloride; 100 parts of pink salt require for this purpose 10'7 parts of metallic tin.
1 34 gr. of gold are to be dissolved in aqua reqia, without excess of the solvent, and
this solution is to be diluted with 480 gr. of water. Then 10 gr. of the pink salt
mixed with 1'07 gr. of tin filings, and 40 gr. of water, are to be exposed to a boiling
heat till the metal is dissolved.  140 gr. of water are now to be poured upon that compound, and the resulting solution is to be gradually added to the gold liquor (slightly
warmed) till no more precipitate forms. This when washed and dried is of a brown
colour, and weighs 4'92 grs. The above method of preparing the solution of the sesquioxide of tin seems to be the best hitherto prescribed.
CASTING  OF METALS.  (See FOUNDING.)  Casts from  elastic moulds.-Being
much engaged in taking casts from anatomical preparations, Mr. Douglas Fox, Surgeon,
Derby, found great difficulty, principally with hard bodies, which, when undercut, or
having considerable overlaps, did not admit of the removal of moulds of the ordinary
kind, except with injury. These difficulties suggested to him the use of elastic moulds,
which, giving way as they were withdrawn from complicated parts, would return to
their proper shape; and he ultimately succeeded in making such moulds of glue which
not only relieved him from all his difficulties, but were attended with great advantages,
in consequence of the small number of pieces into which it was necessary to divide
the mould.
The body to be moulded, previously oiled, must be secured one inch above the surface of a board, and then surrounded by a wall of clay, about an inch distant from its
sides. The clay must also extend rather higher than the contained body: into this,
warm  melted glue, as thick as possible so that it will run, is to be poured, so as to
completely cover the body to be moulded; the glue is to remain till cold, when it will
have set into an elastic mass, just such as is required.
Having removed the clay, the glue is to be cut into as many pieces as may be necessary for its removal, either by a sharp-pointed knife, or by having placed threads in




CASTOR OIL.                                 38f
the requisite situations of the body to be moulded, which may be drawn away when
the glue is set, so as to cut it out in any direction.
The portions of the glue mould having been removed from the original, are to be
placed together and bound round by tape.
In some instances it is well to run small wooden pegs through the portions of glue, so
as to keep them exactly in their proper positions. If the mould be of considerable size,
it is better to let it be bound with moderate tightness upon a board to prevent it
bending whilst in use; having done as above described, the plaster of Paris, as in common casting, is to be poured into the mould, and left to set.
In many instances wax may also be cast in glue, if it is not poured in whilst too hot;
as the wax cools so rapidly when applied to the cold glue, that the sharpness of the
impression is not injured.
Glue has been described as succeding well where the elastic mould is alone applicable; but many modifications are admissible. When the moulds are not used soon
after being made, treacle should be previously mixed with the glue (as employed by
printers) to prevent it becoming hard.
The description thus given is with reference to moulding those bodies which cannot
be so done by any other than an elastic mould; but glue moulds will be found greatly
to facilitate casting in many departments, as a mould may be frequently taken by this
method in two or three pieces, which would, on any other principle, require many.
CAST-IRON SCOURING. Cast-iron surfaces are said to be easily scoured by adding
a little of any kind of organic matter, such as glycerine, stearine, napthaline, creosote to dilute sulphuric acid; zinc and brass yield to the same method, with great
economy of labour, time and material,
CASTOR.  (Eng. and Fr.; Biber, Germ.)  The castor is an amphibious quadruped, inhabiting North America; also found in small numbers in the islands of the
Rhone.  In the arts, the skin of this animal is employed either as a fur or as affording
the silky hair called beaver, with which the best hats are covered. Beaver skins, which
form a very considerable article of trade, are divided into 3 sorts: 1. The fresh beaver
skins from castors, killed in winter before shedding their hair; these are most in re.
quest among the furriers, as being the most beautiful. 2. The dry or lean beavers are
the skins of the animals killed during the moulting season; they are not much esteemed,
as the skin is rather bare. 3. The fat castors: these are the skins of the first sort, which
have been worn for some time upon the persons of the savages, and have got imbued with
their sweat. The last are principally used in the hat manufacture. In France, the
marine otter has been for many years substituted in the place of the castor ox
beaver.
CASTOR or CASTOREUM.  This name is given to a secretion of the castors,
contained in pear-shapcd cellular organic sacs, placed near the genital organs of both the
male and female animals. It is a substance analogous to civet and musk, of a consistence similar to thick honey. It has a bitter acrid taste; a powerful, penetrating, fetid,
and very volatile smell; but, when dried, it becomes inodorous. Several chemists, and
in particular Bouillon Lagrange, Laugier, and Hildebrandt, have examined castor, and
found it to be composed of a resin, a fatty substance, a volatile oil, an extractive matter,
benzoic acid, and some salts.
The mode of preparing it is very simple. The sacs are cut off from {he castors when
they are killed, and are dried to prevent the skin being affected by the weather. In this
state, the interior substance is solid, of a dark color, and a faint smell; it softens with
heat, and becomes brittle by cold. Its fracture betrays fragments of membranes, indicating its organic structure. When chewed, it adheres to the teeth somewhat like wax;
it has a bitter, slightly acrid, and nauseous taste.
The castor bags, as imported, are often joined in pairs by a kind of ligature. Some
times the substance which constitutes their value is sophisticated; a portion of the castoreum being extracted, and replaced by lead, clay, gums, or some other foreign matters.
This fraud may be easily detected, even when it exists in a small degree, by the absence
of the membranous partitions in the interior of the bags, as well as by the altered smell
and taste.
The use of castoreum in medicine is considerable, especially in nerrous and spasmodic
diseases, and it is often advantageously combined with opium.
CASTORINE. A chemical principle lately discovered to the amount of a few parts
per cent. in Castoreum.
CASTOR OIL. The expressed oil of the seeds of the Palma Christi, or Ricinus
communis, a native tree of the West Indies and South America; but which has been cultivated in France, Italy, and Spain. Bussy and Letanu discovered in it 3 species of
fatty matters, obtained partly by saponification, and partly by dry distillation-the margaritic, ricinic, and elaiodic acids. None of these has been separately applied to any
use in the arts.
3D2




388                               CATECHU.
The quantity of castor oil imported in 1835 into the United Kingdom was 1,109,307
lbs.; retained for home consumption, 670,205 lbs. See OILS.
CATECHU, absurdly called Terra Japonica, is an extract made from the wood of
the tree mimosa catechu, which grows in Bombay, Bengal, and other parts of India. It
is prepared by boiling the chips of the interior of the trunk in water, evaporating the
solution to the consistence of sirup over the fire, and then exposing it in the sun to
harden. It occurs in flat rough cakes, and under two forms. The first, or the Bombay,
is of uniform texture, of a dark red color, and of specific gravity 1'39. The second
is more friable and less solid. It has a chocolate color, and is marked inside with red
streaks. Its specific gravity is 1'28.
According to Sir H. Davy, these two species are composed as follows:Bombay.             Bengal.
Tannin -..-                             54-5                 48-5
Extractive  -    -.                   34-0                 36-5
Mucilage    -    -    -                          6*5                  8
Insoluble matters, sand and lime  -    -         5                    7.                                             1_________________________________100.0  100.0
Areka nuts are also found to yield catechu; for which purpose they are cut into
pieces watered in an earthen pot with solution of nitre, and have a little of the bark of
a species of mimosa added to them. The liquor is then boiled with the nuts, and affords
an inspissated lecoction.
Good catechu is a brittle, compact solid, of a dull fracture. It has no smell, but a
very astringent taste. Water dissolves the whole of it, except the earthy matter, which
Is probably added during its preparation. Alcohol dissolves its tannin and extractive.
The latter may be oxydized, and thus rendered insoluble in alcohol, by dissolving the
catechu in water, exposing it for some time to a boiling heat, and evaporating to
dryness.
The tannin of catechu differs from that of galls, in being soluble in alcohol, and more
soluble in water. It precipitates iron of an olive color, and gelatin in a mass which
gradually becomes brown.
It has been long employed in India for tanning skins, where it is said to effect this object
in five days. I have seen a piece of sole leather completely tanned by it in this country in
ten days, the, ox-hide having been made into a bag, with the hair outside, and kept filled
with the solution of catechu. In India it has also been used to Rive a brown dye to
cotton goods, and of late years it has been extensively introduced into the calico prmi
works of Europe. The salts of copper with sal ammoniac cause it to give a bronze
color, which is very fast; the proto-muriate of tin, a brownish yellow; the per-chloride
of.tin, with the addition of nitrate of copper, a deep bronze hue; acetate of alumina
alone, a reddish brown, and, with nitrate of copper, a reddish olive gray; nitrate of iron,
a dark brown gray. For dyeing a golden coffee brown, it has entirely superseded madder; one pound of it being equivalent to six pounds of this root.
A solution or one part of catechu in ten parts of water, which is reddish brown,
exhibits the following results: withAcids  -    -    -        A brightened shade.
Alkalis -    -            A darkened shade.
Proto-sulphate of iron   - Olive brown precipitate.
Per-sulphate of iron    - Olive green    do.
Sulphate of copper -    - Yellowish brown.
Alum   -    -    -    - A brightening of the liquor.
Per-nitrate of iron -    - Olive green precipitate.
Nitrate of copper  -    - Yellowish brown do.
Nitrate of lead    -    - Salmon          do.
Proto-nitrate of mercury - Milk-coffee    do.
Muriate of alumina    - Brown-yellow.
Muriate of tin    -    - Do.    do.
Per-chloride of tin -    - Do.  darker.
Corrosive sublimate    - Light chocolate do.
Acetate of alumina -   - Brightening of the liquor.
Acetate of copper -    -  Copious brown precipitate
Acetate of lead   -    - Salmon colored    do.
Bichromate of potash   - Copious brown    do.
Pure tannin may be obtained from catechu, by treating it with sutpphuric acid and carbonate of lead; but this process has no manufacturing application.




CATGUT.                                 389
CATGUT (Corde a boyau, Fr.; Darmsaite, Germ.), the name absurdly enough given
to cords made of the twisted intestines of the sheep. The guts being taken while warm
out of the body of the animal, are to be cleared of feculent matter, freed from any adhering fat, and washed in a tub of water. The small ends of all the intestines are
next to be tied together, and laid on the edge of the tub, while the body of them is left
to steep in some water, frequently changed, during two days, in order to loosen the
peritoneal and mucous membranes. The bundle of intestines is then laid upon a
sloping table which overhangs the tub, and their surface is scraped with the back of a
knife, to try if the external membrane will come away freely in breadths of about half
the circumference. This substance is called by the French manufacturers filandre, and
the process filer. If we attempt to remove it by beginning at the large end of the
intestine, we shall not succeed. This filandre is employed as thread to sew intestines,
and to make the cords of rackets and battledoors. The flayed guts are put again into
fresh water, and, after steeping a night, are taken out and scraped clean next day, on the
wooden bench with the rounded back of a knife. This is called curing the gut. The
large ends are now cut off, and sold to the pork-butchers. The intestines are again
steeped for a night in fresh water, and the following day in an alkaline lixivium made
by adding 4 ounces of potash, and as much pearl-ash, to a pail of water containing about
3 or 4 imperial gallons. This ley is poured in successive quantities upon the intestines,
and poured off again, after 2 or 3 hours, till they be purified. They are now drawn
several times through an open brass thimble, and pressed against it with the nail, in order to smooth and equalize their surface. They are lastly sorted, according to their
sizes, to suit different purposes.
Whip-cord is made from the above intestines, which are sewed together endwise by the
filandre, each junction being cut aslant, so as to make it strong and smooth. The cord
is put into the frame, and each end is twisted separately; for whip-cord is seldom made
out of two guts twisted together. When twisted, it is to be sulphured (see SULPHURING)
once or twice. It may also be dyed black with common ink, pink with red ink, which
the sulphurous acid changes to pink, and green with a green dye which the color dealers
sell for the purpose. The guts take the dyes readily. After being well smoothed, the
cord is to be dried, and coiled up for sale.
Hatters' cords for bowstrings.-The longest and largest intestines of sheep, after being
properly treated with the potash, are to be twisted 4, 6, 8, 10, or 12 together, according
to the intended size of the cord, which is usually made from 15 to 25 feet long. This
cord must be free from seams and knots. When half dry, it must be exposed twice to
the fumes of burning sulphur; and, after each operation, it is to be well stretched and
smoothed: it should be finally dried in a state of tension.
Clockmaker's cord.-This cord should be extremely thin, and be therefore made from
very small intestines, or from intestines slit up in their length by a knife fitted for the
purpose; being a kind of lancet surmounted with a ball of lead or wood. The wet gut
is strained over the ball which guides the knife, and the two sections fall down into a
vessel placed beneath. Each hand pulls a section. Clockmakers also make use of
stronger cords made of 2 or more guts twisted together.
Fiddle and harp strings. - These require the greatest care and dexterity on the part
of the workmen.  The treble strings are peculiarly difficult to make, and are best made
at Naples, probably because them sheep, from their small size and leanness, afford the
best raw material.
The first scraping of the guts intended for fiddle-strings must be very carefully performed;
and the alkaline leys, being clarified with a little alum, are added, in a progressively stronger
state from day to day, during 4 or 5 days, till the guts be well bleached and swollen.
They must then be passed through the thimble, and again cleansed with the lixivium;
after which they are washed, spun, or twisted and sulphured during two hours. They are
finally polished by friction, and dried.  Sometimes they are sulphured twice or thrice
before being dried, and are polished between norse-hair cords.
It has been long a subject of complaint, as well as a serious inconvenience to musicians, that catgut strings cannot be made in England of the same goodness and strength
as those imported from Italy. These are made of the peritoneal covering of the intestines of the sheep; and, in this country, they are manufactured at Whitechapel, and
probably elsewhere in considerable quantity; the consumption of them for harps, as
well as for the instruments of the violin family, being very great.  Their chief fault is
weakness; whence it is difficult to bring the smaller ones, required for the higher notes,
to concert pitch; maintaining at the same time, in their form and construction, that
tenuity or smallness of diameter, which is required to produce a brilliant and clear tone.
The inconvenience arising from their breaking when in use, and the expense in the
case of harps, where so many are required, are such as to render it highly desirable to
improve a manufacture which, to many individuals may, however, appear sufficiently contemptible.




390                              CEMENTS.
It is well known to physiologists, that the membranes of lean animals are far more
tough than of those animals which are fat or in high condition; and there is no reason to
doubt that the superiority of the Italian strings arises from the state of the sheep in that
country.  In London, where no lean animals are slaughtered, and where, indeed, an
extravagant and useless degree of fattening, at least for the purpose of food, is given to
sheep in particular, it is easy to comprehend why their membranes can never afford a
material of the requisite tenacity. It is less easy to suggest an adequate remedy; but a
knowledge of the general principle, should this notice meet the eyes of those interested in
the subject, may at least serve the purpose of diminishing the evil and improving the manufacture, by inducing them to choose in the market the offal of such carcasses as appear
least overburdened with fat.  It is probable that such a manufacture might be advantageously established in those parts of the country where the fashion has not, as in
London, led to the use of meat so much overfed; and it is equally likely, that in the
choice of sheep for this purpose, advantage would arise from using the Welch, the Highland, or the Southdown breeds, in preference to those which, like the Lincoln, are prone
to excessive accumulations of fat. It is equally probable, that sheep dying of some
of the diseases accompanied by emaciation, would be peculiarly adapted to this
pur pose.
That these suggestions are not merely speculative is proved by comparing the strength
of the membranes in question, or that of the other membranous parts, in the unfattened
Highland sheep, with that of those found in the London markets.
CATHARTINE. The name proposed by MM. Feneulle and Lassaigne for a chemical principle, which they suppose to be the active constituent of senna.
CAUSTIC. Any chemical substance corrosive of the skin and flesh; as potash, called
common caustic, and nitrate of silver, called lunar caustic, by surgeons.
CAVIAR.  The salted roe of certain species of fish, especially the sturgeon.  This
product forms a considerable article of trade, being exported annually from the town of
Astrachan alone, upon the shores of the Caspian sea, to the amount of several hundred
tons. The Italians first introduced it into Eastern Europe from Constantinople, under
the name of caviale. Russia has now monopolized this branch of commerce. It is prepared in the following manner:-The female sturgeon is gutted; the roe is separated from the other parts, and cleaned
by passing it through a very fine scarce, by rubbing it into a pulp between the hands;
this is afterwards thrown into tubs, with the addition of a considerable quantity of salt;
the whole is then well stirred, and set aside in a warm apartment.  There is another
sort of caviar, the compressed, in which the roe, after having been cured in strong brine,
is dried in the sun, then put into a cask, and subjected to strong pressure.
CAWK. The English miner's name for sulphate of baryta, or heavy spar.
CEDRA (Cedrat, Fr.) is the fruit of a species of orange, citron, or lemon, a tree which
bears the same name. Its peel is very thick, and covered with an epidermis which encloses a very fragrant and highly prized essential oil.  The preserves flavored with it
are very agreeable. The citrons are cut into quarters for the dry comfits, but are put whole
into the liquid ones.  The liquorist-perfumer makes with the peel of the cedra an excellent liqueur; for which purpose, he plucks them before they are quite ripe; grates
down the peel into a little brandy, or crts them into slices, and infuses these in the
spirits. This infusion is distilled for making perfume; but the flavor is better wher.
the infusion itself is used. See ESSENCES, LIQUORIST, PERFUMERY.
CELESTINE.  Native sulphate of strontia, found abundantly near Bristol, in the
red marl formation.  It is decomposed, by ignition with charcoal, into sulphuret of
strontia, which is converted into nitrate by saturation with nitric acid, evaporation, and
crystallization. This nitrate is employed for the production of the red light in theatrical
fire-works.
CEMENTATION.  A  chemical process, which consists in imbedding a solid
body in a pulverulent matter, and exposing both to ignition in an earthen or metallic
case.  In this way, iron is cemented with charcoal to form steel, and bottle glass with
gypsum powder, or sand, to form Reaumur's porcelain.
CEMENTS. (Ciments, Fr.; Cimente, Kitle, Germ.) S;ubstances capable of taking the
liquid form, and of being in that state applied between the surfaces of two bodies, so as to
unite them by solidifying. They may be divided into two classes, those which are applied
through the agency of a liquid menstruum, such as water, alcohol, or oil, and those which
are applied by fusion with heat.
The diamond cement for uniting-broken pieces of china, glass, &c., which is sold as a
secret at an absurdly dear price, is composed of isinglass soaked in water till it becomes
soft, and then dissolved in proof spirit, to which a little gum resin, ammoniac, or galbanum, and resin mastic are added, each previously dissolved in a minimum of alcohol.
When to be applied, it must be gently heated to liquefy it; and it should be kept for
use in a well-corked vial. A glass stopper would be apt to fix so as not to be remove




CEMENTS.                                 391
able.  This is the cement employed by the Armenian jewellers in Turkey for glueing the ornamental stones to trinkets of various kinds.  When well made it resists
moisture.
Shellac dissolved in alcohol, or in a solution of borax, forms a pretty good cement.
White of egg alone, or mixed with finely sifted quicklime, will answer for uniting
objects which are not exposed to moisture. The latter combination is very strong, and
is much employed for joining pieces of spar and marble ornaments. A similar composition is used by copper-smiths to secure the edges and rivets of boilers; only bullock's
blood is the albuminous matter used instead of white of egg. Another cement in which
an analogous substance, the curd or caseum of milk is employed, is made by boiling
slices of skim-milk cheeses into a gluey consistence in a great quantity of water, and
then incorporating it with quicklime on a slab with a muller, or in a marble mortar.
When this compound is applied warm to broken edges of stoneware, it unites them very
firmly after it is cold.
A cement which gradually indurates to a stony consistence may be made by mixing
20 parts of clean river sand, two of litharge, and one of quicklime, into a thin putty
with linseed oil. The quicklime may be replaced with litharge. When this cement is
applied to mend broken pieces of stone, as steps of stairs, it acquires after some time a
stony hardness. A similar composition has been applied to coat over brick walls, under
the name of mastic.
The iron-rust cement is made of from 50 to 100 parts of iron borings, pounded and
sifted, mixed with one part of sal-ammoniac, and when it is to be applied moistened with
as much water as will give it a pasty consistency. Formerly flowers of sulphur were used,
and much more sal-ammoniac in making this cement, but with decided disadvantage, as
the union is effected by the oxydizement, consequent expansion and solidification of the
iron powder, and any heterogeneous matter obstructs the effect.  The best proportion of
sal-ammoniac is, I believe, one per cent. of the iron borings. Another composition of the
same kind is made by mixing 4 parts of fine borings or filings of iron, 2 parts of potter's
clay, and 1 part of pounded potsherds, and making them into a paste with salt and
water.  When this cement is allowed to concrete slowly on iron joints, it becomes very
nard.
For making architectural ornaments in relief, a moulding composition is formed of
chalk, glue, and paper paste. Even statues have been made with it, the paper aiding the
cohesion of the mass.
Mastics of a resinous or bituminous -nature which must be softened or fused by heat
ire the following:- 
Mr. S. Varley's consists of sixteen parts of whiting sifted and thoroughly dried by a
red heat, adding when cold a melted mixture of 16 parts of black rosin and 1 of bees'-wax,
and stirring well during the cooling.
Mr. Singer's electrical and chemical apparatus cement consists of 5 lbs. of rosin, 1 of
bees'-wax, 1 of red ochre, and two table-spoonsful of Paris plaster, all melted together.
A cheaper one for cementing voltaic plates into wooden troughs is made with 6 pounds
of rosin, 1 pound of red ochre,  L of a pound of plaster of Paris, and I of a pound of linseed oil. The ochre and the plaster of Paris should be calcined beforehand, and added
to the other ingredients in their melted state. The thinner the stratum of cement that
is interposed, the stronger, generally speaking, is the junction.
Boiled linseed oil and red lead mixed together into a putty are often used by coppersmiths and engineers, to secure joints. The washers of leather or cloth are smeared
with this mixture in a pasty state.
The resin mastic alone is sometimes used by jewellers to cement by heat cameos of
white enamel or colored glass to a real stone, as a ground to produce the appearance of
an onyx. Mastic is likewise used to cement false backs or doublets to stones, to alter
their hue.
Melted brimstone, either alone, or mixed with rosin and brick dust, forms a tolerably
good and very cheap cement.
Plumber's cement consists of black rosin one part, brick dust two parts, well incorporated by a melting heat.
The cement of dihl for coating the fronts of buildings consists of linseed oil, rendered
dry by boiling with litharge, and mixed with porcelain clay in fine powder, to give it the
consistence of stiff mortar. Pipe-clay would answer equally well if well dried, and any
color might be given with ground bricks, or pottery. A little oil of turpentine to thin
this cement aids its cohesion upon stone, brick, or wood. It has been applied to sheets
of wire cloth, and in this state laid upon terraces, in order to make them water tight; but
it is little less expensive than lead.
The bituminous or black cement for bottle-corks consists of pitch hardened by the addition of rosin and brick-dust.
In certain localities where a limestone impregnated with bitumen occurs, it is dried,




392                                CEMENTS.
ground, sifted, and then mixed with about its own weight of melted pitch, either mineral,
vegetable, or that of coal tar. When this mixture is getting semifluid, it may be moulded
into large slabs or tiles in wooden frames lined with sheet iron, previously smeared over
with common lime mortar, in order to prevent adhesion to the moulds, which, being in
moveable pieces, are easily dismounted so as to turn out the cake of artificial bituminous
stone. This cement is manufactured upon a great scale in many places, and used for
making Italian terraces, covering the floors of balconies, flat roofs, water reservoirs, water
conduits, &c. When laid down, the joints must be well run together with hot irons. The
floor of the terrace should be previously covered with a layer of Paris plaster or common
mortar, nearly an inch thick, with a regular slope of one inch to the yard. Such bituminous cement weighs 144 pounds the cubic foot; or a foot of square surface, one inch thick,
weighs 12 pounds. Sometimes a second layer of these slabs or tiles is applied over the
first, with the precaution of making the seams or joints of the upper correspond with the
middle of the under ones. Occasionally a bottom bed, of coarse cloth or gray paper, is
applied. The larger the slabs are made, as far as they can be conveniently transported
and laid down, so much the better. For hydraulic cements, see MORTAR.
An excellent cement for resisting moisture is made by incorporating thoroughly
eight parts of melted glue, of the consistence used by carpenters, with four parts of
linseed oil, boiled into varnish with litharge. This cement hardens in about forty-eight
hours, and renders the joints of wooden cisterns and casks air and water tight. A
compound of glue with one-fourth its weight of Venice turpentine, made as above,
serves to cement glass, metal and wood, to one another. Fresh-made cheese curd, and
old skim-milk cheese, boiled in water to a slimy consistence, dissolved in a solution of
bicarbonate of potash, are said to form a good cement for glass and porcelain. The
gluten of wheat, well prepared, is also a good cement. White of eggs, with flour and
water well-mixed, and smeared over linen cloth, forms a ready lute for steam joints in
small apparatus.
White lead ground upon a slab with linseed oil varnish, and kept out of contact of
air, affords a cement capable of repairing fractured bodies of all kinds. It requires a
few weeks to harden. When stone or iron are to be cemented together, a compound
of equal parts of sulphur with pitch answers very well.
Mr. Joseph Gibbs, a practical civil engineer of eminence, obtained a patent in May,
1850, for improvements in artificial stone, mortar and cements, and in the modes of
manufacturing the same, of which the following abstract is worthy of attention.
"The several descriptions of Roman cement are made from the septaria of either
Harwich or Sheppey, or from the septaria of the lias formation, or from beds of cement
stone found in the upper division of the lias formation, or in the shale beds of the
Kimmeridge clay. All these stones, when manufactured, produce a material of a dark
brown colour, unfit for incrusting buildings so as to imitate stone, unless they are
either coloured by washes, or by painting. Now, amongst the advantages to be obtained
from the cements and mortars I have invented is this, that every description of freestone
may be exactly imitated without any wash or painting whatsoever being applied.
"Again, the cement called Portland cement is made by mixing clay and chalk, or
river mud and chalk, in such proportions together that the combined materials may
contain about the same proportions of lime, silica, and alumina, as are found in cements.
These materials are ground together in water to a great degree of fineness. After
subsidence, and also after obtaining the proper consistency, the pasty materials are dried
in kilns, or otherwise, and afterwards burned like ordinary cements in calcining kilns.
The materials are then ground in proper mills. To these materials, so prepared and so
ground, are added from one-third to one-half of their weight in slag of copper smelting,
or other furnaces, or the slag of over-burnt cement, which, combining with the lime and
silica, forms a cement which is much nearer the colour of stone than any of the Roman
cements heretofore made. Now, as the combination of chalk and clay, or river mud, is
expensive when manufactured, and causes these cements to be very dear; and further,
as the materials are only combined mechanically and not chemically, there is neither
uniformity in their quality, nor can reliance be always placed on their stability; the
object of my invention, therefore, is to lessen the expense of manufacturing artificial
stone, mortars, and cements, and produce a superior quality of cement to those now in
use.
"My invention divides itself into three parts; the first of which relates to mortar
and cements, the second to the manufacture of artificial stone, and the third to the
modes of manufacturing the said mortar cements, and artificial stone.
" I have found by research, analysis, and much experience, that there exists in nature
vast beds of argillaceous marls and marly limestones, or marl stones, which contain the
due admixture of lime, silica, and alumina, from which hydraulic cements and artificial
stone may be manufactured. The principal places for finding this marl and marly




CEMENTS.                                  393
limestone (geologically speaking) are the chalk formation, the Wealden formation, the
Purbeck beds, the las formation, the mountain limestone, and the lowest strata of the
coal measures. In the chalk formation, the marl will be found immediately at the
junction of chalk with and just above the green sand; in that division of the sand
usually called' gault,' or at such places where the fire-stone (or, as it is sometimes
called, the'malen rock') exists, interposing between the gault and the chalk marl.
This chalk marl possesses a varying character, increasing in the amount of silica and
alumina as it approaches either the malen rock or the gault; in fact, sometimes when
there is no malen rock (or fire-stone) the gault becomes a calcareous marl, charged with
sufficient lime to make a cement, but the amount of silica and alumina, and lime composing the marl, can only be ascertained by experiment. The upper beds of marl, and
those nearest to the greystone rock of the chalk formation, will make hydraulic mortar
quite equal, and often superior, to the best lias lime; and the lower beds will make
cement equal to Roman cement, except that it does not contain a very noticeable
quantity of either manganese or iron; consequently it is of light stone colour when
-manufactured, and is better adapted to cover buildings, and represent stone. The chalk
marl may readily be found by the springs of water which issue from the back or
escarpment face of the chalk formation, and above these springs (but in close proximity
thereto) the hydraulic lime will be found, and below the springs the materials for
making cement must be extracted.
" The proper place for obtaining the marly limestone in the Wealden formation is in
what are termed by geologists the Ashburnham beds, above and below and in immediate contact with the Ashburnham limestone. These limestone marls are like perfect
limestone when first extracted, but decompose by exposure to the air after a short time.
The limestone itself, in particular localities, sometimes become a cement-stone or marl
stone, which may be known by its not slackening in water after calcination.
" The material for making cement out of the beds of Purbeck limestone is obtained
from some of the partings which divide the ordinary Purbeck beds of limestone, and
is exceedingly well calculated to make a cement of great purity and whiteness, but all
the beds do not contain in their partings the quality desired, but the proper material
may be readily found by noticing the decomposing character of the shale when exposed to the air.
"The materials which I extract from the lias formation, locally called'rummell' at
the lime quarries at Barrow-on-Soar, in Leicestershire, is an especial bed of marly
limestone, found above and separated from all the lias beds of limestone in that district. The same bed of' rummell' is found in other districts of the lias formation, and
may be readily observed on the coast of Dorsetshire, near Lyme Regis. It is seen on the
face of the limestone cliffs, imbedded in a marly shale, the whole of which decomposes
on exposure to the air. This bed of'rummell' has no local name in the district of Lyme
Regis, not having hitherto been applied to any useful purpose; but it may be easily
found, as it exists in a deep bed of shale between the lias limestone beds and the beds
of cement stone which heretofore have been worked, and are so now (but the cement
from this last-named stone is of a deeper brown colour, and unfit for imitating stone,
whilst the bed of' rummell' will make a cement of a light colour exactly like freestone).
" In some cases, as when I use the hardening materials (to be hereafter described)
in combination with the calcareous marls from the lias formation, I use some of the
partings of calcareous shale existing between the lias beds of workable limestone, provided such calcareous partings or shale beds contain sufficient lime, which shale, after
calcination, I combine with the hardening material, in the manner hereafter to be
directed, either by itself or in combination with the'rummell' of this formation along
with the hardening materials.
" The materials which I extract to make cements from the mountain or carboniferous
limestone are only found in the upper part of that great deposit, and must be sought
for in or at the immediate junction of the limestone shale (which shale lies under the
mill-stone grit, and above the mountain or carboniferous limestone, dividing the two
formations). These materials consist of mountain limestone, limestone shale, and bastard limestone (that is, the limestone which will not slack after calcination, but still
retains its shape after being dipped in water). These two materials are found
above the beds of workable limestone, which beds are wrought for making ordinary
limes (the shales and the bastard limestone, or limestone marl, being always found
together). These shales produce a dark cement, but the bastard limestone produces a
cement of a light stone colour, and therefore more fit for imitating stone.
"In addition to these substances, I extract from this formation sparry iron stone, to
make hardening materials with.
"The materials which I extract from the coal measures for making cement, or for
mixing with the other cementitious materials, are found only in the lowest beds of the
coal measures, often connected with the last two seams of coal, and before that
VOL.                               3 E




394                               CEMENTS.
stratum the millstone grit. These cementitious materials consist, first, of the coal shale
(called metals by miners), and round septaria nodules (boilams by the local miners
about Congleton in Cheshire). The'metals' will not in all cases make cement, but
most of them in contact with the boilams (or septaria balls) will do so. These boilams
are composed chemically of sulphur, lime, iron, and manganese, and are therefore
easily distinguishable; they are, in fact, a species (as well as the'metals') of pyrites.
The'metals' and the septaria balls make excellent cement, of great hardness, but of
dark colour. I use, however, this cement, as well as other materials, in mixing with
some of the cements I have before specified, to give them hardness-the process of
doing which, and the nature of the materials, will be described hereafter-such materials will be called hardening materials.
" When any of the materials just enumerated are to be made into cements, the usual
course of proceeding for making cements is to be followed; that is, by burning in
kilns and grinding in mills, in the way cement is now manufactured; but I recommend
that the marls and marl stones be first dried in kilns or ovens, at a heat fit for baking,
until all moisture be driven off, and that then the calcination be prolonged as much as
possible, but that the heat be kept so low as is only just sufficient to effect complete
calcination,-this being indispensable, to avoid the commencement of vitrification,
which would destroy the adhesive properties of the cement. These observations will
be found equally applicable to kilns, such as are now in use, or to the kiln of the improved description, to be described hereafter, and which forms part of this invention.
" Although I have described certain new materials for making cements and mortars
therefrom, and such materials are capable of forming good cements without any admixture whatever, yet, in some cases, I make a composition of the various cements to
obtain particular qualities; thus, for instance, I take a quantity of the pyrites septaria,
called boilams, and mix it with an equal quantity of the chalk marl before described.
In this case the chalk marl keeps the colour light, and the septaria or boilams of the
coal measures before described give to the chalk marl a considerable degree of
hardness. I also make a mixture of equal parts of the bastard limestone before described for a like purpose, and with the same result; but with the' rummells' of the
lias formation before described, or the rich argillaceous shale of that formation, not
more than one-third or one-quarter part by weight of the septaria or boilams is needful to give great hardness and strength to the cement made therefrom. The same observation applies to the cement stone of the Ashburnham beds already described, as
well as the cement made from the interposing Purbeck shale partings.
"But in many cases a cement is required of a hardness beyond what would be
afforded from either of the cement stones I have described, or the mixture of two or
more of them together; and in these cases I use substances to be combined with any
of these cement stones or their mixtures, which I have called'hardening materials.'
These materials (in addition to the one I have described, namely, the pyritous septaria
or boilams) consist -
"First: Of the slag or cinder derivable from iron blast furnaces.
"Secondly: Slag from puddle furnaces, or from reheating or mill furnaces.
"Thirdly: Slag derivable from copper, lead, or tin furnaces, or the slag from cement
kilns.
" Fourthly: The sparry iron of the carboniferous strata.
"Fifthly: The pyritous earth known by geologists as Folkestone pyrites, which
pyritous earth is a thin lamina, or bead, or band of earth, in concretions just below
the gault strata, and which it separates from the rock and sand bed just below the gault.
The pyrites may be found in other places in similar positions; but the locality just indicated, namely, Folkestone in Kent, will be a sufficient guide to find a similar material
elsewhere. This pyritous earth may be calcined in ordinary lime kilns, the same as
the cement stones I have before enumerated. If this pyrites be mixed with chalk
marl or any other of the white cement stones I have before mentioned, the imitation of
stone will be very exact, and may be sculptured afterwards with the same facility as
ordinary freestone. The same effect may be produced by mixing in the like propor
tions this calcined pyritous earth with the artificial hydraulic cements now commonly
made (and which cements are composed of chalk and clay, or mud, in due proportions,
and ground together before calcination), the pyritous earth or Folkestone pyrites displacing in this case the ground slag with which such cements are now usually combined.
"The various slags and cinders require only to be ground under edgestones to a fine
powder, and then to be mixed with any of the various cements I have enumerated,
namely, the cement from the chalk, the cement from the lias, the cement from the
Wealden and Purbeck beds, the cement from the mountain limestone, and the cement
from the coal measures; these mixtures must be effected by sifting the materials together,
or by some other mode which will effectually incorporate and combine them; and the




CHAINWORK.                                   395
quantities may be generally from one quarter (by weight) to one of slag, mixed with
one of calcareous cement.
" In some cases I grind pyritous septaria of the coal measures, or other equivalent
materials (having the same chemical properties), into a fine powder, and mix such
powder with about its equal weight of some of the calcareous marls after they are made
into cement, instead of mixing such marls with the slags, or with the calcined pyrites tf
Folkestone, as before directed. In other cases, I mix with the cement made from
chalk or other marls an equal weight of any of the cements now in use, or of the
calcined septaria of the London clay basin, called Roman cement stone, more especially
that part of it which is called sandstone; but in the case of using any of the septaria of
the London clay, the marl and the stone may be calcined, and ground together in equal
proportions, or thereabouts.
" Claims:-1st. The manufacture of mortar and cement from chalk marls, the calcareous marls of the Ashburnham beds, the calcareous shales of the Purbeck formation,
the rummell beds of the lias formation, the calcareous and mountain limestome shales,
bastard limestone and the'metals,' and pyritous septaria of the coal formation, all or
any of them, when prepared for the purpose by grinding or pounding, and by treating
with water as described, and whether the same are combined or not combined with
certain hardening materials (afterwards specified), or other cementitious substances.
" 2. The use of the'hardening materials' described, when used in combination with
any of the calcareous substances enumerated in the preceding claim, or in combination
with any other natural calcareous marl or marlstones.
" 3. The use of the calcined Folkestone pyritous earth, the sparry ironstone or white
ironstone of the mountain limestone, and the calcined pyritous septaria of the coal
measures, as' hardening materials' in combination with any artificially-formed cement
composed of chalk, or lime and clay, ground and calcined in the manner now usually
practised for manufacturing artificial cements.
" 4. The mixture of any of the before described marls or marlstones, or pyritous
septaria, from the coal measures, with each other, or with any of the water cements or
limes now in use, or the materials of which the same are composed.
" 5. A particular process of grinding and pounding cement and materials mixed
therewith, as described.
" 6. The consolidation of cement and materials mixed with such cement by concussion, for forming blocks or other solid shapes in moulds.
" 7. A process of making artificial stone by putting plastic materials between lattices
or other convenient forms; and also certain methods of casting hollow parallelograms
in cement, to be afterwards filled up with concrete, for walls of artificial stone.
" 8. The use of a kiln, with fire-vaults under the whole area of such kiln, such vaults
communicating with each other in various directions through spaces between the bricks
composing such vaults.
" 9. The use of a brick with projections for constructing fire-vaults, as described, for
calcining marls, marlstones, cements, and other materials used for making metallic
mortars.
" 10. The use of a circular or continuous kiln, for the purpose of making mortars
and cements."
CERASIN. The name given by Dr. John to those gums which swell, but do not
dissolve in water; such as gum tragacanth.  It is synonymous with BASSORINE,
which see.
CERATE, from cera, wax. An unguent, of rather a stiff consistence, made of oil, or
lard and wax, thickened occasionally with pulverulent matters.
CERINE. A substance which forms from 70 to 80 per cent. of bees'-wax. It may
be obtained by digesting wax, for some time, in spirits of wine, at a boiling temperature.
The myricine separates, while the cerine remains dissolved, and may be obtained from
the decanted liquor by evaporation.  Cerine is white, analogous to wax, fusible at
134~ F., hardly acted upon by hot nitric acid, but is readily carbonized by hot sulphuric acid. When treated with caustic alkaline lye, it is converted into margaric acid
and ceraine.
CERIUM. A peculiar metal discovered in the rare mineral, called cerite, found
only in the copper mines of Bastnaes, near Riddarhytta, in Sweden. Cerium extracted
from its chloride by potassium, appears as a dark red or chocolate powder, which
assumes a metallic lustre by friction. It does not conduct electricity well, like other
metals; it is infusible; its specific gravity is unknown. It has been applied to no use
in the arts.
CERUSE. A name of white lead. See LEAD and WHITE LEAD.
CETINE. The name given by Chevreul to spermaceti.
CHAINWORK is a peculiar style of textile fabric, to which hosiery and tambour
ing belong. See HosIraY.
E 2




396                     CHAMELEON MINERAL.
CHALK. (Craie, Fr.; Kreide, Germ.) A friable carbonate of lime, white, opaque,
soft, dull, or without any appearance of polish in its fracture. Its specific gravity varies
from 2'4 to 2'6. It usually contains a little silica, alumina, and oxide of iron. It
may be purified by trituration and elutriation. The siliceous and ferruginous matters
subside first, and the finer chalky particles floating in the supernatant liquid may be
decanted with it, and obtained by subsidence. When thus purified, it is called whitening
and Spanish white, in England; schlemmkreide, in Germany; blanc de Troyes, and
blanc de Meudon, in France. Pure chalk should dissolve readily in dilute muritaic acid,
and the solution should afford no precipitate with water of ammonia.
CHALK-black. A mineral, called also drawing-slate.
CHALK-French. Steatite, or soap-stone; a soft magnesian mineral.
CHALK-red. A clay coloured with the peroxide of iron, of which it contains
about 17 per cent.
CHALYBEATE is the name given in medicine to preparations of iron. The most
agreeable, and one of the most powerful, forms of such medicines, is the improved
chalybeate water, for which Mr. Henry Bewley, apothecary in Dublin, obtained a
patent in June, 1842. The following is his valuable recipe: Eight ounces of crystalized citric acid being dissolved in about four times their weight of water, heated to
170~ F., are saturated with pure peroxide of iron, in the washed state, after being
precipitated by ammonia from the ferric sulphate. The solution is sweetened, flavoured, and charged highly with carbonic acid gas, so as to make a very palatable
potion, agreeable also to the stomach.
I find by analysis that 100 parts of Mr. Bewley's brilliant citrate of iron contain
28'9 of peroxide, 48-5 of citric acid, and 23 of water; and that a six-ounce phial of his
chalybeate water contains of that citrate a quantity equivalent to nearly 8 grains of
peroxide of iron.
Similar compounds are also specified to be made with other organic salts, as the
tartrate or lactate of iron.-Newton's Journal, xxii. 470.
CHAMELEON  MINERAL.  As this compound-so long known in chemistry
as a mere curiosity, on account of the surprising changes of color which it spontaneously assumes-has of late been largely employed for whitenicg tallow, palm oil,
and decoloring other organic matters, it merits description in this dictionary.  It
exists in two states; one of which is called by chemists the manganate of potash, and
the other the oxymanganate; denoting that the first is a compound of manganic acid
with potash, and that the second is a compound of oxymanganic acid with the same
base. They are both prepared in nearly the same way; the former by calcining
together, at a red heat in a covered crucible, a mixture of one part of the black peroxide of manganese with three parts of the hydrate of potash (the fused potash of the
aDothecary). The mass is of a green color when cold. It is to be dissolved in cold
water, and the solution allowed to settle, and become clear, but by no means filtered
for fear of the decomposition to which it is very prone. When the decanted liquid is
evaporated under the exhausted receiver of an air-pump, over a surface of sulphuric
acid, it affords crystals of a beautiful green color, which should be laid on a clean
porous brick to drain and dry. They may be preserved in dry air, but should be kept
in a well-corked bottle.  They are decomposed by water, but dissolve in weak water
of potash.  On diluting this much, decomposition of the salt ensues, with all the
chameleon changes of tint; red, blue, and violet. Sometimes a green solution of this
salt becomes red on being heated, and preserves this color even when cold, but
resumes its green hue the moment it is shaken: it might, therefore, furnish the crafty
votaries of St. Januarius with an admirable means of mystifying the worshippers at his
shrine. The original calcined mass, in being dissolved, always deposites a considerable
quantity of a brown powder, which is a compound of the acid and peroxide of manganese combined with water. Much of the potash remains unchanged, which may be
recovered.
The oxymanganate of potash is made by fusing, with a strong heat, a mixture of
equal parts of peroxide of manganese and hydrate of potash, or one part of peroxide
and two parts of nitre. The mass is to be dissolved in water, and, if the solution be
green, it should be reddened by the cautious addition of a few drops of nitric acid.
The clarified liquor is to be evaporated to the point of crystallization. Even the
smallest crystals of this salt have such an intense red color, that they appear black
with a green metallic reflection. In the air they gradually assume a steel gray hue,
without undergoing any essential change of nature. A very little of the salt reddens
a large body of water. The least portion of any organic matter added to the solution
of this salt reduces the oxymanganic acid to the state of peroxide, which precipitates
combined with water; and the liquor becomes green or colorless, according to circumstances.
A more permanent oxymanganic salt may be made as follows: —Melt chlorate of
potash over a spirit lamp, and throw into it a few pieces of hydrate of potash, which




CHARCOAL.                                   397
immediately dissolve and form a limpid liquid. When peroxide of manganese in fine
powder is gradually introduced into that melted mixture, it immediately dissolves,
with the production of a rich green colour. After adding the manganese in excess,
the whole is to be exposed to a gentle red heat, in order to decompose the residuary
chlorate of potash. It is now a mixture of manganate of potash, chloride of potassium
and peroxide of manganese. It forms with water a deep green-coloured solution; which
when boiled assumes a fine red colour, in consequence of its becoming an oxymanganate, and it ought to be decanted off the sediment while hot. By cooling, and still
more after further evaporation, the oxymanganate of potash separates in crystals possessed of great lustre; but towards the end colourless crystals of chloride of potassium.
Both the above salts are readily decomposed by organic bodies and other combustibles, whereby they have their acid converted into an oxide, with the disengagement of oxygen, and the destruction of many vegetable and animal colours. In this
respect they resemble the nitrates and chlorates.
CHARCOAL. The fixed residuum of vegetables exposed to ignition out of contact of
air. In the article CARBON, I have described the general properties of charcoal and the
simplest mode of making it. I shall here detail the best systems of manufacturing this
product upon the continent of Europe.
To carbonize wood under a moveable covering, the plan of meiler, or heaps, is employed
very much in Germany. The wood is arranged either in horizontal layers, or in nearly
vertical ones, with a slight slope, so as to form conical rounded heaps of differ.nt sizes.
The former are called lying meiler, fig. 339; the latter standing meiler,figs. 340 and 341.
339                  344             341
Both are distributed in much the same way.
In districts where the wood can be transported into one place by means of rivers, or
mountain-slides, a dry flat space must be pitched upon, screened from storms and floods,
which may be walled round, having a slight declivity made in the ground, toward the
centre. See fig. 342. Into this space the tarry acid will partially fall, and may be
conducted outward, through a covered gutter beneath, into a covered tank.  The
mouth of the tank must be shut, during the coaking, with an iron or stone slab, luted
with clay. A square iron plate is placed over the inner orifice of the gutter, to prevent
342                              d    it being choked with  coal ashes.
Fig. 342 represents a walled meiler
e pP-St —       station; a, the  station; b, the
c    gutter; c, the tank, which is covered with  the slab d; e, a slab
which serves to keep  the gutter
clear of coals.  The cover of the heaps is formed of earth, sand, ashes, or such other
matter as may be most readily found in the woods. They should be kindled in the centre. From 6 days to 4 weeks may be required for charring a heap, according to its size;
hard wood requiring most time; and the slower the process, the better and greater is the
product, generally speaking.
343                Charring  of wood  in mounds
(Haufe or liegende werke), figs. 343
and 344, differs from  that in the
meiler, because the wood  in the
haufe is successively charred, and
the charcoal is raked out by little
and  little.  The product is said
to be greater in this way, and also
1     better.   Uncleft billets, 6 or 8
feet long, being laid  over each
X' ~11~  ~[.-.   I~ ~[        other, are covered with ashes, and
then  carbonized.  The station is
sometimes  horizontal, and  sometimes made to slope.  The length
344@ Q ^        ^          ^   B^  may be 24 feet, the breadth  8
344                          feet; and the wood is laid cross,




398                             CHASCHISCH.
wise. Piles are set perpendicularly to support the roof, made of boughs and leaves,
covered with ashes. Pipes are occasionally laid within the upper part of the mounds,
which serve to catch and carry off some of the liquid products into proper tanks.
Fig. 345 is a vertical section,
345   m  andfig. 346, a half bird's-eye view,
ih     m           I     and half cross section, at the height
of the pit-bottom, of Chabeaus-,    t1^  1.Tl   siere's kiln for making wood charcoal.  a is the oven; b, vertical
air-pipes; c c, horizontal flues for
admitting  air to the kiln; d d,
small pits which communicate by
a;^ ~  ~     -~    8'short horizontal pipes e e, with the
vertical ones; f, the sole of the
kiln, a circle of brickwork, upon
which the cover or hood h reposes;
J^                    1 i  l, k,  Ii, a pipe which leads tc the cistern
k; 1, the pipe destined for carrying
off the gaseous matter; m m, holes
in the iron cover or lid.
<~    3^4~6       ~ The distribution of the wood is
346~ e      like that in the horizontal meikrs,
ACHE<B\                P'or heaps; it is kindled in the cen=^^ ^  ^c ^ \     ^tral vertical canal with burning
Gil^^^  B\  Vfuel, and the lid is covered with
s      \^d,                        a few inches of earth. At the becI  c ~%\evginning of the operation all the
draught flues are left open, but
-            they are progressively closed, as
occasion requires.  In eight kilns
all\^  a    Ciof this kind,.500 decasters of oak
M' 0  ^.]e      wood are carbonized, from  which
y///  D         16,000 hectolitres of charcoal are
^c^^  // y~~~obtained, equal to 64,000 pounds
French, being about 25 per cent.;
~~~~~T =3_4~;~                  ~ besides tar and 3000 velts of
wood vinegar, of from  2~ to 3~,o                ~~Baume.
At Crouy upon the Ourcq, near Meaux, there is a well-constructed kiln for making
turf-charcoal. It resembles most nearly a tar-kiln. In fig. 347, a is the cylindrical
coaking place, whose surrounding walls are heated by
the flame which passes through the intermediate space
b. The place itself is divided by partitions of fire tiles
34^7     Ad1 ^^ e   |l ^     into three stages, through the apertures in which the
flames of the fire c c, rise, and heat the exterior of the
coaking apartment. In order to confine the heat, there
is in the enclosing walls of the outer kiln a cylindrical
hollow space d, where the air is kept stagnant. Through
the apertures left in the upper end at e, the turf is introduced; they are then shut with an iron plate f,
which is covered with ashes or sand. The fire-place
opens above this aperture, and its outlet is provided
with a moveable iron cover g, in which there is a small
C  hole for the issue of the gases. The sole of the kiln
consists of a cast iron slab h, which may be raised by
means of a hook i upon it. This is drawn back after
the carbonization is completed, whereby the charcoal
falls from the coaking space into a subjacent vault. The
volatile products are carried off by the pipe k, and led
into the condensing cistern; the gases escaping to the
fire-place where they are burned. The iron slab is protected from the corrosion of the
acid vapors by a layer of coal ashes.
CHASCHISCH. Hadschy is not the correct term for this narcotic drug, for Hadschy
means a pilgrim; the true name is, according to pronunciation, Chaschisch, the Arab
word for hemp (Cannabis sativa). By this name all intoxicating drugs, whose chief
constituent is this herb, are well known over the whole of the East. The mode of
preparing chaschisch is the following:



CHIMNEY.                                   399
The tops and all the tender parts of the hemp plant are collected after the period of
inflorescence, dried and kept for use. It must be premised that the hemp plant is in
the East distinguished by its narcotic properties, although botanists are unable to detect
any difference between this and the European species. The dried hemp, or chaschisch,
is used1st. Boiled in fat, butter, or oil, with a little water; the filtered product is employed
in all kinds of pastry.
2nd. Powdered for smoking: 5 or 10 grs. of the powder are smoked from a common
pipe (tsubuk) with ordinary tobacco (tiiutum), or from  a water pipe (nargiele) with
another kind of tobacco (tombeki). The tombeki is probably the leaf of a species of
Lobelia; it is smoked in a nargiele, and is uncommonly narcoctic; so much so, that
it is ordinarily steeped in water for a few hours before it is used to weaken it, and the
pipe is charged with it whilst it is yet wet.
3rd. Formed with tragacanth mucilage into pastiles, which are placed upon a pipe
and smoked in similar doses. These two last preparations are so termed esrar (esrar
is the Arab word for "secret"); they are the most active of all the preparations of
chaschisch, and the first pipe will cause cerebral congestion in beginners.
4th.  Made into an electuary with dates or figs and honey. This preparation is of
a dark brown, almost black, colour, and tastes of dates and hemp; it is less active than
the esrar.
5th. Lastly, another electuary is prepared of the same ingredients with the addition
of spices, clove, cinnamon, pepper, amber, and musk. This preparation is used as an
aphrodisaic.
Chaschisch is said not to produce stupor but the most pleasant species of intoxication.
The person under its influence feels with perfect consciousness in the best of all
humours; all impressions from without produce the most grateful sensations; pleasant
illusions pass before his eyes, and he feels comfortably happy; he thinks himself the
happiest man on earth, and the world appears to him Paradise. From this imaginative
state he passes into the every day state, with a perfect recollection of all sensations, and
of every thing he has done and of every word he has spoken. The effects of a continued use of the narcotic are emaciation and nervous debility.
CHEESE (composition of).  Cheese of certain dairies and districts is apt to undergo
a remarkable decomposition whereby valerianic acid is formed. Messrs. Jljenko and
Laskowsi distilled along with water a turbid ammoniacal liquor, which being redistilled
along with some sulphuric acid, and the product neutralized by barytes, the resulting
saline compound proved to be the valerianate of that base, mixed with compounds of
butyric acid, caproic acid, caprylic acid, and capric acid. The cheese was from Limbourg.
Valerianic acid was found by M. Balard in the cheese of Roquefort.
CHICA is a red colouring principle made use of in America by some Indian tribes
to stain their skins.  It is extracted from the bignonia chica by boiling its leaves in
water, decanting the decoction, and allowing it to settle and cool, when a red matter
falls down, which is formed into cakes and dried. This substance is not fusible, and,
when burned, diffuses the same odor as animal bodies do.   t is insoluble in cold water,
very soluble in alcohol and ether, but after the evaporation ofthese liquids, it is recovered
unchanged.  Fats and unctuous oils both dissolve it. It is soluble in carbonated and caustic alkaline leys, from which it is precipitated by the acids without alteration. An excess
of alkali, however, speedily decomposes it. Nitric acid transforms it into oxalic acid, and
a bitter matter. Chlorine makes it white.
The savages mix this pigment with the fat of the cayman or alligator, and rub their
skins with the mixture.  It may probably be turned to account in the arts of civilized
nations.
CHIMNEY.  (Cheminee, Fr.; Schornstein, Germ.)  Chimney is a modern invention
for promoting the draught of fires and carrying off the smoke, introduced into England
so late as the age of Elizabeth, though it seems to have been employed in Italy 100
years before. The Romans, with all their luxurious refinements, must have had their
Epicurean cookery placed in perpetual jeopardy from their kitchen fires, which, having no
vent by a vertical tunnel in the walls, discharged their smoke and frequently their flames
at the windows, to the no small alarm of their neighbors, and annoyance of even the
street passengers.
Chimneys in dwelling houses serve also the valuable purpose of promoting salubrious
circulation of air in the apartments, when not foolishly sealed with anti-ventilating stovechests.
The first person who sought to investigate the general principles of chimney draughts,
in subserviency to manufacturing establishments, was the celebrated Montgolfier. As the
ascent of heated air in a conduit depends upon the diminution of its specific gravity, or,
in other words, upon the increase of its volume by the heat, the ascensional force may,e deduced from the difference between the density of the elastic fluid in the interior of




400                                CHIMNEY.,he chimney, and of the external air; that is, between the different heights of the internal
and external columns of elastic fluid supposed to be reduced to the same density. In the
latter case, the velocity of the gaseous products of combustion in the interior of the chimney is equal to that of a heavy body let fall from a height equal to the difference in height
of the two aerial columns.
To illustrate this position by an example, let us consider the simple case of a chimney
of ventilation for carrying off foul air from a factory of any kind; and suppose that
the tunnel of iron be incased throughout with steam at 212 degrees Fahr. Suppose this
tunnel to be 100 yards high, then the weight of the column of air in it will be to that of
a column of external air 100 yards high, assumed at 32~ F., inversely as its expansion by
1800; that is, as 1000 is to 1-375; or as 72'727 is to 100. The column of external air
at 32~ being 100 yards, the internal column will be represented by 72-727; and the difference=27'27, will be the amount of unbalanced weight or pressure, which is the effective cause of the ventilation. Calculating the velocity of current due to this difference of
weight by the well-known formula for the fall of heavy bodies, that is to say, multiplying
the above difference, which is 27'27, by the constant factor 19.62, and extracting the
square root of the product; thus V 19-62 X 27'27 = 23'13 will be the velocity in yards
per second, which, multiplied by 3, gives 60-30 feet. The quantity of air which passes
in a second is obtained of course by multiplying the area or cross section of the tunnel by
this velocity. If that section is half a yard, that is = a quadrangle 2^ feet by 2, we shall
have 23-13 X 0'5 = 11-565 cubic yards, = 3121 cubic feet.
The problem becomes a little more complicated in calculating the velocity of air which
has served for combustion, because it has changed its nature, a variable proportion of its
oxygen gas of specific gravity 1-111, being converted into carbonic acid gas of specific
gravity 1-524.  The quantity of air passed through well constructed furnaces may, in
general, be regarded as double of what is rigorously necessary for combustion, and the
proportion of carbonic acid' generated, therefore, not one half of what it would be were
all the oxygen so combined. The increase of weight in such burned air of the temperature
of 2120, over that of pure air equally heated, being taken into account in the preceding
calculation, will give us about 19 yards or 57 feet per second for the velocity in a chimney 100 yards high incased in steam.
Such are the deductions of theory; but they differ considerably from practical results,
in consequence of the friction of the air upon the sides of the chimneys, which varies likewise with its form, length, and quality. The direction and force of the winds also exercise
a variable influence upon chimney furnaces differently situated.  In chimneys made of
wrought i'on, like those of steamboats, the refrigeration is considerable, and causes a
diminution of velocity far greater than what occurs in a factory stalk of well-built brick
work.  In comparing the numbers resulting from the trials made on chimneys of different materials and of different forms, it has been concluded that the obstruction to the
draught of the air, or the deduction to be made from the theoretical velocity of efflux,
is directly proportional to the length of the chimneys and to the square of the velocity,
and inversely to their diameter. With an ordinary wrought-iron pipe, of from 4 inches
to b inches diameter, attached to an ordinary stove, burning good charcoal, the difference
is prodigious between the velocity calculated by the above theoretical rule, and that observed by means of a stop-watch, and the ascent of a puff of smoke from a little tow,
dipped in oil of turpentine thrust quickly into the fire. The chimney being 45 feet
high, the temperature of the atmosphere 68~ Fahr., the velocity per second was, -
Mean temperature
Trials.      By theory.       By experiment.            of chimney.
1            26.4 feet          5    feet                190~ Fahr.
2            29-4               5'76                     214
3            34'5               6.3                      270
To obtain congruity between calculation and experiment, several circumstances must
be introduced into our formulae. In the first place, the theoretical velocity must be
multiplied by a factor, which is different according as the chimney is made of bricks,
pottery, sheet iron, or cast iron.  This factor must be multiplied by the square root of
the diameter of the chimney (supposed to be round), divided by its length, increased by
four times its diameter. Thus, for pottery, its expression is 2'06 V -  D; D being the diameter, and L the length of the chimney.
A pottery chimney, 33 feet high, and 7 inches in diameter, when the excess of its mean
temperature above that of the atmosphere was 205~ Fahr., had a pressure of hot air
equal to 11-7 feet, and a velocity of 7-2 feet per second.  By calculating from the last
formula, he same number very nearly is obtained.  In none of the experiments did the
velocity exceed 12 feet per second, when the difference of temperature was more than
410~ Fahr.




CHIMNEY.                                   401
Every different form of chimney would require a special set of experizents to be
mipde for determining the proper factor to be used.
This troublesome operation may be saved by the judicious application of a delicate
differential barometer, such as that invented by Dr. Wollaston; though this instrument
does not seem to have been applied by its very ingenious author in measuring the
draughts or ventilating powers of furnaces.
If into one leg of this differential syphon water be put, and fine spermaceti oil into
the other, we shall have two liquids, which are to each other in density as the numbers
S and 7. If proof spirit be employed instead of water, we shall then have the relation
of very nearly 20 to 19. I have made experiments on furnace draughts with the instrument
in each of these states, and find the water and oil syphon to be sufficiently sensible; for
the weaker draughts of common fire-places the spirits and oil will be preferable
barometric fluids.
To the lateral projecting tube of the instrument, as described by Dr. Wollaston, I
found it necessary to attach a stop-cock, in order to cut off the action of the chimney,
while placing the syphon, to allow of its being fixed in a proper state of adjustment,
with its junction line of the oil and water at the zero of the scale. Since a slight deviation of the legs of the syphon from the perpendicular changes very considerably the
line of the level, this adjustment should be made secure by fixing the horizontal pipe
tightly into a round hole, bored into the chimney stalk, or drilled through the furnace
door.  On gently turning the stop-cock, the difference of atmospherical pressure corresponding to the chimney draught, will be immediately indicated by the ascent of the
junction line of the liquids in the syphon. This modification of apparatus permits the
experiment to be readily rectified by again shutting off the draught, when the air will
slowly re-enter the syphon; because the projecting tube of the barometer is thrust into
the stop-cock, but not hermetically joined; whereby its junction line is allowed to return
to the zero of the scale in the course of a few seconds.
Out of many experiments made with this instrument, I shall content myself with
describing a few, very carefully performed at the breweries of Messrs. Trueman, Hanbury, and Buxton, and of Sir H. Meux, Bart., and at the machine factory of Messrs.
Braithwaite; in the latter of which I was assisted by Captain Ericsson.  In the first
trials at the breweries, the end of the stop-cock attached to the differential barometer
was lapped round with hemp, and made fast into the circular peep-hole of the furnace
door of a wort copper, communicating with two upright parallel chimneys, each 18 inches
square and 50 feet high.  The fire was burning with fully its average intensity at the
time. The adjustment of the level being perfect, the stop-cock orifice was opened, and
the junction level of the oil and water rose steadily, and stood at 11 inches, corresponding
to 1.2s = 0'156 of 1 inch of water, or a column of air 10'7 feet high.  This difference
of pressure indicates a velocity of 26 feet per second.  In a second set of experiments,
the extremity of the stop-cock was inserted into a hole, bored through the chimney
stalk of the boiler of a Boulton and Watt steam-engine of twenty-horse power.  The
area of this chimney was exactly 18 inches square at the level of the bored hole, and its
summit rose 50 feet above it.  The fire-grate was about 10 feet below that level.  Oa
opening the ston-cock, the junction line rose 21 inches.  This experiment was verified
by repetition upon different days, with fires burning at their average intensity, and consuming fully 12 lbs. of the best coals hourly for each horse's power, or nearly one ton
and a third in twelve hours,  If we divide the number 2, by 8, the quotient 0'28 will
represent the fractional part of 1 inch of water, supported in the syphon by the unbalanced pressure of the atmosphere in the said chimney; which corresponds to 19- feet
of air, and indicates a velocity in the chimney current of 35 feet per second. The
consumption of fuel was much more considerable in the immense grate under the wort
copper, than it was under the steam-engine boiler.. In my experiments at Messrs. Braithwaite's factory, the maximum displacement of.the junction line was 1 inch, when the differential oil and water barometer was placed
in direct communication with a chimney 15 inches square, belonging to a steam boiler,
and when the fire was made to burn so fiercely, that on opening the safety-valve of the
boiler, the excess of steam beyond the consumption of the engine rushed out with such
violence as to fill the whole premises. The pressure of one eighth of an inch of water
denotes a velocity of draught of 23'4 feet per second.
In building chimneys, we should be careful to make their area rather too large than
too small; because we can readily reduce it to any desired size, by means of a sliding
register plate near its bottom, or a damper plate applied to its top, adjustable by wires
or chains, passing over pulleys. Wide chimneys are not so liable as narrow ones to
have their draught affected by strong winds. In a factory, many furnace flues are
often conducted into one vertical chimney stalk, with great economy in the first
erection, and increased power of draught in the several fires.
Vast improvements have been made in this country, of late years, in building stalks
VoL. L                              3 F




402                                CHIMNEY.
for steam boilers and chemical furnaces. Instead of constructing an expansive, lofty
scaffolding of timber round the chimney, for the bricklayers to stand upon, and to
place their materials, pigeon-holes, or recesses, are left at regular intervals, a few feet
apart, within the chimney, for receiving the ends of stout wooden bars, which are
laid across, so as to form a species of temporary ladder in the interior of the tunnel.
BY means of these bars, with the aid of ropes and pulleys, everything may be progressively hoisted, for the building of the highest engine or other stalks.  An expert
bricklayer, with a handy laborer, can in this way raise, in a few weeks, a considerable
chimney, 40 feet high, 5 feet 8 inches square outside, 2 feet 8 inches inside at the base,
28 inches outside, and 20 inches inside at the top.  To facilitate the erection, and at
the same time increase the solidity of an insulated stalk of this kind, it is built
with three or more successive plinths, or recedures, as shown in fig. 281.  It is necessary to make such chimneys thick and substantial near the base, in order that they
may sustain the first violence of the fire, and prevent the sudden dissipation of the
heat.  When many flues are conducted into one chimney stalk, the area of the latter
should be nearly equal to the sum of the areas of the former, or at least of as many of
them  as shall be going simultaneously. When the products of combustion from any
furnace must be conducted downwards, in order to enter near the bottom of the main
stalk, they will not flow off until the lowest part of the channel be heated by burning
some wood shavings or straw in it, whereby the air syphon is set agoing. Immediately after kindling this transient fire at that spot, the orifice must be shut by which
it was introduced; otherwise the draught of the furnace would be seriously impeded.
But this precaution is seldom necessary in great factories, where a certain degree of heat
is always maintained in the flues, or, at least, should be preserved, by shutting the
damper plate of each separate flue, whenever its own furnace ceases to act. Such chimneys are finished at top with a coping of stone-slabs, to secure their brickwork against
the infiltration of rains, and they should be furnished with metallic conducting rods, to
protect them from explosions of lightning.
When small domestic stoves are used, with very slow combustion, as has been
recently proposed, upon the score of a misjudged economy, there is great danger of the
inmates being suffocated or asphyxied, by the regurgitation of the noxious burned air.
The smoke doctors who recommend such a vicious plan, from  their ignorance of
chemical science, are not aware that the carbonic acid gas, of coke or coal, must be heated
2500 F. above the atmospheric air, to acquire the same low specific gravity with it.  In
other words, unless so rarefied by heat, that gaseous poison willdescend through the orifice
of the ash-pit, and be replaced by the lighter air of the apartment.  Drs. Priestley and
Dalton have long ago shown the co-existence of these two-fold crossing currents of air,
even through the substance of stone-ware tubes.  True economy of heat, and salubrity,
alike require vivid combustion of the fuel, with a somewhat brisk draught inside of the
chimney, and a corresponding abstraction of air from  the apartment.  Wholesome
continuous ventilation, under the ordinary circumstances of dwelling houses, cannot
be secured in any other way.  Were these mephitic stoves, which have been of late
so ridiculously puffed in the public prints, generally introduced, the faculty would
need to be immediately quadrupled to supply the demand for medical advice; for
headaches, sickness, nervous aliments, and apoplexy, would become the constant inmates
of every inhabited mansion.  The phenomena of the grotto of Pausilippo might then
be daily realised at home, among those who ventured to recline upon sofas in such carbonated apartments; only instead of a puppy being suffocatedpro tempore, human beings
would be sacrificed, to save two penny worth of fuel per diem.
The figures upon the following page represent one of the two chimneys, recently
erected at the Camden Town station, for the steam boilers of the two engines of 60
horse-power each, belonging to the London and Birmingham Railway company. These
engines then drew their train of carriages up the inclined plane of Hampstead Hill
The chimneys were designed by Robert Stephenson, Esq., engineer to the Company,
executed by William  Cubitt, Esq., of Gray's Inn road, - and do equal honour to
both gentlemen, being probably among the most elegant and'substantial specimens of
this style of architecture in the world. In the section, fig. 348.,
A represents a bed of concrete, 6 feet thick, and 24 feet square.
B, brick footings set in cement; the lower course 19 feet square.
c, Bramley-fall stone base, with a chain of wrought iron let into it.
D, a portion, 15 feet high, curved to a radius of 113 feet, built entirely of Malm
paviours, (a peculiarly good kind of bricks).
E, shaft built of Malm paviours in mortar.
F, ditto, built from the inside, without exterior scaffolding.
G, the cap ornamented, (as shown in the plan alongside,) with Portland stone, the
dressings being tied together with copper cramps and an iron bond.
Fiq. 349. represents the mouldings of the top, upon an enlarged scale.




CHINA INK.                                403
Fig. 350., a plan of the foundation, upon an enlarged scale.
Fig. 351., ditto, at the level of the entrance of the flue, as seen in
Fig. 352., the elevation of the chimney.
Fig. 353., plan at the ground level I, in fig. 348. and 352.
K, fig. 348., the lightning conducting roa
349                     352                       348
=350 ~ ~   ~       5                         3 5
Al            i
3 F2 Ad                 53,..    10'    ST          -.
2,,
kind of this useful pigment is seldom met with in our markets. According to a description in a Japanese book, it is made from the condensed smoke or soot of burned
camphor; and hence, when of the best quality, it has this odour. Most of the China
3 a2




404                      CHLORATE OF POTASH.
ink is made from oil-lampblack occasionally disguised as to smell, with musk, or
with a little camphor black. The binding substance is gelatine, commonly made from
parchment or ass' skin; but isinglass answers equally well. A good imitation may
be made by dissolving isinglass in warm water, with the addition of a very little alkali
(soda), to destroy its gelatinizing power; and incorporating with that solution, by levigation on a porphyry slab, as much of the finest lampblack as to produce a mass of
the proper consistence. The minute quantity of alkali serves also to saponify the oil
which usually adheres to lampblack; and thereby to make a pigment readily miscible
with water.
CHINTZ is a peculiar style of fast-printed calico, in which figures of at least five
different colours are impressed upon a white or light coloured ground.
CHLORATE OF POTASH, commonly called oxymuriate of potash. This interesting
saline compound has become the object of a pretty extensive manufacture, in consequence
of its application to make matches for procuring instantaneous light, and a detonating
powder for fire-arms. It may be prepared both in the humid and dry way.
Having made a strong solution of purified potash, or carbonate of potash, with from
two to three parts of water, we pass through it in a Woulfe's apparatus a current of chlorine gas, till it ceases to absorb any more. Chloride of potash and chloride of potassium
alone are formed as long as there is an excess of alkali in the solution; but afterwards,
in the further reaction of the materials, the chloride passes into the state of a chlorate,
and, as such, precipitates from the solution. During the first half of the operation, that
is, till the potash be about one half saturated with chlorine, as indicated by litmus paper
ceasing to be darkened and beginning to be blanched, only the chloride of potassium or
muriate of potash falls. The process should be interrupted at this point in order to remove the salt, to wash it, to add the washings to the liquor, and then to transmit the gas
freely through the solution. As the operation advances, less muriate of potash is formed,
and at length nothing but the pure chlorate is separated in crystals. When finally the
bubbles of gas pass through without being sensibly absorbed, the process is known to be
completed; the liquid may then be allowed to settle, and be poured off from the crystals
of chlorate of potash, which are purified from the muriate by dissolving them in three
times their weight of boiling water, and filtering the solution while hot. On its cooling,
the chlorate will separate in pearly-looking crystalline plates. It may be rendered quite
pure by a second crystallization, in which state it does not affect solution of nitrate of silver.
The above potash ley usually gets a reddish tint in the course of the process in consequence of a little manganesic acid coming over with the chlorine, but it gradually loses
this color as the saturation becomes complete, when the solution turns yellow. The
tubes for conveying the gas should be of large diameter, if they be plunged into the
saline solution, because the crystallization which takes place in it is apt to choke thetm
up. This inconvenience may however be obviated by attaching to the end of the glass
tube, a tube of caoutchouc terminated in a small glass funnel, or simply the neck of a
caoutchouc bottle with a part of its body, whose width will not be readily closed with a
saline crust. The residuary lixivium may be used against another operation, or it may
be evaporated down to half its bulk and set aside to crystallize, whereby some more
chlorate will be obtained, mixed indeed with muriate and carbonate, from which however
it may be separated by a second crystallization. In general the pure chlorate obtained
does not exceed one tenth the weight of the potash employed; because in thus treating
potash with chlorine, five sixths of it are converted into muriate of potash and only one
sixth into chlorate, and a part of the latter adheres to the muriate, or is lost in the mother
waters of the crystallizations.
The chlorate of potash may be more conveniently manufactured, like that of lime, in
the dry way. St. Romer patented at Vienna the following method for that purpose in
1821:- Ten pounds of crystallized peroxyde of manganese are to be finely pulverized,
mixed with ten pounds of plumbago, and thirty pounds of common salt, arnd put into the
leaden retort represented in fig. 287, p. 293. From the middle of the helmet-shaped
lid of this vessel, a lead tube, two feet long, and two inches wide, conducts to the receiver,
which is a square earthen pan, hard glazed both within and without, of the same capacity
with the retort. The end of the tube must be made fast to a frame at the height of six
inches above the bottom of the receiver. Upon its inner sides, four inches apart, brackets
are to be fixed for supporting a series of laths or shelves of white wood, on which a number of little paper or pasteboard boxes are to be laid. In these boxes ten pounds of the
purest carbonate of potash, prepared from tartar, are to be spread. The receiver must
now be covered with a lid made tight by a water lute. Twenty pounds of concentrated
sulphuric acid previously diluted with sixteen pounds of water, and then cooled, are to
be poured upon the mixed materials in the retort,, the lid immediately secured, with the
tube adjusted in the receiver. The whole must be allowed to operate spontaneously without heat for twelve hours. At the end of this time the retort is to be surrounded with a
water bath and steadily heated during twelve hours, and then left to cool for six hours.




CHLORATE OF POTASH.                                   405
The apparatus must now be opened, the cakes of chlorate of potash removed. and freed
from muriate by solution and crystallization.
M. Liebig proposes the following process for obtaining chlorate of potash:Heat chloride of lime in water till it ceases to destroy vegetable colors. In this case a
mixture of chloride of calcium and chlorate of potash is obtained. This is to be dissolved
in hot water, and to the solution concentrated by evaporation, chloride of potassium is to
be added, and then suffered to cool. After cooling, a quantity of crystals of chlorate of
potash is obtained, which are to be redissolved and crystallized again to purify them. M.
Liebig considers that this will be a cheap process for obtaining chlorate of potash. From
12 ounces of chloride of lime, of so bad a quality that it left 65 per cent. of insoluble
matter, he obtained an ounce of chlorate of potash.
The only difficulty to overcome in this process is, from the chloride of lime not being
so easily decomposed by heat as is generally supposed; a solution of it may be kept boiling for an hour without losing its bleaching power. The best method is to form a thin
paste with chloride of lime and water, and then to evaporate it to dryness. If it be required to prepare it by passing chlorine into cream of lime, it is advantageous to keep it
very hot.
The chlorate of potash which separates from the solution by crystallization, has not
the form of scales which it usually possesses. but is prismatic: whether this is occasioned
by some admixture has not been ascertained; but on re-crystallizing, it is obtained in the
usual form.
The solution ought not merely to be left to cool, in order to procure crystals, for the
crystallization is far from being terminated even after complete cooling; crystals continue
to be deposited for 3 or 4 days.
The following modification of the process for making chlorate of potash is that of M.
Yee. A solution of chloride of lime, marking 18~ or 20~ Baume, is to be set upon the fire
in a lead or cast iron pot, and when it begins to get hot, there is to be dissolved in it a
quantity of chloride of potassium sufficient to raise the hydrometer 3 or 4 degrees. It
must be then concentrated as quickl aas possible till it marks 30~ or 31~, taking care that
it does not boil over by the sudden extrication of oxygen. The concentrated liquor is set
aside to crystallize in a cool place; where a deposite of chlorate of potash forms, mixed
with chloride of potassium.  The mother waters being evaporated to the density of 36",
afford another crop of crystals, after which they may be thrown away.
The salts obtained at the first crystallization are to be re-dissolved, and the solution
being brought to 15~ or 16~ is to be filtered, when it will afford upon cooling pure chlorate of potash.
Chlorate or oxymuriate of potash has a cooling, somewhat unpleasant and nitroni
taste. It does not bleach. At 60~ F. 100 parts of water dissolve six parts of it, and at
its boiling point or 2200, sixty parts. When heated to dull ignition in a glass retort, it
gives out 39'15 per cent. of its weight of oxygen, and becomes thereby chloride of
potassium.  When strongly triturated in a mortar it crackles, throws out sparks, and becomes luminous. It deflagrates upon red-hot cinders like nitre: when triturated along with
sulphur, or phosphorus, it detonates with great violence, not without danger to the hands
of the operator, if they be not protected by a thick glove. Similar detonations may te
produced with cinnibar or vermilion, sulphuret of potassium, sugar, volatile oils, &c.,
but they can be effected only by the smart blow of a heated hammer and anvil. A
mixture of sugar or starch with chlorate of potash is readily inflamed by a drop of sulphuric acid, and this experiment is the basis of the preparation of the oxygenated matches,
as they have been commonly called. The following formula forms a good paste for
tipping the said matches, made of narrow slips of either wood or card. Thirty partl of
the chlorate in fine powder are to be mixed gently with a spatula upon paper with ten
parts of flowers of sulphur well levigated, eight of sugar, five of gum arabic, and enough
of vermilion to give the whole a rose tint. We begin by mixing tenderly together
the sugar, the gum, and the salt previously pulverised; we then add as much water
as shall reduce the mixture to a thin paste, and lastly introduce the sulphur; after
which all must be well incorporated.  The points of the matches, either previously
tipped with sulphur or not, are to be dipped in that paste, so as to get coated with a
little of it, and are lastly laid in a warm place till they become thoroughly dry. To
kindle one of them, it must be touched with strong sulphuric acid, which, for this
purpose, is usually kept in a small well-stopped vial, and thickened with amianthus.
Aspen is reckoned the best wood for matches.
Of late years a detonating priming for fire-arms has been much used with the percussion locks. The simplest formula for making it is to take ten parts of gunpowder, to
lixiviate it with water, and to mix the residuum, while moist, with five parts and a
quarter of chlorate of potash, reduced to an extremely fine powder. The paste may be
made pretty thin, for the salt is sparingly soluble in cold water, and it mixes best
when tolerably fluid. This powder when dry is dangerous to handle, being very apt to




406                                CHLORINE.
explode. But this danger is guarded against by letting fall a drop of the paste into each
copper percussion cap, and leaving it to dry there. In the detonation of this powder,
besides muriate of potash, there are generated a little sulphate of potash and chlorine
gas, which rust the metal very fast. For which reason fulminate of mercury is now
preferred by many sportsmen as a detonating powder. See FULMINATE.
The following ingenious and easy way of making this valuable chlorate has been
lately suggested by Professor Graham:-Mix equal atomic weights of carbonate of
potash and hydrate of lime (70 of the former, if pure, and 37 of slaked lime in powder),
diffuse them through cold water, and transmit chlorine gas through the mixture. The
gas is absorbed with great avidity, and the production of a boiling heat. When the
saturation is complete, carbonate of lime remains, and a mixture of muriate and chlorate
of potash, which latter salts are to be separated, as usual, by the difference of their
solubility in water.
It has been remarked on the above process, that it effects no saving of potassa, and
therefore is far inferior to the one long practised in several parts of Germany, especially
at Giessen, and introduced into this country a good many years ago by Dr. Wagenmann, from Berlin. The chlorine is passed into a mixture of one equivalent of chloride of potassium (76), and 6 equivalents of hydrate of lime (222), previously stirred with
water to the consistence of a thin paste. Thus the calcium of the lime unites with the
chlorine to form chloride of calcium, while the chloride of potassium is converted into
chlorate of potassa, which salt is easily separated in crystals by its sparing solubility.
Chlorate of potash may also be made by saturating with chlorine a mixture of 74
parts of chloride of potassium (muriate of potash) and 168 parts of quicklime, brought
to the consistence of a thin pap by the cautious addition of water. The mass being
dissolved in warm water, and evaporated and cooled, yields crystals of chlorate of
potash, while a mother water of chloride of calcium (muriate of lime) remains. The
following process has likewise been prescribed:-Mix 10 parts of good chloride of
lime with water into a pap, and evaporate to dryness, whereby it is converted into
a mixture of chloride of calcium and chloride of lime devoid of bleaching power;
dissolve it in water, filter, concentrate the solution by evaporation, then add to it I
part of chloride of potassium, and cool for crystallization. The salt which may thereby
be separated from the chloride of calcium will afford 083 of pure chlorate of potash. By
this process of Professor Liebig five sixths of the potash are saved, but much oxygen is
wasted in the evaporation to dryness of.the chloride of lime, and consequently much
chloric acid is lost towards the production of the salt. Vee mixes the chloride of lime
pap, before heating it, with the chloride of potassium, boils the mixture smartly, whereby
much oxygen is undoubtedly thrown off, and then sets the liquor aside to crystallize.
L. Gmelin suggests that saturation of the liquor with chlorine before boiling might
be advantageous.  Gay Lussac has suggested to make this valuable salt by precipitating a solution of chloride of lime with carbonate (or sulphate) of potash, saturating the liquor after filtration with chlorine gas, evaporating, and crystallizing.
Profossor Juch's process is to pass chlorine gas into a mixture of 1 pound caustic
lime and 1 pound carbonate of potash, with 8 pounds of water. The resulting chloride
of potash readily separates in the filtered liquid by crystallization from the very soluble
chloride of calcium. By this method potash is not wasted in the useless production
of chloride of potassium.
CHLORATES, compounds of chloric acid with the salifiable bases. The only acid belonging to this class of any manufacturing importance is the following:
CHLORIC ACID; the acid constituent of the preceding salt; it consists of one
equivalent prime of chlorine = 35-476, - 5 of oxygen, = 40-065; of which the sum 75-535
is the prime equivalent of the acid.
CHLORINE; the most energetic of the undecompounded bodies, or chemical elements as they are usually called, exists, under ordinary circumstances, as a greenish yellow gas, but, when exposed to a pressure of 4 atmospheres, it becomes a yellow transparent liquid. In the first state, its density compared to air, reckoned 1-000, is 2-47;
in the second, its density compared to water, 1-000, is 1-33. No degree of cold hitherto
tried, has liquefied the gas when dry. It is obtained by putting into a glass retort a mixture of 3 parts of common salt, with 2 parts of peroxyde of manganese, and
pouring upon it 2 parts of sulphuric acid diluted with its own weight of water; or, more
conveniently, by pouring moderately strong muriatic acid upon peroxyde of manganese in
a retort; and in either case applying the gentle heat of a spirit lamp or a water bath,
while the beak of the retort is plunged under brine upon the shelf of the pneumatic trough.
The gas issues, and may be received in the usual way into inverted glass jars, or vials;
but the first which comes over, being mixed with the air of the retort, must be rejected.
It has a peculiar smell, and irritates the nostrils most violently when inhaled, as also the
windpipe and lungs. It is eminently noxious to animal life, and, if breathed in its undiluted state, would prove instantly fatal. It supports the combustion of many bodies,




CHLORIDE OF LIME.                                407
and indeed spontaneously burns several without their being previously kindled. The
resulting combinations are called chlorides, and act most important parts in many
manufacturing processes.
Water absorbs, at the ordinary temperature of the atmosphere, about double its volume of chlorine, and acquires the colour, smell, and taste of the gas, as well as its power
of destroying or bleaching vegetable colours. When this aqueous chlorine is cooled to
36~ Fahr. dark yellow crystalline plates appear in it of the hydrate of chlorine, which
are composed in 100 parts of 27 7 chlorine, and 72'3 water. If these crystals be heated
to about 45~ they liquefy, and the gas flies off.
Chlorine has a powerful affinity for hydrogen, not only combining with it rapidly in
the gaseous, but seizing it in many of its liquid and solid combinations, as in volatile
oils, which it inflames, and in yellow wax, cotton and flax, which it whitens. The cor
pound of chlorine and hydrogen gases is muriatic acid gas. Manganese, when mixed
with liquid muriatic acid, as in the above process, abstracts the hydrogen, and lets the
chlorine gas go free. When chlorine is passed into water, it decomposes some of it, seizes
its hydrogen to form a little muriatic acid, and enables its oxygen to unite either with
the chlorine, into chlorous acid, or with the remaining water, and to constitute oxygenated water. Hence, aqueous chlorine, exposed to the sunbeam, continually evolves
oxygen, and, ere long, becomes muriatic acid.
This watery compound acts in a powerful way upon coloured vegetable fibres, extracting their hydrogen or colouring element by the twofold affinities of the chlorine
and oxygen for it.
Hence chlorine as a bleaching agent, requires to be tempered by the quiescent affinity
of some alkaline base, potash or lime. Malaria, or morbific and putrescent miasmata,
consists chiefly of hydrogenous matter as their basis, and are best counteracted by
chlorine, where it can be conveniently applied.
Chlorides of Potash, Soda, and Lime.-These are the most important preparations
through which chlorine exercises its peculiar powers upon the objects of manufactures.
When a weak solution of caustic potash or soda is saturated with chlorine, it affords a
bleaching liquor which is still used by some bleachers and calico-printers for their most
delicate processes; but the price of the alkalis has led to the disuse of these chlorides as
a general means. and has occasioned an extensive employment of chloride of lime. Upon
the manufacture of this interesting compound I made an elaborate series of experiments,
several years ago, and published the results in the 13th volume of Brande's Journal for
April, 1822. I have no reason to suppose, from any thing that has been published since,
that the processes there described have been essentially improved, or that any errors,
either theoretical or practical, of any moment, exist in that memoir. I shall therefore
first present my readers with a brief abstract of it, and then make such observations as
subsequent inquiries suggest.
In the researches which I made, at many different times, upon the nature of the chloride of lime, I generally sought to combine the information flowing from both synthesis
and analysis; that is, I first converted a known portion of hydrate of lime into bleaching-powder, and then subjected this chloride to analysis.
Two hundred grains of the atomic proto-hydrate of pure lime were put into a glass
globe, which was kept cold by immersion in a body of water at 50~. A stream of
chlorine, after being washed in water of the same temperature in another glass globe,
connected to the former by a long narrow glass tube, was passed over the calcareous
hydrate. The globe with the lime was detached from the rest of the apparatus from
time to time, that the process might be suspended as soon as the augmentation of weight
ceased. This happened when the 200 grains of hydrate, containing 151-9 of lime, had
absorbed 130 grains of chlorine. By one analytical experiment, it was found that dilute
muriatic acid expelled from 50 grains of the chloride, 20 grains of chlorine, or 40 per
cent.; and by another, from 40 grains, 16'25 of gas, which is 40'6 per cent. From the
residuum of the first 39-7 grail of carbonate of lime were obtained by carbonate of
ammonia; from that of the second, 36'6 of ignited muriate of lime. The whole results
are therefore as follows:Synthesis.   1st Analysis.   2d Analysis.  Mean
Chlorine - -    39-39         40-00        40-62         40-31
Lime- - - -      4600         44-74         46-07        45-40
Water  - - -     1460         15-26         13-31        14-28
100-00       100-00       100-00        100-00




408                         CHLORIDE OF LIME.
Though the heat generated by the action of the dilute acid had carried off in the
analytical experiments a small portion of moisture with the chlorine, yet their accordance
with the synthetic experiment is sufficiently good to confirm the general results. The
above powder appears to have been a pure chloride, without any mixture of muriate.
But it exhibits no atomic constitution in its proportions.
To 200 grains of that hydrate of lime 30 grains of water being added, the powder
was subjected to a stream of chlorine in the above way, till saturation took place. Its
increase of weight was 150 grains.
It ought to be remarked, that in this and the preceding experiment, there was no
appreciable pneumatic pressure employed to aid the condensation of chlorine. In the
last case, we see that the addition of 30 grains of water has enabled the lime to absorb
20 grains more of chlorine, being altogether a quantity of gas nearly equal to that of
the dry lime. Thus, an atom of lime seems associated with seven ninths of an atom of
chlorine.  Analysis by muriatic acid confirmed this composition.  It gave
Chlorine    -    89 5 = 51 8 cubic inches.
Lime        -    39 9
Water       -    20-6
100-0
A great variety of apparatus has been at different times contrived for favouring the
combination of chlorine with the slaked lime for the purposes of commerce. One of
the most ingenious forms is that of a cylinder, or barrel, furnished with narrow wooden
shelves within, and suspended on a hollow axis, by which the chlorine was admitted, and
round which the barrel was made to revolve. By this mode of agitation, the lime-dust,
being exposed on the most extensive surface, was speedily impregnated with the gas, to
the requisite degree. Such a mechanism I saw at MM. Oberkampf and Widmer's celebrated fabrique de toiles peintes, at Jouy, in 1816. But this is a costly refinement, inadmissible on the largest scale of British manufacture.  The simplest, and, in my
opinion, the best construction for subjecting lime-powder to chlorine, is a large chamber
8 or 9 feet high, built of silicious sandstone, having the joints of the masonry secured
with a cement composed of pitch, resin, and dry gypsum  in equal parts. A door is
fitted into it at one end, which can be made air-tight by strips of cloth and clay-lute.
A window on each side enables the operator to judge how the impregnation goes on by
the color of the air, and also gives light for making the arrangements within at the
commencement of the process. As water lutes are incomparably superior to all others,
where the pneumatic pressure is small, I would recommend a large valve or door on this
principle to be male in the roof, and two tunnels of considerable width at the bottom of
each side wall. The three covers could be simultaneously lifted off by cords passing
over a pulley, without the necessity of the workman approaching the deleterious gas,
when the apartment is to be opened. A great number of wooden shelves, or rather
trays, 8 or 10 feet long, 2 feet broad, and 1 inch deep, are provided to receive the riddled
slaked lime, containing generally about 2 atoms of lime to 3 of water. These shelves
are piled one over another in the chamber, to the height of 5 or 6 feet, cross bars below
each keeping them about an inch asunder, that the gas may have free room to circulate
over the surface of the calcareous hydrate.
The alembics for generating the chlorine, which are usually nearly spherical, are in
some cases made entirely of lead, in others of two hemispheres, joined together in the
middle, the upper hemisphere being lead, the under one cast-iron. The first kind of
alembic is enclosed, for two thirds from its bottom, in a leaden or iron case, the interval
of two inches between the two being destined to receive steam from an adjoining boiler.
Those which consist below of cast-iron have their bottom  directly exposed to a very
gentle fire; round the outer edge of the iron hemisphere a groove is cast, into which the
under edge of the leaden hemisphere fits, the joint being rendered air-tight by Roman
or patent cement. In this leaden dome there are four apertures, each secured by a waterlute. The first opening is about 10 or 12 inches square, and is shut with a leaden valve,
with incurvated edges, that fit into the water channel at the margin of the hole. It is
destined for the admission of a workman to rectify any derangement in the apparatus of
rotation, or to detach hard concretions of salt from the bottom.
The second aperture is in the centre of the top. Here a tube of lead is fixed, which
descends nearly to the bottom, and down through which the vertical axis passes. To
its lower end the cross bars of iron, or of wood, sheathed with lead, are attached, by
whose revolution the materials receive the proper agitation for mixing the dense manganese with the sulphuric acid and salt. The motion is communicated either by the hand
of a workman applied from time to time to a winch at top, or it is given by connecting
the axis with wheel work, impelled by a stream of water or a steam-engine. The third




CHLORIDE OF LIME.                                409
opening admits the syphon-formed funnel, through which the sulphuric acid is introduced;
and the fourth is the orifice of the eduction-pipe.
Manufacturers differ much from each other in the proportion of their materials for
generating chlorine. In general, 10 cwt. of salt are mixed with from 10 to 14 cwt. of
manganese, to which mixture, after its introduction into the alembic, from 12 to 14 cwt.
of sulphuric acid are added in successive portions. That quantity of oil of vitriol must,
however, be previously diluted with water, till its specific gravity becomes about 1*6.
But, indeed, this dilution is seldom actually made, for the manufacturer of bleachingpowder almost always prepares his own sulphuric acid for the purpose, and therefore
carries its concentration no higher in the leaden boilers than the density of 1*65, which
from my table of sulphuric acid, indicates " of its weight of water, and therefore I
more of such acid must be used.
The fourth aperture, I have said, admits the eduction pipe. This pipe is afterwards
conveyed into a leaden chest or cylinder, in which all the other eduction pipes also
terminate. They are connected with it simply by water-lutes, having a hydrostatic
pressure of 2 or 3 inches. In this general diversorium the chlorine is washed from
adhering muriatic acid, by passing through a little water, in which each tube is immersed, and from this the gas is let off by a pretty large leaden tube, into the combination room. It usually enters in the top of the ceiling, whence it diffuses its heavy gas
equally round.
Four days are required, at the ordinary rate of working, for making good marketable
bleaching-powder. A more rapid formation would merely endanger an elevation of
temperature, productive of muriate of lime, at the expense of the bleaching quality. But
skilful manufacturers use here an alternating process. They pile up, first of all, the
wooden trays only in alternate shelves in each column. At the end of two days the
distillation is intermitted, and the chamber is laid open. After two hours the workman
enters, to introduce the alternate trays covered with fresh hydrate of lime, and at the
same time rakes up thoroughly the half-formed chloride in the others. The door is then
secured, and the chamber, after being filled for two days more with chlorine, is again
opened, to allow the first set of trays to be removed, and to be replaced by others, con
taiing fresh hydrate, as before. Thus the process is conducted in regular alternation:
thus, to my knowledge, very superior bleaching-powder is manufactured, and thus the
chlorine may be suffered to enter in a pretty uniform stream. But for this judicious
plan, as the hydrate advances in impregnation, its faculty of absorption becoming
diminished, it would be requisite to diminish proportionately the evolution of chlorine,
or to allow the excess to escape, to the great loss of the proprietor, and, what is of more
consequence, to the great detriment of the health of the workmen.
The manufacturer generally reckons on obtaining from one ton of rock-salt, employed
as above, a ton and a half of good bleaching-powder. But the following analysis of the
operation will show that he ought to obtain two tons.
When a mixture of sulphuric acid, common salt, and black oxyde of manganese are
the ingredients used, as by the manufacturer of bleaching-powder, the absolute proportions are, upon the oxygen scale of equivalents: —
1 atom muriate of soda    -    -   7*5             29-70           100'0
1 atom peroxyde of manganese    -   5'5            21'78            73'3
2 atoms oil of vitriol 1-846   -    -   12-25      48-52            163-3
25.25         100.00
And the products ought to be; -
Chlorine disengaged   -       - 1 atom.           4.5          1782
Sulphate of soda     -        - 1 -               90           35-64
Proto-sulphate of manganese   - 1 -               95           37*62
Water       -        -       -2  -               2-25           8-92
25-25        100-00
These proportions are, however, very different from those employed by many, nay,
I believe by all manufacturers; and they ought tc be so, on account of the impurity
of their oxyde of manganese. Yet making allowance for this, I am afraid that many of them
commit great errors in the relative quantities of their materials.
From the preceding computation, it is evident that 1 ton of salt with 1 ton of the
above native oxyde of manganese properly treated, would yield 0-59 of a ton of chlorine,
which would impregnate 1-41 tons of slaked lime, producing 2 tons of bleaching-powder,
stronger than the average of the commercial specimens; or allowing for a little loss,
which is unavoidable, would afford 2 tons of ordinary powder, with a little more slaked
lime.
Fig. 354 represents a retort of lead, well adapted to the evolution of chlorine from the
mixture of salt, manganese, and sulphuric acid, or from manganese and muriatic acid.
VOL. L                              3 G




410                          CHLORIDE OF LIME.
The interior vessel is cast in lead, and it has round its bottom part a cast-iron steam
case. The salt and manganese are introduced by the aperture c, and the sulphuric
364
i,\.
K.
acid by the syphon funnel F. The contact of these three substances is continually
renewed by the agitator or stirrer B, which consists of wrought or cast iron sheathed
with lead. e is the gas discharge pipe. The residuums are drawn off by the bottom
discharge pipe o. The heating case receives its steam by the pipe h.
The chlorine gas,fig. 355. is conveyed from the retort B, into the chamber i, by the tube
E  E. This chamberis divided into four compartments, to receive the gas disengaged
from four retorts, like the above. The bottom of it is covered with a stratum three
or four inches thick of quicklime, newly slaked and sifted, which is stirred about from
time to time, by the rakes L L L L. When the saturation is sufficient, the chloride of
lime is taken out by the doors K xK  x. The size of this apparatus allows 2 cwt. of
manganese, and its equivalent quantity of salt and sulphuric acid, or of muriatic acid,
to be introduced at once into the retort. D is the handle of the agitator.
The same form  of retort will suit perfectly well to prepare chlorine for making
liquid chloride of lime, which is preferred by many bleachers and calico-printers who
have conveniences for preparing it themselves. The most concentrated solutions of the
dry chloride of lime do not mark more than 6~ B. (sp. gray. 1-04), and discolour only
60 volumes of Gay Lussac's solution of indigo, whilst the chloride made in the humid
way marks from 80 to 9~ B. (about 1-060), and discolours 80 volumes of the same
solution.
In the chloride of lime apparatus, most generally used by the skilful calico-printers
of Miilhausen, the mixture of muriatic acid and manganese is put into glass globes,
with long necks, heated upon a sand-bath. The chlorine is conveyed by glass tubes
into a cylindrical stone cistern, containing milk of lime. The furnace of the sandbaths is made of cast iron, and has brick partitions, to give each retort its own fire.
The smoke of all these fires goes off by a flue into sheet iron pipes. The cistern is
made,of siliceous sandstone. Its cover is of wood, coated with a resinous cement; and
it fits at its edges into grooves cut in the stone. A wheel serves to agitate the liquid
continually; its paddles being kept at two inches distance from the sides of the cistern.
The milk of lime is introduced by a funnel, and the chloride is drawn off by a
discharge pipe. I think the lead retort and agitator used in this country greatly
preferable to the experimental laboratory plan described above. In all such apparatus we should avoid giving any pressure to the tubes or vessels, and should not
therefore dip the extremities of the gas pipes beneath the surface of the liquid, but
rather facilitate the combination of the chlorine and the lime, by enlarging the surfaces
of contact and by agitating. Intermediate vessels containing water, or the chemical
cascade of M. Clement, are very useful for absorbing any muriatic acid which may
be disengaged along with the chlorine, and thereby preventing the needless formation of
muriate of lime in the chambers or cisterns of impregnation.
When the solution of the chlorine of lime is mixed with hydrate of lime, it bears,
without decomposing, a pretty high temperature, provided it be not too long continued;
it may even, in certain cases, be raised too near the boiling point without suffering a
marked loss of its discolouring power; but when the chloride is deprived of that
excess of lime, it is decomposed in a short time, even at a heat of 110~ F.
When chlorine is admitted to milk of lime, it infallibly produces some muriate of
lime; but the quantity is kept at a minimum by constantly prescribing an excess of




CHLORIDE OF LIME.                              411
lime to the gas with the agitator, and by keeping the temperature as low as possible.
Hence the influx of gas should not be so rapid as to generate much heat. An automatic
agitator, moved bysteam or water power, is therefore much better than one driven by
the hand of the operator, who is apt to intermit his labours. If the liquor becomes hot
at the end of the process, it should be immediately drawn off into large stone bottles,
and cooled. The rose-colour which sometimes supervenes is due to a minute quantity
of manganese. The strongest liquid chloride of lime that can be prepared will not discolour more than 80 times its volume of Gay Lussac's indigo test.
On acting upon cotton cloth with a concentrated solution of chloride of lime, at from
1100 to 120~ F., pure carbonic acid gas is disengaged, and the texture of the cloth is
injured. Here the hydrogen of the water and the cotton being seized by the chlorine,
the liberated oxygen combines with the carbon to form carbonic acid. In the discharge
troughs, where printed calicoes are passed through strong solutions of chloride of lime,
stalactitic crusts of carbonate of lime come to be formed in this way.
The chlorometre of Gay Lussac consists of a test solution of indigo and a graduated
tube. One part of the best indigo, passed through a silk sieve, is to be dissolved in
nine parts of concentrated sulphuric acid, by the aid of a water-bath heat applied for
six hours. The sulphate of indigo is now to be diffused through such a body of water
that one volume of chlorine gas shall discolour exactly ten times its volume of this dilute
solution. The test liquor should be protected from the agency of light.
Mr. Crum, of Thorniebank, near Glasgow, has lately modified Dr. Dalton's copperas
test for chloride of lime, and made it convenient to a practical man. The doctor justly
considered that the more chlorine any bleaching powder contains, the more of the green
sulphate of iron will it convert into the red sulphate, so that we have only to add successive portions of the chloride to a given weight of the dissolved copperas, and note
the point at which all the iron gets peroxidized. See BLEACHING.
Besides the method of analysis already quoted from my memoir on the manufacture
of the chloride of lime, another occurred to me long ago, which I often practised as an
easy and expeditious test. Chlorine decomposes ammonia. If therefore water of ammonia, faintly tinged with litmus, be added slowly to a solution of a given weight of
chloride of lime, the colour will continue to disappear till the chlorine be all neutralized
by the reaction of the hydrogen of the ammonia. The quantity of liquid ammonia
of a certain strength requisite to neutralize, in this way, a certain volume, say, one
cubic inch, or a thousand grain measures, of chlorine gas, may be assumed as the standard of such a chlorometer. As chlorine or chloride of lime, when mixed with water of
ammonia, causes the disengagement of azote, the quantity of this gas evolved may
also be made the foundation of an accurate and convenient chlorometer. The two substances should be mixed over mercury, in a graduated syphon tube. The shut end A
and the open end B are both graduated to one scale; for example, to hundredths of a
cubic inch, or to grain or 10 grain measures. The tube is to be filled with
A     mercury, and then 10 measures of it are to be displaced at the open end by
inserting a wooden plug. This space being filled with the solution of chloride of lime, is to be turned up into the shut end by covering the open end
with the finger, and inverting the tube; a few drops of water may be sent
through to wash the mercury. The ammonia being now let up will cause a:3   reaction, and evolve a quantity of azote, equivalent to the chlorine present
The action may be quickened by holding the sealed end of the tube obliquely
over a lamp heat. The mercury is protected from the chlorine by the ammonia; and should any notion be entertained of such an action, the ammonia
may be let up first. I have made innumerable researches over mercury with
a detached apparatus of that kind, which combines precision with rapidity
of result. It was by a similar mercurial syphon that I analysed the carbonates, as described in the first edition of my Dictionary of Chemistry, 32 years ago.
M. Gay Lussac takes, as the basis of his indigo chlorometer, the fact, that one pound
of pure crystallized peroxide of manganese is capable of affording, with muriatic acid,
0-7964 parts of a pound of chlorine; or one kilogramme yields 2511 litres; that is,
one pound yields 2511 pound measures. Hence 3'98 grammes of that manganese are
capable of affording 1000 gramme measures, or I litre of chlorine; or, in round numbers, 4 grains will yield 1000 grain measures. This quantity of gas being received
into that volume of milk of lime, constitutes therefore Gay Lussac's primary standard.
The small retort in which the manganese and muriatic acid are put ought to be heated
to ebullition, to discharge every particle of chlorine. To prevent the manganese, in
this experiment, from sticking to the bottom in a cake, it has been proposed to mix it
previously with a little plumbago. See CHLOROMETRY.
For preparing the chlorides of potash and soda, the same apparatus may be
employed as for the liquid chloride of lime. The alkaline solutions should be weak,
containing not more than a pound to the gallon of water. Potash liquor, saturated
3G2




412                        CHLORIDE OF LIME.
with chlorine, is much employed at Paris for whitening linen, under the name of the
water of Javelle, the place where it was first made as a manufacture. One hundred
parts of chlorine are said to saturate 133 parts of pure potash, and 195 of the carbonate:
but the latter should not be used for preparing the bleaching fluid, as the carbonic
acid resists the combination of the chlorine. A chloride of carbonate of soda has
been lately recommended as a disinfecting substance against contagious miasmata or
fomites. One hundred parts of chlorine will saturate 150 of the dry carbonate, and
405 of the crystallized. M. Payen prepares this medicinal chloride, by adding 138
parts of carbonate of soda to a liquid, consisting of water 1800, chloride of lime 100,
at 98~ of strength, by Gay Lussac's standard. The chloride of lime is to be dissolved,
and the sediment well washed; the carbonate of soda, dissolved by heat, is to be poured
into the solution, the precipitate allowed to subside, the clear fluid decanted, and the
solid matter washed upon a filter. The collected solutions are neutral chloride of soda.
Sixty-two parts of the carbonate of soda are then to be dissolved in the remainder of
the water, and added to the preparation; the whole being thug filtered, a limpid liquid
is obtained, indicating 5~ by the hydrometer of Baume.
The chloride of magnesia was long ago proposed by Sir H. Davy for bleaching
linen, as being preferable to chloride of lime, because the resulting muriate of magnesia was not injurious to the fibre of cloth, as muriate of lime may be, under certain
circumstances.  I prepared a quantity of chloride of magnesia, by exposing a hydrate
of that earth in the chlorine chamber of a large manufactory of chloride of lime at
Glasgow, and obtained a compound possessed of considerable discolouring powers;
but I found that the chlorine was so feebly saturated by the base, that it destroyed the
colours of fast-dyed calicoes as readily as chlorine gas or chlorine water did, and was
therefore dangerous for common bleaching, and destructive in clearing the grounds of
printed goods, which is one of the most valuable applications of the calcareous and
alkaline chlorides. The occasion of my making these experiments was the importation
of a considerable quantity of magnesite, or native atomic carbonate of magnesia, from
the district of Madras, by an enterprising friend of mine. Encouraged by the encomiums bestowed on the chloride of magnesia by many chemical writers, he expected
to have benefited both the country and himself, by bringing home the earthy base of
that compound, at a moderate price; but was disappointed to his cost.
Dr. Thomson is of opinion that the bleaching compound of lime and chlorine is not
a chloride of lime, but a combination of chlorous acid with lime and of chlorine with
calcium: consisting in its most concentrated state of
3 atoms of chloride of calcium = 21
1 atom of chlorite of lime - = 11
32
So that about one-third of the weight is chlorite of lime, to which alone the bleaching
powers of the substance are owing. He admits a fact, rather inconsistent with this
opinion, that bleaching powder does not attract moisture from the atmosphere with
nearly so much rapidity as might be expected from a mixture containing two-thirds of
its weight of so deliquescent a salt as muriate of lime; unless this indeed be prevented
by the chloride and chlorite being united into a double salt, which is a mere conjecture
without either proof or analogy. And further, when dilute sulphuric or muriatic acid
is poured upon bleaching powder, a profusion of chlorine is given out immediately,
which he also admits to be inconsistent with the notion of its being a mixture of chloride
of calcium and chlorite of lime, for no such evolution takes place when the above acids
are mixed with solutions of chloride of calcium and chlorate of potash. Though I am
of opinion that bleaching powder is simply a chloride of lime, in which the lime corresponds to the water in the aqueous chlorine, yet I cannot see the truth or appositeness of his last reason, because chlorine is certainly given out when chlorate of potash
is acted upon by dilute muriatic acid, as any man may prove by adding to a mixture
of these two substances a vegetable colour; for it will be speedily blanched. Dr. Thomson considers the chloride which is at present made in Mr. Tennant's great factory, as
containing one atom of chlorine associated with one atom of lime, or, taking his numbers, as consisting of
Hydrate of lime 4'625
Chlorine   -   4'5
or nearly equal weights of the chlorine and the base; indicating a surprising degree
of excellence in the preparation. The average commercial samples of bleaching powder from different factories which I examined some years ago, did not possess nearly
that strength; but varied in their quantity of chlorine from 20 to 28 per cent. In my
synthetic experiments related above, the greatest quantity of chlorine that would combine with the atomic hydrate of lime was in the proportion of 130 to 200; but there is




CHLORINE AND ALKALI.                                 418
no doubt that, if the lime contains additional water, it will condense more gas. I have
never seen a chloride of lime of the strength mentioned by Dr. Thomson, and I should
think there must be some fallacy in his statements. I have recorded in the paper above
quoted an experiment which proves that, with additional moisture, a chloride of lime
may be obtained of the following composition:Chlorine 39'5
Lime  - 39'9
Water - 20-6
100-0
In the article BLEACHING, of the Encyclopaedia Britannica, Dr. Thomson deduces,
from a test trial of Mr. Crum, that the best bleaching powder is a compound of 1 atom
chlorite of lime = 11, 3 atoms chloride of calcium = 21, and 3 atoms of water = 9.
"But," adds he, "in general the whole lime is not accurately saturated with chlorine.
Accordingly, when the bleaching powder is dissolved in water a small residue almost
always remains undissolved. Unless the powder be fresh made, a portion of chlorite
is always converted into chloride of calcium. It is probable, therefore, that the best
bleaching powder, as it comes into the hands of the bleachers, consists of
1 atom chlorite of lime  - 11
3 atoms chloride of calcium 21
6 atoms water -   -   -  6'75
Impurity    -   -    -  2-25
41-00
If we consider the bleaching powder as a compound of chlorine and lime, our mode of
calculating will not be altered. Instead of 1 atom chlorite of lime, and 3 atoms chloride
of calcium, we shall have 4 atoms chloride of lime, 6 atoms water, and 2'25 of impurity
as before."  In such ambiguity does this able chemist place this interesting compound,
for theoretical reasons, of which I cannot see the value. Surely there is no difficulty in
conceiving chlorine to exercise a direct attractive force towards the hydrate of lime, as it
is known to do towards each of its elementary constituents, the oxygen and the calcium.
Such refinements as the preceding tend merely to mystify a plain matter. Even the
chlorous acid here brought into play to form the ideal chlorite, is by his own admission
a hypothetical being. "When chlorate of potash," says Dr. Thomson, "is mixed with
sulphuric acid, and made into small balls the size of a pea, if we expose these balls to a
heat somewhat lower than that of boiling water, a bright yellowish green gas separates,
which may be received over mercury. Its smell is peculiar and aromatic. Water absorbs
at least seven times its volume of it. It destroys vegetable blues. Its constituents are,
1 volume chlorine 2'5  or 4'5
2 volumes oxygen 2-222 or 4.
Thus this compound consists in weight of chlorine 4-5, oxygen 4- 8'5. It has been
called quateroxide of chlorine, but it is more probably a teroxide. It has been supposed
by some to possess acid properties, and has therefore been called chlorous acid. But
this is only as yet a hypothesis.
Surely this, by the doctor's own showing, is very slender authority for renouncing our
long-received doctrines concerning the constitution of bleaching powder. I shall conclude by remarking that the ultra-atomists are now in a dilemma about this substance;
M. Welter, and many French chemists, calling it a sub-chloride of I atom of chlorine
to 2 atoms of lime, and Dr. Thomson showing that Mr. Tennant, the greatest and best
manufacturer of it, has produced it in the state of a chloride, or 1 atom of each. The
fact is, in chloride of lime, as in water of ammonia, alcohol, and muriatic acid, there
is no sufficient reason for definite proportion in any term short of saturation, and therefore we shall find that chloride in every gradation of strength from I per cent. of
chlorine up to 40 per cent.-the strongest which I succeeded in preparing, though I
passed a constant stream of chlorine in great excess over a pure hydrate of lime for
upwards of 24 hours, with frequent renewal of the surface; indeed, till it refused to
absorb aly more gas, as indicated by its remaining stationary in weight.
CHLORINE AND ALKALI (Manufacture of). Mr. Tennant Dunlop of Glasgow
obtained, in March, 1847, a patent for an improved method of producing chlorine. The
process he usually adopts is to bring together common salt, nitrate of soda, or nitric acid
and sulphuric acid, in suitable proportions; heat being then applied, chlorine or an
oxide of azote and muriatic acid are evolved; these gases are caused to pass through
a condenser charged with sulphuric acid of sufficient strength to absorb the oxide of
azote; and then the chlorine and muriatic acid are separated by means of water.
In applying the product resulting from the above process, he obtains nitric acid from




414                            CHLOROMETRY.
the sulphuric acid charged with oxide of azote, which is true nitrous sulphuric acid.
This is effected by the aid of atmospheric air, steam, and water. He introduces the
nitrous sulphuric acid into a suitable vessel, and by the addition of water and heat, he
effects the disengagement of oxide of azote, which being caused to traverse a condenser
with a sufficient quantity of air and steam or water, is by this means transformed into
nitric acid. This acid may be again used in the manufacture of chlorine, and again
recovered, and so on. Sometimes, instead of treating the nitrous sulphuric acid as just
described, the patentee causes the oxide of azote to be evolved, and to pass into a chamber into which a current of sulphuretted hydrogen is streaming; by which means
sulphate of ammonia is obtained and sulphur deposited.
CHLOROMETRY; Chlorometrie, is the name given by the French to the process for
testing the decoloring power of any combination of chlorine, but especially of the commercial articles, the chlorides of lime, potash, and soda. M. Gay Lussac proposed many
years ago the following graduated method of applying indigo to this purpose. As indigo
varies much in its dyeing quality, and of consequence in the proportion of chlorine required for its decoloration, he assumes as the unity of blanching power, one litre of chlorine gas, measured at the mean pressure of 29*6 inches, and at the temperature of melting
ice. This volume of gas, when combined with a determinate quantity of water, is employed to test the standard solution of indigo. For this purpose a solution in sulphuric
acid of any sample of indigo is taken, and diluted with water to such a degree that 10
measures of it, in a graduated tube, are decolored by that one measure of combined chlorine gas. Each measure of indigo solution so destroyed is called a degree, and this measure being divided into five parts, the real test of chlorine is given to fiftieths, which is
sufficiently nice. For the standard of the assays, a chloride of lime as pure and fully
saturated as possible is taken, and dissolved in such a quantity of water, that the solution
shall contain, or be equivalent to, one volume of chlorine gas. Calculation proves that
this condition is exactly fulfilled by dissolving 4938 grammes of the said chloride in half a
litre of water; or in English measures, 5 gr. very nearly in 500 grain measures of water.
This solution, which serves for a type, indicates 100 in the assay, or proof; that is to say,
each single volume destroys the color of 10 volumes of the dilute indigo solution. It may
be remarked that a greater degree of precision is in general attainable with a weak solution of chlorine or a chloride, for example at 4~ or 5~, than with one much stronger;
consequently if, after a preliminary trial, the standard considerably exceeds 10~, a given
volume of water must be added to the solution, and then the above proof must be taken.
If the volume of water added was double, the number of degrees afterward found must
be tripled, to obtain the true title of the chloride. It is, however, to be observed that
the degree of decoloration varies with the time taken in making the mixture; the more
slowly the chlorine is added to the indigo, the less of it escapes into the atmosphere,
and the more effective it becomes in destroying the color.  The best mode of obtaining comparable results, is to pour suddenly into the test quantity of chlorine the
whole volume of tne indigo solution likely to be decolored; but it is requisite to find approximately beforehand, what quantity of indigo-blue will probably be destroyed.
When it comes to the verge of destruction, it is green; but yellowish-brown when entirely decomposed.
I have tried the indigo test in many ways, but never could confide in it. The sulphuric solution of indigo is very liable to change by keeping, and thus to lead to erroneous
results. The method of testing the chlorides by green sulphate of iron, described under
bleaching, is in my opinion preferable to the above.
M. Gay Lussac has recently proposed another proof of chlorine, founded on the same
principle as that by green vitriol, namely, the quantity of it requisite to raise a metallic
substance from a lower to a higher stage of oxydizement. He now prescribes as the
preferable plan of chlorometry, to pour very slowly from a graduated glass tube, a
standard solution of the chloride, to be tested upon a determinate quantity of arsenious
acid dissolved in muriatic acid, till the whole arsenious be converted into the arsenic
acid. The value of the chloride is greater the less of it is required to produce this effect.
It is easy to recognise, by a few drops of solution of indigo, the instant when all the
arsenious acid has disappeared; for then the blue tint is immediately effaced, and cannot be restored by the addition of a fresh drop of indigo solution.
In graduating the arsenical chlorometer, M. Gay Lussac takes for his unity the decolouring power of one volume of chlorine of 32~ Fahr., and divides it into 100 parts.
Suppose that we prepare a solution of chlorine containing its own volume of the gas, and
an arsenious solution, such that, under a like volume, the two solutions shall reciprocally destroy each other. Let us call the first, the normal solution of chlorine, and the
second, the normal arsenious solution. We shall fix at 10 grammes the weight of chloride of lime subjected to trial; and dissolve it in water, so that the total volume of the
solution shall be a litre (1000 grammes measure,) including the sediment. If we take
a constant volume of this solution, 10 centimetres cube (10 gramme measures,) for example, divided into 100 equal parts, and pour into it gradually the arsenious solution




CHOCOLATE.                                  415
(measured by like portions), tillthe chlorine be destroyed, the bleaching power will
be proportional to the number of portions of the arsenious solution, which the chloride
shall have required. If the chloride has destroyed 100 portions of the arsenious solution,
its title will be 100; if it has destroyed 80 portions, its title will be 80, &c., and so forth.
On pouring the acidulous arsenious solution into the chloride of lime, this will become
very acid; the chlorine will be emitted abundantly, and the proof will be quite incorrect.
If, on the contrary, we pour the solution of the chloride of lime into the arsenious solution, this evil will not occur, since the chlorine will always find plenty of arsenious acid
to act upon, whatever be the dilution of the one or the other; but in this case, the standard of the chlorine is not given directly, as it is in the inverse ratio of the number of
portions which are required to destroy the measures of the arsenious solution. If 50
portions of the chloride have been required, the proof will be 100X1-O —=200~; if 200
have been required, the proof will be 100Xo-0=50~, &c. This evil is not, however,
very serious, since we have merely to consult a table, in which we can find the proof
corresponding to each volume of the chloride employed for destroying the constant
measure of the arsenious solution. The arsenious solution should be slightly tinged with
sulphate of indigo, so as to show, by the disappearance of the color, the precise point or
instant of its saturation with chlorine, that is, its conversion into arsenic acid. If the
arsenious acid be pure, the normal solution may be made directly by dissolving 4'439
grammes of it in muriatic acid (free from sulphurous acid), and diluting the solution
till it occupies one litre, or 1000 grammes measure..lnnales de Chimie et Physique,
LX. 225.
CHOCOLATE is an alimentary preparation of very ancient use in Mexico, from
which country it was introduced into Europe by the Spaniards in the year 1520, and by
them long kept a secret from the rest of the world. Linnaeus was so fond of it, that he
gave the specific name, theobroma, food of the gods, to the cacao-tree which produced
it. The cacao-beans lie in a fruit somewhat like a cucumber, about 5 inches long and
3j thick, which contains from 20 to 30 beans, arranged in 5 regular rows with partitions between, and which are surrounded with a rose-colored spongy substance, like
that of water-melons. There are fruits, however, so large as to contain from 40 to 50
beans. Those grown in the West India islands, Berbice and Demarara, are much
smaller, and have only from 6 to 15; their development being less perfect than in
South America. After the maturation of the fruit, when their green color has changed
to a dark yellow, they are plucked, opened, their beans cleared of the marrowy substance, and spread out to dry in the air.  Like almonds, they are covered with a thin
skin or husk. In the West Indies they are immediately packed up for the market
when they are dried; but in the Caraccas they are subjected to a species of slight fermentation, by putting them into tubs or chests, covering them with boards or stones,
and turning them over every morning, to equalize the operation. They emit a good
deal of moisture, lose the natural bitterness and acrimony of their taste by this process,
as well as some of their weight. Instead of wooden tubs, pits or trenches dug in the
ground are sometimes had recourse to for curing the beans; an operation called earthing
(terrer). They are lastly exposed to the sun, and dried. The latter kind are reckoned
the best; being larger, rougher, of a darker brown color, and, when roasted, throw off
their husk readily, and split into several irregular fragments; they have an agreeable
mild bitterish taste, without acrimony. The Guiana and West India sorts are smaller,
flatter, smoother-skinned, lighter-colored, more sharp and bitter to the taste. They
answer best for the extraction of the butter of cacao, but afford a less aromatic and
agreeable chocolate. According to Lampadius, the kernels of the West India cacao
beans contain, in 100 parts, besides water, 53-1 of fat or oil, 16-7 of an albuminous
brown matter, which contains all the aroma of the bean, 10-91 of starch, 71 of gum or
mucilage, 0'9 of lignine, and 2-01 of a reddish dye stuff somewhat akin to the pigment of
cochineal. The husks form 12 per cent. of the weight of the beans; they contain no fat,
but, besides lignine, or woody fibre, which constitutes half their weight, they yield a
light brown mucilaginous extract by boiling in water. The fatty matter is of the consistence of tallow, white, of a mild agreeable taste, called butter of cacao, and not apt to
turn rancid by keeping. It melts only at 122~ Fahr., and should, therefore, make tolerable candles. It is soluble in boiling alcohol, but precipitates in the cold. It is
obtained by exposing the beans to strong pressure in canvas bags, after they have been
steamed or soaked in boiling water for some time. From 5 to 6 ounces of butter may
be thus obtained from a pound of cacao. It has a reddish tinge when first expressed
but it becomes white by boiling with water.
The beans, being freed from all spoiled and mouldy portions, are to be gently roasted
over a fire in an iron cylinder, with holes in its ends for allowing the vapours to escape;
the apparatus being similar to a coffee-roaster. When the aroma begins to be well
developed, the roasting is known to be finished; and the beans must be turned out,
cooled, and freed by fanning and sifting from their husks. The kernels are then




416                             CHOCOLATE.
to be converted into a paste, either by trituration in a mortar heated to 130~ F., or
by the following ingenious and powerful machine. The chocolate paste has usually
in France a little vanilla incorporated with it, and a considerable quantity of sugar,
which varies from one-third of its weight to equal parts. For a pound and a half of
cacao, one pod of vanilla is sufficient.  Chocolate paste improves in its flavour by
keeping, and should therefore be made in large quantities at a time. But the roasted
beans soon lose their aroma, if exposed to the air.
3567
- i
Fig. 357 represents the chocolate mill. Upon the sole A, made of marble, six conical
rollers B n, are made to run by the revolution of the upright axis or shaft q, driven by
the agency of the fly wheel E and bevel wheels 1 K. The sole A rests upon a strong
iron plate, which is heated by a small stove, introduced at the door H. The wooden
frame work F, forms a ledge, a few inches high, round the marble slab, to confine
the cocoa in the act of trituration. c is the hopper of the mill through which the
roasted beans are introduced to the action of the rollers, passing first into the flat
vessel n, to be thence evenly distributed.  After the cacao has received the first trituration, the paste is returned upon the slab, in order to be mixed with the proper quantity
of sugar, and vanilla, previously sliced and ground up with a little hard sugar. When
the chocolate is sufficiently worked, and while it is thin with the heat and trituration,
it must be put carefully into the proper moulds. If introduced too warm, it will be
apt to become damp and dull on the surface; and, if too cold, it will not take the proper
form. It must be previously well kneaded with the hands, to ensure the expulsion of
every air bubble.
In Barcelona, chocolate mills on this construction are very common, but they are
turned by a horse-gin set to work in the under story, corresponding to H in the above
fgure. The shaft G is, in this case, extended down through the marble slab, and is
surrounded:at its centre with a hoop to prevent the paste coming into contact with it.
Each of these horse-mills turns out about ten pounds of fine chocolate in the hour, from
a slab two feet seven inches in diameter.
Chocolate is flavoured with cinnamon and cloves, in several countries, instead of the
more expensive vanilla. In roasting the beans the heat should be at first very slow, to
give time to the humidity to escape; a quick fire hardens the surface, and injures the
process. In putting the paste into the tin plate, or other moulds, it must be well
shaken down to insure its filling up all the cavities, and giving the sharp and polished
impression so much admired by connoisseurs. Chocolate is sometimes adulterated
with starch; in which case it will form a pasty consistenced mass when treated with
boiling vwter. The harder the slab upon which the beans are triturated, the better;
and thence porphyry is far preferable to marble. The grinding rollers of the mill
should be made of iron, and kept very clean.
About eight years ago, samples of chocolate were sent to me for analysis, by
order of the Lords of the Admiralty. It was made at the victualling-yard, Deptford,
for the use of the Royal Navy, by the government chocolate mills, where about




CHOCOLATE.                                   417
400 tons are annually prepared, to be distributed to the sailors and convicts at the
rate of an ounce daily, and to be used at their breakfast. After taking the said chocolate for some time, men in several ships complained of its occasioning sickness,
vomiting, purging, and more serious maladies, terminating in a few cases fatally.  I
examined it with great care, but could find no injurious ingredient in it, and no
chemical alterations from the beans of the Guyaquil coco from. which it was manufactured. But I observed that it consisted of gritty grains, from very imperfect trituration or milling; that these grains were quite immiscible with water, like so much
fine gravel; that they contained many sharp spicula of the coco-bean husks, and that
hence, when swallowed, they were calculated to form  mechanically irritating lodgments in the villous coats of the stomach and bowels, whereby they could produce the
morbid effects certified by several naval surgeons.  It was, moreover, obvious that,
from the insoluble condition of the chocolate, it could be of little use as an article of
food, or as a demulcent substitute for milk, and that, in fact, three-fourths of it were,
on this account, an ineffective article of diet, or were wasted.
Having reported these results and opinions to the Lords of the Admiralty, they
were pleased after a few weeks' consideration, to request me to go down to the victualling-yard at Deptford, and superintend the preparation of a quantity of chocolate
in the best manner I could with the means there provided.  I accordingly repaired
thither on the 13th September, 1842, and experienced the utmost courtesy and cooperation from Sir John Hill, the Captain Superintendent, and his subordinate officers.
The coco-beans had been hitherto milled, after a slight roasting upon the sole of an
oat-kiln, along with their husks. As I was satisfied, from analysis, that the husks
were no better-food than saw-dust, and that they might cause irritation by their minute
spiculee left after grinding between rotating millstones, I set about a plan for shelling
them, but could find no piece of apparatus destined for the purpose. There was, however,' a pea-shelling mill, which had been used only for one day some years before, and
had stood ever since idle*, which, on being cleaned and having its millstones placed at
a proper distance, was found to answer pretty well. The beans for experiment, to the
amount of 6 cwt., had been previously roasted, under my care, at a well-regulated
heat, with much stirring, in the oat-kiln; and, on being cold, were run through the
shelling mill, which was put in communication with the fanners of the flour mill.
By this arrangement, the coco-beans were tolerably shelled, and the kernels separated
from their scaly husks. The weighings were accurately made.
6 cwt. of the Guyaquil coco      -         -    -672 bs.
Lost in roasting     -      -    43
shells       -      -    54   117
waste        -      -    20
Remained for milling       -      -   555
On the 14th September I made a report to the Lords of the Admiralty upon the
experiments of the 13th, of which the following is an outline.  After describing the
pains taken to regulate the roasting temperature, and to equalize the effect upon the
beans by moving them occasionally by a rake, I stated that the oat-kiln was not well
adapted to the purpose of roasting the coco, because it was impossible to turn the beans
regularly and continuously during the process, so that they could not be equally roasted,
and because it was an unwholesome operation for the workmen, who must go into a
chamber filled with noxious gases and fumes, to use the rakes.  When the door of the
kiln was shut, to allow the burned air from the fire below to draw up through it, mischief
might be done to the stratum of coco on the sole, and when the door was again opened,
fo permit a person to go in and stir, time and heat were wasted in replenishing the
chamber with fresh air.  I understood that a revolving-cylinder-roasting machine had
been made by Messrs. Rennie for the chocolate process at Deptford; but, for reasons
unknown to me, it had never been employed.
The diminution of weight by roasting and shelling may be estimated at about 17
per cent. A part of this loss is moisture, which should be completely expelled, to
prevent its causing the chocolate to become mouldy at sea. But a part of the defalcation was also due to some of the coco remaining in the crevices of the pea-splitting
mill and the fanners, which would not be observable if these were in constant employment.  I think, therefore, that the roasted kernels may be estimated in general at 85
per cent. of the raw beans.
Fig. 358 represents the chocolate mills at the victualling-yard, Deptford, as mounted
* It was found that peas in their skin kept better at sea than the split peas, and they were also preferred by the sailors in their natural state.
VOL. I.                               3H




418                              CHOCOLATE.
by the celebrated engineers, Messrs. Rennie. There are four double mill-stones
A, B, c, D, each three feet in diameter, of which the nether rests upon a bed of cast iron,
like a drum-head, kept at the temperature of about 220~ by the admission of steam
to the case below. Over each mill there is a feeding-hopper 1, 2, 3, 4, in communication by the pipes 5, 6, 7, 8, with the general reservoir E, charged upon the floor
above with cocoa through the funnel placed over it. The vertical shafts which turn
these mills are marked F, G, H, L; they are moved by the train of bevel-wheels above,
which are driven by an arm from the main shaft of the steam engine. Each mill can,
of course, be thrown in and out of geer at pleasure. At i, I, I, I, the discharge-spout
358 
~W~~~ I
I Ip                      31
is shown, which pours out the semi-fluid hot chocolate into shallow cylindrical tin pans,
capable of containing about nine pounds of chocolate each. These four mills are capable
of converting upwards of a ton of coco into good chocolate in a day, on the system of
double trituration which I adopted, and two tons on the former rough plan. I found
that the two stones of each mill had been placed so far asunder as would allow entire
beans to pass through, as spurious chocolate, at one operation; but the chocolate thus
discharged was in a very gritty state, whereas good chocolate in the liquefied state should




CHOCOLATE.                                  419
be smooth and plastic between the fingers, and spread upon the tongue without leaving
any granular particles in the mouth. To obtain such a result, I divided the milling
into two steps; for the first, two pairs of the stones, A and c, were set as close together
as for a paint mill (which they closely resemble), and the other two pairs, B and D,
were left at their ordinary distance. The paste obtained from the first set was transferred, while nearly liquid, into the hoppers of the second pairs, from which it issued at
the spouts as thin and smooth as honey from the comb. In subserviency to these experiments, I made an analysis of the Guyaquil coco, which I found to be composed as
follows:Concrete fat or butter of coco, dissolved out by ether   -  -       -37
Brown extractive, extractible by hot water, after the operation of ether  10
Ligneous matter, with some albumine   -       -      -       -      -30
Shells    -       -      -      -      -      -      -       -      -14
Water    -        -      -      -      -      -      -       -      -6
Loss      -       -      -      -                                       3
100
The solid fat of the coco should be most intimately combined by milling with the
extractive albumine, and ligneous matter, in order to render it capable of forming an
emulsion with water; and, indeed, on account of the large proportion of concrete fat
in the. beans some additional substance should be introduced to facilitate this emulsive
union of the fat and water. Sugar, gum, and starch or flour are well adapted for this
purpose.
Under this conviction, I employed in the first of these trials at Deptford, made
with one-half of the above roasted kernels = 277~ lbs., 5 per cent. of sugar, which was
first mixed upon a board with shovels, and the mixture was then put progressively into
the hoppers of the two mills B and D. The paste which ran out of their spouts was
immediately poured into the hoppers of A and c, from which it flowed smooth and very
thin into the concreting pans. The sugar supplied to me was exceedingly moist,
whereas it ought to be dry, like the bag sugar of the Mauritius. The other half
of the coco kernels was milled alone once by the ordinary mills B and D. I subjected next day samples of these two varieties of chocolate to the following examination, and compared them with the sample of chocolate as usually made at Deptford,
as also with a sample of chocolate sold by a respectable grocer in London. A like
quantity of these four samples was treated with eight times its weight of boiling water,
the diffusion well stirred, and then left to settle in a conical wineglass. Of the ordinary Deptford coco, four-fifths rapidly subsided in coarse grains, incapable of forming
any thing like an emulsion with water, and therefore of little or no avail in making a
breakfast beverage.
1. The single-milled chocolate made under my direction formed a smoother emul-.sion than the last, on account of the absence of the coco husks; but its particles were
gritty, and subsided very soon.
2. The sugar double-milled chocolate, on the contrary, formed a milky-looking
emulsion, which remained nearly uniform for some time, and then let fall a soft
mucilaginous deposit, free from grittiness.
3. The shop chocolate formed a very indifferent emulsion, though it was well milled,
because it contained evidently a large admixture of a coarse'branny flour, as is too
generally the case.
I have given small samples of the above No. 2. chocolate to various persons, and
they have considered it superior to what is usually sold by our grocers. The presence
of dry sugar in chocolate would also give it a conservative quality at sea, and prevent
it from getting musty.
The Lords of the Admiralty, after seeing the above two samples of chocolate and
my report thereupon, were, about six weeks afterwards, pleased to request me to make
at their victualling-yard further experiments in the preparation of chocolate; and they
indicated two modes, one of milling twice with the husks, and another of milling twice
without the husks; permitting me, at the same time, to mill a portion of the kernels
with 10 per cent. of sugar, and a second portion of the kernels with 5 per cent. of sugar
and 5 per cent. of the excellent flour used in making the biscuits for the royal navy.
On the 24th October, 1842, I accordingly performed these experiments upon 12 cwt.
of Guyaquil coco as carefully roasted as possible on the kiln.
The loss in drying and slightly roasting the 1344 lbs. of beans was 5 per cent.
1st experiment, 212 Ibs. of roasted coco, milled twice with the husks,
produced of chocolate      -                    -                209 lbs
2d experiment, 191 lbs. ditto, milled twice without husks    -     189
8H2




420                              CHROMATES.
3d experiment, 191 lbs. kernels, milled once along with 19 lbs. of sugar
=210 lbs.   -                                            -      - 212*
4th experiment, 573 lbs. of kernels, milled twice along with 68 lbs. of
flour and 34 of sugar =  675       -       -      -      -       - 669
Sample cakes of these four varieties of chocolate were subsequently sent to me for
examination and report. I found that the chocolate milled twice with the flour and
sugar formed a complete emulsion with hot water, bland and rich, like the best milk,
but the other three were much inferior in this respect.  Sugar alone, with proper
milling, would serve to give the kernels of well roasted coco a perfect emulsive property. Instead of merely milling with rotary stones, I would prefer, for the second
or finishing operation, a levigating mill, in which rollers would be rolled either backwards and forwards, or, when slightly conical, in a circular direction, over a plane
metallic, marble, or porphyry, slab as is now, indeed, very generally practised by the
trade.  The coco-beans should be well selected, without musty taint, and possessed
of a fine aroma, like the best of that imported from  Trinidad.  There is a great
deal of very coarse coco and chocolate on sale in London and in the provincial towns
of the United Kingdom.
Fig. 359. is an end view of one of the chocolate mills with
its mitre-gearing.  I consider the gritty chocolate  hitherto
359 made at Deptford as a very bad substitute for the chocolate
which was made from  coco by the sailors themselves with a
pestle and mortar.
In 1840 the coco cleared for consumption in the United Kingdom was:British plantation  -     - 2,041,492 lbs.
Foreign     -       -      -       186
Coco-nut husks and shells -   753,580
Chocolate and coco paste  -       2,066
Of the cocoa-nut shells, 612,122 lbs. were consumed in Ireland!
and less than 4000 lbs. of coco.
Of coco, 726,116 lbs. were consumed in her Majesty's navy.
How scurvily are the people of Ireland treated by their own
grocers! Upwards of 600,000 lbs. of worthless coco husks served
out to them along with only 4000 lbs. of coco-beans!
The quantity of coco imported in 1850 amounted to 4,478,252
cwts., and in 1851 to 6,773,960 cwts.; the entries for home consumption were 3,103,926 and 3,024,338 cwts.; the re-exports were 1,443,363 and 1,543,455 cwts.; and the
gross amount of duty 16,0591. and 15,7781. respectively.
CHROMATES, saline compounds of chromic acid with the basis.  See CHioMIUM.
Messrs. Swindell and Co. obtained a patent in November, 1850, for obtaining copper,
silver, and chrome, from their ores.
1st. To obtain copper and silver, or copper only, from their ores, according to this
invention, the ores are first roasted to drive off the sulphur, and convert the metals to
the state of oxides, after which the prepared ores are placed in tanks, and a solution
of ammonia or its salts, of a strength of about 0'980, pumped on in sufficient quantity
to saturate them. This solution is removed at the expiration of twelve to twenty-four
hours, and will be found saturated with the metallic oxides, which are to be dissolved
in boiling water and precipitated-the silver by hydrochloric, and the copper by
hydrosulphuric acids or otherwise.
2nd. The ore from which zinc is obtained is the native sulphuret, which is mixed
with about its own weight of common salt (for which muriate of potash, or of any earth,
may be substituted), and exposed in a calcining furnace to a slow protracted heat,
until all the sulphur present is converted into sulphuric acid. The products of this
operation will be sulphate of soda, muriate of zinc, and muriate of iron, which are to
be dissolved out in boiling water, and the two latter precipitated by lime, or other
means, after the sulphate of soda has been separated in the usual manner. The oxide
of zinc, when thus precipitated, may be smelted in the usual way.
In treating chromium (chromite of iron), the ore is pulverized and mixed with
common salt, muriate of potash, or hydrate of lime, and exposed in a reverberatory
furnace to a red or even a white heat, the mixture being stirred every ten or fifteen
minutes, and steam at a very elevated temperature introduced during the operation,.util the desired effect is obtained, which may be ascertained by withdrawing a portion
* This small excess proceeded from a residue of the last experiment.




CHROMIUM.                                      421
from the fhrnace and testing it, as customary.  The products of this operation are
finally treated in the manner usual for chromic and bichromic salts.
The mixture of chromium and common salt produces chromate of soda, the greater
portion, or perhaps all of the iron contained in the chromium being absorbed by the
hydrochloric acid evolved from the salt, and carried off in the form of sesquichloride of
iron. From the first mixture is manufactured pure bichromate of soda, which, by the
addition of hydrochloric acid, may be converted to chlorochromate; and from the last,
or lime mixture, is produced a chromate of that earth, from which, by the addition of
soda or potash, there may be obtained a compound salt, which, with those previously
mentioned, may be advantageously employed in the operation specified in the title.
CHROMIC ACID. To a boiling saturated solution of bichromate of potash, add as
much oil of vitrol as will convert the potash into a bisulphate.  Let the whole cool,
and be then washed with a little water, and stirred, when the liquid decanted from the
granular mass will be nearly pure chromic acid.
The solution of chromic acid in oil of vitriol is preferable as an oxidizing agent to
every other at present known.  See CHROMIUM.
CHROMIUM.  The only ore of this metal, which occurs in sufficient abundance
for the purposes of art, is the octohedral chrome-ore, commonly called chromate of iron,
though it is rather a compound of the oxydes of chromium and iron. The fracture of
this mineral is uneven; its lustre imperfect metallic; its color between iron-black and
brownish-black, and its streak brown. Its specific gravity, in the purest state, rises
to 4-5; but the usual chrome-ore found in the market varies from 3 to 4. According
to Klaproth, this ore consists of oxyde of chromium, 43; protoxyde of iron, 34'7;
alumina, 20'3; and silica, 2; but Vauquelin's analysis of another specimen gave as
above, respectively, 55'5, 33, 6, and 2. It is infusible before the blowpipe; but it acts
upon the magnetic needle, after having been exposed to the reducing smoky flame. It
is entirely soluble in borax, at a high blowpipe heat, and imparts to it a beautiful green
color.
Chrome-ore is found at the Bare Hills, near Baltimore, in Maryland; in the Shetland
Isles, Unst and Fetlar; the department of Var, in France, in small quantity; and near
Portsoy, in Banffshire; as also in Silesia and Bohemia.
The chief application of this ore is to the production of chromate of potash, from
which salt the various other preparations of this metal used in the arts are obtained.
The ore, freed, as well as possible, from its gangue, is reduced to a fine powder, by
being ground in a mill under ponderous edge-wheels, and sifted. It is then mixed
with one third or one half its weight of coarsely bruised nitre, and exposed to a
powerful heat, for several hours, on a reverberatory hearth, where it is stirred about
occasionally. In the large manufactories of this country, the ignition of the above
mixture in pots is laid aside, as too operose and expensive. The calcined matter is raked
out, and lixiviated with water. The bright yellow solution is then evaporated briskly,
and the chromate of potash falls down in the form of a granular salt, which is lifted
out from  time to time from the bottom with a large ladle, perforated with small holes,
and thrown into a draining-box. This saline powder may be formed into regular crystals
of neutral chromate of potash, by solution in water and slow evaporation; or it may be
converted into a more beautiful crystalline body, the bichromate of potash, by treating
its concentrated solution with nitric, muriatic, sulphuric, or acetic acid, or, indeed, any
acid exercising a stronger affinity for the second atom of the potash than the chromic
acid does.
Bichromate of potash, by evaporation of the above solution, and slow cooling, may be
obtained in the form of square tables, with bevelled edges, or flat four-sided prisms.
They are permanent in the air, have a metallic and bitter taste, and dissolve in about one
tenth of their weight of water, at 60~ F.; but in one half of their weight of boiling water.
They consist of chromic acid 13, potash 6; or, in 100 parts, 68-4 -t 31'6. This salt is
much employed in calico-printing and in dyeing; which see.
Chromate of lead, the chrome-yellow of the painter, is a rich pigment of various
shades, from deep orange to the palest canary yellow. It is made by adding a limpid
solution of the neutral chromate (the above granular salt) to a solution, equally limpid,
of acetate or nitrate of lead. A precipitate falls, which must be well washed, and carefully dried out of the reach of any sulphureted vapors.  A  lighter shade of yellow is
obtained by mixing some solution of alum, or sulphuric acid, with the chromate, before
pouring it into the solution of lead; and an orange tint is to be procured by the addition
of subacetate of lead, in any desired proportion.
For the production of chromate of potash from chrome ore, various other processes
have been recommended. The following formulae, which have been verified in practice,
will prove useful to the manufacturers of this important article:1. Two parts of chrome ore, containing about 50 per cent. of protoxyde of chromium 
One part of saltpetre.




422                               CHROMIUM.
II. Four parts of chrome ore, containing 31 per cent. of protoxyde of chromium.
Two parts of potashes.
One part of saltpetre.
III. Four parts of chrome ore.   -    34
Two of potashes.
Four tenths of a part of peroxyde of manganese.
IV. Three parts of chrome ore.
Four parts of saltpetre.
Two parts of argal.
Some manufacturers have contrived to effect the conversion of the oxyde into an acid,
and of course to form the chromate of potash, by the agency of potash alone, in a calcining
furnace, or in earthen pots fired in a pottery kiln.
After lixiviating the calcined mixtures with water, if the solution be a tolerably pure
chromate of potash, its value may be inferred, from its specific gravity, by the following
table:
At specific gravity 1'28 it contains about 50 per cent. of the salt.
1-21                33
1'18                25
1-15                20
1-12                16
1-11                14
1.10                12
In making the red bichromate of potash from these solutions of the yellow salt, nitric
acid was at first chiefly used; but in consequence of its relatively high price, sulphuric,
muriatic, or acetic acid has been frequently substituted upon the great scale.
There is another application of chrome which merits some notice here; that of its green
oxyde to dyeing and painting on porcelain. This oxyde may be prepared by decomposing,
with heat, the chromate of mercury, a salt made by adding to nitrate of pirtoxyde of mercury, chromate of potash, in equivalent proportions. This chromate has a fine cinnabar
red, when pure; and, at a dull red heat, parts with a portion of its oxygen and its
mercurial oxyde.  From M. Dulong's experiments it would appear, that the purest
chromate of mercury is not the best adapted for preparing the oxyde of chrome to be
used in porcelain painting.  He thinks it ought to contain a little oxyde of manganese
and chromate of potash, to afford a green color of a fine tint, especially for pieces that
are to receive a powerful heat.  Pure oxyde of chrome preserves its color well enough
in a muffle furnace; but, under a stronger fire, it takes a dead-leaf color.
The green oxyde of chrome has come so extensively into use as an enamel color for
porcelain, that a fuller account of the best modes of manufacturing it must prove acceptable to many of my readers.
That oxyde, in combination with water, called the hydrate, may be economically
prepared by boiling chromate of potash, dissolved in water, with half its weight of
flowers of sulphur, till the resulting green precipitate ceases to increase, which may be
easily ascertained by filtering a little of the mixture.  The addition of some potash
accelerates the operation.  This consists in combining the sulphur with the oxygen of
the chromic acid, so as to form sulphuric acid, which unites with the potash of the
chromate into sulphate of potash, while the chrome oxyde becomes a hydrate.  An
extra quantity of potash facilitates the deoxydizement of the chromic acid by the formation of'hyposulphite and sulphuret of potash, both of which have a strong attraction
for oxygen. For this purpose the clear lixivium of the chromate of potash is sufficiently
pure, though it should hold some alumina and silica in solution, as it generally does.
The hydrate may be freed from particles of sulphur by heating dilute sulphuric acid
upon it, which dissolves it; after which it may be precipitated, in the state of a
carbonate, by carbonate of potash, not added in excess.
By calcining a mixture of bichromate of potash and sulphur in a crucible, chromic
acid is also decomposed, and a hydrated oxyde may be obtained; the sulphur being
partly converted into sulphuret of potassium, and partly into sulphuric acid (at the
expense of the chromic acid), which combines with the rest of the potash into a
sulphate. By careful lixiviation, these two new compounds may be washed away, and
the chrome green may be freed from the remaining sulphur, by a slight heat.
Liebig and Wohler have lately contrived a process for producing a subchromate of
lead of a beautiful vermilion hue.  Into saltpetre, brought to fusion in a crucible at
a gentle heat, pure chrome yellow is to be thrown by small portions at a time. A
strong ebullition takes place at each addition, and the mass becomes black, and continues so while it is hot. The chrome yellow is to be added till little of the saltpetre
remains undecomposed, care being taken not to overheat the crucible, lest the color
of the mixture should become brown.  Having allowed it to settle for a few minutes,
during which the dense basic salt falls to the bottom, the fluid part, consisting of




CHROMIUM.                                    423
chromate of potash and saltpetre, is to be poured off, and it can be employed again ig
preparing chrome yellow.  The mass remaining in the crucible is to be washed with
water, and the chrome red being separated from the other matters, is to be dried after
proper edulcoration. It is essential for the beauty of the color, that the saline solution
should not stand long over the red powder, because the color is thus apt to become of a
dull orange hue.  The fine crystalline powder subsides so quickly to the bottom after
every ablution, that the above precaution may be easily observed.
As Chromic dcid will probably ere long become an object of interest to the calico
printer, I shall describe here the best method of preparing it.  To 100 parts of yellow
chromate of potash, add 136 of nitrate ofbarytes, each in solution. A precipitate of the
yellow chromate of barytes falls, which being washed and dried would amount to 130
parts.  But while still moist it is to be dissolved in water by the intervention of a little
nitric acid, and then decomposed by the addition of the requisite quantity of sulphuric
acid, whereby the barytes is separated, and the chromic acid remains associated with the
nitric acid, from which it can be freed by evaporation to dryness.  On re-dissolving the
chromic acid residuum in water, filtering and evaporating to a proper degree, 50 parts
of chromic acid may be obtained in crystals.
This acid may also be obtained from chromate of lime, formed by mixing chromate of
potash and muriate of lime; washing the insoluble chromate of lime which precipitates,
and decomposing it by the equivalent quantity of oxalic acid, or for ordinary purposes even
sulphuric acid may be employed.
Chromic acid is obtained in quadrangular crystals, of a deep red color; it has a very
acrid and styptic taste. It reddens powerfully litmus paper. It is deliquescent in the air.
When heated to redness it emits oxygen, and passes into the deutoxyde. When a little of
it is fused along with vitreous borax, the compound assumes an emerald green color.
As chromic acid parts with its last dose of oxygen very easily, it is capable in certain
styles of calico printing of becoming a valuable substitute for chlorine, where this more
powerful substance would not from peculiar circumstances be admissible.  For this ingenious application, the arts are indebted to that truly scientific manufacturer, M. Daniel
Kcechlin, of Muilhouse.  He discovered that whenever chromate of potash has its acid
set free by its being mixed with tartaric or oxalic acid, or a neutral vegetable substance,
(starch or sugar for example,) and a mineral acid, a very lively action is produced, with
disengagement of heat, and of several gases. The result of this decomposition is the active
reagent, chromic acid, possessing valuable properties to the printer.  Watery solutions
of chromate of potash and tartaric acid being mixed, an effervescence is produced which
has the power of destroying vegetable colors.  But this power lasts no longer than the
effervescence. The mineral acids react upon the chromate of potash only when vegetable
coloring matter, gum, starch, or a vegetable acid are present, to determine the disengagement of gas.  During this curious change carbonic acid is evolved; and when it takes
place in a retort, there is condensed in the receiver a colorless liquid, slightly acid,
exhaling somewhat of the smell of vinegar, and containing a little empyreumatic oil.
This liquid heated with the nitrates of mercury or silver reduces these metals. On
these principles M. Kcechlin discharged indigo blue by passing the cloth through a solution
of chromate of potash, and printing nitric acid thickened with gum upon certain spots. It
is probable that the employment of chromic acid would supersede the necessity of having
recourse in many cases to the more corrosive chlorine.
The following directions have been given for the preparation of a blue oxyde of chrome.
The concentrated alkaline solution of chromate of potash is to be saturated with weak
sulphuric acid, and then to every 8 lbs. is to be added 1 lb. of common salt, and half a
pound of concentrated sulphuric acid; the liquid will now acquire a green color. To be
certain that the yellow color is totally destroyed, a small quantity of the liquor is to have
potash added to it, and filtered; if the fluid is still yellow, a fresh portion of salt and of
sulphuric acid is to be added; the fluid is then to be evaporated to dryness, redissolved,
and filtered; the oxyde of chrome is finally to be precipitated by caustic potash.  It will
be of a greenish-blue color, and being washed, must be collected upon a filter.
Chromate of Potash, adulteration of, to detect. The chromate of potash has the
power of combining with other salts up to a certain extent without any very sensible
change in its form and appearance; and hence it has been sent into the market falsified
by very considerable quantizes of sulphate and muriate of potash, the presence of
which has often escaped observation, to the great loss of the dyers who use it so extensively.  The following test process has been devised by M. Zuber, of Miilhouse.
Add a large excess of tartaric acid to the chromate in question, which will decompose
it, and produce in a few minutes a deep amethyst color.  The supernatant liquor
will, if the chromate be pure, afford now no precipitate with the nitrates of barytes or
silver; whence the absence of the sulphates and muriates may be inferred.  We must,
however, use dilute solutions of the chromate and acid, lest bitartrate of potash be precipitated, which will take place if less than 60 parts of water be employed. Nor must




424                              CITRIC  ACID.
we test the liquid till the decomposition be complete, and till the colour verge rather
towards the green than the yellow. Eight parts of tartaric acid should be added to one
of chromate to obtain a sure and rapid result. If nitrate of potash (saltpetre) is the
adulterating ingredient, it may be detected by throwing it on burning coals, when
deflagration will ensue. The green colour is a certain mark of the transformation of the
chromic acid partially into the chrome oxide; which is effected equally by the sulphurous acid and sulphuretted hydrogen.  Here this metallic acid is disoxygenated by the
tartaric, as has been long known. The tests which I should prefer are the nitrates of
silver and baryta, having previously added so much nitric acid to the solution of the suspected chromate, as to prevent the precipitation of the chromate of silver or baryta.
The smallest adulteration by sulphates or muriates will thus be detected.
CHROMIUM, OXIDE OF. —Iix intimately 45 parts of gunpowder with  240 parts
of perfectly dry chromate of potash, and 35 parts of hydrochlorate of ammonia (sal ammoniac), reduce to powder, and pass through a fine sieve; fill a conical glass or other
mould with this powder, gently pressed, and invert so as to leave the powder on a
porcelain slab of any kind. When set on fire at its apex with a lighted match, it will
burn down to the bottom  with brilliant coruscations.  The black residuum, being
elutriated with warm water, affords a fine bright green oxide of chromium.
CHROMIIUMI, green oxide of.-Ignite bichromate of potash with a quarter of its weight
of flowers of sulphur, by projecting the mixture into a red hot crucible in small
successive portions, stirring the pasty mass till the excess of sulphur is burnt off; pulverize the cooled mass, and wash with water till it affords no precipitate with chloride
of barium or acetate of lead. The powder which remains on being gently dried is of a
beautiful green color, and may be used as a pigment, or to prepare pure chromium.
CINNABAR; the native red sulphuret of mercury. It occurs sometimes crystallized
in rhomboids; has a specific gravity varying from 6'7 to 8'2; a flat conchoidal fracture;
is fine grained; opaque; has an adamantine lustre, and a color passing from cochineal to
ruby red. The fibrous and earthy cinnabar has a scarlet hue. It is met with disseminated in smaller or larger lumps in veins, which are surrounded by a black clay, and is associated with native quicksilver, amalgam, with iron-ore, lead-glance, blende, copper-ore,
gold, &c. Its principal localities are Almaden in Spain, Idria in the Schiefergebirge,
Kremnitz and Schemnitz in Hungary; in Saxony, Bavaria, Bohemia, Nassau, China, Japan, Mexico, Columbia, Peru.  It consists of two primes of sulphur, = 32-240, combined with one of mercury, = 202,863; or in 100 parts of 12'7 sulphur - 87'3 mercury.
It is the most prolific ore of this metal; and is easily smelted by exposing a mixture of it
with iron or lime to a red heat in retorts. Factitious cinnabar is called in commerce
VERMILION, which see, as also MERCURY.
CINNAMON. (Cannelle, Fr.; Zimmt, Germ.) Is the inner bark of the laurus cinnamomum, a handsome-looking tree which grows naturally to the height of 18 or 20 feet, in
Java, Sumatra, Ceylon, and other islands in the East Indian seas. It has been transplanted to the Antilles, particularly Guadaloupe and Martinique, as well as Cayenne, but there
it produces a bark of very inferior value to the Oriental.
Cinnamon is gathered twice a year, but not till after the tree has attained to a certain
age and maturity. The young twigs yield a bark of better quality than the larger branches. The first and chief harvest takes place from April to August; the second, from November to January. After having selected the proper trees, all the branches more than
three years old are cut off; the epidermis is first removed with a two-edged pruning knife,
then a longitudinal incision is made through the whole extent of the bark, and lastly, with
the bluntest part of the knife, the true bark is carefully stripped off in one piece. All
these pieces of bark are collected, the smaller ones are laid within the larger, and in this
state they are exposed to the sun, whereby in the progress of drying, they become rolled
into the shape of a quill. These convoluted pieces are formed into oblong bundles of
20 or 30 lbs. weight, which are placed in warehouses, sorted and covered with mats.
Good cinnamon should be as thin as paper, have its peculiar aromatic taste, without
burning the tongue, and leave a sweetish flavor in the mouth  The broken bits of
cinnamon are used in Ceylon for procuring the essential oil by distillation. 445,367 lbs.
of cinnamon were imported into this kingdom in 1835, of which 16,604 only were retained for internal consumption.
CITRIC ACID.  (.cide citrique, Fr.; Citronensaure, Getm.)  Scheele first procured
this acid in its pure state from lemon juice, by the following process. The juice put into a
large tub, is to be saturated with dry chalk in fine powder, noting carefully the quantity
employed. The citrate of lime which precipitates, being freed from the supernatant foul
liquor, is to be well washed with repeated affusion and decantation of water. For every 10
pounds of chalk employed, nine and a half pounds of sulphuric acid, diluted with six
times its weight of water, are to be poured while warm upon the citrate of lime, and well
mixed with it. At the end of twelve  hours, or even sooner, the citrate will be all




CIVET.                                      425
decomposed, dilute citric acid will float above, and sulphate of lime will be found at
the bottom.  The acid being drawn off, the calcareous sulphate must be thrown on a
canvass filter, drained, and then washed with water to abstract the whole acid.
The citric acid thus obtained may be evaporated in leaden pans, over a naked fire till
it acquires the specific gravity 1-13; after which it must be transferred into another vessel, evaporated by a steam or water bath till it assumes a syrupy aspect, when a pellicle
appears first in patches, and then over the whole surface. This point must be watched
with great circumspection, for if it be passed, the whole acid runs a risk of being spoiled
by carbonization.  The steam or hot water must be instantly withdrawn, and the con
centrated acid put into a crystallizing vessel in a dry, but not very cold apartment. At
the end of four days the crystallization will be complete. The crystals must be drained,
re-dissolved in a small portion of water, the solution set aside to settle its impurities,
then decanted, re-evaporated, and re-crystallized. A third or fourth crystallization may
be necessary to obtain a colourless acid.
If any citrate of lime be left undecomposed by the sulphuric acid, it will dissolve in
the citric acid, and obstruct its crystallization, and hence it will be safer to use the
slightest excess of sulphuric acid, than to leave any citrate undecomposed. There should
not, however, be any great excess of sulphuric acid. If there be, it is easily detected by
nitrate of barytes, but not by the acetate of lead as prescribed by some chemical authors;
because the citrate of lead is not very soluble in the nitric acid, and might thus be confounded with the sulphate, whereas citrate of barytes is perfectly soluble in that test
acid.  Sometimes a little nitric acid is added with advantage to the solution of the
coloured crystals, with the effect of whitening them.
Twenty gallons of good lemon juice will afford fully ten pounds of white crystals of
citric acid.
Attempts were made both in the West Indies and Sicily, to convert the lime and
lemon juice into citrate of lime, but they seem to have failed through the difficulty of
drying the citrate for shipment.
The crystals of citric acid are oblique prisms with four faces, terminated by dihedral
summits, inclined at acute angles. Their specific gravity is 1-617. They are unalterable in the air.  When heated, they melt in their water of crystallization; and at a
higher heat, they are decomposed.  They contain 18 per cent. of water, of which onehalf may be separated in a dry atmosphere, at about 100~ F., when the crystals fall into
a white powder.
Citric acid in crystals is composed by my analysis of carbon, 35'8, oxygen 59'7, and
hydrogen 45; results which differ very little from those of Dr. Prout, subsequently
obtained. I found its atomic weight to be 8'375, compared to oxygen 1,000. I cannot
account for Berzelius's statements relative to the composition of this acid.
Citric acid in somewhat crude crystals is employed with much advantage in calicoprinting.  If adulterated with tartaric acid, the fraud may be detected by adding potash
to the solution of the acid, which will cause a precipitate of cream of tartar.
The manufacture of citric acid so closely resembles that of tartaric acid, that the makers
of one commonly fabricate the other. The raw material in this case is pretty generally
a black fluid, like thin treacle, which comes from Sicily, and is obtained by inspissating
the expressed juice of the lemon,-the rind having previously been removed from the
lemon for the sake of its essential oil.  This black juice is impure citric acid, and requires to be treated with chalk, as practised with respect to the first operation on
tartar; by which means, an insoluble citrate of lime is formed; and this, after being
well washed with cold water, is decomposed by sulphuric acid; and the solution, after
undergoing the action of animal charcoal and proper evaporation, yields brownish crystals
on cooling. These are re-dissolved, discoloured, and crystallized three or four times ere
they can be sent into the market, for citric acid is more tenacious of colouring matter than
most of the other vegetable acids.  At Nice, and in the South of France, a portion of
chloride of lime is digested upon the citrate of lime, to bleach it prior to decomposition
by sulphuric acid. For this purpose, the washed citrate is exposed in shallow vessels
to the action of the sun's rays, covered by a weak solution of chloride of lime. In a few
hours decolouration ensues; and it is moreover stated that the mucilage which hangs
about the citrate of lime, and impedes the subsequent crystallization of the acid, is in this
way destroyed, and the number of re-crystallizations requisite to give a saleable aspect
to the citric acid thereby diminished.  The use of chloride of lime for this purpose
seems unknown, or, at least, is not practised in England. Of the samples of citric acid
shown in the Great Exhibition, those from Howards and Kent, of Stratford, Pontifex
and Wood, of Millwall, and J. Huskisson, of Gray's Inn Road, were extremely beautiful;
and in respect to size and crystalline form surpassed anything exhibited in the French,
Prussian, or Italian departments.
CIVET.  (Civette, Fr.; Zibeth, Germ.)  This substance approaches in smell to
musk and ambergris; it has a pale yellow colour, a somewhat acrid taste, a consistence
VOL. L                                 3 I




426                                    CLAY.
like that of honey, and a very strong aromatic odour.  It is the product of two small
quadrupeds of the genus viverra (v. zibetha and v. civetta), of which the one inhabits
Africa, and the other Asia. They are reared with tenderness, especially in Abyssinia.
The civet is contained in a sac, situated between the anus and the parts of generation,
in either sex. The animal frees itself from an excess of this secretion by a contractile
movement which it exercises upon the sac, when the civet issues in a vermicular
form and is carefully collected.  The negroes are accustomed to increase the secretion
by irritating the animal; and likewise introduce a little butter, or other grease, by the
natural slit in the bag, which mixes with the odoriferous substance, and increases its
weight. It is employed only in perfumery.
According to M. Boutron-Chalard, it contains a volatile oil, to which it owes its
smell, some free ammonia, resin, fat, an extractiform matter, and mucus.  It affords by
calcination an ash, in which there are some carbonate and sulphate of potash, phosphate
of lime, and oxide of iron.
CLAY (Argile, Fr.; Thon, Germ.) is a mixture of the two simple earths, alumina
and silica, generally tinged with iron.  Lime, magnesia, with some other colouring metallic oxides, are occasionally present in small quantities in certain natural clays.
The different varieties of clay possess the following common characters:1. They are readily diffusible through water, and are capable of forming with it a
plastic ductile mass, which may be kneaded by hand into any shape.  This plasticity
exists, however, in very different degrees in the different clays.
2. They concrete into a hard mass upon being dried, and assume, upon exposure to
the heat of ignition, a degree of hardness sometimes so great as to give sparks by collision with hardened steel.  In this state they are no longer plastic with water, even
when pulverised. Tolerably pure clays, though infusible in the furnace, become readily
so by the admixture of lime, iron, manganese, &c.
3. All clays, even when previously freed from moisture, shrink in the fire in virtue
of the reciprocal affinity of their particles; they are very absorbent of water in their
dry slate, and adhere strongly to the tongue.
4. Ochrey, impure clays emit a disagreeable earthy smell when breathed upon.
Brongniart distributes the clay into:1. Fire-clays, (argiles apyres, Fr.; feuerfeste, Germ.)
2. Fusible, (schmelzbare, Germ.)
3. Effervescing (brausende, Germ.) from the presence of chalk.
4. Ochrey (ocreuses, Fr.; ockrige, Germ.)
Fire-clay is found in the greatest abundance and perfection for manufacturing purposes in,
1. Slate-clay. (Thon-schiefer, Germ.) Its colour is gray or grayish yellow. Massive,
dull, or glimmering from admixture of particles of mica. Fracture slaty, approaching
sometimes to earthy. Fragments tabular. Soft, sectile, and easily broken. Sp. gr.- 26.
Adheres to the tongue, and breaks down in water.  It occurs along with pit coal; which
see. Slate-clay is ground, and reduced into a paste with water, for making fire-bricks;
for wnich purpose it should be as free as possible from lime and iron.
2. Cortnmon clay or loasm.This is an impure coarse pottery clay, mixed with iron
ochre, and occasionally with mica.  It has many of the external characters of plastic
clay.  It is soft to the touch, and forms, with water, a somewhat tenacious paste;
but is in general less compact, more friable, than the plastic clays, which are more
readily diffusible in water.  It does not possess the property of acquiring in water
that commencement of translucency which the purer clays exhibit.  Although soft
to the touch, the common clay wants unctuosity, properly so called.  The best example of this argillaceous substance is afforded in the London clay formation, which
consists chiefly of bluish or blackish clay, mostly very tough.  Those of its strata which
effervesce with acids partake of the nature of marl.  This clay is fusible at a strong heat
in consequence of the iron and lime which it contains. It is employed in the manufacture of bricks, tiles, and coarse pottery ware.
3. Potter's clay, or Plastic clay.-This species is compact, soft, or even unctuous to
the touch, and polishes with the pressure of the finger; it forms, with water, a tenacious,
very ductile, and somewhat translucent paste.  It is infusible in a porcelain kiln,
but assumes in it a great degree of hardness. Werner calls it pipe-clay. Good plastic
clay remains white, or if gray before, becomes white in the porcelain kiln.
The geological position of the plastic clay is beneath the London clay, and above the
sand which covers the chalk formation. The plastic clay of the Paris basin is described as
consisting of two beds separated by a bed of sand. The lower bed is the proper plastic
clay.  The plastic clay of Abondant, near the forest of Dreux, analyzed by Vauquelin,
gaveSilica, 43-5; alumina, 33-2; lime, 0'35; iron, 1; water, 18.




CLAY.                                     427
This clay is employed as a fire clay for making the bungs or seggars, or coarse earthenware cases, in which china ware is fired.
The plastic clay of Dorsetshire and Devonshire supplies the great Staffordshire potteries. It is gray-coloured, less unctuous than that of Dreux, and consequently more
friable. It becomes white in the pottery kiln, and is infusible at that heat.  It causes
no effervescence with nitric acid, but falls down quickly in it, and becomes higher
coloured.  Its refiactoriness allows of a harder glaze being applied to the ware formed
from it without risk of the heat requisite for making the glaze flow affecting the biscuit
either in shape or colour.  "Most of the plastic clays of France," says M. Brongniart,
" employed for the same ware, have the disadvantage of reddening a little in a somewhat
strong heat; and hence it becomes necessary to coat them with a soft glaze, fusible by
means of excess of lead at a low heat, in order to preserve the white appearance of the
biscuit.  Such a glaze has a dull aspect, and cracks readily into innumerable fissures by
alternations of hot and cold water." Hence one reason of the vast inferiority of the
French stone-ware to the English.
4. Porcelain clay or Kaolin earth.-The Kaolins possess very characteristic properties. They are friable in the hand, meagre to the touch, and difficultly form a paste
with water.  When freed from the coarse and evidently foreign particles interspersed
through them, they are absolutely infusible in the porcelain kiln, and retain their white
colour unaltered. They harden with heat like other clays, and perhaps in a greater
degree; but they do not acquire an equal condensation or solidity, at least when they
are perfectly pure. The Kaolins in general appear to consist of alumina and silica in
nearly equal proportions. Most of the Kaolin clays contain some spangles of mica
which betray their origin from disintegrated granite.
This origin may be regarded as one of their most distinctive features. Almost all
the porcelain clays are evidently derived from the decomposition of the felspars, granites,
and principally those rocks of felspar and quartz, called graphic granite. Hence they
are to be found only in primitive mountain districts, among banks or blocks of granite,
forming thin seams or partings between them. In the same partings, quartz and mica
occur, being relics of the granite; while some seams of Kaolin retain the external form
of felspar.
The most valuable Kaolins have been found:In China and Japan.  The specimens imported from these countries appear pretty
white; but are more unctuous to the touch, and more micaceous than the porcelain
clays of France.
In Saxony. The Kaolin employed in the porcelain manufactories of that country
has a slight yellow or flesh colour, which disappears in the kiln, proving, as Wallerius
observed, that this tint is not owing to any metallic matter.
In France, at Saint-Yriex-la-Perche, about 10 leagues from Limoges. The Kaolin
occurs there in a bed, or perhaps a vein of beds of granite, or rather of that felspar rock
called Pe-tun-tse, which exists here in every stage of decomposition. This Kaolin is
generally white, but sometimes a little yellowish, with hardly any mica. It is meagre
to the touch, and some beds include large grains of quartz, called pebbly by the China
manufacturers. This variety, when ground, affords, without the addition of any fusible
ingredient, a very transparent porcelain.
Near Bayonne. A Kaolin possessing the lamellated structure of felspar, in many
places. The rock containing it is a graphic granite in every stage of decomposition.
In England in the county of Cornwall. This Kaolin or China clay is very white,
and more unctuous to the touch than those upon the continent of Europe mentioned
above. Like them it results from the decomposition of the felspars and granites, occurring in the middle of these rocks. Mr. Wedgewood found it to contain 60 of alumina
or pure clay, and 40 of silica, in 100 parts.
Pure clay, the alumina of the chemist, is absolutely infusible; but when subjected to
the fire of a porcelain kiln, it contracts into about one-half of its total bulk. It must,
however, be heated very cautiously, otherwise it will decrepitate and fly in pieces, owing
to the sudden expansion into steam of the water combined with its particles, which is
retained with a considerable attractive force. It possesses little plasticity, and consequently affords a very short paste, which is apt to crack when kneaded into a
cake.
It is not only infusible by itself, but it will not dissolve in the fusible glasses;
making them merely opaque. If either lime or silica be added separately to pure clay,
in any proportion, the mixture will not melt in the most violent furnace; but if alumina,
lime, and silica be mixed together, the whole melts, and the more readily, the nearer the
mixture approaches to the following proportions:-1 of alumina, 1 of lime, and 8 of
sand. If the sand be increased to five parts, the compound becomes infusible. These
interesting facts show the reciprocal action of those earths which are mixed most commonly in nature with alumina.
312




428                                   CLAY.
Iron in small quantity, but in a state not precisely determined, though probably of
protoxide, does not colour the clays till they are subjected to a powerful heat. There
are very white clays, such as those of Montereau, which do not become red till calcined
in the porcelain kiln; the oxide of iron contained in them, which colours them in that
case, was previously imperceptible.  It appears from this circumstance, that the clays
fit for making fine white stone ware, as also the Kaolins adapted to the manufacture of
porcelain, are very rare.
Iron in larger proportion, usually colours the clays green or slate-blue, before they
have been heated.  Such clays, exposed to the action of fire, become yellow or red according to the quantity of iron which they contain.  When the iron is very abundant,
it renders the clays fusible; but a little lime and silica must also be present for this
effect. The earthenware made with these ferruginous clays can bear but a moderate
baking heat; it is thick, porous, and possesses the advantage merely of cheapness, and
of bearing considerable alternations of temperature without breaking.
Alumina and the very aluminous natural clays which possess most plasticity are apt
to crack in drying, or to lose their shape. This very serious defect for the purposes of
pottery is rectified, in some measure, by adding to that earth a certain quantity of sand
or silica. Thus, a compound is formed which possesses less attraction for water and
dries more equably from the openness of its body. The principal causes of the distortion
of earthenware vessels, are the unequal thickness of their parts, and quicker desiccation
upon one side than another.  Hard burnt stone-ware ground to powder, and incorporated with clay, answers still better than sand for counteracting the great and irregular
contraction which natural pottery paste is apt to experience. Such ground biscuit is
called cement; and its grains interspersed through the ware, may be regarded as so
many solutions of continuity, which arrest the fissures.
The preceding observations point out the principles of those arts which employ clay
for moulding by the wheel, and baking in a kiln.  See PORCELAIN and POTTERY.
The chemical composition of the clays shown at the Great Exhibition was unfortunately not given, as it ought to have been. The injurious effect of this ignorance will,
by-and-by, come under consideration, when speaking of the art of the potter; but, for
the present, we shall content ourselves with a hasty glance at the various specimens of
clay exhibited in Class I.,-adding, as usual, a few practical hints for the analysis of
these substances, together with some analytical investigations recently made upon
average market samples of clay, for the express purpose of elucidating this obscure
subject. In a manufacturing point of view, clays may be conveniently divided into three
classes; for although a fourth (that is to say, common marl clay) exists, yet, as its employment is limited to the making of bricks and other coarse articles in which improvement is nearly hopeless, so far as regards material, we shall confine our observations to
the three finer qualities, named, respectively, china clay or kaolin, fire-clay, and potter's
clay.  In china clay, Jenkins & Courtney, of Truro; Whitley of Truro; C. Thriscutt, of
St. Austell; the West of England China Stone and Clay Company; Truscott, Martyn,
Brown, Michell, and Wheeler, Philip & Co., all of St. Austell; and W. Phillips, of
the Morley Works, near Plympton, together with Sir G. Hodson, Bart., of Wicklow in
Ireland, exhibit some samples of great beauty and apparent purity. In fire-clay, the
articles shown by King & Co., Squires & Son, and F. T. Rafford, of Stourbridge, with
those from Cowan & Co., Ramsey & Co., and Potter, of Newcastle, are excellent; and
a sample from Pease of Darlington, also deserves notice.  In potter's clay, Whiteway,
Watts, & Co., of Dorset; Fayle & Co., of Thames Street, London; W. & J. Peike,
of the Isle of Purbeck; N. Burnet, of Gateshead; and the North Devon Pottery
Company, are the most remarkable, though there are many very respectable looking
samples from other quarters.
In the manufacture of earthenware goods, it is indispensably necessary to mix the clay,
in the first instance, with some infusible material, which does not contract or diminish
under the influence of heat; for all kinds of clay shrink very much by the action of a
high and prolonged temperature, and are therefore liable, during such exposure, to warp
and twist out of shape, or become cracked in the furnace.  Hence a remedy is sought
as above indicated, and for this purpose, silica, in a minute state of division, is generally
preferred; though felspar, and a kind of decomposing granite, called Cornish stone, are
also used. But whatever may be the material, its introduction into the body of the
earthenware is conducted on purely empirical principles, for, as the composition of the
clay is unknown, no attempt can be or is made to effect a combination in unison with
the laws of chemical affinity. The substances employed are recognised only as clay, and
perhaps ground flint; nor is any other test used to ascertain the proper proportion of
each towards the other, than the uncertain judgment of a workman, or the equally
fallacious practice of an established rule.  As, however, all clays, in a state of natural
purity, consist of silica and alumina, united together in definite atomic proportions,
there can be no doubt that perfection in earthenware depends upon this simple law; and




CLAY.                                    429
that the only true mode of fabricating a uniform and really valuable kind of potteryware, would be to follow out the indications of nature, and constantly preserve an atomic
ratio in the admixture of the flint and clay of which that pottery-ware is composed.
Of course, under existing circumstances, this is impossible; for, as we have previously
remarked, the precise composition of the different clays used in the arts is totally unknown; and, independent of any chemical difficulties that may be presumed to exist in
determining this important fact for themselves, our manufacturers may justly plead that
no simple and satisfactory mode of analyzing clay has yet been published.  Hence the
present empirical system is universal; and the accidental admixtures it produces testify
to the truth of our remarks, by cracking and flying to pieces under very trivial alterations of temperature, no less to the annoyance than loss of the public at large.  Nor can
this be wondered at, when it is remembered that, in almost every tea-cup, saucer, or
plate upon our tables, the laws of natural combination have been violated by the prevalence of an artificial and incompatible form of arrangement, the work of sheer ignorance
and chance. So far as our investigations have yet gone, it appears that kaolin, or china
clay, has arisen from the decomposition of felspar under two different conditions; for the
resulting compound is not alike in both cases; though to what cause this difference can
be ascribed we are unable with certainty to say. Felspar, in it original state, has exactly
the same composition as anhydrous alum, with this exception, that in the one case the
bases are united to sulphuric, and in the other to silicic acid.  Felspar, therefore, consists of one atom of potash and one of silica, united to two atoms of alumina and three
of silica; or, in other words, it is formed of the silicate of potash and the silicate of
alumina, combined in the ratio of one atom of the former to two of the latter.  Now, it
is found that, when felspar is long exposed to the action of the weather, it becomes
disintegrated and falls into a state of powder, which, ultimately, by absorbing water,
assumes a pasty consistence, and thus forms the article called china clay. The nature of
this decomposition is not, however, uniform or invariable, for analysis proves that the
residuary produce has not always the same composition. When felspar decomposes in
an absolutely wet or rainy atmosphere, the silicate of potash would appear to be simply
washed away by the excess of water; and, in this case, the resulting clay has a composition of three atoms of silica and two of alumina; but, when merely a moist atmosphere
has existed, then the silicate of potash itself seems to become decomposed, probably by
carbonic acid, thus leaving the whole of the silica united to the alumina; the potash
then escaping as a carbonate. Under such circumstances, we have found china clay to
consist of four atoms of silica and two of alumina; or, what is the same thing, of two of
acid and one of base.  Of course an alternating atmosphere would produce a mixture
of these; and such layers may actually be traced in many specimens of clay, as though
the summer and winter portions of the year had each furnished a distinctly separate
amount of decomposed felspar. But felspar is not the only source from whence our silicate of alumina has been formed; as there are many other minerals which, by the action
of the atmosphere, furnish clays of different compositions: thus, the substances known
to mineralogists under the names leucite, albite, analcime, nepheline, mesotype, and
sodalite, all yield silicate of alumina, which contains, indeed, various proportions of the
two ingredients, but is nevertheless, in a commercial sense, clay. In point of fact even
granite has contributed its quota to the clay formation, for though slowly and imperfectly, yet in time it crumbles down into supersilicate of alumina: as may be noticed
by carefully examining the once smooth surface of the granite on Waterloo and London
Bridges, which is gradually assuming a cavernous character. With such evidence before us of the infinite variety existing in clay, it is surely high time that the attention
of manufacturers was directed to the necessity of analyzing this substance, and adding
to it neither more nor less silica than is sufficient to produce a useful atomic compound.
The proper proportion might soon be arrived at by a few carefully conducted experiments, after which the whole of the uncertainty now connected with differences in the
material would vanish for ever, and with it no small amount of the loss occasionally
caused by earthenware spoilt or broken in the kiln.
To determine the quantity of alumina in clay, a given weight of this substance, say
100 grs., well dried and in fine powder, should be mixed with double its weight of fluor
spar, also in fine powder, then the mixture placed in a platinum or leaden vessel, and
about 400 grs. of strong sulphuric acid poured over it. Next expose the whole to a heat
of from 2120 to 250~ Fahr. for half an hour; then add three or four ounces of water, and
throw the mixture on a filter, adding a little water at the end of the filtration, so as to obtain the whole of the soluble matter.  To the filtered fluid add now an excess of a solution of ammonia, by which the alumina will be precipitated; and this, after being well
washed on a filter, and dried at a red heat, must have its amount determined by the balance. If, however, the precipitate thrown down by ammonia has a deep yellow or red
colour, the presence of iron is indicated; and this must be removed before drying the alumina.  For this purpose, a quantity of tartaric acid should be added, so as to redissolve




430                                  CLAY.
the mixed precipitate, and the solution slightly supersaturated with carbonate of soda;
when, on adding hydrosulphate of ammonia, the iron will separate as a black sulphuret,
leaving the alumina still in solution; from whence it may be obtained by evaporating
the whole to dryness, heating red hot, and then washing away the alkaline salts by
hot water; the alumina is then left pure, and, after being dried, may be weighed. As
the presence of iron in clay is a serious drawback, the quantity of black sulphuret
formed becomes a good indication of the impurity of the sample under examination,
and is therefore worthy of notice.
Although the proportion of alumina in clay is the chief commercial feature required
by the makers of earthenware, yet it may sometimes be requisite to determine also the
amount of silica present; which may be done by fusing together in an iron crucible or
pan, at a full red heat, one part of the clay in question with three parts of pure potash,both being in fine powder, and carefully mixed before fusion. The fused mass must,
when cold, be boiled for some time in water, until it is thoroughly disintegrated; when
it should be poured into a porcelain vessel, and supersaturated with muriatic acid;
after which, by evaporating to dryness, a residue will be obtained, that, after careful
washing with boiling water, consists merely of the silica contained in the clay in question. After being heated red hot, it may be weighed as usual. If lime be suspected to
exist with the alumina in clay, this may be separated, when in solution, by means of
tartaric acid and carbonate of soda, as above indicated; for in such cases, the lime
will fall at once as a carbonate, leaving the alumina behind in the fluid. Independent,
however, of the defects in British earthenware due to the non-atomic admixture of its
ingredients, there are others arising out of the nature of the ingredients themselves;
so that, taken as a whole, we cannot avoid coming to the unpleasant conclusion, that,
in the great arena of competition at the Crystal Palace, England is decidedly beaten in
the manufacture of fine earthenware, even by countries greatly its inferiors in capital,
intelligence, and natural resources. France, Germany, Sweden, Denmark, Spain, Russia, Turkey, and China, all exhibited porcelain of a quality unmatched by anything
in the British department, and no more lamentable contrast could possibly be drawn
than between the chemical apparatus from Saxony and the clumsy abortions, which,
under that name, disfigured some of the compartments claimed by one or two of our
Staffordshire manufacturers.  In the one case we find a really handsome, light, and
elegant article, the glaze of which has evidently penetrated throughout the entire substance of the body, and has converted the whole into a uniform vitrification; in the other,
a thick, coarse, opaque, and spongy mass, is merely glazed over on its extreme surface by
a fusible compound, having no properties in common with the body of the article, and
endowed with very different powers of expansibility by heat; so that, after being used
a few times, the glaze becomes cracked and shivered in a thousand directions, as may be
seen by examining the earthenware in common use throughout Great Britain. Nor is
the unsightly appearance caused by this cracking of the glaze the whole evil; for
earthen vessels thus flawed acquire the property of absorbing fluids into their pores,
and can never afterwards be thoroughly cleaned. In spite, therefore, of "warranted
not to absorb," and other groundless legends of similar import, imprinted upon many
British goods, a piece of really non-absorbent earthenware, for common use, is an actual
curiosity in this country, and invariably suggests the idea of a foreign origin. Now
this deefct can be remedied only in two ways; and, as our manufacturers have vainly
endeavoured to carry out, practically, one of these ways, we are not without hopes of
persuading them to try the other. If a glazing material could be discovered, the expansions and contractions of which, by heat, exactly corresponded with those of the
biscuit ware, or silicate of alumina, under the same influence, then the present system
of covering a spongy body by a coating of vitrifiable glaze would answer the desired intention well enough; for to the cheapness and durability of earthenware would thus be
superadded the cleanliness of glass. But this desideratum has been sought for, over and
over again, during the last half century, and nothing but disappointment has resulted.
In proof of which we have only to ask-where is that glazed earthen vessel, which,
though made expressly for the use of the apothecary, will retain oil, after being two or
three times heated and cooled? The answer to this question must be our argument in
favour of abandoning such a system of glazing, and adopting the only other mode by
which a non-absorbent pottery ware can be fabricated. The body of the ware itself
must undergo a semivitrification, as happens with the finest kind of china; so that, even
if by long use the glaze come to be fairly worn off, still the non-absorbent principle would
remain as perfect as at first. We know that this is impracticable under existing circumstances; and that, so long as the present empirical mode of compounding the materials
of which the body of the ware is made continues, no chance of improvement remains.
A mixture of silica and alumina, in the proportion of four atoms of the former to one of
the latter, would bear or require a certain quantity of fusible material to induce semivitrification throughout the mass; but a compound of three atoms of silica and one of




CLAY.                                     431
alumina would probably be melted down into a worthless slag by exactly the same addition. Here then lies the root of that difficulty which has hitherto so injuriously restricted the employment of felspar and other vitrifiable bodies in the fabrication of British
earthenware. Those who have attempted to use such substances have occasionally succeeded to admiration; and nothing but the uncertainty of the result, and repeated
failures, have induced them to abandon the employment of a class of articles which, if
capable of being controlled, every intelligent manufacturer admits would confer perfection on his art.  But it is a great mistake to suppose that these inequalities of action
arise out of some peculiarity in the vitrifiable materials themselves, or are in any way
the work of chance. The materials are, or ought to be, uniform, and certainly can be
made so, whilst, for the rest, there is no such thing as chance in nature,-the laws of
chemistry are not accidental or variable, they are immutable. We have shown, however,
that clays not only differ from each other, but, as it were, from themselves; since, from
the same pit, and within a few inches of the same spot, clays of very contrary characters may be procured. Plasticity is no more an indication of the presence or purity of
clay, than sweetness is a test of sugar. In a rough way both these qualities have a
value; but the arts are now fast approaching an epoch, when all such fallacious aids
must give place to the guidance of philosophy; and the sooner our manufacturers become convinced of this grand truth the better for themselves and their country. The
propriety of knowing the exact composition of the raw materials employed in any art or
manufacture does not, indeed, admit of dispute-it is imperative; and hence we are the
more astonished at the scantiness of information respecting the analysis of so important
a production as clay. In face of such apathetic ignorance, would any one believe that,
independently of an immense home consumption, our exports of earthenware last year
amounted to a million sterling? Had the clays of this country been of a tolerably uniform composition, like some of those in China and on the continent, of course mere
practice would long ago have enabled our potters to produce articles of the highest
quality. But surely this is a sorry compliment to men surrounded by all the resources
of science and capital. Where there is no difficulty there can be but little merit, and
still less profit. It is the great glory of British enterprise and industry to despise so
low and facile a position.  Our manufacturers must meet and overcome the trivial
impediments connected with variations in the clay they purchase, and, by properly adjusting the other materials (so as to bring on exactly the due amount of vitrification
needed in the body of the ware), produce, from any kind of clay, articles identical with
those which other nations fabricate from  the very finest clays only. With the prodigious commercial and other advantages possessed by Great Britain, the world at large
ought to expect this at our hands, and not the sub-mediocre workmanship displayed in
the Great Exhibition.
Before quitting this subject, a few remarks upon the substances used in the formation
of glazes may not be inappropriate. The million is still supplied with earthenware,
the glaze of which contains lead, and is, consequently, dangerous to health, though,
when well burned on, this danger is greatly diminished, from the increased insolubility
of the silicate of lead in weak acids. It is, however, an objectionable mode of glazing
earthenware, and requires to be watched with caution, more especially where borax is
used at the same time, for the borate of lead is more easily acted on than the silicate. It
has been lately suggested that oxide of zinc would form a sufficiently fusible compound
with silica, and is cheap enough to supplant oxide of lead in the glazing of common
earthenware. The latter assertion is undoubtedly true, and, although we entertain some
suspicions as to the easy fusibility of silicate of zinc, yet this is precisely one of those
problems which, from their important sanitary bearing, deserve immediate investigation.
On the continent a very pure kind of felspar, mixed probably with a little carbonate of
baryta and oxide of tin, forms the only glaze used upon porcelain and the china vessels
intended for chemical purposes. This glaze is practically perfect. It is so hard as to
withstand the attack of a file, and it resists the action of the strongest acids and alkalis
at all temperatures below 3000 Fabr.-the hydrofluoric acid and its salts alone excepted. In the French, Saxon, and Prussian departments of the Crystal Palace, there
were several good specimens which illustrated the value of this kind of glaze
Amongst the English goods-and chiefly those from  Staffordshire-were a variety
of articles made in what is termed Parian, a compound, the unfitness of which for
statuary purposes we now briefly animadvert upon, with reference however only to its
employment in the higher branches of Decorative Art. The employment of this material, or indeed any other form of alumina where sharpness and symmetry are wanted,
cannot be sufficiently condemned, since it is totally contrary to the natural properties
of alumina, and betrays infinite ignorance regarding first principles. The philosophical
mind of Wedgewood would have revolted at so palpable an absurdity; for not alone
was he well acquainted with the continuous contractility of aluminous compounds, but,
taking advantage of that knowledge, he was able to construct an instrument for
measuring high degrees of heat, which, although not rigidly perfect, is at this day still




432                                   COAL.
found the only available guide for furnace operations on a large scale. And the value
of this instrument or pyrometer, as it is termed, depends upon the fact, that the longer
and higher the temperature to which clay is exposed, the smaller it becomes. Now,
bearing in mind that earthenware is an extremely bad conductor of heat, let us imagine
the Greek Slave, for example, correctly modelled in clay or Parian, and subjected to
the heat of a porcelain furnace. The smaller portions of the figure, as the nose, eyelids, fingers, &c., would receive much more of the impress of the fire than the larger
ones,-as the head, shoulders, &c.; consequently, however symmetrical the original
model might have been, the extra contraction in the smaller parts must destroy every
thing like anatomical harmony and beauty. The fingers would become short and
dumpy, and the nose flat and snubbed. But this is a small part of the mischief, for since
clay, when burnt, is a bad conductor of heat, and the action of the fire is from without
to within, the exterior of the figure must contract vastly more than the interior; consequently, the outside becoming too small for the inside, a series of cracks or fissures
make their appearance to compensate for the inequality.  These, of course, are filled
up by a subsequent operation; but, it is needless to add, at the expense of every thing
which would have rendered the result valuable as a work of art. The general appearance
of the Parian figures shown in the Exhibition bears us out in this censure; for the
features are universally flat, soulless, and devoid of expression; nor can we imagine a
more hopeless task than attempting to remedy this defect.
CLOTH, MANUFACTURE OF. See COTTON, FLAX, WEAVING, WOOL.
CLOTH-BINDING.  Nothing places in so striking a point of view the superior
taste, judgment, and resources of London tradesmen over those of the rest of the world,
than the extensive substitution which they have recently made of embossed silks and
calicoes for leather in the binding of books. In old libraries, cloth-covered boards
indeed may occasionally be seen, but they have the meanest aspect, and are no more
to be compared with our modern cloth-binding, than the jupon of a trull with the ballet
dress of Taglioni. The silk or calico may be dyed of any shade which use or fancy may
require, impressed with gold or silver foil in every form, and variegated by ornaments
in relief, copied from the most beautiful productions in nature. This new style of
binding is distinguished not more for its durability, elegance, and variety, than for the
economy and dispatch with which it ushers the offspring of intellect into the world.
For example, should a house eminent in this line, such as that of Westleys, Friarstreet, Doctor's-commons, receive 5000 volumes from Messrs. Longman & Co. upon
Monday morning, they can have them all ready for publication within the incredibly
short period of two days; being far sooner than they could have rudely boarded them
upon the former plan. The reduction of price is not the least advantage incident to
the new method, amounting to fully 50 per cent. upon that with leather.
The dyed cloth being cut by a pattern to the size suited to the volume, is passed
rapidly through a roller press, between engraved cylinders of hard steel, whereby it receives at once the impress characteristic of the back, and the sides, along with embossed
designs over the surface in sharp relief. The cover thus rapidly fashioned, is as rapidly
applied by paste to the stitched and pressed volume; no time being lost in mutual adjustments; since the steel rollers turn off the former of a shape precisely adapted to the
latter. Hard glazed and varnished calico is moreover much less an object of depredation to moths and other insects, than ordinary leather has been found to be.
CLOTH-DRESSING, by Heycock of Leeds, without stretching the warp-threads or
creasing the cloths from list to list. He lays several pieces of cloth in an extended
state above one another upon a wooden platform, until a pile of a suitable thickness is
formed, a perforated plate is then brought down on the cloth by screws, and steam is
admitted into a hollow chamber beneath, from which it penetrates all the folds of the
cloth, but is confined at the sides. It seems to be a purpose-like invention.
COAL.  Under PITCOAL, the composition of several excellent coals is stated, with
their peculiar qualities, as analyzed by me; such as the Llangenneck, Powell's Duffryn
steam  coal, the Blackley Hurst coal, Lancashire, the Varley Rock vein coal, near
Pontypool, &c. The quantity of coals and culm exported in 1850 was 3,351,880 tons,
and in 1851, 3,477,060 tons; declared value respectively, 1,284,2241. and 1,302,0251.
COAL GAS. From what is generally admitted concerning the impurities which exist
in crude coal-gas, it must be evident to those conversant with the principles of chemistry
that these impurities can never be thoroughly removed by any single reagent, for some of
them possess affinities diametrically opposite to the others. Thus, any means employed
to absorb carbonic acid and sulphuretted hydrogen gases would leave the ammonia free;
whilst an agent capable of combining with the latter, would not at all affect the former
impurities. Hence the process of coal gas purification, as now carried on at the best
gas works, is divided into two distinct parts. By one of these the whole of the ammonia and a portion of the carbonic acid and sulphuretted hydrogen are taken away, by
the other, the remainder of the carbonic acid and sulphuretted hydrogen are totally re



COAL.                                 433
moved; so that the gas ultimately passes forth to the consumer fiee from all contamination either by ammonia, carbonic acid, or sulphuretted hydrogen gas. And the absence of these impurities may at any time be demonstrated by applying the following
simple tests: — litmus paper, slightly reddened by an acid, will undergo no change
when held for a few minutes in a current of the gas; this proves the absence of ammonia, for otherwise the paper would become blue. Paper, dipped into a solution of
the acetate of lead, and held in a current of the gas, will remain white, which shows
that the gas is destitute of sulphuretted hydrogen, as, under contrary circumstances,
it would assume a deep brown or black hue. Lastly, if the gas be allowed to blow for
a few minutes through a clear solution of lime in water, the solution will not become
milky and turbid, as it would do if carbonic acid were present in the gas. No coal gas
which does not vindicate its purity by resisting the analytical powers of the above
tests can be regarded as sufficiently good for the purposes of illumination and lleating.
To separate the ammonia from coal gas, a variety of modes is at present in use;
thus, Mr. Lowe employs cold water minutely divided in an apparatus which he terms a
"scrubber," and which is perfectly analogous to the cascade chinique of Clement Desormes. With a similar view Mr. Palmer mixes the gas with steam, and then subjects
the mixture to a condensing temperature, so as to obtain water, minutely divided in
drops, like rain or dew, and therefore presenting a considerable surface for chemical
action. Mr. Johnson prepares a compound, consisting of sulphate and biphosphate of
lime, by acting on burnt bones with sulphuric acid; and this he disposes in trays, so as
to absorb the ammonia and produce a mixture of sulphate of ammonia and phosphate of
lime, which, as might be expected, he finds an extremely efficient fertilizing agent. Mr.
Laming employs a solution of chloride of calcium or muriate of lime, absorbed into sawdust, which he disposes in the same manner as that followed by Mr. Johnson, and by
which the muriate of lime is gradually decomposed with the formation of carbonate of
lime and muriate of ammonia,-the resulting compound being either valuable as a
manure, or as a source for the manufacture of sal ammoniac. Sulphate of lime, and
various other earthy metallic salts, have also been proposed and employed,-such
as the sulphates of magnesia, alumina, zinc, iron, and manganese, and the chlorides of
the same metals. With the exception of the sulphate of lime, they do not, however,
seem to possess any advantage over the modes we have mentioned as now in use for the
absorption of ammonia; and hence it may be as well to examine more minutely the
actions of those methods, and their effects upon the gas undergoing purification.
The process of Lowe is extremely simple in theory, and, where the saving of the ammonia is not an object of importance, has much to recommend it; Here the ammonia
is, so to say, washed out by means of water; and the application of the scrubber may
either be made before or after the other impurities are taken away, with, however, this
difference in the result:-if the gas, after quitting the condenser, is passed at once into
the lime purifier; and the scrubber applied afterwards, nothing but ammonia will
be removed by the water; but if the scrubber be employed in the first instance, then,
with every atom of ammonia taken away, one of carbonic acid and sulphuretted hydrogen will follow, and hence a great economy of lime in this way arises; for the ammonia,
though itself an impurity, thus becomes a purifying agent, and the liquid from the
scrubber consists, not of aqueous ammonia merely, but of a solution of carbonate and
hydrosulphate of ammonia. It is, however, very difficult to separate the whole of the
ammonia, either free or combined with carbonic acid, by Lowe's scrubber, without the
application of a very large body of water; and it has been suggested, that excessive
ablution diminishes considerably the illuminating power of coal gas. This circumstance, if true-and it is far from improbable-demonstrates the necessity of limiting
the action of water upon gas, and must, in some degree, interfere with the employment
of an otherwise invaluable instrument of purification. The plan of Palmer is precisely
similar in its effect to the scrubber of Lowe, but more costly, and, except when conducted with great care, less efficacious, as the entire success depends upon the perfection.
of the condensation; for, unless the condensed water be cooled down to the mean temperature of the atmosphere, little or no ammonia will combine with it; and there is,
moreover, a still greater danger of injuring the light-giving power of the gas by condensed steam, than by an equal weight of cold water. This method cannot, therefore,
be considered as equal to the former, more especially when coal gas, of low specific gravity, is to be purified. The mere recital of Johnson's process almost details its mode of
action; and it would scarcely be necessary to say more concerning it, but for the contrast
it presents to that of Laming, and the substances before alluded to. If the phosphate of
lime or bone earth, mentioned as part of Johnson's mixture, be regarded as a sponge for
holding the sulphuric acid which he employs, then the ammonia is taken up from the gas
by simple elective affinity with the production of sulphate of ammonia; and this is, beyond doubt, a true explanation of the modus operandi in Johnson's case. Here, however,
it will be noticed that nothing but ammonia is removed, for the carbonic acid and sulVOL. I                             3 K




434                                COAL.
phuretted hydrogen remain unaffected; consequently this system might be employed
either before or after lime purification. Now, Laming's plan differs altogether from this
and, as will readily be seen, admits of application only before lime purification. The foul
coal gas from the condenser contains carbonate of ammonia in a gaseous condition; and
it has just been shown, that the process of Laming depends upon the use of muriate of
lime. But at the ordinary temperature of this country these two substances are incompatible with each other; and, consequently, as fast as the carbonate of ammonia is brought
by the current of gas into contact with the muriate of lime, mutual decomposition ensues, and both the ammonia and carbonic acid are solidified; the former becoming converted into muriate of ammonia, and the latter into carbonate of lime, by an interchange
of elements with the muriate of lime used in the process; therefore the result differs
thus far from that of Johnson,-that carbonic acid as well as ammonia is taken from the
gas, and consequently a saving of lime, or other purifying material, effected: of course
sulphate of lime would act in the same way, though less powerfully; whereas metallic
salts, in general, having more affinity, after decomposition, for sulphuretted hydrogen
than for carbonic acid, will produce an economy of lime by removing the former and
not the latter impurity. Such, then, is a descriptive outline of the methods actually
followed at the present day for the purification of coal gas from the ammonia it contains; and although seemingly abundant enough to have exhausted the subject, yet
there is still an extensive field open to improvement even here.
Amongst the large class of ammoniacal compounds known to chemists, it seems
strange that no one has yet taken advantage of that interesting series which suffers
decomposition by the mere application of a moderate temperature, evolving at the same
time pure ammoniacal gas, and yielding, as a residue, the substance originally employed
for purification. We shall enumerate but one or two substances of this kind for the
purpose of illustrating our argument, leaving the whole question as open as ever to
practical investigation. When phosphate of magnesia is exposed to the action of
ammoniacal gas, its acid becomes divided in such a way as to produce the triple salt
called ammoniaco-phosphate of magnesia; and as this is a much more insoluble substance
than the simple phosphate, we have only to pass impure coal gas through a solution or
aqueous mixture of the latter, to insure the precipitation of all the ammonia contained
in the gas; whilst, at the same time, the compound which it has formed with the
phosphate of magnesia is very easily decomposed, so as to admit of a continuous usage
of the same material; for at a temperature considerably below a red heat, the triple
phosphate of magnesia parts with all its ammonia, and becomes simple phosphate again,
with the renewal of its primitive power as an absorber of ammoniacal vapours. But
the ammonia which is expelled by heat might very easily be condensed in water, and
thus originate a valuable commodity for the market. By this means there can be no
doubt phosphate of magnesia might be employed over and over again in the purification of coal gas, whilst the ammonia procured from it would contain neither sulphur
nor any other impurity. An iron vessel might be used for the distillation; and if too
high a heat was not given to the phosphate of magnesia, its purifying action would
remain unaltered; thus presenting altogether a fair opening for the investment of
talent and industry. Similarly, boracic acid deserves attention, from the facility with
which, even at the temperature of boiling water, it parts with the greater portion of
any ammonia previously united to it, at the ordinary heat of the climate in this country.
It offers, consequently, a commodious vehicle for collecting and conveying the ammonia
of gas works into public use, without the risk of nuisance or loss. Many other substances
possessing this double property of absorbing and giving off ammonia by a trifling change
of temperature might be pointed out; but this lies beyond our province; it is the principle only which we attempt to elucidate, with a view to its practical application in
some specific instance.
Presuming that the impure gas has had all its ammonia separated by proper treatment,we have now to consider in what way the carbonic acid and sulphuretted hydrogen
may be most easily got rid of. Lime is the agent commonly selected, and all things
duly admitted, there is a great mass of evidence in its favour,-so much so, indeed, that,
until lately, it has had no competitor. At present, however, the oxide of iron is becoming a formidable rival; and therefore we propose to examine into their respective
merits, which, after all, are less alike than might be supposed in two substances selected
to perform one and the same operation. When properly prepared and moistened, lime
removes from impure coal gas both carbonic acid and sulphuretted hydrogen with
extreme energy, and consequently effects thorough purification after the ammonia has
been got rid of. Oxide of iron combines only with the sulphuretted hydrogen contained in the gas, and not with the carbonic acid; so that coal gas purified in this way
requires subsequent application of lime, or some other material capable of combining
with carbonic acid. Thus far, therefore, the advantage is much in favour of lime. But
when lime has absorbed all the impurity it can attract from coal gas, or, in technical




COAL.                                   435
phrase becomes " foul," it is not only altogether useless, but, much worse than this, it is a
serious nuisance, in consequence of the evolution of sulphuretted hydrogen the moment
it comes in contact with atmospheric air, which arises from the action of the atmo
spheric carbonic acid upon the hydrosulphate of lime contained in the foul mass.
Gas-lime refuse is therefore a grave inconvenience to many gas companies. Now with
oxide of iron no such inconvenience is felt; for this substance in uniting with sulphuretted hydrogen produces a compound which yields no noxious or unhealthy emanations
by the contact of air, but is, under such influence, simply oxidized, and in a great measure
restored to its primitive power, so that it may be used over and over again, ten, twenty,
or even thirty times in succession. These peculiarities give the oxide of iron a decided
superiority in many situations, though up to the present moment its practical application
has been extremely limited. When lime contained in a purifier has ceased to purify
gas, the general impression is that it has been wholly resolved into carbonate and
hydrosulphate of lime; but this is very far indeed from being the case, for even the
foulest lime seldom contains less than one-fifth of all its lime free or uncombined; and
gas-lime refuse is occasionally to be had so imperfectly saturated that fully one-half of
the lime paid for by the gas company may be said to be thrown away. In the first
place, it is not customary to examine the lime itself, so as to determine its chemical
value or combining proportion, and still worse, it is not usual, secondarily, to analyze
the lime refuse with a view to ascertain how much lime is passing away unacted on.
As both of these desiderata may be secured without the application of any great
chemical skill, we shall proceed to give a brief description of the means needed to solve
the trifling problems, beginning with the lime itself. Having selected from the bulk a
fair sample of lime, let this be ground to a fine powder in a clean and dry mortar; then
weigh out 100 grs. of the powder, and place it in a tumbler or other suitable vessel,
where it is to be repeatedly washed with a warm but not hot solution of sal ammoniac
in water,-the temperature being about 80~ or 90~ Fahr.  Great care must be
taken that, in washing the lime, no solid particles are allowed to escape with the ammoniacal solution; and, as soon as it is observed that the fluid containing the sal ammoniac
ceases to restore the colour of reddened litmus paper, after it has been poured upon the
lime, then common water may be used to wash the remaining lime; after which it
must be dried at a red heat, and then weighed;-the loss will indicate the amount of
pure lime present in the 100 grs. taken. This mode of analysis depends upon the fact
that lime, at the temperature indicated, decompose muriate of ammonia and becomes
soluble, but any carbonate of lime, silicate of lime, alumina, or other inactive impurity,
remains undissolved, and may therefore have its quantity determined by the balance.
Foul gas-lime, or refuse, is somewhat more complex, but nevertheless far from difficult in its analysis. Having, as before, selected a fair sample, let 200 grs. be weighed
out, and placed in a stoppered bottle, with an equal weight of sal ammoniac, and four
ounces of water, heated, as before, to about 80~ or 90~; shake the whole well together,
and keep the mixture warm for twenty minutes; then filter rapidly into a stoppered
retort, and wash the filter with two ounces of hot water, which are to be added to the
filtered solution.  Next distil over one-half of the fluid into a receiver containing
100 grs. of sulphate of copper, dissolved in water, and set the fluid remaining in the
retort a'side to cool. Collect the black precipitate now contained in the receiver upon
a filter, and wash it well with hot water, then dry and weigh it: it is the sulphuret
of copper, and contains one-third of its weight of pure sulphur. The fluid in the retort
must now be mixed with an excess of carbonate of soda, and the white precipitate which
ensues well washed, dried, and then weighed. One hundred grains of this precipitate,
which is carbonate of lime, indicate 56 grs. of pure lime; and if from this we deduct
the quantity combined with sulphuretted hydrogen, as given by the sulphuret of copper,
the remainder will be the total quantity of pure lime in the 200 grs. of gas-lime refuse,
which had not been utilized in the purifier. Thus, suppose that 200 grs. of any sample
in question have given 24 grs. of sulphuret of copper, and 80 of carbonate of lime, then
the total amount of lime will be 44-8 grs., from which 14 grs. must be deducted for
that united to sulphuretted hydrogen, since the atom of sulphur is to that of lime as 16
to 28, and 24 grs. of sulphuret of copper contain 8 grs., or one-third of its weight of copper,
which is consequently equal to 14 grs. of pure lime. This supposed sample has therefore given 30'8 grs., or 15'4 per cent. of free lime. Thus, in place of the mere rule of
thumb system, too commonly pursued in gas works, a good gas engineer will control the
entire produce of his manufactory by determining, first, the total amount of sulphur given
off in a gaseous form by the coal he uses; next the chemical power of his lime; and
lastly, whether or not the action and arrangement of the purifying apparatus is such as
to insure the proper saturation of the lime with the impure constituents of the coal gas.
Without the occasional employment of analytical processes, similar to those previously
given, it is altogether impossible to conduct gas-works with that certainty and confidence essential to perfect economy.
3 K 2




436                                   COAL.
It might be supposed that with the purification of coal gas the chief difficulties
of a gas engineer ended, but this is very wide of the truth; for upon no point is
there greater diversity of opinion, and more discrepancy in result, than exists regarding
the proper mode of burning gas for the purposes of illumination and heating. As regards the former question, it seems hitherto to have been impossible of solution, from
the fact that quantity and intensity of light have been confounded together; and persons have been surprised to find that a bright white light, of great intensity to the eye,
has, nevertheless, illuminated a given space worse than a large quantity of dull, yellow,
smoky-looking light. Thus, if when an argand oil lamp is burning with great brilliancy the central aperture for the admission of air be closed, the flame will immediately
become yellow and smoky, yet, on examining the walls of the apartment, it will be
found that they are better illuminated than with the more brilliant light. In the
former case, many of the particles of carbon are consumed before they take on the solid
condition, whereas in the latter, they are all separated from the hydrogen of the oil,
and become red-hot solid bodies ere they inter into combustion. But as the quantity of light is proportioned to the number of solid particles heated, and its intensity to
the elevation of the temperature to which they are heated, it follows, that part of the
carbon is employed in producing heat, to give intensity of light to the remainder, in
the one case, whilst in the other, the whole of the carbon becoming solid reflects a
great quantity of light of less intensity. For the ordinary wants of society, the latter
is the best light. A knowledge of these matters enables us easily enough to explain the
vast difference in illuminating power which one and the same gas displays when consumed in different burners.  Thus, a thin gas, of low specific gravity, which affords an
excellent light in an argand burner, will scarcely yield any light at all with a fish-tail
or bat's-wing; and a rich cannel coal gas, well adapted to either of the latter burners, requires infinite care to prevent it from smoking in an argand. In determining the relative
illuminating powers of different gases, it is therefore necessary to select for each gas that
form of burner best suited to display its light-giving properties, and not continue the
present Procrustean system of cutting down the power of the gas to an arbitrary
standard of burner; the only result of which has been a series of assertions and contradictions too disgraceful for further notice. In photometrical experiments, a spermaceti candle, of a determined size, is commonly employed, and, in a rough way, answers
remarkably well.  But sperm, like wax and tallow, gives quantity of light, but not of
an intensity equal to gas, as may beseen in a moment by contrasting the comparatively
yellow flame of the one with the brilliant white light of the other. They are therefore like
musical instruments tuned to a different pitch, and can never harmonize with each other.
The better plan would be to select olefiant gas as a photometrical standard, since this
compound is uniform in composition, and can be easily prepared at a few minutes'
notice. It possesses, moreover, the advantage of being consumed in similar burners
to that employed for the gas to be tested, and is under the influence of the same barometric and thermometric variations.  The Bunsen photometer, as modified by Mr. A.
King, of Liverpool, is, perhaps, the best instrument to employ in experiments on comparative illumination.  Regarding the ultimate analysis of coal gas little need be said,
as the results have no specific value or meaning.  The only correct mode of analysis is
by passing a known volume of the gas over oxide of copper in a tube heated red-hot,
and collecting first the moisture by chloride of calcium; secondly, the carbonic acid by
hydrate of lime or solution of potash, as followed in ordinary organic analyses; and,
lastly, receiving the incombustible residue over water in the pneumatic receiver: from
which three products, the quantity of hydrogen, carbon, and nitrogen may be deduced.
The ultimate analyses of coal gas, as also the estimation of its value from the condensation of what is termed its olefiant gas, whether by chlorine, sulphuric or nitric acid,
are processes of no practical value to the public, and serve only to mislead the ignorant.
From the vast reduction which is now taking place in the prices of coal gas, its calorific
power has become one of the most interesting questions of the day; and when the waste
of fuel consequent upon lighting a common fire, with the quantity consumed after the
fire is no longer wanted, are carefully inquired into, it seems very clear, that for at least
4 or 5 months of the year it is cheaper to cook by gas in London than by coal, at the existing prices of these articles. An apposite illustration of the correctness of this assertion
is afforded by the warm bath of Mr. Defries, in which 45 gallons of water are heated from
the temperatures of 500 to 100~ Fahr. by 30 cubic feet of gas, and at a cost of only three
pence. Now, to effect this at all by coal would entail an expense of at least fourpence; but
to do so in the same period of time (5 minutes), would certainly entail an outlay of not
less than a shilling. Of course, where the operation is to be repeated, or go on continuously, a different result would ensue; but for extemporaneous use, coal gas will always
be cheaper than coal. But even this surprising economy has been exceeded by a very
elegant arrangment, invented by Mr. F. I. Evans, of Westminster, in which a coil of
iron tubing is so disposed, as to present an immense surface to the heating influence of
the burnt gas, and thus absorb the whole of the heat. In this way, a current of cold




COAL.                                   437
water entering at one end of the tube flows out of the other continuously, and at any
required temperature, according to the velocity of the current, and the quantity of gas
consumed in a given time.  For the requirements of the Humane Society, for the public
hospitals and charities, a simple apparatus of this kind must find a ready application,
and deserves to be better known. According to direct experiments, made with great
care, Mr. Evans has found that common Newcastle coal gas, of sp. gr.'416, has an
evaporative value equal to about 22 times its weight, or, in other words, that 1 lb. of
such gas will convert, theoretically, 22 lbs. of water into steam; and this accords very
well with the results given by Defries with his bath, in which 30 cubic feet of
gas are stated to heat 45 gallons, or 450 lbs. of water at 50~. This is equal to 15 lbs.
similarly heated for each cubic foot of gas, weighing, say 206 grains, or 750 lbs. of
water heated one degree by the same means.  This, estimating the latent heat of
steam at 960, gives 25 parts of water boiled off for every one part of gas consumed,
which is very nearly three times as great as the heating power of good Newcastle
coal.  But practical experiments were wanting to show the real amount of water
which can be boiled off by gas, as burnt in ordinary burners beneath a boiler. This
deficiency has been supplied by Mr. Evans, to whom we are indebted for the following tabular statement:-One cubic foot of gas, weighing about 205 grs., and of sp. gr.'413, boiled off four tenths of a pound of water, or 13-6 times its weight. One cubic foot,
weighing about 290 grs., and of sp. gr. -564, boiled off five tenths of a pound, or 12 times
its weight. One cubic foot, weighing about 360 grs., and of sp. gr.'700, boiled off seventenths of a pound, or 13-6 times its weight. Thus showing that in the case of gas, onethird at least of all the heat evolved passes off unabsorbed by the boiler. In our
comments on coal we had occasion to remark that something like one-half of all
the fuel consumed under steam boilers is wasted; and it now appears that fully onethird of all the gas employed in our culinary operations must be thrown away, and
will continue to be so until the hand of improvement is applied in the proper quarter.
There is, unquestionably, much scope for ingenuity in devising the best forms of
apparatus for burning gas, and utilizing its waste heat. A very elegant little machine,
which promises to elucidate some obscure points as regards the purity of gas, has
lately been added to the ordinary testing chemicals of a gas engineer. This consists of a bent tube, forming, as it were, the horizontal flue of a furnace, in which the
products of combustion arising from gas may be condensed, and afterwards examined
with reference to their nature. Mr. A. Wright, of Westminster, is the inventor and
maker of the apparatus in question, and by its means two curious facts may at almost
any time be demonstrated. One of these is, that sulphuric acid is an invariable product of the combustion of coal gas; the other, that very frequently, and more especially
with cannel coal gas, a substance possessing all the properties of aldehyde makes its
appearance.  The latter seems to be a product of imperfect combustion, and gives rise
to that peculiarly offensive odour produced wherever large quantities of coal gas are
burnt in a close compartment. It is commonly believed by chemists, that coal gas
contains ammonia, which in burning is converted into nitrous or nitric acid; but the apparatus of Mr. Wright demonstrates at once the fallacy of this opinion, by proving that
whenever gas contaminated with ammonia is consumed, the ammonia either passes off
unchanged, or is simply decomposed into its elements; for carbonate of ammonia, and
not nitrate, makes its appearance in the condensed products. Before quitting the
subject of coal gas, it is necessary to say a few words upon the composition and use of
what is called ammoniacal liquor. This fluid condenses in the hydraulic main, and
flows out with the tar, from which it afterwards separates by gravitation.  Its specific
gravity varies, as also does its composition; but the following may be regarded as a
fair average: in one gallon, of specific gravity of 1-017, there were found of sesquicarbonate of ammonia 5984 grains, hydrosulphate of ammonia 420 grains, muriate of
ammonia 985 grains, with a trace of ferrocyanate and sulphocyanate of ammonia;
consequently, if the small quantity of sulphuretted hydrogen existing in ammoniacal
liquor be removed, as it may be by the application of the requisite proportion of
carbonate of lead, an ammoniacal solution will be produced, extremely well adapted
for many useful purposes in the arts, such as scouring woollens, flax, and other
goods, as well as for washing in general.  In all these cases, ammonia is greatly to be
preferred to soda, even at the same price; but as the ammoniacal liquor of many
gas works is actually thrown away, and under no circumstance sells for more than a
farthing a gallon, it is discreditable to our industrial economy that this very obvious
application of ammoniacal liquor should continue to be neglected; more especially
as the fluid, even after being used as above indicated, is still an excellent fertilizing
agent. In the Great Exhibition, there were but few illustrations of the manufactures
peculiar to gas; a circumstance attributable to the risk of permitting the necessary
experiments to take place, by which alone the actual value of any improvement in
gas apparatus can be correctly determined. Hence, in the Crystal Palace, merely
articles of established reputation were shown. which. having been long before the




438                                   COAL.
public eye, by no means represented the existing condition of this branch of manufacture. On this account, although the decision of the executive committee to exclude
experimental gas apparatus seems somewhat unfortunate, yet, when the great value
of the goods shown in the Exhibition is duly considered, there can be but two opinions
concerning the propriety of the step. The various samples exhibited were nevertheless extremely good of their kind, both in the British and Foreign departments.  In
clay retorts, the best specimen was in Class 27., by Cowan & Co., of Blaydonburn,
Newcastle-on-Tyne; and the next in quality stood in the Belgian portion of the Exhibition.  M. Pauvels, of Paris, exhibited a Very good retort also; and there were several satisfactory-looking samples from other quarters.
COAL GAS, COMPOSITION OF. From the most recent investigations into the composition of coal gas, it appears extremely doubtful whether any gaseous compound exists
in it to which the name olefiant gas can, with propriety, be accorded, and it certainly
seems to have been assumed on very hasty and unfounded data, that to the presence of
olefiant gas the illuminating force of common coal gas is chiefly due. Without pretending to deny altogether the presence of the olefiant in the gas of our streets, it is nevertheless susceptible of proof that the quantity which, on the most liberal computation,
can be allowed, is infinitely small and insignificant, and, in a practical sense, warrants
the now prevailing opinion that there is really none. In support of this, it can be shown
that if common coal gas be made to traverse very slowly a great length of tube exposed to the refrigerating effect of a bath of ice and salt, the gas will issue from the other
end of the tube almost entirely deprived of its illuminating power; and a similar result
may be obtained at ordinary temperatures by passing the gas through alcohol and other
reagents. In the case of alcohol, the effect is, however, very instructive, for the alcohol
gains exactly that which the gas loses in illuminating power, and, after the experiment,
it is found to burn with a bright white flame, and to become milky with water.  Now,
on the supposition that the photogenic power of coal gas was due to olefiant, none of
these results should follow, for no such cold would liquefy olefiant gas, nor would
alcohol absorb it in any great degree. Moreover, all attempts to obtain, through the
agency of fuming sulphuric acid, any compound like sulpho-vinic acid have utterly
failed, even when tried upon a rather large scale. Hence, in regarding coal gas, it is theoretically more correct to consider its luminosity, as arising from the presence of various
volatile hydrocarbons or naphthas, rather than from any permanently elastic fluid whatever. This view of the case has latterly become very prevalent, and is now leading to
the most important improvements in the manufacture of illuminating gas. It has long
been known that ordinary bituminous coals will yield a much larger volume of gas than
may, with propriety, as regards the photogenic power of that gas, be taken away from
the coal. This arises from the circumstance, that the first portions of gas are much
richer in hydrocarbons than the remainder of the charge, and a period arrives at which
the gas, though still great in quantity and eminently combustible, ceases to possess any
value whatever as an illuminating agent. Moreover, it is known that the mixed gas
obtained by decomposing water through the agency of carbon at a red heat is also combustible, but devoid of photogenic power; and it is owing to a correct appreciating of
the circumstances upon which the value of common coal gas depends, that both these
and other forms of combustible gas have lately been rendered as permanently luminous
and well-adapted for the production of light as the best kinds of common coal gas.
Having once clearly comprehended the cause of luminosity in ordinary gas, but few
steps are required to perceive that the latter portion of a charge of coal, when distilling
in a retort, needs but a part of the surplus hydrocarbons of the fir, t portion to render it
equally valuable, and we are insensibly drawn to the means of effecting the desired end.
Thus, if the latter portions of the charge be stored away separately, and passed in regular quantities over coal which is undergoing the primary action of destructive distilla.
tion, it is clear that such gas will become charged with the hydrocarbons of that primary
distillation, and thus, in all respects, resemble the first part of the charge, or, in other
words, be made equal to the best gas; at the same time the amount of labour and expense incurred in condensing out these surplus hydrocarbons must be much diminished
by the presence of an amount of gas capable of retaining them permanently in solution
at ordinary temperatures.  Not only, therefore, is it possible to procure in this way a
much larger quantity of gas of an average illuminating power from a given weight of
coal, but the expense of this production is decreased by the diminished condensation
needed for the whole, as compared with that required for a part of the gas under the old
system. But there is a still greater advantage than these, and one scarcely to have been
expected.  These poor gases consist chiefly of hydrogen gas, and it has been discovered
that this gas possesses the remarkable property of preventing the decomposition of
every form of hydrocarbon at a red heat. The consequence, therefore, of passing such
gas over coals, in its primary state of distillation, is to prevent the decomposition of the
various naphthas by the heat employed, and which, without the presence of hydrogen,
would be resolved into solid carbon and light carburetted hydrogen, the former of which




COAL.                                    439
remaining in the retort impairs the utility of that vessel, whilst the illuminating
power of the gas produced is greatly diminished by the loss of solid matter. Now
it has been stated that to these naphthas the luminosity of gas is to be attributed, and
therefore their preservation in the way described, by the action of hydrogen, would of
itself be an immense step in advance of our former practice; but when to this is added
the fact that, with a vastly increased preservation of hydrocarbon, there is also a vastly
increased production of combustible gas to render that hydrocarbon available for
public use, the real merit of the new discoveries in gas-making must strike even the
most thoughtless observer. Of course, the same argument which applies to the use of
the residuary gas from a charge of coal, is equally fitted to illustrate the beneficial operation of the gases evolved by decomposing water with red hot carbon. In this latter
instance, however, an important fact presents itself, for unless the whole of the surplus
watery vapour has been removed or condensed from this water gas, the hydrocarbons
arising from the incipient distillation of the coal. are destroyed, and, therefore, the object sought to be gained is lost. This accounts perfectly for the innumerable failures
which have taken place in attempting to employ steam and water gas for the purpose
of illumination; nor, until this subject was investigated by Mr. T. G. Barlow, does any
one appear to have formed a correct opinion of the cause of such invariable want of
success. Mr. Barlow, however, not only discovered the peculiar preservative power of
hydrogen, but also the no less remarkably destructive action of steam, and hence, by
merely condensing this latter, he has been enabled to employ water gas with a success which bids fair to prove a very profitable manufacturing speculation, and for the
details of which he has secured her Majesty's letters patent in conjunction with Mr.
Gore. For the application of the residuary gas from common coal to the preservation
of the hydrocarbons arising from fixed oils and fats during distillation, and for the
production from coals, lignite, tar, &c., of a larger amount of illuminating gas than
can be obtained by the ordinary process, the public is indebted to Messrs. G. Lowe
and F. L Evans, both well known as engineers in the service of the Chartered Gas
Company. That these improvements will, in some measure, revolutionise the manufacture of gas seems pretty obvious.
To determine with any degree of precision the value of a gas as an illuminating
agent is really a very difficult, though seemingly a very simple affair. The most general method is by the instrument called the Bunsen photometer. The indications
of this instrument (at best but imperfect) have been so largely improved by the
ingenious modifications made in its use by Mr. Alfred King, of Liverpool, that it has
come to occupy a position in the public confidence, to which in its original condition it
had not the slightest title. The great difficulty to overcome was the securing of one
uniform standard of illumination, without which, as a matter of course, the indications of
the photometer were utterly valueless. This indispensable condition has been in a great
meusure arrived at by Mr. King, who employs a spermaceti candle, and ascertains the
amount of spermaceti actually consumed during the experiment, and then reduces this
to one uniform rate of 120 grains of spermaceti burnt per hour as contrasted with an hour's consumption of the gas to be tried at the rate of
five feet per hour, or in a series of ratios, from 2 to 5 feet per hour; there
90 0   are, however, many disturbing causes in the burning both of the candle
and of the gas, and a very serious one results from the fact that the shape
80     of the flame of the gas materially affects its photogenic meter, thus the
flat side of a bat's-wing burner will give almost one-third more light
70     than the edge of the same burner, though the rate of consumption be
unaltered.
60       It is necessary, therefore, to adopt some other means of determining
the value of a gas than by photometry, and it would appear that
50    this may be effected by the agency of bromine.  This substance
possesses in a singular degree the power of removing from coal gas the
40  whole of the vapours upon which its luminosity depends, and if these
vapours were uniform in composition, all that need be done would be to
determine their volume per cent. But this is quite useless, for the vapours
30     differ in themselves to an incredible extent, and therefore it is not only
the volume, but the specific gravity of these vapours also, which must be
20     obtained, or in other words, their total weight, for this weight represents the value of the gas. Now if we take a tube bent, closed at one end,
10     and graduated, as shown in the following figure, we possess at once an
instrument for determining the value of a gas by volume.
This tube must be filled in the first place with water, and so much of
the gas passed up into it as will occupy the graduated portion, when the
residuary water will act as a valve.  Having placed the whole for a few
minutes in a cylindrical vessel containing water, so as to secure a uniform




440                                  COAL.
temperature, the tube must be raised to the water level, and the exact quantity of
gas recorded. When this has been done, a few drops of bromine, in all about the
size of a pea, are to be dropped through the water in the tube, and a stopper or cork
applied; the whole must then be well agitated, until the gas becomes tinged with the
red hue of the bromine, after which the stopper must be removed under water, and a
few drops of a strong solution of potash being added the stopper is to be replaced, and
the whole again agitated until the bromine tint of the gas has disappeared, when the
stopper must be again withdrawn under water, and the tube placed as at first in a
vessel of water to regain its original temperature, when the water-level must be
once more made, and the amount of absorption read off and recorded. This operation
does not last more than 10 or 15 minutes, the barometer need not therefore be consulted. Precisely similar to this, but on a larger scale, is the first part of the opE-ation for determining the weight of the condensed portion. In this case a vessel shaped
as below is necessary.
This, as is evident, differs very slightly from  the tube, the
bottom  being provided with the same water-joint contrivance
for the introduction of the bromine, whilst the stopper is
pierced by a hole, in which a stop-cock is very carefully fixed,
so that after the action of the bromine and caustic potash, the
gas may be removed by an exhausted flask so that its specific
gravity can be readily determined.  Before doing this, it is
however advisable to wash the gas two or three times with cold
water, which is easily done if we introduce the bottle into a
vessel of warm water so as to expand the gas, and thus expel
the fluid through the water-joint tube, which being effected, we
have only to close this opening and immerse the bottle in cold
water, when, by withdrawing the stopper joint, cold water will
rush in, and this may be repeated at pleasure, the object being
to wash the residuary or incondensable gas thoroughly; this
operation requires but a short time, and if we have taken beforehand the specific gravity of the original gas, the amount of its
condensation, and now know the specific gravity of the incondensable portion, it is clear
that we possess the means of knowing the exact weight of that which has been condensed.
Thus, a cannel coal gas at Westminster was analyzed in this way, its illuminating power
by the photometer being 20 candles per 5 feet. This gas had a specific gravity of'48500, and a condensation of 9 per cent., whilst the specific gravity of the uncondensed
portion was'336. But if 100 weigh'33600, then 91, the amount of uncondensed,
must weigh'30576, and this deducted from'48500, leaves'19924 for the condensed
gas, which, as we have seen, is equal to 9-5 per cent., and bringing this to the uniform
standard of 100 measures, we have 2-09 for the specific gravity of this condensed vapour;
and if this specific gravity be multiplied by the amount of condensation, we shall have
the true value of the gas in numbers, which, by a singular coincidence, run very close
with the indications of the photometer as chosen by Mr. King, that is to say, the number of spermaceti candles burning 120 grains per hour, which the gas is equal to when
consumed at the rate of 5 feet per hour. In this instance that number, it will be remembered, was 20, and 2-09, the specific gravity of the condensed gas, multiplied by
9-5, its per centage absorption by bromine, gives 20-855, a very close approximation.
A vast number of experiments have been made, all of which are equally conclusive as
to the value of these indicators.
COALS (heating powers of). An accurate, systematic, and intelligible report upon
the calorific properties of coal has long been needed by the manufacturing and mercantile interests of this country. In addition to the vast importance of such an inquiry, it
would be perhaps impossible to point out a subject on which less difference of opinion
exists as to the extent and nature of the information wanted than the one before us,
Science, properly speaking, has little or nothing to do with the question; the object in
view is purely and exclusively practical, and is meant for the guidance of practical men
and for practical purposes. Theory, above all things, should be carefully avoided in
such investigations; and supremely indifferent about the assistance of any eminent
chemist on such an occasion, we, should, nevertheless, insist strongly upon the necessity
of providing a good stoker. Mr. Hume, M. P., however thought otherwise; and to him
the country is indebted for the first report upon the coals destined for the steam navy. Of
this report we will venture to say at once that a more garbled, more inaccurate, and less
impartial job was never exhibited-nay, not even in the House of Commons. To
begin at the beginning of this disgraceful affair, we will merely remark that Mr. Hume
(whose honesty and integrity are beyond suspicion) directed the attention of the Lords
of the Admiralty to a subject which, if these Lords attended to anything but their salaries, must have occupied their attention years ago. Mr. Hume, after referring their




COAL.                                   441
lordships to an American report, with experiments, on the evaporative value of coals,
says:" They have decided by direct and practical tests the comparative usefulness of
American and English coals, as well as the relative value of the former in their numerous varieties; and I submit to your lordships that a similar inquiry should be instituted
into the comparative usefulness of English, Scotch, and Irish coals, with the view of ascertaining the best for the naval steamers of this country. I may be allowed to point
out to your lordships that there is a public establishment in Craig's-court perfectly
qualified to apply the requisite direct and positive tests to the coals without delay; and
to that establishment may be added one chemist of eminence to assist in what is an
object of great national importance."
Upon this the Admiralty applied to Sir H. de la Beche, who, after the usual preliminary remarks, observes:
"As the funds of the Museum of Economic Geology are, unaided, inadequate to an
investigation of this order, I would suggest that the Admiralty be requested to furnish
aid to the amount of 6001. for the remainder of the year ending the 31st of March, 1846.
With this aid I have little doubt that we should be enabled to accomplish much this
year which may be of value, and have organized a system of inquiry alike effective, and,
viewing its national importance, which can be carried out at comparatively small cost to
the public."
We must content ourselves by guessing at the meaning of the last paragraph, and, as
far as this can be done with safety, we may conclude that, in the opinion of Sir H. de la
Beche, the funds of the Economic, plus 6001., would answer the object in view, to wit,
the obtaining a practical report upon the evaporative power of English, Scotch, and
Irish coals. If anything else is meant, why is 6001. named? The question is very fairly
put by Lord Lincoln, who, in reference to the establishment in Craig's-court, asks, in
plain English, " What is the course you would recommend for making it effective for
the purposes to which such an inquiry would be obviously directed?" Sir H. de la
Beche in answer mentions 6001. in addition to the funds of the Museum of Economic
Geology; yet something more appears to have been given by the following "memorandum":
" The Admiralty having acceded to the recommendation made in the foregoing letter,
and subsequently also supplied additional funds for the investigation, the latter was commenced as soon as the needful apparatus was erected and proper assistance procured,
which could not be accomplished until March, 1846."
Now, what is the meaning of the additional funds supplied for the investigation?
Were the funds of the Economic, plus 6001., spent on apparatus alone? And was it to
the mere erection of this apparatus that Sir H. de la Beche alluded when, in 1845, he
wrote, " With this aid I have little doubt that we should be enabled to accomplish much
this year," &c. 
There is a mystery about the very commencement of that business. Seldom do we find
Government officials ready to comply with the prayer of a petition which has merely
public utility to recommend it; but Mr. Hume has nothing to complain of on that
score in the present instance, for in addition to the Craig's-court establishment he solicited but one chemist, when lo! the investigation falls into the hands of Dr. Lyon
Playfair, Mr. Wilson, Mr. J. Arthur Phillips, MIr. Kingsbury, Mr. Wrightson, Mr.
Galloway, Mr. Hoy, and William  Iutchinson, all and each endowed with qualifications of a peculiar and important character bearing upon the investigation in hand,
and tending of course to render the report superlatively correct, useful, impartial, &c., &c.
There is an old axiom regarding broth made by a multiplicity of cooks, but perhaps it
does not apply to parliamentary reports and chemists.
The mystery does not, however, end here. Mr. HIume had requested that the inquiry
should be made upon English, Scotch, and Irish coals. Now, the following is the list
of coals operated on:NAMES OF COALS EMPLOYED IN THE EXPERIMENTS.
WELSHGraigola,                                Three Quarter Rock Vein,
Anthracite, Jones and Co.                Cwm Frood Rock Vein,
Old Castle Fiery Vein,                   Cwm Nanty Gros,
Ward's Fiery Vein,                       Resolven,
Binea,                                   Pontypool,
Llangenneck,                            Bedwas,
Pontrepoth,                              Ebbw Vale,
Pontrefellin,                            Porth Mawr,
Duffryn,                                 Coleshill.
Mynydd Newydd,
VOL. I                               3 L




442                                   COAL.
SCOTCHIDalkeith Jewel Seam,                      Fordel Splint,
Dalkeith Coronation Seam                  Grangemouth.
Wallsend Elgin.
ENGLIS —
Broomhill,                                Lydney (Forest of Dean).
IRISHSlievardagh Irish Anthracite.
From which it appears that the inquiry has been made almost exclusively upon Welsh
coals, for, out of twenty-seven samples of coal examined,
19 were Welsh,
5,, Scotch,
2,, English,
1 was Irish.
One of two things is very plainly exhibited by this table; either Wales is, above all
other places in the world, blessed with coals " suited to the steam navy," or a most
unjust and uncalled-for selection has been made for private purposes. It is vain to talk
of a next report; it will require years to complete another report, even if such another
disgraceful exhibition of partiality was attempted; and meanwhile our steam navy must
be supplied with the euphonious productions of Wales, to the exclusion of the vast
coalfields of Newcastle.  Of the two samples of English coal examined I am practically
acquainted with but one, for of the Lydney coal I know nothing; as regards the
Broomhill coal, however, I can safely assert that its only recommendation consists in
its belonging to Earl Grey, for at Newcastle it is regarded as an unimportant secondrate coal, the very name of which has not yet found its way into the London market. It
is far inferior for steam purposes to the whole of the undermentioned coals, many of
which are, in fact, the best steam coals for sea-going vessels in the kingdom:Carr's Hartley,                           West Hartley,
Hasting's Hartley,                        Bate's West Hartley,
Hedley's Hartley,                         Buddle's West Hartley,
Newcastle Hartley,                        Davidson's West Hartley,
Percy North Hartley,                      Nelson's West Hartley.
Richardson's Hartley,
Why these and many others have been passed over so unceremoniously to make room
for the wholesale introduction of the Welsh coal remains to be explained; we will now,
however, examine the report itself.
The first circumstance which attracts attention in this report is the appearance of
certain very simple equations, which, although well enough adapted for a boy just
commencing algebra, are singularly out of place here, since those who understand such
things generally prefer to make their own equations; and those who do not are but little
likely to benefit by such a display of learning.
A curious attempt is made at page 13. to prove that the evaporative value of a
bituminous coal is expressed by the evaporative value of its coke:" It is easy," says the report, " from analysis to examine whether the duty performed
by the coal is to be attributed to its fixed ingredients or coke, by estimating the work
which the latter is capable of performing. This maybe done by subtracting the ashes
in the coal from. its amount of coke, and estimating the remainder as carbon; this
carbon multiplied by its heating power, 13268, and divided by 965'7, or the latent heat
of steam, indicates the number of pounds of water which the coke by itself could
evaporate without the aid of the combustible ingredients of the coal. These results are
placed in column 3. of Table 6. (see next page), in juxtaposition with the actual work
done by the coal, and it will be seen that, notwithstanding several striking exceptiona,
which might have been expected, they on the whole show that the work capable of
being performed by the coke alone is actually greater than that obtained by experiments with the original coal."
Now, if this table proves anything, it proves the very reverse of the position attempted
to be established, unless theory is presumed to be equal to practice, which it certainly
is not, or why the necessity of spending upwards of 6001. in practical experiments?
But theory may be justly compared with theory, and then the table, so far from proving
" that the evaporative value of a bituminous coal is expressed by the evaporative value
of its coke," clearly proves that the evaporative power of a bituminous coal is an
immense deal greater than that of its coke; indeed almost double; and that the volatile
ingredients of coal evolve in burning relatively a much greater proportion of heat than




COAL.                                             443
the fixed constituents; this is, indeed, precisely what might have been expected from
the well-known caloric power of hydrogen, which is three times greater than that
EXTRACT FROM TABLE 6., SHOWING THE ACTUAL DUTY AND THAT WHICH IS
THEORETICALLY POSSIBLE OF THE COALS EXAMINED.
Actual Number of  Number of lb.    Total Number             Amount of
lbs. of Water  of Water     oflbs. of Water    Amount of  Sulphate of
conert    rted converted int  o conertible  Ammonia      Ammonia
Name or Locality of Coal  into Steam   Steam by the   into Steam    corresponding    corresponding
by llb. of   Ooke left by    by llb. of    to the Nitrogen   to the Nitrogen
Coal         the Coal.'theCol.       contained in   contained in
the Coal.     the Coal.
Practical.   Theoretical.   Theoretical.
Graigola        - -             9-35         11-301         13563          0497          1-932
Anthracite, Jones and Co. -     946          12-554         14593          0225            990
Old Castle Fiery Vein    -      8-94         10-601         14936          1590          6175
Ward's Fiery Vein   -   -       940                         14614          1238          4808
Binea -   -   -   -             994          11-560         15-093         1586          6-741
Llangenneck          -   -      8 86          10-599        14-260         1299          5-044
Pontrepoth           -   -      8-72          10-873        14-838         0-218         0-848
Pontrefellin      -      -      636           10-841        13787         atrace 
Powell's Duffryn     -.   -    10149         11-134         15-092         176           6835
Mynydd Newydd        -   -      952           9-831         14 904         1 808         7'340
Three Quarter Rock Vein -       8 84             081        13-106         1-299         5044
Cwm Frood Rock Vein    -        870           8'628         14-788         1-347         5 232
Cwm Nanty Gros    -   -         842           8'243         13-932         1-919         7 448
Resolven          -   -         9-53         10-234         13-971         1-675         6-505
Pontypool -         -   -      747            8144          14-295         1639          6364
Bedwas              -   - -     99            8-897         14841          1748          6-788
Ebbw Vale           -   -    1021            10-441         15-635         2-622        10182
Porth Mawr Rock Vein   -        753           6647          12811          1-554          6033
Coleshill       -               80            6-468         12799          1.785          6930
Dalkeith Jewel Seam      -      708           6-239         12-313         1-214          0-471
Dalkeith Coronation -   -       771           6924          12-772        a trace
Wallsend Elgin-   -             8-46          6 560         13'422         1-712          6647
Fordel Splint        -   -      756           6.560         13-817         1-372          5-327
Grangemouth   -          -      740           7-292         13692          1-639          6364
Broomhill -       -      -      730           7-711         14863          2-234          8674
Park End Lydney    - -          852.-567        13-257         1-477          9-61
Slievardagh     - -   -         9-85         10-895         12-482         0-279          1084
of carbon. There is, however, clearly a design throughout this report to extol the
anthracite coals at the expense of the bituminous; and, if Messrs. de la Beche and Co.
could succeed in establishing the fact that the heating power of coal is due solely or
even principally to its relative amount of carbon, it follows that Welsh coal must rise
in the market, for the greater part of the coal from that district is of the anthracite
kind, none of which is worked in the north of England. To prove the absurdity, however, of the above attempt, I will quote two or three cases from Table No. 6.:Theoretical
Name of the Coal.             Weight of Water                Excess
Evaporated             due to Volatile
by          by               Ingredients.
Coke.   Coal.___
WELSH —                                              262
Graigola    -  -             -    11-301        13563        4
Old Castle Fiery Vein    -    10-601            14-936       5073    The thing
Mynydd Newydd   -            -      9831        14-904                   speaks
e J   l a SCOTCH~_                                            for itse lf.
Dalkeith Jewel Seam          -      6-239       12-313       6-074
ENGLISH -
Broomhill                    - -      711       14-863       7-159
After theoretically demonstrating that "the evaporative value of a bituminous coal
is expressed by the evaporative value of its coke, the heat of combustion of its volatile
products proving in practice little more than that necessary to volatilize them," we are
suddenly greeted with the following paragraph:"The whole system  of manufacturing coke is at present very imperfect.  Besides
losing the volatile combustible substances, which, under new adjustments, might be
made of much value, an immense quantity of ammonia is lost by being thrown into the
atmosphere.  Ammonia and its salts are daily becoming more valuable to agriculture,
and it is their comparative high price alone which prevents their universal use to
all kinds of cereal cultivations. By a construction of the most simple kind the cokeovens now in use might be made to economize much of the nitrogen, which invariably
escapes in the form  of ammonia.  As an inducement to this economy, we have ap3L2




444                                  COAL.
pended to Table 6. two columns showing the quantity of ammonia and its corresponding quantity of commercial sulphate which each 100 lbs. of the respective coals
may be made to produce. When it is remembered that the price of sulphate of
ammonia is about 131. per ton, or that 100 tons (of coal, we suppose) in coking is
(are?) capable of producing on an average about six tons of this salt, its neglect is
highly reprehensible."
Nothing has tended half so much to retard the cultivation of chemistry by our
practical manufacturers as the kind of statements of which the above is a sample.
Written by individuals wholly ignorant of the subject of which they treat, these
assertions serve only to amuse practical men, and to demonstrate the stupendous folly
and assurance of their authors. Imperfection is an attribute of humanity, but that
the present system of making coke is very imperfect remains to be proved.
The volatile combustible matter of the coal is not lost; on the contrary, it is
employed as a means of converting the cinder of the coal into coke, and that, too, by
the heat which it evolves in burning; and if that heat was so inconsiderable as the
report would lead us to suppose, mere cinder alone would remain in the coke-oven,
even after the heat had been kept up for ninety-six hours. Perhaps the framers of the
report may want to know the distinction between cinders and coke. Coke, if good,
sinks in water; bad coke or cinder swims. The reason of this is very simple. The
longer and higher the heat to which carbon from wood or coal is exposed the more it
contracts, and consequently the denser it becomes. The volatile combustible matter of
the coal is employed, then, in producing the requisite temperature for coking, and the
oven is so contrived as to retain the heat a sufficient time to produce the necessary
aggregation of the particles of carbon, or, in plain words, the condensation of the coke:
to assert that this volatile combustible matter is lost is perfectly ridiculous. We are
next informed that "an immense quantity of ammonia is lost by being thrown into the
atmosphere," and that by "a construction of the most simple kind this loss might be
avoided"  Lord Dundonald, about fifty years ago, had the same idea, and tried it on
a large scale; it is unnecessary to say that it proved to be a complete failure, although
sulphate of ammonia was then worth four or five times its present price. But the
most absurd part of this scientific soap-bubble is contained in the last sentence:-" 100
tons in coking is capable of producing on an average about six tons of this salt"
(sulphate of ammonia). Now, let us for a few minutes imagine my Lord Grey
desirous as (we have no doubt he is) of making the most of his Broomhill coa.
Passing his eye down column 1. of Table 6., he sees at a glance that 100 tons of coal
will produce 8'674 tons of sulphate of ammonia, worth 131. per ton. Making a little
allowance for loss, he says to himself, "Well, call it 8. tons; and now how much
sulphuric acid is required?" We will suppose him practically acquainted with Dr.
Wollaston's scale, and that, valuing common " chamber acid" at three farthings per
cent., he has arrived at the following conclusion:I.    s..
100 tons of coal, at 3s. 4d. per ton = 16 13  4
62 tons of sulphuric acid, as above = 45 10  0
62  3  4
will produce
1.    s.  d.
8 tons of sulphate of ammonia, worth 110 10  0
and'0 tons of coke, at 8s. 6d. per ton 29 15  0
140 5  0
A promising speculation truly, if his lordship could only economize "the nitrogen
which invariably escapes in the form of ammonia."  But, most unfortunately, the nitrogen does not " invariably escape in the form of ammonia," for in practice nine-tenths
of it invariably escape in the form of nitrogen, as any experienced gas manufacturer
can testify, and as the experiments quoted in the report abundantly prove, for according to Mr. F. C. Wrightson (a pupil of Liebig), who (vide Report, page 6.) had fitted
"himself by special study for an undertaking requiring so much delicacy of manipulation, —according, then, to Mr. Wrightson (page 58.), the Binea coal and the Llangenneck coal gave by actual experiment in 100 parts 0'08 of ammonia, or'310 of sulphate
of ammonia. Now, if we compare this with Table 6. we shall find 
Binea coal   might, could, would, or i 6-741  really did J 0-310
Llangenneck  should produce             5044  produce   0-310
or about 20th of the quantity theoretically obtained by Sir H. De la Beche and Dr. Lyon




COAL.                                   445
Playfair; yet these are the individuals who find fault with our manufacturers, and
pretend to improve our processes. With quite as much practical utility might these
gentlemen have detailed to us the quantity of pure diamond which the coals in question
would produce, if we knew how; as the amount of ammonia which they might give off
if they would. Of the analytical part of the report we will say little more than that it
is in perfect keeping with the rest. In the first place, chloride of calcium is employed
to remove water and ammonia from the gas, although a very little practical knowledge
of gas purification would have taught the operator that, when water and ammonia are
absorbed by chloride of calcium, carbonic acid is also taken up, so as to produce carbonate of lime and muriate of ammonia; and as this carbonic acid must have been
regarded either as ammonia or water, it follows that the experimental results are valueless. The substance which ought to have been employed to absorb water and ammonia
under the circumstances is the fused or glacial phosphoric acid; but what real value can
we attach to experiments made upon less than half a grain of coal, in which the errors,
and errors there are, have been multiplied at least 300,000 times?  For example, at
page 58., we find " Anthracite, from T. Aubrey and Co." The quantity of this coal
taken for analysis was 0'2763 of a grain, or rather more than i of a grain. Now, supposing it had even equalled i of a grain, then to bring this to a pound it must be multiplied 21,000 times, and to raise this last to the weight of water which 1 lb. of such coal
could theoretically evaporate, as represented at column 4. of Table 6., this 21,000 must
he multiplied by 14'593; therefore, if any error occurred in the analysis of this anthracite coal, it has been multiplied upwards of 306,453 times; in regard to the
quantity of water which 1 lb. of such coal can evaporate, as exhibited in column 4. of
Table 6. The idea, however, of weighing the,0ooth of a grain is perfectly new to us,
who have always regarded even the o00th as something too nearly approaching the imponderable. These remarks apply equally to the experiments with litharge; no allowance is made, or notice taken of the error arising from the presence of iron pyrites in
the coal, although this substance would reduce more than 9 times its weight of litharge,
and the error thus produced has been multiplied upwards of 90,000 times in column 6.
of Table 4.; and in the case of the anthracite coal above mentioned this error has been
increased 104,507 times. Nor is the quantity of iron pyrites inconsiderable in many
offthese coals, for, according to Table 3., the following contain a portion of sulphur
equivalent to bisulphuret of iron, as under:- 
Slievardagh  -                  1267 per cwt. of iron pyrites for which
Resolven    -   -   -   -         9'50,,    no  allowance  has been
Bedwas       --                   6-56,,    made in the litharge exCwm Nanty Gros -   -   -         564,,   J periments.
To pretend to attach any value to such experiments, or to the conclusions drawn
from them, is a mere fallacy, and, as the whole of the theoretical part is based upon
these analyses, with them it must fall to the ground as erroneous and illusory. Under
these circumstances it becomes necessary to inquire most carefully into the large and
practical essays made for the purpose of determining the quantity of water evaporated
during many successive hours by considerable quantities of each particular coal.
With a few exceptions, each coal was burnt for eight hours, and the experiment repeated
three times, the quantity of coal consumed and of water evaporated being noted in
each instance, and an average drawn from the three results obtained by each coal. If
carefully conducted, this method ought to have furnished some valuable information,
but the discrepancies in respect to the three results obtained from some of the coals
are so enormous and unaccountable as to render the whole table suspicious, doubtful,
and therefore valueless; indeed, the differences observable between many of the different samples of coal are much less than the experimental differences given by one
and the same coal, and which occasionally amount to little short of twenty per cent.,
as the following table will show [see p. 446.].
The idea of forming a table from experiments producing such discordant results is
altogether preposterous, yet, turn in what direction we may, the same evidence of
blundering and incapacity presents itself. In the first place, the selection of the coals
was bad and unfair in the extreme, and no way calculated to answer the practical
end in view; secondly, the proximate analyses are worthless, from the employment of
chloride of calcium for a purpose for which it was not adapted; thirdly, the ultimate
analyses are made in quantities too small to entitle them to any confidence when their
results are raised to practical purposes; fourthly, the litharge experiments are erroneous; and fifthly, the practical essays by means of the Admiralty boiler are so completely at variance amongst themselves as to defy all arrangement or computation.
The entire report is, in fact, a disgrace to the age and country we live in, and carries
with it all the internal evidence of a job.
As it is possible, however, that the Admiralty may really be serious in its desire to
ascertain the true value of steam-coal, we will venture to throw out a few hints, in order




446                                 COBALT.
Extreme Difference in Three
Name of Coal. ~     Trials as to the Amount
Name ofo.    of Water evaporated
by each respective Coal.
Duffryn -     --                         2-3 per cent.
Old Castle   -    -                     11- 
Ward's -- -                              5'3,
Binea   -    -   -                      14-7,
Llangenneck -    -    -16,,
Mynydd       -    -    -                 4-9 
Three Quarter      -       -  1'4
Graigola        -    -                   2'1
Lydney -      -   -    -11-8,,
Pontrepoth   -    -          -           9'1
Cwm Frood               --               1'3
Anthracite   -56,,
Cwm Nanty Gros -    -    -               48,,
Grangemouth-    -       -    -           6'7
Broomhill    -    -    -    -            52 
Resolven      -    -    -    -          18-9 
Pontypool          -    -               17-7
Bedwas-    -    -    -    -             134 
Porth Mawr  -    -    -    -             95 
Ebbw Vale   -    -           -          15-7,
Fordel Splint -    -         -          14-5 
Coleshill-      -            -          115 
Wallsend Elgin    -    -    -            7'3,,
that that august body of well-paid functionaries may look before they leap into a
subject so intimately connected with our national interests.
In working a seam of coal, experience has shown that the quality of the coal is not
uniform, and that a coal mnay be improving or deteriorating as the workings are carried
on, in one or another direction. From this it follows that any particular coal examined,
say in 1846, isby no means to be regarded as possessing the same value in 1848, since this
may have changed considerably, if the working of the coal has been carried on to any
great extent; and it is the determination of this very fact which constitutes the real
source of utility to be derived from a Government investigation. The proximate value
of a coal is soon determined by actual experiment, from the amount of work done, and
a market value is given in accordance with these rough results; but, when once that
value has become fixed, there it remains for many years, whether the coal continues
uniform or not, and it is only slowly and by degrees that the change becomes apparent.
An establishment for determining matters of this kind is, therefore, much needed, but,
to be useful, it must obviously be permanent. Again, as the transmission of heat from
one body to another is proportional to the difference of temperature between the bodies
themselves, it is clear that the water operated on should have one uniform temperature
in all the experiments, and there are many reasons why this should be the boiling point.
The quantity of water evaporated should not be inferred from the quantity which has
escaped from a boiler during an experiment; independent of the possibility of leakage,
much water is occasionally carried off mechanically by the steam; hence the origin of
"priming"  The most unobjectionable method would be to distil the water and afterwards measure it, the still-head being provided with a return-pipe, as is usual, for the
fluid mechanically projected. The ordinary modes of favouring the transmission of heat
from the furnace to the boiler, and of preventing its escape in any other direction than
into the refrigeratory, should be had recourse to. A chemist is of no use for such investigations; if any chemical question should arise out of the experiments, it would be
better to consult some one of established reputation. The stoker should be intelligent
and practically acquainted with the different modes of fire necessary for anthracitic,
open-burning, and bituminous, or caking coal; for whilst the first of these will take,
nay requires, eighteen or twenty inches of fuel on the bars, the last will not bear more
than four or six, without an enormous loss of heating-power. To this cause must be
ascribed much of the discrepancy apparent in the experimental results obtained by the
Admiralty boiler.-Mr. Lewis Thompson, in "The Chemical Times" for December, 1848.
COBALT.  This metal being difficult to reduce from its ores, is therefore very little
known, and has not hitherto been employed in its simple state in any of the arts; but its
oxide has been extensively used on account of the rich blue colour which it imparts
to glass, and the glazes of porcelain and stone-ware. The principal ores of cobalt are




COBALT.                                     447
those designated by mineralogists under the names of arsenical cobalt and gray cobalt.
The first contains, in addition to cobalt, some arsenic, iron, nickel, and occasionally silver, &c.  The other is a compound of cobalt with iron, arsenic, sulphur, and nickel.
Among the gray cobalts, the ore most esteemed for its purity is that of Taiaberg in
Sweden.  It is often in regular crystals, which possess the lustre and color of polished
steel.  The specific gravity of cobalt pyrites is 6-36 to 4-66.  The Tunaberg variety
afforded to Klaproth, cobalt, 44; arsenic, 55-5; sulphur, 0-5; so that it is an arseniuret. Others, however, contain much sulphur as well as iron. It imparts at the blowpipe
a blue color to borax and other fluxes, and gives out arsenical fumes.
The ore being picked, to separate its concomitant stony matter, is pounded fine
and passed through a sieve; and is also occasionally washed. The powder is then
spread on the sole of a reverberatory furnace, the flue of which leads into a long horizontal chimney.  Here it is exposed to calcination for several hours, to expel the sulphur and arsenic that may be present; the former burning away in sulphurous acid gas,
the latter being condensed into the white oxyde or arsenious acid, whence chiefly the
market is supplied with this article.  This calcining process can never disengage the
whole of these volatile ingredients, and there is therefore a point beyond which it is
useless to push it; but the small quantities that remain are not injurious to the subsequent operations.  The roasted ore is sifted anew; reduced to a very fine powder, and
then mixed with 2 or 3 parts of very pure silicious sand, to be converted into what is
called zaffre.  With this product glasses are generally colored blue, as well as enamels and pottery glaze.  In the works where cobalt ores are treated, a blue glass is prepared with the zaffre, which is well known under the name of smalt or azure blue.
This azure is made by adding to the zaffre 2 or 3 parts of potash, according to its richness in cobalt, and melting the mixture in earthen crucibles. The fused mass is
thrown out while hot into water; and is afterwards triturated and levigated in mills
mounted for the purpose.  There remains at the bottom  of the earthen pot a metallic
lump, which contains a little cobalt, much nickel, arsenic, iron, &c.  This is called
speiss.
As it is the oxyde of cobalt which has the coloring quality, the calcination serves the
purpose of oxydizement, as well as of expelling the foreign matters.
A finer cobalt oxyde is procured for painting upon hard porcelain, by boiling the cobalt
ore in nitric acid, which converts the arsenic into an acid, and combines it with the different metals present in the mineral. These arseniates, being unequally soluble in nitric
acid, may be separated in succession by a cautious addition of carbonate of soda or potash; and the arseniate of cobalt as the most soluble remains unaffected.  It has a rose
color, and is esil;- distinguishable, whence the precipitation may be stopped at the proper
point.  The above solution should be much diluted, and the alkali should be cautiously
added, with frequent agitation.
The cobalt ores, rich in nickel, are exposed to slow oxydizement in the air, whereby
the iron, cobalt, arsenic, and sulphur get oxygenated by the atmospheric moisture, but
the nickel continues in the metallic state. This action of the weather must not be
extended beyond a year, otherwise the nickel becomes affected, and injures the cobalt
blue. The ore hereby increases in weight, from  8 to 10 per cent. Fig. 362 is a
longitudinal section of the furnace: fig. 363, a horizontal section upon a level with the
sole of the hearth.  It is constructed for wood fuel, and the hearth is composed of
fire-bricks or tiles.   The vapors and gases disengaged in the roasting pass off
through the flues a a, into the channels b b, and thence by c into the common vent, or
poison chamber.  See the representation of the poison tower sf Altenberg, under the
article ARSENIC. The flues are cleared out by means of openings left at suitable situations in the brick-work of the chimneys.
~//^7/     /,/,//-//^Z///J _I        The azure manufacture is carried
on chiefly in winter, in order that
362                                            the external cold  may favour the
more complete condensation of the'w\,1a  (  |,    acids of arsenic.  From  3 to 5 cwt.
i- 11  I of Schlich (pasty ore) are roasted at'      I......( 1  1 -      one operation, and its bed is laid
from 5 to 6 inches thick. After two
hours, it must be turned over; and
the stirring must be repeated every
half hour, till no more arsenic is observed to exhale. The process being
then finished, the ore must be raked
//.~Ut~4~~/  out of the furnace, and another charge
introduced.




448                                 COBALT.
The duration of the roasting is
regulated partly by the proportion
of sulphur and arsenic present, and
P A             partly by the amount of nickel;
which must not be suffered to be363                                              come oxydized, lest it should spoil
7Ma z " t   the color of the smalt. The latter.         _.........    ores should be but slightly roasted
so as to convert the nickel into speiss.
The roasted ore must be sifted in a
safety apparatus. The loss of weight
in the roasting amounts, upon the
364                         average, to 36 per cent. Theroasted
ore has a brownish gray hue, and is
called safflor in German, and is distributed into different sorts.  F F S
~ ~  ^~ 7^ > A                            ^fis the finest safre; F S, fine; O S,
f~^;   _        fliT  _j,       _1\ ordinary; and M S, middling. These
I                                 Q~,q~S  [_ 7 ]o.1 i  varieties proceed from various mixI   h  1      I          Ab\ 4        tures of the calcined ores.  The
e  e\^ I i ] IIIIIfiI}[e       I        roasted ore is ground up along with....Hi7~~~~  Asand, elatriated, and, when dry, is
called zaffre.  It is then mixed with
a sufficient quantity of potash foi
converting the mixture into a glass.
//////I////          Figs. 364 and 365, represent a
round smalt furnace, in two vertical
sections, at right angles to  each
other.  The fire-place is vaulted or
arched; the flame orifice a, is in the
365                         middle of the furnace; b is the feed
hole; c, a tunnel which serves as an
ash-pit, and to supply air; d, openings through which the air arrives
i^ T several times inat the fuel, the wood being placed
upon the vault; e, knee holes for
~ lwos'1'tt"""""e-'" -.. taking out the scoriae from  the pot
fi;,   m n  f              e bottoms; f, working orifices, with
cast-iron plates g, in front of them.
~a to~ ~~  / /               Under these are the additional out3 ^____     lets h. The smoke and flame pass'7en 777 an   s are its essent al     off through the orifices i, which terdt   cob a l                              minate in expanded flues, where the
the deeper isand may be calcined or the wood
_______________________     may be baked.  Eight:hours  are
sufficient for one vitrifying operation,
during which the glass is stirred
about several times in the earthen melting pots.
The preparation of the different shades of blue glass is considered a secret in the
smelting works; and marked with the following letters:-F F F C, the finest; F C,
fine; M C, middling; 0 C, ordinary.  A melting furnace, containing 8 pots of glass,
produces in 24 hours, from 24 cwts. of the mixture, 19 cwts. of blue glass; and from
u to a cwt. of scoriae or speiss (speise).  The composition speise, according to Berthier,
is,-nickel, 49'0; arsenic, 37'8; sulphur, 7'8; copper, 1'6; cobalt, 3'2 in 100.  Nickel,
arsenic, and sulphur, are its essential constituents; the rest are accidental, and often
absent. The freer the cobalt ore is from foreign metals, the finer is the colour, and
the deeper is the shade; paler tints are easily obtained by dilution with more glass.
The presence of nickel gives a violet tone.
The production of smalt in the Prussian states amounted, in 1830, to 74523 cwts.;
and in Saxony to 9697 cwts.; in 1825, to 12,310 cwts.
One process for making fine smalt has been given under the title AZURE; I shall introduce another somewhat different here.
The ore of cobalt is to be reduced to very fine powder, and then roasted with much
care. One part, by weight, is next to be introduced, in successive small portions, into
an iron vessel, in which three parts of acid sulphate of potassa has been previously
fused, at a moderate temperature. The mixture, at first fluid, soon becomes thick and
firm, when the fire is to be increased, until the mass is in perfect fusion, and all
white vapours have ceased. It is then to be taken out of the crucible with an iron




COCHINEAL.                                   449
ladle, the crucible is to be recharged with acid sulphate of potash, and the operation
continued as before, until the vessel is useless. The fused mass contains sulphate of
cobalt, neutral sulphate of potassa, and arseniate of iron, with a little cobalt. It is to
be pulverized, and boiled in an iron vessel, with water, as long as the powder continues
rough to the touch. The white, or yellowish white residue, may he allowed to separate
from the solution, either by deposition or filtration. Carbonate of potassa, free from
silica, is then to be added to the solution, and the carbonate of cobalt thrown down is
to be separated and well washed, if possible, with warm water; the same water may be
used to wash other portions of the fused mass. The filtered liquid which first passes
is a saturated solution of sulphate of potassa: being evaporated to dryness in an iron vessel, it may be reconverted into acid sulphate by fusing it with one half its weight of
sulphuric acid: this salt is then as useful as at first.
The oxyde of cobalt thus obtained contains no nickel; so little oxyde of iron is present, that infusion of galls does not show its presence; it may contain a little copper, if
that metal exists in the ore, but it is easily separated by the known methods. Sometimes
sulphureted hydrogen will produce a yellow brown precipitate in the solution of the
fused mass; this, however, contains no arsenic, but is either sulphuret of antimony o;
bismuth, or a mixture of both.
It has been found advantageous to add to the fused mass sulphate of iron, calcined to
redness, and one tenth of nitre when the residue is arseniate of iron, and contains no
arseniate of cobalt. There is then no occasion to act upon the residue a second time for
the cobalt in it.
This process is founded on the circumstances that the sulphate of cobalt is not decomposed by a red heat, and that the arseniates of iron and cobalt are insoluble in
all neutral liquids. It is quite evident, that, to obtain a perfect result, the excess
of acid in the bisulphate of potaSsa must be completely driven off by the red heat
applied.
110,646 lbs. of smalts were imported into the United Kingdom in 1835, and 96,949
were retained for home consumption. In 1834, only 16,223 lbs. were retained.
In 1835, 322,562 lbs. of zaffres were imported, and 336,824 are stated to have been
retained, which is obviously an error. 284,000 lbs. were retained in 1834.
COCCULUS INDICUS, or Indian berry, is the fruit of the Menispermum Cocculus
a large tree, which grows upon the coasts of Malabar, Ceylon, &c. The fruit is
blackish, and of the size of a large pea. It owes its narcotic and poisonous qualities to
the vegeto-alkaline chemical principle called picrotoxia, of which it contains about one
fiftieth part of its weight. It is sometimes thrown into waters to intoxicate or kill fishes;
and it is said to have been employed to increase the inebriating qualities of ale or beer.
Its use for this purpose is prohibited by act of parliament, under a penalty of 2001. upon
she brewer, and 5001. upon the seller of the drug.
COCHINEAL was taken in Europe at first for a seed, but was proved by the obserrations of Lewenhoeck to be an insect, being the female of that species of shield-louse,
or coccus, discovered in Mexico, so long ago as 1518. It is brought to us from Mexico,
where the animal lives upon the cactus opuntia or nopal.  Two sorts of cochineal
are gathered-the wild, from the woods, called by the Spanish name grana silvestra;
and the cultivated, or the granafina, termed also mesteque, from the name of a Mexican
province. The first is smaller, and covered with a cottony down, which increases its
bulk with a matter useless in dyeing; it yields, therefore, in equal weight, much less
color, and is of inferior price to that of the fine cochineal. But these disadvantages
are compensated in some measure to the growers by its being reared more easily, and
less expensively; partly by the effect of its down, which enables it better to resist raine
and storms.
The wild cochineal, when it is bred upon the field nopal, loses in part the tenacity
and quantity of its cotton, and acquires a size double of what it has on the wild opuntias.
It may therefore be hoped, that it will be improved by persevering care in the rearing
of it, when it will approach more and more to fine cochineal.
The fine cochineal, when well dried and well preserved, should have a gray colour,
bordering on purple. The gray is owing to the powder, which naturally covers it,
and of which a little adheres; so also to a waxy fat. The purple shade arises from the
colour extracted by the water in which they were killed. It is wrinkled with parallel
furrows across its back, which are intersected in the middle by a longitudinal one;
hence, when viewed by a magnifier, or even a sharp naked eye, especially after being
swollen by soaking for a little in water, it is easily distinguished from the factitious,
smooth, glistening, black grains, of no value, called East India cochineal, with which it
is often shamefully adulterated by certain London merchants. The genuine cochineal
has the shape of an egg, bisected through its long axis, or of a tortoise, being rounded
like a shield upon the back, flat upon the belly, and without wings.
These female insects are gathered off the leaves of the nopal plant, after it has ripened.
29




450                               COCHINEAL.
its fruit, a few only being left for brood, and are killed, either by a momentary immersion in boiling water, by drying upon heated plates, or in ovens: the last become of an
ash-gray color, constituting the silver cochineal, or jaspeada; the second are blackish,
called negra, and are most esteemed, being probably driest; the first are reddish brown,
and reckoned inferior to the other two. The dry cochineal being sifted, the dust, with
the imperfect insects and fragments which pass through, are sold under the name of
granillo.
Cochineal keeps for a long time in a dry place. Hellot says that he has tried some
130 years old, which produced the same effect as new cochineal.
We are indebted to MM. Pelletier and Caventou for a chemical investigation of cochineal, in which its coloring matter was skilfully eliminated.
Purified sulphuric ether acquired by digestion with it a golden yellow color, amounting
by Dr. John to one tenth of the weight of the insect. This infusion left, on evaporation,
a fatty wax of the same color.
Cochineal, exhausted by ether, was treated with alcohol at 40~ B. After 30 infusions
in the digester of M. Chevreul, the cochineal continued to retain color, although the
alcohol had ceased to have any effect on it. The first alcoholic liquors were of a red
verging on yellow. On cooling, they let fall a granular matter. By spontaneous evaporation, this matter, of a fine red color, separated, assuming more of the crystalline appearance. These species of crystals dissolved entirely in water, which they tinged of a
yellowish-red.
This matter has a very brilliant purple-red color; it adheres strongly to the sides of
the vessels; it has a granular and somewhat crystalline aspect, very different, however,
from those compound crystals alluded to above; it is not altered by the air, nor does it
sensibly attract moisture. Exposed to the action of heat, it melts at about the fiftieth
degree centigrade (122~ Fahr.). At a higher temperature it swells up, and is decomposed with the production of carbureted hydrogen, much oil, and a small quantity of
water, very slightly acidulous. No trace of ammonia was found in these products.
The coloring principle of cochineal is very soluble in water. By evaporation, the
liquid assumes the appearance of sirup, but never yields crystals. It requires of this
matter a portion almost imponderable to give a perceptible tinge of bright purplish red to
a large body of water. Alcohol dissolves this coloring substance, but, as we have already stated, the more highly it is rectified the less of it does it dissolve. Sulphuric ether
does not dissolve the coloring principle of cochineal; but weak acids do, possibly owing
to their water of dilution. No acid precipitates it in its pure state. This coloring principle, however, appears to be precipitable by all the acids, when it is accompanied by the
animal matter of the cochineal.
The affinity of alumina for the coloring matter is very remarkable. When that earth,
newly precipitated, is put into a watery solution of the coloring principle, this is immediately seized by the alumina.  The water becomes colorless, and a fine red lake is obtained, if we operate at the temperature of the atmosphere; but if the liquor has been
hot, the color passes to crimson, and the shade becomes more and more violet, accord
ing to the elevation of the temperature, and the continuance of the ebullition.
The salts of tin exercise upon the coloring matter of cochineal a remarkable action.
The muriatic protoxyde of tin forms a very abundant violet precipitate in the liquid.
This precipitate verges on crimson, if the salt contains an excess of acid. The muriatic
deutoxyde of tin produces no precipitate, but changes the color to scarlet-red. If gelatinous alumina be now added, we obtain a fine red precipitate, which does not pass to
crimson by boiling.
To this colouring principle the name carminium has been given, because it forms the
basis of the pigment called carmine.
The process followed in Germany for making carmine, which consists in pouring a
certain quantity of solution of alum into a decoction of cochineal, is the most simple of
all, and affords an explanation of the formation of carmine, which is merely the carminium and the animal matter precipitated by the excess of acid in the salt, which has
taken down with it a small quantity of alumina; though it appears that alumina ought
not to be regarded as essential to the formation of carmine. In fact, by another process
called by the name of Madame Cenette of Amsterdam, the carmine is thrown down, by
pouring into the decoction of cochineal a certain quantity of the binoxalate of potash.
When carbonate of soda is added, then carminated lake also falls down. That carmine
is a triple compound of animal matter, carminium, and an acid, appears from the circumstance, that liquors which have afforded their carmine, when a somewhat strong
acid is poured into them, yield a new formation of carmine by the precipitation of the
last portions of the animal matter.  But whenever the whole animal matter is thrown
down, the decoctions, although still much charged with the colouring principle, can
afford no more carmine. Such decoctions may be usefully employed to make carminated lakes, saturating the acid with a slight excess of alkali, and adding gelatinous
alumina. The precipitates obtained, on adding acid to the alkaline decoctions of




COCHINEAL.                                  451
carmines, since they do not contain alumina; but the small quantity of alumina which
is thrown down by alum in the manufacture of carmine, augments its bulk and weight
It gives, besides, a greater lustre to the color, even though diluting and weakening it a
little.
The carmines found in the shops of Paris were analyzed, and yielded the same products. They are decomposed by the action of heat, with the diffusion at first of a very
strong smell of burning animal matter, and then of sulphur. A white powder remained,
amounting to about one tenth of the matter employed, and which was found to be alumina. Other quantities of carmine were treated with a solution of caustic potash, which
completely dissolved them, with the exception of a beautiful red powder, not acted on by
potash and concentrated acids, and which was recognised to be red sulphuret of mercury
or vermilion. This matter, evidently foreign to the carmine, appears to have been ad.
ded in order to increase its weight.
The preceding observations and experiments seem calculated to throw some light on
the art of dyeing scarlet and crimson. The former is effected by employing a cochineal
bath, to which there have been added, in determinate proportions, acidulous tartrate of
potash, and nitro-muriatic deutoxyde of tin. The effect of these two salts is now well
known. The former, in consequence of its excess of acid, tends to redden the color,
and to precipitate it along with the animal matter; the latter acts in the same manner,
at first by its excess of acid, then by the oxyde of tin which falls down also with the
carmine and animal matter, and is fixed on the wool, with which it has of itself a strong
tendency to combine. MM. Pelletier and Caventou remark, that " to abtain a beautiful
shade, the muriate of tin ought to be entirely at the maximum of oxydizement; and it
is in reality in this state that it must exist in the solution of tin prepared according to
the proportions prescribed in M. Berthollet's treatise on dyeing."
We hence see why, in dyeing scarlet, the employment of alum is carefully avoided, as
this salt tends to convert the shade to a crimson. The presence of an alkali would seem
less to be feared. The alkali would occasion, no doubt, a crimson-colored bath; but it
would be easy in this case to restore the color, by using a large quantity of tartar. We
should, therefore, procure the advantage of having a bath better charged with coloring
matter and animal substance. It is for experience on the large scale to determine this
point. As to the earthy salts, they must be carefully avoided; and if the waters be selenitish, it would be a reason for adding a ittle alkali.
To obtain crimson, it is sufficient, as we know, to add alum to the cochineal bath, or
to boil the scarlet cloth in alum water. It is also proper to diminish the dose of'the salt
of tin, since it is found to counteract the a tion of the alum.
The alkalis ought to be rejected as a means of changing scarlet to crimson. In fact,
crimsons by this process cannot be permanent colors, as they pass into reds by the action
of acids.
According to M. Von Grotthuss, carmine may be deprived of its golden shade by
ammonia, and subsequent treatment with acetic acid and alcohol. Since this fact was
made known, M. Herschel, color maker at Halle, has prepared a most beautiful
carmine.
The officers of Her Majesty's Customs have lately detected a system of adulterating
cochineal, which has been practised for many years upon a prodigious scale by a mercan.
tile house in London. I have analyzed about 100 samples of such cochineal, from which
it appears that the genuine article is moistened with gum-water, agitated in a box or
leather bag, first, with sulphate of baryta in fine powder, afterward with bone of ivory
black, to give it the appearance of negra cochineal, and then dried. By this means about
12 per cent. of worthless heavy spar is sold at the price of cochineal, to the enrichment
of the sophisticators, and the disgrace and injury of British trade and manufactures.
The specific gravity of genuine cochineal is 1 25; that of the cochineal loaded with
the barytic sulphate, 1-35. This was taken in oil of turpentine and reduced to water as
unity, because the waxy fat of the insects prevents the intimate contact of the latter
liquid with them, and the ready expulsion of air from their wrinkled surface. They are
not at all acted upon by the oil, but are rapidly altered by water, especially when they
have been gummed and barytified.
Landed.           Delivered.      Stock, 1st of January.
December, 1851 -          1,203 bags          692 bags               bags.1850 -            1,605  595 --
12 Months, 1851   -      16,561 -            16,180 -            9,001 -
1850 -          17,765 -            13,096 -            8.620 -
1849 - -        12,604 -            13,594 -            3,951 -
1848 -   -      13,521 -            11,506 -            4,933 -
Humboldt states that so long ago as the year 1736, there was imported into Europe
from South America cochineal to the value of 15 millions of francs. Its high price bad
for a long time induced dyers to look out for cheaper substitutes in dyeing red, and
since science has introduced so many improvements in tinctorial processes, both madder
and lac have been made to supersede cochineal to a very great extent. Its price has, in




452                                  COFFEE.
consequence of this substitution, as well as from more successful modes of cultivation,
fallen very greatly of late years. In January, 1852, the prices of Honduras cochineal
ranged from 2s. 9d. to 5s. per lb., and Mexican from 2s. 7d. to 3s. 4d. per lb.
COCOA, STEARINE, and ELAINE.  Mr. Soames obtained a patent in September,
1829, for making these useful articles, by the following process:He takes the substance called cocoa-nut oil, in the state of lard, in which it is imported
into this country, and submits it to a strong hydraulic pressure, having made it up in small
packages, 3 or 4 inches wide, 2 feet long, and 1 or 11 inches thick. These packages are
formed by first wrapping up the said substance in a strong linen cloth, of close texture,
and then in an outward wrapper of strong sail cloth. The packages are to be placed side
by side, in single rows, between the plates of the press, allowing a small space between
the packages for the escape of the elaine.
The temperature at which the pressure is begun, should be from about 50 to 55 degrees,
or in summer as nearly at this pitch as can be obtained, and the packages of the said
substance intended for pressure, should be exposed for several hours previously to about
the same temperature.  When the packages will no longer yield their oil or elaine freely
at this temperature, it is to be gradually raised; but it must at no time exceed 65 degrees,
and the lower the temperature at which the separation can be effected, the better will be
the quality of the oil expressed.
When the packages are sufficiently pressed, that is, when they will give out no more
oil, or yield it only in drops at long intervals, the residuum in them is to be taken out and
cleansed and purified, which is done by melting it in a well-tinned copper vessel, which
is fixed in an outer vessel, having a vacant space between, closed at the top, into which
steam is admitted, and the heat is kept up moderately for a sufficient time to allow the
impurities to subside; but if a still higher degree of purity is required, it is necessary to
pass it through filters of thick flannel lined with blotting paper.
Having been thus cleansed or purified, it is fit for the manufacture of candles, which
are made by the ordinary process used in making mould tallow candles. Having thus
disposed of the stearine, or what is called the first product, he proceeds with the elaine
or oil expressed from it, and which he calls the second product, as follows: that is to
say, he purifies it by an admixture, according to the degree of its apparent foulness, of
from 1 to 2 per cent. by weight of the sulphuric acid of commerce, of about 1'80 specific
gravity, diluted with six times its weight of water. The whole is then to be violently
agitated by mechanical means, and he prefers for this purpose the use of a vessel constructed on the principle of a common barrel churn. When sufficiently agtated, it will
have a dirty whitish appearance, and is then to be d awn off into another vessel, in which
it is to be allowed to settle, and any scum that rises is to be carefully taken off. In a
day or two the impurities will be deposited at the bottom of the oil, which will then become clear, or nearly so, and it is to be filtered through a thick woollen cloth, after which
it will be fit for burning in ordinary lamps and for other uses.
The process of separating the elaine from the stearine, by pressure, in manner aforesaid, had never before been applied to the substance called cocoa-nut oil, and consequently
no product had heretofore'een obtained thereby from that substance, fit for being manufactured into candles in the ordinary way, or for being refined by any of the usual
modes, so as to burn in ordinary lamps, both which objects are obtained by this method
of preparing or manufacturing the said substance.
Candles well made from the above material are a very superior article.  The light
produced is more brilliant than from the same sized candle made of tallow; the flame is
perfectly colorless, and the wick remains free from cinder, or any degree of foulness durina combustion.
COFFEE.  The coffee is the seed of a tree of the family rubiacece, and belongs to the
Pentandria monogynia of Linneus.  There are several species of the genus, but the only
one cultivated is the Coffaa m.rabica, a native of Upper Ethiopia and Arabia Felix. It
rises to the height of 15 or 20 feet; its trunk sends forth opposite branches in pairs above
and at right angles to each other; the leaves resemble those of the common laurel, although not so dry and thick. From the angle of the leaf-stalks small groups of white
flowers issue, which are like those of the Spanish jasmine. These flowers fade very soon,
and are replaced by a kind of fruit not unlike a cherry, which contains a yellow glairy
fluid, enveloping two small seeds or berries convex upon one side, flat and furrowed upon
the other in the direction of the long axis. These seeds are of a horny or cartilaginous
nature; they are glued together, each being surrounded with a peculiar coriaceous membrane. They constitute the coffee of commerce.
It was not till towards the end of the 15th century that the coffee-tree began to be cultivated in Arabia. Historians usually ascribe the discovery of the use of coffee as a be.
verage to the superior of a monastry there, who, desirous of preventing the monks from
sleeping at their nocturnal services, made them drink the infusion of coffee upon the report of shepherds, who pretended that their flocks were more lively after browsing on the
fruit of that'lant. The use of coffee was soon rapidly spread, but it encountered much




COFFEE.                                   453
opposition on the part of the Turkish government, and became the occasion of public
assemblies. Under the reign of Amurath TTT. the mufti procured a law to shut all the coffee-houses, and this act of suppression was renewed under the minority of Mahomet IV.
It was not till 1554, under Solyman the Great, that the drinking of coffee was accredited in
Constantinople; and a century elapsed before it was known in London and Paris. Solyman Aga introduced its use into the latter city in 1669, and in 1672 an Armenian established the first cafe at the fair of Saint Germain.
When coffee became somewhat of a necessary of life, from the influence of habit
among the people, all the European powers who had colonies between the tropics, projected to form plantations of coffee-trees in them. The Dutch were the first who transported the coffee plant from Moka to Batavia, and from Batavia to Amsterdam. In
1714 the magistrates of that city sent a root to Louis XIV., which he caused to be
planted in the Jardin du Roi. This became the parent stock of all the French coffee plantations in Martinique.
The most extensive culture of coffee is still in Arabia Felix, and principally in the
kingdom of Yemen, towards the cantons of Aden and Moka. Although these countries
are very hot in the plains, they possess mountains where the air is mild. The coffee is
generally grown half way up on their slopes. When cultivated on the lower grounds it
is always surrounded by large trees which shelter it from the torrid sun, and prevent its
fruit from withering before their maturity. The harvest is gathered at three periods; the
most considerable occurs in May, when the reapers begin by spreading cloths under the
trees, then shaking the branches strongly, so as to make the fruit drop, which they collect,
and expose upon mats to dry. They then pass over the dried berries a very heavy roller,
to break the envelops, which are afterwards winnowed away with a fan. The interior
bean is again dried before being laid up in store.
In Demarara, Berbice, and some of our West India islands, where much good coffee
is now raised, a different mode of treating the pulpy fruit and curing the beans is
adopted. When the cherry-looking berry has assumed a deep-red color it is gathered,
and immediately subjected to the operations of a mill composed of two wooden rollers,
furnished with iron plates, which revolve near a third fixed roller called the chops.
The berries are fed into a hopper above the rollers, and falling down between them and
the chops, they are stripped of their outer skin and pulp, while the twin beans are separated from each other. These beans then fall upon a sieve, which allows the skin and
the pulp to pass through, while the hard beans accumulate and are progressively slid
over the edge into baskets. They are next steeped for a night in water, thoroughly
washed in the morning, and afterwards dried in the sun. They are now ready for the
peeling mill, a wooden edge wheel turned vertically by a horse yoked to the extremity of
its horizontal axis. In travelling over the coffee, it bursts and detaches the coriaceous
or parchment-like skin which surrounds each hemispherical bean. It is then freed from
the membranes by a winnowing machine, in which four pieces of tin made fast to an axle
are caused to revolve with great velocity. Corn fanners would answer better than this
rude instrument of negro invention. The coffee is finally spread upon mats or tables,
picked clean, and packed up for shipment.
The most highly esteemed coffee is that of Moka. It.Ls a smaller and a roundes
bean; a more agreeable taste and smell than any other. Its  clor is yellow. Next
to it in European reputation are the Martinique and Bourbon coffees; the former is
larger than the Arabian, and more oblong; it is rounded at the ends; its color is greenish, and it preserves almost always a silver gray pellicle, which comes off in the roasting.
The Bourbon coffee approaches nearest to the Moka, from which it originally sprung.
The Saint Domingo coffee has its two extremities pointed, and is much less esteemed
than the preceding.
The coffee-tree flourishes in hilly districts, where its root can be kept dry, while its
leaves are refreshed with frequent showers. Rocky ground, with rich decomposed
mould in the fissures, agrees best with it. Though it would grow, as we have said, to
the height of 15 or 20 feet, yet it is usually kept down by pruning to that of five feet,
for increasing the production of the fruit, as well as for the convenience of cropping. It begins to yield fruit the third year, but is not in full bearing till the fifth,
does not thrive beyond the twenty-fifth, and is useless in general at the thirtieth.
In the coffee husbandry, the plants should be placed eight feet apart, as the trees throw
out extensive horizontal branches, and in holes ten or twelve feet deep, to secure a constant supply of moisture.
Coffee has been analyzed by a great many chemists, with considerable diversity of
results. The best analysis perhaps is that of Schrader. He found that the raw beans
distilled with water in a retort communicated to it their flavor and rendered it turbid,
whence they seem to contain some volatile oil. On reboiling the beans, filtering, and
evaporating the liquor to a sirup, adding a little alcohol till no more matter was precipitated, and then evaporating to dryness, he obtained 17-58 ner cent. of a yellowish



454                                  COFFEE.
brown transparent extract, which constitutes the characteristic part of coffee, though it
is not in that state the pure proximate principle, called caffeine. Its most remarkable
reaction is its producing, with both the protoxyde and the peroxyde salts of iron, a fine
grass green color, while a dark green precipitate falls, which re-dissolves when an acid
is poured into the liquor. It produces on the solution of the salts of copper scarcely
any effect, till an alkali be added, when a very beautiful green color is produced, which
may be employed in painting.  Coffee beans contain also a resin, and a fatty substance
somewhat like suet. According to Robiquet, ether extracts from coffee beans nearly 10
per cent. of resin and fat, but he probably exaggerates the amount. The peculiar substance cafeine contained in the above extract is crystallizable. It is remarkable in
regard to composition, that after urea and the uric acid, it is among organic products
the richest in azote. It was discovered and described in 1820 by Runge. It does not
possess alkaline properties. Pfaff obtained only 90 grains of cafeine from six pounds
of coffee beans. There is also an acid in raw coffee, to which the name of cafeic acid
has been given. When distilled to dryness and decomposed, it has the smell of roasted
coffee.
Coffee undergoes important changes in the process of roasting. When it is roasted
to a yellowish brown it loses, according to Cadet, 12- per cent. of its weight, and is in
this state difficult to grind. When roasted to a chestnut brown it loses 18 per cent.,
and when it becomes entirely black, though not at all carbonized, it has lost 23 per cent.
Schrader has analyzed roasted coffee comparatively with raw coffee, and he found in
the first 121 per cent. of an extract of coffee, soluble in water and alcohol, which possesses nearly the properties of the extract of the raw coffee, although it has a deeper
brown color, and softens more readily in the air. He found also 10'4 of a blackish
brown gum; 5'7 of an oxygenated extract, or rather apotheme, soluble in alcohol, insoluble in water; 2 of a fatty substance and resin; 69 of burnt vegetable fibre, insoluble.
On distilling roasted wpffee with water, Schrader obtained a product which contained the
aromatic principle of coffee; it reddened litmus paper, n hl  trn and exhaled a stron and agreeable odor of roasted coffee. If we roast coffee in a retort, the first portions of the aromatic principle of coffee condense into a yellow liquid in the receiver; and these may be
added to the coffee roasted in the common way, from which this matter has been expelled and dissipated in the air.
Chenevix affirmed that by the roasting of coffee a certain quantity of tannin possessing
the property of precipitating gelatin is generated. Cadet made the same observation,
and found, moreover, that the tannin was most abundant in the lightly roasted coffee, and
that there was nearly none of it in coffee highly roasted.  Paysse and Schrader, on the
contrary, state that solution of gelatin does not precipitate eithef the decoction of roasted coffee or the alcoholic extract of this coffee. Runge likewise asserts that he could
obtain no precipitate with gelatin; but he says that albumen precipitates from the decoction of roasted coffee the same kind of tannin as is precipitated from raw coffee by the
acetate of lead, and set free from the lead by sriphureted hydrogen. With these results
my own experiments agree.  Gelatin certainly kes not disturb clear infusion of roasted
coffee, but the salts of iron blacken it.
Schrader endeavored to roast separately the different principles of coffee, but none of
them exhaled the aromatic odor of roasted coffee except the horny fibrous matter. He
therefore concludes that this substance contributes mainly to the characteristic taste of
roasted coffee, which cannot be imitated by any other vegetable matter, andwvhich, as we
have seen, should be ascribed chiefly to the altered cafeic acid. According to Garot, we
may extract the cafeine without alteration fiom roasted coffee by precipitating its decoction by subacetate of lead, treating the washed precipitate with sulphureted hydrogen,
and evaporating the liquid product to dryness.
Of late years, much ingenuity has been expended in contriving various forms of apparatus for making infusions of coffee for the table. I have tried most of them. and find,
after all, none so good as a cafetiere d la Belloy, the coffee biggin, with the perforated tinplate strainer, especially when the filtered liquor is kept simmering in a close vessel, set
over a lamp or steam pan. The useful and agreeable matter in coffee is very soluble: it
comes off with the first waters of infusion, and needs no boiling.
To roast coffee rightly we should keep in view the proper objects of this process, which
are to develop its aroma, and destroy its toughness, so that it may be readily ground to
powder.  Too much heat destroys those principles which we should wish to preserve, and
substitutes new ones which have nothing in common with the first, but add a disagreeable empyreumatic taste and smell. If, on the other hand, the rawness or greenness is
not removed by an adequate heat, it masks the flavor of the bean, and injures the beverage made with it. When well roasted in the sheet-iron cylinders set to revolve over a
fire, it should have a uniform chocolate color, a point readily hit by experienced roasters,
who now manage the business very well for the principal coffee-dealers both of Londcn
and Paris, so far as my judgment can determine. The development of the proper aroma




COFFEE.                                   455
is a criterion by which coffee roasters frequently regulate their operations. When it
loses more than 20 per cent. of its weight, coffee is sure to be injured. It should never
be ground till immediately before infusion.
Liebig's views of the process of nutrition have given fresh interest to every analysis
of articles of food. A watery infusion of coffee is used in almost every country as a
beverage, and yet it is uncertain whether it is an article of nutrition or merely a condiment.  A minute examination of the raw seed, or coffee bean as it is called, must
precede the determination of that disputed point. Caffeine is the principle best known,
eing most easily separated from the other substances, resisting most powerfully chemical reagents, and by assuming a crystalline state is discoverable in very small quantities.
The constituents of coffee are: 1. Vegetablefibrine, which is the largest constituent,
being an elastic horny substance, in which the other substances are incorporated. If we
dry the beans at the heat of boiling water for several weeks we can easily reduce them
to a fine powder, and by washing with ether, and then boiling in alcohol and water, we
extract the soluble matter from the fibrine, which may then be boiled with weak solution
of potash, and afterwards weak muriatic acid, as long as any matter is taken up. The
purification being completed by boiling in water the fibrine remains; and when rubbed in a mortar resembles starch; when roasted it gives out the odor nearly of wood.
2. Fatty matter: the beans digested in ether give out a yellow-colored matter, which
on evaporation becomes buttery with an odor of raw coffee, and amounts to 100 of the
beans.
3. Caffeine: the ethereal solution contains caffeine, which may be removed by shaking
with a solution of water.
4. Legumine: in addition to an acid which agrees in its properties with the acid
found in oak and cinchona, we find in the coffee beans legumine similar to that of beans.
The legumine contains sulphur, which is the cause of their blackening a silver vessel in
which the beans may be boiled with an alkali. Legumine and caffeine are the only nitrogenous constituents of coffee beans, consequently the only substances which could be
nutritious, but they are not soluble in hot water as they exist in roasted coffee, and
therefore it may be reckoned merely an exhilarating beverage.
Roasted coffee affords a much richer infusion to hot water containing a minute quantity of carbonate of soda, and improves the quality of coffee on the stomach, by neutralizing the caffeic acids.
Coffee is sold in the shops in its roasted and ground state often adulterated with a
variety of substances, but chiefly with chicory. This is the dried, roasted, and ground
root of a plant called Cichoriumn Intybus, better known under the name of wild succory.
The chicory imported from Belgium and Prussia is better than the British, which is
usually colored with Venetian red, and is sold at a cheaper rate; chicory itself is frequently very impure, containing roasted peas and coffee flights, which are the membranous coat of the bean separated in the act of roasting. If a little genuine ground
coffee be thrown in a wineglassfull of water, it mostly floats, and slowly moistens, communicating scarcely any color to the liquid. Powdered chicory treated in the same
way very speedily absorbs moisture, communicates a deep reddish brown tint to the
water, and in a few minutes falls to the bottom. Hambro' powder contains roasted
starch, and acquires a deep purplish color when moistened with a solution of iodine.
The microscope shows in the chicory powder fragments of dotted ducts which do not
exist in coffee. There is another substance which is mixed with coffee, called refining
powder; it is merely caramel, or burnt sugar. It is used for enabling drained coffee to
afford a dark colored infusion.
If tannin exists in roasted coffee, as maintained long ago by Chenevix, and generally
admitted since, it must be very different from the tannin present in tea, catechu, kino,
oak-bark, willow-bark, and other astringent vegetables; for I find that it is not, like
them, precipitated by either gelatine, albumen, or sulphate of quinine. With regard
to the action upon the animal economy of coffee, tea, and cocoa, which contain one
common chemical principle called caffeine or theine, Liebig has lately advanced some
ingenious views, and has, in particular, endeavored to show that, to persons of sedentary
habits in the present refined state of society, they afford eminently useful beverages,
which contribute to the formation of the characteristic principle of bile. This important
iecreted fluid, deemed by Liebig to be subservient to the function of respiration,
equires for its formation much azotised matter, and that in a state of combination
nalogous to what exists in caffeine. The quantity of this principle in tea and coffee
eing only from 2 to 5 per cent. might lead one to suppose that it could have little effect
upon the system even of regular drinkers of their infusions; but if the bile contains only
one-tenth of solid matter, called choleic acid, which contains less than 4 per cent. of
azote, then it may be shown that 3 grains of caffeine would impart to 500 grains of




456                                    COFFEE.
bile the azote which occurs in that crystalline precipitate of bile called taurinc, which
is thrown down from it by by mineral acids.
One atom  of caffeine, 9 atoms of oxygen, and 9 of water, being placed together,
produce the composition of 2 atoms of taurine. Now this is a very simple combination for the living organism to effect; one already paralleled in the generation of hippuric acid in urine, by the introduction of benzoic acid into the stomach; a physiological discovery made by my son, which is likely to lead to a more successful treatment
of some of the most formidable diseases of man, particularly gout and gravel.
If the preceding views be established, they will justify the instinctive love of mankind
for tea, coffee, and cocoa, in spite of the denunciations and veto of neuropathic, homecepathic, and hydropathic doctors; sorry pathologists-hoc genus onne.  See TEA.
In the years ending 5th January, 1851 and 1852, the imports of coffee were as follows:Importations.       Entries for Home  Gross Amount of
Consumption.         Duty.
1851.     1852.       1851.      1852.    1851.   1852.
Entered before 15th April 1851:    lbs.    lbs.       lbs.       lbs.     tbs.    lbs.
Of British Possessions     36,814,036   1,818,514  28,891,294   6,510.346  505,515  113,931
Foreign                    13,989,116   5,018,806   2,335,546  443,418  61,305  11,637
Entered from 15th April, 1851:
from British Possessions
out of Europe              - -      34.077.563      -     21,486,170   - -   268,599
From other Parts            - -       12,035,269    - -      4,124,230   - -   51,572
50,803,152  52,950,152  31,226,840  32,564,164  566,820  445,739
The duty is 3d. per lb.  The exports in the above years were respectfully 12,169,752
lbs. and 22,712,859 lbs. of which 3,399,333 lbs. and 12,606,333 lbs. were the produce
of British Possessions, and 8,770,419 lbs. and 10,106,526 lbs. were Foreign.
COFFEE ROASTING AND GRINDING.  The gratefulness of the beverage afforded by this
seed depends upon many circumstances, which are seldom all combined. The nature of
the soil, the climate, seed, mode of culture,
and cure, influence greatly the quality of
366                                        the fruit.  But when all these particulars
concur, and the berry is of the finest sort,
and most highly appreciated by the importer, it may be ruined in the roasting;
for if some berries be under and some
over done, the whole when ground will
yield an unpalatable infusion.  The due
point to which the torrefaction should be
carried, may  be determined partly by
__ l  ~the color, and  partly  by the  loss of
11      11_    ^IIDs ~weight, which points, however, are different for each sort of coffee.  But perfect
|T-  i  I   equality of ustulation is difficult of attain1  ment with the ordinary cylindrical ma-__,     _.__ -I_ _. I1     chines.  Messrs. Law, of London and Ed~*~   hn     ll      *~{I:    _   inburgh, coffee merchants to the Queen,:  T 11  -II 1'      _1_l had long been dissatisfied with the partial
-~  -  manner in which the cylinder performed
its contents black, some dark brown, and
_    -     — ~....._ _ *_. -  others paler; results which greatly injure.._____________     _.__ _the flavor of the beverage made with the
-— ^                      -~~~                coffee.  Mr. William  Law  has conquered
all these difficulties by his happy invention of the globular roaster, actuated by a compound motion like that of our earth. This roaster, with its double, rotary motion, is
heated not over an open fire but in an atmosphere of hot air, through a cast metal casing.
The globe is so mounted as to revolve horizontally, and also from time to time vertically,
whereby the included beans were tossed about and intermingled in all directions. Inequality of torrefaction becomes impossible. The consequence is the production of an
article which on being ground evolves the most fragrant aroma, and when infused the
most grateful and exhilarating beverage. The position of the globe infy. 366 shows




COLLODION.                                    457
it as turned up by a powerful leverage out of the cast-iron heater, preparatory to its
being emptied and re-charged.
The coffee, thus equally roasted, is finely ground in a mill between horizontal stones,
like that of a corn-mill, and is thereby capable of giving out all its virtues to either
boiling or cold water.
COKE is carbonized pitcoal.  See CHARCOAL; and PITCOAL at the end.
In manufacturing coke on the large scale, Mr. Wilkinson of Jarrow, near Gateshead, has contrived a system of machinery for saving manual labor in discharging the
coke from the ovens, while he has so arranged the ovens themselves, as to equalize
the distribution of air among the coals, and to improve the produce and increase its
quantity. The preferable size of oven, in his opinion, is 14 feet long, 8 feet wide, with
the floor raised one foot above the level of the ground, and having an inclination to the
front of 6 inches in the length of the bottom; the perpendicular height of the walls,
up to the springer, being 3 feet, while the radius of the arch is 4 feet. He connects
crystallizing and evaporating pans for chemical purposes with a range of 12 coke ovens.
The patentee claims as inventions his forming in the walls of coke ovens, flues with
lateral openings for supplying air to the interior of the oven, as also his peculiar
mechanical apparatus for discharging the coke, and his plan of economizing heat by
evaporation.
COLCOTHAR OF VITRIOL (Rouge d'Angleterre, Fr.; Rothes Eisenoxgd, Germ.)
is the brown-red peroxide of iron, produced by calcining sulphate of iron with
a strong heat, levigating the resulting mass, and elutriating it into an impalpable powder. A better way of making it so as to complete the separation of the acid, is to mix
100 parts of the green sulphate of iron with 42 of common salt, to calcine the mixture,
wash away the resulting sulphate of soda, and levigate the residuum. The sulphuric
acid in this case expels the chlorine of the salt in the form of muriatic acid gas, and
saturates its alkaline base produced by the chemical reaction; whence an oxide will be
obtained free from acid, much superior to what is commonly found in the shops. The
best sort of polishing powder, called jeweller's red rouge, or plate powder, is the precipitated oxide of iron prepared by adding solution of soda to solution of copperas, washing,
drying, and calcining the powder in shallow vessels with a gentle heat, till it assumes
a deep brown-red color. See IRON.
COLLODION.  M. Malgaigne has recently communicated to the French Medical
Journals, some remarks on the preparation of gun-cotton for surgical purposes.
Several French chemists, at the suggestion of M. Malgaigne, attempted to make an
ethereal solution of this compound, by pursuing the process recommended by Mr.
Maynard in the American Journal of Medical Sciences, but they failed in procuring the
cotton in a state in which it could be dissolved in ether. It appears that these experimentalists had employed a mixture of nitric and sulphuric acids; but M. Miallie ascertained, after many trials, that the collodion, in a state fitted for solution, was much
more easily procured by using a mixture of nitrate of potash and sulphuric acid.
For the information of our readers who may be disposed to try this new adhesive
material, we here give a description of M. Miallie's process for its preparation. It
appears from the results obtained from this chemist, that cotton, in its most explosive
form, is not the best fitted for making the ethereal solutionParts by weight.
Finely powdered nitrate of potash  -       -      -       -         40
Concentrated sulphuric acid  -      -      -      -       -      -60
Carded cotton        -      -       -      -      -       -      - 2
Mix the nitrate with the sulphuric acid in a porcelain vessel, then add the cotton, and
agitate the mass for three minutes by the aid of two glass rods. Wash the cotton, without first pressing it, in a large quantity of water, and when all acidity is removed
(indicated bylitmus paper) press it firmly in a cloth. Pull it out into a loose mass, and
dry it in a stove at a moderate heat.
The compound thus obtained is not pure fulminating cotton; it always retains a small
quantity of sulphuric acid, is less inflammable than gun-cotton, and it leaves a carbonaceous residue after explosion. It has, however, in a remarkable degree, the property
of solubility in ether, especially when mixed with a little alcohol, and it forms therewith a very adhesive solution, to which the name of collodion has been applied.
Preparation of Collodion.
Parts by weight
Prepared cotton..-                  8
Rectified sulphuric ether   -      -      -      -       -      - 125
Rectified alcohol    --                   -      -       -      -    8
Put the cotton with the ether into a well-stopped bottle, and shake the mixture ioi
some minutes. Then add the alcohol by degrees, and continue to shake until the whole




COLORS USED IN PAINTING, WITH NOTICES OF THEIR CHEMICAL AND ARTISTICAL PROPERTIES.-By William Linton.                                                                                                                                                                        g
Colors.                 Chemical Designation.                   Preparation.                     Chemical Characteristics.                         Artistical Properties.                       Additional Colors, with Remarks.
Blackened  by Sulphuretted  Hydrogen,
Hydro-Sulphuret  of   Ammonia,  and                                                           There are other Whites of Lead, varying in body
other foul gases, common to most do-   The best White extant for Oil or Resin   and brilliancy, and equally obnoxious to the acmestic atmospheres' for which  reason   vehicles when pure, which is generally   tion  of mephitic vapors; as Krems, lRoman,
t    a rapidly drying and protective vehicle is   ascertained by its exceeding whiteness and   and Venetian Whites, and Sulphate of Lead. The
0 W      F        TA-P WHTE     T                     Carbonate of Lead,            Plates of lead  exposed           ssential to seal it up against such evil  opacity.  Its usual adulterations are Sul-    Whites of Bismuth, Pearl, and Antimony, are
FLAKE WHITE                                  owith                the action  of  vinegar-steam       influences. It has no injurious action   phate of Barytes, Chalk, Pipe-clay, &c.,  injured by light as well as by mephitic vapors.
W4                                                    an excess of Oxide.           in beds of fermenting tan.       upon  Vegetable  and  other colors, a aall of which are partially transparent,   Those of Zinc, Tin, barytei, and  Strontian,
Zi ^~.                                                                                                              some have conjectured. It  is perfectly   and consequently appear darker in unc-   although they are comparatively secure against
soluble in diluted Nitric or Acetic Acid   tnous or resinous vehicles.                        the foul gases, are too feeble in body to be satiso when free from Pipe-clay or Sulphato of                                                     factory in unctuous or resinous vehicles.
Barytes.
~tZ:                   -                     ___                                     A  beautiful Orange  tinted  Yellow, of
Resists the action of the foul gases, light,,tituteofooNap    Yelow, tht Cboo,
CADMIUM  YELLOW                     Sulphuret of Cadmium           A  ombinati   of Cadmtum    &.  It is a moDt dtrblo  nd bhillint |od other Mineral Yellows,   hih                                                                    but the  are
i;  ad                   colpt  ooroo. ^liable  to  injury from  noxious vapors,   of Lead, like all preparations of that metal, are
light, &c.                                     blackened by the foul gases. The Chromate of f
l___________________________  _____ __________________________________  ________o ______________oBarytes is strongly acted upon by light. The.  united oxides of Lead  and Antimony, furnish              0
YELLOW  Chototalo  f        - t~~~A   Solotion  of S~troti             Roi b           t     fb      o     oo          A polo Canary Yollow; aother soift tab-   Naples Yellow, a                 color  readily  affected by Stl-  4
| 4  STRONTIAN  YELLOW              Chromate of Strontiana          dded to  one of Chromate   Riostt acd ih  fecly duo                                                                 al stitute for the faulty Yellows mentioned    ro   otr    l g, 
of Potasb.                    light, and it peofectly durablo.         abooe                                          ts by light, and  by a m            ois t steel spatula.  Turpith  0
STRoN N                      Pota.iMneral, o  Sotbsulphate of Mercury, is rapidly 
p^^      ______________________________________               ___-_______                              __________ __________ ________________blackened by light, and by the foul airs. Opiment or King's Yellow  (Arsenic and Sulphur) is
7       YELLOW  OCHRE                                                                                                                                                                                      equally destructible; also Patent Yellow  (Lead
OXFORD  OCHRE                                                       Native Earths, consisting                                                       The Oxides of Iron are among the most  and Salt heated violently)
ROSMAN  OCHREi                                                                          of                                                                 staple  colors  of  the  palette.   When          The Vegetable Yellows are not to be depended
STONE OCHRE                                                           Silica and Alumina                                                         properly washed and prepared  for oil   upo.  They soon disappear whn applied in deliBROWN  OCHRE                                                                colored by                                                             pnting they are incapable of injuring             t tint  o  thio glazings, especially if subjected
TERRA  Dl SIENNA                                                          Oxide of Iron.                                                            other colors, and may be said to con.   to the action of the solar rays (a summary mode
UMBER                                                                                                                                               stitute  the   soindest   materials  with   of ascertaining the probable results of lengthened
02                                                           Oxides                                                 All Permanent Colors, whether Native   which the chemistry of Nature has fur-   periods in subdued lights). Oanmboe dissolved
of                                                                  or Calcined.                    nishoed the painter for the imitation of   by dEther, or Alcohol, is equally fugitive.
JAUNE DE MARS                                 ron.                  A  Chemical Preparation                                                        her works.
LIGHT RED                                                           Yellow Ochre, Calcined.                                                                                                       There are otter Mineral Reds which are durable;
PT4 ^~~~~~~~~~~~~~~~~~~~~but they acre                                                                                                                                     of inferior quality and are not  needed.
r  ~ ~ ~~~~____~~__________________________ ~_~ ~Native Cinnabar is inferior in every respect to
Vermillion.  Venetian Red isVa                                                                                                                                                                                                                     an inferior repreINDIAN  RED                                                             A Nntative Earthof Indian Red, and Colcothar a still
____                                                                                                                                                                                                          coarser__one___________________ _______________ ________________corer one. Red Lead blackens in oil; and
Cff                                                                                                                                                               -...                                          Iodide of Mercury has no claim to durability.
~ A perf~~ ect ~lyi.~~ pernomanen~t color, no~t aoffec~ted~ 3Among Vegetable Reds, the Madders have the
VERMILLION                        Bisulphuret of Mercury.            Mercury and Sulphur.           b     y  acids  or c austic alkalies. Vaporized   A  beautiful color, and of an excellent  best  reputation  for  standing.   All vegetable
VR ILsNBiupaeofMr y ublimed together.  by a red beat if pure.                                 body                         colors, however, should be looked upon with susI          -                     =                                                  1=I1S 




Consists of Silica, Alumina,                                            Acids,  which  will  not   affect  other
Lime,  Soda,  and   Potash,                                             Mineral Blues, will destroy  the  color
ATiv        Oxide  of  Iron, Magnesia,                                              in  Ultramarine,   This is one  of  its   A  moat invaluable pigment: too well
ULTRAMARINE                   Sulphuric   Acid,  Sulphur,    Prepared from  a mineral    best  chemical  tests,    None  of   the   known and appreciated to require any
ULTRAMARINE                  an      Chlorine   (according             called Lapis Lazuli.           mephitic  gases, or light, or other pig-   comment.Tere are other  Mineral  Blues, but they  are
7J2~~~~~~ ~to   Gmelin,   Varrentrapp,                                                                   ments do it any injury.  It is perfectly                                                              better avoided when the Ultramnarines are avail~and  others), in  its  native                                        durable.                                                                                             able.  The  Oxide of            Cob alt and Alumina form
sand   Ctbbal), in  its  lntie                                         dualb.                                                                                                tbl    ue; and the Oxide of Cobalt and Glass,,. [              ~.)_- ________________ form _Smalt; they are botht blackened hay foul
It is regarded as a corn-                                                                                                                                                  airs.  Prussian and Antwerp Blues are in much
pound  of  Silicate  of Alu-                                                                                                                                                 use from the want of a permanent deep blue: they
mina, Silicate  of  Soda, with   Prepared  by  several diffi-                                                             A  cheap   and really  valuable substitute   are injured by light and alkalies.  Indigo is iiiARTIFICIAL                 Sulphuret of Sodium; the   cult processes, some of which                  Responds to the same tests as the na-            for  the  native  prodict.  Thle  best is   ferior in color and very fugitive.
ULTRAMARINE                  color is owing to the reaction   are kept secret by the ma-                              tive mineral.                     that which  is the  least purple  in  its
of  the  latter   on  the  two   kers.                                                                                     tint.
former constituents.
When Chromate of Mercury
(the Orange precipitate on
CHROME  GREEN                   l           Cromiu                       d C     ma t  ofi  Ptas) i sy    (Thpecolotng Cman      ter inof la meresht           An opaqu  light Green, of a full body.
strongly  ignited, Oxide ofo
~h~(~~~~~  i^~~~~~                                                                     ~ ^Chromium  remains in a
i X p owder..There are other Mineral     Greens.  Those of Cop0                                ___dn_.                                                                                                                                                                                           per, the Enerald Green and Mineral Green, are
TERRA  VERTE                             Oxide of Copper.                                                                                                                                                        very inneuein y oil vehicles. in
0  ______________________                                                                                                     Both quite permanent-native or cal- Beautiful delicate Greens; deservedly
Q) _Native Minerals.                                                                                                         cined.   Like  the  Ultramarines, acids              favorite pigu t with most painters.
~MATLACHITE                  Carbonate of Copper,                                                 dnadestroy their colors. 
=  \.  |MATLAYCHITE       s: _ united with Silicate.                                                                                                       l 
VANDYKE  BROWN                               Decompcsed                   Decayed Wood, Peat, or
COLOGN  EARTH                             Vegetable Matter.                      Bog Earth.
_ i           r__i    (^         ~                   ~           ^               ~ ~                      ~                  These  Browns  are  reputed  permanent. Zdin thel   ipaity withe  opacity with  which                                                                                                                                                                                          The dlark  Browns, though chiefly of vegetable,               in         TT MUMMY                             Vegetable and Animal              White Pitch and Myrrh,            time  generally invests them  in pictures,                                                           norigin,   seem   to be the  only  deep  transparent
MUMMY                                           Matter combined.                  with  Animal Matter.           being attributable  probably to a  loss of                  Dark transparent Brown.                   colors which have the  reputation of being p erna_______________________^                                    _____________________~ ^translucency in the vehicle, rather than                                                                        net.  The  deep  Reds,  Yellows, Greens,  and
to any change in  the pigments: dark                                                                     Blues, are  all more or less of a fugitive nature.
~t ~ <~ I~ A  Mineral Pi'~tch,                                                                 ~ or Resin,   colors R ~ making  the defect more evident
A Mineral Pitch,  or Resin,   tnnlighttonen.
Bt n        found floating on  the Dead   tn l
ASPIHALTUM                                    Bitamen.                  Sea; also after the distillation of natural naphtha.
r       IVORY  BLACK                                Animal Matter.                      Calcined Ivory.                    A  perfectly durable pigment.                       Of a Brownish-black tint.
BLUE  BLACK  Veh                                                       b Mtt         Calcined Vine Stalks.              Quite durable when  the blue tints                       Of Bluisl-blacktint
In recording the defects and liabilities of colors, it should not be forgotten that the painter's vehicle or diluent must have considerable effect in preventing chemical action among
such as are inimical to each other, by isolating and sustaining their component particles from mutual contact. And if the vehicle be of a sound and firmly drying quality, even the external
attacks from damp and foul airs, to which many of the objectionable colors are liable, may often be successfully resisted. But should the vehicle be of a flimsy and impure character, instead                                                                                                                 A
of being a protector, it may become in itself an originator of mischief among the colors.




460                                       COMB.
of the liquid acquires a syrupy consistency. It may be then passed through a cloth,
the residue strongly pressed, and the liquid kept in a well-secured bottle. 
Collodion thus prepared possesses remarkably adhesive properties. A piece of linen
or cotton cloth covered with it and made to adhere by evaporation to the palm of the
hand, will support a weight of twenty or thirty pounds. Its adhesive power is so great
that the cloth will commonly be torn before it gives way. The collodion cannot be
regarded as a perfect solution of the cotton. It contains suspended and floating in it
etable fibre, which has escaped the solvent action of the ether. The
y be separated from these fibres by a filter, but it is doubtful whether
ge.  In the evaporation of the liquid, these undissolved fibres by felting with each other appear to give a greater degree of tenacity and resistance to the
dried mass.
In the preparation of collodion it is indispensable to avoid the presence of water, as
this renders it less adhesive; hence the ether as well as the alcohol should be purely
rectified. The parts to which the collodion is applied should be first thoroughly drie
and no water allowed to come in contact with them until all the ether is evaporated
to dryness by a steam heat, which must be continued for some time so as entirely to
expel the alcohol or ether. The residuary matter should have the transparency and
general characters of common resin.
COLOPHANY, black rosin, the solid residuum of the distillation of turpentine, when
all the oil has been worked off.
COLORING MATTER.  (Matiure colorante, Fr.; Farbstoff, Germ.)  See DYEING,
the several dye-stuffs and pigments.
COLUMBIUM, a peculiar metal extracted from a rare mineral brought from Haddam,
in Connecticut. It is also called Tantalium, from the mineral tantalite and yttro-tantalite,
found in Sweden. It has hitherto no application to the arts. It combines with two successive dosoe of oxygen; by the second it becomes an acid.
COLZA is a variety of cabbage, the brassica oleracea, whose seeds afford, by pressure,
an oil much employed in France and Belgium for burning in lamps, and for many other
purposes. This plant requires a rich but light soil; it does not succeed upon either sandy
or clayey lands. The ground for it must be deeply ploughed and well dunged. It should
be sown in July, and be afterward replanted in a richly-manured field. In October it is
to be planted out in beds, 15 or 18 inches apart. Colza may also be sowed in furrows 8
or 10 inches asunder.
Land which has been just cropped for wheat is that usually destined to colza; it may
be fresh dunged with advantage.  The harvest takes place in July, with the sickle, a
little before the seeds are completely ripe, lest they should drop off. As the seed is productive of oil, however, only in proportion to its ripeness, the cut plants are allowed to
complete their maturation, by laying them in heaps under airy sheds, or placing them in
a stack, and thatching it with straw.
The cabbage-stalks are thrashed with flails, the seeds are winnowed, sifted, spread out
in the air to dry; then packed away in sacks, in order to be subjected to the oil-mill at
the beginning of winter. The oil-cake is a very agreeable food to cattle, and serves to
fatten them. It is reckoned to defray the cost of the mill.
Colza impoverishes the soil very much, as do, indeed, all the plants cultivated for tht
sake of their oleaginous seeds. It must not, therefore, be come back upon again for six
years, if fine crops be desired.   The double ploughing which it requires effectually
cleans the ground. See OILS, UNCTUOUS.
COMB, the name of an instrument made of a thin plate either plane or curved of wood,
horn, tortoise-shell, ivory, bone, or metal, cut out upon one or both of its sides or edges,
into a series of somewhat long teeth, not far apart. which is employed for disentangling,
laying parallel and smooth the hairs of man, horses, or other animals.
A thin steel saw bow, mounted in an iron or wooden handle, is the implement used
by the comb-maker to cut the bone, ivory, and wood into slices of from a twelfth to a
quarter of an inch thick, and of a size suitable to that of the comb.  The pieces of
tortoise-shell as found in commerce are never flat, or, indeed, of any regular curvature,
such as the comb must have. They are therefore steeped in boiling water sufficiently
long to soften them, and set to cool in a press between iron or brass moulds, which impart to them the desired form which they preserve after cooling. After receiving their
outline shape and curvature, by proper flat files or fine rasps, the place of the teeth is
marked with a triangular file, and then the teeth themselves are cut out with a double
saw, composed of two thin slips of tempered steel, such as the main-spring of a watA
notched with very fine sharp teeth. These slips are mounted in a wooden or iron stock
or handle, in which they may be placed at different distances, to suit the width of the
comb-teeth.  A  comb-maker, however, well provided in tools, has an assortment of
double saws set at every ordinary with. The two slips of this saw have their teeth in
different planes, so that when it begins to cut, the most prominent slip alone acts, and




COMBUSTIBLE SUGAR.                                       461
when the teeth of this one have fairly entered into the comb, the other parallel blade
begins to saw.  The workman, meanwhile, has fixed the plate of tortoise-shell or ivory
between the flat jaws of two pieces of wood, like a vice made fast to a bench, so that
the comb intended to be cut is placed at an angle of 45~ with the horizon. He now saws
perpendicularly, forming two teeth at a time, proceeding truly in the direction of the first
tracing.
A much better mode of making combs is to fix upon a shaft or arbor in a lathe a se.
ries of circular saws, with intervening brass washers or discs to keep them at suitable distances; to set in a frame like a vice, in front of these saws, the piece of ivory or horn to
be cut; and to press it forward upon the saws at an angle of 45 degrees, by means of a
regulated screw motion. When the teeth are thus cut, they are smoothed and polished
with files, and by rubbing with pumice-stone and tripoli.
Mr. Bundy, of Camden Town, obtained a patent so long ago as 1796, for an apparatus
of that kind, which had an additional arbor fitted with a series of circular saws, or rather
files, for sharpening the points of the comb-teeth.
More recently, Mr. Lyne has invented a machine in which, by means of pressure, two
combs are cut out at once with chisels from any tough material, such as horn or tortoiseshell, somewhat softened at the moment by the application of a heated iron to it. The
piece of horn is made fast to a carriage, which is moved forward by means of a screw
until it comes under the action of a ratchet-wheel, toothed upon a part of its circumference. The teeth of this wheel bring a lever into action, furnished with a chisel or
knife, which cuts out a double comb from the flat piece, the teeth of which combs are
opposite to each other.  By this means, no part of the substance is lost, as in sawing
out combs. The same carriage may be used, also, to bear a piece of ivory in the hard
state toward a circular saw, on the principles above explained, with such precision, that
from 80 to 100 teeth can be formed in the space of one inch by a proper disposition of
the tool.
Bullocks' horns, after the tips are sawed off, are roasted in the flame of a wood fire.
till they are sufficiently softened; when they are slit up, pressed in a machine between
two iron plates, and then plunged into a trough of cold water, whereby they are hardened. A paste of quicklime, litharge, and water is used to stain'he horn to resemble
tortoise-shell. See HORN.
COMBINATION (Combinaison, Fr.; Verbindung, Germ.); a chemical term which
denotes the intimate union of dissimilar particles of matter, into a homrogeneous-looking compound, possessed of properties generally different from those of the separate
constituents.
COMBUSTIBLE (Eng. and Fr.; Brennstoff, Germ.); any substance which, exposed in
the air to a certain temperature, consumes spontaneously with the emission of heat
and light. All such combustibles as are cheap enough for common use go under the
name of Fuel; which see. Every combustible requires a peculiar pitch of temperature
to be kindled, called its accendible point. Thus phosphorus, sulphur, hydrogen, carbureted hydrogen, carbon, each takes fire at successively higher heats.
COMBUSTIBLE  SUGAR.  When  sugar is acted on  by a mixture of nitric
and sulphuric acids, a peculiar substance is produced, having a close resemblance to
common resin, not only in its appearance and physical characters, but also in regard to
its solubility in alcohol, ether, volatile oils, &c., and insolubility in water. This substance
is, however, extremely inflammable and explosive, and possesses many of the properties
ascribed to the celebrated Greek fire. Its affinity for alcohol and ether is so great that
water will not remove these fluids from it. "Not having yet succeeded in producing
with it any definite basic compound which would enable me to control my results, I
have not attempted its analysis. The only purposes to which I have applied it are to
the formation of fusees for shells, and to the preservation of gunpowder and pyrotech.
nical articles from damp and moisture. As a fusee, it is easily lighted, burns with great
regularity, and appears absolutely incapable of being extinguished, circumstances which
would render it of great use in ricochet practice. As a means of preventing the mischievous effect of damp and moisture on gunpowder it is of great value. The best
mode of application is to plunge the gunpowder for a few seconds into an alcoholic or
ethereal solution of the sugar compound, then withdraw it and allow it to dry at a
gentle heat, say 1200 Fahr., though there is no danger of an explosion at 2120. In this
way the gunpowder is covered by a coat of varnish easy of ignition and insoluble in
water, which cannot therefore penetrate to the gunpowder, the explosive nature of
which is rather augmented than diminished by this treatment. An ethereal solution of
gun-cotton does not answer so well for this purpose, nor is it so manageable. I have
not ascertained how far this new substance is useful in retaining the edges of wounds
in approximation, but its alcoholic solution merits a trial. The following is the method
which I have found most successful in the manufacture of this compound:~
"Mix together sixteen parts of concentrated sulphuric acid and eight parts of nitric




462                                   CONCRETE.
acid, spec. gray. 1 50; place the mixture in cold water, and when the temperature ]hfallen to 600 or less, stir in one part of finely-powdered sugar, which will become past
in a few seconds, and is then to be removed and plunged in cold water, when more sugar
may then be added to the acid mixture, and removed as before. The compound is to
be washed in water and dissolved in alcohol, to which a solution of carbonate of potash
must be added in excess, so as to precipitate the substance, and neutralize its uncombined acid. After careful washing with water, it is again to be dissolved in alcohol or
ether, and cautiously evaporated to dryness by a steam heat, which must be continued for
some time, so as entirely to expel the alcohol or ether. The residuary matter should
have the transparency and general character of common rosin."-Mr. E. Thompson.
COMBUSTION  (Eng. and Fr.; Verbrennung, Germ.) results in common cases from
the mutual chemical reaction of the combustible, and the oxygen of the atmosphere,
whereby a new compound is formed; the heat and light evolved being most probably
produced by the rapid motions of the particles during the progress of this combination.
COMPOUND  COLORS.  If the effects of the coloring particles did not vary according to the combinations which they form, and the actions exercised upon them by the
different substances present in a dyeing bath, we might determine with precision the
shade which ought to result from the mixture of any two colors, or of the ingredients
affording these colors separately. Though the chemical action of the mordants and of
the liquor in the dye-bath often changes the result, yet theory may always predict them
within a certain degree. It is not the color appropriate to the dye-stuffs which is to
be considered as the constituent part of compound colors, but that which they must
assume with a certain mordant and dye-bath.  Our attention ought therefore to be
directed principally to the operation of the chemical agents employed.
1. The mixture of blue and yellow dyes produces green. D'Ambourney, indeed,
says that he has extracted a fast green from the fermented juice of the berries of the
buckthorn (rhamnusfragula), but no dyer would trust to such a color.
2. The mixture of red and blue produces violet, purple, columbine (dove-color),
pansy, amaranth, lilac, mallow, and a great many other shades, determined by the nature and tone of the red and blue dye-stuffs, as well as their relative proportions in the
bath.
3. The mixture of red and yellow produces orange, mordore, cinnamon, coquelicot.
brick, capuchin; with the addition of blue, olives of various shades; and with duns
instead of yellows, chestnut, snuff, musk, and other tints.
4. Blacks of the lighter kinds constitute grays; and, mixed with other colors, produce marrone (marroons), coffees, damascenes. For further details upon this subject, see CALICO PRINTING, DYEING, as also the individual colors in their alphabetical
places.
CONCRETE. The name given by architects to a compact mass of pebbles, sand,
fnd lime cemented together, in order to form  the foundations of buildings.  Semple
mays that the best proportions are 80 parts of pebbles, each about 7 or 8 ounces in
weight, 40 parts sharp river sand, and 10 of good lime; the last is to be mixed with
water to a thinnish consistence, and grouted in. It has been found that Thames ballast,
as taken from the bed of the river, consists nearly of 2 parts of pebbles to 1 of sand, and
therefore answers exceedingly well for making concrete; with from one seventh to one
eighth part of lime.  The best mode of making concrete, according to Mr. Godwin,
is to mix the lime, previously ground, with the ballast in a dry state; sufficient water
is now thrown over it to effect a perfect mixture, after which it should be turned over at
least twice with shovels, or oftener; then put into barrows, and wheeled away for use
instantly.  It is generally found advisable to employ two sets of men to perform this
operation, with three in each set; one man to fetch the water, &c., while the other two
turn over the mixture to the second set, and they, repeating the process, turn over the
concrete to the barrow-men.  After being put into the harrows, it should at once be
wheeled up planks, so raised as to give it a fall of some yards, and thrown into the
foundation, by which means the particles are driven closer together, and greater solidity
is given to the whole mass. Soon after being thrown in, the mixture is observed usually
to be in commotion, and much heat is evolved with a copious emission of vapor.
The barrow-load of ioncrete in the fall, spreading over the ground, will form generally
a stratum of from 7 ~o 9 inches thick, which should be allowed to set before throwing in
i second.
Another method of making concrete, is first to cover the foundation with a certain
quantity of water, and then to throw in the dry mixture of ballast and lime.  It is next
turned and levelled with shovels; after which more water is pumped in, and the operation
is repeated. The former method is undoubtedly preferable.
In some cases it has been found necessary to mix the ingredients in a pug-mill, as in
mixing clay, &c. fof bricks. For the preparation of a concrete foundation, as the hardening should be rapid, no more water should be used than is absolutely necessary to effect




COOLING OF FLUIDS.                                      463
a perfect mixture of the ingredients.  Hot water accelerates the induration.  There is
about one fifth of contraction in volume in the concrete, in reference to the bulk of its
ingredients. To form a cubical yard of concrete, about 30 feet cube of ballast and 31
feet cube of ground lime must be employed, with a sufficient quantity of water.
CONGELATION  (Eng. and Fr.; Gefrierung, Germ.); the act of freezing liquids.
Many means are supplied by chemistry for effecting or promoting this process, but they
do not constitute any peculiar art or manufacture. See IcE-HousE.
COOLING- OF FLUIDS.  In Mr. Derosnes's method, the cooling agents employed
are a current of atmospheric air, and warm water of the same or nearly the same temperature as that of the vapors which are to be operated upon.
Fig. 367 represents merely a diagram of the general features of an apparatus constructed upon the principles proposed to be employed, which will serve to explain the
nature of this improvement.
367                                        Let A be the source ot
l K                      the vapors, or the vessel,
boiler, alembic, or closed
~o  cJL                    pan  that  contains the
liquid or sirup to be evaporated or concentrated.
11  ^''~  11The pipe B, through which
~ll^K^U \k   ^^lthe  vapor passes as it
rises in the boiler, is surrounded by another tube
cof larger diameter, closed
at both ends. A pump ii,
draws from thereservoir E,
IU K  \        warm water, which water
has been heated by its preXJ^,^,               ^y9~ tvious and continual passage through  the apparatus in contact with the
- i                     < ill    II    U II,  surface of the vapor pipes.
This pump forces the water by the pipe F, into the annular space or chamber between the
pipes B and c, in which chamber, by its immediate contact with the pipe B, it acquires the
temperature of the vapors intended to be refrigerated. The pipe G conveys thp water from
the pipe c, into the annular colander or sieve H, which has a multitude of small holes
pierced through its under part, and whence the warm  water descends in the form of
a continued shower of rain. To the end of the pipe B, a distiller's worm i i, is connected,
which is placed beneath the colander is.  The entire length of the worm-pipe should
be bound round with linen or cotton cloth, as a conductor of the heat, which cloth will
be continually moistened by the rain in its descent from  the colander.  As this water
has been heated in passing along the tube c, the shower of rain descending from  the
colander will be at a higher temperature than that of the atmosphere, and, consequently,
by heating the surrounding air as it descends, a considerable upward draft will be
produced through the coils of the worm-pipe.
If the colander and the worm-pipe are enclosed within a chimney or upright tube, as
K K, open at top and bottom, a current of ascending air will be produced within it by
the descending shower of hot water, similar in effect to that which would be produced
in a chimney communicating with a furnace, or to that of the burner of an argana
lamp.   Consequently, it will be perceived that in opposition to the descending rain, a
strong upward current of air will blow through that part of the cylinder K K, which is
beneath the colander. When the air first enters the lower aperture of the chimney oi
tube K, it is of the same temperature and moisture as the external atmosphere; but in
its passage up the tube it meets with a warmer and damper atmosphere, caused by the
teat given out from the hot fluid continually passing through the pipes, and by the hot
shower of rain, and also by the steam evolved from the surfaces of the coils of the worm,
which are continually wetted by the descending rain, the evaporation being considerably
augmented by th-e cloth bound round the worm-pipe, retaining the water as it descends in
drops from coil t. coil.
The atmosphere within the tube being of a higher temperature than without, a
current of air constantly ascends and escapes at the upper aperture K, and its place is
supplied by fresh air from  the surrounding atmosphere, entering the tube below.  The
fresh air thus admitted at the bottom of the tube, being cold and dry, will be suited to
take up the heat and moisture within, because the water within the tube, being in a
state of dispersion as rain, presents to the air many points, or a very extended surface,
and also because it is of a higher temperature than the air; and, besides, cold dry air is
coni inually renewed, and a source of warmth is furnished by the latent caloric to the




464                            COOLING OF FLUIDS.
steam, as fast as it is evolved. Thus a portion of the descending rain, or water, is
evaporated, and the effect of this evaporation is to abstract caloric not only from the
water held in contact with the coils of the worm-pipe by the cloth enveloping it, but also
from the hot vapors which pass through the worm.  This process of evaporation has,
therefore, a cooling power, which is but slight in the lower part of the chimney or tube
K, because the temperature of the water, or rain, and of the worm, at this part, are of
a lower temperature; but its refrigerating power increases as it rises towards the
colander, and there it acquires its maximum of intensity, so that at any point between
the lower aperture of the cylinder and the colander the current of air is always a little
cooler than the atmosphere of the region through which it passes (that is, as its maximum); and in passing this region of higher temperature, it is not only put in equiliorium of temperature, but also made to take up an additional quantity of aqueous vapors,
which equalizes the new temperature it acquires with its capacity of saturation. The
cooling caused by the evaporation acts in an incessant and progressive manner from the
lower aperture of the cylinder to the under side of the colander; and this cooling not
only acts as an agent of the evaporation which the current of air cools, but it refrigerates also, because it becomes warmed in abstracting caloric from the vapors or liquids
passing through the worm; and this refrigeration acts also incessantly and progressively
from the lower part of the tube or chimney to the colander.
The patentee states, in conclusion, that " the velocity or force of the current of air
that passes through the chimney or tube K, can be accelerated by artificial means, either
by conducting the air and vapor passing from the upper aperture of the cylinder into the
chimney or flues of a furnace, or by means of a revolving, forcing or exhausting fan, or
ventilator, or any other contrivance which will produce an increased current of air, but
which is not necessary to be particularly described, as I only wish to explain the principles of a simple apparatus, constructed in any convenient form; and I would remark,
that the area of the lower aperture through which the air is introduced into the chimney
or tube K, and also the area of the upper aperture, or that through which it passes to
the atmosphere, should be in accordance with the effect intended to be obtained.
" It is further to be remarked, that in order to obtain from this apparatus the best
effect, the velocity of the current of air must be itself a maximum; and as the speed or
velocity of the current of air is owing to and determined by the excess of the tempefature of the descending water, or rain, and of the coils of the worm to that of the
exterior atmosphere, it ensues that the temperature of the water, or rain, must be a
maximum.  But this excess of temperature is a maximum only when the source of the
rain is at the same temperature as the vapors to be condensed: if less warm, it would
attract less air; or, if warmer, it would augment the temperature of the vapors intended
to be condensed.  Consequently, the shower of water employed in the tube K, as the
agent for cooling, bestows its maximum of effect when it is as warm as the vapors to be
condensed; therefore, I may express this proposition, viz.,' That in refrigerating with
water, less of it may be expended when it is warm than when it is cold, and that the
least quantity of water will be evaporated when it is as warm  as the aqueous or
spirituous vapors upon which it is to operate.'
*" This proposition may appear strange, nevertheless it is conformable to the laws of
nature; and appears only strange, because until now warm water has not been employed
with currents of air for refrigerating.
"Hence it is necessary to raise the temperature of the water in the colander to the
temperature of the vapors to be condensed: therefore, I cause the lukewarm water,
pumped from the reservoir E, to circulate in the chamber c. In this circulation it also
begins to act as a refrigerating medium, taking up a portion of heat from the vapors that
pass through the pipe B, and afterwards it acts as a further condenser in the cylinder, in
the way described. Finally, the portion of this water that is still in the fluid state, after
having fallen down from coil to coil, arrives lukewarm to the inclined surface L, which
conducts it into the reservoir E, from whence it is pumped up into the chamber c, as
before described.
" The tube or chimney K may have more or less altitude; the higher it is the greater
is the current produced. The force or velocity of the current of air can be governed by
the areas of the introduction and exit apertures. If the cylinder rises only to the height
of the sieve, the effect is much less than when it is prolonged beyond this height. I
would further remark, that if the cylinder was removed, a slight effect might be produced, provided that a current of air be preserved in the cylindrical space limited by the
toils of the worm, and also if the current was produced between the coils; or a central
passage might be formed in an apparatus of another shape than that above described.
"I have only shown the application of the worm, because intending only to explain
the principles of this method of condensing and refrigerating.
"The small quantity of water wasted in this manner of condensation, (that is, that
portion passed off to the atmosphere in the form of vapors' at the upper aperture of the




COPAL.                                           465
cylinder K), may be replaced by a small stream of cold water, which may be brought
to the apparatus, and perhaps most conveniently introduced into the reservoir    or into
the chamber between the pipes n and c.  When operating upon aqueous vapors, the
waste of waters is always less in weight than that of the vapors liquefied. When this
apparatus is applied to the purposes of distillation, the end of the worm should terminate in a vessel 3, which is to receive the produce of the condensation. It will be seen
that this improved process is applicable to various purposes, where condensation or
refrigeration is required; for instance, in the boiling or concentration of sugar; to condensing and refrig;erating distilled vapors, or steam, or saline liquids, either in vacuum
or not; to cooling brewers' worts; and to the refrigeration of other liquors, or any other
processes, when it may be required."
I have inserted the specification of this patent verbatim. M. Derosne has busied himself during a long life with a prodigious number of ingenious little contrivances for
clarifying and boiling syrups, distillation, &c., but he has in this invention taken a
bolder flight, having secured the exclusive privilege of condensing vapors, and cooling
liquors, with hot water, in preference to cold. No man at all versant in the scientific
doctrines, or the practical applications of caloric, will ever seek tomeddle with his monopoly of such a scheme.  He may find, perhaps, some needy coppersmith ready to
espouse that or any other equally foolish project, provided a productive job can be
made of it, against credulous customers.
For some rational methods of cooling liquors and condensing vapors, see REFIIGERATION, STILL, and SUGAR.
COPAL, a resin which exudes spontaneously from  two trees, the Rhus copallinum,
and the Elceocarpus copalifer, the first of which grows in America, and the second in the
East Indies.  A third species of copal-tree grows on the coasts of Guinea, especially on
the banks of some rivers, among whose sands the resin is found. It occurs in lumps of
various sizes and of various shades of color, from the palest greenish yellow to darkish
brown.  I found its specific gravity to vary in different specimens from  1-059 to 1071,
being intermediate in density belween its two kindred resins, animt and amber. Some
rate its specific gravity so high as 1-139, which I should think one of the errors with
which chemical compilations teem.  Copal is too hard to be scratched by the nail,
whence the excellence of its varnish. It has a conchoidal fracture, and is without smell
or taste.  When exposed to heat in a glass retort over a spirit lamp, it readily melts
intoaliquid, which being frther heated boils with explosive jets.  A viscid, oily-looking
matter then distils over. After continuing the process for some time, no succinic acid
is found in the receiver, but the copal blackens in the retort. Anhydrous alcohol
boiled upon it causes it to swell, and transforms it by degrees into an elastic, viscid
substance. It is not soluble in alcohol of 0825 at the boiling point, as I have ascertained. Copal dissolves in ether, and this ethereous solution may be mixed with alcohol without decomposition.  Caoutchoucine acts very slightly upon it by my experiments, even at the boiling temperature of this very volatile fluid; but a mixture of it
with alcohol of 0825, in equal parts, dissolves it very rapidly in the cold into a perfectly
liquid varnish. Alcohol holding camphor in solution also dissolves it, but not nearly so
well as the last solvent. According to Unverdorben, copal may be completely dissolved
by digesting one part of it for 24 hours with one part and a half of alcohol (probably anhydrous), because that portion of copal which is insoluble in alcohol dissolves in a very
concentrated solution of the soluble portion. Oil of petroleum and turpentine dissolve
only I or 2 per cent. of raw copal. By particular management, indeed, oil of turpentine
may be combined with copal, as we shall describe under the article VARNISH.
Fused copal possesses different properties from the substance in its solid state; for it
then may be made to combine both with alcohol and oil of turpentine.
Unverdorben has extracted from the copal of Africa five different kinds of resin, none
of which has, however, been applied to any use in the arts.
The ultimate constituents of copal by my analysis are, carbon 79-87, hydrogen 9'00,
oxygen l'11; being of hydrogen 7 -6 in excess above the quantity necessary to form,
water with the oxygen.
Much information has been received from various sources concerning this somewhat
ill-understood product of late years. It is now known that there are three different
kinds of copal in commerce, but nothing is known of their distinguishing characteristics.
We have East Indian and West Indian copal, and, under the latter name, two very different substances. The East Indian, called also African, is more colorless, soft, and transparent, than the others; it forms a fine surface, and when heated emits an agreeable
odor. It furnishes the finest varnish. Fresh essence of turpentine dissolves it completely, but not old. Essence digested upon sulphur will dissolve double its own weight,
without letting any fall. Fresh rectified oil of rosemary will dissolve it in any proportion, but if the oil is thickened by age it serves only to swell this copal.
30




466                                       COPPER.
When cautiously melted, it may be then dissolved in good essence of turpentine in
any proportion, producing a fine varnish, of little color.
A good varnish may be made by dissolving 1 part of copal, 1 of essence of rosemary,
with from 2 to 3 of pure alcohol. This varnish should be applied hot, and when cold
becomes very hard and durable.
The West India species, or American, comes to us, not in lumps of a globular form,
but in small flat fragments, which are hard, rough, and without taste or smell. It is
usually yellow, and never colorless like the other. Insects are very rarely found in it.
It comes from the Antilles, Mexico, and North America. It will not dissolve in essence
of rosemary.
The third kind of copal, known also as West Indian, was formerly sold as a product
of the East Indies. It is found in fragments of a concavo-convex form, the outer covering of which appears to have been removed. It contains many insects. When rubbed
it emits an aromatic odor. It gives out much ethereous and empyreumatic oil when
melted. It forms a soft varnish, which dries slowly.
Fusel oil, or amyle spirit, has been lately used as a solvent of the hard copal; but it
does not dry into a very solid varnish.
Annexed is an account of the import of anim6 and copal, in the undermentioned
years:~
1841.      1842.        1843.        1844.
Quantities imported          cwts.          -          3336         3359        6493
Quantities exported          cwts.          -          1403         1508        2467
Retained for consumption cwts.               -         2091         2085         270
Nett revenue                     ~          535         295          117          157
COPPER is one of the metals most anciently known.  It was named from the island
of Cyprus, where it was extensively mined and smelted by the Greeks. It has a reddish brown color inclining to yellow; a faint but nauseous and rather disagreeable
taste; and when rubbed between the fingers it imparts a smell somewhat analogous to
its taste. Its specific gravity is from 8'8 to 8'9. It is much more malleable than it is
ductile; so that far finer leaves may be obtained from it than wire. It melts at the
27lth degree of Wedgewood's pyrometer, and at a higher temperature it evaporates in
fumes which tinge the flame of a bluish green. By exposure to heat with access of air,
it is rapidly converted into black scales of'peroxide. In tenacity it yields to iron; but
surpasses gold, silver, and platinum, considerably in this respect.
In mineralogy, the genus copper includes about 13 different species, and each of these
contains a great many varieties. These ores do not possess any one general exterior
character by which they can be recognised; but they are readily distinguished by chemical re-agents. Water of ammonia digested upon any of the cupreous ore in a pulverized state, after they have been calcined either alone or with nitre, assumes an intense
blue color, indicative of copper. The richest of the ordinary ores appear under two
aspects: the first class has a metallic lustre, a copper red, brass yellow, iron gray, or
blackish gray color, sometimes inclining to blue; the second is without metallic appearance, has a red color, verging upon purple, blue, or green, the last tint being the most
usual. Few copper ores are to be met with, indeed, which do not betray the presence
of this metal by more or less of a greenish film.
Dr. Scherer, of Freyberg, has arranged the ores of copper as follows:
Symbol.                                    Copper in 100.
1. Copperglanz (Kupferglaserz) Cu2S                                           779.7
2. Kupferkies, Copper pyrites, Cu2S, Fe2S3                                    34-8
3. Buntkupfererz 3 Cu2S, Fe2S3                                                55-7
4. Fahlerz 4 (Cu2S, FeS, ZnS, AgS (Sb 83 As 83)                              14-41
5. Rotbkupfererz Cu20                                                         88-5
6. Malachit 2 CuO, CO2HO                                                     57-4
7. Kupferlasur (2 (CuO, C02) +  CuO. HO                                       55-3
Both Fahlerz and Buntkupfererz vary greatly in their proportion of copper. Fahlers
is very difficult to convert into pure copper by smelting, on account of the presence of
antimony and arsenic in it.  Kupferglanz is a disulphuret of copper.  Buntkupfererz is
purple or variegated copper ore. Rothkupfererz is the orange or red oxide of copper.
Kuferlasur is blue carbonate of copper.
Pure copper may be obtained in the solid state either by the reduction of the powder of the pure oxide by a stream of hydrogen gas passed over it in an ignited tube, or
by the galvanuplastic process. See ELECTRO-METALLURGY, or ELECTROTYPIE.
1. Native Copper occurs in crystals, branches, and filaments, its most common locality being in primitive rocks. It is found abundantly in Siberia, at the mines of
Tourinski, in those of Hungary, of Fundo-Moldavi in Gallicia, of Fahlun in Sweden.




COPPER.                                        467
of Cornwall, f&c.  The gangues of native copper are granite, gneiss, mica-slate, clay
slate, quartz, carbonate or fluate of lime, sulphate of barytes, &c. The most remarkable masses of native copper hitherto observed were-first, one in Brazil, 14 leagues from
Basa, which weighed 2616 pounds; and secondly, another which Dr. Francis-le-Baron
discovered in America to the south of Lake Superior. It was nearly 15 feet in circumference.
2. Sulphuret of Copper, the vitreous ore of Brochant. The texture of this ore is compact; its fracture, conchoidal, surface sometimes dull; color, iron black or lead gray, often
bluish, iridiscent, or reddish from a mixture of protoxyde. It is easily melted even by
the heat of a candle; but more difficult of reduction than protoxyde. This ore yields to
the knife, assuming a metallic lustre when cut. Its density varies from 4-8 to 5-34. Its
composition, according to Klaproth, is 78-5 copper, 18-5 sulphur, with a little iron and
silica.  Its equivalent constitution by theory is 80 copper + 20 sulphur = 100; whence
78-5 of metal should be associated with 19-6 of sulphur. This ore is therefore one of
the richest ores, and forms very powerful veins, which likewise contain some orange protoxyde. It is to be found in all considerable copper districts; in Siberia, Saxony, Sweden,
and especially Cornwall, where the finest crystals occur.
3. Copper Pyrites resembles in its metallic yellow hue, sulphuret of iron; but the latter
is less pale, harder, and strikes fire more easily with steel. It presents the most lively
rainbow colors.  Its specific gravity is 4-3.  It contains generally a good deal of iron,
as the following analysis will show: copper 30, sulphur 37, iron 33, in 100 parts.  According to Hisinger, the Swedish pyrites contains 63 of copper, 12 of iron, and 25 of sulphur. These ores occur in primitive and transition districts in vast masses and powerful
veins; and are commonly accompanied with gray copper, sulphuret of iron, sparry iron,
sulphurets of lead, and zinc.
4. Gray Copper has a steel gray color, more or less deep, either shining or dull; fracture uneven; a distinct metallic lustre; difficult of fusion at the blowpipe; it communicates to glass of borax a yellowish-red color. Its density in crystals is 4-86. Its composition is very variable; consisting essentially of copper, iron, antimony, and sulphur. The
exploration of this ore is profitable, in consequence of the silver which it frequently contains. It occurs in primitive mountains; and is often accompanied with red silver ore,
copper pyrites, and crystallized quartz.
5. Protoxyde of Copper, or red oxyde of Copper: its color is a deep red, sometimes
very lively, especially when bruised. It is friable, difficult of fusion at the blowpipe, reducible on burning charcoal, soluble with effervescence in nitric acid, forming a green
liquid. Its constitution, when pure, is 88-9 copper +  l11- oxygen =  100.
6. Black oxyde of Copper is of a velvet black, inclining sometimes to brown or blue;
and it acquires the metallic lustre on being rubbed. It is infusible at the blowpipe. Its
composition is, copper 80+ oxygen 20; being a true peroxyde.
7. Hydrosilicate of Copper consists essentially of oxyde of copper, silica, and water.
Its color is green; and its fracture is conchoidal with a resinous lustre, like most minerals
which contain water.  Its specific gravity is 2-73.  It is infusible at the blowpipe alone,
but it melts easily with borax.
8. Dioptase Copper, or Emerald Malachite; a beautiful but rare cupreous mineral, consisting of oxyde of copper, carbonate of lime, silica, and water in varying proportions.
9. Carbonate of Copper, Malachite, is of a blue or green color. It occurs often in
beautiful crystals.
10. Sulphate of Copper, Blue Vitriol, similar to the artificial salt of the laboratory
The blue water which flows from  certain copper mines is a solution of this salt.  The
copper is easily procured in the metallic state by plunging pieces of iron into it.
11. Phosphate of Copper is of an emerald green, or verdigris color, with some spots of
black. It presents fibrous or tuberculous masses with a silky lustre in the fracture.  It
dissolves in nitric acid without effervescence, forming a blue liquid; melts at the blowpipe, and is reducible upon charcoal, with the aid of a little grease, into a metallic globule.
Its powder does not color flame green, like the powder of muriate of copper.
12. Muriate of Copper is green of various shades; its powder imparts to flame a remarkable blue and green color.  It dissolves in nitric acid without effervescence; and is
easily reduced before the blowpipe. Its density is 3-5. By Klaproth's analysis, it consists of oxyde of copper 73, muriatic acid 10, water 17.
13..drseniate of Copper. It occurs in beautiful blue crystals. Before the blowpipe it
melts, exhaling fumes of a garlic odor, and it affords metallic globules when in contact
with charcoal. See mcre upon the ores at the end of this article.
In the article METALLURGY, I have described the mode of working certain coppel
mines; and shall content myself here with giving a brief account of two cupreous formations, interesting in a geological point of view; that of the copper slate of Mansfeldt, and
of the copper veins of Cornwall.
The curious strata of bituminous schist in the first of these localities, are among the




468                                      COPPER.
most ancient of any which contain the exuviae ofbodies not testaceous. Fro
among their tabular slabs the vast multitudes of fossil fish were extracted, which have
rendered the cantons of Mansfeldt, Eisleben, Ilmenau, and other places in Thuringia and
Voigtland so celebrated.  Many of the fish are transformed into copper pyrites. Here,
also, have been found the fossil remains of the lizard family, called Moniiors.
Such is the influence of a wise administration upon the prosperity of mines, that the
thin layer of slate in this formation, of which 100 pounds commonly contain but one
pound and a half of copper, occasionally argentiferous, has been for several centuries the
object of smelting works of the greatest importance to the territory of Mansfeldt and the
adjoining country.
The frequent derangements which this metallic deposite experiences, led skilful directors
of the under-ground operations at an early period to study the order of superposition ot
the accompanying rocks.  From their observations, there resulted a system offacts which
have served to guide miners, not only in the country of Mantldt, but over a great poi
tion of Germany, and in several other countries where the sant series of rocks, forming
the immediate envelope of the cupreous schists, were found to occur in the same ordet
of superposition.
Of the English copper works.-The deposites of copper in Cornwall occur always Ju
veins in granite, or in the schistose rozks which surround and cover it; and hence, the
Cornish miners work mostly in the granite or greenish clay slate; the former of which
they call growan, the latter killas. But tin is sometimes disseminated in small veins in
porphyry or elvan, which itself forms great veins in the above rocks. No stratification
has been observed in Cornwall.
The copper veins are abundant in the killas and rare in the granite; but most numerous near the line of junction of the two rocks. The different kinds of mineral veins in
Cornwall may be classed as follows:1. Veins of elvan; elvan courses, or elvan channels.
2. Tin veins, or tin lodes; the latter word being used by the Cornish miners to signify
a vein rich in ore, and the word course, to signify a barren vein.
3. Copper veins running east and west; east and west copper lodes.
4. Second system of copper veins, or contra copper lodes.
5. Crossing veins; cross courses.
6. Modern copper veins; more recent copper lodes.
7. Clay veins; of which there are two sets, the more ancient, called Cross-Fluckans
and the more modern, called Slides.
There are therefore three systems of copper veins in Cornwall; of which the first is
considered to be the most ancient, because it is always traversed by the two others, and
because, on the contrary, it never cuts them off. The width of these veins does not exceed 6 feet, though occasional enlargements to the extent of 12 feet sometimes take place.
Their length is unknown, but the one explored in the United Mines has been traced over
an extent of seven miles. The gangue of these veins is generally quartz, either pure, or
mixed with green particles analogous to chlorite. They contain iron pyrites, blende, sulphuret, and several other compounds of copper, such as the carbonate, phosphate, arseniate, muriate, &c. The most part of the copper veins are accompanied with small argillaceous veins, called by the miners fluckan of the lode. These are often found upon
both sides of the vein, so as to form cheeks or salebandes.
When two veins intersect each other, the direction of the one thrown out becomes an
object of interest to the miner and geologist. In Saxony it is regarded as a general fact
that the rejected portion is always to the side of the obtuse angle; this also holds generally in Cornwall, and the more obtuse the angle of incidence, the more considerable the
out-throw.
The great copper vein of Carharack, in the parish of Gwenap, is a most instructive
example of intersection. The power of this vein is 8 feet; it runs nearly from east to
weCst, and dips toward the north at an inclination of 2 feet in a fathom. Its upper part
is in the killas, its lower part in the granite.  The vein has suffered two intersections;
the first results from encountering the vein called Steven's fluckan, which runs from northeast to south-west, throwing it out several fathoms.  The second has been caused by
another vein, almost at right angles to the first, and which has driven it 20 fathoms out
to the right side. The fall of the vein occurs, therefore, in one case to the right, and in
the'other to the left; but in both instances, it is to the side of the obtuse angle. This
disposition is very singular; for one portion of the vein appears to have ascended, while
another has sunk.
The mining works in the copper veins are carried on by reverse steps; see MINES
The grand shafts for drainage and extraction are vertical, and open upon the roof side
of the vein, traversing it to a certain depth. These pits are sunk to the lowest point of
the exploration; and, in proportion as the workings descend, by means of excavations
in the vein, the pits are deepened and put into communication toward their bottom with




COPPER.                                        469
each new gallery of elongation, by means of transverse galleries. At present, the main
shafts are fully 160 fathoms deep. Their horizontal section is oblong, and is divided into
two compartments; the one destined for extraction, the other for the pumps. Their timbering has nothing remarkable, but is executed with every attention to economy, the
whole wood employed in these mines being brought from Norway.
The descent of the workmen is effected by inclined shafts scooped out of the vein; the
ladders are slightly inclined; they are interrupted every 10 fathoms by floors; the steps
are made of iron, and, to prevent them from turning under the foot, the form of a miner's
punch or jumper has been given them, the one end being round, and the other being
wedge-shaped.
The ore is raised either by means of horse-gins, or by steam-engine power, most frequently of high pressure.  I shall take the Consolidated Mines as an example.
The draining, which is one of the most considerable sources of expense, both from the
quantity of water, and from the depth of the mine, is executed by means of sucking and
forcing pumps, the whole piston-rods of which, 120 feet long, are attached to a main-rod
suspended at the extremity of the working beam of a steam-engine.
On this mine three steam-engines are erected of very great power, for the purpose of
drainage; the one called the Mlaria engine is of the first-rate force, and most improved
construction. The cylinder is 90 inches in internal diameter, and the length of the
stroke is 9 feet 11 inches.  It works single stroke, and is incased in a coating of bricks
to prevent dissipation of the heat.  The vapor is admitted at the upper end of the
cylinder during the commencement of the fall of the piston, at a pressure capable of
forming an equilibrium with a column of 60 inches of mercury.  The introduction of
the steam ceases whenever the piston has descended through a certain space, which may
be increased or diminished at pleasure. During the remainder of the descent the piston
is pressed merely by this vapor in its progressive expansion, while the under side of
the piston communicates with the condenser. It ascends by the counterweight at the
pump end of the working beam.  Hence, it is only during the descent of the piston that
the effective stroke is exerted. Frequently the steam is admitted only during the sixth
part of the course of the piston, or 18 inches. In this way the power of the engine is
proportioned to the work to be done; that is, to the body of water to be raised. The
maximum  force of the above engine is about 310 horses; though it is often made to act
with only one third of this power.
The copper mines of the Isle of Anglesey, those of North Wales, of Westmoreland,
the adjacent parts of Lancashire and Cumberland, of the south west of Scotland, of the
Isle of Man, and of the south east of Ireland, occur also in primitive or transition rocks.
The ores lie sometimes in masses, but more frequently in veins. The mine of Ecton in
Staffordshire, and that of Cross-gill burn, near Alston-moor in Cumberland, occur in
transition or metalliferous limestone.
The copper ores extracted both from the granitic and schistose localities, as well as
from the calcareous, are uniformly copper pyrites more or less mixed with iron pyrites;
the red oxyde, carbonate, arseniate, phosphate, and muriate of copper, are very rare in
these districts.
The working of copper in the Isle of Anglesey may be traced to a very remote era.  It
appears that the Romans were acquainted with the Hamlet mine near Holyhead; but it
was worked with little activity till about 70 years ago. This metalliferous deposite lies
in a greenish clay slate, passing into talc slate; a rock associated with serpentine and
euphotide (gabbro of Von Buch). The veins of copper are from one to two yards thick,
and they converge towards a point where their union forms a considerable mass of
ore.  On this mass the mine was first pierced by an open excavation, which is now
upwards of 300 feet deep, and appears from above like a vast funnel. Galleries are
formed at different levels upon the flank of the excavation to follow the several small
veins, which run in all directions, and diverge from a common centre like so many radii.
The ore receives in these galleries a kind of sorting, and is raised by means of hand
windlasses to the summit of a hill, where it is cleaned by breaking and riddling.
The water is so scanty in this mine that it is pumped up by a six-horse steam-engine.
A great proportion of it is charged with sulphate of copper. It is conveyed into reservoirs containing pieces of old iron; the sulphate is thus decomposed into copper of cementation. The Anglesea ore is poor, yielding only from 2 to 3 per cent. of copper: a
portion of its sulphur is collected in roasting the ore.
Mechanical preparation of the copper ores in Cornwall.-The ore receives a first sorting, either within the mine itself, or at its mouth, the object of which is to separate all
the pieces larger than a walnut. These are then reduced by the hammer to a smaller
size; after which the whole are sorted into four lots, according to their relative richness.
*The fragment? -if poor ore are pounded in the stamps so that the metallic portion may be
separated by washing.
The rich ore is broken into small bits, of the size of a nut, with a flat beater, formed




470                                    COPPER.
of a piece of iron 6 inches square and 1 inch thick, adapted to a wooden handle. The
ore to be broken is placed upon plates of cast-iron; each about 16 inches square and 1j
inch thick. These iron plates are set towards the edge of a small mound about a yard
high, constructed with dry stones rammed with earth.  The upper surface of this
mound is a little inclined from behind forwards. The work is performed by women,
each furnished with a beater; the ore is placed in front of them beyond the plates; they
break it, and strew it at their feet, whence it is lifted and disposed of to the smeltinghouses.
Inferior ores, containing a notable proportion of stony matters, are also broken with
the beater, and the rich parts are separated by riddling and washing from the useless
matters.
The smaller ore is washed on a sieve by shaking it in a stream of water, which carries
away the lighter stony pieces, and leaves the denser metalliferous. They are then
sorted by hand. Thus by beating, stamping, and riddling in water, the stony substances
are in a great measure separated. The finer ground matter is washed on a plane table,
over which a current of water is made to flow. Finally, the ore nearly fine is put into
a large tub with water, and briskly stirred about with a shovel, after which it settles in
the order of richness, the pure metallic ore being nearest the bottom. The stamps used
for copper ore in Cornwall are the same as those used for tin ores, of which we shall
speak in treating of the latter metal, as well as of the boxes for washing the fine powder
or slime. These, in fact, do not differ essentially from the stamping mills and washing
apparatus described in the article METALLURGY. Crushing rolls are of late years much
employed. See LEAD and TIN.
Cornwall being destitute of coal, the whole copper ore which this county produces
is sent for smelting to South Wales. Here are 15 copper works upon the Swansea and
Neath, which pursue a nearly uniform and much improved process, consisting in a series
of calcinations, fusions, and roastings, executed upon the ores and the matters resulting
from them.
The furnaces are of the reverberatory construction; they vary in their dimensions and
in the number of their openings, according to the operations for which they were intended. There are 5 of them:-1. The calcining furnace cr calciner; 2. The melting
furnace; 3. The roasting furnace or roaster; 4. The refining furnace; 5. The heating
or igniting furnace.
1. The calcining furnace rests upon a vault, c, into which the ore is raked down after
being calcined; it is built of bricks, and bound with iron bars, as shown in the elevation,
fig. 268. The hearth, B Bfigs. 368 and 370, is placed upon a level with the lower horizontal binding bar, and has nearly the form of an ellipse, truncated at the two extremities of
its great axis. It is horizontal, bedded with fire-bricks set on edge, so that it may be removed and repaired without disturbing the arch upon which it reposes. Holes, not visible
in the figure, are left in the shelves before each door, c c, through which the roasted ore
is let fall into the subjacent vault. The dimensions of the hearth B B are immense, being
from 17 to 19 feet in length, and from 14 to 16 in breadth. The fire-place, A, fig. 370, is
from 41 to 5 feet long, and 3 feet wide. The bridge or low wall, b, fig. 374, which separates the fire-place from the hearth, is 2 feet thick; and in Mr. Vivian's smelting-works
is hollow, as shown in the figure, and communicates at its two ends with the atmosphere,
in order to conduct a supply of fresh air to the hearth of the furnace. This judicious
contrivance will be described in explaining the roasting operation. The arched roof of
the furnace slopes down from the bridge to the beginning of the chimney, f, figs. 369,
370, its height above the hearth being at the first point about 26 inches, and from 8 to 12
at the second.
Such great calcining furnaces have 4 or 5 dours, c c c c, fig. 370, one for the fire-place,
as shown at the right hand in fig. 369, and 3 or 4 others for working the ore upon the




COPPER.                                       471
veverberatory hearth.  If there be 3, 2 of them are placed between the vertical binding
bars upon one side, and a third upon the opposite side of the furnace; if there be 4, 2
are placed upon each side facing one another.  These openings are 12 inches square,
and are bound with iron frames.  The chimney is about 22 feet high, and is placed at
one angle of the hearth, as at f, fig. 370, being joined by an inclined flue to the furnace.
For charging it with ore there are usually placed above the upper part of the vault 2
hoppers, E E, in a line with the doors; they are formed of 4 plates of iron, supported in
an iron frame. Beneath each of them there is an orifice for letting the ore down into the
hearth.
These furnaces serve for calcining the ore, and the matts or crude coppers: for the latter
purpose, indeed, furnaces of two stories are sometimes employed, as represented in fig. 373.
The dimensions of each floor in this case are a little less than the preceding. Two doors,
c c, correspond to each hearth, and the workmen, while employed at the upper story, stand
upon a raised moveable platform.
2. Meltingfurnace,figs. 371 and 372.   The form of the
hearth is also elliptical, but the dimensions are smaller than
11     L 371, 372  in the calcining furnace. The length does not exceed 11 or 11l
feet, and the breadth varies from 7 to 8.  The fire-place is
1however larger in proportion, its length being from 31 feet
to 4, and its breadth from 3 to 31; this size being requisite
to produce the higher temperature of this furnace.  It has
fewer openings, there being commonly three; one to the
fire-place at, a second one, o, in the side, kept generally
shut, and used only when incrustations need to be scraped
off the hearth, or when the furnace is to be entered for
repairs; and the third or working-door, G. placed on the
front of the furnace beneath the chimney.  Through it the
scoriae are raked out, and the melted matters are stirred and
puddled, &c.
The hearth is bedded with infusible sand, and slopes
slightly towards the side door, to facilitate the discharge of
~ Ithe metal. Above this door there is a hole in the wall of the
bchimney (fig. 372) for letting the metal escape. An iron gutter, o, leads it into a pit, K,
bottomed with an iron receiving-pot, which may be lifted out by a crane. The pit DM is
filled with water, and the metal becomes granulated as it falls into the receiver.  The
melting furnaces are surmounted by a hopper, L, as shown in fig. 371.
Melting furnaces are sometimes used also for calcination.
3*73 ^~J          I     There are some such near Swansea, which serve this double
/_____~ /JII I    purpose; they are composed of 3 floors (fig. 3*73.) The floor
A is destined for melting the calcined ore; the other two,
/      iB c, serve for calcination.  The heat being less powerful,. i            upon the upper sole c, the ore gets dried upon it, and begins
/                   ^1    to be calcined_-a process completed on the next floor....        Square holes, d, left in the hearths B and c, put them  in
I    communication with each other, and with the. lower one A;
M      these perforations are shut during the operation by a sheet
of iron, removeable at pleasure.
The hearths b and c are made of bricks; they are horizonal at top and slightly vaulted
beneath; they are 2 bricks thick, and their dimensions are larger than those of the inferior hearths, as they extend above the fire-place.  On the floors destined for calcination
the furnace has two doors on one of its sides: on the lower story there are also two; but
they are differently collocated. The first, being in the front of the furnace, serves for
drawing off the scorire, for working the metal, &c.; and the second, upon the side, admits
workmen to make necessary repairs.  Below this door the discharge or tap-hole A is
placed, which communicates by a cast-iron gutter with a pit filled with water. The
dimensions of this furnace in length and breadth are nearly the same as those of the
melting furnace above described; the total height is nearly 12 feet.  It is charged by
means of one or two hoppers.
3. Roasting furnace. -The furnaces employed for this purpose are in general analogous to the calcining ones; but in the smelting works of Hafod, the property of Messrs.
Vivian, these furnaces, alluded to above, present a peculiar construction, for the purpose
of introducing a continuous current of air upon the metal, in order to facilitate its oxydizement.  This process was originally invented by Mr. Sheffield, who disposed of his
patent right to Messrs. Vivian.
The air is admitted by a channel, c c, through the middle of the fire-bridge, fig. 374, and
extending all its length; it communicates with the atmosphere at its two ends c c;
square boles, b b, left at right angles to this channel, conduct the air into the fur



472                                       COPPER.
nac&.   This very simple construction produces a powerful effect in the roasting opertion. It not only promotes the oxydizement of the metals, but burns the smoke, and assists in the vaporization of the sulphur; while by keeping the bridge cool it preserves it
from wasting, and secures uniformity of temperature to the hearth.
4. Refining furnace. - In this, as in the melting furnace, the sole slopes towards
the door in front, instead of towards the side doors, because in the refining furnace the
copper collects into a cavity formed in the hearth towards the front door, from which it
is lifted out by ladles; whereas, in the melting furnaces, the metal is run out by a taphole in the side. The hearth sole is laid with sand; but the roof is higher than in the
melting furnace, being from 32 to 36 inches. If the top arch were too much depressed,
there might be produced upon the surface of the metal a layer ofoxyde very prejudicial
to the quality of the copper. When the metal in that case is run out, its surface solidifies and cracks, while the melted copper beneath breaks through and spreads irregularly over the cake. This accident, called the rising of the copper, hinders it from being
laminated, and requires it to be exposed to a fresh refining process, when lead must be
added to dissolve the oxyde of copper.  This s the only occasion upon which the addition of lead is proper in refining copper. When the metal to be refined is mixed with
others, particularly with tin, as in extracting copper from old bells, then very wide furnaces must be employed, to expose the metallic bath upon a great surface, and in a thin
stratum, to the oxydizing action of the air.
The door G, fig. 372, upon the side of the refining furnace, is very large, and is shn
with a framed brick door, balanced by a counter-weiaht.  This door being open during
the refining process, the heat is stronger at B than atA, (figs. 371, 32.)
5. Heating furnaces, being destined to heat the pigs or bars of copper to be laminated,
as well as the copper sheets themselves, are made much longer in proportion to their
breadth. Their hearth is horizontal, the vault not much depressed; they have only one
door, placed upon the side, but which extends nearly the whole length of the furnace;
this door may be raised by means of a counter-weight, in the same way as in the furnaces
for the fabrication of sheet-iron and brass.
Series of operations to which the ore is subjected. -The ores which are smelted in the
Swansea works are cupreous pyrites, more or less mingled with gangue (vein-stone). The
pyrites is composed of nearly equal proportions of sulphuret of copper and sulphuret of
iron.
The earthy matters which accompany the pyrites are usually silicious, though in some
mines the metalliferous deposite is mixed with clay or fluate of lime. Along with these
substances, pretty uniformly distributed, tin and arsenical pyrites occur occasionally
with the copper; and though these two metals are not chemically combined, yet they
cannot be separated entirely in the mechanical preparations.  The constituent parts of
the ore prepared for smelting are, therefore, copper, iron, sulphur, with tin, arsenic,
and earthy matters in some cases.  The different ores are mixed in such proportions
that the average metallic contents may amount to 81 per cent.  The smelting process
consists in alternate roastings and fusions.  The following description of it is chiefly
taken from an excellent paper, published by John Vivian, Esq., in the Annals of Philosophy for 1823.
In the roasting operation the volatile substances are disengaged mostly in the gaseous
state, while the metals that possess a strong affinity for oxygen become oxydized.  In
ihe fusion the earthy substances combine with these oxydes, and form glassy scoriae or
slags which float upon the surface of the melted metal.
These calcinations and fusions take place in the following order: -
1. Calcination of the ore. 2. Melting of the calcined ore. 3. Calcination of the
coarse metal.  4. Melting of the calcined coarse metal.  5. Calcination of the fine
metal (second matt).  6. Melting of the calcined fine metal.  7. Roasting of the
coarse copper.  In some smelting  works, this roasting is repeated four times; in
which case a calcination and a melting are omitted.  In the Havod works, however,
the same saving is made without increasing the number of roastings.  8. Refining or
toughening the copper.
Besides these operations, which constitute the treatment of copper properly speaking,
two others are sometimes performed, in which only the scoriae are melted.  These may
be designated by the letters a and b.  a is the re-melting of the portion of the scoria
of the second process, which contain some metallic granulations. 6 is a particular melting of the scoria of the fourth operation.  This fusion is intended to concentrate the
particles of copper in the scoriae, and is not practised in all smelting works.
First operation. Calcination of the ore. - The different CJes, on arriving from Cornwall and other distlicts where they are mined, are discharged in continuous cargoes at
the smelting works, in such a way, that by taking out a portion from several heaps at
a time, a tolerably uniform  mixture of ores is obtained; which is very essential in
a foundry, because, the ores being different in qualities and contents, they act as




COPPER.                                        473
fluxes upon each other.  The ore thus mixed is transported to the works in wooden
measures that hold a hundred-weight.  The workmen  intrusted with the calcination
convey the ore into the hoppers of the calcining furnace, whence it falls into the hearth;
other workmen spread it uniformly on the surface by iron rakes. The charge of a furnace is from three tons to three tons and a half. Fire is applied and gradually increased,
till, towards the end of the operation, the temperature be as high as the ore can support
without melting or agglutinating. To prevent this running together, and to aid the extrication of the sulphur, the surfaces are renewed, by stirring up the ore at the end of
every hour. The calcination is usually completed at the end of 12 hours, when the ore
is tumbled into the arch under the sole of the furnace. Whenever the ore is cold enough
to be moved, it is taken out of the arch, and conveyed to the calcined heap.
The ore in this process hardly changes weight, having gained in oxydizement nearly
as much as it has lost in sulphur and arsenic; and if the roasting has been rightly managed, the ore is in a black powder, owing to the oxyde of iron present.
Second operation. Fusion of the calcined ore.-The calcined ore is likewise given to
the melters in measures containing a hundred weight.  They toss it into hoppers, and
after it has fallen on the hearth, they spread it uniformly. They then let down the
door, and lute it tightly. In this fusion there are added about 2 cwt. of scoriae proceeding from the melting of the calcined matt, to be afterwards described. The object
of this addition is not only to extract the copper that these scoria may contain, but
especially to increase the fusibility of the mixture. Sometimes also, when the composition of the ore requires it, lime, sand, or fluor spar is added; and particularly the last
fluxing article.
The furnace being charged, fire is applied, and the sole care of the founder is to keep
up the heat so as to have a perfect fusion; the workman then opens the door, and
stirs about the liquid mass to complete the separation of the metal (or rather of the
matt) from  the scoriae, as well as to hinder the melted matter from  sticking to the sole.
The furnace being ready, that is, the fusion being perfect, the founder takes out the
scoriae by the front door, by means of a rake. When the matt is thus freed from the
scoriae, a second charge of calcined ore is then introduced to increase the metallic bath;
which second fusion is executed like the first. In this way, new charges of roasted ore
are put in till the matt collected on the hearth rises to a level with the door-way, which
happens commonly after the third charge.  The tap hole is now  opened; the matt
flows out into the pit filled with water, where it is granulated during its immersion;
and it collects in the pan placed at the bottom.  The granulated matt is next conveyed into the matt warehouse. The oxydation with which the grains get covered by
the action of the water does not allow the proper color of the matt or coarse metal to
be distinguished; but in the bits which stick in the gutter, it is seen to be of a steel
gray.  Its fracture is compact, and its lustre metallic. The scoriae often contain
metallic grains; they are broken and picked with care. All the portions which include
some metallic particles are re-melted in an accessory process. The rejected scoriae
have been found to be composed of silicious matter 59, oxyde of copper 1, oxyde of
tin 0-7.
In this operation, the copper is concentrated by the separation of a great part of the
matters with which it was mixed or combined. The granulated matt produced, contains
in general 33 per cent. of copper; it is therefore four times richer than the ore; and its
mass is consequently diminished in that proportion. The constituent parts are principally copper, iron, and sulphur.
The most important point to hit in the fusion just described, is to make a fusible mixture of the earths and the oxydes, so that the matt of copper may, in virtue of its greater
specific gravity, fall to the under-part, and separate exactly from the slag. This point is
attained by means of the metallic oxydes contained in the scoriae of the fourth operation,
of which 2 cwt. were added to the charge. These consist almost entirely of black oxyde
of iron. When the ores are very difficult to melt, a measure of about half a hundredweight of fluor spar is added; but this must be done with precaution, for fear of increasing the scoriae too much.
The business goes on day and night. Five charges are commonly put through hands in
the course of 24 hours; but when all circumstances are favorable-that is to say, when
the ore is fusible, when the fuel is of the first quality, and when the furnace is in good
condition, even six charges a day have been despatched.
The charge is a ton and a half of calcined ore, so that a melting furnace corresponds
nearly to a calcining furnace; the latter turning out nearly 7 tons of calcined ore in 24
hours.
The workmen are paid by the ton.
Third operation. Calcination of the coarse metal, or the matt.-The object of this
operation is principally to oxydize the iron, an oxydation easier to execute than in the first




474                                     COPPER.
ealcining, because the metal is now  disengaged from  the earthy substances, which
screened it from the action of the air.
This calcination is executed in the furnace already represented,figs. 296, 297, 298
page 324, exactly in the same way as the ore was calcined. The metal must be perpetually stirred about, to expose all its surfaces to the action of the hot air, and to hinder the
clotting together. The operation lasts 24 hours; during the first six, the fire should be
very moderate, and thereafter gradually increased to the end of the calcination. The
charge is, like that of the first, 3 tons and a half.
Fourth operation.  Melting of the calcined coarse metal, or calcined matt.-In the
fusion of this first calcined matt, some scoria of the latter operations must be added, which
are very rich in oxyde of copper, and some crusts from the hearth, which are likewise
impregnated with it. The proportion of these substances varies according to the quality
of the calcined matt.
In this second fusion, the oxyde of copper contained in the scorie is reduced by the
affinity of the sulphur, one portion of which passes to the state of acid, while the other
forms a subsulphuret with the copper become free.  The matt commonly contains a sufficient quantity of sulphur to reduce the oxyde of copper completely; but if not, which
may happen if the calcination of the matt has been pushed too far, a small quantity of
uncalcined matt must be introduced, which, by furnishing sulphur, diminishes the richness of the scoriae, and facilitates the fusion.
The scoriae are taken out by the front door, by drawing them forward with a rake.
They have a great specific gravity; are brilliant with metallic lustre, very crystalline,
and present, in the cavities, crystals like those of pyroxene; they break easily into very
sharp-edged fragments. They contain no granulated metal in the interior; but it some
times occurs, on account of the small thicknesses of the stratum of scoriae, that these car
ry off with them, when they are withdrawn, some metallic particles.
These scoriae, as we have already stated, under the fusion of the roasted ore, are in
general melted with it. In some cases, however, a special melting is assigned to them.
The matt obtained in this second fusion is either run out into water like the first, or
moulded into pigs (ingots), according to the mode of treatment which it is to undergo.
This matt, called by the smelters fine metal when it is granulated, and blue metal when it
is in pigs, is of a light gray color, compact, and bluish at the surface. It is collected
in the first form when it is to be calcined anew; and in the second, when it must
immediately undergo the operation of roasting. Its contents in copper are 60 per cent.
This operation, which is sometimes had recourse to, lasts 5 or 6 hours. The charge is I
ton.
(b) Particular fusion of the scoriae of the fourth operation.-In re-melting these scoriae,
the object is to procure the copper which they contain. To effect this fusion, the scoriae
are mixed with pulverized coal, or other carbonaceous matters. The copper and several
other metals are deoxydized, and furnish a white and brittle alloy. The scorine resulting
from this melting are in part employed in the first melting, and in part thrown away.
They are crystalline, and present crystals often in the cavities, which appear to belong
to U'silicate of iron. They have a metallic lustre, and break into very sharp-edged
fragments.  The white metal is melted again, and then united to the product of the
second fusion.
Fifth operation. Calcination of the second matt, or fine metal of the smelter.-This is
executed in precisely the same way as that of the first matt. It lasts 24 hours; and the
charge is usually 3 tons.
Sixth operation. Melting of the calcined fine metal.-This fusion is conducted like
that of the first matt. The black copper, or coarse copper, which it produces, contains
from 70 to 80 per cent. of pure metal; it is run into ingots, in order to undergo the
operation of roasting.
The scoriae are rich in copper; they are added to the fusion of the calcined coarse metal
of the fourth operation.
In the smelting houses of Messrs. Vivian, at Hafod, near Swansea, the fifth and sixth
operations have been omitted of late years. The second matt is run into pigs, under the
name of blue metal, to be immediately exposed to the roasting.
The'disposition of the canal a a', fig. 374, which introduces a continuous current of air
to the hearth of the furnace, accelerates and facilitates the calcination of the matt; an
advantage which has simplified the treatment, by diminishing the number of calculations.
Seventh operation. Roasting of the coarse copper, the product of the sixth operation.The chief object of this operation is oxydizement; it is performed either in an ordinary
roasting furnace, or in the one belonging to fig. 302, which admits a constant current of
air. The pigs of metal derived from the preceding melting are exposed, on the hearth
of the furnace, to the action of the air, which oxydizes the iron and other foreign metals
with which the copper is still contaminated. The duration of the roasting varies from




COPPER.                                         475
12 to 24 hours, according to the degree of purity of the crude copper. The temperature
should le graduated, in order that the oxydizement may have time to complete, and that
the volatile substances which the copper still retains may escape in the gaseous form.
The fusion must take place only towards the end of the operation.
The charge varies from a ton and a quarter to a ton and a half.  The metal obtained
i run out into moulds of sand. It is covered with black blisters, like steel of cementation
whence it has got the name of blistered copper. In the interior of these pigs, the copper
presents a porous texture, occasioned by the ebullition produced by the escape of the
gases during the moulding. The copper being now almost entirely purged from the
sulphur, iron, and the other substances with which it was combined, is in a fit state to be
refined.  This operation affords some scoriae; they are very heavy, and contain a great
deal of oxyde of copper, sometimes even metallic copper.
These scoriae, as well as those of the third melting and of the refining, are added to the
second fusion, as we have already stated, in describing the fourth operation.
In some works, the roasting is repeated several times upon the blue metal, in order to
bring it to a state fit for refining.  We shall afterwards notice this modification of the
treatment.
Eighth operation. Refining or toughening. -The pigs of copper intended for refining
are put upon the sole of the refining furnace through the door in the side. A slight heat
is first given, to finish the roasting or oxydation, in case this operation has not already
been pushed far enough.  The fire is to be increased by slow degrees, so that, by the end
of 6 hours, the copper may begin to flow. When all the metal is melted, and when the
heat is considerable, the workman lifts up the door in the front, and withdraws with a
rake the few scoriae which may cover the copper bath.  They are red, lamellated, very
heavy, and closely resemble protoxyde of copper.
The refiner takes then an assay with a small ladle, and when it cools, breaks it in a
vice, to see the state of the copper. From the appearance of the assay, the aspect of the
bath, the state of the fire, &c., he judges if he may proceed to the toughening and what
quantity of wooden spars and wood charcoal he must add to render the metal malleable,
or, in the language of the smelters, bring it to the proper pitch. When the operation of
refining begins, the copper is brittle or dry, and of a deep red color approaching to purple.
Its grain is coarse, open, and somewhat crystalline.
To execute the refining, the surface of the metal is covered over with wood charcoal,
and stirred about with a spar or rod of birch wood.  The gases which escape from the
wood occasion a brisk effervescence.  More wood charcoal is added from time to time,
so that the surface of the metal may be always covered with it, and the stirring is continued with the rods, till the operation of refining be finished, a circumstance indicated
by the assays taken in succession.  The grain of the copper becomes finer and finer,
and its color gradually brightens.  When the grain is extremely fine, or closed, when
the trial pieces, half cut through and then broken, present a silky fracture, and when the
copper is of a fine light red, the refiner considers the operation to be completed; but he
verifies still further the purity of the copper, by trying its malleability.  For this purpose, he takes out a sample in his small ladle, and pours it into a mould.  When the
copper is solidified, but still red-hot, he forges it. If it is soft under the hammer, if it
does not crack on the edges, the refiner is satisfied with its ductility, and he pronounces
it to be in its proper state. He orders the workmen to mould it; who then lift the
copper out of the furnace in large iron ladles lined with clay, and pour it into moulds
of the size suitable to the demands of commerce. The ordinary dimensions of the ingots
or pigs are 12 inches broad, 18 long, and from 2 to 24 thick.
The period of the refining process is 20 hours.  In the first six, the metal heats, and
suffers a kinckof roasting; at the end of this time it melts. It takes four hours to reach
the point at which the refining, properly speaking, begins; and this last part of the
process lasts about 4 hours.  Finally, 6 hours are required to arrange the moulds, cast
the ingots, and let the furnace cool.
The charge of copper in the refining process depends upon the dimensions of the furnace. In the Hafod works, one of the most important in England, the charge varies from
3 to 5 tons; and the quantity of pure copper manufactured in a week is from 40 to 50 tons.
The consumption of fuel is from 15 to 18 parts of coal, for one part of refined copper
in pigs.
When the copper offers difficulties in the refining, a few pounds of lead are added to
it.  This metal, by the facility with which it scorifies, acts as a purifier, aiding the
oxydation of the iron and other metals that may be present in the copper.  The lead
ought to be added immediately after removing the door to skim the surface. The copper
should be constantly stirred up, to expose the greatest possible surface to the action of the
air, and to produce the complete oxydation of the lead; for the smallest quantity of this
metal alloyed in copper, is difficult to clear up in the lamination; that is to say, the
scale of oxyde does not come cleanly from the surface of the sheets.




476                                      COPPER.
The operation of refining copper is delicate, and requires, upon the part of the woric
men, great skill and attention to give the metal its due ductility.  Its surface ought to
be entirely covered with wood charcoal; without this precautionr, the refiniig of the
metal would go back, as the workmen say, during the long interval which elapses in the
moulding; whenever this accident happens, the metal must be stirred up anew with the
wooden pole.
Too long employment of the wooden rod gives birth to another remarkable accident,
for the copper becomes more brittle than it was prior to the commencement of the refining; that is, when it was dry.  Its color is now of a very brilliant yellowish red,
and its fracture is fibrous.  When this circumstance occurs, when the refining, as the,workmen say, has gone too far, the refiner removes the charcoal from the top of the
melted metal; he opens the side door, to expose the copper to the action of the air, and
it then resumes its malleable condition.
Mr. Vivian, to whom we owe the above very graphic account of the processes, has
explained, in a very happy manner, the theory of refining.  He conceives, we may conclude, that the copper in the dry state, before the refining, is combined with a small por
tion of oxygen, or, in other words, that a small portion of oxyde of copper is diffused
through the mass, or combined with it; and that this proportion of oxygen is expelled
by the deoxydizing action of the wood and charcoal, whereby the metal becomes malleable. 2. That when the refining process is carried too far, the copper gets combined with
a little charcoal.  Thus copper, like iron, is brittle when combined with oxygen and
charcoal; and becomes malleable only when freed entirely from these two substances.
It is remarkable, that copper, in the dry state, has a very strong action upon iron  and
that the tools employed in stirring the liquid metal become very glistening, like those
used in a farrier's forge. The iron of the tools consumes more rapidly at that time, than
when the copper has acquired its malleable state.  The metal requires, also, when dry,
more time to become solid, or to cool, than when it is refined; a circumstance depending,
probably, upon the difference in fusibility of the copper in the two states, and which seems
to indicate, as in the case of iron, the presence of oxygen.
When the proper refining point has been passed, another very remarkable circumstance has been observed; namely, that the surface of the copper oxydizes more difficultly,
and that it is uncommonly brilliant; reflecting clearly the bricks of the furnace vault.
This fact is favorable to the idea suggested above, that the metal is in that case combined
with a small quantity of carbon; which absorbs the oxygen of the air, and thus protects
the metal from its action.
Copper is brought into the market in different forms, according to the purposes which
it is to serve.  What is to be employed in the manufacture of brass is granulated.  In
this condition it presents more surface to the action of zinc or calamine, and combines
with it more readily.  To produce this granulation, the metal is poured into a large
ladle pierced with holes, and placed above a cistern filled with water, which must be
hot or cold, according to the form wished in the grains.  When it is hot, round grains
are obtained analogous to lead shot; and the copper in this state is called bean shot.
When the melted copper falls into cold water perpetually renewed, the granulations are
irregular, thin, and ramified; constitutingfeathered shot. The bean shot is the form employed in brass making.
Copper is also made into small ingots, about 6 ounces in weight.  These are intended
for exportation to the East Indies, and are known in commerce by the name of Japan
copper. Whenever these little pieces are solidified, they are thrown, while hot, into cold
water. This immersion slightly oxydizes the surface of the copper, and gives it a fine red
color.
Lastly, the copper is often reduced into sheets, for the sheathing of ships, and many
other purposes.  The Hafod works possess a powerful rolling mill, composed of four
pair? of cylinders.   It is moved by a steam engine, whose cylinder has 40 inches
diameteo,  See the representation of the rolling mill of the Royal Mint, under
GOLD.
The cylinders for rolling copper into sheets are usually 3 feet long, and 15 inches in
diameter.  They are uniform.  The upper roller may be approached to the under one,
by a screw, so that the cylinders are brought closer, as the sheet is to be made thinner.
The ingots of copper are laid upon the sole of a reverberatory furnace to be heated;
they are placed alongside each other, and they are formed into piles in a cross-like arrangement, so that the hot air may pass freely round them all. The door of the furnace
is shut, and the workman looks in through a peep-hole from time to time, to see if they
have taken the requisite temperature; namely, a dull red.  The copper is now passed
between the cylinders; but although this metal be very malleable, the ingots cannot be
reduced to sheets without being several times heated; because the copper cools, and ac
quires, by compression, a texture which stops the progress of the lamination.
These successive beatings are given in the furnace indicated above; though, when the




COPPER.                                    477
sheets are to have a very great size, furnaces somewhat different are had recourse to.
They are from 12 to 15 feet long, and 5 wide. See BRASS.
The copper, by successive heating and lamination, gets covered with a coat of oxde,
which is removed by steeping the sheets for a few days in a pit filled with urine; they
are then put upon the sole of the heating furnace. Ammonia is formed, which acts on
the copper oxyde, and lays bare the metallic surface. The sheets are next rubbed with
a piece of wood, then plunged, while still hot, into water, to make the oxyde scale off;
ind lastly, they are passed cold through the rolling press to smooth them. They are now
cut square, and packed up for home sale or exportation.
The following estimate has been given by MM. Dufrenoy and Elie de Beaumont of
Ite expense of manufacturing a ton of copper in South Wales.
~  s. d.
121 tons of ore, yielding 8 per cent. of copper 55  0  0
20 tons of coals     -      -                 8  0  0
Workmen's wages, rent, repairs, &c.    -   -13  0  0
76  0  0
The exhalations from the copper smelting works are very detrimental to bothvegetable
and animal life. They consist of sulphurous acid, sulphuric acid, arsenic, and arsenious
acids, various gases and fluoric vapors, with solid particles mechanically swept away into
the air, besides the coal smoke. Mr. Vivian has invented a very ingenious method of
passing the exhalations from the calcining ores and matts along horizontal flues, or rather
galleries of great dimensions, with many crossings and windings of the current, and exposure during the greater part of the circuit to copious showers of cold water. By this
simple and powerful system of condensation, the arsenic is deposited in the bottoms of
the flues, the sulphurous acid is in a great measure absorbed, and the nuisance is remarkably abated.
The following figures represent certain modifications of the copper calcining and
smelting copper furnaces of Swansea.
Fig. 376, is the section of the roasting furnace lengthwise; fig. 375, the ground plan;
in which a is the fire-door; b the grate; c the fore-bridge; d the chimney; e e working
375                                                      377
through which the ore is intnTV   ~r, no  J^T                        troduced, spread, and turned
~                                      roof; h the hearth-sole; i i
A16 feet, breadth 1   mean
Fig. 37, is a longitudinal section of the melting furnace; fig. 378, the ground plan,
in which a is the fire-door; b the grate; c the fire bridge; d the chimney;  ote iside
openings;f the working doors; g the raking-out hole; h iron spouts, which conduct
the  melted metal into pits filled with water.
The melting furnace is altogether smaller; but its firing hearth is considerably larger




478                                       COPPER.
than in the roasting furnace.  The long axis of the oval hearth is 14 feet; its short a1
10 feet; its mean height 2 feet.
378
^^78     ^      The principal ore smelted at Chessy is
the azure copper, which was discovered
(fournneau         d       by accident in 1812. Red copper ore, also,
from]__~ 10has  come into operation there since 1825.
a                "47/ t/ /    The average metallic contents of the richest
is ____to d1,azure ore are from  33 to 36 per cent.; of
=e leaves                              the poorer, from  20 to 24. The red ore
The  rein                              contains from  40 to 67 parts in 100.  The
The_    {  \         q          J          ore is sorted, so that the mean contents of
hich1-3 ametal may be 27 per cent., to which 20
per cent. of limestone are addedd  whence
- --— the cinder will amount to 50 per oent. of
iron; thethe ore. A few  per cents. of red copper
slag, with some quicklime and gahrslag, are
added to each charge, which consists of
200 pounds of the above  mixture, and
150 pounds of coke. When the furnace
(fourneau a manche, see the Scotch smelting hearth, under LEAD) is in good action,
from 10 to 14 such charges are worked in 12 hours. When the crucible is full of metal
at the end of this period, during which the cinder has been frequently raked off, the blast
is stopped, and the matte floating over the metal being sprinkled with water and taken
off, leaves the black copper to be treated in a similar way, and converted into rosettes.,
The refining of this black copper is performed in a kind of reverberatory furnace.
The cinders produced in this reduction process are either vitreous and light blue,
which are most abundant; cellular, black, imperfectly fused from  excess of lime; or,
lastly, red, dense, blistery, from defect of lime, from too much heat, and the passage of
protoxyde into the cinders. They consist of silicate of alumina, of lime, protoxyde of
iron; the red contain some silicate of copper.
879
The copper-refining furnace at Chessy, near LyrL Jl,    Jl, \        ons, is of the kind called
T  TT "  Lj I      Spleiss-ofen  (split hearths)
t- r-i'by the Germans.  Fig. 307
i_^_ l~is a section lengthwise in
the dotted line A B of fig.
"l~        ~380, which is the ground
1s/7                      plan.
The foundation-walls are
UII  __Imade of gneiss; the arch,
ml1(^^^^the  fire-bridge, and  the
atvw~~~~~m~ th^    ~~~chimney, of fire-bricks. The
hearth, a, is formed of a
lastly~^^^^~~      Inred~ ^dense mixture of coal-dust,
-~  -- ~" —"~~~"' ~"'   upon a bottom  of well-beat
neath this there is a slag
pr7/7'-7'''  777/7777                 >     bottom  d; e is the upper,
shaped; the longer axis being 8 feet, the shorter 0
feet; in the middle it is 10
inches deep, and furnished with the outlets g g, which lead to each of the Spleiss-hearths
h h,fig. 380. These outlets are contracted with fire-bricks i i, till the proper period of
the discharge. The two hearths are placed in communication by a canal k: they are 34
feet in diameter, 16 inches deep; are floored with well-beat coal ashes, and receive about
27 cwt. for a charge.
1 is the grate; m, the fire-bridge; n, the boshes in which the tuyires lie; o, the
chimney; p, the working door through which the slags may be drawn off. Above
this is a small chimney, to carry off the flame and smoke whenever the door is
opened.
The smelting post or charge, to be purified at once, consists of 60 cwt. of black
copper, to which a little granular copper and copper of cementation is added; the




COPPER.                                           479
consumption of pit-coal amounts to 36 cwt.  As soon as the copper is melted, the
bellows are set a-going, and the surface of the metal gets soon  covered with  a
380
moderately thick layer of cinder, which is drawn off. This is the first skimming or
decrassage.  By and by, a second layer of cinder forms, which  is in like manner
removed; and this skimming is repeated, to allow the blast to act upon fresh metallic
surfaces. After 4 or 5 hours, no more slag appears, and then the fire is increased.
The melted mass now  begins to boil or work (travailler), and continues so to do, for
about A of an hour, or an hour, after which the motion ceases, though the fire be kept
up. The gahltrproof is now taken; but the metal is seldom fine in less than I of an
hour after the boil is over.  Whenever the metal is run off by the tap-hole into the
two basins i i, called SPLIT-HEARTHS, a reddish vapor or mist rises from its surface,
composed of an infinite number of minute globules, which revolve with astonishing
velocity upon their axes, constituting what the Germans called spratzen (crackling) of
the copper. They are composed of a nucleus of metal, covered with a film of protoxyde,
and are used as sand for strewing upon manuscript. The copper is separated, as usual, by
sprinkling water upon the surface of the melted metal, in the state of rosettes, which are
immediately immersed in a stream of water.  This refining process lasts about 16 or 17
hours; the skimmings weigh about 50 cwt.; the refuse is from 15 to 17 per cent.; the
loss from 2 to 3 per cent. The gahrslag amounts to 11 cwt.
The refining of the eliquated copper (called darrlinge) from which the silver has been
sweated out by the intervention of lead, can be performed only in small hearths. The
following is the representation of such a furnace, called, in Gerftian, Kupfergahrheerd.
Fig. 381 is the section lengthwise; fig. 382 is the section across; and fig. 383 is the
ground plan, in which a is the hearth-hollow; b, a massive wall; c, the mass out ef
which the hearth is formed; d, cast-iron plates covering the hearth; e, opening ~r




480                                     (COPPER.
running ott the liquid slag; f, a small wall; g, iron curb for keeping the coals
together.
The hearth being heated with a bed of charcoal, I cwt. of darrlinge are laid over it,
and covered with more fuel: whenever this charge is melted, another layer of the coal
and darrlinge is introduced, and thus in succession  till the hearth become full, or
contain from 21 to 21 cwt. In Neustadt 71 cwt. of darrlinge have been refined in one
furnace, from  which 5 cwt. of gahrcopper has been obtained.  The blast oxydizes the
foreign metals, namely, the lead, nickel, cobalt, and iron, with a little copper, forming
the gahrslag; which is, at first, rich in lead oxyde, and poor in copper oxyde; but, at the
end, this order is reversed. The slag, at first blackish, assumes progressively a copper
red tint. The slag flows off spontaneously along the channel e, from the surface of the
hearth.  The gahre is tested by means of a proof-rod of iron, called gahr-eisen, thrust
though the tuyere into the melted copper, then drawn out and plunged in cold water.
As soon as the gahrspan (scale of copper) appears brownish red on the outside, and
copper red within, so thin that it seems like a net-work, and so deficient in tenacity
that it cannot be bent without breaking, the refining is finished. The blast is then
stopped; the coals covering the surface, as also the cinders, must be raked off the copper,
after being left to cool a little; the surface is now cooled by sprinkling water upon it,
and the thick cake of congealed metal (roudelle) is lifted off with tongs, a process called
schleissen (slicing), or sheibenreissen (shaving), which is continued till the last convex cake
at the bottom of the furnace, styled the kingspiece, is withdrawn. These rondelles are
immediately immersed in cold water, to prevent the oxydation of the copper; whereupon
the metal becomes of a cochineal red color, and gets covered with a thin film  of
protoxyde.  Its under surface is studded over with points and hooks, the result of
tearing the congealed disc from the liquid metal. Such cakes are called rosette copper.
When the metal is very pure and free from  protoxyde, these cakes may be obtained very
thin, one 24th of an inch for example.
The refining of two cwts. and a half of darrlinge takes three quarters of an hour, and
yields one cwt. and a half of gahrcopper in 36 rosettes, as also some gahrslag. Gahrcopper generally contains from 1- to 21 per cent. of lead, along with a little nickel,
silver, iron, and aluminum.
SmeltiMng of the Mannsfeld copper schist, or bituminous Mergelschiefer.-The cupreous
ore is first roasted in large heaps, of 2000 cwts., interstratified with brush-wood, and
with some slates rich in bituminous matter, mixed with the others.  These heaps are
3 ells high, and go on burning 15 weeks in fair and 20 in rainy weather. The bitumen
is decomposed; the sulphur is dissipated chiefly in the form of sulphurous acid; the metal
gets partially oxydized, particularly the iron, which is a very desirable circumstance
towards the production of a good smelting slag.  The calcined ore is diminished one
tenth in bulk, and one eighth in weight; becoming of a friable texture and a dirty yellow
gray color.  The smelting furnaces are cupolas (schachtofen), 14 to 18 feet high; the
fuel is partly wood charcoal, partly coke from the Berlin gas-works, and Silesia. The
blast is given by cylinder bellows, recently substituted for the old barbarous -Blasebllgen,
or wooden bellows of the household form.
The cupreous slate is sorted, according to its composition, into slate of lime, clay, iron,
&c., by a mixture of which the smelting is facilitated. For example, I post or charge may
consist of 20 cwt. of tlMe ferruginous slate, 14 of the calcareous, 6 of the argillaceous, with
3 of fluor spar, 3 of rich copper slags, and other refuse matters. The nozzle at the
tuylre is lengthened 6 or 8 inches, to place the melting heat near the centre of the
furnace.  In 15 hours 1 fodder of 48 cwts. of the above mixture may be smelted,
whereby 4 to 5 cwts. of matte (crude copper, called Kupferstein in Germany) and a
large body of slags are obtained. The matte contains from 30 to 40 per cent. of copper,
and from 2 to 4 loahs (1 to 2 oz. ) of silver. The slags contain at times one tenth theil
weight of copper.
The matte is composed of the sulphurets of copper, iron, silver, zinc, along with some
arsenical cobalt and nickeL.  The slaty slag is raked off the surface of the melted matte
from  time to time.  The former is either after being roasted six successive times,
smelted into black copper; or it is subjected to the following concentration process. It
is broken to pieces, roasted by brushwood and coals three several times in brick-walled
kilns, containing 60 cwts., and turned over after every calcination; a process of four
weeks' duration.  The thrice roasted mass, called spurrost, being melted in the cupola
fig. 385, with ore-cinder, yields the spurstein, or concentrated matte. From 30 to 40 cwts.
of spurrost are smelted in 24 hours; and from 48 to 60 per cent. of spurstein are obtained,
the slag from the slate smelting being employed as a flux. The spurstein contains from
50 to 60 per cent. of copper, combined with the sulphurets of copper, of iron, and
silver.
The spurstein is now mixed with diinnstein (a sulphuret of copper and iron produced
n the original smeltines) roasted six successive times, in the quantity of 60 cwts., with




COPPER.
brushwood and charcoal; a process which requires from 7 to 8 weeks. The product of
this six-fold calcination is the Gahrrost of the Germans (done and purified); it has a
color like red copper ore, varying from blue gray into cochineal red; a granular fracture; it contains a little of the metal, and may be immediately reduced into metallic
copper, called kupfermachen. But before smelting the mass, it is lixiviated with water,
to extract from it the soluble sulphate, which is concentrated in lead pans, and crystallized.
The lixiviated gahroste mixed with from ~ to l of the lixiviated diinnsteinrost, and   to 
of the copper slate slag, are smelted with charcoal or coke fuel in the course of 24 hours,
in a mass of 60 or 80 cwts.  The product is black copper, to the amount of about  the
weight, and 1 of diinnstein or lhin matte. This black copper contains in the cwt. from
12 to 20 loths (6 to 10 oz.) of silver. The dunnstein consists of from 60 to 70 per cent.
of copper combined with sulphur, sulphuret of iron, and arsenic; and when thrice
roasted, yields a portion of metal. The black copper lies undermost in the crucible of
the furnace; above it is the diinnstein, covered with the stone slag, or copper cinder,
resulting from the slate-smelting. The slags being raked off, and the crucible sufficiently
full, the eye or nozzle hole is shut, the dunnstein removed by cooling the surface and
breaking the crust, which is about 1 to } inch thick. The same method is adopted for
taking out the black copper in successive layers.  For the de-silvering of this and similar
black coppers, see SILVER.
385                           384               Fig. 384 is a vertical section
B e t\ ^ ~l..,,1/      through the form  or tuyire in
1^  /^  iFig. 385 is a vertical section in:l      3- A  1     the dotted line   Doffg. 387. a
lXllX          l ^^^  a   l         is the shaft of the furnace, b the
1^^~ ~ \^11^~ 7'~      ^1         rest, cc the forms; d the sole or
1^ X" X                      /1         hearth-stone, which has a slope
I ill _____ 1X     ^    ______ HI      of 3 inches towards the front
1 ~  III   "   1^ wall; e e, &c. casing walls of fire
lp ^  6^  I  ~bricks; ff, &c. filling up walls
7..C.C..              mass throuh which the heat is:is                           c *       built of rubbish st
~~^ II.... 1-'"ill' I'  I         slowly conducted; h h the two
I llll  l^^  _______ F   1. A^^1115      holes through one or other of
f i;7\~j~\       ~i~n   1 I<'  ~,~        which alternately the product of
the smelting process is run off
-\T -— I.  into the fore-hearth.  Beneath
~I~* ~        1   I~I~~~1~1~k                   the hearth-sole there is a solid
387                  3                        body  of loam; and the forehearth is formed with a mixture
V   / //>^l         of coal-dust and clay; k is the
/^ p   A  discharge outlet. Fig. 386 is a
^ IAP~i        -^1^ T~  """''"ll^!p^^l""                horizontal section of the furnace
------ """"""^^l                              through the hole or eye in the' 7',./>f          dotted line  F,  offig. 334; fig.
\'^//7              387, a horizontal section of the
form in the dotted line G H of figs. 384 and 385. The height of the shaft, from the line
E x' to the top, is 14 feet; from E to G, 25 inches; from c to the line below b, 2 feet;
from that line to the line opposite g g, 2 feet. The width at the line g g is 3 feet 3 inches,
and at c 26 inches. The basins i i,fig. 386, are 3 feet diameter, and 20 inches deep.
The refining of copper is said to be well executed at Seville, in Spain; and, therefore,
some account of the mode of operating there may be acceptable to the reader.
The first object is to evaporate in a reverberatory furnace all the volatile substances,
such as sulphur, arsenic, antimony, &c., which may be associated with the sulphur; anil
the second, to oxydize and to convert into scoriae the fixed substances, such as iron, lead,
&c., with the least possible expense and waste. The minute quantities of gold and silver which resist oxydation cannot be in any way injurious to the copper. The hearth
is usually made of a refractory sand and clay with ground charcoal, each mixed in equal
volumes, and worked up into a doughy consistence with water. This composition is
beat firmly into the furnace bottom. But a quartzose hearth is found to answer better,
and to be far more durable; such as a bed of fire-sandstone.
Before kindling the furnace, its inner surface is smeared over with a cream-consistenced mixture of fire-clay and water.
The cast pigs, or blocks of black or crude copper, are piled upon the hearth, each successive layer crossing at right angles the layer beneath it, in order that the flame may
31




482                                     COPPER.
have access to play upon the surface of the hearth, and to heat it to a proper pitch for
making the metal flow.
The weight of the charge should be proportional to the capacity of the furnace, and
such that the level of the metallic bath may be about an inch above the nozzle of the
bellows; for, were it higher, it would obstruct its operation, and were it too low, the
stream of air would strike but imperfectly the surface of the metal, and would fail to
effect, or would retard at least, the refining process, by leaving the oxydation and volatilization of the foreign metals incomplete.
As the scoriae form upon the surface, they are drawn off with an iron rabble fixed to
the end of a wooden rod.
Soon after the copper is melted, charcoal is to be kindled in three iron basins lined
with loam, placed alongside the furnace, to prepare them for receiving their charge of
copper, which is to be converted in them, into rosettes.
The bellows are not long in action before the evaporation of the mineral substances
is so copious, as to give the bath a boiling appearance; some drops rise up to the roof
if the reverberatory, others escape by the door, and fall in a shower of minute spherical
giobules. This phenomenon proves that the process is going on well; and, when it
ceases, the operation is nearly completed. A small proof of copper, of the form of a
watch-case, and therefore called montre, is taken out from time to time, upon the round
end of a polished iron rod, previously heated. This rod is dipped two or three inches
into the bath, then withdrawn and immersed in cold water. The copper cap is detached
from the iron rod, by a few blows of a hammer; and a judgment is formed from its thickness, color, and polish, as to the degree of purity which the copper has acquired. But
these watches need not be drawn till the small rain, above spoken of, has ceased to fall
At the end of about 1I hours of firing, the numerous small holes observable in the first
watch samples begin to disappear; the outer surface passes from a bright red to a darker
hue, the inner one becomes of a more uniform color, and always less and less marked
with yellowish spots. It will have acquired the greatest pitch of purity that the process
can bestow, when the watches become of a dark crimson color.
Care must be taken to stop this refining process at the proper time; for, by prolonging it unduly, a small quantity of cupreous oxyde would be formed, which, finding no
oxygen to reduce it, would render the whole body of copper hard, brittle, and incapable
of lamination.
The basins must now be emptied of their burning charcoal, the opening of the tuyere
must be closed, and the melted copper allowed to flow into them through the tap-hole,
which is then closed with loam. Whenever the surface is covered with a solid crust, it
is bedewed with water; and as soon as the crust is about lj inch thick it is raised upon
hooks above the basin, to drain off any drops, and then carried away from the furnace.
If these cakes, or rosettes, be suddenly cooled by plunging them immediately in water,
they will assume a fine red color, from the formation of a film of oxyde.
Each refining operation produces, in about 12 hours, 1-?- tons of copper, with the consumption of about A of a ton of dry wood.
Care should be taken that the copper cake or rosette be all solidified before plunging
it into water, otherwise a very dangerous explosion might ensue, in consequence of the
sudden extrication of oxygen from the liquid metal, in the act of condensation. On the
other hand, the cake should not be allowed to cool too long in the air, lest it get peroxydized upon the surface, and lose those fine red, purple, and yellow shades, due to a film
of the protoxyde, which many dealers admire.
When a little oxyde of antimony and oxyde of copper are combined with copper,
they occasion the appearance of micaceous scales in the fractured faces. Such metal
is hard, brittle, yellowish within, and can be neither laminated nor wire-drawn. These
defects are not owing to arsenic, as was formerly imagined; but, most probably, to
antimony in the lead, which is sometimes used in refining copper.  They are more
easily prevented than remedied.
According to M. Frirejean, proprietor of the great copper works of Vienne, in
Dauphiny, too low a temperature, or too much charcoal, gives to the metal a cubical
structure, or that of divergent rays; in either of which states it wants tenacity. Too
high a temperature, or too rapid a supply of oxygen, gives it a brick red color, a
radiated crystallization without lustre, or a very fine grain of indeterminate form; the
last structure being unsuitable for copper that is to be worked under the hammer or in
the rolling-press.  The form  which indicates most tenacity is radiated with minute
fibres glistening in mass.  Melted copper will sometimes pass successively through
these three states in the space of ten minutes.
Fig. 388 represents a roasting mound of copper pyrites in the Lower Hartz, near Goslar,
where a portion of the sulphur is collected.  It is a vertical section of a truncated
quadrangular pyramid. A layer of wooden billets is arranged at the base of the pyramid
in the line a a.




COPPER.                                       483
c, a wooden bchimney which stands in the centre of the mound with a small pile of
eharcoal at its bottom, c; d d are large lumps of ore surrounded by smaller pieces; ff
388           i       1                    are rubbish and earth to form a covering
f                             A current of air is admitted under the
f^^^^^ _ ^^^^i^              billets by an opening in the middle of
each of the four sides of the base a a
so that two  principal currents of air
cross under the vertical axis c of the
truncated pyramid, as indicated in the
figure.
The fire is applied through the chimney c; the charcoal at its bottom c, and the piles
a a are kindled. The sulphureous ores. d f, are raised to such a high temperature as
to expel the sulphur in the state of vapor.
In the Lower Hartz a roasting mound continues burning during four months. Some
days after it is kindled the sulphur begins to exhale, and is condensed by the air at the
upper surface of the pyramid.  When this seems impregnated with it, small basins 1 
are excavated, in which some liquid sulphur collects; it is removed from time to time
with iron ladles, and thrown into water, where it solidifies. It is then refined and cast
into roll brimstone.
A similar roasting mound contains, in the Lower Hartz, from 100 to 1iO tons of ore
and 730 cubic feet of wood. It yields in four months about one ton and a half of
sulphur from copper pyrites. Lead ore is treated in the same way, but it furnishes less
sulphur.
There are usually from 12 to 15 roasting heaps in action at once for three smelting
works of the Lower Hartz. After the first roasting two heaps are united to form a third,
which is calcined anew, but under a shed; the ores are then stirred up and roasted for
the third time, whence a crude mixture is procured for the smelting-house.. The most favorable seasons for roasting in the open air are spring and autumn; the
best weather is a light wind accompanied with gentle rain. When the wind or rain
obstructs the operation, this inconvenience is remedied by planks distributed round the
upper surface of the truncated pyramid over the sulphur basins.
Manufacturing assays of copper.-The first thing is to make such a sample as will
represent the whole mass to be valued; with which view, fragments must be taken from
different spots, mixed, weighed, and ground together. A portion of this mixture being
tried by the blow-pipe, will show, by the garlic or sulphurous smell of its fumes, whether
arsenic, sulphur, or both, be the mineralizers. In the latter case, which often occurs,
100 gr. or 1000 gr. of the ore are to be mixed with one half its weight of saw-dust,
then imbued with oil, and heated moderately in a crucible till all the arsenical fumes be
dissipated. The residuum, being cooled and triturated, is to be exposed in a shallow
earthen cup to a slow roasting heat, till the sulphur and charcoal be burned away. What
remains, being ground and mixed with half its weight of calcined borax, one twelfth its
weight of lamp black, next made into a dough with a few drops of oil, is to be pressed
down into a crucible, which is to be covered with a luted lid, and to be subjected, in a
powerful air furnace, first to a dull red heat, and then to vivid ignition for 20 minutes.
On cooling and breaking the crucible, a button of metallic copper will be obtained. Its
color and malleability indicate pretty well the quality, as does its weight the relative
value of the ore. It should be tupelled with lead, to ascertain if it contains silver or
gold. See ASSAY, and SILVER.
If the blow-pipe trial showed no arsenic, the first calcination may be omitted; an,' if
neither sulphur nor arsenic, a portion of the ground ore should be dried, and treated
directly with borax, lamp-black, and oil. It is very common to make a dry assay of
copper ores, by one roasting and one fusion along with 3 parts of black f'ix   Irom thu
weight of the metallic button the richness of the ore is inferred.
The humid assay is more exact, but it requires more skill and time.
The sulphur and the silica are easily got rid of by the acids, which do not dissolve
them, but only the metallic oxydes and the other earths. These oxydes may then be
thrown down by their appropriate reagents, the copper being precipitated in the state of
either the black oxyde or pure metal. 105 parts of black oxyde represent 100 of copper.
Before entering upon the complete analysis of an ore, preliminary trials should be made,
to ascertain what are its chief constituents. If it be sulphuret of copper, or copper
pyrites, without silver or lead, 100 grains exactly of its average powder may be weighed
out, treated in a matrass with boiling muriatic acid for some time, gradually adding a few
drops of nitric acid, till all action ceases, or tin the ore be all dissolved. The insoluble
matter found floating in the liquid contains most of the sulphur; it may be separated
upon a filter, washed, dried, and weighed; then verified by burning away. The incombustible residuum, treated by muriatic acid, may leave an insoluble deposite, which is
to be added to the former. To the whole of the filtered solutions carbonate of potash it




484                                    COPPER.
to be adided; and the resulting precipitate, being washed, and digested repeatedly in wa.
ter of ammonia, all its cupric oxyde will have been dissolved, whenever the ammonia is
ro longer rendered blue.
Caustic potash, boiled with the ammoniacal solution, will separate the copper in the
state of black oxyde; which is to be thrown upon a filter, washed. dried, and weighed.
The matter left undissolved by the ammonia, consists of oxyde of iron, with probably a
little alumina. The latter being separated by caustic potash, the iron oxyde maybe also
washed, dried, and weighed.  The powder which originally resisted the muriatic acid, is
silica..Alssay of copper ores, which contain iron, sulphur, silver, lead, and antimony.
100 grains of these ores, previously sampled, and pulverized, are to be boiled with
nitric acid, adding fresh portions of it from time to time, till no more of the matte? be
dissolved. The whole liquors which have been successively digested and decanted off,
are to be filtered and treated with common salt, to precipitate the silver in the state of a
chloride.
The nitric acid, by its reaction upon the sulphur, having generated sulphuric acid, this
will combine with the lead oxydized at the same time, constituting insoluble sulphate of
lead, which will remain mixed with the gangue.  Should a little nitrate of lead remain
in the liquid, it may be thrown down by sulphate of soda, after the silver has been separated. The dilute liquid, being concentrated by evaporation, is to be mixed with ammonia in such excess as to dissolve all the cupric oxyde, while it throws down all the oxyde
of iron and alumina; which two may be separated, as usual, by a little caustic potash.  The portion of ore insoluble in the nitric acid being digested in muriatic acid,
everything will be dissolved except the sulphur and silica.  These being collected upon
a filter, and dried, the sulphur may be burned away, whereby the proportion of each is
determined.
Ores of the oxyde of copper are easily analyzed by solution in nitric acid, the addition
of ammonia, to separate the other metals, and precipitation by potash. The native carbonate is analyzed by calcining 100 grains; when the loss of weight will show  the
amount of water and carbonic acid; then that of the latter may be found, by expelling it
from another 100 grains, by digestion in a given weight of sulphuric acid. The copper
is finally obtained in a metallic state by plunging bars of zinc into the solution of the
sulphate.
The native arseniates of copper are analyzed by drying them first at a moderate heat;
after which they are to be dissolved in nitric acid.  To this solution, one of nitrate of
lead is to be added, as long as it occasions a precipitate; the deposite is to be drained upon a filter, and the clear liquid which passes through, being evaporated nearly to dryness,
is to be digested in hot alcohol, which will dissolve everything except a little arseniate of
lead. This being added to the arseniate first obtained, from the weight of the whole, the
arsenic acid, constituting 35 per cent., is directly inferred. The alcoholic solution being
now evaporated to dryness, the residue is to be digested in water of ammonia, when the
cupric oxyde will be dissolved, and the oxyde of iron will remain. The copper is procured,
in the state of black oxyde, by boiling the filtered ammoniacal solution with the proper
quantity of potash.
The analysis of muriate of copper~-atacamite-is an easy process.  The ore being
dissolved in nitric acid, a solution of nitrate silver is added, and from the weight of the
chloride precipitated, the equivalent amount of muriate or chloride of copper is given; for
100 of chloride of silver represent 93 of chloride of copper, and 43-8 of its metallic basis.
This calculation may be verified by precipitating the copper of the muriate from its solution in dilute sulphuric acid, by plates of zinc.
The phosphate of copper may be analyzed either by solution in nitric acid, and precipitation by potash; or by precipitating the phosphoric acid present, by means of acetate of
lead. The phosphate of lead thus obtained, after being washed, is to be decomposed by
dilute sulphuric acid. The insoluble sulphate of lead, being washed, dried, and weighed,
indicates by its equivalent the proportion of phosphate of lead, as also of phosphate of
copper; for 100 of sulphate of lead correspond to 92-25 phosphate of lead, and 89-5 phoaphate of copper; and this again to 52-7 of the black oxyde.
Copper forms the bauis of a greater number of important ALLOYS than any other metal.
With zinc, it forms Brass in all its.varieties; which see.
BRONZE and BELL METAL are alloys of copper and tin. This compound is prepared in
crucibles when only small quantities are required; but in reverberatory hearths, when
statues, bells, or cannons are to be cast. The metals must be protected as much as possible during their combination from contact of air by a layer of pounded charcoal, otherwise two evils would result, waste of the copper by combustion, and a rapid oxydizement
of the tin, so as to change the proportions and alter the properties of the alloy. The fused
materials ought to be well mixed by stirring, to give uniformity to the compound. See
BRONZE.




COPPER.                                       485
An ailoy of 100 of copper and 4'17 of tin has been proposed by M. C-naudet for Va
ready manufacture of medals. After melting this alloy, he casts it in roulds made of
such bone-ash as is used for cupels.  The medals are afterward subjected to the action
of the coining press, not for striking them, for the mould furnishes perfect impressions,
but for linishing and polishing them.
By a recent analysis of M. Berthier, the bells of the penduks, or ornamental clocks,
made in Paris, are found to be composed-of copper 72'00, tin 26'56, iron 1l44, in 100
parts.
An alloy of 100 of copper and 14 of tin is said by M. Dussaussy to furnish tools, which,
hardened and sharpened in the manner of the ancients, afford an edge nearly equal to
that of steel.
Cymbals, gongs, and the tamtam of the Chinese are made of an alloy of 100 of copper
with about 25 of tin. To give this compound the sonorous property in the highest degree, it must be subjected to sudden refrigeration. M. D'Arcet, to whom this discovery
is due, recommends to ignite the piece after it is cast, and to plunge it immediately into
cold water. The sudden cooling gives the particles of the alloy such a disposition,
that, with a regulated pressure by skilful hammering, they may be made to slide over each
other, and remain permanently in their new position.  When by this means the instrument has received its intended form, it is to be heated and allowed to cool slowly in the
air. The particles now take a different arrangement from what they would have done
by sudden refrigeration; for instead of being ductile, they possess such an elasticity,
that on being displaced by a slight compression, they return to their primary position
after a series of extremely rapid vibrations; whence a very powerful sound is emitted.
Bronze, bell-metal, and probably all the other alloys of tin with copper, present the same
peculiarities.
The alloy of 100 of copper with from  60 to 33 of tin forms common bell-metal. It is
yellowish or whitish gray, brittle, and sonorous, but not so much so as the preceding.
The metal of house-clock bells contains a little more tin than that of church-bells, and the
bell of a repeater contains a little zinc in addition to the other ingredients.
The bronze-founder should study to obtain a rapid fusion, in order to avoid the causes
of waste indicated above. Reverberatory furnaces have been long adopted for this operatiorn; and among these, the elliptical are the best. The furnaces with spheroidal domes
are used by the bell-founders, because their alloy being more fusible, a more moderate
melting heat is required; however, as the rapidity of the process is always a matter of
consequence, they also would find advantage in employing the elliptical hearths, (see the
form  of the melting furnace, as figured under Smelting of copper ores.)  Coal is now
universally preferred for fuel.
The alloy of 100 of copper with 50 of tin, or more exactly of 32 of the former with
141 of the latter, constitutes speculum metal, for making mirrors of reflecting telescopes.
This compound is nearly white, very brittle, and susceptible of a fine polish with a brilliant surface. The following compound is much esteemed in France for making specula.
Melt 2 parts of pure copper and I of grain-tin in separate crucibles, incorporate thoroughly with a wooden spatula, and then run the metal into moulds. The lower surface
is the one that should be worked into a mirror.
Mr. Edwards, in the Nautical Almanack for 1787, gave the following instructions for
making speculum metal.
The quality of the copper is to be tried by making a series of alloys with tin, in the proportion of 100 of the former to 47, to 48, to 49, and to 50 of the latter metal; whence
the proportions of the whitest compound may be ascertained. Beyond the last proportion,
the alloy begins to lose in brilliancy of fracture, and to take a bluish tint. Having determined this point, take 32 parts of the copper, melt, and add one part of brass and as much
silver, covering the surface of the mixture with a little black flux; when the whole is
melted, stir with a wooden rod, and pour in from 15 to 16 parts of melted tin (as indicated by the preparatory trials), stir the mixture again, and immediately pour it out into
cold water. Then melt again at the lowest heat, adding for every 16 parts of the compound I part of white arsenic, wrapped in paper, so that it may be thrust down to the
bottom of the crucible. Stir with a wooden rod as long as arsenical fumes rise, and then
pour it into a sand mould. While still red hot, lay the metal in a pot-full of very hot embers, that it may cool very slowly, whereby the danger of its cracking or flying into
splinters is prevented.
Having described the different alloys of copper and tin, I shall now treat of the method
of separating these metals from each other as they exist in old cannons, damaged bells,
&c. The process employed on a very great scale in France, during the Revolution, foi
obtaining copper from bells, was contrived by Fourcroy; founded upon the chemical fact
that tin is more fusible and oxydizable than copper.
1. A certain quantity of bell-metal was completely oxydized by calcination'si a rever
beratory furnace; the oxyde was raked out, and reduced to a fine powder.
2. Into the same furnace a fresh quantity of the same metal was introduced; it was




486                                    COPPER.
melted, and there was added to it one half of its weight of the oxvde formed i the first
operation.  The temperature was increased, and the mixture well incorporated; at the
end of a few hours, there was obtained on the one hand copper almost pure, which sub.
sided in a liquid state, and spread itself upon the sole of the hearth, while a compound
of oxyde of tin, oxyde of copper, with some of the earthy matters of the furnace, collected
on the surface of the metallic bath in a pasty form. These scoriae were removed with a
rake, and as soon as the surface of the melted copper was laid bare, it was run out. The
scoriae were levigated, and the particles of metallic copper were obtained after elutriation.
By this process, from 100 pounds of bell-metal, about 50 pounds of copper were extracted,
containing, only one per cent. of foreign matters.
3. The washed scoriae were mixed with ~ their weight of pulverized charcoal; the mixture was triturated to effect a more intimate distribution of the charcoal; and it was then
put into a reverberatory hearth, in which, by aid of a high heat, a second reduction was
effected, yielding a fluid alloy consisting of about 60 parts of copper and 20 of tin; while
the surface of the bath got covered with new scoriae, containing a larger proportion of
tin than the first.
4. The alloy of 60 of copper with 40 of tin was next calcined in the same reverberatory furnace, but with stirring of the mass. The air, in sweeping across the surface of the
bath, oxydized the tin more rapidly than the copper; whence proceeded crusts of oxyde
that were skimmed off from time to time.  This process was continued till the metallic
alloy was brought to the same standard as bell-metal, when it was run out to be subjected
to the same operations as the metal of No. 1.
The layers of oxyde successively removed in this way were mixed with charcoal, and
reduced in a fourneau d manche, or Scotch lead smelting furnace.
I shall not prosecute any further the details of this complicated process of Fourcroy;
because it has been superseded by a much better one contrived by M. Briant. He employed a much larger quantity of charcoal to reduce the scoriae rich in tin; and increased
the fusibility by adding crushed oyster-shells, bottle glass, or even vitrified scoriae, according to the nature of the substance to be reduced; and he treated them directly in a
reverberatory furnace.
The metal, thus procured, was very rich in tin. He exposed it in masses on a sloping
hearth of a reverberatory furnace, where, by a heat regulated according to the proportions
of the two metals in the alloy, he occasioned an eliquation or sweating out of the tin. Metallic drops were seen to transpire round the alloyed blocks or pigs, and, falling like rain
flowed down the sloping floor of the furnace; on whose concave bottom the metal collected, and was ladled out into moulds. When the alloy, thus treated, contained lead, this
metal was found in the first portions that sweated out. The purest tin next came forth,
while the last portions held more or less copper in solution. By fractioning the products.
therefore, there was procured1. Tin with lead.
2. Tin nearly pure.
3. Tin alloyed with a little copper.
A spongy mass remained, exhibiting sometimes beautiful crystallizations; this mass,
commonly too rich in copper to afford tin by liquation, was treated by oxydizement. In
this manner, M. Breant diminished greatly the reductions and oxydations; and therefore
incurred in a far less degree the enormous waste of tin, which flies off with the draught
of air in high and long-continued heats. He also consumed less fuel as well as labor,
and obtained purer products of known composition, ready to be applied directly in
many arts.
He treated advantageously in this manner more than a million of kilogrammes (1000
tuns) of scoriae, for every 2 cwtt. of which he paid 40 centimes (four-pence), while several million kilogrammes of much richer scoriae had been previously sold to other refiners
at 5 centimes or one sous.
I have said that the ancients made their tools and military weapons of Bronze. Several of these have been analyzed, and the results are interesting.
An antique sword, found in 1799, in the peat moss of the Somme, consisted of copper
87-47; tin 12-53, in 100 parts.
The bronze springs for the balistae, according to Philo of Byzantium, were made of
copper 97, tin 3.
Hard and brittle nails afforded by analysis, 92 of copper, and 8 of tin.
Of three antique swords found in the environs of Abbeville, one was found to consist
of 85 of copper to 15 of tin. The nails of the handle of this sword were flexible; they
were composed of copper 95, tin 5.
Another of the swords consisted of 90 of copper and 10 of tin; and the third, of 96
copper, with 4 tin.
A fragment of an ancient scythe afforded to analysis 92*6 copper, and 7-4 tin.
The process of coating copper with tin, exemplifies the strong affinity between the
two metals.  The copper surface to be tinned is first cleared up with a smooth sand



COPPER.                                       487
stone; then it is heated and rubbed over with a little sal ammoniac, till it be perfectly
clean and bright: the tin, along with some pounded rosin, is now placed on the
which is made so hot as to melt the tin, and allow of its being spread over the suriace with
a dossil or pad of tow. The layer thus fixed on the copper is exceedingly thin; Bayen
found that a copper pan, 9 inches in diameter and 3- inches deep, being weighed immediately before and after tinning, became only 21 grains heavier. Now as the area tinned,
including the bottom, amounted to 155 square inches, I grain of tin had been spread over
nearly 7. square inches; or only 20 grains over every square foot.
Copper and.arsenic form  a white-colored alloy, sometimes used for the scales of
thermometers and barometers; for dials, candlesticks, &c. To form this compound, successive layers of copper clippings and white arsenic are put into an earthen crucible;
which is then covered with sea salt, closed with a lid, and gradually heated to redness.
If 2 parts of arsenic have been used with 5 of copper, the resulting compound com
monly contains one tenth of its weight of metallic arsenic.  It is white, slightly
ductile, denser, and more fusible than copper, and without action on oxygen at ordinary
temperatures; but, at higher heats, it is decomposed with the exhalation of arsenious
acid. The white copper of the Chinese consists of 40-4 copper; 31-6 nickel; 254
zinc; and 2'6 iron.  This alloy is nearly silver white; it is very sonorous, well
polished, malleable at common temperatures, and even at a cherry red, but very brittle
at a red-white heat.  When heated with contact of air, it oxydizes, burning with a
white flame.  Its specific gravity was 8-432.  When worked with great care, it may
be reduced to thin leaves, and to wires as small as a needle.  See GERMAN SILVER,
infra.
Tutenag, formerly confounded with white copper, is a different composition from the
above. Keir says it is composed of copper, zinc, and iron; and Dick describes it as a
short metal, of a grayish color, and scarcely sonorous. The Chinese export it, in large
quantities, to India.
COPPER, WHITE, or German silver.  M. Gersdorf, of Vienna, states, that the propor
tions of the metals in this alloy should vary according to the uses for which it is destined.
When intended as a substitute for silver, it should be composed of 25 parts of nickel, 25
of zinc, and 50 of copper. An alloy better adapted for rolling, consists of 25 of nickel,
20 of zinc, and 60 of copper. Castings, such as candlesticks, bells, &c., may be made
of an alloy, consisting of 20 of nickel, 20 of zinc, and 60 of copper; to which 3 of lead
are added. The addition of 2 or 21 of iron (in the shape of tin plate?) renders the pack
fong much whiter, but, at the same time, harder and more brittle.
Keferstein has given the following analysis of the genuine German silver, as made frox
the original ore found in Hildburghausen, near Suhl, in Henneberg:~
Copper                            40-4
Nickel -31-6
Zinc                              25-4
Iron -2-6
100-0
Chinese packfong, according to the same authority, consists of 5 parts of copper, allo)
ed with 7 parts of nickel, and 7 parts of zinc.
The best alloy for making plummer blocks, bushes, and steps for the steel or iron gud
geons and pivots of machinery to run in, is said to consist of 90 parts of copper, 5 ol
zinc, and 5 of antimony.
A factitious protoxyde of copper, of a fine red color, may be made by melting together
with a gentle heat, 100 parts of sulphate of copper, and 59 of carbonate of soda in crys
tals, and continuing the heat till the mass become solid. This being pulverized anl
mixed exactly with 15 parts of copper filings, the mixture is to be heated to whiteness, in
a crucible, during the space of 20 minutes. The mass, when cold, is to be reduced t
powder, and washed. A  beautiful metallic pigment may be thus prepared, at the cost
of 2s. a pound.
All the oxydes and salts of copper are poisonous; they are best counteracted by ad
ministering a large quantity of sugar, and sulphureted hydrogen water.
The following scientific summary of copper ores in alphabetical order may prove acceptable to many readers, amid the present perplexing distribution of the native metallic
compounds in mineralogical systems.
1..Rrseniale of Copper.
A. Erinite, rhomboidal arseniate of copper, micaceous copper, kupferglimmer.
Emerald green: specific gravity 4-043; scratches cale-spar; yields water by heat;
fusible at the blowpipe, and reducible into a white metallic globule. Soluble in nitric
acid; the solution throws down copper by iron.  It consists of arsenic acid 33*78;
oxyde of copper 59-24; water 5; alumina 1-77.  It is found in Cornwall, Ireland,
Hungary.
B. Liroconite; octahedral arseniate of copper; lens ore, so called from the flatness




488                                      COPPER.
of the crystal. BiJe; specific gravity 2-88; scratches calc-spar. It consists of arsenic
acid 14; oxyde of copper 49; water 35.  It is found in Huel-Mutrel, Huel-Gorland,
fluel-Unity, mines in Cornwall.
C. Olivenite; right prismatic arseniate of copper; olive-ore. Dull green; specific
gravity 4-28; scratches fluor; yields no water by heat; fusible at the blowpipe into a
glassy bead, enclosing a white metallic grain. It consists of arsenic acid 45, oxyde of
copper 50-62. It affords indications of phosphoric acid, which the analysts seem to have
overlooked. It occurs in the above and many other mines in Cornwall.
D. ^.Aphanese. Trihedral arseniate of copper. Bluish green, becoming gray upon the
surface; specific gravity 4'28; scarcely scratches calc-spar; yields water with heat; ane
traces of phosphoric acid.
The fibrous varieties called wood copper, contain water, and resemble the last species
in composition.
2.  Carbonate of Copper.
A.  dzurite'; kupferlazur. Blue. Crystallizes in oblique rhomboidal prisms; specific
gravity 3 to 3'83; scratches calc-spar, is scratched by fluor; yields water with heat,
and blackens.  Its constituents are, carbonic acid 25'5; oxyde of copper 69*1; water
5*4.  The Chessy and Banat azurite is most profitably employed to make sulphate of
copper.
B. Malachite,; green carbonate or mountain green. Crystallizes in right rhomboidal
prisms; specific gravity 3-5; affords water with heat, and blackens.  It consists of carbonic acid I8-5; oxyde of copper 72-2; water 9-3.
C.  Mysorine; anhydrous carbonate of copper.  Dark brown generally stained green
or red; conchoidal fracture; soft, sectile; specific gravity 2'62.  It consists of carbonic
acid 16'7; oxyde of copper 60'75; peroxyde of iron 19'5; silica 2'10. This is a rare
mineral found in the Mysore.
3.  Chromate of Copper and Lead; vauquelinite.  Green of various shades; specific
gravity 68 to 7-2; brittle; scratched by fluor; fusible at the blowpipe with froth and
the production of a leaden bead. It consists of chromic acid 28-33; oxyde of lead 60*87;
oxyde of copper 10'8. It occurs at Berezof in Siberia along with chromate of lead.
4.  -Dioptase; silicate of copper; emerald copper.  Specific gravity 33; scratches
glass with difficulty; affords water with heat, and blackens; infusible at the blowpipe.
It consists of silica 43'18; oxyde of copper 45-46; water 11-36. This rare substance
comes from the government of Kirgis.
The silicate of Dillenberg is similar in composition.
5.  Gray copper ore called Panabase, from  the number of metallic bases which it
contains; and Fahlerz. Steel gray; specific gravity 4'79 to 5*10; crystallizes in regular
tetrahedrons; fusible at the blowpipe, with disengagement of fumes of antimony and
occasionally of arsenic; swells up and scorifies, affording copper with soda flux. Is acted
upon by nitric acid with precipitation of antimony; becomes blue with ammonia; yields
a blue precipitate with ferrocyanide of potassum; as also indications frequently of zinc,
mercury, silver, &c. Its composition which is very complex is as follows: sulphur 26-83;
antimony 12*46; arsenic 10*19; copper 40-60; iron 4-66; zinc 3*69; silver 0-60
Some specimens contain from 5 ti 31 per cent. of silver. The gray copper ores are very
common; in Saxony; the Hartz; Cornwall; at Dillenberg; in Mexicoi Peru, &c. The)
are important on accoun both of their copper and silver.  Tennantite is a variety of
Fahlerz. It occurs in Cornwall. Its constituents are, sulphur 28-74; arsenic 11-84;
copper 45-32; iron 9-26.
6.  Hydrated silicate of Copper; or Chrysocolla.  Green or bluish green; specific
gravity 2-03 to 2-16; scratched by steel; very brittle; affords water with heat, and
blackens; is acted upon by acids, and leaves a silicious residuum.  Solution becomes
blue with ammonia. Its constituents are silica 26; oxyde of copper 50; water 17;
carbonic acid 7.
7.  Muriate of Copper.  Gtakamite; green; crystallizes in prisms; specific gravity
4*43. Its constituents arc, chlorine 15-90; copper 14*22; oxyde of copper 54-22; water
14*16; oxyde of iron 1*50.  The green sand of Peru, collected by the inhabitants of
Atakama, is this substance in a decomposed state.
8. Oxyde of Copper.
A.  Black, or Melaconise; a black earthy looking substance found at Chessy and
other places. It is deutoxyde of copper.
B. Protoxyde or red oxyde of copper; ziegelerz. Crystallizes in the regular octahe
dron; specific gravity 5-69; scratches calc-spar; fusible at the blowpipe into the black
oxyde; and reducible in the smoke of the flame to copper; acted upon by nitric acid
with disengagement of nitrous gas; solution is rendered blue by ammonia. Its constituents are oxygen 11*22; copper 88*78.  It occurs near Chessy, and upon the eastern slope
of the Altai mountains.
9.  Phosphate of Copper.  Dark green; crystallizes in octahedrons; specific gravity
3-6 to 3-8; scratches calc-spar; yields water with heat; and affords metallic coppei




COPPER.                                          489
with soda flux;'acted on by nitric acid. Its constituents are, phosphoric acid 287;
Dxyde of copper 63-9; water 7'4. It occurs at the mines of Libethen in Hungary.
10. Pyritous Copper; Kupferkies; a metallic looking substance, of a bronze-yellow
color, crystallizing in octahedrons which pass into tetrahedrons; specific gravity 416;
fusible at the blowpipe into beads attractable by the magnet, and which afterwards
afford copper with a soda flux; soluble in nitric acid; solution is rendered blue by ammonia, and affords an abundant precipitate of iron. Its composition is, sulphur 36;
copper 34-5; iron 30-5; being a combined sulphuret of these two metals. This is the
most important metallurgic species of copper ores. It occurs chiefly in primitive formations, as armong gneiss and mica slate, in veins, or more frequently masses, in very
many parts of the world-Cornwall, Anglesea, Wicklow, &c.  It is found amoni  the
early secondary rocks, in Shetland, Yorkshire, Mannsfeldt, &c.  The finest crystallized
specimens come from Cornwall, Derbyshire, Freyberg, and Saint Marie-aux-Mines in
France.
11. Seleniue of Copper; Berzeline. Is of metallic aspect; silver white; ductile; fusible at the blowpipe into a gray bead, somewhat malleable; is acted upon by nitric acid;
consists of selenium 40; copper 64.
12. Sulphate of Copper; Cyanose.  Blue; soluble, &c. like the artificial sulphates
which see.
Brochcantte is a subsulphate of copper, observed in small crystals at Ekaterinenbourg
in Siberia.
13. Sulphuret of Copper; Kupferglanz. Of a steel gray metallic aspect; crystallizes
in rhomboids; specific gravity 5-69; somewhat sectile, yet brittle; fusible with intumescence at the blowpipe, and yields a copper bead with soda; soluble in nitric acid;
becomes blue with ammonia, but lets fall scarcely any oxyde of iron. Its constituents
are sulphur 19; copper 79-5; iron 0'75; silica 1'00. It occurs in small quantities in
Cornwall, &c.
Thfe chemical preparations of copper which constitute distinct manufactures are, Blue
or Roman vitriol; for which see Sulphate of Copper; Scheele's green and Schweinurtb
green, Verditer, and Verdigris. See these articles in their alphabetical places.
The copper mines, now so important, were so little worked until a recent period, that
in 1799 we are told in a Report on the Cornish mines, "it was not until the beginning of the last century that copper was discovered in Britain." This is not correct for
in 1250, a copper mine was worked near Keswick in Cumberland.  Edward III.
granted an indenture to John Ballanter and Walter Bolbolter, for working all "mines
of gold, silver, and copper;" but that the quantity found was very small is proved from
the fact that Acts of Parliament were passed in the reigns of Henry VIII. and Edward
VI. to prevent the exportation of brass and copper, "lest there should not be metal
enough left in the kingdom, fit for making guns and other engines of war, and for
household utensils;" and in 1665 the calamine works were encouraged by the government, as "the continuing these works in England will occasion plenty of rough copper
to be brought in."
At the end of the seventeenth century some "gentlemen from Bristol made it their
business to inspect the Cornish mines, and bought the copper for 21. 10s. per ton, and
scarce ever more than 41. a ton."
In 1700, one Mr. John Costor introduced an  hydraulic engine into Cornwall, by
which he succeeded in draining the mines, and "he taught the people of Cornwall also
a better way of assaying and dressing the ore."
The value and importance of copper mines since that period has been regularly
increasing.  During a term of about 30 years 220 mines have sold their ores at the
public sales. The following table (p. 490) from a report by Sir Charles Lemon, Bart.
M. P., represents the progress of copper mining, from 1171 to 1837.
The produce of the copper mines of Cornwall since 1845, has been as follows.
Years.            Ore in Tons.        Copper in Tons.        Money Value.
~     s.
1845                162,557               12,883             919,934  6
1846                150,431               11,851             796,182  6
1847                155,985               12,754             889,287  0
1848               147,701                12,422             720,090  0
1849               146,326                11,683             763,614  0
1850               155,025                12,254             840,410  0




490                                    COPPER.
Years.        Tons of Ore.    Tons of Copper.        Oret            per Ton.
1771             27,896            3,347           189,609             81
1780             24,433            2,932           171,231             83
1799            51,273             4,223           469,664            121
1800             55,981            5,187           550,925            133
1802             53,937            5,228           445,094            111
1805            78,452             6,234           864,410            170
1808            67,867             6,795           495,303            100
1809            76,245             6,821           770,028            143
1812            71,547             6,720           549,665            111
1814            74,322             6,369           627,501            130
1816            77,334             6,697           447,959             98
1818             86,174            6,849           686,005            155
1821             98,426            8,514           605,968            103
1825           107,454             8,226           726,353            124
1827           126,700            10,311           745,178            106
1831           146,502            12,218           817,740            100
1837           140,753            10,823           908,613            119
With the improvements in the construction of the steam-engine, the facilities for
working the mines have been increased,  The first steam  engine employed in the
county was set to work at Huel Vor tin mines, near Helstone, in 1713, by Newcomen;
but it was not until the reconstruction of the engine was effected by Watt that steam
power was generally employed for draining the mines. The rapid advance made by
Cornish engineers in the perfection of their engines will be seen by the following return
of the duty, that is, the performance of each, which is reckoned by the number of
millions of pounds lifted a foot high by the consumption of a bushel of coals:Name of Mine.                       Highest Duty.
Stray Park, 1813...       -       29,000,000
Dolcoath, 1816          -.. -  -  -       40,000,000
Consolidated Mines, 1822        -         -     -       44,000,000
Consolidated Mines, 1827        -       -       -       67,000,000
Fowey Consols, 1834..-  -   -       -       97,000,000
United Mines, 1842...-      -      108,000,000
Copper exported:Wrought.             Unwrought.               Total.
Years ending
To all parts.   To India.    To all parts.   To all parts.
Tons.         Tons.          Tons.          Tons.
5th January, 1825 -  -  -         -              -             960
1826-  -  -         -              - 
1827-  -  -          -             -              130
1828 -  -  -        -              -             1329
1829 -  -  -        -              -             1079
1830 -  -  -       5327           1801           2682          8,009
1831 -  -  -       6172           2317           3150           9,322
1832 -  -  -       5171          2423            3714          8,885
1833 -  -  -       5855          2312           4569          10,424
1834 -  -  -       5417           1769           4019          9,436
1835 -  -  -       4787           2104           5283          10,072
1836 -  -  -       5948           1993           5935         11,883
1837 - -  -        6105           1588          3909          10,0140
* Supplement to the Mining Journai, Feb. 28, 1838.




COPPER.                                       491
Statistics of Copper for Cornwall in 1837.-The total quantity of ore sold was 142,089
tons (of 21 cwts.) yielding an average produce of eight per cent; the quantity of fine
copper being 11,209 tons I cwt.; and the average price of the ore 51. 15s. 6d.; the
total amount of the sales for the twelve months being 822,5161. The standard upon
the 5th of January was 1271. 16s.; this was the highest for the year. Upon the 22d of
June it was at the lowest, being only 931. 18s. It went up again to 1201. 10s. upon the
5th of October; but declined with some slight fluctuation to 1071. 18s. upon the 28th
of December. The largest quantity sold at any one ticketing was 4670 tons, upon the
4th of May; and the smallest 1088, upon the 17th of August. The highest produce
was nine and five eighths per cent. upon the 13th of July; and the lowest, seven, upon
the 26th of January. The greatest weekly total was 25,8871., upon the 2d of November, and the least 56941. upon the 17th of August. The average sum per week was
15,8171.*
Quantity of Copper produced in the several districts of Great Britain and Ireland:With Ores from-            1828.      1829.      1830.      1831.      1832.
Tons.     Tons.      To.        Toss.      Tons..
Cornwall      -.          -     1966       9763     10,890     12,218     12,099
Devonshire               -         -  434       318       368        312        249
Other parts of England -      -      71         36         10         31         42
Island of Anglesea    - -  738                 901         815       809        852
Other parts of Wales  -          -     -        2759       123                  237
Ireland  -    -    -                 706       790        768        972        974
Isle of Man    -           -        -            4          9         15         12
Total copper from the ores of
the United Kingdom -    -   12,169    11,994'    13,097    14,480     14,465
Copper smelted from Foreign ores -  -           30        124        100         56
General total -    -    -   12,169    12,024     13,221     14,580     14,541
Table of the produce of Copper Ores and fine Metal in Cornwall, from 1800 to 1830.
Years.     Ores.          Metal.        Value of Ore.       Metal.     Average Standard.
Tons of 21 Cwts.  Tons. Cwt.                     Per Cent. of Ore.  Price per Ton.
~     s. d.                     ~    s. d.
1800     55,981         5187  0    550,925  0  0              9-         133  3  6
1801     56,611         5268  0    476,331  0  0              9_         117  8  0
1802      53,937        5228 15    445,094  0  0              95         110 18  0
1804      64,637        5374 18    507,840 11  0              83         136  5  0
1806      79,269        6863 10    730,845  6  0              81         138  5  0
1808      67,867         6795 13    495,303 10  0            10          100  7  0
1810      66,048         5682 19    570,035  8  0             8-         132  5  0
1812      71,547         6720  7    549,665  6  0             91         111  0  0
1814      74,322         6369 13    627,501 10  0             81         130 12  0
1816      77,334         6697  4    447,959 17  0             85          98 13  0
1818      86,174         6849  7    686,005  4  0             77         134 15  0
1820     91,473          7508  0    602,441 12  0             8-         113 15  0
1822    104,523         9140  8    663,085 13  0              83         104  0  0
1824     99,700         7823 15    587,178  0  0              77         110  0  0
1826    117,308         9026 12    788,971 15  0              75         123  3  0
1828    130,366         9921  1    756,174 16  0              71         112  7  0
1829    124,502         9656 10    717,334  0  0              71         109 14  0
1830    143,296        11,224 19    887,900  0  0             71         114  4  0
1834
1835  } 150,617       12,271 14    893,402 15  0              81        106 11  0
The following table, extracted from  the London Mining Journal, July 18, 1852
gives the comparative averages of the weekly sales of Copper Ores for ten years, to the
second week in July, 1852, at the Royal Hotel, Truro, Cornwall.
* Mining Review, Feb. 28, 1838.




492                                       COPPER.
Price of     Price of
Year.    Tons.   Produce.          Amount.            Standard.    Copper Ore.  Copper Cake.
~   s. d.                                    ~ s.  ~ s. d.
1842     2196       61            9,676 86            108 7          67 13      92 0 0
1843     2986       8            16,788 13 6          105 5          70 14      82 0 0
1844     2021       6            13,012 11 6          107 3          66 6       83 0 0
1845     3205       7            18,254 5 6           107 18         72 15      88 0 0o
1846     2289       8k           12,156 6 6            98 13         65 0       93 9 6
1847     2336       8:      14.184 19 0          105 10         72 2       98 10 1
1848     2372       91           11,039 11t 0          80 2          5419       88 0 0o
1849     2538       81           13,913 5 6            94 9          62 18      79 0 0O
1850     2490       9t           15,395 2 6            97 14         67 13      84 0 0
1851     2541'8t          14,015 14 6           99 14         66 10      84 0 84
An account of the quantities of Foreign wrought and unwrought Copper, and Copper
Ore, imported and exported, and of British wrought and unwrought Copper exported
from  the United Kingdom; together with the quantities and value of Copper Ore
smelted in Cornwall and Swansea, and the quantity of Copper produced in those places;
and in the county of Devon; together with the market prices of sheet and cake Copper. in the year ending 5th January, 1835:r                                                                   Quantity.       Value.
Foreign Copper imported:                                                         ~    s.  d.
Unwrought in bricks or pigs, rose and cast copper, Cwts.    5,389
Part wrought, viz., bars, rods, or ingots, hammered
or raised -                                                     1,968
Wrought plates and coin    -        -     -                            2
-     old for re-manufacture -    -    -                        493
Copper ore Foreign   -        -     -        -                  278,900
Manufactures of copper, entered by weight -                         650
~-             entered at value   -                              5,353  0  0
Foreign copper exported, viz:Unwrought, in bricks and pigs, rose and cast copper —          -     -     -     -    -      -    - Cwts.    6,898
Part wrought, viz., bars, rods, or ingots, hammered
or raised -           -     -     --                            2,013
Old, fit only for re-manufacture  -    -        -                   265
Smelted in the United Kingdom from foreign ore  -                55,456
Manufactures of copper, entered by weight -           -             650
~-             entered at value   -       -                         112  0  40
BRITISH COPPER.
Exported, unwrought, in bricks and pigs -              -  - Cwts.   63,252
wrought sheets, nails, &c.    -         -    -          103,433
-     wire -            -     -           -               56
of other sorts   -    -       -                15,197
Total of British copper exported  -.           -         182,225
Ores sold in Cornwall:Quantity of ore-        -    -      -    -      -    - Tons   150,617
Value of ditto   -    -       -    -    -                                  893,403  0  0
Quantity of metal    -        -     -                 - Tons    12,270
Standard ---- -- -                                                              106 11 0
Produce per cent.    -        --                      -                8
Ores sold, &c. in Swansea:
Quantity of ore-    -    -    -                 -    - Tons    28,746
Value of ditto    -    -    -    -    -                                    223,958  0  0
Quantity of metal    -    -    -    -                   Tons      2,832
Standard   -      -     -     -     -     -     --                             101 18  0
Produce per cent.                                                      97
Copper sold in Devonshire    metal          -             Tons       5,114
Total quantity of copper raised in the United Kingdom, 
exclusive of Anglesea and Staffordshire, and deducting           14 474
1083 tons of metal, value 88,2071., the produce of 4985
Ltons of foreign ore sold at Swansea, included above,    ____




COPPER.                                             493
Quantity of copper ore raised in Cornwall in the year 1846, 150,431 tons; value of,'796,1821. 6s. 6d.
Quantity raised in the year 1847, 155,985 tons; value of, 889,2871. Os.  d.
Quantity of metallic copper produced in the former year, 11,850 tons; in the latter,
12,754.
Produce per cent. 77 and 8- respectively.  See METALLIC STATISTICS.
Imports.     Entries for     Exports,      Exports,       Duty on
Consumption.    Foreign        British.      Imports.
Description.                                   ___ _______-   - ___________-.1850.  1851.  1850.  1851.  1850.  1851.  1850.  1851.  1850.  1851.
Copper ore and regulus,                                                                ~       ~
tons.                  45,862 42,476 45,705 42,219                   -           2,5    211
unwrought and  part
wrought, cwts.      - 97,621 106,064 83,626 103,500 16,685 25,746-   -  -   -   523   647
bricks and pigs, cwts. -. -2    154,678 111,939
sheets, nails, &c. (including mixed or yellow metal for sheathing), cwts.-                                 -..       263,008 216,075
wrought of other sorts,
cwts. - ---                         --      -..                8,468 19,939
COPPERING IRON AND ZINC.  The  great advantages which  would  arise from  perfecting a plan whereby the easily oxidizable metals, such as iron and zinc, could be
coated with copper at a cheap rate, induced Messrs. Eisner & Philip, of Berlin, to
undertake a series of experiments, to ascertain if such could not be effected more economically than by employing the cyanuret of potassium, and in this they have been successful. For coating iron the article must be well cleaned in rain or soft water, and
rubbed before immersing it in the solution, which may be either chloride of potassium,
chloride of sodium, with a little caustic ammonia added, or tartrate of potash, with a
small portion of carbonate of potash.  At the extremity of the wire, in cont ection with
the copper, or negative pole of the battery, is fixed a thin flattened copper plate, and
the article to be coated is attached to the wire from the zinc, or positive pole, and both
are then immersed in the exciting solution, the copper plate only partially.  The liquid
should be kept at a temperature of from 150 to 200 Centigrade, and the success of the
operation depends greatly on the strength and uniformity of the galvanic current. When
the chlorides are employed, the coating is of a dark, natural copper color; and with tartrate of potash, it assumes a red tinge, similar to the red oxide of copper. When sufficiently covered, the article is rubbed in sawdust, and exposed to a current of warm air
to dry, when they will take a fine polish, and resist all atmospheric influence. In
coating zinc with copper, the same general principles will apply as for irotn, only observing that, in proportion to the size of the article, the galvanic current must be less
powerful for zinc. The surfaces must be perfectly smooth, and for this reason it is well
to rub them thoroughly with fine sand, and polish with a brush. Tartrate of potash is
the best existing liquid for coating zinc. By very simple means large articles in iron
and zinc may be coated with copper by the above cheap chemical solutions, which
could not, at any former period, be effected from the high price of cyanuret of potassium.
COPPER MEDALS AND MEDALLIONS may  be readily made in the following  way:Let black oxide of copper, in fine powder, be reduced to the metallic state, by exposing it to a stream of hydrogen, in a gun-barrel, heated barely to redness. The
metallic powder thus obtained is to be sifted, through crape, upon the surface of
the mould, to the thickness of ^ or ^ of an inch, and is then to be strongly pressed upon
it, first by the hand, and lastly by percussion with a hammer. The impression thus
formed is beautiful; but it acquires much more solidity by exposure to a red heat, out
of contact with air. Such medals are said to have more tenacity than melted copper,
and to be sharply defined.
M. Boettger proposes the following improvement upon the above plan of Mr. Osann:~
He prepared the powder of copper easier and of better quality, by precipitating  a
boiling hot solution of sulphate of copper, with pieces of zinc, boiling the metallic
powder thus obtained with dilute sulphuric acid for a little, to remove all traces of the
zinc or oxide, washing it next with water, and drying it in a tubulated retort by the
heat of a water bath, while a stream  of hydrogen is passed over it.  This cuprous
precipitate possesses so energetic an affinity for oxygen, that it is difficult to prevent its
passing into the state of orange oxide. If it be mixed with one half its atotiic weight
of precipitated sulphur, and the two be ground together, they combine very soon into
sulphuret of copper with the evolution of light.




494                                  COPROLITES.
COPPER, PURIFYING.-Copper may be purified by melting 100 parts of it with 10
parts of copper scales (black oxide), along with 10 parts of ground bottle-glass or other
flux.  Mr. Lewis Thompson, who received a gold medal from the Society of Arts for
this invention, says, that after the copper has been kept in fusion for half an hour, it will
be found at the bottom of the crucible perfectly pure; while the iron, lead, arsenic, &c.,
with which this metal is usually contaminated, will be oxidized by the scales, and will
dissolve in the flux, or be volatilized. Thus he has obtained perfectly pure copper
from brass, bell-metal, gun-metal, and several other alloys, containing from 4 up to 50
per cent. of iron, lead, antimony, bismuth, arsenic, &c. The scales of copper are cheap,
being the product of every large manufactory where that metal is worked.
COPPERAS.  (Couperose verte, Fr.: Eisenvitriol, Germ.)  Sulphate of iron.
COPROLITES, OR FOSSIL MANURE.  Wherever there is an out-cropping of the
upper green sand (the stratum  in which coprolites are found)-and it extends a considerable distance around Cambridge-there these peculiar nodules may be met with.
And this, the surface bottom of an ancient deep sea, appears to have been the receptacle
of the bones and fwecal matter of its inhabitants for a long period, which matter is now,
by the united penetrating researches of the chemist and geologist, brought to light, as
containing the fertilizing principle and pabulum of vegetable life, verifying the axiom
of chemistry, that nothing is lost in organic atoms, and that the refuse of former ages.
in an indirect manner, produces the food of the present. The parish of Barnwell contains an extensive area of these coprolites or fossil dung.
The appearance of these nodules is in shape various; generally a hard, black, waterworn looking stone, with excrescences; some with convoluted marks, bearing the
impress of the intestine, and rounded off at the extremities; the surface of all exhibiting lines from the decomposition of its more destructible component parts. Portions
of coral, ammonites, crustacea, sponges, &c., may be found in the agglutinated mass.
They vary in size from a small bird's egg to masses the size of a fist. A large selection
from our own, as well as from distant localities-the lias of Lyme, the chalk of Farnham, the slate of Newhaven, and the crag of Suffolk-are open for the inspection of
those interested in most geological collections.
The process which they go through to render them available for use is as follows:After being selected from the soil, they are well washed by rotary machinery erected
on the spot, and then conveyed by rail to the manufactory, where they are ground to a
very fine powder; an operation, from their hardness, of no small difficulty, vertical
granite and buhr stones being required.  The powder is mixed with about an equal
portion by weight of strong sulphuric acid. This is, I believe, a part of the process
used in the manufactory of Mr. Lawes, who produces a very superior article, and to
whom we are much indebted for his early attention to supply the increasing demand
for phosphates as artificial manures, and who has been supplied with thousands of tons
from digging over a four-acre field at Walton, in Suffolk, the subsoil of which was crag,
producing to the farmer a much richer harvest than grain at the present free-trade
prices. In an article varying, as it necessarily must, from extraneous matter, the component parts materially differ. The following analysis may be taken as an average of
their composition, 100 parts containingEarthy phosphates                                    -  61
Carbonate of lime and iron          -               -  24
Insoluble -                                          -  12
Moisture  -         -       -       -       -        -   3
100
Mr. Lawes, from a sample from the same locality, made 7 more parts of phosphates,
and Mr. Potter 4 less, than the above analysis.
There is a prevalent idea that these coprolites are almost the same as guano. This
is a great mistake; for although our own production yields a larger proportion of the
phosphates, it is devoid of salts of urea and ammonia, which, in combination with the
phosphates, increases to a considerable extent the fertilizing principle for which that
foreign article is so celebrated. It has been the object of artificial manures to supply
synthetically the composition of guano at a much reduced rate.
In respect to the value of coprolites in Suffolk, besides giving employment at the
slack season to many idle hands, a bonus has been given for the right of royalty over the
soils, and 5s. per ton is paid the proprietor for all raised. This, with labor, washinga troublesome and tedious process-and rail charges for delivery in London, costs from
35s. to 40s. per ton.
To show the comparative value of the different substances containing the phosphates,
and that of guano, an analysis of a good sample is here given, and that of the phosphates and carbonate of lime in various bones. That portion contained in the fossil




COPROLITES.                                         495
remains of bones and coprolite is a beautiful illustration of the goodness of the Great
Author of -nature-remains which, after being interred thousands of years, are by the
labors of man brought again into action, that their elementary parts may be again
separated and made subservient to his uses.
Analysis of Guano from  Peru.
Urate a'nd salts of ammonia         -        -       -       -  3405
Various phosphates          -        -       -       -       -  37 04
Carbonate of lime           -       -        -       -       - 1 65
Soda and potash   -         -       -                -       -   892
Silex       -..-                                      -   4-28
Water and indefinite organic matter              -       -    -  14'06
100-00
Comparative Analysis of Bones.
Phosphates.       Carbonate of Lime.
Recent human bones                                      81-09                 10-03
Ancient ditto from Roman tumulus                        76-38                 10-13
Fossil bone from the crag                               60-02                 18'00
Recent ox bones —                       -      -        57'35                  3'85
Sheep bones -            -       -...     -         80.00                 19'03
Bones of the hen       -     -..-                   88-09                 10-04
it  frog  -  -      -     -          -    95-02                  2'04
"      fishes      --          -       -          91-09                  5'03
The followiing two samples from the coast of Suffolk were found to consist ofI.                            II.
Water with a little organic matter   4-00                              3-560
Salts soluble in water (chloride of
sodium and sulphate of soda)  -                traces                       traces
Carbonate of lime           -       -  10-280             8'959
do.  magnesia          -       -            a trace                       a trace
Sulphate of lime  -         -       -            distinct traces       0-611
Phosphate of lime (3 Ca 0, P05) -  70920=PO5 32765                    69-099=PO05 31-924
do.  magnesia          -       -            traces only                   traces
Perphosphate of iron (2 Fe2 03,
3 P05)  -        -       -        -   6-850=P05 3-244               8-616~P05 4-081
Phosphate of alumina (2 Al2 03,
3 P05)  -        -       -       -   1.550==PO  0-870               2-026~ —PO5 1-158
Oxide of Manganese          -       -            traces                       traces
Fluoiide of calcium         -        -   0608                          0-804
Silicic acid colored red by a little
undecomposed silicate of iron  -   5.792                            6-309
100.000==PO5 36-889           100-000~=P0  37.16
1. Fifty grains of the first specimen, in fine powder, when burnt with potash lime,
furnished 0-20 gr. of platino-chloride of ammonium, which is equivalent to 00254 per
cent. of nitrogen.
It is said that the coprolites which Mr. Lawes employs in the manufacture of his
well-known " Coprolite manure," are obtained from the Suffolk coast, and are similar in
character to the above.
In an excellent paper "On the Phosphoric Strata of the Chalk Formations," published
in the first number of the Journal of the Royal Agricultural Society of England
for the last year, Mr. Way observes, that he has found the coprolites from this district
to contain from 52 to 54 per cent. of bone-earth phosphate; and that Dr. Gilbert had
informed him, that in several analyses which he had made of samples taken from
several tons of the ground coprolites, he had found the proportion of phosphate of
lime to vary between 55 and 57 per cent. Mr. Nesbit (Quart. Journ. of Chem. Soc.
Part III. p. 235) found from 22-30 to 28-74 per cent. of phosphoric acid, which is
equivalent to from 48-31 to 59-07 of tribasic phosphate, in those from the tertiary
deposits of this county.
IL This one was brought from  the same part of the coast as the preceding; but
differed from them in its irregularity of form, and in exhibiting imperfect evidences of a
bony structure. The specific gravity it was found impossible to determine, on account
of the numerous air cavities it contained.




496                                         CORAL.
Analysis showed it to possess the following per centage composition
Water driven off at from 3000 to 350~ F.              -       -   2-600
do. and organic matters expelled at a red heat              -   9'000
Chloride of sodium, &c.             -        -       -        -             evident traces
Carbonate of lime                            -       -        -  39'500
do.     magnesia         -       -        -        -        -   0520
Sulphate of lime           --                         -       -             distinct traces
Phosphate of lime (tribasic)    -            -        -       -  15'860=PO5 528
do.    magnesia                   -       -.        -            traces
Perphosphateof iron    -            -        -        -       -   9'200 —PO   4358
Phosphate of alumina   -            -        -        -        -   4708P0  276
Peroxide of iron                -            -        -        -            none
Alumina            -       -        -..       -   6-212
Fluoride of calcium        -        -        -        -       -   1698
Silicic acid       -       -        -        -        -           10601
99'899=-PO5 12.409
The proportion of nitrogen in this specimen was not estimated.
III. This coprolite was discovered in the lias strata of Lyme Regis.
It was rather large, being above 9 ozs. in weight, was of a grayish color, and when
broken exhibited some traces of crystalline structure. It was considerably softer than
either of the preceding, and furnished a grayish-white powder. Many scales of different extinct fishes, and other organic remains, were to be perceived on the external
surface; the greater proportion of them appeared to belong to a species of fish which
is known to ichthyologists by the name of Pholidophorus limbatus.  Its specific gravity
was about 2-644 or 2-700, and the composition per cent. was as follows
I.          II.        Mean.
Water driven off at from 300~ to
3500 F.            -                 -     2'560        2-668       2'6140
Water and organic matters expelled
at a red heat      -        -        -     3680         3-456       3.5680
Chloride  of sodium, with  some
sulphate of soda            -        -        traces      traces       traces
Carbonate of lime -            -       -   23-640        237108       23-6740
do. of magnesia          -        -        none        none         none
Sulphate of lime   -           -        -     1740         1-801       1i7705
Phosphate of do. (tribasic)             -   60'726       60-813       60'7695-=PO5 28-047
do.   magnesia           -        -        a little    a little     a little
Perphosphate of iron           -       -      3-980       4-135        4~0575==PO5 1-922
Phosphate of alumina           -       -        a little    a little     a little
Peroxide of iron    -          -        -     2-094        1-894       1-9940
Alumina    -          -        -       -        none        none         none
Silicic acid, with fluoride of calcium
and loss -         -        -        -     1-580        1-525       1-5525
100-000    100-000    100-0000==PO5 29-969*
The proportion of nitrogen in this specimen was rather large, being 0-0826 per cent.Thornton J. Herapath.
CORAL (Corail, Fr.; Koralle, Germ.) is a calcareous substance, formed by a species
of sea polypus, which construct in concert immense ramified habitations, consisting
of an assemblage of small cells, each the abode of an animal. The coral is, therefore, a
real polypary, which resembles a tree stripped of its leaves. It has no roots, but a foot not
unlike a hemispherical skull-cap, which applies closely to every point of the surface upon
which it stands, and is therefore difficult to detach. It merely serves as a basis or support to the coral, but contributes in no manner to its growth, like the root of an ordinary tree, for detached pieces have been often found at the bottom of the sea in a state of
increase and reproduction. From the above base a stem, usually single, proceeds, which
seldom surpasses an inch in diameter, and from it a small number of branches ramify in
very irregular directions, which studded over with cells, each containing  an insect
The polypi, when they extend their arms, feelers, or tentacula, resemble flowers, whence,
as well as from the form of the coral, they were classed among vegetable productions.
They are now styled zoophites by the writers upon Natural History.
The finest coral is found in the Mediterranean. It is fished for upon the coasts of
Provence, and constitutes a considerable branch of trade at Marseilles. The coral is at* In the first of these analyses, the phosphoric acid was estimated by M. Schuize's method, as per.
phosphate of iron; in the second, as phosphate of lead.




CORK.                                      497
tached to the submarine rocks, as a tree is by its roots, but the branches, instead of
growing upwards, shoot downwards towards the bottom of the sea; a conformation
favorable to breaking them off and bringing them up.  For this kind of fishing, eight
men, who are excellent divers, equip a felucca or small boat, called commonly a coralline.  They carry with them a large wooden cross, with strong, equal, and long arms,
each bearing a stou  Doag-net.  They attach a strong rope to the middle of the cross,
and let it down horizontally into the sea, having loaded its centre with a weight sufficient
to sink it. The diver follows the cross, pushes one arm of it after another into the hollows of the rocks, so as to entangle the coral in the nets. Then his comrades in the boat
pull up the cross and its accompaniments.
Coral fishing is nearly as dangerous as pearl fishing, on account of the number of sharki
which frequent the seas where it is carried on.  One would think the diving-bell in itl
now very practicable state might be employed with great advantage for both purposes.
Coral is mostly of a fine red color, but occasionally it is flesh-colored, yellow, or white.
The red is preferred for making necklaces, crosses, and other female ornaments.  It ic
worked up like precious stones. See LAPIDARY.
CORK (Ligege, Fr.; Kork, Germ.) is the bark of the quercus liber, Linn., a species of
oak-tree, which grows abundantly in the southern provinces of France, Italy, and Spain.
The bark is taken off by making coronal incisions above and below the portions to be
removed; vertical incisions are then made from one of these circles to another, whereby
the bark may be easily detached. It is steeped in water to soften it, in order to be flattened by pressure under heavy stones, and next dried at a fire which blackens its surface.
The cakes are bound up in bales and sent into the market.
There are two sorts of cork, the white and the black; the former grows in France and
the latter in Spain.  The cakes of the white are usually more beautiful, more smooth,
lighter, freer from knots and cracks, of a finer grain, of a yellowish gray color on both
sides, and cut more smoothly than the black. When this cork is burned in close vessels
it forms the pigment called Spanish black.
This substance is employed to fabricate not only bottle corks, but small architectural
and geognostic models, which are very convenient from their lightness and solidity.
The cork-cutters divide the boards of cork first into narrow fillets, which they after
wards subdivide into short parallelopipeds, and then round these into the proper conical
or cylindrical shape.  The beach before which they work is a square table, where 4
workmen are seated, one at every side, the table being furnished with a ledge to prevent
the corks from falling over. The cork-cutter's knife is abroad blade, very thin, and fine
edged. It is whetted from time to time upon a fine-grained dry whetstone. The workman ought not to draw his knife edge over the cork, for he would thus make misses, and
might cut himself, but rather the cork over the knife edge.  He should seize the knife
with his left hand, rest the back of it upon the edge of the table, into one of the notches
made to prevent it from slipping, and merely turns its edge sometimes upright and sometimes to one side. Then holding the squared piece of cork by its two ends, between his
finger and his thumb, he presents it in the direction of its length to the edge; the cork is
now smoothly cut into a rounded form by being dexterously turned in the hand. He next
cuts off the two ends, when the cork is finished and thrown into the proper basket alongside, to be afterwards sorted by women or boys.
Of late years a much thicker kind of cork boards have been imported from Catalonia,
from which longer and better corks may be made. In the art of cork-cutting the French
surpass the English, as any one may convince himself by comparing the corks of their
champagne bottles with those made in this country.
Cork, on account of its buoyancy in water, is extensively employed for making floats
to fishermen's nets, and in the construction of life-boats. Its impermeability to water has
led to its employment for inner soles to shoes.
When cork is rasped into powder, and subjected to chemical solvents, such as alcohol,
&c., it leaves 70 per cent. of an insoluble substance, called suberine. When it is treated
with nitric acid, it yields the following remarkable products: - White fibrous matter
0-18, resin 14*72, oxalic acid 16-00, suberic acid (peculiar acid of cork) 14*4 in 100
parts.
Machine cork-cutting. - A patent was obtained some years ago by Sarah Thomson for
this purpose.  The cutting of the cork into slips is effected by fixing it upon the sliding
bed of an engine, and bringing it, by a progressive motion, under the action of a circurar
knife, by which it is cut into slips of equal widths.  The nature or construction of a.
machine to be used for this purpose may be easily conceived, as it possesses no new mechanical feature, except in its application to cutting cork.  The motion communicated
to the knife by hand, steam, horse, or other power, moves at the same time the bed also.
which carries the cork to be cut.
The second part of the invention, viz., that for separating the cork into square pieces,
after it has been cut into slips as above, is effected by a moving bed as before, upon which
32




498                              COTTON DYEING.
the slips are to be placed and submitted to the action of a cutting lever, which may be
regulated to chop the cork into pieces of any given length.
The third part of the invention, viz., that for rounding or finishing the corks, consists
of an engine to which is attached a circular knife that turns vertically, and a carriage
or frame upon its side that revolves on its axle horizontally.
This carriage or frame contains several pairs of clamps intended respectively to hold
a piece of the square cut cork by pressing it at the ends, and carrying it lengthways perpendicularly; which clamps are contrived to have a spindle motion, by means of a pinion
at the lower end of their axles, working into a spur-wheel.
The machinery, thus arranged, is put in motion by means of bands and drum-wheels,
or any other contrivance which may be found most eligible; and at the same time that
the circular knife revolves vertically, the frame containing the clamps with the pieces of
cork, turns horizontally, bringing the corks, one by one, up to the edge of the knife, when,
to render each piece of cork cylindrical, the clamps, as above described, revolve upon their
axes, independently of their carriage, by which means the whole circumference of the
cork is brought under the action of the knife, the superfluous parts are uniformly pared
off, and the cork finished smooth and cylindrical. The quantity entered for home consumption amounts to about 2200 tons per annum.
CORROSIVE SUBLIMATE; bichloride of mercury.
CORUNDUM.  This mineral species includes sapphire, corundum stone, and emery.
It consists of pure alumina colored from admixture with oxide of iron.
Blue Sapphire,              Corundum,           Emery,
China.                    Bengal.           Naxos.
Alumina       -     98-5              84-0            89-5              860
Lime   -    -        05                0'0             010               30
Silica   -    -      00                6-5             55                30
Oxide of iron-       1-0               7 5             1.25              40
100'0 Klapr.       98-0 Chen.    98-2 Tennent.   960 Tennent.
The perfectly white crystals of sapphire are pure alumina.
There are two varieties of the perfect corundum; the sapphire so called, and the
Oriental ruby; of which the latter has a rather less specific gravity, being 39 against,3'97. Their form is a slightly acute rhomboid, which possesses double refraction, and is
inferior in hardness only to the diamond. The sapphire occurs also in 6-sided prisms.
COTTON   DYEING.  (Teinture  de  Coton, Fr.;  Baumwollenfdrberei,  Germ.)
Cotton  and  linen yarns  and  cloths  have nearly the same affinity for dyes, and
may therefore with propriety be treated, in this respect, together. After they have
acquired  the proper degree of whiteness (see BLEACHING), they are still unfit to
receive and retain the dyes in a permanent manner.  It is necessary, before dipping
them into the dye-bath, to give them  a tendency to condense the coloring particles
within their cavities or pores, and to communicate such chemical properties as will
fix these particles so that they will not separate, to whatever ordinary trial they may
be subjected. All the colors which it would be desirable to transfer to these stuffs unfor.
tunately do not possess this permanence. Men of science engaged in this important art have
constantly aimed at the discovery of some new processes which may transfer into the class
of fast colors those dyes which are at present more or less fugitive. Almost all the
goods manufactured of cotton, flax, or hemp, are intended to be washed, and ought,
therefore, to be so dyed as to resist the alkaline and soapy solutions commonly used in
the laundry.  Vitalis distinguished dyed cottons into three classes; 1. the fugitive, or
fancy-colored (petit teint), which change their hue or are destroyed by one or two
boils with soap; 2. those which resist five or six careful washings with soap, are good dyes,
(bon teint); and those which were still more durable, such as Turkey reds, may be called
fast colors (grand teint).  The colors of Brazil-wood, logwood, annotto, safflower, &c.,
are fugitive; those made with madder without an oily base, are good; and those of madder with an oily mordant, are fast. It is, however, possible to point out certain processes
for giving these different orders of dyes a greater degree of fixity.
I shall describe, in the five following paragraphs, the operations conducive to the fixation of colors upon cotton and linen.
1. Galling. Either gall-nuts alone, or sumach alone, or these two substances united,
are employed to give to cotton the fast dye preparation. 2 or 3 ounces of galls for every
pound of cotton, being coarser pounded, are to be put into a copper containing about
30 gallons of water for every 100 pounds of cotton, and the bath is to be boiled till the bits




COTTON FACTORY.                                      499
of gallsfeelpasty between the fingers. The fire being withdrawn, when thebath becomes
moderately cool, it is passed through a hair-cloth sieve. If during this operation the
iquor should become cold, it must be made once more as hot as the hand can bear. A
portion of it is now transferred into another vessel, called a back,'in which the cotton is
worked till it be well penetrated with the decoction. It is then taken out, wrung at the
peg or squeezed in a press, and straightway hung up in the drying-houst. Some more
of the fresh decoction being added to the partially exhausted liquor in the back, the pro
cess is resumed upon fresh goods.
The manipulation is the same with sumach, but the bath is somewhat differently made;
because the quantity of sumach must be double that of galls, and must be merely infused
in very hot water, without boiling. When galls and sumach are both prescribed, their
baths should be separately made and mixed together.
2..dluming. Alum is a salt which serves to prepare cotton for receiving an indefinite
variety of dyes. Its bath is made as follows: For 100 pounds of scoured cotton, about
30 gallons of water, being put into the copper, are heated to aboy. _22~"F., when 4 ounces
of alum, coarsely pounded, are thrown in for every pound of cotton, and instantly dissolved. Whenever the heat of the bath has fallen to about 98~ F., the cotton is well
worked in it, in order that the solution may thoroughly penetrate all its pores. It is then
taken out, wrung at the peg or squeezed in the press, and dried in the shade. The solution of alum is of such constant employment in this kind of dyeing, that it should be
made in large quantities at a time, kept in the alum tun, where it can suffer no deteriora
tion, and drawn off by a spigot or stop-cock as wanted.
There are certain colors which require alum to be deprived of a portion of its acid excess, as a supersalt; which may be done by putting 1 ounce of crystals of soda into the
tun for every pound of alum.  But so much soda should never be used as to cause any
permanent precipitation of alumina. When thus prepared, it is called saturated alum,
though it is by no means neutral to litmus paper; but it crystallizes differently from ordinary alum.
Cotton does not take up at the first aluming a sufficient quantity of alum; but it must
receive a second, or even a third immersion. In every case the stuff should be thoroughly
dried, with an interval of one or two days between each application; and it may even be
left for 10 or 12 hours moist with the alum bath before being hung in the air. When
the cotton is finally dry, it must be washed before being plunged into the dye bath; otherwise, the portion of alum not intimately combined with the cotton, but adhering externally to its filaments, would come off by the heat, mix with the bath, alter the color
by dissolving in it, and throw it down to the bottom of the copper, in the form of a lake,
to the great loss of the dyer. Madder reds, weld yellows, and some other colors are
more brilliant and faster when acetate of alumina, prepared with acetate of lead, alum,
and a little potash, is used, than even saturated alum. This mordant is employed cold,
and at 40 Baum6.
3. Mordants. See this article in its alphabetical place.
4. Dye baths are distinguished into two classes; the coloring bath, and the dyeing bath.
The former serves to extract the coloring matters of the different substanecs with the
exception of madder, which is always used in substance, and never as- an extract, infusion, or decoction. In all these cases, when the color is extracted, that is. wnen the dye
bath is completed by the degree of heat suited to each substance, it is tnen allowed to
cool down a certain way, and the cotton is worked or winced through iR, LO get the wishedfor tint.  This is what is called the dye bath.  Several coloring batns are made in the
cold; and they serve to dye also in the cold; but the greater part require a heat of 90~ or
1000 to facilitate the penetration of the stuffs by the coloring particles. The description
of the several dye baths is given under the individual dyes.
5. Of the washing after the dyeing.-The washing of the cottons after they have received the dyes, is one of the most important operations in the business. If it is not carefully performed, the excess of color not combined with the fibres is apt to stain whatever
it touches. This inconvenience would be of little consequence, if the friction carried
off the color equaly from all the points; but it does not do so, and hence the surface appears mottled. A well-planned dye house should be an oblong gallery, with a stream of
water flowing along in an open conduit in the middle line, a series of dash-wheels arranged against the wall, at one side, and of dyeing coppers, furnished with self-acting
Winces or reels against the other. In such a gallery, the washing may be done either by
hand, by the rinsing machine, or by the dash-wheel, according to the quality of the dye,
and the texture of the stuffs. And they may be stripped of the water either by the jack
and pin, by the squeezing roller, or by the press. Wooden pins are placed in some dye
houses on each side of the wash cistern or pool.  They are somewhat conical, 1 foot
high, 31 inches in diameter at the base, l at the top, are fixed firmly upright, and at a
level of about 3 feet above the bottom of the cistern, so as to be handy for the workmen.




500                               COTTON FACTORY.
See BRAZIL WOOD, FUSTIC, MADDER, BLACK DYE, BROWN DYE, &c., as also BLEACHING,
BRAN, CALICO PRINTING, DUNGING, DYEING, &C.
Cotton may be distinguished from Linen in a cloth fabric by means of a good microscope; the former fibres being flat, riband-like and more or less contorted or shrivelled,
and the latter straight, round, and with cross knots at certain distances. These two
fibrous matters may be also distinguished by the action at a boiling heat of a strong
caustic lye, made by dissolving fused potash in its own weight of water. By digestion
in this liquor, linen yard becomes immediately yellow, while the cotton yarn remains
white. The best way of operating is to immerse a square inch of the cloth to be tested
for two minutes in the above boiling hot caustic lye, to lift it out on a glass rod, press
it dry between folds of blotting-paper, and then to pull out a few of the warp and weft
threads-when the linen ones will be found of a deep yellow tint, but the cotton, white
or very pale yellow.
COTrON (Alckalized). The mercurized cotton, as it has been called, is chemically identical with the natural, but instead of having its fibres flattened and twisted, it has them
cylindrical, as seen in the microscope. In fact, the moment they are touched by the
alkaline lye they untwist themselves, contract in length, and retain the rounded form
after the soda is removed by washing. We can thus conceive how a larger quantity of
dye may be imbibed, as the substance becomes more porous.  The formula of the
sodaed cotton is given by Mr. Gladstone as C4i HI   02 KO, when potash is the alkali
employed.
COTTON  FACTORY  (General Construction  of).-There is no textile rubstance
whose filamnents are so susceptible of being spun into fine threads of uniform twist,
strength, and diameter, as cotton wool. It derives this property from the smoothness,
tenacity, flexibility, elasticity, peculiar length, and spiral form of the filaments; hence,
when a few of them are pulled from a heap with the fingers and thumb, they lay hold
of and draw out many others.  Were they much longer they could not be so readily
attenuated into a fine thread, and were they much shorter the thread would be deficient
in cohesion. Even the differences in the lengths of the cotton staple are of advantage
in adapting them to different styles of spinning and different textures of cloth.
If we take a tuft of cotton wool in the left hand, and seizing the projecting fibres with
the right, slowly draw them out, we shall perceive with what remarkable facility the
glide past each other, and yet retain their mutual connexion, while they are extended
and arranged in parallel lines, so as to form a little riband susceptible of considerable
elongation. This demonstration of the ductility, so to speak, of cotton wool, succeeds
still better upon the carded fleece in which the filaments have acquired a certain
parallelism; for in this case the tiny riband in being drawn out by the fingers to a
moderate length, may at the same time receive a gentle twist to preserve its cohesion
till it becomes a fine thread.
Hence we may imagine the steps to be taken or the mechanical processes to be
pursued in cotton spinning.  After freeing the wool of the plant from  all foreign
substances of a lighter or a heavier nature, the next thing is to arrange the filaments in
lines as parallel as possible, then to extend them into regular ribands, to elongate these
ribands by many successive draughts, doubling, quadrupling, or even octupling them
meanwhile, so as to give them perfect equality of size, consistence and texture, and at the
same time to complete the parallelism of the fibres by undoing the natural convolutions
they possess in the pod. When the rectilinear extension has been thus carried to the
fineness required by the spinner, or to that compatible with the staple, a slight degree
of torsion must accompany the further attenuation; which torsion may be either
momentary, as in the tube roving machine, or permanent, as in the bobbin and fly frame.
Finally, the now greatly attenuated soft thread, called a fine roving, is drawn out and
twisted into finished cotton yarn, either by continuous indefinite gradations of drawing
and twisting, as in the throstle, or by successive stretches and torsions of considerable
lengths at a time, as in the mule.
Mechanical spinning consists in the suitable execution of these different processes by
a series of different machines. After the carding operation, these are made to act
simultaneously upon a multitude of ribands and spongy cords or threads by a multitude
of mechanical hands and fingers.  However simple and natural the above described
course of manufacture may appear to be, innumerable difficulties stood for ages in the
way of its accomplishment, and so formidable were they as to render their entire
removal of late years in the cotton factories of England one of the greatest and most
honorable achievements of human genius.
1. The cleaning and opening up or loosening the flocks of cotton wool, as imported
in the bags, so as to separate at once the coarser and heavier impurities as well as those
of a lighter and finer kind.




COTTON FACTORY.                                           501
2. The carding, which is intended to disentangle every tuft or knot, to remove every
remaining impurity which might have eluded the previous operation, and finally to
prepare for arranging the fibres in parallel lines, by laying the cotton first in a fleecy web,
and then in a riband form.
3. The doubling and drawing out of the card-ends or ribands, in order to complete the
parallelism of the filaments, and to equalize their quality and texture.
4. The roving operation, whereby the drawings made in the preceding process are
greatly attenuated, with no more twist than is indispensable to preserve the uniform
continuity of the spongy cords; which twist either remains in them, or is taken out
immediately after the attenuation.
5. The fine roving and stretching come next; the former operation being effected by
the fine bobbin and fly frame, the latter by the stretcher mule.
6. The spinning operation finishes the extension and twist of the yarn, and is done
either in a continuous manner by the water twist and throstle, or discontinuously by
the mule; in the former, the yarn is progressively drawn, twisted, and wound upon the
bobbins; in the latter it is drawn out and twisted in lengths of about 56 inches, which
are then wound all at once upon the spindles.
7. The seventh operation is the winding, doubling, and singeing of the yarns, to fit
them for the muslin, the stocking, or the bobbin net lace manufacture.
8. The packing press, for making up the yarn into bundles for the market, concludes
this series.
9. Tc the above may be added the operations of the dressing machines, and,
10. The power-looms.
The site of the factory ought to be carefully selected in reference to the health of the
operatives, the cheapness of provisions, the facilities of transport for the raw materials,
and the convenience of a market for the manufactured articles.  An  ab                   supply
of labor, as well as fuel and water for mechanical power, ought to be primary considerations in setting down a factory. It should therefore be placed, if possible, in a
populous village, near a river or canal, but in a situation free from marsh malaria,
and with such a slope to the voider stream  as may ensure the ready discharge of
all liquid impurities.  These circumstances happily conspire in the districts of Stockport, Hyde, Stayleybridge, I)uckenfield, Bury, Blackburn, &c., and have eminently
favored the rapid extension of the cotton manufactures for which these places are preeminent.
Mr. Orrell's Cotton Factory.-The mill consists of a main body with two lateral
wings, projecting forwards, the latter being appropriated to store-rooms, a countinghouse, rooms for winding the yarn on bobbins, and other miscellaneous purposes.
The building has 6 floors besides the attic story. The ground-plan comprehends a plot
of ground 280 feet long by 200 feet broad, exclusive of the boiler sheds.
The right-hand end, A (fig. 389) of the principal building, is separated from the main
body by a strong wall, and serves in the three lower stories for accommodating two
ninety-horse steam engines, which are supplied with steam from a range of boilers
contained in a low'shed exterior to the mill.
The three upper stories over the steam engine galley are used for unpacking, sorting,
picking, cleaning, willowing, batting, and lapping the cotton wool. Here are the
willow, the blowing, and the lap machines, in a descending order, so that the lap
machine occupies the lowest of the three floors, being thus most judiciously placed on
the same level with the preparation room of the building. On the fourth main floor of
the factory there are, in the first place, a line of carding engines arranged, near and
parallel to the windows, as shown at B, B, in the ground plan (fig. 389), and, in the
second place, two rows of drawing frames, and two of bobbin and fly frames, in alternate
lines, parallel to each other, as indicated by D, c, D, c, for the drawing frames, and
E, E, E, E, for the bobbin and fly frames in the ground plan. The latter machines are
close to the centre of the apartment.
The two stories next under the preparation room are occupied with throstle frames,
distributed as shown at F, F, in the ground plan. They stand in pairs alongside of
each other, whereby two may be tended by one person.  These principal rooms are
280 feet long, and nearly 50 feet wide. The two stories over the preparation room, viz.,
the fifth and sixth floors from the ground, are appropriated to the mule jennies, which
are placed in pairs fronting each other, so that each pair may be worked by one man.
Their mode of distribution is shown at G G, in the ground-plan.  The last single
mule is seen standing against the end wall, with its head-stock projecting in the
middle.
The ground floor of the main building, as well as the extensive shed abutted behind
it, marked by N, H, is, in the plan, is devoted to the power looms, the mode of placing
which is plainly seen at H, H, H.




502                  COTTON FACTORY.
389
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COTTON FACTORY.   503
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504                              COTTON FACTORY.
The attic story accommodates the warping mills, and the warp dressing machines
subservient to power weaving.
The winding machines, and some extra mules (self-actors) are placed in the wings
the five winding machines being in the two top rooms of the left wing.
We shall briefly sum up the references in the ground-plan as follows:A, the grand apartment for the steam engines.
B, the distribution of the carding engines, the moving shaft or axis running in a
straight line through them, with its pulleys for receiving the driving bands.
c, c, the drawing frames.
D, D, the jack, or coarse bobbin and fly frames.
E, E, the fine roving or bobbin and fly frames.
F, the arrangement of the throstle frames, standing in pairs athwart the gallery, in
the 2d and 3d flats.
G, the mules are here represented by their roller beams, and the outlines of their headstocks, as placed in the 5th and 6th stories.
Hi, the looms with their driving pulleys projecting from the ends of their main axes.
Sometimes the looms are placed in parallel straight lines, with the rigger pulleys of the
one alternately projected more than the other, to permit the free play of the drivingbelts; sometimes the looms are placed, as generally in this engraving, alternately to the
right and left, by a small space, when the pulleys may all project equally. The former
plan is the one adopted in Mr. Orrell's mill.
i, represents the cast-iron girders which support the floors of this fire-proof building.
K, K, are closets placed in each floor, in the recesses of a kind of pilasters built against
the outside of the edifice. These hollow shafts are joined at top by horizontal pipes,
which all terminate in a chest connected with the suction axes of a fan, whereby a constant draught of air circulates up the shafts, ventilates the apartments, and prevents the
reflux of offensive effluvia from the water-closets, however careless the work-people may
be.  The tunnels toward the one end of the building are destined for the men; toward the other for the women., L, are the staircases, of a horse-shoe form, the interior space or shaft in the middle
being used for the teagle or hoist. In the posterior part of the shaft a niche or groove
is left for the counter-weight to slide in, out of the way of the ascending and descending
platform.
M, M, are the two porters' lodges, connected to the corner of each wing by a handsome
iron balustrade. They are joined by an iron gate.
It will be observed that the back loom-shed has only one story, as shown in section,
(fig. 391). In the ground-plan of the shed, N represents the roofing, of wood-work.
The rafters of the floors rest at their ends upon an iron plate, or shoe with edges (as it
is called), for the girders to bear upon.
The two steam engines, of fully 90 horse power each, operate by cranks, which
stand at right angles upon the shaft marked a both in the plan and section. In the
centre, between the bearings, is a large cog-wheel, driving a smaller one upon the
shaft marked b in both figures, to which the fly-wheel c belongs. That prime motion
wheel is magnificent, and possesses a strength equal to a strain of 300 horses. From
this shaft motion is given to the main or upright shaft d, in the section, by two bevel
wheels, visible at the side and on the top of the great block of stone, about 5 tons
weight (fig. 391), which gives a solid basis to the whole moving apparatus.
The velocity of the piston in these steam engines is 240 ft. per minute.
The first shaft makes 44-3 revolutions per minute; the main upright shaft 58-84
per minute. The steam engines make 16 strokes per minute; and the length of their
strokes is 7 ft. 6 in.
As the one engine exerts its maximum force when the other has no force at all, and
as the one increases as the other diminishes in the course of each pair of strokes, the
two thus cooperate in imparting an equable impulsion to the great geering and shafts,
which, being truly made, highly polished, and placed in smooth bearings of hard brass,
revolve most silently and without those vibrations which so regularly recurred in the
old factories, and proved so detrimental to the accurate performance of delicate spinning
frames.
To the horizontal ramifications from the upright shaft any desired velocity of rotation
may be given by duly proportioning the diameters of the bevelled wheels of communication between them; thus, if the wheel on the end of the horizontal shaft have one
half or one third the diameter of the other, it will give it a double or a triple speed.
In the lowest floor, the second bevel wheel above the stone block drives the horizontal
shaft e, seen in the ground plan; and thereby the horizontal shaft f, at right angles to
the former, which runs throughout the length of the building, as the other did through
its breadth, backward. The shaft f lies alongside of the back window wall, near the




COTTON FACTORY.                                        [503]
ceiling; and from it the tranverse slender shafts proceed to the right and left in the
main building, and to the shed behind it, each of them serving to drive two lines of
looms. These slender or branch shafts are mounted with pulleys, each of which drives
four looms by four separate bands.
In the second and third floors, where the throstles are placed, the shaft d is seen in
the section to drive the following shafts:Upon the main upright shaft d (fig. 390), there are in each of these stories two
horizontal bevel wheels, with their faces fronting each other (shown plainly over dd), by
which are moved two smaller vertical bevel wheels, on whose respective axes are two
parallel shafts, one over each other, g, g, which traverse the whole length of the building.
These two shafts move therefore with equal velocities, and in opposite directions. They
run along the middle space of each apartment; and wherever they pass the rectangular
line of two throstle frames (as shown at F in the ground plan) they are each provided with
a pulley; while the steam pulleys on the axes of two contiguous throstles in one line
are placed as far apart as the two diameters of the said shaft-pulleys. An endless strap
goes from the pulley of the uppermost horizontal shaft g, round the steam or drivingpulley of one throstle frame; then up over the pulley of the second or lower shaft, g;
next up over the steam pulley of a second throstle; and, lastly, up to the pulley of the
top shaft, g. See g g in the throstle floors of the cross section.
In the preparation room, three horizontal shafts are led pretty close to the ceiling
through the whole length of the building. The middle one, h (see the plan fig. 389),
is driven immediately by bevel wheels from the main upright shaft d (fig. 390). The
two sides ones, i, i, which run near the window walls, are driven by two horizontal shafts,
which lead to these side shafts. The latter are mounted with pulleys, in correspondence
with the steam pulleys of two lines of carding engines, as seen between the cards in
the plan.  The middle shaft h, drives the two lines of bobbin and fly frames, E, E, E,
(see cross section), and short shafts i, i, seen in the cross section of this floor, moved
from the middle shaft h, turning in gallows fixed to the ceiling, over the drawing
and jack frames, give motion to the latter two sets of machines.  See c D in the cross
section.
To drive the mules in the uppermost story, a horizontal shaft k (see longitudinal and
cross sections, as well as ground plan) runs through the middle line of the building,
and receives motion from bevel wheels placed on the main upright shaft, d, immediately
beneath the ceiling of the uppermost story. From that horizontal shaft, kc, at every
second mule, a slender upright shaft, 1, passing through both stories, is driven (see both
sections). Upon these upright branch shafts are pulleys in each story, one of which
serves for two mules, standing back to back against each other. To the single mules
at the ends of the rooms the motions are given by still slenderer upright shafts, which
stand upon the head stocks, and drive them by wheel-work, the steps (top bearings) of
the shafts being fixed to brackets in the ceiling.
In the attic, a horizontal shaft, mm, runs lengthwise near the middle of the roof, and
is driven by wheel work from the upright shaft. This shaft, in, gives motion to the
warping mills and dressing machines.
This cotton mill having been erected according to plans devised and executed by
that very eminent' engineer, Mr. Fairbairn, of Manchester, may be justly reckoned a
model of factory architecture.  It is mounted with 1,100 power looms, of which 100
require steam power equivalent to 25 horses to impel them, inclusive of the preparation
and spinning operations competent to supply the looms with yarn.  A third steam
engine is added.
Ten looms, with the requisite dressing, without spinning, are considered to be equivalent to 1 horse power in a steam engine.  Steam  power equivalent to 1 horse will
drive500 mule spindles,
300 self-actor spindles,
180 throstle spindles of the common construction; in which estimate the requisite
preparation processes are included.
In Mr. Orrell's mill there are 6,474 spindles in each
of the throstle-frame floors   -        -       -  12,948  spindles
And 14 pairs of mules in each of the 2 mule floors,
containing altogether          -       -        -  24,928      I
19 self-actors in the wing, containing         -       -   V,984       "
Total yarn spindles  -  45,860




[504]                            COTTON FACTORY.
One of the most compact and best-regulated modern factories, on the small scale,
which I visited in Lancashire, consisted of the following system of machines
1willow, 1 blowing machine, 1 lap machine, capable, together, of cleaning and
lapping 9,000 pounds of cotton per week, if required.
21 cards, breakers, and finishers, which carded 5,000 lbs. of cotton every week of
69 hours' work, being about 240 lbs. per card.
3drawing-frames, of 3 heads each.
3coarse bobbin and fly frames.'7 fine         do.                 No stretcher mule.
12 self-actor mules, of Sharp and Roberts's construction, of 404 spindles each
=4,848 mule spindles.
10 throstle frames, of 236 spindles each =2,360 spindles.
7 dessing machines.
236 power looms.
2warping mills.
300 winding spindles for winding the warp.
The rovings have 4 hanks in the pound, and are spun into yarn No. 38 on the
throstle, as well as the mule.
One bobbin of the roving (compressed) lasts 5 days on the self-actors, and 6 days on
the throstles.
According to the estimate of Peile & Williams, of Manchester, 66 horses power of
a steam engine are equivalent to 396 power looms, including 16 dressing machines;
the cloth being 36 inches wide upon the average, and the yarn varying in fineness from
12's to 40's, the mean being 26's.  Here, the spinning and  preparation not being
included, the allowance of power will appear to be high. The estimate given above
assigns 10 looms, with the requisite dressing, to 1 horse; but the latter assigns no more
than 6.
For the following experimental results, carefully made with an improved steamengine indicator, upon the principle of Mr. Watt's construction, 1 am indebted to Mr.
Bennet, an eminent engineer in Manchester.  His mode of proceeding was to determine, first of all, the power exerted by the factory steam engine when all the machines
of the various floors-were in action; then to detach, or throw out of geer, each system
of machines, and to note the diminution of force now exercised. Finally, when all the
machines were disengaged, he determined the power requisite to move the engine itself,;
as well as the great geering-wheels and shafts of the factory.
He found at the factory of S. A. Beaver, Esq., in Manchester, that 500 calico looms
(without dressing) took the power of 33 horses, which assigns 15 looms to 1 horse
power.
At Messrs. Birlie's factory, in Manchester, he found that 1,080 spindles in 3 selfaetor mules took 2.59 horses, being 417 spindles for I horse power; that 3,960 spindles
in 11 self-actors took 8.33 horses, being 4T5 spindles per horse power; 1080 spindles
in 3 self-actors took 2 horses, being 540 spindles per horse.
At Messrs. Clarke & Sons, in Manchester, that 585 looms for weaving fustians of
various breadths took 54 horses power, exclusive of dressing machines, being 11 looms
to 1 horse.
At J. A. Beaver's, on another occasion, he found that 1,200 spindles, of Danforth's
construction, took 21 horses, being 57 spindles per horse power; and that in a second
trial the power of 22 horses was required for the same effect, being 54 Danforth's
spindles per horse power.
An excellent engine of Messrs. Bolton & Watt, being tried by the indicator, afforded
the following results in a factory:A 60 horse boat-engine (made as for a steam boat) took 14- horses
power to drive the engine with the shafts -            -       -        -  14-5
3' blowing machines, with their three fans  -             -       -       -  21-55
10 dressing machines -          -        -       -       -        -       -  1025
12 self-actor mules, of 360 spindles each (720 spindles per horse power)   6-00
6 Danforth throstle frames, containing 570 spindles (96 in each), being
93 spindles to I horse power          -        -       -       -        - 6-20
At Bollington, in a worsted mill, he found that 1061 spindles, including preparation,
took  I horse power upon throstles.  N. B. There is no carding in the long wool or
worsted manufacture for merinos:~
At Bradford, in Yorkshire, he found that a 40 horse power boat-engine, of Bolton
& Watt's, drove 598 calico looms, 6 dressing machines (equivalent to dress warp for
180 of the said looms), and 1 mechanic's workshop, which took 2 horses power. Other
engineers estimate 200 common throstle spindles, by themselves, to be equivalent to the
power of 1 horse.




COTTON FACTORY.                                           505
The shafts which drive the cards revolve about 120 times per minute, with a driving
pulley of from 15 to 17 inches in diameter.
The shafts of the drawing, and the bobbin and fly frames, revolve from 160 to 200
times per minute, with pulleys from 18 to 24 inches in diameter.
The shafts of throstle frames in general turn at the rate of from 220 to 240 times per
minute, with driving pulleys 18 inches in diameter, when they are spinning yarn
of from No. 35 to 40. The shafts of mules revolve about 130 times per minute, with
pulleys 16 inches in diameter.
The shafts of power looms revolve from  110 to 120 times per minute, with pulleys 15
inches in diameter.
The shafts of dressing machines revolve 60 times per minute, with pulleys 14 inches
in diameter.
Before quitting the generalities of the cotton manufacture I way state the following
facts communicated also by Mr. Bennet:A wagon-shaped boiler, well set, will evaporate 12 cubic ft. of water with 1 cwt. of
coals; and a steam boiler with winding flues will evaporate 17 cubic ft. with the same
weight of fuel: 7-2- lbs. of coals to the former boiler are equivalent to I horse power
exerted for an hour, estimating that a horse can raise 33,000 lbs. 1 foot high in a
minute.
The first cotton mill upon the fire-proof plan was erected, I believe, by the Messrs.
Strutt, at'Belper, in the year 1797; that of Messrs. Phillips & Lee, at Manchester, in
1801; that of H. Houldsworth, Esq., of Glasgow, in 1802; and that of James Kennedy,
at Manchester, in 1805; since which time all good factories have been built fire-proof,
like Mr. Orrell's.
The heating of the apartment of cotton factories is effected by a due distribution of
cast-iron pipes, of about 7 or 8 inches diameter, which are usually suspended a little
way below  the ceilings, traverse the rooms in their whole length, and are filled with
steam from boilers exterior to the building. It has been ascertained that one cubit
foot of boiler will heat fully more than 2,000 cubic ft. of space in a cotton mill, and
maintain it at the temperature of about 750 Fahr. If we reckon 25 cubit ft. contents
of water in a waggoned-shaped steam  boiler as equivalent to 1 horse power, such a
boiler would be capable of warming 50,000 cubic ft. of space; and therefore a 10
horse steam boiler will be able to heat 500,000 cubic ft. of air from the average
temperature, 500, of our climate, up to 75~, or perhaps even 80~ Fahr.
It has been also ascertained that in a well-built cotton mill, one superficial foot of
exterior surface of cast-iron steam pipe will warm 200 cubic ft. of air. In common cases
for heating churches and public rooms, I believe that one half of the above heating surface will be found adequate to produce a sufficiently genial temperature in the air. The
temperature of the steam is supposed to be the same with that in Mr. Watt's lowpressure engines, only a few degrees above 2120-the boiling point of water.
The pipes must be freely slung, and left at liberty to expand and contract under
the changes of temperature, having one end at least connected with a flexible pipe of
copper or wrought iron, of a swan-neck shape.  Through this pipe the water of
condensation is allowed to run off.  The pipes should not be laid in a horizontal
direction, but have a sufficient slope to discharge the water. The pipes are cast from
half an inch to three quartLrs thick in the metal. In practice the expansion of steam
pipes of cast-iron may be taken at about one tenth of an inch in a length of 10 feet,
when they are heated from a little above the freezing to the boiling point of water.
The upper surface of a horizontal steam pipe is apt to become hotter than the bottom,
if the water be allowed to stagnate in it; the difference being occasionally so great, as
to cause a pipe 60 feet long to be bent up 2 inches in the middle.
In arranging the steam pipes provision ought to be made not only for the discharge
of the water of condensation, as above stated, but for the ready escape of the air; otherwise the steam will not enter freely. Even after the pipes are filled with steam, a little
of it should be allowed to escape at some extreme orifice, to prevent the re-accumulation
of air discharged from the water of the steam boiler. In consequence of water being
left in the pipes serious accidents may happen; for the next time the steam is admitted
into them, the regularity of heating and expansion is impeded, some part of the pipe
may crack, or a violent explosion may take place, and the joints may be racked to a
very considerable distance, every way, from the place of rupture, by the alternate
expansions and condensations. The pipes should therefore be laid, so as to have the
least possible declivity, in the direction of the motion of the steam.
Formerly, when drying rooms in calico printing works were heated by iron stoves, or
cockles, their inmates were very unhealthy, and became emaciated; since they have
been heated by steam pipes the health of the people has become remarkably good, and
their appearance frequently blooming.
COTTON   MANUFACTURE.   (Filature  de  Coton, Fr.;  Baumwollenspinnerte,




506                         COTTON MANUFACTURE.
Germ.)  Cotton is a filamentous down, which invests the seeds of the plant called go.
~sypium by Linnueus, and placed by him in the class monadelphia, and order monandria,
but belonging to the natural family of malvacece. It has a cup-shaped calyx, obtusely
five-toothed, enclosed in a three-cleft exterior calyx; the leaflets are united at their base,
of a heart shape, and toothed; stigmas three to five; capsule three to five celled and
many seeded; seeds bearing a downy wool.  Thirteen species are described by Decandolle, but their characters are very uncertain, and no botanist can assign to a definite
species of the plant, the very dissimilar staples of the cotton filaments found in commerce.
The leaves are generally palmate and hairy; and the blossoms are large, and of a beautiful yellow. The gossypium religiosum of Tranquebar has white blossoms in some of
its varieties, to which probably the white cotton of Rome, cultivated in the Jardin des
Plantes at Paris, belongs.  The filaments differ in length, flexibility, tenacity, and thick
ness, in different cottons, whence the great differences of their value to the cotton-spinner, aa the prices current in the market show. Thus, at Liverpool, on the 1st of December, 1835, the following values were assigned to the following cottons:s. d.   s. d.
Sea-island            -1  6 to 2  6
Demarara and Berbice          -       -      -       0  9      1  0
Pernambuco            -       -       -       -       0        1  1
Egyptian      -       -       -       -       -      0 11    1  2
New Orleans           -       -       -       -       0  7     1  0
Bahia         -       -       -      -       -       0  8    0 10
Upland Georgia        -       -       -       -                0 111
West Indian           -       -       -       -       0  7    0  9
Surat         -       -       -       -      -       0  6    0  8
Madras        -       -       -       -      -       0  6    0  8
Bengal        -       -       -      -       -       0  5    0  61
But it is to be observed, that there are varieties of the Sea-island Georgian cotton, so
highly prized by the spinner of fine yarn, as to fetch 3s., 4s., or even 5s. per pound.
The filaments of cotton, when examined with a good microscope, are seen to be more
or less riband-like, and twisted; having a breadth varying from.oI of an inch in the
strongest Smyrna or candle-wick cotton of the Levant, to  51~0 of an inch in the finest
Sea-island.
The main distinction between cottons in the pod, is that of the black seeded and the
green seeded; for the former part with their downy wool very readily to a pair of simple
rollers, made to revolve nearly in contact, by the power of the human arm; while the
latter retain the wool with much force, and require to be ginned, as the operation is
called, by a powerful revolving circular saw-mechanism, usually driven by horse or water
power. After the cotton wool is thus separated from the seeds, it is packed in large
canvass bags, commonly with the aid of a screw or hydraulic press, into a very dense
bale, for the convenience of transport. Each of the American bags contains about 340
lbs. of cotton wool. When this cotton is delivered to the manufacturer, it is so foul and
flocky, that he must clean and disentangle it with the utmost care before he can subject
it to the carding operation.
E    F.,,. ~ n390 g     Fig. 390, A B, is a roller, about 9 inches in diameter,
which revolves in the direction of the arrow.  This
cylinder consists of a parallel series of oblique pointed
circular saws made fast to one axis, and parted from
each other by wooden rings nearly one inch and a half
~ /~   in thickness. Above the cylinder, is a kind of hopper
E F, into which the ginner throws the seed cotton, which
N~t111"             falls upon a grating, up through which small segments
of the saw-teeth project, so as to lay hold of the fibres in their revolution, and pull them
through, while the seeds, being thus separated, roll down the slope of the grid, to be
discharged from the spout i K.  M  is a cylindrical brush placed below  the grating,
which revolves against the saw-teeth, so as to clear them  of the adhering cotton
filaments.
The willow, which was originally a cylindrical willow basket, whence its name, but is
now  a box made of wood, with revolving iron spikes, is the first apparatus to which
cotton wool is exposed, after it has been opened up, picked, and sorted by hand or a
rake, in what is called a bing.  The willow exercises a winnowing action, loosens the
large flocks, and shakes out much of the dirt contained in them.  The frame of the
willow is about 2 feet wide, and turns with its spikes at the rapid rate of 600 revolutions
per minute, whereby it tosses the cotton about with great violence. The heavy impurities fall down through the grid bottom. It is exposed, however, for only a few
minutes to the action of this machine. For factories, which work up chiefly the coarser
-nd fouler cottons of India, and Upland Georgia, the conical self-acting willow, us




COTTON MANUFACTURE.                                      507
constructed by Mr. Lillie at Manchester, is much employed. In it, the cotton is put in at
the narrow end of the truncated cone, which, being spiked, and revolving rapidly within
a nearly concentric case upon a horizontal axis, wafts it on towards the wide end, while
its impurities are partly shaken out through the grid or perforated bottom, and partly
sucked up through revolving squirrel wire cages, by the centrifugal action of a fan. This
is a powerful automatic engine, deserving the study of the curious, and is as safe as it is
powerful. The cone of this huge machine makes from 400 to 600 turns per minute, and
will clean 7200 pounds, or 24 bags, in a day.
After shaking out the grosser impurities by the willow, the cotton spinner proceeds
to separate each individual filament of cotton wool from its fellow, so as to prepare it
for carding, and to free it from every particle of foreign matter, whether lighter or
heavier than itself. This second operation is performed by what are called batting
(beating), scutching, and blowing machines, which are all now much the same, whatever difference of signification the name may have.  Indeed, each machine not only
beats, scutches, bht blows.  Fig. 391 exhibits a longitudinal section of a good
-             I      blowing engine of modern construction.
The machine is about 18 or 19 feet long,
and three feet across within the case. The
~^ ~whole frame is made of cast-iron, lined
with boards, forming a close box, which has
merely openings for introducing the raw
cotton wool, for taking out the cleansed
wool, and removing the dust as it collects
at the bottom. These doors are shut during the operation of the machine, but may
&^^^  //^                       be opened at pleasure, to allow the interior
to be inspected and repaired.
The introduction of the cotton is effected
by means of an endless cloth or double
apron, which moves in the direction of
the arrow a a, at the left end of the figure,
by passing round the continually revolving
\^^~ ^ I       ~~rollers at b and c. The two rollers at e,
being the ones which immediately introduce the cotton into the jaws, as it were,
of the machine, are called the feed rollers.
The batting arm, or revolving diameter,
0^ ^1^1'^^ ^          f e, turns in the direction of the arrow, and
04   ^ o/llll^^^l        strikes the flocks violently as they enter, so
as to throw down any heavy particles upon
the iron grating or grid at n, while the
light cotton filaments are wafted onwards'.                         with the wind, from  the rotation of the
scutcher in the direction of arrow a', along
-^^J.^li   \ ~)~                   the second travelling apron, upon which the
t 1 /-'F          squirrel cage cylinder presses, and applies
the cotton in the form of a lap.  Above the
/ -J I ^             cylindric cage h, which turns in the direction of its arrow, there is a pipe k, the
Jo1^\^\               continuation of the case i. This pipe,
o ^  ^lp   ~*~ SI  though broken off in the figure, communicates by a branch pipe with an airsucking fan ventilator, not seen in this
figure, but explained under FOUNDRY. The
cage h, by its rotation, presses down, as we
have said, the half-cleaned cotton upon the
cloth a', which carries it forward to the
second scutcher f', by the second set of
feed rollers e'. The second scutcher throws
down the heavy dust upon the second
grid n', through which it falls upon the
bottom  of the case. The first scutcher
makes about 1280 strokes of each of its
two arms in a minute; the second 1300.
The feed rollers for each are fluted. The feed cloth is either sustained by a board, or
is made of parallel spars of wood, to secure it against bagging, which would render the




508                         COTTON MANUFACTURE.
delivery of the cotton irregular. The feed rollers make 8 turns in the minute; and as
their diameter is 11 inches, they will introduce 8 times their circumference, or 37*7 inches
of the cotton spread upon the apron in that time. Upon every 12th part of an inch of
the cotton, therefore, nearly 3 blows of the scutcher arm will be applied. The second
feed rollers move relatively with more slowness, so that for every 2'4 blows of the
scutcher, only one twelfth of an inch of cotton wool is presented.
The fan is enclosed in a cylindrical case. The wings or vanes revolve from 120 to
150 times in the minute; and while they throw the air out with nearly this velocity
at their eccentric outlet in the circumference, they cause it to enter, with equal velocity, at the centre. With this centre the squirrel cage is connected by a pipe, as above
3^92               1    stated.  The sound filaments of
the cotton are arrested by the
I "^ _ _____sieve surface of the cylindric cage,...............   and nothing but the broken fragments and the light dust can pass
through.
The cotton wool in the blowing
machine is wafted by the second
scutcher into the space x, W, w,
provided with a fine grid bottom;
or it is sometimes wound up there
by rollers into a lap.
In fig. 391 an additional ventilator is introduced beneath at m,
o, o, to aid the action of the
scutchers in blowing the cotton
onwards into the oblong trough
a.  The outlet of that fan is at
t; and it draws in the air at its
axis q. u and v are two doors
or lids for removing the cleaned
cotton wool.  This last fan is
suppressed in many blowing machines, as the scutchin   arms
supply a sufficient stream of air.
The dotted lines show  how  the
motion is transmitted from  the
first mover at s, to the various
^^S?.    -"-^ ^_       _______^   parts of the machine. 6' 6' represent the bands leading to the
L  main  shafting of the mill.  A
^/  t^^./ ^  jJ^ /        I!          machine of this kind can clean
^^,  ^^ ^'\'/i/:V~"1    fully 600 pounds of short-stapled
cotton wool in a day, with the
/I /\   I^I i superintendence of one operative,
usually a young woman, to distribute the cotton upon the first
feed cloth.
The second Blowing machine
is usually called a lap machine,
0//,^^'^^  ^ln~l -~~ ^'''          because, after blowing and scutchf^ F"^^^l^             I'''~ ^^  ^ ^   ing the cotton, as above described,
it eventually coils the fleece upon./ -                     ~~"^j'i /  a ~a wooden roller at the delivering
/~ j   end of the apparatus. It is some- ^^ ^       ^^'              I ^ ~ times, also, called  a  spreading
machine.  A   section  of  it is
shown in fig. 392. The breadth
of this machine is about 3 feet, as
131         the lap formed is prepared for
the usual breadth of the breaker
cards, namely, 3 feet. Where the
cards are only 18 inches broad,
the lap machine is also made of
the same breadth. In the figure we see the feed-cloth, the scutching barrel, the
squirrel suction, and spreading cage, and the rollers for coiling up the lap. The
lever shown below is for removing the pressure weight from  the axis of the lap




COTTON MANUFACTURE.                                      509
rollers, when a full one is to be removed, and replaced by an empty one. m, at the top,
is the commencement of the pipe which leads to the suction fan, or ventilator.  The
thickness of the lap in this machine must be nicely regulated, as it determines, in a
great measure, the grist of the card-ends, and even the rovings. In 12 hours such a lap
machine will prepare 650 pounds of cotton.
Fig. 393 is the first scutching machine, now never seen except in the oldest factories.
A B is the feed cloth; G H and M N are the two scutcher frames.' 4Ii illY'lgttl     A
Carding is the next operation in a cotton factory.  Cards are destined to disentangle
the individual filaments from  each other, and to lay them  lengthwise, instead of being
doubled up and convoluted, as they usually  are  in  leaving the blowing and lap
machines.  Carding consists in the mutual action of two opposite surfaces, which are
studded thick with oblique angled hooks. The wires of which these hooks are made must
be very hard drawn in order to render them stiff and elastic. The middle part of the
figures shows one of the staples or double teeth, the structure of which has been partly
394                                      395
explained under CARD.  Suppose a, fig. 394, to be a piece of a card fillet, and b to be
another piece, each being made fast with pins to a board; the teeth of these two cards
are set in opposite directions, but are very near together, and parallel. Now  suppose
a flock or tuft of cotton placed between two such bristling surfaces. Let a be moved
in the direction of its arrow, and let b be moved in the opposite direction, or even let it
remain at rest. Every filament of the cotton will be laid hold of by each set of teeth,
when their surfaces are thus drawn over each other; the teeth of a will pull them in a
forward direction, while those of b will tend to retain them, or to pull them backwards.
The loops or doublings will, by both movements, be opened or drawn out, so that the
flocks will be converted into rows of parallel filaments, lying alongside or before each
other. Each tooth will secure to itself one or more of them, and by the friction of its
sides, as well as the hooks of its points, will draw them to their utmost elongation.
Though one stroke of the opposite cards be inadequate to produce this equable arrangement, yet many repeated strokes must infallibly accomplish the end in view, of laying
the fibres parallel.
Let us suppose this end effected, and that all the fibres have been transferred to the
card a, a transverse stroke of b will draw over to it a certain number of them, and indeed at each stroke there will be a new partition between the two cards, with increased
parallelism, but still each card will retain a great deal of the cotton. To make one
card strip another, the teeth of one of them must be placed in a reverse position, as
shown infig. 395.
If a be now drawn in the direction of its arrow along the face of b, it will inevitably
comb out all, or almost all, the filaments from it, since the hooks of b have, in this position, no power of retaining them. Even the doubled fibres or loops will slip over the
sloping point of b, in obedience to the traction of a. By considering these two relative
positions of the cards, which take place in hand cards, simply by reversing one of them
any person will be able to understand the play of a cylinder card against its flat top, or
against another cylinder card, the respective teeth being in what we may call the teasing
position of fig. 394; and also the play of a cylinder card against the doffer cylinder,
in what may be called the stripping position of fig. 395.
Cylinder cards, so essential to the continuity and despatch of cotton factory labor,
were the ingenious invention of Lewis Paul of Northampton, but were greatly improved
ind brought into nearly their present operative state by Sir Richard Arkwright. A
23




510                         COTTON MANUFACTURE.
carding engine consists of one or more cylinders, covered with card-leather (sometimes
called card cloth), and a set of plane surfaces similarly covered, made to work against
each other, but so that their points do not come into absolute contact.  Some cards
consist entirely of cylinders, the central main cylinder being surrounded by a series of
smaller ones called urchins or squirrels. These are used solely for preparing the coarser
stapled cotton, and sheep's wool for the wool spinner.
Fig. 396 represents a card of excellent construction, which may be called a breaker
and finisher, as it is capable of working up the fleece roll of the lapping machine di
rectlv into a card-end or riband fit for the drawing machine. In fine spinning mills
there are always, however, two cards; ene coarser, called a breaker, which turns oft
396,,
the cotton in a broad fleece of extreme thinness, which is lapped round a cylinder
and constitutes the material presented to the finisher card, which has teeth of a finel
construction.
a is one of the two upright slots, which are fixed at each side of the engine for receiving the iron gudgeons of the wooden cylinders round which the fleece of the lapping
machine is rolled. The circuMference of this coil rests upon a roller b, which is made to
turn slowly in such a direction as to aid the unfolding of the lap by the fluted cylinders
e. The lap proceeds along the table seen beneath the letter c, in its progress to the fluted
rollers, which are an inch and one sixth in diameter, and have 28 flutings in their circumference. g is a weight which hangs upon the axis of the upper roller, and causes
it to press upon the under one: f is the main card drum; g g g, the arch formed by
the flat top cards; h, the small card cylinder for stripping off the cotton, and therefore
called the doffer, as we have said; i, the doffer-knife or comb for stripping the fleecy
web from the doffer; k I q m, the lever mechanism for rsoving these parts. At d there is
a door for permitting the tenter to have access to the interior of the engine, and to remove whatever dirt, &c. may happen to fall into it. In fig. 397 we see the manner of fixing the flat tops g g over the drum; and for making the matter clearer, three of the tops
are removed. Upon the arched cast-iron side of the frame, a row of strong iron pins k
are made fast in the middle line; and each top piece has, at each of its ends, a hole,
which fits down upon two such opposite pins. 1 1 are screws whose heads serve as
supports to the tops, by coming into contact with the bottom of the holes, which are not
of course bored through the wood of the tops. By turning the heads of these screws a
little the one way or the other, the pins may be lengthened or shortened in any degree,
so as to set the tops very truly in adjustment with the drum teeth revolving beneath
them.  h' is the small runner or urchin, and i' the large runner; both of which are
spirally covered from end to end with narrow card fillets in the same manner as the
doffer. The main drum is on the contrary covered with card cloth, in strips laid on
parallel to its axis, with interjacent parallel smooth leather borders. The teeth of these
several cards are set as represented in the figure, and their cylinders revolve as the arrows
indicate. The runners as well as the dofier cylinder may be set nearer to or farther
from the drum f; but the screws intended for this adjustment are omitted in the draw..
ings, to avoid confusion of the lines.
The card-end or fleece taken off the doffer h by the crank and comb mechanism i k m,
passes through the tin plate or brass funnel n,fig. 396, whereby it is hemmed in and
contracted into a riband, which is then passed through between a pair of drawing rollers o. It is next received by the rollers i v, which carry it off with equable velocity,
and let it fall into the tin cans placed below, or conduct it over a friction pulley, to be
wound along with many other card-ends upon a lap roller or large bobbin. The latter
mechanism is not shown in this figure. A sloping curved tin or brass plate, channelled or




COTTON MANUFACTURE.                                       511
ridged along its surface, conducts the card ribands separately; there are two smooth
iron rollers for condensing the several ribands, and a wooden pin round which the ribands
are lapped, resting between two leather-covered rollers, one of which receives motion
from mill gearing, and imparts it by friction to the lap roller over it.  The iron ends of
the lap roller lie in upright slots, which allow them freedom to rise as the roller gets
illed with fleece.
The two pairs of rollers at o effect the extension of the card-end, and reduce its size.
The under rollers are made of iron and fluted; the upper ones are also made of iron,
but they are covered with a coat of leather, nicely glued on over a coat of flannel, which
two coats render them both smooth and elastic. Two weights, w, press the upper cylinders steadily down upon the under ones.  Between the first and second pair there is a
certain interval, which should be proportioned to the length of the cotton staple. The
second, or that furthest from the funnel, revolves with greater velocity than the first, and
therefore turns out a greater length of riband than it receives from its fellow; the consequence is a corresponding extension of the riband in the interval between the two pairs
of rollers.
The motions of the several parts of the engine are effected in the following way. The
band, p p, fig. 397, which comes down from the pulley upon the main shaft near the ceiling
of the work-rc-om, drives, by means of the pulley q, the drum f, fig. 396, with a velocity
of from 120 to 140 revolutions in a minute. From another pulley r, on the axis of the
drum, the axis of t is driven by the band s working round the pulley t on its end. This
shaft drives the crank and lever mechanism of the stripper knife i. A third pulley of the
same size as r is fixed just within the frame to the other end of the drum, and from it a
crossed or close band r' goes to a pulley upon the small runner h', to give this its rapid
rotation. Upon the opposite end of the engine in fig. 396, these wheels and pulleys
are marked with dotted lines. Here we may observe, first, a pulley y upon the drum, and
a pulley a', which receives motion from  it by means of the band z. The axis of a'
carries in front a pinion m', which sets in motion the wheel W.  The latter imparts motion, by means of a pinion and intermediate wheel o', to the wheel h on the doffer
cylinder, and consequently to that cylinder on the one hand; and it turns, by the carrier
wheel p', a wheel x, whose axis is marked also with x in fig. 396, upon the other
hand. The axis of x', fig. 396, carries, towards the middle of the engine, a very broad
wheel, which is represented by a small dotted circle. The toothed wheel v of the smooth
-oller v', fig. 396, and the two toothed wheels o o, fig. 396, of the under rollers o o, fig.
396, work into that broad wheel. The wheel of the second or delivery fluted roller is
seen to be smaller than that of the first, by which means the difference of their velocities
is obtained. The large runner i is driven from the main drum pulley, by means of the
band s', and the pulley u', fig. 396. The said band is crossed twice, and is kept in tension by the pulley t', round which it passes. The motion of the fluted rollers e, which
feed in the cotton fleece, is effected by means of a bevel wheel b on the end of the doffer,
which works into a similar wheel c' on the oblique axis d' (dotted lines across the drum),
of the pinion e' upon the lower end of the same axis which turns the wheel f', upon the
under feed roller.
Each of the feed rollers, fig. 397, bears a pinion e e at one end, so that the upper roller
turns round with the under one. The roller b, fig. 396, is set in motion by means of
33




b12                        COTTON MANUFACTURE.
its wheel x'; which is driven by a wheel v' on the other end of the under feed roller,
throungh the intervention of the large carrier wheel w'. The original or first motion of
b must be as quick as that of the fluted feed rollers e, in order that the former may uncoil
as much lap as the latter can pass on.
The annexed table exhibits the proper velocities of the different cylinders and rollers
of the carding engine, which, however, are not invariable, but may be modified according
to circumstances, by changing the pinions e', fig. 396, and w', according to the quality or
length of the colton staple. The velocities stated in the table will be obtained when the
pulley a', fig. 396, is made greater than y in the proportion of 3 to 2, and the wheels
and pinions have the following number of teeth: m', 18; n', 50; its pinion, 18; h, 128;
x, 24; the broad wheel upon the shaft of x, 37 teeth; the wheel o of the first fluted
roller, 35; that of the second, 21; v, 44; b' and e', 54; e', 10; f', 63.
Diameter in  Circumference Revolutions in
Names of the parts.          inches.     in inches.   one minute.   Velocity.
Drum f-   - -                            35   109 9    130    14287
Doffer h    -    -    -    -             14         43-96          4-38       1925
Runner or urchin i' -    -    -        6-25         19-62          5-          98-1.Ditto h'    -    -          -         3-5          11-         470-        5170'
Fluted feed roller e -    -    -       1-167         3-664        0-696         255
First drawing roller o -    -          1             3-14        68-71       21575
Second ditto   -    -                  1167          3-664      114-52       419-6
Smooth delivery roller v     -         2-5           7-85        54-66       42908
The operation of the runners, h' and i', becomes very plain on comparing their speed
with one another and with that of the main-drum, and taking into account the direction
of the card teeth.  The cotton wool, taken off from  the feed-rollers by the drum, is
caught by the opposite teeth of the large runner i', which, on account of its slower surface rotation (98 inches per minute), may be considered to be at rest with reference to the
drum, and therefore, by holding the cotton in its teeth, will commence its carding. The
small runner h', in consequence of its greater surface velocity (5170 inches per minute)
will comb the cotton-wool back out of the teeth of the large runner, but it will give it
up in its turn to the swifter teeth of the drum, which, in carrying it forwards, encounters the teeth of the top cards, and delivers up the filaments to their keeping for some
time. We thus see how essential the runners are to the perfection as well as to the acceleration of the carding process for ordinary cotton wool, though for the slenderer and.onger filaments of the sea-island kind they are not so well adapted. In cleaning the
carding-engines the little runner must be looked to every time that the drum is examined.
The large runner and the doffer require to be cleaned together. The quantity of cotton
spread upon the feed-cloth, the velocity of it, and of the drawing-rollers, must all be
carefully adjusted to the grist of the yarn intended to be spun.
Suppose the sizes and velocities to be as represented in the preceding table, that the
engine is a double card 36 inches broad, and that it is furnished with a lap from the lapmachine of which 30 feet in length weigh 5 lbs. In one minute the surface of the feedrollers, e, passes 2'55 inches of that lap onwards; in the same time the main-drum will
work it off.. To card the whole 30 feet, therefore, 141 minutes, or 2 hours and 21 minutes
will be required. In this time the circumference of the rollers, u v, moves through a
space of 141 X 42,908 in. = 5042 ft., and delivers a card-end of that length, weighing
5 lbs., minus 6 per cent. for waste, that is, 4 lbs. III oz. One pound will form a riband
1072 feet long, being, according to the English mode of counting, about number j, or
0-357. The extension of the cotton-fleece to this degree proceeds as follows:-In the
141 minutes which the feed-rollers take to introduce the 30 feet of lap, the doffer, h.,
makes 617-58 revolutions, and the comb, or doffer knife, i, detaches from the doffer teeth
a thin fleecy web of 2262 feet in length. The first drawing pair of fluted rollers,
b_________   by its quick motion, with the aid of the funnel,
in, converts this fleece into a riband 2535 feet
~1"    ~JI long. The second pair of the fluted rollers ex0,1                    tends this riband to 4390 feet, since their surface velocity is greater than the first pair in that
A     I       proportion. The slight elongation (of only 112
feet, or about I4) which takes place between
the delivery fluted rollers and the smooth cylinders, v, u, serves merely to keep the card-end
steadily upon the stretch without folding.  Fig.
398 is a plan of the card and the fleece, where h
^I --                            is the cylinder, n is the funnel, u the pressing
398                                rollers, and h' the card-ends in the can.




COTTON MANUFACTURE.                                        513
Figs. 399, 400, represent skeletons of the old cards to facilitate the comprehension of
these complex machines.  Fig. 399 is a plan; F is the main drum; m M is the doffer
399        [400
knife or comb; G the carded fleece hemmed in by the funnel a, pressed between the rollers b, and then falling in narrow fillets into its can. Fig. 400, K L are the feed rollers;
A B the card drum; c D the tops; E F the doffer card; M N the doffer knife; d. b, c, the
card-end passing between compressing rollers into the can a.
The drawing and doubling are the next operation.  The ends, as they come frm the
cards, are exceedingly tender and loose, but the filaments of the cotton are not as yet laid
so parallel with each other as they need to be for machine spinning. Before any degree
of torsion therefore be communicated, a previous process is required to give the filaments
a level arrangement in the ribands. The drawing out and doubling accomplish this purpose, and in a manner equally simple and certain.  The means employed are drawingrollers, whose construction must here be fully explained, as it is employed in all the following machines; one example of their use occurred, indeed, in treating of the cards.
Let a and b, fig. 401, represent the section of two rollers lying
\\\\\\\\\\\\\401  g\\ over each other, which touch with a regulated pressure, and turn i
contact upon their axes, in the direction shown by the arrows.
These rollers will lay hold of the fleecy riband presented to them at. a, draw it through between them, and deliver it quite unchanged.
The length of the piece passed through in a given time will be'    equal to the space which a point upon the circumference of the
f^J^   [_         roller would have percured in the same time; that is, equal to the
periphery of one of the rollers multiplied by the number of its entire revolutions.  The same thing holds with regard to the transmission of the riband through between a second pair of rollers,
c, d, and a third, ef. Thus the said riband issues from the third pair exactly the same
as it entered at a, provided the surface speed of all the rollers be the same. But if the
surface speed of c and d be greater than that of a and b, then the first-named pair will
deliver a greater length of riband than the last receives and transmits to it. The consequence can be nothing else in these circumstances than a regulated drawing or elongation of the riband in the interval betwixt a, b, and c, d, and a condensation of the filaments as they glide over each other, to assume a straight parallel direction. In like
manner the drawing may be repeated by giving the rollers, e,f, a greater surface speed
than that of the rollers, c and d. This increase of velocity may be produced, either by
enlarging the diameter, or by increasing the number of turns in the same time, or
finally by both methods conjoined. In general the drawing-machine is so adjusted, that
the chief elongation takes place between the second and third pair of rollers., while that
between the first and second is but slight and preparatory. It is obvious, besides, that
the speed of the middle pair of rollers can have no influence upon the amount of the
extension, provided the speed of the first and third pair remains unchanged. The rollers, a, b, and c, d, maintain towards each other continually the same position, but they
may be removed with their frame-work, more or less, from the third pair, e, f, according
as the length of the cotton staple may require. The distance of the middle point from
b and d, or its line of contact with the upper roller, is, once for all, so calculated, that it
shall exceed the length of the cotton filaments, and thereby that these filaments are never
in danger of being torn asunder by the second pair pulling them while the first holds
them fast. Between d andf, where the greatest extension takes place, the distance must
be as small as it can be without risk of tearing them in that way; for thus will the uniformity of the drawing be promoted. If the distance between d and f be very great, a
riband passing through will become thinner, or perhaps break in the middle; whea.e we
see that the drawing is more equable, the shorter is the portion submitted to extension at
a time, and the nearer the rollers are to each other, supposing -.hem always distant
enough not to tear the staple.




514                        COTTON MANUFACTURE.
The under rollers, b df, are made of iron, and, to enable them to lay firmer hold of the
filaments, their surfaces are fluted with triangular channels parallel to their axes. The
upper rollers, a c e, are also made of iron, but they are smooth, and covered with a double coating, which gives them a certain degree of softness and elasticity. A coat of
flannel is first applied by sewing or glueing the ends, and then a coat of leather in the
same way.  The junction edges of the leather are cut slanting, so that when joined by
the glue (made of isinglass dissolved in ale) the surface of the roller may be smoothly
cylindrical. The top rollers are sometimes called the pressers, because they press by
means of weights upon the under ones. These weights are suspended to the slight rods
ke k'; of which the former caperates on the roller e alone, the latter on the two rollers
a and e together. For this purpose the former is hung to a c shaped curve i, whose
upper hook embraces the roller e; the latter to a brass saddle h, which rests upon a and
c. A bar of hard wood, g, whose under surface is covered with flannel, rests, with
merely its own weight, upon the top rollers, and strips off all the loose hanging filaments.
Similar bars with the same view are made to bear up under the fluted rollers b d f, and
press against them by a weight acting through a cord passing over a pulley. Instead
of the upper dust-covers, light wooden rollers covered with flannel are occasionally
applied.
Were the drawing of a riband continued till all its fibres acquired the desired degree
of parallelism, it would be apt, from excessive attenuation, to tear across, and thereby
to defeat the purpose of the spinner. This dilemma is got rid of in a very simple way,
namely, by laying several ribands together at every repetition of the process, and incorporating them by the pressure of the rollers. This practice is called doubling. It is an
exact imitation of what takes place when we draw a tuft of cotton wool between our
fingers and thumb in order to ascertain the length of the staple, and replace the drawn
filaments over each other, and thus draw them forth again and again, till they are all
parallel and of nearly equal length. The doubling has another advantage, that of causing
the inequalities of thickness in the ribands to disappear, by applying their thicker to their
thinner portions, and thereby producing uniformity of substance.
402                                  403                S      uv.J qJ
The drawing frame, as shown in section in figs. 401, 403, and in a back view in fig.
402, will require, after the above details, little further explanation. 1 1 are the weights
which press down the top rollers upon the under ones, by means of the rods k k' and hook
i. Each fluted roller is, as shown atf, fig. 402, provided in the middle of its length with
a thinner smooth part called the neck, whereby it is really divided into twe fluted portions,
represented by e e in the figure. Upon this middle neck in the pressure rollers, the hook
i and the saddle h immediately bear, as shown in the formerfig. 401. The card-ends, to
the number probably of six, are introduced to the drawing frame either from tin cans,
placed at e e,fig. 403, and at A,fig. 402, or from lap-bobbins; and, after passing through it,
the ribands or slivers are received either into similar tin cans, as g, or upon other lapbobbins upon the other side. These appendages may be readily conceived, and are therefore
not exhibited in all the drawings. Three of the slivers being laid together are again introduced to the one fluted portion a b, fig. 401, and three other slivers to the other portion.
The sloping curved tin or brass plate s, fig. 402, with its guide pins t, serves to conduct
the slivers to the rollers. When the two threefold slivers have passed through between the
three pairs of rollers, and been thereby properly drawn, they run towards each other in an
oblique direction, behind the last roller pair e ffig. 401, and unite, on issuing through the




COTTON MANUFACTURE.                                      515
eonical funnel m, fig. 402, into a single riband or spongy sliver; which is immediately
carried olf with equable velocity by two smooth cast-iron rollers, n o, figs. 402 and 403,
and either dropped into a can, or wound upon a large bobbin. The surface speed of
these rollers is made a trifle greater than that of the delivery drawing rollers, in order to
keep the portion of sliver between them always in an extended state. Four fluted drawing portions are usually mounted in one drawing frame, which are set a-going or at rest
together. To save all unnecessary carrying of the cans from the back to the front of
the frame, the drawing heads are so placed, that the first and third discharge their slivers
at the one side, and the second and fourth at the other. By this arrangement, the cans
filled behind one head, are directly pushed aside in front of the next drawing head; by
which alternate distribution the work goes on without interruption.
The fast pulley u,fig. 403, by which the whole machine is driven, derives its motion
from  the main shaft of the mill by means of the band w. The similar pulley 2, which
sits loose upon the axis, and turns independently of it, is called the loose pulley; both
together being technically styled riggers. When the operative desires to stop the machine, he transfers the band from the fast to the loose pulley by means of a lever, bearing
a fork at its end, which embraces the band. Upon y, four pulleys such as x are fixed,
each of which sets in motion a drawing head, by means of a band like w going round
the pulleys x and u.  On account of the inverted position of the heads, which requires
the motion of u to be inverted, the bands of the first and third heads are open, but those
of the second and fourth are crossed. Every head is provided with a loose pulley v, as well
as the fast pulley u, in order to make the one stop or move without affecting the others.
The shaft of the pulley u is the prolonged shaft of the backmost fluted roller f. It carries besides a small pulley q, which, by means of the band r, and the pulley p,fig. 402,
sets in motion the undermost condensing roller o. The upper roller n presses with its
whole weight upon it, and therefore turns by friction.  The toothed wheel-work, by
which the motions are communicated from the backmost fluted roller to the middle and
front ones, is seen in fig. 403.
The wheel f, fig. 401, of 20 teeth, works in a 44-toothed carrier-wheel, on whose
axis there are two smaller wheels; 2 with 26 teeth, and 1 with 22 teeth. The wheel d,
fig. 403 of the middle roller, and the wheel b of the front roller, are set in motion by other
carrier wheels; the first has 27 teeth, and the last 40. For every revolution of b, the
roller d makes nearly 13 turns, and the roller f 4 revolutions. The top rollers revolve,
as we have stated, simply by the friction of contact with the lower ones. Now suppose
the diameter of the rollers b and d to be 1 inch or 12 lines, that of f 11 inches or 15
lines, the surface velocities of the three pairs of rollers in the series will be as 1, 1I, and
5. Every inch of the cotton sliver will be therefore extended between the first and second
pairs of rollers into lj inches, and between the second and third or delivery pair into 5
inches; and after the sliver has passed through all the four drawing heads, its length
will be increased 625 times   5 X 5 X 5 X 5.
The further the drawing process is pushed, the more perfectly will its object be accomplished, namely, the parallelism  of the filaments.  The fineness of the appearance
of the sliver after the last draught depends upon the number of doublings conjointly
with the original fineness and number of drawings. The degree of extension may be
increased or diminished, by changing the wheels in fig. 403, for others with a different
number of teeth. Thus the grist or fineness of the sliver may be modified in any desired
degree; for, when the subsequent processes of the mill remain the same, the finer the
drawings the finer will be the yarn. For spinning coarse numbers or low counts, for
example, six card-ends are usually transmitted through the first drawing head, and converted into one riband. Six such ribands again form one in the second draught; six of
these again go together into the third sliver; and this sliver passes five-fold through the
last draught. By this combination 1080 of the original card-ends are united in the
finished drawn sliver =6 X 6 X 6 X 5. The fineness of the sliver is, however, in consequence of these doublings, not increased, but rather diminished. For, by the drawing,
the card-end has been made 625 times longer, and so much smaller; by the doubling
alone it would have become 1080 times thicker; therefore, the original grist is to the
j'resent as I to the fraction 4?ULL; that is, supposing 1072 feet of the riband delivered
by the card to weigh one pound, 625 feet, the sliver of the last drawing, will also weigh
a pound, which corresponds in fineness to number 024, or nearly ^.
The rearmost or last drawing roller has a circumference of nearly 4 inches, and makes
about 150 revolutions per minute; hence, each of these drawing heads may turn off
35,000 feet of sliver in 12 hours.
Some manufacturers have lately introduced a double roller beam, and a double draught
at the same doubling, into their drawing frames. I have seen this contrivance working
satisfactorily in mills where low counts were spun, and where the tube roving frame was
employed; but I was informed oy competent judges, that it was not advisable where a
level yarn was required for good printing calicoes




516                         COTTON MANUFACTURE.
The loss which the cotton suffers in the drawing frame is quite inconsiderable. It
consists of those filaments which remain upon the drawing rollers, and collect, in a
great measure, upon the flannel facing of the top and bottom cleaner bars. It is thrown
among the top cleanings of the carding engine.  When from  some defect in the rollers,
or negligence in piecing the running  slivers, remarkably irregular portions occur
in the ribands, these must be torn off, and returned to the lap machine to be carded
anew.
The fifth operation may be called the first spinning process, as in it the cotton sliver
receives a twist; whether the twist be permanent, as in the bobbin and fly frame, or be
undone immediately, as in the tube-roving machine.  In fact, the elongated slivers of
parallel filaments could bear little further extension without breaking asunder, unless the
precaution were taken to condense the filaments by a slight convolution, and at the same
time to entwine them  together.  The twisting should positively go no further than to
fulfil the purpose of giving cohesion, otherwise it would place an obstacle in the way of
the future attenuation into level thread. The combination of drawing and twisting is
what mainly characterizes the spinning processes, and with this fifth operation, therefore,
commences the formation of yarn. As, however, a sudden extension to the wished-for
fineness is not practicable, the draught is thrice repeated in machine spinning, and after
each draught a new portion of torsion is given to the yarn, till at last it possesses the
degree of fineness and twist proportioned to its use.
The preliminary spinning process is called roving. At first the torsion is slight in
wro-nortion to the extension, since the solidity of the still coarse sliver needs that cohesive
aid only in a small degree, and looseness
404    Ha    >        i   of texture must be maintained to facilitate
to the utmost the further elongation.
Fig. 404 is a section of the can roving
frame, the ingenious invention of Ark
wright, which, till within these 14 years,
was the principal machine for communi
cating the incipient torsion to the spongy
I  111/11        cord furnished by the drawing heads. It
differs from  that frame in  nothing but
the twisting mechanism; and consists ot
two pairs of drawing rollers, a and b, be
tween which the sliver is extended in the
usual way; c are brushes for cleaning tho
rollers; and d is the weight which presses
0      "~             ^         \      the upper set upon the lower. The wiping
covers (not shown here) rest upon a b.
The surface speed of the posterior or second
pair of rollers is 3, 4, or 5 times greater
than that of the front or receiving pair,
- ~-  ~>  ~ ^J~1~   according to the desired degree of attenua.
tion. Two drawn slivers were generally united into one by this machine, as is shown in
the figure, where they are seen coming from the two cans e e, to be brought together by
the pressure rollers, before they reach the drawing rollers a b. The sliver, as it escapes
from these rollers, is conducted into the revolving conical lantern g, through the funnel
f at its top. This lantern-can receives its motion by means of a cord passing over a
pulley kc, placed a little way above the step on which it turns. The motion is steadied
by the collet of the funnel f, being embraced by a brass busk. Such a machine generally contained four drawing heads, each mounted with two lanterns; in whose side there
was a door for taking out the conical coil of roving.
The motion imparted to the back roller by the band pulley or rigger m, was conveyed
to the front one by toothed wheel work.
The vertical guide pulley at bottom, n, served to lead the driving band descending
from the top of the frame round the horizontal whorl or pulley upon the under end of
the lantern. The operation of this can-frame was pleasing to behold; as the centrifugal
force served both to distribute the soft cord in a regular coil, and also to condense a great
deal of it most gently within a moderate space. Whenever the lantern was filled, the
tenter carried the roving to a -simple machine, where it was wound upon bobbins by
hand. Notwithstanding every care in this transfer, the delicate texture was very apt to
be seriously injured, so as to cause corresponding injuries in every subsequent operation,
and La the finished yarn. Messrs. Cocker and Higgins, of Salford, had the singular
merit, as I have said, of superseding that beautiful but defective mechanism, which had
held a prominent place in all cotton mills from almost the infancy of the factory system,
by the following apparatus.
The Bobbin and Fly frame is now the great roving machine of the cotton manufac



COTTON MANUFACTURE.                                      517
ture; to which may be added, for coarse spinning, the tube roving frame. Of such a
complicated machine as the bobbin and fly frame, it is not possible to give an ade405                       quately detailed description in the
d   space due to the subject in this
Dictionary.  Its mechanical com-' -i0in'''lJb^ L^" ~   q.^~TLS i  _    binations are, however, so admirable as to require such an account
Ci >> "'  ^   c  ^ as will make its functions intelligible by the general reader.
d
406
i. -iZ i         -~1 1|1 1 1    Fig. 405 exhibits a back view oi
\  _  ----   -this machine; and Jig. 406 a secIL J^   ^^^ UB-~.~. ^""       tion of some   of the o eparts not very
St/~\  "^1  -— 1" visible in the former figure.  The
back of the machine is the side at
which the cotton is introduced between the drawing rollers.'"^  n ^  *"'^  \^" ^"   r^The cans, or lap-bobbins filled
with slivers at the drawing frame,
are placed in the situation marked., fig. 406, in rows parallel with
t e length of the machine.  The
sliver of each can, or the united
__'I_______11____      slivers of two contiguous cans, are
conducted upwards along the sur
_                  face of a sloping board f, and
through an iron staple or guide e,
betwixt the usual triple pair of
drawing rollers, the first of which
is indicated by a, b. In fig. 405,
for the purpose of simplifying the
figure, the greater part of these
rollers and their subordinate parts
are omitted.  After the slivers
_______ 1'1  U-    l         have  been  sufficiently  extended. L.....~1    ^  11111 ^-^'^^       and attenuated between the rollers,
n -^~ ^"- _j' ""  l   ^=j  =={i they proceed forwards, towards the
spindles i i i, where they receive
the twist, and are wound upon the
bobbins h. The machine deline
ated contains thirty spindles, but
many bobbin and fly frames conLl.ln- M, i airtain double or even four times that
number. Only a few of the spin
dles are shown in fig. 405, for feai
of confusing the drawing.
With regard to the drawing functions of this machine, I have already given abundant




518                       COTTON MANUFACTURE.
explanation, so far as the properties and operation of the rollers are concerned. The
frame-work of this part of the machine, called the roller-beam, is a cast-iron bench, upon
which nine bearers, c, are mounted for carrying the rollers. The fluted rollers a a a, fig.
407, are constructed in four pieces for the whole length, which are parted from each
other by thinner smooth cylindric portions, 2, called necks. Seven such partings for
four rollers, and one parting for two rollers, constitute together the 30 fluted rollers of
which the whole series consists. The coupling of these roller subdivisions into one
cylinder, is secured by the square holes x, and square pins y, fig. 407, which fit into the
407                                  holes of the adjoining subdivision. The
~       _'v                          top or pressure rollers b, are two-fold over
the whole set; and the weighted saddle
~za   z. Z                           presses upon the neck w, which connects
every pair, as was already explained under
fig. 402. These weights g g, fig. 406, are applied in this as in the drawing frame; d are
the bars faced with flannel for cleaning the top rollers. A similar bar is applied beneath
the rollers, to keep the flutings clean.
The structure and operation of the spindles a may be best understood by examining
408         the section fig. 408. They are made of iron, are cylindrical from' ^ g         the top down to a2, but from this part down to the steel tipped rounded
points they are conical. Upon this conical portion there is a pulley
k, furnished with two grooves in its circumference, in which the cord
runs that causes the spindle to revolve. The wooden bobbin h is
slid upon the cylindrical part, which must move freely upon it, as
will be presently explained. To the bobbin another two-grooved
pulley or whorl g is made fast by means of a pin r, which passes
through it; by removing this pin, the bobbin can be instantly taken
off the spindle. The upper end of the spindle bears a fork s t,
which may be taken off at pleasure by means of its left-handed
ft       - -— screw; this fork, or flier, has a funnel-formed hole at v. One arm
of the fork is a tube, s, u, open at top and bottom; the leg, t, is
added merely as a counterpoise to the other. In fig. 406, for the
sake of clearness, the forks or fliers of the two spindles here represented are left out; and in fig. 405, only one is portrayed for the
y' r^ ^       same reason. It is likewise manifest from  a comparison of these
two figures that the spindles are alternately placed in two rows, so
that each spindle of the back range stands opposite the interval
2        between two in the front range. The object of this distribution
is economy of space, as the machine would need to be greatly longer
if the spindles stood all in one line. If we suppose the spindles and
k     nil        the bobbins (both of which have independent motions) to revolve
simultaneously and in the same direction, their operation will be
as follows: The sliver, properly drawn by the fluted rollers, enters
the opening of the funnel v, proceeds thence downwards through
the hole in the arm of the fork, runs along its tube u, s, and then
winds round the bobbin. This path is marked, in fig. 408, by a dotted line.
The revolution of the spindles in the above circumstances effects the twisting of the
dliver into a soft cord; and the flier s, t, or particularly its tubular arm s, lays this cord
upon the bobbin. Were the speed of the bobbins equal to that of the spindles, that is,
did the bobbin and spindle make the same number of turns in the same time, the process would be limited to mere twisting. But the bobbin anticipates the fliers a little,
that is, it makes in a given time a somewhat greater number of revolutions than the
spindle, and thereby effects the continuous winding of the cord upon itself. Suppose
the bobbin to make 40 revolutions, while the spindle completes only 30; 30 of these revolutions of the bobbin will be inoperative towards the winding-on, because the fliers follow at that rate, so that the cord or twisted sliver will only be coiled 10 times round the
bobbin, and the result as to the winding-on will be the same as if the spindle had stood
still, and the bobbin had made 40-30 = 10 turns. The 30 turns of the spindles serve,
therefore, merely the purpose of communicating twist.
The mounting and operation of the spindles are obviousmy the same as they are upon
the household flax wheel. In the bobbin and fly frame there are some circumstances
which render the construction and the winding-on somewhat difficult, and the mechanism
not a little complicated. It may be remarked, in the first place, that as the cord is wound
on, the diameter of the bobbin increases very rapidly, and therefore every turn made
round it causes a greater length of roving to be taken up in succession. Were the
motions of the bobbins to continue unchanged in this predicament, the increased
velocity of the winding-on would require an increased degree of extension, or it would




COTTON MANUFACTURE.                                      519
occasion the rupture of the cord, because the front fluted rollers move with uniform
speed, and therefore deliver always the same length of sliver in the same time. It
is therefore necessary to diminish the velocity of the bobbins, or the number of their
turns, in the same proportion as their diameter increases, in order that the primary
velocity may remain unchanged.  Moreover, it is requisite for the proper distribution
of the cord upon the bobbin, and the regular increase of its diameter, that two of its
successive convolutions should not be applied over each other, but that they should be
laid close side by side. This object is attained by the up and down sliding motion of the
bobbin upon the spindle, to the same extent as the length of the bobbin barrel. This
up and down motion must become progressively slower, since it increases the diameter
of the bobbin at each range, by a quantity equal to the diameter of the sliver. What
has now been stated generally, will become more intelligible by an example.
Let it be assumed that the drawing rollers deliver, in 10 seconds, 45 inches of
roving, and that this length receives 30 twists. The spindles must, in consequence
make 30 revolutions in 10 seconds, and the bobbins must turn with such speed, that
they wind up the 45 inches in 10 seconds. The diameter of the bobbin barrels being
11 inches, their circumference of course 4- inches, they must make 10 revolutions more
in the same time than the spindles. The effective speed of the bobbins will be thus
30-+10==40 turns in 10 seconds.  Should the bobbins increase to 3 inches diameter,
by the winding-on of the sliver, they will take up 9 inches at each turn, and consequently 45 inches in 5 turns. Their speed should therefore be reduced to 30~5=35
turns in 10 seconds.  In general, the excess in number of revolutions, which the
bobbins must make over the spindles, is inversely as the diameter of the bobbins.
The speed of the bobbins must remain uniform during the period of one ascent or
descent upon the spindle, and must diminish at the instant of changing the direction
of their up and down motion; because a fresh range of convolutions then begins with
a greater diameter. When, for example, 30 coils of the sliver or roove are laid in one
length of the bobbin barrel, the bobbin must complete its vertical movement up or
down, within 30 seconds in the first case above mentioned, and within 60 seconds in
the second case.
The motions of the drawing rollers, the spindles, and bobbins, are produced in the
following manner:-A  shaft c', figs. 405 and 406, extending the whole length of the
machine, and mounted with a fly wheel d', is set in motion by a band from the running
pulley upon the shaft of the mill, which actuates the pulley a'. b' is the loose pulley
upon which the band is shifted when the machine is set at rest. Within the pulley a',
but on the outside of the frame, the shaft c' carries a toothed wheel b2 with 50 teeth,
which by means of the intermediate wheel c2 turns the wheel d2 upon the prolonged
shaft of the backmost fluted roller (m2, fig. 406.)  This wheel d2 has usually 54 teeth;
but it may be changed when the roove is to receive more or less twist; for as the
spindles revolve with uniform  velocity, they communicate the more torsion the less
length of sliver is delivered by the rollers in a given time. Upon the same shaft with
d2, a pinion e2 of 32 teeth is fixed, which works in a wheel f2 of 72 teeth. Within
the frame a change pinion g2 is made fast to the shaft of f2. This pinion, which has
usually from 24 to 28 teeth, regulates the drawing, and thereby the fineness or number
of the roving. It works in a 48-toothed wheel h2 upon the end of the backmost fluted
roller a, fig. 406. The other extremity of the same roller, or, properly speaking, line of
rollers, carries a pinion 12, furnished with 26 teeth, which, by means of the broad
intermediate wheel k2, sets in motion the pinion t'2 of 22 teeth upon the middle roller.
When the diameter of all the drawing rollers is the same, suppose 1 inch, their proportional velocities will be, with the above number of teeth in the wheel work, if g2 have
24 teeth, as I: 1l18:4'5; and the drawn sliver will have 41 times its original length.
The front or delivery roller of the drawing frame is of late years usually made 14  or
11 inches in diameter. If 625 feet of the sliver from the drawing frame weighed one
pound, 2790 feet of the roving will now go to this weight, and the number will be
1-12; that is, I hank and 12 hundredths to the pound. The front pair of fluted
rollers makes about 90 revolutions, and deliver;, 282*6 inches of roving in the minute,
when of one inch diameter.
The spindles i (figs. 405 and 406), rest, with their lower ends, in steps 7, which are
fixed in an immoveable beam or bar m. To protect it from dust and cotton filaments,
this beam is furnished with a wooden cover n, in which there are small holes for the
passage of the spindles right over the steps. In fig. 405, two of the eight covers n, which
compose the whole range 77, are removed to let the steps be seen. The cylindrical part
of each spindle passes through a brass ring o; and all these 30 rings, whose centres
must be vertically over the steps 1, are made fast to the copping beam p. This beam
is so called, because it is destined not merely to keep the spindles upright by the rings
attached to it, but, at the same time, to raise and lower along the spindles the bobbins




520                         COTTON MANUFACTURE.
which rest on these rings; for which purpose the two racks, or toothed bars m2 nt,
made fast to it, are designed, as will be presently explained. To effect the revolution
of the spindles, there are attached to the main shaft c' two whorls or pulleys e'f, each
bearing four grooves of equal diameter. Each of these pulleys puts one half of the
spindles in motion, by means of a cord, which, after going round the whorls k turns
four times about the pulleys of the shaft c'. Two guide pulleys h', each four-grooved,
and two others i', with a single groove, which turn independently of the others, upon
the above shaft, serve to give the whorl cords the proper direction, as well as to keep
them tight. The spindles revolve 200 times or thereby in the minute; and therefore
impart two turns or twists to every three inches of the roving.
The revolution of the bobbins is independent of that of the spindles, although it likewise proceeds from  the shaft c', and differs from  it in being a continually retarded
motion. The simplest method of effecting this motion, is by means of the wooden or
tin plate   k", which revolves equally with the shaft c', and at the same time slides
along it.
The manner in which this operates is shown in section in fig. 409. Here we perceive the rod q2, which extends from the base toward the narrow end of the truncated
cone, and p2 a forked bearer or carrier made fast to the shaft c' by a screw, which
compels the cone, by means of that rod, to obey the movements of c'. In the large end
of the cone there is an aperture, through which the bearer can be got at. The smaller
end carries outside a projection o 2, provided with a groove, which is embraced by the
forked end of a rod q',fig. 410, that serves to shove the cone along upon the shaft c'.
Directly under the cone, there is an upright round pillar p', upon which the holder oof the two guide pulleys' is adjustable. A bar r92 placed along-side of the holder,
prevents its turning round, but allows it to slide along p' by friction. The weight of the
bolder and the pulley is sufficient to distend the endless band n, which runs from the
cone Wc', through under the pliley 1', and round the small drum m' on the shaft s2. A
pulley or whorl t2, with four grooves, is made fast by means of a tube to this shaft, and
slides along it backwards and forwards, without ever ceasing to follow its revolutions.
The shaft possesses for this purpose a long fork, and the interior of the tube a corresponding tongue or catch. There is besides upon the tube beneath the pulley, at u2, a
groove that goes round it, in which the staple or forked end of an arm like V2, fig. 410,
made fast to the copping beam p, catches.  By the up and down movement of that
beam, the pulley t 2 takes along with it the arm that embraces the tube, which therefore
rises and falls equally with the bobbins h', and their pulleys or whorls q. This is
requisite, since the bobbins are made to revolve by the pulleys t 2, by means of two endless
cords or bands.
The most intricate part of the mechanism is the adjustment, by which the revolution
of the bobbins is continually retarded, and their up and down, or copping motion, along
the spindles, is also retarded in like proportion. The vertical pulley f' (towards the
left end of the shaft c) has at its right side a somewhat larger disc or sheave g',
with a perfectly uniform, but not a very smooth surface. Upon this she? ve, a smaller
horizontal pulley x' rubs, whose upper face is covered with leather to increase the friction
The under end of the shaft.y2 of the pulley x' turns in a step, which is so connected with
the arm v' of the large bent lever t' v', that it always stands horizontally, whatever
direction the arms of that lever may assume. The shaft y2 is steadied at top by an




COTTON MANUFACTURE.                                      521
annular holder or bush, which embraces the fast arm x2 with its forked end. Upon its
opposite side, this arm carries a pulley y2, upon which a cord goes, that is made fast to
the holder of the shaft y2, and loaded with the weight z'.   The weight presses the
pulley x' against the surface of g', in such wise as to effect the degree of friction necessary
in ordqr that the revolution of g' may produce an uninterrupted revolution in x. A
pinion w', whose length must be equal at least to the semi-diameter of the sheave g' is
placed upon the under end of the shaft y2. It has 22 teeth, and takes into a 62-toothed
horizontal wheel z2. Upon the upper end of this wheel the conical pinion a3 is made
fast, which may be changed for changing the speed, but usually has from 28 to 30 teeth.
By this pinion the conical wheel b3 is turned, which has 30 teeth, and whose shaft is c3.
This shaft carries upon its opposite end a six-leaved pinion, d3, which takes into the
calender wheel f3, formed with cogs like a trundle, upon the long shaft e3. In fig. 411
the wheel f3 is exhibited with its pinion d3. Here we may remark, that in the circumference of the wheel there is a vacant place,;3, void of teeth. When, by the motion of
the wheel, the pinion comes opposite to this opening, it turns round about the last tooth
of the wheel, falls into the inside of the toothed circle marked by the dotted lines, and
thus gives now an inverse movement to the wheel f3, while itself revolves always in the
name direction. This reversed motion continues till the opening g3 comes once more
411                                       412
dependnt parts, the wheel, with its shaft e3, revolves alternately to the right hand
and the left. That this result may ensue, the shaft c3 of the pinion must be able to
slide endwise, without losing its hold of a3 and M3.  This adjustment is effected by
placing the end of the said shaft, nearest b3, in a box or holder i3, in which it can turn,
and which forms a vertical tube to this box, as a downward prolongation which is fixed
to the tail of the conical pinion a3. Fig. 412 shows this construction in section upon
an enlarged scale. The second bearer of the shaft nearest d3, must possess likewise the
means of lateral motion.  When therefore the pinion d3 shifts through the opening
of the wheel f3 outwards or inwards, its shaft c3, makes a corresponding small angular
motion upon the pivot of a0, by means of the tube i3; a3 and 63 remain thereby completely in gear with one another.
The above-described alternate revolutions of the wheel f3 serve to produce the up
and down motions of the bobbins. The shaft e3 has for this purpose two pinions n2 32,
which work in the rack teeth m2 m2 of the copping rail p, and thus alternately raise and
sink it with the bobbins which rest upon it. The weight of the copping beam and all
its dependant parts, is poised by two counterweights m4, whose cords run over the
pulleys 04 04 04, fig. 405, and have their ends made fast to the frame, so as to make the
upward motion as easy as the downward. The two upper pulleys out of the three of
each weight are fixed to the frame; the under one, round which the cord first runs, is
attached to the cooping beam, rising and falling along with it.
As long as the friction disc x' remains at the same height, the pulley g' derives its
motion from the same circle of the said disc, and the up and down motion of the copping
beam is also uniform. But when that disc ascends so as to describe with its edge a small
circle upon the face of g', its motion must become proportionally more slow. This is the
method, or principle of retarding the copping motionsof the bobbins. It has been shown,
however, that the rotation of the bobbins should be also retarded in a progressive manner.
This object is effected by means of the cone k', which, as the band n progressively
approaches towards its smaller diameter, drives the pulleys or whorls q of the bobbins
with decreasing speed, though itself moves uniformly quick with the shaft c. To effect
this variation, the cone is shifted lengthwise along its shaft, while the band running
upon it remains continually in the same vertical plane, and is kept distended by the
weight of the pulley o'. The following mechanism serves to shift the cone, which may.
be best understood by the aid of the figures 413, 414, and 410. A long cast iron bar mi3,




522                         COTTON MANUFACTURE.
which bears two horizontal projecting puppets, o3 03, is made fast to the front uprigh
face of the copping beam A. Through the above puppets a cylindrical rod 13 passes freely
413
414
0_                                     __.,.   _____
which is left out in fig. 410, that the parts lying behind it may be better seen. Upoa
this rod there is a kind of fork, p3 p3, to which the alternating rack bars q3 are made
fast. The teeth of these racks are at unequal distances from each other, and are so
arranged, that each tooth of the under side corresponds to the space between two teeth
in the upper side. Their number depends upon the number of coils of roving that may
be required to fill a bobbin; and consists in the usual machines of from 20 to 22. The
rod n3 may be shifted in the puppet 03, like the fork p3 of the rack-rod, upon the rod
3,~ and along the surface of n3, where two wings u3 u3 are placed, to keep the fork in
a straiht direction. Upon the bar m3, there are the pivots or fulcra of two stop catches
W3 x3, of which the uppermost presses merely by its own weight, but the undermost by
means of a counterweight y3, against the rack, and causes them thus to fall in between
the teeth.  In fig. 414, v3 shows the pivot of the catch or detent w3 by itself, the
detent itself being omitted, to render the construction plainer. A pushing rod 13, upon
which there is a pin above at 53, that passes behind the rack rod, between this and
the bar m3, has for its object to remove at pleasure the one or the other of the two
catches; the upper, when the upper end of the rod pushes against it; the under, by
means of the above mentioned pin 53. Both the catches are never raised at once, but
either the under or the upper holds the rack bar fast, by pressing against one of the
teeth. The vertical motion up or down, which the rod 13 must take to effect the lifting
of the catches, is given to it from the copping beam p; since upon it a horizontal arm
V2, fig. 414, is fixed, that lays hold of that rod. Upon the pushing rod are two rings,
h3 and k3, each made fast by a screw.  When the copping beam is in the act of going
up, the arm v3 at the end of this movement, pushes against the ring V3, raises up the
rod 13, and thus removes the catch w3, fig. 410, from the teeth of the rod q3, before
which it lies flat. At the descent of the copping rail, v2 meets the ring k3, when the
motion in this direction is nearly completed, draws down the rod 13 a little, by means of
the same, and thereby effects the removal of the catch x3, fig. 414, from the rod q3.
Every time that one of the catches is lifted, the rack recovers its freedom to advance a
little bit in the direction of the arrow; so far, namely, till the other catch lays hold upon
the tooth that next meets it. The reason is thus manifest why the teeth of the upper
and under sides of the bar q3 are not right opposite to each other, but in an alternate
position.
From the rack-bar, the sliding of the cone k', and the raising of the shaft yi, each by
minute steps at a time, is produced as follows: -
A large rectangular lever ti, v0, whose centre of motion is at p4, has at the upper end
of its long arm ti, a long slot through which a stud r3 upon the rack q3 goes, (figs. 413,
414, 410,) so that the lever must follow the motions of the rack bar.  The end of the
short arm of the lever bears, as already mentioned, the step of the shaft y2; hence the
friction disc xi will be raised in proportion as the rack bar advances, and will come
nearer to the middle point of gi'; consequently, its revolution and the shifting of the
bobbins will become slower.  Upon the cylindrical rod n3, the piece St S1 furnished
with a long slot is made fast, by means of a tube O8, (fig. 410,) and a screw. A fork
u u, which by means of the screw nut a4 is made fast in the slot, embraces the arm t1 of
the beut lever; and a tube r1 riveted to the surface of s5, is destined to take up the draw
rod qi of the cone kl,fig. 410. A weight f4, whose cord 64 is made fast to the cylindrical rod n3, endeavors to draw this rod continually in the direction of the arrow. In
consequence of this arrangement, every time that the pushing bar 13 lifts up one of the
catches, the cone k', the lever Ai v', and by it the rack bar qs, are set in motion. It is




COTTON MANUFACTURE.                                     523
obvious, that the motion of the eone may be made greater or less, according as the fork
u u is fixed further up or down in the slot of sl.
The number of the teeth upon the bar q3 is so ordered, that the bobbins are quite full
when the last tooth has reached the catch and is released by it. The rack bar, being
restrained by nothing, immediately slides onwards, in consequence of the traction of the
weight f4, and brings the machine to repose by this very movement, for which purpose
the tollowing construction is employed. A rectangular lever which has its centre of
motion in g4 is attached to the side face of the beam A, and has at the end of its horizontal arm a pulley d4, over which the cord b4 of the counterweight f4 is passed. The
end of the perpendicular arm is forked and embraces the long and thin rod k4t, to whose
opposite end the fork 14 is made fast. Through this fork the band which puts the machine in motion passes down to the pulley a'. With the bent lever another rod c4 is
connected at Mhi which lies upon the puppet e3 with a slot at e4, and hereby keeps the
lever g in its upright position notwithstanding the weight f4. In the moment when, as
above stated, the rack bar q3 becomes free, the arm p3 of its fork pushes in its rapid
advance against the under oblique side of e4, raises this rod, and thereby sets the lever g4
free, whose upright arm bends down by the traction of the weight, drives the rod kt
before it into the ring 4 fastened to it, and thus, by means of the fork 14, shifts the band
upon the loose pulley bl. But the machine may be brought to repose or put out of gear
at any time merely by shifting the rod k4 with the hand.
The operation of the bobbin and fly frame may be fully understood from the preceding
description. A few observations remain to be made upon the cone ki, the rack-bar q3,
and the speed of the work.
When we know the diameter of the empty bobbins, and how many turns they should
make in a given time in order to wind-on the sliver delivered by the fluted rollers and the
spindles; when we consider the diameters of the spindle pulleys q, and t2, as also the
drum imfig. 405, we may easily find the diameter which the cone must have for produtcing that number of turns. This is the diameter for the greatest periphery of the
base. The diameter of the smaller is obtained in the same way, when the diameter of
the bobbins before the last winding-on, as well as the number of turns necessary in a
given time, are known.
A bobbin and fly frame of the construction just described delivers from  each spindle
in a day of twelve hours, from 6 to 8 lbs. of roving of the fineness of 1 English counts.
One person can superintend two frames, piece the broken slivers, and replace the full
bobbins by empty ones. The loss of cotton wool in this machine consists in the portions
carried off from the torn slivers, and must be returned to the lapping machine.
The fine bobbin and fly frame does not differ essentially from the preceding machine.
The rovings from the coarse bobbin and fly frame are placed in their bobbins in a frame
called the creel, behind and above the roller beam, two bobbins being allowed for one
fluted portion of the rollers. These rovings are united into one, so as to increase the
uniformity of the slivers.
The invention of the beautiful machine above described is due to Messrs. Cocker and
Higgins, of Manchester, and as lately improved by Henry Houldsworth, jun., Esq., it
may be considered the most ingeniously combined apparatus in the whole range of productive industry.
In the fine roving frame the sliver is twisted in the contrary direction to that of the
coarse roving frame. For this reason the position of the cone is reversed, so as to present in succession to the band, or strap, diameters continually greater, in order that the
rotation of the bobbins may be accelerated in proportion as their size is increased,
because here the flier and the bobbin turn in the same direction, and the winding-on
is effected by the precession of the bobbin; but if the winding-on took place by its falling
behind, as in the coarse bobbin and fly frame, that is, if the flier turned less quickly than
the bobbin, the rotatory speed of the bobbin would be uniformly retarded; in which case
the cone would be disposed as in the coarse frame.
When, by any means whatever, a uniform length of thread is delivered by the rollers
in a given time, the bobbin must wind it up as it is given out, and must therefore turn
with a speed decreasing with the increase of its diameter by successive layers of thread.
Hence proceeds the proposition, that the velocity of the bobbin must be in the inverse
ratio of its diameter, as already explained.
With respect to the bobbin and fly frame, the twist is given to the sliver by
means of a spindle, or flier, which turns in the same direction with the bobbin, but
quicker or slower than it, which establishes two predicaments. The first case is where
the flier turns faster than the bobbin.  Here the winding-on goes in advance, as in
the coarse roving frame, or as in throstle spinning, where the yarn is wound on merely
in consequence of the friction of the lower disc or washer of the bobbin upon the
copping rail, and of the drag of the yarn. The second case is where the flier revolves
more slowly than the bobbin. Here the winding goes on in arrear, and as the bobbin




524                          COTTON MANUFACTURE.
turns faster, it must receive a peculiar motion, which is uniformly retarded in the ratio
of its increase of diameter. This is the case with the fine bobbin and fly frame. When
the cone is placed as in fig. 405, the winding-on, in either the coarse or fine frame, results from the difference, whether greater or less, between the rotatory speed of the flier
and bobbin.
The motion of the bobbin and spindle is simultaneous, and takes place in the same
direction, with a difference varying more or less with the varying diameters of the
bobbins.  To render the matter still clearer, suppose for a moment the spindle to be
motionless, then the bobbin must revolve with such a speed as to lap-on the roving as
fast as the rollers deliver it. The sliver comes forward uniformly; but the bobbin, by
its increase of diameter, must revolve with a speed progressively slower. Now, suppose the spindle set a-whirling, it is obvious that the bobbin must add to the movement
requisite for winding-on the sliver, that of the spindle in the case of winding-on in
arrear, or when it follows the fliers, and subtract its own motion from the twisting
motion of the spindles, in the case of winding-on in advance, that is, when the bobbin
precedes or turns faster than the fliers; for the diameter of the bobbin being 1^
inches, 10 turns will take up 45 inches. Deducting these 10 turns from the 30 made
by the spindle in the same time, there will remain for the effective movement of the
bobbin only 20 turns; or when the diameter of the bobbin becomes 3 inches, 5 turns
will take up the 45 inches, if the spindle be at rest; but if it makes 30 turns in the
time, the effective velocity of the bobbin will be 25 turns, = 30    5. Hence in the
fine bobbin and fly frame, the number of turns of the spindle, minus the number of
turns made by the bobbin in equal times, is in the inverse ratio of the diameter of the
bobbin.  We thus perceive, that in the coarse frame the bobbin should move faster
than the spindle, and that its speed should always diminish; whilst in the fine frame
the bobbin should move slower than the spindle, but its speed should always increase.
It is easy to conceive, therefore, why the cones are placed in reverse directions in the
two machines.  Not that this inversion is indispensably necessary; the cone of the fine
roving frame might, in fact, be placed like that of the coarse roving frame; but as the
torsion of the roving becomes now considerable, and as on that account the bobbin would
need to move still faster, which would consume a greater quantity of the moving power,
it has been deemed more economical to give its movement an opposite direction.
We mentioned that the twist of the sliver in the fine roving frame was the reverse of
that in the coarse; this is a habit of the spinners, for which no good reason has been
given.
The divisions of the rack-bar, and the successive diameters of the cone, must be
nicely adjusted to each other. The first thing to determine is, how much the rack
should advance for every layer or range of roving applied to the bobbin, in order that
the cone may occupy such a place that the strap which regulates the pulley barrel may
be at the proper diameter, and thus fulfil every condition. The extent of this progressive movement of the rack depends upon the greater or less taper of the cone, and
the increase which the diameter of the bobbin receives with every traverse, that is, every
layer of roving laid on.  But care should be taken not to taper the cone too rapidly, especially in the fine roving frame, because in its progress towards the smaller end the strap
would not slide with certainty and ease. We have already shown that the number of
effective turns of the bobbin is inversely, as the diameter of the bobbin; or directly, as
the successive diameters of the different points of the cone.
H. Houldsworth, jun. Esq. has introduced a capital improvement into the bobbin and
fly frame, by his differential or equation-box mechanism, and by his spring fingers, which,
by pressing the soft sliver upon the bobbin, cause at least a double quantity to be wound
upon its barrel. With the description of his patent equation-box, I shall conclude the
description of the bobbin and fly frame.
Fig. 415 represents a portion of a fly frame with Mr. Houldsworth's invention.
a a a are the front drawing rollers, turning upon bearings in the top of the machine,
and worked by a train of toothed wheels, in the way that drawing rollers are usually
actuated.
From  the drawing rollers, the filaments of cotton or other material, b b, are brought
down to, and passed through the arms of the fliers c c, mounted on the tops of the
spindles d d, which spindles also carry the loose bobbins e e. In the ordinary mode of
constructing such machines, the spindles are turned by cords or bands passing from a
rotatory drum round their respective pulleys or whirls f, and the loose bobbins e, turn
with them by the friction of their slight contact to the spindle, as before said; in the
improved machine, however, the movements of the spindles and the bobbins are independent and distinct from each other, being actuated from different sources.
The main shaft of the engine g, turned by a band and rigger A as usual, communicates
motion by a train of wheels h, through  the shaft i, to the drawing rollers at the
reverse end of the machine, and causes them to deliver the filaments to be twisted.




COTTON MANUFACTURE.                                   525
Upon th e main shaft g, is mounted a cylindrical hollow box or drum-pulley, whence
one cord passes to drive the whirls and spindles f and d, and another to drive the
bobbins e.
1  415=                        417
L -I         " 
This cylindrical box pulley is made in two parts, k and 1, and slipped upon the axle with
a toothed wheel m  intervening between them. The box and wheel are shown detached
confined by a fixed collar n, as in the machine shown at fig. 415, they constitute two
distinct pulleys, one being intended to actuate the spindles, and the other the bobbins.
In the web of the wheel m, a small bevel pinion o, is mounted uponwan axle standing
p and q, respectively fixed upon bosses, embracing the shaft in the interior of the boxes pl
and 1. Now  it being remembered that the pinion q, and its box I, are fixed to the shaft
g, and turn with it, if the loose wheel m be independently turned upon the shaft, with a
different velocity, its pinion o, taking into q, will be made to revolve upon its axle, and
to drive the pinion p, and pulley box at, in the same direction as the wheel m; and this
rotatory movement of the box Jk and wheel m, may he faster or slower than the shaft g,
and box 1) according to the velocity with which the wheel m is turned.
Having explained  the  construction  of the  box pulleys k  and 1, which are the peculiar
features of novelty claimed under this patent, their office and advantage will be seen by
describing the general movements of the machine.
The main shaft g, being turned by the band and rigger A, as above said, the train of
seen in the figure) that actuates the whole series of drawing rollers a. Upon the shaft
i there is a sliding pulley r, carrying a band s, which passes down to a tension pulley t,
the surface of the cone u, and causes the cone to revolve by the friction of the band
running against it. The pulley r is progressively slidden along the shaft i, by means of
a rack and weight not shown, but well understood as common in these kind of machines,
and which movement of the pulley is for the purpose of progressively shifting the band
s from  the smaller to the  larger diameter of the cone, in order that  the  speed of its
rotation may gradually dimiish as the  bobbisf y the winding-on of the yarns.
At th    d end of the    aleifth  c i  small pinion v is fixed, which takes into the
teeth of the loose wheel m, and, as the cone turns, drives the wheel m round upon the
shaft g, with a        speed dependant always upon the rapidity of the rotation of the cone.
Now  the box pulley r, being fixed to the main shaft g, turns with one uniform  speed,
and by cords passing from it over guides to the whorls f, drives all the spindles and
fliers, which twist the yarns with one continued uniform velocity; but the box pulley k,




526                         COTTON MANUFACTURE.
being loose upon the shaft, and actuated by the bevel pinions within, as described, is
made to revolve by the rotation of the wheel m, independent of the shaft, and with a
different speed from the pulley box 1; cords passing from this pulley box k, over guides
to small pulleys under the bobbins, communicate the motion, whatever it may be, of the
pulley box k, to the bobbins, and cause them to turn, and to take up or wind the yarn
with a speed derived from this source, independent of, and different from, the speed of
the spindle and flier which twist the yarn.
It will now be perceived, that these parts being all adjusted to accommodate the
taking up movements to the twisting or spinning of any particular quality of yar
intended to be produced, any variations between the velocities of the spinning and
taking up, which another quality of yarn may require, can easily be effected, by merely
changing the pinion v, for one with a different number of teeth, which will cause the
wheel m, and the pulley box k, to drive the bobbins faster or slower, as would be required
in winding-on fine or coarse yarn, the speed of the twisting or spinning  aeing the
same.
The rovings or spongy cords, of greater or less tenuity, made on the bobbin and fly,
or tube roving frame, are either spun immediately into firm cohesive yarn, or receive a
further preparation process in the stretching frame, which is, in fact, merely a mulejenny, without the second draught and second speed, and therefore need not be described
at present, as it will be in its place afterwards.
The finishing machines of a cotton mill, which spin the cohesive yarn, are of two
classes; 1. the water-twist or throstle, in which the twisting and winding are performed
simultaneously upon progressive portions of the roving; and, 2. the mule in which the
thread is drawn out and stretched, with little twist, till a certain length of about 5 feet
is extended, then the torsion is completed, and the finished thread is immediately wound
upon the spindles into double conical coils called cops.
The water-twist frame, so called by its inventor, Sir R. Arkwright, because it was first
driven by water, is now generally superseded by the throstle frame, in which the mechanical spinning fingers, so to speak, are essentially the same, but the mode of communicating the motion of the mill-gearing to them is somewhat different. Fig. 418 exhibits
a vertical section of the throstle. This machine is double, possessing upon each side of
its frame a row of spindles with all their subsidiary parts. The bobbins, filled with
rovings from the bobbin and fly, or the tube frame, are set up in the creel a a, in two
ranges. b, c, d, are the three usual pairs of drawing rollers, through which the yarn
is attenuated to the proper degree of fineness, upon the principles already explained.
At its escape from the front rollers, every thread runs through a guide eyelet e of wire,
which gives it the vertical direction down towards the spindles f, g. The spindles which
perform at once and uninterruptedly the twisting and winding-on of the thread delivered
by the rollers, are usually made of steel, and tempered at their lower ends. They stand
at g in steps, pass at ID through a brass bush or collet which keeps them upright, and
revolve with remarkable speed upon their axes. The bobbins h, destined to take up the
yarn as it is spun, are stuck loosely upon the spindles, and rest independently of the
rotation of the spindles upon the copping beam 1, with a leather washer between. Upon
the top of the spindles an iron-wire fork, called a fly or flier, i, k, is made fast by a
left-hand screw, and has one of its forks turned round at the end into a little ring.
The branch of the flier at f is tubular, to allow the thread to pass through, and to
escape by a little hole at its side, in order to reach the eyelet at the end of that fork.
From this eyelet i, it proceeds directly to the bobbin. By the twirling of the spindle,
the twisting of the portion of thread between the front roller d and the nozzle f is
effected. The winding-on takes place in the following way:-Since the bobbin has no
other connexion with the spindle than that of the thread, it would, but for it, remain
entirely motionless, relatively to the spindle. But the bobbin is pulled after it by the
thread, so that it must follow the rotation of the spindle and fly. When we consider
that the thread is pinched by the front roller d, and is thereby kept fully upon the
stretch, we perceive that the rotation of the bobbin must be the result. Suppose now
the tension to be suspended for an instant, while the rollers d deliver, for example, one
inch of yarn. The inertia or weight of the bobbin, and its friction upon the copping
beam 1, by means of the leather washer, will, under this circumstance, cause the bobbin
to hang back in a state of rest, till the said inch of yarn be wound on by the whirling
of the fly i, and the former tension be restored. The delivery of the yarn by the drawing
rollers, however, does not take place inch after inch, by starts, but at a certain continuous rate; from whence results a continuous retardation or loitering, so to speak, of the
bobbins behind the spindles, just to such an amount that the delivered yarn is wound up
at the same time during the rotation.
This process in spinning is essentially the same as what occurs in the fine bobbin
and fly frame, but is here simplified, as the retardation regulates itself according to
the diameter of the bobbin by the drag of the thread. In the fly frame the employmen.




COTTON MANUFACTURE.                                  527
of this te&an is impossible, because the roving has too little cohesion to bear the strain;
and hence it is necessary to give the bobbins that independent movement of rotation
which so complicates this machine.
The up and down motion of the bobbins along the spindles, which is required for
the equal distribution of the yarn, and must have the same range as the length of the
bobbin barrels, is performed by the following mechanism. Every copping rail, 1, is
made fast to a bar m, and this, which slides in a vertical groove or slot at the end of
the frame, is connected by a rod n, with an equal-armed, moveable lever o. The rod p
carries a weight r, suspended from this lever; another rod, q, connects the great lever o
with a smaller one s, t, upon which a heart-shaped disc or pulley, u, works from below
at t. By the rotation of the disc a, the arm t, being pressed constantly down upon it by
the reaction, the weight r must alternately rise and fall; and thus the copping rail 1 must
obviously move with the bobbins h up and down; the bobbins upon one side of the frame
rising, as those upon the other sink. Strictly cuasidered, this copping motion should
become slower as the winding-on proceeds, as in the fly roving frame; but, on account
of the smallness of the finished thread, this construction, which would render the
machine complicated, is without inconvenience neglected, with the result merely that the
coils of the yarn are successively more sparsely laid on, as the diameter of the bobbin
increases.
The movement of the whole machine proceeds from the shaft of a horizontal drum,
which drives the spindles by means of the endless bands x x. Each spindle is mounted
with a small pulley or wharf, w, at its lower part, and a particular band, which goes
round that wharf or whorl, and the drum y. The bands are not drawn tense, but hang
down in a somewhat slanting direction, being kept distended only by their own weight.
Thus every spindle, when its thread breaks, can readily be stopped alone, by applying a
slight pressure with the hand or knee, the band meanwhile gliding loosely round the whorl.
The velocities of rotation of the three drawing rollers are, according to this arrangement, in the proportion of 1: 12: 8; and as their diameters are the same, namely, one
inch, the elongation of the yarn in spinning is eight-fold. If, for example, the roving
was of the number 43, the yarn would become No. 36. The extension of the thread
may be changed by changing the wheels of the drawing rollers. To perceive the power
of this change, let us put, for example, in the place of the 18-toothed wheel of the back
rollers, a wheel with 16 teeth; we shall find that the elongation will amount, in that
case, only to 71 times, whence the number of the yarn would come out 32 = 7a X 4k.
The extension by the throstle is extremely various: it amounts, in some cases, to only 4
times; at others to 10, 12, or even 15.
The copping motion of the bobbins is produced in consequence of a bevel pinion working in a small bevel wheel upon an upright shaft; while this wheel gives a slow motion
by means of a worm screw to the wheel of the heart-shaped pulley u, fig. 418.
418                         The driving pulley makes about 600
turns in a minute; and as the diameter of
the drum y, fig. 418, is six times the did e l             W a~~~  iri  Q  ameter of the spindle wharves w, it will
-^^fcl. ^l>          give 3600 turns to the spindle in that time.
e:i; T,_   I       r,/,,,,~,X ~~/,,~,.e  If the pulley be driven faster, for example,
l /, / /  /       700 times in a minute, it will increase the
revolutions of the spindles to 4200. The
degree of twist which will be thereby imparted to the yarn, depends, with like speed
7 i g    In l  \       \   /  1 -~l7-  of spindles, upon the rate at which the soft
\'~ II A3 l \ I    / /       illl         yarn is delivered by the drawing-rollers;';I    \\/m fI!  jn  for the quicker this delivery the quicker is
the winding-on, and the less twist goes into
a given length of yarn. If, for example,' 51- v  2  2   w J x   ^-^  ~ 2the front rollers d turn 24 times in a
minute, giving out of course 72 inches of
g^7g  i fllr l^ ~= ^"b&             yarn in this time, upon which the 3600
r~ (Q\~tJ~1"    l revolutions of the spindle are expended,
0         _J ~^   I      there will be 50 twists to every inch of
yarn. By changing the wheel-work of
fig. 418, or by sticking greater or smaller wharves upon the spindles, the proportion between their velocity and that of the drawing rollers, and thence the degree of twist, can
be modified at pleasure.
The number of spindles in a throstle frame 12 feet long is about 60 on each side.
The drawing rollers are coupled together as in the bobbin and fly frame, so that each
row forms one continuous cylinder. There is a complete roller beam on each side
each of the rollers of the front row is pressed bv its top rollers with a weight of ten
34




528                       COTTON MANUFACTURE.
twelve pounds; but those of the middle and back rows bear weights of only one poun.
In the throstles, there is a guide bar which traverses a small way horizontally to the left
and right, in front of the roller beam, to lead the thread along different points of the
rollers, and thus prevent the leather of the top ones from being grooved by its constant
pressure in one line.
For the service of 240 spindles, in two double frames, one young woman and an assistant piecer are sufficient. They mend the broken ends, and replace the empty bobbins
in the creel with full ones, and the full bobbins of the throstle by empty ones. The
average quantity of yarn turned off in a week of 69 hours is about 24 hanks per spindle
of 30's twist. Throstle yarn is of a firm wiry quality, adapted to the warps of fustians
and other strong stuffs, as well as to the manufacture of stockings and sewing thread.
There are many modifications of the throstle system besides the one above described;
the most celebrated of which are Danforth's, called the American throstle, Montgomery's,
and Gore's. I must refer for an account of them to my work entitled " The Cotton Manufacture of Great Britain," where they are minutely described and illustrated with
accurate figures.
Mule-spinning.-~The general principles of the mule have been already stated. This
machine is so named because it is the offspring, so to speak, of two older machines the
jenny and the water-frame. A mule is mounted with from 240 to 1000 spindles, and
pins, of course, as many threads.
Fig. 419 represents the
original jenny of Harends419 withwhorlsgreaves, by which  one
person   was enabled to
its upper jaw a littewynodertospin from 16 to 40 threads
4at once. The soft cords
of rovings wo
D^  J   Jpsble conical cops  upon
i                 sk ewers were placed in
the inclined f
twisng and then winding-on  the  spun  yarn
were set upright in steps
and bushes at A, being
furnished near their lower
its upper jaw a little way, in order to allow a few inches of the soft roving to be
pushed forward upon its
with proper speed by the
right hand of the operais. Whenever one 8tretcd
was thereby  spun, the
home towards  A;  the
wards the water - twiul




COTTON MANUFACTURE.                                     529
frame. The rovings mounted upon bob421              K               bins in the creel A A, have their ends led
through  between the three sets of twin
rollers below  B B, thence down through
the eyelet hooks upon the end of the fliers
of the spindles c, and finally attached to
their bobbins. The spindles being driven
by the band D D upon their lower part, continuously twist and wind the finished yarn
upon the bobbins; constituting the first!   unremitting automatic machine for spinning
which the world ever saw.
Contrast with the above admirable sys--              tem, the primitive cotton wheel of India, as
represented in the annexed figure 421.  By
the aid of mechanical fingers, one Englishman at his mule can turn off daily more
yarn and of far finer quality than 200 of
the most diligent spinsters of Hindostan.
Fig. 422 is a transverse section of the mule, in which its principal parts are shown.
Adz  -a
-The machine consists of two main parts; a fixed one corresponding in some mea.
sure to the water-frame or throstle, and a moveable one corresponding to the jenny.
The first contains in a suitable frame the drawing roller-beam and the chief moving
machinery: the second is called the carriage, in which the remainder of the moving
mechanism and the spindles are mounted.
The frame of the fixed part consists of two upright sides, and two or more intermediate
parallel bearings, upon which the horizontal roller beam a, the basis of the drawing rollers
is supported. b, c, d, are the three ranges of fluted iron rollers; e, f, g, are the upper iron
rollers covered with leather; h, the wooden wiper-rollers covered with flannel, which
being occasionally rubbed with chalk, imparts some of it to the pressure rollers beneath,
s0 as to prevent the cotton filaments adhering to them. The rollers are made through



530                         COTTON MANUFACTURE
out the whole length of the mule in portions containing six flutings, which are coupled
together by squared ends fitted into square holes.
IThe skewers upon which the bobbins containing the rovings from the bobbin and fly
or stretching frame are set up, are seen at a, al, at, arranged in thtee rows in the
creel z. The soft threads unwound from  these bobbins, in their way. to the drawing
rollers, pass first through eyelets in the ends of the wire arms bl, then through the
rings or eyes of the guide bar w, and enter between the back pair of rollers. The
lumber of these bobbins is equal to the number of spindles in the mule, and twice as
great as the number of fluted portions of the rollers; for two threads are assigned to
each portion.
The carriage consists of two cast-iron side pieces, and several cast-iron intermediate
similar pieces, such as f2, which all together are made fast to the planks b2, c2, d2. The
top is covered in with the plank k2. The carriage runs by means of its cast-iron grooved
wheels, upon the cast-iron railway 12, which is fixed level on the floor.
The spindles stand upon the carriage in a frame, which consists of two slant rails xI,
x2, connected by two slender rods y2, and which frame may be set more or less obliquely.
The lower rail carries the brass steps for the points of the spindles bs; upon the upper
rail brass slips are fixed pierced with holes through which the tops of the spindles play.
The spindles are as usual made of steel, perfectly straight, turned truly round, and are
all arranged in one plane.  To each of them a small wooden or cast-iron whorl g2 is
made fast. They are distributed into groups of 24, and the whorls are arranged at
such different heights, that only two of them in each group are upon a level with each
other. A small brass head h2, which every spindle has beneath the upper slant rail of
the frame x2, prevents their sitting down into the step, during  their rotation, or
sliding off their cop of yarn.
c3 are drums, mounted in the carriage in a plane at right angles to the plane in
which the spindles are placed.  At top they have a double groove for a cord to run
in, and the motion which they receive from the great fly wheel, or rim of the mule (not
visible in this view) they impart to the spindles. Such a drum is assigned to every 24
spindles; and therefore a mule of 480 spindles contains 20 drums. In the middle of
the carriage is seen the horizontal pulley k3, furnished with three grooves, which stands
in a line with the drums c3.
The motion is given to the drums c3, upon the right hand half of the carriage, by a
single endless band or cord which proceeds from  the middle groove of the pulley k3.
The rotation of the spindles is produced by a slender cord, of which there are 12 upon
each drum c3; because ev'ery such cord goes round the drum, and also every two wharves
which stand at the same level upon the spindles. It is obvious that the drums, and
consequently the spindles, must continue to revolve as long as the main rim of the mule
is turned, whether the carriage be at rest or in motion upon its railway.
If we suppose the carriage to be run in to its standing point, or to be pushed home
to the spot from which it starts in spinning, its back plank d2 will strike the post q3
upon the fixed frame, and the points of the spindles will be close in front of the roller
beam.  The rollers now begin to turn and to deliver threads, which receive immediately
a portion of their twist from the spindles; the carriage retires from the roller beam
with somewhat greater speed than the surface speed of the front rollers, whereby the
threads receive a certain degree of stretching, which affects most their thicker and less
twisted portions, and thereby contributes greatly to the levelness of the yarn. When
the carriage has run out to the end of its course, or has completed a stretch, the fluted
rollers suddenly cease to revolve (and sometimes even beforehand, when a second
stretch is to be made), but the spindles continue to whirl till the fully extended threads
have received the proper second or after-twist. Then the carriage must be put up, or run
back towards the rollers, and the threads must be wound upon the spindles.
This is the order of movements which belong to the mule. It has been shown how
the rotation of the spindles is produced.
For winding-on the yarn the carriage has a peculiar apparatus, which we shall now
describe. In front of it, through the whole extent to the right hand as well as the left,
a slender iron rod, d5, runs horizontally along, in a line somewhat higher than the middle of the copping portion of the spindles, and is supported by several props, such as
e6. Upon each end of the two rods, ds, there is an arm, gI; and betwixt these arms an
iron wire, called the copping wire, f5, is stretched, parallel with the rod ds.  For the
support of this wire, there arc several slender bent arms hs extended from the rod Cit
at several points betwixt the straight arms g5. The rod d5 has, besides, a wooden
handle at the place opposite to where the spinner stands, by which it can be readily
grasped. This movement is applied at the left division of the machine, and it is communicated to the right by an apparatus which resembles a crane's bill. The two arms,
gs, in the middle of the machine, project over the rods ds, and are connected by hinges
with two vertical rods ji, which hang together downwards in like manner with two arms
15, proceeding from a horizontal axis k5.




COTTON MANUFACTURE.                                         531
By means of that apparatus the yarn is wound upon the spindles in the following
Imanner.  As long as the stretching and twisting go on, the threads form an obtuse angle
with the spindles, and thereby slide continually over their smooth rounded tips during
their revolution, without the possibility of coiling upon them. When, however, the spinning process is completed, the spinner seizes the carriage with his left hand and pushes
it back towards the roller beam, while with his right hand he turns round the handle of
the rim or fly wheel, and consequently the spindles. At the same time, by means of
the handle upon the rod d5, he moves the copping-wiref5, so that it presses down all the
threads at once, and places them in a direction nearly perpendicular to the spindles;
as shown by the dotted line ys. That this movement of the copping wire, however, may
take place without injury to the yarn, it is necessary to turn the rim beforehand a little
in the opposite direction, so that the threads may get uncoiled from the upper part of the
spindles, and become slack; an operation called in technical language the backing off.
The range upon which the threads should be wound, in order to form a conical cop upon
the spindle, is hit by depressing the copping wire to various angles, nicely graduated by
an experienced eye.  This faller wire alone is not, however, sufficient for the purpose of
winding-on a seemly cop, as there are always some loose threads which it cannot reach
without breaking others.
Another wire called the counter-faller 15, must be applied under the threads.  It may
be raised to an elevation limited by the angular piece p5; and is counterpoised by a very
light weight m5, applied through the bent lever no, which turns upon the fulcrum o5.
This wire, which applies but a gentle pressure, gives tension to all the threads, and
brings them regularly into the height and range of the faller fs. This wire must be
raised once more, whenever the carriage approaches the roller beam.  At this instas  a
new stretch commences; the rollers beian again to revolve, and the carriage resumes its
former course.  These motions are performed by the automatic machinery.
There is a little eccentric pulley mechanism for moving the guide beam to and fro
with the soft yarns, as they enter between the back rollers. On the right hand end of
the back roller shaft, a worm screw is formed which works into the oblique teeth of a
pinion attached to the end of the guide beam, in which there is a series of holes for the
passage of the threads, two threads being assigned to each fluted roller.  In the flat disc
of the pinion, an eccentric pin stands up which takes into the jointed lever upon the end
of the guide beam, and, as it revolves, pushes that beam  alternately to the left and the
right by a space equal to its eccentricity.  This motion is exceedingly slow, since for
each revolution of the back roller, the pinion advances only by one tooth out of the 33
which are cut in its circumference.
After counting the number of teeth in the different wheels and pinions of the mule, or
measuring their relative diameters, it is easy to compute the extension and twist of the
yarns; and when the last fineness is given to ascertain their marketable value. Let the
ratio of speed between the three drawing rollers be I: 1-3-: 7^; and the diameter of the
back and middle roller three quarters of an inch: that of the front roller one inch; in
which case the drawing is thereby increased 1 times, and 7' X lI = 10.  If the rovings
in the creel bobbins have been No. 4, the yarn, after passing through the rollers, will be
No. 40.  By altering the change pinion (not visible in this view) the fineness may be
changed within certain limits, by altering the relative speed of the rollers. For one revolution of the great rim or fly wheel of the mule, the front roller makes about 6 tenths of
a turn, and delivers therefore 22'6 lines or l2ths of an inch of yarn, which, in consequence of the tenfold draught through the rollers, corresponds to 2*26 lines of roving fed
in at the back rollers. The spindles or their whorls make about 66 revolutions for one
turn of the rim.  The pulleys or grooved wheels on which the carriage runs, perform
0*107 part of a turn while the rim makes one revolution, and move the carriage 24*1
lines upon its rails, the wheels being 6 inches in diameter.
The 22-6 lines of soft yarn delivered by the front rollers will be stretched 1 lines
by the carriage advancing 24-1 lines in the same time. Let the length of the railway,
or of each stretch, be 5 feet, the carriage will complete its course after 30 revolutions of
the rim wheel, and the 5 feet length of yarn (of which 561 inches issue from the drawing
rollers, and 34 inches proceed from  the stretching) is, by the simultaneous whirling of
the spindles, twisted 1980 times, being at the rate of 33 twists for every inch. The
second twist, which the threads receive after the carriage has come to repose, is regulated according to the quality of the cotton wool, and the purpose for which the yarn is
spun.  For warp yarn of No. 40 or 50, for example, 6 or 8 turns of the rim wheel, that
is, from  396 to 528 whirls of the spindles for the whole stretch, therefore from 7 to 9
twists per inch will be sufficient. The finished yarn thus receives from 40 to 42 twists
per inch.
One spinner attends to two mules, which face each other, so that he needs merely
turn round in the spot where he stands, to find himself in the proper position for the
other mule. For this reason the rim wheel and handle, by which he operates, are not




532                    - COTTON MANUFACTURE.
placed in the middle of the length of the machine, but about two fifths of the spindles
are to the righ. hand and three fifths to the left; the rim wheel being towards his righ
hand. The carriage of the one mule is in the act of going out and spinning, while the
of the other is finishing its twist, and being put up by the spinner.
The quantity of yarn manufactured by a mule in a given time, depends direct?
upon the number of the spindles, and upon the time taken to complete every stretch ox
the carriage. Many circumstances have an indirect influence upon that quantity, and
particularly the degree of skill possessed by the spinner. The better the machine, the
steadier and softer all its parts revolve, the better and more abundant is its production.
When the toothed wheels do not work truly into their pinions, when the spindles shake
in their bushes, or are not accurately made, many threads break, and the work is
much injured and retarded. The better the staple of the cotton wool, and the more
careful has been its preparation in the carding, drawing, and roving processes, the more
easy and excellent the spinning will become: warmth, dryness, cold, and moisture
have great influence on the ductility, so to speak, of cotton. A temperature of 650 F.,
with an atmosphere not too arid, is found most suitable to the operations of a spinning
mill. The finer the yarn, the slower is the spinning. For numbers from 20 to 36
from 2 to 3 stretches of warp may be made in a minute, and nearly 3 stretches of weft;
for numbers above 50 up to 100, about 2 stretches; and for numbers from 100 to 150,
one stretch in the minute. Still finer yarns are spun more slowly, which is not
wonderful, since, in the fine spinning mills of England, the mules usually contain
upwards of 500 spindles each, in order that one operative may manage a great number
of them, and thereby earn such high wages as shall fully remunerate his assiduity
and skill.
In spinning fine numbers, the second speed is given before the carriage is run out to
the end of its railway; during which course of about six inches, it is made to move very
slowly. This is called the second stretch, and is of use in making the yarn level by
drawing down the thicker parts of it, which take on the twist less readily than the
thinner, and therefore remain softer and more extensible. The stretch may therefore
be divided into three stages. The carriage first moves steadily out for about 4 feet,
while the drawing rollers and spindles are in full play; now the rollers stop, but the
spindles go on whirling with accelerated speed, and the carriage advances slowly about
6 inches more; then it also comes to rest, while the spindles continue to revolve for a
little longer, to give the final degree of twist. The acceleration of the spindles in the
second and third stages, which has no other object but to save time, is effected by a
mechanism called the counter, which shifts the driving band, at the proper time, upon the
loose pulley, and, moreover, a second band, which had, till now, lain upon its loose pulley, upon a small driving pulley of the rim-shaft. At length, both bands are shifted upon
their loose pulleys, and the mule comes to a state of quiescence.
The SELF-ACTOR MULE, or the IRON MAN, as it has been called in Lancashire, is an
invention to which the combinations among the operative spinners obliged the masters
to have recourse. It now  spins good yarn up to 40s with great uniformity ana
promptitude, and requires only juvenile hands to conduct it, to piece the broken yarns,
to replace the bobbins of rovings in the creel, and to remove the finished cops from the
spindles.
The self-acting mules were first constructed, I believe, by Messrs. Eaton, formerly of
Manchester, who mounted ten or twelve of them in that town, four at Wiln, in Derbyshire, and a few in France. From their great complexity and small productiveness, the
whole were soon relinquished, except those at Wiln. M. de Jong obtained two patents
for self-acting mules, and put twelve of them in operation in a mill at Warrington, of
which he was part proprietor; but with an unsuccessful result. I saw the debris of one
of M. de Jong's self-actors in the factory of M. Nicholas Schlumberger, at Guebwiler,
in Alsace, where the machine had been worked for three months, without advantage,
under the care of the inventor, who is a native of that valley.
The first approximation to a successful accomplishment of the objects in view, was an
invention of a self-acting mule, by Mr. Roberts, of Manchester; one of the principal
points of which was the mode of governing the winding-on of the yarn into the form of
a cop; the entire novelty and great ingenuity of which invention was universally admitted, and proved the main step to the final accomplishment of what had so long been a
desideratum. For that invention a patent was obtained in 1825, and several headstocks
upon the principle were made, which are still working successfully.
In 1830, Mr. Roberts obtained a patent for the invention of certain improvements;
and by a combination of both his inventions, he produced a self-acting mule, which is
generally admitted to have exceeded the most sanguine expectations, and which has been
extensively adopted. There are probably, at present, upwards of half a million of spin.
dles of Messrs. Sharp, Roberts, and Co.'s construction, at work in the United Kingdom,
and giving great satisfaction to their possessors. The advantages of these self-actors
are the following:



COTTON MANUFACTURE.                                      533
The saving of a spinnerj's wages Lto each pair of mules, piecers only being required,
as one overlooker is sufficient to manage six or eight pairs of mules. The production
of a greater quantity of yarn, in the ratio of from 15 to 20 per cent. The yarn possesses a more uniform  degree of twist, and is not liable to be strained during the spinning, or in winding-on, to form the cop; consequently, fewer threads are broken in these
processes, and the yarn, from having fewer piecings, is more regular.
The cops are made firmer, of better shape, and with undeviating uniformity; and, from
being more regularly and firmly wound, contain from one third to one half more yarn
than cops of equal bulk wound by hand,; they are consequently less liable to injury in
packing or in carriage, and the expense of packages and freight (when charged by
measurement) is considerably reduced.
From  the cops being more regularly and firmly wound, combined with their superior
formation, the yarn intended for warps less frequently breaks in winding or reeling, consequently there is a considerable saving of waste in those processes.
Secondly, the advantages connected with weaving.
The cops being more regularly and firmly wound, the yarn, when used as weft, seldom breaks in weaving; and as the cops also contain a greater quantity of weft, there
are fewer bottoms, consequently there is a very material saving of waste in the process
of weaving.
From  those combined circumstances, the quality of the cloth is improved, by being
more free from  defects caused by the breakage of the warp or weft, as well as the selvages being more regular.
The looms can also be worked at greater speed; and, from  there being fewer stoppages, a greater quantity of cloth may be produced.
That the advantages thus enumerated, as derivable from the use of self-acting mules,
have not been overrated, but, in many instances, have been considerably exceeded, I
have, by extensive personal inquiry and -observation, had ample opportunity of ascertaining.
Statement of the quantity of yarn produced on Messrs. Sharp, Roberts, and Co.'s selfacting mules, in twelve working hours, including the usual stoppages connected with
spinning, estimated on the average of upwards of twenty mills:
No. of Yarn.         No. of Twist.                  No. of Weft.
16    -    -    44 hanks    -    -    44 hanks per spindle.
24.-    -    4     -~    -             4A 
32    -    -    4 -             -    -    4 
40    -    -    31 -            -    -    4           ~
Of the intermediate numbers the quantities are proportionate.
Results of trials made by Messrs. Sharp, Roberts, and Co., at various mills, to ascertain the comparative power required to work self-acting mules, in reference to handmules, during the spinning, up to the period of backing off.
Particulars of the trials referred to, and their results:~
At what Mill, and the Description of  No. and kind   ~5  I g           1    Total Force
Mule.                 of Yarn.    j'^      Employed in
~.0      1^^         ~5^     Spinning.
Messrs. Birley and Kirk.        Weft.       Ins.                 lbs.       lbs.
Self-acting mule, 360 sps. -- 30 to 34          12        58        30          5463
Hand-mule, 180 sps. -             ditto       15        36        26    X2=7366
Messrs. Leech and Vandrey.       Twist.
f Self-acting mule, 324 sps. -      36          12        70        36          7912
Hand-mules, 324 sps.    -  -        36          29        58        161         7273
Messrs. Duckworth 4 Co.         Twist.
Self-acting mule, 324 sps. -  -     40          12        62        33          6421
Hand-mule, 324 sps. -  -  -         40          47        36        154         6646
The mode adopted to make the trials was as follows, viz.:
A force, indicated by weight in pounds, was applied to the strap working upon the
* The trial was disadvantageous for the hand-mules, being two for 360 spindles.
1 The trial was disadvantageous for the self-acting mules, being driven by a very short and light verticel
atran, the hand-mul% having a long horizontal strap.




534                                COURT PLASTER.
driving-pulley of the respective mules, sufficient to maintain the motion of the mule
whilst spinning, which weight, being multiplied by the length of strap delivered by each
revolution of the pulley, and again by the number of revolutions made by the pulley
whilst spinning, gave the total force in pounds, applied to the respective mules whilst
spinning; for instance, suppose a mule to be driven by a pulley 12 inches diameter (3*14
feet in circumference), such pulley making 58 revolutions during the spinning as above,
and that it required a force equal to 30 lbs. weight to maintain the motion of the mule,
then 30 lbs. X 3.14 feet circumference of pulley X 58 revolutions in spinning = 5,463 lbs.
of force employed during the spinning, to the period of backing off.
Mr. James Smith, of Deanstone cotton works in Scotland, obtained a patent for the
invention of a self-actor, in February, 1834. He does not perform the backing-off by
reversing the rotation of the spindle, as in common mules, or as in Mr. Roberts', but by
elevating the counterfaller wire, which, being below  the ends of the yarn or thread,
along the whole extent of the carriage, thereby pulls off or strips the spiral coils at the
point of the spindle, instead of unwinding them, as of old.  This movement he considers to be of great importance towards simplifying the machinery for rendering the
mule self-acting; and the particular way in which he brings the stripper into action is
no doubt ingenious, but it has been supposed by many to strain the yarn. He claims as
his invention the application and adaptation of a mangle wheel or mangle rack to the
mule, for effecting certain successive movements, either separately or in conjunction; he
claims that arrangement of the carriages of a pair of mules, by which the stretch is
caused to take place over part of the same ground by both carriages, and thereby the
space required for the working of the pair of mules is greatly diminished; and he claims
the application of a weight, spring, or friction, for balancing the tension of the ends of
the threads.
A patent was granted, in April, 1835, to Mr. Joseph Whitworth, engineer in Man
chester, for some ingenious modifications of  thhe mule, subservient to
automatic purposes.  His machinery is designed, first, to traverse the carriage in and
out, by means of screws or worm-shafts, which are placed so as to keep the carriage
parallel to the drawing rollers, and prevent the necessity of squaring bands, hitherto
universally employed: secondly, his invention consists in an improved manner of working the drums of a self-acting mule by gear; thirdly, in the means of effecting the
backing off; fourthly, in the mechanism  for working  the. faller-wire in building
the cops; and fifthly, in  the apparatus for effecting the winding of the yarns upon
the spindles. As regards the throstles and doubling, frames, his improvements apply,
first, to the peculiar method of constructing and adapting the flyers and spindles, and
producing the drag; and, secondly, to the arrangement of the other parts of the doubling
machinery.
See  LACE-MAKING, SINGEING, TEXTILE  FABRIC, THREAD  MANUFACTURE, and
WEAVING.
We extract the following from the Circular of Hermann Cox and Co., dated 19th
July, 1852.
Export from  1st January to 5th Jfay, as follows:
1852.              1851.
Exportations of Yarn  -          -       -    60,399,189 lbs.    42,630,812 lbs.
Manufactured Goods  -   509,350,295 yds.  493,915,720 yds.
consequently a considerable surplus on both over last year; the official return till 5th
June, just out, again shows an increase, viz.:
1852.              1851.
Exportations of Yarn  -          -       -    63,418,111 lbs.    54,634,370 lbs.
Manufactured Goods  -   649,341,927 yds.. 630,581,674 yds.
The following is a return of exports from Hull, from 1st January till 30th June:
Manufactured
Twist.            Other Yarn.       Cotton Goods.     Raw Cotton.
1852.    -  33,182 bales.    12,115 bales.    11,536 bales.    65,186 bales.
1851.    -  31,601,            9,634,         11,347,,        33,054,




COTTON.                                                 535
AMERICA.
1351.                  1852.
Stock 1st September in the Ports  -                  -       148,000 bales.          128,000 bales.
Receipts till 22d June            -        -         -     2,250,000,           2,936,0*
2,398,000,          3,064,000
Shipments to Europe till 22d June                    -     1,758,000               2,263,000
640,000,            801,000
Deduct Stock 22d June             -        -         -       304,000,             201,000
American Consumption for 1851    -                   -       336,000 bales.          600,000 bales.
Last year the American spinners took from  the above-named last date till 1st Sept.,
137,000 bales.
FRANCE.
Notwithstanding 96,348 bales larger supply, the stock is still 12,293 bales smaller
than last year.
1851.
Stock,        Imports         Total.      Deduct Stock,        Leaves for
1st January.   to 1st July.      Total.         1st July.       Consumption.
Havrre          -       39,825        210,140         249,965          78,377         171,588 bales.
Marseilles    -         15,095          26,124         41,219           17,479         23,740
54,920       236,264         291,184           95,856        195,328 bales.
or'7,512 bales per week.
1852.
Havre           -       22,767        297,514        320,281            75,271       245,010 bales.
Marseilles    -           7,661         35,098         42,759            8,292         34,467,,
30,428       332,612        363,040            83,563       279,477 bales.
or 10,749 bales per week this year against 7,512 bales in the same period last year, or
7,326 bales average of 1851.
REMAINING CONTINENT.
We find the consumption of the first six months of 1851 and 1852 to be as follows:
i851.
Stock,       Direct       Total      Deduct Stock,    Leaves for
lst January.    Imports.        a          lst July.    Consumption.
Hamburg          -      -     -       6,300        33,730       40,030          6,730       333.00 bales.
Bremen                                   8 -  -  19  21,191     21,280         12,133        9,147,
Petersburg and Sweden         -       5,575         7,000       12.575          4,000        8,575
Amsterdam        -      -     -       1,362         4,888        6,250          2,698       3,552
Rotterdam        -      -     -         467         1,912        2,379          1,333        1,046
Antwerp  -..     -       4,578        25,173       29,751          8,500      21,251t
Trieste    -.      -     -      22,596        79.582      102,178         49,004       53,174
Spain, Portugal, and Italy    -       6,000        68,000       74,000          8,000      66,000
46,967      241,476      288,443         92,398      196,045 bales.
Add Export from England    -   95,300
Total...     -  291,345 bales.
or 11,205 bales per week.




536                                     COTTON.
1852.
Stock,      Direct      Total.     Deduct Stock    Leaves for
1st January.   Imports.                 l st July.  Consumption.
Hamburg -       -                   5,900      65,929       71,829        17,990      53,839 bales.
Bremen   -      -                   1,664      16,303       17,967         3,304      14.663
Petersburg and Sweden       -       2,000      23,000       25,000         5,000      20,000
Amsterdam       -     -     -       2,101       6,890        8.991         4,157       4,834
Rotterdam       -     -               928      11,581       12,509         8,350       4,159
Antwerp  -      -     -     -       1,196      54,282       55,473        22,000      33,478,
Trieste   -     -     -     -      25,914      72,392       98,306        29,857      68,449
Spain, Portugal, and Italy    -     4,219      97,000      101,219         9,000      92,219
347,377                    99,658     291,641 bales.
Export from England   -    147,000,
Total      -      -     -   438,641 bales.
or 16,870 bales per week, against 11,205 bales in the first half of last year, or against
11,664 bales average of the whole period of 1851.
The total consumption of all countries according to the preceding statements is as
follows:
England   -          -        -        -   39,683 bales, against 29,851 bales, 1851.
America   -           -       -        -   11,538,,         6,461
France       -        -       -        -   10,749,         7,512,
Remaining Continent           -        -   16,870,,       11,205
18,840                   55,029 bales per week.
To which we, however, consider it advisable to add, that this increase in the consumption for the first half year (viz., 23,811 bales per week) should not be taken as any
criterion against the consumption of the same period last year, when it was so much
restricted through the drooping state of prices, and when spinners were induced to use
up their whole stocks.  We affirm therefore that this increase of consumption should
only be considered in comparison with the average consumption of the whole of last
year, viz.:
In England    -           -        -        -       -        -   31,973 bales in 1851.
America.        -.-                                -    9,479,,
France        -        -        -       -             -         7,326         it
Remaining Continent             -       -        -        -   11,664          P
60,442 bales per week.
Against   -         -   78,840,  this year.
We have thus far represented the consumption-the extraordinary increase of the
same in all countries, without exception, proves how cheap food, with peace, tends to
enlarge consumption; and it remains therefore only to be hoped that the favorable
prospects for the ensuing crop be not blighted.. It is clearly evident that present prices
do not affect the consumption; for the planters they are sufficiently remunerative to
induce an extension of the culture, and so provide for the world such stocks as would
prevent any ill effect arising from a future small or bad crop.
It shall now  be our endeavor to point out the position of stocks in all Europe
on the 31st December this year, supposing the consumption to continue at its present
rate:
The American crop  -                     -        -        -        -  3,000,000 bales.
Of which were received by the last list of 22d June                 -  2,936,329,
Remain to receive   -            -       -        -        -        -     63,671
Stocks in the ports and on shipboard 22d June              -        -    201,773 
265,444
The average stock left in the ports during the last six years
was about 150,000 bales, but we will take for this year
only       -       -        -        -        -       -        -    100,000
Would leave for all Europe                    -            -        -    165,444,
Suppose American spinners take nothing more from 22d June
till 1st September.




COTTON.                                         537
Brought forward       -      -    165,444 bales.
From America, floating to England   -          -      -       -    150,000,,..,,,   to other countries    -    -       -    100,000,,,,  India,,   to England   -         -       -       -    100,000,,
to receive from other countries till 31st December, equal to last year.
England      - from Egypt, Brazils, and Sundries   -  83,000
France       -,,  Egypt, Brazils, and Smyrna    -  26,000
Trieste, and
other Ports,,,  Egypt, Brazils, and Smyrna    -  40,000
--        149,000
Total supply for Europe       -       -       -       -       -    664,444,,
Add stocks in all European ports on 1st July              -   -    900,421,,
Total       -  1,564,865,,
Quantity of American, next crop, to be received in England          150,000,,
Ditto in Continental ports    -        -       -      -       -      75,000,,
1,789,685 bales.
Therefore, if the present consumption of Europe were to continue to the end of the
year, the stock would be only 39,084 in all European ports, not enough for one week.
Table of Imaginary Stocks in Great Britain on 31st December, 1852.
The American crop    -         -       -       -      -           3,000,000 bales.
Of which were received by the last list of 22d June  -        -  2,936,329,,
Remain to receive       -      -       -       -       -      -      63,671,,
Stocks in the ports and on shipboard 22d June          -      -    201,773,
265,444
The average stock left in the ports during the last six years was
about 150,000 bales, but we will take for this year only       100,000,,
165,444,,
We will suppose American spinners to take nothing more till
1st September, and supposing the 32 ships loading for
France, and 125 for other ports take only         -      -      65,444,,
Would leave for Great Britain                  -.       -    100,000,,
As the stocks in the interior markets are only one third of those
of last year, shipments after August must fall very short;
but supposing England to receive from 1st September till
31st December   -         -                                    150,000,,
Now floating to England        -       -       -      -       -    150,000,,
From India we will suppose   -         -       -       -      -    100,000,,
From Brazils, Egypt, &c., like last year in the same period  -       83,000,,
Total to receive  -    583,000,
Add stock 1st July in Great Britain  -         -       -      -    717,200,,
1,300,200 bales
Export
until 1st July last year was 95,300 bales, for the same period this
year 147,000 bales.  We have shown that the Continental stocks,
notwithstanding so much larger receipts, are only near on a par
with those of last year; this leads us to suppose that our market
must later assist those by large exports, but we will take such only
equal to last year, viz.    -                      -.                   121,000 bales.
Leaves      -       -       -      -       -  1,179,200,
Whereas the present rate of consumption requires till 31st Dec.  -  1,031,758 bales.
This would leave us a stock at this year's end of all descriptions of 147,442 bales only,
not sufficient for the consumption of four weeks; supposing, however, the consumption
to fall to only 33,000 bales per week, the remaining stock would be only 321,000 bales,
against 494,000 bales at the end of last year.




IMPORT AND STOCK OF COTTON IN LIVERPOOL —31st JULY, 1852.                                                                                                                                      C
Tota
Description.              Import in                                 Dlvr.EsiaeStc..          Pie.                                             Import,                                      oa
July.InRy                                                           Mnh,          1tJuy             stJl                                                                                                                      t
In~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~3s Julry, Ins Juliy,                                                                                                                       Imo
I~ ~ ~ ~ ~~~.Inthul,   7Months,                          31tJl,           3s       uy3s   uy               1tJlI                   Whence.                7 Months,    71 lMonths,             182
~1852.                    1851.            185`2.           1851.            185'2.          1851.'     185'2.    ]      1851.                                           18]                 81
Sea Island]18.]
Stie  do. —aa 3(-                                                                                                                                            8   a         [2  S.......h ~                       9' —— ~-886   [ 112,442    -     -11967
Uplained                           13419           14[4              5                                                                               5y/,  14         4 4~/2   9 /~2     Charleston      -'      160,095          135,266          1630
Moblen.                                                                )  3,!9 1 892 1 7133  1,036,596  767,042      513,200          540,000       4y/,   6~   [  3'~   6       [Northern Ports   -            -      1176             1390             1712
Newoble ~n |                                                                                                                                        4Y,.  6~,   [  3Y/    5Y/2  [New Orleans, &c.               -   [879,009             66[6              8,1
New  Orleans J                                                      4~    7~4~  ~  3~/~   "I~}~  /  Pernambuco'    -                                                        - ~  41,750  ]            97,086   I       59,486~~4 7 Y  3 4    7 Perambco    -  1,10  9,08  51,48
Aracati and Ceara                                                                                  14,100   ~ ~ ~~~~~ ~~                ~~~~~~~~6~  7/4 [,  6  7/z Y2    Bahia  - - -] 18,789   ]     11,51'2   [      26,614
Aracati  and Ceara ~   9,0, 2   5,149   6,089  40,170            39,316           13,90       0                 6      7x       53/~4    7    Mara h           a      m              20 979           93,161   ]  99,7570aanham  0,27923,16129,57
Bahia and Muceio                     6,345            2,745           9,528           20,019q          18,722            8,800          10,700       6      7         6Y               euin~                                                                   74
Alaranbam                 ~~~5,281    I     3,281            3,204          26,509           20,531           20,900           3,0 
Demerara  161     164               35              777              258                              150    ~ ~       ~~ ~ ~~~~~~~~51/    6  4 ~4    5.~   ] West Indies, &c,  -      [,.7           2,199   [       6,8?9
Demerara  - -  -   1 ~ ~   1 6 4           3 5            7 7 7            ~5    8           5 0            150    5~/'~  1'2      |  5~/'~2   6a/~  /  Egypt -' - - 12/    93,5Egypt5993              4     5,045707 9     62,34
West India, &c.             ~          -985           1,085             5`29           4,501            2,106            5,300           1,000       51ff. 9        4, 5~ Boby -2700                                                     907               593
Egyptian~~~ -                  686             844        0,13           F,089           41,759            330             3500           Y   12           4    9       Mars -                                    -    [       4,595            5,980
Surat and Madras  ~         2,124~         16,1'24          13,39)7         109,580         115,77'2          31,500           79,800       3      4,/'/    9 YZ   4.~4    Calcutta-701701,0
Bengal... 100                                100'      944            1,200              100              50(      3 Y    4Y2',   4 Y 1
Total   -      -       -      185,729      1,~6,029             191,138        1,299,1S5 —        999,106 —--     645,050          715,750          -         /                            --                      1,57,0,505 |     1,260,576   [1,749,8
The sales duiring, the month of July amounted to 2T7,260 bales, of which 109,420 were taken as taken on speculation and for export, consisting of 93,510 American, 4.430 Pernambuco, 1,170
Bahiia, 20AMaranha~m, 3,80( Egy~ptiani, and6,490 EastlIndlia. The actual exp~ort wasl15,000Amierican, 1,6(t0 Brazil, andl1,500 Surat; and fi'om 1st ofJanuary to 31stJuly, ]06,300 American,
7,000 Brazil, 200 West India, 300 Egyptian, and 28,600 Surat, &c.  Prices advanced du'inthmoh~.pel.
IMPORT, DELIVERY, AND STOCK OF COTTON, IN GREAT BRITAIN,iFIRST SEVEN MONqTHS, 1851 AND 1852.
1851.                                                                                                        1852.
American.            Brazil.      W~est Indies.   Egyptian.    East India.                Total.             American.            Brazil.    West Indies.   Egyptian.    East India.                   Total.
Stoc, 1t Jauar    -            -          9~77,710           6 8, 65 0         1,510          34,870    ~      143~,38 0          5'21,120              245,810             49,520    ~     4,310 7O2,910                    17',05             4~94,600
Import, 7   months  - ~            ~~~~~~~1,f}91,501    61,-,59           3, 418          45,539           148,416          1,356,633             1,363,80 809 5 507                             9,     3             69 4           1,59'2,469
1,370(.211         13~ 09,4)~ —  4928          80,409           991,79 —--— 6 "    1,877,753                                                                                    9,609.1  3,4 5    2,01 87,06 ~~9,4
Taken for   export - -          ~      ~~~~~~~83,500  6, 600                 -   -         2e0            46,900            137,300               106',850             71,000           200               300           53.950            168,300
12267113,809                4,9'28          80,10 ot          44,8196         1,7,40,453            1,502.769           123,455           9,117          118,344          165,084           1,918,769
Estimated stock, 31st July -           -          5,0058,',~00                        2,000           37,~00           136,550            809,150               540;000(            43,600          4,000            54,700           72,050            7147350
Taken for consumption                             71971             65,o0j'2,9'28          4'2,309 -- - 108,346                938,303               962,769            79,855           5,117            63,644           93,034            2041
Or p e r      w    e     e k         ~~~~~~ ~ ~~~~~~22,7'27  2,143          96,953,572                         30,933                31,739             2,633               192,0983,6
Total import, 1851  -          -     1,      3'i97,112    "   10'~,670...8,476         63,83 3          32(;,474 —--     1,904,565
Total export, 1851  -          -                  151,950            12,0()0           9200              900           103,450            268,500
Weekly consumption, 1851 -? 4,463                                     2,2'27            105            1,440             3,738             31,973
Import last 5 monthis 1851 -                      299,611      1    46,911            5,058           18,294      1    178,058            547,932




COTTON REPORT OF HERMANN COX & CO., IN LIVERPOOL AND LONDON, DATED AuGUtrsT 6th, 1852.
Sales.                  Sorts.                   ProsentPriee.                          Supply.                     Export.            Consumption.             On Hand.
From Jan. ItoAug.6.                                                                       FromJan 1. ug.6.   FromJan.l.toAug.6.  From Liverpool alone,    Ou August6.    Jan. 1.
This             ~                             Ord.  Goo   Mid.  Good  Fair.  Good  Tlis Week.                       -          ~                     ~
Week.                                           Go.Ord Mi.  Mlid.                Fair.
1812.     1851.                                                                           18tS.      1851.      1652.      1651.      1655.     1851.    1852.    1851.    1852.
250    20,210    17,260  Sea Island         15    16 1-2 18    19    20    21          11,772    487743    42070 
10,690   404,940     29,650  Georgia -    -5           5 1-8 5 3.8 5 5-8 6       6 1-4                                    106788      5766   94770  715600  584,000  524,800 236,120
6010   290,039   146,270  Mobile  -    -            5 3-16 5 7-16511-16 6         1-4    3743          7           78                                             
25,300   727,240   389,060  New Orleans -  5 1-8 5 1-4 5 1-2 5 3-4 6 3-87,       850        63,
2,800    55,770    85,830  Pernam.&c. -  6 1-2 6 5-8 6 8-4 6 7-81 7             7 1-4    1,503      42,541     28,078                                                               12,320^
420    25,520    20,720  Bahia & Maceio  61-4 61-2 65-8 63-4 7                7 1-8     2,151        18,775  11,435       76         5,211   144,400  112,140  42,890   55,350  2,10 0
1,820    27,580    26,180  Maranham            6 1-4 6 1-2 6 5-8 6 3-4 6 7-8 7             - -    20,217       23,161                                                                9,8 810
5,980    87,740    47,950  Egyptische          5 8-4 6      6 1-2, 6 3-4 7      7 1-2     7117    100,516      46,676                                                               13,0
8,580   169,930   183,910  Surat --                         4 1-8 4 1-4 4 3-8, 4 1-2                                                                              5627,0992102,768
~,~,o.~~  ~~~~         -r -:                      I              -:T9          102,: ~:6~:
-       1,770     5,690  Madras -           -4 -4 1-8 4 1-4:  4 38                                                   } 281907      21,269    84,040   94,700   29,180   76,650      340
0       1,300     1,120  Bengal  -          8 1-2  3 5-8  3 3-4  8 7-8 4     4 1-2          -       704      1 700                             5        8                           9
670      5,240     8,880  Diverse -        -        - -          -      -      -      -     4      4,869       8,80__                                                        3____
3,386                            5,280    3,1      8,350__  1,2      4
57,060 1,817,270  1,156,970- -- -- --                                                     55,320  1,568,157  1,288,756    142,961      84,046 1,182,490  925,610 666,230  693,280 423,780 T
3,888_0...0 ~~Weekly Average    38,145   29,859 
OFFICIAL LIST FROM AMERICA.
NEW YORK, JULY 14, 1852.                                                                          NEW YORK, JULY 21, 1852.
In Vessels to                                                                                     In Vessels to
Exported.        ~          ~~On Hand.                                                            Exported. -~~        ~~On Hand.
England.   France.   North Europe.  Overland.    Total.                                           England.   France.   North Europe.  Overland.    Total.
1852    2,972,024   1,588,637   414,479      164,883      170,370  2,337,869      155,189         1852    2,977,884   1,607,416    417,555     164,383      174,476  2,363,830      127,834
1851    2,286,977   1,301,747    290,597     116,047      128,782  1,837,173      235,549         1851   2,296,126   1,322,340    290,683      117,193      133,032  1,863,248      204,613
~ ~    ~               ~            ~           ~ ~_______                                                                                                             - 2    4,  - ~. ~. ~. ~. ~6~9
685,047     286,890    123,882 1    48,836       41,588    500,696       80,860                   681,758     285,076    126,872      47,190        41,444    500,582      76,779       ^




IMPORT OF COTTON WOOL INTO LIVERPOOL IN THE YEAR 1851, AND FOR THE EIGHT PREVIOUS YEARS, WITH THE GENERAL IMPORT INTO GREAT
BRITAIN FOR THE LAST TEN YEARS, AND THE STOCKS OF THE DIFFPSF.-T DIESCRIPTIONS REMAINING ON HAND AT THE CLOSE OF 1850 AND 1851.                                                                                                           o
a.          5 g'I  ~   I               MonthAly Import.                 Imported into Liverpool.            1841.       1844.         1845.         1846.        1847.       1848.        3849.
~,5                               0.~*m   "S   S   ^   1^1       ia                  Uoited States                  1,286,384   1,158,845   1,313,905         933,921      8-29,91   1,296.903   1,382,520
~<3      ~            ~                  1811.            1818.               Brazil.         98,586      111,509      110,843        83,901      109,820      100,142      163,530
_____________________'o1oen aro a,,d Berbice
January       -      75,900        6,766         -           435         11,650          955           81,706          119,624              West lIdica..'.           15,038       14,831         6,754        9,219        5,608        6,087        7,970
February    -        519989        4,940         -                                                                                              t 8,6  2  81  1,   Essi Indies  110,868   142,817       82,530        46,432      122,049      136,012      106,960
March -    -        183,639       11,738         -            37         17,532        6,048          121,194           78,151                yypt,&c..                      48,953       61,326       79,154       19,011        20,712       127,820      71,320
April  -    -       113,147        6,824         -           255         13,734        7,081          141,041          224,139.1,559,829   1,489,328   1,653,195   1,121.126   1,087,500   1,566,961   1,732,300
May   -    -        159,853       12,546         -           151         17,990        6,1257         296,797          155,345'        ~'~' ~'               ~'~~' ~'~- ~ - ~
June   -    -    185,127          11,582         -           134          5,178       14,821          217,242          115,199
July   -    -    166,997           7,321         -           645         10,1297       7,631          192,891          171,666         Imported into Great Britain.          1845.        1846.        1847.         1848.        1849.        1850.        1851.
August        -      91,398        7,912         -           238         29,363        6,156          135,067          151,796
September  -         35,302        8,718         -           294         11,106        2,172           67,59-2         114,814                ~                                ~.  -~                                         ~            ~             ~
October       -      31,807       13,910         -           191         39,603        5,173           90,684           94,363       siom  United States..   1,499,683       992,497      872,700   1,374.342   1,477,220   1,182,202   1,395,887
November  -          46,733        7,139         -           732         28,9712       3,895           87,471           75,617              Brazil..                 110,851       83,950      110,385      100,185      163,530       170,155      108,644
December   -         87,617        9,148         -            17          8,146        1,316          108, 04          114,257             Demerara and Herbice                9,1         83,9530    61 660           7,835        9,460        4,666        4,799
1 -   1,331,549    108,644  3,90,2  232,939  65,Wea4lades679,174                                                                                13,5076,6057821                         94605,666                 4,73
Totals 1851.._ 1,137,149         188,644          -        3,983        112,939       65,467        1,748,501       1^,133,034              East Indies.:.     158,087       91,665      122.8012     27,572        182,010      309,109      326,437
Totals 1850 -   1,125,875    170,155             -         4,355        192,535       80,114        Increase of Import, 1851,               Egypt,&o...      82,063        60,668      120,73-2     19,933_       72,720       80,254       67,172
___________________^__________._____________ ________'   ___________'_______175,467                                                                  _______________________________1,859,328 1,42,310 1,33,1279  1,730,067 1,904,940 1,746,386 1,982,939
GENERAL IMPORT, CONSUMPTION AND STOCK IN GREAT BRITAIN-FROm 1841 TO 1851, INCLUSIVE.
STOCK   IN   LIVERPOOL,                                                                              Liverpool.   London.  Glasgow, Total Import.   Total Con.   Aea                         Total Stock.  Eqs alto             H
d~~~~~'c. ~~~~~~weekly con,                                 week'a Con.
list    Sea                                 Total                    Maran            W   In   Egyp                                   184        1,1254,108      75,260       67,863        1,397,241        1,192,220       22,927         164,534         24
De       Sa    Orlans Bowed Mobile                  Pemm.Bahia.  ham.  Dem &.W'                  han E   Surat. Bengal Total.    1843            1,559,829        61,247      125,191        1,746,265       1,403,477        26,988         785,952         29
Dec.  island.            _____    ___        r.   _____      _&___Aner.                                                           1844       1,489,328       77,778      114,027        1,681,133        1,414,565       27,203         903,060         33
-          ~        ~        ~         ~.~               ~       ~' ~.~ ~.~                                  ~        ~        ~-       1845      1,653,195       68,264      138,369        1,859,828        1,568,718       30,168       1,060,270         35
1851   2,330  121,560  60,480  51,750 286,120  12,320 10,030  27,130  140    3,830   19,830 113,990    340  423,730    1846                      1,133,036       36,167        73,107       1,242,310        1,162,590        30,049        545,790         18
1850   4,296  130,928  90,140  35,870 261,234  19,435 17,909  11,269   40                778   32,167  89,577  2,370  454,879    1848            1,566,064       69,911      182,392        1,738,96         1,15128,         291,05        4916,39          21
1849   5,410  156,200  65,301  51,421)278,332  29,815 26,998  38,359   89    1,435   35,318  57,82?  -   -  468,175    1849                      1,732,300       11,490        91,800       1,984,940        1,598,330        38,100        559,418         18
I            I                                                                         1858       1,173,034       98,331       81,971        1,746,386        1,5032,863      28,884         112,019         18
1848   6,180  126,160  50,840  52,030,1235,210  22,78  10,480  35,660   60    1,570   14,450  72,4701  1,170  393,340    1851                    1,748,501       65,780        88,658       1,902,939        1,662,001        31,962        495,104          15k,
GENERAL IMPORT, EXPORT, QUANTITY TAKEN OUT OF THE PORTS FOR CONSUMPTION, AND STOCK, AT THE CLOSE OF 1851, 1850, AND 1849.
IMPORT.                                         EXPORT.                                  ANNUAL CONSUMPTION.                               WEEKLY CONSUMPTION.                                         STOCK.
Liver.   Lon.   Glas-  Othoer   Ttl Liepo.Len-   Glos-    le                              otlLvr             Lon.-  OGlas- Other   TtLcn                                   1'a s    P  Theta.                       a. rB Gas-  Other
pool.    don.   gow.  P s                                   don.   g.                Total. Liverp.   don.   g.  Por               Total.  Liverpool.  don.              -               tal. Liverpool.             gee.  Ports.  Total.
America    -  1,337,549  1,670  43,368  13,300  1,395,887  153,817              1,450     429   1,000  156,6961,184,992    10   80,145  23,920  1,389,157    22,789                  2    1,541    460   24792   23610                150   7,544   2,505  216,312
Brazil       -    108,644  -   -   -   - -   -    108,644            8,944    - - - - - -                   8,944   115,346  -.     -              115,346      2,219-             -      -    -      2,219    49,480          40   - - -             49,520
Dem.W. I.&e         3,902    630       267   -   -         4,799       180    - - - - - -                     180      4,752    810 - - - -                  5,562         91       16    -                     it- 107  3,970       210   -   - -   -         4,180
East Indian       132,939 63,090  22,308   8,100    326,437   45,355   52,580   -   -   2,000   99,935   147,445  5,820  10,100  11,960    175,325                      2,835      112       194    230    3,371   114,330   52,630   4,094   1,000  1772,054
Egyptian, &c.    65,467    390   1,055          260       67,172       940~ -              - -~   -    _-     640    76,511    100   -   -   -   -          76,611      1,471         2    -   -   -  -    1,473        19,830       290   2,916   -   -123,036
Totals 1851   1,748,501 65,780  66,998  21,660  1,002,939  209,236   54,030               429   3,000  266,695 1,529,046  6,830  90,245  35,880  1,662,001   29,405                131     1,735    60    31,062   423,730    53,320  14,554   3,500  495,114
Totals 1850   1,573,03490,381   59,321  23,650  1,746,386  108,999   69,688   1,885   1,680  274,192 1,386,521 10,270  89,242  16,000  1,502,063    26,664                         197    1,716    307   28,884   454,879   49,730  14,830   2,590  522,029
Totals 1849   1,732,300 51,490  91,000  30,150  1,904,940  188,830   63,100   2,850   3,800  258,580 1,461,100  6,320  97,918  25,080  1,590,330   28,101                          121      1,881    480   30,583   468,170   39,760 44,480   7,000  559,410




PRICES THIRTY-FIRST DECEMBER.
Years.                                Ordin. to Mid.              Fair to Good Fair.              Good to Fine.                 Years.                                Ordin. to Mid.              Fair to Good Fair.                ood to Fine.
1851            Bowed                38d. @   4d. 11-16            3d. (a)  5d.                  51d. @   5:d.                  1851            Orleans.             31d.      4d. 13-16          5d. (a  5d.                    5d. t   Id.
1850             Ditto               61 -   1                      71 -8                         8  -8      8                   1850             Ditto               6 ~ -7                       8~~81                          81-9
1849             Ditto               5.1 -6 6] -6                            6 6} 1-  61                                        1849             Ditto                    - 61                    61-7                          71-8
1848             Ditto               31 -4                         4-4                          4 4   -  4-41                   1848             Ditto              31-4                          41-41                          5- 6
1847             Ditto               31 -  4                       41 -  41                     5  - 51                         1847             Ditto               31-41                        5-51                           6          7
1846             Ditto               6  -  6                      7 1- 7                        7  -  71                        1846            Ditto               5  -  7                       71-71                          8  -8
1845             Ditto               31 -  3                      41 -41                        41 -  4                         1845             Ditto              31 -4                         4 4 — 5-61
1844             Ditto               31 - 3                        41 -41                       41-  5                          1844             Ditto               8  -  5                      4  -                           51-7
1843             Ditto               4 ~ - 4               5   51- 51 -  51                                                     1843             Ditto               41 -5                         5-  5                        6-  7
1842             Ditto               4  -  4                       51 -  51                      51 -  6                        1842             Ditto               4  -  5                       51   51                       61 — 71
Cl
U~~~~~~~~~~~
COTTON CROP OF THE UNITED STATES.                                                                                      CONSUMPTION.                                             GROWTH. 
Export to Foreign Ports.________                                                                                                                       Quantity consumed
181.  181.                                               To France                                                                                                                          and in the hands of
~1851.  1850.                      I             ~Gr  To Francet                                                                                        Total Crop of Bales.          Manufacturers.
B n  Continent..
Bales.
NewOrleans   -    -    -    933,369            781,886    New Orleans  -               582,3873     262,268     844,641    Total crop of the United States, 1851           -    - -,355,257      1850-51   2,355,257                404,10)8
Alabama  -             -          451,748      350,952    Alabama -                    249,897       71,880      321,777    Add stocks on hand at the commencement                                      1849-50   2,090,706                487,769
Florida   -    -    -    -        181,264      181,344    Florida   -          -     -  56,187       14,367       70,547      of the year 1st September, 1850.                                          1848-9    2,728,596                518,039
Georgia   -           -.    32-2,376       343,635    Georgia  - -          -      137,143       16,504     153,647    In the southern ports...      91,754                   1847-8.2,347,634               531,772
South Carolina-    -    -         387,075      384, 265    South Carolina -            203,970       64,048     268,018    In the northern ports    -    -           -         76,176                   1846-7     1,778,651               427,967
North Carolina   -          -      12,98        11861    North Carolina -    -                                                                                                             167,930      1845-6    2,100,537                422,597
Virginia, &c.  -    -    -         19,940      -    -      Virginia                1-     -                      -          M         k      f — 1                                                      1844-5    2,394,503                389,006
~~Texas  -    -              ~- ~- ~45,820  31,263    Baltimore.8141                                              ae sP-     811843-4    2,030,409                                                                            346,744
Texas                                                                                                                4-     Mae                                                        ['pl  f2.523,187
Total crop of the U. States   5,355,540   2,09e,706    Philadelphia   -    -             1,691        2,691        2,691   deduct the export to foreign                                                 1842-3    2,378,875               525,129
lotal cro  ot the  _tates   2350,540-,096,706 New York      -           184,815      136,980     321795        poos                              1,588,710                               1841-2    1683,574                 267,850
Boston               - -      1,802       1,450        2,852    Less foreign included    -    -         1,877634,945                                                           297288
~~~~~~~~~Texas-.o                                                                                                                                             o 1,917,653aov             1848-1      1,634,045              297,288
Total crop of 1851, as above          -   2,355,540    T a            -    --                         2261         2261    Stockson hand at the close of the year 1st                                   1839-40   2,17,835                 295,193
Crop of last year-            -               5,096,706    Total      -    -    -   1,418,265      570,445   1,988,710        September, 1851.                                                          1838-9     1,360,532               26,18
Crop of year before              -           2,728,526                                                                      lathe sosthern pools        -    -    89,844                                1837-8      1,301,497               46,1063
-f    Total last year -    -   1,106,771      483,384   1,590,155    In the northern ports    -    -          9,60                                 1836-7     1,4    30              22540
Increase          ty        -    -                             -    -    -    318,304                                                                                                            1035-6      1,360,755              236,733
efrom ltyear    2-,21    Icease  - -    -                      311,494       87,8611         5      Burnt at New York and Baltimore -    -              3,14                    1834-5,5,38                 216,888
Decreaae from year befora-    -3373,359' -  oi119r07  1 1833-4      1,205,394              196,413
The shipments from Mississippi are included in the,19           1832-3      1,070,438              194,412
experts from  New Orleans.                  Taken for home use-. 404,108 91
exports from New Orle ans.   ITaken for borne use                                                              404..0




MONTHLY IMPORT INTO L IV E RPOO L IN 1851.                                                                                                                                                             c
6~~~
Jaur...~..         18 541         9 s3s        5 767        49,054         75,900          2-,814,1 ~ ~ I3 0-,19 15s,3                                                                                          96            1,079,0
February  -    -     10'434       19'476   [     7',141       220-,9388     59,989             605           2 01       4'11           [4  4-,95                                                  537        18,783         939  [        9,568             86,516
March                -  -}16'380  I36'518              16,281  ]114,430   {183,639                   3,661        1,I134        6,928  {      38           1171              43             2  32      6,063        20,998         534    {      33,870
A'I       -   ~~~15,0412!   4',7~9       27,950   [65,469 {   11,90'929,270
A    1                                                                          3,871             -        2,939         14            6,8t24            2             111%108         1       1,4           -     -  {    01,030-            141,046
Mary            --      J  30,`260       2 6,144    59,165, 144,'282           2 059,851         4,203 I    4,086            4,`251{        6           12'4               2     {       128 [    6',270         17,359         631     {    94,400            996,797
-J-ne                  120-95!   99598  {34,041   {116,193   { 185,1'27                       8,106  {        I q        2,705  {     38           1,2               0               9         480           518          -     -        9,5                1,0
Jul             - {     9;490  { 16,231           2 7,352   {114,9'24   [ 167,997               3,94'2  I    1,295         2,154                       7,11             3               1,3          027          -     -        1,7                9,9
AUgUSt        - -    J       3,3'20  J    9,-255       18,32~9       60,494         91]84U9                       383          -     -792                                  -23,5           933          -     -        3,5                3,6
September~~~~ ~~~~ ~ ~ ~ ~          ~ -   109  1,78,3  517     35,25           298              2 4,01 ~71                                             9 I8 3,8`12                           9106             4            3,6                   9
October~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -94 — -,32  56095  93,3663187 1,5  -    -                            11            117                         55,173      39635,- 496                                    0684
September   -                             34b9         1000                                                                      8~7 6, 331,163                        4~50                                                                {    9,3    3,9  892 - -3,690  1,7
Deebr   -     -      2,703       12,809         7,539    6 5,702   {    87357,45         459           3,194                       9,4 {    9                        79,120         856                -        1,9                0,593
October~~~~~~~-     -f2, 1-1                                                                                                                                                         ~     0-                                     -{44,
74                                      -                               5 6         554           5115          18          1123                88''st         79,1713      9192,18           7990           1,7,61
Totals~~ ~ ~ ~ of3  /5   5,609 /,1       9iU3,N6  I      1,1257           1,52,          ~5 98,..... of 184            16,5          18 38,40491                82}9         1,81,9               0,008       5309 /-i 4    3 2 6                        3,4245          12      4     6,239   - 12             10-5              0          186,259 9        173;471
Amrca          e       c      3146         76emb7460e 4r68 11  -8                                8   10-         ],70       92,0,088                                  3,9840 114250 1510                    89140 87,60 15446,4750,8,90 139,4
Brazil  -   ~~~~~~~~ ~~~~~ ~ ~ ~~10,457 143,580 17960'  1,1  3y8         730          8,5           3,194 I' 557             9840'           ~0   - 1 6           84,20                         110,6930  0,4  6,4      7 1         108,598
Total Bag, &C. -                      /948,2 1(087 12080    15173,4081 1,431'12 11 50 65        1 560437    1 542,   1,3760177441590-  1                 38, ~0 1,85 7 3     1 —243,970 1 —-,0 1931 71;1,90,8             I9    17810,0,1
Tak         frlom   ue-       9016,912   94[   5 18,0382{9 0 0;    15-077'9,298  11,3899109 -Um610'.~ 8 [53,09 49,15              4'20  1{0,1    1,0227    1              740,40    [,5~     7    1,56444 [, 7]3 3     "00 1506,45   -8~ 60  18,'5'2,          1;,3'2,494    -
Amer~~~~~~~ican73,456    17635,309               76,360450 [   846,79      1,014,180      830 1,605  0-36,17580   19634,00   1 810,1,90                     2400007,2,3 00   210,53         1701,000   2,3741,600 2I8,0               0910          3500




Prices this Date.        Upland.           New Orleans.              Mobile.             Sea Island.         Pernambuco.               Bahia.             Maranhani.               Paras.              Egyptias.               Sssrat.             Bengal.
1851.       Fair        54. (a   Od.    5c. ~    Od.              54.  (    04.    134. (a) Od.               6d. i, 0.             6d.  (11  Od.                                 Q.d.  @ 04.  04.          (    Od. 6+Id. (a)  Od. 0.    8d. (  Od.
Extreme  4~6    4-8                                      4-6    10-24   51-7                                               51 ~        5 ~-71                            0-0    51-8+    21~4                                          8 3          4
1850.  Fair   71-  80 81 - 0    8-0    15-                                                       10 S- 0    81-0    8~-0                                                          0-0    81-0    5~1 0    51~0
Extreme  6~-81   61-10    61-81   11-24    7 ~-9                                                                          71~81                 71-9                     0~0                 7  -10                41~6+    51-6
1849.   Fair   6~-0    61- 0                                      6 ~-0    121-  60                           6  -0                 61-                   6 ~-0                   0~0                 6-~0                  4           0         41- 0
Extremel  5i   ~    7             51    ~ 8             57    - 7j             91    -~ 20           611    ~- 71          6      ~- 7           6      ~- 7             0     ~ 0           6      ~-   8 1-5    31      ~   5          4      ~8
STOCK OF COTTON IN LIVERPOOL, LONDON, AND GLASGOW, FOR THE YEARS                                                                                  GENERAL IMPORT, STOCK, AND CONSUMPTION OF COTTON
1847, 1848, 1849, 1850, and 1851.                                                                                                     FOR THE YEAR 1851.
~~~~~~~~~~~~~  +.~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~~~~~~~~~~~~~~~~.
In Liverpool       -       t,330          60,480   t121,560   51,750   49,480         150       3,S8O    19,830      114,330        423,730       Stock on hand, lat January, 1851.    2t2,710            68,650   1,460       34,9200  143,380      521,120
London, &c.   -    -n- 0,110                      -    -   -               40       Ct        280        160        3,630         16,3t0       Imported  from  lat Jan. to 31satDec.  1,396,950    107,690   5,760         67,340'320,780   1,904,520
London, Ac. —                 -        2,150...                40       60        280        160       53,630         56,320.     _    ___      ____      ____       ____  _       ____
Total supply for 1851  -    -    -   1,669,660    176,340   7,t-20    102,360  470,160   2,425,640
Glasgow -    -             70          2,470        2,340    2,660-           -      -         -      2,920         4,090         14,550
_______~_______     ~              ~            _______   _______    _______   _______   ______________  _____________________     Stock on shand,31stDee. 1811. -  t215,810  49,520 4,310  tt,910 172,050  494,600
Total in 1851      -      0,400           65,100    123,900   51,410   49,520         210       4,100   22,910       172,050        494,600                                               1       0          4        1,       0    0,
_ ______ -~ _______  ~ -    ~ ~~  _______' _______  _______  _______  _______  _____ _J __________ ^  ___________                           1,423,850  1 126,820   2,910       79,3500' 298)110 11,931,04
Total in 1850      -      4,650          093,340    134,780   39,940   68,650          40       1,420   34,920       143,380        521,120       Export to the Continent, &c.    -          151,950      12,000      200         960'103,450       268,500
Total in 1849      -      6,050           76,760    171,820   62,680   95,170           90      1,001 38,000         105,870        158,340      Taken for home consumption 1851.  1,071,900   114,000    0,710                70,450:104,660    1,665,140
Total in 1848      -       7,050!    58,170    145,820   61,190   68,590            60      2,570   16,920       135,680        496,050       Or average per week -    -    -             24,458       2,208       52       1,509     3,744       31,971
Total in 1847      -       7,310          51,930    130,650   49,430   59,200          100      2,030   26,090       125,200        451,940       Weekly average ir 1850   -    -             20,705       3,339      105       1,572:  3,373         29,094




546                                 COTTON (GUN).
COTTON  SPINNING.  Messrs. Tatham, Cheetham, and Duncan, obtained in 1846
a patent for sundry improvements in apparatus for cotton spinning. Their first invention applies to the scutcher, a machine by which the cotton is cleansed and lapped
in a compact and even sheet or lap upon a roller preparatory to its being fed into the
carding engine, and consists in a new arrangement of rollers for compressing or calendering the sheet of cotton previous to its being lapped upon the roller; and also in a
new method of weighting the calendering rollers, whereby the pressure is gradually increased as the sheet of cotton approaches the lap. The second part of the invention
consists in the employment of an apparatus for collecting the fibres of cotton from the
dust which is blown by the fan from the scutcher.
The third part of the invention is an improvement upon machinery patented by
Tatham  & Cheetham in March, 1844, which caused the sliver to be twisted as it is
delivered from the carding engine into the tin-can receptacle.
The fourth relates to the application of gutta percha tintawan for covering rollers
used in the several machines employed in cotton spinning. These substances may be
used either alone, or combined with sulphurets, &c.
The fifth invention relates to the "flyer" now usually employed in "presser frames.
Here the legs or arms of the flyer (being jointed above the top or elbow) are caused to act
upon the bobbin like tongs, and thus dispense with the small spur or level at the bottom
of the flyer, called the presser. Through the boss or upper part of the flyer the sliver
or roving of cotton passes to the hollow arm. The top part and arms are joined together, and swivel upon a central pin or stud.  At this joint a coiled spring,exactlysimilar to the ordinary snuffers-spring, is inserted, one end of which is to be fast to the head,
and the other end to the arm of the flyer; whereby the desired elasticity is imparted to
the arms, to effect the pressure on the bobbin. The lower end of the arm must be smaller, to lap one or two folds of the roving around it to create the drag usually obtained
by the folds around the common press or level.-Newton's Journal, xxxi., p. 7
In cotton spinning machines the roving and slubbing frames move at a great velocity,
and are liable to vibrations, and consequently to much wear and tear, which Mr. Edmund Hartley, of Oldham, has tried to remedy by patented contrivances, while the
speed is increased. He has also sought to improve the backing off motion in self-actor
mules. For description of his invention, see Newton's Journal, vol. xxxvi., p. 300.
COTTON (G-UN).  M. Schonbein, the patentee, states that the invention consists in
the manufacture of explosive compounds applicable to mining purposes and to projectiles, and as substitutes for gunpowder, by treating and combining matters of vegetable
origin with nitric and sulphuric acids.
The matter of vegetable origin which he prefers, as being best suited for the purposes
of the invention, is cotton, as it comes into this country, freed from extraneous matters;
and it is stated to be desirable to operate on the clean fibres of the cotton in a dry
state.  The acids are nitric acid of from 145 to 1'50 specific gravity, and sulphuric acid
of 1'85 specific gravity.
The acids are mixed together in the proportions of 1 measure of nitric to 3 measures
of sulphuric acid, in any suitable or convenient vessel not liable to be affected by the
acids. A great degree of heat being generated by the mixture, it is left to cool until its
temperature falls to 600 or 500 Fahr. The cotton is then immersed in it, and in order that
it may become thoroughly impregnated or saturated with the acids, it is stirred with a
rod of glass or other material not affected by the acids. The cotton should be introduced
in as open a state as practicable. The acids are then poured or drawn off, and the cotton
gently pressed by a presser of glazed earthenware, to press out the acids, after which
it is covered up in the vessel, and allowed to stand for about an hour. It is subsequently
washed in a continuous flow of water until the presence of the acids is not indicated by
the ordinary test of litmus paper. To remove any uncombined portions of the acids
which may remain after the cleansing process, the patentee dips the cotton in a weak
solution of carbonate of potash, composed of 1 oz. of carbonate of potash to 1 gallon
of water, and partially dries it by pressing, as before. The cotton is then highly explosive, and may be used in that state; but, to increase its explosive power, it is dipped in
a weak solution of nitrate of potash, and, lastly, dried in a room heated by hot air or
steam to about 150~ Fahr.
It is considered probable that the use of the solutions of carbonate of potash and
nitrate of potash may be dispensed with, although actual experience does not warrant
such an omission. The patentee remarks, that nitric acid may be employed alone in
the manufacture of explosive compounds, but that, as far as his experience goes, the
article when so manufactured is not so good, and far more costly.
When used, care should be taken to employ a much less quantity by weight, to produce the same result, than of gunpowder; and it has been found that three parts by
weight of the cotton produce the same effect as eight parts by weight of the Towerproof gunpowder.




COTTON (GUN).                                         547
The cotton, when prepared in the manner before mentioned, may be rammed into a
piece of ordnance, a fowling-piece, or musket; or may be made up into the shape of
cartridges; or may be pressed, when damp, into moulds of the form of the bore of the
piece of ordnance for which it is intended, so that, when dried, it shall retain the required figure; and it may also be placed in caps, like percussion caps, and made to explode by impact.~ Lastly, the patentee states, that although he prefers the use of cotton,
other matters of vegetable origin may be similarly treated with acids to form an explosive compound, and that acids of an inferior specific gravity may be employed.
COTTON (GUN), spontaneous combustion of, (by Dr. Gladstone).-" Gun-cotton, as commonly produced, especially for preparation of collodium, is a mixture of two distinct
though analogous substances.  The one is designated pyroxyline, and has the formula
02 { 5NO o 
It leaves no residuum on explosion; is insoluble in ether, &c. The other has received
the appellation Cotton-xyloidine, and the formula
4  3N04 I  20
It leaves a residue on explosion; is soluble in ether, &c.
"1 Pyroxyline.-This substance is produced only when cotton or cotton-xyloidine is
immersed in a mixture of nitric acid, of sp. gr. 1'5, with strong oil of vitrol.  Although
it contains so large an amount of oxide of nitrogen, I am acquainted with no clear instance in which it has undergone spontaneous decomposition. Specimens obtained by
the action of the mixed acids on cotton-xyloidine have shown no indications of change;
and pyroxyline obtained in a compact translucent form, from  solution in acetic ether,
has also remained unaltered.
"1 Cotton-Xyloidine.-This may be prepared in a state of purity, and in a pulverulent
condition, by dissolving cotton or pyroxyline in nitric acid of about sp. gr. 1'45, and
precipitating the substance by water.
" 1Several specimens of this compound made from both sources have hitherto suffered
no decompositions, but they have been generally kept in the dark. One sample of precipitated cotton-xyloidine placed in a stoppered bottle remained in a cupboard, the door
of which was sometimes opened and sometimes closed.  After the lapse. of about three
years it suddenly began to evolve nitric oxide and water: the action continued for a
few weeks, and then nothing remained but a small quantity of a transparent gummy
mass of a light brown color, and possessed of a very peculiar odor. Several months
produced no further alteration.
"This product of decomposition, which had about the tenacity and consistency of
ordinary gum, was not explosive: when heated in a closed tube, per se, it gave off red
fumes, and afterward swelled up, being carbonized, and evolving empyreumatic oils. It
was found to be insoluble in cold water, but when boiled in that liquid, it swelled up as
a gelatinous mass, and became disintegrated. There resulted a solution which reddened
litmus paper slightly, containing, however, no oxalic acid, but a small quantity of another acid, which gave a flocculent white-lead salt, insoluble in excess of acetic acid;
the substance in question, though insoluble in cold water, dissolved readily in aqueous
solution of potash: yet it appeared to be altered in combining with the alkali, for it
was not re-precipitated when the potash was supersaturated by an acid.
" Starch-Xyloidine.-This is the well-known substance produced when starch  is
treated with strong nitric acid, and water is added to the viscid mass. Its composition
varies; but it is in general analogous to, if not identical with, that ascribed above to
cotton-xyloidine.
"A large specimen, freely exposed to the light during more than four years, remained unaltered.
"Higher Starch Compound.-When ordinary starch-xyloidine is treated with a mixture of fuming nitric and sulphuric acids, and subsequently washed, it is found to have
greatly increased in weight. The resulting substance is more combustible than the
original xyloidine, and differs from it in several respects, but is not identical with the
pyroxyline obtained from woody fibre.
"A sample of this product, which had been left eight or nine months in a room where
light freely entered, was found wholly decomposed; nitrous fumes and vapor of water
had been evolved, leaving a dark sticky residue. This new substance was soluble in
water and in alcohol; crystallizing from the latter in tufts, which under the microscope
had a beautiful arborescent appearance.  It remained a couple years or more dissolved
in a very small quantity of water.  What changes may have taken place in it during
that period is unknown, since no proper examination had been previously made, but
after the lapse of that time, the solution was found to be almost black and strongly acid.




548                                 COTTON (GUN).
When neutralized with an alkali it gave a copious precipitate on the addition of nitrate
of silver, and a flocculent salt, or rather mixture of salts, with chloride of calcium,
which, when dried and heated with hydrate of potash, evolved ammonia. At the bottom of the vessel containing the aqueous solution there had grown a compound crystal,
transparent and colorless, with the exception of a few brown specks. It had the rhomboidal form which oxalic acid usually assumes, and upon further examination and
analysis proved to be that substance.
"A small sample of this same starch compound, which had been washed repeatedly
with glacial acetic acid for complete purification, and which had been kept constantly
in the dark was found to have suffered decomposition, nothing remaining but a viscous acid liquid. When examining these decomposed explosive compounds, I found in
my laboratory a bottle filled with a brown sticky mass; the label having been destroyed by evolved acid, it could not be positively identified, but I have good reason
to believe it had originally been the higher starch compound: the substance had a
strong odor of hydrocyanic acid. Its solution, in either water or alcohol, had a strong
acid reaction. It gave no precipitate with chloride of calcium. Flocculent salts containing metallic oxides or baryta, all easily soluble in nitric acid, were readily produced.  Its combinations with the alkalis gave dark brown aqueous solutions, from
which they separated in an amorphous form on evaporation, but though exceedingly
soluble in water, they were precipitated on the addition of alcohol. The mass was
probably a mixture of different acids, principally non-azotized, for little nitrogen was
discoverable; and although oxalic acid itself was absent, it is by no means improbable
that some higher members of the series, Cn Hn  04 were present.
"Nitro-Mannite.-This substance, first described by MM. Flores Domonte and Menard, is formed when mannite is dissolved in fuming nitric acid, and precipitated by
sulphuric acid. Its formula, according to Strecker, is C02 Hs (NO4 ) 012. It is the
only known crystallizable body belonging to this group.
"My sample of nitro-mannite kept in a glass tube, generally in the dark, has suffered some decomposition; acid fumes have been given off but the action has not proceeded far.
"Sugar Compound.-It is well known that cane-sugar submitted to the action of
mixed nitric and sulphuric acids is converted into a pasty explosive substance, readily
soluble in alcohol, but insoluble in water, to which, however, it communicates an intensely bitter flavor.  According to the observations of H. Voh, several different
compounds are produced simultaneously in this reaction.  Diabetic sugar similarly
treated gives a similar substance.
"' I have kept samples of this product, some of which had been merely kneaded with
water until the acid was removed, others regained from solution in alcohol. They
have shown little signs of decomposition.
"Milk-Sugar Compound.-By the same treatment a substance is obtained from milksugar closely resembling that just described. Like the previous compound, it can be
purified by solution in alcohol, but does not present itself in a crystalline form.
"A sample kept in paper was found to be much decomposed.
" Caramel Compound.-I procured a similar compound from pure caramel, prepared
by means of absolute alcohol.  The caramel having been dried and pounded, was
placed in fuming nitric acid: it dissolved; upon the addition of sulphuric acid, a darkcolored oil separated, which became hard and yellow when washed with water.  It
was soluble in alcohol, but came out from solution without crystallizing, and always
of the same color. The compound bore a close resemblance in its various properties
to those obtained from sugar.
"The sample kept by me has suffered little or no alteration.
" Gum  Compound.-At least two different substances of this explosive character may
be produced by the action of nitric acid on gum. If the gum be treated with the fuming
acid, it dissolves into a mucilaginous solution, from which water precipitates a white
body, slightly soluble in that liquid, and very soluble in alcohol. A sample of this
substance has not yet suffered any decomposition.
"If sulphuric acid be added to the solution of gum in fuming acid, it precipitates a
white substance resembling that from sugar, but not nearly so soluble in alcohol, and
very slightly in ether. Moreover, it is only softened, not melted, by a temperature of
212~ Fahr. No specimen of this compound was preserved.
" While treating upon this subject, it may not be amiss to append a few observations
upon another decomposition of pyroxyline. When good gun-cotton is heated at a temperature a little exceeding that of boiling water, it becomes brown in color, and is disintegrated. The odor of nitrous fumes, along with that of some cyanogen compound,
is very perceptible. It thus becomes explosive at a lower temperature than formerly,
a fact which may account for some of those hitherto unexplained accidents which have
arisen from this article, for it is evident that gun-cotton exposed for some time to a




CRANES (TUBULAR).                                          549
degree of heat quite insufficient under ordinary circumstances to cause explosion, may
yet be eventually dissipated from the formation of this product.
"The brown substance thus obtained underwent no visible alteration in the space of
four years.  When examined lately it was found to be very soluble in water, but insoluble in alcohol or ether.  Its aqueous solution tasted  somewhat bitter, it reacted
slightly acid, no crystals were obtained on evaporation. When boiled with a solution
of potash, it evolved ammonia.  When mixed with a salt of lead or copper it formed
brown flocculent precipitates, but none appeared with a silver or lime salt. The organic
substance which fell in combination with oxide of lead, contained a large amount of
nitrogen.  That portion of the fibre which had not become brown with heat was found
to be no longer pyroxyline; when freed from the brown matter by washing with water,
and dried, it left little residue on explosion; but on the other hand, it dissolved very
readily in ether, alcohol, or cold sulphuric acid; properties of cotton-xyloidine, but not of
the original substance.  Wlhenl, however, the manner of its production is considered, we
can hardly conceive it identical with a body which would require the introduction of two
atoms of hydrogen if formed from pyroxyline.  Whether this change which gun-cotton
undergoes at a high temperature is at all analogous to the spontaneous decomposition
mentioned above, can scarcely be determined, but the presence of azotized compounds
in considerable quantity, and of ammonia, rather indicates the reverse.
" The rationale of these decompositions is far from being elucidated by the observations
here recorded, but as the substances thetmlselves are not now in existence, nor are capable
of being procured without long delay, I cannot pursue the investigation further. The
only general conclusion which can be drawn appears to be, that several substances of
the character above described have a tendency to suffer spontaneous decomposition from
being oxidized into non-azotized acids at the expense of the peroxide of nitrogen, NO4,
they contain, which is reduced to the condition of nitric oxide, NO2, and evolved as such,
a portion of water being always gaiven off at the same time."
COURT  PLASTER  is a "'considerable object of manufacture.   It is made  as
follows:
Black silk is strained and brushed over ten or twelve times with the following preparation:-Dissolve' an ounce of balsam of benzoin in 6 ounces of rectified spirits of
wine; and in a separate vessel dissolve 1 ounce of isinglass in as little water as may be.
Strain each solution, mix them, and let the mixture rest, so that any undissolved parts
may subside; when the clear liquid is cold it will form a jelly, which must be warmed
before it is applied to the silk. When the silk coated with it is quite dry it must be
finished off with a coat of a solution of 4 ounces of Chian turpentine in 6 ounces of
tincture of benzoin, to prevent its cracking.*
COW  DUNG  SUBSTITUTE, in calico printing.  Sulphate, carbonate and  phosphate of lime and soda.
CRANES, Tubular, of  Mr. W. Fairbairn.-Among  the many  happy  applications of the hollow-girder system of our great engineer, this is one of the most ingenious.
"Fig. 425 is a vertical section of a crane, constructed according to my said invention,
and calculated for lifting or hoisting weights up to about 8 tons. Fig. 426 is an
elevation of the same; figs. 427, 428, 429, and 430, are cross-sections, on the lines a b,
c d, ef, g h; andfig. 431 a transverse vertical section on the line i k.  A A is the jib, which
in its general outline, is of a crane-neck form, but rectangular in its cross-section, as
particularly shown in figs. 428, 429, and 430. The four sides are formed of metal
plates, firmly riveted together. Along the edges the connection of the plates is effected
by means of pieces of angle iron. The connections of the plates at the cross-joints
on the convex or upper side of the jib, are made by the riveting on of a plate, which
covers or overlaps the ends of the two plates to be joined; the rivets at this part are
disposed as represented in fig. 432 (a plan of the top plates), and known as'chain
riveting;' B B is the pillar, which is firmly secured by a base plate p, to a stone foundation B; and fits at top into a cup-shaped bearing c, which is so firmly secured to
the side plates of the jib, at or near to the point where the curvature commences, and
on which bearing the jib is free to revolve. Fig. 431 is a transverse vertical section
of the lower part of the jib, showing the manner of fitting the bearings for the chainbarrel (which is placed in the interior), and the spindles and shafts of -the wheel-geering,
by which the power is applied there to D, is the chain pulley, which is inserted in an
aperture formed in the top of the jib. The chain passing over this pulley, enters the
interior of the crane, and is continued down to the chain barrel. E is a pulley or roller,
which is interposed about half-way between the chain-pulley and the chain-barrel, for
the purpose of preventing the chain rubbing against the plates. Fig. 433 is a plan of
the lower plates.
*Paris's Pharmacologia.




550                         CRANES (TUBULAR).
Fig. 434 is a vertical section of another crane constructed upon the same principle
as that just described, but calculated for lifting much greater weights (says 20 tons);
it differs in having the lower or concave side A A, of the jib strengthened by means of
three additional plates B B B, whereby the interior is divided into one large and three
smaller cells, as shown in figs. 435 and 436, which are cross sections upon the lines a 6,
426
427                                                    u HiS 429
433
432
and e d of fig. 434. This arrangement of the cells to strengthen the lower or concave
side is advisable, in order to obtain sufficient resistance to the compression exerted by
the load lifted, without unnecessarily increasing the weight of the other parts.
The tension exerted upon the upper or convex plates does not require so much materials to withstand it; c, is the toe of the jib, which rests in a step formed in the bottom of the cylindrical castings D, which is built into the masonry forming the basis of
the machine. E E are two of a set of pulleys, which are mounted between two rings FF,




CRAPE.                                         551
a hand-wheel, is geered, so that, by turning the hand-wheel, the jib of the crane is made
to move round in any required direction. o is the chain-barrel; Pthe chain-wheel;
B t pulleys or rollers which support the chain, and prevent its rubbing against the plates
"In the cranes and hoisting machines which I have described, the chain-barrels are
inclosed within the jib, and the spindles of the wheel-gearing are also inside; and this
is the disposition of those parts, which I prefer; but it will be obvious that they may be
also placed outside of the jib, in a manner similar to that generally followed in the construction of ordinary cranes.  And having now described my said invention, and in
what manner the same is to be performed, I declare that what I claim is the construction of cranes and other light lifting or hoisting machines, with jibs composed of a series
of metal plates, arranged and combined so as to form a connected series of tubular or
cellular compartments, as before exemplified and described."
CRAPE.  (Cre'pe, Fr.; Krepp, Germ.)  A  transparent textile fabric, somewhat
like gauze, made of raw silk, gummed and twisted at the mill. It is woven with any
crossing or tweel. When dyed black, it is much worn by ladies as a mourning dress.
Crapes are crisped (crepes) or smooth; the former being double, are used in close
mourning, the latter in less deep. White crape is appropriate to young unmarried
females, and to virgins on taking the veil in nunneries. The silk destined for the
first is spun harder than for the second; since the degree of twist, particularly for the
warp, determines the degree of crisping which it assumes after being taken from the
loom. It is for this purpose steeped in clear water, and rubbed with prepared wax.




552                                 CRAYONS.
Crapes are all woven and dyed with the silk in the raw state. They are finished with
a stiffening of gum water.
Crape is a Bolognese invention, but has been long manufactured with superior
excellence at Lyons in France, and Norwich in England. There is now a magnificent
fabric of it at Yarmouth, by power-loom machinery.
There is another kind of stuff, called crepon, made either of fine wool, or of wool and
silk, of which the warp is twisted much harder than the weft. The crepons of Naples
consist altogether of silk.
CRAYONS.  (Eng. and Fr.; Pastelstifte, Germ.)  Slender, soft, and somewhat
friable cylinders, variously colored for delineating figures upon paper, usually called
chalk drawings. Red, green, brown, and other colored crayons, are made with fine
pipe or china clay paste, intimately mixed with earthy or metallic pigments, or in
general with body or surface colors, then moulded and dried. The brothers Joel, in
Paris, employ as crayon cement the following composition: 6 parts of shellac, 4 parts
of spirit of wine, 2 parts of turpentine, 12 parts of a coloring powder, such as Prussianblue, orpiment, white lead, vermilion, &c., and 12 parts of blue clay. The clay being
elutriated, passed through a hair sieve, and dried, is to be well incorporated by tritu.
ration with the solution of the shellac in the spirit of wine, the turpentine, and the
pigment; and the doughy mass is to be pressed in proper moulds, so as to acquire the
desired shape. They are then dried by a stove heat.
In order to make cylindrical crayons, a copper cylinder is employed, about 2 inches
in diameter, and 1~ inches long, open at one end, and closed at the other with a perforated plate, containing holes corresponding to the sizes of the crayons. The paste is
introduced into the open end, and forced through the holes of the bottom by a piston
moved by a strong press. The vermicular pieces that pass through are cut to the
proper lengths, and dried. As the quality of the crayons depends entirely upon the
fineness of the paste, mechanical means must be resorted to for effecting this object iq
the best manner. The following machine has been found to answer the purpose exceed
ingly well.
440            439_   
FF
furnished within with a circular basin of wood I, which receives the materials to be




CREOSOTE.                                        553
over the sides of the muller, and comes again through the holes i, so as to be repeatedly
subjected to the grinding operation. This millstone is mounted upon an upright shaft
3, which receives rotary motion from the bevel-wheel work x, driven by the winch L
The furnace in which some kinds of crayons, and especially the factitious black-lead
pencils, are baked, is represented infig. 439, in a front elevation; and infig. 440, which
is a vertical section through the middle of the chimney.
A A, six tubes of greater or less size, according as the substance of the crayons is a
better or worse conductor of heat. These tubes, into which the crayons intended for
baking are to be put, traverse horizontally the laboratory B of the furnace, and are supported by two plates c, pierced with six square holes for covering the axes of the tubes
A.  These two plates are hung upon a common axis D; one of them, with a ledge, shuts
the cylindrical part of the furnace, as is shown in the figure. At the extremity of the
bottom, the axis  supported by an iron fork fixed in the brickwork; at the front it
crosses the plate c, and lets through an end about 4 inches square to receive a key, by
means of which the axis D may be turned round at pleasure, and thereby the two plates
c, and the six tubes A, are thus exposed in succession to the action of the fire in an
equal manner upon each of their sides. At the two extremities of the furnace are two
chimneys E, for the purpose of diffusing the heat more equably over the body of the
crayons.  F, fig. 439, is the door of the fire-place, by which the fuel is introduced;
fig. 440, the ash-pit; H, the fire-place; i, holes of the grate which separate the fireplace
from the ash-pit; K, brickwork exterior to the furnace.
General Lomet proposes the following composition for red crayons. He takes the
softest hematite, grinds it upon a porphyry slab, and then carefully elutriates it. He
makes it into a plastic paste with gum arabic and a little white soap, which he forms
by moulding, as above, through a syringe, and drying, into crayons. The proportions
of the ingredients require to be carefully studied.
CRAYONS, lithographic. Various formulae have been given for the formation of these
crayons.  One of these prescribes, white wax, 4 parts; hard tallow-soap, shellac, of
each 2 parts; lamp black, I part. Another is, dried tallow soap and white wax, each
6 parts; lainp black, 1 part. This mixture being fused with a gentle heat, is to be cast
into moulds for forming crayons of a proper size.
CREOSOTE, or the flesh-preserver, from xpea5 and acorc, is the most important of the
five new chemical products obtained from wood tar by Dr. Reichenbach. The other four,
paraffine, eupione, picamar, and pittacal, have hitherto been applied to no use in the arts,
and may be regarded at present as mere analytical curiosities.
Creosote may be prepared either from tar or from  crude pyroligneous acid.  The tar
must be distilled till it acquires the consistence of pitch, and at the utmost till it begins
to exhale the white vapors of paraffine. The liquor which passes into the receiver
divides itself into 3 strata, a watery one in the middle, placed between a heavy and a light
oil. The lower stratum alone is adapted to the preparation of creosote.
1. The liquor, being saturated with carbonate of potash, is to be allowed to settle, and
the oily matter which floats at top is to be decanted off.  When this oil is distilled, it
affords, at first, products lighter than water, which are to be rejected, but the heavier oil
which follows is to be separated, washed repeatedly by agitation, with fresh portions of
dilute phosphoric acid, to free it from ammonia, then left some time at rest, after which
it must be washed by water from all traces of acidity, and finally distilled along with
a new portion of dilute phosphoric acid, taking care to cohobate, or pour bask the distilled product repeatedly into the retort.
2. The oily liquid thus rectified is colorless; it contains much creosote, but at the
same time some eupione, &c.  It must therefore be mixed with potash ley at 1*12 sp.
grav., which dissolves the creosote. The upione floats upon the surface of that solution,
and may be decanted off.  The alkaline solution is to be exposed to the air, till it
Blackens by decomposition of some foreign matter. The potash being then saturated
with dilute sulphuric acid, the creosote becomes free, when it may be decanted or
syphoned off and distilled.
3. The treatment by potash, sulphuric acid, &c., is to be repeated upon the brownish
creosote till it remains colorless, or nearly so, even upon exposure to air. It must be
now dissolved in the strongest potash ley, subjected to distillation anew, and, lastly, redistilled with the rejection of the first products which contain much water, retaining only
the following, but taking care not to push the process too far.
In operating upon pyroligneous acid, if we dissolve effloresced sulphate of soda in it to
saturation, at the temperature of 1670 F., the creosote oil will separate, and float upon
the surface. It is to be decanted, left in repose for some days, during which it will part
with a fresh portion of the vinegar and salt. Being now saturated while hot, with carbonate of potash, and distilled with water, an oily liquor is obtained, of a pale yellow
color. This is to be rectified by phosphoric acid, &c., like the crude product of creosote
from tar.




554                                   CRUCIBLES.
Creosote is apparently composed of 76-2 carbon,'7  hydrogen, and 160 oxygen, in
100 parts. It is an oily-looking liquid, slightly greasy to the touch, void of colon
acrid burning taste, and capable of corroding the epidermis in a short time. It possesses
a penetrating disagreeable smell, like that of highly smoked hams, and, when inhaled Up
the nostrils, causes a flow of tears.  Its specific gravity is 1037, at 580 F.  Its consist.
ence is similar to that of oil of almonds. It has no action upon the colors of litmus ot
turmeric, but communicates to white paper a stain which disappears spontaneously in a
few hours, and rapidly by the application of heat.
It boils without decomposition at 398~ F., under the average barometric pressure,
remains fluid at 16~ F., is a non-conductor of electricity, refracts light powerfully, and
burns in a lamp with a ruddy smoky flame.
When mixed with water at 58~ F. it forms two different combinations, the first being a
solution of I part of creosote in 400 of water; the second, a combination of 1 part of
water with 10 parts of creosote. It unites in all proportions with alcohol, hydric ether,
acetic ether, naptha, eupione, carburet of sulphur, &c.
Creosote dissolves a large quantity of iodine and phosphorus, as also of sulphur with
the aid of heat, but it deposites the greater part of them in crystals, on cooling. It combines with potash, soda, ammonia, lime, baryta, and oxyde of copper. Oxyde of mercury
converts creosote into a resinous matter, while itself is reduced to the metallic state.
Strong sulphuric and nitric acids decompose it.
Creosote dissolves several salts, particularly the acetates, and the chlorides of calcium
and tin; it reduces the nitrate and acetate of silver. It also dissolves indigo blue; a
remarkable circumstance. Its action upon animal matters is very interesting. It coagun
lates albumen, and prevents the putrefaction of butchers' meat and fish. For this pur.
pose these substances must be steeped a quarter of an hour in a weak watery solution of
creosote, then drained and hung up in the air to dry. Hence Reichenbach has inferre4
that it is owing to the presence of creosote that meat is cured by smoking; but he is not
correct in ascribing the effect to the mere coagulation of the albumen, sincefibri  alone,
without creosote, will putrefy in the course of 24 hours, during the heats of summer. It
kills plants and small animals. It preserves flour paste unchanged for a long time.
Creosote exists in the tar of beech-wood, to the amount of from 20 to 25 per cent., and
In crude pyroligneous acid, to that of 1.
It ought to be kept in well-stoppered bottles, because when left open it becomes progressively yellow, brown, and thick.
Creosote has considerable power upon the nervous system, and has been applied to the
teeth with advantage in odontalgia, as well as to the skin in recent scalds. But its medicinal and surgical virtues have been much exaggerated. Its flesh-preserving quality
is rendered of little use, from the difficulty of removing the rank flavor. which it
unparts.
Having been employed by a chemical manufacturer to examine his creosote, and compare it with others with a view to the improvement of his process, I found that the
article, as made by eminent houses, differed considerably in its properties.
The specific gravities varied in the several specimens as follows: 1, a specimen given
me by Messrs. Zimmer and Sell, at their factory in Sachsenhausen, by Frankfort-on-theMaine, had a specific gravity of 1'0524; 2, a sample made in the north of England, sp.
gr. 1'057, and its boiling point varied from 3700 to 3800 Fabr. Mr. Morson's creosote,
which is much esteemed, has a sp. gr. of 10.70, and boils first at 2800, but progressively rises in temperature up to 4200, when it remains stationary. The German creosote was distilled from the tar of the pyrolignous acid manufacture. Creosote, I believe,
is often made from Stockholm tar. Berzelius gives the sp. gr. of creosote at 1'037, and
its boiling point at 2030 C.=397.40 F. I deemed it useless to subject to ultimate analysis products differing so considerably in their physical properties. They were all very
sollble in potash lye.
CROSS-FLUCKANS or FLOOKANS. The name given by the Cornish miners to
clay veins of more ancient formation.
CRUCIBLES (Creusets, Fr.; SchmeLtiegel, Germ.) are small conical vessels, narrower
at the bottom than the mouth, for reducing ores in docimasy by the dry analysis, for
fusing mixtures of earthy and other substances, for melting metals, and compounding
metallic alloys. They ought to be refractory in the strongest heats, not readily acted
upon by the substances ignited in them, not porous to liquids, and capable of bearing
considerable alternations of temperature without cracking; on which account they
should not be made too thick. The best crucibles are formed from a pure fire-clay,
mixed with finely-ground cement of old crucibles, and a portion of black-lead or graphite.  Some pounded coke may be mixed with the plumbago. The clay should be
prepared in a similar way as for making pottery ware; the vessels after being formed
must be slowly dried, and then properly baked in the kiln. Crucibles formed of a
mixture of 8 parts in bulk of Stourbridge clay and cement, 5 of coke, and 4 of graphite,




CRYSTAL.                                       555
have been found to stand 23 meltings of 76 pounds of iron each, in the Royal Berlin
foundry. Such crucibles resisted the greatest possible heat that could be produced, in
which even wrought iron was melted, equal to 1500 or 1550 Wedgewood; and. bore
sudden cooling without cracking. Another composition for brass-founding crucibles is
the following: ^ Stourbridge clay; - burned-clay cement; 1 coke powder;  pipe clay.
The pasty mass must be compressed in moulds. The Hessian crucibles from Great Almerode and Epeterode are made from a fire-clay which contains a little iron, but no
lime; it is incorporated with siliceous sand. The dough is compressed in a mould,
dried, and strongly kilned. They stand saline and leaden fluxes in docimastic operations very well; are rather porous on account of the coarseness of the sand, but are
thereby less apt to crack from sudden heating or cooling. They melt under the fusing
point of bar iron. Beaufoy in Paris has lately succeeded in making a tolerable imitation of the Hessian crucibles with a fire-clay found near Namur in the Ardennes.
Berthier has published the following elaborate analyses of several kinds of crucibles:Hessian.  Beaufay. English for St. Etienne  Pots Bohemian Gl ass Pots Bo
a   Cast Steel. Cast Steel. at NemourslGlass Pots. of Creusot.
Silica   -  -  -    70-9     64-6      63-7      65-2      67-4      68-0      68-0
Alumina  -  -    24-8        34-4      20-7      250        320       29-0     28-0
Oxyde of Iron -      38        1.0       4-0      72         0-8       22        20
Magnesia -         trace      -          -       trace trace           0 5 trace trace
Water  -  -                             103 -         /3     1I
Wurzer states the composition of the sand and clay in the Hessian crucibles as follows;~
Clay; silica 10I; alumina 65'4; oxydes of iron and manganese 1-2; lime 0-3; water 23
Sand;       95-6            221                                  1.5       0-8
Black lead crucibles are made of two parts of graphite and one of fire clay; mixed
with water into a paste, pressed in moulds, and well dried; but not baked hard in the
kiln. They bear a higher heat than the Hessian crucibles, as well as sudden changes of
temperature; have a smooth surface, and are therefore preferred by the melters of gold
and silver. This compound forms excellent small or portable furnaces.
Mr. Anstey describes his patent process for making crucibles, as follows: Take two
parts of fine ground raw Stourbridge clay, and one part of the hardest gas coke, previously pulverized, and sifted through a sieve of one eighth of an inch mesh (if the
coke is ground too fine the pots are very apt to crack). Mix the ingredients together with
the proper quantity of water, and tread the mass well. The pot is moulded by hand upon
a wooden block, supported on a spindle which turns in a hole in the bench; there is a
gauge to regulate the thickness of the melting pot, and a cap of linen or cotton placed
wet upon the core before the clay is applied, to prevent the clay from sticking partially
to the core, in the taking off; the cap adheres to the pot only while wet, and may be
removed without trouble or hazard when dry. He employs a wooden bat to assist in
moulding the pot; when moulded, it is carefully dried at a gentle heat. A pot dried as
above, when wanted for use, is first warmed by the fire-side, and is then laid in the furnace with the mouth downwards (the red cokes being previously damped with cold
ones in order to lessen the heat); more coke is then thrown in till the pot is covered,
and it is now brought up gradually to a red heat. The pot is next turned and fixed in a
proper position in the furnace, without being allowed to cool, and is then charged with
cold iron, so that the metal, when melted, shall have its surface a little below the mouth
of the pot. The iron is melted in about an hour and a half, and no flux or addition of
any kind is made use of. A pot will last for fourteen or even eighteen successive meltings, provided it is not allowed to cool in the intervals; but if it cool, it will probably
crack. These pots, it is said, can bear a greater heat than others without softening, and
will, consequently, deliver the metal in a more fluid state than the best Birmingham pots
will. See a figure of the crucible mould under STEEL.
CRYSTAL is the geometrical form possessed by a vast number of mineral and saline
substances; as also by many vegetable and animal products. The integrant particles of
matter have undoubtedly determinate forms, and combine with one another, by the
attraction of cohesion, according to certain laws, and points of polarity, whereby they
assume a vast variety of secondary crystalline forms. The investigation of these laws
belongs to crystallography, and is foreign to the practical purpose of this volume.
* This crucible had been analyzed before being baked in the kiln.




556                        CURRYING OF LEATHER.
structions are given under each object of manufacture which requires crystallization,
how to conduct this process. See BORAX, SALT, &c.
CUDBEAR was first made an article of trade in this country, by Dr. Cuthbert
Gordon, from whom  it derived its name, and was originally manufactured on a great
scale by Mr. G. Mackintosh, at Glasgow, nearly 80 years ago. Cudbear or persio is a
powder of a violet red color, difficult to moisten with water, and of a peculiar but not
disagreeable odor.  It is partially soluble in boiling water, becomes red with acids and
violet blue with alkalis.  It is prepared in the same way as archil, only towards the
end the substance is dried in the air, and is then ground to a fine powder, taking care to
avoid decomposition, which renders it glutinous In Scotland they use the lichen tartareus, more rarely the lichen calcareus, and omphalodes; most of which lichens are
imported from Sweden and Norway, under the name of rock moss. The lichen is suffered
to ferment for a month, and is then stirred about to allow any stones which may be present to fall to the bottom.  The red mass is next poured into a flat vessel, and left to
evaporate till its urinous smell has disappeared, and till it has assumed an agreeable
color verging upon violet.  It is then ground to fine powder.  During the fermentation
of the lichen, it is watered with stale urine, or with an equivalent ammoniacal liquor of
any kind, as in making archil.
CUPELLATION is a mode of analyzing gold, silver, palladium, and platinum, by
adding to small portions of alloys, containing these metals, a bit of lead, fusing the
mixture in a little cup of bone earth called a cupel, then by the joint action of heat and
air, oxydizing the copper, tin, &c., present in the precious metals. The oxydes thus produced are dissolved and carried down into the porous cupel in a liquid state, by the
vitrified oxyde of lead. See ASSAY, GOLD, and SILVER.
CURRYING  OF  LEATHER  (Corroyer, Fr.; Zurichten, Germ.) is the art of
dressing skins after they are tanned, for the purpose of the shoe-maker, coach and harness
maker, &c., or of giving them the necessary smoothness, lustre, color, and suppleness.
The currier's shop has no resemblance to the tanner's premises, having a quite different
set of tools and manipulations.
The currier employs a strong hurdle about a yard square, made either of basket twigs,
or of wooden spars, fixed rectangularly like trellis work, with holes 3 inches square,
upon which he treads the leather, or beats it with a mallet or hammer, in order to soften
it, and render it flexible.
The head knife, called in French couteau a revers, on account of the form of its edge,
which is much turned over, is a tool 5 or 6 inches broad, and 15 or 16 long; with
two handles, one in the direction of the blade, and the other perpendicular to it, for the
Q> ~~4~41      ~          purpose  of guiding  the
^^^^^^^41                                     edge  more  truly  upon
447                the skin.  The pommel
(paumelle)  is so  called
I43                       442I                              because  it clothes  the
f~'~ ~1 ^~palm  of the hand, and
performs  its  functions.
It is made of hardwood
and is of a rectangular
*/u ~ //| shape, 1  foot  long  5'^ y^          \. j          inches broad, flat above
and rounded below. It is
G/ y/^ ~^F\              furrowed over the rounded surface with transverse
These  groin
section sharp-edged isosceles  triangles.   Figs.
441   and   442,  represent the pommel in an
uppwr and under view. The flat surface is provided with a leather strap for securing,t to the hand of the workman. Pommels are made of different sizes, and
witL grooves of various degrees of fineness.  Cork pommels are also used, but they
are rot grooved. Pommels serve to give grain and pliancy to the skins.
The stretching iron, fig. 443, is a flat plate of iron or copper, fully a fourth of an
inch tick at top, and thinning off at bottom in a blunt edge, shaped like the arc of a
circle of large diameter, having the angles a and b rounded, lest in working they should
penetrate the leather. The top c is mounted with leather to prevent it from hurting the
hands. A copper stretching knife is used for delicate skins. The workman holds this
tool nearly perpendicular, and scrapes the thick places powerfully with his two hands,
especially those where some tan or flesh remains. He thus equalizes the thickness of




CURRYING OF LEATHER.                                     557
the skin, and renders it at the same time more dense and uniform in texture. This
tool is of very general use in currying.
The round knife, figs. 444 and 445 (lunette in French), is a circular knife from 10 to
12 inches in diameter, with a round 4 or 5 inch hole in its centre, for introducing the
hands and working it. It is concave, as shown in the section fig. 445, presenting the
form of a spherical zone. The concave part is that applied to he klin. Its edge is not
perfectly straight; but is a little turned over on the side opposite to the skin, to preven
444                  445              it from  entering too far into the leather.  The urrier first slopes off with
the head knife from the edges, a porJ J ^    )    j   tion equal to what he afterwards removes with the round one.  By this
division the work is done sooner and
^Q            ^ _446^         /                 more exactly. All tVe   le         greased
skins are dressed with the rolnd knife.
The cleaner is a straight two-handled knife two inches broad, of which
there are two kinds, a sharp-edged and a blunt one. Fig. 446.
The mace is made of wood, having a handle 30 inches long, with a cubical head or
mallet; upon the two faces of which, parallel to the line of the handle, there are 4 pegs
of hard wood turned of an egg-shape, and well polished, so as not to tear the moistened
leather when it is strongly beat and softened with the mace.
The horse or trestle, fig. 447, consists of a strong wooden frame, A B CD, which serves as
a leg or foot. Upon the middle of this frame there are two uprights, E F, and a strong
cross beam, G, for supporting the thick plank H, upon which the skins are worked. This
plank may be set at a greater or less slope, according as its lower end is engaged in one
or other of the cross bars, I I I I, of the frame. In the figure, a skin K is represented upon
the plank with the head knife upon it, in the act of being pared.
A  cylindrical bar fixed horizontally at its ends to two buttresses projecting from the
wall, serves by means of a parallel stretched cord, to fix a skin by a coil or two in order
to dress it. This is accordingly called the dresser. The tallow cloth is merely a mop
made of stout rags, without the long handle; of which there are several, one for wax,
another for oil, &c.  Strong-toothed pincers with hook-end handles, drawn together
by"an endless cord, are employed to stretch the leather in any direction, while it is being
dressed. The currier uses clamps like the letter U, to fix the edges of the leather to his
table. His polisher is a round piece of hard wood, slightly convex below, with a handle
standing upright in its upper surface, for seizing it firmly. He first rubs with sour beer,
and finishes with barberry juice.
Every kind of tanned leather not intended for soles or such coarse purposes, is
generally curried before being delivered to the workmen who fashion it, such as shoemakers, coachmakers, saddlers, &c. The chief operations of the currier are four:~
1. Dipping the leather, which consists in moistening it with water, and beating it
with the mace or a mallet upon the hurdle.  He next applies the cleaners, both blunt
and sharp, as well as the head knife, to remove or thin down all inequalities. After the
leather is shaved, it is thrown once more into water, and well scoured by rubbing the
grain side with pumice stone, or a piece of slaty grit, whereby it parts with the bloom, a
whitish matter, derived from the oak bark in the tan pit.
2. Applying the pommel to give the leather a granular appearance, and correspondent
flexibility. The leather is first folded with its grain side in contact, and rubbed strongly
with the pommel, then rubbed simply upon its grain side; whereby it becomes extremely
flexible.
3. Scraping the leather.  This makes it of uniform thickness.  The workman holds
the tool nearly perpendicular upon the leather, and forcibly scrapeb the thick places with
both his hands.
4. Dressing it by the round knife. For this purpose he stretches the leather upon
the wooden cylinder, lays hold of the pendent under edge with the pincers attached to
his girdle, and then with both hands applies the edge of the knife to the surface of the
leather, slantingly from above downwards, and thus pares off the coarser fleshy parts of
the skin.  This operation requires great experience and dexterity; and when well performed improves greatly the look of the leather.
The hide or skin, being rendered flexible and uniform, is conveyed to the shed or drying
house, where the greasy substances are applied, which is called dubbing (daubing) or
stuffing. The oil used for this purpose is prepared by boiling sheep-skins or doe-skins,
in cod oil. This application of grease is often made before the graining board or pommel
is employed.
Before waxing, the leather is commonly colored by rubbing it with a brush dipped
into a composition of oil and lamu black on the flesh side, till it be thoroughly black; it is




558                                   CUTLERY.
then black-sized with a brush or sponge, dried, tallowed with the proper cloth, and
slicked upon the flesh with a broad, smooth lump of glass; sized again with a sponge
and when dry, again curried as above described.
Currying leather on the hair or grain side, tehe same in
the first operation with that dressed on the flesh, till it is scoured. Then the first black
is applied to it while wet, by a solution of copperas put upon the grain, after this has
been rubbed with a stone; a brush dipped in stale urine is next rubbed on, then an iroa
slicker is ased to make the grain come out as fine as possible.  It is now  stuffed with
oil.  When dry, it is seasoned; that is, rubbed over with a brush dipped in copperas
water, on the grain, till it be perfectly black. It is next slicked with a good grit-stone,
to take out the wrinkles, and smooth the coarse grain. The grain is finally raised with
the pommel or graining board, by applying it to the leather in different directions.
When thoroughly dry, it is grained again in two or three ways.
Hides intended for covering coaches are shaved nearly as thin as shoe hides, and
blacked upon the grain.
CUTLERY.  (Coutellerie, Fr.; Messerschmidwaare, Germ.)  Three kinds of steel
are made use of in the manufacture of different articles of cutlery, viz., common steel,
shear steel, and cast steel. Shear steel is exceedingly plastic and tough. All the edge
tools which require great tenacity without great hardness are made of it, such as table
knives, scythes, plane-irons, &c.
Cast steel is formed by melting blistered steel in coveiO crucibles, with botte glass,
and pouring it into cast-iron moulds, so as to form it into ingots; these ingots are then
taken to the tilt, and drawn into rods of suitable dimensions.  No other than cast steel
can assume a very fine polish, and hence all the finer articles of cutlery are made of it,
such as the best scissors, penknives, razors, &c.
Formerly cast steel could be worked only at a very low heat; it can now be made so
as to be welded to iron with the greatest ease. Its use is consequently extended to
making very superior kinds of chisels, plane-irons, &c.
Forging of table knives. - Two men are generally employed in the forging of table
knives; one called the foreman or maker, and the other the striker.
The steel called common steel is employed in making the very common articles; but
for the greatest part of table knives which require a surface free from flaws, shear steel
is generally preferred.   That part of the knife termed the blade, is first rudely formed
and cut off.  It is next welded to a rod of iron about ^ inch square, in such a manner,as to leave as little of the iron part of the blade exposed as possible.  A sufficient quantity
of the iron now attached to the blade, is taken off from the rod to form the bolster or
shoulder, and the tang.
In order to make the bolster of a given size, and to give it at the same time shape
and neatness, it is introduced into a die, and a swage placed upon it; the swage has a
few smart blows given it by the striker. This die and swage are, by the workman,
called prints.
After the tangs and bolster are finished, the blade is heated a second time, and the
foreman gives it its proper anvil finish; this operation is termed smithing.  The blade
is now heated red-hot, and plunged perpendicularly into cold water.  By this means it
becomes hardened.  It requires to be tempered regularly down to a blue color: in which
state it is ready for the grinder.
Mr. Brownill's method of securing the handles upon table-knives and forks, is, by
lengthening the tangs, so as to pass them completely through the handle, the ends of
which are to be tinned after the ordinary mode of tinning iron; and, when passed
through the handle, the end of the tang is to be spread by beating, or a small hole
drilled through it, and a pin passed to hold it upon the handle. After this, caps of
metal, either copper plated or silver, are to be soldered on to the projecting end of the
tang, and while the solder is in a fluid state, the cap is to be pressed upon the end of
the handle and held there until the solder is fixed, when the whole is to be cooled by
being immersed in cold water.
Mr. Thomason's patent improvements consist in the adaptation of steel edges to the
blades of gold and silver knives.  These steel edges are to be attached to the other
metal, of whatever quality it may be, of which the knife, &c. is made, by means of
Bolder, in the ordinary mode of effecting that process. After the edge of steel is thus
attached to the gold, silver, &c., it is to be ground, polished, and tempered by immersion
in cold water or oil after being heated. This process being finished, the other parts of
the knife are then wrought and ornamented by the engraver or chaser, as usual.
A patent was obtained in 1827, by Mr. Smith of Sheffield, for rolling out knives at one
operation.
In the ordinary mode of making knives, a sheet of steel being provided, the blades are
cut out of the sheet, and the backs, shoulders, and tangs, of wrought iron, are attached to




CUTLERY.                                         559
the steel blades, by welding at the forge. The knife is then ground to the proper shape,
and the blade polished and hardened.
Instead of this welding process, the patentee proposes to make the knives entirely of
steel, and to form them by rolling in a heated state between massive rollers; the shoulders or bolsters, and the tangs for the handles being produced by suitable recesses in
the peripheries of the rollers; just as railway rails are formed. When the knife is to
be made with what is called a scale tang, that is, a broad flat tang, to which the handle
is to be attached in two pieces, riveted on the sides of the tang, the rollers are then only
to have recesses cut in them, in a direction parallel to the axis for forming the bolster.
The plate of steel, having been heated, is to be pressed between the two rollers, by
which the blades and the parts for the scale tangs will be pressed out flat and thin, and
those parts which pass between the grooves or recess will be left thick or protuberant,
forming the bolster for the shoulder of the blade.   But if the tangs are to be round in
order to be fixed into single handles, then it will be necessary also to form transverse
grooves in the rollers, that is, at right angles to those which give shape to the bolsters,
the transverse grooves corresponding in length to the length of the intended tang.
When the plates of steel have been thus rolled, forming three or more knives in a
breadth, the several knives are to be cut out by the ordinary mode of what s called slitting, and the blades and shoulders ground, hardened, and polished in the usual way.
Forks are generally a distinct branch of manufacture from that of knives, and are
purchased of the fork makers by the manufacturers of table knives, in a state fit for receiving the handles.
The rods of steel from which the forks aie made, are about Aths of an inch square.
The tang and shank of the fork are first roughly formed.  The fork is then cut off,
leaving at one end about 1 inch of the square part of the steel.  This part is afterwards
drawn out Rfat to about the length of the prongs.   The shank and tang are now
heated, and a proper form given to them by means of a die and swage. The prongs are
afterwards formed at one blow by means of the stamp; this machine is very similar to
that used in driving piles, but it is worked by one man.   It consists of a large anvil
fixed in tI block of stone nearly on a level with the ground.  To this anvil are attached
two rods of iron of considerable thickness, fixed twelve inches asunder, perpendicularly to
the anvil, and diagonally to each other.  These are fastened to the ceiling.  The hammer or stamp, about 100 lbs. in weight, having a groove upon either side corresponding to
the angles of the upright rods, is made to slide freely through its limited range, being
conducted by its two iron supporters.  A rope is attached to the hammer, which goes
over a pulley on the floor of the room above, and comes down to the person who works
the stamp: two.corresponding dies are attached, one to the hammer, and the other to
the anvil. That part of the fork intended to form the prongs, is heated to a pretty white
heat and placed in the lower die, and the hammer containing the other die is made to
fall upon it from a height of about 7 or 8 feet.  This forms the prongs and the middle
part of the fork, leaving a very thin substance of steel between each prong, which is
afterwards cut out with an appropriate instrument called a fly-press.  The forks are now
annealed by surrounding a large mass of them with hot coals, so that the whole shall
become red-hot.  The fire is suffered gradually to die out, and the forks to cool without
being disturbed.   This process is intended to soften, and by that means to prepare them
for filing. The inside of the prongs is then filed, after which they are bent into their
proper form and hardened.  When hardened, which is effected by heating them red-hot
and plunging them into cold water, they are tempered by exposing them to tho degree of
heat at which grease inflames. See STAMPS.
Penknives are generally forged by a single hand, with the hammer and the anvil sim
ply. * The hammer in this trade is generally light, not exceeding 3j lbs.   The breadth
of the, face, or the striking part, is about one inch; if broader, it would not be convenient for striking so small an object. The principal anvil is about 5 inches, and 10 upon
the face, and is provided with a groove into which a smaller anvil is wedged.  The
smaller anvil is about 2 inches square upon the face.  The blade of the knife is first'drawn out at the end of the rod of steel, and as much more is cut off along with it as
is thought necessary to form the joint. The blade is then taken in a pair of tongs, and
*heated a second time to finish the joint part, and at the same time to form a temporary
tang for the purpose of driving into a small haft used by the grinder.  Another heat is
taken to give the blade a proper finish.  The small recess called the nail-hole, used in
opening the knife, is made while it is still hot by means of a chisel, which is round on
one side, and flat upon the other.
Penknives are hardened by heating the blade red-hot, and dipping them into water up
to the shoulder.  They are tempered by setting them side by side, with the back downwards upon a flat iron plate laid upon the fire, where they are allowed to remain till they
are of a brown or purple color.
36




560                                  CUTLERY.
The blades of pocket knives, and all that come under the denomination of spring
knives, are made in the same way.
The forging of razors is performed by a foreman and striker, as in making table
knives.
They are generally made of cast steel.  The rods, as they come from the tilt, are
about U inch broad, and of a thickness sufficient for the back of a razor.
There is nothing peculiar in the tools made use of in forging razors: the anvil is a,ittle rounded at the sides, which affords the opportunity of making the edge thinner, and
saves an immense labor to the grinder.
Razors are hardened and tempered in a similar manner to penknives. They are,
however, left harder, being only let down to yellow or brown color.
The forging of scissors is wholly performed by the hammer, and all the sizes are made
by a single hand. The anvil of the scissor-maker weighs about 11 cwt.; it measures,
on the face, about 4 by 11 inches. It is provided with two grates or grooves for the reception of various little indented tools termed by the workman bosses; one of these
bosses is employed to give proper figure to the shank of the scissors; another for forming that part which has to make the joint; and a third is made use of for giving a proper
figure to the upper side of the blade. There is also another anvil placed on the same
block, containing two or three tools called beak-irons, each consisting of an upright stem
about 6 inches high, at the top of which a horizontal beak projects; one of these beaks
is conical, and is used for extending the bow of the scissors; the other is a segment of a
cylinder with the round side upwards, containing a recess for giving a proper shape and
smoothness to the inside of the bow.
The shank of the scissors is first formed by means of one of the bosses, above described, leaving as much steel at the end as will form the blade. A hole is then punched
about I inch in width, a little above the shank. The blade is drawl out and finished,
and the scissors separated from the rod a little above the hole. It is heated a third time,
and the small hole above mentioned is extended upon the beak-irons so asto form the
bow. This finishes the forging of scissors. They are promiscuously made in this way,
without any other guide than the eye, having no regard to their being in pairs. They
are next annealed for the purpose of filing such parts of them as cannot be ground, and
afterwards paired.
The very large scissors are made partly of iron, the blades being of steel.
After the forging, the bow and joints, and such shanks as cannot be ground, are
filed. The rivet hole is then bored, through which they are to be screwed or riveted
together. This common kind of scissors is only hardened up to the joint. They
are tempered down to a purple or blue color. In this state they are taken to the
griinder.
Grinding and polishing of cutlery.-The various processes which come under this
denomination are performed by machinery, moving in general by the power of the steamengine or water-wheel.
Grinding wheels or grinding mills are divided into a number of separate rooms; every
room contains six places called troughs; each trough consists of a convenience for running a grindstone and a polisher at the same time, which is generally occupied by a man
and a boy.
The business of the grinder is generally divided into three stages, viz., grinding,
glazing, and polishing.
The grinding is performed upon stones of various qualities and sizes, depending on the
articles to be ground. Those exposing much flat surface, such as saws, fenders, &c.,
require stones of great diameter, while razors, whose surface is concave, require to be
ground upon stones of very small dimensions. Those articles which require a certain
temper, which is the case with most cutting instruments, are mostly ground on a wet
stone; for which purpose the stone hangs within the iron trough, filled with water to
such a height that its surface may just touch the face of the stone.
Glazing is a process following that of grinding: it consists in giving that degree of
lustre and smoothness to an article which can be effected by means of emery of the
various degrees of fineness. The tool on which the glazing is performed, is termed a
glazer. It consists of a circular piece of wood, formed of a number of pieces in such a
manner that its edge or face may always present the endway of the wood. Were it
made otherwise, the contraction of the parts would destroy its circular figure. It is
fixed upon an iron axis similar to that of the stone. Some glazers are covered on the
face with leather, others with metal, consisting of an alloy of lead and tin; the latter
are termed caps. In others, the wooden surface above is made use of. Some of the
leather-faced glazers, such as are used for forks, table knives, edge tools, and all the
coarser polished articles, are first coated with a solution of glue, and then covered with
emery. The surfaces of the others are prepared for use by first turning the face very




CIDER.                                        561
true, then filling it with small notches by means of a sharp-ended hammer and' lastly
filling up the interstices with a compound of tallow and emery.
The pulley of the glazer is so much less than that of the stone, that its velocity is
more than double, having in general a surface-speed of 1,500 feet in a second.
The process of polishing consists in giving the most perfect polish to the different
articles. Nothing is subjected to this operation but what is made of cast steel, and has
been previously hardened and tempered.
The polisher consists of a circular piece of wood covered with buff leather, the surface of which is covered from time to time, while in use, with the crocusof iron, called
also colcothar of -vitriol.
The polisher requires to run at a speed much short of that of the stone, or the glazer.
Whatever may be its diameter, the surface must not move at a rate exceeding 10 or 80
feet in a second.
CYANATES;, saline compounds of cyaBic acid with the bases potash, soda, ammonia, baryta, &c. The first is prepared by calcining at a dull red heat, a mixture of
ferro-cyanide of potassium (prussiate of potash) and black oxide of manganese. The
cyanates have not hitherto been applied to any use in the arts.
CYANHYDRIC ACID; another name for the hydrocyanic or prussic acid.  See
PRUSSIAN BLUE and PRUSSIC ACID.
CYANIDES; compounds of cyanogen with the metals; as cyanide of potassium,
sodium, barium, calcium, iron, mercury. The last is the only one of importance in a
manufacturing point of view, since from it prussic acid is often made.
CYANIDES, FERRO.  Double compounds of cyanogen with iron, and of cyanogen
with another metal, such as potassium, sodium, barium, &c. The ordinary yellow prussiate of potash lhas this constitution, and is called the ferro-cyanide.
CYANIDE OF POTASSIUM.  This salt, so much used now in the electrotype processes, is prepared, according to Liebig's formula, by mixing 8 parts of pounded prussiate
of potash, sharply dried, with 3 parts of pure carbonate of potash, fusing the mixture
in an iron crucible, by a moderate red heat, and keeping it so, till the glass or iron rod
with which the fluid mass should be occasionally stirred, comes out covered with a
white crust.  The crucible is then to be removed from  the fire; and after the disengaged iron has fallen to the bottom, the supernatant fluid, still obscurely red hot, is to
be, poured off upon a clean surface of iron or platinum. After concretion and cooling,
the wite saline mass is to be pounded while hot, and then kept in a well-stopped bottle. It consists of about only 60 per cent. of cyanide of potassium, and I of cyanate of
potash.  For most purposes, and the analysis of ores, the latter ingredient is no ways
detrimental. It contains much of other potash salts.
CYANOGEN.  A gaseous compound of two prime equivalents of charcoal =  12, and
OTe of azote =  14 = 26; hydrogen being the radix, or 1. It consists of two volumes
of vapor of carbon, and one volume of azote, condensed into one volume; and has therefore a density equal to the sum of the weights of these three gaseous volumes = l'815.
Cyanogen is readily procured by exposing the cyanide of mercury to a dull red heat in
a retort; the gas is evolved and may be collected over mercury. Its smell is very sharp
and penetrating; it perceptibly reddens tincture of litmus; it is condensable by pressure
at a low temperature into a liquid; and by a still greater degree of cold, it is solidified.
When a lighted taper is applied to a mixture of cyanogen and oxygen, an explosion takes'
place; carbonic acid is formed, and the azote is set at liberty.
For a connected view of the various compounds of cyanogen employed in the arts, see
PRUSSIAN BLUE.
CIDER  (Cidre, Fr.;.Apfelwein, Germ.); the vinous fermented juice of the apple.
The ancients were acquainted with cider and perry, as we learn from the following passage of Pliny the naturalist: "Wine is made from the Syrian pod, from pears and apples
of every kind." Book xiv. chap. 19.  The terrh cider or cidre in French, at first written
sidre, is derived from the Latin word sicera, which denoted all other fermented liquors
except grape wine. Cider seems to have been brought into Normandy by the Moors of
Biscay, who had preserved the use of it after coming into that country from Africa. It
was afterwards spread through some other provinces of France, whence it was intro.
duced into England, Germany, and Russia. It is supposed that the first growths of Nor~.
inandy afford still the best specimens of cider. Devonshire and Herefordshire are the
counties of England most famous for this beverage.
Strong and somewhat elevated ground, rather dry, and not exposed to the air of the
sea, or to high winds, are the best situations for the growth of the cider apple. The
fruit should be gathered in dry weather. The juice of apples is composed of a great
deal of water; a little sugar analogous to that of the grape; a matter capable of causing
fermentation with contact of air; a pretty large proportion of mucilage, with malic acid,
acetic acid, and an azotized matter ini a very small quantity. The seeds contain a bitter
substance and a little essential oil; the pure parenchyma or cellular membrane constitutes




562                                      CIDER.
not more than two per cent. of the whole. After the apples are gathered, they are left
in the barn-loft for fifteen days or upwards to mellow; some of them in this case, however, become soft and brown. This degree of maturation diminishes their mucilage,
and develops alcohol and carbonic acid; in consequence of which the cider suffers no
injury. There is always, however, a little loss; and if this ripening goes a little further
it is very apt to do harm, notwithstanding the vulgar prejudice of the country people
to the contrary.  Too much care, indeed, cannot be taken to separate the sound from
the spoiled apples; for the latter merely furnish an acid leaven, give a disagreeable
taste to the juice, and hinder the cider from fining, by leaving in it a certain portion
of the parenchyma, which the gelatinous matter or the fermentation has diffused through
it. Unripe apples should be separated from the ripe also, for they possess too little
saccharum to be properly susceptible of the vinous fermentation.
In France, where cider-making is most scientifically practised, it is prepared by
crushing the apples in a mill with revolving edge-stones, turned in a circular stone cistern by one or two horses. When the fruit is half mashed, about one fifth of its weight
of river water is added, or the water of lakes. The latter has been found by experience to be preferable to other water.
In some places a mill composed of two cast-iron fluted cylinders, placed parallel to
each other under the bottom of a hopper, is employed for crushing the apples. One of
the cylinders is turned by a winch, and communicates its motion in the opposite direction by means of the flutings working into each other.  Each portion of the fruit must
be passed thrice through this rude mill in order to be sufficiently mashed; and the same
quantity of water must be added as in the edge stone mill.
After the apples are crushed they are usually put into a large tub or tun for 12 or 24
hours. This steeping aids the separation of the juice, because the fermentative motion
which tak s place in the mass breaks down the cellular membranes; but there is always
a loss of alcohol carried off by the carbonic acid disengaged, while the skins and seeds
develop a disagreeable taste in the liquid.   The vatting might be suppressed if the apples
were so comminuted as to give out their juice more readily.  With slight modifications,
the process employed in rasping and squeezing the beet-roots might in my opinion be
applied with great advantage to the cider manufacture. See SUGAR.
After the vatting, the mashed fruit is carried to the press and put upon a square wicker
frame or into a hair bag, sometimes between layers of straw, and exposed stratum super
stratum  to strong pressure till what is called a cheese or cake is formed. The mass
is to be allowed to drain for some time before applying pressure, which ought to
be very gradually increased.   The juice  which  exudes with  the least pressure
affords the best cider; that which flows towards the end acquires a disagreeable taste
from the seeds and the skins.  The must is put into casks with large bungholes, where
it soon begins to exhibit a tumultuous fermentation.  The cask must be completely
filled, in order that all the light bodies suspended in the liquid when floated to the top
by the carbonic acid may flow over with the froth; this means of clearing cider is
particularly necessary with the weak kinds, because it cannot be expected that these
matters in suspension will fall to the bottom of the casks after the motion has ceased.
In almost every circumstance besides, when no saccharine matter has been added to the
must, that kind of yeast which rises to the top must be separated, lest by precipitation
it may excite an acid fermentation in the cider.   The casks are raised upon gawntrees
or stillions, in order to place flat tubs below them to receive the liquor which flows over
with the froth.  At the end of two or three days, for weak ciders which are to be
drunk somewhat sweet, of 6 or 10 days or more for stronger ciders, with variations for
the state of the weather, the fermentation will be sufficiently advanced, and the cider may
be racked off into other casks.  Spirit puncheons preserve cider better than any other,
but in all cases the casks should be well seasoned and washed. Sometimes a sulphur
match is burned in them before introducing the cider, a precaution to be generally
recommended, as it suspends the activity of the fermentation, and prevents the formation
of vinegar.
The cider procured by the first expression is called cider without water.  The cake
remaining in the press is taken out, divided into small pieces, and mashed anew, adding
about half the weight of water, when the whole is carried back to the press and treated
as above described.  The liquor thus obtained furnishes a weaker cider which will not
keep, and therefore must be drunk soon.
The cake is once more mashed up with water, and squeezed, when it yields a liquor
which may be used instead of water for moistening fresh ground apples.
The processes above described, although they have been long practised, and have
therefore the stamp of ancestral wisdom, are extremely defective. Were the apples ground
with a proper rotatory rasp which would tear all their cells asunder, and the mash put
through the hydraulic press in bags between hurdles of wicker-work, the juice would
be obtained in a state of perfection fit to make a cider superior to many wines




DAGUERREOTYPE.                                         563
An experimental process of this kind has been actually executed in France upon a considerable scale, with the best results. The juice had the fine flavor of the apple, was
fermented by itself without any previous fermentation in the mash, and afforded an
excellent strong cider, which kept well.
When the must of the apples is weak or sour, good cider cannot be made from it
without the addition of some saccharine matter. The syrup into which potato farina
is convertible by diastase (saccharine ferment), see STARCH and SUGAR, would answer
well for enriching poor apple-juice.
The value of apples to produce this beverage of good quality is proportionate to the
specific gravity of their juice. M. Couverchel has given the following table, illustrative
of that proposition:Juice of the green renette, queen apple (reinette verte)  -        -1094
English renette                                          1080
Red renette           -       -       -               -1072
Musk renette..-.1069
Fouillet raye         -                                  1064
Orange apple                          -       -       -1063
Renette of Caux                                          1060
Water                 -       -       -       -       -  1000
Cider apples may be distributed into three classes-the sweet, the bitter, and the
sour. The second are the best; they afford a denser juice, richer in sugar, which clarifies well, and when fermented keeps a long time; the juice of sweet apples is difficult
to clarify; but that of the sour ones makes bad cider. Late apples are in general to
be preferred. With regard to the proper soil for raising apple-trees, the reader may
consult with advantage an able essay upon "The Cultivation of Orchards and the
making of Cider and Perry," by Frederick Falkner, Esq., in the fourth volume of the
Royal Agricultural Journal. He adverts judiciously to the necessity of the presence
of alkaline and earthy bases in the soils of all deciduous trees, and especially of such
as produce acid fruits.
In November, 2340 kilogrammes of apples (2k tons English, nearly) are supposed to
afford 1000 litres (22011 gallons) of pure cider; and 600 litres of a small cider made
with the marc mixed with water and pressed. But many persons mix all together, and
thus manufacture 1600 litres out of the above weight of fruit.  In France, the fermented
liquor, as soon as it is clear, is often racked off into casks containing the fumes of burning sulphur, whereby it ceases to ferment, and preserves much of its sugar undecomposed. It is soon afterwards bottled. Average cider should yield 6 per cent. of alcohol on distillation.
D.
DAGUERREOTYPE. This new and most ingenious invention, for producing pictures by the action of light, is due to M. Daguerre and M. Niepee, two Frenchmen. It
was purchased from them by the French government for the benefit of the nation at
large; but was made the subject of an exclusive patent in this country by M. Daguerre,
as our government never purchases any scientific invention.
The fixation of the images, formed in the focus of the camera obscura, is made on
very smooth surfaces of pure silver plated on copper. The process is divided into five
operations. 1. The first consists in polishing and cleaning the silver surface, by friction with cotton fleece imbued with olive oil, upon the plate, previously dusted over
with very finely-ground dry pumice-stone out of a muslin bag.  The hand of the
operator should be moved round in circles, of various dimensions. The plates should
be laid upon a sheet of paper solidly supported.  The pumice must be ground to
an impalpable powder upon a porphyry slab with water, and then dried. The sturface is next to be rubbed with a dossil of cotton, slightly moistened with nitric acid,
diluted with sixteen parts of water, by applying the tuft to the mouth of the phial o!
acid, and inverting it for a moment. Two or three such dossils should be used in
succession.  The plate is lastly to be sprinkled with pumice powder or Venetian
tripoli, and rubbed clean with cotton.
The next step is to heat the plate by placing it in a wire frame (fig. 449), with the
silver surface uppermost, over a spirit lamp, meanwhile moving it so as to act equally
on every part of the plate. In about five minutes a whitish coating will indicate that
this operation is completed. The plate must now be laid upon a flat metal or marble
slab to cool it quickly. The white surface is to be brightened by rubbing it with
cotton and pumice powder. It must be once more rubbed with the cotton imbued
With acid, and afterward dried by friction with cotton and pumice; avoiding to touch




564                              DAGUERREOTYPE.
the plate with the -fingers, or with the part of the cotton held in them, or to breathe
upon the plate, since spots would thereby be produced. After cleaning with cotton
alone, the plate is ready for the next operation.
2. Here the following implements are required: 1, the box represented in figs. 450
and 451; 2, the thin board or frame, fig. 452; four small metallic bands of the same
a    4__ _1__
449
454
c a d   d    4  d —--..-. II       __....
d 4, d 
_                      d,
metals as the plates, also shown infig, 452, a small handle and a box of small nails or
tac-ks, and a phial of iodine.
After fixing, by the metallic bands and the small nails, the plate upon the thin
board, with the silver uppermost, several particles of iodine are then to be spread in
the dish d, at the bottom of the box, figs. 450, and 451. The thin board with the plate,
is next placed, with the silver beneath, upon small supports at the four corners of the
box, and its cover is applied. The plate must be left in this position till the surface of
the silver acquires a fine golden hue, caused by the vapors of the iodine rising through
the gauze cover of the dish, and condensing upon it; but it should not be allowed to
assume a violet tint. The room should be darkened, and no heat should be employed.
When the box is in constant use it gets impregnated with iodine, and acts more uniformly and rapidly; but in general states of the atmospheric temperature this operation
will be effected in about twenty minutes. If the purple color be produced, the plate
must be repolished, and the whole process repeated.
The plate with its golden hue is to be introduced with its board into the frame, figs.
453,454,455, which is adapted to the camera obscura. During this transfer the light must
not be suffered to strike upon the surface of the plate; on which account, the camera
obscura may be lighted briefly with a small wax taper.
3. The plate is now submitted to the third operation, that of the camera obscura,
figs. 456 and 448, and with the least possible delay. The action of this machine is obviously quicker the brighter the light which acts upon it; and more correct, according
as the focus is previously accurately adjusted to the place of the plate, by moving
backwards and forwards a roughened pane of glass, till the focal point be found; and
the plate is to be inserted precisely there, see figs. 453, 454, 455. This apparatus exactly replaces the ground glass. While the prepared plate is being fastened, the camera
must be closed. The darkening shutters, b b, of the apparatus are opened by means of
the two semicircles, a a. The plate is now in a proper position to receive and retain
the impression of the image of the objects presented the moment that the camera is
opened. Experience alone can teach the proper length of time for submitting the plato
to the concentrated rays of light; because that time varies with the climate, the seasons, and the time of day.  More time should not be allowed to pass than what is
necessary for fixing a distinct impression, because the parts meant to be clear would
be apt to become clouded.
4. The fourth is the operation with quicksilver, which must follow as soon as possible the completion of the third. Here a phial of quicksilver, a spirit-lamp (the
apparatus represented in figs. 457 and 458), and a glass funnel with a long neck, are
required. The funnel is used for pouring the mercury into the cup c, placed in the




DAGUERREOTYPE.                                        565
bottom of the apparatus, so as to cover the bulb of the thermometer f. No daylight
must now be admitted, but that of a small taper only should be used by the operator
in conducting the process.  The board with the plate is to be withdrawn from  the
k 
460 //^                ^,-^                 I                     ^459
L          __ i_     _.~ ~
C                                                     461
f \   h                    I M
camera, and inserted into the grooves of the blackened board, b, fig. 457. This black
board is laid back into the box at an angle of 45~ with the horizon; the prepared
metal surface h being placed undermost, so that it may be viewed through the side
glass g; and the cover, a, of the box must be put down gently, to prevent any particles of mercury from being thrown about by the agitation of the air. The whole
being thus prepared, the spirit-lamp is lighted, and placed under the cup containing
the mercury, and left there until the thermometer indicates a temperature of 140'
Fahr., when the lamp is to be removed. The heat should in no case be permitted to
exceed 1670 F.
The impression of the image of nature is now actually made upon the plate; but it
is yet invisible; and it is only after a lapse of several minutes that faint tracings of
the objects begin to be seen through the peep-glass by the momentary gleam of a
taper. The plate should be left in the box till the thermometer has cooled to 1130 F.,
when it is to be taken out.
After each operation, the interior of the apparatus, and the black board or frame,
should be carefully wiped, in order to remove every particle of mercury.
The picture may now be inspected in a feeble light, to see how far the process has
succeeded. The plate, freed from the metallic bands, is to be placed in a box, provided with a cover and grooves, to exclude the light, till it is made to undergo the fifth
and last operation, which may be done after any convenient interval of time without
detriment, provided the plate be kept in the dark. The following articles are now
required: 1, strong brine, or a weak solution of hyposulphate of soda; 2, the apparatus represented in figs. 459 and 460; 3, two troughs of tin-plate; 4, a jug of distilled water. The object of this process is to fix the photogenic picture. One of the




566                              DAGUERREOTYPE.
troughs is to be filled with brine to the depth of an inch, and the other with pure
water, both liquids being heated somewhat under the boiling pitch. The solution of
hyposulphite of soda is preferable, and does not need to be warm. The plate is to be
first immersed in the pure water for a moment, and transferred immediately to the
saline solution, and moved to and fro in it to equalize the action of the liquor. Whenever the yellow tint of the iodine is removed, the plate is to be lifted out by the
edges, and dipped straightway in the water-trough. The apparatus offigs. 459, and 460,
is then brought into use, with a vessel filled with distilled water, hot, but not boiling.
The plate, when lifted out of the water-trough, is to be placed immediately on the
inclined plane e; and without allowing it time to dry, is to be floated over with the
hot distilled water from the top, so as to carry off all the saline matter. As the quicksilver which traces the images will not bear touching, the silvered plate should be secured by a cover of glass, made tight at the edges by pasting paper round them.
Infg. 451, which is a plan view of the iodine-box apparatus, c is an interior cover;
d is the iodine-dish; e is the thin board to which the silvered plate is fixed, as shown
at fiq. 450; g is the cover of the box; h h are small rods, at the four corners of the
inclined lining, k, of the box, to support the lid c; j is a gauze of wire-cloth cover, to
diffuse the iodine vapor; k is the wooden lining, sloping like a hopper; d d, in fig.
454, are buttons to fasten the board on the doors; e shows the thickness of the frame;
f is the silvered plate. In fig. 461, a is the ground glass of the camera; b is a mirror
inclined about 45~ to the horizon, by means of the rod 1. The image of the object is
easily brought into focus by moving forward or backward the sliding-box d, in laying
hold of it with both hands by the projections a, fig. 454. When the focus is adjusted,
the thumbscrew, h, fixes the whole.  The mirror is kept closed by two hooks at f,
which take into small eyes at g.  The frame and ground glass plate are withdrawn
and replaced by the frame carrying the prepared plate, as represented in fig. 448, with
the shading doors, b, open in the camera. These doors and the sliding-box d are lined
with black velvet. The object glass is achromatic and periscopic, the-concave being
outside in the camera; its diameter is about 3k inches, and focus about 13 inches. A
diaphragm is placed before the object glass, at 31 inches from it, and its aperture may
be closed by a plate moving in a pivot. This camera reverses the objects from left to
right; but this may be obviated by placing a plane mirror on the outside beyond the
aperture of the diaphragm, as at f, fig. 456, where it is fixed by means of a screw, k.
Loss of light is thereby occasioned.
Fig. 457 is an upright section, andfig. 458, a front elevation of the mercurial apparatus.  a, the cover; b, the black board, with grooves to receive the board, hA; c, the
cup of quicksilver; d, the spirit-lamp; e, a small cock, through which the quicksilver
may be run off, if the apparatus be laid to one side; f, the thermometer; g, a glass
window; h, the board bearing the metallic plate; 1, a stand for the spirit-lamp, which
is held by the ring k, so that its flame may strike the bottom of the cup. The whole
of the inside of the apparatus should be blackened and varnished.
Fig. 459 is a front view of the washing apparatus made of tin plate, varnished. The
plates, to be washed, are laid on the angular ledge, d; e is a ledge to conduct the water
to the receptacle c. Fig. 460 is a side view of the washing apparatus. The patent
was enrolled in February, 1840. (See Newton's Journal, C. S. xvi., 1.)
Mr. Richard Beard having purchased from  M. Daguerre a license to practise his
invention above described, received from a foreigner a communication of certain improvements, for which he obtained a patent in June, 1840. The first of these is the
substitution of a concave reflecting mirror for the lens in the camera obscura. Fig.
462 represents in section a slight wooden box, a a, open at the front, opposite to
the person sitting for the portrait. In the back part of the box a concave mirror,.
6, is placed, to reflect the rays coming from the person. A small frame, e, is fixed to
an adjustable pedestal, d, which slides in grooves in the bottom of the box, for the
purpose of being set at the focal point of the mirror. In this frame, c, a polished
surface is first to be placed for trial, to receive the image correctly, as observed by the
operator, by looking through the opening, e, in the top of the box. The prepared
silvered plate is now substituted in the exact place for the trial one. The luminous
impression being made, the slide, d, is withdrawn, and the plate removed; carefully
shut up in a box from the light.
The second object of this patent is making the prepared surface more uniform, by
passing two plates, with their silvered faces in contact, several times between hardened
rollers, annealing them at a low red heat after each passage.
His third object is to use a compound of bromine and iodine, instead of the latter
alone, for coating the silver; which increases its sensibility to light, thereby shortening
and improving the operation of taking likenesses. He also recommends to use a combination of iodine with nitric acid. Finally, Mr. Beard finds that by placing a screen
of any desired color behind the sitter, the appearance of his Daguerreotype portrait ia
improved. (Newton's Journal, xxiii., 112.)




DAGUERROTYPE.                                      537
M. A. J. F. Claudet, who had also purchased a license from M. Daguerre, obtained
a patent in December, 1841, for certain improvements upon the original process. His
first object is to give the front of the camera obscura such an aperture as to admit
the largest object-glass intended to be used; and of such he provides a series of different dimensions, each attached to its board, that may be fitted by a slide to the front
of the camera.
One of the greatest difficulties in the Daguerrotype process was the impossibility of
ascertaining the precise moment at which the light had produced, on the prepared
plate, the effect requisite for the vapor of mercury to bring out the image. By apply.
ing that vapor to the plate while the silver surface is being acted upon by the light,
the operator is enabled to see when his picture is complete. Another advantage of
this joint operation is, that the effect of the mercury upon those parts of the plate
which have been acted upon by the light, are more perfect when caused to take place
immediately under the luminous influence. Hence, instead of using the distinct box
with the cup of quicksilver, he places a cup containing that metal in the camera ob.
scura, with its spirit-lamp, and exhales the vapors there. When the mercury has risen
to the proper temperature, the aperture of the object-glass is thrown open, and the
light, reflected from the object to be delineated, is allowed to operate.
He watches the effect through an opening in the side of the camera, where he views
the prepared plate by the light of a lantern passing through a piece of red or orangecolored glass in the (other) side of the camera. Whenever the light and mercury,
by their simultaneous action, have produced a good image, the object-glass is covered.
and the silver plate, with its picture, removed, in order to be washed and finished.
M. Claudet embellishes his Daguerrotype portraits by placing behind the sitter screens
of painted scenery, which furnish pleasing back grounds. He specifies also various
kinds of artificial illumination, to b  used in the absence of solar light.  (Newton's
Journal, C. S. xx. 430.)
According to M. Barnard, Daguerre's iodized plate should be exposed for half a
minute to the action of chlorine, mixed with a large proportion of common air;
whereby it becomes so sensitive, that the pictorial impression is produced in the short
space of time necessary for removing and replacing the screen of the camera. The
mercury is afterward employed; as also the hyposulphite wash.  Daguerrotype pictures are colored by dusting over them powders of proper hues, which are immediately
washed by passing the plate through water. What remains of the color after this ablution does not seem in the least to injure the appearance or alter the form of the
image. It would seem that those parts of the picture which were at first black, retain,
after being washed, a larger proportion of the coloring matter than the lighter parts.
Several valuable improvements seem  to have been made in Vienna upon the Daguerrotype process; and among others, the mode of using chloriodine.
The best form of box for applying the chloriodic vapor is square, with its bottom of
plate glass, supported a little above the table by feet, a thumb-screw being one of
them, in order to give a certain inclination to the glass plate for spreading the chloriodine over it uniformly. A sheet of white paper being laid beneath the box, enables
the operator to see whether the liquid chloriodine is properly distributed. There is a
groove round the top of the box, into which the ledge of the lid fits tight. A thermometer is placed in the box.
Voigtla~d's lenses consist of two achromatic object-glasses placed apart; the first nearest the object, having an aperture of 18 lines; the second one of 19 lines; the solar focus of the two s 531;nches. A system of lenses of so short a focus with so large apertures affords from 11 to 12 times more illumination than Daguerre's original apparatus
did. The finest p)rtraits can be produced in the course of from 10 to 30 seconds with
this arrangement. Such an apparatus, elegantly made in brass, costs only 120 gulden,
or about 10 guineas.
Voigtland has recently made a camera with two object-glasses, as above arranged,
each having an aperture of 37 lines, and a combined focus of 12 inches. By means of
this instrument, portraits 5' inches in size can be made. The landscapes produced in
them are very beautiful. Its price is 144 gulden, about 12 guineas. Along with the
above apparatus, a box with a bottom of amalgamated copper is used for applying the
vapor of mercury.
By peculiar methods of polishing the silvered copper plate, peculiar tones and tints
may be given to the picture. The olive-oil and pumice-powder are indispensable for
removing the scratches from the plate and to render its surface uniform. If a delicate
blue tone be desired, the plate should be a second time polished with sulphuric ether
and washed tripoli; and a third time with dilute nitric acid and Paris red, rubbing the
plate lastly with a peace of washleather and crocus. But if a brownish black tone be
wished for, a like series of operations is to be gone through, only instead of the ether
and tripoli, spirit of ammonia and Vienna lime is to be used.




568                           DAMASCUS BLADES.
To give the plate the utmost sensibility to light, a film of iodine should be given in
the first place. If with dry iodine, this should be strewed, then covered with cotton,
and lastly with a sheet of paper, and the plate above the last, but not so as to touch it.
This may be done also with a solution of 1 part of iodine in 6 of spirits of wine, put
into a saucer, which is laid on the bottom of the box, and covered with gauze. The
plate is to be removed whenever it has acquired a faint brazen tint. By this means the
plate receives the impressions of light so well as to produce good contrasts between the
white and the dark places.  The application of bromine afterward causes a rapid
reception of the image, and occasions the deep black shades of an object. The best
form is brome water, made by dissolving the bromine in a little distilled water, and then
adding more, when it is wanted, till the solution acquires a straw-yellow  color. A
delicate thermometer being put into the box, the solution is to be spread uniformly on
its glass bottom, the plate being laid on above and covered up, while the time of exposure must'e counted by seconds, with a clock or watch. If the temperature be
41~ F., the time should be 258 seconds.
50~  230  -
59~                         201  -
68~                         158  -
77~                         113  -
By attending to these instructions, exact results may be always obtained.
A second mode of experimenting is with bromiodine; prepared by dissolving I part
of bromine in an alcoholic solution of 5 parts of iodine; and diluting this mixture with
water, till it acquires the color of Bavarian beer. The action of this application upon
the plate is so rapid as hardly to leave time for consideration. It must be watched every instant till the dark gold yellow tint appear, when it is ready for the camera.
The best time of day for Daguerrotype operations is from an hour after the sun rises
till he comes within 45~ of the meridian, and not again till he has passed the meridian
by 45~. When the sitting is too long, the parts which should be pure white become
of a dirty blue tint, and the dark parts become brown. The picture is burnt, so to
speak.
Chloride of gold applied to the picture has the effect of fixing and enlivening the
tints. A small grate being fixed by a clamp to the edge of a table, the plate is laid
upon it with the image uppermost, and overspread evenly with solution of chloride of
gold, by means of a fine broad camel-hair brush, without letting any drop over the edge.
A spirit lamp is now brought under the plate, and moved to and fro till a number of
small steam bubbles appear upon the image. The spirit lamp must be immediately
withdrawn. The remainder of the chloride solution must be poured back into the phial,
to be used on another occasion. It is lastly to be washed and examined. This operation has been repeated three or four times with the happiest effect, of giving fixity and
force to the picture. It may then be wiped with cotton without injury.
By dusting various pigment powders from small cotton-wool dossils upon the picture,
previously coated with an alcoholic solution of copal, and nearly dry, the appearance of a
colored miniature has been very successfully imitated. The varnish must be applied
delicately with one stroke of a broad brush of badger hair.*
DAGUERREOTYPE ENGRAVING. This new art, patented by M. A. F. J. Claudet on the
21st November, 1843, is established on the followiug facts. A mixed acid, consisting
of water, nitric acid, nitrate of potash, and common salt, in certain proportions, being
poured upon a Daguerreotype picture, attacks the pure silver, forming a chloride of
that metal, but does not affect the white parts, which are produced by the mercury of
the picture. This action does not last long. Water of ammonia, containing a little
chloride of silver in solution, dissolves the rest of that chloride, which is then washed
away, leaving the naked metal to be again attacked, especially with the aid of heat.
The metallic surface should have been perfectly purified by means of alcohol and caustic potass. For the rest of the ingenious but complex details, see Newton's Journal,
C. S., vol. xxv., p. 112.
DAHLINE, the same as Inuline, the fecula obtained from  elecampane, analogous in
many respects to starch. It is not employed in the arts.
DAMASCUS BLADES, are swords or scymitars, presenting upon their surface a variegated appearance of watering, as white, silvery, or black veins, in fine lines, or fillets;
fibrous, crossed, interlaced or parallel, &c. They are brought from the East, being fabricated chiefly at Damascus, whence their name. Their excellent quality has become
proverbial; for which reason these blades are much sought after by military men, and
are high priced. The oriental processes have never been satisfactorily described; but
of late years methods have been devised in Europe to imitate the fabric very well.
* See Praktische Anweisung zum Daguerrotypiren, Leipzig, &c. 1843.




DAMASK.                                       569
Clouet and Hachette pointed out the three following processes for producing Damascus blades: 1, that of parallel fillets; 2, that by torsion; 3, the mosaic. The first,
which is still pursued by some French cutlers, consists in scooping out with a graving
tool the faces of a piece of stuff composed of thin plates of different kinds of steel.
These hollows are by a subsequent operation filled up, and brought to a level with the
external faces, upon which they subsequently form tress-like figures. 2. The method of
torsion which is more generally employed at present, consists in forming a bundle of
rods or slips of steel, which are welded together into a well-wrought bar, twisted
several times round its axis.  It is repeatedly forged, and twisted alternately; afte.
which it is slit in the line of its axis, and the two halves are welded with their outsides
in contact; by which means their faces will exhibit very various configurations. 3. The
mosaic method consists in preparing a bar, as by the torsion plan, and cutting this baz
into short pieces of nearly equal length, with which a fagot is formed and welded
together; taking care to preserve the sections of each piece at the surface of the blade.
In this way, all the variety of the design is displayed, corresponding to each fragment of
the cut bar.
The blades of Clouet, independently of their excellent quality, their flexibility, and
extreme elasticity, have this advantage over the oriental blades, that they exhibit in the
very substance of the metal, designs, letters, inscriptions, and, generally speaking, all
kinds of figures which had been delineated beforehand.
Notwithstanding these successful results of Clouet, it was pretty clear that the watered
designs of the true Damascus cimeter were essentially different.   M. Brdant has at
last completely solved this problem.  He has demonstrated that the substance of the
oriental blades is a cast-steel more highly charged with carbon than our European steels,
and in which, by means of a cooling suitably conducted, a crystallization takes place
of two distinct combinations of carbon and iron.  This separation is the essential condi.
tion; for if the melted steel be suddenly cooled in a small crucible or ingot, there is no
damascene appearance.
If an excess of carbon be mixed with iron, the whole of the metal will be converted
into steel; and the residuary carbon will combine in a new proportion with a portion of
the steel so formed.  There will be two distinct compounds; namely, pure steel, and
carbureted steel or cast-iron.   These at first being imperfectly mixed will tend to
separate, if while still fluid they be left in a state of repose; and form a crystallization
in which the particles of the two compounds will place themselves in the crucible in an
order determined by their affinity and density conjoined.  If a blade forged out of steel
so prepared be immersed in acidulous water, it will display a very distinct Damascus
appearance; the portions of pure steel becoming black, and those of carbureted steel
remaining white, because the acids with difficulty disengage its carbon.  The slower
such a compound is cooled, the larger the Damascus veins will be.  Travernier relates
that the steel crucible ingots, like those of wootz, for making the true oriental Damascus,
come from Golconda, that they are of the size of a halfpenny roll, and when cut in two,
form two swords.
Steel combined with manganese forges easily, but it is brittle when cold; it displays
however the Damascus appearance very strongly.
A mixture of 100 parts of soft iron, and 2 of lamp black, melts as readily as ordinary
steel. Several of the best blades which M. Breant presented to the Societd d'Encouragement are the product of this combination.  This is an easy way of making cast-steel
without previous cementation of the iron. 100 parts of filings of very gray cast-iron, and
100 parts of like filings previously oxydized, produced, by their fusion together, a beautiful
damascene steel, fit for forging into white arms, sabres, swords, &c.  This compound is
remarkable for its elasticity, an essenial quality, not possessed by the old Indian steel.
The greater the proportion of the oxydized cast-iron, the tougher is the steel. Care should
be taken to stir the materials during their fusion, before it is allowed to cool; otherwise
they will not afford a homogeneous damasc. If the steel contains much carbon it
is difficult to forge, and cannot be drawn out except within a narrow range of temperature.
When heated to a red-white it crumbles under the hammer; at a cherry-red it becomes
bard and brittle; and as it progressively cools it becomes still more unmalleable. It resembles completely Indian steel, which European blacksmiths cannot forge, because they
are ignorant of the suitable temperature for working it.  M. Breant, by studying this
point, succeeded in forging fine blades.
Experience has proved that the orbicular veins, called by the workmen knots or
thorns (ronces), which are seen upon the finest Eastern cimeters, are the result of the
manner of forging them, as well as the method of twisting the Damascus bars. If
these be drawn in length, the veins will be longitudinal; if they be spread equally in all
directions, the stuff will have a crystalline aspect; if they be made wavy in the two
directions, undulated veins will be produced like those in the oriental Damascus.
DAMASK is a variegated textile fabric, richly ornamented with figures of flowers,




570                              DAMASKEENING.
fruits, landscapes, animals, &c., woven in the loom, and is by far the most rich, elegant,
and expensive species of ornamental weaving, tapestry alone excepted.  The name is
said to be derived from Damascus, where it was anciently made.
Damask belongs to that species of texture which is distinguished by practical men by
the name of tweeling, of which it is the richest pattern. The tweel of damask is usually
half that of full satin, and consequently consists of eight leaves moved either in regular
succession or by regular intervals, eight leaves being the smallest number which will admit of alternate tweeling at equal intervals.
In the article CARPET, two representations have been given of the damask drawloom.
The generic difference of tweeling, when compared with common cloth, consists in the
intersections, although uniform and equidistant, being at determinate intervals, and not be.
tween the alternate threads. Hence we have specimens of tweeled cloth, where the intersections take place at the third, fourth, fifth, sixth, seventh, eighth, or sixteenth interval
only. The threads thus deflecting only from a straight line at intervals, reserve more
of their original direction, and a much greater quantity of materials can be combined in
an equal space, than in the alternate intersection, where the tortuous deflection, at every
interval, keeps them more asunder. On this principle tweeled cloths of three and four
leaves are woven for facility of combination alone. The coarser species of ornamented
cloths, known by the names of dornock and diaper, usually intersect at the fifth, or half
satin interval. The sixth and seventh are rarely used, and the intersection at the
eighth is distinguished by the name of satin in common, and of damask in ornamental
tweeling. It will further be very obvious, that where the warp and woof cross only at
every eighth interval, the two sides of the cloth will present a diversity of appearance;
for on one side the longitudinal or warp threads will run parallel from one end of a web
to the other, and, on the other, the threads of woof will run also parallel, but in a transverse direction across the cloth, or at right angles to the former. The points of intersection being only at every eighth interval, appear only like points; and in regular tweeling
these form the appearance of diagonal lines, inclined at an angle of 450 (or nearly so) to
each of the former.
The appearance, therefore, of a piece of common tweeled cloth is very similar to that
of two thin boards glued together, with the grain of the upper piece at right angles to
that of the under one. That of an ornamental piece of damask may, in the same manner, be very properly assimilated to a piece of veneering, where all the wood is of the
same substance and color, and where the figures assume a diversity of appearance from
the ground, merely by the grain of the one being disposed perpendicularly to that of the
other. See TEXTILE FABRIC.
From this statement of the principle, it results that the most unlimited variety of figures
will be produced, by constructing a loom by which every individual thread of warp may
be placed either above or below the woof at every intersection; and to effect this, in
boundless variety, is the object of the Jacquard mounting; which see.
The chief seat of this manufacture is probably the town and neighborhood of Dunfermline, in Fifeshire, and Lisburn and Ardoyne, near Belfast, where it is considered as
the staple, having proved a very profitable branch of traffic to the manufacturer, and
given employment to many industrious people.
The material used there is chiefly linen; but many have been recently woven of cotton,
since the introduction of that article into the manufacture of cloth has become so prevalent. The cotton damasks are considerably cheaper than those of linen; but are not
considered either so elegant or durable. The cotton, also, unless frequently bleached, does
not preserve the purity of the white color nearly so well as the linen.
DAMASKEENING; the art of ornamenting iron, steel, &c., by making incisions upon
its surface, and filling them up with gold or silver wire; chiefly used in enriching sword
blades, guards, and gripes, locks of pistols, &c.
Its name shows the place of its origin, or, at least, the place where it has been practised in the greatest perfection; viz., the city of Damascus, in Syria; though M. Felibien
attributes the perfection of the art to his countryman, Cursinet, who wrought under the
reign of Henry IV.
Damaskeening is partly mosaic work, partly engraving, and partly carving. As mosaic
work it consists of pieces inlaid; as engraving, the metal is indented, or cut in intaglio;
and as carving, gold and silver are wrought into it in relievo.
There are two ways of damaskeening; in the first, which is the most beautiful, the
artists cut into the metal with a graver, and other tools proper for engraving upon
steel, and afterwards fill up the incisions, or notches, with a pretty thick silver or gold
wire. In the other, which is only superficial, they content themselves to make hatches,
or strokes across the iron, &eC., with a cutting knife, such as is used in making smral
files. As to the first, it is necessary for the gravings or incisions to be made in the dove




DECOMPOSITION.                                    571
tail form; that the gold or silver wire, which is thrust forcibly into them, may adhere the
more strongly. As to the second, which is the more usual, the method is this:-Having
heated the steel till it changes to a violet, or blue color, they hatch it over and across
with the knife; then draw the ensign or ornament intended, upon this hatching, with a
fine brass point or bodkin. This done, they take fine gold wire, and conducting or chasing
it according to the figures already designed, they sink it carefully into the hatches of the
metal with a copper tool.
DAMASSIN is a kind of damask, with gold and silver flowers, woven in the warp and
woof; or occasionally with silk organzine.
DAMPS, in mining, are noxious exhalations, or rather gases, so called from the German
dampf, vapor. There are two principal kinds of mine gases, the fire-damp, or carbureted
hydrogen, and the choke-damp, or carbonic acid gas. See MINES.
DAPHNINE;' the bitter principle of the Daphne.lpina.
DATOLITE. A mineral composed of silica, lime, and boracic acid.
DECANTATION (Eng. and Fr.;.bgiessen, Germ.) is the act of pouring off the clear
supernatant fluid from any sediment or deposite. It is much employed in the chemical
arts; and is most conveniently effected by a syphon.
DECOCTION (Eng. and Fr.;.A1bkochung, Germ.) means either the act of boiling
a liquid along with some organic substance, or the liquid compound resulting from that
act.
DECOMPOSITION (Eng. and Fr.; Zersetzung, Germ.) is the separation of the constituent principles of any compound body. The following table, the result of important
researches recently made by M. Persoz, Professor of Chemistry at Strasburgh, shows the
order in which decompositions take place among the successive substances.
Nitric Acid.                           Muriatic Acid.
Oxyde of Magnesium                      Oxyde of Magnesium
-  Silver                        -      Cobalt
-  Cobalt                        -      Nickel
-  Nickel                    Protox. of Mercury
Protox. of                    Cerium
Oxyde of Zinc                           Oxyde of Zinc
Protox. of Manganese                    Protox. of Manganese
Oxyde of Lead                              -      Iron
-     Cadmium                          -      Uranium
-     Copper                            -     Copper
-     Glucinum                          -     Tin
-     Alumium                      Oxyde of Glucinum
-     Uranium                          -      Alumium
-     Chromium                         -      Uranium
Protox. of Mercury                         -     Chromium
Oxyde of Mercury                           -     Iron
-     Iron                             -     Tin
-     Bismuth                         -      Bismuth
-     Antimony
By means of the cupric oxyde we may separate, 1, the ferric oxyde from the manganous
oxyde; 2, the cobaltic, nickelic, zincic and cerous oxydes from the urinic, ferric, chromic,
and aluminic oxydes; 3, the ferrous oxyde from the chromic oxyde, when dissolved in the
muriatic acid.
In boiling a muriatic solution of the cobaltic, nickelic, and manganous oxydes, with the
mercuric oxyde, the first two oxydes alone are precipitated. Alumina separates the cadmic oxyde from the bismuthic oxyde, the stannous oxyde from the stannic oxyde, and the
stannous oxyde from the antimonic acid. The cupric oxyde separates also by precipitation, the aluminic, uranic, chromic, titanic, and vanadic oxydes from all the oxydes which
are precipitable in the state of sulphuret, by hydrosulphuret of ammonia.
As an example of this mode of analysisDissolve pech-blende in aqua regia, precipitate its copper by sulphureted hydrogen,
boil the liquid along with nitric acid, in order to transform all the uranium into uranic
acid. Next boil it along with cupric oxyde, which precipitates only the uranic and ferric
oxydes. Redissolve the precipitate in nitric acid, and boil the solution with mercuric
oxyde, which does not precipitate the ferric oxyde. Finally, separate the copper and the
mercury from the uranium, by means of sulphureted hydrogen. In this process we may
substitute plumbic oxyde for the cupric oxyde, and succeed equally well.
Knowledge, like the above, of the elective affinities and habitudes of chemical bodies,
simple and compound, imparts to its possessor an irresistible power over the unions and




572                       DEPOSITION OF METALS.
disuniorns of the elements, which he can exercise with certainty in effecting innumerable
transformations in the arts.
DECREPITATION  (Eng. and Fr.; Verknister, Germ.) is the crackling noise
attended with the flying asunder of their parts, made by several salts and minerals,
when heated.  It is caused by the unequal sudden expansion of their substance by the
heat. Sulphate of baryta, chloride of sodium, calcareous spar, nitrate of baryta, and many
more bodies which contain no water, decrepitate most violently, separating at the natural
joints of their crystalline structure. Some chemists have preposterously enough ascribed
the phenomenon to the expansion of the combined water into steam.  What a specimen
of inductive philosophy!
DEFECATION (Eng. and Fr.; Klaren, Germ.), the freeing from dregs or impurities.
DEFLAGRATION (Eng. and Fr.; Verpuffung, Germ.), the sudden blazing up of a
combustible; as of a charcoal or sulphur when thrown into melted nitre.
DELPHINIA.  The vegeto-alkaline principle of the Delphinium  staphysagria, or
&Savesacre. It is poisonous.
DELIQUESCENT  (Zerfliessen, Germ.) is said of a soad which attracts so much
moisture from the air as to become spontaneously soft or liquid; such as potash and
muriate of lime.
DEPHLEGMATION is the process by which liquids are deprived of thei watery particles. It is applied chiefly to spirituous liquors, and is now nearly obsolete, as involving
the alchemistical notion of a peculiar principle called phlegm.
DEPHLOGISTICATED; deprived of phlogiston, -  formerly supposed to be the
common combustible principle.  It is nearly synonymous with oxygenated. The idea
originally attached to the word having proceeded from false logic, the word itself should
never be used either in science or manufactures.
DEPILATORY  (Depilatoire, Fr.; Enthaarensmittel, Germ.) is the name of any
substance capable of removing hairs from the human skin without injuring its texture.
They act either mechanically  or chemically.   The first are commonly glutinous
plasters formed of pitch and rosin, which stick so closely to the part of the skin where
they are applied, that when removed, they tear away the hairs with them. This method
is more painful, but less dangerous than the other which consists in the solvent
action of a menstruum, so energetic as to penetrate the pores of the skin, and destroy
the bulbous roots of the hairs. This is composed either of caustic alkalis, sulphuret of
baryta, or arsenical preparations. Certain vegetable juices have also been recommended
for the same purpose; as spurge and acacia.  The bruised eggs of ants have likewise
been prescribed.  But the oriental rusma yields to nothing in depilatory power.
Gadet de Gassincourt has published in the Dictionnaire des Sciences Medicales, the following recipe for preparing it.
Mix two ounces of quicklime with half an ounce of orpiment or realgar, (sulphuret
of arsenic;) boil that mixture in one pound of strong alkaline ley, then try its strength
by dipping a feather into it, and when the flue falls off, the rusma is quite strong enough.
It is applied to the human skin by a momentary friction, followed by washing with
warm water.  Such a caustic liquid should be used with the greatest circumspection,
beginning with it somewhat diluted.  A  soap is sometimes made with lard and the
above ingredients; or soft soap is combined with them; in either case to form a depilatory pommade. Occasionally one ounce of orpiment is taken to eight ounces of quicklime,
or two to twelve, or three to fifteen; the last mixture being of course the most active.
Its causticity may be tempered by the addition of one eighth of starch or rye flour, so as
to form a soft paste, which being laid upon the hairy spot for a few minutes, usually carries away the hairs with it.
The rusma should never be applied but to a small surface at a time, for independently
of the risk of corroding the skin, dangerous consequences might ensue from absorption
of the arsenic.
DEPOSITION  OF METALS.  Felted fabrics have been coated with metals of
various kinds, by means of electricity, in the following way:-A plate of copper, for
example, as a dye or matrix, is coated on one side with a resinous, non-conducting
varnish, and on the other with graphite or plumbago, and the cloth is strained over it,
and cemented to it. The matrix being immersed in a solution of sulphate of copper,
and connected with a zinc pole of a galvanic battery; while another plate of copper is
immersed in the solution and connected with the copper pole of the battery, the deposition of the metal upon the matrix commences. When the surface of the matrix is
covered with a thin film of copper, the depositing metal begins to penetrate the interstices of the cloth, and if the operation is continued sufficiently long, will appear in small
globules at the other side. As soon as the required thickness of metal has been deposited, the matrix is removed from the solution, and the cloth separated therefrom.
The surface of the metallic coating will be either plain or ornamented, according as the




DEXTRINE.                                         573
surface of the matrix is prepared, whether with a raised or sunk pattern. And the
metallic deposit may be afterward gilt or otherwise ornamented. Other details are
given in the specification of M. Julius Schatlaendcr.-Newton's Journal, C. S., xxv., 96.
DESICCATING  APPARATUS.  The useful problem  of depriving  timber of its
moisture has received a complete solution by Messrs. Davison & Symington, who in
November, 1843, patented a method of transmitting currents of air highly heated (by
an arrangement similar to those employed in the hot blast of iron-smelting), through
casks made of green wood, or through chambers in which the deals or planks are piled
up.  The same imeans have since been found effective for cleansing old tainted beer
tuns, or wine hogsheads, of their fermentative qualities; and hence they are now very
generally had recourse to in breweries. A fan or other blowing machine is used for
propelling the heated air. Mechanical friction with chains or otherwise is used in conjunction with the ventilating process.
Desiccating System. " When we first noticed this system we instanced its application
to the seasoning of beer casks, as the most striking exemplification of its efficacy which
then offered itself to our observation; but though we have been fully borne out in our
views of the importance of that application, by the subsequent adoption of Messrs.
Davison & Symington's plans in some of the largest breweries in the kingdom, this
turns out to be, after all, but one of the least of the triumphs which the system has
achieved.  From  the seasoning of casks the patentees have gone on, step by step, till
take seasoning of wood and wooden articles of every description; and
ge of benefiting largely, not only every art and manufacture of which
lent, but the public at large.  We have been obligingly permitted by
them  to inspect and make extracts from  their'Dry Seasoning Book,' and some of
these extracts afford the best possible proofs of the advantages derivable from this desiccating system. They are records of work actually done-not by way of experiment
merely, but in the ordinary course of an established and fast increasing trade. Each
extract shows, first, the weight of the wood when sent in to be seasoned; next, the
daily diminution in weight produced by the desiccating process; and lastly, the total
quantity of moisture expelled-moisture which if allowed to remain in the wood could
tend only to produce rot and decay. The extracts give also, in the case of planks, the
degree of shrinkage in width produced. Some of the results are exceedingly startling.
Mahogany is reduced in weight by desiccation 24'4 per cent., and pine planks 34,5.
The woods least affected are fir and white deal, which lose 12'50 per cent. The degree of shrinkage produced is still more remarkable; amounting, in both the cases noticed, to no less than three fourths. It will be observed, moreover, that all these
effects are produced in the course of a few days, some ten or twelve at most, w-sile by
the ordinary mode of drying they could hardly be accomplished in as many months."
-Mr. Robertson, in his Mechanics' Magazine.,We need scarcely add that the less moisture there is left in wood, the greater its
strength-the more complete its fitness for every purpose to which it can be applied.
DETONATION.  See FULMINATING, for the mode of preparing detonating powder
for the percussion caps of fire-arms.
DEUTOXIDE literally means the second oxide, but is usually employed to denote a
compound containing two atoms or two prime equivalents of oxygen to one or more of
a metal.  Thus we say deutoxide of copper, and deutoxide of mercury.  Berzelius has
abbreviated this expression by adopting the principles of the French nomenclature of
1787; according to which the higher stage of oxidizement is characterized by the termination ic, and the lower by ous, and he writes accordingly cupric and mercuric, to
designate the deutoxides of these two metals; cuprous and mercurous to designate their
protoxides.  I have adopted this nomenclature in the article DECOMPOSITION, and in
some other parts of this Dictionary, as being short and sufficiently precise.
DEXTRINE is a matter of a gummy appearance into which the interior substance
of the molecules of starch are converted, through the influence of diastase or acids. It
derives its names from the circumstance that it turns, more than any other body, the
plane of polarization to the right hand. It is white, insipid, without smell, transparent,
in thin plates, friable, with a glassy fracture when well dried. It is not altered by the
heat of boiling water, but at 280~ F. it becomes brown, and acquires the flavor of
toasted bread. It is not colored by iodine, like starch, it does not form mucic acid with
the nitric, as common gum does, and it is transformed into grape sugar, when heated
along with dilute sulphuric acid or diatase.
Dextrine is much employed by the French pastrycooks and confectioners: it is a
good substitute for gum arabic in medicine. For the conversion of potato or other
starch into dextrine, by the action of diastase, see BREWING.
This substance has exactly the same chemical composition as starch, consisting of 24
atoms of carbon, 20 of hydrogen, and 10 of oxygen (Dumas); but it is distinguished




574                                  DIAMOND.
from starch by its solubility in cold water, like gum, and not being affected by iodine.
British gum, as it is called, or roasted starch, is merely dextrine somewhat discolored;
a substance apparently used for the paste on the Queen's head post office letter stamps.
A process discovered by M. Payen, and patented in France by M. Henz6, for making
dextrine, consists in moistening one ton of dry starch with water containing 41 lbs. of
strong nitric acid. The starch thus uniformly wetted, is made up into small bricks or
loaves, and dried in a stove. It is then rubbed down'into a coarse powder, and ex.
posed in a stove-room to a stream of air heated to about 1600 F. Being now triturated,
sifted, and heated in a stove to about 228~ F., it forms a perfect dextrine of a fair color,
because the acid acts as a substitute for the higher heat, used in making the British
gum. Such an article makes a fine dressing for muslin and silk goods, and is much
employed in French surgery, for making a stiff paste support to the bandages of frac
tured limbs.
DIAMOND. Since this body is merely a condensed form of carbon, it cannot in a
chemical classification be ranked among stones; but as it forms in commerce the most
precious of the gems, it claims our first attention in a practical treatise on the arts.
Diamonds are distinguishable by a great many peculiar properties, very remarkable and
easily recognised, both in their rough state, and when cut and polished.  Their most
absolute and constant character is a degree of hardness superior to that of every mineral,
whence diamonds scratch all other bodies, and are scratched by none.  Their peculiar
adamantine lustre, not easy to define, but readily distinguishable by the eye from that of
every other gem, is their most obvious feature. Their specific gravity is 3,55. Whether
rough or polished, diamonds acquire by friction positive electricity, but do not retain it
for more than half an hour. The natural form of diamonds is derivable from an octahedron, and they never present crystals having one axis longer than the other. Their structure is very perceptibly lamellar, and therefore, notwithstanding their sreat hardness.
they are brittle and give way in the line of their cleavage, affording a direct means of
arriving at their primitive form, the regular octahedron.
The diamond possesses either single or double refraction, according to its different crystalline forms; its refractive power on light is far greater than it ought to be in the ratio
of its density; the index of refraction being 2'44, whence Newton long ago supposed it te
consist of inflammable matter. Its various forms in nature present a circumstance peculiar
to this body; its faces are rarely terminated by planes, like most other native crystals,
but they are often rounded off, and the edges between them are curved.  When these
secondary faces are attentively examined with a lens, we remark that they are marked
with strive, sometimes very fine and almost imperceptible, but at others well defined; and
that these striae are parallel to the edges of the octahedron, and consequently to those of
the plates that are applied on the primitive faces of this figure.
Diamonds are usually colorless and transparent; when colored, their ordinary tint
verges upon yellow, or smoke-yellow, approaching sometimes to blackish-brown. Green
diamonds are next to yellow the most common; the blue possess rarely a lively hue, but
they are much esteemed in Scotland. The rose or pink diamonds are the most valued of
the colored kind, and exceed sometimes in price the most limpid; though generally
speaking the latter are the most highly prized.
The geological locality of the diamond seems to be in diluvial gravel, and among con.
glomerate rocks; consisting principally of fragments of quartz, or rolled pebbles of quartz
mixed with ferruginous sand, which compose sometimes hard aggregated masses.  This
kind of formation is called cascalho in Brazil.  Its accompanying minerals are few  in
number, being merely black oxyde of iron, micaceous iron ore, pisiform iron ore, fragments
of slaty jasper, several varieties of quartz, principally amethyst.- In Mr. Heuland's
splendid collection there was a Brazilian diamond imbedded in brown iron ore; another
in the same, belonging to M. Schuch, librarian to the Crown Princess of Portugal; and
in the cabinet of M. Eschwege there is a mass of brown iron ore, containing a diamond
in the drusy cavity of a green mineral, conjectured to be arseniate of iron. From these
facts it may be inferred with much probability that the matrix or original repository of the'
diamond of Brazil is brown iron ore, which occurs in beds of slaty quartzose micaceous
iron ore, or in beds composed of iron-glance and magnetic iron ore, both of which are
apparently subordinate in that country to primitive clay slate.
The loose earth containing diamonds lies always a little way beneath the surface of
the soil, towards the lower outlet of broad valleys, rather than upon the ridges of the
adjoining hills.
Only two places on the earth can be adduced with certainty as diamond mines, or
rather districts; a portion of the Indian peninsula, and of Brazil.
India has been celebrated from the most remote antiquity as the country of diamonds.
Its principal mines are in the kingdoms of Golconda and Visapour, extending from




DIAMOND.                                       575
Cape Comorin to Bengal, at the foot of a chain of mountains called the Orixa, which
appear to belong to the trap-rock formation.  In all the Indian diamond soils, these
gems are so dispersed, that they are rarely found directly, even in searching the richest
spots, because they are enveloped in an earthy crust, which must be removed before they
can be seen. The stony matter is therefore broken into pieces, and is then, as well as
the looser earth, washed in basins scooped out on purpose. The gravel thus washed is
collected, spread oat on a smooth piece of ground, and left to dry. The diamonds are
now recognised by their sparkling in the sun, and are picked out from the stones.
The diamond mines of Brazil were discovered in 1728, in the district of Serro-doFrio. The ground in which they are imbedded has the most perfect resemblance to that
of the East Indies, where the diamonds occur.  It is a solid or friable conglomerate,
consisting chiefly of a ferruginous sand, which encloses fragments of various magnitude
of yellow and bluish quartz, of schistose jasper, and grains of gold disseminated with
oligist iron ore; all mineral matters different from those that constitute the neighboring
mountains; this conglomerate, or species of pudding-stone, almost always superficial,
occurs sometimes at a considerable height on the mountainous table-land. The most
celebrated diamond mine is that of Mandarga, on the Jigitonhonha, in the district of
Serro-do-Frio to the north of Rio Janeiro. The river Jigitonhonha, three times broader
than the Seine at Paris, and from 3 to 9 feet deep, is made nearly dry, by drawing the
waters off with sluices at a certain season; and the cascalho or diamond-gravel is removed
from the channel by various mechanical means, to be washed elsewhere at leisure. This
cascalho, the same as the matrix of the gold mines, is collected in the dry season, to be
searched into during the rainy; for which purpose it is formed into little mounds of 15
or 16 tons weight each. The ~washing is carried on beneath an oblong shed, by means
of a stream of water admitted in determinate quantities into boxes containing the cascalho. A negro washer is attached to each box; inspectors are placed at regular distances on elevated stools, and whenever a negro has found a diamond, he rises up and
exhibits it. If it weighs 171 carats, he receives his liberty. Many precautions are
taken to prevent the negroes from secreting the diamonds.  Each squad of workmen
consists of 200 negroes, with a surgeon and an almoner or priest.
The flat lands on either side of the river are equally rich in diamonds over their whole
surface, so that it becomes very easy to estimate what a piece of ground not yet washed
may produce.
It is said that the diamonds surrounded with a greenish crust are of the first water,
or are the most limpid when cut. The diamonds received in the different mines of the
district are deposited once a month in the treasury of Tejuco; and the amount of what
was thus delivered from 1801 to 1806, may be estimated at about'18 or 19 thousand carats per annum.
On the banks of the torrent called Rio Pardo, there is another mine of diamonds.
The ground presents a great many friable rocks of pudding-stone, distributed in irregular strata. It is chiefly in the bed of this stream that masses of cascalho occur, peculiarly rich in diamonds. They are much esteemed, particularly those of a greenish-blue
color. The ores that accompany the diamond at Rio Pardo differ somewhat from those
of the washing grounds of Mandanga, for they contain no pisiform iron ore; but a great
many pebbles of slaty jasper. This table land seems to be very high, probably not less
than 5500 feet above the level of the sea.
Tocaya, a principal village of Minas Novas, is 34 leagues to the northeast of Tejuco,
in an acute angle of the confluence of the Jigitonhonha and the Rio Grande. In the
bed of the streamlets which fall westward into the Jigitonhonha, those rolled white
topazes are found which are known under the name of minas novas with blue topazes, and
aquamarine beryls. In the same country are found the beautiful cymophanes or crysoberyls so much prized in Brazil. And it is from the cantons of Indaia and Abaite that
the largest diamonds of Brazil come; yet they have not so pure a water as those of the
district of Serro-do-Frio, but incline a little to the lemon yellow.
Diamonds are said to come also from the interior of the island of Borneo, on the banks
of the river Succadan, and from the peninsula of Malacca.
It is known that many minerals become phosphorescent by heat, or exposure to the
sun's light. Diamonds possess this property, but all not in equal degree, and certain
precautions must be observed to make it manifest. Diamonds need to be exposed to the
sunbeam for a certain time, in order to become self-luminous; or to the blue rays of the
prismatic spectrum, which augment still more the faculty of shining in the dark. Diamonds susceptible of phosphorescence exhibit it either after a heat not raised to redness,
or the electric discharge. They possess not only a great refractive power in the mean
ray of light, but a high dispersive agency, which enables them to throw out the most
varied and vivid colors in multiplied directions.
Louis de Berquem discovered, in 1476, the art of cutting diamonds by rubbing them
37




576                                  DIAMOND.
against one another, and of polishing them with their own powder. These operations
may be abridged by two methods:  1. by availing ourselves of the direction of the
laminse of the diamond to split them in that direction, and thus to produce several facets.
This process is called cleaving the diamond.  Some, which appear to be made crystals,
resist this mechanical division, and are called diamonds of nature. 2. by sawing the
diamonds by means of a very delicate wire, coated with diamond powder.
Diamonds take precedence of every gem for the purpose of dress and decoration; and
hence the price attached to those of a pure water increases in so rapid a proportion, that,
beyond a certain term, there is no rule of commercial valuation. The largest diamond
that is known seems to be that of the Rajah of Mattan, in the East Indies. It was of the
purest waeter, and weighs 367 carats, or at the rate of 4 grains to a carat, upward of 3
ounces troy. It is shaped like an egg, with an indented hollow near the smaller end;
it was discovered at Landak about 100 years ago; and though the possession of it
has cost seeral wars, it remained in the Mattan family for 90 years. A governor of
Batavia, after ascertaining the qualities of the gem, wished to be the purchaser, and
offered 150,000 dollars for it, besides two war brigs with their guns and ammunition,
together with a certain number of great guns, and a quantity of powder and shot. But
this diamond possessed such celebrity in India, being regard as a talisman involving
the fortunes of the Rajah and his family, that he refused to part with it at any price.
The Mogul diamond passed into the possession of the ruling family of Kabul, as has
been invariably affirmed by the members of that family, and by the jewellers of Delhi
and Kabul. It has been by both parties identified with the great diamond, now known
under the name of the KoH-I-NooR, or mountain of light, which was displayed by its
present proprietor, her Majesty the Queen, at the recent Great Exhibition. It is now
being properly cut by skilful Dutch artists, under the charge of Messrs. Garrard,
jewellers in London, in order to bring out all its lustre, and remove some superficial
specks or clouds. The weight of it has been of old various stated.
The diamond possessed, in the time of the traveller Tavernier, by the emperor of
Mogul, a kingdom now no more, weighed 279 carats, and was reckoned worth upwards
of 400,0001. sterling. It was said to have lost the half of its original weight in
the cutting. After these prodigious gems, the next are:-1. That of the emperor of
Russia, bought by the late empress Catharine, which weighs 193 carats. It is said to
be of the size of a pigeon's egg, and to have been bought for 90,0001., besides
an annuity to the Greek merchant of 40001. It is reported that ~he above diamond
formed one of the eyes of the famous statue of Sheringan, in the temple of Brama, and
that a French grenadier, who had deserted into the Malabar servce, found the means of
robbing the pagoda of this precious gem; and escaped with it to Madras, where he
disposed of it to a ship captain for 2,0001., who resold it to a Jew for 12,0001. From
him it was transferred for a large sum to the Greek merchant. 2. That of the emperor
of Austria, which weighs 139 carats, and has a slightly yellowish hue. It has, however,
been valued at 100,0001. 3. That of the king of France, called the Regent or Pitt
diamond, remarkable for its form and its perfect limpidity. Although it weighs only 136
carats, its fine qualities have caused it to be valued at 160,0001., though it cost only
100,0001.
The largest diamond furnished by Brazil, now in possession of the crown of Portugal,
weighs, according to the highest estimates, 120 carats. It was found in the streamlet
of Abaite, in a clay-slate district.
The diamonds possessed of no extraordinary magnitude, but of a good form and a
pure water, may be valued by a certain standard rule. In a brilliant, or rose-diamond
of regular proportions, so much is cut away that the weight of the polished gem does
not exceed one half the weight of the diamond in the rough state; whence the value of
a cut diamond is esteemed equal to that of a similar rough diamond of double weight,
exclIsive of the cost of workmanship. The weight and value of diamonds are reckoned
by carats of 4 grains each; and the comparative value of two diamonds of equal quality
but different weights, is as the squares of these weights respectively. The average price
of rough diamonds that are worth working is about 21. for one of a single carat; but as
a polished' diamond of one carat must have taken one of 2 carats, its price in the rough
state is double the square of 21., or 81. Therefore, to estimate the value of a wrought
diamond, ascertain its weight in carats, double that weight, and multiply the square of
this product by 21.
Hence, a wrought diamond of I carat is worth ~ 8
2       -          32
3       -           72
4       -          128
5       -         200
6       -         288




DIAMOND.                                        577
~
of 7 carats is worth  392
8       -           512
9       -           612
10       -           800
20       -          3200, beyond which weight the prices
can no longer rise in this geometrical progression, from the small number of purchasers
of such expensive toys. A very trifling spot or flaw of any kind lowers exceedingly
the commercial value of a diamond.
Dianmonds are used not only as decorative gems, but for more useful purposes, as for
cutting glass by the glazier, and all kinds of hard stones by the lapidary.
On the structure of the glazier's diamond we possess some very interesting observations and reflections by Dr. Wollaston.  He remarks, that the hardest substances
brought to a sharp point scratch glass, indeed, but do not cut it, and that diamonds
alone possessed that property; which he ascribes to the peculiarity of its crystallization
in rounded faces and curvilinear edges. For glass-cutting, those rough diamonds are
always selected which are sharply crystallized, hence called diamond sparks; but cut
tiamonas are never used. The inclination to be given to a set diamond in cutting glass
is comprised within very narrow  limits; and it ought, moreover, to be moved in the
direction of one of its angles.  The curvilinear edge adjoining the curved faces, entehing
as a vwedse into the furrow opened up by itself, thus tends to separate the parts of the
glass; and in order that the crack which causes the separation of the vitreous particles
may take place, the diamond must be held almost perpendicular to the surface of the
glass. The Doctor proved this theory by an experiment. If, by suitable catting with the
wheel, we make the edges of a spinel ruby, or corundum-telesie (sapphire) curvilinear,
anrd tie adjacent faces curved, these stones will cut glass as well as a glazier's diamond, but
being less hard than it, they will not preserve this property so long. He found that upon
giving the surface of even a fragment of flint the same shape as that of the cutting
diamond, it acquired the same property; but, from its relative softness, was of little duration.  The depth to which the fissure caused by the glazier's diamond penetrates, does
not seem to exceed the two-hundredth of an inch.
I shall here introduce Mr. Milburn's valuable observations on the choice of rough
diamonds, as published in his work on Oriental Commerce.
The color should be perfectly crystalline, resembling a drop of clear spring water, in the
middle of which you will perceive a strong light, playing with a great deal of spirit. If
the coat be smooth and bright, with a little tincture of green in it, it is not the worse,
and seldom proves bad, but if there is a mixture of yellow with green, then beware of it;
it is a soft greasy stone, and will prove bad.
If time stone has a rough coat, so that you can hardly see through it, and the coat be
white and look as if it wvre rough by art, and clear of flaws or veins, and no blemish cast
in the body of the stone twhich may be discovered by holding it against the light), the
stone will prove good.
It often happens that a stone will appear of a reddish hue on the outward coat, not
unlike the color of rusty iron, yet by looking through it against the light, you may observe
the heart of the stone to be white (and if there be any black spots, or flaws, or veins in
it, they may be discovered by a true eye, although the coat of the stone be the same), and
such stones are generally good and clear.
If a diamond appears of a greenish bright coat, resembling a piece of green glass,
inclining to black, it generally proves hard, and seldom  bad; such stones have been
known to have been of the first water, and seldom worse than the second; but if any
tincture of yellow seems to be mixed with it, you may depend on its being a very bad
stone.
All stones of a milky cast, whether the coat be bright or dull, if ever so little inclining
to a bluish cast, are naturally soft, and in danger of being flawed in the cutting; and
though they should have the good fortune to escape, yet they will prove dead and milky,
and turn to no account.
All diamonds of cinnamon color are dubious; but if of a bright coat mixed with
a little green, then they are certainly bad, and are accounted among the worst of colors.
You will meet with a great many diamonds of a rough cinnamon-colored coat, opaque;
this sort is generally very hard, and, when cut, contain a great deal of life and spirit;
but the color is very uncertain; it is sometimes white, sometimes brown, and sometimes
of a fine yellow. Rough diamonds are frequently beamy, that is, look fair to the eye,
yet are so full of veins to the centre, that no art or labor can polish them. A good
diamond should never contain small spots of a white or gray color of a nebulous form;
it should be free from small reddish and brownish grains, that sometimes occur on their
surface, or in their interior. A good diamond should split readily in the direction of the
cleavage; it sometimes happens, however, that the folia are curved, as is the case in twin




578                               DIAMOND DUST.
crystals. When this happens, the stone does not readily cut and polish, and is therefore of inferior value.
In the cut and polished gem, the thickness must always bear a certain proportion to
the breadth. It must not be too thin nor thick; for, when too thin, it loses much of
its fire, and appears not unlike glass.
The term carate is said to be derived from the name of a bean, the produce of a species
of erytthina, a native of the district of Shangallas, in Africa, a famous mart of gold-dust.
The tree is called kuara, a word signifying sun in the language of the country; because
it bears flowers and fruit of a flame color. As the dry seeds of this pod are always of
nearly uniform  weight, the savages have used them  from  time immemorial to weigh
gold. The beans were transported into India, at an ancient period, and have been
long employed there for weighing diamonds.  The carat of the civilized world is, in
fact, an imaginary weight, consisting of 4 nominal grains, a little lighter than 4 grains
troy (poids de mare); it requires 74 carat grains and J- to equipoise 72 of the other.
In valuing a cut diamond, we must reckon that one half of its weight has been lost in
the lapidary's hands; whence its weight in this state should be doubled before we
calculate its price by the general rule for estimating diamonds. The French multiply
by 48 the square of this weight, and they call the product in francs  he value of the
diamond.  Thus, for example, a cut diamond of 10 carats would be worth (10 X 2
X  48= 19,200 francs, or 7681., allowing only 25 francs to the pound sterling.
The diamond mines of Brazil have brought to its government, from the year 1730
till 1814, 3,023,000 carats; being at the average rate annually of 36,000 carats, or a
little more than  16 lbs. weight.   They have not been  so productive in the later
years of that period; for, according  to Mr. Mawe, between  1801 and  1806, onl]
115,675 carats were obtained, being 19,279 a year. The actual expenses incurred by
the government, during this interval, was 4,419,700 francs; and, deducting the production in gold from the washings of the diamond gravel, or cascalho, it is found that
the rough diamonds cost in exploration, per carat, 38 francs 20 c., or nearly 31s.
British money.  The contraband is supposed to amount to one third of the above
legitimate trade. Brazil is almost the only country where diamonds are mined at the
present day; it sends annually to Europe from 25 to 30 thousand carats, or from 10 to
16  ltbs.
DIAMONDS, cutting of.  Although the diamond is the hardest of all known substances, yet it may be split by a steel tool, provided a blow be applied; but this requires
a perfect knowledge of the structure, because it will only yield to such means in certain
directions. This circumstance prevents the workrnLA from forming facettes or planes
generally, by the process of splitting; he is therefore obliged to resort to the process
of abrasion, which is technically called cutting. The process of cutting is effected by
fixing the diamond to be cut on the end of a stick, or handle, in a small ball of
cement, that part which is to be reduced being left to project. Another diamond is
also fixed in a similar manner; and the two stones being rubbed against each other
with considerable force, they are mutually abraded, flat surfaces, or facettes, being
thereby produced.  Other facettes are formed by shifting the diamonds into fresh
positions in the cement, and when a sufficient number are produced, they are fit for
polishing. The stones, when cut, are fixed for this purpose, by imbedding them in soft
solder, contained in a small copper cup, the part, or facette, to be polished, being left to
protrude.
A flat circular plate of cast-iron is then charged with the powder produced during
the abrasion of the diamonds; and by this means a tool is formed which is capable of
producing the exquisite lustre so much admired on a finely-polished gem.  Those
diamonds that are unfit for working, on account of the imperfection of their lustre or
color, are sold, for various purposes, under the technical name of Bort. Stones of this
kind are frequently broken in a steel mortar, by repeated blows, until they are reduced
to a fine powder, which is used to charge metal plates, of various kinds, for the use of
jewellers, lapidaries, and others.  Bort, in this state of preparation, is incapable of
polishing any gems; but it is used to produce flat surfaces on rubies and other precious
stones.
Fine drills are made of small splinters of bort, which are used for drilling small holes
in rubies, and other hard stones, for the use of watch-jewellers, gold and silver wiredrawers, and others, who require very fine holes drilled in such substances. These drills
are also used to pierce holes in china, where rivets are to be inserted; also for piercing
holes in artificial enamel teeth, or any vitreous substances. however hard.
DIAMOND  DUST.  The demand for diamond dust within a few  years has increased very materially, on account of the increased demand for all articles that are
wrought by it, such as cameos, intaglios, &c.  Recently there has been a discovery
made of the peculiar power of diamond dust upon steel; it gives the finest edge to all




DiASIASE.                                        579
kinds of cutlery, and threatens to displace the hone of Hungary. It is well known that
in cutting a diamond (the hardest substance in nature), the dust is placed on the teeth
of the saw-to which it adheres, and thus prevents the instrument from making its way
through the gem.  To this dust, too, is to be attributed solely the power of man to
make brilliants from rough diamonds; from the dust is obtained the perfection of the
geometrical symmetry, which is one of the chief beauties of the mineral, and also that
adamantine polish, which nothing can injure or affect, save a substance of its own
nature.
DIAMOND  MICROSCOPES were first suggested by Dr. Goring, and have been
well executed by Mr. Pritchard.  Previous to grinding a diamond into a spherical
figure, it should be ground flat and parallel upon both sides, that by looking through
it, as opticians try flint glass, we may see whether it has a double or triple refractive
power, as many have, which would render it useless as a lens.  Among the 14 different crystalline forms of the diamond, probably the octahedron and the cube are
the only ones that will give a single vision. It will, in many cases, be advisable to
grind diamond lenses plano-convex, both because this figure gives a low spherical
aberration, and because it saves the trouble of grinding one side of the gem. A concave tool of cast iron, paved with diamond powder, hammered into it by a hardened
steel punch, was employed by Mr. Pritchard. This ingenious artist succeeded in completing a double convex of equal radii, of about J — of an inch focus, bearing an aperture of -- of an inch with distinctness upon opaque objects, and its entire diameter
upon transparent ones. This lens gives vision with a trifling chromatic aberration; in
other respects, like Dr. Goring's Amician reflector, but without its darkness, its light is
said to be superior to that of any compound microscope whatever, acting with the same
power, and the same angle of aperture.  The advantage of seeing an object without
aberration by the interposition of only a single magnifier, instead of looking at a picture of it with an eye-glass, is evident. We thus have a simple direct view, whereby
we slhall see more accurately and minutely the real texture of objects.
DIAPER, is the name of a kind of cloth, used chiefly for table linen.  It is known
among the French by the name of toilefourre, and is ornamented with the most extensive
figures of any kind of tweeled cloth, excepting damask. The mounting of a loom for
working diaper is, in principle, much the same as a draw-loom, but the figures being
less extensive, the mounting is more simple, and is wrought entirely by the weaver,
without the aid of any other person. As tweeled cloths, of any number of leaves, are
only interwoven at those intervals when one of the leaves is raised, the woof above, and
the warp below, is kept floating or flushed, until the intersection takes place. Of consequence, the floating yarn above appears across the fabric, and that below longitudinally. This property of tweeled cloths is applied to form the ornamental figures of all
kinds of tweeled goods, merely by reversing the floating yarn when necessary. In the
simpler patterns, this is effected by a few additional leaves of treddles; but when the
range of pattern becomes too great to render this convenient, an apparatus called a back
harness is employed, and the cloth woven with this mounting is called diaper. Diapers
are generally five-leaf tweels; that is to say, every warp floats under four threads of
woof, and is raised, and of course interwoven with the fifth. This is done either successively, forming diagonals at 450 upon the cloth, or by intervals of two threads, which
is called the broken tweel. The latter is generally, if not universally, adopted in the
manufacture of diaper.  The reason of preferring the broken to the regular tweel,
where ornaments are to be formed, is very obvious. The whole depending upon reversed
flushing to give the appearance of oblique or diagonal lines, through either, would
destroy much of the effect, and materially injure the beauty of the fabric. The broken
tweel, on the contrary, restores to the tweeled cloth a great similarity of appearance to
plain, or alternately interwoven fabrics, and at the same time preserves the facility of
producing ornaments by reversing the flushing. The simplest kinds of reversed tweels
will be found described under TEXTILE FABRICS.
DIASTASE. This curious substance, extracted by water from crushed malt, and precipitated from that infusion by alcohol, as is described under FERMENTATION, has been
made the subject of new researches by M. Guerin Varry. The conclusions deducible
from his interesting experiments are the following:~
1. One part of diastase, dissolved in 30 parts of cold water, put with 408 parts of potato starch out of contact of air, did not exercise the slightest action upon this substance
in the course of 63 days, under a temperature varying from 680 to 790 Fahr.
2. Two parts of diastase do not in the course of an hour cause the globules of three
parts of starch to burst, at a temperature approaching very nearly to that of the hot water
which bursts them into a paste. It follows that diastase acts no part in the process of
germination, towards eliminating the teguments of the starch, or transforming its interior portion into sugar, and a gummy matter assimilated by plants.




580                            DIES FOR STAMPING.
3. Diastase liquefies and saccharifies the paste of starch without absorption or disengagemen t of gas; a reaction which takes place equally in vacuo as in the open air.
4. 100 parts of starch made into a paste with 39 times their weight of water, mixed
with 6'13 parts of diastase dissolved in 40 parts of water, and kept for an hour between
1400 and 149o Fahr., afforded 86-91 parts of sugar.
5. A paste containing 100 parts of starch, and 1393 parts of water, put in contact
with 12'25 parts of diastase dissolved in 367 parts of cold water, having been maintained at 680 Fahr. during 24 hours, produced'7 64 parts of sugar.
6. The preceding experiment, repeated at the temperature of melting ice, afforded at
the end of 2 hours, 11 82 parts of sugar.
7. The most favorable proportions and circumstances for the production of a great
quantity of sugar, are a slight excess of diastase or barley malt (at least 25 per cent.
of the latter), about 50 parts of water to one of starch, and a temperature between 1400
and 1490 Fahr.  It is of the greatest consequence for the saccharification to take
place as speedily as possible, so that the sugar produced may not be left in contact with
much guiumy matter (dextrine), in which case the diastase will not convert the latter
into sugar. In fact, the liquefaction and saccharification should proceed simultaneously.
8. The sugar of starch prepared either with diastase, or sulphuric acid, crystallizes
in cauliflowers, or in prisms with rhomboidal facets. It has the same composition as
sugar of grapes.
9. Diastase even in excess does not saccharify the gummy matter dissolved in the
water along with the starch-sugar, but when the gum  is insulated, it is convertible
almost entirely into sugar.
10. Gum arabic, cane sugar, and beer yeast, suffer no change from diastase.
11. A watery solution of diastase readily decomposes on keeping, either in contact
or out of contact of air.
12. When starch-sugar, whether obtained by means of diastase or sulphuric acid,
is submitted to the spirituous fermentation, the sum of the weights of the alcohol, carbonic acid, and water of crystallization of the sugar, is less than the weight of the
sugar by about 31 per cent.  This difference proceeds in a great measure from the formation of some acetic acid, lactic acid, volatile oil, and probably some other unknown
products in the act of fermentation.
DIDYM.  A new metal, found in oxide of cerium, and so called as being associated
in that ore as a twin brother of lanthanum.
DIES FOR  STAMPING.  (Coins, Fr.; Mfinzstampeln, Germ.)  The first circumstance that claims particular attention in the manufacture of dies, is the selection of the
best kind of steel for the purpose, and this must in some measure be left to the experience of the die-former, who, if well skilled in his art, will be able to form a tolerably
correct judgment of the fitness of the metal for the purpose, by the manner in which it
works upon the anvil.  It should be rather fine-grained than otherwise, and above all
things perfectly even and uniform in its texture, and free from spots and patches finer or
coarser than the general mass.  But the very fine and uniform  steel with a silky fracture, which is so much esteemed for some of the purposes of cutlery, is unfit for our
present purpose, from the extreme facility with which it acquires great hardness by pressure, and its liability to cracks and flaws. The very coarse-grained or highly crystalline
steel is also equally objectionable; it acquires fissures under the die-press, and seldom
admits of being equally and properly hardened. The object, therefore, is to select a steel
of a medium quality as to fineness of texture, not easily acted upon by dilute sulphuric
acid, and exhibiting a uniform  texture when its surface is washed, over with a little
aqua-fortis, by which its freedom from pins of iron, and other irregularities of composition, is sufficiently indicated.
The best kind of steel being thus selected, and properly forged at a high heat into
the rough die, it is softened by very careful annealing, and in that state, having been
smoothed externally, and brought to a table in the turning lathe, it is delivered to the
engraver.
The process of annealing the die consists in heating it to a bright cherry red, and suffering it to cool gradually, which is best effected by bedding it in a crucible or iron pot
~of coarsely-powdered charcoal, that of animal substances being generally preferred. In
this operation it is sometimes supposed that the die, or at least its superficial parts, becomes super-carbonized, or highly-converted steel, as it is sometimes called; but experience does not justify such an opinion, and I believe the composition of the die is
scarcely, certainly not materially, affected by the process, for it does not remain long
enough in the fire for the purpose.
The engraver usually commences his labors by working out the device with small
steel tools, in intaglio; he rarely begins in relief (though this is sometimes done); and
having ultimately completed his design, and satisfied himself of its general effect and




DIES FOR STAMPING.                                        581
correctness, by impressions in clay, and dabs, or casts in type metal, the die is ready for
the important operation of hardening, which, from various causes, a few of which I
shall enumerate, is a process of much risk and difficulty; for should any accident now
occur, the labor of many months may be seriously injured, or even rendered quite
useless.
The process of hardening soft steel is in itself very simple, though not very easily
explained upon mechanical or chemical principles.  We know  by experience that it
is a property of this highly valuable substance to become excessively hard, if heated
and suddenly cooled; if, therefore, we heat a bar of soft malleable and ductile steel red
hot, and then suddenly quench it in a large quantity of cold water, it not only becomes
hard, but fraCile and brittle. But as a die is a mass of steel of considerable dimensions, this hardening is an operation attended by many and peculiar difficulties, more
especially as we have at the same time to attend to the careful preservation of the
engraving. This is effected by covering the engraved face of the die with a protecting
face, composed of fixed oil of any kind, thickened  with  powdered  charcoal: some
persons add pipe-clay, others use a pulp of garlic, but pure lamp-black and linseed oi.
answer the purpose perfectly.  This is thinly spread upon the work of the die, which,
if requisite, may be further defended by an iron ring; the die is then placed with its
face downwards in a crucible, and completely surrounded by powdered charcoal. It is
heated to a suitable temperature, that is, about cherry red, and in that state is taken out
with proper tongs, and plunged into a body of cold water, of such magnitude as not
to become materially increased in tempera ture; here it is rapidly moved about, until all
noise ceases, and then left in the water till quite cool. In this process it should produce
a bubbling and hissing noise; if it pipes and sings, we may generally apprehend a rack
or fissure.
No process has been found to answer better than the above simple and common mode
of hardening dies, though others have had repeated and fair trials. It has been proposed
to keep up currents and eddies of cold water in the hardening cistern, by means of
delivery-pipes, coming from a height; and to subject the hot die, with its face uppermost, to a sudden and copious current of water, let upon it from a large pipe, supplied
from  a high reservoir; but these means have not in any way proved rore successful,
either in saving the die or in giving it any good qualities. It will be recollected, from
the form of the die, that it is necessarily only, as it were, case-hardened; the hardest
strata being outside, and the softer ones within, which envelop a core, something in
the manner of the successive coats of an onion; an arrangement which we sometimes
have an opportunity of seeing displayed in dies which have been smashed by a violent
blow.
The hardening having been effected, and the die being for the time safe, some further steps may be taken for its protection; one of these consists in a n-ery mild kind of
tempering, produced  by putting it into water, gradually raised to the boiling point,
till heated throughout, and the i suffering it gradually to cool. This operation renders
the die less apt to crack in very cold weather. A great safeguard is also obtained by
thrusting the cold die into a red-hot iron ring, which just fits it in that state, and which,
by contracting as it cools, keeps its parts together under considerable pressure, preventing the spreading of external cracks and fissures, and often enabling us to employ a
split or die for obtaining punches, which would break to pieces without the protecting
If the die has been successfully hardened, and the protecting paste has done its duty,
by preserving the face from all injury and oxydizement, or burning, as it is usually
called, it is now to be cleaned and  polished, and in this state constitutes what is
technically called a MATRIX; it may, of course, be used as a multiplier of medals, coins,
or impressions, but it is not generally thus employed, for fear of accidents happening
to it in the coining press, and because the artist has seldom perfected his work upon
it in this state.  It is, therefore, resorted to for the purpose of finishing a PUNCH, or
steel impression for relief.  For this purpose a.proper block of steel is selected, of
the same quality, and with the same precautions as before, and being carefully annealed,
or softened, is turned like the matrix, perfectly true and flat at the bottom, and obtusely
conical at top. In this state, its conical surface is carefully compressed by powerful and proper machinery upon the matrix, which, being very hard, soon allows it to
receive the commencement of an impression; but in thus receiving the impression, it
becomes itself so hard by condensation of texture as to require, during the operation, to
be repeatedly annealed, or softened; otherwise it would split into small superficial fistures, or would injure the matrix; much practical skill is therefore required in taking
this impression, and the punch, at each annealing, must be carefully protected, so that
the work. may not be injured.
Thus, after repeated blows in the die-press, and frequent annealing, the impression




582                                  DIGESTER.
from the matrix is at length perfected, or brought completely up, and having been
retouched by the engraver, is turned, hardened, and collared, like the matrix, of which
it is now  a complete impression in relief, as we have before said, is called a
punch.
This punch becomes an inexhaustible parent of dies, without further reference to the
original matrix; for now by impressing upon it plugs of soft steel, and by pursuing with
them an exactly similar operation to that by which the punch itself was obtained, we
procure impressions from it to any amount, which of course are facsimiles of the matrix,
and these dies being turned, hardened, polished, and, if necessary, tempered are employed
for the purposes of coinage.'The distinction between striking medals and common coin is very essential, and the
work upon the dies is accordingly adjusted to each.  Medals are usually in very high
relief, and the effect is produced by a succession of blows; and as the metal in which
they are struck, be it gold, silver, or copper, acquires considerable hardness at each
stroke of the press, they are repeatedly annealed during the process of bringing them up.
In a beautiful medal, which Mr. Wyon some time since completed for the Royal Navy
College, the obverse represents a head of the King, in very bold relief; it required
thirty blows of a very powerful press to complete the impression, and it was necessary
to anneal each medal after every third blow, so that they went ten times into the fire
for that purpose. In striking a coin or medal, the lateral spread of the metal, which
otherwise would ooze out as it were from between the dies, is prevented by the application of a steel collar, accurately turned to the dimensions of the dies, and which,
when left plain, gives to the edge of the piece a finished and polished appearance; it is
sometimes grooved, or milled, or otherwise ornamented, and occasionally lettered, in
which case it is made in three separate and moveable pieces, confined by a ring, into
which they are most accurately fitted, and so adjusted that the metal may be forced intc
the letters by its lateral spread, at the same time that the coin receives the blow of the
screw-press.
Coins are generally completed by one blow of the coining-press. These presses are
worked in the Royal Mint by machinery, so contrived that they shall strike, upon an
average, sixty blows in a minute; the blank piece, previously properly prepared and annealed, being placed between the dies by part of the sale mechanism.
The number of pieces which may be struck by a single die of good steel, properly
hardened and duly tempered, not unfrequently amounts at the Mint to between three and
four hundred thousand, but the average consumption of dies is of course much greater,
owing to the variable qualities of steel, and to the casualties to which the dies are
liable: thus, the upper and lower die are often violently struck together, owing to an
error in the layer-on, or in that part of the machinery which ought to put the blank into
its place, but which now and then fails so to do. This accident very commonly arises
from the boy who superintends the press neglecting to feed the hopper of the layer-on
with blank pieces. If a die is too hard, it is apt to break or split, and is especially subject to fissures, which run from letter to letter upon the edge. If too soft, it swells, and
the collar will not rise and fall upon it, or it sinks in the centre, and the work becomes
distorted and faulty. He, therefore, who supplies the dies for an extensive coinage has
many accidents and difficulties to encounter. There are eight presses at the Mint, frequently at work for ten hours each day, and the destruction of eight pair of dies per day
(one pair for each press) may be considered a fair average result, though they much more
frequently fall short of, than exceed this proportion. It must be remembered that each
press produces 3600 pieces per hour, but, making allowance for occasional stoppages, we
may reckon the daily produce of each press at 30,000 pieces; the eight presses, therefore, will furnish a diurnal average of 240,000 pieces.
DIGESTER is the name of a strong kettle or pot of small dimensions, made very
strong, and mounted with a safety valve in its top. Papin, the contriver of this apparatus, used it for subjecting bones, cartilages, &c. to the solvent action of high-pressure
steam, or highly heated water, whereby he proposed to facilitate their digestion  in
the stomach.  This contrivance is the origin of the French cookery pans, called
rsutoclares, because the lid is self-keyed, or becomes steam-tight by turning it round
under clamps or ears at the sides, having been previously ground with emery to fit the
edge of the pot exactly. In some autoclaves the lid is merely laid on with a fillet of
linen as a lute, and then secured in its place by means of a screw bearing down upon its
rentre from an arched bar above. The safety valve is loaded either by a weight placed
trertically upon it, or by a lever of the second kind pressing near its fulcrum, and
acted upon by a weight which may be made to bear upon any point of its graduated
arm.
Chevreul has made a useful application of the digester to vegetable analysis.  His
instrument consists of a strong copper cylinder, into which enters a tight cylinder of




DISTILLATION.                                          583
silver, having its edge turned over at right angles to the axis of the cylinder, so as to
form the rim of the digester. A segment of a copper sphere, also lined with silver,
stops the aperture of the silver cylinder, being applied closely to its rim. It has a
conical valve pressed with a spiral spring, of any desired force, estimated by a steelyard.
This spring is enclosed within a brass box perforated with four holes; which may be
screwed into a tapped orifice in the top of the digester. A tube screwed into another
hole serves to conduct away the condensable vapors at pleasure into a Woulfe's
apparatus.
DIMITY is a kind of cotton cloth originally imported from  India, and now manufactured in great quantities in various parts of Britain, especially in Lancashire. Dr.
Johnson calls it dimmity, and describes it as a kind of fustian. The distinction between
fustian and dimity seems to be, that the former designates a common tweeled cotton
cloth of a stout fabric, which receives no ornament in the loom, but is most frequently
dyed after being woven.  Dimity is also a stout cotton cloth, but not usually of so thick
a texture; and is ornamented in the loom, either with raised stripes or fancy figures,
is seldom  dyed, but usually worn white, as for bed and bed-room  furniture.  The
striped dimities are the most common, they require less labor in weaving than the
others; and the mounting of the loom being more simple, and consequently less expensive, they can be sold at much lower rates. See TEXTILE FABRICS, for particular details
of the plan of mounting them.
DISINFECTION  OF CLOTHING, ({Messrs. Davison and Symington's patent process).
-The absorption of noxious effluvia by clothes or soft and porous articles of merchandise, has been long recognised as a fact by men who have directed special attention to
this subject.
The use of the various liquid disinfectants, which have of late been proposed, is not
applicable to articles of clothing; and the common practice of baking clothes in ovens
is liable to lead to their destruction, owing to the impossibility of regulating the temperature to which it is necessary to expose them.  The only plan which combines
economy with certainty of disinfection, is that which has been patented by Messrs.
Davison and Symington, and which is now  extensively employed in various manufactures.  This plan consists in exposing the articles of clothing in a large chamber to
rapid currents of air heated to a temperature insufficient to injure them, i. e. varying
from 2001 to 250~.  We have had an opportunity of witnessing this process as applied
to certain branches of manufacture, and the results were of the most satisfactory kind.
In the case of infected clothing, it is obvious, that while a high temperature tends to
destroy the animal poisons, a rapid current of air, constantly passing through the chamber,
tends to carry them off.  The temperature of the current of air can be so regulated that
common albumen is speedily dried into a yellow transparent solid, without coagulation,
or if necessary, the heat may be increased from 4000 to 5000, according to the nature
of the articles which are exposed. Dr. Copland has already directed the attention of
the profession to this process, aud observes that, " the great advantage of this method
is its easy applicability to all kinds, and to any number of objects and articles without
injury to their textures or fabrics." From an inspection of one of these chambers, when
the temperature of the current of air was 1160, we can state that the process of Messrs.
Davison and Symington for the drying and disinfecting of the clothing of cholera and
fever patients, will be far more efficacious than the common plan of washing and baking.
In our opinion, an apparatus of this kind, fitted up in large hospitals, infirmaries,
prisons and workhouses, as well as all quarantine stations, would be admirably adapted
to prevent the diffusion of infectious diseases.
DISTILLATION  (Eng. and Fr.; Brailntweinbreanerei, Germ.) means, in the commercial language of this country, the manufacture of intoxicating spirits; under which are
comprehended the four processes, of mashing the vegetable materials, cooling the worts,
exciting the vinous fermentation, and separating by a peculiar vessel, called a still, the
alcohol combined with more or less water. This art of evoking the fiery demon of
drunkenness from his attempered state in wine and beer, was unknown to the ancient
Greeks and Romans.  It seems to have been invented by the barbarians of the north of
Europe, as a solace to their cold and humid clime; and was first made known to the
southern nations in the writings of Arnoldus de Villa Nova, and his pupil, Raymond
Lully of Majorca, who declares this admirable essence of wine to be an emanation of
the Divinity, an element newly revealed to man, but hid from antiquity, because the huiman race were then too young to need this beverage, destined to revive the energies of
modern decrepitude.  He further imagined that the discovery of this aqua r'ite, as it was
called, indicated the approaching consummation of all things-the end of this world.
However much he erred as to the value of this remarkable essence, he truly predicted its
vast influence upon humanity, since to both civilized and savage nations it has realized
greater ills than were threatened in the fabled box of Pandora.




584                                 DISTILLATION.
I shall consider in this place the first three of these subjects, reserving for the article
STILL an account of the construction and use of that apparatus.
Whiskey, from  the Irish word Usquebaugh, is the British name of the spirituous
liquor manufactured by our distillers, and corresponds to the Ean de vie of the French,
and the Branntwein of the Germans.  It is generated by that intestine change which
grape juice and other glutino-saccharine liquids spontaneously undergo when exposed to
the atmosphere at common temperatures; the theory of which will be expounded under
the article FERMENTATION.  The production of whiskey depends upon the simple fact,
that when any vinous fluid is boiled, the alcohol, being very volatile, evaporates first, and
may thereby be separated from the aqueous vegetable infusion in which it took its birth.
Sugar is the only substance which can be transformed into alcohol. Whatsoever fruits,
seeds, or roots afford juices or extracts capable of conversion into vinous liquor, either
contain sugar ready formed, or starch susceptible of acquiring the saccharine state by
proper treatment.  In common language,                         the intswe
juices of fruits is called wine; and that from the infusions of farinaceous seeds, beer
though there is no real difference between them  in chemical constitution.  A  similar
beverage, though probably less palatable, is procurable from the juices and infusions of
many roots, by the process of fermentation. Wine, cider, beer, and fermented wash of
every kind, when distilled, yields an identical intoxicating spirit, which differs in these
different cases merely in flavor, in consequence of the presence of a minute quantity of
volatile oils of different odors.
I. The juices of sweet fruits contain a glutinous ingredient which acts as a ferment in
causing their spontaneous change into a vinous condition; but the infusions of seeds,
even in their germinated or malted state, require the addition of a glutinous substance
called yeast, to excite the best fermentation. In the fabrication of wine or beer for drinking, the fermentative action should be arrested before all the fruity saccharum  is
decomposed; nor should it on any account be suffered to pass into the acetous stage
whereas for making distillery wash, that action should be promoted as long as the
proportion of alcohol is increased, because the formation of a little acetic acid is not
injurious to the quality of the distilled spirit, but rather improves its flavor by the
addition of acetic ether, while all the undecomposed sugar is lost.  Distillers operate
upon the saccharine matter from corn of various kinds in two methods; in the first they
draw off a pure watery extract from the grain, and subject this species of wort to fermentation; in the second they ferment and distil the infused mass of grains.  The
former is the practice of the distillers in the United Kingdom, and is preferable on
many accounts; the latter, which is adopted in Germany, Holland, and the north
of Europe, is less economical, more uncertain in the product, and affords a cruder
spirit, in consequence of the  fetid  volatile  oil evolved  from  the  husks in  the
still.  The substances employed by the distillers may be distributed into the following
classes
1. Saccharine juices.  At the head of these stands cane-juice, which fresh from the
mill contains from  12 to 16 per cent. of raw  sugar, and like the must of the grape
enters into the vinous fermentation without the addition of yeast, affording the specie*
of spirit called Rum, which is possessed of a peculiar aroma derived from an essential
oil in the cane.  An inferior sort of rum  is fabricated from  molasses, mixed with the
skimmings and washings of the sugar pans.  When molasses or treacle is diluted with
twenty times its weight of warm water, and when the mixture has cooled to 78" F. if
one twelfth of its weight of yeast be added, fermentation will speedily ensue, and an
ardent spirit will be generated, which when distilled has none of the aroma of rum;
proving this to reside in the immediate juice or substance of the cane, and to be dissipated at the high temperature employed in the production of molasses.  Though the
cane juice will spontaneously undergo the vinous fermentation, it does so more slowly
and irregularly than the routine of business requires, and therefore is quickened by the
addition of the lees of a preceding distillation.  So sensible are the rum  distillers of
the advantage of such a plan, that they soak woollen cloths in the yeast of the fermenting vats, in order to preserve a ferment from one sugar season to another.  In Jamaica
and some other of our colonies, 50 gallons of spent wash or lees are mixed with 6 gallons of molasses, 36 gallons of sugar-pan skimmings (a substance rich in aroma), and
8 gallons of water; in which mixture there is about one twelfth part of solid saccharum.  Those who attend more to the quality than the quantity of their rum, will use
a smaller proportion of the spent wash, which is always empyreumatic, and imparts more
or less of its odor to the spirit distilled from  it.  The fermentation is seldom complete
in less than 9 days, and most commonly it requires from  12 to 15; the period being
dependant upon the capacity of the fermenting tun, and the quality of its contents.
The liquid now  becomes clear, the froth having fallen to the bottom, and few bubbles
of gas are extricated from it, while its specific gravity is reduced from 1-050 down tc
O'992. The sooner it is subjected to distillation after this period, the better, to prevent




DISTILLATION.                                       585
the loss of alcohol by the supervention of the acetous stage of fermentation, an accident
very liable to happen in the sugar colonies. The crude spirit obtained from the large
single still at the first operation, is rectified in a smaller still. About 114 gallons of
rum, proof strength, specific gravity 0'920, are obtained from 1200 gallons of wash.
Now these 1200 gallons -weigh 12,600 lbs., and contain nearly one eighth of their weight
of sugar=1575 lbs.; which should yield nearly its own weight of proof spirit, whose
bulk is40=%7 -5 7    1712 pound measures —171'2 gallons; whereas only 114 are obtained;
proving the processes to be conducted in a manner far from economical, even with every
reasonable allowance.
Mr. Edwards gives the following estimate: "The total amount of sweets from an
estate in Jamaica which mnakes 200 hogsheads of sugar, is 16,666 gallons.  The wash set
at the rate of 12 per cent. sweets should return 34,720 gallons of low wines, which should
give 14,412 gallons of rum, or 131 puncheons of 110 gallons each."
By my own experiments on the quantity of proof spirit obtainable from molasses by fermentation (afterwards to be detailed), one gallon of sweets should yield one gallon of
spirit; and hence the above 16,666 gallons should have afforded the same bulk of rum.
But here we are left somewhat in the dark, by not knowing the specific gravity of the rum
spoken of by Mr. Edwards. The only light let in upon us is when he mentions rum oilproof, that is, a spirit in which olive oil will sink; indicating a density nearly the same
with our actual excise proof, for olive oil at 60~ F. has the specific gravity 0'919. When
a solution of sugar of the proper strength is mixed with wine lees, and fermented, it
affords a spirit by distillation not of the rum, but of the brandy flavor.
The sweet juices-of palm trees and cocoa nuts, as also of the maple, and ash, birch,
&c., when treated like cane juice afford vinous liquors from which ardent spirits, under
various names, are obtained; as arrack, &c.; the quantity being about 50 pounds of
alcohol of 0'825 for every 100 pounds of solid saccharine extract present. Honey similarly treated affords the metheglin so much prized by our ancestors. Good whey, freed
from curd by boiling., will yield 4 per cent. of spirit of wine, when fermented with the
addition of a little yeast.
2. The juices of apples, pears, currants, and such fruits, afford by fermentation quantities of alcohol proportional to the sugar they contain. But the quality of the spirit is
much better when it is distilled from vinous liquids of a certain age, than from recently
fermented must.  Cherries are employed in Germany, and other parts of the Continent,
for naking a high-flavored spirit called Kirseh-wasser, or cherry water.  The fully ripe
fruit is crushed by a roller press, or an edge-stone mill, along with the kernels; the pulp
is fermented in a mass, the liquid part is then drawn off, and distilled. More or less
prussic acid enters from the kernels into this spirit, which renders it very injurious, as a
liquor, to many constitutions. I was once nearly poisoned by swallowing a wine glass of
it in the valley of Chamouni. The ripened red fruit of the mountain ash constitutes a
good material for vinous fermentation. The juice being mixed with some water and a
little yeast, affords when well fermented, according to Hermstaedt, 12 pounds, or 1,
gallons, of alcohol from 2 bushels of the ripe berries.
3. Many roots contain sugar, particularly beet, from which no less than 7 per cent. of
it may be extracted by judicious means. Hermstaedt recommends to mash the steam
boiled clean roots, and add to the paste two thirds of its weight of boiling water, and a
thirtieth of its weight of ground malt, mixing the materials well, and then leaving them
three hours in a covered vessel. The mixture must now be passed through a wire sieve,
with meshes of one third of an inch square each; the residuum is washed with a little
cold water, and, when the temperature has fallen to 770 F., the proper quantity of yeast
must be added, and the fermentation suffered to proceed in a covered tun. In 5 or 6
days it will be complete, and will afford by distillation, from 100 pounds of beet root,
about 10 or 12 pounds of proof spirits. Carrots and parsnips, when similarly treated,
yield a considerable quantity of alcohol.
II. ardent spirits or whiskey from fecula or starchy materials.
I have already pointed out, in the article BEER, how the starch is transformed into a
saccharine condition, by malting and mashing; and how a fermentable wort may be obtained from starchy meal. By like operations may all vegetable substances, which consist chiefly of starch, become materials for a whiskey distillery.  To this class belong
all the farinaceous grains, potatoes, and the pods of shell fruits, as beans, vetches, horsechestnuts, acorns, &c.
1. Whiskey from corn.  All those species of corn which are employed in breweries
answer for distilleries; as wheat, rye, barley, and oats; as well as buckwheat, and maize or
Indian corn.  The product of spirits which these different grains afford, depends upon
the proportion of starch they contain, including the small quantity of uncrystallizable
sugar present in them. Hermstaedt, who has made exact experiments upon the subject,
reckons a quart (Prussian or British) of spirits, containing 30 per cent. of the absolute
alcohol of Richter, for 2 pounds of starch. Hence 100 pounds of starch should yield




586                                DISTILLATION.
35 pounds of alcohol; or 4'375 gallons imperial, equal to 7'8 gallons of spirits, excise
proof.
100 pounds of the following grains afford in spirits of specific gravity 0.9427, con.
taining 45 per cent. of absolute alcohol, (=  -.of British proof,) the following quantities:Wheat, 40 to 45 pounds of spirits; rye, 36 to 42; barley, 40; oats, 36; buckwheat,
40; maize, 40.  The mean of the whole may be taken at 40 pounds, equal to 4{ gallons
imperial, of 0-9427 specific gravity = 3'47 gallons, at excise proof. The chief difference
in these several kinds of corn consists in their different bulks under the same weight; a
matter of considerable importance; for since a bushel of oats weighs little more than the
half of a bushel of wheat, the former becomes for some purposes less convenient in use
than the latter, though it affords a good spirit.
Barley and rye are the species of grain most commonly employed in the European
distilleries for making whiskey. Barley is mostly taken either partly or altogether in
the malted state; while the other corns are not malted, but merely mixed with a certain
proportion of barley malt to favor the saccharine fermentation in the mashing. It is
deemed preferable to use a mixture of several sorts of grain, instead of a single one; for
example, wheat with barley and oats; or barley with rye and wheat; for the husks of
the oats diffused through the wheat flour and rye meal keep it open or porous when
mashed, and thus favor the abstraction of the wort; while the gluten of the wheat tends
to convert the starch of the barley and oats into sugar. When the whole of the grain,
however, is malted, a much more limpid wort is obtained than from a mixture of malt
with raw grain; hence the pure malt is preferable for the ale and porter brewer while
the mixture affords a larger product, at the same cost of materials, to the distiller. When
barley is the only grain employed, from one third to one sixth of malt is usually mixed
with it; but when wheat and rye are also taken, the addition of from one eighth to one
sixteenth of barley malt is sufficient. Oats are peculiarly proper to be mixed with wheat,
to keep the meal open in the mashing.
The following are the proportions used by some experienced Scotch distillers.
250 bolls, containing 6 bushels each, being used for a mashing, consist of,
25 bolls of oats, weighing 284 lbs. per boll, or 471 lbs. per bushel;
42          malt           240                 40
25          rye            320                 53a
158          barley         320                 53^
250                                       mean 48^
From each boll, weighing 291 lbs., 14 imperial gallons of proof whiskey are obtained
on an average; equivalent to 1l12 gallons at 25 over proof.
The malting for the distilleries is to be conducted on the same principles as for the
breweries, but the malt ought to be lightly kiln-dried, and that preferably at a steam heat,
instead of a fire, which is apt to give an empyreumatic smell to the grain that passes into
the spirits. For such persons, indeed, as relish the smell of burned turf, called teat-reek
in Scotland, the malt should be dried by a turf fire, whereby the whiskey will acquire
that peculiar odor.
But this smell, which was originally prized as a criterion of whiskey made from pure
malt, moderately fermented and distilled with peculiar care, has of late years lost its
value, since the artifice of impregnating bad raw grain whiskey with peat-smoke has been
extensively practised.
Dr. Kolle, in his treatise on making spirits, describes a malting kiln with a copper
plate heated with steam, 18 feet long, and 12 feet broad, on which a quantity of malt
being spread thin, is changed evexy 3 or 4 hours, so that in 24 hours he turns out upwards
of 28 cwt. of an excellent and well kilned article. The malt of the distiller should be as
pale as possible, because with the deepening of the color an empyreumatic principle is
generated.
When Indian corn is the subject of distillation, it must be malted in the same way as
described in the article BEER.  According to Hermstaedt, its flour may be advantageously mixed with the crushed malt in the mash tun. But its more complete dissolution may be accomplished by Siemen's mode of operating upon potatoes, presently to be
described.
1. Mashing. Barley and raw grain are ground to meal by millstones, but malt is merel
crushed between rollers. If only one tenth or one eighth of malt be used with nine
tenths or seven eighths of barley, some husks of oats are added, to render the mash
mixture more drainable.
When 40 bushels of barley and 20 of malt form  one mashing, from 600 to 700
gallons of water, heated to 1500 F., are mixed with these 60 bushels in the mash tun,




DISTILLATION.                                      587
and carefully incorporated by much manual labor with wooden oars, or in great concerns
by the mechanical apparatus used in the breweries. This agitation must be continued
for 2 or 3 hours, with the admission from time to time of about 400 additional gallons of
water, at a temperature of 190~, to counteract the cooling of the materials.  But since
the discovery of diastase, as the best heat for saccharifying starch is shown to be not
higher than 160~ F., it would be far better to mash in a tun, partially, at least, steam
incased, whereby we could preserve the temperature at the appropriate degree for generating the greatest quantity of sugar.
If the wort be examined every half-hour of the mashing period, it will be found
to become progressively sweeter to the taste, thinner in appearance  but denser in
reality.
The wort must be drawn off from the grains whenever it has attained its maximum
density, which seldom  exceeds 150 lbs. per barrel; that is, 360 +            142, or 42'    360
per cent. As the corn of the distiller of raw  grain has not the same porosity as the
brewer's, the wort cannot be drawn off from the bottom of the tun, but through a series
of holes at the level of the liquor, bored in a pipe stuck in at the corner of the vessel.
About one third only of the water of infusion can thus be drawn off from  the pasty
mass. More water is therefore poured on at the temperature of 190~, well mixed by
agitation for half an hour, then quietly infused for an hour and a half, and finally drawl
off as before. Fully 400 gallons of water are used upon this occasion, and nearly as
much liquor may be drawn off.  Lastly, to extract from  the grains everything soluble,
about 700 gallons of boiling hot water are turned in upon them, thoroughly incorporated, then left quietly to infuse, and drawn off as above. This weak wort is commonly
reserved for the first liquor of the next mashing operation upon a fresh quantity of meal
and malt.
The English distiller is bound by law to make his mixed worts to be let down into the
fermenting tun of a specific gravity not less than 1'050, nor more than 1-090; the Scotch
and Irish distillers not less than 1-030, nor more than 1-080; which numbers are called,
gravity 50, 90, 30, and 80, respectively.
With the proportion of malt, raw grain, and water, above prescribed, the infusion first
drawn off may have a strength == 20 per cent. = spec. gray. 1-082, or 73 lbs. per barrel;
the second of 50 lbs. per barrel, or 14 per cent.; and the two together would have a
strength of 61'2 lbs. per barrel = 17 per cent., or spec. gray. 1070. From experiments
carefully made upon a considerable scale, it appears that no more than four fifths of the
soluble saccharo-starchy matter of the worts is decomposed in the best regulated fermentations of the distiller from raw grain. For every 2 lbs. so decomposed, I lb. of alcohol,
spec. gray. 0-825, is generated; and as every gallon of spirits of the spec. gray. 0909
contains 4'6 lbs. of such alcohol, it will take twice 4'6 or 9'2 lbs. of saccharine matter to
produce the said gallon. To these 9'2 lbs., truly transmuted in the process, we must add
one fifth, or 184 lbs., which will raise to 1104 the amount of solid matter employed in
producing a gallon of the above spirits.
Some distillers mash a fourth time; and always use the feeble wort so obtained in
mashing fresh grain.
2. As the imperfect saccharine infusion obtained from raw grain is much more acescent than the rich sugary solution got from malt in the breweries, the distiller must
use every precaution to cool his worts as quickly as possible, and to keep them clear from
any acetous taint. The different schemes of cooling worts are considered under BEER
and REFRIGERATION. As the worts cool, a quantity of starchy matter is precipitated, but
it is all carefully swept along into the fermenting tun, and undoubtedly contributes to increase the production of alcohol. During the winter and temperate months, when the
distilleries are most actively at work, the temperature at which the worts are set is
usually about 700 F. When much farinaceous deposite is present, the heat may be only
650, because, in this case, a slow fermentation seems to favor the conversion of that
starch into sugar. In some German distilleries a little chalk is mixed with the worts, to
check acidity.
3. The fermentation.
The yeast added to the worts as a ferment, ought to be the best top barm of the
London porter breweries. About 1 gallon of it is requisite for every 2 bushels of meal
and malt worked up in the mashing process; and of this quantity only a certain proportion is introduced at the beginning; the remainder being added by degrees, on the second
and third days.
Should the fermentation flag, a little more may be added on the fourth or fifth day,
and the contents of the tun may be roused by an agitator. About 8 or 9 gallons may be
introduced four days in succession to the quantity of worts extracted from 60 bushels of
the farinaceous materials; or the third day's dose may be intermitted, and joined to the
fourth on the subsequent day.




588                                 DISTILLATION.
Great diversity and no little caprice prevail among distillers in respect of the periods of
administering the yeast; but they should be governed very much by the appearance of
the fermentation.  This process continues from  nine to twelve or even fourteen days,
according to circumstances; the tuns being left quite open during the first five days, but
being covered moderately close afterwards to favour the full impregnation of the liquor
with carbonic acid, as a fermenting agent.  In consequence of the great attenuation of
the wort by the generation of so much alcohol, no good body of yeast continues to float
on the surface, and what is formed is beat down into the liquor on purpose to promote
the fermentation. The temperature of the wash gradually increases till towards the end
of the fourth day, when it attains its maximum height of about 25~ above the pitch of
550 or 60~ at which it may have been set.  The time of the greatest elevation of temperature, as well as its amount, depends conjointly upon the quality of the yeast, the
nature of the saccharo-starchy matter, and the state of the'weather. It is highly probable that the electrical condition of the atmosphere exercises a considerable influence
upon fermentation.  We know the power of a thunder-storm  to sour vinous fluids. An
experimental inquiry into the relation between electricity and fermentation, could not fail
to prove both curious and profitable.
The dimunition of the density of the wort is carefully watched by the distiller, as the
true criterion of the success of his process. This attenuation, as he calls it, is owing
partly to the decomposition of the sugar, which communicated its gravity to the solution,
and partly to the introduction of the lighter alcoholic particles. Were a' the saccharostarchy matter resolved into gaseous compounds, the wort would become water; but since
a part of it remains undecomposed, and a portion of alcohol is produced at the expense
of the decomposed part, the degree of attenuation becomes a somewhat complicated problemn in a theoretical point of view; the density due to the residuary sugar being masked
and counteracted by the spirit evolved. Could the alcohol be drawn off as it is formed,
the attenuation would probably become greater, because the alcohol checks the fermentative action, and eventually stops it, before all the saccharum is decomposed. After the
wash has taken its highest degree of temperature, not much more spirit is found to be
generated; were this therefore removed by proper means, the remaining vegetable matter would undoubtedly yield a farther product of alcohol.
In the attenuation of raw-grain wash, the specific gravity seldom arrives at 1'000; but
most commonly stops short at 1-002 or 1'004.  When the vinous fermentation comes to
an end, the acetous is apt to commence, and to convert a portion of the alcohol into vinegar; a result which is easily ascertained by the increasing specific gravity, sour smell,
and acidulous reaction of the wash upon litmus paper, which remains after the paper is
heated, showing that the red color is not caused by carbonic acid.
Fermentation proceeds with more uniformity and success in the large tuns of the distiller, than in the experimental apparatus of the chemist; because the body of heat
generated in the former case maintains the action.  But I have succeeded in obviating
this inconvenience in operating upon 80 or 90 gallons, by keeping up the temperature,
when it begins to flag, by transmitting hot water through a recurved pipe plunged into
the tun.
We have already mentioned that one gallon of spirits, one in ten over-proof, is upon
the average generated from  11l04 lbs. of starch sugar; hence we conclude that one
pound water-measure of spirits at proof (=r JL imperial gallon) is produced from one pound
of the saccharum.
Malt whiskey.-The treatment and produce of malt distilleries are in some respects
different from  those of raw  grain.   Having been professionally employed by the
proprietors of both, I am  prepared to state the peculiarities of the latter, by an
example.  500 bushels of ground malt are first mashed with 9000 gallons of water,
heated to the temperature of 1600 F.: 6000 gallons of worts are drawn off into the
coolers, and let down into the fermenting tun at 680.  From  3 to 4 per cent. of a
mixture of London porter yeast with quick Scotch barm  are added, and well stirred
through the mass. At the end of two or three days, in general, the fermentation is
finished. On the residuary grains of the malt, from 4500 to 5000 gallons of water at
1800 are run, which after proper mashing as before, are drawn off; then 4500 more are
poured on, the drainage of which is added to the second. Both of these together, constituting 9000 gallons, are heated next day, and employed for the mashing of 500 bushels
of fresh malt. During the fermentation, the wash which was set at the spec. grav. 1'065,
comes down to water = I000.
The wash is distilled in two stills, appropriated to it, of about 800 gallons capacity
each, provided with a rotatory chain apparatus for preventing the lees from  adhering to
the bottom of the still. Into about 800 gallons of wash 8 lbs. of soap are put. The
liquor obtained at this first distillation is called low wines. These low wines are redis*
tilled in the spirit stills; the first and last portions of liquid being more or less blue or
milky in color, and rank ia flavor, are run into a separate receiver called the faints-back)




DISTILLATION.                                       589
while the middle portion, constituting in a well-managed distillery, from three fourths to
four fifths of the whole, are received into the spirit-back. The faints are mixed with a'arge
quantity of water, and redistilled, in order to free them from  the fetid oil derived from
the husks of the sgrain.  The interception of this noxious oil may be best effected by a
self-regulating bath, between the capital of the still and the refrigeratory, as will be
explained in treating of STILLS.  The capitals of the common Scotch stills are made from
15 to 20 feet Mhih, in order to prevent the chance of the wash boiling over into the
worm; and they are, towards the beginning of the process, struck from  time to time
with a rod, and by the sound emitted it is known whether they be empty, partially
filled, or in danger of an overflow; in which  case the fire is damped, by a spout
near the furnace door, connected by a leather pipe with an elevated reservoir of wa*,r.
When very pure spirits are wished for, a third or even a fourth distillation is had recourse
to; there beingz a quantity of water mixed each time with the spirit in the still, to prevent its acquiring a harsh alcoholic flavor.
According to some experienced distillers from raw  grain, the mashing temperature of
the first liquor should not exceed 140' F.; whereas with imat;t may be safely and
beneficially 1650 or 1700.  When rye is used instead of malt, 90 bushels of it are mixed
with 190 bushels of raw grain, constituting 280 bushels in whole, for the mashing of
which 5200 gallons of water are required.  An hour and a half more time is necessary
for settling the mashing of the above mixture, than of grain alone.  Gin is made in this
way.
The distiller of malt whiskey calculates on obtaining two gallons of proof spirits from
one bushel of malt, in average years.  The highest yield is 20 gallons per quarter of 8
bushels; and the lowest is 16, when the malt and fermentation are indifferent. The best
temperature to set the fermenting tun with malt wash is about 70~ or 72~ F.
When malt is 5s. the bushel, 6 bushels at 30s. will yield 12 gallons of proof spirits.
These cost therefore 2s. 6d. per gallon for the malt; to which must be added 3d. per
bushel for the amount of malt duty not returned, or lid. on the gallon; this added to the
Scotch duty of 3s. 4d. the gallon, makes the price altogether 5s. 111d.; besides the ex.
penses in fuel, yeast, labor, and rent, which may be estimated at 81d. per gallon.  But 3d.
may be deducted for what is paid by the dairymen for the spent wash and grains. The
total cost, therefore, exclusive of use of capital, is 6s. 5d. per gallon in Scotland.
The following is the work of a Scotch distillery, where good malt whiskey was
made.
One bushel of the malt weighed 35 lbs., or the boll, = 6 bushels, 210 lbs. In mashing
each boll of malt, 110 gallons of water were run on it at 1600 F. As soon as the fermenting tun of 3000 gallons capacity was charged with the wash at from 640 to 740 F., 2
gallons per cent. of barm  were added.  When the wash had become attenuated from
1060 to 1'010, another gallon of barm was introduced.
The temperature of the fermenting wash sometimes rises to 96~, which is, however,
an extreme case, and not desirable.  When the bubbles of carbonic acid mount in rapid
succession, it is reckoned an excellent sign. If the tun be small, and stand in a cool
apartment, it should be started at a higher temperature than in the reverse predicament.
Should the fermentation be suffered to flag, it is in t;eneral a hopeless task to restore
vigorous action. Some try the addition of bubs, that is, of some wort brought into a state
of rapid fermentation in a tub, by a large proportion of yeast, but seldom  with much
success. Indeed, the law prohibits the addition of any wort to the tun at a later period
than 24 hours after it is set; so that if bubs are used afterwards, the distiller is apt to
incur a penalty.
The maximum  quantity of proof spirits obtained on the great scale at any time from
raw grain mixed with from  one fourth to one eighth of malt, seems to be 22 gallons per
quarter.
By the British laws a distiller is not allowed to brew and distil at the same time;
but he must work alternately, one week, for instance, at fermentation, and next week at
distillation.
In fermenting solutions of sugar mixed with good yeast, the attenuation has been
carried down to 0984, and even 0'982, that is, in the language of the excise, 16 and 18 degrees below water, from 1060, the density at which it was originally set in the tun. This
was excellent work done on the scale of a great distillery nearly 30 years ago, when distillation from sugar was encouraged, in consequence of bad corn harvests.
In an experiment which I made in 1831, for the information of a committee of the
House of Commons, on the use of molasses in the breweries and distilieries, I dissolved
1 cwt. of raw sugar in water, so as to form 741 gallons, inclusive of 2 gallons of yeast.
The specific gravity of the mixture was 10593 on the 31st of March. By the 6th of
April, that is, in 6 days, the gravity had sunk to 0992, or 8 degrees under water, which
was reckoned a good attenuation, considering the circumstances and the small quantity
operated upon. By distillation it afforded at the rate of 14-875 gallons of proof spirits
for 100 gallons of the wash.




590                                DISTILLATION.
When the distillers first worked from sugar, they only obtained upon an average from
I cwt. 10'09 gallons imp. of proof spirit; but they afterwards got no less than ll92
imp. gallons.
The following experiment, which I made upon the fermentation of West India molasses
into spirits, for the information of the said committee, may prove not uninteresting to
my readers.  150 lbs. were dissolved in water and mixed with 2 gallons of yeast,
weighing exactly 20 lbs.  The wash measured 70 gallons, and had a spec. gravity of
1-0647 at 600 F.  In two days the gravity had fallen to 1-0055; in three days to
1'0022; and in five days to 1-001. The temperature was Kept up at from 800 to 90~ F.,
during the last two days, by means of a steam  pipe, to favor the fermentation.  The
product of spirits was 11 gallons, and -1-5 of a gallon.   Now 150 lbs. of the above
molasses -were found to contain of solid matter, chiefly uncrystallizable, 112 lbs. And as
112 lbs. of sugar are estimated by the revenue laws to afford by fermentation ll gallons
imp. of proof spirit, the result of that experiment upon molasses must be considered
satisfactory, bearing in mind that the saccharine substance in molasses has been not only
partially decomposed by heat, but is mixed with some of the glutinous or extractive matter
of the cane.
Since the alteration of the excise laws relative to distillation in 1825 and 1826, when
permission was given to set the wort at lower gravities, the quantity of spirits produced
from I quarter of corn has been much increased, even up to fully 20 gallons; and the
proportion of malt has been much diminished. The latter was soon reduced from three
sevenths malt, and four sevenths barley, or two fifths malt and three fifths barley, to one
fifth of malt and now to one tenth or even one sixteenth.
A discussion having lately taken place in Ireland between certain persons conneted
with the distilleries and the officers of the excise, whether, and to what extent, raw
grain worts would pass spontaneously into the vinous fermentation, the Board in London
requested me to superintend a series of researches in a laboratory fitted up at their office,
to settle this important point. I shall content myself here with giving the result of one
experiment, out of several, which seems to me quite decisive.  Three bushels of mixed
grains were taken, consisting of two of barley, one half of oats, and one half of malt,
which, being coarsely ground by a hand-mill, were mashed in a new tun with 24 gallons
of water at 155~.  The mash liquor drawn off amounted to 18 gallons, at the density of
1-0465; and temperature of 82~ F.  Being set in a new tun, it began to ferment in the
course of 12 hours, and in 4 days it was attenuated down to gravity 1-012. This yielded,
upon distillation in low wines, 3-22 gallons, and by rectification, in spirits, 3-05; while
the quantity equivalent to the attenuation by the tables was 3-31, being an excellent
accordance in such circumstances.
The inquisitorial regime imposed by law upon our distilleries, might lead a stranger
to imagine that our legislators were desirous of repressing by every species of annoyance
the fabrication of the fiery liquid which infuriates and demoralizes the lower population
of these islands. But alas! credit can be given them for no such moral or philanthropic
motive. The necessity of the exchequer to raise a great revenue, created by the wasteful
expenditure pf the state, on the one hand, and the efforts of fraudulent ingenuity on the
other, to evade the payment of the high duties imposed, are the true origin of that regime.
Examinations in distilleries are constantly making by the officers of excise. There is a
survey at 6 o'clock in the morning, when the officers take their accounts and gauges,
and make calculations which occupy several hours.  At 10 o'clock they again survey,
going over the whole premises, where they continue a considerable time, frequently till
the succeeding officer comes on duty; at 2 in the afternoon another survey takes place,
but not by the same people; at 6 in the evening the survey is repeated; at 10 there
comes another survey by an officer who had not been engaged in any of the previous
surveys of that day. He is not relieved till 6 o'clock next morning. In addition to these
regular inspections, the distilleries are subject to frequent and uncertain visits of the
surveyor and general surveyor. "We are never," says Mr. Smith, the eminent distiller
of Whitechapel, "out of their hands."*
Before the fermented wort goes into the still, a calculation is made of the quantity
of wash drawn from the wash back, and which is first pumped into what is called the
wash charger.  If the quantity in the wash charger exceeds the quantity in the wash
back, the distiller is charged upon the higher quantity; if it contains less, he must pay
according to the wash back, as being the larger quantity. When the quantity of wash is
all transferred to the charger, the discharge cock of the wash charger is unlocked, and
the wash is allowed to be drawn off from the charger into the still, the charging and
discharging cock of the still being locked by the officer. There can be no transfer of
wash but through the pumps, which are locked also.  The first distillation from  the
wash is worked into the low-wine receiver, which is also a locked up vessel; then of
* Report of Committee on Molasses, 2198.




DISTILLATION.                                       591
those low wImes, the strength and quantity are ascertained by the excise.   The account
of them affords a comparison with the quantity which the contents of the wash-kac k had
been estimated to produce; they are then pumped from  the low wine receiver, through
pumps previously locked into the low wine charger, which is also a locked up vessel;
from the locked up charger, after the officer has done his duty regarding it, they are allowed to be drawn off into the low wine still, which is a distillation of the second extraction;
then that low wine still works into another locked up cask, called the spirit receiver, for
the receiving of raw spirits; when that distillation is finished, the officer, attending again
on regular notice for that purpose, takes the quantity and strength of the spirits therein,
and upon the quantity so ascertained he charges the duty.  In distilling low wines, one
portion of them goes into the spirit receiver, and a portion into what is called the faint
receiver, which is another locked up vessel. These faints are in the next distillation
united with the low wines, from  the succeeding wash-back on their second distillation,
and are worked together; the united produce of these goes partly into the spirit cask,
and partly back again into the faint cask.  The operation is thus continued till all the
backs in the house are emptied.*
There is a kind of ardent spirits manufactured in Holland, vulgarly called Dutch gin,
Hollands, and sometimes geneva, from genievre, the French for juniper, a plant with the
essential oil of whose berries it is flavored.   One cwt. of ground malt mixed with two
cwts. of rve meal are mashed for two hours, with about 450 gallons of water at the temperature of 160  FP.  The mash drawn off is reduced with cold water till the liquid part
has the density of 45 lbs. per barrel, = specific aravity 1-047; and is then put all together
into the fermenting back at the temperature of 80~ F. One or two gallons of yeast are
added.  The fermentation soon becomes so vigorous as to raise the heat to 90~ and upwards, but it is not pushed far, being generally over in two days, when the gravity of the
wash still indicates 12 pounds of saccharum per barrel.   By this moderate attenuation,
like that practised by the contraband distillers of the Highlands of Scotland, it is supposed
that the fetid oil of the husks is not evolved, or at least in very small quantity.   The
grains are put into the alembic along with the liquid wash, and distilled into low wines,
which are rectified twice over, some juniper berries and hops being added at the last distillation. But the junipers are sometimes bruised and put into the mash. The produce
of worts so imperfectly fermented, is probably little more than one half of what the
British distiller draws from the same quantity of grain. But the cheapness of labor and
of grain, as well as the superior flavor of the Skiedam spirits, enables the Dutch distiller
to carry on his business with a respectable profit. In opposition to the above facts, Dubrunfaut says that about one third more spirits is obtained in Holland from grain than in
France, because a very calcareous spring water is employed in the mashing operation.
Were this account well founded, all that the distillers of other countries would have to do
would be merely to introduce a portion of chalk into their mash tuns, in order to be on a
par with the Dutch. But the statement is alto-ether a mistake.
In the vine countries, the. inferior wines or those damaged by keeping, as also a fermented mash of the pressed grapes, mixed with water, are distilled to form the cau de Vic
de Cognac of the French, called Brandy in this country. It contains less essential oil,
and that of a more agreeable flavor, than corn spirits. See BRANDY.
Berzelius says that there are distillers who are guilty of putting a little arsenious acid
into the still; that the spirits contain pretty frequently traces of arsenic, which may be
detected by adding to them a little muriatic acid, then evaporating off the alcohol, and
passing a current of sulphureted hydrogen gas through the residuary liquid, which will
give it the characteristic orpiment yellow tinge, arsenic being present. Copper, which is
sometimes introduced into distilled grain, or even malt spirits, in consequence of the soap
employed in the process of distillation, may be detee1tr/d best by the brown precipitate which
it occasions with ferroprussiate of potash. No arscrvc is ever used in this country.
When damaged grain has been mashed in making whiskey, a peculiar oily substance
makes its appearance in it. On approAching the nostrils to such whiskey slightly heated,
this volatile matter irritates the pituitary membrane and the eyes very powerfully. These
spirits have exactly the smell of an alcoholic solution of cyanogene; they intoxicate more
powerfully than pure alcohol of equal strength, and produce even temporary phrensy,
with subsequent sickness and disordered functions. This volatile body is not cyanogene,
though it be so like it, for it forms no such combinations as cyanogene does. It may be
extracted from diluted alcohol by agitating it with an unctuous oil, and then distilling the
oil along with water. At the end of 3 or 4 months, this volatile matter disappears in a
great measure, even when the spirits impregnated with it are enclosed in well-corked
bottles; obviously from its undergoing a spontaneous decomposition. It may be preserved much longer in the state of a watery solution.
When acetic ether is added to well purified or clean spirits, such as the distillers call
* Thomas Smith, Esq., of Whitechapel Road, in Report of Molasses Committee, Part It. p. 149.
38




592                               DISTILLATION.
silent whiskey, it gives it somewhat of the flavor of brandy. For this purpose, also, the
spirits are rectified from bruised prunes, or the lees of the cognac distilleries, whereby
they acquire additional flavor. The astringent taste of old brandy is imitated by the introduction of a little catechu into the British spirits. Burned sugar is employed as a
coloring in these imitations.
IV. Of making whiskey from  potatoes.-This root, in certain localities where it
abounds at a moderate price, is an excellent material for fermenting into alcohol. When
sound, it possesses from 20 to 25 per cent. of solid substance, of which starch constitutes at least three fourths; hence 100 pounds contain from 16 to 22 pounds of starch
susceptible of being saccharified.  In the expressed juice there is a small quantity of
tartaric acid.
Previously to mashing, potatoes must be first well washed in a horizontal cylindrical
cage revolving partially in a trough of water, as will be described in tiuating of the
manufact.4re of sugar from beet root. They must be then boiled in a close vessel with
steam, provided with a perforated bottom a few inches above the real one. The top has
an opening with a cover fitted tightly to it; through that the potatoes are intr'duced
and immediately above the false bottom there is a similar aperture through which the
boiled potatoes are taken out.  The steam-pipe enters at the top, runs down the
side a little way, and terminates in a widened mouth.  The large lids are secured by
cross bars, the small hole by folds of linen. In the lower valve there are two small holes
closed with pins, for inserting a wire to feel whether the potatoes be sufficiently boiled.
If so, the steam is immediately stopped off, the lower lid is removed, and the potatoes
pulled out with a hook into a
465                                                 tub.  They must be immeec  ss^^sfsg ~                                      diately made into a bomoge464                  neous paste before they get
D~  I                   -          ~cold.  Fig. 464 represents, in
plan, or horizontal section, the
apparatus used in France for
A.   this purpose.  A a are two
a^ ~ ~   ~         - E.cylinders covered with wire
EC         C  C-    0''_'_____ "                cloth, but open at the ends;
^j". m  _ f 1    ^                     iW      l -. c c and D D are two pieces of
A~dd       \   -- L.~ -=,. i,      wood fixed on the two axes,
in the form of two cones, with?[ ^ L- i       _.    A E    L l         the adjoining surfaces truncated; upon which, as also
>~1           _._                         upon iron rings E r, of the
~ ~ ~ -~ ~'-^  same diameter, made fast to
the axes, the wire cylinder rests.  Of the two wheels G H, the smaller has 18, the
greater has 21 teeth. The diameter of each cylinder is 14 inches, the length 18.
Above and between the two cylinders, there is a hopper for the reception of the boiled
potatoes. This machine triturates 1200 pounds of potatoes per hour. Their paste must
be forthwith mashed with some ground wheat or barley, and a proportion of malt; then
be set a fermenting.
As in the above mode of trituration, the potatoes are apt to cool to such a degree as to
obstruct their ready admixture with water, it is better to make them into a paste in the
vessel in which they are steamed. The apparatus contrived by Siemens fully answers
this end. It consists essentially of a tub A, represented in fig. 465, in section. It is
cylindrical, and made of planks from 3 to 4 inches thick, joined firmly and steam-tight;
the upper anAl under ends being well secured with iron hoops. The lower part is about 2
inches more in diameter than the upper. About a foot from the bottom, in a circular
groove, a cast iron partition w, or disc full of holes, is made fast, which serves the purpose of a searce, the apertures being an inch asunder; above, from  * to J~ of an inch
in diameter, and below, scooped out to half an inch. This disc is half an inch thick in
the edges, and five fourths of an inch in the middle.
Through the female screw  a in the top of the cylinder, there passes the screwed
rod b, one and a half inches thick, provided at top with a strong cross bar c c, for
turning it round. The under end of this rod has a square piece terminating in a short
screw, upon which a wrought iron cross is secured  by means of a screw  nut,
so as to stand at right angles to the rod. This cross is composed of two distinct
arms; of Wvhich one of them is mounted on the upper side with little knives an inch
and a half long; the other, upon the under side, with a wire brush, that may be made
to rub against the perforated cast iron disc. On the side of the cylinder at E, fig. 465,
there is a narrow aperture provided with a bung secured by a cross bar, and near the
bottom  at H  there is another like it.  Both openings serve for taking out the
residuary matter. Through the opening E, the above two arms are introduced; and
secured to the square of the rod by the screw nut. In the top there is an openingx




DISTILLATION.                                      593
for putting in the potatoes which may be shut in the same way.  From the lid there
likewise issues a lateral tube F, which terminates in a tubfid of water; for condensing
the waste steam. G is the tube connected with the steam boiler, for conducting the steam
into the space under the iron disc w.
With this apparatus the potatoes are prepared as follows: when the screw rod is so
fixed that the cross touches the disc, the cylinder is to be filled with washed potatoes to
within one foot of the top, leaving them some space to expand. The orifice D is to be
then closed, and the steam admitted. When the potatoes are boiled enough, two laborers
lay hold of the lever handles c c, of the screw rod b, and turn it round with the effect of
screwing up the spiked cross, and of triturating the potatoes; an operation which may
be still more effectually done by screwing it down again. The potato paste is now let
off by the plug hole H. into the tub L, where it is mixed with about 30 per cent. of boiling water, and one thousandth part of potash, made caustic with quicklime, in order to
dissolve the albuminous matter coagulated by the heat, and give complete fluidity to the
mass. The alkali also neutralizes the tartaric acid present.  The mashed matter must
now be mixed with the crushed malt diffused through 40 or 50 pounds of cold water for
every 100 pounds of potatoes, which lowers the temperature to 167~. The wort must
be then diligently stirred during two hours; mixed with 40 or 50 pounds of cold water
for 100 pounds of potatoes, and, when  reduced  to the temperature of 770, put
into the fermenting tun along with the proper quantity (3 or 4 per cent.) of yeast.
As potatoes readily pass into the acetous fermentation, the admixture of the malt, the
mashing, and the cooling should be rapidly performed, while the utmost cleanliness must
be observed.
The fermentation is brisk, probably from the agency of the albumen, and furnishes a
good head of barm, which answers well for the bakers; 100 pounds of potatoes yield
from 18 to 20 pounds measure of spirits, nine elevenths of our excise proof; or about 16
pounds measure of proof, = about 1- gallons.
It has been observed that after the month of December potatoes begin to yield a
smaller product of fermented spirits; and when they have once sprouted or germinated,
they afford very little indeed. From the difficulty of keeping and transporting potatoes,
distillation from them, even though our laws now permit it, can never become general till
some plan be adopted for overcoming these disadvantages. A scheme of this kind, however, has been successfully practised in Vienna, which consists in subjecting the washed
potatoes to strong pressure in a perforated chest by a hydraulic or screw press, whereby
they lose about three fourths of their weight, and may then be readily dried into a white
flour, that may be kept for several years without injury, and transported to considerable
distances with comparative ease. This flour, mixed with a moderate quantity of ground
malt, and saccharified by mashing With water, at the temperature of 1670 F., becomes
capable of affording a sweet wort convertible by fermentation  either into beer or
whiskey.
Horse-chestnuts, according to Hermstaedt, are an eligible material for producing alcohol, as 128 pounds of them afford 100 pounds of meal; which 100 pounds yield, by
proper treatment, 34 pounds of spirits, containing 36 per cent. of absolute alcohol, by
Richter's tables. Barley to the extent of 10 pounds per 100 should be ground vp with
them, after they have been boiled in a steam apparatus, not only for the purpose of
softening them, but freeing them from their bitter astringent matter. Acorns are pro
ductive of alcohol by similar treatment.
The best means hitherto discovered for depriving bad whiskey of its nauseous smell
and taste is to pass it through well burned and coarsely pulverized charcoal, distributed
as follows in a series of cylindrical casks. Each vessel must have a double bottom, the
false one being perforated with conical holes, and placed a few inches above the true.
Upon this perforated board a layer of chopped clean straw, one inch thick, is laid; and
over the straw, a stratum of small river gravel, the size of large peas. This is to be
covered with a pretty thick stratum of the charcoal, previously freed from dirt and dust
by washing; upon which a piece of close canvass is to be spread, and pressed down by
a thin bed of river sand. The cylinder or cask should be filled with these successive
layers to within two inches of its top, and it is then to be closed air-tight. Immediately
below the head, a round orifice is pierced in the side, for receiving an overflow tube,
which is either screwed rectangularly to another elbow pipe, or is bent (when of block
tin) so as to enter tight into an orifice beneath the false bottom of the second cylinder or
cask. In this way, the series may be continued to any desired number of vessels; the
last discharging the purified spirit into the store-back. The foul spirit must be made to
flow into the bottom space of the first cylinder down through a pipe in communication
with a charging-back placed upon such an elevated level as to give sufficient pressure to
force the spirits up through the series of filters; the supply-pipe being provided with a
regulating stop-cock. The spirit may be filtered downwards through sand and cloth in




594                                   DOCIMACY.
its final passage to the receiver. It has been found, with very crude spirits, that eight
successive cylidders were required to deprive them entirely of the rank flavor.
Fig. 466 represents one form of the worm-safe, which is a contrivance for permitting
trivance for  permitting  the distiller to
observe and note at any period of the
distillation the alcoholic strength or the
specific gravity of his  spirits, without
-^^^   ft'                          ^ ^   access to the still or the means of puralpl~~    {\\       ^11loining the product before it has paid duty.
The nose-pipe of the worm-tub terminates
llin, and is firmly cemented to the side of the
IThe fjl ~~~~glass globe, a, from whose bottom the diss
dutar;iT    1 III            ~charge-pipe descends vertically, but has a
D ^IVIDI~ I S   Allstop-cock upon it, and a branch small pipe
b, turned up parallel to the former.  This
branch is surmounted with a glass cylinder,
c, which, when the stop-cock is opened, gets
filled with the spirits, and then receives a
a ^^^^llj^   Q I             ~hydrometer to show the gravity of the fluid.
quantityill  IThe stop-cock mechanism is so contrived,
466          I  ^^^^i                    ^that only one full of the small glass cylinder can be obtained at a time.
The following is the gross produce of
the excise duties on British distilled spirits
for the United Kingdom  annually from
1830 to 1840 inclusive: 1831, 5,196,1751.;
1832, 5,163,3731.; 1833, 5,258,5721.; 1834,
5,287,0321.; 1835, 5,073,2761.; 1836, 5,485,8831.; 1837, 5,006,697t.; 1838, 5,451,7921.; 1839, 5,363,2201.; 1840, 5,208,0401.
The net produce is very nearly the same. In 1838, 26,486,543 millions of gallons paid
duty; in 1839, 25,190,843; and in 1840, 21,859,337.  See RUM, SPIRITs, and STILL.
DIVIDIVI, is an  indigenous production  of Jamaica.  Mr. Rootsey  obtained
ft mean produce of 6-625 grs. of leather from  60 grs. of dividivi, while the same
quantity of the best Aleppo galls yielded only a mean produce of 4'625.  Hence it
appears from  Sir Humphry Davy's estimate, that the 60 grs. of dividivi contain
380475 grs. or 5-079 per cent, of tannin and 60 grs. of galls, on 2-12704 grains, or 345
per cent. Sixty grs. of oak bark yielded only 1-75 grains of leather; whence it follows
that it contains but 0805 of a grain of tannin to the drachm, or not more than 1-34166
DOCIMACY, from  the Greek  AOKtpaw, I prove  (Docihnaie, Fr.; Probierkunst,
Germ.); is the art by which the nature and proportions of an ore are determined.
This analytical examination was originally conducted in the dry way, the metal being
extracted from its mineralizers, by means of heat and certain fluxes. But this method
was eventually found to be insufficient and even fallacious, especially when volatile
metals were in question, or when the fluxes could absorb them.  The latter circumstance became a very serious evil, whenever the object was to appreciate an ore that wal
to be worked at great expense.  Bergmann first demonstrated, in an elaborate disser<
tation, that the humid analysis was much to be preferred; and since his time the dry
way has been consecrated chiefly to the direction of metallurgic operations, or, at
least, it has been employed merely in  concert with the humid, in trials upon the
small scale.
After discovering an ore of some valuable metal, it is essential to ascertain if ita
quantity and state of combination will justify an adventurer in working the mine, and
smelting its products. The metal is rarely found in a condition approaching to purity;
it is often disseminated in a mineralizing gangue far more bulky than itself; and more
frequently still it is combined with simple non-metallic substances, such as sulphur,
carbon, chlorine, oxygen, and acids, more or less difficult to get rid of.  In these
compound states its distinctive characters are so altered, that it is not an easy task
either to recognise its nature, or to decide if it can be smelted with advantage. The
assayer, without neglecting any of the external characters of the ore, seeks to penetrate,
so to speak, into its interior; he triturates it to an impalpable powder, and then subjects
it to the decomposing action of powerful chemical reagents; sometimes with the aid of
alkalis or salts appropriate to its nature, he employs the dry way by fire alone; at
others, he calls in the solvent power of acids with a digesting heat; happy, if after a
series of labors, long, varied, and intricate, he shall finally succeed in separating a
notable proportion of one or more metals either in a pure state, or in a form of combination such, that from  the amount of this known compound, he can infer, with
precision, the quantity of fine metal, and thereby the probable value of the mine. The
blow-pipe, skilfully applied affords ready indications of the nature of the metallic




DONARIUM.                                          595
constituents, and is therefore usually the preliminary test. The separation of the
several constituents of the ore can be effected, however, only by a chemist, who joins
to the most extensive knowledge of the habitudes of mineral substances, much experience, sagacity, and precision, in the conduct of analytical operations.  Under the
individual metals, as also in the articles METALLURGY, MINES, and ORES, I have endeavored to present such a copious and correct detail of docismastic processes, as will serve to
guide the intelligent student through this most mysterious labyrinth of nature and art.
DONARIUM, a recently discovered metal.-Dr. Bergemann  received  through Mr.
Krantz a mineral from Brerig in Norway, which is found in the same zircon-syenite
that contains wdhlerite and eukolite, and he discovered in it the oxide of a new metal
combined with silicic acid. This metal he calls JDonariun, after the god Donar, and
he assigns to it the symbol Do.
The silicate of the oxide of donarium, Do2 03 Si 03 +2 H 0, is yellowish red, in some
fragments passing into brown, in others into yellow; when scratched or powdered, it
is light orange. In thin films it is almost transparent, the thicker ones translucid.
Some pieces have a distinctly laminated structure, in others the fracture is more flat, or
conchoidal. Its hardness is between that of fluor spar and apatite; its spec. grav.==597.
Small films heated in a platina spoon break down into a dark brown mass, which
rehssumes an orange color when cold: the larger pieces lose their transparency. By
heating it in a glass tube, watery vapor is driven off. Fragments held by the platina
forceps in the flame of a spirit lamp decrepitate. Heated by the blowpipe on charcoal,
it does not melt, a slight vitrification being sometimes observed on the edges, perhaps
in consequence of the intermixture of some foreign substance. Fused with soda, the
silicic acid is dissolved. The other constituents are seen in the non-transparent mass,
by the help of a glass, as small yellow particles. Borax yields a yellow bead, which
is colorless when cold. The phosphates produce in the external part of the flame a
reddish glass, which is colorless when cold; in the inner part of the flame the bead
becomes yellow, and when cold is colorless.
The mineral is readily and completely decomposed by acids, and yields when treated
by hydrochloric acid a clear and transparent gelatinous matter. At the same time
some carbonic acid is evolved. The color of the solution is deep yellow, like that of a
concentrated solution of iron. The mineral is also affected by diluted acids, even by
tartaric acid. After having been exposed to a strong heat, the essential parts of the
mineral are no longer acted upon even by concentrated acids.
The analysis showed the presence of lime, water, and the new oxide, also some traces
of magnesia, manganese, carbonate of soda, and iron.
The oxide of donarium belongs to the class of earthy bodies, and ranks next to
zirconia and yttria. The hydrate, which is thrown down by ammonia of a beautiful
white color, becomes yellow, and at last yellowish red, losing its hydrate water in the
air. By heat the latter is completely removed, and the oxide, which is insoluble in
muriatic acid, can be perfectly deprived by this acid of the contained iron. The analysis
showed the constituents to be:Silicic acid........-  17'695
Oxide of donarium           -                                        -  71-247
Carbonate of lime          -        -       -       -       -       -   4'042
Oxide of iron               -               -..        -   0-310
Magnesia and oxide of manganese             -       -       -        -   0214
Potash and a little soda  -         -       -       -        -       -   0303
Water    -         -        -       -       -       -.       -   6900
100741
The metal is obtained as a black powder, by treating the oxide with potassium.
If the alkaline solution be directly poured off and the powder washed with water,
it can be kept for from 24 to 36 hours under water without alteration; but if it
remains under hot water, a yellowish gray mass is gradually formed, in consequence of
oxidation. The black metallic powder forms heavy flocculi, which soon conglomerate
and are easily separated by filtration. When in the dried state they assume a metallic
lustre when rubbed with an agate; and then can be preserved in this condition for
several hours, even in a damp atmosphere, without developing any smell. The specific
gravity is nearly =='735.  The powder thrown into a flame burns with a reddish light,
and yields the red oxide; so also, if the black powder be heated in a platina spoon, it
burns, and moreover appears to glow, but only transitorily.  Neither cold nor boiling
muriatic acid affects the metal; nitric acid acts not when cold, and but slowly when
heated; nitro-muriatic acid readily produces the red oxide, of which a small portion
is dissolved; by the application of a few drops of sulphuric acid a sulphate is formed,
while at the same time the smell of sulphurous acid is perceived. The grayish yellow




596                                DRYING HOUSE.
substance produced by potash water, quickly forms, when heated by itself or moistened
with nitric acid, the red oxide. This powder also, when thrown into the flame of a
spirit lamp, glows.
Hydrated  Oxide of -Donarium.-The precipitate produced by ammonia from  the
muriatic solution of the mineral is, by long digestion with sulphuric acid, converted
into sulphate of the oxide of donarium, and from this the hydrated oxide is precipitated
by ammonia.  The voluminous precipitate, dried  at ordinary temperatures, forms
yellow gummy masses, the powder of which is reddish. In this condition the substance
represents the pure hydrated oxide, which, like oxide of iron, probably combines with
different proportions of water. The water is expelled by a slight increase of temperature.  The hydrate is dissolved by all acids at common temperatures, and   ore so
when heated.  If muriatic acid be employed, no chlorine is developed.
Oxide of Donarium  is obtained by heating the hydrate to redness.  Its sp. gray. is
5'576, color deep red; its form heavy glittering scales. Finely powdered it is orange;
darker when strongly heated, and lighter again when cold. Muriatic acid, nitric acid,
aqua regia, and even fluoric acid, have no effect upon the oxide which las been heated
to redness. By the continued action of concentrated sulphuric acid it is rendered
soluble, if it be afterward mixed with much water. If the oxide, however, be exposed
only to that temperature which expels the water from the hydrate, it is slightly acted
~upon by muriatic acid, without the development of chlorine.
DORNOCK  is a species of figured linen of stout fabric, which derives its name
from a town in Scotland, where it was first manufactured for table-cloths. It is the
most simple in pattern of all the varieties of the diaper or damask style, and therefore
the goods are usually of coarse quality for common household wear. It receives the
figure by reversing the flushing of the warp and woof at certain intervals, so as to
form squares, or oblong rectangles upon the cloth. The most simple of these is a succession of alternate squares, forming an imitation of a checker board or mosaic work.
The coarsest kinds are generally woven as tweels of three leaves, where ever  thread
floats over two, and is intersected by the third in succession.  Some of the  nr are
tweels of four or five leaves, but few of more; for the six or seven leaf tweels are seldom or never -used, and the eight leaf tweel is confined almost exclusively to damask.
See TEXTILE FABRIC.
DRAGON'S BLOOD, (Sang dracon, Fr.; Drachenbluit, Germ.) is a resinous substance,
which comes to us sometimes in small balls about the size of a pigeon's egg, sonmtimes
in rods like the finger, and sometimes like irregular cakes. Its color, in lump, is dark
brown red; in powder, bright red; friable; of a shining fracture; sp. gray. 1-196.
It contains a little benzoic acid, is insoluble in water, but dissolves readily in alcohol,
ether, and oils. It is brought from the East Indies, Africa, South America, as the
produce of several trees, the Draccena Draco, the Pterocarpus santalinus, Pterocarpus
Draco. and the Calamus Rotang.
Dragon's blood is used  chiefly for tinging  spirit and  turpentine varnishes, for
preparing gold lacquer, for tooth tinctures and powders, for staining marble, &c.
According to Herbenger, it consists of 9'07 parts of red resin, 2 of fat oil, 3 of benzoic
acid, 1-6 of oxalate, and 3-7 of phosphate of lime.
DRUGGET is a coarse, but rather slight, woollen fabric, usoA for covering carpets,
and as an article of clothing by females of the poorer classes. It is now-a-days nearly
superseded by coarse cotton goods.
DRYING  HOUSE.  An apartment fitted up in  a peculiar manner for drying
calicoes and other textile fabrics. Mr. Southworth, of Sharples, a Lancashire bleacher,
obtained a patent, in 1823, for the following ingenious arrangement, which has been
since generally adopted, with certain modifications, in most of our extensive bleaching
and printing works.  Fig. 467 is a section of the drying-house, where a is a furnace
and boiler for the purpose of generating steam; it is furnished with a safety valve in
the tube b, at top, and from this tube the steam main c passes down to the floor of the
basement story.  From this main, a series of steam-pipes, as dd, extend over the surface
of the floor, and from them heat is intended to be diffused for the purpose of warming
the drying-house.
Along the middle of the building a strong beam of timber e e extends, and is supported by cast-iron pillars; from this beam to bearings on the side walls, a series of
rails are carried in a cross direction, over which rails the wet cloth is to be hung in
folds, and the steam or evaporation emitted in drying is allowed to escape through
apertures or ventilators in the roof.
The mode in which the cloth is delivered on to the rails, on either side of the beam,
will be best understood by reference to the delivering carriage, which is shown with
its rollers partly in section.
The wet cloth is first to be coiled upon a roller, and then placed in the carriage, as
atf, with its pivots bearing upon inclined planes. The carriage is to be placed at the




DRYING MACHINE.                                             597
commencement of the rails, running upon the middle beam, and also upon the sidebearings or railways extending along the side walls of the building, parallel to and
upon a level with the same beam. It is made to travel by means of an endless band
I3n
passing over two riggers, g and i, in fig. 467, and over pulleys and a band-wheel
attached to the carriage, as will be explained. The rigger g, which moves this endless
band, is actuated by bevel geer, seen at i, which is put in motion by a pinion at the end
of a revolving shaft leading from a steam engine.
In the same fig., k k is the endless band passing over a pulley under the band-wheel
and over the pulley 2i, by which it will be perceived that the traversing of the band, as
described, would cause these pulleys and wlheels to revolve.  On the axle of the bandwheel in, there is a drum against which the roll of wet cloth f presses, and as this
drum revolves, the roll of wet cloth is, by its friction, made to turn in a contrary direction, and to deliver off the cloth on to the periphery of the drum, whence it
passes over a roller and descends to the rails.  Upon the end of the axle of the
band wheel in, there is a pinion which takes into the teeth of the large wheel, and
upon the axle of this large wheel there is a pinion that actuates the intermediate wheel
which  turns another toothed wheel.  This last-mentioned toothed wheel takes into
cogs upon the side railway, and hence, as the train of wheels moves round, the carriage
to which the wheels are attached is slowly impelled forward.
As soon as the wheels begin to move, and the carriage to advance, the wet cloth
begins to uncoil, and to pass down over the first roller; a small roller attached to the
carriage, as it passes over the rails in succession, holds the cloth against each rail for a
short space of time, and prevents it from slipping, by which means the cloth descends
in folds or loops between the rails, and is thereby made to hang in a series of folds or
loops, as shown in the figure.
It will be perceived that as the pivots of the cloth rollerf bear upon inclined planes,
the roller will continually slide down as the cloth diminishes in bulk, keeping in contact with the drum, and delivering the cloth from the roller on to the several rails, as
described.
In order to stop the carriage in any part of its course, or to adjust any of the folds of
the cloth, a man is usually placed upon the platform travelling with the carriage,
over which he has perfect command.  This apparatus may be also employed for taking
the cloth when dried off the rails; in which case the carriage must be made to travel
backward, and by first guiding the end of the cloth on to the rollerf, and then putting
the wheels in a retrograde motion, the cloth will be progressively coiled upon the roller
f, in a similar way to that by which it was uncoiled.
DRYING   MACHINE   (CENTRIFUGAL), (Ilydro-extracteur;  Machine &  essorer,
Fr.)-By this contrivance, Pentzoldt was enabled to deprive all kinds of wet clothes
in a few  minutes of their moisture, without compression  or heat.  Kelly, a dyer,
and Alliott, a bleecher, have since obtained a patent for the above machine with
improvements.  Fig. 468 represents a partial section of the machine.  A, A, is the
frame; B, the vertical shaft turning in the step a, fixed on the bridge b. This shaft
bears on its upper part a friction cone c, from which it receives its movement of rotation,




598                                DRYING MACHINE.
as will be shown presently; c is a drum containing two concentric compartments d e,
of the form represented in the figure; this drum moves freely upon the shaft a, and
468.
4   Cf  d~ ld  lC
rests when it is not in motion  upon two conical projections f, g, which  form  a
part of the shaft.  These two compartments are each  composed mainly  of metal,
and their sides consist of tinned iron wire coiled circularly at very small distances
from each other, and soldered together crosswise by small slips of metal. The top,
which covers the inner compartment d, is secured by bolts and screws to a circle of
iron which retains the wire sides of the same metal, but that which serves as a cover
to the little compartment e, in which alone the goods are placed, is disposed so that
it may be removed with ease, when these are to be introduced or withdrawn. It is
furnished with an outer and inner border, disposed so that when the top is fixed the
inner border presses upon the convex circumference of the central compartment, while
the exterior border falls oatside of the edges of the other compartment. While the
machine is at work, the second plate is maintained in its place by pins or bolts, not
shown in the figure.
The sides of the outer compartment d, are connected with the bottom by means of a
prolongation of cross bands of metal which unite the wires and are riveted or soldered
to the two outer plates. The wires of the interior compartment are attached by an
iron hoop, to which they are riveted and soldered, and are united to the bottom plate
by means of a rim upon this plate; a rim somewhat flattened upon the sides which are
riveted and soldered.
D, is a regulator suspended in the inner compartment d, and whose two branches h., h,
are loaded. These two branches having room to play around the bolts which serve as
points of attachment, and which are fixed to the upper plate, terminate in kneed branches whose extremities rest upon a rope g, which projects from the shaft. E, is an exterior envelope secured to the frame A, A. It encloses the whole drum except at top,
and serves to catch the water thrown out of the goods. At y there is a stopcock for
the discharge of this water, and the bottom contains besides the end of a pipe by which
hot air is introduced.
The vertical shaft B receives a movement of rotation and carries with it the drum.
The more rapid this movement is the more does the centrifugal force tend to expel
the water contained in the clothes or yarn to be dried. But as this force might also
displace the central shaft, if the weight was not rightly distributed in the drum, and
cause the dislocation of the machine when the great velocity requisite for quick
drying is given to it, the regulator D is tested to prevent accident. The branches
of this regulator spread wider the more the velocity is increased, and raise consequently the drum c above the conical enlargements, which permits the drum to be
somewhat misplaced and to rectify its position conformably to the inequalities of its
load, so that its centre of gravity may always coincide with its centre of rotation. The
drum is connected with the shaft as is shown in z, leaving it free to take the requisite
adjustment. To hinder it from rising too suddenly, a spiral spring k is fixed over the
shaft immediately above the conical enlargement g. In order to maintain the equilibrium more certainly, the apparatus is surrounded with a hollow crown F, half filled
with water, and if during the revolution of the machine the weight of the goods
predominates on one side, that of the water which accumulates on the other side serves
the more to counterbalance it. The effect of this crown may be increased by dividing it




DUNGING.                                        599
into two compartments or more. G, is a large pipe by which steam or hot air is introduced into the belly of the drum, which is pierced in this place with a great number of
small holes to receive it.
The rotary movement is transmitted to the drum in the following way.
is a conical disc mounted upon the extremity of a shaft which actuates the cone c
and the shaft B by means of friction; L is a cone fixed upon the extremity of the shaft.
K L "is another cone of the same dimension, but whose base fronts the top of the other
and which is placed on the shaft r" commanded by the prime mover.  M is the belt
which embraces the two cones, and whose lateral displacement, effected by means of a
fork, permits the velocity of the machine to be regulated at pleasure. N is the pulley
which directly receives the movement. In place of a single friction discianothermaybe
employed, if judged necessary, and placed between the two, an additional friction pole in
order better to equalize the friction. In this case the disc and additional cone should
turn freely upon their own shafts.  We may also adopt another arrangement for the
bottom of the vertical shaft. The shaft immediately above the step is surrounded by
a loose rim, around which a certain quantity of lead shot, or other granular matter, is
contained in the rim  in the box which serves for the step.  The top of this box is
pierced with an opening, into which, when thle machine is at rest, a cord connected with
the shaft sinks, controlled by the shaft, and when the drum is raised by the action of the
regulator D, this cord quits its place, which allows the shaft to displace the shot a little,
and to take a position conformably to the point of the centre of gravity.
But after all great attention should be paid to the proper working of the machine.
DUCTILITY  (Streckbarkeit, Germ.) is the property of being drawn out in length
without breaking, possessed in a pre-eminent degree by gold and silver, as also by many
other metals, by glass in the liquid state, and by many semifluid resinous and gummy
substances. The spider and the silk-worm exhibit the finest natural exercise of ductility
upon the peculiar viscid secretions from which they spin their threads. When a body
can be readily extended in all directions under the hammer, it is said to be nilleable and
when into fillets under the rolling press, it is said to be laminable.
Table of the ductility and malleability of Metals.
Metals ductile and      Brittle metals      Metals in the order   Metals in the order of
malleable in alphabetical      in             of their wire-drawing    their laminable
order.          alphabetical order.        ductility,             ductility.
Cadmium.             Antimony.              Gold.                  Gold.
Copper.              Arsenic.               Silver.                Silver.
Gold.                Bismuth.               Platinum.              Copper.
Iron.                Cerium.?              Iron.                  Tin.
Iridium.             Chromium.              Copper.                Platinum.
Lead.                Cobalt.                Zinc.                  Lead.
Magnesium.           Columbium.             Tin.                   Zinc.
Mercury.             Iridium.               Lead.                  Iron.
Nickel.              Manganese.             Nickel.                Nickel.
Osmium.              Molybdenum.            Palladium.?           Palladium.?
Palladium.           Osmium.                 Cadmium.?            Cadmium.?
Platinum.             Rhodium.
Potassium.           Tellurium.
Silver.              Titanium.
Sodium.              Tungsten.
Tin.                 Uranium.
Zinc. ____________ ______________________________________
There appears to be, therefore, a real difference between ductility and malleability;
for the metals which draw into the finest wire are not those which afford the thinnest
leaves under the hammer or in the rolling press. Of this fact iron affords a good illustration. Among the metals permanent in the air, 17 are ductile and 16 are brittle. But
the most ductile cannot be wire-drawn or laminated to any considerable extent without
being annealed from time to time during the progress of the extension, or rather the
sliding of the particles alongside of each other, so as to loosen their lateral cohesion.
DUNGING, in calico-printing, is the application of a bath of cowdung, diffused
through hot water, to cotton goods in a particular stace of the manufacture.  Dunging
and scouring are commonly alternated, and are two of the most important steps in the
process.  The operation of dunging has for its objects
1. To determine the entire combination of the aluminous sub-salts with the stuffs, by




600                                   DUNGING.
separating almost all the acetic acid which was not volatilized in the stove-drying of the
mordant.
2. To dissolve and carry off from the cloth a portion of the thickening matters.
3. To separate from the cloth the part of the mordant that is uncombined, and merely
mixed mechanically with the gum or starch.
4. To prevent, by the peculiar action of the dung, the uncombined mordant, as well as
the acetic acid with which the bath is apt to get loaded, from affecting the blank parts
of the cloth, or being injurious to the mordant.
The aluminous base or mordant on the cloth, more or less neutralized by the dunging,
is next subjected to the dash-wheel or fulling mill, where by the stream of water the
remainder of the thickening and other impurities are washed away.
No very exact analysis has been made of cowdung. Morin's, which is the most recen(
and elaborate, is as follows:Water - -...70-00
Vegetable fibre         -    -    -     -    24-08
Green resin and fat acids -    -     -         1*52
Undecomposed biliary matter             -      0*60
Peculiar extractive matter (bubuline)-    -   1-60
Albumen    -    -    -    -    -    -          040
Biliary resin -           -    -    -    -   1-80
According to M. Kcechlin's practical knowledge on the great scale, it consists of a
moist fibrous vegetable substance, which is animalized, and forms about one tenth of its
weight; 2. of albumen; 3. of animal mucus; 4. of a substance similar to bile; 5. of
muriate of soda, muriate and acetate of ammonia, phosphate of lime and other salts; 6.
of benzoin or musk.
Probably the hot water in which the calico-printer diffuses the dung exerts a powerful
solvent action, and in proportion as the uncombined mordant floats in the bath it is precipitated by the albumen, the animal mucus, and the ammoniacal salts; but there is reason to think that the fibrous matter in part animalized or covered with animal matter,
plays here the principal part; for the great affinity of this substance for the aluminous
salts is well known.
All practical men are aware that the affinity of cotton for alumina is increased by
its combination with oil or animal substances, to such a degree as to take it from the
dung bath; which would not be possible without this combination. It would therefore
appear that the principal function of dunging is to hinder the uncombined mordant,
diffused in the dung bath, from attaching itself to the unmordanted portion of the
cloth, as already observed; for if we merely wished to abstract the thickening stuffs, or
to complete by the removal of acetic acid the combination of the aluminous base with
the goods, dung would not be required, for hot water would suffice. In fact, we may
observe, that in such cases the first pieces passed through the boiler are fit for dyeing;
but when a certain number have been passed through, the mordant now dissolved in the
water is attracted to the white portions of the cloth, while the free acid impoverishes
the mordanted parts, so that they cannot afford good dyes, and the blank spaces are
tarnished.
The cowdung may be in some measure replaced by bran, but not with perfect success.
The former both answers the purpose better and is cheaper. The bran is only preferred
for the most delicate yellows, for cochineal pinks and lilachs, to which the dung may
sometimes impart a greenish cast. It is to be presumed that the action of the bran in
this process has much analogy with that of the dung, and that the ligneous fibre is the
most active constituent; with which the gluten and mucilage co-operate, no doubt, in
seizing the aluminous salts.
It seems to be ascertained that the mordant applied to the cloth does not combine entirely with it during the drying; that this combination is more or less perfect according
to the strength of the mordants, and the circumstances of the drying; that the operation
of dunging, or passing through hot water, completes the combination of the cloth with
the aluminous base now insoluble in water; that this base may still contain a very minute quantity of acetic acid or sulphate of alumina; that a long ebullition in water
impoverishes the mordant but a little; and that even then the liquid does not contain an3
perceptible quantity of acetate or subsulphate of alumina.
The mariner of immersing the goods, or passing them through the dung bath, is ap
important circumstance. They should be properly extended and free from folds, which
is secured by a series of cylinders.
The cistern is from 10 to 12 feet long, 41 feet wide, and 6 or 8 feet deep. The
piece passes alternately over the upper rollers and under rollers near the bottom.
There are two main squeezing rollers at one end, which draw the cloth through between
them. Whenever the goods come out of the bath they are put into the dash-wheel.




DYEING.                                       601
The immersion should take place as fast as possible, for the moment the hot water pene.
trates the mordanted cloth, the acetic acid quits it; and, therefore, if the immersion was
made slowly or one ply after another, the acid as well as the uncombined mordant become
free, would spread their influence, and would have time to dissolve the aluminous subsalts now combined with the cloth; whence inequalities and impoverishment of the colors
would ensue.
It is difficult to determine the number of pieces which may be passed through a given
luantity of dung and water.  This depends upon the state of the mordants, whether
they are strong or acid, and on the quantity of the surface covered with the figures.
The number varies usually from  20 to 60 pieces, for from 240 to  300 gallons of water
and 6 gallons of dung. The time of the immersion varies with the concentration of the
mordants, and the nature of their thickening.  The temperature must be regulated by
the same circumstances; for starch or flour paste a much warmer bath is needed than
for gum.  The heat varies usually from 130~ to 212" F.  When the printing is heavy
and the thickening is starch or flour, the goods are usually twice diinged, with two washings between the two dungs.  A strong acid mordant is more difficult to dung and to
wash than a neutral mordant, especially when it is to receive the madder dye.  Sometimes a little chalk is added to the bath, when the goods have been padded in an acid
mordant.  Too much dung is injurious to weak mordants, as well as to pinks.  It has
also been iremarked that a mordant when neutralized does not produce as brilliant tints,
especially yellows. The latter are obtained of a finer shade when, instead of dunging,
they are exposed for an hour in a stream of water, provided its temperature is not too
low.  In winter they are passed through a slightly chalky water, then washed at the
wheel., and dyed in quercitron or weld.
A very able and learned memoir upon this subject, by M. Penot, Professor of Chemistry, appeared in the Bulletin of the Society of Mulhausen, in October, 1834, with an
ingenious commentary upon it, under the title of a Report by M. Camille Koechlin, in
March, 1835.
Experience has proved that dunging is one of the most important steps in the process
of calico printing, and that if it be not well performed the dyeing is good for nothing.
Before we can assign its peculiar function to the dung in this case, we must know its
composition. Fresh cow's dung is commonly neutral when tested by litmus paper; but
sometimes it is slightly alkaline, owing, probably, to some peculiarity in the food of the
animal.
The total constituents of 100 parts of cow dung are as follows: Water, 69*58; bitter
matter, 0-74; sweet substance, 0-93; chlorophylle, 0-28; albumine, 063,; muriate of
soda, 0-08; sulphate of potash, 0-05; sulphate of lime, 025; carbonate of lime, 024;
phosphate of lime, 0-46; carbonate of iron, 0-09; woody fibre, 26-39; silica, 0-14;
loss, 0' 14.
In dunging calicoes the excess of uncombined mordant is in part attracted by the
soluble matters of the cow's dung, and forms an insoluble precipitate, which has no
affinity for the cloth, especially in presence of the insoluble part of the dung, which
strongly attracts alumina. The most important part which that insoluble matter plays,
is to seize the excess of the mordants, in proportion as they are dissolved by the water
of the bath, and thus to render their reaction upon the cloth impossible.  It is only in
the deposite, therefore, that the matters carried off from the cloth by the dung are to
be found.
M. Camille Kmechlin ascribes the action of cow dung chiefly to its albuminous constituent, combining with the alumina and iron, of the acetates of these bases dissolved
by the hot water of the bath.  The acids consequently set free, soon become evident by
the test of litmus paper, after a few pieces are passed through, and require to be got rid
of either by a fresh bath or by adding chalk to the old one. The dung thus serves also
to fix the bases on the cloth, when used in moderation. It exercises likewise a disoxydating power on the iron mordant, and restores it to a state more fit to combine with coloring matter.
DYEING, (Teinture, Fr.; Fdrberei, Germ.) is the art of impregnating wool, silk,
cotton, linen, hair, and skins, with colors not removable by washing, or the ordinary
usage to which these fibrous bodies are exposed when worked up into articles of furniture
or raiment.  I shall here consider the general principles of the art, referring for the
particular dyes, and peculiar treatment of the stuffs to be dyed, to the different tinctorial
substances in their alphabetical places; such as cochineal, indigo, madder, &c.
Dyeing is altogether a chemical process, and requires for its due explanation and
practice an acquaintance with the properties of the elementary bodies, and the laws
which regulate their combinations. It is true that many operations of this, as of other
chemical arts, have been practised from  the most ancient times, long before any just
views were entertained of the nature of the changes that took place. -Mankind, equally
in the rudest and most refined state, have always sought to gratify the love of distinction




602                                    DYEING.
by staining their dress, sometimes even their skin, with gaudy colors. Moses speaks of
raiment dyed blue, and purple, and scarlet, and of sheep skins dyed red; circumstances,which indicate no small degree of tinctorial skill. He enjoins purple stuffs for the works
of the tabernacle and the vestments of the high priest.
In the article CALICO PRINTING, I have shown from Pliny that the ancient Egyptians
cultivated that art with some degree of scientific precision, since they knew the use of
mordants, or those substances which, though they may impart no color themselves, yet
enable white robes (candida vela) to absorb coloring drugs (colorem sorbendibus medicamentis).  Tyre, however, was the nation of antiquity which made dying its chief
occupation and the staple of its commerce. There is little doubt that purple, the sacred
symbol of royal and sacerdotal dignity, was a color discovered in that city, and that it
contributed to its opulence and grandeur.  Homer marks no less the value than the
antiquity of this dye, by describing his heroes as arrayed in purple robes. Purple habits
are mentioned among the presents made to Gideon by the Israelites from the spoils of the
kings of Midian.
The juice employed for communicating this dye was obtained from  two different
kinds of shellfish, described by Pliny under the names of purpura  and
was extracted from a small vessel, or sac, in their throats, to the amount of only one
drop from each animal. A darker and inferior color was also procured by crushing the
whole substance of the buccinum.  A certain quantity of the juice collected from a vast
inumber of shells being treated with sea-salt was allowed to ripen for three days; after
which it was diluted with five times its bulk of water, kept at a moderate heat for six
days more, occasionally skimmed to separate the animal membranes, and when thus
clarified was applied directly as a dye to white wool, previously prepared for this purpose
by the action of lime-water, or of a species of lichen called fucus. Two operations were
requisite to communicate the finest Tyrian purple; the first consisted in plunging the
wool into the juice of the purpura: the second, into that of the buccinum. Fifty drachms
of wool required one hundred of the former liquor, and two hundred of the latter. Sometimes a preliminary tint was given with coccus, the kermes of the present day, and the
cloth received merely a finish from the precious animal juice. The colors, though prob.
ably not nearly so brilliant as those producible by our cochineal, seem to have been very
durable, for Plutarch says, in his Life of Alexander, (chap. 36,) that the Greeks found
in the treasury of the King of Persia a large quantity of purple cloth, which was as
beautiful as at first, though it was 190 years old.*
The difficulty of collecting the purple juice, and the tedious complication of the dyeing
process, made the purple wool of Tyre so expensive at Rome, that in the time of Augustus a pound of it cost nearly 301. of our money.f  Notwithstanding this enormous price,
such was the wealth accumulated in that capital, that many of the leading citizens decorated themselves in purple attire, till the emperors arrogated to themselves the privilege
of wearing purple, and prohibited its use to every other person. This prohibition operated so much to discourage this curious art as eventually to occasion its extinction, first in
the western and then in the eastern empire, where, however, it existed in certain imperial
manufacturies till the eleventh century.
Dyeing was little cultivated in ancient Greece; the people of Athens wore generally
woollendresses of the natural color. But the Romans must have bestowed some pains
upon this art. In the games of the circus parties were distinguished by colors. Four of
these are described by Pliny, the green, the orange, the gray, and the white. The following ingredients were used by their dyers.  A crude native alum mixed with copperas,
copperas itself, blue vitriol, alkanet, lichen rocellus, or archil, broom, madder, woad, nutgalls, the seed of pomegranate, and of an Egyptian acacia.
Gage, Cole, Plumier, Reaumur, and Duhamel have severally made researches concerning the coloring juices of shell-fish caught on various shores of the ocean, and have succeeded in forming a purple dye, but they found it much inferior to that furnished by other
means. The juice of the buccinum is at first white; it becomes by exposure to air of a
yellowish green bordering on blue; it afterwards reddens, and finally changes to a deep
purple of considerable vivacity.  These circumstances coincide with the minute description of the manner of catching the purple-dye shell-fish which we possess in the work of
an eye-witness, Eudocia Macrembolitissa, daughter of the Emperor Constantine VIII.,
who lived in the eleventh century.
The moderns have obtained from the New World several dye-drugs unknown to the
ancients; such as cochineal, quercitron, Brazil wood, logwood, annatto; and they have
* "Among other things, there was purple of Hermione (?) to the amount of five thousand talents."
(Plutarch's Lives, translated by Langhorne, Wrangham's edition, vol. v. p. 240.) Horace celebrates the
Laconian dye in the following lines:~
Nec Laconicas mihi
Trahunt honesta purpuras clienta.
(Carm. lib. ii., Ode 18.)
$ Pliny says that a pound of the double-dipped Tyrian purple was sold in Rome for a hundred crows.




DYEING.                                       603
discovered the art of using indigo as a dye, which the Romans knew only as a pigment.
But the vast superiority of our dyes over those of former times must be ascribed principally to the employment of pure alum and solution of tin as mordants, either alone or
mixed with other bases; substances which give to our common dye-stuffs remarkable
depth, durability, and lustre. Another improvement in dyeing of more recent date is the
application to textile substances of metallic compounds, such as Prussian blue, chrome
yellow, manganese brown, &c.
Indigo, the innoxious and beautiful product of an interesting tribe of tropical plants,
which is adapted to form the most useful and substantial of all dyes, was actually denounced as a dangerous drug, and forbidden to be used, by our parliament in the reign of
Queen Elizabeth. An act was passed authorizing searchers to burn both it and log-wood
in every dye-house where they could be found. This act remained in full force till the
time of Charles II.; that is, for a great part of a century. A foreigner n ight have supposed that the legislators of England entertained such an affection for their native woad,
with which their naked sires used to dye their skins in the old times, that they would
allow no outlandish drug to come in competition with it. A most instructive book might
be written illustrative of the evils inflicted upon arts, manufactures, and commerce, in
consequence of the ignorance of the legislature.*
Colors are not, properly speaking, material; they are impressions which we receive
from the rays of light reflected, in a decomposed state, by the surfaces of bodies.  It is
well known that a white sunbeam consists of an indeterminate number of differently colored rays, which being separated by the refractive force of a glass prism, orm the solar
spectrum, an image distinguishable into seven sorts of rays; the red, orange, yellow,
green, blue, indigo, and violet. Hence, when an opaque body appears colored, for example, red, we say that it reflects the red rays only, or in greatest abundance, mixed with
more or less of the white beam, which has escaped decomposition.  According to this
manner of viewing the coloring principle, the art of dyeing consists in fixing upon stuffs,
by means of corpuscular attraction, substances which act upon light in a different manner
from the surfaces of the stuffs themselves. The dyer ought, therefore to be familiar with
two principles of optics; the first relative to the mixture of colors, and the second to their
simultaneous contrast.
Whenever the different colored rays, which have been separated by the p.,-m, are
totally reunited, they reproduce white light.  It is evident, that in this composition
of light, if some rays were left out, or if the colored rays be not in a certain proportion,
we should not have white light, but light of a certain color.  For example; if we
separate the red rays from the light decomposed by a prism, the remaining colored
rays will form  by their combination a peculiar bluish green.  If we separate in like
manner the orange rays, the remaining colored rays will form  by their combination
a blue color.  If we separate from the decomposed prismatic light the rays of greenish
yellow, the remaining colored rays will form a violet. And if we separate the rays of
yellow bordering on orange, the remaining colored rays will form by their union an indigo
color.
Thus we see that every colored light has such a relation with another colored light
that, by uniting the first with the second, we reproduce white light; a relation which we
express by saying that the one is the complement of the other. In this sense, red is the
complementary color of bluish green; orange, of blue; greenish yellow, of violet; and
orange yellow, of indigo.  If we mix the yellow ray with the red, we produce orange;
the blue ray with the yellow, we produce green; and the blue with the red, we produce
violet or indigo, according as there is more or less red relatively to the blue.  But these
tints are distinguishable from the orange, green, indigo, and violet of the solar spectrum,
because when viewed through the prism they are reduced to their elementary compound
colors.
If the dyer tries to realize the preceding results by the mixture of dyes, he will succeed
only with a certain number of them. Thus, with red and yellow he can make orangee;
with blue and yellow, green; with blue and red, indigo or violet.   These facts' the
results of practice, have led him to conclude that there are only three primitive colors;
the red, yellow, and blue.  If he attempts to make a white, by applying red, yellow,
and blue dyes in certain quantities to a white stuff, in imitation of the philosopher's experiment on the synthesis of the sunbeam, far from succeeding, he will deviate still further
from his purpose, since the stutff will by these dyes become so dark colored as to appear
black.
The fact must not, however, lead us to suppose that in every case where red, yellow,
and blue are applied to white cloth, black is produced.  In reality, when a little ultramarine, cobalt blue, Prussian blue, or indigo, is applied to goods with the view of giving
them the best possible white, if only a certain proportion be used, the goods will appear
whiter after this addition than before it. What happens in this case? The violet blue
* Author, in Penny Cyclopedia.




604                                    DYEING.
forms, with the brown yellow of the goods, a mixture tending to white or less colored
than the yellow of the goods and the blue together were.  For the same reason, a mix.
ture of Prussian blue and cochineal pink has been of late years used in the whitening or
the azuring of silks, in preference to a pure blue; for on examining closely the color l
the silk to be neutralized, it was found by the relations of the complementary colors, that
the violet was more suitable than the indigo blue formerly used. The dyer should know
that when he applies several different coloring matters to stuffs, as yellow and blue, for
example, if they appear green, it is because the eye cannot distinguish the points which
reflect the yellow from those which reflect the blue; and that, consequently, it is only
where the distinction is not possible, that a mixture or combination appears.  When we
examine certain gray substances, such as hairs, feathers, &c., with the microscope, we
see that the gray color results from black points disseminated over a colorless or slightly
colored surface.  In reference to compound colors, this instrument might be used with
advantage by the dyer.
The dyer should be acquainted also with the law  of the simultaneous contrast of
colors.  When the eye views two colors close alongside of each other, it sees them
differing most in their optical composition, and in the height of their tone, when the two
are not equally pale or full-bodied.  They appear most different as to their optical composition, when the complementary of the one of them is added to the color of the other.
Thus, put a green zone alongside of an orange zone; the red color complementary of
green, being added to the orange, will make it appear redder; and in like manner the
blue, complementary of orange, being added to the green, will make it appear more intensely blue.  In order to appreciate these differences, let us' take two green stripes and
two orange stripes, placing one of the green stripes near one of the orange: then place
the two others so that the green stripe may be at a distance from the other green stripe,
but on the same side, and the orange at a distance from the other orange, also on the
same side.
As to the contrast in the height of the tone, we may satisfy ourselves by taking the
tones No. I, No. 2, No. 15, and No. 16, from a graduated pallet of reds: for example,
by placing No. 2 and No. 15 close alongside, putting No. I at a distance from No. 2
on the same side, and No. 16 at a distance from  No. 15 on the same side,-we shall
see (if the pallet is sufficiently lowered in tone) No. 2 equal to No. I, and No.15
equal to No. 16; whence it follows that No. 2, by the vicinity of No. 15, will appear
to have lost some of its color; while No. 15 will appear to have acquired color.  When
black or gray figures are printed upon colored grounds, these figures are of the color
complementary of the ground.  Consequently, in order to judge of their color, we must
cut out spaces in a piece of gray or white paper, so as to allow the eye to see nothing
but the figures; and if we wish lo compare figures of the same color, applied upon
grounds of different colors, we can judge rightly of the figures only by insulating them
from the grounds.
The relations of dyeing with the principles of chemistry, constitute the theory of the
art, properly speaking; this theory has for its basis, the knowledge-1. of the species of
bodies which dyeing processes bring into contact; 2. of the circumstances in which these
species act; 3. of the phenomena which appear during their action; and 4. of the properties of the colored combinations which are produced. These generalities may be specified under the ten following heads:1. The preparation of the stuffs to be dyed, whether fibres, yarn, or cloth; under
the heads of ligneous matter, cotton, hemp, flax; and of the animal matters, silk and
wool.
2. The mutual action of these stuffs, and simple bodies.
3. The mutual action of these stuffs, and acids.
4. The mutual action of these stuffs, and salifiable bases, as alumina, &c.
5. The mutual action of these stuffs, and salts.
6. The mutual action of these stuffs, and neutral compounds not saline.
7. The mutual action of these stuffs, and of one or more definite compounds.
8. Of dyed stuffs considered in reference to the fastness of their color, under the in.
fluence of heat, light, water, oxygen, air, boilings with soap, and reagents.
9. Of dyeing, considered in its connexions with chemistry.
10. Of dyeing, considered in its relations with caloric, mechanics, hydraulics, and
optics.
1. The preparation of stuffs.
The operations to which stuffs are subjected before dyeing, are intended-1. to separate from them  any foreign matters; 2. to render them  more apt to unite with the
coloring tinctures which the dyer proposes to fix upon them, in order to give them a
more agreeable, or more brilliant aspect, or to lessen their tendency to assume a soiled
appearance by use, which white surfaces so readily do.  The foreign matters are eithel
naturally inherent in the stuffs, or added to them in the spinning, weaving, or othel




DYEING.                                      605
manipulation of manufacture. The ligneous fibres must be freed from the colored azot~zed varnish on their surface, from a yellow coloring matter in their substance, from
some lime and iron, from chlorophylle or leaf-green, and from pectic acid; all natural
combinations. Some of these principles require to be oxygenized before alkaline leys
can cleanse them, as I have stated in the article BLEACHING, which may be consulted in
reference to this subject. See also SILK and WOOL. A weak bath of soda has the property of preparing wool for taking on a uniform dye, but it must be well rinsed and aired
before being put into the dye-vat.
2. Mutual action of stuffs and simple bodies.
Stuffs chemically considered being composed of three or four elements, already in a
state of reciprocal saturation, have but a feeble attraction for simple substances. We
know in fact, that the latter combine only with each other, or with binary compounds,
and that in the greater number of cases where they exert an action upon more complete
compounds, it is by disturbing the arrangement of their elements, and not by a resulting
affinity with the whole together.
3, 4. Although stuffs may in a general point of view be considered as neutral in
relation to coloring reagents, yet experience shows that they are more disposed to combine with acid thn with a lkaline compounds; and that consequently their nature seems
to be more alkaline than acid. By steeping dry wool or other stuff in a clean state in
an alkaline or acid solution of known strength, and by test'ng the liquor after the stuff
is taken out, we shall ascertain whether there be any real affinity between them, by the
solution being rendered more dilute in consequence of the abstraction of alkaline or acid
particles from it. Wool and silk thus immersed, abstract a portion of both sulphuric and
muriatic acids; obut cotton and flax imbibe the water, with the rejection of a portion of
the acid. The acid may be again taken from the stuffs by washing them with a sufficient
quantity of water.
5. The affinity between saline bodies and stuffs may be ascertained in the same way
as that of acids, by plunging the dry stuffs into solutions of the salts, and determining
the density of the solution before the immersion, and after withdrawing the stuffs.
Wool abstracts alum from its solution, but it gives it all out again to boiling water.
The sulphates of protoxyde of iron, of copper, and zinc, resemble alum in this respect.
When silk is steeped for some time in solution of protosulphate of iron, it abstracts the
oxyde, gets thereby dyed, and leaves the solution acidulous. Wool put in contact with
cream of tartar decomposes a portion of it; it absorbs the acid into its pores, and leaves
a neutral salt in the liquor. The study of the action of salts upon stuffs is at the present day the foundation of the theory of dyeing; and some of them are employed immediately as dye-drugs.
6. Mutual action of stuffs, and neutral compounds not saline.
Several sulphurets, such as those of arsenic, lead, copper, antimony, tin, are susceptible of being applied to stuffs, and of dyeing them in a more or less fast manner. Indigo,
hematine, breziline, carmine, and the peculiar coloring principles of many dyes belong
to this division.
7. Mutual action of goods with one or more definite compounds, and dye-stuffs.
I shall consider here in. a theoretical point of view, the most general results which
a certain number of organic coloring matters present, when applied upon stuffs by the
dyer.
Indigo. This dye-drug, when tolerably good, contains half its weight of indigotine.
The cold vat is prepared commonly with water, copperas, indigo, lime, or sometimes carbonate of soda, and is used almost exclusively for cotton and linen; immersion in acidulated watet'Is occasionally had recourse to for removing a little oxyde of iron which
attaches itself to the cloth dyed in this vat.
The indigo vat for wool and silk is mounted exclusively with indigo, good potashes of
commerce, madder, and bran. In this vat, the immediate principles with base of carbon
and hydrogen, such as the extracts of madder and bran, perform the disoxydizing function of the copperas in the cold vat. The pastel vats require most skill and experience,
in consequence of their complexity. The greatest difficulty occurs in keeping them in a
good condition, because they vary progressively as the dyeing goes on, by the abstraction
ef the indigotine, and the modification of the fermentable matter employed to disoxygenate the indigo. The alkaline matter also changes by the action of the air. By the successive additions of indigo, alkali, &c., this vat becomes very difficult to manage with
profit and success. The great affair of the dye -'s the proper addition of lime; too much
or too little being equally injurious.
Sulphate of indigo or Saxon blue is used also to dye silk and wool. If the wools be
ill sorted, it will show their differences by the inequalities of the dye. Wool dyed in this
bath put into water saturated with sulphureted hydrogen, becomes soon colorless, owing
to the disoxygenation of the indigo. The woollen cloth, when exposed to the air for some
time resumes its blue color, but not so intensely as before.




606                                    DYEING.
The properties of hematine explain the mode of using logwood. When stuffs are
dyed in the infusion or decoction of this wood, under the influence of a base which acts
upon the hematine in the manner of an alkali, a blue dye, bordering upon violet, is
obtained. Such is the process for dyeing cotton and wool a logwood blue by means of
verdigris, crystallized acetate of copper, and acetate of alumina.
When we dye a stuff yellow, red, or orange, we have always bright tints; with blue,
we may have a very dark shade, but somewhat violet; the proper black can be obtained
only by using the three colors, blue, red, and yellow, in proper proportions. Hence we
can explain how the tints of yellow, red, orange, blue, green, and violet, may be browned,
by applying to them one or two colors which along with themselves would produce
black; and also we may explain the nature of that variety of blacks and grays which
seems to be indefinite. Nutgalls and sulphate of iron, so frequently employed for the
black dye, give only a violet or bluish gray. The pyrolignite of iron, which contains
a brown empyreumatic matter, gives to stuffs a brown tint, bordering upon greenish
yellow in the pale hues, and to chestnut brown in the dark ones. By galling cotton
and silk, and giving them a bath of pyrolignite of iron, we may, after some alternations, dye them black. Galls, logwood, and a salt of iron, produce merely a very deep
violet blue; but by boiling and exposure to air, the hematate of iron is changed, becoming red-brown, and favors the production of black. Galls and salts of copper dye stuffs
an olive drab, logwood and salts of copper, a violet blue; hence their combination should
produce a blact. In using sumach as a substitute for galls, we should take into account
the proportion of yellow matter it contains. When the best possible black is wanted
upon wool, we must give the stuff a foundation of indigo, then pass it into a bath of logwood, sumach, and proto-sulphate of iron. The sumach may be replaced by one third of
its weight of nutgalls.
8. Of dyed stuffs considered in reference to the fastness of their colors, when exposed
to water, light, heat, air, oxygen, boiling, and reagents.
Pure water without air has no action upon any properly dyed stuff.
Heat favors the action of certain oxygenized bodies upon the carbonaceous and hydro.
genous constituents of the stuff; as is seen with regard to chromic acid, and peroxyde of
mnanganese upon cotton goods. It promotes the solvent action of water, and it even affects
some colors. Thus Prussian blue applied to silk, is reduced to peroxyde of iron by long
boilin.
Light without contact of air affects very few dyes.
Oxygen, especially in the nascent state, is very powerful upon dyes. See BLEACHING.
The atmosphere in a somewhat moist state affects many dyes, at an elevated tern
perature. Silk dyed pink, with safflower, when heated to 4000 F., becomes of a dirty
white hue in the course of an hour. The violet of logwood upon alumed wool becomes
of a dull brown at the same temperature in the same time. But both stand a heat of
3000 F. Brazil red dye, turmeric, and weld yellow dyes, display the same phenomena.
These facts show  the great fixity of colors commonly deemed tender.  The stuffs
become affected to a certain degree, under the same circumstances as the dyes. The
alterability even of indigo in the air is shown in the wearing of pale blue clothes; in
the dark blue cloth there is such a body of color, that it resists proportionally longer;
but the seams of coats exhibit the effect very distinctly. In silk window curtains, which
have been long exposed to the air and light, the stuff is found to be decomposed, as well
as the color.
Boiling was formerly prescribed in France as a test of fast dyes. It consisted in
putting a sample of the dyed goods in boiling water, holding in solution a determinate
quantity of alum, tartar, soap, and vinegar, &c. Dufay improved that barbarous test.
He considered that fast-dyed cloth could be recognised by resisting an exposure of twelve
hours to the sunshine of summer, and to the midnight dews; or of sixteen days in
winter.
In trying the stability of dyes, we may offer the following rules:~
That every stuff should be exposed to the light and air; if it be intended to be worn*
abroad, it should be exposed also to the wind and rain; that carpets, moreover, should be
subjected to friction and pulling, to prove their tenacity; and that cloths to be washed
should be exposed to the action of hot water and soap.
In examining a piece of dyed cotton goods, we may proceed as follows:~
Suppose its color to be orange-brown. We find first that it imparts no color to boiling water; that protoebloride of tin takes out its color; that plunged into a solution
of ferroprussiate of potash it becomes blue; and that a piece of it being burned, leaves
a residuum of peroxyde of iron; we may thence conclude that the dyeing matter is
peroxyde of iron.
Suppose we have a blue stuff which may have been dyed either with indigo or with
Prussian blue, and we wish to know what it will become in use. We inquire first into
the nature of the blue. Hot water slightly alkaline will be colored blue by it, if




DYEING.                                       607
it has been dyed with sulphate of indigo; it will not be colored if it was dyed in the indigo
vat, but it will become yellow by nitric acid. Boiling water, without becoming colored
itself, will destroy the Prussian blue dye; an alkaline water will convert its color into an
iron rust tint; nitric acid, which makes the indigo dye yellow, makes that of Prussian
blue green. The liquor resulting from boiling alkaline water on the Prussian blue cloth,
will convert sulphate of iron into Prussian blue.
9. Division. Of dyeing viewed in its relation to chemistry.
The phenomena of dyeing have been ascribed to very different causes; by some they
were supposed to depend upon mechanical causes, and by others upon the forces from
which chemical effects flow.  Hellot, in conformity with the first mode of explanation,
thought that the art of dyeing consisted essentially in opening the pores in order to admit
coloring matters into them, and to fix them there by cooling, or by means of a mordant
imagined to act like a cement.
Dufay in 1737, Bergmann in 1776, Macquer in 1778, and Berthollet in 1790, had recourse to chemical affinities, to explain the fixation of the coloring principles upon stuffs,
either without an intermediumgo,  walnut peels, annotto; or by the intervention of an acid, a salifiable base, or a salt, which were called mordants.  When bodies
present phenomena which we refer to an attraction uniting particles of the same
nature, whether simple or compound, to form an aggregate, or to an affinity which
unites the particles of different natures to form them into a chemical compound, these
bodies are in apparent contact.  This happens precisely in all the cases cf the mutual
action of bodies in an operation of dyeing; if their particles were not in apparent contact, there would be absolutely no change in their respective condition.  When we see
stuffs and metallic oxydes in apparent contact, form a mutual union of greater or less
force, we cannot therefore help referring it to affinity.  We do not know how many
dyes may be fixed upon the same piece of cloth; but in the operations of the dye-house
sufficiently complex compounds are formed, since they are always stuffs, composed of
three or four elements, wvhich are combined with at least binary acid or basic compounds; with simple salts compounded themselves of two immediate principles at least
binary; with double salts composed of two simple salts; and finally with organic dyestuffs containing three or four elements.  We may add that different species belonging
to one of these classes, and different species belonging to different classes, may unite
simultaneously with one stuff.  The union of stuffs with coloring matters appears, in
general, not to take place in definite proportions; though there are probably some
exceptions.
We may conclude this head by remarking, that, besides the stuff an, the coloring
matter, it is not necessary, in dyeing, to distinguish a third body, under the name of mor"
dant; for the idea of mordant does not rest upon any definite fact; the body to which
this name has been given being essentially only one of the immediate principles of the
colored combination which we wish to fix upon the stuff.
10. Division. Of dyeing in its relation with caloric, mechanics, hydraulics, pneumatics,
and optics.
Dyeing baths, or coppers, are heated directly by a furnace, or by means of steam conducted in a pipe from a boiler at a certain distance from the bath.  In the first case, the
vessels are almost always made of copper; only, in special cases, for the scarlet and some
delicate silk dyes, of tin; in the second case, they are of copper, iron, or wood. A direct
fire is more economical than heating steam pipes, where there is only one or two baths to
heat, or where the labors are often suspended. Madder and indigo vats, w   n heated by
steam, have it either admitted directly into the liquor, or made to circulate t rough pipes
plunged into it, or between the copper and an exterior iron or wood case.  See the end
of this article.
Everything else being equal, dyeing with heat presents fewer difficulties towards obtaining an evenly color, than dyeing in the cold; the reason of which may be found in the
following facts:-The air adhering to the surface of stuffs, and that interposed between
the fibres of their constituent yarns, is more easily extricated in a hot bath than a cold
one, and thus allows the dye liquor to penetrate more easily into their interior: in the
second place, the currents which take place in a hot bath, and which tend incessantly to
render its contents uniform, by renewing continually the strata of liquid in contact with
the stuff, contribute mainly to render the dyeing evenly.  In cold dyeing, it is necessary
to stir up the bath from time to time: and when goods are first put in, they must be carefully dipped, then taken out, pressed, and wrung, several times in succession till they be
uniformly moistened.
The mechamlical relations are to be found in the apparatus employed for wincing,
siring, and pressing the goods, as we have described under CALICO PRINTING and
BANDANA.  The hydraulic relations refer to the wash-wheels and other similar apparatus, of which an account is given under the same articles.  The optical relations
39




608                                    DYEING.
have been already considered. In the sequel of this article an automatic dyeing vat wil
be described.
The extracts of solutions of native dye-stuffs may be divided into two classes, in refer.
ence to their habitudes with the oxygen of the atmosphere; such as continue essentially
unaltered in the air, and such as suffer oxydation, and thereby precipitate a determinate
coloring matter.  The dyes contained in the watery infusions of the different vegetable
and animal substances which do not belong to the second class are feebly attached to
their solvents, and quit them  readily for any other bodies that possess an attraction for
them.   On this principle, a decoction of cochineal, logwood, brazil wood, or a solution
of sulphate of indigo, by digestion with powdered bone black, lose their color, in consequence of the coloring particles combining by a kind of capillary attraction with the
porous carbon, without undergoing any change.  The same thing happens when wellscoured wool is steeped in such colored liquids; and the color which the wool assumes
by its attraction for the dye, is, with regard to most of the above colored solutions, but
feeble and fugitive, since the dye may be again abstracted by copious washing,ith simple
water, whose attractive force therefore overcomes that of the wool. The aid of a high
temperature, indeed, is requisite for the abstraction of the color from the wool and the
bone-black, probably by enlarging the size of the pores, and increasing the solvent power
of the water.
Those dye-baths, on the contrary, whose coloring matter is of the nature of extractive
cr apotheme, form a faster combination with stuffs.  Thus the yellow, fawn, and brown
dyes, which contain tannin and extractive, become oxygenated by contact of air, and insoluble in water; by which means they can impart a durable dye. When wool is impreg
nated with decoctions of that kind, its pores get charged by capillarity, and when the liquid
becomes oxygenated, they remain filled with a color now become insoluble in water. A
similar change to insolubility ensues when the yellow liquor of the indigo vat getsoxydized
in the pores of cotton and wool, into which it had been introduced in a fluid state. The
same change occurs when protosulphate of iron is converted into persulphate, with the
deposition of an insoluble peroxyde in the substance of the stuff.  The change here
effected by oxydation can, in other circumstances, be produced by acids which have the
power of precipitating the dye-stuff in an insoluble state, as happens with decoction of
fustic.
Hence we perceive that the dyeing of fast colors rests upon the principle, that the
colors dissolved in the vat, during their union with the stuff, should suffer such a change
as to become insoluble in their former menstruum.  The more this dye, as altered in its
union with the stuff, can resist other menstrua or agents, the faster it will be.  This is
the essential difference between dyeing and painting; or applying a coat of pigment devoid of any true affinity for the surface.
If we mix a clear infusion of a dye with a small quantity of a solution of an earthy
or metallic salt, both in water, the limpid liquids soon become turbid, and there gradually subsides sooner or later, according to the nature of the mixture, a colored
precipitate, consisting of the altered dye united with a basic or subsalt.  In this compound the coloring matter seems to act the part of an acid, which is saturated by a
small quantity of the basis, or in its acid relationship is feeble, so that it c in also
combine with acids, being in reference to them a base.  The decomposition of a salt, as
alum, by dyes, is effected principally through the formation of an insoluble subsalt,
with which the color combines, while a supersalt remains in the bath, and modifies, by
its solvent reaction, the shade of the dyed stuff.  Dyed stuffs may be considered as
composed of the fibrous body intimately associated with the coloring matter, the oxyde,
and acid, all three constituting a compound salt.  Many persons have erroneously
imagined, that dyed goods contained none of the acid employed in the dye bath; but
they forget that even potash added to alum does not throw down the pure earthy basis,
but a subsalt; and they should not ascribe to coloring matter a power of decomposition
at all approaching to that of an alkali. Salts, containing stroag acids, saturate a very
large quantity of coloring matter, in proportion to their place in the scale of chemical
equivalents.  Mere bases, such as pure alumina, and pure oxyde of tin, have no power
of precipitating coloring matter; when they seem to do so, they always contain some
acid.
Such salts, therefore, as have a tendency to pass readily into the basic state, are peculiarly adapted to act as mordants in dyeing, and to form colored lakes. Magnesia affords
as fine a white powder as alumina, and answers equally well to dilute lakes, but its
soluble salts cannot be employed to form lakes, because they do not pass into the basic
state.  This illustration is calculated to throw much light upon dyeing processes in
general.
The color of the lake depends very much upon the nature of the acid, and the
basis of the precipitating salt.  If it be white, like alumina and oxyde of tin, the lake'will have, more or less, the color of the dye, but brightened by the reflection of white




DYEING.                                       609
right from the basis; while the difference of the acid occasions a difference in the hue.
The colored bases impart more or less of their color to the lakes, not merely in virtue of
their own tints, but of their chemical action upon the dye.
Upon these principles a crimson precipitate is obtained from infusions of cochineal by
alum and salt of tin, which becomes scarlet by the addition of tartar; by acetate of
lead, a violet blue precipitate is obtained, which is durable in the air; by muriate of
lime, a pink brown precipitate falls, which soon becomes black, and at last dirty green;
by the solution of a ferruginous salt, the precipitates are dark violet and black; and,:n like manner, all other salts with earthy or metallic bases, afford diversities of shade
with cochineal. If this dye stuff be dissolved in weak water of ammonia, and be precipitated with acetate of lead, a green lake is obtained, which, after some time, will
become crueen on the surface by contact of air, but violet and blue beneath. Hence it
appears, that the shade of color of a lake depends upon the Jegree of oxydation or
c~hange of the color caused by the acid of the precipitating salt, upon the degree of oxydation or color of the oxyde which enters into union with the dye, and upon its quantity
in reference to that of the coloring principle.
Such lakes are the difficultly soluble salts which constitute the dyeing materials of
stuffs. Their particles, however, for the purposes of dyeing, must exist in a state of
extremely fine division in the bath liquor, in order that they may penetrate along with it
into the minute pores of textile fibres, and fill the cavities observed by means of the
microscope in the filaments of wool, silk, cotton, and flax. I have examined these stuffs
with an achromatic microscope, and find that when they are properly dyed with fast colors, the interior of their tubular texture is filled, or lined at least, with coloring matter.
When the bath contains the coloring particles, so finely divided that they can pass
through filtering paper, it is capable of dyeing; but if the infusion mixed with its mordant be flocculent and ready to subside, it is unfit for the purpose. In the latter case,
the ingredients of the dye have already become aggregated into compounds too coherent
and too gross for entering into combination with fibrous stuffs. Extractive matter and
tannin are particularly liable to a change of this kind, by the prolonged action of heat in
the bath. Hence, also, an alkaline solution of a coloring matter affords no useful dye
bath, when mixed with the solution of a salt having an earthy or metallic basis.
These circumstances, which are of frequent occurrence in the dye-house, render it
necessary always to have the laky matter in a somewhat soluble condition, and to effect
its precipitation within the pores of the stuffs, by previously impregnating them with the
saline solutions by the aid of heat, which facilitates their introduction.
When a mordant is applied to any stuff, the portion of it remaining upon the surface
of the fibres should be removed; since, by its combination with the coloring matter, it
would be apt to form  an external crust of mere pigment, which would block up the
pores, obstruct the entrance of the dye into the interior, and also exhaust to no purpose
the dyeing power of the bath. For this reason the stuffs, after the application of the
mordant, are drained, squeezed, washed, and sometimes (particularly with cotton and
linen, in calico printing) even hard dried in a hot stove.
The saline mordants, moreover, should not in general possess the crystallizing property
in any considerable degree, as this opposes their affinity of composition for the cloth. On
this account the deliquescent acetates of iron and alumina are more ready to aid the
dyeing of cotton than copperas and alum.
Alum is the great mordant employed in wool dyeing. It is frequently dissolved in
water, holding tartar equal to one fourth the weight of the alum in solution; by which
addition its tendency to crystallize is diminished, and the resulting color is brightened.
The alum  and tartar combine with the stuff without suffering any change, and are
decomposed only by the action of the coloring matters in the dye bath. The alum operates solely in virtue of its sulphuric acid and earthy basis; the sulphate of potash present in that salt being rather injurious. Hence, if a sulphate of alumina free from iron
could be readily obtained, it would prove a preferable mordant to alum. It is also probable, for the reasons above assigned, that soda alum, a salt much less apt to crystallize
than potash or ammonia alum, would suit the dyer very well. In order to counteract the
tendency of common alum to crystallize, and to promote its tendency to pass into a basic
salt, one eighth part of its weight of potash is added to its solution, or the equivalent in
chalk or soda.
We shall conclude this account of the general principles of dyeing, with Mr. Delaval's
observations on the nature of dyes, and a list ^f the different substances used in dyeing,
in reference to the colors produced by them.
Sir Isaac Newton supposed colored matters to reflect the rays of light; some bodies
reflecting the more, others the less, refrangible rays most copiously; and this he conceived
to be the true, and the only reason of their colors. Mr. Delaval, however, proved, in
the 2d vol. of the " Memoirs of the Philosophical and Literary Society of Manchester,"
that, " in transparent colored substances, the coloring substance does not reflect any




610                                    DYEING.
light; aw. that when, by intercepting the light which was transmitted, it is hindered
from passing through substances, they do not vary from their former color to any other
color, but become entirely black;" and he instances a considerable number of colored
liquors, none of them endued with reflective powers, which, when seen by transmitted
light, appeared severally in their true colors; but all of them, when seen by incident
light, appeared black; which is also the case of black cherries, black currants, black
berries, &c., the juices of which appeared red when spread on a white ground, or otherwise viewed by transmitted instead of incident light; and he concludes, that bleached
linen, &c., 1" when dyed or painted with vegetable colors, do not differ in their manner
of acting on the rays of light, from natural vegetable bodies; both yielding their colors
by transmitting through the transparent colored matter the light which is reflected from
%he white ground:" it being apparent, from  different experiments, "that no reflecting
vower resides in any of their components, except in their white matter only," and that
transparent colored substances, placed in situations by which transmission of light
through them is intercepted, exhibit no color, but become entirely black."
The art of dyeing, therefore, (according to Mr. Delaval,) "consists principally in covering white substances, from which light is strongly reflected, with transparent colored
media, which, according to their several colors, transmit more or less copiously the rays
reflected from the white," since " the transparent media themselves reflect no light; and
it is evident that if they yielded their colors by reflecting, instead of transmitting the
rays, the whiteness or color of the ground on which they are applied, would not in anywise alter or affect the colors which they exhibit."
But when any opaque basis is interposed, the reflection is doubtless made by it, rather
than by the substance of the dyed wool, silk, &c., and more especially when such basis
consists of the white earth of alum, or the white oxyde of tin; which, by their strong
reflective powers, greatly augment the lustre of colors. There are, moreover, some
opaque coloring matters, particularly the acetous, and other solutions of iron, used to
stain linen, cotton, &c., which must necessarily themselves reflect, instead of transmitting the light by which their colors are made perceptible.
The compound or mixed colors, are such as result from the combination of two differently colored dye stuffs, or from dyeing stuffs with one color, and then with another.
The simple colors of the dyer are red, yellow, blue, and black, with which, when skilfully blended, he can produce every variety of tint.  Perhaps the dun or fawn color
might be added to the above, as it is directly obtained from a great many vegetable substances.
1. Red with yellow, produces orange; a color which, upon wool, is given usually with
the spent scarlet bath. To this shade may be referred flame color, pomegranate, capuchin, prawn, jonquil, cassis, chamois, cafe au lait, aurora, marigold, orange peel, mordoris, cinnamon, gold, &c.  Snuff, chestnut, musk, and other shades are produced by
substituting walnut peels or sumach for bright yellow. If a little blue be added to orange,
an olive is obtained. The only direct orange dyes are annotto, and subehromate of lead;
see SILK and WooL Dyeing
2. Red with blue produces purple, violet, lilach, pigeon's neck, mallow, peach-blossom.
bleu de roi, lint-blossom, amaranth.
3. Red with black; brown, chocolate, marone, &c.
4. Yellow with blue; green of a great variety of shades, such as nascent green, gay
green, grass green, spring green, laurel green, sea green, celadon green, parrot green,
cabbage green, apple green, duck green.
5. Mixtures of colors, three and three, and four and four, produce an indefinite dives
sity of tints; thus red, yellow, and blue, form brown olives, and greenish grays; in
which the blue dye ought always to be first given, lest the indigo vat should be soiled by
other colors. Red, yellow, and gray, (which is a gradation of black,) give the dead-leaf
tint, as well as dark orange, snuff color, &c. Red, blue, and gray, give a vast variety
of shades; as lead gray, slate gray, wood-pigeon gray, and other colors, too numerous to
specify. See BROWN DYE.
The following list of dyes, and the coloring substances which produce them, may prove
useful.
Red. Cochineal, kermes, lac, madder, archil, carthamus or safflower, brazil wood,
logwood, periodide of mercury, alkanet.
Yellow. Quercitron, weld, fustic, (yellow wood,) annotto, sawwort, dyer's broom, turmeric, fustet, (rhus cotinus,) Persian and Avignon berries, (rhamnus islfectorius,) willow,
peroxyde of iron; chromate of lead, (chrome yellow,) sulphuret of arsenic, hydrosulphuret of antimony; nitric acid on silk.
Blue. Indigo, woad or pastel, Prumsian blue, turnsole or litmus, logwood with a salt
of copper.




DYEING.                                      611
Black. Galls, sumach, logwood, walnut peels, and other vegetables which contain
tannin and gallic acid, along with ferruginous mordants. The anacardium of India.
Green. These are produced by the blue and yellow dyes skilfully combined; with the
exception of the chrome green, and perhaps the copper green of Schweinfurt.
Orange. Annotto, and mixtures of red and yellow dyes; subchromate of lead.
Brown. See the remarks at the beginning of this article; BROWN in its alphabetical
place; CALICO PRINTING, CATECHU, and MANGANESE.
Fawn, Dun, or Root. Walnut peels, sumach, birch-tree, henna, sandal wood.  See
CALICO PRINTING, for a great variety of these dyes.
Figs. 469 and 470 represent in a cross and longitudinal section the automatic dyeing
~team copper, si generally employed in the well-appointed factories of Lancashire.
A is the long reel, composed at each end of six
radial iron arms or spokes, bound at their outer ex^Q469                      tremities with a six-sided wooden frame; these two
terminal hexagons are connected by long wooden
laths, seen above and below A in fig. 470. t shows
the sloping border or ledge of the copper. B and c
0fi^^    A       are rollers laid horizontally, for facilitating the continuous motion of the series of pieces of goods
stitched together into an endless web, which are
made to travel by the incessant rotations of the reel.
Immediately above the roller B in fig. 469, all the
spare foldings of the web are seen resting upon the
sloping wooden grating, which guides them onwards
in the direction indicated by the arrow.  The dye
stuffs are put within the middle grating, like a hencoop, marked G. Each copper is 6 feet long, 31 feet
j,^11 ll 9ln  \  wide, 36 feet deep, exclusive of the top ledge,
inches high. Such steam coppers are usually erected
in pairs, and moved by a common horizontal bevel
wheel seen at D in fig. 470, fixed upon a vertical shaft,
shifted into gear by a wheel at its top, with one of the driving shafts of the factory. Upon
each side of D, the two steam pipes for supplying the right and left hand coppers are
seen; each provided with a stop cock for admitting, regulating, or cutting off the steam.
These steam pipes descend at E E, the horizontal branch having several orifices in its
upper surface. The horizontal shaft in a line with the axes of the reels, and which
turns them, is furnished upon each side with a clutch for putting either of the reels into
or out of gear, that is to say, setting it a going, or at rest, in a moment by the touch of a
forked lever.
The steam pipe of distribution E lies horizontally near the bottom of the middle coop,
as shown under G in fig. 469, and sends up the steam through its numerous orifices,
among the dye-stuffs and water by which it is covered. Thus the infusion or decoc



612                              EAU DE COLOGNE.
tion is continually advancing in the copper, during the incessant locomotion of the
endless web. The horizontal pipe traverses the copper from end to end, and is not
stopped short in the middle. Each of these coppers can receive two, three, or more
parallel pieces of goods at a time, the reel and copper being divided into so many compartments by transverse wooden spars.
E.
EARTHS.  (Terres, Fr.; Erden, Germ.)  Modern science has demonstrated that the
substances called primitive earths, and which prior to the great electro-chemical career
of Sir H. Davy, were deemed to be elementary matter, are all compounds of certain
metallic bases and oxygen, with the exception of silica, whose base, silicon, being analogous to boron, has led that compound to be regarded as an acid; a title characteristic
of the part it extensively performs in neutralizing alkaline bodies, in mineral nature,
and in. the processes of art. Four of the earths, when pure, possess decided alkaline
properties, being more or less soluble in water, having (at least 3 of them) an acrid
alkaline taste, changing the purple infusion of red cabbage to green, most readily saturating the acids, and affording thereby neutro-saline crystals. These four are baryta,
strontia, lime (calcia), magnesia. The earths proper are five in number; alumina,
glucina, yttria, zirconia, and thorina. These do not change the color of infusion of cabbage or tincture of litmus, do not readily neutralize acidity, and are quite insoluble in
water.  The alkalis are soluble in water, even when carbonated; a property which
distinguishes them from the alkaline earths. Lithia must for this reason be considered
to be an alkali. See the above substances in their alphabetical places.
EAU  DE  COLOGNE.  This well-known perfume is a solution of different volatile
oils in pure strong spirit.  The principal condition for the preparation of a fine water, is
the employment of a spirit quite devoid of fusel-oil (oil of grain), and of all foreign odor.
In respect to the proportion and kind of oils employed, we have numerous formulae.
It is of importance that these oils, which are usually purchased of the druggists of the
south of France, should be of the finest quality, and that no oil should be used in sufficient quantity to allow of its peculiar odor being recognisable in the mixture. The
oils are to be dissolved in spirit, and the mixture allowed to stand for some weeks (or
still better for some months) to improve its odor. Distillation does not effect this; on
the contrary a fresh distilled water requires to be kept a much longer time.  Distillation is indeed objectionable, for on account of the great volatility of the spirit, the oils
in part remain behind in the still. Distillation can improve the odor only when the
less volatile oil has been used in too great a quantity, and we wish to obtain a better
proportion. Before all things, we should employ a pure, old, strong spirit, and not too
much of, nor a too strongly smelling oil.
The different sorts of volatile oil which are obtained from varieties of citrons, oranges,
and lemons, in different states of maturity, are the most important; and, therefore, it
is most important to ascertain their purity and goodness.
Forster gives the following formula for the preparation of a fine eau de Cologne:
Take of rectified spirit 82 per cent. of Tralles (=sp. gr. 0855), 6 (wine) quarts; essence
of oranges, essence of bergamot, essence of citron, essence of limette, and essence of
petits grains, of each, Jj; essence of cedro, essence of cedrat, essence de Portugal, and
essence de neroli, of each ^ss; oil of rosemary, 3ij; and oil of thyme, 3j.
Otto gives the following formula for a good eau de Cologne: Rectified spirit of 86
per cent. of Tralles (=0'846 sp. gr.), 200 (wine) quarts; oil of citrons, lb. iv; oil of
bergamot, lb. ij; oil of neroli, 5lb.; oil of lavender, lb. ss; oil of rosemary, ^ lb.; and
spirit of ammonia, iss.  Mix.  Don't distil.
This preparation has long possessed great celebrity, in consequence chiefly of the
numerous virtues ascribed to it by its venders; and is resorted to by many votaries of
fashion as a panacea against ailments of every kind. It is, however, nothing more
than aromatized alcohol, and as such, an agreeable companion of the toilet. Numerous
fictitious recipes have been offered for preparing eau de Cologne; the following may
be reckoned authentic, having been imparted by Farina himself to a friend.
Take 60 gallons of silent brandy; sage, and thyme, each 6 drachms; balm-mint and
spearmint, each 12 ounces; calamus aromaticus, 4 drachms; root of angelica, 2 drachms
camphor, 1 drachm; petals of roses and violets, each 4 ounces; flowers of lavender, 2
ounces; flowers of orange, 4 drachms; wormwood, 1 ounce; nutmegs, cloves, cassia,
lignea, mace, each 4 drachms. Two oranges and two lemons, cut in pieces. Allow the
whole to macerate in the spirit during 24 hours, then distil off 40 gallons by the heat
of a water bath. Add to the product:
Essence of lemons, of cedrat, of balm-mint, of lavender, each I ounce 4 drachms;




EBULLITION.                                      613
neroli and essence of the seed of anthos, each 4 drachms; essence of jasmin, 1 ounce;
of bergamot, 12 ounces. Filter and preserve for use.
Cadet de G-assincourt has proposed to prepare eau de Cologne by the following recipe:
Take alcohol at 320 B., 2 quarts; neroli, essence of cedrat, of orange, of lemon, of bergamot, of rosemary, each 24 drops; add 2 drachms of the seeds of lesser cardamoms,
distil by the heat of a water bath a pint and a half. When prepared as thus by simple
mixture of essences without distillation, it is never so good.
EAU DE LUCE, is a compound formed of the distilled oil of amber and water of
ammonia.
EBULLITION.  (Eng. and Fr.; Kochen, Germ.)  When the bottom  of an open
vessel containing water is exposed to heat, the lowest stratum of fluid immediately
expands, becomes therefore specifically lighter, and is forced upward by the superior gravity of the superincumbent colder and heavier particles. The heat is in this way diffused
through the whole liquid mass, not by simple communication of that power from particle to particle as in solids, called the conduction of caloric, but by a translation of the
several particles from the bottom to the top, and the top to the bottom, in alternate
succession. This is denominated the carrying power of fluids, being common to both
liquid and gaseous bodies.  These internal movements may be rendered very conspicuous and instructive, by mingling a little powdered amber with water, contained in a
tall glass cylinder, standing upon a sand-bath. A column of the heated and lighter
particles will be seen ascending near the axis of the cylinder, surrounded by a hollow
column of the cooler ones descending near the sides. That this molecular translation
or locomotion is almost the sole mode in which fluids get heated, may be demonstrated
by placing the middle of a pretty long glass tube, nearly filled with water, obliquely
over an* argand flame. The upper half of the!quid will soon boil, but the portion under
the middle will continue cool, so that a lump of ice may remain for a considerable time at
the bottom. When the heat is rapidly applied, the liquid is thrown into agitation, in
consequence of elastic vapor being suddenly generated at the bottom of the vessel, and
being as suddenly condensed at a little distance above it by the surrounding cold
columns. Thec e alternate expansions and contractions of volume become more manifest
as the liquid becomes hotter, and constitute the simmering vibratory sound which
is the prelude of ebullition. The whole mass being now heated to a pitch compatible
with its permanent elasticity, becomes turbulent and explosive under the continued
influence of fire, and emitting more or less copious volumes of vapor, is said to
boil. The further elevation of temperature, by the influence of caloric, becomes
impossible in these circumstances with almost all liquids, because the vapor carries off from them as much heat in a latent state as they are capable of receiving from
the fire.
The temperature at which liquids boil in the open air varies with the degree of atmospheric pressure, being higher as that is increased, and lower as it is diminished. Hence
boiling water is colder by some degrees in bad weather, or in an elevated situation, with
a depressed barometer, than in fine weather, or at the Wxttom of a coal-pit, when the
barometer is elevated. A  high column of liquid, also, by resisting the discharge
of the steam, raises the boiling point. In vacuo, all liquids boil at a temperature about
1240 F. lower than under the average atmospheric pressure. For a table of elasticities,
see VAPOR.  Gay Lussac has shown that liquids are converted into vapors more readily,
or with less turbulence, when they are in contact with angular or irregular, than
with smooth surfaces; that they therefore boil at a heat 2~ F. lower in metallic than in
glass vessels, probably owing to the greater polish of the latter. For example, if into
water about to boil in a glass matrass, iron filings, ground glass, or any other insoluble
powder be thrown, such a brisk ebullition will be instantly determined as will sometimes
throw the water out of the vessel; the temperature at the same time sinking two degrees
F. It would thence appear that the power of caloric, like that of electricity, becomes
concentrated by points.
The following table exhibits the boiling heats, by Fahrenheit's scale, of the most important liquids
Ether, specific gravity 07365 at 480    -       -      -       -       -       -   1000
Carburet of sulphur      -       -       -       -       -      -           -         113
Alcohol, sp. gray. 0-813 -               -       -     Ure      -       -       -  173-5
Nitric acid,      1-500 -        -       -      -   Dalton    -         -       -    210
Water. —                      -.- -.       -       -    212
Saturated solution of Glauber salt       -      -      Biot    -        -       -   213*
do.    do.      Acetate of lead   -         -      do.     -       -            2151
do.    do.      Sea salt   -        -       -     do.      -               -   2241
do.    do.      Muriate of lime,  -         -     Ure      -       -       -    285
do.    do.             do.         I 4  water 2, do.       -       ~       -    230
do.    do.             do.     35-5 +   do. 64-5, do.      -       -             235




614                     EBULLITION ALCOHOLMETER.
Saturated solution of Muriate of lime 40 5+water 59-5 Ure,    -           -        -   240'
Muriatic acid, sp. gray. 1-094         -                 Dalton, -         -       -   232
do.         do.    1127          -       -          do.          -           - 222
Nitric acid,      do.     1-420        -       -           do.    -        -       -   248
do.          do.     1-30.           do.    -        -       - 236
Rectified petroleum           -        -       -         Ure,    -         -       -   306
Oil of turpentine    -        -        -       -           do.     -       -       - 316
Sulphuric acid, sp. gray. 1-848        -       -         Dalton, -         -           600
do.          do.     1-810        -       -           do.    -                -   4T3
do.          do.     1780         -       -           do.    -                -   435
do.          do.     1700         -       -           do.    -                -   374
do.         do.      1-650        -       -           do.    -                -   350
do.         do.      1-520        -       -           do.    -        -       -   290
do.         do..    1-408         -       -           do.    -                -   260
do.         do,      1-300        -                  do.    -         -       -   240
Phosphorus  -          -       -       -       -          do.    -         -       -   554
Sulphur        -       -       -       -       -          do.      -       -       -   570
Linseed oil   -        -       -       -       -           do.    -        -       -   640
Mercury        -       -.       -       -         Dulong, -         -       -   662
do,               -       -       -       -         Crighton,         -       -   656
Saturated  solution  of Acetate soda, containing 60 per cent. Griffiths,           -   256
do.                  Nitrate of soda,          60                do.          -   246
do.                  Rochelle salt,            90                do.          -   240
do.                  Nitre,                    74                do.          -   238
do.                  Muriate of ammonia,   50                    do.          - 236
do.                  Tartrate of potash,       68                do.          -   234
do.                  Muriate of soda,          30                do.          -   224
do.                  Sulphate of magnesia, 5P7-5                 do.          -   222
do.                  Borax,                  52-5                do.          -   222
do.                  Phosphate of soda,?                do.          -   222
do.                  Carbonate of soda,          I               do.          -   220
do.                  Alum,                     52                do.          -   220
do.                  Chlorate of potash,       40                do.          -   218
do.                  Sulphate of copper,    45                   do.          - 216
471                    EBULLITION  ALCOHOLMETEl.   That  the  boiling
temperature of water is increased by holding neutrosaline and saccharine substances in solution has been
long known, and has been the subject of many experiments, made partly with the view of ascertaining'     from that temperature the proportion of the salt or.sugar, and partly with the view of obtaining a practical liquid bath.  But it seems to have been reserved
for the Abb6 Brossard-Vidal, of Toulon, to have
discovered that the boiling temperature of alcoholic
liquors is, in most cases, proportional to the quantity
of alcohol, irrespectively of the quantity of neutrosaline or saccharine matter dissolved in them. When,
however, such a quantity of dry carbonate of potasli,
or sugar, is added to a spirituous liquor as to abstract or fix in the solid state a portion of the water
r*L~               present, then the boiling temperature of that mixture
will be lowered in proportion to the concentration
of the alcohol, instead of being raised, as would be
the case with water so mixed.  But, generally speak1    HI               ing, it may be assumed as a fact, that the boiling
I   jll               point of an alcoholic liquor is not altered by a
moderate addition of saline, saccharine, or extractive
matter.  On this principle, M. Brossard-Vidal conI-:1 ^ l~a~ll       structed the instrument represented in fig. 471, for
determining by that temperature the proportion of
(1    81^^   i ^^li8    alcohol present.  His chief object was to furnish the
revenue boards of France with  a means of estimating directly the proportion of alcohol in wines,
so as to detect the too common practice of introducing brandy into their cities and towns under the
mask of wine, and thereby committing a fraud upon
the octroi; as the duty on spirits is much higher
than on wines.




EBULLITION ALCOHOLMETER.                                          615
The above instrument consists of a spirit-lamp, surmounted by a small boiler, into
which a large cylindric glass bulb is plunged, having an upright stem of such calibre,
that the quicksilver contained in them may, by its expansion and ascent when heated,
raise before it a little glass float in the stem, which is connected by a thread with a similar glass bead, that hangs in the air. The thread passes round a pulley, which turning
with the motion of the beads causes the index to move along the graduated circular
scale. The numbers on this scale represent per centages of absolute alcohol, so that
the number opposite to which the index stops, when the liquor in the cylinder over
the lamp boils briskly, denotes the per centage of alcohol in it.
That instrument was placed in my hands three years ago by Mr. Field, who had
obtained a patent in this country for determining thereby the strength of spirituous
liquors.  I have made a great many experiments on the boiling points of alcohol at
various successive degrees of watery dilution,
1)      ED   ooE          and verified the general utility of the contriv472                C n^ance; but I found the construction of the inC op o 5 l    B ^^ AR   Hi ^ strument subject to general defects.  The mass
a Q,2l x    1^^ 3 k           of mercury to be heated in the large bulb was
I  \~    i 9 2 ^:  so great as to occasion some loss of alcohol in
v   ^:  the course of the experiment; the length of the
rjll~l^';-   ~ > SD ID t = thread was liable to be affected by the moisture
l ~       so  t I _ 9 t ~   of the air; it occasionally failed. to move the
l 0 6 15, 70  lo     pulley with  sufficient delicacy  on  account of
JD=1 l          AO I  l*  friction, and when the spirit in the lamp got
1 L  e ^0    755~    heated in its case, it flared up and burned the
thread, thus rendering the apparatus useless till
Fs1-^1, I'   a fresh thread was experimentally adjusted to
the beads.
On these accounts I renounced the construction of M. Vidal, and adopted the more simple
and  direct form  of indication  represented in
It  consists, 1, of a flat spirit-lamp  A, surrounded by a saucer for containing cold water
to keep the lamp cool, should many experiments
require to be made in  succession; 2, of the
1 A~"""illlS   ^"B        ^^^^^^ boiler B, which fits by its bottom  cage c, upon
II'1111^     ILthe case of the lamp.  At the point c, is seen
the edge of the damper-plate for modifying the
flame of the lamp, or extinguishing it when the
CQZ       i   experiment is completed.  D is the thermometer,
made with a very minute bore, in the manner
M           ^ —^~-"^IB  measuring  the height of a mountain  by  the
A.        ^boiling point of water on its summit.  The bottom of the scale in the ebullition thermometer,
is marked p for proof on the left side, and 100
(of proof spirit) on the right side. It corresponds to 1786 Fahr. very nearly, or the
boiling point of alcohol of 0920 specific gravity.  The following table gives the boiling points corresponding to the indicated densities:
Temp. Fahr.                Specific gravity.    Temp. Fahr.               Specific gravity.
178-6      -        -  0-9200  P.              185-6       -           0-9665  50 U. P.
179-75     -        -  09321  10 U. P.    189-0            -           0-9729   60
180-4       -       -  0-9420  20,           191-80       -       -  09786  70
181-00     -        -  0.9516  30,           196-4       -        -  0-9850  80,
183-40     -        -  0-960    40,          202-0       -        -  0-992    90,
The above table is the mean of agreat many experiments. When alcohol is stronger
than 0-92, or the excise proof, its boiling point varies too little with its progressive increase of strength, to render that test applicable in practice. In fact, even for proof
spirits, or spirits approaching in strength to proof, a more exact indication may be ob
tained by diluting them  with their own bulk of water, before ascertaining their
strength, and then doubling it.
The boiling point of any alcoholic liquor is apt to rise if the heat be long-continued,
and thereby to lead into error in using this instrument. This source of fallacy may be
in a great measure avoided by adding to the liquor in the little boiler about a teaspoonful (thirty-five grains) of common culinary salt, which has the curious effect of
arresting the mercury in the thermometer at the true boiling point of the spirit, wine,




616                    EBULLITION ALCOHOLMETER.
or beer, to enable a correct reading to be had. The small measure marked M, holds
the requisite quantity of salt.
The thermometer is at first adjusted to an atmospheric pressure of 29'5 inches
When that pressure is higher or lower, both water and alcohol boil at a somewhat
higher or lower temperature. In order to correct the error which would hence arise
in the indications of this instrument under different states of the weather, a barometrical equation is attached by means of the subsidiary scale ^ to the thermometerD.
Having stated the principles and the construction of the ebullition alcoholmeter, I
shall now describe the mode of its application.
First.-Light the spirit lamp A.
Second.-charge the boiling vessel B, with the liquid to be tested (to within an inch
of the top), introducing at the same time a paper of the powder; then place the vessel
B (the damper plate being withdrawn) on to the lamp A.
Third.-Fix the thermometer D on the stem attached to B, with its bulb immersed in
the liquid. The process will then be in operation.
The barometrical scale indicated on the thermometer is opposite the mean boiling
point of water. Prior to commencing operations for the day, charge the boiler B with
water only, and fix the instrument as directed; when the water boils freely, the mercury
will become stationary in the stem of the thermometer, opposite to the true barometrical indication at the time. Should the mercury stand at the line 29-5, this will be the
height of the barometer, and no correction will be required; but should it stand at any
other line, above or below, then the various boiling points will bear reference to that
boiling point.
In teting spirituous or fermented liquors of any kind, when the mercury begins to
rise out of the bulb of the thermometer into the stem, push the damper-plate half-way
in its groove to moderate the heat of the flame. When the liquor boils freely, the mercury will become stationary in the stem; and opposite to its indication, on the left, the
under-proof per-centage of spirit may be read off at once, if the barometer stand that
day at 29'5 inches; while on the right hand scale, the per centage of proof spirit is
shown; being the difference of the former number from 100. The damper-plate is to
be immediately pushed home to extinguish the flame.
The alcoholmeter will by itself only indicate the per centage of alcohol contained in
any wine, but by the aid of the hydrometer, the proportionate quantity of saccharum
in all wines may be readily and easily determined.  The hydrometer will show  the
specific gravity of the liquid upon reference to table No. I, annexed. In testing a
sample of wine, first take the specific gravity, and suppose it to be 989, then charge the
boiler of the alcoholmeter with the wine, as directed, and at the boiling point it indicates the presence of alcohol at 69'6 per cent.YP whose specific gravity will be found to
be 979; deduct that gravity from the gravity of the bulk, or 989, and 10 will remain,
which 10 degrees of gravity, upon reference to the wine table, will be found to represent
25 lbs. of saccharine or attractive matter in every 100 gallons, combined with 30 4 th
gallons of proof spirit.
Sike's hydrometer will only show the sp. gr. of liquids lighter than water (or 1000),
and for wines in general use, the gravities being lighter than that article, will answer
every purpose; but there are wines whose gravities are heavier than water, such as
mountain, tent, rich Malagas, lachrymfe Christi, &-c., to embrace which additional weights
to the hydrometer will be required, as for cordialized spirits, &c.  In testing a sample
of rich mountain, its sp. gr. was found to be 1039, or 39 degrees heavier than water,
that wine at the boiling point indicated the alcohol 72'5 per cent. uP; but 980 sp. gr.
deducted from 1039 leaves 59 degrees of sp. gr.; against 59 of the wine tables will be
found 147-5 or 147k lbs. of saccharine or extractive matter, combined with 271 gallons
of proof spirit to every 100 gallons.
Should the barometer for the day show any other indication above or below the
standard of 29'5, the thermometer scale will then only show the apparent strength,
and reference must be had to the small ivory indicator, F, it being the counterpart of
the barometrical scale of the thermometer; thus should the barometer indicate 30,
place 30 of the indicator against the boiling point of the liquid, and opposite the line of
29-5 will be found the true strength.
Example 1. Barometer at 30.-Suppose the mercury to stop at the boiling-point
72-uP, place 30 of the indicator against 72 on the thermometer, and the line of 29-5 will
cut 69'6-uP, the true strength.
Example 2. Barometer at 29.-Suppose the mercury to stop at the same point, 72-uP,
place 29 of the indicator against 72 on the thermometer, and the line 29-5 will cut
74-uP, the true strength.
For malted Liquors.-To all brewers and dealers in fermented liquors, the principle,
by its application, will supply a great desideratum, as it will not only show the alcohol
created in the wort by the attenuation, as well as the original weight of the wort prior




No. 1.
TABLE OF SPECIFIC GRAVITIES, by Sikes's Hydrometer, adapted to Field's Patent Alcoholmeter for Cordialized Spirits.
TEMPERATURE 60~. SPECIFIC GRAVITY OF WATER 1000~.
60         170              80            90            100          110            120         130         140       150       160        ITO0       180
Wt..                 S.G. S. G    Wt.   S.         G.  Wt.   S. G.             S.G.  Wt.  S.       G. Wt. S.   G. Wt. S.  G. Wt. S.  G. Wt. S.G. Wt.  S.G. Wt. S. G. 
60    922    70    942    80    961    90    981   100  1000  110   1020  120   1041  130  1063 140 1085 150 1107 160 1129 170 1152 180 1175    t
1    924      1    943      1    963      1    983       1  1002    1   1022    1   1044          1  1065   11087    11109   11131   1 1155   11178 
2    926      2    945      2    965      2    985       2  1004    2   1024    2   1046          2  1067   21089   21111   2 1134   2 1157   21180 
3    928      3    947      3    967      3    987       3  1006    3   1026    3   1048          3  1069   31091   31113   31136   31159   31182 
4    930      4    949      4    969      4    989       4   1008    4   1029    4   1050    4  1071   4 1093   4 1116   4 1139   4 1162   4 1185    W
5    932      5    951      5    971      5    991       5  1010    5   1031    5   1052          5  1074   51096   5 1118   51141   51164   5 1187 
6    934      6    953      6    973      6    993       6  1012    6   1033    6   1054          6  1076   6 1098   6 1120   6 1143   6 1166   6 1189    -
7    936      7    955      7    975      7    995       7  1014    7   1035    7   1056    7  1078'71100   7 1123'71145   7 1168   7 1191?
8    938      8    957      8    977      8    997       8  1016    8   1037    8   1058    8  1080   81102   81125   81148   8 1171   81194
9    940      9    959      9    979      9    999       9  1018    9   1039        9   1061    9  1082   9 1104   9 1127   9 1150   9 1173   9 1196
10    942    10    961    10    981    10   1000    10  1020   10   1041   10   1063   10  1085  10 1107  10 1129  10 1152  10 1175  10 1199
The foregoing Table, which shows the Specific Gravity on the bulk of the mixture, bears reference to the Table (No 2) of the Alcoholmeter following. 
1ooo.




618                    EBULLITION ALCOHOLMETER.
No. 2.
TABLE, showing the lbs. of Sugar per Gallon in Cordialized Spirits, with Per-Centages
to be added to the indicated Strength, per the Alcoholmeter.
Difference of    10    15    20   25    30    35   40  45   50    Difference of
Gravity.                                                                  Gravity.
4 oz.  6 oz.  8 oz. 10 oz. 12 oz. 14 oz.      oz.  oz.
Libs. of Sugar   or 25   371    50    624    75    871   10   1-2  1-4   Llbs. of Sugar
per Gallon.   to 100. to 100. to 100. to 100. to 100. to 100.            per Gallon.
Sp. Grav. Per Cent.                                                       Per Cent. Sp. Grav.
of Spirit.  of Spirit.                                                   of Spirit.   of Spirit.
920      Pf.    1'6   2-5   3-4   44    5-3   6-2   71  8-1  9-0    Pf.           920
923      2-5    1-6   2-5   3-3   4-3   5-2   6-1   6-9  7-8  8-8    2-5          923
926      5-     1'5   2-4   3'2   4-2   5-0  55    6'8  7-7  8-6           -      926
929      7*5    1*5    2-3   3-2   4-1   4-9   5-8   6-6  7'5  8-4    75          929
932    10'    14    2-2   3'1   4'0   4'8   57   6-5  7-4  8-2  10'               932
935    12'5    14    2-2   3-1   3-9   4-7   5-5   6-3  72  8-0  12-5             935
938    1        1'4   2'1   3-0   3'8   4-6   5-4   6-2  70'78   15             938
940    175    1-3   2-1   2'9   3'7   4-5   5-3   6-0  6-8  7'6  175              940
943    20'    13   2-0   2-8   3'6   4-4   5-2   5-9  6-7  75   20'               943
945    22-5    1-3   2-0   2'7   3-5   4-3   5'0   5-7  6-5  7-3   22-5    945
948    25'      1'2   1-9   26   3-4   4-1   4-8   5-5  6-3  7-0   25'            948
950    27'-5    1'2   1-9   2'-5   3-3   4-0   4-7   5-3  6-1  6-8  27-5          950
952    30'    1-1   1-8   2'4   3-1   3-8   4-5   5-1  5-8  6-5  30-              952
954    32'5    1-1   1-7   2-3   3-0   3-6   4-3   4-8  5-5  6-2   32-5           954
956    35-    1-0   1-6   2'2   2'9   3-5'        41  4-6  5-3  6-0   35'         956
958    37'5    1'0   1'6   2'1   2-8   3-4   3-9   4-4  5-1  5-8  37-5            958
960    40'.9   1'5   2-0   2'7   3-2   3'8   4-3  4-9  5-5  40             960
962    42-5    -9    15   2-0   2-6   3-1   3-6   4-1  4'7  5-3   42-5            962
964    45-        9   1'4   1-9   2-5   3-0   3-5   40  4-6  5-1  45-             964
965    47'5'8   1*4    19   2-4   2-9   3'4   3-9  4-4  4-9  47-5             965
967    50'        8    1-3   1-8   2-3   2-8   3-3   3-8  4-3  4-8  50'           967
969    52-5    -7    12   1-7   2'2   2'6    31   3-6  41  4-5   52-5             969
970    55-       -7   1-2   1-6   2-0   2-4   2-9   3-4  3-8  4-2  55-            -970
972    575       -6   1'1 11  15     -9   2-2   2-7   3-1  3-5  3-9  57-5         972
973    60'       -6   1-0   1'4    1-8   2'1   2-5   2-9  3-3  3-6  60'           973
974    62-5    -6   1-0   1-3   1-7   2-0   2-4   2-7  31  3-4   62-5             974
976    65'.5    -9   1-2   1-5   1-8   2-2   2-5  2-8  3-1   65'           976
977    67'5       5     -8   1-1   1-4   1*7    2-0   2-3  2-6  2-9  67-5         977
979    70-       -4    -7   1-0   13    1-5   18'   21  24  26   70               979
980    72-5    -4.7.9   1-1   1-3   1-6   1-9  2-1  2-3   72-5             980
982    75'       -3'6    -8   1-0   1-2   1'4   1-6  1-8  2-0   75-            982
983    77-5    -3.5.7.9   1-0   1-2   14  1-6  1-8  77-5               983
984    80-       -2    -4'6'8.9   1-0   1-2  1-4  1-6   80-           984
986    82-5    -2'3    *5'7'8'9   10  12  1-4   82'5              986
988    85' *'2  *4'6.7'8'9  1-0  1-2   85-         988
990    87-5'1'2'3         5'6'7      8   -9  1-0  87-5       990
992    90-'1'1'2'4.5'6   *7    8.9  90'             992
994    92-'5    -'1     2     *3    *4      5    -6   -7   -8   92-5       994
996    95       -      -'1'2.3      4    -5'6  -7   95'         996
998    975      -- --           -     1'2     3    -4    5    6   97-5       998
to fermentation, but it will indicate the value of malt liquors in relation to their component parts. It will likewise be a ready means of testing the relative value of worts
from sugar compared with grain, as well as being a guide to the condition of stock
beers and ales.
To ascertain the strength of malt liquors and their respective values, the instrument
has been supplied with a glass saccharometer, testing-glass, and slide-rule. Commence
by charging the testing-glass with the liquid, then insert the saccharometer, to ascertain
its present gravity or density per barrel, and at whatever number it floats, that will
indicate the number of pounds per barrel heavier than water.
Example 1.-Suppose the saccharometer to float at the figure 8, that would indicate
8 lbs. per barrel; then submit the liquid to the boling test, with the salt as before
directed, and suppose it should show (the barometrical differences being accounted for)
90oup, that would be equivalent to 10 per cent. of proof alcohol. Refer to the slide-rule,




EBULLITION ALCOHOLMETER.                                         619
and place A on the slide against 10 on the upper line of figures, and facing B on the
lower line will be 18, thus showing that 18 lbs. per barrel have been decomposed to
constitute that per centage of spirit; then, by adding the 18 lbs. to the present 8 lbs.
per barrel, the result will be 26 lbs., the original weight of the wort after leaving the
copper..Example 2.-The saccharometer marks 10 lbs. per barrel, and at the boiling point it
indicates 88-uP, equivalent to 12 gallons of proof spirit per cent.; place A against 12,
and opposite B will be 211 lbs. per barrel, when, by adding that to the 10 lbs. present,
31k lbs. will be the result.
To ascertain the relative Valiue.~-Suppose the price of the 26 lbs. beer to be 36s. per
barrel, and the 31 lbs. beer to be 40s. per barrel, to ascertain which beer will be the
cheapest, place 26 on the opposite side of the rule against 36, and opposite 31J ibs. will
be 43s. 7d., showing that the latter beer is the cheapest by 3s. 7d. per barrel.
By taking an account of the'malt liquors by this instrument prior to stocking, it
may be ascertained at any time whether any alteration has taken place in their condition, either                                     fermentation and consequent loss of saccharum, or whether by an apparent loss of both, acetous fermentation has been going
on towards the ultimate loss of the whole.
This instrument will likewise truly indicate the quantity of spirit per cent. created
in distillers' worts, whether in process of fermentation or ready for the still, the only
difference will be in the allowances on the slide-rule.
N.B.-The saccharometers applicable to the foregoing rules for beers, ales, &c., have
been adjusted at the temperature 600 Fahrenheit, and will be found correct for general purposes; but where extreme minuteness is required, the variation of temperature
must be taken into account, therefore for every 10 degrees of temperature above 60,
3 ths of a pound must be added to the gross amount found by the slide-rule; on the
contrary, for every 10 degrees below 600, -  ths of a pound must be deducted.
For cordializecd Spirits.-The operation in this instance is somewhat different from
that of beers which have the alcohol created in the original worts; whereas, in cordialized spirits, gins, &c., the alcohol is the original, and the saccharine matter, or
sugar, is an addendum.
If 100 gallons of spirit are required at a given strength, say 50 per cent. under proof,
50 gallons of proof spirit, with the addition of 50 gallons of water, would effect that
object, and upon testing it by the alcoholmeter, it would be found as correct as by the
hydrometer.  But in cordializing spirit it is different, for to the 50 gallons of proof
spirit, 50 gallons of sugar and water would be added, thereby rendering the hydrometer
useless, except for taking the specific gravity of the bulk, and, according to the quantity
of sugar present, so a relative quantity of water must have been displaced; and as the
sugar has no reducing properties, the alcoholmeter will only show the strength of the
cordial in relation to the water contained in it, as the principle indicates, irrespectively
of saccharine or extractive matter present.
Suppose, in making 100 gallons of cordial at 50-uP, 3 lbs. of sugar are put to the
gallon, or 300 lbs. to the 100 gallons, that 300 lbs., displacing 18I-Jth gallons of water,
only 31-33th gallons of water instead of 50 have been applied; the sugar, without
reducing properties, making up the bulk of 100 gallons, which is meant to represent
50 per cent. uP.
The alcoholmeter will only show at the full point of ebullition the alcoholic strength
in relation to the water in the 100 gallons of the mixture, or 35 per cent. up, leaving 15
per cent. to be accounted for on the bulk.
As the quantity of sugar present must be determined before that per centage can be
arrived at, a double object will be effected by so doing, namely, eliciting in all instances
the quantity of sugar present, as well as the per centage of spirit to be accounted for.
Example.~-In taking the sp. gr. of a cordial, suppose it to be found 1076, then
submit the liquid to the boiling point, and having ascertained the per centage of alcohol, and it proves to be 35-uP, the sp. gr. of alcohol at that strength will be found to be
956; deduct 956 from the sp. gr. of the bulk, or 1076, and 120 will remain; refer that
to its amount on the head line of table No. 2, namely, 120, under which will be found
3, representing 3 lbs. of sugar to the gallon; and by running the eye down its column
to opposite the alcoholic strength indicated (35 up) will be found 14-9, which represents
the per centage of water displaced by the sugar, and which amount of 14-9, added to
the 35 per cent. ascertained, makes the total upon the bulk 49-9 per cent.-P, with 3 lbs.
of sugar to the gallon.
For Gins, &c.-Example 3.  In taking the sp. gr., suppose it to be found 957; then
submit to the boiling point, and it proves to be 14-uP, whose sp. gr. is 937, which,
deducted from 957, leaves sp. gr. 20; on the head-line of table No. 2, under 20, will
be found j, or j lb. of sugar to the gallon, and on running the eye down to opposite




620                                      ELAINE.
14-u, will be found 3-0, which, added to the 14, makes the total on the bulk 17 per
cent-up, with 60 lbs of sugar to the 100 gallons.
To chemists for their tinctures, &c., this instrument will be found essentially useful.'-N.B.-Care must be taken that the mercury is entirely in the bulb of the thermometer before it is fixed on the stem for operation, and in all cases (except for water)
the salt must be used.
Conclusion.-Wines are peculiarly subject to be mystified by adulterations of various
kinds. It will prove of great advantage to the public when the relative quantity of
fruit, or saccharum, and alcohol requisite to constitute the normal wine of each species
is well ascertained.
Some beers possess a remarkable narcotic power, by which they cause drowsiness
and stupor without corresponding previous exhilaration. Such beverages may justly
be suspected of having been sophisticated with occulus indicus, opium, or some analogous drug; and this suspicion may become certainty, if they be shown by the alcoholmeter to contain only a few per cents. of fermented spirit.
IThe instrument in its complete state is made and sold by Mr. Joseph Long, Little
Tower Street. The tables, of which the above is only a portion, and the barometric
indicator, have been constructed by him and Mr. Atlee.. EDGE TOOLS.  Mr. James Bouydell welds iron and steel together in such a manner that when cut up to form edge tools, the steel will constitute a thin layer to form
the cutting edge. He piles a slab or plate of steel upon two or more similar plates
of iron, heats in a furnace to a good welding heat, and then passes between grooved
or other suitable rollers, to convert it into bars; the steel being in a thin layer either on
one of the outer surfaces of the bar, or between two surfaces of iron according to the
kind of tool to be made therefrom. The bars thus produced are cut up and manufactured into the shape of the desired articles by forging. If the cutting edge is to extend
but a short distance, the steel is applied only near one edge of the pile. In this manner hatchets, adzes, choppers, knives of all kinds, scissors, scythes, chisels, gouges, &c.,
may be economically manufactured; the steel being used merely for forming the edge,
while the requisite stiffness of the tools is obtained by the iron. The compound bars
which have the steel on one side are suitable for chisels and other tools, which have a
cutting edge on one side, the iron being ground away when making or sharpening the
tool.  Mr. B. manufactures spades on a somewhat similar plan.-Newton's Journal,
vol. xxvi. p. 183.  See CUTLERY and STEEL.
EDULCORATE, (Edulcorer, Fr.; Aussissen, Germ.) is a word introduced by the
alchemists to signify the sweetening, or rather rendering insipid, of acrimonious pulverulent substances, by copious ablutions with water. It means, in modern language,
the washing away of all particles soluble in water, by agitation, or trituration with this
fluid, and subsequent decantation or filtration.
EFFERVESCENCE.  (Eng. and Fr.; Aufbrausen, Germ.)  When gaseous matter is
suddenly extricated with a hissing sound during a chemical mixture, or by the application of a chemical solvent to a solid, the phenomenon, from its resemblance to that
of simmering or boiling water, is called effervescence. The most familiar example is
afforded in the solution of sodiac powders; in which the carbonic acid gas of sesquicarbonate of soda is extricated by the action of citric or tartaric acid.
EFFLORESCENCE, (Eng. and Fr.; Verwittern, Germ.) is the spontaneous conversion
of a solid, usually crystalline, into a powder, in consequence either of the abstraction
of the combined water by the air, as happens to the crystals of sulphate and carbonate
of soda; or by the absorption of oxygen and the formation of a saline compound, as in
the case of alum schist, and iron pyrites. Saltpetre appears as an efflorescence upon
the ground and walls in many situations.
EGGS, HATCHING.  See INCUBATION, ARTIFICIAL.
EIDER DOWN, is a kind of precious down, so called because it is obtained from
the Eider-duck.  These birds build their nests among precipitous rocks, and the female
lines them with fine feathers plucked from her breast, among which she lays her five
eggs.  The natives of the districts frequented by the eider-ducks let themselves down
by cords among the dangerous cliffs, to collect the downs from the nests. It is used
to fill coverlets, pillows, cushions, &c.
ELAINE is the name given by Chevreul to the thin oil, which may be expelled
from tallow, and other fats, solid or fluid, by pressure either in -their natural state or
after being saponified, so as to harden the stearine. It may be extracted also by digesting the fat in 7 or 8 times its weight of boiling alcohol, spec. gray. 0798, till it dissolves
the whole.  Upon cooling the solution, the stearine falls to the bottom, while the elaine
collects in a layer like olive oil, upon the surface of the supernatant solution reduced
by evaporation to one eighth of its bulk. If this elaine be now exposed to a cold temperature, it will deposit its remaining stearine, and become pure. See FAT, OILs, and
STEARINE.




ELASTIC BANDS.                                   621
ELASTIC BANDS. (Tissus Elastiques, Fr.; Federharz-zeige, Germ.)  The manu
facture of braces and garters, with threads of caoutchouc, either naked or covered
seems to have originated, some time ago, in Vienna, whence it was a few years since
imported into Paris, and thence into this country. At first the pear-shaped bottle of
Indian rubber was cut into long narrow  strips by the scissors; a single opertive
turning off only about 100 yards in a day, by cutting the pear in a spiral direction. He
succeeded next in separating with a pair of pincers the several layers of which the bottle
was composed..  Another mode of obtaining fine threads was to cut them out of a bottle
which had been rendered thin by inflation with a forcing pump. All these operations
are facilitated by previously steeping the caoutchouc in boiling water, in its moderately
inflated state. More recently, machines have been successfully employed for cutting
out these filaments, but for this purpose the bottle of caoutchouc is transformed into
a disc of equal thickness in all its parts, and perfectly circular. This preliminary operation is executed as follows: 1. the bottle, softened in hot water, is squeezed between
the two plates of a press, the neck having been removed beforehand, as useless in this
point of view; 2. the bottle is then cut into two equal parts, and is allowed to consolidate by cooling before subjecting it to the cutting instrument.  When the bottle is
strong enough, and of variable thickness in its different points, each half is submitted to
powerful pressure in a very strong cylindrical mould of metal, into which a metallic
plunger descends, which forces the caoutchouc to take the form of a flat cylinder with a
circular base. The mould is plunged into hot water during the compression. A stem or
rod of iron, which goes across the hollow mould and piston, retains the latter in its place,
notwithstanding the resilience of the caoutchouc, when the mould is taken from the press.
The mould being then cooled in water, the caoutchouc is withdrawn.
The transformation of the disc of caoutchouc into fine threads is performed by two
machines; the first of which cuts it into a riband of equal thickness in its whole extent,
running in a spiral direction from the circumference to the centre; the second subdivides this riband lengthwise into several parallel filaments much narrower but equally
thick.
The following figs. 473, 474, 475, represent the machine for cutting the spiral riband.
The disc D, placed horizontally, turns round its vertical axis, so as to present it
473                                                                               474
475




622                          ELECTIVE AFFINITY.
which advances as the screw turns, and carries with it a tie i, which in its turn pushes
the disc D, carried upon a shoulder constantly toward the knife. This shoulder is
guided by two ears which slide in two grooves cut in the thickness of the table.  The
diameter of the pinion p is about one fifth of that of the wheel P; so that the arbor
A turns five times less quickly than the arbor'; and the fineness of the screw v contributes further to slacken the movement of translation of the disc.
When the disc is all cut down, the shoulder, the tie, and the nut, are brought back
to their original position by lifting the nut, which is hinged on.  The disc is fixed
upon the shoulder by means of sharp points, and an upper washer.  The shoulder and
the washer have a very small diameter, in order that the knife may, in cutting down the
disc, advance as near as possible to the centre.
The rotatory movement of the disc and its shoulder, is given by an endless screw
w, w, which governs a pinion p', provided with 10 teeth, and carried by the shaft A,
upon which the shoulder is mounted.  The arbor A' of this endless screw  receives
its motion from the first shaft A, by means of the wheels s and s' mounted upon these
shafts, and of an intermediate wheel s".  This wheel, of a diameter equal to that of
the shaft A", is intended merely to allow  this shaft to recede from the shaft A.  The
diameter of the wheel of this last shaft is to that of the two oth] ri in the ratio of 10
to 8.
Second machine for subdividing the ribands.  Fig. 476.-The riband is engaged
between the circular knives, c, c, which are mounted upon the rollers R,; thin brass
washers keep these knives apart at a distance which may be varied, and two extreme
washers mounted with screws on each roller maintain the whole system.  The axes of
these rollers traverse two uprights M, M, furnished with brasses, and with adjusting
screws to approximate them at pleasure. The axis of the lower roller carries a wheel
476
X: r~', which takes into another smaller wheel r' placed upon the same shaft as the pulley P,
which is driven by a cord.  The diameter of the wheel r is three times greater than the
wheel r.  The pulley r is twice the size of the wheel r'; and its cord passes round a
drum 1, which drives the rest of the machine.
The threads, when brought to this state of slenderness, are put successively into tubs
filled with cold water; they are next softened in hot water, and elongated as much as
possible in the following manner: -They are wound upon a reel turned quickly, while
the operative stretches the caoutchouc thread with his hand. In this way it is rendered
8 or 10 times longer. The reels when thus filled are placed during some days in a cold
apartment, where the threads become firm, and seem to change their nature.
This state of stiffness is essential for the success of the subsequent operations. The
threads are commonly covered with a sheath of silk, cotton, or linen, by a braiding machine, and are then placed as warp in a loom, in order to form a narrow web for braces,
garters, &c.  If the gum were to exercise its elasticity during this operation, the different threads would be lengthened and shortened in an irregular manner, so as to form
a puckered tissue.  It is requisite therefore to weave the threads in their rigid and inextensible, or at least incontractile condition, and after the fabric is woven to restore
to the threads of caoutchouc their appropriate elasticity.  This restoration is easily
effected by passing a hot smoothing iron over the tissue laid smoothly upon a table covered
with blanket stuff. See BRAIDING MACHINE.
ELECTIVE  AFFINITY  (Wahlverwandtschaft, Germ.) denotes the order of preference, so to speak, in which the several chemical substances choose to combine; or
really, the gradation of attractive force infused by Almighty Wisdom among the different
objects of nature, which determines perfect uniformity and identity in their compounds




ELECTRIC TELEGRAPHS.
aMidst indefinite variety        nation   The            of thiscombin 
~ B -TR.TEL ] -ist.See 1)'EOMPOSITION
o red   -teL RrH.   Jag etic Needle Telegrap       After   rste n   s
e mutual action of eleetric currents and magn ti 
asain consequen of an idea suggested to him by the i1lustr npro.
a sany cirate tsneedl here were letters of the alphabe n and to  ake
e~~~~~~~~~t employs
aseparat. needle,"
dis  0    i  of the galvanometer, followed
~    qu~~~~~~~~ ~~~~each of                             act on
el verhwefgr  inventift                             more recently by'Wheatstone's
e eocit of electricity, gave renewe d impulse to these 
i        trated Ampere's idea on a small sa          b a
~~~~~eaeis hch   e....."e"';           a small scale, b  rate wit
Of Pontid Out the  ificulties which enveloped it than to..'t  a view
noses.   redl de spported  a ph  had thirty galvano.. propose it for pact
ses. AP t        dlegray s.metri needles and thirtyon
Pedac  nelete   fprsd    a screen which it carried with i    deflected and thus x
P o s e d ~~~~~~~~~~~ ~ a   wedfle tt e rdDa f
Baro' firs telegraph was of the same chara t
needles   Schelling and Fechner Proposed to limit this numbr b yem
Ing fewer needlesand observing their combined motions,  difsenthaer being
indicat ~ ~    ~uedln accordng   to - - -  -ln          d   eesame characrer      en
nnia  to the number of needles in   ti
Mr. Bain haspropodsed  to rdini ters; Were.
oso  to fix thre magnet and deflect tle  il
nedehtt  neos needle telegraph are  that I  h
ofele;the  t two needles outro thsaways incued   wtha henha onernemach
ndse thus alw s iAuded in the circuit thatthe o     ri
thatbya  keyb peculive, whlic  he generally used, will  oduce 20 signals and
formed.   Y    n             his   nrivanee, these  several cicuts can be readily
e    rfou, needles 200 ignal  can be gi.
ofl ath e   ftedtion)   ange ed leawas   not   of  itself  sufliciently    violent   to    ring   a bell   i
ge      was made  that one of the needles by its dein  o ud
on accou   of the difficulties which attended  the  early expe  t o   e 
p resently describe.  As it is not  t;
a   itryof telegraph8, thep aboveetin illus                                    er
will above illstrations of the chief applications of the galvan.
pllpsewl sufflce.
C       The instruments to be first dec'    e   r  h   neto   ogv
Cooke and Charles Wheat       desribed  are  the  inventions of Messrs.   o
stn,  *R S-   They  are of  two  kinds:  the    W.i tegl
t w o   k i n d s:   a   o n e,   i n   W h i c h   a
40




624                           ELECTRIC TELEGRAPHS.
single galvanometer is employed; the other, in which there is a pair of galvanometers.
The former will serve our present purpose, as the mechanical adjustments of the latter
are merely the double of this. I have removed the case fromthe instrument in order
to give a clear view of all the essential parts; and have engraved a back view of it (fig.
477) with the battery E attached as if for use; and the circuit of the galvanometerA
completed by the wire w w.
"The instrument is possessed of a two-fold character; it is passive, or ready for
receiving signals from another instrument; it is active, or ready for transmitting signals
to another instrument. By describing first how it is fitted for receiving signals, and
then how it is arranged for transmitting them, we shall be better able conveniently to
analyze it, and to comprehend its general structure.  The frame of the coil  is of brass
or (which is in many respects better) of polished wood or of ivory; it is screwed upon
the face of the instrument, which face is a brass plate varnished on the inner side.
Looking at the coil, a short wire from its right-hand end comes to a screw terminal,
which latter, by a slip of brass neatly laid on the instrument case, is connected with
another terminal u. The left-hand end of the coil comes also to a terminal, from which
a slip of brass descends to a brass plate here, partly hidden; but its form may be gathered
from a similar plate, visible on the left side. These twin plates are in metallic connection by means of the two upright springs, plainly shown in the drawing. The springs
are of stout steel, and press strongly on two points in a short insulated brass rod n, which
is screwed in the wooden framework of the instrument. The left-hand plate is connected with the terminal D, also by a slip of brass.  If now, the two terminals u and 
are connected by a wire w w, the circuit will be complete, as follows: from the terminal
u into the coil at the right-hand side; out of the coil, at the left-side downwards to the
right-hand plate; up the right-hand steel spring, across the brass rod n to the left-hand
steel spring; downward by this spring to the left-hand plate, thence by the slip of
brass to the terminal D, and thence by the wire w w the terminal u, whence we started.
If now the wire from  u went up the line of railway, and the wire from Ddown the
line, and the circuit were in some way kept complete on the large scale, as it has been
here described on the small scale, any electric current passing along the wire from a
distant station, would traverse this coil in its course, would deflect the needle, and so
make a signal. I should here mention that for the sake of regularity, we adopt one
unvaried order in attaching wires to the instrument; it is to put the up wire on the
terminal, shown by u on the figure, the coils being all uniformly wound.
"So far for receiving a signal-now for sending one. Were we to go out on the
open railway, taking with us a battery, and to cut any one of the wires, and place its
two ends, thus obtained, upon the two terminal ends of the battery, a current would
pass along the line, and the needles on that wire would be deflected; and if we changed
hands so as to reverse the connections, the deflections of the needle would be reversed.
The same would happen were we to cut a wire inside the office, or inside the telegraph, and to treat it in a similar way. Now, in every apparatus contrived for transmitting signals, we have a place corresponding to such a cut wire; and near this place
are the poles of the battery, mounted and moveable, so that they may be readily
applied in the breach, one way or other as required. The place here (fig. 47i7) is the
top of the springs. They are not joined to the brass rod n; but, as I said before, press
hard upon it, and can readily be raised with the finger, or otherwise. It is obvious
that, when either of them  is raised, the circuit is broken.  Now, near this place is a
mechanical contrivance, by which the poles of the battery may make a breach in
the circuit, and be applied in the breach in either direction. The drum B is of boxwood, the ends c and z being capped with brass, and insulated from each other by
the wood, b, left between them.  The drum  is moveable by a handle, not in sight
here, and is supported as shown in the present figure. A stout steel wire c' is screwed
beneath into the c end of the drum; and a similar z' is screwed above into the z end.
These two wires are the poles of the battery, z' being connected with the zinc end,
and c' with the copper, thus:-from the copper end of the battery a wire is led to
the terminal c; thence a slip of brass leads to a curved brass spring which presses
closely on the drum at c; from the zinc end of the battery a wire goes to the terminal
z, and thence a slip of brass leads to a similar curved spring, pressing on the continuation
of the z end of the drum, as shown in the figure. It will be seen that, whenever the
drum  is moved, the steel wire z' will lift up one or other of the upright steel springs;
it is now lifting up the right-hand one, and so breaks the circuit; but, by a little further
motion of the drum, the wire c' will press upon the boss below, as shown in the figure,
and thus there will be a battery pole on each side of the breach, and a signal will be
made on  this, and on  all instruments connected with it.  And, from  the peculiar
arrangement with the drum, the motion can be changed as rapidly as the hand can
move.  I have shown the battery connections exactly as they occur in practice; and
the connections are such that, if the right-hand springs are moved off, the needle moves
to 0-v right, and, if the left, to the left.  The needle on the face of the instrument always




ELECTRIC TELEGRAPHS.                                       625
has its north end upward, and the needle within the coil its north end downward, so
that if we look at the face of an instrument, and see the top end of the needle move to
tIie right, we may be sure that in the half of the coil nearest to us the current is ascending"
Thus the wires are the channels through which electric influences, are conveyed to
great distances with inconceivable velocity, and the moveable magnets, or galvanometers,
to which the wires are attached at the stations, are the parts of the apparatus by
which signals are made. The mode of interpreting these signals is thus described by
the author:" DOUBLE-NEEDLE CODE.-Having described the apparatus and means employed for
producing at pleasure the transmission of signals to distant places, it now remains to
us to explain the manner of interpreting these signals, so that each person shall understand the ideas the other would convey.
" We have to describe how, out of only two needles, each of which has but two
movements, the telegraph alphabet is formed. On the face of the instrument are the
letters of the alphabet arranged, as it will be seen, seriatim in two lines, beginning at
the left, and ending at the right, as iti writing. The commencing series from A to P
is above the top end of the needles; and the concluding series from R to Y below the
bottom end. It will also be seen that some letters are engraved once, some twice, and
others three times. To make a letter engraved once, requires one motion of the needle;
to make one engraved twice, two motions of the needle; and to make one engraved three
times, three motions. In respect to the UPPER row, the needle nearest to the letter is
moved, and it is moved so as to point toward the letter.  In respect to theLOWERrow,
both needles are moved, and their lower end is made to point in the direction of the
letter required.  Six of the letters C, D, L, M, and U, V, require a twofold motion
of tlhe needle or needles, first to the right then to the left for C, L, and U, and first to
the left then to the right for D, M, and V. These six letters are engraved intermediate,
and with a double row between.  The alphabet produced by this arrangement is of a
simple character, and is very readily acquired. To the stranger it appears confused;
but when he has the key to it the difficulty disappears; it might at first sight appear
that a dial instrument-a telegraph, that is, provided with alphabets engraved on a
circulr dial, and an index made to revolve, and point to any required letter, is more
simple; several such telegraphs exist; and among them are some very happily arranged;
and there is something so simple in the fact of being able to point to any desired letter,
that it is no wonder the public generally may, on a hasty glance, and before studying
the practical merits of the case, be ready to decide in their favor, and prefer them to
any other plan, the A, B, C of which is less obvious.
"But is it such a very serious matter to learn another alphabet? Every schoolboy, now-a-days, knows some half-dozen alphabets; there are ROMAN letters large,
and ROMAN letters small; MANUSCRIPT letters large, and manuscript letters small;
Oll JSUnlisl large, and Old English small; GREEK large, and Greek small, and so on,
and all different, and not one of them in which the letters are represented by so few
strokes of the pen as are the telegraph letters by beats of the needle. Take one of our
plainest alphabets as an example; the ROMAN  CAPITALS, for instance, and place
a few of them in juxta-position with the corresponding telegraph signals:A       \\            E          /          G        /I
B       \\\           F        //           H        \
"The simplicity of these symbols is obvious. Two diagonal and one horizontal
line are required for the Roman A; two diagonal lines for the telegraph A; one
vertical and three horizontal lines make the Roman E; one diagonal the telegraph E,
and so on; the difference being that all the world have learned the Roman alphabet,
and only a chosen few have studied the telegraphic symbols. That the latter really
are simple and distinctive: that they are full of meaning and very legible; that they
are applicable to ordinary language, and good, ay, very good I no one will for a moment
doubt, who has seen the rapidity and accuracy with which a telegraph officer receives
a dispatch.
"To one who sees a telegraph in operation for the first time, the effect borders on
the marvellous; setting out of the question the fact that the needles are caused to
move by an individual perhaps a hundred miles off; the motion of the needles hither
and thither; quicker than the untrained eye can follow; the want of all apparent order
and rule in their movement; the ringing of the changes between one and the other,
and both; the quiet manner in which the clerk points his needle to the letter E, in
rapid intervals, implying that he understands the word; while, to the uninitiated
looker-on, all is wonder and mystery, and confusion; and the rare occurrence of the
clerk pointing to +^  implying he did not understand; and, finally, the quiet manner
with which the clerk tells you, very coolly, as the result of his operations, "That the
very pretty girl, with bright blue eyes and long curls, has sailed for Boulogne in the
Princess Clementine, now leaving Folkstone Harbor; and that she is accompanied by




626                         ELECTRIC TELEGRAPHS.
the tall, handsome man, with the dark moustache and military cloak.' As he tells you
this, and says,'Message and answer, forty words two rates at 10s. 6d., one guinea,
porterage a shilling-one pound two.'  If you happen to be the papa of the pair of
blue eyes, you are bewildered, and wish you were an electric current, and could be
sent after them."-From Electric Telegraph Manipulation, by C. V. Walker.
An invention  apparently very simple and comprehensive for electro-telegraphic
correspondence, was made the subject of a patent in February, 1851, in Newton's
Journal. It consists in the use of such parts or arrangements of apparatus as will
allow two or more persons, by the agency of electricity, to send or receive signals or
intelligence by one common wire of communication or main conductor, whilst the
rapidity or closeness in the order of succession of the signals, consequent on the indefinite short time the main conductor is in actual use in conveying the electric current
for transferring the signal shall be such, that all the persons so employed in these
telegraphic operations can be continually and simultaneously occupied, in like manner
as if each one of them had a distinct wire of communication all the time waiting for
or appropriated to his particular use. By this invention the same practical telegraphic
results are obtained, through agency of the one wire or main conductor, as, in the
varieties of the electric telegraph before known or used, would require several distinct
wires of communication.  According to this improved plan of working, the wire of
communication or electric conductor may be considered as a public word road, or an
omnitelegraphic way; whereas, in contradistinction, the conductor, as heretofore used,
may be considered a private word road, or a unitelegraphic way. In addition to the
ability of allowing divers parties simultaneously to telegraph at will either all in the same
or in contrary directions, over or along one wire of communication, this improvement
enables each one of the operators, so employed, to have and to use as many distinct
short wires or accessory conductors, all related to the main conductor, as the operators
may desire to have separate signals; whereby the facility of making and receiving or
recording signals or intelligence is greatly increased. Thus, for example,-suppose ten
men at each end of the wire of communication are all using the same wire of communication which connects the distant places, their practical telegraphic facilities would be
greater than could be had by the old system, if these twenty men had twenty different
wires of communication in place of only one such wire; and would be as great as could
be had by the old system, if each of those twenty men had as many such wires as they
might desire to make or receive different signals.  Thus, supposing twenty-five signals to
be made and twenty-five to be received, for each of these twenty men, 1,000 separate wires
or main conductors would be required, in order to accomplish what, by the new system,
requires only one such main conductor, aided by 1,000 short wires or accessory conductors, or signal-making and signal-receiving wires, which need be of but a few inches in
length severally, or so long as to reach to, or be systematically put into, electric relation
with the respective ends of the main conductor or wire of communication; or, otherwise
by motion be successively brought into electric communication with, and so momentarily
forming in succession, portions of the conductor, by which the electric current, circuit,
or line of inductive action is established, maintained, or broken, from time to time. It
may be stated that this improvement rests upon taking advantage of the circumstance
that, practically speaking, no sensible portion of the time employed in working the
telegraph is expended in the actual transmission of the electric influence, which is the
medium or agent of the communication, but that is due to the operation of making or
recording the signals. One wire, reaching between the distant places, is therefore capable
of being the instrument of transmitting an indefinite number of different signals in a second of time, provided that suitable adaptations are made to enable so many different signals to be separately placed upon one end of the main conductor, and received or recorded
at the other end of the conductor, in an intelligible manner. There are an indefinite number of methods of applying to practice this improvement, differing more or less in kinds
of apparatus used, and in modifications of electrical actions applied. But all are substantially the same improvement; inasmuch as their action would be to set apart distinct
and small and successive fractions of a second or other period, and assign and apply
such small fractions of time to different uses or for different persons; so that, although
many persons should all simultaneously be employed in using one common wire of communication, yet all the signals so transmitted by it may be successive; the rapidity of the
electric conduction admitting, by this invention, the divers signals to be transmitted
successively along the wire, and yet so quickly the one after the other, as to give a like
practical result, as if they were simultaneously transmitted by separate wires or main
conductors.  A  convenient mode of applying this improvement to practice, and for
illustrating the principle of the invention, may be understood by referring to the diagram
(fig. 478), wherein two pendulums, supposed to be actuated by clock work or other
suitable means, are indicated; such pendulums being made to vibrate as nearly as
possible together in position and in time of vibration. At the chief station A, the




ELECTRIC TELEGRAPHS.                                         627
standard pendulum  is situate; and the dependent telegraph station is also provided
with a pendulum, as at B.  D, D are the pendulum  rods, with these balls or weights;
E, tlhe prolonged end of the pendulum rods, which should be much longer in proportion
than represented in the drawing; F, slight springs, united to the prolonged end of the
C    Z                     C
A                                        T
D   "'        478
e It 
I L
L f  ^         -^    I'
pendulum rods; and p,, p, and, s, p, are two grooves or pathways, so made that the
pring F shall fall into the groove P,, P, when the pendulum makes the vibration from
left to right, and shall fall into the groove P, s, P, when making the vibration from right
to left; c, c, is the main conductor or wire of communication, connecting the two telegraphic stations A and B together; x, x, are ground plates and ground wires. At station
A, there are metallic points over which the spring F passes, touching the surface each
vibration,-which points are connected with the conductors L, x. The groove P, B, P,
at station B, is of metal, and in electric communication with L and x. The spring F, in
moving in either of the grooves P, P, P, or in the p, s, P, of station A, is kept in its path by
an insulated or non-conducting guide; z is a Leyden jar, prime conductor of an electrical
machine, or galvanic pile, kept constantly charged, or capable of giving a great number
of visible sparks or electric pulsations per second, on making or breaking the electric
circuit or line of inductive action. The wire c, c, c, has a metallic connection with the
upper end of the pendulum rods, which are also metallic as well as their prolonged terminations. In this condition of things, whenever the spring F, at station A, passes over
x, K, in its vibrations, there will be an electric communication or circuit from z to Y,
through L,, x, to the ground at station A; also from z to the metallic groove P, P, p, at
station B, and to the ground there; provided the pendulum at station B is making its
vibration from left to right, when the pendulum at station A carries its spring F over
the conducting point R. At K on the left-hand side of the standard pendulum, there are
two metallic faces near together; by this arrangement it can be known at station a when
the pendulum at station A is in motion, and the position of its vibrations exactly determined; so that the pendulum at B can be from time to time set in motion, accelerated
or retarded, in order to maintain that degree of synchronism in the action of the pendulums, and similarity of position, which are necessary for success of the telegraphic operations.  When the pendulum at B is correctly timed in its motions, there will be visible
two sparks on the left-hand side, and one spark on the right-hand side, of the conducting groove at K, K, at station a, equal distance from the centre of vibration; but when
this pendulum is not in its proper position or motion, these sparks can be seen at other
places along the groove.  Hi  and H2, at both stations are signal-making wires; and
G1, 02, at both stations, are signal-receiving wires. These signal wires are to be supposed as numerous in each set as the number of different signals desired to be usedsay not less than the letters of the alphabet; a smaller number is, however, shown
in  the drawing for distinctness' sake.  All the signal-receiving wires reach  into
the groove or pathways P, s, P, in  such  a manner, that the spring F shall touch
and slide over the flattened faces or ends of these wires in succession each time
the pendulum  moves from  right to left.  The signal-making wires on the contrary,




628                                ELECTRO-GILDING.
stand a little off, out of the groove or pathway, but are intended to be so mounted that
each may be raised with the pressure of the finger, and brought into the line of the
groove or pathway, to be touched by the springF, when the pendulum  swings Trom
left to right. All these signal wires are united by one end to the conductor, a, but
are free and independent at the other end. The free end of the signal-receiving wires
may have a width of half an inch, more or less, where F passes over them. The corresponding ends of the signal-making wires may be put on edge or line; so that the
signal-making wires can be touched by F but for a moment, whilst the signal-receiving
wires will be touched for a sensible time byF, in passing over them.
Under these circumstances, if any one of the signal-making wires Hi, at station A, be
touched and brought into contact with the end F, of the vibrating pendulum, a conducting circuit or electric current will be established for the moment, the corresponding pendulum  at station B will be in front of the group of signal-receiving wires l of
that station. Therefore, from the electric circuit existing for that moment of contact,
there would be a spark visible upon the flattened end of that one of the signal-receiving
wires which corresponds to that one of the signal-making wires at the other station, which
may have been pressed upon and brought into the pathway of; all these signal wires
in each set being marked by and signifying the different letters of the alphabet, &c.
It is obvious, that if the left-hand wire of each set be marked a, the next b, next e, &c.,
then, should a, b, or c, of a signal-making group i, station A, be   ressed upon and
touched by F, this act will be known at station, by the appearance of a spark on the
end of that one of the signal-receiving wires a, b, or c, of group I station B, corresponding to that wire which may have been so touched at stationA.  Thus, at will, can any
signal or letter be sent from station A to station B, and during the operation of signalmaking, by one person at station A, to another at station B. It will now be seen that
another person, or the same person at station B, by the use of the wires ui, can telegraph
in reply to station A, by making use of the set of wires I of each station, in a manner
similar to those in which the wires Il, before described, were used. Suppose that the
time of a double vibration of these pendulums is equal to the time necessary for conveniently making and observing a signal, then, by the use of the four sets of signal
wires above named, a person may send to or receive signals from or between stations
A and B reciprocally; or four persons may be continually and simultaneously employed
in making and receiving signals at each station. The use of these signal-wires referred
to, as able to employ four persons in continual telegraphic intercourses, will in no
way interfere with the simultaneous employment of two or four other operators using
the other signal wires on the right-hand half of the vibrations marked a2 and 02; so
also by lengthening out the ends of the pendulum rods, or increasing the angular motion of the pendulums, more space or places may be had for carrying out a larger number of telegraphic operations indefinitely.
It has been said that the pendulum at station B may be kept adjusted to the motions
of the regulating pendulum, by the appearance of sparks at K, K; but this synchronism
may be more. perfectly maintained by using any of the known forms of electro-magnets.
In the above illustration the electric spark from an electrical machine has for simplicity
been chosen as the visible signal; but should it be desired to make signals by the
hydro-electric current and the deflection of a needle, then each one of the signal-receiving wires, before uniting with the common conductor L, may be lengthened out sufficiently to form the coil of a galvanometer; and the current passing through any one
of these wires can make itself known, or a signal be so given, by the deflection of the
needle of the galvanometer belonging to that particular signal-receiving wire so signalized; or, in like manner, those prolonged signal-receiving wires may each one enclose
a bar of iron, in place of a magnetic needle, so as to have an electro-magnet and keeper
belonging to each one of these wires; then the passage of the current through any of
the wires may give magnetism to the bar, or actuate the magnet or its keeper; and
from this motion the signals may be perceived, or recorded and printed in any convenient form. From the above explanations, it will be obvious that divers stations and
complex systems of telegraphic lines of communications can be established on the principle of this invention; and it will be also understood, that the invention is susceptible
of an indefinite number of modifications or forms, as respects the apparatus employed
in carrying it into use. The patentee claims, rendering available conducting power of
electric telegraph wires, so that they may transmit one or more electric currents (in the
same or opposite directions) during the time that must necessarily elapse between the
transmission of succeeding signals which have reference to one and the same communication.-Newton's Journal, xl. 36.
ELECTRO-GILDING  AND   SILVERING.   According  to Le Docteur  Philipp,
the vessel required for this purpose should be made of the same material as that
commonly employed for flower-pots: before being used it must be tested in the following manner: On being filled with water, if it becomes simply damp, without allowing
the water to filter through it, it is fit for use, but not otherwise. This vessel is sur



ELECTRO-METALLURGY.                                      629
rounded by a cylinder of zinc, and then introduced into another vessel (a wooden tub
for instance) containing dilute sulphuric acid. The earthen vessel is intended to contain he solution of gold or silver, and is furnished with a web of copper wire, which
is made to communicate with the zinc by means of one or more conducting wires. The
objects to be gilt or silvered are placed upon the net-work. The earthen vessel containing a zinc cylinder, and some hydrochloric acid, is introduced into another vessel, containing the solution of gold or silver, placed in the centre of a wire web partition,
which communicates with the zinc cylinder by means of a conducting wire.  In the
first case, the articles which are to receive the thickest coating are placed nearest the
outer sides of the apparatus; in the second, nearest to the earthen vessel: in both cases
it is advisable to shift their position occasionally. By combining these different
arrangements, the deposit obtained is more abundant, and more equally distributed
upon the surface to be gilded or to be silvered. For this purpose an opening is made
in the centre of the web in which the zinc cylinder is inserted, with connecting wires
to the web.  When the articles to be operated upon can be easily suspended from  a
given point, the web of the apparatus may be made with wider meshes, and the articles
suspended vertically between them. Dr. Philipp prefers a single galvanic arrangement
to a battery, as it affords more solid deposition.
ELECTRO-METALLURGY.  By this elegant art perfectly exact copies of any
object can be made in copper, silver, gold, and some other metals, through the agency
of voltaic electricity. The earliest application of this kind seems to have been practised about 16 years ago, by Mr. Bessemer, of Camden Town, London, who deposited
a coating of copper on lead castings, so as to produce antique heads in relief, about 3
or 4 inches in size. He contented himself with forming a few such ornaments for his
mantelpiece; and though he made no secret of his purpose, he published nothing upon
the subject. A letter of the 22d of May, 1839, written by Mr. J. C. Jordan, which appeared in the Mechanics' Mag. for June 8, following, contains the first printed notice of the
manipulation requisite for obtaining electro-metallic casts; and to this gentleman, therefore, the world is indebted for the first discovery of this new and important application
of science to the uses of life. It appears that Mr. Jordan had made his experiments in
the preceding summer, and having become otherwise busily occupied, did not think of
ublishing till he observed a vague statement in the Journals, that Professor Jacobi, of
it. Petersburg, had done something of the same kind.  Mr. Jordan's apparatus consisted
of a glass tube closed at one extremity with a plug of plaster of Paris, and nearly filled
with a solution of sulphate of copper. This tube, and its contents, were immersed in
a solution of common salt. A plate of copper was plunged in the cupreous solution,
and was connected by means of a wire and solder, with a zinc plate dipped in the
brine. A  slow  electric action was thus established through the moist plaster, and
copper was deposited on the metal in a thin plate, corresponding to the former in
smoothness and polish; so that when he used an engraved metal matrix, he obtained
an impression of it by this electric agency. " On detaching the precipitated metal,"
says he, " the most delicate and superficial markings, from the fine particles of powder
used in polishing to the deeper touches of a needle or graver, exhibited their correspondent impressions in relief with great fidelity. It is, therefore, evident that this
principle will admit of improvement, and that casts and moulds may be obtained
from any form of copper. This rendered it probable that impressions might be obtained
from those other metals having an electro-negative relation to the zinc plate of the
battery. With this view a common printing type was substituted for the copper-plate,
and treated in the same manner. This, also, was successful; the reduced copper
coated that portion of the type immersed in the solution. This, when removed, was
found to be a perfect matrix, and might be employed for the purpose of casting, where
time is not an object.  Casts may probably be obtained from  a plaster surface surrounding a plate of copper, &c."
On the 12th of September following the above publication, Mr. Thomas Spencer
read a paper " On Voltaic Electricity applied to the purpose of working in Metal,"
before the Polytechnic Society of Liverpool; which he had intended to present to the
British Association at Birmingham in the preceding August, but not being well received
there, he exhibited merely some electro-metallic casts which he had prepared. The
society published Mr. Spencer's paper, and thereby served to give rapid diffusion to the
practice of electro-metallurgy.
One of the most successful cultivators of this art has been Mr. C. V. Walker,
secretary to the London Electrical Society. He has published an ingenious little work
in two parts, entitled Electrotype Manipulation, where he presents, in a lucid manner,
the theory and practice of working in metals, by precipitating them from their solutions
through the agency of voltaic electricity. His first part is devoted to the explanation
of principles, to the preparation of moulds, to the description of the voltaic apparatus
to be used, to bronzing, to coating busts with copper, to the multiplication of engraved
plates, and to the deposition of other metals.




630                        ELECTRO-METALLURGY.
Fig. 479. represents a single-cell voltaic apparatus for electro-metallurgy. z is
479      a rod of amalgamated zinc, m is the mould on which the metal
is to be deposited; w, is the wire joining them; cisa strong
^     solution of sulphate of copper in the. large vessel; p, is a tube
or cylinder of porous earthenware, standing in the other, and
--       containing dilute sulphuric acid. The solution of blue vitriol is
kept saturated, during the progress of its depositing copper, by
[    piling crystals of the salt upon the shelf, shown by the dots under p.
_     The mould to be coated should not be too small in reference to
the surface of zinc under voltaic action. The time for the depoc     sition to be effected depends upon the temperature; and is less the
H  X   higher this is within certain limits; and at a freezing temperature
it ceases almost entirely. When a mould of fusible metal is used,
U     it should not be placed in the voltaic apparatus till everything
-    is arranged, otherwise oxide will be deposited upon it, and spoil
the effect. When the circuit is completed the mould may be im.
mersed, but not before. Wax moulds are rendered electric conductors, and thereby depositors as follows: After breathing on
the wax, rub its surface with a soft brush dipped in plumbago; breathing and
rubbing alternately till the surface be uniformly covered. Attach a clean wire
to the back of the mould, connecting it by plumbago with the blackened wax.
Sealing-wax is coated in like manner.  Casts of Paris plaster are first well imbued with melted wax or tallow, and then black-leaded.  Objects in Paris plaster
should be thoroughly penetrated with hot water, but not wet on the surface,
before wax casts are made from them. Moulds are best taken from medals in stearine
(stearic acid). For plating and gilding by electro-chemical agency, the following
simple plan of apparatus is used. Fig. 480, is a rectangular porcelain vessel, which
contains in its centre a porous cell for containing the solution of oxide of silver or
gold, by means of cyanide of potassium; and this porous cell is surrounded at a little
distance by a similarly formed vessel of zinc. The connexion is formed between the
zinc and the suspended object to be coated, either by a pinching screw, or by the
pressure of its weight upon the wire. The dilute acid which excites the zinc should,
in this case, be very weak, in reference to the strength of the cyanide solution, which
should be recruited occasionally by the addition of oxide.
It has been found that with cyanide solutions of gold and shyer in the electrochemical apparatus, the nascent cyanogen at the positive pole or plate, in a decomposition cell, will act upon and dissolve gold and silver. Two ot three of Daniell's
cylindric cells, as shown at a in fig. 481, of a pint size, for actiiq upon solutions of
gold or silver, will in general suffice. The decomposition cell b is made of glass or
porcelain. The zinc may be amalgamated, and excited with brine; the copper cell
contains, as usual, a solution of blue vitriol. To the end of the wire attached to the
copper cylinder of the battery, a plate of silver or gold is affixed; and to the end of
the wire attached to the zinc cylinder is affixed the mould, or surface, to be plated or gilt.
The plates of silver or gold and zinc should be placed face to face as shown in the figure
in the decomposition cell; which is filled by the cyanide solution. A  certain degree
Df heat favors the processes of electro-gilding and plating. The surface is dead as first
obtained, but it may be easily polished with leather and plate-powder, and burnished in
whole or in parts with a steel or agate tool.




ELECTRO-METALLURGY.                                     631
In March, 1840, Messrs. Elkington obtained a patent for the use of prussiate of
potash, as a solvent for the oxides of gold and silver in the electro-chemical apparatus
for plating and gilding metals. They also " sometimes employ a solution of protoxide
(purple of Cassius) in the muriates of potash, &c."  The chemical misnomers, in their
specification are very remarkable, and do great discredit to the person employed to
draw it up. Prussiate of potash is the ordinary commercial name of a salt very different
from the cyanide of potassium-the substance really meant by the patentees-and the
purple of Cassius is very different from protoxide of gold.
In plating or gilding great care must be bestowed in making the articles clean, bright,
and perfectly free from the least film of grease. For this purpose, they should be
boiled in a solution of caustic alkali, then scoured with sand and water, next dipped
into a dilute acid, and finally rinsed with water. A solution of the nitrate or cyanide
of mercury may also be used with advantage for cleaning surfaces. The following
metals have been deposited by electro-chemistry:Gold, platinum, silver, copper, zinc, nickel, antimony, bismuth, cobalt, palladium,
cadmium, lead, and tin; of these, the first five are the most important and valuable.
The gilding solution may be prepared by placing slips or sheets of gold in a solution
of cyanide of potassium, and attaching to the negative pole of a voltaic battery, a small
plate of gold, but to the positive pole a much larger one; whereby the latter combines with the cyanogen, under the influence of positive electricity, and forms a solution. Or, oxide of gold, precipitated from the chloride by magnesia, may be dissolved
in the solution of the cyanide.
For making copper medals, &c., a plate of amalgamated zinc is to be put into a
vessel of unglazed earthenware, or of any other porous substance, filled with dilute sulphuric acid; which vessel is set into a trough of glass, glazed pottery, or pitched wood,
containing blue vitriol in the state of solution, as well as in the state of crystals upon a
perforated shelf, near the surface of the liquid.
The moulds to be covered with copper are to be attached by a copper wire to the
zinc plate. The surface of zinc excited by the acid should be equal to that of the
moulds; with which view a piece of zinc, equivalent in size to the mould, should be
suspended in front of it.
For depositing copper upon iron, Messrs. Elkington use a solution of ferrocyanide
of copper in cyanide of potassium in the decomposition trough, instead of sulphate of
copper) neutralizedfrom time to time with a little caustic alkali, as in the common
practice ot making medals, &c., of copper. I should imagine that the black oxide of
copper dissolved in solution of cyanide of potassium would answer better; as the iron
in the ferrocyanide might be rather injurious. The iron to be coppered being previously
well cleaned from rust, &c., with the aid of a dilute acid, is to be plunged into the
cyanide solution heated to 1200 Fahrenheit, and connected by a wire with the negative
pole of a voltaic battery, as formerly described. In from five to ten minutes, the iron
will be completely coated. It is then to be scoured with sand, and plunged into solution
of sulphate of copper; whereby it will show black spots wherever there are any defective places. In this case, it is to be cleaned and replaced under the cyanide solution,
in the decomposition cell for a minute or two. Zinc may be deposited from a solution
of its sulphate by a like arrangement.
Metallic cloth may be made as follows:-On a plate of copper attach quite smoothly
a stout linen, cotton, or woollen cloth, and connect the plate, with the negative pole of
a voltaic battery; then immerse it in a solution of copper or other metal, connecting a
piece of the same metal as that in the solution with the positive pole; decomposition
takes place, and the separated metallic particles in their progress toward the metal
plate or negative pole, insinuate themselves into the pores of the tissue, and form a complete sheet of flexible metal. Lace is metallized by coating it with plumbago, and then
subjecting it to the electro-metallurgic process.
The gilding solution should be used in the electric process at a temperature of
1300 F. The more intense the electric power, the denser and harder is the metallic
coat deposited.
Metallic silver may be combined with cyanogen by subjecting it to the joint action
of a solution of cyanide of potassium and positive electricity. Or cyanide of silver may
be precipitated from the nitrate by a little cyanide of potassium, and afterward dissolved
by means of an excess of cyanide of potassium. The quantity of electric power or surface-size of the battery should in all cases be proportioned to the surface of the articles
to be placed or gilt, and the electric intensity or number of sets of jars proportioned to
the density of the solution. Plating is accomplished in from 4 to 6 hours. The articles
rhould be weighed before and after this operation, to ascertain how much silver they
have taken on.
Messrs. Elkington make their moulds with wax, combined with a little phosphorus,
which reduces upon their surfaces a thin film of gold or silver, from solutions of these




632                       ELECTRO-METALLURGY.
metals, which films are better than the black-leaded surfaces for receiving the copper
deposit. They also recommend to add a little alkali to the solution of sulphate of
copper, intended to afford a deposite of metal. The single cell, first described above,
is best adapted for this purpose.
M. Ruolz employs for gilding, a solution of sulphuret of gold in sulphuret of potas.
sium, which he prepares by precipitating a solution of gold in aqua regia, by sulphu.
retted hydrogen, and redissolving the precipitate with sulphuret of potassium. By
the use of this solution of gold, he obtains a very beautiful and solid gilding, and at less
expense than with cyanide of potassium. Every metal which is a negative electrode to
gold may be gilded.
Platinizing is effected best by means of a solution of the potash-chloride of platinum
in caustic potash.  1 milligramme (0'015 grain) covers completely a surface of 50
square centimeters (2 inches square); the film of platinum is only one hundredth of a
milligramme thick.
M. Bcettger has shown that we may easily tin copper and brass in the moist way by
dissolving peroxide of tin (putty) in hydrate of potash (caustic potash ley), putting at
the bottom of the vessel holding that solution some turnings of tin, setting the piece of
copper or brass upon the turnings, and making the liquor boil. An electric current is
produced by the contact of the dissimilar metals; and as the tin is withdrawn by the
copper or brass from the solution, it is restored to it by the turnings. Zinking may be
done in the same way; by putting pieces of zinc into a concentrated solution of chlorine,
by setting the piece of metal to be zinked in contact with these pieces, and applying heat
to the vessel containing the whole.
For certain new methods of constructing and arranging voltaic batteries for electrometallurgic operations, a patent was obtained by Dr. Leeson in June, 1842.
Fig. 482, is a longitudinal section of the battery, andg. 483, a plan view of the frame
to which the metal plates are attached. a is a rectangular wooden trough, containing
a wooden frame b, formed with vertical grooves in its sides, to receive a series of porous
cells c, c, c. The plates of the battery are suspended in the fluid or fluids by brass
iorks d, d, fastened to a wooden frame e, e, which rests upon the trough a, and is con.
nected to the other frame b, by two pinsf, when they are required to be raised togethe
out of the trough a, a.
The battery may be charged as usual with one or two fluids; one of them in the latter
case being contained in the porous cells c, c, c: and plates of copper and zinc, or any
other suitable metals may be employed.
The second improvement consists in cleaning copper and zinc plates after they have
been used in a battery, by the employment of a voltaic battery; and also in amalga483




ELECTROTYPIE.                                          633
mating or coating with mercury the surfaces of zinc plates, by the same means to render
them suitable for being used in the construction of the voltaic apparatus.
The third improvement consists in exciting electricity by a combination of nitric,
sulphuric, or muriatic acid, with any of the following substances; viz, impure ammoniacal or lime liquor of the gas works, solutions of alkaline and earthy sulphurets, the
alkalies and their carbonates, or lastly, the acidulous sulphate of iron generated from
iron pyrites.
Another of Dr. Leeson's manifold improvements for depositing metallic alloys consists in the employment of one battery, "with the alternating cathode," represented in
fig. 484. It is composed of a beam, a, mounted on the shaft, b, which turns in bearings
carried by standards, c; the beam communicates with the anode of the battery by the
wire, d, and a vibrating motion is given to it by the rod, e, from the shaft, f, which is
driven by an electro-magnetic engine, or any other suitable prime mover. g, g, are
two vessels containing mercury, connected by wires, h, h, with the cathode plates of
the two metals composing the alloy (but if the alloy is to consist of more than two metals,
then more vessels, g, will be required, one for each cathode plate); these plates are
immersed in a solution composed of similar salts of the different metals to be  eposited,
together with the anode, or surface to be deposited upon, which is connected by a wire
with the cathode of the battery.  A  communication is established between the two
cathode plates, or supply of metals, and the anode of the battery, by means of the rods,
i, i, which are caused, by the vibration of the beam, a, to dip alternately into either the
one or the other of the vessels, g; and thus each metal will be deposited on the article
to be coated, during the time that the connection is established between it and the battery, by the immersion of its rod into the vessel of mercury. The relative proportions
of the two metals is adjusted by lengthening or shortening the rods, i, i, as shown in
the figure, so that they may be immersed for a longer or shorter period in the mercury.
Where the electrical current enters the electrolyte, is the anode; where it leads it,
is the cathode.
The patentee describes ten other improvements, which seem to be ingenious. See
Newton's Journal, xxii. 292.
ELECTROTYPIE BY TaERMO-ELECTRICITY.  1. For silvering.-Dissolve I troy pound
of silver in nitric acid, dilute with a gallon of water, precipitate the silver by solution
of carbonate of soda (1 lib.) at 100~ Fahr.; wash the precipitate on the filter with
warm water.  In another vessel dissolve 8 libs. of hyposulphite of soda in 21 gallons
of water at 100~, add I lib. of carbonate of soda with the carbonate of silver, stirring
until the silver be dissolved. Filter the solution for use. It is advantageous to add
1 lib. avoirdupois of hyposulphite, and one-third of a pound of carbonate of soda for
every pound troy of silver that may be deposited.
2. Gold solution.-One ounce troy of fine gold is dissolved in nitro-muriatic acid, and
the solution is evaporated till it assumes a deep red color, and crystallizes upon cooling.  Dilute with a pint of pure water and filter.  Heat this solution to about 2000
Fahr., and precipitate the gold by water of ammonia.  Wash the precipitate well on
the filter with hot water. Dissolve this gold in 1 gallon of water containing 8 ounces
of hyposulphite of soda, and boil together for an hour. The solution when filtered is
fit for use.  In gilding, this solution may be warmed to about 1300 Fahr.  A  small
anode of gold, of about one-tenth the size of the article to be gilded, and a current of
two pairs of common galvanic plates, are used.
3. Copper solution.-Dissolve 1 pound of carbonate of copper in 8 pounds of hyposulphite of soda, and 1 pound of carbonate of soda dissolved in 21 gallons of distilled
water at 1000 Fahr., or thereabouts, and filtered to obtain a clear solution. It is then
fit for use, with currents of electricity at 1000 Fahr.
Description of the thermo-electric battery.-100 pieces of German silver, containing
from  20 to 25 per cent. of nickel, and 100 pieces of iron, each piece being I inch
broad, I foot long, and one-eighth of an  inch in  thickness.  These 200  pieces
are soldered to each other, so that iron is always combined with German silver.
To get a compact form, 10 rows must be first arranged (every one of 20 pieces or
10 pairs), and these rows must be so soldered to each other that they are parallel, and
the whole take the form of a square; taking care that the several pieces are soldered
together in such a way that iron will always be in connection with German silver.
When the whole is united, it is placed in a rim or frame of iron plate, I foot 2 inches
high, but so that the metals do not touch each other, nor the iron rim or frame, and fill
the rim with plaster of Paris or clay, so that all soldered parts of the series of plates
or bars are uncovered, that is, the under ends I inch, and the upper ends 3 inches.
The clay is covered at the surface with a layer of pitch.  The frame containing the
series of bars or plates, is so placed that the lower end of the series (I inch) dip into
a sand bath which is heated nearly to redness.  The upper ends (3 inches) are to




634                                         ELEMENTS.
be kept as cold as possible, and for this purpose a current of cold water is caused to
flow from one vessel over this battery to another vessel. The upper end of the metals
(3 inches) may be covered with a lac or varnish. There is an anode wire leading from
the German silver plate; and an artule wire leading from  the iron plate.
The thermo-electric apparatus is intended for the deposition of metals, from the above
described solutions.
ELEMENTS  (Eng. and Fr.; Grundstoffe, Germ.)  The ancients considered fire, air,
water, and earth, as simple substances, essential to the constitution of all terrestrial
beings.   This hypothesis, evidently  incompatible with  modern  chemical discovery,
may be supposed to correspond, however, to the four states in which matter seems to
exist; namely, 1. the unconfinable powers or fluids,-caloric, light, electricity; 2. ponderable gases, or elastic fluids; 3. liquids; 4. solids. The three elements of the alchemists, salt, earth, mercury, were, in their sense of the words, mere phantasms.
1. Equivalents.      II. Atomic Weights.    ehat ialn Lauren
Denomination of the Substances.                           __
0==100.     H==l.       0==100.     H=l.       0=100.    H==l.
Aluminium       -~-~-   Al.                170-900      13694      17-900       27-388     85-63      13-70
Antimony        -      -      -   Sb.    1612-903      129-269     806-452     129-239    403-25      64-50
Arsenicum       -      -      -   As.      938-800      75-224     469-400      75-224    468 50      75e00
Barium  -..          Ba.      855-290      68-533     855-290     137-066    425-00      6800
Bismuth -       -.      -   Bi.    1330-377      106-600    1330-377     213-200   1312-50    210e00
Boron   -       -      -      - B.         136204       10-914     136-204      21-828     67-50      10-80
Brome  -        -      -      -   Br.      999-620      80-098     499-819      80-098    500-00      80-00
Cadmium         -      -          Cd.    696-767        55-831     696-767     111-662    350-00      56-00
Calcium -       -.          Ca.      251-651      20-164     250-000      40-000    125-00      20-00
Carbon  -       -      -          C.        75-120       6-019      75-120      12-038     75-00      12-00
Cerium (Marignac)   -             Ce.      590-800      47-264     590 800      94-528      -         -
Chlorine -         -      -       Cl.      443-280      35-517     221-640      35-517    221-87      35-50
Chromium        -            -   Cr.       328-870      26-352     328-870      52-704    162-50      26-00
Cobalt  -       -             -   Co.    368.650        29-539     368-650      59-078    185-00      29-60
Copper  -       - -               Cu.    395-600        31-699     395-600      63-398    198.75     31-80
Didymium (Marignac)           -   D.       620-000      49-600     620-000      99-200      -         -
Erbium          -..   E.         -           -           -           -          -         -
Fluorine -      ~..   Fl.      235-433      18-865     117-717      18-865    116-85      18-60
Gold     -             -          Au.   2458-330       196-982    1229-165     196-982   1225-00    196-00
Glucinium       -      -          G.        87-124      6-981       87-124      13-962      -          ~
Hydrogen        -      -          H.        12-480       19000       6-240       19000      6-25      1900
Iodine   -..          1.      1585-992     127-082    792-996      127-082    787-50    126-00
Iridium  -..          Ir.     1232-080      98-724    1232-080     197-448      -         -
Iron     -                        Fe.      350-527     28-087     350-527      56-174    175-00      28-00
Lanthanium (Marignac)         -   La.      588-000      47-040     588-000      94-080      -         -
Lead    -       -      -          Pb.   1294-645       103-738    1294-645     207-476    650-00    104-00
Lithium  -         -.   Li.       81-660       6-543      81-660      13-086     40-16       6-40
Magnesium       -      -      -   Mg.    158-140        12-671     158-140      25342      75-00      12-00
Mang-anese      -      -          Mn.    344.684        27-619     344-684      55-238    175-00      28-00
Mercury -..      -   Hg.   1251-290       100-026    1250-000     200-000    625-00    100-00
Molybdenum    -        -      -   Mo.    596-100        47-764     596-100      95-528      -         -
Nickel  -.      -      -   Ni.      369-330      29-594     369-330      59-188    185-00     29-60
Niobium-.      -          Nb.              -           -           -                -         -
Nitrogen -      -      -      -   N.       175-060      14-027      87-530      14-027     87-50     14-00
Norium  -       -      -.   No.        -           -           -           -          -         -
Osmium -        -      -     -   Os.   1242-624         99-569    1242-624     199-138      -         -
Oxygen -                      -   0.       100000        89000     100.000      16-000    100-00     16-00
Palladium       -      -      -   Pd.      655.477      53-323    665-477      106-646      -         -
Pelopium        -      -      - Pe..-           -           -           -          -         -
Phosphorus    -''  P.        392-041      31.414     196-021      31-414    200-00     32-00
Platinum        -      -      -   Pt.    1232-080       98-724    12329080     197-448    618-75     99-00
Potassium       -'     - K.          488-856      39-171    488-856      78-342    243-75      39-00
Rhodium         -      -     -   R.        651-962      52-240    651-962      104-326      -         -
Ruthenium, according to Claus  Ru.    6519000           52-163    651-000     104-326       -         -
Selenium        -      -     -   Se.       495-285     39-686     495-285      79-372    490-90      78-50
Silicium -      -      -.   Si.      277-778     22-258     277-778      44-516      87-50     14-00
Silver   -      -..   Ag.    1349-660       108-146    1349-660    216-292    675-00    108-00
Sodium  -       -.      -  Na.    289-729        23-215     289-729      46-430    143-75      23-00
Sulphur -       -..  S.        200-750      16-086    200-750      32-171    200-00      32-00
Strontium              -      -   Sr.     545-929       43-744    545-929      87-488    275-00      44-00
Tantaliam       -      -      -  Ta.    1148-365        92-016    1148-365     184-032      -         -
Tellurium       -             -   Te.      801-760      64-244     801-760     128-488    800-00    128-00
Terbium -       -..  Tb.         -           -           -           -          -         ~.
Thorium -       -      -      -   Th.    743-860        59-604     743.860     119-208      -          ~
Titanium-       -             -   Ti.      301-550      24-158     301-550      48-316      -         -
Tin      -      -      -      - Sn.        735-294      58-918     735294      117-836    368-75     59-00
Tungsten        -      -      -   W.    1188-360        95-220     1885360     190-442    600-00     96-00
Uranium-        -.      -  U.        742-875      59-525     742-875     119-050    750-00    120-00
Vanadium        -         -   -   V.       856-892      68-661    856-892      137-322      -         -
Yttrium  -      -             -   Y.         -           -           -           -          -         -
Zinc     -      -      -      -   Zn.      406-591      32-579     406-591      65-158    206-25     33-00
Zirconium                         Zr.       419-728     33-632     419-728      67-264       ~ -
In modern science, theterm Element signifies merely a substance which has not yet
been resolved by analysis into any simpler form of matter; and it is therefore synonymous




EMBALMING.                                              635
with undecompounded.  This class comprehends 62 different bodies, of which no less
than 52 are metallic. Five may be styled Archceal, from the intensity and universality
of their affinities for the other bodies, which they penetrate, corrode, and apparently
consume, with the phenomena of light and heat. These 5 are chlorine, oxygen, iodine,
bromine, fluorine. Eight elements are eminently inflammable when acted upon by any
of the preceding five, and are thereby converted into incombustible compounds.  The
simple non-metallic inflammables are hydrogen, azote, sulphur, phosphorus, selenium,
carbon, boron silicon.
The preceding table exhibits all the undecompounded bodies in alphabetical order,
with their prime equivalent numbers, atomic weights, or reciprocal combining and
saturating  proportions, in  reference to  oxygen  and  hydrogen, reckoned  100,000,
or 1-0.
The numbers contained in columns I. and  II. are deduced from  those given by
Berzelius, in the fifth edition of his Lehrbuch; and in column III. those atomic weights
are added which  Gerhardt and Laurent have quoted in the first number of the fifth
volume of the Comptes Rendus.
The following is a table of atomic weights corrected and fixed by various chemists
in recent times:o          Equivalents.           Atomic Weights.
Denomination of the Substances.                               -
O=100.             H=l.       O=o00.       H=1.
Calcium (Erdmann and Marchand)-        -  Ca.       250-000e     20-000     250000       40000
Carbon           (ditto).               C.        75-000       6.000      75000       12000
Hydrogen      -          -.  H.         12-000  1000             6250        1-000
Iron (Erdmann and Marchand)            -  Fe.       350-000      23-000     250100       5600
Mercury      (ditto)..           g.    1250000      100000    1250000        200-000
Phosphorus (Pelouze) -     -        -  -  P.        400'000      32-024     200150        32024
Sodium       (ditto)          -.  Na.       287-170      22-973     287170       45046
Strontium    (ditto)  -.               Sr.      548-020      43-841     548020       87-682
Sulphur (Erdmann and Marchand) -           S.       200-000      16'000     200000        32000
Within the last few years the following atomic weights have been revised
Barium  -         -        -        -       -  Ba.   856-770 Marignac.
Calcium -         -        -       -        -  Ca.   350.000 Erdm. and March.
Chromium          -        -       -        -  Cr.    833-500 Lefort.
Chromium          -        -       -        -  Cr.    835-091 Moberg.
Fluorine          -        -        -       -  Fl.    237-500 Louyet.
Magnesium         -        -       -        -  Mg.   152-550 Jacquelain.
Magnesium         -        -       -        -  Mg.   154-490 Svanberg.
Magnesium         -        -       -        -  Mg.   150.000 March. and Scheer.
Molybdenum    -'       -        -  Mo.   574750 Berlin.
Molybdenum    -            -       -        -  Mo.   574-829 Svanb. and Struve.
Tungsten          -        -       -        -  W.  1150-780 Schneider.
ELEMI is a resin which exudes from  incisions made during dry weather through
the bark of the amyris elemifera, a tree which grows in South America and Brazil. It
comes to us in yellow, tender, transparent lumps, which readily soften by the heat of
the hand. They have a strong aromatic odor, a hot spicy taste, and contain 121 per
cent. of etherous oil. The crystalline resin of elemi has been called Elemine. It is
used in making lacquer, to give toughness to the varnish.
ELUTRIATE.   (Soutirer, Fr.; Schlemmen, Germ.)   When  an  insoluble pulverulent matter, like whitening or ground flints, is diffused through a large body of
water, and the mixture is allowed to settle for a little, the larger particles will subside.
If the supernatant liquid be now carefully decanted, or run off, with a syphon, it will
contain an impalpable powder, which-on repose will collect at the bottom, and may be
taken out to dry. This process is called elutriation.
ELVAN.  The name given  by  the Cornish miners to porphyry, as also to the
heterogeneous rocky masses which occur in the granite or in the clay slate, deranging
the direction of their metallic veins, or even the mineral strata; but elvan generally
indicates a felspar porphyry.
EMBALMING.   (Embaument, Fr.;  BEinbalsamen, Germ.)   Is  an  operation  in
which balsams (baumes, Fr.) were employed to preserve human corpses from putrefaction; whence the name.
The ancient Egyptians had recourse to this process for preserving the bodies of
numerous families, and even of the animals which they loved or worshipped.  An
excellent account of their methods is given in Mr. Pettigrew's work upon Mummies.
Modern chemistry has made us acquainted with many means of counteracting putre



636                           EMBOSSING CLOTH.
faction more simple and efficacious than the Egyptian system  of salting, smomue
spicing, and bitumenizing. See PUTREFACTION.
EMBOSSING  CLOTH. Mr. Thomas Greig, of Rose Bank, near Bury, patented
an invention, in November, 1835, which consists in an ingenious construction of machinery for both embossing and printing silk, cotton, woollen cloth, paper, and othel
fabrics, in one or more colors, at one operation.
Figs. 485, 486 represent three distinct printing cylinders of copper, or other suitable
material, A, B, c, with
485                                                     their necessary  appen^-.  y   M,  danges for printing three
L^^~"""""  _   4?i\ 3^i^/^^}1 a    D different  colors  upon
the fabric as it passes
through  the  machine
OaW/    I                either of these cylinderi
A, B, or c, may be em.
ployed as an embossing
cylinder, without  per-.^    i?^  wl   l --        forming the printingpro
cess, or may be made to
effect both operations at
the same time.
The fabric or goods
to be operated upon being first wound tightly
upon a roller, that roller
is to be mounted upon
-~- ~"  ""  an axle or pivot, bearing
in arms or brackets at
the back of the machine,
as shown at D.  From
this roller the fabric
486    a a a a is conducted between tension rails, and
passed  under the bed
cylinder or paper bowl
x, and from thence prot _____j _______                   ceeds over a carrier roller.., and over steam boxes
HI    ^  {Uy^  not shown in the draw-S_''  l      ing, or it may be conducted into a hot room,
for the purpose of drying
-         ~~~the colors.
The cylinders A, B,,
and c, having" neither engraved or raised surfaces,
ll   IH~u^^   lU~l   are connected to feeding
rollers b b b., revolving
in the ink or colored
troughs c c c; or endless   ts, called sieves, may be employed, as in ordinary printing
machines, for supplying the color, when the device on the surface of the cylinders is
raised: these cylinders may be furnished with doctors or scrapers when required, or the
same may be applied to the endless felts.
The blocks have adjustable screws g g, for the purpose of bringing the cylinders up
against the paper bowl, with any required degree of pressure: the cylinder a is supported by its gudgeons running in blocks, which blocks slide in the lower parts of the
side frames, and are connected  to perpendicular rods i, having adjustable screw
nuts.
The lower parts of these rods bear upon weighted levers k k, extending in front of the
Machine; and by increasing the weights 1 1, any degree of upward pressure -nay be given
to the cylinder B.
The color boxes or troughs c c c, carrying the feeding rollers b b b, are fixed on boards
which slide in grooves in the side frames, and the rollers are adjusted and brought into
contact with the surface of the printing cylinders by screws.
If a back cloth should be required to be introduced between the cylindrical bed or
paper bowl E, and the fabric a a a, as the ordinary felt or blanket, it may, for printing
and embossing cotton, silk, or paper, be of linen or cotton; but if woollen goods are to
be operated upon, a cap of felt, or some such material, must be bound round the paper




EMBOSSING CLOTH.                                      637
bowl, and the felt or blank-et must be used for the black cloth, which is to be conducted
over the rollers H and L
For the purpose of embossing the fabric, either of the rollers A, B, or c, may be
employed, observing that the surface of the roller must be cut, so as to leave the pattern
or device elevated for embossing velvets, plain cloths, and papers; but for woollens the
Ievice must be excavated, that is, cut in recess.
The pattern of the embossing cylinder will, by the operation, be partially marked
through the fabric on to the surface of the paper bowl E; to obliterate which marks
from the surface of the bowl, as it revolves, the iron cylinder roller G is employed; but
as. in the embossing of the same patterns on paper, a counter roller is required to
produce the pattern perfectly, the iron roller is in that case dispensed with, the impression given to the paper bowl being required to be retained on its surface until the operation is finished.
In this case the relative circumferences of the embossing cylinder, and of the paper
bowl, must be exactly proportioned to each other; that is, the circumference of the bowl
must be equal, exactly, to a given number of circumferences of the embossing cylinder,
very accurately measured, in order to preserve a perfect register or coincidence, as they
continue revolving between the pattern on the surface of the embossing cylinder, and
that indented into the surface of the paper bowl.
The axle of the paper bowl E          L, turns in brasses fitted into slots in the side frames, and
it may be raised by hand from its bearings when required, by a lever k, extending in
front. This lever is affixed to the end of a horizontal shaft L, L, crossing the machine
seen in the figures, at the back of which shaft there are two segment levers r, Pr, to which
bent rods Q, Q, are attached, having hooks at their lower ends, passed under the axle of
the bowl. At the reverse end of the shaft L, a ratchet-wheel r, is affixed, and a pall or
click mounted on the side of the frame takes into the teeth of the wheel r, and thereby
holds up the paper bowl when required.
When the iron roller G, is to be brought into operation, the vertical sci ews t,!, mounted in the upper parts of the side frames, are turned, in order to bring down the brasses N.,
which carry the axle of that roller and slide in slots in the site frames.
The cylinders A, B, and c, are represented hollow, and may be kept at any desired temperature during the operation of printing, by introducing steam into them; and under the
color boxes c, c, c, hollow chambers are also made for the same purpose. The degree of
temperature required to be given to these must depend upon the nature of the coloring
material, and of the goods operated upon. For the purpose of conducting steam to these
hollow cylinders and color boxes, pipes, as shown at v, v, v, are attached, which lead from
a steam boiler. But when either of these cylinders is employed for embossing alone, or
for embossing and printing at the same time, and particularly for some kinds of goods
where a higher temperature may be required, a red-hot heater is then introduced into the
hollow cylinder in place of steam.
If the cylinder B is -employed as the embossing cylinder, and it is not intended to
print the fabric by that cylinder simultaneously with the operation of embossing, the
feeding roller b, must be removed, and also the color box c, belonging to that cylinder; and the cylinders A and c, are to be employed for printing the fabric, the one
applying the color before the embossing is effected, the other after it. It is however
to be remarked, that if A, and c, are to print colors on the fabric, and B to emboss it,
in that case it is preferred, where the pattern would allow it. A and c, are wooden rollers having the pattern upon their surfaces, and not metal, as the embossing cylinders must
of necessity be.
It will be perceived that this machine will print one, two, or three colors at the same
time, and that the operation of embossing may be performed simultaneously with the
printing, by eithez of the cylinders A, B, or c, or the operation may be performed conseculively by the cylinders, either preceding or succeeding each other.
The situations of the doctors, when required to be used for removing any superfluous
color from the surface of the printing cylinder, are shown at d, d, d; those for removing
any lint which may attach itself, at e, e, e. They are kept in their bearings by weighted
levers and screws, and receive a slight lateral movement to and fro, by means of the vertical rod m, which is connected at top to an eccentric, on the end of the axle of the roller
14 and at its lower end to a horizontal rod mounted at the side of the frame; to this horizontal rod, arms are attached, which are connected to the respective doctors; and thus,
by the rotation of the eccentric, the doctors are made to slide laterally.
When the cylinders A, B, or c, are employed for embossing only, those doctors will not
be required. The driving power is communicated to the machine from any first mover
through the agency of the toothed gear, which gives rotatory motion to the cylinder B.
and from thence to the other cylinders A, and c, by toothed geer shown in Fig. 485.
EMBOSSING  OF LEATHER.  Beautiful ornaments in basso-relievo for decorating the exteriors or interiors of buildings, medallions, picture-frames, cabinet work,




638                       EMBROIDERING MACHINE.
&c., have been recently made by the pressure of metallic blocks and dies, for which
invetion a patent was obtained in June, 1839, by M. Claude Schroth. The diesaremade
of type metal, or of the fusible alloy with bismuth, called d'Arcet's. The leather is
beaten soft in water, then wrung, pressed, rolled, and fulled as it were, by working
it with the hands till it becomes thicker and quite supple. In this state it is laid on
the mould, and forced into all its cavities by means of a wooden bone, or copper tool.
In other cases, the embossing is performed by the force of a press. The leather, when
it has become dry, is easily taken off the mould, however deeply it may be inserted
into its crevices, by virtue of its elasticity. A full detail of all the processes is given
in Newton's Journal, vol. xxii. p. 122.
EMBOSSING WOOD.  (Bossage, Fr.; Erhabenes, Arbeit, Germ.)  Raised figures
upon wood, such as are employed in picture-frames and other articles of ornamental
cabinet work, are usually produced by means of carving, or by casting the pattern in
plaster of Paris, or other composition, and cementing, or otherwise fixing it on the
surface of the wood.  The former mode is expensive; the latter is inapplicable on
many occasions. The invention of Mr. Streaker may be used either by itself, or in aid
of carving; and depends on the fact, that if a depression be made by a blunt instrument
on the surface of the wood, such depressed part will again rise to its original level by
subsequent immersion in the water.
The wood to be ornamented having been first worked out to its proposed shape, is in
a state to receive the drawing of the pattern; this being put on, a blunt steel tool, or
burnisher, or die, is to be applied successively to all those parts of the pattern intended
to be in relief, and, at the same time, is to be driven very cautiously, without breaking
the grain of the wood, till the depth of the depression is equal to the intended prominence of the figures. The ground is then to be reduced by planing or filing to the
level of the depressed part; after which, the piece of wood being placed in water, either
hot or cold, the part previously depressed will rise to its former height, and will then
form an embossed pattern, which may be finished by the usual operations of carving.
For this invention the Society of Arts voted to Mr. Streaker their silver Isis medal,
and ten guineas.
EMBROIDERING  MACHINE.  (Machine a broder, Fr.; Steckmasehine, Germ.)
This art has been till of late merely a handicraft employment, cultivated on account of its
elegance by ladies of rank. But a few years ago M. Heilmann, of Mulhause, inventedamachine of a most ingenious kind, which enables a female to embroider any design with 80
or 100 needles as accurately and expeditiously as she formerly could do with one. A brief
account of this remarkable invention will therefore be acceptable to many readers. It
was displayed at the national exposition of the products of industry in Paris for 1834, and
was unquestionably the object which stood highest in public esteem; for whether at rest
or in motion, it was always surrounded with a crowd of curious visiters, admiring the
figures which it had formed, or inspecting its movements and investigating its mechanism.
130 needles were occupied in copying the same pattern with perfect regularity, all set in
motion by one person.
Several of these machines are now mounted in France, Germany, and Switzerland.
I have seen one factory in Manchester, where a great many of them Sire doing beautiful
work.
The price of a machine having 130 needles, and of consequence 260 pincers or fingers
and thumbs to lay hold of them, is 5000 francs, or 2001. sterling; and it is estimated to
do daily the work of 15 expert hand embroiderers, employed upon the ordinary frame. It
requires merely the labor of one grown-up person, and two assistant children.  The
operative must be well taught to use the machine, for he has many things to attend to;
with the one hand he traces out, or rather follows the design with the point of the pantograph; with the other he turns a handle to plant and pull all the needles, which are
seized by pincers and moved along by carriages, approaching to and receding from the
web, rolling all the time along an iron railway; lastly, by means of two pedals, upon
which he presses alternately with the one foot and the other, he opens the 130 pincers
of the first carriage, which ought to give up the needles after planting them in the stuff,
and he shuts with the same pressure the 130 pincers of the second carriage, which is to
receive the needles, to draw them from the other side, and to bring them back again.
The children have nothing else to do than to change the needles when all their threads
are used, and to see that no needle misses its pincers.
This machine deserves particular attention, because it is no less remarkable for the
happy arrangement of its parts, than for the effects which it prodnces. It may be described under four heads: 1. the structure of the frame; 2. the disposition of the web; 3. the
arrangement of the carriages; and 4. the construction of the pincers.
1. The structure of the frame. It is composed of cast-iron, and is very massive.
Fig. 487 exhibits a front elevation of it.  The length of the machine  depends
upon the number of pincers to be worked.   The model at the exposition had 260




EMBROIDERING MACHINE.                                        639
pincers, and was 2 metres and a half (about 100 inches or 8 feet 4 inches English)
Fong.  The figure here given has been shortened considerably, but the other proportions are not disturbed. The breadth of the frame ought to be the same for every
machine, whether it be long or short, for   s the breadth which determines the length of
the thread to be put into the needles, and there is an advantage in giving it the full
breadth of the model machine, fully 100 inches, so that the needles may carry a thread
at least 40 inches long.
Disposition of the piece to be embroidered.-We have already stated that the pincers
which hold the needles always present themselves opposite to the same point, and that
in consequence they would continually pass backward and forward through the same
hole, if the piece was not displaced with sufficient precision to bring successively opposite
the tips of the needles every point upon which they are to work a design, such as a flower.
The piece is strained perpendicularly upon a large rectangular frame, whose four
sides are visible infig, 487; namely, the two vertical sides at  F, and the two horizontal
sides, the upper and lower at F' F".  We see also in the figures two long wooden rollers
41




640                       EMBROIDERING MACHINE.
gree, for each of these beams bears upon its end a small ratchet wheel g, g; the teeth
of one of them being inclined in the opposite direction to those of the other. Besides
this system of lower beams, there is another of two upper beams, which is however but
imperfectly seen in the figure, on account of the interference of other parts in this view
of the machine.  One of these systems presents the web to the inferior needles, and
the other to the upper needles. As the two beams are not in the same vertical plane,
the plane of the web would be presented obliquely to the needles were it not for a
straight bar of iron, round  whose edge the cloth passes, and  which  renders it
yertical. The piece is kept in tension crosswise by small brass temnplets, to which the
strings g" are attached, and by which it is pulled toward the sides of the frame F. It
remains to show  by what ingenious means this frame may be shifted in every possible
direction. M. Heilmann has employed for this purpose the pantograph which draughtsmen use for reducing or enlarging their plans in determinate proportions.
b V'f" 6" (fig. 487) represents a parallelogram of which the four angles b, V, f' b" are
jointed in such a way that they may become very acute or very obtuse at pleasure,
while the sides of course continue of the same length; the sides b b' and b  " are prolonged, the one to the point d, and the other to the point c, and these points c and d
are chosen under the condition that in one of the positions of the parallelogram, the
line c d which joins them passes through the point f; this condition may be fulfilled in
an infinite number of manners, since the position of the parallelogram remaining the
same, we see that if we wished to shift the point d further from the point b', it would
be sufficient to bring the point c near enough to b", or vice versda; but when we
have once fixed upon the distance b' d, it is evident that the distance b" c is its necessary
consequence.  Now the principle upon which the construction of the pantograph rests
is this; it is sufficient that the three points d, f, and c be in a straight line, in one only
of the positions of the parallelogram, in order that they shall remain always in a
straight line in every position which can possibly be given to it.
We see in the figure that the side b c has a handle B" with which the workman puts
the machine in action.  To obtain more precision and solidity in work, the sides of the
pantograph are joined, so that the middle of their thickness lies exactly in the vertical
plane of the piece of goods, and that the axes of the joints are truly perpendicular to
this plane, in which consequently all the displacements are effected. We arrive at
this result by making fast to the superior great cross bar D" an elbow piece d", having a
suitable projection, and to which is adapted in its turn the piece d, which receives in a
socket the extremity of the side b, a; this piece d' is made fast to d" by a bolt, but it
carries an oblong hole, and before screwing up the nut, we make the piece advance or
recede, till the fulcrum point comes exactly into the plane of the web. This condition being
fulfilled, we have merely to attach the frame to the angle f of the parallelogram, which is
done by means of the piece F".
It is now  obvious that if the embroiderer takes the handle aB" in his hand and makes
the pantograph move in any direction whatever, the point f will describe a figure similar to the figure described by the point c, and six times smaller, but the point f cannot
move without the frame, and whatever is upon it moving also.  Thus, in the movement
of the pantograph, every point of the web describes a figure equal to that described by
the point f, and consequently similar to that described by the point c, but six times
smaller; the embroidered object being produced upon the cloth in the position of that
of the pattern.  It is sufficient therefore to give the embroidering operative who holds
the handle B", a design six times greater than that to be executed by the machine, and to
afford him at the same time a sure and easy means of tracing over with the point c, all the
outlines of the pattern. For this purpose he adapts to c, perpendicularly to the plane
of the parallelogram, a small style terminated by a point c', and he fixes the pattern
upon a vertical tablet E, parallel to the plane of the stuff and the parallelogram, and
distant from  it only by the length of the style c c"; this tablet is carried by the iron
rod e', which is secured to a cast iron foot E', serving also for other purposes, as we shall
presently see.  The frame loaded with its beams and its cloth forms a pretty heavy
mass, and as it must not swerve from its plane, it needs to be lightened in order that the
operative may cause the point of the pantograph to pass along the tablet without straining or uncertainty in its movements. M. Heilmann has accomplished these objects in the
following way. A cord e attached to the side b c of the pantograph passes over a return
pulley, and carries at its extremity, a weight which may be graduated at pleasure; this
weight equipoises the pantograph, and tends slightly to raise the frame.  The lower
side of the frame carries two rods H and H, each attached by two arms h h, a little bent
to the left; both of these are engaged in the grooves of a pulley. Through this mechanism a pressure can be exercised upon the frame from  below  upwards, which may be
regulated at pleasure, and without preventing the frame from moving in all directions,
it hinders it from deviating from the primitive plane to which the pantograph was adjust.
ed.  The length of the rods H ought to be equal to the amount of the lateral movement




EMBROIDERING MACHINE.                                     641
of the frame. Two guides i i carried by two legs of cast iron, present vertical slits in
which the lower part of the frame F' is engaged.
Disposition of the carriages.-The two carriages, which are similar, are placed the one
to the right, and the other to the left of the frame.  The carriage itself is composed
merely of a long hollow  cylinder of cast iron L, carrying at either end a system of two
grooved castors or pulleys L', which roll upon the horizontal rails K; the pulleys are mounted upon a forked piece 1', with two ends to receive the axes of the pulleys, and the piece' is itself bolted to a projecting ear 1 cast upon the cylinder.
This assemblage constitutes properly speaking the carriage, resting in a perfectly
stable equilibrium upon the rails K, upon which it may be most easily moved backwards
and forwards, carrying its train of needles to be passed or drawn through the cloth.
M. Heilmann has contrived a mechanism  by which the operative without budging
from his place may conduct the carriages, and regulate as he pleases the extent of their
course, as well as the rapidity of their movements. By turning the axes M" in the one
direction or the other, the carriage may be made to approach to, or recede from the
web.
When one of the carriages has advanced to prick the needles into the stuff, the other
is there to receive them; it lays hold of them with its pincers, pulls them through,
performs its course by withdrawing to stretch the thread, and close the stitch, then it
goes back with the needles to make its pricks in return. During these movements the
first carriage remains at its post waiting the return of the second. Thus the two chariots
make in succession an advance and a return, but they never move together.
To effect these movements M. Heilmann has attached to the piece o' made fast to
he two uprights A c and A Dof the frame, a bent lever n o n' n" moveable round the
point o; the bend n' carries a toothed wheel o', and the extremity n" a toothed wheel
o"; the four wheels M M' o' and o" have the same number of teeth and the same
diameter; the two wheels o' and o" are fixed in reference to each other, so that it is
sufficient to turn the handle N to make the wheel o" revolve, and consequently the
wheel o'; when the lever n o is vertical, the wheel o' touches neither the wheel M nor the
wheel AM'; but if it be inclined to the one side or the other, it brings the wheel o' alternately into gear with the wheel M or the wheel M'.  As the operative has his two hands
occupied, the one with the pantograph and the other with the handle of impulsion, he
has merely his feet for acting upon the lever n o, and as he has many other things to
do, M. Heilmann has adapted before him a system of two pedals, by which he executes
with his feet a series of operations no less delicate than those which he executes with his
hands.
The pedals P are moveable round the axis p, and carry cords p' wound in an opposite
direction upon the pulleys P'; these pulleys are fixed upon a moveable shaft P", supported upon one side by the prop E', and on the other in a piece K' attached to the two
great uprights of the frame. In depressing the pedal p (now raised in the figure), the
upper part of the shaft e" will turn from  the left to the right, and the lever n o will become inclined so as to carry the wheel o' upon the wheel M', but at the same time the
pedal which is now depressed will be raised, because its cord will be forced to wind itself
upon its pulley, as much as the other cord has unwound itself; and thus the apparatus
will be ready to act in the opposite direction, when wanted.
Disposition of the pincers.-The shaft L' carries, at regular intervals of a semi-diameter, the appendages q q cast upon it, upon which are fixed, by two bolts, the curved
branches Q destined to bear the whole mechanism of the pincers. When the pincers are
opened by their appropriate leverage, and the half of the needle, which is pointed at
each end, with the eye in the middle, enters the opening of its plate, it gets lodged in an
angular groove, which is less deep than the needle is thick, so that when the pincers are
closed, the upper jaw presses it into the groove. In this way the needle is firmly held,
although touched in only three points of its circumference.
Suppose, now, that all the pincers are mounted and adjusted at their proper distances
upon their prismatic bar, forming the upper range of the right carriage. For opening all
the pincers there is a long plate of iron, u, capable of turning upon its axis, and which.
extends from the one end of the carriage to the other. This axis is carried by a kind of
forks which are bolted to the extremity of the branches Q. By turning that axis the,
workman can open the pincers at pleasure, and they are again closed by springs.  This.
movement is performed by his feet acting upon the pedals.
The threads get stretched in proportion as the carriage is run out, but as this tension
has no elastic play, inconveniences might ensue which are prevented by adapting to the
carriage a mechanism by means of which all the threads are pressed at the same time by
a weight susceptible of graduation. A  little beneath the prismatic bar, wiich carries
the pincers, we see in the figure a shaft, Y, going from one end of the carriage to the
other, and even a little beyond it; this shaft is carried by pieces y which are fixed to the
arms Q, and in which it can turn. At its left end it carries two small bars y' and w', and




642                                   EMERY.
at its right a single bar y', and a counterweight (not visible in this view); the ends of
the two bars y' are joined by an iron wire somewhatstout and perfectly straight. When
the carriage approaches the web, and before the iron wire can touch it, the little bar 
presses against a pin, w', which rests upon it, and tends to raise it more and more. In
what has preceded we have kept in view only the upper range of pincers and needles,
but there is an inferior range quite similar, as the figure shows, at the lower ends of the
arms Q. In conclusion, it should be stated, that the operative does not follow slidingly
with the pantograph the trace of the design which is upon the tablet or the picture, but
he must stop the point of the style upon the point of the pattern into which the needle
should enter, then remove it, and put it down again upon the point by which the needle
ought to re-enter in coming from the other side of the piece, and so on in succession. To
facilitate this kind of reading off, the pattern upon the tablet is composed of right lines
terminated by the points for the entrance and return of the needle, so that the operative
(usually a child) has continually under her eyes the series of broken lines which must
be followed by the pantograph; if she happens to quit this path an instant, without having left a mark of the point at which she had arrived, she is under the necessity of looking at the piece to see what has been already embroidered, and to find by this comparison
the point at which she must resume her work, so as not to leave a blank, or to repeat
the same stitch.
Explanation of figure.
A, lower cross bars, which unite the legs of the two ends of the frame.
a, the six feet of the front end of the frame.
a', the six feet of the posterior end of the frame.
a", curved pieces which unite the cross bars A" to tht uprights.
B", handle of the pantograph.
b b' b", three of the angles of the pantograph.
c, point of the side b b" on which the point is fixed.
c", point of the pantograph.
D", cross bar in form of a gutter, which unites the upper parts of the frame.
d, fixed point, round which the pantograph turns.
E, tablet upon which the pattern to be embroidered is put.
E', support of that tablet.
e, cord attached at one end to the side b c of the pantograph passing over a guide pul.
ley, and carrying a weight at the other end.
e', iron rod by which the tablet E is joined to its support B'.
F, F, uprights of the cloth-carrying frame.
F, F', horizontal sides of the same frame.
o, four roll beams.
G", the piece of cloth.
g", the strings, which serve to stretch the cloth laterally.
EMERALD (Emeraude, Fr.; Smaragd, Germ.), is a precious stone of a beautiful
green color; valued next to diamond, and in the same rank as oriental ruby and
sapphire. It occurs in prisms with a regular hexagonal base; sp. gray. 2,7; scratches
quartz with difficulty; is scratched by topaz; fusible at the blowpipe into a frothy
bead; the precipitate afforded by ammonia, from  its solution, is soluble, in a great
measure, in carbonate of ammonia. Its analysis is given very variously by different
chemists. It contains about 14 per cent. of glucina, which is its characteristic constituent; along with 68 of silica, 16 of alumina, a very little lime and iron. The beautiful emerald of Peru is found in a clay schist mixed with some calcareous matter. A
stone of 4 grains weight is said to be worth from 41. to 51.; one of 8 grains, 101.; one
of 15 grains, being fine, is worth 601; one of 24 grains fetched, at the sale of M. de
Dree's cabinet, 2400 francs, or nearly 1001.
The beryl is analogous in composition to the emerald, and is employed (when of the
common opaque kind, found near Limoges), by chemists, for procuring the earth
glucina.
EMERY. This mineral was long regarded as an ore of iron; and was called by
Haiiyfer oxide quartzifere. It is very abundant in the island of Naxos, at cape Emeri,
whence it is imported in large quantities. It occurs also in the islands of Jersey and
Guernsey, at Almaden, in Poland, Saxony, Sweden, Persia, &c. Its color varies from
red brown to dark brown; its specific gravity is about 4*000; it is so hard as to scratch
quartz and many precious stones. By Mr. Tenant's analysis, it consists of alumina,
80; silica, 3; iron, 4. Another inferior kind yielded 32 of iron, and only 50 of
alumina.
We have recent accounts of emery discoveries in Minesota, but nearly all that is used
at present in the arts comes from Turkey, near ancient Smyrna. Dr. Lawrence Smith,
the American geologist, made a discovery of a deposit of emery while residing in
Smyrna, and he made an examination of the locality in 1847.




EMERY.                                           643
Dr. Smith having reported his discoveries to the Turkish government a commission
of inquiry was instituted, and the business soon assumed a mercantile form. The monopoly of the emery of Turkey was sold to a mercantile house in Smyrna, and since
then the price has diminished in the market.
The mining of the emery is of the simplest character. The natural decomposition
of the rock in which it occurs facilitates its extraction. The rock decomposes into an
earth, in which the emery is found imbedded. The quantity procured under these circumstances is so great that it is rarely necessary to explore the rock. The earth in the
neighborhood of the block is almost always of a red color, and serves as an indication
to those who are in search of the mineral. Sometimes, before beginning to excavate,
the spots are sounded by an iron rod with a steel point, and when any resistance is met
with, the rod is rubbed in contact with the resisting body, and the effect produced on
the point enables a practised eye to decide whether it has been done by emery or not.
The blocks which are of a convenient size are transported in their natural state, but are
frequently broken by large hammers; when they resist the action of the hammer, they
are subjected to the action of fire for several hours, and on cooling they most commonly
yield to blows. It sometimes happens that large masses are abandoned, from the impossibility of breaking them into pieces of a convenient size, as the transportation, either
on camels or horses, requires that pieces shall not exceed 100 lbs. each in weight.
Emery appears to be a mechanical mixture of corundum and oxide of iron.
When reduced to a powder, it varies in color from  dark grey to black.  The color
of its powder affords no indication of its commercial value. The powder examined
under the microscope shows the distinct existence of two minerals, corundum and oxide
of iron. Emery, when moistened, always affords a very strong argillaceous odor. Its
hardness is its most important property in its application to the arts, and was ascertained by Mr. Smith in the following manner:-Fragments were broken from the piece
to be examined, and crushed in a diamond mortar with two or three blows of a hammer,
then thrown into a sieve with 400 holes to the inch. The powder is then weighed, and
the hardness tested with a circular piece of glass, about four inches in diameter, and a
small agate mortar. The glass is first weighed, and placed on a piece of glazed paper;
the pulverized emery is then thrown upon it at intervals, rubbing it against the glass
with the bottom of the agate mortar. The emery is brushed off the glass from time to
time with a feather, and when all the emery has been made to pass once over the glass,
it was collected, and passed through the same operation three or four times. The glass
was then weighed, again subjected to the same operation, the emery by this time being
reduced to an impalpable powder. This series of operations is continued until the loss
sustained by the glass is exceedingly small. The total loss in the glass is then noted,
and when all the specimens of emery are submitted to this operation under the same
circumstances, an exact idea of their relative hardness is obtained. The advantages of
using glass and agate are, that the latter is sufficiently hard to crush the emery, and in
a certain space of time to reduce it to such an impalpable state, that it has no longer any
sensible effect on the glass; and, on the other hand, the glass is soft enough to lose
during this time sufficient of its substance to allow of accurate comparative results.
By this method, the best emery was found capable of wearing away about half of its
weight of common French window-glass. The blue sapphire of Ceylon, pulverized and
experimented with in this manner, wears away more than four-fifths of its weight
This furnished the standard of comparison.
In the ordinary process, the lumps of emery ore are broken up in the same manner as
stone is for repairing Macadamised roads, and into lumps of similar size. These lumps
then crushed under stampers, such as are used for pounding metallic ores, driven by
water or by steam power. It is supposed that the stampers leave the fragments more
angular than they would be if they were ground under runners, a mode which is sometimes employed. The coarse powder is then sifted through sieves of wire cloth, which
are generally cylindrical, like the bolting cylinders of corn-mills; but the sieves are
covered with wire cloth, having in general about ninety to sixteen wires to the inch.
No. 16 sieve gives emery of about the size of mustard-seed; and coarser fragments, extending nearly to the size of pepper-corns, are also occasionally prepared for the use of
engineers. The sieves have sometimes as many as 120 wires to the inch; but the very
fine sizes of emery are more commonly sifted through lawn sieves. The finest emery
that is obtained from the manufacturers is that which floats in the atmosphere of the
stamping-room, and is deposited on the beams and shelves, from which it is occasionally
collected. The manufacturers rarely or never wash the emery; this is mostly done by
the glass-workers, and such others as require a greater degree of precision than can be
obtained by sifting.
Washing emery by hand is far too tedious for those who require very large quantities
of emery, such as the manufacturers of plate-glass and some others who generally adopt
the following method:-Twelve or more cylinders of sheet copper, of the common




644                                      EMERY.
height of about two feet, and varying from about three, five, eight, to thirty or forty
inches in diameter, are placed exactly level, and communicating at their upper edges,
each to the next, by small troughs or channels; the largest vessel has also a waste-pipe
near the top. At the commencement of the process, the cylinders are all filled to the
brim with clean water; the pulverised emery is then churned up with abundance of
water in another vessel, and allowed to run into the smallest or three-inch cylinder,
through a tube opposite the gutter leading to the second cylinder. The water during
its short passage across the three-inch cylinder, deposits in that vessel such of the
coarsest emery as will not bear suspension for that limited time; the particles next finer
are deposited in the five-inch cylinder, during the somewhat longer time the mixed
steam takes in passing the brim of that vessel; and so on. Eventually the water forms
a very languid eddy in the largest cylinder, and deposits therein the very fine particles
that have remained in suspension until this period; and the water, lastly, escapes by
the waste-pipe nearly or entirely free from emery. In this simple arrangement, time
is also the rneasure of the particles respectively deposited in the manufacture to which
the emery is applied. When the vessels are to a certain degree filled with emery, the
process is stopped, the vessels are emptied, the emery is carefully dried and laid by,
and the process is recommenced.
Emery paper is prepared by brushing the paper over with thin glue, and dusting the
emery-powder over it from a sieve. There are about six degrees of coarseness. Sieves
with thirty and ninety meshes per linear inch, are in general the coarsest and finest
sizes employed. When used by artizans, the emery-paper is commonly wrapped around
a file or a slip of wood, and applied just like a file, with or without oil, according to
circumstances. The emery-paper cuts more smoothly with oil, but leaves the workdull.
Emery cloth only differs from emery-paper in the use of thin cotton cloth instead of
paper, as the material upon which the emery is fixed by means of glue. The emery
cloth, when folded around a file, does not ply so readily to it as emery-paper and is apt
to unroll. Hence smiths, engineers, and others, prefer emery-paper and emery-sticks;
but for household and other purposes, where the hand alone is used, the greater durability of the cloth is advantageous.
Emery-sticks are rods of board about eight or twelve inches long, planed up square;
or with one side rounded like a half-round file. Nails are driven into each end of the
stick as temporary handles; they are then brushed over one at a time with thin glue, and
dabbed at all parts in a heap of emery-powder, and knocked on one end to shake off the
excess. Two coats of glue and emery are generally used. The emery-sticks are much
more economical than emery-paper wrapped on a file, which is liable to be torn.
Emery-cake consists of emery mixed with a little beeswax, so as to constitute a solid
lump, with which to dress the edges of buff and glaze wheels. The ingredients should
be thoroughly incorporated by stirring the mixture whilst fluid, after which it is frequently poured into water, and thoroughly kneaded with the hands, and rolled into
lumps before it has time to cool. The emery-cake is sometimes applied to the wheels
whilst they are revolving; but the more usual course is, to stop the wheel, and rub in
the emery-cake by hand. It is afterwards smoothed down by the thumb.
Emery-paper, or patent razor-strop paper, an article in which fine emery and glass
are mixed with paper pulp, and made into sheets as in making ordinary paper; the
emery and glass are said to constitute together 60 per cent. of the weight of the paper,
which resembles drawing-paper, except that it has a delicate fawn color. The emerypaper is directed to be pasted or glued upon a piece of wood, and when rubbed with a
little oil, to be used as a razor-strop.
In  1842, Mr. Henry  Barclay took  out a  patent for a method  of combining
powdered emery into discs and laps of different kinds, suitable to grinding, cutting,
and polishing glass, enamels, metals, and other hard substances. The process of
manufacture is as follows:-Coarse emery-powder is mixed  with  about half its
weight of pulverized Stourbridge loam and a little water or other liquid, to make a
thick paste; this is pressed into a metallic mould by means of a screw-press, and after
having been thoroughly dried, is baked or burned in a muffle or close receiver at a
temperature considerably above a red heat, and below the full white heat. In this case,
the clay or elumina serves as a bond, and unites the particles very completely into a
solid artificial emery-stone, which cuts very greedily, and yet seems hardly to suffer
perceptible wear.
Superfine grinding emery is formed into wheels exactly in the same manner as the
above, but the proportion of loam is then only one-fourth instead of one-half that of the
emery.  Those emery stones, which are of medium fineness, cut less quickly, but more
smoothly than the above.
Flour-emery, when manufactured into artificial stones, requires no uniting substance,
but the moistened powder is forced into the metal mould and fired; some portions of
the alumina being sufficient to unite the whole. These fine wheels render the works




ENAMELS.                                        645
submitted to them exceedingly smooth, but they do not produce a high polish on account
of the comparative coarseness of the flour-emery.
The alumina of emery is believed to be aggregated to the same degree of hardness as
in corundum or adamantine spar; which is one of the hardest minerals known. Emery
is extensively employed for grinding metals, glass, &c.; for which purpose it is reduced
to powders of different degrees of fineness by grinding and elutriation.
2,000 tons per annurm at from  50 to 70 dollars each, according to quality, are consumed in the United Kingdom.
EMPYREUMA, means the offensive smell produced by fire applied to organic
matters, chiefly vegetable, in close vessels. Thus, empyreumatic vinegar is obtained
by distilling wood at a red heat, and empyreumatic oil from many animal substances in
the same way.
ENAMELS (Emaux, Fr.; Schmelzglas, Germ.) are varieties of glass, generally opaque
and colored, always formed by the combination of different metallic oxydes, to which
certain fixed fusible salts are added, such as the borates, fluates, and phosphates.
The simplest enamel, and the one which serves as a basis to most of the others, is
obtained by calcining first of all a mixture of lead and tin, in proportions varying from
15 to 50 parts of tin fcr 100 of lead. The middle term appears to be the most suitable
for the greater number of enamels; and this alloy has such an affinity for oxygen, that
it may be calcined with the greatest ease in a flat cast-iron pot, and at a temperature not
above a cherry red, provided the dose of tin is not too great. The oxyde is drawn off to
the sides of the melted metal according as it is generated, new pieces of the alloy being
thrown in from time to time, till enough of the powder be obtained. Great care ought
to be taken that no metallic particles be left in the oxyde, and that the calcining heat be
s low as is barely sufficient; for a strong fire frits the powder, and obstructs its subse-,uent comnminution. The powder when cold is ground in a proper mill, levigated with
water, and elutriated, as will be described under Red lead. In this state of fineness and
purity, it is called calcine, or flux, and it is mixed with silicious sand and some alkaline
matter or sea-salt. The most ordinary proportions are, 4 of sand, I of sea-salt, and 4 of
calcine. Chaptal states that he has obtained a very fine product from 100 parts of calcine, made by calcining equal parts of lead and tin, 100 parts of ground flint, and 200
parts of pure subcarbonate of potash. In either case, the mixture is put into a crucible,
or laid simply on a stratum of sand, quicklime spontaneously slaked, or wood-ashes,
placed under a pottery or porcelain kiln. This mass undergoes a semi-vitrification; or
even a complete fusion on its surface. It is this kind of frit which serves as a radical
to almost every enamel; and by varying the proportions of the ingredient, more fusible,
more opaque, or whiter enamels are obtained. The first of these qualities depends on
the quantity of sand or flux, and the other two on that of the tin.
The sea-salt employed as a flux may be replaced either by salt of tartar, by pure
potash, or by soda; but each of these fluxes gives peculiar qualities to the enamel.
Most authors who have written on the preparation of enamels, insist a great deal on
the necessity of selecting carefully the particular sand that should enter into the composition of the frit, and they even affirm that the purest i^ not the most suitable.  Clouet
states, in the 34th volume of the.nnales de Chimie, that the sand ought to contain at
least 1 part of talc for 3 of silicious matter, otherwise the enamel obtained is never very
glassy, and that some wrinkled spots from imperfect fusion are seeen on its surface; and
yet we find prescribed in some old treatises, to make use of ground flints, fritted by means
of salt of tartar or some other flux. It would thence appear that the presence of talc is
of no use towards the fusibility of the silica, and that its absence may be supplied by increasing the dose of the flux.  In all cases, however, we ought to beware of metallic
oxydes in the sand, particularly those of iron and manganese, which most frequently occur,
and always injure the whiteness of the frit.
The ancients carried the art of enamelling to a very high perfection, and we occasionally find beautiful specimens of their work, of which we know neither the composition,
nor the manner of applying it.  Then, as at present, each artist made a mystery of the
means that succeeded best with him, and thus a multitude of curious processes have been
buried with their authors. Another cause contributes powerfully to this sort of declen-.sion in the arts. Among the vast number of recipes which have been published for the
formation of enamels, there are several in which substances are mentioned that can no
longer be procured, whether owing to a change of denomination, or because the substances cannot now be found in commerce, or because they are not of the same nature as of
old. Hence, in many cases, we find it impossible to obtain satisfactory results.  What
we have now said renders it desirable that the operations should be resumed anew, or
upon new bases, and availing ourselves of all the known chemical facts, we should employ
in the production of enamels, raw materials of the purest kind.
The Venetians are still in possession of the best enamel processes, and they supply the
French and other nations with the best kinds of enamel, of every colored shade.




646                                  ENAMELS.
Enamels are distinguished into transparent and opaque; in the former all the elements
have experienced an equal degree of liquefaction, and are thus run into crystal glass,
whilst in the others, some of their elements have resisted the action of heat more, so that
their particles retain sufficient aggregation to prevent the transmission of light.   This
effect is produced, particularly by the oxyde of tin, as we shall perceive in treating of
white enamel.
The frits for enamels that are to be applied to metallic surfaces require greater fusibility, and should therefore contain more flux; and the sand used for these should be calcined
beforehand with one fourth its weight of sea-salt; sometimes, indeed, metallic fluxes are
added, as minium or litharge.  For some metallic colors, the oxydes of lead are very injurious, and in this case recourse must be had to other fluxes. Clouet states that he had
derived advantage from the following mixtures, as bases for purples, blues, and some
other delicate colors:
Three parts of silicious sand, one of chalk, and three of calcined borax; or, three of
glass (of broken crystal goblets), one of calcined borax, one fourth of a part of nitre, and
one part of well washed diaphoretic antimony. These compositions afford a very white
enamel, which accords perfectly well with blue.
It is obvious that the composition of this primary matter may be greatly varied; but
we should never lose sight of the essential quality of a good enamel; which is, to acquire,
at a moderate heat, sufficient fluidity, to take a shining surface, without running too thin.
It is not complete fusion which is wanted; but a pasty state, of such a degree as may
give it, after cooling, the aspect of having suffered complete liquefaction.
Dead-whit. Enramel.-This requires greater nicety in the choice of its materials than
any other enamel, as it must be free from every species of tint, and be perfectly white;
hence the frit employed in this case should be itself composed of perfectly pure ingredients. But a frit should not be rejected hastily because it may be somewhat discolored,
since this may depend on two causes; either on some metallic oxydes, or on fuliginous
particles proceeding from vegetable or animal substances. Now the latter impurities may
be easily removed by means of a small quantity of peroxyde of manganese, which has
the property of readily parting with a portion of its oxygen, and of thus facilitating the
combustion, that is to say, the destruction of the coloring carbonaceous matter. Manganese indeed possesses a coloring power itself on glass, but only in its highest state of
oxydizement, and when reduced to the lower state, as is done by incombustible matters,
it no longer communicates color to the enamel combinations.  Hence the proportion of
manganese should never exceed what is just; for the surplus would cause color. Sometimes, indeed, it becomes necessary to give a little manganese color, in order to obtain a
more agreeable shade of white; as a little azure blue is added to linens, to brighten or
counteract the dulness of their yellow tint.
A white enamel may be conveniently prepared also with a calcine composed of tw&
parts of tin and one of lead calcined together; of this combined oxyde, one part is melted
with two parts of fine crystal and a very little manganese, all previously ground together.
When the fusion is complete, the vitreous matter is to be poured into clear water, and the
frit is then dried, and melted anew.  The pouring into water and fusion are sometimes
repeated four times, in order to secure a very uniform combination. The crucible must be
carefully screened from smoke and flame. The smallest portions of oxyde of iron or copper admitted into this enamel will destroy its value.
Some practitioners recommend the use of washed diaphoretic antimony (antimoniate
of potash, from metallic antimony and nitre deflagrated together) for white enamel; but
this product cannot be added to any preparation of lead or other metallic oxydes; for it
would tend rather to tarnish the color than to clear it up; and it can be used therefore
only with ordinary glass, or with saline fluxes.  For three parts of white glass (without
lead) one part of washed diaphoretic antimony is to be taken; the substances are well
ground together, and fused in the common way.
Blue enamel.-This fine color is almost always obtained from the oxyde of cobalt or
some of its combinations, and it produces it with such intensity that only a very little can
be used, lest the shade should pass into black.  The cobalt blue is so rich and lively
that it predominates in some measure over every other color, and masks many so that
they can hardly be perceived; it is also most easily obtained. To bring it out, however,
in all its beauty, the other colors must be removed as much as possible, and the cobalt"
itself should be tolerably pure.  This metal is associated in the best known ores with a
considerable number of foreign substances, as iron, arsenic, copper, nickel, and sulphur,
and it is difficult to separate them completely; but for enamel blues, the oxyde of cobalt
does not require to be perfectly free from all foreign metals; the iron, nickel, and copper,
bezg most prejudicial, should be carefully eliminated. This object may be most easily
attained by dissolving the ore in nitric acid, evaporating the solution to a sirupy consistence, to expel the excess of acid, and separate a portion of arsenic.  It is now diluted
with water, and solution of carbonate of soda is dropped slowly into it with brisk agita.




ENAMELS.                                        647
tion, till the precipitate, which is at first of a whitish gray, begins to turn of a rose-red.
Whenever this color appears, the whole must be thrown on a filter, and the liquid
which passes through must be treated with more of the carbonate of soda, in order
to obtain the arseniate of cobalt, which is nearly pure. Since arsenic acid and its
derivatives are not capable of communicating color themselves, and as they moreover
are volatile, they cannot impair the beauty of the blue, and hence this preparation
affords it in great perfection.
Metallic fluxes are not the most suitable for this color; because they always communicate a tint of greater or less force, which never fails to injure the purity of the blue.
Nitre is a useful addition, as it keeps the oxyde at the maximum of oxydation, in which
state it produces the richest color.
Yellow Enamel.-There are many processes for making this color in enamel; but it
is somewhat difficult to fix, and it is rarely obtained of a uniform  and fine tint.  It
may be produced directly with some preparations of silver, as the phosphate or sulphate;
but this method does not always succeed, for too strong a heat or powerful fluxes readily
destroy it, and nitre is particularly prejudicial.   This uncertainty of success with the
salts of silver causes them to be seldom employed; and oxydes of lead and antimony are
therefore preferred, which afford a fine yellow when combined with some oxydes that are
refractory enough to prevent their complete vitrification.  One part of white oxyde of
antimony may be taken with from one to three parts of white lead, one of alum, and
one of sal-ammoniac.  Each of these substances is to be pulverized, and then all are to
be exactly mixed, and exposed to a heat adequate to decompose the sal-ammoniac. This
operation is judged to be finished when the yellow color is well brought out.  There is
produced here a combination quite analogous to that known under the name of Naples
yellow.. Other shades of yellow may be procured either with the oxyde of lead alone, or by
adding to it a little red oxyde of iron; the tints varying with the proportion of the
latter.
Clouet says, in his memoir on enamels, that a fine yellow is obtained with pure oxyde
of silver, and that it is merely necessary to spread a thin coat of it on the spot to be colored. The piece is then exposed to a moderate heat, and withdrawn as soon as this has
reached the proper point. The thin film of metallic silver revived on the surface being
removed, the place under it will be found tinged of a fine yellow, of hardly any thickness.
As the pellicle of silver has to be removed which covers the color, it is requisite to avoid
fixing this film with fluxes; and it ought therefore to be applied after the fusion of the
rest. The yellows require in general little flux, and they answer better with one of a
metallic nature.
Green Enamel.-It is known that a green color may be produced by a mixture of yellow
and blue; but recourse is seldom had to this practice for enamels, as they can be obtain.
ed almost always directly with the oxyde of copper; or still better with the oxyde of
chrome, which has the advantage of resisting a strong heat.
Chemists describe two oxydes of copper, the protoxyde, of an orange red color, which
communicates its color to enamels, but it is difficult to fix; the deutoxyde is blue in the
state of hydrate, bat blackish-brown when dry, and it colors green all the vitreous combinations into which it enters.  This oxyde requires, at most, one or two proportions of
flux, either saline or metallic, to enter into complete fusion; but a much smaller dose is
commonly taken, and a little oxyde of iron is introduced. To four pounds of frit, for instance, two ounces of oxyde of copper and 48 grains of red oxyde of iron are used; and
the ordinary measures are pursued for making very homogeneous enamel.
The green produced by the oxyde of chrome is much more solid; it is not affected by a
powerful fire, but it is not always of a fine shade. It generally inclines too much to the
dead-leaf yellow, which depends on. the degree of oxygenation of the chrome.
Red Enamel.-We have just stated that protoxyde of copper afforded a fine coloc
when it could be fixed, a result difficult to obtain on account of the fugitive nature of
this oxyde; slight variations of temperature enabling it to absorb more oxygen.  The
proper point of fusion must be seized, for taking it from the fire whenever the desired
color is brought out.  Indeed, when a high temperature has produced peroxydizement,
this may be corrected by adding some combustible matter, as charcoal, tallow, tartar,
&c.  The copper then returns to its minimum of oxydizement, and the red color which
had vanished, reappears.  It is possible, in this way, and by pushing the heat a little,
to accomplish the complete reduction of a part of the oxyde; and the particles of metallic
copper thereby disseminated in a reddish ground, give this enamel the aspect of the
stone called avanturine.  The surest and easiest method of procuring protoxyde of
copper is to boil a solution of equal parts of sugar, and sulphate or rather acetate of
copper, in four parts of water.  The sugar takes possession of a portion of the oxygen
of the cupreous oxyde, and reduces it to the protoxyde; when it may be precipitated in
the form of a granular powder of a brilliant red.  After about two hours of moderate




648.ENAMELS.
ebullition, the liquid is set aside to settle, decanted off the precipitate, which is washed
and dried.
This pure oxyde, properly employed by itself, furnishes a red which vies with the fines'
carmine, and by its means every tint may be obtained from red to orange, by adding a
greater or smaller quantity of peroxyde of iron.
The preparations of gold, and particularly the oxyde and purple of Cassius, are likewise employed, with advantage, to color enamel red, and this composition resists a powerful fire tolerably well. For some time back, solutions of gold, silver, and platinum have
been used with success instead of their oxydes; and, in this way, a more intimate mixture may be procured, and, consequently, more homogeneous tints.
Black Enamel.-Black enamels are made with peroxyde of manganese orprotoxyde of
iron; to which more depth of color is given with a little cobalt.  Clay alone, melted
with about a third of its weight of protoxyde of iron, gives, according to Clouet, a fine
black enamel.
Violet Enamel.-The peroxyde of manganese in small quantity by itself furnishes,
with saline or alkaline fluxes, an enamel of a very fine violet hue; and variations of
shade are easily had by modifying the proportions of the elements of the colored
frit. The great point is to maintain the manganese in a state of peroxydation, and consequently to beware of placing the enamel in contact with any substance attractive of
oxygen.
Such are the principal colored enamels hitherto obtained by means of metallic oxydes;
but since the number of these oxydes is increasing every day, it is to be wished that new
trials be made with such as have not yet been employed.  From  such researches some
interesting results would unquestionably be derived.
Of painting on Enamel.-Enamelling is only done on gold and copper; for silver swells
up, and causes blisters and holes in the coat of enamel.  All enamel paintings are, in
fact, done on copper or gold.
The goldsmith prepares the plate that is to be painted upon.  The gold should be 22
carats fine: if purer, it would not be sufficiently stiff; if coarser, it would be subject to
melt; and its alloy should be half white and half red, that is, half silver and half copper;
whereby the enamel with which it is covered will be less disposed to turn green, than if
the alloy were entirely copper.
The workman must reserve for the edge of the plate X small fillet, which he calls the
border. This ledge serves to retain tlhe enamel, and hinders it from falling off when
applied and pressed on with a spatula. When the plate is not to be counter-enamelled, it
should be charged with less enamel, as, when exposed to heat, the enamel draws up the
gold to itself, and makes the piece convex. When the enamel is not to cover the whole
plate, it becomes necessary to prepare a lodgment for it.  With this view, all the outlines of the figure are traced on the plate with a black-lead pencil, after which recourse
is had to the graver.
The whole space enclosed by the outlines must be hollowed out in bas-relief, of a
depth equal to the height of the fillet, had the plate been entirely enamelled. This
sinking of the surface must be done with a flat graver as equally as possible; for if
there be an eminence, the enamel would be weaker at that point, and the green would
appear. Some artists hatch the bottom of the hollow with close lines, which cross each
other in all directions; and others make lines or scratches with the edges of a file broken
off square. The hatchings or scratches lay hold off the enamel, which might otherwise
separate from the plate. After this operation, the plate is cleansed by boiling it in
an alkaline lye, and it is washed first with a little weak vinegar, and then with clear
water.
The plate thus prepared is to be covered with a coat of white enamel, which is done
by bruising a piece of enamel in an agate or porcelain mortar to a coarse powder like
sand, washing it well with water, and applying it in the hollow part in its moist state.




ENAMELS.                                              649
The plate may meanwhile be held in an  ordinary forceps.  The enamel powder is
spread with a spatula. For condensing the enamel powder, the edges of the plate are
struck upon with the spatula.
Whenever the piece is dry, it is placed on a slip of sheet iron perforated with several
small holes, see fig. 490, which is laid on hot cinders; and it is left there until it
ceases to steam. It must be kept hot till it goes to the fire; for were it allowed to cool
it would become necessary to heat it again very gradually at the mouth of the furnace
of fusion, to prevent the enamel from decrepitating and flying off.
490
491                                                          -
C           ^^_^                                 492                       493               4
495
F   IH  1  7                                                         F         0
Before describing the manner of exposing the piece to the fire, we must explain the
construction of the furnace. It is square, and is shown in front elevation in fig. 491.
It consists of two pieces, the lower part A, or the body of the furnace, and the upper
part B, or the capital, which is laid on the lower part, as is shown in fig. 492, where these
two parts are separately represented. The furnace is made of good fire-clay, moderately
baked, and resembles very closely the assay or cupellation furnace. Its inside dimensions are 9 inches in width; 13 inches in height in the body, and 9 in the capital. Its
general thickness-is 2 inches.
The capital has an aperture or door cfig. 491, which is closed by a fire-brick stopper
m, when the fire is to be made active. By this door fuel is supplied.
The body of the furnace has likewise a door D, which reaches down to the projecting
shelf E, called the bib (mentonniere), whose prominence is seen at E, fig. 491. This
shelf is supported and secured by the two brackets, F, F; the whole being earthenware.
The height of the door D, is abridged by a peculiar fire-brick G, which not only covers
the whole projection of the shelf E, but enters within the opening of the door D, filling
its breadth, and advancing into the same plane with the inner surface of the furnace.
This plate is called the hearth; its purpose will appear presently; it may be taken out
and replaced at pleasure, by laying hold of the handle in its front.
Below the shelf E, a square hole, ii, is seen, which serves for admitting air, and for
extracting the ashes. Similar holes are left upon each side of the surface, as is shown
in the ground plan of the base, fig. 492, at H.
On a level with the shelf, in the interior of the furnace, a thin fire-tile i rests, perforated with numerous small holes. This is the grate represented in a ground view in
fig. 490. Figs. 493, 494, 495, represent, under different aspects, the muffle. Fig. 492 shows
the elevation of its further end; fig. 494, its sides; and fig. 495, its front part. At r,
fg. 492, the muffle is seen in its place in the furnace, resting on two bars of iron, or,
still better, on ledges of fire-clay, supported on brackets attached to the lateral sides of
the furnace. The muffle is made of earthenware, and as thin as possible. The fuel
consists of dry beech-wood, or oaken branches, about an inch irk diameter, cut to the
length of nine inches, in order to be laid in horizontal strata within the furnace, one
row only being placed above the muffle. When the mufflie has attained to a white red
heat, the sheet iron tray, bearing its enamel plate, is to be introduced with a pair of
pincers into the front of the muffle, and gradually advanced toward its further end.
The mouth of the muffle is to be then closed with two pieces of charcoal only, between
which the artist may see the progress of the operation. Whenever the enamel begins
to flow, the tray must be turned round on its base to insure equality of temperature;




6050                              ENAMELLING.
and as soon as the whole surface is melted, the tray must be withdrawn with its plate
but slowly, lest the vitreous matter be cracked by sudden refrigeration.
The enamel plate, when cold, is to be washed in very dilute nitric acid, and afterwards in cold water, and a second coat of granular enamel paste is to be applied, with
the requisite precautions. This, being passed through the fire, is to be treated in the
same way a third time, when the process will be found complete. Should any chinks
happen to the enamel coat, they must be widened with a graver, and the space
being filled with ground enamel, is to be repaired in the muffle. The plate, covered
with a pure white enamel, requires always to be polished and smoothed with sandstone
and water, particularly if the article have a plane surface; and it is then finally glazed
at the fire.
The painting operation now follows. The artist prepares his enamel colors by pounding them itn an agate mortar, with a pestle of agate, and grinding them on an agate slab,
with oil of lavender, rendered viscid by exposure to the sun in a shallow vessel, loosely
covered with gauze or glass. The grinding of two drachms of enamel pigment into an
impalpable powder, will occupy a laborer a whole day. The painter should have along.
side of him a stove in which a moderate fire is kept up, for drying his work whenever
the figures are finished. It is then passed through the muffle.
Enamelling at the Lamp.-The art of the lamp enameller is one of the most agreeable
and amusing that we know.  There is hardly a subject in enamel which may to, be
executed by the lamp-flame in very little time, and more or less perfectly, according to
the dexterity of the artist, and his acquaintance with the principles of modelling.
In working at the lamp, tubes and rods of glass and enamel must be provided, of all
sizes and colors.
The enamelling table is represented in fig. 488, round which several workmen, with
their lamps, may be placed, while the large double bellows D below is set a-blowing by a
treadle moved, with the foot. The flame of the lamp, when thus impelled by a powerful
jet of air acquires surprising intensity. The bent nozzles or tubes, A A A A, are made
C glass, and are drawn to points modified to the purpose of the enameller.
Fig. 489 shows, in perspective, the lamp A of the enameller standing in its cistern B;
the blowpipe c is seen projecting its flame obliquely upwards. The blowpipe is adiust.
able in an elastic cork D, which fills up exactly the hole of the table into which it enters.
When only one person is to work at a table provided with several lamps, he sits down at
the same side with the pedal of the bellows; he takes out the other blowpipes, and plugs
the holes in the table with solid corks.
The lamp is made of copper or tin-plate, the wick of cotton threads, and either tallow
or oil may he ised. Between the lamp and the workman a small board or sheet-'of
white iron B, called the screen, is interposed to protect his eyes from the glare of light.
The screen is fastened to the table by a wooden stem, and it throws its shadow on his
face.
The enamelling workshop ought to admit little or no daylight, otherwise the artist,
not perceiving his flame distinctly, would be apt to commit mistakes.
It is impossible to describe all the manipulations of this ingenious art, over which
taste and dexterity so entirely preside. But we may give an example. Suppose the
enameller wishes to make a swan. HIe takes a tube of white enamel, seals one of its
ends hermetically at his lamp, and while the matter is sufficiently hot, he blows on
it a minikin flask, resembling the body of the bird; he draws out, and gracefully bends
the neck; he shapes the head, the beak, and the tail; then, with slender enamel rods
of a proper color, he makes the eyes; he next opens up the beak with pointed scissors;
lie forms the wings and the legs; finally attaching the toes, the bird stands complete.
The enameller also makes artificial eyes for human beings, imitating so perfectly the
colors of the sound eye of any individual, as to render it difficult to discover that he
has a blind and a seeing one.
It is difficult to make large articles at the blowpipe; those which surpass 5 or 6 inches
become nearly unmanageable by the most expert workmen.
ENAMELLING OF CAST IRON AND OTHER HOLLOW  WARE FOR SAUCEPANS, &c.-In December, 1799, a patent was obtained for this process by Dr. Samuel Sandy Hickling.
His specification is subdivided into two parts:~
1. The coating or lining of iron vessels, &c., by fusion with a vitrifiable mixture,
composed of 6 parts of calcined flints, 2 parts of composition or Cornish stone, 9 parts of
litharge, 6 parts of borax, 1 part of argillaceous earth, 1 part of nitre, 6 parts of calx of
tin, and 1 part of purified potash. Or, 2dly,
8 parts of calcined flints, 8 red lead, 6 borax, 6 calx of tin, and 1 of nitre. Or, 3dly,
12 of potter's composition, 8 borax, 10 white lead, 2 nitre, 1 white marble calcined,
1 argillaceous earth, 2 purified potash, and 5 of calx of tin. Or, 4thly,
4 parts calcined flint, 1 potter's composition, 2 nitre, 8 borax, I white marble calcine, J argillaceous earth, and 2 calx of tin.




ENAMELLING.                                        651
Whichever of the above compositions is taken, must be finely powdered, mixed, fused;.he vitreous mass is to be ground -when cold, sifted, and levigated with water. It is
then made into a pap with water or gum-water. This pap is smeared or brushed ovet
the interior of the vessel, dried, and fused with a proper heat in a muffle.
Calcined bones are also proposed as an ingredient of the flux.
The fusibility of the vitreous compounds is to vary according to the heat to be applied
to the vessel, by using various proportions of the siliceous and fluxing materials. Col.
ors may be given, and also gilding.
The second part or process in his specification describes certain alloys of iron and
nikel, which he casts into vessels, and lines or coats them with copper precipitated
from its saline solutions. It also describes a mode of giving the precipitated copper a
brassy surface by acting upon it with an amalgum of zinc with the aid of heat.
A factory of such enamelled hollow wares was carried on for some time, but it was
given up for want of due encouragement.
A patent was granted to Thomas and Charles Clarke on the 25th of May, 1839, for
a method of enamelling or coating the internal surfaces of iron pots and saucepans, in
such a way as shall prevent the enamel from  cracking or splitting off from the effects
of fire. The specification prescribes the vessel to be first cleansed by exposing it to
the action of dilute sulphuric acid (sensibly sour to the taste) for three or four hours,
then boiling the vessel in pure water for a short time, and next applying the composition.
This consists of 100 lbs. of calcined ground flints; 50 lbs. of borax calcined, and finely
ground with the above. That mixture is to be fused and gradually cooled.
40 lbs. weig^t of the above product is to be taken with 5 lbs. weight of potter's clay;
to be ground together in water until the mixture forms a pasty-consistenced mass,
which will leave or form a coat on the inner surface of the vessel about one sixth of an
inch thick. When this coat is set, by placing the vessel in a warm  room, the second
composition is to be applied. This consists of 125 lbs. of white glass (without lead),
25 lbs. of borax, 20 lbs. of soda (crystals), all pulverized together and vitrified by fusion, then ground, cooled in water, and dried. To 45 lbs. of that mixture, 1 lb. of soda
is to be added, the whole mixed together in hot water, and when dry, pounded; then
sifted finely and evenly over the internal surface of the vessel previously covered with
the first coating or composition, while this is still moist. This is the glazing. The
vessel thus prepared is to be put into a stove, and dried at the temperature of 212~ F.
It is then heated in a kiln or muffle, like that used for glazing china. The kiln being
brought to its full heat, the vessel is placed first at its mouth to heat it gradually, and
then put into the interior of the fusion of the glaze. In practice it has been found advantageous also to dust the glaze powder over the fused glaze, and apply a second
fluxing heat in the oven. The enamel, by this double application, becomes much
smoother and sounder.
Messrs. Kenrick of West Bromwich having produced in their factory and sent into
the market some excellent specimens of enamelled saucepans of cast iron, were sued by
Messrs. Clarke for an invasion of their patent rights; but after a long litigation in
chancery, the patentees were nonsuited in the court of exchequer. The previous process of cleansing with dilute sulphuric acid appeared by the evidence on the trial to
have been given up by the patentees, and it was also shown by their own principal
scientific witness that a good enamelled iron saucepan could be made by Hickling's
specification. In fact, the formulae by which a good enamel may be compounded are
almost innumerable; so that a patent for such a purpose seems to be untenable, or at
least most easily evaded. I have exposed the finely-enamelled saucepans of Messrs.
Kenrick to very severe trials, having fused even chloride of calcium in them, and have
found them to stand the fire very perfectly without chipping or cracking. I consider
such a manufacture to be one of the greatest improvements recently introduced into
domestic economy; such vessels being remarkably clean, salubrious, and adapted to
the most delicate culinary operations of boiling, stewing, making of jellies, preserves,
&c. They are also admirably fitted for preparing pharmaceutical decoctions, and ordinary extracts.
The enamel of the said saucepans is quite free from lead, in consequence of the glass
which enters into its composition being quite free from that metal. In several of the
saucepans which were at first sent into the market by Messrs. Clarke, their enamel
was found on analysis by several chemists to contain a notable proportion of oxide of
lead. In consequence of the quantity of borax and soda in the glaze, this oxide was so
readily acted upon by acids, that sugar of lead was formed by digesting vinegar in them
with a gentle heat. The presence of this noxious metal formed, in my opinion, a legitimate ground for contesting the patent, being in direct violation of the terms of the
specification. Messrs. Kenwick's wares have been always free from this deleterious
metal. Messrs. Clarke, I understand, have for some time been careful to reject from




652                               ENAMELLING.
their enamel-composition all glass which contains lead; and they now manufacture also
wholesome enamelled ware.  Thus the public have profited in a most important point
by the aforesaid litigation.
Enamelled iron saucepans had been many years ago imported from  Germany, and
sold in London. I had occasion to analyze their enamel, and found to my surprise
that it contains abundance of litharge or oxide of lead. The Prussian government has
issued an edict prohibiting the use of lead in the enamelling of saucepans, which are so
extensively manufactured in Peiz, Gleiwitz, &c. Probably the German ware sent to
England was fabricated for exportation, with an enamel made to flux easily by a dose
of litharge. The composition of the said enamel is nearly the same with that which I
found upon some of the earlier saucepans of Messrs. Clarke. Had their patent been
sustained, the important legal question would have arisen, whether it gave the patentees
the power of preventing dealers from continuing to sell what they had been habitually
doing for a great many years.
A suitable oven or muffle for lining or coating metals with enamel may have the following dimensions:The outside, 8 feet square, with 14-inch walls; the interior muffle, 4 feet square at
bottom, rising 6 inches at the sides, and then arched over; the crown may be 18 inches
high from the floor: the muffle should be built of firebrick, 2' inches thick. Another
arch is turned over the first one, which second arch is 7 inches wider at the bottom, and
4 inches higher at the top. A 9-inch wall under the bottom of the muffle at its centre
divides the fireplaces into two, of 16 inches width each, and 3 feet 3 inches long. The
flame of the fire plays between the two arches and up through a 3-inch flue in front, and
issues from the top of the arch through three holes, about 4 inches square; these open
into a flue, i0- + 9 inches, which runs into the chimney.
The materials for the enamel body (ground flint, potter's clay, and borax) are first
mixed together and then put into a reverberatory furnace, 6 feet 6 inches long, by 3
feet 4 wide, and 12 inches high. The flame from an 18-inch fireplace passes over the
hearth. The materials are spread over the floor of the oven, about 6 inches thick, and
ignited or fritted for four or five hours, until they begin to heave and work like yeast,
when another coating is put on the top, also 6 inches thick, and fired again, and so on
the whole day. If it be fired too much, it becomes hard and too refractory to work in
the muffles. The glaze is worked in an oven similar to the above. It may be composed
of about one half borax and one half of Cornish stone in a yellowish powder procured
from the potteries. This is fritted for 10 hours, and then fused into a glass which is
ENAMELLED  CAST-IRON.  Cast-iron vessels have been exceedingly well enamelled
under two different patents within these few years; at first, by Mr. Clark, of Wolverhampton, and in November, 1846, by Messrs. Kenrick, of West Bromwich. Before
the enamel is applied, the surface of the iron should be made quite clean and bright.
The enamel consists of two coats; the one forming the body, and the other the glaze.
The body is made by fusing 100 lbs. of ground flints, and 75 of borax, and grinding
40 lbs. of this frit with 5 lbs. of potter's clay in water till it is brought to the consistence of a pap. A coating of this pap being applied and dried, but not hard, the
glaze powder is sifted over it. This consists of 100 parts of Cornish stone, in fine
powder, 117 of borax, 35 of soda-ash, 35 of nitre, 35 of sifted slaked lime, 13 of white
sand, and 50 of pounded white glass. These are all fused together; the frit obtained
is pulverized. Of this powder 45 pounds are mixed with 1 pound of soda-ash, in hot
water; and the mixture being dried in a stove is the glaze powder. When this powder
has been very finely sifted over the body coat, the cast iron article is put into a stove,
kept at a temperature of about 2120, to dry it hard; after which it is set in a muffle
kiln to be fused into a glaze.
The inside of pipes is enamelled (after being cleaned) by pouring the above body
composition through them while the pipe is being turned about, to insure its being
uniformly coated. After the body has become set, the glaze pap is poured in in a like
manner. The pipe is finally fired in the kiln.
ENAMELLED  LEATHER.  Instead of enamelling  the grain surface as heretofore,
Mr. Kossiter removes that surface by splitting or puffing, and then produces what is
called "a finish" upon the surface thus formed, by means of a roller, or glass instrument. Or the flesh side may be thus prepared for enamelling; and it is less liable to
crack, and the enamel to become cloudy, than the grain side. He also shaves hides and
skins by knives set tangentially upon a rotary axis, with a certain degree of obliquity.
He squeezes the grease out of the skins by hard pressure between rollers; and be uses
a rotary brush to clear away all filth.
ENAMELLING METALS.  In  February, 1847, Mr. Walton  patented  a method  of




ETCHING VARNISH.                                     653
enamelling copper and other vessels, by coating them (after their surfaces are scaled
by heat and cleaned) with powders of*a vitrifiable kind applied in a thin pasty state
with a brush, then drying and firing them.  His formula for the composition is as
follows: 6 parts of flint glass, 3 of borax, 1 of red lead, and 1 of oxide of tin; mixed,
fritted, ground into powder, made into a thin paste with water, applied, dried, and fused
on by the heat of an enamel kiln (see POTTERY). A second and even a third coat is
prescribed. Into the second he puts calcined bone in powder, with china clay and
carbonate of potash. These materials areefritted, ground, and mixed with certain of
the former vitrifiable materials. Being reduced to a creamy consistence with water in
a porcelain mill, the mixture is painted on with a brush, or applied by dipping, dried,
and fired. One of his formulae consists of 4 parts of ground felspar, 4 of white sand,
4 of carbonate of potash, 1 of arsenic, 6 of borax, I of oxide of tin, 1 of nitre, 1 of
whiting-being in my opinion a most injudicious farrago, for which a much better and
simpler combination of vitrifiable china-like materials might be substituted.Newton's
Journal, xxx.L p. 183.
EPSNOMI SALTS.  Sulphate of Magnesia.
EQUIVALENTS, CHEMICAL.  (Stochiometrie, Germ.)  This expression was first
employed by Dr. Wollaston, to denote the primary proportions in which the various
chemical bodies reciprocally combine; the numbers representing these proportions
being referred to one standard substance of general interest, such as oxygen or hydrogen
reckoned unity, or 1,000. Dr. Dalton, who is the true author of the grand discovery
of definite and multiple chemical ratios, calls these equivalent numbers atomic weights,
when reduced to their lowest terms, either hydrogen or oxygen being the radix of the
scale.  Though it belongs to a chemical work to discuss the principles and develop the
applications of the Atomic Theory, I shall be careful, upon all proper occasions, to
point out the vast advantages which the chemical manufacturer may derive from it, and
to show how much he may economize and improve his actual processes by its means.
See ELEMENT.
ESSENCES are either ethereous oils, in which all the fragrance of vegetable products
reside; or the same combined and diluted with alcohol. See OiLs, ETHEREOUS.
ESSENCE D'ORIENT, the name of a pearly looking matter procured from  the
blay or bleak, a fish of the genus cyprinus. This substance, which is found principally
at the base of the scales, is used in the manufacture of artificial pearls. A large quantity of the scales being scraped into water in a tub, are there rubbed between the hands
to separate the shining stuff, which subsides on repose. The first water being decanted,
more is added with agitation till the essence is thoroughly washed from all impurities;
when the whole is thrown upon a sieve; the substance passes through, but the scales
are retained. The water being decanted off, the essence is procured in a viscid s"te, of
a bluish white color, and a pearly aspect. The intestines of the same fish are also
covered with this beautiful glistening matter. Several other fish yield it, but in smaller
proportion. When well prepared, it presents exactly the appearance and reflections of
the real pearls, or the finest mother of pearl; properties which are probably owing to the
interposition of some portions of this same substance, between the laminae of these
shelly concretions. Its chemical nature has not been investigated; it putrefies readily
when kept moist, an accident which may, however, bo counteracted by water of ammonia. See PEARLS.
ETCHING  Varnish. (Aetzgrund-Deckfirniss, Germ.)  Though the practice of this
elegant art does not come within the scope of our Dictionary, the preparation of the varnishes, and of the biting menstrua which it employs, legitimately does.
The varnish of Mr. Lawrence, an English artist resident in Paris, is made as follows:
Take of virgin wax and asphaltum, each two ounces, of black pitch and burgundy-pitch
each half an ounce. Melt the wax and pitch in a new earthenware glazed pot, and add
to them, by degrees, the asphaltum, finely powdered. Let the whole boil till such time
as that, taking a drop upon a plate, it will break when it is cold, on bending it double
two or three times betwixt the fingers. The varnish, being then enough boiled, must be
taken off the fire, and after it cools a little, must be poured into warm water that it may
work the more easily with the hands, so as to be formed into balls, which must be
kneaded, and put into a piece of taffety for use.
Care must be taken, first, that the fire be not too violent, for fear of burning the
ingredients, a slight simmering being sufficient; secondly, that whilst the asphaltum is
putting in, and even after it is mixed with the ingredients, they should be stirred continually with the spatula; and thirdly, that the water into which this composition is
thrown should be nearly of the same degree of warmth with it, in order to prevent a
kind of cracking that happens when the water is too cold.
The varnish ought always to be made harder in summer than in winter, and it will
become so if it be suffered to boil longer, or if a greater proportion of the asphaltum or




654                                  ETHER.
brown rosin be used. The experiment above mentioned, of the drop suffered to cool,
will determine thehe gree of hardness or softness that may be suitable to the season
when it is used.
Preparation of the hard varnish used by Callot, commonly called the Florence Varnish:-Take four ounces of fat oil very clear, and made of good linseed oil, like that
used by painters; heat it in a clean pot of glazed earthenware, and afterwards put to it
four ounces of mastick well powdered, and stir the mixture briskly till the whole be well
melted, then pass the mass through a piece rbf fine linen into a glass bottle with a long
neck, that can be stopped very securely; and keep it for the use that will be explained
below.
Method of applying the soft varnish to the plate, and of blackening it:-The plate
being well polished and burnished, as also cleansed from all greasiness by chalk or Spanish white, fix a hand-vice on the edge of the plate where no work is intended to be, to
serve as a handle for managing it when waiin'; then put it upon a chafing dish, in which
there is a moderate fire, and cover the whole plate equally with a thin coat of the varnish; and whilst the plate is warm, and the varnish upon it in a fluid state, beat every
part of the varnish gently with a small ball or dauber made of cotton tied up in taffety,
which operation smooths and distributes the varnish equally over the plate.
When the plate is thus uniformly and thinly covered with the varnish, it must be
blackened by a piece of flambeau, or of a large candle which affords a copious smoke;
sometimes two or even four such candles are used together for the sake of despatch,,nat
the varnish nmay noc grow cold, which if it does during the operation, the plate must be
heated again, that it may be in a melted state when that operation is performed; but
great care must be taken not to ourn it, which, when it happens, may be easily perceived
by the varnish appearing burnt, and losing its gloss.
The menstruum used and recommended by Turrell, an eminent London artist, for
etching upon steel, was prepared as follows:Take Pyroligneous acid 4 parts by measure,
Alcohol          1 part, mix, and add
Nitric acid      I part.
This mixed liquor is to be applied from 1x to 15 minutes, according to the depth
desired. The nitric acid was employed of the strength of 1'28-the double aquafortis of
the shops.
The eau forte or menstruum for copper, used by Callot, as also by Piranesi, with a slight
modification, is prepared with 8 parts of strong French vinegar,
4 parts of verdigris,
4 ditto sea salt,
4 ditto sal ammoniac,
1 ditto alum,
16 ditto water.
The solid substances are to be well ground, dissolved in the vinegar, and diluted with
the water; the mixture is now to be boiled for a moment, and then set aside to cool.
This menstruum is applied to the washed, dried, and varnished plate, after it has suffered the ordinary action of aquaf;rtis, in order to deepen and finish the delicate touches.
It is at present called the eau forte d passer.
ETHER is the name of a class of very light, volatile, inflammable, and fragrant
spirituous liquids, obtained by distilling, in a glass retort, a mixture of alcohol with
almost any strong acid.  Every acid modifies the result, in a certain degree, whence
several varieties of ether are produced. The only one of commercial importance is
sulphuric ether, which was first made known under the name of sweet oil of vitriol,
in 1540, by the receipt of Walterus Cordus.  Froberus, 190 years after that date,
directed the attention of chemists afresh to this substance, under the new denomination
of ether.
There are two methods of preparing it; by the first, the whole quantity of acid and
alcohol are mixed at once, and directly subjected to distillation; by the second, the alcohol is admitted, in a slender streamlet, into a body of acid previously mixed with a little
alcohol, and heated to 2200 Fahr.
1.' Mix equal weights of alcohol at spec. grav. 0830, and sulphuric acid at 1842, by
introducing the former- into a large tubulated retort, giving it a whirling motion, so
that the alcohol may revolve round a central conical cavity. Into this species of whirlpool the acid is to be slowly poured. The mixture, which becomes warm, is to be
forthwith distilled by attaching a spacious receiver to the retort, and applying the heat
of a sand-bath. The formation of ether takes place only at a certain temperature. If
the contents of the retort be allowed to coot, and be then slowly heated in a water-bath,
alcohol alone will come over for some time without ether, till the mixture acquires tht




ETHER.                                        655
proper degree of heat. The first receiver should be a globe, with a tube proceeding
from its bottom, into a second receiver, of a cylindric shape, surrounded with ice-cold
water. The joints must be well secured by lutes, after the expanded air has been
allowed to escape. The liquid in the retort should be kept in a steady state of ebullition. The ether, as long as it is produced, condenses in the balloon and neck of the
receiver in strie; when these disappear the process is completed. The retort must now
be removed from the sand; otherwise it would become filled' with white fumes containing sulphurous' acid, and denser striae would flow over, which would contaminate the
light product with a liquid called sweet oil of wine.
The theory of etherification demonstrates that when strong sulphuric acid is mixed
with alcohol, there is formed, on the one hand, a more aqueous sulphuric acid, and, on
the other, sulphovinic acid. When this mixture is made to boil, the sulphovinic acid is
decomposed, its dihydrate of carbon combines with the alcohol, and constitutes ether;
while the proportion of sulphovinic acid progressively diminishes. Mr. Hennell, of the
Apothecaries' Hall, first explained these phenomena, and he was confirmed in his views
by the interesting researches of Serullas. The acid left in the retort is usually of a
black color, and may be employed to convert into ether half as much alcohol again; an
experiment which may be repeated several times in succession.
The most profitable way of manufacturing ether has been pointed out by Boullay.
It consists in letting the alcohol drop in a slender stream into the acid, previously heated
to the etherifying temperature. If the acid in this case were concentrated to 1846, the
reaction would be too violent, and the ether would be transformed into bicarbureted
hydrogen (dihydrate of carbon).  It is therefore necessary to dilute the acid down to
the density oC 1'780; but this dilution may be preferably effected with alcohol, instead of
water, by mixing three parts of the strongest acid with 2 of alcohol, specific gravity
O'830, and distilling off a portion of the ether thereby generated; after which the stream
of alcohol is to be introduced into the tubulure of the retort through a small glass tube
plunged into the mixture; this tube being the prolongation of a metallie syphon, whose
shorter leg dips into a bottle filled with the alcohol. The longer leg is furnished with a
stop-cock, for regulating at pleasure the alcoholic streamlet. The distilled vapors should
be transmitted through a worm of pure tin, surrounded by cold water, and the condensed
fluid received in a glass bottle. The quantity of alcohol which can be thus converted
into ether by a given weight of sulphuric acid, has not hitherto been accurately deter
mined; but it is at least double.  In operating in this way, neither sulphurous acid nor
sweet oil of wine is generated, while the residuary liquid in the retort continues limpid
and of a merely brownish yellow color. No sulphovinic acid is formed, and according to
the experiments of Geiger, the proportion of ether approaches to what theory shows to
be the maximum  amount. In fact, 57 parts of alcohol of 083 sp. gray. being equivalent to 46-8 parts. of anhydrous alcohol, yield, according to Geiger, 331 parts of ether;
and by calculation they should yield 37f.
The ether of the first distillation is never pure, but always contains a certain quantity
of alcohol. The density of that product is usually 0'78, and if prepared by the first of
the above methods, contains, besides alcohol, pretty frequently sulphurous acid, and
sweet oil of wine; impurities from which it must be freed. Being agitated with its
bulk of milk of lime, both the acid and the alcohol are removed at the same time; and
if it be then decanted and agitated, first with its bulk of water, next decanted into a
retort containing chloride of calcium in coarse powder, and distilled, one third of perfectly pure ether may be drawn over. Gay Lussac recommends to agitate the ether,
first with ttfice its volume of water, to mix it, and leave it in contact with powdered
unslaked lime for 12 or 14 hours, and then to distil off one third of pure ether. The
remaining two thirds consist of ether containing a little alcohol. If in preparing ether
by Boullay's method, the alcohol be too rapidly introduced, much of this liquid will
come over unchanged. If in this state the ether be shaken with water, a notable quantity of it will be absorbed, because weak alcohol dissolves it very copiously. The above
product should therefore be re-distilled, and the first half that comes over may be considered as ether, and treated with water and lime. The other half must be exposed
afresh to the action of sulphuric acid.
Pure ether possesses the following properties. It is limpid, of spec. grav. 0713, or
0'715 at 600; has a peculiar penetrating strong smell; a taste at first acrid, burning,
sweetish, and finally cooling. It has neither an acid nor alkaline reaction; is a nonconductor of electricity, and refracts light strongly.  It is very volatile, boiling at
960 or 970 F., and produces by its evaporation a great degree of cold. At the temperature of 62'4, the vapor of ether balances a column of mercury 15 inches high,
or half the weight of the atmosphere. When ether is cooled to ~240 F. it begins to
crystallize in brilliant white plates, and at ~470 it becomes a white crystalline solid.
When vapor of ether is made to traverse a red hot porcelain tube, it deposites within it
one half per cent. of charcoal, and there are condensed in the receiver one and two thirds
42




656                               EVAPORATION.
pei cent. of a brown oil, partly in crystalline scales, and partly viscid. The crystalline
portion is soluble in alcohol, but the viscid only in ether. The remainder of the decomposed ether consists of bi-carburetel hydrogen gas, tetrahydric carburet, carbonic oxyde
gas, and one per cent. at most of gaseous carbonic acid.
Ether takes fire readily, even at some distance from a flame, and it should not there.
fore be poured from one vessel to another in the neighborhood of a lighted candle. It
may be likewise set on fire'by the electric spark. It burns all away with a bright fuliginous flame. When the vapor of ether is mixed with 10 times its volume of oxygen, it
burns with a violent explosion, absorbs 6 times its bulk of oxygen, and produces 4 times
its volume of carbonic acid gas.
Ether alters gradually with contact of air; absorbing oxygen, and progressively changing into acetic acid and water. This conversion takes place very rapidly when the ether
is boiled in an open vessel, while the acid enters into a new combination forming acetic
ether. Ether should be preserved in bottles perfectly full and well corked, and kept in
a cool place, otherwise it becomes sour, and is destroyed. In contains in this state 15 per
cent. of its bulk of azote, but no oxygen gas, as this has combined with its elements.
Ether is composed of oxygen 21'24; hydrogen 13'85; carbon 65-05. This composition may be represented by 1 prime equivalent of water, and 4 primes of bi-carburetted
hydrogen gas; in other words, ether contains for 1 prime of water, once as much olefant
gas as alcohol, and its prime equivalent is therefore 468-15 to oxygen 100. By my analysis, as published in the Phil. Trans. for 1822, ether is composed of oxygen 2710; hydrogen 13-3; and carbon 59-6 in 100 parts. The density of my ether was 0*700.
One volume of vapor of ether consists of one volume of aqueous vapor and two
volumes of olefiant gas (bi-carbureted hydrogen), while alcohol consists of two volumes
of each.
ETHER, ACETIC, is used to flavor silent corn spirits in making imitation brandy. It
may be prepared by mixing 20 parts of acetate of lead, 10 parts of alcohol, and 11I of
concentrated sulphuric acid; or 16 of the anhydrous acetate, 5 of the acid, and 4j of absolute alcohol; distilling the mixture in a glass retort into a very cold receiver, agitating
along with weak potash ley the liquor which comes over, decanting the supernatant ether,
and rectifying it by re-distillation over magnesia and ground charcoal.
Acetic ether is a colorless liquid of a fragrant smell and pungent taste, of spec. grav.
0'866 at 450 F., boiling at 166~ F., burning with a yellowish flame, and disengaging fumes
of acetic acid. It is soluble in 8 parts of water.
Acetic ether may be economically made with 3 parts of acetate of potash, 3 of very
strong alcohol, and 2 of the strongest sulphuric acid, distilled together. The first product
must be re-distilled along with one fifth of its weight of sulphuric acid; as much ether
will be obtained as there was alcohol employed.
ETHIOPS is the absurd name given by the -alchemists to certain black metallic preparations. Martial ethiops was the black oxyde of iron; mineral ethiops, the black sulphuret
of mercury; and ethiops per se, the black oxyde of mercury.
EVAPORATION (Eng. and Fr.; A.bdarnpfen; Jbdunsien, Germ.) is the process by
which any substance is converted into, and carried off in, vapor. Though ice, camphor,
and many other solids evaporate readily in dry air, I shall consider, at present, merely the
vaporization of water by heat artificially applied.
The vapor of water is an elastic fluid, whose tension and density depend upon the
temperature of the water with which it is in contact. Thus the vapor rising from
water heated to 1650 F. possesses an elastic force capable of supporting a column of mercury 10-8 high; and its density is such that 80 cubic feet of such vapor contain onc pound
weight of water; whereas 321 cubic feet of steam of the density corresponding to a temperature of 212~ and a pressure of 30 inches of mercury, weigh one pound. When the
temperature of the water is given, the elasticity and specific gravity of the vapor emitted
by it may be found.
Since the vapor rises from the water only in virtue of the elasticity due to its gaseous
nature, it is obvious that no more can be produced, unless what is already incumbent upon the liquid have its tension abated, or be withdrawn by some means. Suppose the
temperature of the water to be midway between freezing and boiling, viz., 1220 Fahr., as
also that of the air in contact with it, to be the same but replete with moisture, so that
its interstitial spaces are filled with vapor of corresponding elasticity and specific gravity with that given off by the water, it is certain that no fresh formation of vapor can
take place in these circumstances. But the moment a portion of vapor is allowed to es
cape, or is drawn off by condensation to another vessel, an equivalent portion of vapor
will be immediately exhaled from the water.
The pressure of the air and of other vapors upon the surface of water in an open vessel,
does not prevent evaporation of the liquid; it merely retards its progress. Experience
shows that the space filled with an elastic fluid, as air or other gaseous body, is capable
of receiving as much aqueous vapor as if it were vacuous, only the repletion of that




EVAPORATION.                                    657
space with the vapor proceeds more slowly in the former predicament than in the lat.
ter, but in both cases it arrives eventually at the same pitch. Dr. Dalton has very in.
geniously proved, that the particles of aeriform bodies present no permanent obstacle tc
the introduction of a gaseous atmosphere of another kind among them, but merely obstruct
its diffusion momentarily, as if by a species of friction. Hence, exhalation at atmospheric
temperatures is promoted by the mechanical diffusion of the vapors through the air with
ventilating fans or chimney draughts; though under brisk ebullition, the force of the
steam readily overcomes that mechanical obstruction.
The quantities of water evaporated under different temperatures in like times, are
proportional to the elasticities of the steam corresponding to these temperatures. A
vessel of boiling water exposing a square foot of surface to the fire, evaporates 725
grains in the minute; the elasticity of the vapor is equivalent to 30 inches of mercury.
To find the quantity that would be evaporated from the same surface per minute at a
heat of 880 F. At this temperature the steam incumbent upon water is capable of supporting 128 inch of mercury; whence the rule of proportion is 30: 1'28: 725  3093
showing that about 31 grains of water would be evaporated in the minute. If the air
contains already some aqueous vapor, as it commonly does, then the quantity of evaporation will be proportional to the difference between'"e elastic force of that vapor, and
what rises from the water.
Suppose the air to be in the hygrometric state denoted by 0'38 of an inch of mercury,
then the above formula will become: 30: 1-28 - 0-38:: 725: 21-41; showing that not
more than 211 grains would be evaporated per minute under these circumstances.
The elastic tension of the atmospheric vapor is readily ascertained by the old experiment of Le Roi, which consists in filling a glass cylinder (a narrow tumbler for
example) with cool spring water, and noting its temperature at the instant it becomes
so warm that dew ceases to be deposited upon it. This temperature is that which corresponds to the elastic tension of the atmospheric vapor. See VAPOR, Table of.
Whenever the elasticity of the vapor, corresponding to the temperature of the water
is greater than the atmospheric pressure, the evaporation will take place not only from
its surface, but from  every point in its interior; the liquid particles throughout the
mass assuming the gaseous form, as rapidly as they are actuated by the caloric, which
subverts the hydrostatic equilibrium among them, to constitute the phenomena of ebullition. This turbulent vaporization takes place at any temperature, even down to the
freezing point, provided the pneumatic pressure be removed from  the liquid by the
air pump, or any other means. Ebullition always accelerates evaporation, as it serves
to carry off the aqueous particles not simply from the surface, but from the whole body
of the water.
The vapors exhaled from  a liquid at any temperature, contain more heat than the
fluid from which they spring; and they cease to form whenever the supply of heat into
the liquid is stopped. Any volume of water requires for its conversion into vapor five
and a half times as much heat as is sufficient to heat it from the freezing to the boiling
temperature. The heat, in the former case, seems to be absorbed, being inappreciable by
the thermometer; for steam is no hotter than the boiling water from which it rises. It
has been therefore called latent heat; in contradistinction to that perceived by the touch
and measured by the thermometer, which is called sensible heat. The quantity of heat
absorbed by one volume of water in its conversion into steam, is about 10000 Fahr.;
it would be adequate to heat 1000 volumes of water, one degree of the same scale; or
to raisr  -ne volume of boiling water, confined in a non-conducting vessel, to 11800.
Were tne vessel charged with water so heated, opened, it would be instantaneously emptied by vaporization, since the whole caloric equivalent to its constitution as steam, is
present. When, upon he other hand, steam  is condensed by contact with cold substances, so much heat is set free as is capable of heating five and a half times its weight
of water, from 32? to 212? F. If the supply of heat to a copper be uniform, five hours
and a half will be required to drive off its water in steam, provided one hour was taken
in heating the water, from the freezing to the boiling pitch, under the atmospherical
pressure.
Equal weights of vapor of any temperature contain equal quantities of heat; for
example, the vapor exhaled from one pound of water, at 770 F., absorbs during its
formation, and will give out in its condensation, as much heat as the steam produced by
one pound of water, at 212? F. The first portion of vapor with a tension=30 inches,
occupies a space of 27'31 cubic feet; the second, with a tension of 092 inch, occupies a
space of 890 cubic feet.* Suppose that these 890 volumes were to be compressed into
27*31 in a cylinder capable of confining the heat, the temperature of the vapor would
rise from 770 to 212?, in virtue of the condensation, as air becomes so hot by corn* One pound avoirdupois of water contains 27-72 cubic inches; one cubic inch of water forms 1696 cubit
iaches of steam at 212" F.: therefore one pound of water will form 27*31 cubic feet of such steam: and 0-92
30: * 2731: 890 cubic feet.




658                               EVAPORATION.
pression in a syringe, as to ignite amadou.  The latent heat of steam at 212  F. is
1180~-180=1000; that of vapor, at 77~, is 1180~45=1135; so that, in fact, the
lower the temperature at which the vapor is exhaled, the greater is its latent heat, as
Joseph Black and James Watt long ago proved by experiments upon distillation and the
steam engine.
From the preceding researches it follows, that evaporation may be effected upon two
different plans:1. Under the ordinary pressure of the atmosphere; and that either,
A, by external application of heat to boilers, with a, an open fire; b, steam; c, hot
liquid media.
B, by evaporation with air; a, at the ordinary temperature of the atmosphere; b, by
currents of warm air.
2. Under progressively lower degrees of pressure than the atmospheric, down to
evaporation in as perfect a vacuum as can be made.
It is generally affirmed, that a thick metallic boiler obstructs the passage of the heat
through it so much more than a thin one, as to make a considerable difference in their
relative powers of evaporating liquids. Many years ago, I made a series of experiments
upon this subject.  Two cylindrical copper pans, of equal dimensions, were provided 
but the metal of the one was twelve times thicker than that.of the other.  Each being
charged with an equal volume of water, and placed either upon the same hot plate of
iron, or immersed, to a certain depth, in a hot solution of muriate of lime, I found that
the ebullition was greatly more vigorous in the thick than in the thin vessel, which I
ascribed to the conducting substance up the sides, above the contact of the source of
heat, being 12 times greater in the former case than in the latter.
If the bottom of a pan, and the portions of the sides, immersed in a hot fluid medium,
solution of caustic potash or muriate of li    me, forbe corrugated, so as to contain
a double expanse of metallic surface, that pan will evaporate exactly double the quantity
of water, in a given time, which a like pan, with smooth bottom and sides, will do
immersed equally deep in the same bath.  If the corrugations contain three times the
quantity of metallic surface, the evaporation will be threefold in the above circumstances. But if the pan, with the same corrugated bottom and sides, be set over a fire,
or in an oblong flue, so that the current of flame may sweep along the corrugations, it
will evaporate no more water from its interior than a smooth pan of like shape and
dimensions placed alongside in the same flue, or over the same fire.  This curious fact
I have verified upon models constructed with many modifications.  Among others, I
caused a cylindrical pan, 10 inches diameter, and 6 inches deep, to be made of tinplate, with a vertical plate soldered across its diameter; dividing it into two equal
semi-cylindrical compartments.  One of these was smooth at the bottom, the other
corrugated; the former afforded as rapid an evaporation over the naked fire as the
latter, but it was far outstripped by its neighbor when plunged into the heated liquid
medium.
If a shallow pan of extensive surface be heated by a subjacent fire, by a liquid medium
or a series of steam pipes upon its bottom; it will give off less vapor in the same time
when it is left open, than when partially covered.  In the former case, the cool incumbent air precipitates by condensation a portion of the steam, and also opposes
considerable mechanical resistance to the diffusion of the vaporous particles.  In the
latter case, as the steam issues with concentrated force and velocity from the contracted
orifice, the air must offer less proportional resistance, upon the known hydrostatic
principle of the pressure being as the areas of the respective bases, in communicating
vessels.
In evaporating by surfaces heated with ordinary steam, it must be borne in mind
that a surface of 10 square feet will evaporate fully one pound of water per minute, or
725X 10 = 7250 gr., the same as over a naked fire; consequently the condensing surface must be equally extensive.  Suppose that the vessel is to receive of water 2500
lbs., which corresponds to a boiler 5 feet long, 4 broad, and 2 deep, being 40. cubic
feet by measure, and let there be laid over.the bottom of this vessel 8 connected tubes
each 5 inches in diameter and 5 feet long, possessing therefore a surface of 5 feet square.
If charged with steam, they will cause the evaporation of half a pound of water per
minute. The boiler to supply the steam for this purpose must expose a surface of 5
square feet to the fire.  It has been proved experimentally that 10 square feet surface
of thin copper can condense 3 lbs. of steam per minute, with a difference of temperature
of 90 degrees Fahr.  In the above example, 10 square feet evaporate I lb. of water
per minute; the temperature of the evaporating fluid being 2120 F., consequently
3: I    90: 9-SI. During this evaporation the difference of the temperature is therefore  =  30g. 3 Consequently the heat of the steam placed in connexion with the interior of the boiler, to produce the calculated evaporation, should be, 212 + 30 = 242?,
corresponding to an elastic force of 53-6 inches of mercury. Were the temperature of




EVAPORATION.                                    659
the steam only 224, the same boiler in the same time would produce a diminished quan
tity of steam, in the proportion of 12 to 30; or to produce the same quantity the boiler oi
tubular surface should be enlarged iyi the proportion of 30 to 12.  In general, however,
steam boilers employed for this mode of evaporation are of such capacity as to give an
unfailing supply of steam.
I shall now illustrate by some peculiar forms of apparatus, different systems of evaporation. Fig. 496 explains the principles of evaporating in vacuo. A B represents
es=-_L-^-~                 ^ 496
a pan or kettle charged with the liquor to be evaporated.  The somewhat wide orifice
C, secured with a screw-plug, serves to admit the hand for the purpose of cleaning it
thoroughly out when the operation is finished; h is the pipe of communication with the
steam boiler; b is a tube prolonged and then bent down with its end plunged into the
liquor to be evaporated, contained in the charging back, (not shown in the figure). H is
glass tube communicating with the vacuum pan at the top and bottom, to show by the
height of the column the quantity of liquid within.  The eduction evaporating pipe
c is provided with a stop-cock to cut off the communication when required. i is a tube
for the discharge of the air and the water from the steam-case or jacket; the refrigerator
E is best formed of thin copper tubes about 1 inch in diameter, arranged.zig-zag or spirally
ike the worm of a still in a cylinder. The small air-tight condenser F, connected with
the efflux pipe f of the refrigerator, is furnished below with a discharge cock g, and
surrounded by a cooling case, for the collection of the water condensed by the refrigerator. In its upper part there is a tube k, also furnished with a cock, which communicates
with the steam boiler, and through which the pan A B is heated.
The operation of this apparatus is as follows: after opening the cocks c, f g,
and before admitting the cold water into the condenser E, the cock of fhe pipe k is
opened, in order that by injecting steam it may expel the included air; after which the
cocks k and g are to be shut. The water must now be introduced into the condenser,
and the cock b opened, whereon the liquid to be evaporated rises from the charging back,
through the tube b, and replenishes the vacuum pan to the proper height, as shown by
the register glass tube H. Whenever the desired evaporation or concentration is effected, the cock c must be closed, the pipe k opened, so as to fill the pan with steam, and
then the efflux cock a is opened to discharge the residuary liquor. By shutting the
cocks a and k, and opening the cock b, the pan will charge itself afresh with liquor, and
the operation will be begun anew, after b has been shut and c opened.
The contents of the close water cistern F, may be drawn off during each operation.
For this purpose, the cock f must first be shut, the cold water is to be then run out of
the condenser G, and k and g are to be opened.  The steam entering by k makes the
water flow, but whenever the steam itself issues from the cock g, this orifice must be
immediately shut, the cock f opened, and the cold water again introduced, whereupon
the condensed water that had meanwhile collected in the under part of the refrigerator,
flows off into the condenser vessel F.  Since some air always enters with the liquor




660                             EVAPORATION.
sucked into the pan, it must be removed at the time of drawing off the water from the
two condensers, by driving steam through the apparatus. This necessity will be less
urgent if the liquor be made to boil before being introduced into the vacuum pan.
Such an apparatus may be modified in size and arrangement to suit the peculiar object
in view, when it will be perfectly adapted for the concentration of extracts of every kind,
as well as saline solutions containing vegetable acids or alkalis. The interior vessel of
A B should be made of tinned or plated copper. For an account of Howard's vacuum
pan, made upon thMe same principle, see SUGAR.
When a boiler is set over a fire, its bottom should not be placed too near the grate, lest
it refrigerate the flame, and prevent that vivid combustion of the fuel essential to the
imaximum production of heat by its means. The evil influence of leaving too little room
between the grate and the copper may be illustrated by a very simple experiment. If a
small copper or porcelain capsule containing water be held over the flame of a candle a
little way above its apex, the flame will suffer no abatement of brightness or size, but
will continue to keep the water briskly boiling. If the capsule be now lowered into the
middle of the flame, this will immediately lose its brightness, becoming dull and smoky,
covering the bottom of the capsule with soot; and owing to the imperfect combustion,
though the water is now surrounded by the flame, its ebullition will cease.
Fig. 497 is a section of two evaporating coppers en suite, so mounted as to favor the
497
full combustion of the fuel. A is the hearth, in which wood or coal may be burned. For
coal, the grate should be set higher and be somewhat smaller. a is the door for feeding
the fire; d, an arch of fire-bricks over the hearth; c, a grate through which the ashes
fall into the pit beneath, capable of being closed in front to any extent by a sliding door
b. B and c are two coppers incased in brickwork; f the flue. At the end of the hearth
near m, where the fire plays first upon the copper, the sole is made somewhat lower and
wider, to promote the spreading of the flame under the vessel. The second copper, c,
receives the benefit of the waste heat; it may be placed upon a higher level, so as to
discharge its concentrated liquor by a stop-cock or syphon into the first. When coals
are burned for heating such boilers, the grate should be constructed as shown in the
figure of the brewing copper, page 122.
Fig. 498 represents a pan for evaporating liquids, which are apt, during concentration, to let fall crystals or other sediment.
498     These would be injured either by the fire play
c(ing upon the bottom of the pan, or, by adhesion
~...........                to it, they would allow the metal to get red hot,
and in that state run every risk of being burnt
I               or rent on the sudden intrusion of a little liquor
I      \\'      through the incrustation. When large coppers
have their bottoms planted in loam, so that the
4    l ^                              flame circulates in flues round their sides, they
l   ~( ((~, ~             A is a pear-shaped pan, charged with the
I'Q III  Ga    liquid to be evaporated; it is furnished with a
i        g ml 3 In                dome cover, in which there is an opening with
r;   6 in III~-lla flange f, for attaching a tube, to conduct the
6                                 steam wherever it may be required. a is the
^      fire-place; b the ash-pit. The conical part terA ^                   minates below in the tube g, furnished with a
stop-cock at its nozzle h.  Through the tube
c d c', furnished above and below with the stopcocks c and c', the liquid is run from  the




EXPANSION.                                         661
charging back or reservoir.  During the operation, the upper cock c is kept partially
open, to replace the fluid as it evaporates; but the under cock c' is shut. The flame
from the fire-place plays round the kettle in the space e, and the smoke escapes downwards through the flue i into the chimney. The lower cylindrical part g remains thus
comparatively cool, and collects the crystalline or other solid matter. After some time,
the under stop-cock c', upon the supply-pipe, is to be opened to admit some of the cold
liquor into the cylindrical neck. That cock being again shut, the sediment settled, and
the large stop-cock (a horizontal slide-valve would be preferable) h opened, the crystals
are suffered to descend into the subjacent receiver; after which the stop-cock h is shut,
and the operation is continued.  A construction upon this principle is well adapted for
heating dyeing coppers, in which the sediment should not be disturbed, or exposed to the
action of the fire. The fire-place should be built as for the brewing copper.
Fig. 499 represents an
^499 in   ^oblong evaporating  pan,
in which the flame, after
beating along its bottom,
I  llllllltlll lllllll ltl ull ml 1 lllll. l!ti Il iltt llll lil flll!!!!iIi IIit i  turns   up   at    its   further
___________,_,.                           end, plays back along its
surfacend passes off in
l0  toI5 feet long,4to6
feet broad, and I or 1
feet deep. The fire-bricks, upon which the pan rests, are so arranged as to distribute
the flame equably along its bottom.
For the following scheme of generating, purifying, and condensing steam, Mr. Charles
Clarke, merchant, London, obtained a patent in January, 1843. His apparatus for
converting sea-water, &c., economically into good fresh water, is represented in figs.
500, 501, 502. A is the supply cistern, which communicates with a pipe a, with a
self-regulating eduction apparatus B. c is a strong wrought iron cylinder, fitted at
bottom into a flanged ring-place c, and covered with a conical top; it is about two
thirds filled with the water to be operated upon. D is a cylindrical furnace concentric
with the water cylinder c; d is an upward air and water-tight tube, which serves both
as a feed-pipe, through which the fuel is supplied to the furnace, and as a passage
for the escape of the smoke and other gaseous products of combustion; e is a hinged
trap-door through which the fuel is passed into the tube d: h is a chimney into which
the pipe d terminates: and i, a damper, by which the degree of activity given to the
furnace can be regulated at pleasure; f is an open air-pipe, which leads from the
outside, through the boiler, into the furnace, a little way above the fire-bars, and
assists in securing a good draught through the furnace into the chimney. To the
water cylinder c there are attached gauge-cocks, g g, for ascertaining from time to
time the height of the water; I is a cock or tap for drawing off the brine, and other
residual matters which collect at the bottom of the boiler; m is a screw-cap and hole,
through which access may be had to the interior of the water cylinder c, when it
needs to be cleaned; E is a short pipe fitted into the conical top of the water cylinder
c, which conveys the steam generated in it into the steam-head or receiver F:  is a
concave plate, resting upon the top of the pipe E, a little larger than that pipe, and
kept steady by a weight, k, of one or more pounds, suspended from  it by wires.
This plate prevents, in a great measure, the escape-water escaping into the steam-head
(an accident commonly called priming in steam engines); because, till the steam has
acquired a pressure exceeding that of the counterweight k, it cannot raise the weight
o, so as to escape freely into the steam-head F, since any particle of water must, during
the rising of the cap G, strike against it, and drop back, either into the water cylinder
c, through the pipe z, or into the space round that pipe at the bottom of the steamhead H; whence it may be withdrawn by the cock shown in the drawing. H is a
pipe which conveys the steam from the steam-head F to the rectifier a. This consists
simply of a cylinder (about one third the size of the cylinder c) laid horizontally, in
the 1 wer part of which a body of water speedily collects, and serves to retain any
particle of undecomposed matter, which may come over with the steam, as it continues to flow in from the boiler; whereby only its purer portions may pass off from
the rectifier a, by the pipe N. n is a cock or tap, at the bottom of the cylinder R for
drawing off its water occasionally; Rit is a second steam-rectifier, like R, into which the
steam passes from the pipe N, and is thereby still further purified; but when the
proportion of saline matter is small, Ra may be dispensed with, and for very foul water,
two or three more such rectifiers may be added.
The condenser for liquefying the purified steam, and aerating the resulting water,
is shown at ti, t, t'. It is composed of conical upright compartments communicating
with each other; the chamber ti is surrounded by the water in the cistern A (slightly




6b2                               EVAPORATION.
heated by the steam in that chamber), while the chambers t and t are exposed freely
to the air. The lowest of these, t3, terminates at bottom in a tube, u, containing at the
mouth of the cone two or three plates of perforated zinc, for admission of the atme\iV —
502                                         5
sphere.  An upright steam-tight tube of zinc, at about the middle of the lowest
chamber, t3, and is continued to the top of the uppermost chamber, ti, having two lateral
branches. This tube is closed at its lower end, but open at top, and at the ends of the
two branches, to give a draught of cool air into the tube, and a rapid flow of heated
air from the top of the tube. W, W, are pipes which pass externally from about the
middle of the chamber t2, to near the bottom of the chamber 13. At their tops they
are of large dimensions, as represented, but diminish gradually to small pipes at bottom,
Of these pipes, there should be as many as can be conveniently applied, in order that
the process of condensation may be effectually promoted.
From the second rectifier, RI, the steam is conveyed by a pipe, w, of gradually in.
creasing dimensions, to near the top of the middle chamber, t., whence it diffuser itself
through the three chambers, where it gets condensed. The hottest steam passes into
11, and is there most powerfully condensed. The main body of the water produced
therefrom, either drops directly into the bottom of the chamber t3, or runs down the in.
clined sides of the chambers ti, 12, t3, thence through the outer pipes W, W, and out at
the bottom of the tube, getting partially aerated in its progress, by means of the air ascending constantly through the tube u.
Z, Z, is an auxiliar steam-pipe from the rectifier RI, passing twice or thrice close
round the water supplying the cistern, A, and terminating in a cylinder which communicates by pipes with the chambers, t2 and t3; whereby all the water thus condensed




EVAPORATION.                                           663
may fall through the perforated zinc plates, into the general discharge tube, u. x is
an outer casing of wood or metal, leaving a small space round the condenser, with
draught-holes, x, x, for the admission of air.  The refrigerator is made of protected
metal "(tinned copperl)," and divided into three compartments, y', y, y.,
In the top ofyl, the end of the discharged tube u is inserted; and at a little distance
from this tube there are air apertures, a, a, furnished with shutters in the inside,
slanting from the top downward, to prevent as much as possible the escape outward
of any vapor which may occasionally be carried down with the water from  the condenser.  The middle compartment, y2, is perforated, convex at top, and concave at
bottom; so that the water that drops from the tube u, in the convex topof y, falls off
laterally through small pipes into the chamber y2, while its concave bottom turns the
water into a central filtering-box, c, that projects a little into y3, set to receive it.
For aerating this water, the bottom of y2 is covered about an inch deep with small
pebbles. 3y3, which is the reservoir of the purified cool water, is perforated with small
holes. cl, ct, are small pipes for promoting a continual upward flow of cold air. y3 is
furnished with a tap to draw off its water, as required.
For redistilling or rectifying spirituous liquids, the apparatus, fig. 501, is employed;
in which the supply cistern A is much larger, and close at top; the upper condensing
chambers, tP, 1, are also larger, but the lowest, t3, is narrowed.   The second rectifier
offtg. 500, is removed. The feints collect in the bottom of the rectifier R, to be drawn
off by a cock; while the rectified spirit passes off at top into the condenser. The refrigerator has only two compartments, and no pebbles.   F  is a funnel into which the
spirits may be returned for redistillation.
For extracting the soluble matter of vegetable infusions, the apparatus, shown in
fig. 502,is used.  The rectifier is vertical, has a screw-capped hand-hold, foradmitting
the vegetables. g is a steam-pipe; and h is a funnel for returning portions of the
liquid extract. R is connected by a pipe, k, with the condenser, T, made in two portions, fitted water-tight together, but separable for the purpose of cleansing. The
steam which passes from the boiler into the rectifier R disengages the soluble portion
of the vegetable substances, and if they be volatile, carries them off to the condenser;
if not, it combines and falls with them to the bottom of the vessel, whence this portion
of the extract is drawn off by the cock, and a fresh charge may be introduced. The
steam is shut off from  the rectifier R by a cock on pipe g.  When the steam is afterward admitted to assist the process of maceration, the supply of it is regulated by the
stop-cocks in the pipes g and k.-Newton's Journal, xxiii. p. 247, C. S.
In each experiment 1,840 lbs. weight were burnt, and the relative quantities of water
evaporated show the relative economic effect. Two kinds of coal were used: Knowles's
Clifton coal, a free burning kind which does hot cake, and produces a considerable
quantity of ashes; Barker and Evan's Oldham  coal, a slow burning rich caking coal,
yielding little ashes. The boiler was a 24-horse power, of Watt's waggon shape.
Mr. II. Houldsworth's Economy of Evaporation.
Effect per Minute.    rated by  Ae
Weight of Charge.          Air.                                            ratare ia  nomic
Clifton coal:                                Lbs.   Galls.  Galls.  Lbs.  Degrees.
460 lbs.   - No air     -.     -   4-64    2-5      992'  5-41    973     106   b
460 lbs.   - 45 square  inches constant                                                   e
aperture    -    -    -   4-68    3-21    1263    6-85    1165    135   -
230 lbs.   - Air regulated partly by the                                                  0
eye, and partly by a scale,
varying in some degree with                                                ~
the action of combustion  -   4-43    3-09    1280    6-94    1122    136   ^
230 lbs.   - 45 square inches    -    -   4-65    3-05    1210    6-6    1220    129   >,
230 lbs.   - No air  -    -         -      4-43    2-3     942    5-12    995    100 0
460 lbs.   - Air through two pipes 6 in.                                                  0
in diameter, each regulated                                               5
by light    -           -   4-65    3-13    1250    6-8    1160    134   g
Oldham coals'
230 lIbs.   - No air  -    -    -      -   31-7    2-65    1340    7-3     690    100
230 lbs.   - 35 square inches constant
230 lbs.   - 24  square inches constant   4
aperture    -    -    -   3-82    2-82    1360    7-4    1050       102   3
460 & 230 lbs. Air regulated by a scale    -   3-84    2.94    1410    7.7    1070    106   ^
230 lbs.   - Air regulated so as to produce no smoke    -    -   3-61    287    1530    8-3    1053        114   ^
Hald Oldham,
half Clifton-  -    -         -     -      4.0.5    29     1320    7-2    1060




664                                EXPANSION.
The average heat given in the first flue, as ascertained by a pyrometer and deduced
from pyrometric diagrams. The air was admitted partly at the door and partly at the
bridge; at the latter point through one of Mr. Williams's diffusion boxes, except in the
last experiment with Clifton coal. They showed the effect of admitting air in greater
or less quantity permanently or periodically by a uniform or varying aperture; and the
general result arrived at is, that by the simple and inexpensive plan of admitting air
into the furnaces at both the door and bridge by permanent apertures always open,
varying in aggregate area from 12 to 3 square inches (according to the quality of the
coals) for every square foot of area of grate, an important saving in fuel is effected, and
of the dense smoke prevented, without any special care of the fireman.
Deductions from the experiments on Clifton Coal:Gain in evaporation by regulated admission of air     -      - 35 per cent.
Do.         by 45 square inches constant aperture     - 34
Do.         by charges of 460 lbs. instead of 230 lbs. - 4
Steam produced in a given time:No air           -     230 lbs. charges    -     - 100
No air           -   - 460 lbs. do.       -      - 109
53 square inches air - 230 lbs. do.       -      - 132
Air regulated-      - 230 lbs. do.        -      - 134
53 square inches    - 460 lbs. do.        -      - 140
showing that the admission of air increases the production of steam in a given time
from.30 to 40 per cent.
EUDIOMETER, is the name of any apparatus subservient to the chemical examination of the atmospheric air. It means a measure of purity, but it is employed merely to
determine the proportion of oxygen which it may contain. The explosive eudiometer, in
which about two measures of hydrogen are introduced into a graduated glass tube, containing five measures of atmospheric air, and an electric spark is passed across the mix.
ture, is the best of all eudiometers; and of these the syphon form, proposed by me in a
paper published by the Royal Society of Edinburgh in 1819, is probably the surest and
most convenient. Volta's explosive eudiometer, as made in Paris, costs 3 guineas; mine
may be had nicely graduated for 6 or 8 shillings.
EXPANSION (Eng. and Fr.; Ausdehnung.  Germ.) is the increase of bulk experienced
by all bodies when heated, unless a change of chemical texture takes place, as in the
case of clays in the potter's kiln. Table I. exhibits the linear expansion of several solids
by an increase of temperature from 320 to 2120 Fahr.; Table II. exhibits the expansion
in bulk of certain liquids.
TABLE 1.-Linear Dilatation of Solids by Heat.
Dimensions which a bar takes at 2121, whose length at 320 is 1I000000.
Dilatation   Dilatation
Substances                    Authority,           in       in Vulgar
Decimals.   Fractions.
Glass tube -    -    -    -     -   Smeaton      -    -   1-00083333
do.. -         -.    -     Roy  -    -    -        1-00077615
do.    -    -    -    -     -   Deluc's mean -    -   1-00082800       T- I'
do.-    -    -         -        Dulong and Petit       1-00086130    yy48
do. —   Lavoisier and Laplace  1-00081166                              iL
Plate glass        -         -          do.         do.    1-000890890    u.4
do. crown glass             -       do.         do.    1-00087572        1 -
do.    do..           -         do.         do.    1-00089760        IL
do.    do.               -          do.         do.    1-00091751    9l0
do. rod    -                    Roy    -      -    -   1-00080787
Deal -----   Roy, as glass -                                    -
Platina  -      -     -      -      Borda  -    -    -   1-00085655
do.    -.      -    -       -   Dulong and Petit       1-00088420    1do.-      --                    Troughton   -    -   1-00099180
do. and glass -    -    -    -   Berthoud  -    -      1-00110000
Palladium          -                Wollaston   -    -   l00100000
Antimony -Smeaton -  -   1-00108300
Cast-iron prism                     Roy    -    -    -   1-00110940
Cast-iron -Lavoisier,byDrYoung 1-00111111
Steel                               Troughton   -    -   1-00118990




EXPANSION.                                       665
Dilatation   Dilatation
Substances.                     Authority,              in       in Vulgar
Decimals.   Fractions.
Steel rod -Roy   -  -  -  l00114470
Blistered Steel  -    -     -         Phil. Trans. 1795, 428  1-00112500
do.          -    -               Smeaton -    -    -   1'00115000
Steel not tempered    -    -          Lavoisier and Laplace  1'00107875        ~
do.  do.             -    -             do.          do.      1-00107956        1
do. tempered yellow  -    -             do.          do.      1-00136900      9
do.  do.       do.   -    -             do.          do.      1-00138600
do.  do.       do. at a higher heat     do.          do.      1-00123956
Steel -Troughton  -  -  1-00118980
Hard Steel -     -    -        -      Smeaton -    -    -   1'00122500
Annealed steel -    -                 Muschenbroek         -   1-00122000
Tempered steel -    -                      do.       -     -   1-00137000
Iron  -    -     -       -            Borda   -    -    -   1-00115600
do.  -          -    -    -          Smeaton -    -    -   1-00125800
Soft iron, forged -    -              Lavoisier and Laplace  1-00122045
Round iron, wire drawn    -              do.          do.      1-00123504
Iron wire -Troughton   -  -  1-00144010
Iron -Dulong and Petit -  1-00118203
Bismuth       -    -    -    -        Smeaton -    -    -   1-00139200          84
Annealed gold   -     -     --        Muschenbroek        -   1-00146000
Gold -Ellicot, by comparison 1-00150000
do. procured by parting   -          Lavoisier and Laplace  1-00146606        -42
do. Paris standard, unannealed -        do.           do.     1-00155155       ~
do.    do.          annealed    -       do.           do.     1-00151361        1
Copper    -         -            -   Muschenbroek         -   1-0019100        66
do.      -        -- -      -       Lavoisier and Laplace  1-00172244        -1
do.         -    -             -       do.          do.      1-00171222.i
do.      -        -- -      -       Troughton    -    -   1-00191880         W 84
do.      -     -    -     -    -   Dulong and Petit  -   1-00171821            1
Brass      -    -    -    -    -   Borda   -    -    -   1-00178300
do.       -       -- -    -         Lavoisier and Laplace  1-00186671
do.       -    -     -    -     -       do.          do.      1-00188971
Brass scale, supposed from Hamburg  Roy        -    -    -   1-00185540
Cast brass -Smeaton -  -  -  1-00187500
English plate-brass, in rod  -        Roy      -    -    -   1'00189280
do.       do.  in a trough form     do.      -    -    -   1-00189490
Brass -    -     -       -            Troughton    -    -   1-00191880
Brass wire -    -                     Smeaton -    -    -   1-00193000
Brass -    -     -       -            Muschenbroek        -   1-00216000
Copper.8, tin I -    -     --        Smeaton -    -    -   1-00181700
Silver-                               Herbert -    -    -   1-00189000
do. -                               Ellicot, by comparison 1-0021000
do. —                               Muschenbroek  - 1-00212000
do. of cupel  -      -     --       Lavoisier and Laplace  1-00190974
do. Paris standard -      -     -      do.           do.      1-00190868
Silver                                Troughton    -    -   1-0020826           "4
Brass 16, tin I-    -    -            Smeaton -    -    -   1-00190800
Speculum metal -               -         do.   -     -         1-00193300
Spelter solder; brass 2, zinc I   -      do.   -     -    -   1'00205800
Malacca tin      -    -    -          Lavoisier and Laplace  1-00193765        316
Tin from Falmouth   -    -    -          do.          do.      1-00217298        1
Fine pewter    -    -    -            Smeaton -    -    -   1-00228300         462
Grain tin  -          -          -       do.   -    -    -   1-00248300
Tin-                                  Muschenbroek   -  1-00284000
Soft solder; lead 2, tin 1   -        Smeaton -    -    -   1-00250800
Zinc 8, tin 1, a little hammered.do.   -    -    -   1-00269200
Lead -    -    -    -                 Lavoisier and Laplace  1-00284836        35
do.-       -    -    -     --        Smiaton -    -    -   1-00286700
Zinc -     -     -    -     --           do.   -    -    -   1-00294200
Zinc, hammered out 1 inch per foot       do.   -    -    -   1-00301100         1
Glass, from 320 to 2120    -    -   Dulong and Petit  -   1-00086130            J61
do.  from 2120 to 3920   -    -        do.        do.   -   1-00091827           T -9
do.  from 3920 to 5720   -    -        do.        do.   -   1-000101114         I7
The last two measurements-by an air thermometer.




666                                  EXTRACTS.
TABLE II.
Expansion of certain Liquids by being Heated from 320 to 212~.
Expansion    Expansion
Substances.                      Authority,              in       in Vulgar
Decimals.    Fractions.
Mercury  -         -      -       -   Dulong and Petit  -   0'01801800
do.   in glass -        -       -      do.        do.   -   0-01543200           A
Water, from  its maximum density    Kirwan          -       -   0*04332             1
1                                                       ~~~~~~~~~~~~~2W9
Muriatic acid (sp. gr. 1-137)     -   Dalton        -       -   0-0600              1
Nitric acid (sp. gr. 1'40) -       -     do.        -       -   0-1100              I
9
Sulphuric acid (sp. gr. 1-85)      -     do.        -       -   0'0600              1
Alcohol (to its boiling point)?   -      do.        -       -   0-1100
Water    -         -       -       -     do.        -       -   00460               1
Water, saturated with common salt    do.            -       -   0-0500              2L
Sulphuric ether (to its boiling point)?   do.      -       -   00''V)              Tl
Fixed oils        -       -.     do.        -       -   O'0800 0. 
Oil of turpentine -       -.     do.        -       -   00700
If the density of water at 390 be called  -      -       -    1-00000,
at 2120 it becomes         -       -       -    0-9548,
and its volume has increased to            -    1-04734;
at 770 it becomes -        -       -       -    0-9973587,
and its volume has increased to only       -    1-00265,
which, though one fourth of the whole range of temperature, is only JL of the to.
tal expansion. Water at 600 F. has a specific gravity of -    0-9991953,' 
and has increased in volume from 390 to  -    1-00008,
which is only about -I- of the total expansion to 2120, with -I- of the total range of
temperature.
All gases expand the same quantity by the same increase of temperature, which from
32~ to 212' Fahr. = -800 = A, or 100 volumes become 1-375. For each degree of Fahr.
the expansion is 4~I0
When dry air is saturated with moisture, its bulk increases, and its specific gravity
diminishes, because aqueous vapor is less dense than air, at like temperatures.
The following table gives the multipliers to be employed for converting one volume of
moist gas at the several temperatures into a volume of dry gas.
Temperature.           Multiplier.           Temperature.            Multiplier.
530 F.                0-9870                 640                   0-9799
54                    0'9864                 65                    0-9793
55                    0-9858                 66                    0-9786
56                    0-9852                 67                    0-9779
57                    0-9846                 68                    0-9772
58                    0-9839                 69                    0-9765
59                    0-9833                 70                    0-9758
60                    0-9827                 71                    0-9751
61                    0-9820                72                     0-9743
62                    0-9813                73                     0-9735
63 0-9806_______________________________
Expansion       ~ of certain Solids.Absolute                Dilatation of a
Expansion of certain Solids.                Dilatation.        Metre.
Brass  -       -       -       -       -       -      0-00187821          1-8782
Hammered iron          -       -       -       -     0-00122043           1-2204
Carrara marble         -.-                    0-00084867          08486
Marble of St. Beat    -.       -       -      0-00041810         04181
Marble of Saht         -       -       -       -      0-00056849          0-5685
Stone of Vernon on Seine    -          -       -      0'00043027          0-4303
Stone of St. Lew               -       -       -      0-00064890          0-6489
Stone of Veilvie (volcanic)                    -     0-00020390           0-2039
Alloy of D'Arcet       -               -       -     0-00169688           1-6968
Bismuth                -       -       -.     0-00121034           1-2103




FAINTS.                                       667
EXTRACTS.  (E~xtraits, Fr.; Extracten, Germ.)  The older apothecaries used this
term to designate the product of the evaporation of any vegetable juice, infusion, or
decoction; whether the latter two were made with water, alcohol, or ether; whence
arose the distinction of aqueous, alcoholic, and etherous extracts.
Fourcroy made many researches upon these preparations, and supposed that they
had all a common basis, which he called the extractive principle. But Chevreul and
other chemists have since proved that this pretended principle is a heterogeneous and
very variable compound. By the term  extract therefore is now  meant merely the
whole of the soluble matters obtained from vegetables, reduced by car.eful evaporation
to either a pasty or solid consistence. The watery extracts, which are those most commonly made, are as various as the vegetables which yield them; some containing
chiefly sugar or gum  in great abundance, and are therefore innocent or inert; while
others contain very energetic impregnations.  The conduct of the evaporating heat is
the capital point in the preparation of extracts. They should be always prepared if
possible from the juice of the fresh plant, by subjecting its leaves or other succulent
art, to the action of a powerful screw or hydraulic press; and the evaporation should
be effected by the warmth of a water bath, heated not beyond 1000 or 120~ F. Steam
heat may perhaps be applied advantageously in some cases, whereat is not likely to decompose any of the principles of the plant. But by far the best process for making
extracts is in vacuo, upon the principles explained in the article EVAPORATION. It is
much easier to fit up a proper apparatus of this kind, than most practical men imagine.
The vacuum may either be made through the agency of steam, as there pointed out, or
by means of an air- pump.  One powerful air-pump may form  and maintain a good
vacuum under several receivers, placed upon the flat-ground flanges of so many basins,
each provided with a stop-cock at its side for exhaustion. The air-less basin containing
the juice being set on the shelf of a water-bath, and exposed to a proper temperature,
will furnish in a short time a large quantity of medicinal extract, possessing the
properties of the plant unimpaired.
For exceedingly delicate purposes, the concentration may be performed in the cold,
by placing saucers filled with the expressed juice over a basin containing sulphuric
acid, putting a glass receiver over them, and exhausting its air.
These preparations of vegetables for medicinal use are made either by evaporating the
infusions of the dried plant in water, or in alcohol, or the expressed juice of the fresh
plant; and this evaporation may be effected by a naked fire, a sand bath, an air bath, a
steam heat, or a liquid balneum of any nature, all of which may be carried on either in
the open air, or in vacuo. Of late years, since the vacuum-pan has been so successfully
employed in concentrating syrups in sugar-houses, the same system has been adopted for
making pharmaceutical extracts. An elegant apparatus of this kind invented by Mr.
Barry, of Plough Court, was made the subject of a patent about 35 years ago. The
use of the air-pump for evaporating such chemical substances as are readily injured by
heat, has been very common since Professor Leslie's discovery of the efficacy of the combined influence of rarified air and an absorbing surface of sulphuric acid in evaporating
water at low temperatures. It has been supposed that the virtues of narcotic plants in
particular might be better obtained and preserved by evaporation in vacuo than otherwise, as the decomposing agency of heat and atmospheric oxygen would be thereby excluded. There is no doubt that extracts thus made from the expressed juices of fresh
vegetables possess, for some time at least, the green aspect and odor of the plants in
far greater perfection than those usually made in the air, with the aid of artificial heat.
Dr. Meurer, in the Archiv. der Pharmacie for April, 1843, has endeavored to show that
the color and odor are of no use in determining the value of extracts of narcotics,
that the albumen left unchanged in the extracts made in vacuo tends to cause their
spontaneous decomposition, and that the extracts made with the aid of alcohol, as is
the practice in Germany, are more efficacious at first, and much less apt to be injured
by keeping. M. Baldenius has, in the same number of the Archiv., detailed experiments to prove that the juices of recent plants mixed with alcohol, in the homoeopathic
fashion, are very liable to spontaneous decomposition. To the above expressed juice,
the Germans add the alcoholic tincture of the residuary vegetable matter, and evapora.
ting both together, with filtration, prepare very powerful extracts.
F.
FAHLERZ.  Gray copper-ore, called also Panabase, from  the many oxides it contains.
FAINTS is the name of the impure spirit which comes over first and last in the




668                  FAIRBAIRN'S TUBULAR BRIDGES.
distillation of whiskey; the former being called the strong, and the latter, which is much
more abundant, the weak faints. This crude spirit is much impregnated with fcetid
essential oil, is therefore very unwholesome, and must be purified by rectifications.
FAIRBAIRN'S TUBULAR BRIDGES.  Of the tubular bridge system, the Con.
way and Menai are the first, and will probably for ever remain the most remarkable
specimens, to attest the scientific genius of Mr. W. Fairbairn, their inventor and constrnctor. His claims, indeed, are exclusive and palpable. Mr. Robert Stephenson, however, has fortunately for himself, claimed the entire merit of having not only first
conceived the idea of constructing a tubular bridge of such huge dimensions as to
allow the passage of locomotive engines and railway trains through the interior of it,
and of such length as to span distances of from 400 to 500 feet, but of having assured
himself by laborious investigation and calculation of "the perfect feasibility of the
work," without consulting any one else on the subject; and he has assigned to Mr.
Fairbairn, in a very slighting fashion the place of a mere after adviser, of one who,
in common with two other gentlemen  (Mr. Eaton  Hodgkinson and Mr. Edwin
Clarke), but not more than'either of them, assisted him in working out the construction
which he "first broached."  Mr. Fairbairn maintains, on the contrary, that the idea
of a tubular bridge, though it unquestionably originated with Mr. Stephenson, was
in his hands nothing more than a crude conception, very hesitatingly entertained, until
he (Mr. Fairbairn) was called in to work it out, and that it has been wholly owing to
his determined perseverance in the execution of the task confided to him, and to his
numerous and elaborate experiments, that " the true principle on which tubular bridges
should be constructed has been established, and thereby Mr. Stephenson's vague idea
successfully carried into execution."
"At the period of the consultation in April, 1845, there were no drawings illustrative
of the original idea of the bridge, nor had any calculations been made as to the strength,
form, or proportions of the tube. I was asked whether such a design was practicable,
and whether I could accomplish it: it was ultimately arranged that the subject should
be investigated experimentally, to determine not only the value of Mr. Stephenson's
original conception, but that of any other tubular form of bridge which might present
itself in the prosecution of my researches. The matter was placed unreservedly in my
hands; the entire conduct of the investigation was intrusted to me; and, as an experimenter, I was to be left free to exercise my own discretion in the investigation of
whatever forms or conditions of the structure might appear to me best calculated to
secure a safe passage across the Straits."  (W. Fairbairn's Correspondence.)
In commenting on the treatise of Mr. Fairbairn  " on the Construction of the
Britannia and Conway Bridges," the editor of the Mechanics' Magazine says, "We
have read it carefully, and not without strong prepossessions in favor of the inculpated
party, but we feel honestly bound, however, to say, that the perusal has left us convinced, in spite of all leanings, that Mr. Fairbairn has not received at Mr. Stephenson's
hands that justice to which lie was entitled, but, on the contrary, has been treated most
ungenerously and ungratefully.  We will not say, that but for Mr. Fairbairn the
tubular bridge idea would never have been carried out into practice, for that would
be to assume that he engrossed in his single person all the practical skill of the
country; but, looking into the facts of the case as they stand, and as we see them
established in the volume before us beyond all possibility of dispute, we hesitate not
to affirm, that it is more owing to Mr. Fairbairn, than to any one other individual
whatever, not excepting Mr. Stephenson himself, that it is now the triumphant reality
which it is.  Another might possibly have done the part which fell to the lot of
Mr. Fairbairn as well, but none could possibly have done it better. He conceived
and directed all the preliminary experiments,-all at least with an exception or two,
which were of any practical value, exhibiting therein a combination of philosophical
painstaking with mechanical skill and ingenuity, such as is not often witnessed; he
finally settled the form which it was best to give to the tube, and arranged the
whole of the executive details; he personally superintended the construction of the
Conway Bridge, which our readers are aware is but the Menai or Britannia Bridge
on a smaller scale; and he only retired from further co-operation with Mr. Stephenson
in the affair, when nothing new was left to be discovered or achieved. The motives
for his retirement are thus very fairly and temperately stated:"'I have now brought down this correspondence to the period when my official con
nection with the Chester and Holyhead Railway Company as engineer, for the construction of the tubular bridges, may be said to have virtually ceased, and I should
willingly have passed over in silence the remainder of the events which transpired, were
it not that the completeness of the narrative, as well as the justification of my conduct
demanded some explanation, independently of the regret which I experienced in withdrawing from an undertaking to which I had devoted so much time and thought,-an




FAIRBAIRN'S TUBULAR BRIDGES.                                      669
undertaking fraught with the greatest interest, and which had, as it were, grown up in
all its magnificent proportions under my own directions.  I can truly say that the disagreement which took place with Mr. Stephenson is on my part much deplored. But I
trust that the reader of the foregoing pages will at least have arrived at the conclusion,
that I had taken the most important part in developing, and giving a practical form
to Mr. Stephenson's idea, and also in the superintending the construction and erection
of the first Conway tube. The fact is, I labored almost incessantly in devising plans,
or in watching over the practical details of the work, from the day in which Mr.
Stephenson's suggestion was communicated to me until the close of my engagement;
and I can sincerely say that I was always actuated by the principle of leaving nothing
undone which could in any way contribute to the successful accomplishment of the
undertaking.  Regardless of the prognostications of failure with which the scheme was
assailed, and in despite of the opposition of those whose assistance I had solicited, I
uniformly advocated the peculiar principle on which the Conway Bridge has been constructed.
"' Such being my position, and viewing the extent of services I had rendered, it will, I
think, be generally allowed that it was very natural that I should desire to have my
name publicly associated with Mr. Stephenson's as joint engineer for these bridges.
Indeed, it may very fairly be said that I might have ventured to claim this distinction,
since it had been conferred upon me by the Board of Directors on Mr. Stephenson's own
recommendation.  If, instead of success having crowned our efforts, failure had unfortunately ensued, would not my reputation have suffered as well as Mr. Stephenson's?
The working plans having gone forth with my name alone attached to them, and from
my being recognised as the acting engineer, might not the whole blame have been conveniently thrown on me in case of failure?
"'It was not, however, on any of these grounds that I was induced to resign my
appointment, for there had not then occurred any opportunity where I conceived it
necessary to have my position publicly recognised; and I had always believed that,
when the proper time came, Mr. Stephenson would be the first to establish that position,
and acknowledge the services I had rendered.  The recognition was, however, very
shortly afterwards denied me. The first Conway tube having been completed, and the
success of the principle established, I conceived that the construction of the remaining
tubes simply required a close attention to the system of construction already adopted,
and therefore might safely be entrusted to those gentlemen whose constant presence
during the building of the first tube had rendered them thoroughly acquainted with the
whole details of the work. By such an arrangement, moreover, the Company would save
the amount which had hitherto been paid for my services, and I should be enabled to
devote my time to other pursuits which I had neglected for this work, and which now
urgently demanded my attention. This was one reason for my retirement; but what
chiefly led me to this decision, was the position assumed by Mr. Stephenson, his public
misrepresentation of the position I held under the Company, and his endeavor to
recognise my services as the labors of an assistant under his control, and acting entirely
under his direction. Had Mr. Stephenson in his public address done me the justice to
state my independent claim to some of the most important principles observed in the
construction of the tubes, I might, perhaps, have continued my services until the final
completion of the whole undertaking; and, most assuredly, this work would never have
come before the public.  I now  appeal to the preceding pages of this narrative,
whether Mr. Stephenson's assertions are borne out by the simple statement of facts?
I have overstated nothing, concealed nothing; and the reader is left to draw his own
conclusions from these facts, after having become acquainted with the course pursued
by Mr. Stephenson, which I will in conclusion concisely relate.' (p. 171.)
" Mr. Fairbairn proceeds then to give an account of a public dinner to celebrate the
completion of the Conway Bridge, which took place on the lith of May, 1848; on
which occasion it was, Mr. Stephenson first openly assumed that position in regard to Mr.
Fairbairn and the undertaking, which has made the present appeal to public justice
necessary. Mr. Stephenson's speech was confessedly a studied affair-he had announced
beforehand that he would avail himself of the opportunity of' setting the question at
rest;' but for all that it does not take Mr. Fairbairn many words to demolish it
utterly.
I' The inaccuracies, both as to facts and dates, in the statements of Mr. Stephenson,
are very numerous.  It simply requires a reference to the short description of the
Ware Bridge, and to the drawings, to disprove the assertion, that it is a thin tubular
bridge, although not precisely the same as the present, yet in principle precisely the
same; and it can easily be shown too, that considering the Ware Bridge as a simple
girder bridge, it is exceedingly defective in design. Is there anything new- in this application of wrought-iron plate girders? As well might it be said that the combination




670                  FAIRBAIRN'S TUBULAR BRIDGES.
of wrought-iron deck beams, so many years applied in iron ships for the support of the
decks, is a " counterpart of the proposed cellular top for the Britannia tubes." I really
cannot but regret that Mr. Stephenson, whose name will be always associated with the
grandest bridge that has ever been constructed, should have committed himself in
making such an erroneous assertion as that it was by reviving and extending his original
conception of this imperfect structure at Ware, that he was led to originate the bridges
crossing the Conway and Menai Straits.
"'Mr. Stephenson's remarks further admit of the disingenuous construction that his
scheme was matured before the Bill for the Chester and Holyhead Railway was passed
by Parliament, and before I was consulted, and that he was at that early period acquainted with the present design of the bridge. He refers to the incredulous glances
which were directed towards him when the description of the bridge was explained to
the Committee; and intimates, " that it was not until the Bill had been obtained, and it
became necessary to commence, that he requested my assistance." Now, my advice was
asked by Mr. Stephenson before his evidence to the Parliamentary Committee was given,
and he announced his idea to that Committee strengthened by more than one opinion of
itsfeasibility. Let the reader turn again to the earlier letters of the correspondence, and
he will find of what a crude and dangerous scheme that idea consisted; how totally
dissimilar in form and principle it was to the present tubular structures, and how
slowly Mr. Stephenson was persuaded to give up his earliest conceptions. Again; Mr.
Stephenson states that he called in the aid of Mr. Hodgkinson and myself at the
same time; now it is essential to the proof of my claims that this assertion should be
explicitly contradicted. It was 1, and not Mr. Stephenson, who solicited Mr. Hodgkinson's co-operation, and this was not done until I had been actively engaged for
several months in my experimental researches, and after I had discovered the principle
of strength which was offered in the cellular top, and not only proved the impracticability of Mr. Stephenson's original conception, but had given the outline of that form
of tube which was ultimately carried into execution.
"'When Mr. Stephenson had made up his mind to claim  in the manner he did the
whole merit of the undertaking, it is not difficult to understand his reason for giving
Mr. Clarke, his own assistant, so prominent a position. I willingly bear my testimony
to the great value of the services rendered by Mr. Clarke, to his talents, and to the
great energy which he displayed in working out his several duties, but these had no
reference whatever to the designing of the structures.' (p. 178.)
" There is one part of the case on which we think Mr. Fairbairn does not insist enough,
though, in our judgment, it is of itself decisive of the inordinateness of Mr. Stephenson's
pretensions. Mr. Stephenson and his friends, for obvious reasons, slur it over altogether.  We refer to Mr. Fairbairn's appointment to be joint engineer along with Mr.
Stephenson to the Conway and Britannia Bridges. The evidence of this is a Minute
of the Board of Directors of the Chester and Holyhead Railway, dated 13th May, 1846,
which we here quote at length from the work before us.
"'Resolved-~st. That Mr. Fairbairn be appointed to superintend the construction
and erection of the Conway and Britannia Bridges, in conjunction with Mr. Stephenson.
"'2d. That Mr. Fairbairn have, with Mr. Stephenson, the appointment of such
persons as are necessary, subject to the powers of their dismissal by the Directors.
"' 3d. That Mr. Fairbairn furnish a list of the persons he requires, with the salaries
he proposes for all foremen or others above the class of workmen.
"'4th. That advances of money be made on Mr. Fairbairn's requisition and certificates, which, with the accounts, or vouchers, are to be furnished monthly.
"' 5th. That the Directors appoint a bookkeeper at each spot, the Conway and the
Menai.'
"To talk, after this, of Mr. Fairbairn's being only entitled to a secondary and subordinate place in the affair, is to outrage all truth and propriety.
" We can but regard with profound pity the hallucination which has betrayed a man
of Mr. Stephenson's genius and worth (this unfortunate episode notwithstanding) into
so false a position.
" We do not overlook that we have as yet Mr. Fairbairn's statement of the case only,
and that we may expect to see, ere long, something of a very opposite complexion from
Mr. Stephenson or some of his friends. We shall give all due consideration to any such
counter-statement when it comes before us; but so well is all Mr. Fairbairn says borne
out by written, and therefore unalterable proofs, that we do not, in the meanwhile,
hesitate to avow our firm belief that nothing which can possibly be adduced in the
way of either evidence or argument, can ever alter materially the conclusion at which
we have already arrived."-Mechanic's Magazine.)
FAIRBAIRN's TUBULAR GIRDER BRIDGES.-William  Fairbairn, Esq., of Manchester,
F. R. S., and Member of the Institute of France, has been long recognised as the most
accomplished of our factory engineers and the most skilful of our millwrights, by his




FAIRBAIRN'S TUBULAR BRIDGES.                                         671
admirable fire-proof buildings and his magnificent hydraulic machines. Having a few
ears ago directed his constructive genius to the building of iron steam-ships, he
became thereby well acquainted with the prodigious stiffness and strength of which
hollow girders of thin sheet iron were susceptible. He was naturally pitched upon by
Mr. Stephenson, the engineer of the Chester and Holyhead Railway, as the fittest person to execute the tubular bridge which was regarded by him as the only means of
carrying ponderous railway trains over the tremendous sea-gulf of Menai's Straits or
Conway's roaring flood. The tidal torrents of these two places being deep and rapid,
required to be crossed by bridges of extraordinary span and strength. No centrings
or other substructures usually resorted to for mounting such huge pontitectures could
be erected. In such a dilemma, the most obvious resource of the engineer was a suspension bridge; but the failure of more than one attempt of that kind had proved the
impossibility of running railway trains over such bridges with safety.
Under Mr. Stephenson's direction, numerous other schemes had been devised. Both
timber and cast-iron arches had been thought of; and a model of a very handsome
bridge for crossing the Menai Straits on the latter principle had been constructed, and
submitted to  the consideration  of a parliamentary committee.  The possibility of
throwing cast-iron arches over so great a span as 450 ft. was however questionable;
and the security of such a bridge must have been endangered by the great changes
which the material would have been subjected to from atmospheric influences, and from
vibrations produced by the passage of heavy trains.  But a more important objection
even than these caused the withdrawal of this design. The Lords Commissioners of the
Admiralty, as conservators of the navigation, opposed the erection of any structure
which should offer a hindrance to the free passage of vessels under it, and insisted on a
clear headway of 105 ft. from the level of high water. Mr. Stephenson then conceived
the original idea of a huge tubular bridge, to be constructed of riveted plates, and supported by chains,* and of such dimensions as to allow of the passage of locomotive
engines and railway trains through the interior of it. The illustrious Galileo, in demonstrating the strength of tubular structures, adverted to the quills of birds and the
stalks of corn; but in our days we see that idea amplified into colossal dimensions.
It was with reference to this expedient, after all others had been found inapplicable,
that Mr. Fairbairn was consulted by him, and requested to give his opinion-first, as
to the practicability of the scheme; and secondly, as to the means necessary for carry
ing it out. The consultation took place early in April, 1845. Mr. Stephenson conceived that the tube should be either of a circular or egg-shaped sectional form; and
he was strongly impressed with the primary importance of the use of chains, placing his
reliance in them as the principal support of the bridge. He never for a moment entertained the idea of making the tube self-supporting. The wrought-iron tube, according
to his idea, was indeed entirely subservient to the chains, and intended to operate from
its rigidity and weight as a stiffener, and to prevent, or at least to some extent counteract, the catenary principle of construction.
"February 23d, 1846.
"My dear Sir,
"I have been considering the principle on which you purpose attaching the chain
for the support of the tube; and with every deference to your judgment, I am almost
inclined to differ with you upon that point.
" It appears to me that the great and important consideration is to relieve the strain
~upon the tube. It is quite clear that a series of chains on each side of the plates, well
fitted and tightly screwed up, would tend to stiffen the sides, and give greater rigidity
to these parts. This is, however, not what is wanted. The rigidity is required on the
top side; as in all the experiments the sides seldom get out of form unless distorted by
the crushing of the top side. Under these circumstances the stiffening should in my
opinion be on the top platform of the tube."- William Fairbairn to Mr. Robert Stephenson.t
For many months afterwards, and even up to the time of the experiments on the
model tube in December 1846, Mr. Stephenson insisted on the application of such
chains. "I always felt," says Mr. Fairbairn, "that in a combination of two bodies,
the one of a perfectly rigid, and the other of a flexible nature, there was a principle of
weakness; for the vibrations to which the one would be subjected, would call into
operation forces whose constant action upon the rivets and fastenings of the other could
not but tend to loosen them, and thus, by a slow but sure agency, to break up the
bridge."
In consequence of the favorable opinion entertained by Mr. Stephenson on the cylin* These chains, not only superfluous hut dannerous, would have cost 150.0001.
t Conway and iMenai Bridges, by W. Faiibaii n, C. E., p. 48.
43




672                   FAIRBAIRN'S TUBULAR BRIDGES.
drical tubes, it was deemed expedient to commence experiments upon models of that
kind, and to extend them  subsequently to elliptical tubes.  Experiments carefully
made, demonstrated the weakness of these two forms, and the vastly greater strength of
the rectangular tubes, which were accordingly adopted with cellular top and bottom.
In Mr. Stephenson's examination before the Select Committee of Railways of the
House of Commons, 5th and 6th of May, 1845, he says: "I am  instituting a series of
experiments in conjunction with Mr. Fairbairn of Manchester, who is already in possession of experiments on iron ships, which place the thing beyond all doubt. He has
ascertained that a vessel of 250 ft. in length supported at the ends will not yield with
all the machinery in the middle.
"Have your calculations been submitted to any other engineers?
"I have made them, in conjunction with Mr. Fairbairn of Manchester, whose experience
is greater than any other man's in England. There is an iron vessel now building by Mr.
Fairbairn 220 ft. in length; and he says that he will engage, that, when it is finished,
it shall be put down on the stocks at each end, and shall have 1000 tons of machinery
in the middle of it, and it will not affect it. But that is not so strong as a tube, and
therefore, any experiment that this would carry out, the tube would fully bear."
The floating of the first Conway tube —" The transport of a huge mass of iron 412 ft
long, 25 ft. 6 in. high, 15 ft. wide, and weighing not less than 1300 tons, was a task of
no ordinary difficulty. No former effort with which we are acquainted can, I think, be
said to have equalled it, when the unwieldiness of its form, and the extraordinary natural
difficulties to be encountered, are taken into consideration. Many of the works of the
ancients are stupendous in conception and colossal in dimensions; and it has been a
constant matter of inquiry, in what manner a people, ignorant of the mechanical appliances which we possess, could raise structures which have resisted all the inroads of
time, and which are to the present generation objects of awe and admiration. In more
recent times, the transport of the immense granite block which forms the base of the
statue of Peter the Great at St. Petersburg, was looked upon as a most extraordinary
achievement; but it cannot he said to have been so formidable an undertaking as the
moving of the Conway tube.  The granite block was a compact mass, being 42 ft. at
the base, 21 ft. thick, and 17 ft. high, and capable of being moved on rollers, &c., to the
raft which carried it down the Neva to the site of the city; but in the case of the Conway tube, after the most anxious consideration, and when numerous schemes and proposals had been weighed, examined, and rejected, that of floating the mass on pontoons
or barges was decided upon as the most feasible and most secure, the centre of gravity
being in this case, necessarily raised several feet. In addition to this disadvantage, the
whole had to be handled and manceuvred in probably the most difficult tideway in
Europe, where the current rushes through a narrow gorge of great depth to fill the
broad expanse of the inland bay, at a rate of 6 or 7 miles an hour; and the utmost
nicety had moreover to be observed in bringing the tube to its place, as there was only
a clearance of 12 inches; that is, the distance between the opposite masses of masonry
was only 12 inches greater than the length of the tube. All these obstacles may well
be termed formidable; and I therefore conceive that the utmost praise is due to Mr.
Stephenson for the admirable arrangements and contrivances which rendered the first
attempt at so gigantic an operation perfectly successful."
I have quoted these liberal remarks of Mr. Fairbairn in proof of his good feeling towards the engineer associated with him conformably to the Minute of the directors of
the Chester and Holyhead Railway, of date May 13, 1846, already quoted.
How defective, and even erroneous, Mr. Stephenson's conceptions were of the tubular
girder construction so late as the 26th October, 1846, appears, from his staling in a
letter of that date addressed to Mr. Fairbairn, "that this was not the first time he had
the idea of employing wrought-iron tubular bridges; for three years ago, or thereabouts, I had erected at Ware, on the Northern and Eastern Railway, a cellular platform of wrought-iron. It was, in fact, I believe, a counterpart of the proposed top of
the Britannia bridge."
"As this statement," says Mr. Fairbairn, "has been frequently repeated since the
letter was written, I feel myself called upon to show that Mr. Stephenson has no claim
to originality in this bridge, and that it has no resemblance whatever, either in principle
or construction, to the Conway or Britannia tubes. On the contrary, the bridge in
question is constructed upon the principle of the common cast-iron girder bridge, each
separate beam being formed of wrought-iron plates connected together by angle irons.
This form of wrought-iron girder had been long in use before the erection of the Ware
Bridge; and it is defective as well in principle as in construction; the great body of the
material is not in the top flanches, as it ought to be, in order to attain the section of
greatest strength. In Experiments 14, 15, and 16 (see Appendix and p. 10 in the
Report), it is clearly shown that the top flanche of a wrought-iron girder, if made solid,




FAIRBAIRN'S TUBULAR BRIDGES.                                  673
should be more than twice the area of the bottom flanche. Now it appears that the
top flanche in the said bridge at Ware is to the bottom flanche as 4 to 15 nearly; an
exceedingly defective structure. If this beam were turned upside down it would carry
imore than double the weight. From the defective principle upon which the bridge is
constructed, it is evident that Mr. Stephenson was not then acquainted with the proper
form of wrought-iron girder bridges. Nor is this surprising, as no experimental facts
were at that time in existence to show the difference between the two resisting forces
of compression and extension of wrought-iron beams."-Conway and Britannia Bridges,
by Mr. Fairbairn, pp. 113, 114.
"It is impossible to trace any analogy between a combination of this form of beam
and a tubular girder with a cellular top. The beams in the Ware Bridge do not offer a
united resistance to strain in the manner which beams with a cellular structure do; on
the contrary, each beam has its distinct part of the load to carry, and that imperfectly,
for want of a due proportion in the top and bottom flanches."-Ibidem.
A striking proof of the accuracy of Mr. Fairbairn is afforded by the fact, that it was
not till the latter part of 1846, that Mr. Stephenson finally made up his mind to abandon the use of the chains, for in the engravings of both the Conway and Britannia
Bridges, which were published in that year, there is attached to them the name of
Robert Stephenson, Esq., engineer. These drawings represent, with tolerable accuracy,
the proportions and forms of the tubes of both bridges as they now  exist,-viz.,
the long, low, rectangular galleries, which Mr. Fairbairn's experiments had shown to
be much better adapted to the purpose than the elliptical tubes proposed by Mr.
Stephenson. But mark, in both cases the chains are absolutely shown attached to the tubes.
They are a prominent feature in the drawing, and therefore conclusive evidence that
up to that time at least, and notwithstanding the discovery of the increased strength
and security to be derived from the adoption of the tube with a rectangular section,
and the distribution of the material on the top side in the form of cells, Mr. Stephenson still thought the auxiliary support indispensable.
From the moment that Mr. Fairbairn commenced this experimental investigation,
the whole matter, as regarded the development of the best form of the tubes, was unreservedly in his own hands. Mr. Stephenson was not present at the experiments, he
neither superintended nor directed them, but was simply made acquainted with results,
and approved, when completed, what Mr. Fairbairn did. And now what did Mr. Fairbairn's experiments show? They first of all confirmed his own early opinion, that the
security of the bridge, if built at all, must depend solely upon the self-contained strength
of the tnbe, and that the application of any form of catenary would introduce into the
structure an agency of a destructive tendency. They proved the weakness and total inadequacy of either of the sectional forms of tubes (cylindrical or elliptical), thought
of by Mr. Stephenson. They led Mr. Fairbairn, after carefully observing all the signs
and symptoms of weakness shown by the models when under strain, to recommend, as
a stronger form  of tube one having a rectangular section. They brought to light
some curious and anomalous appearances exhibited by wrought-iron when subjected to
a crushing force. They showed that tubes of a uniform distribution of material, when
loaded with an increasing weight, first yielded on the upper side; and this fact, therefore, induced Mr. Fairbairn, first, to thicken the material in that part, and, subsequently, led him to suggest that distribution of the material in the form of hollow
cells or tubes, wherein lies the secret of the strength of this system of tubular construction.
Mr. Fairbairn therefore, reasoning from his experiments,-lst, suggested the rectangular sections for the tubes; 2d, discovered that important and beautiful element of
strength and lightness, the cellular arrangement of the top; and 3d, was mainly instrumental in causing the final abandonment of chains.
Beyond this, after he was appointed engineer with Mr. Stephenson for the structure,
he worked out the detail of the tubes, had the whole of the working drawings for the
tubes of both bridges made at his own office, and under his constant supervision, proportioned the different parts, and (again the result of reasoning from experiment) suggested that admirable system of chain riveting which is adopted in those parts of the
tubes liable to a tensile strain, and which adds in a material degree to the strength of
the structure.
A bridge with several spans of nearly 500 feet each was wanted, which should not
only be unyielding with its own necessarily enormous weight but which should possess
within itself such an excess of strength as would satisfy an incredulous public that it
would be abundantly safe when subjected to the shocks and vibrations of a heavy locomotive engine with its accompanying train passing across it at a speed of forty miles an
hour. The situations both at Conway and the Straits afford obstacles of extraordinary
magnitude: at both places the estuaries were of great depth, defying the use of scaffold



674                 FAIRBAIRN'S TUBULAR BRIDGES.
ing to assist in the erection of the bridges, and the tides washed through with appalling
impetuosity. The Menai or Britannia Bridge was moreover to stretch from shore to
shore at a giddy height of more than 100 feet from the level of high water, and, as if
to render insuperable the obstacles which Nature had raised to the progress of the engi.
neer s work, an arbitrary but absolute order was issued from the controllers of the
navigation that the whole was to be accomplished without hindrance or obstruction to
the rights which they guarded. The manner in which all these necessities were complied with is well known. The Britannia and Conway Bridges exist, the pride of the
country which possesses them, triumphs of the constructive arts, and immortal monuments to the men who were associated in their contrivance and execution. It is to be
deplored in every respect that jealousies and rivalries should have arisen under circumstances where so much renown and merit was to be divided. The grandeur and boldness of the conception was Robert Stephenson's, but the merits of the existing structure,
the ingenuity of the arrangement, and proportions of the material,-the discovery, in
fact, of the tubular principles of construction,-are William Fairbairn's.
As an outgrowth of the remarkable introductory experiments made in connection
with these wonders of North Wales, we must regard the equally important, though
less imposing tubular girder system; the new and scientific discovery of great advantages to be derived from a peculiar combination of material, applied to the simple
and generally used beam or girder. A tubular girder, as the name implies, is a hollow
beam constructed of metal plates firmly riveted or fastened together. When subjected
to a transverse strain or load tending to break it, the law, which is applicable to
every body, be it solid or hollow, is observable. The parts of the girder above the
neutral axis have to arrange themselves to a resistance of a compressive strain, while
those below that line are violently subjected to a force tending to draw them asunder.
The extreme difficulty of wrought-iron and its great power to resist tension, were well
known, and in the earlier stages of the inquiry it was considered feasible, and frequent
efforts were made to arrange the parts in such manner that these known properties
might be taken advantage of in both the upper and lower sides of the girder, but every
experiment baffled the ingenuity of the contrivance, and nature soon taught the
constructor that her unerring laws were not to be disregarded.  This point being
established, viz., that no distribution of the metal in a tubular girder could change the
character of the forces which would act upon it, Mr. Fairbairn's great merit lies in
the ingenuity with which he adapted his new material to those strains.  In the top or
upper side of the girder he distributed it, in that beautiful cellular form which imparts
the real strength and security to the structure, and in the bottom he connected the
parts by an ingenious system of fastening which assimilated the strength of the joints
with that of the solid plate.
The description of one of the best constructed tubular girders will give the most
correct idea of their power and peculiarity. We select for illustration the beautiful
503
bridge erected across the Trent at Gainsborough. Fig. 603 represents a general elevation of the bridge which carries the Lincolnshire railway across the Trent. Its total
length is 332 feet, the two main spans being 154 feet each. The width of roadway
between the two main girders is 26 feet, giving ample room for a double line of railway. The width of the centre pier is 12 feet, and the tubular girders have a bearing
on each land abutment of 6 feet. Fig 504 represents a cross section form of the main
girders, and to this we must direct especial attention in order to make the peculiarities
of the system well understood. The height of each girder from end to end is 12 feet;
this parallelism is not the best form to give a maximum  resistance with a minimum
amount of material; but from the greater facilities of construction is preferable to the
parabolic form, and practically the proportions of the strength may be adjusted by
varying the thicknesses, instead of the linear dimensions of the parts.
Thie Bottom of the Girder.-The bottom is framed of double thicknesses of long rolled
plates, connected together in the manner hereafter described. Being subjected solely
to a tensile strain, the material is condensed as much as possible, so as to assimilate
that part of the structure to one unbroken solid sheet, which, if practicable, would be
the best distribution of form. Each plate is 12 feet long by 18 inches wide, varying
in thickness according to its position from the centre line of each span, where the greatest




FAIRBAIRN'S TUBULAR BRIDGES.                               675.... /        1.
i                 t; 21  II
\ i W    ~i.':    4'.-1.
60450      J
amount of material is accumulated. The bottom is necessarily connected to the sides
of Lthe girder by long bars of heavy L or angle iron, firmly riveted to-both
I~~~~~~~~~~~~~~~~~~~~~~~~~~~I
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676                  FAIRBAIRN'S TUBULAR BRIDGES.
The Sides of the Girder.-The side plates are 2 feet wide throughout, and of uniform
thickness, excepting in the immediate neighborhood of the piers and abutments, where
they are strengthened and stiffened by pillars of strong T iron, to offer a due resistance
to the dead weight of the girder itself. The joints are made with external covering
plates 4- inches wide, and internal ribs of T  iron, which suffice to keep the side plates
rigid, and enable them to accomplish their duty of separating the top and bottom of
the girder.
The Top of the Girder.-In this part the principal novelty and ingenuity are observable. A single sheet of iron, like a sheet of paper is easily put out of shape by a compressive strain. It crumples up, and at once loses all power of resistance. A sheet of
common writing paper, which when placed on edge will nearly support itself, when
rolled into a cylinder, say of 1 inch diameter, will carry a considerable weight. In
the same manner a given sectional area of plate, if placed in that simple form in the
top of the Trent girder, would crumple up with a comparatively small weight, but
when distributed according to Mr. Fairbairn's tubular arrangement it offers extraordinary resistance to compression.
505.............,',_ ____...........................
The value of this arrangement will be understood when it is stated that notwithstanding the superior tenacity of wrought-iron, a well constructed tubular girder only requires
an excess of sectional area in the top over the bottom of 1. In the Trent girder (see
fig. 504), the top compartment is 3 feet I inch wide, and 15 inches deep, divided by a
vertical plate into two rectangular cells, and all firmly connected by rivets, and L iron.
Those angle irons constitute important elements in its strength. Since the construction of
the Trent bridge, the cost of construction of tubular girders has been much diminished by
a. different arrangement of the parts of the top compartment, as shown in the following,
fig. 506. This form is equally powerful in its resistance. When the span of the bridge.-..-........~~ —.. —...-.~~~~~~~t..... —-~...~ ~ ~..~..
reaches 180 or 200 feet, the top compartment is arranged as shown in fig. 507, and
when it is under 60 feet as shown iafig. 508.  It will be noticed that in every case the




FAIRBAIRN'S TUBULAR BRIDGES.                                  677
cells are proportioned, so as to admit of the entrance of a man for the purposes of
painting or repairs.
507,..508    -.14 -. -l  509
i
The Cross Beams or Supports of the Roadway.-These are generally, and ought to be
universally, made of iron. In the Trent bridge they are made hollow or box beams, as
shown in the annexed figure, fig. 509. Their construction is now much simpler and
equally good, thusfig. 510.
510                       The Riveting.-Upon the judicious fas-.   A,,~ >,  tenings of the plates together depends in
a great measure the safety of a tubular
girder bridge.  The system  of riveting
followed in the several parts should have
r eference to the strains which occur in
those parts. What are technically called
"lap joints," where the ends of the plate
^ISWtIBSI  ll  ^  I overlap each other, and are connected by
a single row  of rivets, (vide fig. 511,)
should be avoided in every part of the
J Hillll 111I* H structure, as they.have been proved to'   B IBIllil                  h be weak and insufficient.  Mr. Fairbairn
{ll'llHllll~l j     i        (Phil Trans. part ii. 1852) gives the value
Il  llt'll ill'i  of single and double riveted joints, as 70
JIL       ~-    and 56 respectively, the solid plate being
assumed to be 100.
Butt joints" and covering plates are used throughout the girder, the length and
substance of these covering plates and the number of rivets varying according to situation. In the top compartment the ends of the plates having been carefully fitted to
each other, so as to take their portion of the strain the moment the load is applied, are
covered by strips of sufficient width to receive a double row of rivets, one on each side
of the joint, thus, as shown in fig. 512. This arrangement effectually prevents some
such effect as indicated infig. 513, which would occur were the lap joint used, and the
load very great. In the tops the rivets are generally spaced 3 inches apart from centre
to centre.




678                   FAIRBAIRN'S TUBULAR BRIDGES.
As before mentioned, instead of simple strips covering the vertical joints of the side
plates, inside T  iron bars are used to afford stiffness, and prevent the approach of the
-_<___________',511  top and bottom (vide fig. 514.)  Thus, the rivets
being spaced 3 inches, the strips give to the exNWv.rN vi-MMM          ternal elevation of the girder the appearance of
a series of panels.
513        In the bottom  an exceedingly ingenious and
beautiful arrangement of riveting has ben introduced  by Mr. Fairbairn.  It is evident that
to join two plates together (these two plater
JJ. —.~.~-~...^^lt^^^^l^^      -      having to resist a force tending constantly to
separate them) a certain number of rivets or pins
514     are required, and according to the old system of
to jointing, these rivets were placed in single rows
along the edge of the plates, being in fact either
sinle lap joints, or single butt joints. Suppose
the plates inf. 515 to be each 2 feetwide, and
^ inch thick, and that to connect them  there
were wanted 16 rivets, each I inch diameter. It is evident the resisting powers of
the plates are weakened exactly by the amount of material punched out, in this case
one-third, the section of resistance be           ing through the
line c d.  But if these 16 rivets, instead of being placed all parallel with the joint,
are arranged as shown in fig. 516 and covered with long   covering plates' instead
of the plates only.  instead of.  These proportions will readily explain the saving
following figure of the "bottom" of the Trent bridge will show how it is
-,a. V0  a                            I Oa  QG llllllllQnlll G nllii al  0 000
long corner pieces, as may be noticed at a, in fig. 518, which is a view  of a short
length of the bottom of the main Trent girder.  Having thus described the tubular
figures (fig. 519, 520) will indicate modifications of the system which have gained




FAIRBAIRN'S TUBULAR BRIDGES.                                      679
518
OleI                 19:ol Io                                   Io-oJ
0oo 0o oo oo0                                                     of
0                     0 0o                 0o.!            010
619          *                                                         520
1 9*                  W C                 1
The Proportions and Strength of Tubular Girders.-The limits of this article will not
admit of a, lengthened examination of these interesting topics. A well proportioned
beam  or girder should have such a sectional distribution of its material, that when
subjected to a transverse strain, the top should yield to compression and the bottom
to extension at one and the same time; and as nearly all materials offer unequal
resistances to the two forces, direct experiment can alone determine the exact relative
proportions of the two parts. Thus, the resisting power of cast-iron to compression
is nearly six times greater than that which it offers to extension; but Mr. Fairbairn's
ingenious distribution of the wrought-iron plates in the "cellular top" has enabled
him to fix the relative sectional areas of the tops and bottoms of tubular beams in
the ratio of 12 to 11.
The tables of the following page show the proportions for tubular girder bridges of
spans from 30 up to 300 feet.
Mr. Fairbairn's formula for calculating the strength of tubular girder bridges has
been much disputed, but at the same time it has had many able defenders, and may be
followed with perfect reliance and safety. If it errs, it errs on the right side-that of
understating the real strength; it is
a do
where w~~the centre breaking weight in tons irrespective of the weight of the girder
a = sectional area of bottom in inches
d-depth of beam in inches
<c=a constant derived from experiment for the particular form of girder, and
I -length.of girder between the supports in inches.
The formula always assumes a well made and well proportioned girder,: having the
relative areas of 12 to 11 in the top and bottom and the chain riveting.
The constant c for the tubular girders we have described was ascertained to be 80.
Let us now find by this formula the strength of one of the spans of the Trent bridge




680                  FAIRBAIRN'S TUBULAR BRIDGES.
TABLE showing the Proportions of Tubular Girder Bridges, from 30 to 160 Feet
Span.'
Centre Breaking     Sec. Area of      Sec. Area of      Depth at the
Span.           Weight of       Bottom of one       Top of one       Girder in the
Bridge.           Girder.           Girder.            Middle.
Feet. In.          Tons.            Inches.            Inches.         Feet. In.
30  0             180               14-63             17'06              2   4
35  0             210               17'06             19-91              2    8
40  0              240              19-50             2275               3    1
45  0             270               21-94             25-59              3    6
50  0             300               24-38             28-44              3  10
55  0              330              26-81             31-28              4    3
60  0              360              29-25             34-13              4'7
65  0              390              31-69             36-97              5   0
10  0              420              34-13             39-81              5    5
15  0             450               36-56             42-67              5    9
80  0             480               39-00             45-50              6   2
85  0             510               41-44             48-34              6    7
90  0             540               43-88             51-19              6  11
95  0             570               46-31             54-03              1    4
100  0              600              48-75             56-88              7    8
110  0              660              53-63             62-56              8    6
120  0              720              58-50             68-25              9    3
130  0              780              63-38             73-94             10    0
140  0              840              68-25             79-63             10    9
150  0              900              73-13             85-31             11    6
TABLE showing the Proportions of Tubular Girder Bridges, from 160 to 300 Feet
Span.
Centre Breaking     Sec. Area of      Sec. Area of      Depth at the
Span.          Weight of        Bottom of one       Top of one       Girder in the
Bridge.           Girder.           Girder.           Middle.
Feet. In.           Tons.            Inches.            Inches.         Feet. In.
160  0              960               90-00            105-00            10  8
170  0             1020               95-63            111-56            11  4
180  0             1080              101-25            118-13            12  0
190  0             1140              106-88            124-69            12  8
200  0             1200              112-50            131-25            13  4
210  0             1260              118-13            137-81            14  0
220  0             1320              123-75            144-38            14  8
230  0             1380              129-38            150-94            15  4
240  0             1440              135-00            157-50            16  0
250  0             1500              140-63            164-06            16  8
260  0             1560              146-25            170-63            17  4
270  0             1620             151-88             177-19            18  0
280  0             1680              157-50            183-75            18  8
290  0             1740              163-13            190-31            19  4
300  0             1800              168-75            196.88            20  0
which we have described.  By reference to fig. 504, it will be observed that here
a=-58-5, d-144, and l-1848.
adc    58X144X80   364-6 tons
1          1848
as the weight which a tubular girder 154 feet between the supports will carry suspended from one point in the centre before fracture. Now the actual weight of this
girder itself is under 70 tons, and it may safely be asserted that no other form of construction would give so favorable a result. The centre breaking weight of one girder being
3641 tons, it. would carry 729 tons equally distributed along its entire length, and there
being two main girders to the bridge, the ultimate strength of the structure is in round
numbers, 1,500 tons. It would be possible, by both lines of railway being covered with




FAIRBAIRN'S TUBULAR BRIDGES.                                     681
heavy goods train, to have a load on the bridge of about 250 tons at one and the same
time, and we thus see there is a margin of strength of six times the greatest possible
load. Engineers differ in opinion as to the excess of strength which it is desirable
that railway structures should possess; some are satisfied with even as low an ultimate
breaking strength as three times the load; but with a comparatively untried material,
and one moreover liable to deterioration from atmospheric influences, the larger excess
is the better.
On the discovery of Mr. Fairbairn's cellular arrangement for the top compartment of
the Conway and Britannia Bridges, several able mathematicians advocated the introduction of iron cylindrical instead of rectangular cells, as being a better distribution of
the material to resist the compressive strain. Mr. Fairbairn's original views were in
the same direction, but were abandoned on account of the complexity of construction
and the difficulties of manufacture, and it is curious to notice now that subsequent
scientific investigations have confirmed the practical engineer's views, and shown that
the rectangular cells are superior in strength. Mr. Tate especially thus ingeniously
argues:~-" The cells in a transverse strain undergo a different kind of strain to what
they are subjected to in a simple crushing force equally distributed over the section of
the tube. In this case all the parts of the section are equally compressed, and it is
reasonable to conclude that the best form of cell will be that in which the material is
equally distant from the axis of pressure; but the case of transverse strain is very
different, the upper edge undergoes the greatest strain, and of the other parts that which
is nearest the natural axis of the beam undergoes the least; in this case therefore the
material in the square cells is symmetrically distributed with respect to the axis of
pressure, the neutral axis of the beam."
The Durability of Tubular Girders.-On this head there is as yet but a very limited
experience as a basis for positive assertion. There can be no doubt that if neglected the
effects of oxidation upon the wrought-iron plates and rivets would speedily be productive of very disastrous results.  On the other hand, there are many existing examples of wrought-iron structures, such as iron ships and other vessels, suspension
bridges, zc., which with proper care and attention have withstood the wear and tear of
constant exposure and use without any serious impairment of their powers of resistance,
for periods of upward of thirty years. It will be noticed too that tubular bridges
have been designed with an especial view to the easiest access to every part for the
purposes of painting and repairs, and it is not therefore improbable that with attention
these structures will prove to be more durable than either cast-iron, timber, or other
structures similarly situated.
Their Cost.-In estimating the cost of a tubular girder bridge, one of their most
important recommendations must not be overlooked, viz., the saving which they afford
in the construction of the masonry, abutments, and piers. For example, in the formation of a bridge of 150 feet span, if cast iron or stone be the material employed, vast
sums of money would have to be expended in the formation of ponderous and solid
abutments to receive the thrust of the arch and its load, whereas with the girder bridge
two simple well-constructed walls giving a bearing of five or six feet to the ends of the
girders is all that is necessary, the girders themselves receiving and maintaining the
strain due to the load. The m-ere iron superstructure may thus in some cases appear
costly, but when the whole of the adjuncts of a bridge are taken into consideration
there is perhaps no other form of pontitecture which can compete with the wroughtiron girder when the clear space exceeds 70 feet. In estimating the cost of the iron
superstructure it may be assumed, when the value of manufactured iron is at an
average rate, at 201. per ton weight fixed and erected.
General Advantages-.The more prominent advantages of these ingenious structures,
viz. lightness, strength, security, and economy, have been referred to in the foregoing
remarks. In addition they are a ready resource to the engineer in localities where
he is limited for space. Thus, in crossing at a low level a road, river, or canal, a height
of 15 inches from the bottom of the bridge to the level of the roadway will suffice for
a width of bridge which will admit of a double line of railway or ordinary turnpike
road.
Again, the structures are inexpensively fixed.  The Trent girders, for example,
were constructed on the railway  embankment close to the west abutment of the
bridge, and drawn across to their permanent places without the expense of scaffolding,
&c. in the river.  The main girders themselves, in addition to forming the main
strength of the bridge, form parapets and protection to the traffic.
In conclusion, it may be stated that, although devoid of the massive but imposing
elegance of the stone arch or the fairy lightness of the suspension roadway, the beauty
of a tubular girder bridge consists in its usefulness and its evident fitness for the
work it has to perform.
THE BRIDGE OVER THE RHINE BT COLOGNE.-" During the course of autumn, 1849,




682                 FAIRBAIRN'S TUBULAR BRIDGES.
Mr. Fairbairn of Manchester, was induced by representations made to him through
a high official functionary, to propose to the Prussian Government a plan for an iron
bridge across the Rhine at Cologne on the tubular principle. This plan met with the
entire approbation of the scientific world at Berlin, was sanctioned by the King, and
was all but adopted by the Prussian Cabinet.  It happened, however, that imultaneously with the proposal of Mr. Fairbairn, one Oberbaurath Lentze had become convinced
that a suspension bridge was the true means of communication across the Rhine. He
had arrived at this conclusion after years of patient investigation, and so far worthy of
all praise, though it somewhat unfortunately chanced that his discovery was some thirty
years too late, so that his labors, which would have been at the height of science in 1820,
have only served to illustrate a job in 1850. Here, in England, we have some little
notion of the nature of jobs, but we question whether any more colossal in this kind has
ever been perpetrated in our palmiest days of corruption than the attempt of our worthy
friend Herr Van der Heydt, in whose paper, if we are not mistaken, the celebrated
figment of the payment of 6,0001. to the editors of the'Times' by the Danish Government first appeared, to bolster up the scheme of M. Lentze, and to throw cold water
upon that of Mr. Fairbairn. What mattered it that Baron Humboldt, the Nestor of
hysical science, sided with Mr. Fairbairn, or that the King of Prussia, in one of his
happy moments, had graciously extended his royal protection to the English engineer?
Was not M. Van der Heydt, and the whole army of the Prussian bureaucracy, whose name
is Legion, arrayed on the other side? Still the English scheme must be burked officially;
it was to be smothered in due form with the cushion of bureaucracy; so a commission
was appointed to inquire into the English tubular bridges; and of whom do our readers
suppose that it consisted? Why of Herr Oberbaurath Lentz himself and another person,
who, after due deliberation, set off for England on their scientific mission. Why need
we detail at length the wanderings of these duumviri of bureaucracy? how they landed
in England-how they were received with marked courtesy by Mr. Fairbairn-how they
saw the Conway Bridge, the Britannia Bridge, and other structures of minor dimensions
in Lancashire?  Suffice it to say that they were quite blind to the merits of tubular
bridges, and made their report dead against tubular bridges and strongly in favor of
suspension bridges-a report which was adopted by the government that is to say,
by Herr Van der Heydt, who forthwith issued his famous notice, calling upon the
engineers of the whole world to compete for the honor of contributing to theglorification of Herr Oberbaurath Lentze, whose plans have been long since in the bureau of
M. Van der Heydt, and in all probability will be ultimately carried out."-Times.
W. Fairbairn, Esq., to Baron Humboldt.
" My dear Baron Humboldt,-I gather, from an article which has recently appeared
in the'Times' newspaper, and from a communication which his Excellency M. Van
der Heydt has honored me with, that a most unfortunate decision has been come to by
the authorities at Berlin, with reference to the important structure by which it is intended to connect the opposite banks of the Rhine at Cologne. It having been my good
fortune to have been consulted, many months ago, on the subject of this important
bridge, and to have visited Berlin for the purpose of submitting my proposals, I hold it
due to the warm recommendation which emanated from our excellent friend in London, the Chevalier Bunsen-to the lively interest you manifested in favor of the object
of my journey, and also to the gracious approval expressed by His Majesty the King
of Prussia in person-to make known as widely as possible the insuperable objections
which, in my opinion, attach to the limited programme which has recently been issued
from the bureau of the Minister of Public Works.
"So far as words can be allowed to convey an intimation of a genuine conviction, M.
Van der Heydt acknowledged at the palace, on the 1st of November last, that no structure should ever be allowed to cross the Rhine which was not calculated to meet, with
perfect security, the utmost requirements of the most extended traffic, and the possible
contingencies of great military operations. Your own enlarged conceptions at once
prompted you to acknowledge that the design (which at that time had received the
sanction of the authorities) was totally unfit for these purposes, and to admit that a suspension bridge, owing its strength to a flexible catenary, was inadequate to the transport
of heavy weights. But when I submitted the results which had been accomplished in
this country by the judicious application of a material until recently untried in such
structures-when I announced the successful realization of one of the boldest coBlceptions of modern times-when I stated  that tidal streams, such as the river
Conway and the Menai Straits, had been crossed by solid and unyielding bridges
of enormous span, which were capable nevertheless of sustaining ten times the greatest
possible strain that the heaviest railway traffic could, in practice, subject them to-.
when I had shown that this new principle of construction was peculiarly adapted




FAIRBAIRN'S TUBULAR BRIDGES.                                  683
to surmount the numerous difficulties which the passage of the Rhine offers, by
requiring very few and comparatively small piers in the stream, and thus allowing
of the passage of large timber rafts in the summer, and offering the least possible
resistance in times of floods and breaking up of ice in the winter; and, above all,
when I had proved that a structure so much superior could be erected and fixed
at an outlay considerably below that which had been demanded for a very imperfect.one-I confess I was not prepared to find the Minister of an enlightened and
powerful people asking for the assistance of the world at large to perpetuate a
scheme unworthy of Prussia, unworthy of the practical scientific knowledge of the
age, and in opposition to the deliberate and carefully-weighed opinion of Science's
greatest ornament.
"Pardon me for the warmth with which I address to you this remonstrance;
but 1 feel that your unwearied exertions, and the friendship which you unreservedly
testified to me, call upon me to urge, as forcibly as I can, the retracing of the unfortunate steps already taken. We live in times of progress. A scientific discovery,
or a practical improvement of any kind, cannot be confined to a particular locality or
to one countryv, it becomes at once the property of all. The community of Knowl
edge-the most powerful destroyer of national prejudices and antipathies, as it is
the surest foundation for general and permanent peace and good will-must ride over
and bear down individual ignorance and petty bureaucratic objections. Punctuality
and rapidity in our inter-communications have become almost essentials of our existence; and in this manner all Europe may be said to be interested in the completion
of that railway system which will traverse the Prussian dominions from one extremity
to the other.
"And now let me point out the lamentable imperfections which characterise the
Minister's programme, and the limitations and requirements which will effectually
trammel the efforts of men of genius, and deter those of experience and reputation from
entering at all upon the competition.
"It is an express condition of, the scheme that the railway communication is not
to be continuous, and the public will therefore continue to suffer the annoyance
and inconvenience of considerable delays; for it may be safely said that the proposal
of disintegrating a train at one terminus and drawing it across to the other by men
or horses, bit by bit, and hour by hour, will offer equal, if not greater, obstacles to
a rapid journey than the existing system  does. How much better would it be that
the bridge should embody within itself such elements of strength and durability
as would afford at all times and in all seasons a safe transit to those means of
locomotion which constitute the wonder and glory of the age?  Instead of such a
permanent and substantial structure, will the Prussian Government sanction the erection of one, the feeble and rickety constitution of which would shudder at the very
sight of a locomotive? Surely not! Public opinion must step in and forbid it. What
is wanted is a bridge to connect the existing railways, not one that will permanently
separate them.
"But again; it is stated that the difference between the levels of the existing
railways and that required for the roadway of the intended bridge is too great to be
overcome by the locomotive within a short distance of length. The objection is purely
imaginary; for I can state from personal examination, that the necessary gradient
would not be so heavy as several which are worked with great ease in this country
Besides, on the left bank of the Rhine the terminus of the Aix-la-Chapelle line is at the
right level; and that on the side of Deutz may without difficulty be reached by any
easy gradient of less than I in 100.
"Without meaning the slightest disrespect to the author of the design for the chain
bridge, I must repeat my firm and deliberate conviction, that it would prove an incomplete and unsatisfactory structure. A permanent, inflexible, durable, and handsome
tridge, of enormous strength (the breaking weight of the bridge I proposed, with the
span of 310 feet. was equal to 6,000 tons or 120,000 cwt., equally distributed over
each span, giving as the ultimate strength of the bridge, with four spans, 24,000 tons,
or 480,000 cwts.), adapted, by arrangements which I have now in progress of execution
for similar purposes in this country, to give every possible facility to the navigation,
of the river-calculated to carry across the heaviest railway train at any speed, and
which you might cover with the most powerful ordnance from end to end, may beerected at Cologne within the sum which has been demanded for the chain bridge.
These statements are not the imaginings of a sanguine mind; but their accuracy may
be corroborated by numerous examples of a similar character which have been erectedi
in this country.
"If, therefore, the determination of the Minister of Public Works to erect a chain
bridge cannot be shaken, I confidently anticipate that such an event will not be allowed
to pass by without a strong protest on the part of those who are in advance of tho



684                  FAIRBAIRN'S TUBULAR BRIDGES.
knowledge and judgment displayed by the authors of the invitation which has been
issued to the engineering world.
"My letter has attained a much greater length than I at first anticipated  M   anxiety to forward your own forcibly expressed views on the subject of a fixed bridge
must be my apology for it.
"With an expression of my profound esteem, and with best wishes for your continued
good health,
Believe me to remain, my dear Baron Humboldt, your very faithful and very
obedient servant,
"Manchester, April 15."
FAIRBAIRN'S WROUGHT-IRON GIRDER BRIDG.  Report on the Strength, Elasticity, and
other Properties of Wrought-Iron Girder Bridges as applicable to Railways and other
Structures. By W. Fairbairn, Esq., C. E. (From the Appendix to Report of the Commissioners appointed to inquire into the application of Iron to Railway Structures.)
~-"The idea of crossing the River Conway and the Menai Straits on the line of the
Chester and Holyhead Railway (two of the most formidable barriers ever presented to
the engineer), properly belongs to Mr. R. Stephenson.
"To carry this into practice, required the united skill of the mechanical as well as
the civil engineer; and it is highly gratifying to find that the successful completion of
the first of the Conway tubes has not only attained that object, but it has established a
new era in the history of bridges, by the development of the properties of a hitherto
untried material, and enables the engineer of the present day to conquer obstacles
which, at no very distant date, were considered insurmountable.
"An undertaking of such importance to the scientific world, to the public, and to
those more immediately interested, involving heavy responsibilities on the engineer;
before anything definite could be accomplished, it became absolutely necessary to institute a series of experiments to determine the practicability of such a structure, including other inquiries into the proportions and other properties of the tube. At the
request of Mr. Stephenson, I had the honor of being selected to conduct this inquiry.' Experiments on circular, elliptical, and rectangular tubes were accordingly undertaken; but it soon became evident from the results obtained that those of a rectangular
form were best calculated for the purpose. It was not, however, until I had adopted
the tube with the corrugated top that the real value of the tubular form became apparent, and, in fact, absolutely requisite in that part to offer sufficient resistance to the
crushing force.
"I will not trouble the Commissioners with the details of the experiments, but
simply state that it evidently became necessary to adopt some other shape than those
of the circular and elliptical kind, and so to proportion the top and bottom sides of the
tube as to effect a balance of the resisting forces of extension and compression, and thus
to ensure the maximum  force of resistance in every part. These proportions were
*clearly indicated by the rectangular form; and the formation of cells on the top side
give more effective powers of resistance to the crushing force than had been heretofore
accomplished by the single plate.
"This discovery of the cellular top, and the greatly increased value which a tube
thus constructed gave to the experiments, at once suggested a modified form of tubular
girder adapted to shorter spans. This description of bridge is now becoming general;
and from its superior powers of resistance, greater security, and its adaptation to almost
every description of span, we may reasonably infer that wrought iron is cheaper and
safer, if not equally durable with any other description of materials. It may, and I
*have no doubt it will be urged, that wrought-iron is much more subject to oxidation
and decay than cast-iron or stone; a circumstance which cannot be disputed; but that
can only arise from gross negligence on the part of those having charge of the structure,
as two coats of good oil paint every three years will effectually protect it, and render it
durable for almost any length of time. Besides, the girders, as now constructed, are
accessible in every part, and, by careful attention, I can see no reason why they should
not last 500 instead of 50 or 100 years. Another objection brought against this description of bridge is, the risk of the rivets becoming loose; and from  the number of
joints, the whole is considered by some as dangerous and insecure. Now, as regards
this objection, no real weight can be attached to it; as the parties raising it cannot be
acquainted with the nature and solidity of the work. It is next to impossible for a
single rivet to get loose (unless the work is improperly executed);, and in the whole
of my experience, I am  not acquainted with any description of jointing so certainly
secure, and so well adapted to resist any description of strain, as that of riveted plates.
I speak practically and unhesitatingly on this subject; and I have only to instance
steam boilers, iron ships, and other vessels subjected to severe strain, as examples of




FAIRBAIRN'S TUBULAR BRIDGES.                                      685
the strength and tenacity of riveted plates; in fact, rivets seldom or never get loose,
but retaiin their position under every species of strain, and become, as it were, integral
parts of the structure in common with the plates themselves.
" In submitting these remarks to the consideration of the Commissioners, and in
order to bear them out, it may not be uninteresting briefly to notice a few of the results
of the experiments illustrative of this subject, anI to show, with a greater degree of
exactitude, the nature and value of this description of structure. For these objects, I
beg to insert a few of the earlier experiments on different descriptions of tubes, as recorded in a report addressed to Mr. Stephenson and the directors of the Chester and
Holyhead Railway, the particulars of which have already been before the public."
(Here follow the details of the experiments referred to.)
The experiments-, of which the above is a brief notice, have led to other improvements of great utility in practical science, and probably of equal value with those for
which they were originally undertaken.
"I have already stated that the difficulty which the weakness of the material to
resist a crushing force occasioned, was overcome by the adoption of the cellular form
of top; but another, and, to my mind, very serious difficulty presented itself, in the reduction in the strength of the plates at the joints by the ordinary method of riveting,
in the bottom and those parts where the tensile strain came into operation. This led
to a new system of riveting, which, without weakening the body of the plate to so great
an extent as formerly, gives ajoint of almost equal strength with the plate itself, and
thus adds in a most material manner to the security of the structure.
" Consequent upon the experiments and the results obtained therefrom, numerous
advantages presented themselves in the construction of wrought-iron girders. The
strength, ductility, and comparative lightness of the material are the important elements
of these girders; and their elasticity, retention of form, and other properties, render
them infinitely more secure than those composed of cast-iron, which, from the brittle
nature of the material and imperfections in the castings, are liable to break without
notice, and to which the wrought-iron girder is not subject. This is, however, probably of less importance, as the wrought-iron girder will be found not only cheaper,
but (when well constructed, and upon the right principle) upwards of three times the
strength of cast-iron. I have elsewhere stated to the Commissioners that the experiments attracted the notice generally of railway engineers, and, amongst others, that of
Mr. Vignoles, who immediately gave an order for two wrought-iron girder bridges for
the Blackburn and Bolton Railway Company:-one to cross the Liverpool and Leeds
Canal, and the other over the turnpike road, both in the vicinity of Blackburn. These
bridges were constructed simultaneously with another of similar form (with a cast-iron
top) executed by Mr. Dockray, under the direction of Mr. Robert Stephenson, for
carrying the turnpike road over the London and North-Western Railway at Camden
Town.  Those for the Blackburn and Bolton Railway were, however, the first adapted
for railway traffic; and although they are probably not so well proportioned as others
since constructed, they nevertheless exhibit extraordinary powers of resistance; and
conceiving that a description of these bridges, with the tests to which they were subjected, might be useful, I have great pleasure in submitting the same, with the necessary drawings, to the consideration of the Commissioners.
Explanation of the Engravings, descriptive of the Hollow Girder Bridge over the Turnpike
Road near Blackburn.
"Fig. 521 is an elevation or side view of the girder, each 66 ft. long, and bedded on
cast-iron base plates.
"g. 522 is a transverse section of the bridge, showing the sides of the cross-beams,
and the cross sections of the outside and middle girders.
" Fig. 523 is an enlarged transverse section of the outside girder, showing the attachment of the cross-beams, which are riveted to the bottom of the girder, exclusive
of two bolts A A, which extend through the bottom plates and angle iron of the girder,
and the top and bottom plates of the cross-beam.
" Fig. 524 is an enlarged view of a part of the side of the large girder, exhibiting a
transverse section of the cross beam, at B, which is made of wrought-iron, with the top
and bottom plates so proportioned as to equalise its powers of resistance to the force of
compression on the top, and that of tension on the bottom. It also exhibits the mode
of riveting up the joints of the side plates with the covering strip co c, and the additional strength as obtained by the attachment of T iron in the interior of the tube.
"Fig. 525 is a plan of the bridge, showing on one side the platform and the rails, and.
on the other the cross-beams, which in this bridge are placed 6 ft. asunder; but in those
more recently constructed, I have placed them at distances of only 4 ft, and consider
this arrangement preferable.




686                  FAIRBAIRN'S TUBULAR BRIDGES.
521
56~ ~~23        eL_ ~25
1_'     If!1   I    I                             ~.'
"From the above description it will be seen that the whole i a trong and perfectl
rigid structure.  With three longitudinal girders, a bridge of this description will
support a load equally distributed of 760 tons; and in order to render it safe, under
every species of strain, the middle girder is made nearly double the strength of those on
the outside. This is essential, as two trains may be passing the bridge at the same
moment; in which case the middle girder would be subjected to a pressure equal to
double the load on the outside girders.
"In the construction of bridges of larger span, I generally prefer only two large longitudinal girders with strong cross-beams every three feet, of sufficient length to admit two
lines of rails, and sufficient room for two trains to pass at the same time. This mode of
construction is preferable to the three girders, as it effects greater simplicity in the
structure, and, from every appearance, renders the bridge equally effective and secure.
"' Having thus described the advantages peculiar to this description of bridge, I will
now direct the attention of the Commissioners to the tests to which the Blackburn
Bridge was subjected, previous to its opening for public traffic. The experiments were
made in the presence of Captain Coddington, the Government Inspector of Railways
and Mr. Flanagan, engineer of the line, as follows:
"Three locomotive engines, weighing 60 tons, were coupled together, and passed
over the bridge at velocities varying from 5 to 15, and 25 miles an hour. This load
(60 tons) produced a deflection of'025 of a foot, or about 1%ths of an inch, and that
without any perceptible increase in the deflection arising from the different rates of
speed. In fact the deflection was fotind to be the same at all velocities.
"After these tests were made, two wedges or inclined plates were fitted to the rails,
fig. 526, at the middle of the bridge, and the engines run over them at the rate of 1 to
526
RAIL
10 miles an hour. The shock of the engines, as they respectively fell upon the girders,
from a height of one inch, the thickness of the wedge at D, gave an increased deflection
from 025 to'035 of a foot, and another set of wedges, IJ feet in height gave a further
increase of deflection (at the same velocity) of'035 to.045 of a foot.
"From the above experiments it appears evident that wrought-iron girders are well




FATS.                                       687
calculated to resist not only a heavy dead weight, but the force of impact administered
with an unsparing hand; for, in fact, the girders were not injured by the blows inflicted
by engines falling a height of 1 inches upon them, but restored themselves to their
original position from which they were deflected by the shock.
" On the whole we may, therefore, reasonably conclude that the present structure is
not only the strongest, but the best calculated to resist strain when applied to large
spans, and particularly in situations where bridges, with a perfectly horizontal so
are alone admissible.
(Signed)    "WILuA
1 Manchester, April 26th, 1848."
FAN (Eventail, Fr.; Fiacher, Germ.) is usually a semi-circular piece of silk or paper,
pasted donble, enclosing slender slips of wood, ivory, tortoise-shell, whale-bone, &c.,
arranged like the tail of a peacock, in a radiating form, and susceptible of being folded
together, and expan4ed at pleasure. This well-known hand ornament is used by ladies
to cool their faces by agitating the air. Fans made of feathers, like the wing of a bird,
have been employed from time immemorial by the natives of tropical countries.
Fan is also the name of the apparatus for winnowing corn. For an account of the
powerful blowing and ventilating fan machine, see FOUNDRY and VENTILATOR.
FARINA  (Farine, Fr.; Mehl, Germ.) is the flour of any species of corn, or starchI
root, such as potato, arrow root, &c. See BREAD and STARCH.
FATS.(Graisses, Fr.; Fette, Germ.) occur in a great number of the animal
tissues, being abundant under the skin in what is called the cellular membrane, round
the kidneys, in the folds of the omentum, at the base of the heart, in the mediastintm,
the imesenteric webb, as well as upon the surface of the intestines, and among many ol
the muscles. They vary in consistence, color, and smell, according to the animals
from which they are obtained; thus, they are generally fluid in the cetaceous tribes,
soft and rank-flavored in the carnivorous, solid and nearly scentless in the ruminants,
usually white and copious in well-fed young animals; yellowish and more scanty in the
old. Their consistence varies also according to the organ of their production; being
firmer under the skin, and in the neighborhood of the kidneys, than among the moveable
viscera. Fat forms about one twentieth of the weight of a healthy animal. But as
taken out by the butcher it is not pure, for being of a vesicular structure, it is always
enclosed in membranes, mixed with blood, blood-vessels, lymphatics, &c. These foreign
matters must first be separated in some measure mechanically, after the fat is minced
small, and then more completely by melting it along with hot water, passing it through
a sieve, and letting the whole cool very slowly. By this means a cake of cleansed fat
will be obtained. Many plans of purifying fats have been proposed; one of the best is
to mix two per cent. of strong sulphuric acid with a quantity of water, in which the
tallow is heated for some time with much stirring; to allow the materials to cool, to
take off the supernatant fat, and re-melt it with abundance of hot water. More tallow
will thus be obtained, and that considerably whiter and harder than is usually procured
by, the melters.
I have found that chlorine and chloride of lime do not improve, but rather deteriorate, the appearance of oils and other fatty bodies. According to Appert, minced suet
subjected to the action of high-pressure steam in a digester, at 2500 or 2600 F., becomes
so hard as to be sonorous when struck, whiter, and capable, when made into candles, of
giving a superior light. A convenient mode of rendering minced tallow, or melting it, is
to put it in a tub, and drive steam through it from numerous orifices in ramifying pipes
placed near the bottom. Mr. Watt assures me that his plan of purifying fats, patented
in March, 1836, has been quite successful. He employs dilute sulphuric acid, to which
he adds a little nitric acid, with a-very small quantity of bichromate of potash, " to supply oxygen;" and some oxalic acid. These are mixed with the fat in the steaming
tub. When the lumps of it are nearly dissolved, he takes for every ton of fat, one
pound of strong nitric acid, diluted with one quart of water; to which he adds two
ounces of alcohol, naphtha, sulphuric ether, or spirits of turpentine; and after introducing this mixture, he continues the boiling for half an hour. The fat is finally
washed. As I do not comprehend the modus operandi of these ingredients, I shall
abstain from any comment upon the recipe.
Others have proposed to use vegetable or animal charcoal first, especially for rancid
oils, then to heat them with a solution of sulphate of copper and common salt, which is
supposed to precipitate the fetid albuminous matter. Milk of lime has been also prescribed: but it is, I believe, always detrimental.
Davidson treats whale oil with infusion of tan, in order to separate the gelatine and
albumine in flocks; next with water and chloride of lime, to destroy the smell; and
lastly, with dilute sulphuric acid, to precipitate all the lime in the state of a sulphate.
This is certainly one of the cheapest and most effective methods of purifying that
substance.                                44




688                                   FATS.
Braconnot and Raspail have shown that solid animal fats are composed of very small,
microscopic, partly polygonal, partly reniform particles, which are connected together
by very thin membranes. These may be ruptured by mechanical means, then separated
by triturating the fresh fats with cold water, and passing the unctuous matter through
a sieve. The particles float in the water, but eventually collect in a white granulas
crystalline appearance, like starch. Each of them consists of a vesicular integument, of
the nature of stearine, and an interior fluid like elaine, which afterwards exudes. The
granules float in the water, but subside in spirits of wine. When digested in strong
alcohol, the liquid part dissolves, but the solid remains. These particles differ in shape
and size, as obtained from different animals; those of the calf, ox, sheep, are polygonal,
from  I to -1  of an inch in diameter; those of the sow are kidney-shaped, and from
to  I'o; those of man are polygonal, and from -3 to  I   those of insects are spherical,
and at most I  of an inch.
Fats all melt at a temperature much under 212" F. When strongy heated with contact of air, they diffuse white pungent fumes, then blacken, and take fire. When subjected to distillation, they afford a changed fluid oil, carbureted hydrogen, and the other
products of oily bodies. Exposed for a certain time to the atmosphere, they become
rancid, and generate the same fat acids as they do by saponification. In their fresh
state they are all composed principally of stearine, margarine, and oleine, with a little
coloring and odorous matter; and, in some species, hircine, from the goat; phocenine,
from the dolphin; and butyrine, from butter. By subjecting them to a great degree ot
cold, and compressing them between folds of blotting paper, a residuum is obtained, consisting chiefly of stearine and margarine; the latter of which may be dissolved out by
oil of turpentine.
Beef and Mutton Suet.-When fresh, this is an insipid, nearly inodorous fat, of a firm
consistence, almost insoluble in alcohol, entirely so if taken from the kidneys and mesenteric web of the ox, the sheep, the goat, and the stag. It varies in its whiteness, consistence, and combustibility, with the species and health of the animals. That of the
sheep is very white and very solid. They may all be purified in the manner above described. Strong sulphuric acid developes readily the acid fats by stirring it through
melted suet. Alkalis, by saponification, give rise at once to the three acids,-the stearic,
margaric, and oleic. Beef suet consists of stearine, margarine, and oleine; mutton and
goat suet contain a little hircine. The specific gravity of the tallow of which common
candles are made is, by my experiments, 0'936. The melting point of suet is from 980
to 1040 F. The proportion of solid and fluid fat in it is somewhat variable, but the former is in much larger proportion. Mutton suet is soluble in 44 parts of boiling alcohol,
of 0*820; beef suet in 44 parts. Marrow fat consists of 76 of stearine, and 24 of oleine;
it melts at 115~ F.
Hog's-lard is soft, fusible at 810 F., convertible, by an alkaline solution, into a stearate,
margarate, oleate, and glycerine. Its sp. grav. is 0938, at 50~ F. It consists of 62 of
oleine, and 38 of stearine, in 100 parts.
Goose-fat consists of 68 oleine and 32 stearine.
Butter, in summer, consists of 60 of oleine and 40 of stearine; in winter, of 35 of
oleine, and 65 of stearine; the former substance being yellow, and the latter whito,
It differs, however, as produced from the milk of different cows, and also according to
their pasture.
The ultimate constituents of stearine, according to Chevreul, are 79 carbon, 11*7
hydrogen, and 9'3 oxygen, in 100 parts.
1,294,009 cwts. of the tallow imported in 1837 were retained for internal consumption.
See MARGARINE, OLEINE, SOAP, STEARINE.
The following statement is given on the authority of Braconnot:-~
Oleine.         Stearine.
Fresh Butter in summer       -      -                  Q60              40
in winter       -      -       -          37              63
Hog's Lard   -        -      -      -       -          62               38
Ox Marrow             -             -       -          24               76
Goose Fat    -        -      -      -       -          68               32
Duck Fat      -       -      -       -      -'72              28
Ox Tallow     -       -      -       -      -          25               75
Mutton Suet  -        -      -       -      -          26               74
M. Dumas says that butter contains no stearine. The purification and decoloration
of fats have been the object of many patents. Under CANDLE, Hempel's process for
refining palm-oil and extracting its margarine is described.
About 30 years ago, palm-oil was deprived of color to a certain degree by mixing
with the melted oil, previously freed from its impurities by filtration, some dilute nitric




FATS.                                      689
acid, wooden vessels being used, and the oil being in a melted state. This process was
both expensive and imperfect. More lately whitening has been prescribed by means
of chromic acid, which, in the act of decomposition into chromic oxide, gives out
oxygen, and thereby destroys vegetable colors.  One pound of bichrorate of potash
in solution is to be mixed with two pounds of strong sulphuric acid, diluted beforehand with about two gallons of water; and this mixture is to beincorporated by
diligent stirring with 2 cwt. of the filtered palm-oil, at a temperature of about
100 F., contained in a wooden vessel. The palm-oil is afterward to be washed in
warm lime-water, to which some solution of chloride of lime may be advantageously
added. By this process, well managed, a fat may be obtained from  palm-oil fit for
making white soap.  Tallow may be also blanched to a considerable degree by a like
operation.
Instead of sulphuric acid, the muriatic may be used to convert the chromic acid into
chromic oxide in the above process, and thereby to liberate the blanching oxygen.
The resulting solution of green muriate of chrome being freed from some adhering oil,
is to be mixed with so much milk of lime as just to neutralize the excess of acid that
may be present. The clear green muriate is then to be decomposed in a separate
vessel, by the addition of well-slaked and sifted lime, in some excess. The green mixture of lime and chrome-oxide is now to be dried, and gently ignited, whereby it is
converted into yellow chromate of lime, with some unsaturated lime. This compound
beinir decomposed by dilute sulphuric acid, affords chromic acid, to be applied again in
the decoloring of palm-oil, on the principles above explained.
Mr. Prynne obtained a patent in March, 1840, for purifying tallow for the candlemaker, by heating it along with a solution of carbonate of potash or soda for 8 hours,
letting the whole cool, removing the tallow to another vessel, heating it by means of
iteam up to 206~ F., along with dry carbonate of potash (pearlash): letting this mixture cool very slowly; and finally removing the tallow to a vessel enclosed in steam, so
as to expel any subsidiary moisture.-Newton's Journal, xxi. 258.
A patent for a like purpose was obtained in June, 1842, by Mr. H. H. Watson. He
avails himself of the blanching power of oxygen, as evolved from manganate of potash
(chameleon mineral), in the act of its decomposition by acids, while in contact with
the melted fat. He prescribes a leaden vessel (a well-joined wooden tub will also
serve) for operating upon the melted tallow, with one twentieth of its weight of the
manganate, dissolved in water, and acidulated to the taste. The whole are to be well
mixed, and gradually heated from 1500 up to 2120 F., and maintained at that temperature for an hour.  On account of the tendency of the dissolved manganate to
spontaneous decomposition, it should be added to the dilute acid, mixed with the fat
previously melted at the lowest temperature consistent with its fluidity.
Palm-oil may be well blanched in the course of 12 hours by heat alone; if it be
exposed in a layer of one or two inches to the air and sunshine, upon the surface of
water kept up at nearly the boiling point by a coil of steam-pipes laid in the bottom of
a square cistern of lead or wood, well jointed.
Mr. Wilson, of Vauxhall, has applied centrifugal action to the separation of the more
liquid from the more solid parts of fatty matters, using in preference the hydro-extractors
used by Seyrig and Co., for drying textile fabrics. Mr. Wilson employs a stout cotton
twill in addition to the wire grating; and in order to avoid the necessity of digging the
concrete parts, and to prevent them from clogging the interstices for the discharge of
the oily matter, he places the whole in a bag 8 inches in diameter, and of such length
that when laid on the rotating machine against the grating the two ends will meet.
The speed of the machine must be kept below that at which stearic acid or stearine
would pass; which is known by the limpidity of the expressed fluid. To take advantage of the liquefying influence of heat, he keeps the temperature of his room about 20
F. above that of the substances under treatment.
The improved fat and candle factory, called Price's, of which Mr. Wilson, of Belmont,
Vauxhall, seems to be the main conductor and schemer, is mounted upon a colossal
scale. It has five separate works near London, great plantations of cocoa-nut trees in
Ceylon, with a capital of about half a million sterling, an annual division of profits to
the amount of 50,0001., and it employs about 800 work-people, whose physical and moral
well-being is well looked after by the benevolent manager of the whole concern. See
CANDLES.
Tallow imported for home consumption in 1850, 1,219,101 cwt.; in 1851, 1,085,660
cwt. Gross amount of duty received, l8,2701. and 68,0351. respectively; the duty being
Id. per cwt. from British possessions, and Is. 6d. per cwt. from foreign countries.
FAT BLEACHING. By transmitting streams of atmospheric air through heated palmoil and other colored and odorous fatty matters, they are deprived so far of their
color and smell as to be capable of forming white soaps. Mr. A  Dunn obtained a
patent for this object in 1843.




890                                 FEATHERS.
FAULTS (Failles, Fr.), in mining, are disturbances of the strata which interrupt
the miner's operations, and put him at fault, to discover where the vein of ore or bed of
coal has been thrown by the convulsions of nature. Many examples ot faults are exhib'
ited under PITCOAL.
FEATHERS (Plumes, Fr.; Federn, Germ.) constitute the subject of the manufacture
of tlhe Plumassier, a name given by the French (and also the English) to the artisan who
prepares the feathers of certain birds foromaments to the toilet of ladies and for military
men, and to him also who combines the feathers in various forms. We shall content ourselves with describing the method of preparing ostrich feathers, as most others are prepared in the same way.
Several qualities are distinguished in the feathers of the ostrich; those of the male, in
particular, are whiter and more beautiful.  Those upon the back and above the wings
are preferred; next, those of the wings, and lastly, of the tail. The down is merely the
feathers of the other parts of the body, which vary in length from 4 to 14 inches. This
down is black in the males, and gray in the females.  The finest white feathers of the
female have always their ends a little grayish, which lessens their lustre, and lowers their
price.  These feathers are imported from Algiers, Tunis, Alexandria, Madagascar, and
Senegal; this being the order of their value.
The scouring process is thus performed:-4 ounces of white soap, cut small, are dissolved in 4 pounds of water, moderately hot, in a large basin; and the solution is made
into a lather by beating with rods. Two bundles of the feathers, tied with packthread,
are then introduced, and are rubbed well with the hands for five or six minutes.  After
this soaping they are washed in clear water, as hot as the hand can bear.
The whitening or bleaching is performed by three successive operations.
1. They are immersed in hot water mixed with Spanish white, and well agitated in it;
after which they are washed in three waters in succession.
2. The feathers are azured in cold water containing a little indigo tied up in a fine cloth.
They should be passed quickly through this bath.
3. They are sulphured in the same way as straw hats are (See SUL.PHURING)  they are
then dried by hanging upon cords, when they must be well shaken from time to time to
open the fibres.
The ribs are scraped with a bit of glass cut circularly, in order to render them very
pliant.  By drawing the edge of a blunt knife over the filaments they assume the curly
form so much admired.  The hairs of a dingy color are dyed black.  For 20 pounds
of feathers, a strong decoction is made of 25 pounds of logwood in a proper quantity of
water.  After boiling it for 6 hours, the wood is taken out, 3 pounds of copperas are
thrown in; and, after continuing the ebullition for 15 or 20 minutes, the copper is taken
from the fire. The feathers are then immersed by handfuls, thoroughly soaked, and worked
about; and left in for two or three days. They are next cleansed in a very weak alkaline
ley, and soaped three several times.  When they feel very soft to the touch, they must
be rinsed in cold water, and afterwards dried.  White feathers are very difficult to dye
a beautiful black.  The acetate of iron is said to answer better than the sulphate, as a
mordant.
For dying other colors, the feathers should be previously well bleached by the action
of the sun and the dew; the end of the tube being cut sharp like a toothpick, and the
feathers being planted singly in the grass. After fifteen days' exposure, they are cleared
with soap as above described.
Rose color or pink, is given with safflower and lemon juice.
Deep red, by a boiling hot bath of Brazil wood, after aluming.
Crimson.  The above deep red feathers are passed through a bath of cudbear.
Prune de Monsieur. The deep red is passed through an alkaline bath.
Blues of every shade, are dyed with the indigo vat.
Yellow; after aluming, with a bath of turmeric or weld.
Other tints may be obtained by a mixture of the above dyes.
Feathers have some more useful employments than the decoration of the heads of
women and soldiers.  In one case, they supply us with a soft elastic down on which we
can repose our wearied frames, and enjoy sweet slumbers. Such are called bed feathers.
Others are employed for writing, and these are called quills.
Goose feathers are most esteemed for beds, and they are best when plucked from the
living bird, which is done thrice a year, in spring, midsummer, and the beginning of
harvest. The qualities sought for in bed feathers, are softness, elasticity, lightness, and
warmth.  Their only preparation when cleanly gathered is a slight beating to clear
away the loose matter, but for this purpose they must be first well dried either by the sun
or a stove.  Bleaching with lime water is a bad thing, as they never can be freed from
white dust afterwards.
The feathers of the eider duck, anas mollissima, called eider down, possess in a superior degree all the good qualities of goose down.  It is used only as a covering to beds,
and never should be slept upon, as it thereby loses its elasticity.




FELTED CLOTH.                                       691
Quills for writing.  These consist usually of the feathers plucked out of the wings of
geese. Dutch quills have been highly esteemed, as the Dutch were the first who hit upon
the art of preparing them well, by clearing them both inside and outside from a fatty
humor with which they are naturally impregnated, and which prevents the ink from flowing freely along the pens made with them.  The Dutch for a long time employed hot
cinders or ashes to attain this end; and their secret was preserved very carefully, but it
at length transpired, and the process was then improved. A bath of very fine sand must
be kept constantly at a suitable temperature, which is about 140~ F.; into this, the quill
end of the feather must be plunged, and left in it a few instants.  On taking them out
they must be strongly rubbed with a piece of flannel, after which they are found to be
white and transparent.  Both carbonate of potash in solution and dilute sulphuric acid
have been tried to effect the same end but without success. The yellow tint which gives
quills the air of age, is produced by dipping them for a little in dilute muriatic acid, and
then making them perfectly dry.  But this process must be preceded by the sand-bath
operation. The above is the French process.
Quills are dressed by the London dealers in two ways; by the one, they remain of their
natural color; by the other, they acquire a yellow tint.  The former is called the Dutch
miethod, and the principal workman is called a Dutcher.  He sits before a small stove fire,
Into which he thrusts the barrel of the quill for about a second, then lays its root quickly
below his blunt-edged knife called a hook, and, pressing this firmly with the left hand,
iraws te quill briskly through with his right.  The bed on which the quill is laid to re
eive this pressure is called the plate. It is a rectangular smooth lump of iron, about 3
inches long, 11 broad, and 21 thick, which is heated on his stove to about the 350th degree Fahr. The hook is a ruler of about 15 inches in length, somewhat like the patteniaker's knife, its fulcrum being formed at the one end by a hook and staple, and the
power of pressure being applied by the hand at the other end.  The quill, rendered soft
and elastic by the heat, endures the strong scraping action of the tobl, and thus gets
stripped of its opaque outer membrane, without hazard of being split.  A skilful workman can pass 2000 quills through his hands in a day of 10 hours.
They are next cleaned by being scrubbed by a woman with a piece of rough dog-fish
skin, and finally tied up by a man in one quarter of a hundred bundles.
In another mode of dressing quills, they are steeped a night in decoction of turmeric, to
stain them yellow; taken out and dried in warm sand contained in a pot, then scraped by
the Dutcher as above described.  The first are reckoned to make the best pens, though
"he second may appear more beautiful.
Crow quills for draughtsmen, as well as swan quills, are prepared in the same way.
The quills plucked from well-fed living birds have most elasticity, and are least subject to
be moth-eaten.  The best are those plucked, or which are spontaneously cast in the
month of May or June, because they are then fully ripe.  In the goose's wing the five
exterior feathers only are valuable for writing.  The first is the hardest and roundest of
all, but the shortest. The next two are the best of the five. They are sorted into those
of the right and the left wing, which are differently bent.  The heaviest quills are, generally speaking, the best. Lately, steaming for four hours has been proposed as a good
preparation.
FECULA (Fecule, Fr.; Stdrkemehl, Germ.) sometimes signifies corn flour, sometimes
starch from whatever source obtained.
FELDSPAR (Orthose, Fr.; Feldspath, Germ.) is a mineral crystallizing in oblique
rhomboidal prisms, susceptible of two clivages; lustre more pearly than vitreous;
spec. gray. 2-39 to 2-58; scratches glass; yields no water when calcined; fusible at
the blowpipe into a white enamel; not affected by acids.  The liquid left from  its
analytical treatment with nitrate of baryta, nitric acid, and carbonate of ammonia,
affords on evaporation an alkaline residuum which precipitates platina from its chloride,
and appears from this, as well as other tests, to be potash. Feldspar consists of-silica,
66-75; alumina, 17-50; potash, 12; lime, 1-25; oxyde of iron, 0-75.  Rose.  This
mineral is a leading constituent of granite; and in its decomposed state furnishes the
petuntse or Cornish stone, so much used in the porcelain and best pottery manufactures.
FELTED CLOTH. This woollen fabric, made without spinning and weaving, was
made the subject of a patent by Mr. T. R. Williams in February, 1850. A  copious
description of the process is given in Newton's Journal, xxii. 1.
Varnisheed or Japanned Felt is made by imbuing the stuff of coarse hat bodies with
drying oil, prepared by boiling 50 lbs. of linseed oil with white lead, litharge, and
Umber, of each one pound. The felt is to be dried in a stove, and then polished by
pumice-stone. Five or six coats of oil are required. The surface is at last varnished.
When the object is intended to be stiff, like visors, the fabric is to be impregnated first




692                                  FERMENT.
of all with flour-paste, then stove-dried, cut into the desired shape, next imbued with
the drying-oil, and pumiced repeatedly; lastly placed, to the number of 20, in a hot
iron mould, and exposed to strong pressure. Japanned hats, made in this way, are sold
in France at Is. 3d. a piece; and they will stand several years' wear.
FELTING.  (Feutrage, Fr.; Filzen, Germ.) is the process by which loose flocks
of wool, and hairs of various animals, as the beaver, rabbit, hare, &c., are mutually interlaced into a compact textile fabric. The first step toward making felt is to mix, in
the proper proportions, the different kinds of fibres intended to form the stuff; and then,
by the vibratory strokes of the bowstring, to toss them up in the air, and to cause them
to fall as irregularly as possible, upon the table, opened, spread, and scattered. The
workman covers this layer of loose flocks with a piece of thick blanket stuff slightly
moistened; he presses it with his hands, moving the hairs backward and forward in
all directions. Thus the different fibres get interlaced, by their ends pursuing ever
tortuous paths; their vermicular motion being always, however, root foremost As the
matting gets denser, the hand pressure should be increased in order to overcome the in
creasing resistance to the decussation.
A first thin sheet of soft spongy felt being now formed, a second is condensed upon it
in like manner, and then a third, till the requisite strength and thickness be obtained.
These different pieces are successively brought together disposed n a way suitable to the
wished-for article, and united by continued dexterous pressure. The stuff must be next
subjected to the fulling-mill. See HAT MANUFACTURE.
FERMENT (Eng. and Fr.; Hefe, Germ.) is the substance which, when added in a
small quantity to vegetable or animal fluids, tends to excite those intestine motions and
changes which accompany fermentation.  It seems to be the result of an alteration which
ve. etable albumen and gluten undergo with contact of air amidst a fermenting mass.
The precipitate or lees which fall down when fermentation is finished consist of a mixture of the fermenting principle with the insoluble matters contained in the fer:,ented
liquor, some of which, like hordeine, existed in the worts, and others are probably generated at the time.
To prepare a pure ferment, or at least a compound rich in that principle, the precipitate separated during the fermentation of a clear infusion of malt, commonly called
yeast or barm, is made use of. This pasty matter must be washed in cold distilled water,
drained and squeezed between the folds of blotting paper. By this treatment it becomes
a pulverulent mass, composed of small transparent grains, yellowish gray when viewed
in the compound microscope. It contains much water, and is therefore soft, like moist
gluten and albumen. When dried, it becomes like these bodies, translucid, yellowish
brown, horny, hard, and brittle.  In the soft humid state it is insipid, inodorous, insoluble in water and alcohol. If, in this state, the ferment be left to itself at a temperature of from 600 to 70' F., but not in too dry a situation, it putrefies with the same phenomena as vegetable gluten and albumen, and leaves, like them, a residuum resembling
old cheese.
At the beginning of this change, particularly if the ferment be enclosed in a limited
portion of air, there is an absorption of oxygen gas with a fivefold disengagement of carbonic acid gas; while acetic acid makes its appearance in the substance. When distilled
by itself it affords the same products as gluten. Dilute acids dissolve it very readily;
and so does potash with the production of ammonia, a peculiar circumstance, for in dissolving gluten the alkali causes no such evolution.
The property possessed by yeast of determining the fermentation of a properly diluted
solution of sugar is very fleeting, and is lost by very trifling alterations. It is destroyed
by complete desiccation, and cannot be restored by moistening it again. The attempts
made in London \o squeeze out the liquid part of yeast in bags placed in a powerful press,
and to obtain a solid cake, in order to transport ferment to India, have had but a very
partial success; for its virtue is so impaired that it will rarely excite a perfect fermentation in the best prepared worts. The same method is adopted in Germany, to send yeast
to only moderate distances; and therefore with more advantage.
If yeast be boiled for ten minutes, it loses the greater part of its fermenting power,
ind by longer boiling it becomes inert.
When alcohol is poured upon yeast, it immediately destroys its fermenting faculties,
though, on filtering it off, it seems to carry no remarkable principle with it. One thousandth part of sulphuric acid equally deprives yeast of its peculiar property, apd so does
a little strong acetic acid. All the acids and the salts, especially those which part readily
with their oxygen, produce the same effect. A very small quantity of sulphurous acid,
or sulphites, mustard powder, particularly the volatile oil of mustard, and in general the
volatile oils that contain sulphur, as well as the vegetables which yield them, such as
horse-radish and garlic, all kill the fermenting agent. Lastly, fermentation is completely
stopped by a moderate depression of temperature.




FERMENTATION.                                       693
During fermentation the yeast undergoes a change; it loses the property of causing
another wort to ferment. This change probably depends upon the chemical reaction
between the ferment and the sugar that is decomposed; for a certain quantity of yeast
can effect the fermentation of only a certain quantity of sugar, and all the sugar
exceeding this quantity remains unaltered in the liquor. It has been concluded from
some rather loose experiments, that one part and a half of yeast (supposed to be in the
dry state), is adequate to the fermentation of a solution of 100 parts of pure sugar.
When such a solution is fermented by the precise proportion of yeast, the fermenting
principle is exhausted, for no new yeast is formed in it. There is a deposit indeed to
about half the weight of the yeast employed, of a white matter insoluble in water.
which affords no ammonia by dry distillation, and is incapable of acting as a ferment
upon a fresh saccharine solution.
Of all the bodies convertible into yeast during fermentation, vegetable gluten and
albumen possess the most rapid and energetic powers.  But ordinary glue, isinglass,
animal fibrine, curd or caseum, albnumine, urine, and other azotized substances, all
enjoy the property of causing a solution of sugar to ferment; with this difference,
that whilst yeast can establish a complete fermentation in less than an hour, at a temperature of about 680, the above substances require several days, with a heat of from
170 to 87c F., for becoming ferments, and for occasioning fermentation. Substances
devoid of nitrogen do not produce a ferment.
FERMENTATION.  (Eng. and Fr.; Gahrung, Germ.)  When organic substances.
ander the influence of water, air, and warmth, are abandoned to the reciprocal operation
of their proximate principles (sugar, starch, gluten, &c.), they are entirely changed and
decomposed, so that their ultimate principles (oxygen, hydrogen, carbon, and in some cases
azote) combine in new proportions, and thus give birth to various new compounds.  To
this process, the general name of fermentation has been given.  These operations and
their products differ according to the differences of the substances, and of the circumstances in which they are placed. The following may be enumerated as sufficiently distinct
species of fermentation. 1. The saccharine fermentation, in which starch and gum are
changed into sugar. 2. The vinous fermentation. in which sugar is converted into alco.
hol. 3. The mucilaginous fermentation, in which sugar is converted into slime, instead
of alcohol. 4. The acetous fermentation, in which alcohol and other substances are converted into vinegar. 5. The putrid fermentation or putrefaction, which characterizes
particularly the decomposition of azotized organic substances.
1. The saccharine fermentation. When a paste made by boiling one part of starch
with twelve parts of water is left entirely to itself, water merely being stirred in as it
evaporates, at the end of a month or two in summer weather it is changed into sugar,
equal in weight to from one third to one half of the starch, and into gum, equal to from
one fifth to one tenth, with a residuum of starch paste somewhat altered.  This saccharifying process advances much quicker through the co-operation of vegetable albumine or gluten, acting as a ferment. If we boil two parts of potato starch into a
paste with twenty parts of water, mix this paste with one part of the gluten of wheat
flour, and set the mixture for 8 hours in a temperature of from  122* to 1670 F., the
mixture soon loses its pasty character, and becomes by degrees limpid, transparent, and
sweet, passing at the same time first into gum, and then into sugar. The remainder
consists of the unchanged starch with the altered gluten, which has become sour, and
has lost the faculty of acting upon fresh portions of starch. It is probable, however,
that the sugar formation in the first case, when the starch undergoes a spontaneous
change, may be due to the action of a small portion of gluten and albumine left in
the starch, since a putrefactive smell is eventually evolved indicative of that azotized
matter. The gum into which during this process the starch is first converted, and which
becomes afterwards sugar, is of the same nature as British gum, formed by the roasting
of starch.
This production of sugar takes place in the germination and kiln-drying of malt; and
the mashing of the brewer as well as the sweetening of bread in baking, rests upon the
same principles. In many cases the vinous fermentation precedes the saccharification,
or accompanies it; the starchy parts of the fermenting mass changing into sugar,
while the previously formed sugar becomes wine or beer. In the sweetening of fruits
by keeping, a similar process occurs; the gummy and starchy fibres become sugar from
the action of the glutinous ferment which they contain; as happens also to the juices of
many fruits which sweeten for a little while after they have been expressed.
The nature of this sugar formation through the influence of gluten upon starch, is undoubtedly the same as the conversion of starch into sugar, by boiling it with sulphuric
acid; though the whole theory of this change is not entirely developed.
The most energetic substance for the conversion of starch into sugar, is the malt of
barley.  According to the researches of Payen and Persoz, the gum  which by this




694                             FERMENTATION.
process is first formed, may be prevented from going into sugar, by merely exposing it
to a boiling heat, and hence we have it in our power either to make sugar or gum at
pleasure. Of finely ground malt from 10 to 25 parts must be taken for 100 parts of starch.
Into a pan placed in a water bath, 400 parts of water being warmed to from 77 to 860 F.,
the ground malt must be stirred in, and the temperature must be raised to 1400. The 100
parts of starch must now be added, and well mixed. The heat is then to be increased
to 158~ F.; and be so regulated that it shall not fall below 149~, nor rise above 1670.
In the course of 20 or 30 minutes the originally milky and pasty liquid will become
gradually more attenuated, and eventually it will turn as fluid nearly as water. This
is the point of time in which the starch has passed into gum, or into the substance
lately denominated dextrine by the chemists. Should this mucilaginous matter, which
appears to be a mixture of gum and a little starchy sugar, be wished for in that state,
the temperature of the liquid must be suddenly raised to the boiling point, whereby
the further action of the malt upon it is stopped. But on the other hand, if sugar
be desired, then the temperature must be steadily maintained at from  158~ to 1670'or three quarters of an hour, in which time the greater )Dart of the starch will have
become sugar, and from the evaporation of the fluid a starchy syrup will be obtained,
entirely similar to that procurable by the action of very dilute sulphuric acid upon
starch.
sugar, and from the evaporation of the fluid a starchy sirup will be obtained, entirely
similar to that procurable by the action of very dilute sulphuric acid upon starch.
Trhe substance which operates this saccharine change, or the appropriate yeast of the
sugar fermentation, which had been previously imagined to be a residuum of gluten or
vegetable albumen in the germinated grain, has been traced by Payen and Persoz to a
peculiar proximate vegetable principle called by them diastase. This substance is generated during the germination of barley, oats, and wheat, and may be obtained separate*
by infusing the ground malt in a small quantity of cold water, straining off the liquor,
then filtering it, and heating the clear solution in a water-bath to the temperature of
1580 F. The greater part of the vegetable albumen is thus coagulated, and must be
separated by a fresh filtration; the liquid is afterwards treated with alcohol as long as
the flocculent precipitate of diastase falls. In order to purify it still more completely
from the azotized matter, it may be once more dissolved in water, and again precipitated
by alcohol.  When dried at a low temperature, it appears as a white solid, which contains no azote, is insoluble in strong alcohol, but dissolves in weak alcohol and water.
Its solution is neutral and tasteless; and if left to itself, it changes spontaneously, sooner
or later, according to the degree of warmth, and becomes sour. At the temperature of
from 1490 to 168~, it has the property of converting starch into gum or dextrine, and
sugar; and, when sufficiently pure, it does this with such energy, that one part of it is
capable of saccharifying 2000 parts of dry starch. It acts the more rapidly the larger
its proportion.  Whenever the solution of diastase with starch or dextrine has bees
heated to the boiling point, it loses the property of transforming these substances. One
hundred parts of well malted barley appear to contain about one part of this new body.
2. The Vinous Fermentation.-In this fermentation the sugar existing in watery solution is, by the operation of the ferment or yeast, converted into alcohol, with disengagement of carbonic acid gas. If we dissolve one part of pure sugar in ten parts of water,
and leave the solution in a temperature of from 680 to 770 F., which is that most favorable to fermentation, it will remain unaltered. But if we stir into that solution some beer
yeast, the phenomena of fermentation soon appear in the above circumstances; for carbonic acid gas is evolved, with intestine movements of the liquid, and an increase of its
temperature. A body of yeast rises to the surface, and exhibits a continual formation and
rupture of air bubbles. At length the sugar being in a great measure decomposed, the
motions cease, the liquor becomes clear, and instead of being a sirup, it is now a dilute
alcohol. The yeast has by this time fallen to the bottom in a somewhat compact form,
and of a whitish color, deprived of the property of exciting fermentation in fresh sirup,
provided no undue excess of it was added at first, for that alone would remain effective.
Experience shows that for the conversion of a determinate quantity of sugar by fermentation, a determinate quantity of yeast is necessary, which has been estimated at abou:
1J per cent. in the dry state. When the yeast has been decomposed by fermenting its
definite proportion of sugar, it loses its fermentable property, and leaves the excess of
sugar unaffected, forming a sweet vinous solution. The same thing happens if the yeast
be separated from the wort by a filter in the progress of the fermentation, for then all
intestine motion speedily stops, although much saccharine matter remains.
In the juices of sweet fruits, of grapes, for example, the ferment is intimately associated with the sugar. It is at first soluble and inactive, till it absorbs oxygen from the
atmosphere, whereby it becomes an operative ferment, but, at the same time, insoluble,
so as to precipitate at the end of the process. When the expressed juice of the grape,
or must, is enclosed in a vessel out of contact of air, and there subjected to the heat of




FERMENTATION.                                       695
boiling water, the small portion of oxygen present is rendered inactive, and the liquor experiences no fermentative change. If the grapes be squeezed in an atmosphere deprived
of oxygen, and confined in the same, the juice will also remain unaltered. Recently expressed grape juice is limpid, and manifests the commencement of fermentation by the
separation of the yeasty substance, which can take place only with access of air. The
Solution becomes turbid after a certain time, gas begins to be evolved, and the separated
ferment decomposes the sugar. At the end of the process the yeast collects at the bottom of the vessel, usually in larger quantity than was sufficient to complete the fermentationr; and hence a considerable portion of it possesses still the fermentative faculty.
The fermentation itself, when once begun, that is, whenever the yeasty particles are
ei olved and float in the liquid, for which evolution a very minute quantity of oxygen is
sufficient, is thenceforth independent of the contact of air, and goes on as well in close
as in open vessels; so that the production of alcohol and carbonic acid depends solely
upon the mutual reaction of the ferment and the sugar.
The yeast, which may be obtained tolerably pure from a fine infusion of malt in a
state of fermentation, after being washed with cold water to separate the soluble, gummy,
and saccharine matter, and after being pressed between folds of blotting paper, constitutes a pulverulent, grayish yellow, granular substance, destitute of both taste and smell
insoluble both in water and alcohol. Cold water dissolves, indeed, only  -   and boiling
water very little more.
The essentially operative constituent of yeast is a peculiar azotized matter, which in
the wine vat is mixed with some tartar and other salts, and in the beer tun with gum,
-starch, &c. This animalized substance may be obtained in a separate state, according
to Braconnot, by acting upon the washed yeast powder with a weak ley of carbonate of
potash, and by decomposing the solution with vinegar, whereby the matter is thrown
down in a gelatinous form.  The substance thus obtained is insoluble in cold water
and alcohol, but dissolves readily in very dilute alkaline leys, and even in lime water
When diffused through water, it assumes a homogeneous aspect, as if it were really
dissolved; but when this mixture is heated, the animalized matter coagulates and
separates in thick flocks. In this state it has lost its former properties, being no longer
soluble in alkaline leys, even when concentrated. Acids exercise no solvent power over
this peculiar matter; they precipitate it from its solutions, as do also the earthy and
metallic salts, which, moreover, combine with it. This is also the case with tannin.
The combination of the ferment stuff with acids increases the stability of its constitution,
and counteracts its tendency to influence solutions of sugar. These properties of the
operative principle of yeast explain many of the phenomena of fermentation, as we shall
presently see.
- The animalized matter of yeast resembles gluten, albumen, caseum, and other azotized
substances; if any one of these be put into a saccharine solution ready for fermentation,
it will begin to operate a change, when aided by warmth and time, if it be previously
decomposed in some measure to facilitate its influence; or if these substances be brought
into a slightly putrescent state beforehand, they will cause more speedy fermentation.
Thus white of egg, when added to saccharine liquors, requires a period of three weeks,
with a temperature of 96" F., before it will excite fermentation; afterwards the excess
of the albumen forms a precipitate which may be used instead of yeast upon other sweet
worts. The rapidity with which such azotized substances are capable of being converted
into ferments of more or less purity and power is very variable; vegetable gluten and
albumen being best fitted for this purpose. This conversion is accelerated when the
sweet liquor in which the substance is diffused or dissolved has already begun to ferment;
whence it appears that the presence of carbonic acid gas, combined with the liquor, is
here of singular influence. Upon it, in fact, the formation and elimination of the yeast
in fermenting liquors depend.
A solution of pure sugar, which has been made to ferment by the addition of yeast,
furnishes no new yeast; but there remains after the process a portion of the yeast originally mixed, in an altered inoperative condition, should its quantity have been exactly
adequate to the decomposition of the sugar, or in an operative state, should the quantity
have been originally excessive.
- But if the fermentable liquor contains vegetable albumen and gluten, as is commonly
the case with the sweet juices of fruits and beer worts, these substances become changed
into ferments in the course of the fermentation induced by the yeast, and, being superfluous, so to speak, for that particular process, they remain entire at the end, and may be
collected for use in other operations.
Upon this principle is founded the increased production of yeast, and the manufacture
of what has been called artificial barm, in which the fermentation is conducted chiefly
with a view to the formation of yeast. To the fermenting mass, those kinds of meal are
added, which abound in albumen and gluten, as barley, beans, or wheat, for instance;




B96                             FERMENTATION.
and the process is similar to the production of a great lump of leaven, from the action
of a small piece of it upon dough. The following prescription will illustrate this subject
Take three ounces of bean flour, add to it five quarts of boiling water, and boil the
mixture for half an hour. Pour the decoction into a vessel, and stir into it, while hot,
56 ounces of wheaten flour. After the mixture cools to the temperature of 540 F., add
to it about two quarts of beer barm, stirring the whole well together. About 24 hours
after the commencement of the fermentation, incorporate with the mixture 1 2 ounces of
barley or bean flour, till it becomes a uniform dough, which must be thoroughly kneaded
rolled out into cakes about an inch thick, and cut into pieces of the size of a dollar.
These cakelets must be dried upon laths in the sun in favorable weather, and then put
up in a dry situation. For use, one of these discs is to be broken into pieces, laid in
warm water, and set in a warm place during 12 hours. The soft mass will then serve
the purpose of beer yeast.
Or we may mix equal parts of barley malt, wheat malt, and crushed rye, pour water
at the temperature of 122~ F. over them into a tub till it stand a span above their surface; then stir well together, and allow the whole to remain at rest for a few hours,
till it cools to about 65~ F. We must now add for each pound of the mingled meals,
a quarter of an ounce of beer barm.  The tub must be then covered, and preserved at
* temperature of 630 F. The husks, as they begin to rise to the surface, in consequence
of the fermentation, must be taken off and squeezed through a cloth over the vessel.
When the meal comes afterwards to subside to the bottom, the whole must be strained
through a canvass bag, and freed from the superfluous moisture by squeezing   The bag
with its doughy mass must next be surrounded with dry ashes, to remove the remaining
humidity, and to arrest any further fermentation.  This consistent ferment may be used
instead of beer yeast.
It is difficult to prepare an artificial yeast without barm.  The best process for this
purpose is the following.  Take five parts of honey, one part of powdered tartar, and
sixteen parts of wheat or barley malt, stir the whole in water of the temperature of 122
F., and place in a fermenting heat; when the yeast will, as usual, be eliminated.
The change which gluten or vegetable albumen undergoes in the different kinds of
meal, when it becomes a ferment, consists apparently in an oxydation, since analysis
shows that this ferment contains more oxygen than gluten does.
It has been already stated that yeast in its liquid condition readily putrefies, and
becomes altogether useless for the process of fermentation.  In order to preserve it for
some time, it must be dried to such a degree as to resist spontaneous decomposition
without losing its fermentative faculty; but completely dried yeast loses that property,
and does not recover it by being again moistened.  Beer barm may be dried aaer being
washed several times with cold water, till the last quantity comes off clear; but the insoluble portion must be allowed to settle fully before the water is poured away from it.
The residuum  being freed as much as possible from water, by drainage and pressure
between flannel cloths, is to be dried in the shade by a current of warm air as quickly
as possible, with the aid of frequent turning over.  It must be afterwards kept in dry
earthen vessels. Yeast may also be preserved a short time in activity by being kneaded
with as much barley or wheat flour as it can take up without losing the doughy consistence. Dried yeast has, however, always an impaired activity. The easiest and most
certain method of preserving yeast in its primitive power, is by mixing it, after pressure
in flannel, with as much pulverized sugar as will render it dry, and putting up the mixture in air-tight vessels.  The fermentative power of yeast is destroyed by the following
means: I. as already stated, by making it completely dry either by the evaporation of
the water, or its abstraction by alcohol; 2. by boiling, which if continued for ten minutes
renders yeast quite inoperative; 3. by the action of such substances as dissolve out its
essential constituents; by alkalis, for instance, since the particles of yeast seem to be
operative only in their insoluble granular state; 4. by such substances as form combinations with it, and thereby either alter its nature, or at least increase the cohesion of its
constituent parts, so that they can no longer operate upon sweet liquors by the decomposing affinity of its ultimate particles.  Such bodies are the acids, especially the mineral
ones, tannin and most salts, particularly the metallic, which unite with the yeast into new
compounds. The volatile oils which contain sulphur exercise the same paralyzing influence upon yeast.
The circumstances which promote, and are necessary to, the vinous fermentation are,
conformably to the above views, the following:-1. The presence of the proper quantity
of active yeast, and its proper distribution through the worts. If in the course of a slack
fermentation the yeast subsides to the bottom, the intestine motions cease entirely, but
they may be excited anew by stirring up the ingredients, or rousing the tun, as the brewers say.  2. A certain degree of warmth, which should never be less than 510 F., nor
more than 860; the temperature of from 680 to 770 being the most propitious for the




FERMENTATION.                                         697
conmmencement and progress of fermentation.  When other circumstances are the same,
the rapidity of the fermentation is proportional to the temperature within certain
limits, so that, by lowering it, the action may be moderated at pleasure. 3. The fermentation proceeds the better and more equably the greater the mass of fermenting
liquor, probably on account of the uniformly high temperature, as well as the uniform
distribution of the active particles of the yeast by the greater energy of the intestine
movements. 4. The saccharine solution must be sufficiently diluted with water; when
too much concentrated it will not ferment.  Hence very sweet musts furnish wines
containing much undecomposed sugar. For a complete fermentative action, onepart of
sugar should be dissolved in ten parts of water.
Fermentation may be tempered or stopped: 1. by those means which render the
yeast inoperative, particularly by the oils that contain sulphur, as oil of mustard; as
also by the sulphurous and sulphuric acids. The operation of the sulphurous acid in
obstructing the fermentation of must consists partly, no doubt, in its absorbing oxygen,
whereby the elimination of the yeasty particles is prevented. The sulphurous acid,
moreover, acts more powerfully upon fermenting liquors that contain tartar, as grape
juice, than sulphuric acid. This acid decomposes the tartaric salts, and combining
with their bases, sets the vegetable acid free, which does not interfere with the fermentation; but the sulphurous acid operates directly upon the yeast: 2, by the separation
of the yeast, either with the filter or by subsidence; 3, by lowering the temperature to
450 F.  If the fermenting mass become clear at this temperature, and be drawn off
from the subsided yeast, it will not ferment again, though it should be heated to the
proper pitch.
The products of vinous fermentation are carbonic acid gas, and alcohol; of which the
former escapes during the process, except in the case of the sparkling wines, like chami
kig~n, that are partially fermented in close vessels. The alcohol remains in the fermented liquor.   100 parts of sugar afford by complete decomposition nearly 50 parts of alcohol. According to Thenard, 100 parts of sugar are converted into 46-8 parts of carbonic
acid, and 4938 of alcohol; besides 3'82 parts of carbon otherwise employed, which the
sugar contained, above what is present in the former two products.   This chemist found
in the fermented liquor 4 per cent. of an extractive matter, soluble in water, and having
an acidulous reaction, to whose formation, probably, that excess of carbon may be necessary.  In what way the action of the yeasty particles -upon the saccharine substance is
carried on in the vinous fermentation, or what may be the interior working of this process, is not accurately understood.  The quantitative relation of the carbonic acid and
alcohol to the sugar is pretty well made out; but the determination of the ultimate principles of the ferment itself, before and after the vinous change, and of the residuum dissolved in the fermented liquor, has not been well ascertained.  It is probable that the
yeast undergoes in the process a similar decomposition to that of the putrefactive, and
that its elementary constituents enter into new combinations, and abstract so much carbon
and hydrogen from the sugar, that the remainder, amounting to 96 per cent. of the whole,
may constitute one atom of alcohol and one of carbonic acid.
3. The sliithy or glutinous fermentation.-This process takes place in weak solutions
of sugar, at ordinary fermenting temperatures, where, from defect of good yeast, the
vinous fermentation cannot proceed. In such circumstances, from one part of sugar, one
third part of gum is formed. According to Desfosses, however, 100 parts of sugar afford
109'48 of gum or slime.  This is formed when one part of sugar is dissolved in twenty
parts of water, which had been previously boiled with washed barm or gluten, and then
filtered. The process proceeds slowly and quietly, equally well in close vessels, as with
contact of air, and continues at ordinary temperatures about 12 days; but it goes on more
rapidly and completely at the heat of from 770 to 86~ F.  A small quantity of hydrogen
and carbonic acid gas is disengaged, in the proportion of two to one by volume.  The
fermented liquor becomes turbid, and assumes a tough thready appearance, like a decoction of linseed.  A small addition of sulphuric or sulphurous acid, of muriatic acid and
alum, or of tannin, impedes this species of fermentation; because these substances combine, as in the vinous fermentation, with the ferment into an insoluble precipitate, unsusceptible of further change. In many wines, especially when bottled, this slimy fermentation occurs, and occasions their ropiness, which may be best remedied or prevented by
the addition of as much tannin as will precipitate the dissolved mucous matter.  This
species of fermentation attacks very rapidly the rinsing waters of the sugar refiner,
which always contain some fermentative gluten.  A  little alum is the best preventive
in this case, because it precipitates the dissolved ferment.
4. The acetous or sour fermentation.-In this process, alcohol, more or less dilute, is
resolved into water and vinegar in consequence of the operation of the ferment; oxy.




698                              FERMENTATION.
dizement of the alcohol being effected by the oxygen of the atmospherical air. The
requisites of this process have been already detailed under the article AcIc ACID.
They are the presence of atmospherical air; alcohol diluted to a certain degree with
water ferment or yeast, and a temperature above 66~ F.  The most active ferments are
such substances as have already passed into the acetous state; hence vinegar, especially
when it contains some yeasty particles, or is combined with porous and spongy bodies,
so as to multiply its points of contact with the vinous liquor, is particularly powerful.
Common yeast may also be employed for vinegar ferments, if it be imbued with a little
vine~garwith leaven, crusts of bread soaked in vinegar, the stalks and husks of grapes
sawdust and shavings of beech or oak impregnated with vinegar, or the slimy sediment
of vinegar casks called mother; all of which operate as ferments chiefly in consequence
of the vinegar which they contain.  The inside shavings of the staves of vinegar tuns
act on the same principle.
The acetous fermentation may, r.oreover, go on along with the vinous in the same
liquor, when this contains sugar as well as alcohol. Whilst the acidification of the alcohol
is effected by the absorption of oxygen from the atmosphere, the sugar becomes alcohol
with disengagement of carbonic acid, and then passes into vinegar.  Since most liquors
intended for making vinegar, such as wine, juices of fruits, ales, &c., contain still a little
sugar, they disengage always a little carbonic acid. Besides spirits, some other substances, such as gum, the mucilage of plants, and starch paste, directly ferment into vinegar.
Sugar also seems to be convertible into vinegar without any vinous change.  The albuminous matter of potato juice, precipitated by vinegar, serves as a proper ferment for
that purpose, when added in its moist state to weak sirup. 5. See PUTREFACTION.
Mr. William Black, in his treatise on Brewing, has, with much ingenuity and apparent
truth, endeavored to show that the process of fermentation is strongly influenced by
electricity, not only that of the atmosphere, as has been long known from the circumstance
of beer and wine becoming speedily sour after thunderstorms, but the voltaic, produced
by electric combinations of metals in the fermenting tuns.   He therefore recommends these tuns to be made with as little metallic work as possible, and to be insulated
from  the floor of the brewhouse.  For the propriety of this advice he adduces some
striking examples. Wort which had become stationary in its fermentation, on being
pumped out of square gyles imbedded in the floor, into casks placed upon wooden
stillions,began immediately to work very well, and gained about 6 degrees of attenuation
while throwing off its yeast. From the stagnation of the process in the gyles, he had
in the morning predicted an approaching thunderstorm, which accordingly supervened
in the course of the evening. In further support of his views he instances the fact, that,
in dairies where the milk is put into porcelain vessels, and placed upon wooden shelves,
it is seldom injured by lightning; but when contained in wooden or leaden vessels, and
placed upon the ground, it almost invariably turns sour in thunder) weather.  His
general conclusion is, " that the preservation or destruction of beer depends upon electricity; and the most certain mode of preservation is to insulate as much as possible,
both the squares and all other utensils or vessels connected with the brewing or storing
of beer."
Mr. Black further considers that unsoundness of worts is often the result of electricity
excited between the mash tun and the copper.
Why is beer liable to get spoiled in thunder-storms, though apparently well insulated
in glass bottles?
I shall conclude this article with Mr. Black's description of the phenomena of beer
fermentation.  In every regular process there are five distinct stages. In the first
we see a substance like cream forming all round the edges of the gyle tun; which extends towards the centre until the whole is creamed over, constituting the first change.
Next a fine curl appears like cauliflower, which also spreads over the square surface,
and according to the strength and appearance of this curl, the quality of the fermentation may be predicated. This he calls the second stage. What is technically called'the stomach or vinous vapor now  begins to be smelt, and continues to gain strength
till the process is concluded. From the vinous energy of this odor, and the progressive
attenuation of the wort, the vigor of the fermentation may be inferred. The experienced
brewer is much guided in his operations by the peculiarity of this effluvium. The third
change is when the cauliflower or curling top rises to a fine rocky or light yeasty head;
and when this falls down, the fourth stage has arrived. Finally the head should rise to
what is called close yeasty, having the appearance of yeast all over. About this period
the gas becomes so powerful as to puff up occasionally in little bells or bladders about the
size of a walnut, which immediately break. The bells should appear bright and clear.
If they be opaque or whey colored, there is some unsoundness in the wort. The great.




FERMENTATION.                                      699
point is to add just so much yeast as to carry the fermentation completely through
these five changes at the regular periods.
The term fermentation has been of late extended to several operations besides those
formerly included under it. The phenomena which it exhibits under these different
phases and the changes which it effects among the various subjects of its operations, are
no less striking and mysterious in their principle than important in their application to
the arts of life. Fermentations are now arranged into twelve classes-1, the alcoholic;
2, the glucosic or saccharine; 3, the viscous or mucous; 4, the lactic; 5, the ascetic; 6,
the gallic; 7, the pectic; 8, the benzoilic; 9, the sinapic; 10, the ammoniacal; 11, the
putrid; and 12, the fatty.
Fermentation, in the most general sense, may be defined to be a spontaneous reaction, a chemical metamorphosis, excited in a mass of organic matter by the mere
presence of another substance, which neither extracts from, nor gives to, the matter
whiich it decomposes any thing whatever. This process requires the following conditions:-1. A  temperature from  450 to 900 F.; 2. Water; 3. The contact of air;
4. The presence of a neutral organic azotized matter,-in a very small quantity, and of a
crystallizable non-azotized substance, in considerable quantity.  The former is the
ferment, the latter undergoes fermentation. In ordinary chemical actions we perceive
one body unite to another to form a new compound; or one body turn another out of
a combination, and take its place, in virtue of a superior affinity. These effects are
foreseen and explained by the intervention of that molecular force which governs all
chemical operations, that attractive power which unites the particles of dissimilar
bodies. Thus, also, in the ordinary phenomena of decomposition, we perceive the
agency of heat at one time, at another of light, or of electricity; forces of which though
we are not acquainted with the essence, yet we know the exact effect under determinate circumstances. But fermentation, on the contrary, can be explained neither by
the known laws of chemical affinity nor by the intervention of the powers of light, electricity, or heat. Fermentation reduces complex organic substances to simpler compounds, thereby reducing them nearer to the constitution of mineral nature. It is an
operation analogous, in some respects, to that effected by animals upon their vegetable
food.
With a good microscope, any person:nay convince himself that ferment or yeast is
an organized matter, formed entirely of globules, or of corpuscles slightly ovoid, from
the three to the four thousandth part of an inch in diameter. Sometimes their surface
seems to have a little tail, which has been regarded as a bud or germ attached to the
mother cell. Whenever the fermentation begins, the yeast does not remain an instant
idle. These small round bodies become agitated in all directions, and if the substance
undergoing fermentation is mixed with an azotized matter, as in beer-worts, the corpuscles become larger, the small tails get developed, and on acquiring a certain size
they separate from the parent globule, to live by themselves and give birth to new corpuscles.* In the fermentation of beer from malt, this series of multiplications produces
a quantity of yeast seven times greater than what was added at the commencement.
Were the above ingenious speculations demonstrated with certainty, we should be led
to admit, in all these phenomena, actions truly vital, and a reproduction like that of
buds in the vegetable kingdom. The existence of a vital force seems to be rendered
probable by the fact that in incomplete fermentation, such as that of fine syrup with too
little yeast, the ferment loses its properties and powers. If, however, we add to the solution of pure sugar an albuminous substance, a caseous or fleshy matter, the development of yeast becomes manifest, and an additional quantity of it is found at the end
of the operation. Thus with nourishment, ferment engenders ferment. It is for this
reason that a little fermenting must, added to a body of fresh grape-juice, excites fermentation in the whole mass. These effects are not confined to alcoholic fermentation.
The smallest portions of sour milk, of sour dough, or sour juice of beet-root, of putrefied
flesh or blood, occasion like alterations in fresh milk, dough, juice of beet-roots, flesh,.
and blood. But further, and which is a very curious circumstance, if we put into a liquid containing any fermenting substance, another in a sound state, the latter would
suffer decomposition under the influence of the former. If we place urea in presence
of beer-yeast, it experiences no change; while if we add to it sugar-water in a fermenting state, the urea is converted into carbonate of ammonia. We thus possess two modes
of decomposition, the one direct, the other indirect.
Although yeast has all the appearances of an organized substance, it is merely by analogy that its multiplication by growth is assumed, for this is a phenomenon very difficult
of experimental demonstration. When' blood, cerebral substance, gall, pus, and such
like substances, in a putrid state, are laid upon fresh wounds in animals, vomiting, de* M. Turpin, M. Cagniard Latour, M. Qudvenne, and Professor Mitscherlich.




700                              FERMENTATION.
debility, and death soon supervene. The scratches from bones in putrid bodies have
been often the causes of disease and death to anatomists. The poison in bad sausages
is of the same class of ferments. In Wurtemberg, where sausages are prepared from
very miscellaneous matters, as blood, livers, brains, and offal of many other kinds, with
bread, meal, salt, and spices, fatal results from eating them are not uncommon. Death
in these cases is preceded by the gradual wasting of the muscular fibre, and of all the
like constituents of the human body; so that the patient becomes emaciated, dries into
a complete mummy, and soon expires. The cadaver is stiff as if frozen, and is not
subject to putrefaction. During the progress of the sausage disease, the saliva becomes
viscid, and emits an offensive smell. No peculiar poison can be detected by analysis
in the sausages; but they are rendered wholesome food for animals by the action of
alcohol, or by that of boiling water, which destroy the noxious fomes without acquiring
it themselves; and thus decompose the putrefactive ferment of the sausages. When
this, however, passes unchanged through the stomach into the circulating system, it
imparts its peculiar action to the constituents of the blood, operating upon it as yeast
does upon wort.  Poisons of a like kind are produced by the body itself in some
diseases.  In plague, small-pox, measles, &c., substances of a peculiar fermentative
nature are generated from the blood, which are capable of inducing in the blood of a
healthy person a decomposition like that of which themselves are the subjects. The
morbid virus reproduces itself, and multiplies indefinitely, just as the particles of yeast
do in the fermentation of beer. The temperature of boiling water, and alcohol applied
to matters imbued with such poisonous secretions, renders their poison inert. Many
acids, chlorine, iodine, bromine, empyreumatic oils, smoke, creosote, strong decoction
of coffee, have the same salutary effect. All these agents are known to counteract fermentation, putrefaction, and that dry wasting of organic matter called eremacausis, or slow
combustion. It is most deserving of remark that the poisons chemically neutral or alkaline,
such as those of small-pox in man, and of typhus ruminantium in cows, lose their bane.
ful power when subjected to the action of the stomach; whereas that of bad sausages,
which is acid, resists the modifying power of the digestive organs.
Alcoholic fermentation has been copiously discussed in the Dictionary. I may here
add that ammonia, being a product of that change in solution of pure sugar, proves the
presence of azote in the yeast; and that sulphuretted hydrogen, being made manifest in
the disengaged gaseous products, by their blackening paper imbued with acetate of lead,
proves the presence of sulphur.  The acid liquor accompanying yeast may be washed
away, without impairing materially its fermenting power, while the acid so removed has
of itself no such virtue.
Yeast, freed from all soluble matters by water, alcohol, and ether, contains, independently of ashes-carbon, 50'6; hydrogen, 7*3; azote, 15; oxygen, sulphur, and phosphorous, 27* 1. in 100 parts. Viewed atomically, yeast bears a close analogy to albumen.
Like albuminous matter, yeast takes a violet tint with muriatic acid, and it may be replaced as ferment by gluten.  Caseum (the curd of milk) and flesh operate the same
effect. All these fermentative powers have the same globular appearance in the microscope with yeast. When the activity of yeast has been destroyed by heat, &c., it
can be restored by the positive energy of the voltaic battery, which causes its combination with oxygen. The best proportion of sugar and water, for exhibiting the phenomena of fermentation, is I of the former to 3 or 4 of the latter, and 5 parts of sugar to 1
of fresh yeast may be added; though in the course of fermentation, 100 parts of sugar
do not consume 2 parts of yeast, estimated in the dry state. The quickest fermenting
temperature is from 680 to 860. A very little oil of turpentine or creosote, or of the
mineral acids, prevents or stops fermentation completely; oxalic and prussic acids have
the same effect, as also corrosive sublimate and verdigris. It has been known from
time immemorial in Burgundy, that a little red precipitate of mercury, when added to
the must-tun, stopped the fermentation. All alkalies counteract fermentation, but when
they are saturated it recommences. The first person who described the microscopic
globules of yeast with precision was D1smazihres, who arranged them among the mycodermes (fungus-skinned), under the name of mycoderma cerevisiae. They have not
the flattened form of the globules of blood, but are rather egg-shaped. One small black
point may be seen on their surface, which, after some days, is associated with 3,4, or 5
others.  Their average diameter is from   ~-  to    - of an inch.  Sometimes more
minute globules cluster round one of ordinary size, and whirl about with it, when the
liquor in which the globules float is agitated.
Fresh yeast loses, by drying, 68 parts in the 100, and becomes solid, horny-looking,
and semitransparent, breaking readily into gray or reddish fragments. With water, it
resumes immediately its pristine appearance. When fresh yeast is triturated with its
own weight of white sugar, it forms a liquid possessing the fluidity of oil of almonds
and a yellow  color.  The globules continue unchanged, except perhaps becoming




FERMENTATION.                                     701
asomewhat smaller. Yeast in the dry state retains its fermentative virtue for a long
time.
Saccharine Fermentation is that by which starch and dextrine are converted into
sugar, as shown remarkably in the action of diastase upon these bodies. If we mix 2
parts of starch paste with 1 part of dry gluten, and keep the mixture at a temperature
of from 1220 to 1400 Fahr., we obtain a good deal of sugar and dextrine. Some lactic
acid is also formed. Flour paste, long kept, spontaneously produces sugar by a like
reaction.  See FERMENTATION in the Dictionary.
Lactic Fermentation.-Almost all azotized organic matters, after being modified by
the contact of air, become capable of giving rise to this fermentation. Oxygen does
not come into play, except as the means of transforming the animal substances into a
ferment. Diastase and caseum are well adapted to exhibit this change. The body
that is to furnish the lactic acid may be any one of the neutral vegetable matters, possessing a like composition with lactic acid, such as cane-sugar, grape or potato sugr,
lextrine, and sugar of milk. All the agents which stop the alcoholic, stop also the
lactic fermentation; while diastase and caseum are its two best exciters. For producing abundance of lactic acid, we have merely to moisten malt, to expose it to the air
for a few days, then to triturate it with a quantity of water, and leave the emulsion for
some days more in the air, at a temperature between 67~ and 86~ F. We then saturate
the liquor with chalk, after having filtered it, and thereby obtain the lactate of lime
which may be crystallized in alcohol, to deprive it of the dextrine and earthy phosphates;
and then decomposed by sulphuric acid.
Lactic Acid, formed from curd (caseum), exhibits more remarkable phenomena. Thus
whfn milk is left alone for some time it becomes sour, and coagulates. The coaulum
S formed of caseum and butter; while the whey of it contains sugar of milk and some
salts. The coagulation of the caseum  has been occasioned by the lactic acid, which
was generated in consequence of an action which the caseum itself exercised upon the
sugar of milk. Thus with the concourse of air, the caseum becomes a ferment, and
excites the conversion of the sugar of milk into lactic acid. The lactic acid in its turn
coagulates the caseum, which in the consolidation of its particles attracts the butter.
The caseum then ceases to act upon the sugar of milk, and consequently produces no
more lactic acid.
But now, if the lactic acid already formed be saturated, the caseum will redissolve,
and the phenomena will recommence in the same order. This is easily done by adding
a due dose of bicarbonate of soda to the soured milk. In the course of 30 hours a
fresh portion of lactic acid will be generated, and will have coagulated the milk again.
We may also add some sugar of milk to the liquid, and to a certain extent convert it
into lactic acid. Milk boiled, and kept from contact of air, will not coagulate, and
remains fresh for many months. Animal membranes, modified by exposure to moist air
for some time, form a true ferment for the lactic fermentation, and acidify solutions of
sugar, dextrine, and gum, but the membranes must not be putrescent. Cane-sugar,
starch-sugar, and sugar of milk, by assuming or losing a little water, acquire the constitution of lactic acid.
Viscous or Mucous Fermentation.-Every one is acquainted with this spontaneous
modification of white wine and ale, which gives them a stringy or oily aspect, and is
called in French graisse, or fat of wines, and in English the ropiness of beer. The
viscous fermentation may be excited by boiling yeast with water, and dissolving sugar
in the decoction, after it has been filtered. The syrup should have a specific gravity
from 1040 to l'055, and be kept in a warm place. It soon assumes the consistence
and aspect of a thick mucilage, like linseed tea, with the disengagement of a little carbonic acid and hydrogen, in the proportion of 2 or 3 of the former gas to I of the
latter. A ferment of globular texture like that of yeast is formed, which is capable
of producing viscous fermentation in any saccharine solution to which it is added, provided the temperature be suitable. The viscid matter being evaporated to dryness
forms transparent plates, of a sub-nauseous taste, and soluble in water, but less easily
than gum arabic. Its mucilage is, however, thicker than that of gum, and yields with
nitric acid, oxalic acid, but no mucic acid. Four parts of sugar, treated as above
described, furnish 2*84 of unchanged sugar, and 1'27 of the mucilage; from which it
appears that water becomes fixed in the transformation. Muriatic, sulphuric, sulphurous acids, and alum, prevent the production of the viscous fermentation, by precipitating
its ferment. It is probably the soluble portion of gluten which is the cause of this species of fermentation. It has been found, accordingly, that tannin, which precipitates the
said glutinous ferment, completely stops the viscous fermentation, or graisse, of wines.
It is owing to the tannin which the red wines derive from the grape-stalks, with which
they are long in contact during fermentation, that they are preserved from this malady
of the white wines. The gluten of must is of two kinds the one soluble in virtue of




70.2                             FERMENTATION.
the alcohol and tartaric acid, and producing the viscous, the other insoluble, and
producing the alcoholic fermentation. The art of the wine maker consists in precipitating the injurious ferment, without impeding the action of the beneficial one; an art
of considerable delicacy with regard to sparkling wines.
JAcid Fermentation has been fully discussed under acetic acid. It requires the presence of ready formed alcohol and air. The lactic fermentation, on the contrary, may
take place with starchy or saccharine substances, without the intervention of alcohol or
constant exposure to the atmosphere; and when once begun, it can go on without air.
Acetification has a striking analogy with nitrification, as is shown by the necessity of a
high temperature, and the utility of porous bodies for exposing the liquid on a great
surface to the air.
Benzoic Fermentation is that which transforms the azotised neutral crystalline matter,
existing in bitter almonds, which has no action upon the animal economy, into new and
remarkable products, among others the hydrure of benzoile and hydrocyanic (prussic)
acid, which together constitute the liquid, called oil, or essence, of bitter almonds, a
compound possessed of volatility and poisonous qualities.  The attentive study of this
fermentation has revealed a great fact in vegetable physiology, the spontaneous production, by means of certain artifices, of certain volatile oils, not pre-existing in the
plants, yet capable of being generated in the products of their decomposition. The
volatile oil of bitter almonds constitutes in this respect a starting point, from which
have proceeded the oil of mustard, the oil of spiraea, and which will likely lead to other
discoveries of the same kind. See ALMOND and AMYGDALINE.
Sinapic Fermentation is that by which the oil of mustard is formed, and which takes
place by the contact of water, under certain conditions, of too refined and scientific a
nature for this practical work.
Pectic Fermentation.-Pectic acid may be obtained from  the expressed juice ofcai
rots. and it seems to be formed in the process of extraction by the reaction of albumine
in the carrots upon a substance called pectine; a transformation analogous therefore
with that which takes place in the formation of the essence of bitter almonds.
Gallic Fermentation.-Gallic acid does not exist ready formed in nut-galls, but Is
generated from their tannin when they are ground, made pasty with water, and exposed
to the air. This conversion may be counteracted by the red oxide of mercury, alcohol,
sulphuric, muriatic, and nitric acids, bromine, essence of turpentine, creosote, oxalic,
acetic, and prussic acids. The tannin disappears in the sequel of the above metamorphosis.
Fatty Fermentation.-All fats are transformed by the action of an alkaline or other
base into certain acids, the stearic, margaric, the oleic, ethalic, &c. When these acids
are once formed, they can not by any means, hitherto known, be reconverted into the primitive fat. By the fixation of water in the acid and the base (called glycerine), a change
is effected which can not be undone, because the glyceric base is incapable by itself to
displace the water, once combined in the hydrated fat acid. The circumstances necessary to the fatty fermentation, are like those of other fermentations; namely, the cooperation of an albuminoid matter, along with water, and a temperature of from 600 to 860
F.; under these conditions, the matter becomes warm, and assumes speedily the charac
ter of rancidity; acid is generated, and the carbonate of soda can then form salts, while
the fatty acid is liberated; a circumstance impossible when the fat was 9cted upon in
the neutral state. This altered fat, treated with water, gives up to it glycric alcohol.
Digestive Fermentation.-Digestion of food may be considered in its essential features
as a peculiar fermentative process. The gastric juice is a genuine ferment. Tiedmann,
Gmelin, and Prout, have shown that the gastric juice contains muriatic acid; and
Eberli has made interesting experiments on the digestion of food out of the body, with
water containing a few drops of the same acid. He observed that when this liquid con
tained none of the mucous secretion of the stomach, it did not dissolve the aliments put
into it; but with a little of that mucus it acquired that property in an eminent degree.
Even the mucus of the bladder had a like effect. Schwann and Vogel have produced
this digestive principle in a pure state, called by them pepsine, as obtained most abundantly from the stomachs of swine. The glandular part of that viscus being separated
from the serous, is cut into small pieces, and washed with cold distilled water. After
digestion for 24 hours, that water is poured off, and fresh water is poured on. This
operation is repeated for several days, till a putrid odor begins to be felt. The watery
infusion thus obtained is precipitated by acetate of lead. This white flaky precipitate
contains the pepsine, accompanied with much albumen. It is then washed, mixed with
water, and subjected to a stream  of sulphuretted hydrogen.  The whole being now
thrown on a filter, the coagulated albumen remains on the paper, along with the sul



FERMENTATION.                                      703
phuret of lead, while the pepsine liquor passes, associated with some acetic acid. If to
this liquor a very small quantity of muriatic acid be added, it becomes capable of carrying on artificial digestion. Dry pepsine may be obtained by evaporating the above
filtered liquor on a water bath, to a syrupy consistence, then adding to it absolute
alcohol, which causes, a bulky whitish precipitate. This dried in the air constitutes
pepsine. It contains a minute quantity of acetic acid, which may be removed completely, by heating it some hours on the water bath. The white powder then obtained
is soluble in water, and betrays the presence of no acid whatever. According to Vogel,
this substance is composed of, carbon, 5772; hydrogen, 5'67; azote, 21'09; oxygen,
&c., 15.52 == 100. Vogel has proved the analogy between the action of pepsine and
diastase by the following experiment:He dissolved two grains of pepsine in very weak muriatic acid, and put into this
liquor heated to 810 F., small bits of boiled beef. In the course of a few hours the
pieces became transparent on their edges, and not long after they were completely dissolved. He now added fresh morsels in succession, till those last put in remained unchanged. He found by analysis, that 1*98 grains of the pepsine were left, showing how
minute a portion of this ferment was necessary to establish and effect digestion.  In
fact, we may infer that pepsine, like yeast, serves to accomplish digestion without any
waste of its own substance whatever, or probably with its multiplication.
Rennet, with which milk i, coagulated in making cheese, is somewhat of the same
nature as pepsine. -It has been called chymosine. But the simplest digesting liquor is
the following:If 10,000 parts of water by weight be mixed with 6 parts of ordinary muriatic acid
and a little rennet, aliquor is obtained capable of dissolving hard boiled white of egg,
beef, gluten, &c., into a transparent jelly in a few hours.
^.9mmoniacal Fermentation.-Under this title may be described the conversion of urea
into carbonate of ammonia under the influence of water, a ferment, and a favorable
temperature. Urea is composed in atoms; reckoned
In volumes,          Carbon 4; hydrogen 8; azote 4; oxygen 2;
which by fixing          ~                  4;   -                2;
give                          4;           12;        4;          4:
which is 4 vol. of carbonic acid, and 8 of ammonia; equivalent to ordinary carbonate
of ammonia. The fermentation of urea plays an important part in the reciprocal offices
of vegetable and animal existence. By its conversion into carbonate of ammonia, urea
becomes a food fit for plants; and by the intervention of the mucous ferment which urine
contains, that conversion is effected. Thus the urea constitutes a neutral and innocuous substance while it remains in the bladder, but is changed into a volatile, alkaline,
and acrid substance, when it is acted upon by the air. Yeast added to pure urea mixed
with water, exercises no action on it in the course of several days; but when added to
urine, it soon causes decomposition, with the formation of carbonate of ammonia, and
disengagement of carbonic acid. The deposite on chamberpots ill-cleaned acts as a very
powerful ferment on urine, causing the complete decomposition of fresh urine in one
fifth of the time that would otherwise be requisite.
Nitrous Fermentation, as exhibited in the formation of ftitric acid from the atmosphere,
and consequent production of nitrates in certain soils, has been with much probability
traced to the action of ammonia on oxygen, as the interr-edium or ferment.
Caseous and putrid Fermentations.-Curd is converteo, into cheese, when after being
coagulated by rennet, it is left to itself under certain conditions; and this constitutes the
true distinctive character of caseum. In the production of cheese there is evidently the
intervention of a peculiar ferment which is gradually formed, and the decomposition of
the curd into new products.
For animal and vegetable matters to run into putrefaction, they must be in contact
with air and water, at a certain temperature; viz., between the freezing and boiling
points of water. The contact of a putrid substance acts as a ferment to fresh animal
and vegetable matters. The reagents which counteract fermentation in general stop
also putrefaction. In this process, myriads of microscopic animalcules make their appearance, and contribute to the destruction of the substances.
A dispute having taken place between some distillers in Ireland and officers of
Excise, concerning the formation of alcohol in the vats or tuns by spontaneous fermentation, without the presence of yeast, the Commissioners of Excise thought fit to cause
a series of experiments to be made upon the subject, and they were placed under my
general superintendence. An experiment was made on the 6th of October, with the
following mixture of corn:45




704                           FERMENTATION.
2 Bushels of Barley, weighing  -      -      -       -100lbs. 5 oz.
2 Bushel of Malt,      -       -      -      -      - 21    7
i Bushel of Oats        -      -      -      -       - 20   12
Total, 3 Bushels, weighing  -      -      - 142    8
The bruised corn was wetted with 26 gallons of water at the temperature of 160~ F.,
and, after proper stirring, had 8 gallons more of water added to it at the average temrn.
perature of 194~. The mash was again well stirred, and at the end of 45 minutes
the whole was covered up, having at that time a temperature of 138~ F. Three hours
afterward, 16 gallons of wash only were drawn off; being considerably less than
should have been obtained, had the apparatus been constructed somewhat differently,
as shall be presently pointed out. The gravity of that wash was 1'060, or, in the lan.
guage of the distiller, 600.  After a delay of two hours more, twenty additional
gallons of water at the temperature of 200~ were introduced, when the mash was well
stirred, and then covered up for two hours, at which period 23 gallons of fine worts
of specific gravity 1'042 were drawn off. An hour afterward 12 gallons of water at
2003 were added to the residual grains, and in an hour and a half 11 gallons of wort
of the density 1'033 were obtained. Next morning the several worts were collected
in a new mash tun. They consisted of 48 gallons at Vie temperature 80~, and of a
specific gravity 2'0465 when reduced to 600. Being set at 800, fermentation soon
commenced; in two days the specific gravity had fallen to 1'0317, in three days to
1'018, in four days to 1'013, and in five days to 1.012, the temperature having at last
fallen to 78~ F. The total attenuation was therefore 34~0, indicating the production
of 3'31 gallons of proof spirit, while the produce by distillation in low wines was 3'22;
and by rectification in spirits and feints it was 3*05. The next experiment was commenced on the 12th of October, upon a similar mixture of corn to the preceding.
48 gallons of worts of 1'043 specific gravity were set at 82~ in the tun, which next
day was attenuated to 1P0418, in two days to 1P0202, in three days to 1P0125, and in
five. days to 1P0105, constituting in the whole an attenuation of 32-0, which indicates
the production of 3*12 gallons of proof spirits; while the produce of the first distiJll
tion was 2'93 in low wines, and that of the second in feints and spirits was 2'66. Ina.
these experiments the wash, when fermenting most actively, seemed to simmer and boil
on the surface, with the emission of a hissing noise, and the copious evolution of carbonic acid gas. They prove beyond all doubt that much alcohol may be generated in
grain worts without the addition of yeast, and that, also, at an early period; but the
fermentation is never so active as with yeast, nor does it continue so long, or proceed
to nearly the same degree of attenuation. I was never satisfied with the construction
of the mash tun used in these experiments, and had accordingly suggested another
fZrm, by which the mash mixture could be maintained at the proper temperature
during the mashing period. It is known to chemists that the diastase of malt is the
true saccharifying ferment which converts the fecula, or starch of barley and other
corn, into sugar; but it acts beneficially only between the temperatures of 1450 and
1680 F. When the temperature falls below the former number, saccharification languishes; and when it rises much above the latter, it is entirely checked. The new
mash tun was made of sheet zinc, somewhat wider at bottom  than top; it was
placed in a wooden tun, so much larger as to leave an interstitial space between the
two of a couple of inches at the sides and bottom. Through this space a current
of water at 1603 was made to circulate slowly during the mashing period. Three
bushels of malt, weighing 125 lbs. 3 oz., were wetted with 30 gallons of water at 1670,
and the mixture being well agitated, the mash was left covered up at a temperature
of 1400 during three hours, when 19 gallons of fine worts were drawn off at the specific gravity of 1'0902 or 902~0. Twenty gallons more water at 167~ were then added
to the residuum, which afforded after two hours 28 gallons of wort at the gravit3
1'036; 12 gallons of water at 167~ were now poured on, which yielded after other
two hours 15 gallons at the gravity 1P0185. Forty gallons of fine worts at 1'058
gravity and 68~ temperature were collected in the evening of the same day, and let
into the tun with 5 per cent. of yeast. The attenuation amounted in six days to 54~.
The third wort of this brewing, amounting to 15 gallons, being very feeble, was mixed
with 7 gallons of the first and second worts, put into a copper, and concentrated by
boiling to 11 gallons, which had a gravity 1'058 at 60~ F. They were separately
fermented with 5 per cent. of yeast, and suffered an attenuation of 482~. The produce
of spirit from both indicated by the attenuation was 5*36 gallons; the produce in low
wines was actually 5'52, and that in spirits and feints was 5'33, being a perfect accord.
ance with the Excise tables.
The next experiments were made with a view of determining at what elevation of
temperature the activity or efficiency of yeast would be paralysed, and how far the




FERMENTATION.                                     705
attenuation of worts could be pushed within six hours, which is the time limited by
law for worts to be collected into the tun, from the time of beginning to run from the
coolers. When worts of the gravity 1'0898 were set at 96~ Fahr., with 5 per cent. of
yeast, they attenuated 26.9~0 in 6 hours; worts of 1-0535 gravity set at 1100 with
5 per cent. of yeast, attenuated 160 in about 5 hours; but when worts of 30533 were
set, as above, at 120~, they neither fermented then, nor when allowed to cool; showing that the activity of the yeast was destroyed. When fresh yeast was noW added to
the last portion of worts, the attenuation became 5-8 in 2 hours, and 28.40 in 3 days;
showing that the saccharine matter of the worts still retained its fermentative faculty.
Malt worts, being brewed as above specified, were set in the tun, one portion at a temperature of 700, with a gravity of 1'0939, and 5 per cent. of yeast, which attenuated
66~ in 3 days; other two portions of the same gravity were set at 120~ with about 10
per cent. of yeast, which underwent no fermentative change or attenuation in 6 hours,
all the yeast having fallen to the bottom of the tuns. When these two samples of
worts were allowed, however, to cool to from 74~ to 720, fermentation commenced
and produced in two days an attenuation of about 79~. It would appear, from these
last two experiments, that yeast to the amount of 5 per cent. is so powerfully affected
by strong worts heated to 120~ as to have its fermentative energy destroyed; but that
when yeast is added to the amount of 10 per cent., the 5 parts of excess are not permanently decomposed, but have their activity merely suspended till the saccharine
liquid falls to a temperature compatible with fermentation. Yeast, according to my
observations, when viewed in a good acromatic microscope, consists altogether of translucent spherical and spheroidal particles, each of about the 6000th part of an inch in
diameter. When the beer in which they float is washed away with a little water, they
are seen to be colorless; their yellowish tint, when they are examined directly from
the fermenting square or round of a porter brewery, being due to the infusion of the
brown malt. The yeast of a square newly set seems to consist of particles smaller
than those of older yeast, but the difference of size. is not considerable. The researches of Schulze, Cagniard de la Tour, and Schwann, appear to show, that the
vinous fermentation, and the putrefaction of animal matters, processes which have beep
hitherto considered as belonging entirely to the domain of chemical affinity-are
essentially the results of an organic development of living beings. This position
seems to be established by the following experiments: 1. A matrass or flask containing a few bits of flesh, being filled up to one third of its capacity with water, was
closed with a cork, into which two slender glass tubes were cemented air-tight. Both
of these tubes were passed externally through a metallic bath, kept constantly melted,
at a temperature approaching to that of boiling mercury.  The end of one of the
tubes, on emerging from the bath, was placed in communication with a gasometer.
The contents of the matrass were now made to boil briskly, so that the air contained
in it and the glass tubes was expelled. The matrass being then allowed to cool, a
current of atmospherical air was made constantly to pass through it from the gasometer, while the metallic bath was kept constantly hot enough to decompose the living
particles in the air. In these experiments, which were many times repeated, no infusoria or fungi appeared, no putrefaction took place, the flesh underwent no change,
and the liquor remained as clear as it was immediately after being boiled. As it was
found very troublesome to maintain the metallic bath at the melting pitch, the following modification of the apparatus was adopted in the subsequent researches: A flask
of three ounces capacity, being one fourth filled with water and flesh, was closed with
a tight cork, secured in its place by wire. Two glass tubes were passed through the
cork; the one of them was bent down, and dipped at its end into a small capsule containing quicksilver, covered with a layer of oil; the other was bent on leaving the
cork, first into a horizontal direction, and downward for an inch and a half, afterward
into a pair of spiral turns, then upward, lastly horizontal, whence it was drawn out to DI
point. The pores of the cork having been filled with caoutchouc varnish, the contents
of the flask were boiled till steam issued copiously through both of the glass tubes, and
the quicksilver and oil became as hot as boiling water. In order that no living par.
tidles could be generated in the water condensed beneath the oil, a few fragments of:orrosive sublimate were laid upon the quicksilver. During the boiling, the itame of
ft spirit lamp was drawn up over the spiral part of the second glass tube, by means of
a glass chimney placed over it, so as to soften the glass, while the further part of the
tube was heated by another spirit lamp, to prevent its getting cracked by the condensation of the steam. After the ebullition had been kept up a quarter of an hour, the
flask was allowed to cool, and get filled with air through the hot spiral of the second
tube. When the contents were quite cold, the end of this tube was hermetically
sealed, the part of it between the point and the spiral was heated strongly with the
flames, and the lamps were then withdrawn. The matrass contained now nothing but




706                              FERRIC ACID.
boiled flesh and gently ignited air. The air was renewed occasionally through the
second tube, its spiral part being first strongly heated, its point then broken off, and
connected with a gasometer, which caused the air to pass onward slowly, and escape
at the end of the first tube immersed in the quicksilver. The end of the second tube
was again hermetically closed, while the part interjacent between it and the spiral was
exposed to the spirit flame. By means of these precautions, decoctions of flesh were
preserved, during a period of six weeks, in a temperature of from 140 to 200 R. (630
to 770 F.), without any appearance of putrefaction, infusoria, or mouldiness: on opening the vessel, however, the contents fermented in a few days, as if the; had been
boiled in the ordinary manner. In conducting such researches, the greatest pains
must be taken to render the cork and junctions of the glass tubes perfectly air-tight.
The following more convenient modification of the experiment, but one equally successful and demonstrative, was arranged by F. Schulze. The glass tubes connected
with the flask were furnished each with a bulb at a little distance from the cork; into
one of which globes caustic alkaline ley being put, and into the other strong sulphuric acid, air was slowly sucked through the extremity of the one tube, while it
entered at the other, so as to renew the atmosphere over the decoction of flesh in the
flask. In another set of experiments, four flasks being filli I with a solution of canesugar containing some beer-yeast, were corked and plunged in boiling water till they
acquired its temperature. They weie then taken out, inverted in a mercurial bath,
uncorked, and allowed to cool in that position. From one third to one fourth of theii
volume of atmospherical air was now introduced into each of the flasks; into two of
them through slender glass tubes kept red hot at a certain point, into the other two
through glass tubes not heated. By analysis it was found that the air thus heated
contained only 19'4 per cent. of oxygen, instead of208; but, to compensate for this
deficiency, a little more air was admitted into the two flasks connected with the heated
tubes than into the two others.  The flasks were now corked and placed in an inverted position, in a temperature of from 103 to 140 R. (540 to 63` F.).  After a
period of from four to six weeks, it was found that fermentation had taken place in
both of the flasks which contained the non-ignited air —for, in loosenin the corks,
some of the contents were nroeicted with force-but, in the other two flasks, there
was no appearance of fermentation, either then, or in double the time. As the extract
of nux vomica is known to be a poison to infusoria (animalcules), but not to vegetating
mould, while arsenic is a poison to both, by these tests it was proved that the living
particles instrumental to fermentation belonged to the order of plants of the confervoid family. Beer yeast, according to Schwann, consists entirely of microscopic fungi,
in the shape of small oval grains of a yellowish white color, arranged in rows oblique
to each other. Fresh grapes must contain none of them; but after being exposed to
the air at 20" R., for 36 hours, similar grains become visible in the microscope, and
may be observed to grow larger in the course of an hour, or even in half that time.
A few hours after these plants are first perceived, gas begins to be disengaged. They
multiply greatly in the course of fermentation, and at its conclusion subside to the bottom
of the beer in the shape of a yellow white powder.
FERRIC ACID. This new compound having been prescribes as a source of supplying oxygen to persons confined in diving-bells and in mines, by M. Payerne, in a
patent recently granted to him, merits notice in a practical work.  M. Fremy is
the discoverer of this new  acid, which he obtains in the state of ferrate of potash, by projecting 10 parts of dry nitre in powder upon 5 parts of iron filings,
ignited in a crucible; when a reddish mass, containing much ferrate of potash, is
formed. The preparation succeeds best when a large crucible, capable of holding
about a pint of water, is heated so strongly that the bottom and a couple of inches
above it, appear faintly, but distinctly red, in which state the heat is just adequate to
effect due deflagration without decomposition. An intimate mixture of about 200 grains
of dried nitre with about one half its weight of the finest iron filings, is to be thrown at
once upon the side of the crucible. The mixture will soon swell and deflagrate. The
crucible being taken from the fire, and the ignited mass being cooled, is to be taken
out with an iron spoon, pounded, immediately put into a bottle, and secluded from the
air, in which it would speedily attract moisture, and be decomposed. It is resolved
by the action of water, especially with heat, into oxygen gas, peroxide, and nitrate
Df iron.
Mr. J. D. Smith prepares the ferrate of potash by exposing to a full red heat a mixlure of finely powdered peroxide of iron with four times its weight of dry nitre. It
has an amethyst hue, but so deep as to appear black, except at the edges. Oxygen is
rapidly evolved by the action of the sulphuric or nitric acid upon its solution. He considers the atom of iron to exist in this compound, associated with 3 atoms of oxygen, or
double the proportion of that in the red oxide. Hence 52 grains of pure ferric acid




FIBRE, VEGETABLE.                                    707
should give off 12 grains of oxygen, equal to about 35 cubic inches; but how much of
the ferrate of potash may be requisite to produce a like quantity of oxygen cannot be
stated, from the uncertainty of the operation by which it is produced.
FERRIC-CYANIDE  OF  POTASSIUM, or Red  Prussiate of  Potash.   This
beautiful and useful salt, discovered by L. Gmelin, is prepared by passing chlorine gas
through a weak solution of the prussiate of potash (ferro-cyanide of potassium) till it
ceases to affect solution of red sulphate of iron, taking care to agitate the liquid all the
while, and not to add an excess of chlorine. On looking through the weak solution to
the flame of a candle, one may see the period of change from the greenish to the red
hue, which indicates the completion of the process.  The liquor being filtered and
evaporated in a dish with upright sides, will eventually afford crystalline needles, possessed of an almost metallic lustre, and a yellow color, inclining to red. These being
dissolved and recrystallized, will become extremely beautiful. This salt is composed
of 33-68 parts of potassium, 16'48 of iron, and 47-84 of cyanogen. It is therefore a
dry salt. It dissolves in 38 parts of cold water, and as it forms then the most delicate
test of the protoxide of iron, is very useful in Clorometry.-See APPENDIX.
The solution of this salt affords the following colored precipitates with the solutions
f3 the respective metals:
Titanium       -     -      -      -  Brownish yellow.
Uranium       -      -      -     -  Reddish brown.
Manganese   -        -      -     -  Brownish gray.
Cobalt        -      -      -     -  Deep reddish brown.
Nickel        -      -      -     -  Yellowish brown.
Copper            -.       -     -  Dirty yellowish brown.
Silver        -      -      -     -  Orange yellow.
Mercury        ~     -      -      -  Yellow, with both the protoxide and
peroxide salts.
Tin           -      -      -      -  White.
Zinc          -      -      -      -  Orange Yellow.
Bismuth       -      -      -      -  Yellowish brown.
Lead          -      -      -      -No precip.
Iron protoxide -                      Blue.
-   peroxide-        -      -      -No precip.
The ferric-cyanide of potassium has been introduced into dyeing and calico-printing.
In case an excess of chlorine has been used in preparing the above salt, Posselt
recommends to add to its solution, when near the crystalline point, a few drops of
potash lye, in order to decompose a green substance that is present, which takes place
with the precipitation of a little peroxide of iron.
FERROCYANATE, or, more correctly, FERROCYANIDE.  (Ferrocyanure, Fr.;
Eisencyanid, Germ.)  Several compounds of cyanogen and metals possess the property
of uniting together into double cyanides; of which there are none so remarkable in this
respect, as the protocyanide of iron. This appears to be capable of combining with
several simple cyanides, such as that of potassium, sodium, barium, sI'"ontium, calcium,
and ammonium. The only one of these double cyanides of any importance in manufactures is the first, which is described under its commercial name, PRUSSIATE OF.
POTASH.
FERROPRUSSIATES; another name for Ferrocyanides.
FIBRE, VEGETABLE, called  also LTGNINE (Ligneux, Fr.; Pflanzen-faserstoff,
Germ.), is the most abundant and general ingredient of plants, existing in all their parts,
the root, thi leaves, the stem, the flowers, and the fruit; amounting in the compact wood
to 97 or 98 per cent. It is obtained in a pure state by treating saw-dust successively with
hot alcohol, water, dilute muriatic acid, and weak potash ley, which dissolve, first, the
resinous; second, the extractive and saline matters; third, the carbonate and phosphate
of lime; and, lastly, any residuary substances. Ligneous fibres, such as saw-dust, powdered barks, straw, hemp, flax, linen, and cotton cloth, are convertible by the action of
strong sulphuric acid into a gummy substance analogous to dextrine, and a sugar resembling that of the grape.
If we put into a glass mortar 24 parts, by weight, of dry old cordage, chopped small,
and sprinkle over it 34 parts of sulphuric acid, by degrees, so as to avoid heating the
mixture, while we constantly stir it; and if, in a quarter of an hour, we triturate the
mass with a glass pestle, the fibres will disappear without the disengagement of gas.
A tenacious mucilage will be produced, almost entirely soluble in water. The gum
being thus formed, may be separated from the acid by dilution with water, and addition
of the requisite quantity of chalk; then straining the saturated liquid through linen
cloth, concentrating it by evaporation, throwing down any remaining lime by oxalic




708                                    FIBRIE.
acid, filtering anew, and mixing the mucilage with alcohol in great excess, which will
take up the free acid, and throw down the gum. From  24 parts of hemp fibres thus
treated, fully 24 parts of a gummy mass may be obtained, containing, however, probabiy
some water.
When, instead of saturating the diluted acid paste with chalk, we boil it for 10 hours,
the gummy matter disappears, and is replaced by sugar, which may be purified without
any difficulty, by saturation with chalk, filtration and evaporation to the consistence of
sirup. In 24 hours crystallization begins, and, in 2 or 3 days, a concrete mass of grape
sugar is formed; which needs merely to be pressed strongly between old linen cloths
doubled, and then crystallized a second time. If this sirup be treated with bone black,
a brilliant white sugar will be procured. 20 parts of linen rags yield 23 of good sugar.
Bracounot.  Guerin got 871 of dry sugar from 100 parts of rags, treated with 250 of sulphuric acid. See WooD.
FIBRINE (Eng. and Fr.; Thierischer Fasers/off, Germ.) constitutes the principal part
of animal muscle; it exists in the chyle, the blood, and may be regarded as the most
abundant constituent of animal bodies. It may be obtained in a pure state by agitating
or beating new drawn blood with a bundle of twigs, when it will attach itself to them in
long reddish filaments, which may be deprived of color by working them with the hands
under a streamlet of cold water, and afterwards freed from any adhering grease by digestion in alcohol or ether.
Fibrine, thus obtained, is solid, white, flexible slightly elastic, insipid, inodorous, denser
than water, but containing four fifths of its weight of it, and without action on litmus.
When dried, it becomes semi-transparent, yellowish, stiff, and brittle: water restores its
softness and flexibility. 100 parts of fibrine consist of 53-36 carbon, 19-68 oxygen, 7l02
hydrogen, and 19'31 azote. As the basis of flesh, it is a very nutritious substance, and is
essential to the sustenance of carnivorous animals.
FILE (Lime, Fr.; Feile, Germ.) is a well known steel instrument, having teeth upox
the surface for cutting and abrading metal, ivory, wood, &c.
When the teeth of these instruments are formed by a straight sharp-edged chisel, extending across the surface, they are properly called files; but when by a sharp-pointed tool, in
the form of a triangular pyramid, they are termed rasps. The former are used for all the
metals, as well as ivory, bone, horn, and wood; the latter for wood and horn.
Files are divided into two varieties, from the form of their teeth. When the teeth are
a series of sharp edges, raised by the flat chisel, appearing like parallel furrows, either
at right angles to the length of the file, or in an oblique direction, they are termed single
cut. But when these teeth are crossed by a second series of similar teeth, they are said
to be double cut. The first are fitted for brass and copper, and are found to answer better when the teeth run in an oblique direction. The latter are suited for the harder metals, such as cast and wrought iron and steel. Such teeth present sharp angles to the substance, which penetrate it, while single cut files would slip over the surface of these metals. The double cut file is less fit for filing brass and copper, because its teeth would be
very liable to become clogged with the filings.
Files are also called by different names according to their various degrees of fineness.
Those of extreme roughness are called rough; the next to this is the bastard cut; the
third is the second cut; the fourth, the smooth; and the finest of all, the dead smooth.
The very heavy square files used for heavy smith-work, are sometimes a little coarser than
the rough; they are known by the name of rubbers.
Files are also distinguished from  their shape, as flat, half-round, three-square, foursquare, and round. The first are sometimes of uniform breadth and thickness throughout,
and sometimes tapering.  The cross section is a parallelogram. The half-round is generally tapering, one side being flat, and the other rounded. The cross section is a segment of a circle, varying a little for different purposes, but seldom equal to a semi-circle.
The three-square generally consists of three equal sides, being equilateral prisms, mostly
tapering; those which are not tapering are used for sharpening the teeth of saws. The
four-square has four equal sides, the section being a square. These files are generally
thickest in the middle, as is the case with the smith's rubber. In the round file, the section is a circle, and the file generally conical.
The heavier and coarser kinds of files are made from the inferior marks of blistered
steel. Those made from the Russian iron, known by the name of old sable, called from
its mark CCND, are excellent. The steel made from the best Swedish iron, called hoop
L or Dannemora, makes the finest Lancashire files, for watch and clock makers; a manufacture for which the house of Stubbs in Warrington is celebrated.
The steel intended for files is more highly converted than for other purposes, to give
them  proper hardness. It should however be recollected, that if the hardness be not
accompanied with a certain degree of tenacity, the teeth of the file break, and do but little
service.
Simasl files are mostly made of cast steel, which would be the best for all others, if




FILE.                                      709
it were not for its higher price.  It is much harder than the blistered steel, and from
having been in the fluid state, is entirely free from those seams and loose parts so common
to blistered steel, which is no sounder than as it comes from the iron forge before conversion.
The smith's rubbers are generally forged in the common smith's forge, from the converted bars, which are, for convenience, made square in the iron before they come into
this country. The files of lesser size are made from bars or rods, drawn down from the
blistered bars, and the cast ingots, and known by the name of tilted steel.
The file-maker's forge consists of large bellows, with coke as fuel.  The anvil-block,
particularly at Sheffield, is one large mass of mill stone girt.  The anvil is of considerable size, set into and wedged fast into the stone; and has a projection at one end, with
a hole to contain a sharp-edged tool for cutting the files from  the rods.  It alsc
contains a deep groove for containincg dies or bosses, for giving particular forms to the
files.
The fiat and square files are formed entirely by the hammer.  One man holds the hot
bar, and strikes with a small hammer. Another stands before the anvil with a two-handed hammer.  The latter is generally very heavy, with a broad face for the large files.
They both strike with such truth as to make the surface smooth and flat, without what is
called hand-harmmering.  This arises from their great experience in the same kind of
work. The expedition arising from the same cause is not less remarkable.
The half-round files are made in a boss fastened into the groove above mentioned.
The steel being drawn out, is laid.upon the rounded recess, and hammered till it fills
the die.
The three-sided files are formed similarly in a boss, the recess of which consists of two
sides, with the angle downwards. The steel is first drawn out square, and then placed
in a boss with an angle downwvards,so that the hammer forms one side, and the boss two.
The round files are formed by a swage similar to those used by common smiths, but a
little conical.
The file-cutter requires an anvil of a size greater or less, proportioned to the size of his
files, with a face as even and flat as possible. The hammers weigh from one to five or six
pounds. The chisels are a little broader than the file, sharpened to an angle of about 20
degrees.  The length is just sufficient for them to be held fast between the finger and
thumb, and so strong as not to bend with the strokes of the hammer, the intensity of
which may be best conceived by the depth of the impression. The anvil is placed in the
face of a strong wooden post, to which a wooden seat is attached, at a small distance below the level of the anvil's face. The file is first laid upon the bare anvil, one end projecting over the front, and the other over the back edge of the same.  A leather strap
now goes over each end of the file, and passes down upon each side of the block to the
workman's feet, which, being put into the strap on each side, like a stirrup, holds the file
firmly upon the anvil as it is cut. While the point of the file is cutting, the strap passes
over one part of the file only, the point resting upon the anvil, and the tang upon a prop
on the other side of the strap.  When one side of the file is single cut, a fine file is run
slightly over the teeth, to take away the roughness; when they are to be double cut,
another set of teeth is cut, crossing the former nearly at right angles.  The file is now
finished upon one side, and it is evident that the cut side cannot be laid upon the bare
anvil to cut the other. A flat piece of an alloy of lead and tin is interposed between the
toothed surface and the arvil, while the other side is cut, which completely preserves the
side already formed. Similar pieces of lead and tin, with angular and rounded grooves,
are used for cutting triangular and half-round files.
Rasps are cut precisely in the same way, by using a triangular punch instead of a fiat
chisel. The great art in cutting a rasp is to place every new tooth as much as possible
opposite to a vacancy.
NMany abortive attempts have been made to cut the teeth of files by machinery. The
following plan. for which a patent was obtained by Mr. William Shilton, of Birmingham, in April, 1833, is replete with ingenious mechanical resources, and dleserves to
succeed.
The blanks of steel for making the files and rasps, are held in a pair of clamps in
connexion with a slide, and are moved forward at intervals under the head of the tilt
hammer which carries the tool; the distance which the blank is to be advanced at
every movement being dependant upon the required fineness or coarseness of the cut of
the file, which movement is effected and regulated by a rack and pinion, actuated by a
pall and ratchet wheel, or the movement may be produced by any other convenient
means.
When the machine is employed for cutting or indenting the teeth of rasps, the cutting
tool being pointed and only producing one tooth at a blow, the tilt hammer carrying the
tool mast be made to traverse at intervals across the width of the blank piece of steel




710                                     FILE.
from one edge to the other and back again; the blank being advanced in iength only
when the hammer has produced the last cut or tooth toward either edge of the rasp.
In order to render this invention better understood, two views of the apparatus for pro.
ducin-g the cross-cut or teeth of the files are given.
528 ^Fig. 527  is an elevation of the
upper part of the file-cutting machine,
_m ^^^  -) ______as seen on one side; fig. 528 is a
plan or horizontal view, as the machine appears on the top.'[i. 0 ft-^                         a, is the head of the tilt hammer
placed in the end of the lever b,
which  is mounted  on an  axle c
_ — -  1   ^3 ~   turning in proper bearings in the
frame work of the machine; d, is the
tilt wheel mounted on another axle s,
also turning in bearings on the frame
work of the machine, and having any
required  number of projections or
tappets upon it fordepressing the tail
or shorter end of the hammer or tilt
lever b.
^52~7                               The tilt wheel d, receives its rotatory motion from  the toothed wheel
/Al\w                     gf, mounted upon the same axle, and
h^f~~ "^           it takes into gear with a pinion g,
upon the main shaft h which is ac^^7u1,  ft^-i-i-:^ ~"     tuated by a band passed from any
first mover to ths end,
or in any other convenient manner.
The bed upon which the blank piece',n~  ^      of steel bears is marked i. This bed
is firmly supported  upon  masonry
placed upon proper sleepers; j, is
i-~~~ - ^~ i~1-~               one of the blank pieces of steel under
operation, and is shown secured in
i     the pair of jaws or holding clamps A*,
mounted on centre pins in the slide
1, fig. 528; which slide is held down
by a spring and slide beneath, and is
moved backwards and forwards in the machine upon the (v) edges m, m, of the frame,
by means of the rack n, and its pinion; the latter being mounted upon the axle of the
ratchet wheel p, and which ratchet wheel is made to turn at intervals by means of the
pall q, upon the end of the lever r, fig. 528.  This lever is depressed, after every cut
has been effected upon the blank by means of the teeth or tappets of the wheel s, coming
in contact with the inclined plane t, upon the lever r.  The tappet wheel s, is mounted
upon the end of tae axle e, of the tilt wheel, and consequently revolves with it, and by
depressing the lever r, every time that a tooth passes the inclined plane t, the click q,
is made to drive the ratchet wheel p, and thereby the advancing movement of the blank
is effected after each blow of the tilt hammer.
There is a strong spring u, attached to the upper side of the tilt hammer, its end being
confined under an adjustable inclined plane v, mounted in the frame w, which inclined
plane can be raised or lowered by its adjusting screws as required, to produce more or
less tension of the spring.
A similar spring is placed on the under side of the tilt hammer, to raise and sustain
the cutter or tool clear of the bed after every blow, and in conjunction with safety holders or catchers, to counteract any vibration or tendency the spring u may have to cause
the hammer to reiterate the blow.
The end of the lower spring acts on an inclined plane, mounted in the frame w, which
has an adjusting screw similar to v, to regulate the tension of the spring.
In case the under spring should raise, that is, return the hammer, with sufficient force
or velocity to cause the top spring u, to reiterate the blow, the ends of the safety holders
or catchers are made to move under and catch the tail of the lever b, immediately on its
being raised by the under springs, which is effected by the following means:-The hold.
ers are mounted upon a plate or carriage 1, fig. 527, which turns upon a small pin or
axle mounted in the cars of a cross bar; the upper ends of the holders are kept inclined
towards the tail of the tilt hammer by means of a spring fixed to the cress bar, and which
acts upon one end of the plate or carriage 1.




FILE.                                      711
In order that the holders may be removed out c~f the way of the tail of the hammer b,
when the tilt wheel is about to effect a blow, the tooth of the tilt wheel which last acted
upon the hammer comes in contact with an inclined plane fixed on the plate or carriage
1, and by depressing that end of the plate, causes the upper ends of the holders to be
withdrawn from under the tail of the hammer b.  The tilt wheel continuing to revolve,
the next tooth advances, and depresses the tail of the hammer, but before it leaves the
tail of the hammer, the tooth last in operation will have quitted the inclined plane and
allowed the spring to return the holders into their former position. After the tooth has
escaped from the tail of b, the hammer will immediately descend and effect the blow or
cut on the blank, and as the tail of the hammer rises, it will come in contact with the
inclined planes at the upper ends of the holders, and force them backwards; and as soon
as the tail of the hammer has passed the top of the holders, the spring will immediately
force the holders forward under the tail of the hammer, and prevent the hammer rising
again until the next tooth of the tilt wheel is about to depress the end of the hammer,
when the same movements of the parts will be repeated, and the machine will continue
in operation until a sufficient length of the blank of steel (progressively advanced under
the hammer) has been operated upon, when it will be thrown out of gear by the
following means:~
Upon the sliding bar 6 there is placed an adjustable stop, against which the foremost
end of the slide 1,fJig. 528, comes in contact as it is moved forwatl by the rack n, and
its pinion. The sliding bar 6 is connected at its left end to the bent lever 8, the other
end of this lever being formed into a forked arm, which embraces a clutch upon the main
shaft, and as the slide 1 continues to advance, it will come in contact with a stop; and
when it has brought a sufficient length of the blank pieces of steel under the operation
of the cutting tool, the slide 1, in its progress, will have moved that stop and the bar 6
forward, and that bar, by means of the bent lever 8, will withdraw the clutch on the
main shaft, from locking into the boss of the fly-wheel, and consequently stop the further
progress of the machine; the rigger and fly-wheel turning loosely upon the main shaft.
The cut file can now be removed from out of the clamps, and reversed to cut the other
side, or another blank piece put in its place; and after throwing back the pall q of the
ratchet wheel p, the slide 1, and with it the fresh blank may be moved back into the
machine by turning the winch handle, on the axle of the ratchet wheel p, the reverse
way, which will turn the pinion backwards, and draw back the rack n, without affecting
any other parts of the machine; and on moving back the bar 6, by the handle 11, placed
on the stop, the clutches will be thrown into gear again, and the machine proceed to cut
the next blank.
When the blanks have been thus cut on one side, and are reversed in the machine to
form the teeth upon the other side, there should be a piece of lead placed between the
blank and the bed to protect the fresh cut teeth.
It will be seen that the position of the stop upon the bar 6 will determine the length
or extent of the blank piece of steel which shall be cut or operated upon; and in order
that the progressive movement of the blanks under the cutting tool may be made to suit
different degrees of fineness or coarseness of the teeth (that is, the distance between the
cuts), there is an adjusting screw upon the lever r, the head of which screw stops against
the under side of an ear projecting from the frame-work, and thereby determines the
extent of the motion of the lever r, when depressed by the tappets of the wheel s, acting
upon the inclined plane t, consequently determining the number of teeth the ratchet
wheel p shall be moved round by the pall q; and hence the extent of motion communicated by the radk and pinion to the slide 1, and the blank j, which regulates the distance
that the teeth of the file are apart, and the lever r is forced upwards by a spring pressing
against its under side.
It will be perceived that the velocity of the descent of the hammer, and consequently
the force of the blow, may be regulated by raising or lowering the inclined plane v of the
spring u; and in order to accommodate the bed upon which the blanks rest to the different inclinations they may be placed at, that part of the bed is formed of a semi-globular
piece of hardened steel, which fits loosely into a similar concavity in the bed r, and is
therefore capable of adjusting itself so that the blanks shall be properly presented to the
cutting tool, and receive the blow or cut in an equal and even manner; or the piece of
steel may be of a conical shape, and fit loosely in a similar shaped concavity.
There are guides, 16, placed on the top of the bed i, for the purpose of keeping the
blanks in their proper position towards the cutting tool, and these can be regulated to
suit blanks of any width, by turning the right and left handed screw 17. There is also
another adjustable stop on the jaws or clamps k, which serves as a guide when placing
the blanks within the jaws; and 19 is a handle or lever for raising the clamps when
required, which has a weight suspended from  it for the purpose of keeping down the
blanks with sufficient pressure upon the bed.
The cutting tool in the face of the hammer, can be placed at any required angle or




712                                       FILE.
inclination with the blank, it being secured in the head of the hammer by clamps and
screws. In cutting fine files a screw is employed in preference to the rack and pinion,
for advancing the slide 1, and the blank piece of steel in the machine.
Hardening of files.-This is the last and most important part of file making. Whatever may be the quality of the steel, or however excellent the workmanship, if it is not
well hardened all the labor is lost.
Three things are strictly to be observed in hardening; first, to prepare the file on the
surface, so as to prevent it from being oxydated by the atmosphere when the fe is red
hot, which effect would not only take off the sharpness of the tooth, but render the
whole surface so rough that the file would, in a little time, become clogged with the
substance it had to work. Secondly, the heat ought to be very uniformly red throughout,
and the water in which it is quenched, fresh and cold, for the purpose of giving it the
proper degree of hardness. Lastly, the manner of immersion is of great importance, to
prevent the files from warping, which in long thin files is very difficult.
The first object is accomplished by laying a substance upon the file, which, when it
fuses, forms, as it were, a varnish upon the surface, defending the metal from the action
of the oxygen of the air.  Formerly the process consisted in first coa!ing the surface of
the file with ale grounds, and then covering it over with pulverized common salt (muriate of soda). After this coating became dry, the files were heated red hot, and hardened;
after this, the surface was lightly brushed over with the dust of cokes, when it appeared
white and metallic, as if it had not been heated. This process has lately been improved,
at least so far as relates to the economy of the salt, which, from the quantity used, and
the increased thickness, had become a serious object. Those who use the improved
method are now consuming about one fourth the quantity of salt used in the old method.
The process consists in dissolving the salt in water to saturation, which is about three
pounds to the gallon, and stiffening it with ale grounds, or with the cheapest kind of
flour, such as that of beans, to about the consistence of thick cream. The files require
to be dipped only into this substance, and immediately heated and hardened.  The
grounds or the flour are of no other use than to give the mass consistence, and by that
means to allow a larger quantity of salt to be laid upon the surface. In this method
the salt forms immediately a firm coating. As soon as the water is evaporated, the
whole of it becomes fused upon the file.  In the old method the dry salt was so loosely
attached to the file, that the greatest part of it was rubbed off into the fire, and was
sublimed up the chimney, without producing any effect.
The carbonaceous matter of the ale grounds is supposed to have some effect in giving
hardness to the file, by combining with the steel, and rendering it. more highly carbonated. It will be found, however, upon experiment, that vegetable carbon does not combine with iron, with sufficient facility to produce any effect, in the short space of time
a file is heating for the purpose of hardening. Some file makers are in the habit of
using the coal of burnt leather, which doubtless produces some effect; but the carbon
is generally so ill prepared for the purpose, and the time of its operation so short, as to
render the result inconsiderable. Animal carbon, when properly prepared and mixed
with the above hardening composition, is capable of giving hardness to the surface even
of an iron file.
This carbonaceous matter may be readily obtained from any of the soft parts of animals, or from blood. For this purpose, however, the refuse of shoemakers and curriers
is the most convenient. After the volatile parts have been distilled over, from an iron
still, a bright shining coal is left behind, which, when reduced to powder, is fit to mix
with the salt. Let about equal parts, by bulk, of this powder, and muriate of soda be
ground together, and brought to the consistence of cream, by the addition of water.
Or mix the powdered carbon with a saturated solution of the salt, till it become of
the above consistence.  Files which are intended to be very hard should be covered
with this composition previous to hardening. All files intended to file iron or steel,
particularly saw files, should be hardened with the aid of this mixture, in preference to
that with the flour or grounds. Indeed, it is probable that the carbonaceous powder
might be used by itself, in point of economy, since the ammonia or hartshorn, obtained
by distillation, would be of such value as to render the coal of no expense. By means
of this method the files made of iron, which, in itself, is unsusceptible of hardening,
acquire a superficial hardness sufficient for any file whatever. Such files may, at the
same time, be bent into any form; and, in consequence, are particularly useful for scuilptors and die-sinkers.
The next point to be considered is the best method of heating the file for hardening.
For this purpose a fire, similar to the common smith's fire, is generally employed. The
file is held in a pair of tongs by the tang, and introduced into the fire, consisting of
very small cokes, pushing it more or less into the fire for the purpose of heating it
regularly. It must frequently be withdrawn with the view of observing that it is not
too hot in any part. When it is uniformly heated, from  the tang to tie point, of a




FILTRATION.                                      713
hwrry red color, it is fit to quench in the water. At present an oven formed of firebricks is used for the larger files, into which the blast of the bellows is directed, being
open at one end, for the purpose of introducing the files and the fuel.  Near to the top
of the oven are placed two cross bars, on which a few files are placed, to be partially
heating. In the hardening of heavy files this contrivance affords a considerable savying, in point of time, while it permits them also to be more uniformly. and thoroughly
heated.
After the file is properly heated for the purpose of hardening, in order to produce the
greatest possible hardness, it should be cooled as soon as possible. The most common
method of effecting this is by quenching it in the coldest water. Some file-makers have
been in the habit of putting different substances in their water, with a view to increase
its hardening property. The addition of sulphuric acid to the water was long held a
great secret in the hardening of saw files. After all, however, it will be.found that clear
spring water, free from  animal and vegetable matter, and as cold as possible, is the best
calculated for hardening files of every description.
In quenching the files in water, some caution must be observed. All files, except the
half-round, should be immersed perpendicularly, as quickly as possible, so that the upper
part shall not cool. This management prevents the file from warping. The half-round
file must be quenched in the same steady manner; but, at the same time that it is kept
perpendicular to the surface of the water, it must be moved a little horizontally, in the
direction of the round side, otherwise it will become crooked backwards.
After the files are hardened, they are brushed over with water and powdered cokes,
when the surface becomes perfectly clean and metallic. They ought also to be washed
well in two or three clean waters, for the purpose of carrying off all the salt, which, if
allowed to remain, will be liable to rust the file. They should moreover be dipped into
lime-water, and rapidly dried before, the fire, after being oiled with olive oil, containing a
little oil of turpentine, while still warm. They are then finished.
FILLIGREE (Filigrane, Fr.; Filigran, or Feine Drahtgeflecht, Germ.) is, as the last
term justly expresses it, intertwisted fine wire, used for ornamenting gold and silver
trinkets. The wire is seldom drawvn round, but generally flat or angular, and soldered
by gold or silver solder with borax and the blowpipe. The Italian word, fiiligrana, is
compounded of filurn and granum, or granular net-work; because the Italians, who first
introduced this style of work, placed small beads upon it.
FILTRATION (Eng. and Fr.; Filtriren, Germ.) is a process, purely mechanical, for
separating a liquid from the undissolved particles floating in it, which liquid may be either
the useful part, as in vegetable infusions, or of no use, as the washings of mineral precipitates.  The filtering substance may consist of any porous matter in a solid, foliated, or pulverulent form; as porous earthenware, unsized paper, cloth of many kinds, or
sand. The white blotting paper sold by the stationers, answers extremely well for filters
in chemical experiments, provided it be previously washed with dilute muriatic acid, to
remove some lime and iron that are generally present in it. Filter papers are first cut
square, and then folded twice diagonally into the shape of a cornet, having the angular
parts rounded off. Or the piece of paper being cut into a circle, may be folded fan-like
from the centre, with the folds placed exteriorly, and turned out sharp by the pressure of
the finger and thumb, to keep intervals between the paper and the funnel into which it
is fitted, to favor the'percolation. The diameter of the funnel should be about three
fourths of its height, measured from the neck to the edge. If it be more divergent, the
slope will be too small for the ready efflux of the fluid. A filter covered with the sediment is most conveniently washed by spouting water upon it with a little syringe. A
small camel's-hair paint brush is much employed for collecting and turning over the contents in their soft state. Agitation or vibration is of singular efficacy in quickening percolation, as it displaces the particles of the moistened powders, and opens up the pores
which had become closed. Instead of a funnel, a cylindrical vessel may be employed,
having its per-forated bottom covered with a disc of filtering powder folded up at the
edges, and made tight there by a wire ring. Linen or calico is used for weak alkaline
liquors; and flannels, twilled woollen cloth, or felt-stuff, for weak acid ones.  These
filter bags are often made conical like a fool's cap, and have their mouths supported by a
wooden or metallic hoop. Cotton wool put loose into the neck of a funnel answers well
for filtering oils upon the small scale. In the large way, oil is filtered in conical woollen
bags, or in a cask with many conical tubes in its bottom, filled with tow or cotton wool.
Stronger acid and alkaline liquors must be filtered through a layer of pounded glass,
quartz, clean sand, or bruised charcoal. The alcarrhazas are a porous biscuit of stone
ware made in Spain, which are convenient fr filtering water, as also the porous filtering
stone of Teneriffe, largely imported into England at one time, but now superseded in a
great measur eby the artificial filters patented under many forms, consisting essentially
of strata of gravel, sand, and charcoal powder.
It is convenient to render the filter self-acting, by accommodating the supply of liquid




714                                 FILTRATION.
to the rate of percolation, so that the pressure upon the porous surface may be always
equally great. Upon the small scale, the lamp-fountain or bird's-glass form, so generally
used for lamps, will be found to answer.
Fig. 529 represents a glass bottle, A, partly filled with the fluid to be filtered, supported
in the ring of a chemical stand, and having its mouth inverted into the same liquor in
the filter funnel. It is obvious that whenever this liquor by filtration falls below the
lip of the bottle,'air will enter into it. let down a fresh supply to feed the filter, and
keep the funnel regularly charged. If larger quantities are to be operated upon, the
529~ —'         following apparatus may
529                              t   5  J                  be employed.  Fig. 530,
Q    530           rc                       A B, is a metallic vessel
which may be made airA Jt \                         /^\                    tight; c is the under pipe,
_^~_____^^~___^^J~~~ j                      provided with a stopcock,
1______-^jj~                         A                    a,^R   for letting down the
\__ the cock R 1) SO aliquor into the filter a b.
The upper pipe t, through
which the fluid is poured
by means of the funnel E,
has also a stopcock which
opens or  shuts, at the
/^~~~~~ ~~same time, the small side
tube u t, through which
during the entrance of the
fluid, the air is let off from
B                    the  receiver.   A  glass
tube, g, shows the level
_______~  ^of the liquor in the body
1,__^EEE__  ^ R r^^  t    of the apparatus. In using
it, the cock a must be first'                                  closed, and the  cock 
must be opened to fill the
receiver. Then the filter
is set a going, by re-opening the cock A, so as to keep the fluid in the filter upon a level with the opening of the
tube c. Both these pieces of apparatus are essentially the same.
In many manufactures, self-acting filters are fed by the plumber's common con533                                                            531
B                  A    m' C   m                       m,]'M
trivance of a ball-cock, in which the sinking and rising of the ball, within certain
limits, serves to open or
532                  ~ -        i        shut off  the  supply ot
A         it          liquor, as it may be required or not. Dumont
-t                i         has adopted this expedient
IX~~~~~~~  _^s~~, Lp^   i'       for his system of filtering
sirup through a stratum of
"m~a  e       t \'       granularly ground animal
charcoal or bone-black.
Bl    J  j   ^^^  ^^~   Fig. 531 is a front view
of this apparatus with 4
filters, c; andfig. 532isa
t^~ )._~~.~  ~~~~L1.._~,.cross section. The frame-,,  - ~~~work B supports the cistMe  A, in which the sirup is contained. From it the liquor flows through the stopcock




FILTRATION.                                      715
b, and the connexion-tube a, into the common pipe c, which communicates, by the short
branch tubes e, with each of the four filters. The end of the branch tube, which is inside
of the filter tub, is provided with a stop-cock d f, whose opening, and thereby the efflux
of the liquor from the cistern through the tube a, is regulated by means of the float-ball g.
Upon the brick~work D the filter tub stands, furnished at h with a false bottom of zinc or
copper pierced with fine holes; besides which, higher up at i there is another such plate
of metal furnished with a strong handle k, by which it may be removed, when the bone
black needs to be changed. In the intervening space 1, the granular coal is placed.  o is
the cover of the filter tub, with a handle also for lifting it.  One portion of it may be raised by a hinge, when it is desired to inspect the progress of the filtration within. m m is a
slender vertical tube, forming a communication between the bottom part h, and the upper
portion of the filter, to admit of the easy escape of the air from that space, and from among
the bone black as the sirup descends; otherwise the filtration could not go on. p is the
stolpcock through which the fluid collected in the space under h, is let off from time to time
into the common pipe qfig. 531. r is a trickling channel or groove lying parallel to the
tube q, and in which, by means of a tube s, inserted at pleasure, the sirup is drawn off
in case of its flowing in a turbid state, when it must be returned over the surface of the
charcoal.
The celerity with which any fluid passes through the filter depends, 1. upon the porosity of the filtering substance; 2. upon the pressure exercised upon it; and 3. upon the extent of the filtering surface. Fine powders in a liquor somewhat glutinous, or closely
compacted, admit of much slower filtration than those which are coarse and free; and the
former ought, therefore, to be spread in a thinner stratum and over a more extensive surface than the latter, for equal effect; a principle well exemplified in the working of Du-mont's apparatus, just described.
In many cases filtration may be accelerated by the increase of hydrostatic or pneumatic pressure. This happens when we close the top of a filtering cylinder, and connect it by a pipe with a cistern of fluid placed upon a higher level. The pressure of the
air may be rendered operative also either by withdrawing it partially from  a close
vessel, into which the bottom of the filter enters, or by increasing its density over the
top of the liquor to be filtered. Either the air pump or steam  may be employed to
create a partial void in the receiver beneath the filter. In like manner, a forcing pump
or steam may be employed to exert pressure upon the surface of the filtering liquor.  A
common syphon may, on the same principle, be made a good pressure filter, by making
its upper leg trumpet-shaped, covering the orifice with filter paper or cloth, and filling
the whole with liquor, the lower leg being of such length so as to create considerable
pressure by the difference of hydrostatic level. This apparatus is very convenient either
on the small or great scale, for filtering off a clear fluid from a light muddy sediment.
The pressure of the atmosphere may be elegantly applied to common filters, by the apparatus represented infig. 533, which is merely a funnel enclosed within a gasometer. The
case A n bears an annular hollow vessel a b, filled with water, in which receiver the cylindrical gasometer d, e, f, i, is immersed. The filter funnel is secured at its upper
edge to the inner surface of the annular vessel a b. In consequence of the pressure of
the gasometer regulated by the weight g, upon the air enclosed within it, the liquid is
equally pressed, and the water in the annular space rises to a corresponding height on the
outer surf&J? of the gasometer, as shown in the figure. Were the apparatus made of
Jieet iron, the annular space might be charged with mercury.
In general, relatively to the application of pressure to filters, it may be remarked,
that it cannot be pushed very far, without the chance of deranging the apparatus, or
rendering the filtered liquor muddy.   The enlargement of the surface is, generally
speaking, the safest and most efficacious plan of increasing the rapidity of filtration,
especially for liquids of a glutinous nature. This expedient is well illustrated in the creased
bag filter now in use in most of the sugar refineries of London. See SUGAR.
In many cases it is convenient so to construct the filtering apparatus, as that the
liquid shall not descend, but mount by hydrostatic pressure.  This method has two
advantages: 1. that without much expensive apparatus, any desired degree of hydrostatic pressure may be given, as also that the liquid may be forced up through several filtering surfaces placed alongside of each other; 2. that the object of filtering, which is to
separate the particles floating in the fluid without disturbing the sediment, may be perfectly attained, and thus very foul liquids be cleared without greatly soiling the filtering
surface.
Such a construction is peculiarly applicable to the purification of water, either alone,
or combined with the downwards plan of filtration. Of the former variety an example
is shown in fig. 534. The wooden or zinc conical vessel is provided with two perforated bottoms or sieves e e, betwixt which the filtering substance is packed. Over
this, for the formation of the space h h, there is a third shelf, with a hole in its middle,
through which the tube d b is passed, so as to be water tight. This places the upper




716                                 FILTRATION.
open part of the apparatus in communication with the lowest space a. From the compartment h h a small air tube 1 runs upwards. The filtering substance consists at bottom
of pebbles, in the middle of gravel, and at the top of fine sand, which may be mixed with
coarsely ground bone black, or covered with a layer of the same. The water to be filtered being poured into the cistern at top, fills through the tube b d the inferior compartment
a, from which the hydrostatic pressure forces the water upward through the perforated
shelf, and the filtering materials. The pure water collects in the space h h, while the air
escapes by the small tube 1, as the liquid enters. The stopcock i serves to draw off the
filtered water. As the motion of the fluid in the filter is slow, the particles suspended in
it have time to subside by their own gravity; hence there collects over the upper shelf at
d, as well as over the under one at a, a precipitate or deposite which may be washed out
of the latter cavity by means of the stopcock m.
As an example of an upwards and downwards filter, fig. 535 may be exhibited. A BCD
535                                   is a wooden or metallic cistern furA.     _                  -D                       nished with the perforated shelf
E 1   1                        534          c dnear its under part, upon which
1~ 11 1 ^          ff  ~a vertical partition is fixed through
I   F    ^    E    1    %1             0   the axis of the vessel.   A  semi1Id a       circular perforated shelf is place.
$F=^ ^   I __________     i    h    ~l at a, and a second similar one at
- l"a   ~"b                         it h    ^ \ b.  These horizontal shelves rest
e   upon brackets in the sides of the
xII H      C G   I                          cisterns, so that they may be readily lifted out.   The space G is
filled with coarse sand, J with modM         b_ a^  C ^ J ~ l  erately fine, and H with very fine.
d             L i,.   M  is   p m 2  C  e  "       The foul water is oured into the
J                                     chamber E, and presses through
G J H and into the space F; whence
33 l. I. X.......... C                             it may be drawn by the stopcock f.
Fig. 536 represents in section a filtering apparatus consisting of two concentric
chambers; the intericr being destined for downwards filtration, and the exterior for
upwards.  Within the larger cistern A, a smaller one B is placed concentrically, with its
536        g                                 -  under part, and is left open from
j-l^TiM ~ i —                - "       distance to distance, to make a
1- 1 o  r          communication  between  the  in__ ^ ^ Igl   -terior. cavity  and  the  exterior
l   A                     A_,         annular  space.  These  cavities
e     i        ~   -~~~1 -are filled  to  the mar ed  height
__________ ~with  sand  and  gravel.   The
_ l   I ~      I=        inner cylindrical space has fine
t<I          S/_ _                 =           _ ~r ~-'~    _  1 sand  below, then  sharper sand
with   granular  charcoal,  next
byfP e-''-Y-_e~=  ~  ~-  ~~              coarse  sand, and  lastly  gravel..j —'. *E, —|Fi;- l        The  annular space has in like
manner fine  sand  below.  The
foul water is introduced by the
"  ____ Nut         pipe x, the orifice at whose end
is  acted  upon  by  a  ball-cock
_     with  its levera; whereby the
water is kept always at the same
level in the inner vessel. The water sinks through the sand strata of the middle vessel,
passes outwards at its bottom into the annular space, thence up through the sand in it,
and collecting above it, is let off by the stopcock on the pipe b. When a muddy deposite
forms after some time, it may be easily cleared out. The cord e, running over the pulleys
f f, being drawn tight, the ball lever will shut up the valve. The stopcock d made fast
to the conducting tube E must then be opened, so that the water now overflows into the
annular space at A; the tube c, in communication with the inner space B, being opened
by taking out the stopper h. The water thereby percolates through the sand strata in the
reverse direction of it3 usual course, so as to clear away the impurities in the space B, and
to discharge them by the pipe c h. An apparatus of this kind of moderate size is capable
of filtering a great body of water. It should be constructed for that purpose of masonry;
but upon a small scale it may be made of stone-ware.
A convenient apparatus for filtering oil upwards is represented in fig. 537. g is an til
cask, in which the impure parts of the oil have accumulated over the bottom. Immediately above this, a pipe a is-let in, which communicates with an elevated water cistern




FIRE ARMS.                                       717
~. f is the filter (placed on the lid of the cask), furnished with two perforated shelves,
one at e and another at d; which divide the interior of the filter into three corn537        partments.  Into the lower space immediately over the shelf e,
the tube b, furnished with a stopcok, enters, to establish a
communication with the cask; the middle cavity e is filled with
= ~L ~ a  coarsely ground charcoal or other filtering materials; and the
-- upper one has an eduction pipe, 1. When the stopcocks of the
tubes a and b are opened, the water passes from the cistern into
*   a-^^^^  the oil cask, occupies from its density always the lowest place,
and presses the oil upwards, without mixing the two liquids;
whereby first the upper and purer portion of the oil is forced
through the tube b into the filter, and thence out through the
a   pipe 1. When the fouler oil follows, it deposites its impurities
in the space under the partition c, which may from time to time
be drawn off through the stopcock k, while the purer oil is
pressed upwards through the filter.  In this way the different
strata of oil in the cask may be filtered off in succession, and
kept separate, if found necessary, for sale or use, without running any risk of mixing up the muddy matter with what is clear.  According to the
height of' the water cistern n, will be the pressure, and, of course, the filtering force.
When the filter gets choked with dirt, it may be easily recharged with fresh materials.
In filtering caustic alkaline leys through linen or quartz, it is proper to exclude the
free contact of air; which is done by enclosing the upper vessel, and attaching a pipe of
communication between its cover and the shoulder of the lower vessel or recipient of the
leys. In proportion as these flow down, they will displace their bulk of air, and drive
it into the top of the upper vessel above the foul leys.
Many modifications of the above described apparatus are now on sale in this country;
but certainly the neatest, most economical, and effective means of transforming the water
of a stagnant muddy pool into that of a crystalline fountain, is afforded by the Royal
Patent Filters of George Robins.
FIRE ARMS, MANUFACTURE OF. This art is divided into two branches, that of the
metallic and of the wooden work. The first includes the barrel, the lock, and the mounting, as also the bayonet and ramrod, with military arms. The second comprises the stock,
and in fowling pieces, likewise the ramrod.
1. The Barrel. Its interior is called the bore; its diameter, the calibre; the back
end, the breech; the front end, the muzzle; and the closing of the back end, the breech
pin or plug. The barrel is generally made of iron. Most military muskets and lowpriced guns are fashioned out of a long slip of sheet-iron, folded together edgewise
round a skewer into a cylinder, are then -lapped over at the seam, and welded at a
white heat. The most ductile and tenacious soft iron, free from all blemishes, must be
selected for this slip. It is frequently welded at the common forge, but a proper airfurnace answers better, not being so apt to burn it. It should be covered with ashes
or cinders. The shape of the bore is given by hammering the cylinder upon a steel
mandril, in a groove of the anvil. Six inches of the barrel at either end are left open
for forming the breeck and the muzzle by a subsequent welding operation; the extremity put into the fire be.ng stopped with clay, to prevent the introduction of cinders.
For every length of two inches there are from two to three welding operations, divided
into alternating high and low heats; the latter being intended to correct the defects of
the former. The breech and muzzle are not welded upon the mandril, but upon the
horn of the anvil; the breech being thicker in the metal, is more highly heated, and is
made somewhat wider to save labor to the borer. The barrel is finally hammered in
the groove of the anvil without the mandril, during which process it receives a heat
every two minutes. In welding, the barrel extends about one third in length; and
for muskets, is eventually left from 3 to 3k feet long; but for cavalry pistols, only 9
inches.
The best iron plates for gun-barrels are those made of stub iron, that is, of old
horse-shoe nails welded together, and forged into thin bars, or rather narrow ribands.
At one time damascus barrels were much in vogue; they were fashioned either as above
described, from plates made of bars of iron and steel laid parallel, and welded together,
or from ribands of the sawie damascus stuff coiled into a cylinder at a re4 heat, and then
welded together at the seams. The best modern barrels for fowling pieces are constructed of stub-nail iron in this manner. The slip or fillet is only half an inch broad,
or sometimes less, and is left thicker at the end which is to form the breech, and thinner
at the end which is to form the muzzle, than in the intermediate portion. This fillet
being moderately heated to increase its pliancy, is then lapped round the mandril in a
spiral direction till a proper length of cylinder is formed; the edges being made to
overlap a little in order to give them a better hold in the welding process. The coil




718                                   FIRE ARMS.
being taken ofl the mandril and again heated, is struck down vertically with its muzzlJ
end upon the anvil, whereby the spiral junctions are made closer and more uniform. It
is now welded at several successive heats, hammered by horizontal strokes, called jumping, and brought into proper shape on the mandril. The finer barrels are made of still
narrower stub-iron slips, whence they get the name of wire twist.  On the Continent
barrels are made of steel wire, welded together lengthwise, then coiled spirally into a
cylinder.  Barrels that are to be rifled require to be made of thicker iron, and that of
the very best quality, for they would be spoiled by the least portion of scale upon their
inside.  Soldiers' muskets are thickened a little at the muzzle to give a stout holding to
the bayonet.
The barrels thus made are annealed with a gentle heat in a proper furnace, and
slowly cooled.  They are now ready for the borer, which is an oblong square bit of
steel, pressed in its rotation against the barrel, by a slip of wood applied to one of its
flat sides, and held in its place by a ring of metal. The boring bench works horizontally, and has a very shaky appearance, in respect at least of the bit. In some cases,
however, it has been attempted to work the barrels and bits at an inclination to the
horizon of 30~, in order to facilitate the discharrrel is held
in a slot by only one point, to allow it to humor the movements of the borer which
538                                            would otherwise be infallibly
0'                                          broken.  The bit, as repre5V38                                           sented in fig. 538, has merely
its square head inserted into a
Q 539~                    ~ I~ ~~*~~~~~~.   n  I          clamp-chuck of the lathe, and
^^^^"-^^ffl   plays freely through the rest
P7^'  ^  ^1 ^   of its length.
Fig. 539 represents in plan
the boring  bench for musket
barrels; f f is the sledge or
carriage frame in which the barrel is supported; a is the revolving chuck of the lathe,
into which the square end of the bit, fig. 538, is inserted; b is the barrel, clamped at its
middle to the carriage, and capable of being pressed onwards against the tapering bit of
the borer, by the bent lever c, worked by the left hand of the operative against fulcrum
knobs at d, which stand about two inches asunder. Whenever the barrel has been
thereby advanced a certain space to the right, the bent end of the lever is shifted against
another knob or pin. The borer appears to a stranger to be a very awkward and unsteady
mechanism, but its perpetual vibrations do not affect the accuracy of the bore. The
opening broach may be of a square or pentagonal form, and either gradually tapered
from its thickest part, or of uniform diameter till within two inches of the end, whence
it is suddenly tapered to a point.
A series of bits may be used for boring a barrel, beginning with the smallest and ending with the largest. But this multiplication of tools becomes unnecessary, by laying
against the cutting part of the bit slips of wood, called spales, of gradually increasing
thickness, so that the edge is pressed by them progressively further from the axis. The
bore is next polished. This is done by a bit with a very smooth edge, which is mounted
as above, with a wedge of wood besmeared with a mixture of oil and emery. The inside
is finished by working a cylindrical steel file quickly backwards and forwards within it,
while it is revolving slowly.
In boring, the bit must be well oiled or greased, and the barrel must be kept cool by
letting water trickle on it; for the bit, revolving at the rate of 120 or 140 times a minute,
generates a great deal of heat. If a flaw be detected in the barrel during the boring,
that part is hammered in, and then the bit is employed to turn it out.
Many sportsmen are of opinion that a barrel with a bore somewhat narrowed towards
the muzzle serves to keep shot better together; and that roughening its inside with
pounded glass has a good effect, with the same view. For this purpose, also, fine spiral
lines have been made in their interior surface. The justness of its calibre is tried by
means of a truly turned cylinder of steel, 3 or 4 inches long, which ought to move without
friction, but with uniform contact from end to end of the barrel. Whatever irregularities
appear must be immediately removed.
The outer surface of the barrel is commonly polished upon a dry grindstone, but it is
better finished, and less dangerously to the workman, at a turning lathe with a slide rest.
If a stone be used, it should be made to revolve at the mouth of a tunnel of some kind,
into which there is a good draught to carry off the ferruginous particles. A piece of
moist cloth or leather should be suspended before the orifice.
Rifle barrels have parallel grooves of a square or angular form cut within them, each
groove being drawn in succession.  These grooves run spirally, and form  each an
aliquot part of a revolution from the chamber to the muzzle. Rifles should not be too
deeply indented; only so much as to prevent the ball turning round within the barrel,




FIRE ARMS.                                      719
and the spires should be truly parallel, that the ball may glide along with a regular
pace. See infra.
The Parisian gun-makers, who are reckoned very expert, draw out the iron for the
barrels at hand forges, in fillets only one ninth of an inch thick, one inch and a half
broad, and four feet long. Twenty-five of these ribands are laid upon each other, between
two similar ones of double thickness, and the bundle, weighing 60 pounds, bound with
wire at two places, serves to make two barrels.  The thicker plates are intended to
protect the thinner from the violence of the fire in the numerous successive heats necessary to complete the welding, and to form the bundle into a bar two thirds of an inch
broad, by half an inch thick; the direction of the individual plates relatively to the
breadth being preserved.  This bar, folded flat upon itself, is again wrought at the
forge, till it is only half an inch broad, and a quarter of an inch thick, while the plates of
the primitive ribands are now set perpendicular to the breadth of the narrow fillet; the
length of which must be 15 or 16 feet French (16 or 17 English), to form a fowling
piece from 28 to 30 inches long.  This fillet, heated to a cherry red in successive
portions, is coiled into as close a spiral as possible, upon a mandril about two fifths
of an inch in diameter.  The mandril has at one end a stout head for drawing   out
by means of the hammer and the grooves of the anvil, previous to every heating. The
welding is performed upon a mandril introduced after each heat; the middle of the
barrel being first worked, while the fillets are forced back against each other, along the
surface of the mandril, to secure their perfect union. The original plates having in the
formation of the ultimate long riband become very thin, appear upon the surface of the
barrel like threads of a fine screw, with blackish tints to mark the junctions. In making
a double-barrelled gun, the two are formed from the same bundle of slips, the cuils of the
one finished fillet being turned to the right hand, and those of the other to the left.
The Damascus barrels forged as above described, from  a bundle of steel and iron
plates laid alternately together, are twisted at the forge several times, then coiled and
welded as usual. Fifteen Parisian workmen concur in one operation: six at the forge;
two at the boring mill; seven at filing, turning, and adjusting; yet all together make
only six pairs of barrels per week, which are sold at from 100 to 300 francs the pair, ready
for putting into the stock.
The breeching is of three kinds: the common; the chamber, plug, or mortar, fig. 540;
541            and the patent, fig. 541.  The common
~~~~~~540.was formerly used  for soldiers' muskets
and inferior pieces.   The  second is a
trifling  improvement upon it.   In the
patent breeching, the screws do not in7 ^-  ^^   ^  ^      I?     terfere with the touch-hole, and the ignition
is quicker in the main chamber.
The only locks which it is worth while
to describe are those upon the percussion
principle, as flint locks will certainly soon
cease to be employed  even in  military
muskets.  Forsyth's lock (fig. 542) was
an ingenious contrivance. It has a magazine a, for containing the detonating powder, which revolves round a roller b, whose
IIBK                                  end is screwed  into the breech of the
barrel. The priming powder passes through
a small hole in the roller, which leads to a
channel in communication with the chamber
of the gun.
The pan for holding the pruning is placed immediately over the litt. e hole in the roller.
There is a steel punch c, in the magazine, whose under end stands above the pan, ready




720                                FIRE ARMS.
to ignite the priming when struck upon the top by the cock d, whenever the trigger i
drawn. The punch immediately after being driven down into the pan is raised by the action
of a spiral spring. For each explosion, the magazine must be turned so far round as to
let fall a portion of the percussion powder into the pan; after which it is turned back,
and the steel punch recovers its proper position for striking another blow into the
pan.
The invention of the copper percussion cap was another great improvement upon the
detonating plan.  Fig. 543 represents the ordinary percussion lock, which is happily
divested of three awkward projections upon the flint lock, namely, the hammer, hammer
spring, and the pan.  Nothing now appears upon the plate of the lock, but the cock
or striking hammer, which inflicts the proper blow upon the percussion cap.  It is
concave, with a small metallic ring or border, called a shield or fence, for the purpose
of enclosing the cap, as it were, and preventing its splinters doing injury to the sportsman
as also protecting against the line of flame which may issue from the touch-hole in the
cap nipple.  This is screwed into the patent breech, and is perforated with a small
hole.
543
The safety lock of Dr. Somerville is a truly humane invention. Its essential feature
is a slide stop or catch, placed under the trigger A, fig. 544. It is pulled forward into
a notch in the trigger, by means of a spring B, upon the front of the guard, which is
worked by a key c, pressing upon the spring when the piece is discharged.  In another
safety plan there is a small moveable curved piece of iron, A, which rises through an opening
B, in the lock-plate c, and prevents the cock from reaching the nipple, as represented in
the figure, until it is drawn back within the plate of the lock when the piece is fired.
To fire this gun, two different points must be pressed at the same time.  If by
accident the key which works the safety be touched, nothing happens, because the trigger
is not drawn; and the trigger touched alone can produce no effect, because it is locked.
The pressure must be applied to the trigger and the key at the same instant, otherwise
the lock will not work.
The French musket is longer than the British, in the proportion of 44'72 inches to 42
but the French bayonet is 15 inches, whereas the British is 17.




FIRE ARMS.                                      721
Eng. Dimensions.     Fr. Dimensions.
Diameter of the bore   -     -            -  0.75 in.           0-69 in.
Diameter of the ball   -          -       -  0-676              0-65
Weiht of the ball in oz.   -    -         -  106                0-958
Weight of the firelock and bayonet in lbs. - 12-25             10-980
Length of the barrel and bayonet -        - 59-00              59-72
Withinthese few years a great many contrivances have been brought forward, and
several have been patented for fire arms. The first I shall notice is that of Charles
Random, Baron de Berenger. Fig. 545 shows the lock and breech of a fowling piece,
with a sliding protector on one of the improved plans; a is the hammer, b the nipple of
the touch-hole, c a bent lever, turning upon a pin, fixed into the lock-plate at d. The
upper end of this bent lever stands partly under the nose of the hammer, and while in
that situation stops it from striking the nipple. A slider g f h, connected with the under
palt of the gun-stock, is attached to the tail of the bent lever at i; and when the piece
is brought to the shoulder for firing, the hand of the sportsman pressing against the bent
part of the slider at g, forces this back, and thereby moves the end of the lever c forward
from under the nose of the cock or hammer, as shown by the dotted lines. The trigger
being now drawn, the piece will be discharged; and on removing the hand from the end
g, of the slider f, the spring at h acting against the guard, will force the slider forward,
and the lever into the position first described.
Mr. Redford, gun-maker of Birminghan, proposes a modification of the lock for
small fire-arms, in which the application of pressure to the sear spring for discharging
the piece is made by means of a plug, depressed by the thumb, instead of the force of
the finger exerted against the trigger.  Fig. 546 represents a fowling piece partly in
section. The sear spring is shown at a. It is not here connected with the trigger as in
other locks; but is attached by a double-jointed piece to a lever b, which turns upon a
fulcrum pin in its centre.  At the reverse end of this lever an arm  extends forwards,
like tiat of an ordinary sear spring, upon which arm the lower end of the plug c is
intended to bear; and when this plug is depressed by the thumb bearing upon it, that
end of the lever b will be forced downwards, and the reverse end will be raised, so as to
draw up the end of the sear spring, and set off the piece. For the sake of protection,
the head of the plug c is covered by a moveable cap d, forming part of a slider e, which
moves to and fro in a groove in the stock, behind the breech end of the barrel; this
slider e is acted upon by the trigger through levers, which might be attached to the other
side of the lock-plate; but are not shown in this figure, to avoid confusion. When the
piece is brought to the shoulder for firing, the fore-finger must be applied as usual to
the trigger, but merely for the purpose of drawing back the slider e, and uncovering the
head of the plug; when this is done, the thumb is to be pressed upon the head of the plug,
and will thus discharge the piece. A spring bearing against the lever of the slider e, will,
when the finger is withdrawn from the trigger, send the slider forward again, and cover
the head of the plug, as shown.
It is with pleasure I again advert to the humane ingenuity of the Rev. John Somerville,
of Currie. In April, 1835, he obtained a patent for a further invention to prevent the
accidental discharge of fire arms. It consists in hindering the hammer from reaching the
nipple of a percussion lock, or the flint reaching the steel of an ordinary one, by the
interposition of moveable safety studs or pins, which protrude from under the false
breech before the hammers of the locks, and prevent them from descending to strike.




722                                 FIRE ARMS.
These safety studs or pins are moved out of the way by the pressure of the right hand of
the person using the gun only when in the act of firing, that is, when the force of the
right hand and arm is exerted to press the butt end of the stock of the gun against the
shoulder while the aim is taken and the trigger pulled. In carrying the gun at rest, the
proper parts of the thumb or hand do not come over Mr. Somerville's moveable buttons or
studs.
Fig. 547 is a side view of part of a double percussion gun; and fig. 548 is a top or
plan view, which will serve to explain these improvements, and show one, out of many,
methods of carrying them into effect.  A is the stock of the gun; B the barrels; c the
breech; nD the nipples; E the false breech, on the under side of which the levers which
work the safety studs or pins are placed; F is the shield of the false breech; G, triggers;
H the lock-plate; and i the hammers: all of which are constructed as usual: a a are
the safety studs or pins, which protrude before the shield F, and work through guide
pieces on the under side of the false breech.   The button piece is placed in the
position for the thumb of the right hand to act upon it; but when the pressure of the
baU of the right thumb is to produce the movement of the safety studs, it must be placed
AnT
in or near the position K; and when the heel of the right hand is to effect the move
menats of the safety studs, the button piece must be placed at L, or nearly so.
548             D                                         549
In these last two positions, the lever (which is acted upon by the button piece to work
the safety studs through a slide) would require to be of a different shape and differently mounted. When the hammers are down upon the nipples after discharging the
gun, the ends of the safety pins press against the inner sides of the hammers. When this
invention is adapted to single-barrelled guns, only one pin, a, one lever and button piece
will be required.
Mr. Richards, gun-maker, Birmingham, patented, in March, 1836, a modification of
the copper cap for holding the percussion powder, as represented fig. 549; in which
the powder is removed from the top of the cap, and brought nearer the mouth; a being
the top, b the sides, and c the position of the priming. The dotted lines show the direction of the explosion, whereby it is seen that the metal case is opened or distended only
in a small degree, and not likely to burst to pieces, as in the common caps, the space
between a and c being occupied by a piece of any kind of hard metal d, soldered or otherwise fastened in the cap.
George Lovell, Esq., director of the Royal Manufactory of Arms at Enfield, has recently made a great improvement upon the priming chamber. He forms it into a vertical double cone, joined in the middle by the common apex; the base of the upper cone
being in contact with the percussion cap, presents the most extensive surface to the fulminate upon the one hand, while the base of the under one being in a line with the interior
surface of the barrel, presents the largest surface to the gunpowder charge, upon the
other. In the old nipple the apex of the cone being at its top, afforded very injudiciously
the minimum surface to the exploding force.
Guns, Rifling of the Barrels. -The outside of rifle barrels is, in general, octagonal,
After the barrel is bored, and rendered truly cylindrical, it is fixed upon the rifling
machine. This instrument is formed upon a square plank of wood 7 feet long, to which
is fitted a tube about an inch in diameter, with spiral grooves deeply cut internally
through its whole length; and to this a circular plate is attached, about 5 inches
diameter, accuratd.y divided in concentric circles, into from 5 to 16 equal parts, and
supported by two rings made fast to the plank, in which rings it revolves. An arm
connected with the dividing graduated plate, and pierced with holes, through which a




FIRE ARMS.                                  723
pin is passed, regulates the change of the tube in giving the desired number of grooves
to the barrel. An iron rod, with a moveable handle at the one end, and a steel cutter in
the other, passes through the above rifling tube. This rod is covered with a core of lead
one foot long. The barrel is firmly fixed by two rings on the plank, standing in a straight
line on the tube. The rod is now drawn repeatedly through the barrel, from end to end,
until the cutter has formed one groove of the proper depth.  The pin is then shifted to
another hole in the dividing plate, and the operation of grooving is repeated till the whole
number of riflings is completed. The barrel is next taken out of the machine, and finished.  This is done by casting upon the end of a small iron rod a core of lead, which,
when besmeared with a mixture of fine emery and oil, is drawn, for a considerable time,
by the workmen, from the one end of the barrel to the other, till the inner surface has
become finely polished. The best degree of spirality is found to be from a quarter to
half a revolution in a length of three feet.
Military Rfles.-An essential improvement in this destructive arm has lately been introduced into the British service at the suggestion of Mr. Lovell.
The intention in all rifles is to impart to the ball a rotatory or spinning motion
round its axis, as it passes out through the barrel. This object was attained, to a certain
degree, in the rifles of the old pattern, by cutting seven spiral grooves into the inside of
the barrel, in the manner shown by fig. 550, the spherical ball, fig. 551, being a little
553                  552                    550            551
larger than the bore, was driven down with a mallet, by which the projecting ribs were
forced into the surface of the ball, so as to keep it in contact with their curvatures, during
its expulsion. Instead of this laborious and insecure process, the barrel being now cut
with only two opposite grooves, fig. 552, and the ball being formed with a projecting
belt, or zone, round its equator. of the same form as the two grooves, fig. 553, it enters
This mode of rifling is not, however, new in England.  In fact it is one of the
oldest upon record; and appears to have fallen into disuse from faults in the execution.
The idnt was revived within the last few years in Brunswick, and it was tried in
Hanover also, but with a lens-shaped (Linsenf6rmig) ball. The judicious modifications
and improvemedts it has finally received in Mr. Lovell's hands, have brought out all its




724                               FIRE ARMS.
advantages, and rendered it, when skilfully used, a weapon of unerring aim, even at the
prodigious distance of 700 yards.
The locks, also, for the military service generally, are now receiving an important improvement by means of his labors, having been simplified in a remarkablemanner. The
action of the main spring is reversed, as shown byfig. 554; thus rendering the whole
mechanism more solid, compact, and convenient; while the ignition of the charge
being effected by percussion powders in a copper cap, the fire of the British line will,
in future, be more murderous than ever, as a miss-fire is hardly ever experienced with
the fire-arms made at the Royal manufactury, under Mr. Lovell's skilful superintendence.
Barrel-welding by Machinery.-The barrels of musquets, birding-guns, &c., or what
are called plain, to distinguish them from those denominated stub or twisted barrels,
have of late years been formed by means of rolls, a process in which the welding is
first effected on a short slab of thick iron, and then the barrel is brought down to its
destined length, and form, by repeatedly passing it between a pair of rolls, that have
been previously grooved to the exact shape of the barrel intended to be made.
This method has entirely superseded the skelp-welding by hand described in the
Dic. of Man., p. 471, and is conducted as follows:
The iron being thoroughly refined, and reduced into flat bars by the process described at length at p. 705, is cut by the shears into slabs or lengths of 10 to 12 inches,
and 10 to 101 lbs. weight, or less, according to the description of gun-barrel that is
intended to be made. These slabs are then heated, and bent in their whole length, by
means of conveniently grooved bending rolls, until they assume the form of rough tubes,
555    of the kind of section shown by A, fig. 555. They are then placed c. the
hearth of the reverberatory furnace (Dict. p. 701), and brought to a full
welding heat, and as soon as the edges of a tube come to a semi-fluid state
it is taken out and passed between rolls having grooves somewhat smalle;
in diameter than the exterior of the tube, by which means the tube
is perfectly welded from  end to end; and if care be taken in the
manage ment of the heat, and the juncture be kept clear of dirt and cinders, the iron
will be found perfectly homogeneous in every part, and there will be no appearance
whatever of the seam where the edges came together. These tubes are repeatedly
heated, and passed between the barrel rolls, which are of sufficient diameter to admit
of gradually decreasing grooves, the whole length of the intended barrel being indented
on their surfaces.
To preserve the tubular form, and insure regularity in the size of the bore during
the welding process, they are taken out of the furnace, bv thrusting into them a tool
called a mandril B, which consists of a long rod of iron, having a short steel treblett on
its end, of the diameter that the bore of the barrel is meant to bore. This rod is so
adjusted by means of a strong iron plate c, near its handle, which is of wood, and long,
that when passed with the heated tube on it between two tranverse holding bars, the
short steel treblett D, shall be found exactly between the point of impact of the barrelrolls, E E.
The adhesion of the hot iron to the surface of the rolls is strong enough to draw the
tube off the mandril, which thus keeps the bore open from end to end, and by repeating
the process through the whole series of grooves in the rolls, the barrel is gradually
elongated, and brought down to the exact form required: any superfluous length at the
muzzle is then cut off. The breach end is then adjusted by the hammer-a tripple-seat
welded on by hand jT it be intended for a percussion lock, and then the barrel is ready
to go forward to the mill to be bored, turned, and finished.
Gun-barrels formed by this mechanical method are found to stand proof better than
those worked by hand, because the heat is more equalized; and any imperfections in
the original mass of iron are more dispersed over the whole extent of the tube.
Mr. Wells Ingram, of Bradford street, Birmingham, has lately perfected a very complete lathe for turning the exterior of gun-barrels of all descriptions, a process which is




FIRE ARMS.                                    725
fast superseding the use of the grindstone, for equalising the barrels of all kinds of firearms.
I am indebtedfor this article to Mr. Lovell, Director of the Royal Arms Manufactory.
See MUSQUEt.
Since the first edition of the Dictionary large strides have been made towards increasing the efficacy of military fire arms; the French had found in their skirmishes
with Abd-el-Kader in Africa, that the long matchlocks of the Arabs told at fearful odds
against their men at distances where the ordinary French musquet was powerless of
offence.
After a while it was found that this increased range was due solely to the greater
elevation taken by the natives in aiming, and their expertness in judging their distances, taught by long practice and experience; for the Arab arms and ammunition
taken at Constantine were found of the rudest construction.
These observations led the French officers of artillery to institute all sorts of experiments to render their small arms more effective; by the adoption of wall-pieces of
wider bore; by introducing a more general use of rifled barrels, but at the same time
avoiding the tedious method of loading by means of mallets formerly observed with
such kind of arms.
The first attempt towards such object was that proposed by M. Delvigne, an officer
of the royal ex-guardfi, ig, 557), in which the upper orifice of the chamber that
~) ix ) ^~~~) p557
contained the powder took the form of a cup, wherein the ball (somewhat wider in
diameter) was received, and by two or three smart blows of a heavy-headed rammer (also
cupped out for the purpose) became expanded latterly, and thus the rotary motion was
imparted to it by the spiral grooves of the barrel in passing out.  Colonel Poncharra
suggested the addition of a wood bottom or sabot under the ball and a greased woollen
patch; and Colonel Thouvesino proposed (fig. 558) a steel stem or pillar about 2 inches
558
long inserted into the face of the breech-pin; round this pin, the charge of powder was
received, and the diameter of the ball, when resting on the top of the pin was enlarged
by the blows of the heavy-headed rammer, as suggested by Delvigne.
This system took the name of " Carabine a Tige," and has been very generally intro.
duced for the service of fusilier battalions in continental armies; very grave objections,
however, have been found against it in use, from the impossibility of keeping the
chamber (or post round the pin) clear; and from  the severe labor to the soldier in
ramming down and enlarging the diameter of the ball sufficiently to ensure the rotary
motion desired.
But if the ultimate results thus attained with spherical balls turned out not entirely
satisfactory, it was made clearly manifest, in the course of the experiments carried on,
that no insuperable difficulty stands in the way of rendering the fire of infantry very
much more accurate and powerful, by the use of rifled barrels throughout the army,
and thus leading to a verification of the prediction made by Robins above one hundred
years ago, that "whatever state shall thoroughly comprehend the nature and advantages of rifled barrel pieces, and having facilitated and completed their construction,
shall introduce into their armies their general use, with dexterity in the management
of them, will by this means acquire a superiority which will almost equal any thing
that has been done at any time."
But besides smoothing the way to such an essential improvement, it has been elicited
of late years, that when the accuracy of flight is secured by the rotary motion derived
from the rifling, the bullet, instead of being limited to the form of a sphere as heretofore, may, up to certain limits, be elongated with considerable increase of destructive effect; and with an augmentation of range very much beyond anything that has hitherto been considered to lie within the reach of small arms-placing them, in fact, with
reference to artillery and cavalry, in the first place instead of the last
An immensely extended field has thus been opened to experimenters, 1st Mons.
Didon proposed a true oval (fig. 559) as the best form of bullet, so that when shortened
by the blows of the heavy rammer and widened in its diameter it might be brought
nearer to the spherical shape before leaving the barrel.




726                                   FIRE ARMS.
2d. Mona Delvigne took a patent for a bullet (fig. 560) under the designation of
"Cylindro Ogivale;" it had a conical opening behind, in which he imagined that Ile
force of the powder would exert itself with sufficient energy to expand the lead permanently, and so make the ball take the rotary movement derived from the rifling, without any fatigue to the soldier in loading; with this projectile, indeed, the operation is
but slightly more difficult than with the ordinary cartridge and smooth barrels.
559              560                561                 562563
The bullet (fig. 561) of the "Carabine a Tige" was called   Cylindro Conique," and
was said to possess this advantage over the preceding, that, being brought more to a
point in front, it bored its way through the air with greater ease, and thus retained
greater velocity, and of course more extended range; and with this bullet it was that
Mons. Tamisier introduced three sharp-edged channels round it, which he stated were
necessary to keep its flight steady, by offering a resistance to the action of the air.
Finally Mons. Mini6, an officer of the French line, suggested (fig. 562) the addition of
a denoyau or culot to the hollow ball of Delvigne. This, in the form ot a little cup
made of sheet iron, is placed in the orifice of the conical hollow of the ball behind, and
by the energy of the powder is driven into the ball, enlarging its diameter permanently,
and thus giving all the accuracy of the rifle, with nearly the same facility of loading as
with the plain barrel.
The principle of the invention, as thus developed, has, we learn, been adopted by our
government for the general use of the army, seeing that it offers so great advantages
over the system of plain barrels, but the bullet (fig. 563), as modified by the Inspector
of Small Arms, has on its exterior no channels, they being found not only useless as to
steadying the flight of the projectile, but absolutely injurious in lowering its velocity.
The bullet in its improved form, too, being more truly balanced in its proportions, and
made by mechanical means instead of by casting, has no tendency to the gyrations
which appear to have so puzzled French artillerists, and for which they have invented
the word " derivation," and wasted much learned disquisition.
Though well satisfied with the results of their course of experiments, our neighbors,
however, do not appear to have come to any final decision as yet; indeed, the fact of
being able to make use of an elongated projectile with a rifle has let loose such a crowd
of inventors, that they seem to be entirely bewildered. In Switzerland every Canton
has its pecuilar form of bullet, each one, of course, being the best, and from the length
and size of a small caterpillar upwards, every man seems to have his own maggot,
which he vaunts before the world.
But even if it were ever to happen, which is not likely, that these various projectors
could be brought to agree as to the best form of projectile, they will then find out,
that although by the general introduction of rifled and elongated bullets an immense
advantage has been realised over plain barrels, their plans, based as they all are upon
a system of loading at the muzzle, are at best but one step in advance; and that a good
sound military fire-arm loading at the breech will, after all, remain the great desideratum-an arm that, without any less accuracy or power to reach masses of artillery or
cavalry at a thousand yards' distance, will enable the soldier to triple the quantity of
his fire at any moment that he may be called upon to repel a charge of cavalry or at
tack or defend a breach at close quarters; of such simple construction, and so easily
handled in every position of the body, that the soldier can pour every shot of his most
murderous fire upon the enemy with unerring precision, whilst he himself may lay
coolly behind a stone or in a ditch in entire security.
These are no longer wild imaginings, although so many hundreds of attempts towards
the same object, from the earliest period to the present day, have been one alter another
seen invariably to fail. The Germans have been long and steadily pursuing the great
object, until at length Herr Dreysa, of Sbmmerda in Thuringia, has succeeded, after
more than twenty years of continued labor, in establishing a musquet, under the name




FIRE-WORKS.                                         727
of "Zimndnadelgewehr," which if not quite perfect, has been found to work so well in
the bands of the men, that the Prussian government has already 80,000 in possession,
and they are going on to arm the whole of their line regiments and Landwehr with
them.
Even with the assistance of a diagram, it is hardly possible to convey a clear notion
of the construction of this musquet, because the several parts work one within the
other, and their combination, which is without pin or screw, is hard to comprehend by
a mere description.
There is a strong socket fig. 564), a, open on the upper side, screwed on to the barrel,
564
b, which is rifled in the usual manner; within this socket is a slider c, which in fact
constitutes the lock, as it contains the spiral spring and mechanism that produces
ignition by percussion; it has a stout hebel or handle, by which it is moved backwards
and forwards freely.
The cartridge (fig. 565) consists of the ball a, the sabot b, or bottom of hardpaper, and
holding the priming matter, and lastly the charge of powder, c, the whole
being made up in paper pasted together.  In use, the slider being drawn
back, the soldier puts the cartridge with the point of the ball in front into
the open breech of the barrel, pushes the slider forward, and secures its close
junction by a turn to the right against an inclined edge of the open socket.
The spiral spring is then brought into action (or the gun is cocked) by
pressing the spring case forward with the thumb.
On pulling the trigger, the interior needle, from which the musquet takes
its name, is darted forward through the charge of powder into the percusb    I sion. primer in the sabot, and thus effects the ignition inside the barrel.
The principle of loading at the breech carries with it so many other
advantages beyond that by the muzzle, that many ingenious men are occupying  themselves with its imtprovement;  Lefaucheur and Robert in
France; Montigny in Belgium; Kufahl Schultz and Friedrix in Prussia;
c     Sears and Needham in England, have lately brought forward various plans;
and now that the idea is taken up upon a right base, there can be little
doubt that eventually a system will be hit upon, that shall secure all the
requisites for military service, and avoid all objections.
But it is clear, from the recent publications on gunnery and the observations of ancient
warriors, that the advocates for heavy battalion movements, for drawing up their
infantry in long lines and compact bodies for destruction by artillery, will be with
difficulty brought to look with patience upon the scrambling and desultory sort of
warfare which the general introduction of these improved rifles must bring about.
Time, however, daily goes on to work wonders upon prejudice, and the day will come
when it will be found that cross-belts and blank-cartridges may be abolished without
utter ruin to the army; and that men behind trees, with effective weapons in their
hands, may be more dangerous enemies, at long ranges, than when strapped up and
paraded out in masses, and-carrying arms that at any distance over 300 are powerless
of offence.
FIRE-DAMP; the explosive carburetted hydrogen of coal mines.  See PITCOAL.
FIRE-WORKS.  (Feux d'artifice, Fr.; Feuerwerke, Germ.)  The composition  of
luminous devices with explosive combustibles, is a modern art resulting from the discovery of gunpowder. The finest inventions of this kind are due to the celebrated
Ruggieri, father and son, who executed in Rome and Paris, and the principal capitals of
Europe, the most brilliant and beautiful fire-works that were ever seen. The following
description of their processes will probably prove interesting to many of my readers.
The three prime materials of this art are, nitre, sulphur, and charcoal, along with filings
of iron, steel, copper, zinc, and resin, camphor, lycopodium, &c. Gunpowder is used
either in grain, half crushed, or finely ground, for different purposes. The longer the iron
filings, the brighter red and white sparks they give; those being preferred which are
made with a very coarse file, and quite free from rust. Steel filings and cast-iron borings contain carbon, and afford a more brilliant fire, with wavy radiations. Copper
filings give a greenish tint to flame; those of zinc a fine blue color; the sulphuret of
antimony gives a less greenish blue than zinc, but with much smoke; amber affords
a yellow fire, as well as colophony, and common salt; but the last must be very dry.
Lampblack produces a very red color with gunpowder, and a pink with nitre in excess.




728                                FIRE-WORKS.
It serves for making golden showers. The yellow sand or glistening mica, communicates
to fire-works golden radiations. Verdigris imparts a pale green; sulphate of copper and
sal-ammoniac, a palm-tree green. Camphor yields a very white flame and aromatic fumes,
which mask the bad smell of other substances.  Benzoin and storax are used also on
account of their agreeable odor. Lycopodium burns with a rose color and a magnificeni
flame; but it is principally employed in theatres to represent lightning, or to charge the
torch of a fury.
Fire-works are divided into three classes: 1. those to be set off upon the ground; 2.
those which are shot up into the air; and 3. those which act upon or under water.
Composition for jets offire; the common preparation for rockets not more than  of an
inch indiameter, is; gunpowder, 16 parts; charcoal, 3 pauts. For those of larger diam<
eter; gunpowder, 16; steel filings, 4.
Brilliant revolving wheel; for a tube less than I of an inch; gunpowder, 16; steel
filings, 3. When more than I: gunpowder, 16; filings, 4.
Chinese or Jasmine fire; when less than I of an inch: gunpowder, 16; nitre, 8; charcoal (fine), 3; sulphur, 3; pounded cast-iron borings (small), 10. When wider than I:
gunpowder,, 16; nitre, 12; charcoal, 3; sulphur, 3; coarse borings, 12.
fixed brilliant; less than I in diameter: gunpowder, 16; steel filings, 4; or, gunpowder,, 16; and finely pounded borings, 6.
Fixed suns are composed of a certain number of jets of fire distributed circularly, like
the spokes of a wheel. All the fusees take fire at once through channels charged with
quick matches. Glories are large suns with several rows of fusees. Fans are portions
of a sun, being sectors of a circle. The Patte d'oie is a fan with only three jets.
The mosaic represents a surface covered with diamond shaped compartments, formed
by two series of parallel lines crossing each other. This effect is produced by placing at
each point of intersection, four jets of fire, which run into the adjoining ones.  The intervals between the jets must be associated with the discharge of others, so as to keep
up a succession of fires in the spaces.
Palm trees.  Ruggieri contrived a new kind of fire, adapted to represent all sorts of
trees, and especially the palm.  The following is the composition of this magnificent
green fire-work: crystallized verdigris, 4 parts; sulphate of copper, 2; sal-ammoniac, 1.
These ingredients are to be ground and moistened with alcohol. An artificial tree of any
kind being erected, coarse cotton rovings about 2 inches in diameter, impregnated with
that composition, are to be festooned round the trunk, branches, and among the leaves;
and immediately kindled before the spirits have had time to evaporate.
Cascades imitate sheets or jets of water.  The Chinese fire is best adapted to such
decorations.
Fixed stars. The bottom of a rocket is to be stuffed with clay, and one diameter in
height of the first preparation being introduced, the vacant space is to be filled with the
following composition, and the mouth tied up. The pasteboard must be pierced into the
oreparation, with five holes, for the escape of the luminous rays, which represent a star.
Composition of fixed stars
Ordinary.    Brighter.       Colored.
Nitre -        -      -  16             12             0
Sulphur       -       -   4              6             6
Gunpowder meal        -   4            12             16
Antimony    -         -   2              1             2
Lances are long rockets of small diameter, made with cartridge paper. Those which
burn quickest should be the longest. They are charged by hand without any mould,
with rods of different lengths, and are not strangled at the mouth, but merely stuffed with
a quick match of tow. These lances form the figures of great decorations; they are
fixed with sprigs upon large wooden frame works, representing temples, palaces, pagodas, &c. The whole are placed in communication by conduits, or small paper cartridges
like the lances, but somewhat conical, that they may fit endwise into one another to any
extent that may be desired. Each is furnished with a match thread fully II inches long,
at its two ends.
Composition for the white lances: nitre, 16; sulphur, 8; gunpowder, 4 or 3. For a
bluish-white: nitre, 16; sulphur, 8; antimony, 4. For blue lances: nitre, 16; antimony,
B. For yellow: nitre, 16; gunpowder, 16; sulphur, 8; amber, 8. For yellower ones:
nitre, 16; gunpowder, 16; sulphur, 4; colophony, 3; amber, 4. For greenish ones: nitre,
16; sulphur, 6; antimony, 6; verdigris, 6. For pink lances: nitre, 16; gunpowder, 3;
lampblack, 1.  Others less vivid are made with nitre, 16; colophony, 3; amber, 3; lycopodium, 3.
Cordage is represented in fire-works, by imbuing soft ropes with a mixture cf nitre, 2;
sulphur, 16; antimony, I; resin of juniper, 1.




FIRE-WORKS.                                         729
The Bengal flames rival the light of day.  They consist of, nitre, 7; sulphur, 2; an.
timony, 1. This mixture is pressed strongly into earthen porringers, with some bits
of quick match strewed over the surface. These flames have a fine theatrical effect for
conflagrations.
Revolving suns, are wheels upon whose circumference rockets of different styles are
fi~xed, and which communicates by conduits, so that one is lighted up in succession after
another.  The composition of their common fire is, for sizes below I of an inch: gunpowder meal, 16; charcoal, not too fine, 3. For larger sizes: gunpowder, 20; charcoal, not too fine. 4. Forfiery radiations: gunpowder, 16; yellow micaceous sand, 2
or 3.  For mixed radiations: gunpowder, 16: pitcoal, 1; yellow sand, I or 2.
The waving or double Catherine wheels, are two suns turning about the same axis in
opposite directions. The fusees are fixed obliquely and not tangentially to their peripheries. The wheel spokes are charged with a great number of fusees; two of the four
wings revolve in the one direction, and the other two in the opposite; but always in
a vertical plane.'The girandoles, caprices, spirals, and some others have on the contrary a horizontal
rotation. The fire-worker may diversify their effects greatly by the arrangement and
color of the jets of flame. Let us take for an example the globe of light. Imagine a
large sphere turning freely upon its axis, along with a hollow hemisphere, which revolves also upon a vertical axis passing through its under pole. If the two pieces be
covered with c'olored lances or cordage, a fixed luminous globe will be formed, but if
horizontal fusees be added upon the hemisphere, and vertical fusees upon the sphere,
the first will have a relative horizontal movement, the second a vertical movement,
which being combined with the first, will cause it to describe a species of curve, whose
effect will be an agreeable contrast with the regular movement of the hemisphere.
Upon the surface of a revolving sun, smaller suns might be placed, to revolve like satellites round the primaries.
Ruggieri exhibited a luminrous serpent pursuing with a rapid, winding pace a butterfly which flew continually before it. This extraordinary effect was produced in the
following way.  Upon the summits of an octagon he fixed eight equal wheels turning
freely upon their axles, in the vertical plane of the octagon. An endless chain passed
round their circumference, going from  the interior to the exterior, covering the outside semi-circumference of the first, the inside of the second, and so in succession;
whence arose the appearance of a great festooned circular line.  The chain like that of
a watch, carried upon a portion of its length a sort of scales pierced with holes for receiving colored lances, in order to represent a fiery serpent. At a little distance there
was a butterfly constructed with white lances. The. piece was kindled commonly by
other fire-works, which seemed to end their play, by projecting the serpent from the
bosom of the flames. The motion was communicated to the chain by one of the wheels,
which received it like a clock from the action of a weight. This remarkably curious
mechanism was called by the artists a salamander.
The rockets which rise into the air with a prodigious velocity, are among the most
common, but not least interesting fire-works.  When employed profusely they form
those rich volleys of fire which are the crowning ornaments of a public fete. The
cartridge is similar to that of the other jets, except in regard to its length, and the necessity of pasting it strongly, and planing it well; but it is charged in a different manner.  As the sky-rockets must fly off with rapidity, their composition should be such
as to kindle instantly throughout their length, and extricate a vast volume of elastic
fluids. To effect this purpose, a small cylindric space is left vacant round the axis;
that is, the central line is tubular. The fire-workers call this space the soul of the rocket
(ame de lafusie).  On account of its somewhat conical form, hollow rods, adjustable to
different sizes of broaches or skewers, are required in packing the charge; which must
be done while the cartridge is sustained by its outside mould, or copper cylinder. The
composition of sky-rockets is as follows (see next page).
The cartridge being charged as above described, the pot must be adjusted to it, with
the garniture; that is, the serpents, the crackers, the stars, the showers of fire, &c.
The pot is a tub of pasteboard wider than the body of the rocket, and about one-third
of its length. After being strangled at the bottom like the mouth of a phial, it is attached to the end of a fusee by means of twine and paste. These are afterward covered
with paper.  The garniture is introduced by the neck, and a paper plug is laid over it.
The whole is enclosed within a tube of pasteboard terminating in a cone, which is firmly
pasted to the pot. The quick-match is now finally inserted into the soul of the rocket.
The rod attached to the end of the sky-rockets to direct their flight, is made of willow
or any other light wood. M. Ruggieri replaced the rod by conical wings containing
explosive materials, and thereby made them fly further and straighter.
The garnitures of the sky-rocket pots are the following:1. Stars are small, round, or cubic solids, made with one of the following compo



730                                FISH-HOOKS.
When the bore is            of an inch;            to 174;           l;
Nitre  -       -       -            16                  16                  16
Charcoal       -                     7                   8                  9
Sulphur        -                     4         4                   4
Brilliant Fire.
Nitre  -       -       -            16                  16                  16
Charcoal               -             6                   7                  8
Sulphur                -             4                   4                   4
Fine steel filings     -             3                   4                   5
Chinese Fire.
Nitre  -       -       -            16                  16                  16
Charcoal               -             4                   5                   6
Sulphur        -       -             3                   3                   4
Fine borings of cast-iron            3 coarser           4 mixed             5
sitions, and soaked in spirits. White stars, nitre, 16; sulphur, 8; gunpowder, 3. Others
more vivid consist of nitre, 16; sulphur, 7; gunpowder 1.
Stars for golden showers, nitre, 16; sulphur, 10; charcoal, 4; gunpowder, 16; lamp.
black, 2. Others yellower are made with nitre, 16; sulphur, 8; charcoal, 2; lampblack,
2; gunpowder, 8.
The serpents are small fusees made with one or two playing cards; their bore being
less than half an inch.  The lardons are a little larger, and have three cards; the e.
tilles are smaller. Their composition is, nitre, 16; charcoal, not too fine, 2; gunpowder
4; sulphur, 4; fine steel filings, 6.
The petards are cartridges filled with gunpowder and strangled.
~The saxons are cartridges clayed at each end, charged with the brilliant turning fire,
and perforated with one or two holes at the extremity of the same diameter.
The cracker is a round or square box of pasteboard, filled with granulated gunpowder,
and hooped all round with twine.
Roman candles are fusees which throw out very bright stars in succession.  With the
composition (as under) imbued with spirits and gum-water, small cylindric masses are
made, pierced with a hole in their centre. These bodies, when kindled and projected
into the air, form the stars. There is first put into the cartridge a charge of fine gun.
powder of the size of the star; above this charge a star is placed; then a charge of
composition for the Roman candles.
The stars, when less than A of an inch, consist of nitre, 16; sulphur, 7; gunpowder, o.
When larger, of nitre, 16; sulphur, 8; gunpowder, 8.
Roman candles, nitre, 16; charcoal, 6; sulphur, 3. When above I of an inch, nitre,
16; charcoal, 8; sulphur, 6.
The girandes, or bouquets, are those beautiful pieces which usually conclude a fireWork exhibition; when a multitude of jets seem to emblazon the sky in every direction,
and then fall in golden showers. This effect is produced by distributing a number of
cases open at top, each containing 140 sky-rockets, communicating with one another
by quick-match strings planted among them. The several cases communicate with each
other by conduits, whereby they take fire simultaneously, and produce a volcanic display.
The water fire-works are prepared like the rest; but they must be floated either by*
wooden, bowls, or by discs and hollow cartridges fitted to them.
Blue fire for lances may be made with nitre, 16; antimony, 8; very fine zinc filings, 4.
Chinese paste for the stars of Roman candles, bombs, &c.:-Sulphur, 16; nitre, 4;
gunpowder meal, 12; camphor, 1; linseed oil, 1; the mixture being moistened with
spirits.
The feu grigois of Ruggieri, the son:-Nitre, 4; sulphur, 2; naptha, 1. See PYROTECHNY and ROCKETS.
The red fire composition is made by mixing 40 parts of nitrate of strontia, 13 of flowers
of sulphur, 5 of chlorate of potash, and 4 of sulphuret of antimony.
White fire is produced by igniting a mixture of 48 parts nitre; 131 sulphur; 7^ sulphuret of antimony; or, 24 nitre, 7 sulphur, 2 realgar; or, 75 nitre, 24 sulphur, I cAarcoal; or, finally, 100 of gunpowder meal, and 25 of cast-iron fine borings.
The blue fire composition is 4 parts of gunpowder meal; 2 of nitre; sulphur and
zinc, each 3 parts.
FISH-HOOKS  (Hamecons, Fr.; Fishangeln, Germ.) are constructed with  simple
tools, but require great manual dexterity in the workmen. The iron wire of which they




FLANNEL.                                      731
they are made should be of the best quality, smooth and sound. A bundle of such
wire is cut in lengths, either by shears or by laying it down upon an angular wedge of
hard steel fixed horizontally in a block or anvil, and striking off the proper lengths by
the blows of a hammer. In fashioning the barbs of the hooks, the straight piece of wire
is laid down in the groove of an iron block made on purpose, and is dexterously struck
by the chisel in a slanting direction, across so much of the wire as may be deemed
necessary. A sharp-pointed little wedge is thus formed, whose base graduates into the
substance of the metal.
The end of the wire where the line is to be attached is now flattened or screw-tapped;
the other end is sharp pointed, and the proper twisted curvature is given. The soft iron
hooks are next case-hardened, to give them the steely stiffness and elasticity, by imbedding them in animal charcoal contained in an earthen or iron box; see CASE-HARDENING; after which they are brightened by heating and agitating them with bran, and
finally tempered by exposure to a regulated temperature upon a hot iron plate. Hooks
for salt-water fishing are frequently tinned, to prevent them wearing rapidly away in
rust. See TIN PLATE.
FLAKE WHITE is the name sometimes given to pure white-lead.
FLAME (Flumme, Fr. and Germ.) is the combustion of an explosive mixture of an
inflammable gas or vapor with air. That it is not, as many suppose, combustion merely
at the exterior surface, is proved by plunging a fragment of burning phosphorus or sulphur into the centre of a large flame of alcohol.'Either of these bodies will continue to
burn there with its peculiar light; thus proving that oxygen is mixed with the whole of
the burning vapor. If we mix good coal gas with as much atmospheric air as can convert all its carbon into carbonic acid, the mixture will explode with a feeble blue light;
but if we mix the same gas with a small quantity of air, it will burn with a rich white
flame. In the latter case the carbonaceous particles are precipitated, as Sir H. Davy
first showed, in the interior of the flame, become incandescent, and constitute white
light: for from the ignition of solid matter alone can the prismatic rays be emitted in
that concentrated union. Towards the interior of the flame of a candle, a lamp, or a gas
jet,, where the air is scanty, there is a deposition of solid charcoal, which first by itsignition, and afterwards by its combustion, increases in a high degree the intensity of the
light. If we hold a piece of fine wire gauze over a jet of coal gas close to the orifice,
and if we then kindle the gas, it will burn above the wire with its natural brilliancy;
but if we elevate the gauze progressively higher, so as to mix more and more air with it
before it reaches the burning point, its flame will become fainter and less white. At a
certain distance it becomes blue, like that of the above explosive mixture. Since the
combustion of all the constituents is in this case direct and complete, the heat becomes
greatest in proportion nearly as the light is diminished. If a few platina wires be held
in that dim flame they will grow instantly white hot, and illuminate the apartment. On
reversing the order of this experiment, by lowering progressively a flat piece of wire
gauze from the summit towards the base of a gas flame, we shall find no charcoal deposited at its top, because plenty of air has been introduced there to convert all the carbon
of the gas into carbonic acid, and therefore the apex is blue; but as we descend, more
and more charcoal will appear upon the meshes. At the very bottom, indeed, where the
atmospheric air impinges upon the gauze, the flame is again blue, and no charcoal can
therefore be deposited.
The fact of the increase of the brilliancy and whiteness of flame by the developmen
and ignition of solid matter in its bosom illustrates many curious phenomena. We can
thus explain why olefiant gas affords the most vivid illumination of all the gases; because,
being surcharged with charcoal, its hydrogen lets it go in the middle of the flame, as it
does in an ignited porcelain tube, whereby its solid particles first get ignited to whiteness, and then burn away. When phosphorus is inflamed it always yields a pure white
light, from the ignition of the solid particles of the snowy acid thus produced.
In the blowpipe the inner blue flame has the greatest heat, because there the combustion of the whole fatty vapor is complete. The feeble light of burning hydrogen, carbonic oxyde, and sulphur, may, upon the principles now expounded, be increased by
simply placing in them a few particles of oxyde of zinc, slender filamants of amianthus, or
fine platina wire. Upwards of twenty years ago I demonstrated, in my public lectures
in Glasgow, that by narrowing the top of a long glass chimney over an argand flame
either from oil or coal gas, the light could be doubled at the same cost of material. The
very tall chimneys used by the Parisian lampists are very wasteful. I find that with a
narrow chimney of half the length of theirs, I can have as good a light, and save 30 per
cent. of the oil. Thus the light of a flame may be increased by diminishing its heat, or
the intensity of its combustion; and conversely the heat of a flame may be increased by
diminishing its light.
FLANNEL; a plain woollen stuff, of a rather open and slight fabric.




732                                        FLAX.
FLAX.  The general appellation of the fibrous produce used in the manufacture of
linen threads, &c, of the plant Linum usitatissimum, which is cultivated, not for this
produce only, but for that of its seed, employed in agriculture for feeding and fattening cattle, as well as in commerce for making the oil so well known as "linseed
oil."
This plant grows to the height of 2 or 3 feet, having a round and hollow stem, which
divides into several branches, bearing blue flowers; these become the seed-pods of 10
cells, each of which contains one seed.  As varieties, we distinguish the "spring" flax
with short knotty stems, whose seed capsules at the period of maturity open with a
perceptible sound; and the "close" flax, with longer, smoother stems, whose capsules
give out the seed only when thrashed; the latter variety is the one most generally cultivated. Owing to the many improvements recently made in the various processes of
the flax manufacture, all the operations for converting the raw plant to its ultimate
useful and ornamental state have been greatly simplified and facilitated, and much attention has been paid to improving its cultivation, which has necessarily produced
many changes in the formerly established modes of husbandry.
Flax may be grown upon a great variety of soils: the best is a sound, dry, deep loam,
with a clay subsoil; this should be properly drained, as too much underground or surface
water is alike injurious. It is necessary that the land should be brought to an exceedingly fine state by frequent ploughings and harrowings, commenced in the autumn
previous to the sowing, which should take place toward the end of March, or beginning of April.  From  2 to 2- bushels of seed  are required  for one acre: the
seed selected should be of a bright brown color, heavy, shining, and of an oily feel,
avoiding such as have hard ends. Riga is the best for the greatest variety of soils,
though Dutch is frequently used with great success. American does not generally suit,
as it is apt to produce a coarse, branchy stem. The manner of sowing should be varied
according to the purpose for which the crop is intended. When grain is the object of
the grower, the sowing should be thin, as the plants then put out more branches, and
thus yield more seed, but the fibrous produce becomes soft and meagre; the contrary
is the case when the sowing is thick. Being one of the most tender plants offield cultivation, it requires very peculiar care in weeding, so as not to be injured by either the
neglect or excess of this work, which should be done when the plants are about 3
inches high, that is, about a month after sowing. Guano and bone dust are suitable
manures if farm dung is scarce.  The following artificial manure, it has been said, will
replace chemically the constituents of the plants produced from an acre of land, viz:Muriate of potash         -        -       -       -        30 lbs.?
Common salt   -           -        -       -       -        28 lbs.
Burned gypsum, powdered            -       -        -       34 lbs.
Bone dust         -       -        -       -        -       54 lbs.
Sulphate magnesia          -5 —                     -        6 lbs.
The average produce of seed is 12 bushels to the acre.
In regard to flax being considered a wasting crop for the land there are some observations to be made that may controvert that idea and establish one more sound in
its place.
Assuming that the ashes of plants left after they are consumed by fire form  a
criterion of the quantity of nutritive matter they have extracted from the soil, there
may at first sight appear much truth in the prevailing opinion as to the exhausting nature of the flax crop, since the ashes of this plant are 50. of the whole, which
is a large proportion. But as no ashes result from burning -the pure fibre, which
is solely the part that may not be reconsumed  upon the land, it proves that the
fertility of the soil is not injured by that production.  The nutrition withdrawn
by the other parts can be as easily replaced by this plant as by any other, ~9~ths by
the water alone in which the steeping is to be afterward carried on, and which should
therefore be kept and employed as a liquid manure, to which must be added that
more solid resulting from  feeding cattle on the seed or oil cake, and from  the ashes
of the chaff, and thus a far greater part of the constituent of this plant is returned
than of almost any other. Though the color of the flax is rather improved by letting
the water run in a small stream through the steeping-pond during the operation, yet
perhaps it may be a greater object to retain it for manure than to waste it for that purpose.
Whenever the flax is ripe, which is shown by the bottom of the stalk becoming yellow, and the leaves beginning to drop off, it must be immediately reaped by pulling it
up by the roots. The seeds are still immature, fit merely for the oil press, and not for
sowing.  When the seed crop is the object, the plant must be suffered to acquire its
full maturity; in which case the fibres are less fine and soft.
The flax is carried off the field in bundles to be rippled, or stripped of its seeds, which




FLAX.                                       733
is done by drawing it by hAfidfuls, through an iron comb with teeth eight inches long,
fixed upright in a horizontal beam. When the seeds are more fully ripened, they may
be separated by the thrashing mill.
The operations next performed upon the flax will be understood by attending to the structure of the stem.  In it two principal parts are to be distinguished; the woody heart or
boon, and the hal (covered outwardly with a fine cuticle), which encloses the former
like a tube, consisting of parallel lines. In the natural state, the fibres of the harl are
ched firmly, not only to the boon, but to each other, by means of a green or yellowish,)stance. The rough stems of the flax, after being stripped of their seeds, lose in moisre, by drying in warm air, from 55 to 65 per cent. of their weight; but somewhat less,hen they are quite ripe and woody. In this dry state they consist in 100 parts of from
0 to 23 per cent. of harl, and from 80 to 77 per cent. of boon. The latter is composed
wpon the average of 69 per cent. of a peculiar woody substance, 12 per cent. of a matter
luble in w'ater, and 19 per cent. of a body not soluble in water, but in alkaline leys..he harl contains at a mean 58 per cent. of pure flaxen fibres, 25 parts soluble in water
(apparently extractive and albumen), and 17 parts insoluble in water, being chiefly
gluten. By treating the harl with either cold or hot water, the latter substance is dyed
brown by the soluble matter, while the fibres retain their coherence to one another
Alkaline leys, and also, though less readily, soap water, dissolve the gluten, which seems
to be the cement of the textile fibres, and thus set them free.
The cohesion of the fibres in the rough harl is so considerable that by mechanical
means, as by beating, rubbing, &c., a complete separation of them cannot be effected,
unless with great loss of time and rupture of the' filaments.   This circumstance
shows the necessity of having recourse to some chemical method of decomposing the
gluten. The process employed with this view is a species of fermentation, to which the
flax stalks are exposed; it is called retting, a corruption of rotting, since a certain degree
of putrefaction takes place. The German term is rusting.  This is the first important
step in the preparation of flax. After the retting is completed, the boon of the stalks
must be removed by the second operation called breaking, and other subordinate processes. The harl freed from the woody parts contains still a multitude of fibres, more or less
coherent, or entangled, and of variable lengths, so as to be ill adapted for spinning. These
are removed by the heckle, which separates the connected fibres into their finest filaments,
removes those that are too short, and disentangles the longer ones.
1. Of retting.-The fermentation of this process may be either rendered rapid by steeping the flax in water, or slow by using merely the ordinary influence of the atmospheric
damp, dews, and rain. Hence the distinction of water-retting and dew-retting.  Both
may also be combined.
Prior to being retted, the flax should be sorted according to the length and thickness of
its stalks, and its state of maturity: the riper the plant, the longer must the retting last.
The due length of the process is a point too little studied.
Wafer-retting.-When flax stalks are macerated in water, at a temperature not too
low, fermentation soon begins, evinced in the dingy infusion, by disengagement of
carbonic acid gas, and the production of vinegar. If the flax be taken out at the end of
a few days, dried, and rubbed, the textile filaments are found to be easily separable from
each other. By longer continuance of the steep, the water ceases to be acid, it becomes
to a certain degree alkaline, from the production of ammonia, diffuses a fetid odor, from
the disengagement of sulphureted hydrogen gas, along with the carbonic acid; the acetous
fermentation being in fact now changed into the putrid. The filaments become yellowish
brown, afterwards dark brown, and lose much of their tenacity, if the process be carried
further.
When the operation is conducted with discernment, the water-retting may be completed
by the acetous fermentation alone, as the putrefaction should never be suffered to proceed
to any length; because when over-retted, flax is partially rotten, gets a bad color, and
yields a large proportion of tow.
For water-retting, the flax must be bound up in sheaves, placed in layers over each
other in the water, or sometimes upright, with the roots undermost. Straw may be put
below to keep it from touching the ground, and boards may be laid upon the top, with
weights to hold it immersed about a foot beneath the surface, especially when the fermentative gases make it buoyant. As soon as it sinks at the end of the fermentation, it
must be inspected at least twice a day, and samples must be taken out to see that no
over-retting ensues. A single day too long often injures the flax not a little. We may
judge that the retting is sufficient when the harl separates easily from the boon by the
fingers, when the boon breaks across without bending, and when several stalks knotted
together sink to the bottom upon being thrown into the water. For this completion, a




734                                       FLAX.
shorter or longer time is required according to the quality of the flax, the temperature,
c, so that the term may vary from  five to fourteen days.  It may be done either in
running or in stagnant water. For the latter purpose, tanks five feet deep are dug in the
ground. In stagnant water, the process is sooner finished, but it is more hazardous and
gives a deeper stain to the fibres, than in a stream, which carries off much of the color.
The best place for steeping flax is a pond with springs of water at its bottom; or a
tank into which a rivulet of water can be occasionally admitted, while the foul water
is let off. For every fresh quantity of flax, the pond should be emptied, and supplied
with clear water.  Water impregnated with iron stains flax a permanent color, and
should therefore never be used. After retting, the flax should be taken out without
delay, rinsed in clean water, and exposed in an airy situation to dry by the sun.
Rough rippled flax stalks, well seasoned before being retted, and dried afterward,
show a loss of weight, amounting to 20 or 30 per cent., affecting both the boon and the
harl. This loss is greater the finer the stems, and the longer the retting. The harl
contains, besides the textile filaments, a certain portion of a glutinous cement; but
nothing soluble in water. The destruction of the gluten can not be pushed to the last
point by steeping, without doing an essential injury to the filaments.
Dew-retting.-The fetid and noxious exhalations which the water-retting diffuses
over an extensive district of country, and the danger of over-retting in that way, especially with stagnant water, are far from recommending that process to general adoption. Dew-retting accomplishes the same purpose, by the agency of the air, dews, and
rain, in a much more convenient, though far slower manner. The flax, with this view,
should be spread out thin upon meadow or grass lands, but never upon the bare ground,
and turned over, from time to time, till the stems, on being rubbed between the fingers,
show that the harl and the boon are ready to part. The duration of dew-retting is,
of course, very various, from two to six or eight weeks, as it depends upon the state
of the weather; a moist air being favorable, and dry sunshine the reverse. The loss
of weight by dew-retting is somewhat less than by water-retting; and the textile fibres
are of a brighter color, softer and more delicate to the touch.
Mixed retting.~-This may be fairly regarded as the preferable plan, the retting being
begun iii the water and finished in the air. The flax should be taken out of the steep
whenever the acetous fermentation is complete, before the putrid begins, and exposed,
for two or three weeks, on the grass.
Within the last two years, the hazardous and tedious process  above described has
been attempted to be superseded by steeping the flax plant in vats of water artificially
heated to 70~ Fahr., whereby the effects are produced in sixty or seventy hours. Drying
by fire in kilns is pernicious alike to the seed or fibrous produce; as in the former it
dries up too soon the nutritious particles that would be absorbed by the seed from its
pod or outer covering, and in the latter impairs the rich and oily property of the flax.
The following is a description of an establishment for the prosecution of Mr. Schenck's
process, situated at Newport river, county Mayo. The tenements containing the vats
and drying shelves are simple wooden sheds of cheap construction. In one end of the
building are four vats set parallel to each other the length of the house; they are made
of inch deal in the form of a parallelogram, fifty feet long, six broad, and four deep.
There are false bottoms perforated with holes; underneath these are introduced the
steam-pipes, crossing the vats, and having stop-cocks at their entrance, by which the
steam can be let on from the main pipe as required. The steam is generated in a small
boiler, which also serves to turn two hydro-extractors, a patent apparatus used to drive
off a portion of the water with which the flax is saturated, on being taken from the
vats.  The flax is packed into the empty vats, on the butt ends, in a half sloping
position, precisely as in the case of a steep pool, only one layer being the depth. The
water is then let in, and a frame fastened over the top of the flax, answering the end
of stones and straw or soda in the steeping pools, for prevention of the rising of the
flax in course of fermentation. This process is now renounced.
The steam is then let into the pipes by turning the stop-cocks, and the water is some
eighteen or twenty hours in becoming heated to the required point, 85~ or 90~. The
fermentation then commences, and no further steam  is required, the action going on
until the flax is thoroughly retted, which is in forty hours afterward, being sixty from
the time of the admission of the water. At the end of the sixty hours, the flax is taken
out the water allowed to run off, and the vat permitted to cool. The same process is
then repeated with fresh water and fresh flax. When taken from the water, the flax
is packed in the hydro-extractor, which is a round vessel of iron made to revolve by
steam power with great velocity, the water being driven out of the flax on the principle
of the centrifugal force. Thirty beets or small handfuls are placed in this machine at
a time, and about 20 lbs. of water are extracted in from three to five minutes. A few
hours suffice for the contents of a vat, each vat containing 2 tons of flax straw. The
hydro-extractor only separates a portion of the water; the flax now remains to be




FLAX.                                         735
thoroughly dried.  In summer, or indeed, for six months in the year, this can be
accomplished, as usual, by spreading upon grass land in the open air. During winter,
however, it is necessary to procure other means of drying. A shed has therefore been
erected, communicating by doors with the vat house, filled with ranges of shelves, composed simply of railings of lathwood in five or six tiers.  The flax is spread lightly
along these shelves by women, and the house is heated by steam-pipes.  This house is
capable of drying the full of one vat per diem. The flax, when dried, is made up in
beets or handfuls, of a size suited for feeding into the breaking rollers of the mill.
2. The breaking is performed by an instrument called a brake. In order to give the
wood or boon such a degree of brittleness as to make it part readily from the har],
whereby the execution of this process is rendered easy, the flax should be well dried in
the sun, OF what is more suitable to the late period of the year, in a stove. Such is
often attached to the bakers'ovens in Germany, and otherflax-growing countries.  The
drying temperature should never exceed 120~ F., for a higher heat makes it brittle,
easy to tear, and apt to run into tow.  Before subjecting the flax to the brake, the
stems should be equalized and laid parallel by the hand, and the entangled portions
should be straightened with a coarse heckle. The brake has one general construction,
and consists of two principal parts, the frame or case, and the sword or beater. In the
simplest brakes, the frame e,fig. 566, is a piece of wood cleft lengthwise in the middle,
supported by the legs a and c.  The sword f, also of hard wood, is formed with an edge
beneath, and turns round the centre of motion at q, when seized by the handle h, and
moved up and down. As it descends, the sword enters the cleft of the frame, and breaks
the flax stalks laid transversely upon it, scattering the boon in fragments.
____ <       ^~ 566
7i3
e                         - 
between the two applications.
47




736                                        FLAX.
to the harl which hand mechanisms are apt to do. The following may be regarded as
one of the best constructions hitherto contrived for breaking flax. Fig. 569 is a view
of the right side of this machine. Fig. 570, the view from behind, where the broken
570                                            569
e a  a  ~                     e   
r                                                       )n
flax issues from between the rollers. The frame is formed by the two side pillars or
walls a, a, which are mortised into the bottom b, b; and are firmly fixed to it by
braces. Two transverse rods d, d, secure the base, two others d' d", the sides. In each
of these a lateral arm e, is mortised in an oblique direction; a cross bar f, unites both
arms.  Fig. 571 shows the inside of
571    ^       \_^                    the left side of the frame, with the
subsidiary  parts.  The three rollers,
g, if k, may  be made of red beech,
with  iron  gudgeons, and  fluted  in
their length, each of the flutes being
The  large  roller g, bears upon the
right side, a handle h, which on being
0       Mh               turned, sets the whole train in motion.
The side partitions a, a, are furnished
with brasses in whose round holes, 1, g,
fig. 571, the gudgeons g work.  For
the  extremities of the  two  smaller
a                        rollers, there are  at a  and  e slots
in  brasses, as  may  be seen  in fig.
El1                       569.  Within  the partition  a, there
are movable brasses 1, for the pivots
of i and k, shown in fig. 571.  Each
brass slides in  a  groove, between
two  ledges.   A  strong  cord  made
fast at in to  the  partition  a, runs
over the brass of i, next over that
of k, then  descends perpendicularly,
and  passes  over  the  cross bar  it,
EZJ                             EJ__________ ^ __________ ^^   ^.figs. 569  and  570.   This construction being repeated at both ends of
the rollers, the rod n binds both cords.  Against the cross bar d' of the frame,
a lever o is sustained, which lies upon the rod n, and carries a weight p. The
farther or nearer this weight hangs toward the end of the lever, it stretches the cord
more or less, and presses by means of the brasses 1, the rollers i, k, toward the main
roller g. A table q, serves for spreading out the flax to be broken, and a second one r,
for the reception of the stalks at their issuing from between the rollers. Both tables




FLAX.                                       737
hang by meants of iron hooks to rings of the frame s, t, figs. 569 and 571, and are
supported by the movable legs u, u, u, figs. 569 and 570. In using the machine the
operative lays an evenly spread handful of flax upon the table q, introduces their root
ends with his left hand between the rollers g and i, and turns round the handle A, with
the right. The stems are first broken betwixt g and i, then between g and k, and come
out upon the table r. The handle is moved alternately forward and backward, in
order that the flax may be rolled alternately in the same directions, and be more
perfectly broken. The boon falls down in very small pieces, and the harl remains
expanded in parallel bands. This should be drawn over the points of a heckle, then
laid for a couple of days in a cellar to absorb some moisture, and afterward worked
once more through the machine, whereby the flax acquires a peculiar softness.
The advantages of this brake machine are chiefly the following:It takes up little room, and from its simplicity is easily and cheaply constructed; it requires no more power to work, than the ordinary hand-brake; it tears none of the filaments, and grinds nothing except the boon, in consequence of the flutings of the rollers
going much less deep into each other, than the sword of the hand-brake; it prevents al
entanglements of the flax, whence in the subsequent heckling the quantity of short fibres
or tow is diminished; and it accomplishes the cleaning of even the shortest flax, which
cannot be well done by hand machines.
The comminution of the boon of the stems, which is the object of the Iceaking
process, can however be performed by thrashing or beating, although in this way the
separation of the woody matter from the textile fibres is much less completely effected.
It is the practice in Great Britain, instead of
breaking, to  employ  a water-driven wooden
^572g        mallet, between which and a smooth stone the
flax is laid.  In that part of Belgium where
^^\                   the preparation of flax has been studied, the
brake is not used, but beating by means of the
\  ott-hammer, to the great improvement, it is
said, of the flax. The Bott-hammer, fig. 572, is
a wooden block, having on its under face channels or flutings, 5 or 6 lines deep, and it is fixed
~\\          to a long bent helve or handle.  In using it, a
\ \         bundle of the dried flax stalks is spread evenly
upon the floor, then powerfully beaten with the
hammer, first at the roots, next at the points,
and lastly in the middle. When the upper surtfltItt'llltI'tll   face has been well beat in this way, it is turned
over, that the under surface may get its turn.
The flax is then removed, and well shaken to
By the brake or the hammer the whole wood is never separated from the textile
fibres, but a certain quantity of chaffy stuff adheres to them, which is removed by another
operation. This consists either in rubbing or shaking.  The rubbing is much practised
in Westphalia, and the neighboring districts.  In this process, the operative lays the
rubbinz apron on a piece of dressed leather, one foot square, upon her knee; then seizes
a bundle of flax in the middle with her left hand, and scrapes it strongly with the Ribbeknife held in her right, fig. 573. This tool, which consists of a wooden handle s, and a
thin iron blade r, with a blunt and somewhat bent edge, acts admirably in cleaning and
also in parting the filaments, without causing needless waste in flax previously well
broken.
The winnowing, which has the very same object as the rubbing, is, however, much
more generally adopted than the latter.  Two distinct pieces of apparatus belong to it,
namely, the swing-stock and the swing-knife. The first consists of an upright board with
a groove in its side, into which a handful of flax is so placed that it hangs down over
half the surface of the board.  While the left hand holds the flax fast above, the right
carries the swing-knife, a sabre-shaped piece of wood from 1A to 2 feet long, planed to
an edge on the convex side, and provided with a handle.  With this knife the flax is
struck parallel to the board, with perpendicular blows, so as to scrape off its woody asperities. The breadth of the swing-knife is an important circumstance; when too narrow it
easily causes the flax to twist round it, and thereby tears away a portion of the fibres.
When 8 or 10 inches broad, it is found to act best. Knives made of iron will not answer,
for they injure the filaments.
Figs. 574, 575 show  the best construction of the swing-stock.  The board a has
for its base a heavy block of wood b, upon which two upright pins e e, are fixed.  The
band f, which is stretched between the pins, serves to guide the swing-knife in its
movements, and prevent the operative from wounding his feet.  The under edge of the
groove c, upon which the flax comes to be laid, is cut obliquely and rounded off (see d




738                                      FLAX.
tnfig. 574); thus we perceive that the swing-knife can never strike against that edg, s
as to injure the flax.
Fig. 576 exhibits the form of a very convenient implement which is employed ia
575                       Belgium instead of the swing-knife. It is a sort of
~_F~j'   576          wooden hatchet, which is not above two lines thic
/  k / y and at the edge g h is reduced to the thickness of the
~   / c          back of a knife. The fly k gives force to the blow,
a. I. ^   /.^:\        ^and preserves the tool in an upright position. The
I  | gR \    short flat-pressed helve i is glued to that side of the
L ~JIEj    (     ~^   leaf which in working is turned fromtheswing-stock;
l~"',,-.   _[  4       i0     and is, moreover, fastened with a wooden pin.
The rubbing and swinging throw off the coarsest
574                      sort of tow, by separating and shaking out the shortest
fibres and those that happen to get torn. That tow i
used for the inferior qualities of sacking, being mixed
with many woody fibres.
We may in general estimate that 100 pounds of
the stalks of retted flax, taken in the dry state, afford
from 45 to 48 pounds of broken flax, of which, in the
swinging or scutching, about 24 pounds of flax, with 9 or 10 pounds of scutch tow are
obtained. The rest is boon-waste.  The breaking of 100 pounds if stalks requires, in the
ordinary ro-airne of a double process by hand, about 20 hours; and with the above described machine, from 17 to 18 hours. To scutch 100 pounds of broken flax clean, 130
hours of labor are required by the German swinging method.
Mr. Bundy obtained a patent in 1819, for certain machinery for breaking and preparing flax, which merits description here.  Fig. 577, A A A A, is the frame, made either of
wood or metal, which supports the two conical rollers B and c. These revolve independently of each other in proper brass bearings. A  third conical roller D is similarly
supported under the top piece E of the machine. All these rollers are frusta of cones,
made of cast iron. Whatever form of tooth be adopted, they must be so shaped and
disposed with regard to each other as to have considerable play between them, in order
to admit the quantity of flax stem which is intended to be broken and prepared. The
upper piece E of the machine which carries the upper conical roller D, is fixed or attached to the main frame A A A A by strong hinges or any other moveable joint at G, and
rods of iron or other sufficiently strong material; H H is attached at its upper end by a
joint to the top piece E, through a hole near T, and is fixed at its lower end by another
joint K to the treadle or lever K L, which turns upon the joint or hinges M. A spring or
weight (but the former is preferable for many reasons) is applied to the machine in such
manner, that its action will always keep the upper piece E, and consequently the upper
roller D, in an elevated or raised position above the rollers B and c, when the machine is
not in action; and of course the end L of the treadle will also be raised, which admits of
the flax to be worked being introduced between the rollers, viz., over the two lower
rollers B, c, and under the upper roller D; such a spring may be applied in a variety of
ways, as between the top piece E, and the top or platform of the machine at N;  or it




FLAX.                                          789
rollers B, c, and under the upper roller D; such a spring may be applied in a variety of
ways, as between the top piece E, and the top or platform of the machine at N; or it
may be a strong spiral wire spring, having its upper end fastened to the platform while
its lower extremity is fixed to the rod H H, round which it coils as shown at o, or it may
be placed under the end L of the treadle; but in every case its strength must be no
more than will be just sufficient to raise the upper roller D about two inches from the
lower rollers, otherwise it will occasion unnecessary fatigue to the person working the
machine.
The manner of using it is as follows: the upper and lower rollers being separated as
aforesaid, a small handful of dried flax or hemp stems is to be introduced between them,
and held extended by the two hands, while the rollers are brought together by the pressure of the foot upon the treadle L. This pressure being continued, the flax or hemp is
to be drawn backwards and forwards by the hands between the rollers, in a direction
at right angles to their axes, and eventually withdrawn by pulling with one hand only.
The foot is now to be removed until the flax or hemp is again replaced, and each end
is this way to be drawn several times through the machine, until such ends are respectively finished.
By a succession of these operations, using the pressure of the foot upon L, each time
that the flax or hemp is introduced between the rollers, and regulating such pressure
according to the progress of the work, the flax or hemp will soon be sufficiently worked
and the fibre brought into a clean and divided state fit for bleaching; or if it be reuired to spin it in the yellow state, it may be made sufficiently fine by a longer continuation of the same process, particularly if worked between the smaller ends of the
rollers.
Indeed, the operation may be commenced and continued for some time, with the
larger part of the rollers, and finished with their smaller ends; and, in this point of
view, the invention of conical rollers will be found both convenient and useful; for as
the flutes, grooves, or teeth vary in their distance from each other at all points between
the large and small ends, so it becomes almost impossible for the workman to draw the
flax or hemp through such rollers in the same track; and thus the breaking of the boon
must be much more irregular, and the fibre will be much more effectually cleansed than
it can be by the flutes, grooves, or teeth of cylinders, or other such contrivances formerly
employed; because they would probably fall frequently upon the same points of the
fibres. If it is intended that the flax shall be bleached before it is spun, then the second
part of Mr. Bundy's invention may be had recourse to, which consists in moving certain
trays or cradles in the water, or other fluid used for bleaching the flax or hemp in the
manner following, viz.: The flax or hemp, after lAving been broken and worked in the
machine, should be divided into smaller quantities of about one ounce each, and these
should be tied loosely in the middle with a string, and in this state laid in the trays or
cradles, and then be soaked in cold soft water for a day or two, when each parcel should
be worked separately, while wet, through a machine, precisely similar to that already
described, except only that the rollers should be cylindrical, and made entirely of wood
with metal axles, and the teeth, which will be parallel, should be similar in form to
those shown in section at Q, fig. 578. Such operation will loosen the gluten and colouring
matter, for the rinsing and wringing which must follow. The flax must then be again
disposed in a flat and smooth manner, in such trays or cradles, and once more set to
soak in sufficient soft water to cover it, in which a small quantity of soap, in the proportion of about seven pounds of soap to each hundred weight of flax, has been previously dissolved, and in this state it should remain for two or three days longer, and
then be finally worked through the machine, rinsed with clear water, and wrung:
which will render it sufficiently white for most purposes.
Can flax be prepared without retting?-The waste of time and labour in the steeping
of flax; the dyeing of the fibres consequent thereon, which must be undone by bleaching; the danger of injuring the staple by the action of putrescent water; and, lastly,
the diminished value of flax which is much water-retted, are all circumstances which
have of late years suggested the propriety of superseding that process entirely by
mechanical operations.  It was long hoped, that by the employment of breaking
machines, the flax merely dried could be freed from its woody particles, while the textile filaments might be sufficiently separated by a subsequent heckling. Experience
has, however, proved the contrary. The machines, which consisted for the most part of
fluted rollers of iron or wood, though expensive, might have been expected to separate
the ligneous matter from the fibres; but, in the further working of the flax no advantage was gained over the water-retting process.
1. Unretted flax requires a considerably longer time for breaking than retted, under
the employment of the same manipulations.
2. Unretted stalks deliver in the breaking and heckling a somewhat greater product
than the same weight of flax which has been retted; but there is no real advantage in
5 B 2




740                                        FLAX.
this, as the greater weight of the unretted flax consists in the remainder of ligneousor
glutinous matter, which being foreign to the real fibre, must be eventually removed.
In the bleaching process, the water and the alkaline lyes take away that matter, so that
the weight of the bleached fibre is not greater from the unretted than the retted flax.
3. The parting of the fibres in the unretted stalks is imperfectly effected by the
heckling; the flax either remains coarser as compared with the retted article, and affords
a coarser thread, or if it be made to receive greater attenuation by a long-continued
heckling, it yields incomparably more torn filaments and tow.
4. The yarn of unretted flax feels harder, less glossy, and rougher; and, on account
of these qualities, turns out worse in the weaving than the retted flax. Nor is the yarn
of unretted flax, whether unbleached or bleached, in any degree stouter than the yarn
of the retted flax.
5. Fabrics of unretted flax require for complete bleaching about a sixth less time and
materials than those of the retted. This is the sole advantage, but it is more than
counterbalanced by the other drawbacks above specified.
The foregoing operations having brought the flax into the ordinary fibrous merchantable state, suitable for the spinner, it now remains to pass through the following processes, by which it is manufactured into yarns for sale or use, viz., 1st, heckling  2nd
preparing, 3rd, spinning, 4th, reeling, 5th, drying, and 6th, making up.
6. Heckling. The operation of heckling has for its objects, 1st, that of combing
or straightening the filaments entangled as coming from the scutching. 2d, tha of
splitting them, with a view of lessening and equalizing their size. In accomplishing
these objects the material is unavoidably divided into two portions. The long and
straight fibres constituting the first, called "line," and the short, broken, and confused
of the second, " tow." Both the line and tow are capable of being spun, but the line is
much the more valuable, being used for the better descriptions of yarns, &c., with
greater facility than the tow for the inferior. The aim, therefore, of good heckling is to
produce the larger proportion of line from a given quantity of flax, the attainment of
which leaves much scope for care and judgment, whether the older method of heckling  by hand  or the more recent by machine is adopted.  In hand heckling the
instruments are a comb-fashioned too], called the heckle or hackle; a surface studded
more or less thickly with metal points, called heckle teeth; over which the flax is drawn
in such a way that the above three required operations may be properly accomplished.
The heckles ordinarily used for hand heckling in this country are in the form of
rectangular parallelograms, presenting a line of 7 inches towards the worker and 4 to 5
inches deep. The first tool employed is called the " ruffer," the pins of which are about
A inch square at their base, and 7 inches long, and brought to a fine point; the second is
the " common 8," which is always used after the " ruffer;" then the " fine 8," the " 10," the
"12," the " 18." The pins of all these tools are similarly placed to those of the ruffer,
but are somewhat shorter in length and are more slender as the tools increase in fineness.
In all these tools the pins are held in wooden stocks of about I inch in thickness and
covered with sheet tin. This sheet tin, through which the pins are driven, helps to support them and prevent the wood from splitting. These tin covered stocks are only of a
size necessary for the extent of pins employed, and are themselves screwed to other larger
pieces of board, a little
579 11ii                           580 s[                         broader and  some inches
longer  than  themselves,
and  by  which  they  are
~   1I    ^e               "                                 "  ultimately  fixed  to  the
heckler's bench, inclining
somewhat backward with
their  points  from   the
worker,  and  a  sloping
board behind to prevent
the   flax   entering   too
much    in    the    pins,
of  a  heckle; fig.  580.
581      front  view   of  heckle;
fig.   581.  heckle,   &c.
fixed up for working. a pins; b tin covered stock; c foundation board; d beam of table
or bench; e back board;/f table to receive the tow, &c.; g hand of workman. Such is
the form of heckle used in England, and also the manner they are, of whatever description, fixed for work.




FLAX.                                        741
582
In Germany the common construction of the heckle is the following; (see
fig. 582.)  Fig. 582. is the ground...I  sqplan, andfig. 583. is the section. Upon
an oblong plank a b, two circular or
square blocks of wood c and d are
fixed, in  which  the  heckle  teeth
stand  upright.  To  give  these  a
583                  llll                   firmer hold they are stuck into holes
^    /~ ~ d    \in a brass or iron plate, with which
~1,                                I    _  the upper surface of c and d is covered.
Both  heckles may be  either associated upon one board or separated; and of different finenesses; that is, the teeth of the
one may be thinner, and stand closer together; because the complete preparation of the
flax requires for its proper treatment, a two-fold heckling; one upon the coarse, and one
upon the fine heckle; nay, sometimes 3 or 4 heckles are employed of progressive fineness.
The heckle teeth are usually made of iron, occasionally of steel, and from 1 to 2 inches
long. Their points must be very sharp and smooth, all at an equal level, and must all
graduate very evenly into a cylindrical stem, like that of a sewing needle, without any
irregularity. The face of the heckle block must be uniformly beset with teeth, which
is done by different arrangements, some persons setting them in a circle, and others in
parallel rows. The coarse heckle is furnished with teeth about one-tenth of an inch
thick, one and a quarter of an inch long, and tapering from the middle into a very fine
point. In the centre of the circular heckle is a tooth planted; the rest are regularly
set in 12 similar concentric circles, of which the outermost is 51 inches in diameter.
The fine heckles contain no fewer than 1,109 teeth. Instead of making the points of
the teeth round, it is better to make them quadrangular, in a rhombus form, in which
case the edges serve to separate or dissect the fibres.
The operation of manual heckling is simple in principle, although it requires much
experience to acquire dexterity.
The workman having first divided the flax into handfuls or stricks, of which there
are 300 to 400 to the cwt., proceeds to grasp one as flatly spread as possible between his
forefinger and thumb, by about its middle, and wind the top end round his hand in order
the better to prevent the slipping of the fibres; he then begins by a circular swing of
his arm to lash the root end into the heckle, taking care to commence as near the
extremity as possible, now and then collecting the fibres by holding his left hand in front
of the tool, turning the strick from time to time; ihe thus gradually works up as near as
possible to his right hand, when he seizes the ruffed part of the strick and holds it in
the same manner as at first, and proceeds by similar treatment to " ruff " the top end;
when this is finished the "ruffed" work is taken to the tool called a "common 8," the
pins of which are much closer placed than those of the ruffer, and are only 4 or 5
inches long.  This "8" is always used after the ruffer, but from it the work can be
taken to any of the finer tools, viz. 8, 10, 12, and sometimes 18. It is usual and better
to dress both ends over each tool before taking the work to the next. The pins of all
these tools are 4 inches long, in order, as was supposed, to have sufficient spring. The
flax is not lashed into them as into the ruffers, neither are the ends required to be
wound round the hand.  But the root end of the flax is always the one to be first
worked, and the heckling begun at nearly the extremity of the strick, which on being
drawn through the heckle is received by the left hand of the workman, and by it carried back and laid upon the back board and over the point of the pins, for the angle
of inclination of the heckles and a slight lowering of the right hand causes it to enter
sufficiently on being drawn forward. As it is impossible to ruff or dress entirely up to
the hand, when the hold is changed in either operation, there must of necessity be left
a certain space to be repassed through the tools; this is called the "shift," but the
less length that is required for this purpose the better for the yield of lime. The
numerous long fibres that slip from the strick in ruffing must be collected and drawn
from the mass of tow attached to them, when they can be relaid in the strick, or kept
to be dressed separately under the name of " shorts," and from time to time the short
fibres or tow sticking to the teeth of the finer tools are removed. Whenever onehalf of the length of the strake of flax is heckled, it is turned round to heckle the
other half. This process is repeated upon each heckle. From 100 pounds of wellcleaned flax, about 45 or 50 pounds of heckled line may be obtained by the- hand
labour of 12 hours; the rest being tow, with a small waste in bony particles of dust.
The process is continued, till by careful handling little more tow is formed.
To aid the heckle in splitting the filaments, three methods have been had recourse
to; beating, brushing, and boiling with soap-water, or an alkaline lye.
Beating flax either after it is completely heckled, or between the first and second




742                                        FLAX.
heckling, is practised in Bohemia and Silesia. Each heckled tress of flax is folded in
the middle, twisted once round, its ends being wound about with flaxen threads; and
this head, as it is called, is then beat by a wooden mallet upon a block and repeatedly
turned round till it has become hot. It is next loosened out, and rubbed well between
the hands. The brushing is no less a very proper operation for parting the flax into fine
filaments, softening and strengthening it without risk of tearing the fibres. This process requires in tools, merely a stiff brush made of swines' bristles, and a smooth
board, 3 feet long and 1 foot broad, in which a wooden pin is made fast. The end of
the flax is twisted two or three times round this pin to hold it, and then brushed
through its whole length. Well heckled flax suffers no loss in this operation; unheckled, only a little tow; which is of no consequence, as the waste is thereby
diminished in the following process. A cylindrical brush turned by machinery might
be employed here to advantage. These have been tried in establishments for machine
spinning, but not found advantageous.
The boiling of flax with potash lye alone, or with lye and soap, dissolves that portion
of the glutinous cement which had resisted the retting, completes the separation of the
fibres, and was therefore supposed a good practical means of improving flax. When
it is performed upon the heckled fibres, a supplementary brushing is requisite to free
it from the dust, soapy particles, &c., but this also is now abandoned.
Afachine heckling.-As intimated above, the object of all heckling was that of producing a good yield of line with tows of good quality, that is to say, free from broken
unsplit fibres, lumps and knots: the care and attention to do this, together with the
expense and uncertain results of the individual skill of workmen, urged manufacturers
some time since to attempt the establishment of machines for dressing flax mechanically.
Therefore many contrivances have been made with this view, but it was long doubted
whether any of them made such good work with so little loss as hand labour.  In
heckling by the hand,'it was supposed the operative would feel at once the degree of
resistance, and be able to accommodate the traction to it, or throw the flax more or less
deeply among the teeth, according to circumstances, and draw it with suitable force and
velocity. For a considerable period these ideas, or rather prejudices as they may now
be called, seemed to be confirmed: for the earlier attempts to supersede hand heckling,
like those in many other undertakings, though partially favourable, were upon the whole
somewhat discouraging: in attaining one point desired another one was lost, for too much
still depended upon the care and attention, if not upon the actual skill, of the attendants.
Therefore, a review of those machines that really came into operation, to a more or less
limited extent, as well as a slight mention of some of those patented, but never publicly
shown, may not be useless as a lesson for preventing a repetition of things already
known, as well also for illustrating the steps by which these first prejudices have been gradually overcome. The first heckling machine invented, or at least published, was called
the " Peter," and was intended to imitate as closely as possible the movements of the
hand heckles. In commencing the work, the flax was first divided into small convenient
portions or handfuls, of about 4 ounces each, called " stricks," and which, before being
taken to the machine, were slightly straightened and dressed over the ordinary hand
" ruffer." Each of these stricks was then placed between a pair of short iron bars, one
of these bars having an indentation along its middle, and the other a corresponding
projection; thus, when tightened together by screws 4j inches apart (such a length being
equal to a hand-heckler's grasp), the flax was firmly held while exposed to the action of
the heckles, (this pair of bars with screws being called a " holder "). This holder was
then suspended from movable levers over a truncated rectangular cylinder, upon the
truncated angles of which were fixed, at a certain angle, heckles sinrilar to those used in
the manual operation. The levers supporting the holders received from a crank a short
up and down motion, so timed in their oscillations as to strike the holder nearly against
the points of the pins at the time they were passing under, coming thus as nearly as possible to the effect of a man striking in and drawing through the heckles, with the exception that the flax remained nearly stationary, and the heckle was drawn through it by
the rotation of the cylinder; such machine carried two holders. The tow made and collected in the heckles, was seized and taken off by boys stationed for that purpose, while
another at the ring of a bell took out and changed the sides of the stricks to be
presented to the action of the heckles, and subsequently withdrew them from the first
machine to another similar but with finer heckles, and thus continued till the root end
(always the first to be operated upon) was dressed to the desired degree of fineness, when
they would be taken to a table where another set of boys, previously to removing the
first holder, put on a second to the already heckled part, leaving a short length of 2j
or 3 inches to be reheckled. This operation is termed shifting, and the space left the
" shift," and is thus performed and so called at the present day; the only change in the
holder now in use being, that one screw is used for two stricks instead of two screws
for one strick. Fig. 584. will more clearly show the construction of this machine.




FLAX.                                        743
A square truncated  cylinder carrying the
584     4           heckles; B oscillating arm or lever for supportI1d U^^^***^^  *^ing the holder; c c c framing; D crank and
shaft; E connecting rod from  crank to oscillating arm; F, F, F, F heckles; G G G   backboard;
ni holder. The first motion was given by pulleys
*:,'/^ on the shaft D, which revolved 4 times to 1 of
the heckle cylinder, by the intervention of
suitable wheels.  The worm and wheels for the
/"  //1 A: "    bell motion were attached in the usual manner
ji2         e cGi    to the shaft of the cylinder.
Machines of this construction continued in
-~~""~~~~"~~J —^ ~ rather limited use  without any  change  or
competition till about the year 1825, when a
~g^\\ a I ^ ^patent was taken for a machine known as the
r     pendulum  machine.  The flax in the holder
being suspended  and swung backwards and
forwards while the heckle remained fixed, thus
the flax was heckled, stroke for stroke, on each
of its sides. The boys as in the last described, snatching off the tow as it was formed,
and at certain times, that is at each rise of the pendulum, for it had a rising and fallng motion to imitate the hand workers in commencing at the extreme end of the flax,
passing the holder from one recess to another of the pendulous table, so as to arrive at
the progressively finer tools when ranged along the machine, but sometimes the different tools were fixed upon the angles of a square cylinder that presented a finer range,
the whole length of the machine, by turning up a new angle at each rise of the pendulunm, when the labour of the boys was simply to put in the tow and take out from it the
lax.  The adjoining diagram, (ig. 585.) without entering on any details of a machine'at was so little used, will make the theory of its action quite clear.
^,~~- ~.~~^,.-~""                 A heckle  bench  sometimes revolving so as to present different
T/  /            *\         degrees of heckles at its various
ID     j                 i         t~'~h angles, sometimes stationary with,,,~'-"~)         f the gradations of heckles upon its
length; B B, pendulum  arms; c c,
equal wheels working  into each
\. /.S~!"'*       other; D D, crank arms; E radial
slide-bars to preserve the holder
85\yS  ^ B   f~B>                           table vertical; H, holder  table;?F, F, F, F, heckles; G, G, back boards;
0                                   rII^J  i, direction in which the holders
0^1^^                            swing; there were the same wheels,
ic., at each end of the machine,
and the holder table H  reached.^"""   a^..-           -..from one to the other. The wheels
/            \Nr''             ^^               "\  c, c, with all attached to them, were
G ^'^1   ^^    ^  ^^..           ) made to rise and lower upon the
\  heckles, and the back-boards G to
rise   when   the  heckle   bench
0C))          ^^    III    y^            ^Q)       About the same time  another
patent was taken out for a machine,
~Z ^^   ^    ^ ii   where the holders were suspended
above one end of a travelling sheet
of heckles.  This machine  also
required hand labour to turn and transfer the stricks, though the tow was caused to
fall clear from the heckles by mechanical means. The following sketch (fig. 586.) shows
the principle upon which this machine works, and though never much employed at
the time of its appearance, -has subsequently served as a foundation for those that are
now in the zenith of their prosperity.
A A (fig. 586.) sheet of heckles; B support for holders; c, c carrier pulleys for the sheet
of heckles. Fig. 587., a larger view of the heckle bar G G, in order better to show the
faller D D D in the staples or grooves E, E, andfa. 588. at the end of the heckle-bar G G;
F, F, pins of the heckles, between the rows of which the faller D D D acts to push the
tow off the pins. There is a clearing faller D to each heckle, which is kept to the bottom of the heckles at that part of their course where they are in contact with the flax,
but at the turn F D fly beyond the points, as shown by the effect of the centrifugal force.
All these machines, possessing great similarity of features in regard to the personal




UI4.4                                        FLAX.
587                                       15
B                                           2      B
attention required, never came into such general operation as to supersede entirely
hand-dressing, either from  their own defects or prejudices against their employment.
About the year 1830, in consequence of the new mode of spinning, hereafter to be described, being carried on with considerable energy, it was found advantageous to cut the
flax into 2, 3, or more lengths previously to heckling, which rendered it necessary to hav,
machines peculiarly adapted for this new short description of material. This machine,
known as the excentric or circular machine, deserves considerable attention for its own
inherent merits, and the extensive utility it has proved to be of in suggesting the
principal parts of those by which it has been supplanted. In its original form it was
made of a breadth suitable for only one strick, and consisted of a cylinder 3 ft. diameter,
upon the whole circumference of which at intervals of 3 or 4 inches were fixed the
heckles.  As each machine could only carry one description of heckle, it was necessary to employ a series of these machines, called a "class," when the flax required to
be dressed over a succession of finer tools, each succeeding machine carrying a finer tool
than its predecessor. The heckles were cleared of tow by coming in contact at one
part of their revolution with a brush roller, which also revolved in contact with a
cylinder covered with card clothing, the points of the pins being in such a direction as
to clear the brush from tow, and allow itself to be in its turn cleared by the oscillations
of a comb, whence by rollers the tow was brought into a sliver. In order to preserve the
continuity of the supply of tow, and maintain the regularity of the sliver produced by it,
the holders with the flax were presented to the heckle cylinder in a manner peculiar to
this machine,and in endless succession by means of certain circular carriers placed at each
end of the heckle cylinder, but excentric thereto, and at such a distance apart as
each should bear one end of the holder as it extended across the cylinder parallel




FLAX.                                             745
to its axle. Thus, the holders introduced at that part of the circumference of these
carriers furthest from  the heckles were carried forward, while the flax was in operation, till they were brought almost into contact with the points of the pins, when by
the intervention of a slide they were withdrawn from the machine, but with one side
only of the flax dressed, and that but on one tool; therefore, the holder required
replacing in the same machine, in order that the second side of the strick should be
dressed as was the first. The holders then required to be carried by hand to each
succeeding machine of the class.
The preceding figure (589.) shows the leading features of these machines:
A A (fig. 589.) heckle cylinder; B B excentric wheel to carry holders in its recesses
It, hI, h,  h,; c slide upon which the holders were laid so as to fall into the recesses
h, h of wheel B; D slide for taking out holders; E brush cylinder with brushes; G
cylinder covered with card clothing; H holder come out; i doffing comb. The space
of the holder carrying wheel was filled with holders, and so maintained in endless
succession, and thus each served in some measure to keep the end of its preceding
one down into the heckles.
About 1833, a machine was patented  consisting of two parallel cylinders, over
which the flax was carried, revolving in its progress so as to present the alternate
sides of the strick to the heckles, the progressively finer tools being ranged along these
cylinders, so that having passed the length of one cylinder one end was completely
finished.  When the holder was taken out, " shifted," and replaced, it was carried
back along the second cylinder, and thus returned to where it commenced, finished.
This machine, however, never was carried further than the experimental one for the
patent.
Another machine the same year made its appearance, and which for some time enjoyed much celebrity. It consisted of two parallel vertical sheets of heckles running
together, and so geared that the heckles of one intersected the interstices of the other.
The flax suspended in its holder from a species of trough passed between these two
sheets, and was thus heckled simultaneously on each side in its course through the
progressively finer heckles from one end of the machine to the other.
A, A (590.) heckle sheets; B B holder trough or slide; c, c, c, c, pulleys for carrying the
-     m  -  I i
A             A
~              ^1
heckle sheets; D, D brush rollers; x, x, rollers covered with card clothing to clear the
brushes; r, F doffer combs; G, G, G, G heckles; iH holder; i, i brushes.
At about the same period a foreign machine was patented, known as Evans's machine, of which the following description will give a correct idea of its principle
of action, and also of its holders, which are different from those already described.
VOLT.                                        2 G




746                                     FLAX.
There are two series of combs, seefig. 591., attached to two movable frames represented
592            By at a and b. Each frame is formed by vertical
-'691    ^nif~~~~   (,)  bars a b, with lateral branches or arms,..    which carry the heckle points. The branchI     es or arms are parallel, and at equal dis
tances apart, but fixed in such positions in.' -..               l ~i^^^-  ^II each frame that they may occupy the interH^. -:~-n59^^1^   3vening space when the frames are brought
a  together asfig. 592.  The frames are put in
motion by means of revolving cranks to
]   which they are attached as shown in  ig.,  592., and when the cranks turn upon their
axes, the branches of one frame pass be1 tween those of the other without touching.
-    This forms what may be called a set of
7    combs; the points of the combs of one set
being opposed to the points of the combs in the other set.
The way in which the series of combs that compose one set act upon the flax, is
shown in the side view, fig. 591. When the cranks are nearly vertical, the points of
both frames are away from the flax, but as the cranks move round in the direction of
the arrows, the frames come into another position, and it is then that the points or
heckles of one of the frames a, begin to penetrate the flax, and descending they comb
or divide its fibres. The rotation of the cranks continuing, the two frames a and b
come into the position shown atfig. 591., the points of the frame a withdrawing from
the flax, and those of the frame b approaching and pushing the fibres off from the
former, which are now combed by the descending stroke of the points.
It will hence be perceived that as the combs of the frame a and b respectively
advance, they will push forward the whole of the strick of flax, and render it impossible for the fibres to be raised and entangled, as each frame in advancing clears the
fibres from the points which preceded it.
A single set, however, of such combs or heckles acting only on one side of the flax
would but imperfectly perform the operation of opening its fibres; it is therefore
necessary, in order to accomplish the desired object in the most effectual way, that
two such sets of combs or heckles should be brought to act on opposite sides of the
strick of flax, suspended in the position shown in the figures. The cranks of the two
opposite sets of comb-frames or heckles a, b, and c, d, are connected by a pair of
toothed wheels e, f, asfig. 594., or by four toothed wheels, by which the heckles are
actuated at once, the two sets moving in opposite directions, but with similar speeds,
and the combing or heckling of the material will go on in the way shown in the
figure last indicated. The tow being collected as drawn off the lower end of the
sticks on to a slowly revolving cylinder or brush roller, whence it is doffed by a comb
and delivery rollers.
The clamps or holders differ considerably from the clamps which are commonly
used. I shall therefore particularly describe their construction, before showing them
in operation. Figs. 594. and 596. are views of the clamp in two different positions;
a and b are two boards united together by a
594 ~"^lC                               hinge e, at top, which of course allows them to
shut and open. The lower parts, forming the
jaws of the clamps, are made with teeth or indentations, between which parts the ends of
the flax or hemp are securely held when the
Y \ y\  JJ I   clamps are brought together; d d, are two
d^i J&^4^ ^H          595  J y^       pieces projecting from  the board b, at the end
of each of which is an eye shown by dots, and
at the back of the board a, (see fig. 594.) there
is a double armed lever e, turning upon a fixed pin f, which lever carries two circular
wedges g g. These wedges pass into the eyes of the pieces d d, when the clamps are
closed, and hold them fast. There is a segment ratchet h, at the upper part of the
board a, which turns upon a stud i, and is pressed downward by a spring k. This
ratchet receives the end of the lever e, and consequently keeps the circular wedges
firm in the eyes, which hold the clamps securely together, and prevent their opening by the shaking of the machine.
When it is required to open the clamps, the ratchet A, must be raised, and the lever e
pushed aside by its handle 1, which draws the circular wedgef from the eyes of the
pieces d d, and the boards of the clamps immediately separate. For the convenience
of suspending the holders in the machines, a piece of sheet iron m is bent at right
angles, and fastened to the back of the board b, as seen infig. 595., forming a groove
by means of which the holders are enabled to slide into the machine and hang there.




FLAX.
About the year 1840 an improvement took place in the excentric circular, by which
one screw of the holder retained two stricks, and the machines made wide enough to
take four stricks, and also a movement was made by which the holder was carried over
two cylinders, so that each side of the strick was dressed before taking out. These
improved machines had a very extensive sale, as wages and the necessity of attention
were much reduced by them. Also the third machine, herein-before described, was revived, having a rising and falling motion for the holder support, and was known as the
Belfast machine; and similar improvement was made in the double vertical sheet machine. But, as none of these sufficiently dressed the line for the finest yarns, a machine
called the " crank machine" was invented for that purpose, but was in use for a very short
time; its object was more to perfect the dressing after the excentric machine than to do
the whole work itself. In this machine the flax was suspended, and then struck simultaneousl on each side by heckles having an abrupt angular movement, first to strike
into, and then draw down the line, in order to draw off the tow; the work was begun
at the end and gradually advanced up to the holder.
A, A (fig. 596.) arms for carrying the heckles; B, B,
trough or slide for holders; c c sliding piece to carry
pivots or the carriers A, A, 0so as to rise and fall by the
motion of the bell crank D; *E connection of bell-crank
D with excentric F, to give the downward stroke when
the heckles are closed upon the flax by the action
of the crank, c, connected by arm i with the carrier
A  A; H holder; K connecting rod for the carriers A, A;
L and M pivots for the respective carriers A, A; N, N the
m    heckles.
0 /     ~q~ \ ~^ i\ This machine, capable of doing the work but very
\*  _ ^ak (^ i slowly, and with  great expense of heckles, was at\ L \^ i   ttempted to be improvcd upon by another made of two
parallel cylinders constructed of a series of bars run[\ 0         ning  at equal speeds in contrary directions. Upon
]D/        these bars were fixed the heckles, which were kept in
l[)  f    a horizontal position during their entire revolution, by
D      \         a crank at the end of each bar, guided in a circular pal
0) J         excentric to that of the bars themselves. The flax suspended passed with a rising and falling motion from
one eiia of the machine to the other, each succeeding heckle being finer than its
preceding.
A A (fig. 597.) circular discs keyed to the shafts B, B; c, c circular discs running
upon the excentric bosses D, D; E, E heckle bars; F slide for holders; G holder.
The discs A, A are alike at each end of the machine, and have suitable bearings to
carry the heckle shafts E by th&ir round necks A, A. The discs c, c have similar and
equal number of bearings to carry the cranked ends of the heckle bars c, and are carried
round by them from the movement communicated to A A. By this arrangement the
5C2




'~~748     ~FLAX.
pins of the hele are always in the position shown, and penetrate the flax at right
angles to its length.
As all the preceding machines have now passed into oblivion, it may be as well to
trace the reasons. The fault of the first was the great attention it required to turn the
stricks and to carry them by hand from tool to tool; the want of the rising and falling
motion caused the heckles to strike at once into the middle of the flax, thereby reducing the yield of line, and rendering the tow knotty and torn.  Though some of these
defects were remedied in the second, there still remained the transferring of the flax,
the taking out of the tow, to be performed by the attendant, and the motion of the line
through air was objectionable. In the third another step was gained, that of taking
out the tow; but, for the want of the rising and falling, the work was too abruptly
torn into. The fourth was suitable but for short flax; it was very expensive on account
of the liability of the holders falling upon the heckles, and the turning and transferring
the flax by and, even when afterwards these expenses were slightly reduced by the
improvement above alluded to. The fifth, never cominig out of the workshop, was
perhaps found deficient for want of the rising and falling,which, though partially obviated by the cylinder end being conical, might, even by this mode of palliation, lead to
further difficulties of a practical nature, aud by the turning movement being continued, a
further inconvenience would no doubt have been found in the edges of the stricks being
as long exposed to the heckles as the sides. The sixth, for a long time popular, was
found, by heckling both sides at the same time, to tear away the flax, and from the impossibility of getting the pins to work near up to the holder, a long shift was required,-another reason by which the yield was reduced. Seventh; Evans' machine,
though only put up for experiment in this country, has been more extensively tried
abroad; but it made tow so knotty for want of a clear stroke through, that it was
immediately, and is now perhaps entirely, abandoned everywhere. Eighth; the crank
machine was very troublesome and expensive, and could hardly ever be said to have got
beyond its experimental state. It is now altogether laid aside. Ninth; the -double
cylinder machine answers well for very short line, but, for much the same reason as
the abo've, makes but indifferent tow, and its use is now nearly discontinued.
Besides the above there have been several others patented; some have never been
wholly constructed, and others never been used: neither appear to have suggested any
principles or modes of action capable of being modified into a useful or practical state.
We now come to explain those heckling machines by which the flax-spinning trade
is at present actually carried on, in which it will be seen that the best parts of all the
preceding are combined, so as to form machines of the utmost efficiency, and capable'
of working with a closer approximation to the utmost degree of economy.
The first in order is the transverse sheet ma~chine. This machine is on the same
principle as the third, above described, having a horizontal sheet to each heckle, but
each running in an opposite direction, and a rising and falling trough, along which the
holders are impelled from one end of the machine to the other. It is so arranged, that
when one side of the strick is heckled the slide or trough rises, and the holder being
A     A.




FLAX.                                            749
suddenly pushed forward, the flax thereto attached comes in contact with the next
sheet running in a reverse direction, and has thereby its other side dressed. This is
repeated over as many tools as may be desired, generally three, but sometimes four.
For the better elucidation refer to Jig. 598., section of machine.
A A (fig. 598.) frame; B B heckle bearing sheet running in the direction of the arrow
c c another heckle sheet running in the opposite direction; D holder, and its rising and
falling support in the form of a trough, along which it slides from one end of the machine
to the other; E chain to which is attached the balance weight of slides, &c.  F, G, ii the
carriers of the sheets, of which F and H are keyed to their respective shafts, as it is by
them the sheets B, B and c, c are driven, and drive their carriers G loose upon the shaft.
It is somewhat objectionable in the above machine, that the holder slide has to rise
to a great height, so as to take the ends completely off the tool, otherwise the strick
is liable to be crossed by one side being for the moment pulled in one direction, and
the other in a contrary; and also that the tow and waste might be apt to collect in
the spaces where the sheets cross each other, and thus occasion derangement.
The following, known as Baxter's self-acting cylinder and sheet machines (these
appellations being given accordingly as cylinders or endless sheets were employed to
carry the heckles), of which the distinctive feature is turning the holders, avoids this
inconvenience.
The holders from which the flax is suspended are supported above the centre of the
cylinder (when a cylinder is employed), or of the rotatory carrier of the endless sheet,
when that method of applying the heckles is adopted; but instead of their supporting
slide or trough being in one continuous piece, it is divided, according as the machine is
intended for 3 or 4 gradations of tools, into 6 or 8 divisions, each equal to the length of
the holder. Of these half the number always remain in a direction paralle to the axis
of the cylinder, while the others, placed between or alternately with them, are connected
together by gearing, so as to turn simultaneously in a horizontal direction, and the whole
are combined to approach and recede to and from the heckles together by a falling and
rising motion. The brushes, card-clothed cylinder, and comb, when employed, are
similarly combined for clearing and delivering the tow as those already described for
the same purpose in the excentric circular machine; but in general for the sheet machines
a simple faller is found sufficient. Thus, the flax introduced into the first division when
the slide is at the top of its course, is dressed during its descent, and "dwell" upon
the first half length of the first tool; on being risen it is pushed forward by mechanism into the next division of the slide, which then by turning half round, or end for
end, presents the second side of the strick to the second half of the same tool, upon which
it thus becomes dressed, as was the first: on again rising, the flax is pushed into the third
division of the slide, which presents the side of the strick that was second on the first
tool to be first exposed to the action of the second, and thus, at each rise, is the flax
advanced towards the finer tools, turning at each alternate advance, till the required
number of tools is passed over. This is the construction generally employed, but it is
sometimes necessary that each holder turns in its place, thus heckling each side of the
strick on the same identical heckle; thus the flax is more worked, for it is exposed to
6 or 8 gradations of tools, instead of 3 or 4 by the other method, but a machine upon
the former will do nearly double the weight of flax than upon the latter mode of working. Though the progress but of one holder has here been traced, it must be understood that there are necessarily 6 or 8 in simultaneous operation, according to the
description of machine; for the propelling motion being at one end requires the full
complement of holders to push one another forward. This machine and the last perform pretty nearly the same quantity of work, which, with 6 or 7 boys, amounts to about
1 cwt. per hour, and are applicable for long flax, and for cut as far as 60 or 70 leas;
the latter is sometimes used with 4 gradations of tools as far as 100 leas. The construction of these machines, whether cylinder or sheet, is so similar, that the same letters
and figures refer to the same parts of each. Figs. 599. and 600. front and profile views
of cylinder machine, and Figs. 601. and 602. front and profile of sheet machine.
A A general framing; B driving pulley on the shaft of brush roller; c c main cylinder;
D D brush roller; E E card-covered roller; F, F rails constituting part of the falling and
rising head, and to which are fixed the movable parts for turning the holder; G G the
first part of the slides along which the holders pass; Hi, n the alternate turning parts; i, i
the holders, those No. 1. are with the side as put in, and those No. 2. are when turned;
K, K, K supports from the rail F to fixed parts of slides G; L the supports with pivots for
the turning parts of the slide H Hi; to these pivots are fixed respectively the wheels
m, o, q; the intermediate wheels n, p being loose upon their axis, serve to connect the motion of the series; R lever and lock to retain the wheels fixed during the fall and rise; s
support for the lever P.; T support for the pendulous lever u, which by the pusher v drives
the holders forward when introduced into the slide; w slide inclined to conduct the holders on a table; x x doffing comb shaft; Y connector between the rails F and balance
weight lever z; a a excentric to give the up  and down motion to moving head;




750                                           FLAX.
b friction bowl; c balanes weight: this arrangement of connector, lever weight and
excentrics are the same at each end of the machine, as the shaft d, upon which the excentries are fixed, extends the whole length of the machine; e, f, g train of wheels and
pinions to reduce the speed of cylinder shaft c to the excentric shaft d; h, i wheel
and pinions to drive the excentric by which  the doffing  comb is moved by the con599', 
1q.11  I~q-1FM _I
#i   i   Wxm a' n  T  I~r  Inrv[ luff..............................................................
_............................,.
D=       =       1      1lh
_ 11111..............
D       J                                  11E




FLAX.                                            51
caused by the rise and fall of the head. The following figures show the form of
the " sheet" machines, but which do not, from  their similarity of principle and construction to the foregoing, require a detailed description; as the only differences are




152                                     FLAX.
that a sheet is used to carry the heckles instead of a cylinder, and doffer bars for
knocking out the tow instead of the more complicated arrangement of brush, comb, &e.
Those machines that are now employed for finest work are called Marsden's intersecting machine, and combined intersecting.
The intersecting machine is so called from the peculiarity of its construction, being
somewhat similar in principle to that already described, of two cylinders of heckles
carried on cranked bars, but instead of their being so closely placed together, there are
but six, eight, or more bars bearing the heckles, forming as it were a sort of a skeleton
cylinder, of which there are two, parallel to each other in each machine: the flax
passes along the machine between these two cylinders, and is struck by their heckles
alternately, and in successive order on its opposite side. Marsden's combined intersecting machine has in addition to these cylinders a pair of sheets of heckles, by which
the first tool work is performed previously to the flax arriving at the intersecting
cylinders, and the flax is rather more severely heckled. In both of these machines the
holder slide is provided with a rising and falling motion, as being absolutely necessary for
the production of good work: these machines penetrate the flax better than the cylinder,
as from its position between the heckles, the flax is rigorously exposed to their effect,
but the tow thereby produced is rather more lumpy and uneven, and is, therefore, considered inferior to that, from the cylinder machines, see figs. 603. 604. 605. of combined intersecting machine.
Fig. 603. end view; fig. 604. side view; fig. 605. sheets; fig. 606. holder; A A A framing; B B holder trough or slide; c jointed rod, having a horizontal motion to push forward
the holders by the clicks a, a, which catch the holders in one direction only; D pendulous




FLAX.                                     758
ever receiving a reciprocity motion from the radial arm E, at the rising and falling
of the sliding head; i support for the pendulous lever D; G, Q carriers of the heckle
bearing sheets, H, H;i, i heckles fixed to the sheets or straps H; K K card-clothed cylinder
for receiving the tow from the brush cylinder; L doffing comb; Mw brush cylinder;
N N, o o slide shafts, upon which are keyed the carrier arms p, r of the intersecting
heckle bars Q, Q:, R crank arms fixed to the heckle bars, and guided by their extremities in the slides o, o, by which the peculiar position of the heckles is maintained;
s, connector between sliding head and lifter excentric, or cam; T, u the friction bowl
for pulling downwards the slide head, to which a tendency is given to rise by balance
weights, not necessary to be shown; v wheel commanding excentric to give the oscillations to the doffing combs.
In all heckling machines, whether those of sheets or cylinders running in opposite
directions, and not therefore requiring the turning motion for the holder, or those with the
turning motion, and having therefore but one sheet or cylinder; or again those called
the intersecting and combined intersecting, the hand labour required, and the number
of holders or work turned out in a given time, are nearly the same for similar degrees
of dressing, and all these machines are provided with change pillions, to increase or
diminish the quantity of heckling in any required degree.
The hand labour consists, first, of dividing the flax into stricks,.for long flax, of 4 or
5 ozs. each, and for cut, 1^ to 2 ozs. Then screwing these into the holders, and when
one end is worked, taking out the holders, performing the "shift," and replacing them,
VOL. 1          I l
ag:,9
I * c_!!l!!!_~~~OME
- 4 ~~~~~~~~~~~~~~11M
q~~~~~~~~~~~~~~~~~~~ fit,
|~ ~~ A
errciigarcirct   oinfomterda  r  Eath  risigad aln




754                                     FLAX.
l.,,..........
1.^~~~~~~~~~~~~~......
i'? "........
606
by which it is evident that the manual work is reduced to nearly the lowest possible
point; for the taking out the holder and performing the shift are the only operations that
can by possibility be done mechanically; and it is desirable that this should be so effected,
not only with a view of saving the expense in wages, but to avoid the waste and entanglement, and consequent reduction of yield, to which by handling the flax is exposed,
and at the same time reduce to the utmost degree all need for reliance upon the care
and attention of the workers employed. A holder with this intention was patented about
three years since, which, from its novelty of construction, deserves a record, for though
not yet in active operation, it only requires time to remove the groundless prejudices
opposed alike to this as to all other innovations.
Previously, however, to entering upon a description of this holder, it will be necessary, in order to make our account of heckling machines now actually in use complete,
to describe one much used in France, and patented for that country, January, 1846. It
is there known as the peigneuse mecanique system Busk, from  the name of its inventor,
an English machinist (whose transferring excentric and double cylinder machines have
already been described).
Flax heckle, called Peigneuse Mecanique, on the system of Busk, as described in a
French publication industriel.-It has been found in practice that to obtain the best
results, it is absolutely necessary to attack the flax by the end of the strick, and to
continue it slowly and gradually till the points of the heckle act on the middle; then
to obtain the greatest product in long line and the best quality of tow, it is necessary
to heckle it alternately on each side of the strick, continuing thus on the first, second,
third and fourth heckle, &c.
The machine which we offer to the public as the invention of Mr. Busk, the author
of many ameliorations in flax-spinning machines, unites in itself all the different points
of perfection indicated, without any of the inconveniences of the rival systems. The
force requisite to drive it is hardly one-half of a horse-power; is capable of heckling
on any number of heckles, and without increase of hand-work, about 500 kilogrammes
(~ ton) daily, more or less, according to the nature of the flax. It is applied with
equal advantage to the long or the cut line.  It may be conducted or managed by




FLAX.                                            55
4 or 5 children merely, employed to screw and unscrew the clamps (presses), an easy
operation..Description of the machine. - Fig. 607. longitudinal elevation of the mechanical
heckle.
5i                         G:                              [~         _         11.....I
_ -                                           dI
~^   ^MmmM               ilm!-iD~lltltl~sII l#.tillll~lltlllllll ll Wi!i{i\ililllii iiltii /tiil'lllt/ ii  i\ \
A. Large cylindert, in whose  cirilcumference the heckle teeth  are fixed.   The distancellt
between the points varies according to the perfection  which is desired in   t   he eckling
11~~~~602 




1756                                      FLAX.
and the quality of the flax. The length of the cylinder (2 metres 40 cents) admits of
multiplying the heckle points, and varying their distances.
B. Small plates (planchettes) fixed between the heckles, to determine the depth
to which the points shall act in heckling. These plates are moveable, so as to be
arranged at pleasure.
c. Carriage bearing the pincers in which the stricks are fixed. D. Upright arbours
on which the carriage rises and falls by means of the sockets E, fixed to the carriage, to
guide its ascent and descent, effected by aid of an excentric placed on the side of the
machine. This carriage is balanced by counter weights. One of its sides is furnished
throughout all its length with a cast-iron rack, in which all the pincer bearers (which
are toothed on their upper part) work.
F. The pincer carriers, whose upper part is a toothed wheel, and whose lower part
terminates in hooks (crochets) that receive the pincers in wood. Rigid bars connect
the pincers in the upper part; so that they all work at the same time.
G. Wooden pincers clasping the stricks of flax by means of a screw.
H. Cylinder with brushes for removing the tow, which had been retained by the
heckle points, and carrying them to the cylinder i, furnished with cards.
J. Heckle which deposits its tow into a box placed to receiveit.  All the pincers G
being furnished with flax are fixed in the hooks of the pincer bearers.  On setting the
machine in motion, the carriage G, commanded by an excentric intended to give it a progressive velocity, calculated proportionally to the thickness of the strick, descends and
puts the flax in contact with the heckle teeth fixed round the large cylinder A, actuated
by a continuous movement.  When this operation is terminated, all the stricks of flax
submitted to the action of the cylinder having been heckled on one side, the excentric,
which had caused the carriage to descend, makes it mount again; at which moment the
other excentric acts destined to communicate to all the pincers the horizontal motion;
and, as the pincer bearers are in toothed geer with the carriage, the consequence is
that in advancing the pincer bearers pivot on themselves, so that the carriage descending anew, presents to the action of the heckle points the other face of the flax.
This action in being thus repeated even to the extremity of the carriage, works on
the flax by heckle teeth closer and closer together. When they have arrived at this
point, the pincer carriers continue to advance, passing by the back of the machine:
but this side of the carriage having no rackwork, the pincer bearers do not pivot (turn
round) and proceed without changing position, at which point the heckled flax is
replaced by the unheckled.
- The tow  is disengaged by the brush-cylinder, and transmitted to the cylinder
mounted with cards: a heckle then detaches it and drops it into a box.
Such was the state of heckling machines when the holder above alluded to was first
contrived with a view of being applied to this machine, for which it is peculiarly
adapted.
All the holders that have hitherto been used are similar to'those described at the
beginning of the article, consisting of two clamps of wood or iron pressed together by
screws, except in Evans's machine, where an inclined plane was used for that purpose.
But the holders now referred to are on an entirely different principle; the holding pressure being produced by the effect of leverage of, the clamps or jaws themselves, which
are for this reason, and also for better supporting the end of flax out of operation, made
from 7 to 9 inches broad; and while one of their edges are hooked or fastened together
by a pair of double-acting hinges, similar to those used at the bottom of turnpike-gates,
the others are held together by a clasp, and thus the flax is very firmly grasped or held
by the pressure at the joint or hinge, and the end of the flax not exposed to the heckle
is held vertical and straight by the breadth of the clamps. These holders do not slide
of themselves along a trough, as do the other description, but there are " carriers " for
them attached to the sliding and turning apparatus, by which they are carried forward
and turned as desired. These carriers are so constructed as to retain the holder by one
of its clamps or jaws always vertical, but leaves the other free to fold from one side to
the other; when this folding takes place, which is during the dwell of the other holders
upon the heckles, that end of the flax which was contained between the clamp becomes
liberated, and the previously pendant one is lapped up and enclosed between them,
when the rise of the head taking place, the catch replaces itself, and the holder is carried forward to return along the second cylinder of the machine, and ultimately arrives
at the place where it was frst put in with the line completely dressed. As all these
movements are performed automatically by the machine itself the whole of the wages
necessary, when the other holders are used, for taking out, and screwing and unscrewing, and replacing them, amounting to nearly half of the whole expense, is si,'
besides much indirect trouble and confusion.
A 1, A 2, jaws of the holder; B B carriage or frame for supporting the holder; c c, a
toothed wheel, having a groove on one side to allow it to be carried by the rails of the




FLAX.                                        757
moving head of the mach'ne, of which fig. 609, is a plan or bird's-eye view; D, D, links or
bars connecting the series of wheels c, c. These wheels are of such a diameter, that
E                  ^~                 E
610                                                       611
when propelled from 1 to 2, they will at the same time make one exact half revolution; and thus the holder attached to each presents its opposite side to the heckles
at each advance similar to other machines. To cause this half revolution, the teeth
of the wheels c, c engage those of the racks E, E and F, F; but the slides are so made as
to maintain the wheels in one position from E to F at one end of the machine, and from
F to E at the other; G H the position and place where the holder stands to be shifted;
and i K when first put in or to be taken out of the machine; L A, axis of heckle cylinder
to dress the flax after " shifting;" therefore its coarser tools are at end M; N o axis of
cylinder for dressing the root ends; therefore, its coarser tools are at end N.  The
arrows show the direction of movement of all these parts. The mode of action of the
holder is as follows. The jaw A 2 is first laid upon a table, and the flax placed upon
it, when the jaw A 1 is caused to engage the pin 3, which are similar at each end of
the holder, when it is folded down upon A 2, and the catch fixed to 2 engages the rack
fixed to A 2 at 5, and the whole is firmly combined together and placed into the carrier,
and maintained by the pins projecting for the purpose from A 1 entering into vertical
grooves in the carrier, when, having passed over the heckles on cylinder N o, it ultimately
arrives at G H, when, during the descent of the sliding head, the lever attached to the
catch 5 strikes against a fixed point, and is thereby lifted out of the rack, thus leaving
at liberty the jaw A 2 to turn. This is effected by a projecting pin 2, being actuated
by a crank having a suitable intermitting motion, which carries it in the direction of
the dotted line, while the hinge pins quit recess 3, and the other enters the recess 4,
and the rack engages the catch opposite to the one it has quitted; and thus the shift
is completed with a length equal to the thickness of the holder at 3, 4.
The cutting of flax, which is done in order the better to select and separate its
various qualities, is an operation of some delicacy, and requires a peculiar machine
for the purpose, which, though not complicated, requires great nicety in its making
and arrangement; for the flax must not be cut too abruptly, but be gradually reduced
to a taper and somewhat natural end. The cutting should be done before the flax is
heckled. The machine for the purpose consists of a species of circular saw about 20
in. diameter; but, instead of a single blade, is constructed of 3 or 4 plates of steel,
each about i in. thick, and having angular projections from their circumference. This
revolves at a considerable velocity, while the flax firmly grasped in each hand by its
ends, is still further held and slowly carried against the saw by two pair of grooved
pulleys pressed together by a considerable weight. It is thus partly sawn and partly
broken through.  Flax may be cut into 2, 3, and sometimes 4 divisions: and sometimes the dead harsh fibres that are frequently found at each of its ends only are cut
off and used as tow; but more generally the different portions are heckled and used
for the purposes they are sorted for.
Description offlax cutting machine.  (figs. 612, 613.)  A A, framing; B, the grooved
pulleys for holding and carrying the flax; c c, the driving pulley; D, saw or cutter;




758                                         FLAX.
C
r, F, wheels for geering together the pair of holding pulleys; G, H, i, K, pinions and
wheels for producing the proper relative speeds between the cutter and pulleys; L,
weight, which by levers M and N, causes the pressure of the holding pulleys.
4th. Preparing.-By this term is understood those preliminary operations through
which both line and tow must pass after the heckling and before the spinning process.
The mechanism  and modes of proceeding for this purpose, which consist of repeated
drawings, are similar for "long" line or "cut;" though the dimensions and fineness
of the machinery must be made suitable for their various lengths and qualities. But
in the preparation of tow a peculiar additional operation is demanded, as a conse
quence of the different state of the fibres of which the material is composed; this operation, termed "carding," has for object to bring the highly irregular and entangled
mass into a somewhat more homogeneous and uniform  state, previously to its being
afterwards drawn and equalised in a manner similar to line.
In the preparation of line the first operation is called "spreading," and the machine
employed a "spreader," or first drawing: those subsequently are the second and third
"drawings" (sometimes a fourth is used), and lastly the "roving." It is upon the
spreader that the separate stricks of line are first combined and drawn into long
uniform bands or ribbons, called "slivers," of determinate lengths. This is effected
by subdividing the stricks into two or three portions, and then placing them consecutively slightly elongated; and overlaying each other about Iths of their length upon
and in the direction of an endless creeping sheet or apron. The machines are generally
made with two of these creeping sheets or aprons, and upon each sheet are thus laid two
distinct lines of stricks; each of which forms a thick uniform body of line, capable
of being maintained to an indefinite length. These endless creeping sheets supply
continuously another part of the machine, where the body of "line" is drawn out
to between 20 and 60 times its original length, according to whether it is composed
of cut or long flax. This part of the machine comprises a pair of holding or back
rollers; an endless succession of bars called fallers, bearing combs of closely ranged
steel pins, through which the slivers are drawn; a pair of drawing rollers; an arrangement of diagonal or doubling bars; and a pair of delivering rollers; is generally termed the " gill frame," or " gill head," probably from the French word
"aiguilles" (needles), as descriptive of the combs, and to distinguish this machine
from those formerly used for the same purpose, which simply consisted of a series of
rollers under and over which the line was passed.
The following figures 614, 615, show the outline of the present most approved gill
spreader or first drawing.
A A, general frame of the machine; B, driving pulleys; c, auxiliary frame for endless
sheets; D, D, D, D, rollers for carrying the endless sheets or aprons; E, E, conductors to guide
and slightly condense the four bodies or slivers of line; F, can for receiving the sliver; G,
lever for weight on front or drawing roller; H, lever for weight on back roller; K, delivering roller shaft, spring and bell, which, by the intervention of geering between
it and the front roller, is caused to ring when any desired length of sliver is delivered.
a a, the iron drawing roller or boss; b b b, the wooden or pressing roller, by the pressure




FLAX.
of which upon a a the sliver is held during the greater velocity of these rollers over
that of c; the holding or back rollers elongate in exact proportion of its augmentation;
the holding roller c is in like manner pressed against another in order to assist the "gills"
in retaining the fibres; k, k, hooked rods to connect the weighted lever h with the holding roller c, and by the pressure thus caused insure its effect; dd, the sheet or surface
of " gills" composed of separate bars, as seen atfig. 614*, 615.*; e, rubber or cleaner of
pressing roller b; f', f, conductors to contract laterally the sliver at the moment of drawing; g, plate of metal having diagonal openings at an angle of 45~ (this plate is sometimes
called the "doubling bars," having been first made of separate bars) to the original
course of the sliver, in order to enable it to be turned in a rectangular direction and guided
to the delivering rollers h,h; this direction of the sliver is more distinctly seen atfg. 617.;
i, hanger or connector of pressing roller b to its weight lever c; 1, I, the screws or worm
shaft for carrying the gill bar dd; mm, the shaft with bevel wheels by which the screws
and raising the gill bars; pp, weighted guide lever or bell cranks for guiding the falle
Ull,       o       o    _          -        F     
| l _ i-  ^MUM    M
A:l             m4




760                  FLAX.'.''        P
613*
anIIy___h




FLAX.                                        761
in its descent, and moderating the shock caused by its weight when coming in contact
with the lower slide or support; q and r, worm and wheel for bell motion; s, t, u, v, o,
x, line of wheels from pulley to front roller and from front roller to back; 1, 2, 3, line
of geering from back roller to sheet; 4, 5, 6, 7, line of geering from roller to delivering
roller; 8, front roller to brush; y y, from back shaft to back roller.
The machines for the second, third, and fourth drawings, though in principle essentially
the same, yet differ in some of their minor details from the foregoing, as they do not require the feeding sheet to supply them, the " sliver," from the spreader having sufficient
coherence as to allow itself to be drawn from the cans direct by the back rollers of these
machines-neither is a bell motion requisite to determine the length of slivers produced
by them.  The subjoined sketches show the general parts requisite (figs. 616, 617.)
617
A A (fig. 616. 617.) framing; B, driving pulley; c, support of sliver carrier; D, roller
for carrying sliver; E, conductors; F, can containing the slivers from the first drawing;
G, receiving can; RH i, the heckle carrying spirals; I, the diagonal or doubling bars;
K, delivering rollers; L, the drawing rollers; m, mn, mn, the retaining rollers.
The roving frame is the same in regard to the arrangement of its back and front
618E
5 E~




'162                                         FLAX.
rollers and gills, as the drawing frames; and as the position and manner of regulating
the spoles'are generally the same as adopted for cotton, the description of these parts
therefore does not require to be repeated; but an improvement patented a few years
since by Mr. P. Fairbairn, of Leeds, of that part of these frames which relates to
regulating the taking up movement of the bobbin merits particular attention, as by it
the inconveniences of the older method of a weighted belt and cone, and those of the
more recent disc frames, are entirely overcome. The principle of this improvement
consists of driving a pulley by pressure between two discs running at equal speeds in
opposite directions, as seen at figs. 618, 619, 620.
Figs. 618, 619. To obtain the variable speed, instead of using a cone and belt as in
some frames, or the pulley and single disc as in others, a b, the horizontal driving discs,
the lower one a is keyed to the shaft d, while the upper b is free to turn upon it; i, bevel
wheel fitted to or forming one piece with the upper disc b; c bevel wheel keyed to shaft
d; e intermediate bevel wheel geering in the bevel wheels c and i, so as to turn them
in opposite directions, and consequently the disc to which they are directly or indirectly attached; g the variable pulley covered with leather and resting upon the lower
disc a, and itself pressed upon by the weight of disc b; it is thus driven at speeds
varying according to its approach to or from the shaft d, thus answering the purpose
of the traversing leather belt of the cone movement; h shaft keyed in the pulley g,
from which the variable motion is transferred to the bobbins.
A series of preparing machines, termed a " system," consists in general of 1 spreading
of 4 slivers at the drawing rollers, united into one by the doubling bars at the delivering
roller, 2 frames of second drawing, in all 24 bosses 2 frames, third drawing containing together 36 bosses: if a fourth drawing is required, 2 frames of 24 bosses each, or 48 bosses
in all. 180 spindles of roving in 3 frames will well supply 3000 spindles of medium
spinning. The mode of using this "system " is, as has already been said, first to spread
the stacks of line upon the feeding-sheet of the "spreader," then to receive the sliver or
slivers there produced into cans capable of holding 1,000 to 1,200 yards of slivers. Those
cans specially intended to receive the slivers from this machine are all made to one regular weight; thus, when filled, the weight of line each contains is correctly ascertained,
and by the bell motion the length is also known. Upon this basis is founded the method
of producing any desired number of yarn, and by doubling the slivers, a degree of
equalisation that the simple spreading would be unable to effect, for at each drawing
and at the roving several of the slivers from the preceding drawing are put together,
to be again reduced to one for this object alone. Hence, the weight of a determinate
length in yards of the desired yarn being known, a calculation is made, combined of the
drafts and number of doublings the material has to undergo, to determine what the
weight should be of that length of slivers contained in the cans from the spreader. It
is ordinary to put 10 or I 5 of these " cans " together, to form  what is called a " set,"
the slivers of which are united at the second drawing with the subsequent drawings
and rovings: the combination of two or three slivers at each boss is sufficient.




FLAX.'63
Though the above is descriptive of the "gill" frames now in use, yet it should be
understood they are by no means the first or only results of the attempts made to
correct the defective principle of the original roller machines, which were incapable
of holding or retaining the flax with a sufficient degree of regularity, owing to its
unequal length and unadhesive nature. The consequences were that the yarns produced were "lumpy" and unlevel, making it evident that some improved means were
necessary for more completely restraining and regulating the drawing of the fibres.
The most obvious way to do this was to introduce some mode of partial detention by
creating a friction among the fibres to imitate the action of the fingers in hand-spinning.
This lea to causing the slivers to pass through and among several ranks of serrated
pins, which was found very nearly to attain the object, and certainly greatly improved
the levelness and uniformity of the slivers.  Thus the use of "gills" became gejeral
about thirty years since.
Those first brought into general use were constructed with circular discs or plates
for carrying the faller or gill bar, which at the same time were guided by their ends
passing in fixed slides so as to bring the gill in as vertical a position and as near the
I    t 
6212
drawing roller as possible. The figures (621,622.) are profile and front views of the
working parts of one of these gills:-A, slotted plate or disc, of which a pair were keyed
upon a shaft B, so as to carry each end of the faller, D, passing through the slots c, c; E
the fixed excentric slide; G, H the drawing rollers; E the holding rollers.
This was succeeded by the " chain gill," in which the fallers were carried forward
by an endless series of connected links, or jointed together " slotted plates," instead of
the simple circular. The object of this was to increase the flat surface of gill bars
between the holding and drawing rollers, making it more suitable for the longer descriptions of material. The slides and rollers, being similar in these machines to those
in the former, are not repeated, but the sketch of five slotted plates is given infig. 623,
623    f   ilBl[HHIf
From the evident importance of bringing the retaining effects of the gills as closely
as possible to the point where the movement of the drawing fibres is greatest, several
attempts have been made to improve the above described gills in this respect. With
bE2




'164                                      FLAX.
this view  Messrs. Taylors & Wordsworth patented a gill of considerable ingenuity,
(fig. 624.) which therefore deserves mention, though it never came into use. Its description is as follows:a b the faller or "gill bar" in one piece, which were carried forward by an endless
chain; c, d slides placed horizontally over the gill sheet guiding the ends of certain
bell-cranks e/, jointed at their angle in the recess fg e of the gill bar, and at their other
end to the gill or comb g. By this arrangement, as long as the bell-cranks are in the
parallel parts of the slides c, d, the gill teeth will be above the faller a 6, but when they
arrive at the contracted part the guided ends will be brought into the position Q Q, and
consequently the gill depressed is G 2; this is so timed as to cause them to clear the
drawing roller, when, on again continuing their course, they are again caused to rise
and penetrate the sliver by the reversed inclination of the slides c,d at the back roller.
The objection to this ingenious machine was the largeness of the space suddenly
c.
Q.... -..............
625, \., 
M.~~~~~~




FLAX.                                          765
nmann~er they were first constructed, to approach closer than even in the most perfected
construction of the others, to the side of the drawing roller, and still maintain the pins in
a vertical position.  Recently this object has been more perfectly attainedb  apatented
improved construction adopted by Messrs. P. Fairbairn & Co., whereby the obstacle to the
faller wholly touching the roller has been removed, and thus producing the full holding
effect of the gill to the latest possible moment. This is effected by employing a method
of supporting the spirals by their working in tubular recesses in the side plate of the
machine; along these recesses are longitudinal openings through which the faller end
passes to enter between the threads of the spiral, and which serve also as slides to suport the faller.  As by this means the supports or plummet blocks that intervened
between. the end of the spirals and the roller are suppressed, the faller is enabled to
advance to the place they formerly occupied. Fig. 625. and 626. show this comparison of
the older and more recent methods. A, B spirals; c, c the parts by which they are sup
ported, being infi. 625. small pivots in plummet block D D, and infig.626.hollowtubeike recesses in frame plate c c; E, E pinions to work the upper and lower spiral together;
~F bearings; G drawing-rollers; H pressing-rollers; i i passage of the faller's descent.
Here it may be as well to observe that the same parties have still more lately introduced another important amelioration in these machines for remedying the noise and
wear and tear which ordinarily attend them by the abrupt and violent descent of the
faller. Fig. 627. shows a sectional front view of a head having this improvement
62T
applied. A A supports for screws; b, c top and bottom screws; d, d, the new cams fixed
on shafts parallel with the screws, and revolving at the same speed.  Thus, these cams
d, d receive the faller e e at their largest diameter, at the moment they are free to
descend, and guide them gradually down to the lower slide.
Thus constructed, the " screw gill " continues to be the most esteemed in principle,
though not without some serious objections in practice. For the abrupt and angular
movements of the " faller " even here not only liberate too suddenly a portion of the
fibres that should be but gradually relaxed at the moment of being drawn, but cause
considerable wear and tear to itself, the slides, and the gills attached to it; to which
cause of destruction must be added the great friction of the worm movement; these,
however, in "line" preparing, where the fbres are long and straight, and the drafts employed large, and where, consequently, a comparatively slow movement of the gills is
required, are not so much felt as in the preparation of tow, where they become serious.
In " tow preparing" the first operation, as before stated, consists of "carding," which
is generally repeated over two separate machines, which are respectively called the
" breaker" and the "finisher" cards. They are essentially the same in principle, and
vary but little in construction, the only difference being that the " breaker " is fed or
supplied by the disjointed parcels of tow from a creeping sheet (as the spreader with
"lne,") and delivers its slivers into a can, whereas the finisher is fed from a bobbin upon
which several of the slivers from the " breaker" are united by a machine expressly for
that purpose, called a "lap frame;" this card thus receives its supply of work in a very
regular form, and previously to delivering it in the form of slivers causes them to pass
over a gill, to consolidate and strengthen them before delivering them into the receiving
can: it is also generally clothed with a finer description of wire filleting than the
breaker.  Though it is the better method to card thus the tow twice, yet this second
carding is sometimes dispensed with; in that case this auxiliary " gill " is similarly
fixed to. the first card or breaker. The cards employed for tow are machines of con-'siderable weight and importance, the main cylinder, or, as it is sometimes called, " swift,"
being from 4 to 5 feet diameter and 4 to 8 feet long; those most generally employed
are 6 feet long. Previously to entering upon the detailed description of a card, it may
be as well first to trace in general terms the progress of its operations, as tending to
elucidate the explanation of the machine itself.
The tow is first divided by weighing into small parcels of 10 to 20 drachms; these are
then shaken out and spread so as to cover certain definite portions of the creeping
feeding sheet, by which they are conducted to the first pair of rollers called the feeders.
These rollers are covered with a leather band, in which are fixed in close array a
number of wire points about j an inch long, and having a tangential inclination to the




'766                                       FLAX.
circumference of the rollers, which are about 21 inches diameter.  The tow, passing at a
slow rate of progression between these rollers, is by them gradually presented to the
points with which the swift is likewise covered, also set in leather bands, but which are
about 2 inches wide; these points, the same length as those of the feeders, have an
inclined direction pointing to that in which the cylinder turns. The much greater
velocity of the   cylinder" combs and somewhat opens and breaks the tow as it slowl
arrives in contact, and the inclination of the pins at the same time carries it forward.
All such lumps and fibres as are not sufficiently opened and straightened by this first
contact, remaining prominent on the surface of points on the cylinder, are carried by it
against another roller, whose axis is parallel, and whose wire-covered circumference is
brought as near as possible, without absolute contact, in order to catch and retain these
prominent lumps and fibres; the points of this roller (called a "worker") are inclined
in a direction opposed to the movement of the swift, and, therefore, hold the "tow" to
be again combed and straightened as at first it was by the feeders: this is repeated eight or
nine times, by having that number of workers to the card; each of these workers has its
attendant roller, also covered with wire points, by whose inclination in a contrary
direction, and by the greater velocity of the roller, the tow is stripped from the workers,
to be again laid on to the cylinder. The strippers, though running at a greater velocity
than the workers, are still slower than the cylinder. The tow thus carried forward
gradually improving in openness and regularity as it passes each pair of "workers and
strippers," finally arrives at the roller called a doffer, of which there are two or three upon
a card, the wire points of which are in such a direction as to hook or catch the "tow"
as it flies."  The use of these several doffers is, that by placing each succeeding one
progressively nearer the swift, the longer and shorter fibres are successively and separately taken off. Each doffer is cleared by an oscillating comb, and the slivers conducted, if intended for the lap machine, into a can by delivering rollers; but if finished,
these delivering rollers are as it were the back rollers of the auxiliary gill, patented for
this application by Messrs. Fairbairn and Co.; whereby the slivers are not only saved
from all danger of derangement in their loose and porous state as direct from a card, but
the hitherto double expense of carding, and first drawing is reduced to that of carding
alone.
A A A, (fig. 627.) framing; B, swift or main cylinder; c, feed rollers, D, D, D, strippers to
feed rollers and workers driven by one belt from pulley E, and maintained tight by the
movable pulley F; G, G, G, workers; i, i, i, the three doffers; iH, iH, H, intermediate wheels
to connect the movement of the doffers with one another; K, K, K, oscillating combs for
their respective doffers; L, delivering rollers: M, back roller of auxiliary gill; N, gill
surface; o, p, drawing rollers; o, delivering rollers and bell motion for measuring the




FLAX.
628                                                    3         629
slivers into the cans R; s s, doubling plate; T, pulley for driving auxiliary gills by bell
from the pulley n.
The lap frame to which allusion has already been made as the necessary adjunct to
the cards when double carding is to be performed, is employed to collect together a
number of slivers from the "breaker" by winding or lapping them upon a cylindrical
piece of wood, which may be described as a bobbin shank, thus producing an equalisation
of the slivers of tow as the making up of sets effected in line preparing; from 50 to
60lbs. of tow is the usual complement of one of these bobbins, the length and the
diameter, when full, about 22 inches; thus, a 6 feet wide finisher card will take off these
bobbins at once; from 15 to 20 is the number of slivers usually wound together, and
the completion of a bobbin by the ringing of a bell, connected with the measuring
cylinder of the machine. The following is a descriptive drawing of the lap machine.
A   A, (fig. 630. & 631.) framing; B, measuring and pressing cylinder; c, c, c, driving
pulleys connected with different geering to change the speed as the bobbins fill; D, bobin or shank intended to be filled; E, table to receive the bobbin when about to be taken
from the machine; F, weight to increase the effect of pressure of the measuring cylinder
by the connecting rods G, G, G, which are split for part of their length in order to pass
the shaft H, and at another gg have racks into which work pinions keyed on the shaft of
620
-                              F  -




768                                          FLAX.
the hand wheel i, for the convenience of raising and lowering the cylinder and weight.
The shaft is is divided at the plates K and L., and provided with sockets to receive the
end of the bobbin shank B, which is introduced by sliding back the piece H n, and
returning it by lever m, and thus is coupled and turns together with two pieces of shaft
H, as also the disc plates K and L, which are to serve as temporary ends to the bobbin
during the time of its filling, and thus by turning with it avoid that rubbing and
felting effect upon the edges of the tow so injurious in the machines formerly constructed,
and by the bobbin acting as the driver to the cylinder the slivers are drawn tighter,
and thereby avoid those plaites that the other machines were so liable to produce.
As before mentioned, some objections were found to the working of the screw-gill, of
a nature detrimental to the machines themselves, which, though not of great importance
in "line," were much aggravated in tow preparing, as the lesser drafts there employed
cause a greater wear and tear of the fallers and gills. The objection to these machines,
however, is not confined to this point only, but extends also to their effect upon the
material itself. The fibres of the tow sliver, as coming from the cad, are in a light and
much confused state, which renders them liable to be easily separated; so that the faller,
by its sudden descent, has a tendency to draw some down, and become lapped by them,
as well as to make so marked a difference in the thickness of the sliver, by the withdrawal of the retaining comb, as materially to injure the quality of the yarn. Thus
this " gill " was not enabled to hold its place in tow spinning, when other circumstances
led to greater attention being paid to this important branch of the flax business, and it
became a desideratum to have a machine free from these defects, and capable of working
without derangement, at much greater velocity than was safe with the "screw-gill."
These desiderata the "rotary " gill, patented by Messrs. Fairbairn & Co., amply supplies.
For in this gill the circular form of the gill sheet obviates the necessity of having
several fallers, and the simple motion creates neither friction nor abruptness of effect,
while the retention of the fibres being continuous, the slivers produced are perfectly
level and uniform, consequently these gills are extensively applied, as the auxiliary gill
explained in carding, as well as for the subsequent drawings and rovings of tow, and
sometimes, as will be afterwards seen, to coarse spinning. The theoretical construction
of these rotary gills will be seen by the annexed sketch.
M, (fig. 632.) back rollers, but when applied to a card at top and bottom holding rollers
are again employed; N, the rotary gill sheet having the pins inclined backwards, so as
to insure the impalement of the sliver when the fibres begin to draw: p and o, the drawing and pressing rollers; the doubling bars or plates are the same to these gills as to
the " screw-gills."
Subsequently to the carding the preparation of tow is completed by making up sets




FLAX.                                          769
^    f   )  f)    ^I NK                           tSm
M~~
632f
w'~~,
of cans for the second drawing, as explained for line; these slivers are doubled and
drawn once or twice more, and then roved. The drafts used in tow preparing are
from 6 to 8, for as the fibres are shorter, it necessitates the employment of less draft.
In both line and tow preparing, lesser drafts are employed as the stages advance, the
gills finer, and the conductors narrower; also for both materials much attention is
requisite to keep the various parts of the machines in good order, free from bent or
broken pins, and chipped or indented rollers, for no subsequent operation can cure
the defects that may be produced by negligence in these particulars. The drawing
and roving frames for tow are shown infigs. 633, 634, 635.
A A, (fig. 634.) drawing framing; B, driving pulleys; c, rotary gill sheet; p, drawing
roller; E pressing; F, G, pairs of delivering rollers; A, doubling plate; rback conductor; K back roller wheel with pulley to turn the sliver rail.
A A, (fig. 634 & 635.) roving frame; B, pulley and fly wheel combined; c, drawing
roller: D, rotary gill; a a, stand for gill movement. The regulation of the bobbins
is effected in the same manner as already described for line roving.
6th. Spinning.-This operation consists in drawing the "rovings" down to the last
degree of tenuity desired, and twisting them into hard cylindrical cords, which are
called "yarns."
There are three modes of performing this operation; the first, and perhaps oldest, is
that where the drawing and twisting are performed altogether, with the material preserved dry, and without breaking or shortening the fibre; the second is that which
likewise, without changing the length of the fibres, draws them while dry, but wets
them  just at the moment before twisting.  This method is the nearest imitation of
hand spinning, and makes the yarn more solid and wiry than the first; as the fibres
of flax losing their elasticity while wet, unite and incorporate better with one another.
The third mode of spinning has been much more recently introduced than either of
VOL.i                                      6 F




770                                       FLAX.
634 1srW
635
the others, and by it the fibres are wetted to saturation previously to being drawn,
whereby they are not only much reduced in length, but their degree of fineness is increased by the partial solution of the gummy matter, inherent in the flaxen material:
owing to these circumstances equally good yarns can be produced by this mode of
spinning from line and tow of inferior quality, to what could be employed upon either
of the others, and not only that, but much finer yarns can be now spun than were
possible previous to its introduction. It has therefore not only nearly superseded all
other methods of spinning for yarns from 20's to the finest, but has much increased
the extent and importance of the flax manufacture.
The only difference in spinning frames for " line or tow," when employed for the
older methods, consists in the length of reach, which generally involves the necessity
of having separate machines for each material, though sometimes they are made with
a capacity to be adapted to either purpose. In the third method the same machines
were used promiscuously for " line or tow."
The yarns spun wholly dry are used for the coarse description of woven goods, as
packing canvass corn sacks, and when partially bleached for sheetings and towellings




FLAX.                                        771
as from its greater elasticity and openness it fills up better in weaving. Those spun
636          partially wetted are employed for a somewhat superior description of linen goods, and the solid silky appearance qualifies them  for drills, damasks, &c., as well as for sewing
Iand  shoe  threads; a  somewhat inferior material, by this
manner  of treatment, makes an  equally good  yarn  as a
better material spun dry.  The yarn produced from  this wet
principle is rather inclined to have a cottony appearance, and
from  the comparative ease with which an inferior material can
be made, to represent an apparently fine good yarn, the application of yarns thus produced is exceedingly various and sometimes deceptive, though when good materials are used, these
yarns afford durable and handsome drills, shirtings, lawns, and
cambrics, as well as fine sewing threads.
1The mechanical arrangement for twisting, and then wind-'ing the yarn upon a bobbin, is called the "throstle" principle,
supposed to be so called from  the whistling noise they create
I   when working at full speed, which is from  2,500 to 4,000
revolutions a minute.  The following diagram will explain the
principle, which is applied alike to all the modes of spinning
above described.
A A, (fig. 636.) the spindle; B, the bobbin, loose and independent of the spindle in regard to turning, and rising, and
lowering, but through which the spindle passes; c c, the flyer
screwed to the spindle top; D, table  called  bobbin lifter,
as while at work it rises and lowers to lay  the yarn  on
ithe whole bobbin equally; E, a small cord to press on the
Ibobbin by the weight F; G, pulley by which  the spindle is
j          driven.
Many  attempts have  been  made  to  improve  upon  this
principle, in order to avoid or lessen the strain  upon the
thread in its passage from  the drawing rollers to the flyer
eye; but, till recently, without any degree of success.  The
only improvement at present known, and which promises
to become general, is that where the necessity to have a top to the bobbin is avoided.
It will be seen from the above diagram, that the yarn is compelled to rub the top of
the bobbin, and the friction thereby created quickly causes it to become rough; and
therefore it has a tendency to catch and break the thread. The desirableness, therefore, of having a clear course for the yarn was evident, and this improvement that
we are about to explain produces the effect by employing what is called a coping
motion, which, like that used in mule spinning, preserves the layers of thread upon the
bobbin ever in a pointed or conical state, and therefore self-supporting without the aid
of the wooden end of the bobbin. See COTTON SPINNING.
The arrangement of the rollers for holding and drawing the slivers or rovings, as
well as the plates and rollers for aiding to retain the twist of the rovings, in order to
render their elongation more equable when to be drawn dry and spun upon the older
methods, will be seen infig. 637.
A, (fig. 637.) roving bobbin; B, back or holding roller; c, carrying roller, d flat plate
with a slightly curved face; the carrying roller and plate are so placed as to cause a
degree of friction to the roving when passing over them, so as to retain the twist, and
thus act as the pins in the " gill frames;" e, tin conductor for contracting the roving
at the moment of being drawn; f, metal roller; g, wooden roller pressed against the
drawing roller in order to pinch the roving; h, lever and weight. When it is intended
to wet the yarn previously to twisting, the trough i is used, in which is water, which
is supplied to the roller g by the capillary attraction of a piece of cloth immersed
therein, and bearing against the roller by lever ks.
The machines for " wet" spinning are of a very different construction and appearance;
as the close proximity of the holding and drawing rollers prevents the intervention of
holding rollers or friction bars, while the force requisite to draw the rovings at the short
reaches used, varying from 2^ to 4 inches, requires each pair to be deeply and accurately
fluted into one another. The water used is heated, in order by the expulsion of the
fixed air more rapidly and completely to saturate the rovings while passing through
it. The following drawings and description will be sufficient to give an accurate idea
of the principle of these machines, which are generally 20 to 30 feet in length, and
contain 200 to nearly 300 spindles; that is, 100 to 160 on each side.
A A A A, (fig. 638. & 639.) framing; B B, stand for roving bobbins; c, driving pulleys
fixed upon the axle of cylinder D, from which pass endless cords to drive the spindles
5F




'l2                                       FLAX.
A
C
Id)
a
e e; F, step rail of spindles; G, collar rail for ditto; H, bobbin lifter; i i, front roller; x K,
back roller; i, back pressing roller; Y, top pressing roller (these are generally made of
box wood, but sometimes of gutta percha); N, N, levers in connection with the excentric to
produce the rise and fall of the bobbin lifter; o o, thread plate; Q, Q, saddles or transverse
Cars resting on the axles of the back and front pressing rollers,so that one lever and weight
acts for both by the connecting rod to lever r r, which, in order to cause more pressure
on the drawing than on the back roller, is placed on the saddle nearer the former than
the latter. 1, 2, 3, 4, 6, 6,'7, 8, train of wheelwork, by which the movements are dis



FLAX.
tributed. a, a, a, the trough of hot water maintained by steam-pipes at the desired temperature; b, b, guide rods or pipes to cause the roving to pass under the water. In
order to avoid the rollers becoming indented by the roving always passing on the same
place, they are caused to traverse the breadth of the rollers by a traversing guide rail,
moved by an excentric at the worm and wheel c; d, flyers, andf, spindles.
Here it may be proper to introduce a description of the machines for twisting the
yarns when spun into " threads" used for sewing, &c.  The yarns spun for this purpose
should always be made of a somewhat superior description of line to that employed for
the same number of yarns for weaving, and have rather less twist. They are generally
taken while wet on the spinning bobbins to the twisting frame, and, when combined
together, the union is effected by a torsion in the opposite direction to the original twist
of the separate yarns.
6. Reeling. - This operation consists in winding the yarn off the bobbins of the
spinning or twisting frames, and forming it into hanks or skeins. The various denominations of the skeins into which yarn is reeled, and then the forms or combinations
they are made up into, are as follows:The lea containing 300 yards
10 leas making           I hank
20 hanks                 1 bundle
6 bundles,,             I packet.
It is by the standard lea of 300 yards that the description of yarn is known from the
number contained in 1 lb. weight; thus No. 20. contains 20 leas or 6000 yards for 1 lb.
weight. In Scotland, the subdivisions are rather different from the foregoing, which
are employed in England and Ireland; the lea, however, remaining the same:~
38 leas make 1 spindle
6, I rand
12 rands,,      I dozen.
The reeling is peformed upon exceedingly simple machines, generally put in motion
by the hand of the person attending them, though sometimes they are driven by
the motive power of the factory. The reel is made sufficiently long to receive twenty
bobbins, and the barrel upon the yarn is found in one length; the diameter, however,
varies so as to suit the different-sized yarns to be reeled. For the coarsest yarns and
down to 16. and 20., the largest circumference is used of 3 yards, from that to about
No. 100. 2j yards, and for the finest yarn 1k yards is found most convenient. These
various circumferences are compensated either by putting a great number of threads




774                                      FLAX.
into each "tye," or increasing the number of tyes, so that opposite to each one of the
20 bobbins an entire hank should be formed before taking theach
" stripping," one bundle is turned off. To facilitate the stripping, one of the rails of the
barrel is made to fall in, and thus slacken the hanks; care is taken to leave the leas
bands very loose, in order to allow the yarn to be spread out in drying and bleaching.
The determinate lengths of yarn, when wound on the reel, are notified by the ringing
of a bell connected with the axle of the barrel. Figure below shows the form of an
ordinary hand-reel.
D^  _______  D     A A (fig. 640.) framing; B B
8640                                            reel barrels; c box or trough to
BJJiV  ~     receive empty bobbins, &C.; D ]
_ A =.    ^  ~^^\.     bobbins in position of being reeled;
/  E E guide rails moveable so as to
place the  leas side by side on the
reel; ff bell wheels; g     bells
for each reel barrel suspended on
springs.
To these hand-reels there are
TheseA^ objetion  renmany objections; for it is evident
the inrdcio  o  a reel ta  atm                that the correctness of measure depends entirely upon the attention
^;ipr   I  ^^ q   q          \/^of the reeler, and the stoppages
to be woundarising from  the breaking  of a
s fo~                 ~.... whenathreadbr,thread or the finishing of a bobbin
rah einterrupt the work of all the others.
These objections rendered it necessary to attempt some ameliorations of the system by
the introduction of a reel that should automatically prevent these causes of error.
Such a reel was patented a few years since, and is now in general use in Scotland;
it is so contrived as to have the capacity of stopping itself when a thread breaks, when
a bobbin finishes, and leas and hanks complete:; and having but four or five bobbins
in one compartment, the stoppages affect but few at a time; and as this machine can
be worked by less skilful persons without possibilit of error, much saving is effected
both in wages and material. The annexed figure (641.) shows the principle of this
improved reel.
A A (fig 641.) framing; B reels; c, c pendulums on which are hung the bobbins
to be wound off; D driving shaft with ratchet wheels opposite to each pendulum,
so that when a thread breaks, the pendulum to which it was attached falls into the
ratchet wheel, and thus stops it.
The drying of wet spun yarns should always, when possible, be done in the open air
uy spreading the hanks upon horizontal poles through them, with another similar pole
resting inside upon their lower extremities, in order to keep them straight. If artificial heat is employed, that from steam or hot water is preferable, and it should
never exceed 900 Fahr., as otherwise the yarn is apt to become harsh.




FLAX.                                    775
7. Making up.-By this operation is first produced upon the yarns a certain softness and suppleness, and then the hanks are folded and tied up in conveniently-sized
packages.
In order to give the yarns that soft and mellow feel so agreeable and characteristic
of flax yarns, the hanks, when brought from the drying, are what is called shaken
down and pin-worked. This is done by separating a few at a time, and passing them
on to a strong arm of wood fixed to a wall or pillar, when with a heavy baton put
through them, the workman proceeds to stretch the hanks with a sudden check or
jerk, which operation he repeats in two or three places so as to thoroughly straighten
and shake them loose; he then, using the same baton as a lever, twists them lightly
backwards and forwards till the desired degree of suppleness is obtained. A brush
is sometimes used to aid the straightening and separating, as well as to increase the
gloss on the yarn. The hank or hanks will then be found to have assumed a flat
shape, as on the reel, which facilitates their folding with a dexterous twist by their
middle, when they are laid in square piles upon a table with their twisted folds one
upon another. They are maintained in the perpendicular by a few supports fixed in
the table. Sometimes these packages, which, according to the sizes of the yarn, consist of from i of a bundle to 5 or 6 bundles, are bound together by some of their own
hanks, but sometimes by cords in three or four places of their length. It is, however,
better to employ a bundling press than an ordinary table, as the yarn can then be
made up more solidly, thus both improving its appearance, and causing it to occupy
less space for packing and stowage. The bundling presses are made upon the same
principle, but on a smaller scale, for making up the small packets, in which sewing
threads are generally presented for sale, and are upon the following construction,
(figs. 642, 643)
642                                                CO n M F      643
D                   ID                                  D
AF...._..             \
~   _
A...
Fig. 642. front view; Fig. 643. profile. A A A frame; B table or flat top of frame; o
rising table; D D iron uprights fixed to B; E E bars hinged at one end to uprights D D,
to shut across the press, and be caught and latched down by the spring catch L fixed
to the upright D along one side of the press; F F racks for lifting the table c by the
pinions on shaft G; H crossed levers for turning the shaft G; I ratchet wheel engaging
the detent K, and thus retaining the shaft G in any required position, and thus of course
maintaining the pressure of table c against the top cross-bars z.
8. Weaving, is the operation by which the yarns are combined into textile fabrics,
such as canvas, linen, drills, damasks, &c., and a great variety of other denominations
of article for use and ornament.
Hitherto the weaving of linens has been carried on by the ancient and well known
hand process, so ancient and so well known as to place the operative practising it
among the worst paid of any other art. Now, however, there are several extensive and
thriving establishments, where machinery has taken the place of much squalid misery,
and at much cheaper rates produces to consumers superior articles, and still affords good
payment to the operative. The improvements in power weaving which have led to
this result are not founded upon one or even a few successful inventions or contrivances,
but are the combination of a great many that have occupied much time to mature.
Many difficulties had to be overcome in the weaving of flax that did not exist in that of
other materials; and for a considerable period the expense of linens rendered their




17176                                   FLAX.
consumption so limited, as to make their production by power weaving but a very
secondary object. The greatest obstacle of a practical nature to the introduction of the
automatic weaving of linens was, the stubbornness or want of elasticity in the yarn,
which caused frequent breakages, and much confusion. In woollen or cotton goods,
if a thread or yarn should chance to be a little tighter than the others in the warp, its
elasticity will allow it to come up to the general bearing of the others when the weft
is struck up by the reed; but in linen, from the want of that elasticity, a thread so
situated would break, and by crossing some others cause them, if not to be broken
direct by that circumstance, at all events cause an obstruction to the shuttle that would
lead to further mischief. Hence it was most material in linens to have such a method
of winding the yarns upon the warp beams that should insure the greatest regularity;
but strange to say, that point, though now attained, was at first wholly lost sight of.
That circumstance, as well as the great mistake of attempting to use the same looms as
are found suitable for cotton, produced so much discouragement in the earlier attempts
as to give rise to a high degree of prejudice against the possibility of success in this
undertaking, which may account for the backwardness in which this branch of the
flax manufacture was found till quite recently. See article FLAX WEAVING LOOM.
The new roving machine, called by the ingenious inventor, Mr. W. K. Westley, of
Leeds, the SLIVER RovING FRAME, seems to be a philosophical induction happily drawn
from the nature of the material itself, and accommodated to its peculiar constitution.
It is remarkable for the simplicity of its construction, and, at the same time, for its
comprehensiveness; requiring no nicety of adjustment in its application, and no tedious apprenticeship to be able to work it.
It is known, that the glutinous matter of the plant may be softened by water, and
hardened again by heat; of this fact advantage is taken, in order to produce a roving
wholly without twist; that is, in the form of a ribbon or sliver, in which the fibres are
held together by the glutinous matter which may be natural to them; or which may,
for that purpose, be artificially applied.  The sliver roving, as long as it remains dry,
possesses all requisite tenacity, and freely unwinds from the bobbin, but on becoming
again wetted in the spinning frame, it readily admits, with a slight force, of being
drawn into yarn, preserving the fibres quite parallel.
The diagram, fig. 644., shows in explanation, that
A, is the drawing roller of the roving frame in front of the usual comb.
B, the pressing drawing roller.
c, a shallow trough of water.
D, a cylinder heated by steam.
z, a plain iron roller for winding.         F, a bobbin lying loose upon the winding
roller, and revolving upon it, by the friction
of its own weight.
The roving, or sliver, as shown by the
dotted line, after leaving the drawing rol644                     lers, A, B, passes through the water, in the
trough c, which softens the gluten of the
fibres; and then it is carried round by the
steam  cylinder D, which dries it, and de/                 >^          livers it hard and tenacious to the bobbin
F, on which it is wound by the action of the
roller E.
M~^  yl   TQ   j;        This is the whole of the mechanism  required in producing the sliver roving. All
/ J.'  ^J'  the complex arrangements of the common
cone roving are superseded, and the machine
at once becomes incomparably more durable, and easier to manage; requiring only
half the motive power, and occupying only half the room. A frame of 48 bobbins is
only 6 feet long, and affords rovings sufficient to supply 1200 spinning spindles.
This machine, though here described, is but little used, being capable of but very
limited application.                                                          A.
The following sketch shows the arrangement of the machinery in the most important
rooms in a modern flax mill of l000 to 8000 spindles, capable of producing, weekly,
about 1900 bundles of line yarn, No. 25.'s to 120.'s; and about 700 bundles of tow
yarn, No. 10.'s to 40.'s.
There are three systems of long line machinery for No. 25.'s to 70.'s; two systems of




FLAX.                                          7
645
E    El                      it 1              1
cut line machinery for No. 10.'s to 120.'s; and three systems of tow machinery for No.
10.'s to 40.'s.
The building is 56 feet wide and 162 feet long; which is a very suitable and convenient size, and which admits of the most economical arrangement of the machinery.
The following is a description of the machines shown in the preparing room: -
A, A, two of Baxter's patent sheet hackling machines for long tow.
B, a flax-cutting machine.
c, one of P. Fairbairn & Co.'s patent double line of holder hackling machines for cut
line.
D, D, are two breaker cards 4 feet diameter X 6 feet wide.
E, lap machine.
F, F, F, are three finisher cards 4 feet diameter X 6 feet wide, with P. Fairbairn &
Co.'s patent rotary gill drawing heads attached.
G, G, are two patent rotary gill drawing frames for long tow, 12 slivers each.
n, i, two ditto regulating roving frames 48 spindles each for long tow.
i, is a screw gill second drawing frame of 3 heads for cut line tow.
K, is a screw gill third drawing frame of 3 heads for cut line tow.
L, a screw gill regulating roving frame of 72 spindles for cut line tow.
X, M, M, are three long line first drawing frames or spreaders of 4 bosses each.
N, N, N, are three long line second drawing frames of 2 heads each.
o, o, o, are three long line third drawing frames of 2 heads each.
P, P, H, three long line regulating roving frames 60 spindles each.
Q, Q, are two cut line spreaders of 4 bosses each.
s, r, two cut line second drawing frames 2 heads each.
s, s, two cut line third drawing frames 2 heads each.
N, T, two cut line regulating roving frames 72 spindles each.
The spinning room contains 34 spinning frames of 184 to 244 spindles each, apportioned to the several systems as described below.
I. System of long line machinery for spinning No. 25.'s to 40.'s.
1 Baxter's patent sheet hackling machine, 6 tools.
1 spreading or first drawing frame, 4 bosses.
1 second drawing frame, 2 heads 4 bosses each.
1 third drawing frame, 2 heads 6 bosses each.
1 patent disc regulating roving frame 60 spindles, 10 spindles per head, 8 inches
X 4 inches bobbin.
5 spinning frames 21 inches pitch, 200 spindles each, 1000 spindles.
The production of this system is about 66 bundles, or say, 420 lbs. of No. 30.'s yarn
per day.
II. Two systems of long line machinery for No. 40.'s. to 70.'s.
1 Baxter's patent sheet hackling machine, 8 tools.
2 spreaders or first drawing frames 4 bosses each.
2 second drawing frames, 2 heads of 6 bosses each.
2 third drawing frames, 2 heads of 8 bosses each.
2 patent disc regulating roving frames, 60 spindles each, 12 spindles per head, 6
inches X 3~ inches bobbin.
10 spinning frames, 220 spindles each, 2~ inches pitch, 2200 spindles. Production
about 130 bundles, or 472 lbs. of No. 55.'s yarn per day.
VoL.. I.                                5 G




778                                  FLAX.
646
X,,,X,,,S      _ _   _,       _._ Li_ L__i__..            t
III. Two systems of three cut line machinery for No. 40.'s to 120.'s (one for 40.'s to
70.'s, and one for 70.'s to 120.'s).
1 flax cutting machine.
1 P. Fairbairn & Co.'s patent double line of holder hackling machine.
2 spreaders or first drawing frames 4 bosses each.
2 second drawing frames, 2 heads each, 6 slivers per head.
2 third drawing frames, 2 heads each, 8 slivers per head.
2 patent disc regulating roving frames, 72 spindles each, 12 spindles per head,
6 X 3+ inches bobbin.
5 spinning frames 220 spindles each, 2+ inches pitch, = 1100 spindles.
5 spinning frames 244 spindles each, 2+ inches pitch, = 1220 spindles.
Production about 65 bundles or 236 lbs. of No. 53.'s yarn per day, and about 50
bundles or 105 lbs. of No. 95.'s yarn per day.
IV. Two systems of long tow machinery for No. 10.'s to 25.'s.
1 breaker card 4 feet diameter 6 feet wide, doffed by rollers.
1 lap machine.
2 finisher cards 4 feet X 6 feet with P. Fairbairn & Co.'s patent rotary gill drawing frames attached.
2 patent rotary gill drawing frames 12 slivers each.
2 patent rotary gill disc regulating roving frames, 48 spindles each, 8 inches X 4
inches bobbin.
3 spinning frames, 184 spindles each, 8 inches pitch for No. 10.'s to 18.'s = 552
spindles.
3 spinning frames 200 spindles each, 21 inches pitch for No. 16.'s to 25.'s = 600
spindles.
Production about 39 bundles, or 488 lbs. No. 16.'s per day, and about 39 bundles,
or 312 lbs., No. 25.'s per day.
V. One system of cut tow machinery for No. 25.'s to 40.'s.
1 Breaker card 4 feet diameter 6 feet wide, doffed by combs.
1 Finisher card with P. Fairbairn & Co.'s patent rotary gill drawing frame
attached.
1 Screw gill second drawing frame 3 heads each, 4 bosses per head.
1 Screw gill third drawing frame 3 heads each, 6 bosses per head.
1 Screw gill patent disc regulating roving frame 72 spindles, 12 spindles per head,
6 X 3+ inches bobbins.
3 spinning frames of 220 spindles each; 2+ inches pitch, = 660 spindles.
Production about 36 bundles. or 240 lbs. of No. 30.'s per day.
The reeling is generally carried on in the attic above the spinning room, and the
number of reels required is about the same as the number of spinning frames.
Summary view.
There are 3200 spindles long line, producing 196 bundles, or, 890 lbs. of yarn per day.
1152,,  long tow,,,    78,,     800
2320,,    3 cut line,,,   115,,       340,,
660,,     cut tow,,,    36,,        240,,
7332 spindles                   425 bundles   2270 lbs. of yarn per day.
The waste in line spinning is generally about 10 per cent., and in tow spinning about
25 per cent., so that the quantity of raw flax required to produce the above stated
quantity of yarn would be about 20 cwts. of flax for long line and long tow spinning
and about 6 cwts. of flax for cut line and cut tow spinning.




FLAX.
Claussen's Patent Process.-The great interest which has of late been excited in
the puiAic, mind with respect to flax, in part by the enlarged sphere of application which
is supposed to be opened out to it by the discoveries of Mr. Claussen, and more particularly from the fact, that it is a material of home growth, and capable of production
in unlimited quantities in Ireland, would seem to demand from us special comment.
We are -not the less inclined to this course, as the public is ever ready to take upon
trust the practicableness of any new projects, when their promised results chime in
with any feeling of sympathy which happens to pervade the community; thus where
the interest of Ireland is concerned, we find that commercial schemes for aiding its advancement are eagerly seized upon, and confided in almost without inquiry; but this
is far from a prudent course. There can be no question that the flax trade is the
growing manufacture of Ireland, and, as such, too much attention cannot be given to
the production of the raw material; it has therefore been encouraged in every legitimate way, but it may be questioned whether the late announcements which have
been made of its almost universal applicability to textile fabrics, will not tend to
direct capital to too great an extent into this now thriving branch of industry, and
thereby quickly induce a false and ruinous competition between manufacturers.
Flax, though apparently, from its fibrous character, better suited by nature than
either cotton or wool to be formed into thread, nevertheless presents many difficulties to
manufacturers, which are quite foreign to the working of these short staples, and which
can only be in part remedied by the adoption of a somewhat different process of manufacture. In contradistinction to cotton, which may be considered the fruit of the plant,
flax is the filamentous substance contained in the stalk of the plant. It has therefore
to be obtained from stripping off the bark or woody coating, termed the "boon."
But, in order to effect this, as well as to detach the fibres from each other, it is
necessary to dissolve the gum or resinous sap, which pervades the plant, and binds
the several parts together. Various plans have been suggested for attaining this
end; and it is upon the efficiency of the process adopted that the ultimate success
of the flax trade mainly depends.  When it is understood that the growth of the
flax plant is principally in the hands of small farmers without capital, and that the
bulk of the flax, when reaped, is so disproportionate to the yield for manufacturing
purposes as to preclude the removal of the article to any great distances in the
state of straw, it will readily be seen, that no process of dissolving the gum or of
"retting" as it is termed-requiring the purchase of expensive apparatus, or demanding the exercise of scientific knowledge-can  be brought into general use,
however efficient that process may prove to be. It cannot, therefore, be wondered at
that the old plans of water-retting and dew-retting still prevail, although a far
superior method, which we shall presently explain, has been introduced.
Retting is simply bringing the plant to a certain stage of decay, which causes a perfect loosening or separation of its fibres. In carrying out the water-retting process pits
are dug in the ground and filled with water, and the flax is thrown in in bundles and
pressed down by weighted boards, to keep it under water. After a short time, fermentation commences, and in about ten days (more or less, according to the mean temperature) the decaying process will have proceeded sufficiently far; the flax is then taken
out and dried, and the boon is removed by hand. The retting may be carried on in
either running or stagnant water; but the latter, although the more expeditious method,
requires closer watching, to prevent the flax from losing its strength of fibre by over
decay. It will be obvious that large masses of vegetable matter exposed to putrefaction
must generate such exhalations as are very injurious to the health of the community.
Yet this practice not only prevails, but will, as we think, necessarily increase in proportion to the increase in the growth of the plant, unless some energetic means are adopted
to put down the practice. Dew-retting is a process that is less objectionable, but its
operation is far slower, and it is altogether beyond the means of many farmers to adopt.
In this instance the flax is strewn thinly over meadow or grass land, and then submitted
to the action of the air, dews, and rain, which, in a period varying (according to the
mean temperature) between three and six weeks, will effect the required disunion of the
plant.  This plan has an advantage over the water-retting, inasmuch as the flax is
yielded of a brighter colour,-the latter process being very apt to impart a deep stain
to the fibres, as well as to destroy their tenacity.
The improved plan of retting, above alluded to, was introduced into Ireland from
the United States in 1847, by Mr. Schenck of New York. It had been tried there successfully on hemp; the strength of the fibre, when made into cables, having been proved
in some of the government navy yards to exceed any that had been retted on the old
system. The process was patented in the United Kingdom  in 1846, and is now in
profitable work near Belfast. A recent inspection of the factory will enable us to
state in detail the manner of proceeding to separate the long fine fibres of the flax from
the boon. The principal apartment in the building contains a number of large circular
6 G 2




'780                                    FLAX.
vats, in which the flax is steeped, and these are provided with steam-pipes connected to
the steam engine boiler. The flax to be operated upon is placed in these vats andpiled
up to a given height; strong cross-bars of wood, forming a kind of framework, are then
laid above the flax and secured to the respective vats,-the object of this framing being
to keep the flax down in the vat, as otherwise it would rise as it swelled in fermenting,
and protrude above the water. When a mass of flax is thus secured, water is run into
the vats, and as it becomes absorbed, more water is added. Steam is now admitted into
and made to circulate through the steam-pipe at the bottom of the vat, so as to raise the
water to about 90~ Fahr., and maintain it at that temperature. In a few hours acetous
fermentation is established in the vat, and the decomposition of the resinous or gummy
matter in the stalk proceeds with rapidity. After about sixty hours the decomposition
is completed, and that without the exudation of any inodorous or noxious effluvium. The
water surcharged with the mucilage is then drawn off, the framing is removed, and the flax
is taken out of the vat to be dried, either in the open air or by artificial means. Thus,
not only is the objection to the old plan, on the score of injury to health, removed, but
a considerable economy in point of time is effected; the flax also is less liable to deterioration in colour and strength of fibre, if ordinary care is used in conducting the operation.  When the weather is favourable for drying in the open air, the flax, tied up, in
tufts or handfuls, is suspended in rows tier above tier, in an open framing, covered in at
top by a penthouse roof. This mode of packing admits of a large quantity of flax being
stowed in a small compass, and yet allows of a free access of air through the whole mass.
When it has hung a sufficient time to dry, it is next submitted to the scutching operation.
Or, instead of open air drying, the flax, in damp weather, is piled loosely in a drying
chamber, into which a current of air, heated after Messrs. Davison & Symingtons
method, is passed, and the moisture is quickly expelled. The cost of this operation, as
carried on at the works, must be very trifling, as the waste steam from the engine,
which works on the high-pressure principle, is found amply sufficient for heating the
air; an advantage consequent on this mode of heating is, that no carelessness on the
part of the attendants will render the air liable to be heated to an extent that would injure the flax. The flax having been retted and dried, is next carried to the rolling or
crushing mill, and there passed, by hand, between rotating horizontal rollers, which
crack the boon already loosened by the retting process, and spread, or partially separate,
the long fibres. The flax, as it is delivered out of the machine, is gathered up by boys,
and handed to others, who submit it by handfuls to the action of rotating knives. These
knives are attached to the face of a vertical wheel, several of which are mounted on one
and the same shaft, at about three feet apart, and receive motion from the engine.
There is an attendant stationed at every wheel, whose duty is to submit the flax to the
action of the knives, by holding it over a fixed bar, contiguous thereto, and allowing the
rotating-knives to strike the flax in the direction of its length. When the boon on the
half length of the flax is broken away or knocked off, the flax is turned over and the
other end is subjected to similar treatment. To further clear the flax of the woody particles, it is again submitted to a similar operation before another set of wheels,-the
action of the knives being, in this instance, more thorough and searching, as the flax
has now approached nearer to a stick of fine fibres. Having undergone this treatment,
the flax is now ready for sale in the market; and it is in this state that it enters the
flax mill to be acted upon by the heckling-machine, for the removal of the tow or short
staple, prior to undergoing the various operations of preparing and spinning, to convert
it into yarn. From  this description, it will be understood, that, so long as the cultivation of flax is in the hands of small farmers, Mr. Schenck's process is not likely.to
put the old practice out of use; for the water-retting is carried on at little or no outlay
of money; and the cleaning of the flax by hand is made a sort of wet-day occupation:
the bulk of the flax in the state of dry straw,-which, as we have before said, is so
disproportionate to the amount of useful fibre as virtually to prevent its carriage to any
distant part prior to undergoing the retting operation-scarcely exceeds, when carried
to the market, 20 per cent. of its original weight.
M. Claussen's patented process (the merits of which have been so confidently paraded),
does not seem to be in favour with the Irish flax spinners, although the specimens contained in the Exhibition appeared to the eye to realize everything that could be wished:
but here, as in many other manufactures, it is not the attainment of a high degree of excellence that is the difficulty, but the cost at which such a result may be arrived at.
Thus flax may be dressed from the straw, as, indeed, it was once proposed to be done,
without being subjected to the retting process. The waste of material, however, soon
showed the impracticability of the plan, although a good article was produced; it is
possible, therefore, that M. Claussen's specimens may have been obtained without regard
to cost. We do not assert this as a fact, but rather to show, that in commercial matters
no just conclusions can be arrived at without the question of cost being taken into
account.  His mode of treating the flax will be readily understood from the following




FLAX.                                          781
description, which we have compiled from his specification. The straw, having been
stripped of its seeds, is steeped in a solution of caustic alkali, of about the strength of 10
Twaddle's hydrometer, either in a boiling state, which renders an immersion of six
hours sufficient, or at a temperature of 150~ Fahr., which will necessitate the continuance of an immersion for about twelve hours. By this means the glutinous matters,
which connect the fibres with the woody portions of the plant, are dissolved, and the
colouring matters contained in the straw are discharged and prevented from staining the
fibres. When the flax is required to be spun in long staple, the straw is next steeped
for about two hours in dilute sulphuric acid, containing one part of acid to from two to
five hundred parts of water, for the purpose of ridding it of the alkali which it has taken
up; the straw is then removed from the acid-bath and well washed in water: this isone
process. But the one which has raised the public curiosity, is that which purports to
split the fibres into fine filaments like those of cotton or wool. This operation is
effected as follows:-The straw is put into a bath containing a strong solution of
bicarbonate of soda, and allowed to remain there for three or four hours. When well
saturated with the bicarbonate, it is immersed in water, acidulated with sulphuric acid,
in the proportion of one part of acid to two hundred parts of water; the sulphuric acid
will then combine with the soda and effect the disengagement of carbonic acid gas in the
fibrous tubes, which gas, by its expansive force, will split the fibres intofinefilaments,
having the appearance of fine cotton wool, and capable of similar treatment. This splitting process may be applied to the plant either in the state of straw, or after it has been
retted and brought to the state of long fibre; and it is therefore capable of general
application, as far as the inconvenience arising from bulk is concerned. What manufacturers will eventually say to working up fibres that have been steeped in sulphuric acid,
may depend upon the means taken to extract this corroding substance from the flax; but
at present we think there is a strong feeling against its use.
Mr. Claussen's patent process for treating flax is described as follows, in his specification of March, 1851:"1. My said invention, in so far as respects improvement in bleaching, has reference
to the bleaching of all kinds of vegetable productions, and of fabrics or articles composed of such productions, and consists of the following improved processes. In the
usual methods of bleaching fabrics, such as calico, the goods are first immersed in
a bleaching liquor (commonly the solution of hypochlorite of lime,'the chloride of
lime' of commerce), and then are steeped in a bath of water, acidulated with sulphuric
acid. By this plan, the chlorine is set free, either in its simple form, or in combination
with oxygen (as chlorous or hypochlorous acids), or in chemical union with the
hydrogen of the water (as hydrochloric acid), and thus either is wasted, by its escape,
or is rendered injurious to the fabric, by remaining too long in contact with it.
"Now instead of this I adopt the following process, whereby the whole, or a great
portion of the chlorine, or chloro-compound, is kept in a combined state, and recovered
for further use.  By the term'chloro-compound,' I do not mean a salt containing' chlorine,' but an acid having'chlorine' for its base, such as chlorous or hypochlorous acid.
" In this process, then, of bleaching, I take the goods, after they have passed through
the bleaching liquor (say a solution of the hypochlorite of lime), and then steep them
in a strong solution of some salt, whose acid has a more powerful affinity for lime than
hypochlorous acid; thus a strong solution of sulphate of magnesia may be employed,
the sulphuric acid of which, having a strong affinity for lime, combines with the earthy
base of the bleaching salt above-mentioned, and forms sulphate of lime, and the chlorocompound being thus liberated unites with the magnesia of the sulphate of magnesia,
and forms a new salt (hypochlorite of magnesia), having bleaching properties similar to
the lime-salt first employed.
"This newly formed compound may be, in the next instance, used as a primary
bleaching agent, and may again be subjected to the process of double decomposition, as
in the foregoing example.  Thus, the goods having been exposed to the action of
hypochlorite of magnesia in solution, may then be steeped in a liquid holding in solution
some carbonate or other salt, for whose base the hypochlorous acid has a greater affinity
than for the magnesia. In such a case, the carbonic acid having also a strong attraction
for the magnesia, combines with it, to form a carbonate of that earth, and the liberated
chloro-compound, instead of escaping, or remaining so long in contact with the goods
as to injure them, combines with the base of the carbonate employed to produce decomposition, and forms a new salt, having bleaching properties. This salt may also
be brought under the same laws of double decomposition, as exemplified before, and with
similar results.
"Thus, if the carbonate employed in the foregoing instance had been carbonate of
bar tes, and a solution of sulphate of magnesia or of lime were brought into contact
with the resulting chloro-compound salt of barytes, a precipitate of the base, as a




'782                                      FLAX.
ulphate of barytes, will take place, and the chloro-compounds will unite with the lime
or magnesia, to form a bleaching salt.
" I would mention, however, that, in bleaching flax, or other like vegetable material
for making linen, no compounds should be used which are likely, during their decomposition, to evolve any gaseous matters, such as carbonic acid or chlorine, as, by their
development and expansion in the fibrous tubes, the flax, or any similar material, would
be rendered not so fit for spinning with the ordinary flax spinning machinery; but in
bleaching flax, or any similar material which is to be combined with other materials
for spinning and felting, according to my invention, compounds evolving gas may be
safely used, as I shall hereafter more fully specify and explain.
"For the purpose of bleaching by the method of double decomposition, I do not
confine myself to the compounds already mentioned as examples, nor to any particular
salts or class of salts; but I claim a right to use salts, which, when placed under the like
circumstances, as before exemplified in the case of goods treated by the hypochlorite of
lime and the sulphate of magnesia, will be subject to the same chemical law of decomposition, and will produce the same result. However, I may particularise as among the
salts suitable for decomposing the chloro-compounds, or assisting themselves in the
process of bleaching, the carbonates (such as the carbonate or bicarbonate of soda),
sulphates (as sulphate of magnesia, &c.), nitrates (as nitrate of soda, &c.) acetates
(as acetates of potash and of lead, &c.), prussiates (as prussiates of potash, &c.),
chromates (as chromate and bichromate of potash, &c.), tartrates (as tartrate and
bitartrate of potash, &c.); but I repeat that I do not confine myself to these, which are
merely given as examples.
" Another mode of bleaching which I sometimes employ, and which is especially
applicable to goods composed of both animal and vegetable fibre, is as follows:-I take
the goods, after they have been steeped in any of the ordinary bleaching liquors, such
as the solution of hypochlorite of lime (chloride of lime), and while they are still wet,
I expose them to the fumes of sulphur, slowly burning in a suitable chamber or stove.
In this case, I have two powerful bleaching agents at work, viz., the hypochlorite compound, and the sulphurous acid produced by the combustion of the sulphur.  A
portion of the sulphurous acid combines with the base of the chloro-compound salt, to
form a sulphate of lime or magnesia, as the case may be, and a small portion of
sulphuric acid may also in this case be formed, which, with the earth or base, would
form  a sulphate.  In this way the chlorine, or chloro-compound, remaining in the
wetted goods is liberated, and allowed to act freely upon the articles to be bleached.
In this last method of bleaching I have ascertained that there may be occasionally
substituted for the ordinary and known bleaching liquids certain chromates, manganates, and hypermanganates, &c.
"Secondly. My improvements in the preparation of materials for spinning and felting
have special relation to flax and hemp, and other plants, to which the same may be
applicable: and the processes I use to prepare the same, though possessed of some
features common to the whole, vary according to the purposes to which the fibre
obtained from the said materials is to be applied, that is to say, according as the fibre is
required to be long or short, fine or coarse, and the machinery in which it is to be spun
is adapted to the spinning of one or other sort of fibre. By the term'fibre,' as used
throughout the specification, I mean that portion of each plant which is capable of
being spun or felted; and my invention applies to the'fibre' surrounding the stems
of dicotyledonous plants, and to that existing in the stems and leaves of monocotyledonous plants.
"In the following exemplifications of my improved modes of preparation, I shall
throughout suppose flax or hemp to be the material operated upon.
" If I have to deal with the plant from the time of its being first cut down or pulled
for use, I take it in the state of straw (after the seed had been stripped from it), and
subject it to the following, which I call my'primary process':
" I first steep the straw in a solution of a caustic alkali of about 1~ of Twaddle's
hydrometer, and for such a length of time as may be most convenient. If despatch is
required, I use the solution in a boiling state; in which case an immersion of about six
hours is sufficient. If more time can be conveniently allowed, I employ a solution of a
temperature of about 150~ Fahr., and prolong the immersion for about twelve hours;
and so in proportion to the degree of temperature. The solution may be even used at a
lower temperature, with a corresponding prolongation of time, but in no case need the
immersion exceed a couple of days at the utmost.
"The object of the preceding treatment is two-fold:-first to decompose, dissolve, or
remove (more or less, as required), the glutinous, gummy, or other matters, which
connect the fibre with the woody portions of the plants; and second, to discharge or
decompose any oleaginous, colouring, or extraneous matter contained in the straw, without allowing the matters so discharged to stain the fibre; and these results are obtained




FLAX.                                          783
by the action of the alkaline solution.  In the preceding mode of preparing vegetable
materials, I generally use a solution of caustic soda; but other alkaline liquors will
answer the purpose,-such as a solution of caustic potash, or of lime dissolved in or
diffused in water, or, indeed, any substance having the like power of removing, discharging, or decomposing the colouring, glutinous, gummy, or other foreign matters
contained in the straw, and which would interfere with the whiteness of the fibre, or
with its ready separation and manufacture.
If the fibre is required to be long, like that now commonly spun in flax machinery,
I subject the straw to a second process, for the purpose of getting rid of any of the
alkali still adhering to the straw or fibre, and for the purpose of completing (if necessary) the removal of any glutinous, gummy colouring, or extraneous matters.
"To this end I will take the straw from the alkaline solution, and steep it for about
two hours in water acidulated by sulphuric acid, in the proportion of about one part
of the acid to from two to five hundred parts of water.  Some other dilute acids will
also answer this purpose, such as dilute muriatic acid, &c.; but sulphuric acid is to be
preferred. Or, I transfer the straw, while yet wet with the alkaline solution, to
a suitable chamber or stove, where I subject it to the action of sulphurous acid, or the
fumes produced by the slow combustion of sulphur. In both cases, the acid combines
with any free alkali remaining on the straw or fibre, to form a sulphite or sulphate,
according to the acid employed; while an excess of either sulphuric or of sulphurous
acid will complete the decomposition, discharge, or removal of the glutinous, colouring,
and other matters.
" I next remove the straw from the acid bath, or sulphur chamber or stove, and wash
or otherwise treat it with water, till all soluble matters are removed.
If the fibre is required to be discolorised, the straw may now be exposed to one of
the bleaching processes which I have already described, or to any of the other known
bleaching processes. It may then be dried, and made ready for breaking and crushing,
by the means ordinarily followed in the manufacture of long flax.
"1 I would mention here that, in some cases it will be found advantageous to pass the
straw between rollers, or to break it roughly or partially, before subjecting it to the
process above described, for the purpose of facilitating the action of the chemical
agents upon it.
By the aforesaid method, I am enabled to remove from the straw certain matters,
which water alone can discharge. The fibre thus prepared is also freer to heckle, and
the straw more easy to scutch, than fibre and straw treated in the ordinary way.
Much time and much material are also saved; while the noxious exhalations attendant
upon the water-rotting system are wholly prevented.
"If the fibre is required to be short, so that it may be felted or carded, and adapted for
spinning on cotton, silk, wool, worsted or tow-spinning machinery, either alone or in
combination with cotton, hair, fur, silk, or shoddy, I take the fibre, after treating it by
the processes just described, and divide it in proper lengths, by some suitable instrument or machine. I then transfer the straw or fibre to a bath containing a strong
solution  of bicarbonate, or even  carbonate of soda, or any  other similar compound; but the first two of these are to be preferred, as most abounding in carbonic
acid. In this bath I allow it to remain for about three or four hours, during which
time the fibre becomes well saturated with the salt. I then immerse the materials.
impregnated with the solution of the carbonates before named, for about a couple of
hours in water acidulated by sulphuric acid, of about the strength of one part of acid
to two hundred parts of water. Or, instead thereof, I expose the saturated materials,
while wet, to the action of burning sulphur in a suitable chamber or stove.
" In this operation it appears that a certain portion of gas being developed in the
fibrous tubes, splits and divides them by its expansive power into filaments, having the
character and appearance of fine cotton wool; in which state they may be dyed and
manufactured like cotton or wool.
"The same means of effecting the splitting of the fibre may of course be employed in
the preparation of long fibre, and I do not limit myself to its use for the preparation of
short fibres alone, but when the fibre is of its original length, the solution employed
takes a longer time to penetrate the interior.
" The decomposition of the bicarbonate of soda or other suitable compound, with
which the fibre is saturated, may be also effected by means of electric agency, when a
like evolution of gas and splitting up of the fibre will take place.
"After the fibre has been subjected to the splitting process, it must be carefully
washed to remove all soluble matters, and then dried.
"The splitting process may be applied to the plant, either in the straw (the wood of
which is to be afterwards removed by proper means and machinery), or in the state of
long fibre, whether prepared by my before-described process, or by any of the usual
and known processes.
"* Thirdly, my invention, in so far as it relates to improvements in yarns and felts,




784                                       FLAX.
consists in composing the same of the following new combination of materials. I
manufacture a yarn which I call'flax cotton yarn,' composed partly of flax fibre
prepared and cut into short lengths, as aforesaid and partly of cotton, varying the proportions at pleasure.  This yarn is much stronger thanyar  composed of cotton alone,
and also much whiter and more glossy, while it is equally capable of being spun in the
ordinary cotton spinning machinery.
" I also manufacture yarns composed in like manner, partly of hemp fibre or of jute,
or of phormium tenax, or of other like vegetable fibre (china grass excepted), prepared
and cut into short lengths, as aforesaid, and partly of cotton, which yars each possess
the same properties (more or less) as the flax-cotton yarn.
"I manufacture also a yarn, which I call'flax-wool yarn,' composed partly of flax
prepared and cut into short lengths as aforesaid, or of any other like vegetable fibr6
(cotton and china grass excepted) and partly of wool, or of that description of it called' tschudy,' or partly of fur or hair, or partly of any two or more of the said materials;
which yarn is stronger than any yarn composed of wool alone.  Some wools also,
which are too short to be spun by themselves, may, by being mixed with flax fibre, cut
into short lengths, form a material very suitable for spinning.
" I manufacture also a yarn, composed partly of flax or other like vegetable fibre
(china grass excepted), prepared and cut into short lengths, as aforesaid, and partly of
waste silk, that is, silk of the short lengths in which it exists before reeling, or silk
rags cut into short lengths and carded.
" Lastly, flax-felts, of a fineness and softness equal to the best felts composed wholly
of wool, and superior to them in point of durability, are also produced by a mixture
of flax fibre, prepared and cut into short lengths, as aforesaid, with wool fur, hair or
any other feltable material.
"And I declare that what I claim, as secured to me by the said letters patent, is as
follows:" First,-I claim the method of bleaching by double decomposition, before described,
whereby the various bleaching agents and compounds used may be recovered and
economised.
" Second,-I claim the method of bleaching by the combined action of chlorides, or
carbonates, or chromates, or any other bleaching agent, with fumes of sulphur, as
before described.
"Third,-I claim the preparing of flax and hemp, and of all vegetable fibre capable
of being spun or felted, from whatever description of plants obtainable, by steeping the
plant from which the fibre is derived, while in the state of straw, stem, leaf, or fibre,
first in a solution of caustic soda, or other solution of like properties, and then in a
bath of dilute sulphuric or other acid, as before exemplified and described.
"Fourth,-I claim the preparing of the said vegetable fibre for spinning in cotton
and silk machinery, and for being confined with cotton, wool, raw silk, or other
materials of short staple, by firstly steeping the same in a solution of caustic soda, or
other solution of like properties. Secondly, steeping them in a bath of dilute sulphuric
or other suitable acid, or exposing them to the fumes of sulphur. Thirdly, saturating
them with a solution of bicarbonate of soda or any other like agent, and then decomposing such salt, however such decomposition may be effected; and, fourthly,
cutting them up into short lengths, all as before exemplified and described.
"Fifth,-I claim the employment generally in the preparation of flax, hemp, and
other sorts of vegetable fibre, of the mode of splitting by gaseous expansion, as before
described, whether the fibre is long or short, and whatever may be the purpose to
which the same is to be applied.
"Sixth,-I claim the manufacture of yarns and felts from a combination of flax, or
like vegetable fibre (china grass excepted), prepared and mixed, as aforesaid, with
cotton wool,'tschudy,' silk waste, fur, and hair, all or any of them as before exemplified and described."
Another process for treating flax is shortly to be introduced, which is said to surpass
that of M. Claussen in its results. This is the patented invention of Mr. Bower, of
Hunslet, but as his specification is not yet enrolled, we withhold, for obvious reasons,
the details of his plan, and forbear to express any opinion of its practicability. The treatment of flax, in its early stages, is a matter of vast importance to this country; and perhaps there is no one problem throughout our manufactures whose solution would better
repay the successful experimenter, than how the facilities for working cotton and wool
are to be communicated to flax.-Newton's Journal, October, 1851.
Mr. D. F. Bower obtained in March, 1851, a patent for retting and preparing flax,
in which he submits the flax, after steeping it for six days in cold or hot water, to the
pressure of rollers once and again, with steeping, in order to expel the glutinous matter,
and then dries it. Line is treated with dilute water.of ammonia, or alkaline saline
solution. He also avails himself of the air-pump, along with the above solvents, for
the extraction of the gluten by means of hot water.




FLAX.                                        785
With the object of giving the flax grower the means of rendering his produce fit
for the market, Mr. M'Pherson, of Edinburgh, has constructed a portable breaking and
scutching machine, suitable for a farmstead. It consists of two rectangular wooden
cases, of unequal size, connected together side by side, the smaller containing the
breaking apparatus, and the larger the parts for scutching the flax. The small case is
provided with a horizontal table, having a fluted surface, whereon the flax is laid; and
over the table a fluted roller is caused to travel, for the purpose of cracking the boon,
or woody portion of the flax plant. The axes or pivots of the roller move in horizontal
guides, which can be lifted by depressing a treadle, for the purpose of raising the roller,
and the traverse of the roller is effected by its connection, through a rod, with a crank
on the end of a short horizontal shaft, which is caused to revolve by horse or other
power. The shaft also carries a spur wheel, gearing into a pinion upon another horizontal shaft, that extends through the large case. Upon this second shaft (within the
large case) are fixed two discs or bosses, to which four pairs of long radial arms are
bolted; and to the outer ends of each pair of arms is fastened a wooden beater, of a
L shape, in the transverse section. At the top of the large case two channels are
made to receive the clamps, in which the stricks of flax to be scutched are held to
receive the blows of the beaters. The flax is first laid upon the fluted table, and submitted to the action of the traversing roller until the boon is broken up and sufficiently
loosened from the fibre; it is then removed, and secured in given quantities between
a pair of clamps, in such a manner that one-half the length of the plant is pendent
therefrom.  Clamps or holders thus filled are successively passed into one of the
channels in the large case, and as they are pushed forwards towards the other end of
the machine, the stricks of flax are brought under the action of the rotating beater,
whereby the pendent portion of the flax is cleared of its boon. When this is effected,
the holders are removed from the channels and opened, to turn the end of the flax;
the clamps are then again tightened and introduced into the other channel, to bring
the other end, in like manner, under the action of the beaters. When the apparatus
is in full operation, both channels will be full of holders; and the introduction of a
fresh holder at one end is the means whereby a holder, containing a strick of scutched
flax, is discharged at the opposite end. This machine, according to the statement of
the inventor, is calculated, by the application of from three to four horse power, to
clean half an acre of flax per diem.
Mr. Plummer, of Newcastle-upon-Tyne, has exhibited machinery, and of a new con
struction, for breaking and scutching flax, and for heckling what is technically known
as " cut line." The breaker consists of a cast-iron framing, carrying five fluted rollers
of similar diameters, and connected together by geering wheels, so that the driving
of the axle of one by a band and pulley will cause the other to rotate at the same
speed. This machine is provided with two platforms, the one for conducting the
flax to the rollers, and the other for guiding it out of the machine. The rollers are so
arranged as to bite the flax three times during its passage through the machine; and
the top rollers are weighted, for insuring a proper amount of pressure being put upon
the flax.
The scutching machine consists of a rotary vertical disc inclosed in a casing, and
carried by an axle working in suitable bearing, supported by the frame of the machine.
On each side of the disc radial beaters, or wooden knives, having a bevelled edge on
their inner face, are fixed; but on one side of the disc the beaters are alternated by
radial brushes, the object being to submit the flax, first to the action of the beaters
only, and then to effect the more thorough separation of the boon from the fibre by
the combined action of brushes and a second set of beaters. An opening is formed in
the front of the case through which the flax is introduced by hand to the action of
the beaters. When one end is cleaned, the operator turns ends, and again submits
the flax to the scutching operation. By the use of a solid disc in place of radial arms
(as hitherto used) for carrying the beaters, it would seem  that greater speed than
hitherto applied may be used without the risk of breaking the staple, as the objection
presented by the arms, of causing the flax to lash round them, and thereby get broken
when working at great speed, is necessarily avoided.
The next stage of treating flax is to subject it to the action of the heckling machine,
whereby the flax is combed out, and its fibres are subdivided to the extent required;
the short entangled fibres being at the same time removed from the more valuable
staple. The extent to which the separation is carried is to produce a yield of only
from  50 to 80 lbs. of "dressed line," as the more valuable staple is termed, out of
112 lbs. of scutched flax, the remainder constituting the raw material known as tow,
which in general goes to form an inferior description of yarn. If the flax is intended
to be spun to a fine quality of yarn, or a "high number," it is cut into two, three, or
more lengths, before being submitted t9 the heckling machine; the coarser parts of the
staple, that is, the extremities, being separated from the others, to form a medium
VoL. L                                  6 H




1i86                                           FLAX.
quantity of yarn, while the middle portions are selected for conversion into fine yarn.
The action of the heckling machine, as far as the operation itself is concerned, is the
same whether the long or short staple be heckled; but, to effect the operation economically, that is, without making an undue amount of tow, different constructions of
machines are preferred for dressing the long and the cut line. For heckling the latter
kind of staple, Mr. Plummer exhibited a machine embracing some novel points deserving
of notice. It is of that class of machines which have two heckle cylinders revolving in
opposite directions, and dressing both sides of the strick of flax simultaneously, but
which have hitherto met with very partial success, as the cost with which they work
scarcely compensates for the waste of material they occasion, from the fact of two sets
of heckles entering the strick simultaneously, and tearing through it without the power
of yielding to the entangled or interlocked fibres. Now, in order to remedy this evil in
art, one of the cylinders is mounted on sliding bearings; so that each strick of flax, on
eing first presented to the heckle-pins, will be partially combed by the cylinder, which
is mounted in stationary bearings, before the traversing cylinder approaches to act upon
the strick. These cylinders are furnished with three grades of heckle-pins, and the
rows on the first, or coarsest set, are alternated by rows of brushes. The motion for
traversing the holders, containing the stricks of flax through the machine, is somewhat
novel and ingenious. Mounted near one end of the holder trough (which receives its
up-and-down motion for bringing the length of stricks gradually under the operation
of the heckle cylinders by the ordinary arrangements of mechanism) is a short axle,
which carries three pinions, two of which take into vertical racks, attached to the end
framing; and the central pinion geers into a rack formed on a horizontal reciprocating
bar, carried by the trough, and provided with loose pendent fingers. As the trough
ascends to take in a fresh holder, the pinions, working on the fixed vertical racks, are
rotated, and thus the central pinion is made to draw forward its rack with the sliding rod;
by which means the pendent fingers are brought in contact with the holders, and caused
to propel them forward. On the descent of the trough, the reverse action takes place;
and the reciprocating bar being slidden back, the fingers, which are hinged so as to
pass back over the holders, are brought to a proper position for propelling them forward on the next ascent of the trough; this reciprocating bAr is common to many heckling machines, but the mode of actuating it appears to us to be both new and simple.
On the ascent of the trough to receive another holder, and discharge at the same time a
holder of heckled flax, the traversing cylinder is caused to retire by a simple mechanical
contrivance, and thus allow of the strick of flax just received into the machine, as well
as those, which, in consequence, have been shifted forward to a finer set of heckle pins,
to be brought, first under the action of the heckle cylinder, which works in stationary
bearings, and then under the action of the pins of the traversing cylinder, as before
explained; the ascent of the trough being made the means of driving back the cylinder,
and its descent allowing of its moving forward to operate upon the flax.  The heckle
cylinders are cleaned as usual by rotating brushes; and an endless band of lattice-work
is provided for gathering the tow into a proper receptacle. Whether or no this machine is destined to take a permanent place in our flax manufactories, a mere inspection of it in its quiescent state is not sufficient to enable us to judge: as regards compactness, it has greatly the advantage of the double cylinder machines of Messrs.
Lawson & Sons, of Leeds, whose contribution we shall next notice; but we can give
no opinion of their relative merits in other respects.
This firm has made by far the largest display of flax machinery; and, indeed, the
credit is mainly due to them that the Great Exhibition has represented this important
branch of our manufactures. Their contribution may be briefly stated to have included
a complete set of machinery for heckling, spreading, drawing, and roving long and cut
flax; also for carding, drawing, and roving tow; for spinning coarse and fine flax yarn;
and likewise for manufacturing thread. For treating short flax, a pair of cylinder
heckling machines were exhibited. The cylinders, instead of being set abreast of each
other, and acting simultaneously on the flax, are mounted in a line, and revolve in
opposite directions, so that the flax is dressed, first on one side by one cylinder, and
then on the opposite side by the other cylinder. The objection to this arrangement is>
as before indicated, the want of compactness; as machines working on this principle
are required to be double the length of those which turn the strick and heckle both sides
on the same heckle-pins, or heckle it simultaneously on both sides. To remedy this objection, however, Messrs. Lawson apply two troughs to the machine, and are thus enabled
to submit two rows of stricks to the action of the same rotating heckle cylinder. The
mode of traversing the flax holders through the machine is analogous to that described
in reference to Mr. Plummer's machine, and therefore need not to be repeated. The
cylinders are furnished with two grades of heckle-pins; and between each row, rising
and falling plates (which take their motion from excentrics) are fitted for the purpose




FLAX.                                               8
of determining the depth that the heckle-pins shall enter the stricks. Between the
rows of the finer grade of heckles, small flat brushes being set in one edge of the rising
and falling plates form a sort of bed for the flax to lie on while under the action of the
heckles. The stricks, in passing over one cylinder, are heckled on one side; they are
then brought under the action of the second cylinder, which, revolving in an opposite
direction, will finish the other side of the strick. The machine exhibited by this firm
for operating upon long fibres is provided with two endless bands of heckles, set side by
side, and arranged so as to present an inclined surface to the flax. These bands are set
at opposite inclines, and revolve in different directions, for the purpose of operating
upon different sides of the stricks of flax. These are the only arrangements of heckling
and machinery which the Exhibition contained. It must, therefore, be considered as
very deficient in this respect, as the rival inventions of Messrs. Marsden, of Manchester,
and Messrs. Combe, of Belfast, for turning the stricks of flax, and causing them to be
operated upon on both sides by the same cylinder (which have recently been the cause
of so much litigation) are unrepresented. So also is a still more recent improvement
of Messrs. Combe, for heckling both sides of the strick without turning, by the use of
but one cylinder. In this machine (which we have had recently an opportunity of seeing
in action at Belfast) the means of operating on both sides of the strick is obtained by
merely reversing the direction of rotation of the cylinder, while the trough is ascending
to take in a fresh holder. Another arrangement of a promising character, for passing
once through the machine, has recently been devised by Messrs. Harding, Cocker, &
Co., of Lille; but as this machine was not included in their contribution to the
Exhibition, we conclude that it is not yet brought into the market. The flax, after
leaving the heckling machine, is slightly combed by hand, and sorted into parcels,
according to the quality of the staple; it is then packed away in a cool, dry, dark room,
and by lying there for a few months its quality is said to improve. When the flax is
taken from the "dressed line store," it is subjected to the action of the following
machines, for the purpose of converting it into yarn, viz; 1f The first drawing frame,
or spreader, the use of which is to convert the. flax, as delivered from the heckling
machine, into a continuous sliver or band of filaments; 2. The second drawing frame,
by which the sliver is attenuated; 3. The third drawing frame, whereby several slivers
from the second drawing frame are united together and redrawn, to obtain a finer sliver,
with greater regularity of fibre; 4. The roving frame, which further elongates the
sliver, and converts it into a spongy cord or roving; 5. The throstle frame, which
extends the spongy or loose roving, and spins it into yarn. The flax drawing frame is
very different in construction to that formerly described as employed for drawing cotton,
although the action is precisely analogous. Its constructions and mode of operation
may be thus briefly described: at the back of the machine is an endless travelling feedcloth, on which the stricks of flax are laid, so as to overlap each other, and which carries
the flax to what are termed the back holding rollers. In front of these rollers, and
arranged parallel thereto, is a series of " gills " or straight bars furnished with hecklepins, whose office is to receive the flax as it is delivered from between the holdingrollers, and carry it forward to the drawing-rollers. These gills are supported and
traversed by their extremities, taken into the threads of two screw shafts, set at right
angles to the holding rollers, which shafts, as they rotate, carry the gills forward.
When they have arrived at the end of the shaft they severally fall, and are received by
a pair of screw shafts below, having a quicker thread, which carry them back to the
holding rollers, and a sweep, on the end of these shafts, lifts the gills up again into geer
with the upper screw shafts. Thus an endless chain, as it were, of gills is provided,
which, having a somewhat greater speed than the holding rollers, combs the flax straight
and delivers it with perfectly parallel fibres to the drawing rollers. By these the sliver
is drawn to the requisite fineness, and then, passing between a pair of calendering
rollers, it is delivered to a can. The cans of sliver, thus produced, are now set up
behind the second drawing frame, to undergo the second operation. This frame, and
also the third, are similar in construction to the first; the only difference being, that
they are fed from cans instead of by a cloth; and as the progress of drawing out the sliver
advances, the size of the working parts are required to be less, and the fineness of the
gills to be increased. The operation of drawing is the same in all cases; but in the
second and third frames, the sliver is doubled, to give it an evenness, or structural
equality, as it is elongated.
Messrs. Lawson have exhibited screw gill spreaders (as the first drawing frame is
termed) for both long and cut flax; also gill frames for completing the drawing of the
long and short fibre, but further than being well made machines, they present no points
for comment.
Messrs. Higgins & Sons have also exhibited a screw gill spreader and a second
drawing frame for long lines. In the former of these machines the front top rollers are
weighted by an arrangement of compound levers, which is said to have the advantage
5 H 2




'188                                      FLAX.
of coinvenience over the ordinary plan; and in the latter, the roller and gills are driven
at the middle instead of the side of the machine; thus relieving the rollers of a great
portion of the strain to which they are ordinarily exposed, and permitting of the use
of smaller rollers, which, for some descriptions of work, is considered of importance.
The sliver, as it is delivered into cans from the third drawing frame, is taken to the
roving frame to be still further reduced and wrought into a loose thread; but as this
operation is precisely similar, whether for long line, cut line, or tow, it may be well to
explain briefly the means of bringing tow to a proper state for undergoing the first
spinning process before speaking of the roving frame. The tow, which we have said is
the short and irregular fibres combed out of the strick of flax by the heckling machine,
is subjected to the action of a carding engine, somewhat similar in construction to that
used for carding cotton.  It consists principally of a large central cylinder, covered with
wires, cards, and surrounded by card rollers termed "workers " and "strippers," revolving incontact therewitlh. The tow is carried into the machine by an endless travelling
cloth, which delivers it to a pair of feed rollers, situate below the main cylinder, whereby it is transferred to the large cylinder. By this it is brought under the action of
the workers, when combed or carded; and it is then stripped or "doffed " from  the
cylinder by card rollers, which in their return are relieved of the staple by doffer combs;
these take it off in the form of a sliver, and it is eventually delivered from the machine
by delivering rollers into cans. In order to prevent the liability of the sliver breaking
byy being pressed down into the cans, and also to avoid the necessity of using a separate
machine. for performing the first drawing operation, it has lately been the practice to
apply. one or more gill-drawing heads to the carding engine, according to the number
of strippers employed and slivers produced, and carry on the carding and the first
drawing processes simultaneously.  This arrangement, patented by Messrs. Fairbair
& Co., was applied to Messrs. Lawson & Son's carding engine. It is provided with
three strippers, which are capable (by being set at different distances from the main cylinder) of taking off different lengths of staple from the card surface, and thereby
sorting out or dividing the qualities of the tow. In this machine, however, there is
but one gill-head; all the slivers, therefore, are united in the first drawing process, and
form together a continuous sliver; the completion of the operation of drawing tow is
precisely similar to that already described with reference to long and cut line.
To obtain a flax roving, it is usual, after drawing the sliver to the required amount,
to put in its slight twist. Messrs. Higgins exhibited a roving frame with six heads and
sixty spindles, for producing roving of this kind.  This roving frame is, in fact, to describe it shortly, a drawing frame, with the addition of spindles; the gills and rollers
being driven according to their improved plan, before noticed.
The roving frame for cut flax exhibited by Messrs. Lawson, is intended to produce a
roving without twist, which, for obtaining fine qualities of yarn, is very desirable; the
gummy matter in the flax is here taken advantage of to give the roving the necessary
cohesive property. A correct notion of the construction of this roving frame may be
best conveyed by tracing the progress of the sliver through the machine. The sliver
passes from the can over a pulley through fixed guides over travelling gills, between a
pair of drawing rollers, then into a trough containing hot water (for the purpose of dissolving the gummy matter in the flax), then over a heated cylinder which dries the
staple, and finally it is wound on to a bobbin, which rests upon and turns in contact
with a horizontal fluted roller. Rovings thus produced are capable, it is said, of being
drawn to almost any degree of fineness, with little reference to the material; because,one fibre can be glued to another; at any portion of its length a roving can be made.
Messrs. Lawson also contributed machinery for wet and dry spinning, viz., a dry tow
spinning frame, with 100 spindles; a fine spinning frame for spinning the roving through
cold water; a double water frame, with 136 spindles; and a double twisting frame with
96 spindles. The only noticeable novelty in these machines (the construction of which
will be understood from the description already given of cotton spinning machinery) is
a new tape motion for driving the spindles. A spinning frame, by Messrs. Higgins,
containing 144 spindles was also exhibited; but further than being a specimen of good
design and workmanship, it calls for no special remark.
Retting of Flax.-Mr. Watt's system of flax retting may be briefly described as follows:-The flax straw is delivered at the works by the grower, in a dry state, with the
seed on. The seed is separated by metal rollers, and afterwards cleaned by fanners.
The straw is then placed in close chambers, with the exception of two doors, which
serve the purpose of putting in and discharging the straw. The top, which is of cast
iron, serves the double purpose of a top and condenser. The straw is then laid on a
perforated false bottom of iron, and the doors being closed, and made tight by means
of screws, steam is driven in by a pipe round the chambers, and between the bottoms;
and, penetrating the mass, at frst removes certain volatile oils contained in the plant,
and afterwards is condensed on the bottom of the iron tank, and descends as a continuous shower of condensed water, saturating the straw. This water is a decoction
of extractive matter, to which attach the fibrous and more porous portions. This liquor
is run off from time to time, the more concentrated portions being used for feeding.




FLAX.                                        789
The process is shortened by using a pump, or such an arrangement as rapidly washes
the mass, with the water allowed to accumulate.  In about eight or twelve hours,
varying with the nature of the straw, it is removed from the chambers, and, having
been robbed of its extractive matter, it is then passed through the rollers for the purpose of removing the epidermis, or skin of the plant, and of discharging the greater
part of the water contained in the saturated straw, and while in the wet and swollen
state, splitting it up longitudinally. The straw then (being free of all products of
decomposition) is easily dried, and in a few hours ready for scutching.
In the experimental trial, personally superintended, throughout all its details, by
the Committee, a quantity of flax straw, of ordinary quality, was taken from the bulk
of the stock at the works, weighing 131 cwts. with the seed on. After the removal of
the seed, which, on being cleaned thoroughly from the chaff, measured 3} Imperial
bush., the straw was reduced in weight to 10 cwt. 1 qr. 21 lbs. It was then placed in
the vat, where it was subjected to the steaming process for about eleven hours. After
steeping, wet-rolling, and drying, it weighed 7 cwt. 0 qrs. 11 lbs.; and, on being scutched,
the yield was 187 lbs. of flax; and of scutching tow, 12 lbs. 61 ozs. fine, and 35 lbs. 3,ozs. coarse.  The yield of fibre, in the state of good flax, was, therefore, at the rate of
13 lbs. from the cwt. of straw with seed on; 18 lbs. from the cwt. of straw without
seed; 26 lbs. from the cwt. of steeped and dried straw.
The time occupied in actual labour, in the processes, from  the seeding of the flax to
the commencement of the scutching, was 13+ hours, to which, if 11 hours be added for
the time the flax was in the vat, 24 hours would be the time required up to this point
The scutching, by four stands, occupied six hours sixteen minutes.  But, in this statement, the time required for drying is not included, as, owing to some derangement in
the apparatus, no certain estimate could be made of the actual time required in that
process. It would appear, however, that about thirty-six hours would include the
time necessary, in a well-organized establishment, to convert flax straw into fibre for
the spinner.
The cost of all these operations, in this experiment, leaving out the drying, for the
reasons noted, appeared to be under 101. per ton of clean fibre, for labour, exclusive of
general expenses.
A portion of the fibre was sent to two spinning-mills to be hackled, and to have a
value put upon it. The valuation of the samples varied from 561. to 701. per ton, according to the quality of the stricks of fibre sent, and the yield on the hackle was considered quite satisfactory.
On the results of this experiment, which was necessarily of a limited nature, the
Committee think it best to offer no general remarks. They are sufficiently favourable
to speak for themselves. It remains to be ascertained whether the qualities of flax fibre
prepared by this method are such as to suit the spinner and manufacturer. They have
been informed, by a spinner who has been trying some flax prepared by Mr. Watt's
system, that the yarn made from it appears equal in all respects to what is ordinarily
spun from good Irish flax, of the finer sorts. They believe that, before long, information will be given by several individuals who are about to carry out more extended
trials on the spinning and manufacturing departments.
The Committee conceive that the most prominent and novel feature of this plan
consists in the substitution of maceration, or softening, for fermentation. In the steep
ing of flax, both by cold and hot water, the fibre is freed from the substance termed
gum, by the decomposition of the latter, while in Watt's system the maceration of the
stems loosens the cuticle and gum, which are further separated mechanically in the
crushing operation, and, after the drying of the straw, readily part with the wood,
under the action of the scutch-mill.
Before concluding this statement, the Committee wish to call attention to a very
curious feature in Mr. Watt's invention. The water from the vats, in place of being
offensive and noxious, as is the case with ordinary steep water, contains a certain
amount of nutritive matter. This arises from its being an infusion of the flax stems,
in place of holding in suspension or solution the products of the decomposition of the
gum, and other substances contained in the stems. The inventor is now employing
this water, along with the chaff of the seed-bolls, for feeding pigs.  It is of much interest, therefore, to note in how far this may be found practically to answer, as, between the seed, the chaff, and the water, by far the greatest portion of what the flax
plant abstracts from the soil, would thus be returned in the shape of manure. However this may turn out, the avoidance of all nuisance in smell, and of the poisonous
liquid which causes some damage among fish when let off into rivers, is a matter of
some consequence.
Appended to this report is a note of the time occupied in the different processes
during the experiment, and of the number of persons employed in each.
It is to be hoped that so promising a plan may, on more extended experience, be
found fully to warrant the high anticipations formed from what is already known
concerning it.                              (Signed on behalf of the Committee),
RICHARD NIvEN, Chairmar.
Belfast, 3d Nov., 1852.




790                                       FLAX.
APPENDIX.
Note of the time occupied, and of the number of persons employed in each of the
processes witnessed by the Committee, on the experimental trial of Mr. Watt's system
of preparing flax fibre:No. of persons employed.   Time occupied.
Men. Women and Boys. Hours. Minutes.
Seeding,.4                                      8             1     15
Placing in Vat,   -    -    -    -4                                 0      15
Cleaning Seed,   -    -                -    -                               0
Taking out of Vat,    -                -    -                             30
Wet-rolling and putting in Drying
Room, --                       -                  16              2 20
Rolling for Scutching, -0                            11 1-                  8
Stricking for do.,       -0                             4-    47
Total,        11         49            13      15
Scutching,          -    -    -            4          0             6      16
Cultivation of Flax in Flanders.-There is a very fine long variety of flax which is
cultivated in the neighbourhood of Courtray, in Flanders; it requires a very good soil
to grow in, and the stem is so long and slender, that, if it were not supported, the
least wind would break it and lay it flat, in which case, the quality of the flax would be
much impaired and the quantity reduced. To prevent this, short stakes are driven into
the ground in a straight line, at 8 or 10 feet from each other, and long slender rods are
tied to them with oziers, about I foot or 18 inches from the ground, forming a slight
railing to support the flax; a number of these are placed in the same manner at a short
distance from each other in parallel lines all over the field, and the flax is thus prevented from being beat down.  A better method, which is not commonly adopted, is
to have stakes in regular rows, and thin ropes tied to them, instead of rods; by having
these lengthwise and others across them at right angles, a kind of large net is spread
over the whole field, and none of the flax can possibly be laid flat. By using cheap
rope, or strong tar-twine from old cables, the expense is not very great, and much less
room is taken up than by the rods. When the flax is pulled, the stakes are taken up,
and removed to a dry place till they are wanted again.
The most common variety of flax is of a moderate length, with a stronger stem; if
it is not sown very thick it will throw out branches at top and produce much seed; it
is therefore a matter of calculation whether it will be most profitable to have finer flax
with less seed, or an inferior quality with an abundance of seed.
There is a small variety which does not rise above a foot, grows fast, and ripens its
seed sooner. When linseed is the principal object, this variety is preferred; but the
flax is shorter, and also coarser.
Another variety of flax has a perennial root, and shoots out stems to a considerable
height. It came originally from Siberia, and was much recommended at one time, but
its cultivation did not spread. If it were sown in wide rows, and kept free from weeds
by hoeing, it might, perhaps, be profitably cultivated for the seed; and if the flax is
inferior in quality, it might still be of some value for coarse manufactures; it requires, however, to be renewed every three or four years and sown in fresh ground.
The soil best adapted to the growth of flax is a deep rich loam, in which there is
much humus, or vegetable mould.  It should be mellow  and loose to a considerable
depth, with a sound bottom, neither too dry nor too moist; either extreme infallibly
destroys the flax; it is therefore not suited either to hot gravelly soils or cold wet clays,
but any other soil may be so tilled and prepared as to produce good flax. It thrives
well in the rich alluvial land of Zealand and the Polders, but it is also raised with great
success in the light sands of Flanders, but much more careful tillage and manuring are
required. The land on which flax is sown must be very free from weeds, the weeding
of this crop being a very important part of the expense of cultivation. These circumstances suggest the best mode of preparing the land. A long fallow, such as is sometimes given to the land in Essex, including two winters and a summer, may be a good
preparation on the heavier loams, which should be trenched, ploughed, and worked deep;
the manure should be dung fully rotten, or a compost of earth and dung; it should be
put on the land in autumn, and well incorporated before the seed is sown. If the land
is sufficiently clean, a crop of potatoes well manured may be substituted with advantage
for the fallow; but at least double the usual quantity of dung should be given to this
crop, that enough may remain in the ground for the flax. Lime may be used if the soil
contains a great portion of clay; but in the lighter loams there is some doubt of its
advantage for flax. At all events it should not be used immediately before the flax is
sown, but for some previous crop. Peat-ashes are excellent; they improve the soil and
keep off insects, which are apt to injure the roots of the flax. For want of peat-ashes,
those made by the burning of weeds and earth in a smothered fire are a good substitute.
But the most effective manure is the sweepings of the streets in towns, mixed with the
emptying of privies, and the cleaning out of the butchers' stalls and shambles. On
lirh10 soils much manure is required; and where night-soil cannot be obtained in




FLAX.                                         791
sufficient quantities, rape-cakes, from which the oil has been expressed, dissolved in
cow's urine, form the best manure.  In many parts of Flanders, 500 rape-cakes are
used for every acre of flax, besides the usual quantity of Dutch ashes and of liquid
manure, which is the drainings of dunghills, and the urine of cattle collected in a
cistern, and allowed to become putrid.
In southern climates flax is sown before winter, because too great heat would
destroy it.  It is then pulled before the heat of summer.  In northern climates the
frost, and especially the alternations of frost and thaw, in the early part of spring,
would cause the flax to perish; it is, consequently, sown as early in spring as may be,
so as to avoid the effect of hard frost This is in March or April, in Great Britain and
Ireland, and in Holland and Flanders.  In no country is the ground better prepared
for the growth of flax than in Flanders; and it may, therefore, be interesting to follow
the whole process of Flemish cultivation for several crops, preparatory to that of flax,
which is the most important produce in that country, and that which, when well
managed, gives the greatest profit to the farmer. The best flax grows near Courtray.
The soil is a good deep loam, rather light than heavy. It is not naturally so rich as
the soil of the Polders in Flanders and Zealand, but the tillage and cultivation are far
more perfect, and the produce, if not more abundant, is of a finer quality.  Every
preceding crop has a reference to the flax, and is so cultivated as to improve the
texture of the soil, which is abundantly manured, in order to leave a considerable
surplus in the ground. If the land has not been trenched all over with the spade, to
the depth of 18 or 20 inches, it has been equally well stirred by the narrow open
drains, which are dug out 12 or 15 inches deep every year, between the stitches, in
which it is laid by the plough. These drains or water furrows are a foot wide, and
from a foot to 18 inches deep. The earth taken out of them is spread evenly over the
land after the corn is sown. When the ground is ploughed again, care is taken that
the place of these water-furrows shall be shifted a foot on each side. Thus, in six
years, the whole soil is deepened and thoroughly mixed with whatever manure has
been put on.  This produces the same effect as trenching, and even more perfectly.
The whole of the land in which the best flax grows has been so treated for several
generations, and may  be looked upon as a species of compost 18 inches deep.
Potatoes or colza are usually planted with a double portion of manure, after which
wheat is sown, slightly manured; then rye with turnips sown the same year, after the
rye. These are taken up in September or October, and stored for winter use. The
land has been well weeded while the turnips were growing, and all the manure is decomposed and mixed with the soil. It is ploughed in stitches before winter, some
manure having being previously spread over it if necessary: and it is left to the
mellowing effects of frost and snow. As soon as the winter is over, and the snow is
melted, the final preparation goes on. Deep ploughing and harrowing further divide
and pulverize it; the surface is laid as level and as smooth as possible; and if there is no
fear of too much wet, which in this light loam soon disappears, the whole is laid flat
and level as a bowling-green, or else divided into beds, with water-furrows between
them.  On this the liquid manure is poured out, and the Dutch ashes spread, if any
are used, or the rape-cakes, as mentioned before.  The harrows are drawn over the
land, and it is left so a few days, that the manure may sink in. It is then again
harrowed, and ithe linseed is sown broadcast by hand, very thick, and even about
11 cwt. to the acre. A bush harrow or a hurdle is drawn over, merely to cover the
seed, which would not vegetate were it buried half an inch deep. According to the
state of the land, it is rolled or not, or the seed is trodden in by men, as is done with
fine seeds in gardens. This is only in the lightest soils. Most commonly the trainean
is drawn over the land. This is a wooden frame with boards nailed closely over it,
which is drawn flat over the ground, to level and gently press it. In a short time the
plants of flax come up thick and evenly, and with them also some weeds. As soon as
the flax is a few inches high, the weeds are carefully taken out by women and children,
who do this work on their hands and knees, both to see the weeds better, and not to
hurt the flax with their feet.  They tie pieces of coarse flax round their knees, and
creep on with their face to the wind if possible. This is done that the tender flax
which has been bent down by creeping over it, may be assisted by the wind in rising.
This shows what minute circumstances are attended to by this industrious people. The
weeding is repeated till the flax is too high to allow of it.
The seed which is used is generally obtained from Riga, it being found that the flax
raised from home-grown seed is inferior after the first year.  But many intelligent men
maintain that if a piece of ground were sown thin with linseed, so that the flax could
rise with a strong stem and branch out, and if the seed were allowed to ripen, the
Flemish seed would be as good as that from Riga; but it still remains to be proved
whether it would be cheaper to raise it or to import it.
When the flax begins to get yellow at the bottom of the stem, it is time to pull it, if
very fine flax is desired, such as is made into thread for lace or fine cambric; but then
the seed will be of little or no value. It is therefore generally left standing until the
capsules which contain the seed are fully grown, and the seed formed. Every flax



'92                                     FLAX.
grower judges for himself what is most profitable onthewhole. Thepullingthenbegins,
which is done carefully by small handfuls at a time. These are laid upon the ground to
dry, two and two obliquely across each other. Fine weather is essential to this part
of the operation. Soon after this they are collected in the larger bundles, and placed
with the root end to the ground, the bundles being slightly tied near the seed end; the
other end is spread out that the air may not have access, and the rain may not damage
the flax. When sufficiently dry they are tied more firmly in the middle, and stacked
in long narrow stacks on the ground. These stacks are built as wide as the bundles
are long, and about 8 or 9 feet high. The length depends on the crop: they are
seldom made above 20 or 30 feet long. If the field is extensive, several of these stacks
are formed at regular distances; they are carefully thatched at top, and the ends, which
are quite perpendicular, are kept up by means of two strong poles driven perpendicularly
into the ground. These stacks look from a distance like short mud walls, such as are
seen in Devonshire. This is the method adopted by those who defer the steeping til
another season. Some carry the flax as soon as it is dry under a shed, and take off the
capsules with the seed by rippling, which is drawing the flax through an iron comb
fixed in a block of wood; the capsules which are too large to pass between the teeth of
the comb are thus broken off and fall into a basket or cloth below. Sometimes, if the
capsules are brittle, the seed is beaten out by means of a flat wooden bat, like a small
cricket bat. The bundles are held by the root end, and the other end is laid on a board
and turned round with the left hand while the right with the bat breaks the capsules,
and the linseed falls on a cloth below. The flax may then be immediately steeped: but
the most experienced flax-steepers defer this operation till the next season. In this case
it is put in barns, and the seed is beat out at leisure in winter. When flax is housed, care
must be taken that it be thoroughly dry; and if the seed is left on, which is an advantage to it, mice must be guarded against, for they are very fond of linseed, and would
soon take away a good share of the profits by their depredations.
Steeping the flax is a very important process which requires experience and skill to
do it properly. The quantity and colour depend much on the mode of steeping, and
the strength of the fibre may be injured by an injurious mode of performing this operation. The object of steeping is to separate the barkfromthewoodypartofthestem,by
dissolving a glutinous matter which causes it to adhere, and also destroying some minute
vessels which are interwoven with the longitudinal fibres, and keep them together in a
kind of web. A certain fermentation or incipient putrefaction is excited by the steeping,
which must be carefully watched and stopped at the right time. The usual mode of
steeping is to place the bundles of flax horizontally in the shallow pool or ditches of
stagnant water, keeping them under water by means of poles or boards with stones or
weights laid upon them. Water nearly putrid was supposed the most efficacious; and
the mud is often laid over the flax to accelerate the decomposition, but this has been
found to stain the flax, so that it was very difficult to bleach it or the linen made from it
afterwards. The method adopted by the steepers of Courtray, where steeping flax is a
distinct trade, is different. The bundles of flax are placed alternately with the seeed end
of the one to the root end of the other, the latter projecting a few inches; as many of
these are tied together near both ends as form a thick bundle about a foot in diameter.
A frame made of oak-rails nailed to strong upright pieces in the form of a box 10 feet
square and 4 deep, is filled with these bundles set upright and closely packed. The
whole is then immersed in the river, boards loaded with stones being placed upon the
flax till the whole is sunk a little under the surface of the water. The bottom does not
reach the ground, so that the water flows over and under it. There are posts driven in
the river, to keep the box in its place, and each steeper has a certain portion of the bank,
which is a valuable property. The flax takes somewhat longer time in steeping in
this manner than it does in stagnant or putrid water, and it is asserted by those who
adhere to the old method that the flax loses more weight; but the colour is so much
finer, that flax is sent to be steeped in the Lys from every part of Flanders. When it is
supposed that the flax is nearly steeped sufficiently, which depends on the temperature
of the air, the flax being sooner steeped in warm weather than in cold, it is examined
carefully every day, and towards the latter part of the time several times in the day, in
order to ascertain whether the fibres really separate from the wood the whole length of
the stem.  As soon as this is the case the flax is taken out of the water: even a few
hours more or less than is necessary will make a difference in the value of the flax. If
it is not steeped enough, it will not be easily scutched, and the wood will adhere to it. If
it has been too long in the water, its strength is diminished and more of it breaks into tow.
The bundles are now untied, and the flax is spread evenly in rows slightly overlapping
each other on a piece of clean smooth grass which has been mown or fed off close. Fine
weather is essential to this part of the process, as rain would now much injure the flax.
It is occasionally turned over, which is done dexterously by pushing a long slender rod
under the rows, and taking up the flax near the end which overlaps the next row and
turning it quite over. Thus, when it is all turned, it overlaps as before, but in the
contrary direction. It remains spread out upon the grass for a fortnight, more or less
according to the season, till the woody part becomes brittle, and some of the finest fibres




FLAX.                                         919
separate from it of their own accord. It is then taken up, and as soon as it is quite dry
it is tied up again in bundles, and carried into a barn to be broken and heckled at
leisure during the winter.
The total annual production of flax in Belgium amounts, by a recent estimation, to
about forty millions of pounds. Its total value is calculated at about two millions and
a half sterling. This flax is of very superior quality, and is principally employed in
the manufacture of the finest class of fabrics. Attempts are being now made on a large
scale to cultivate this important plant in England and Ireland. Belgium exports about
five millions of pounds of flax to England. That flax grown in the Courtray district is
universally considered to be of the finest quality.
FLAX WEAVING LooM.-A A A, Fig. 648., frame of loom; B, beam on which the yarn
for warp is wound; c cloth receiving beam; D driving pulleys and fly-wheel; E hand
rail for supporting the reed; F swords of supports of going part; G picking sticks lor
driving the shuttle; H leather straps for connecting the picking sticks with their
actuating levers L; M, N, jaws of a clamp to cause the retaining friction on the collars
of the beam B, by which friction the quantity of weft is regulated; o end of lever,
bearing the weight by which the jaws are brought together; P, lever, keyed at one end
to the upright shaft Q, and connected with the ether to the fulcrum of the weighted
lever o; a lever, one end of which is also keyed to the upright shaft Q, and the other is
provided with a wood sole, and is pressed by a strong spring against the yarn wound
upon the beam B. It will be seen that, as the yarn is taken off the beam B, and its
diameter consequently reduced, the lever P moves the fulcrum of the weighted lever o,
and thus regulates the pressure upon the clamps m and N, causing an equal tension
upon the yarn from the full to the empty beam; a treddles, actuated by the cams b,
driven by the wheels c, d, e, from the picking shaft f; g, g shuttle boxes at each end
of the going part; h, h arrangement of levers to conduct equally each end of the geers
i, i. This loom has also, in addition to the ordinary stopping arrangement connected
with the shuttle, one also for relaxing the reed in case the shuttle should be arrested
in its course across the warp, whereby the danger, ordinarily incurred by that accident,
of breaking many threads in the warp, is avoided; it will also be seen that the bands
called picking bands are superseded by the ends of the picking levers striking the shuttle
direct; thus, by these improvements, drills are currently woven in this loom at the rate
of 120 to 130 picks per minute.
Imports of flax and tow, or codilla of hemp and
flax  -      -        -       -        -       - cwts.  1,822,918         1,194,184
Linen yarn exported  -          -        -        -   lbs. 18,220,688      18,518,273
Linen manufactures exported (including linen  -
yarn, 881,3121. and 935,9391.) declared value -       ~  4,839,779        5,053,792
VoL. L                                       6I




m94                                         FLINT.
AIM
FLINT.  (Pierre & fusil, Fr.; Feuerstein, Germ.)  The fracture of this fossil is
perfectly conchoidal, sometimes glossy, and'sometimes dull on the surface. It is very
hard, but breaks easily, and affords very sharp-edged splintery fragments; whence it is
a stone which strikes most copious sparks with steel. It is feebly translucid, has so fine
and homogeneous a texture as to bear polishing, but possesses little lustre. Its colours
are very various, but never vivid. The blackish-brown flint is that usually found in
the white chalk. It is nearly black and opaque, loses its colour in the fire, and becomes
grayish-white, and perfectly opaque. Flints occur almost always in nodules or tubercular concretions of various and very irregular forms. These nodules, distributed in
strata among the chalk, alongside of one another and almost in contact, form extensive
beds; interrupted, indeed, by a multitude of void spaces, so as to present, if freed from
the earthy matter in which they are imbedded, a species of network with meshes, very
irregular both in form and dimension.
The nodules of silex, especially those found in the chalk, are not always homogeneous
and solid. Sometimes there is remarked an organic form towards their centre, as a
madrepore or a shell, which seems to have served as their nucleus; occasionally the
centre is hollow, and its sides are studded over with crystals of quartz, carbonate of
iron, pyrites, concretionary silex or calcedony, filled with pulverulent silica nearly pure,
or silex mixed with sulphur; a very singular circumstance.
Flints are observed to be generally humid when broken immediately after being dug
out of the ground; a property which disappears after a short exposure to the air.
When dried they become more brittle and more splintery, and sometimes their surfaces
get covered at old fractures with a thin film or crust of opaque silex.
Flints calcined and ground to a powder enter into the composition of all sorts of fine
pottery ware.
The next important application of this siliceous substance is in the formation of gunflints, for which purpose it must be cut in a peculiar manner. The following characters
distinguish good flint nodules from such as are less fit for being manufactured. The
best are somewhat convex, approaching to globular; those which are very irregular,
knobbed, branched and tuberose, are generally full of imperfection. Good nodules
seldom weigh more than 20 pounds; when less than 2, they are not worth the working.
They should have a greasy lustre, and be particularly smooth and fine grained. The
colour may vary from  honey-yellow  to blackish-brown, but it should be uniform
throughout the lump, and the translucency should be so great as to render letters legible
through a slice about one-fiftieth of an inch thick, laid down upon the paper. The




FLINT.                                          795
fracture should be perfectly smooth, uniform, and slightly conchoidal; the last property
being essential to the cutting out of perfect gun flints.
Four tools are employed by the gun-flint makers.
First, a hammer or mace of iron with a square head, from 1 to 2 pounds weight, with
a handle 7 or 8 inches long. The tool is not made of steel, because so hard a metal
would render the strokes too harsh, or dry, as the workmen say, and would shatter the
nodules irregularly, instead of cutting them with a clean conchoidal fracture.
Second, a hammer with 2 points, made of good steel well hardened, and weighing
from 10 to 16 ounces, with a handle 7 inches long passing through it in such a way
that the points of the hammer are nearer the hand of the workman than the centre of
gravity of the mass.
Third, the disc hammer or roller, a small solid wheel or flat segment of a cylinder,
parallel to its base, only two inches and a third in diameter, and not more than 12
ounces in weight. It is formed of steel not hardened, and is fixed upon a handle 6
inches long, which passes through a square hole in its centre.
Fourth, a chisel tapering and bevelled at both extremities, 7 or 8 inches long, and 2
inches broad, made of steel not hardened; this is set on a block of wood, which serves
also for a bench to the workmen. To these 4 tools a file must be added, for the purpose of restoring the edge of the chisel from time to time.
After selecting a good mass of flint, the workman executes the four following operations on it.
1. He breaks the block. Being seated upon the ground, he places the nodule of flint on
his left thigh, and applies slight strokes with the square hammer to divide it into smaller
pieces of about a pound and a half each, with broad surfaces and almost even fractures.
The blows should be moderate, lest the lump crack and split in the wrong direction.
2. He cleaves or chips the flint. The principal point is to split the flint well, or to
chip off scales of the length, thickness, and shape adapted for the subsequent formation
of gun-flints. Here the greatest dexterity and steadiness of manipulation are necessary;
but the fracture of the flint is not restricted to any particular direction, for it maybe
chipped in all parts with equal facility.
The workman holds the lump of flint in his left hand, and strikes with the pointed
hammer upon the edges of the great planes produced by the first breaking, whereby the
white coating of the flint is removed in small scales, and the interior body of the flint
is laid bare; after which he continues to detach similar scaly portions from the clean
mass.
These scaly portions are nearly an inch and a half broad, two inches and a half
long, and * about one-sixth of an inch thick in the middle. They are slightly convex
below, and consequently leave in the part of the lump from which they were separated
a space slightly concave, longitudinally bordered by two somewhat projecting straight
lines or ridges. The ridges produced by the separation of the first scales must naturally
constitute nearly the middle of the subsequent pieces; and such scales alone as have
their ridges thus placed in the middle are fit to be made into gun-flints. In this manner the workman continues to split or chip the mass of flint in various directions, until
the defects usually found in the interior render it impossible to make the requisite fractures, or until the piece is too much reduced to sustain the smart blows by which the
flint is divided.
3. He fashions the gun-flints. Five different'parts may be distinguished in a gunflint. 1. The sloping facet or bevel part, which is impelled against the hammer of the
lock. Its thickness should be from two to three twelfths of an inch; for if it were
thicker it would be too liable to. break; and if more obtuse, the scintillations would be
less vivid. 2. The sides, or lateral edges, which are always somewhat irregular.
3. The back or thick part opposite the tapering edge. 4. The under surface, which is
smooth and rather concave. And 5. The upper face, which has a small square plane
between the tapering edge and the back, for entering into the upper claw of the cock.
In order to fashion the flint, those scales are selected which have at least one of the
above-mentioned longitudinal ridges; the workman fixes on one of the two tapering
borders to form the striking edge, after which the two sides of the stone that are to form
the lateral edges, as well as the part that is to form the back, are successively placed on
the edge of the chisel in such a manner that the convex surface of the flint which rests
on the forefinger of the left hand, is turned towards that tool. Then with the disc hamneath, and thereby breaks it exactly along the edge of the chisel.
4. The finishing operation is the trimming, or the process of giving the flint a smooth
and equal edge; this is done by turning up the stone and placing the edge of its
tapering end upon the chisel, in which position it is completed by five or six slight strokes
of the disc hammer. The whole operation of making a gun-flint, which I have used so
many words to describe, is performed in less than one minute. A good workman is able
to manufacture 1,000 good chips or scales in a day (if the flint-balls be of good quality),
6I 2




'196                            FLOUR. OF WHEAT.
or 500 gun-flints. Hence, in the space of three days, he can easily cleave and finish
1,000 gun-flints without any assistance.
A great quantity of refuse matter is left, for scarcely more than half the scales are
good, and nearly half the mass in the best flints is incapable of being chipped out; so
that it seldom happens that the largest nodules furnish more than 50 gun-flints.
Flints form excellent building materials; because they give a firm hold to the mortar
by their irregularly rough surfaces, and resist, by their nature, every vicissitude of
weather. The counties of Kent, Essex, Suffolk, and Norfolk, contain many substantial
specimens of flint-masonry.
FLOOKAN.  The name given by the Cornish miners to a vein of clay-stone, often
nearly vertical.
FLOOR  CLOTH  MANUFACTURE  has  become  of late  years a  very  large
branch of trade. The cloth is a strong somewhat open canvas, woven of flax with a
little hemp, and from 6 to 8 yards wide, being manufactured in appropriate looms,
chiefly at Dundee. A piece of this canvas, from 60 to 100 feet in length, is secured
tight in an upright open frame of oaken bars, in which position it receives the foundation coats of paint, 2 or 3 in number, first on the back side, and then on the front; but it
is previously brushed over with glue-size, and rubbed smooth with pumice stones.
The foundation paint made with linseed oil and ochre, or any cheap colouring matter,
is too thick to be applied by the brush, and is therefore spread evenly by a long narrow
trowel, held in the right hand, from a patch of it laid on just before with a brush in the
left hand of the workman. Each foundation coat of the front surface is smoothed by
pumice whenever it is hard enough to bear the operation. When both sides are d, the
painted cloth is detached from the frame, coiled round a roller, in this state transferred
to the proper printing room, where it is spread flat on a table, and variously figured
and coloured devices are given to it by wooden blocks, exactly as in the block printing
of calicoes, and in the wood printing of books. The blocks of the floor cloth manufacture are formed of two layers of white deal and one of pear tree timber, placed with
their grain crossing one another alternately. There is of course a block for each colour
in the pattern, and in each block those parts are cut away that correspond to the impression given by the others; a practice now well understood in the printing of two or
more colours by the press. The faces of the blocks are so indented with fine lines,
that they do not take up the paint in a heavy daub from the flat cushion on which it
is spread with a brush, but in minute dots, so as to lay on the paint (somewhat thicker
than that of the house painter) in a congeries of little dots or teeth, with minute interstices between. Applied in this way, the various pigments lie more evenly, are more
sightly, and dry much sooner than if the prominent part of the block which takes up
the colour were a smooth surface. The best kinds of floor cloth require from two to
three months for their production.
FLOSS, of the puddling furnace, is the fluid glass floating upon the iron produced&
by the vitrification of the oxides and earths which are present
FLOSS-SILK  (Filoselle, Bourre de sole, or fleuret, Fr.), is the name given to the
portions of ravelled silk broken off in the filature of the cocoons, which is carded like
cotton or wool, and spun into a soft coarse yarn or thread, for making bands, shawls,
socks, and other common silk fabrics. The floss or fleuret, as first obtained, must be
steeped in water, and then subjected to pressure, in order to extract the gummy matter,
which renders it too harsh and short for the spinning wheel. After being dried it is
made still more pliant by working a little oil into it with the hands. It is now ready
to be submitted to the carding engine. (See COTTON MANUFACTURE.) It is spun upon
the flax wheel.
The female peasants of Lombardy generally wear clothes of homespun floss silk. Of
late years, by improved processes, pretty fine fabrics of this material have been produced, both in England and France.  M. Ajac, of Lyons, presented at one of the
French national exhibitions of the objects of industry, a great variety of scarfs and
square shawls, of bourre de soie, closely resembling those of cachemire.
FLOUR; the finely ground meal of wheat, and of any other corns or cerealia.  See
BREAD.
FLOUR  OF WHEAT, Adulterations of, to detect.-The first method is by specific
gravity. If potato flour be added, which is frequently done in France, since a vessel
which contains one pound of wheat flour will contain one pound and a half of the fecula,
the proportion of this adulteration may be easily estimated. If gypsum or ground
bones be mixed with the flour, they will not only increase its density still more; but
they will remain after burning away the meal.
The second method is by ascertaining the quantity of gluten which the suspected
sample will afford, by the process prescribed under the article BREAD. The two following chemical criteria may also be employed.
1st. Nitric acid has the property of colouring wheat flour of a fine orange yellow,
whereas it affects the colour neither of fecula nor starch.




FLY POWDER.
2nd. Pure muriatic acid colours good wheat flour of a deep violet, but dissolves
fecula or starch, and forms with it a light, colourless, viscous fluid, decomposable by
alkalis. It may also be observed, that as fecula absorbs less water than flour, this
affords a ready means of detection.
The adulteration with bean or pea flour may be detected by pouring boiling water
upon it, which developes the peculiar smell of these two substances.
FLOWERS (Fleurs, Fr.; Blumen, Germ.) of benzoin, of sulphur, of zinc, &c. is the
appellation given by the older chemists to such substances as were obtained in a pulverulent or rather minutely crystalline form by the process of sublimation.
FLOWERS, ARTIFICIAL, MANUFACTURE  OF.  The art of representing by
flowers, leaves, plants, &c., vegetable nature in her ornamental productions, constitutes the business of the artificial florist. The Italians appear to have been the first
people in Europe who excelled in the art of making artificial flowers; but of late years
the French have been most ingenious in this branch of industry.
Ribbons folded in different forms and of different colours were originally employed
for imitating flowers, by being attached to wire stems. This imitation soon gave way
to that by feathers, which are more delicate in texture, and more capable of assuming
a variety of flower-like figures. But a great difficulty was encountered in dyeing them
with due vivacity. The savages of South America manufacture perfect feather flowers,
derived from the brilliant plumage of their birds, which closely resemble the products
of vegetation. The blossoms and leaves are admirable, while the colours never fade.
The Italians employ frequently the cocoons of the silk-worm for this purpose; these
take a brilliant dye, preserve their colour, and possess a transparent velvety appearance, suitable for petals. Of late years, the French have adopted the finest cambric for
making petals, and the taffeta of Florence for the leaves. M. de Bernardiere employs
whalebone in very thin leaves for artificial flowers; and by bleaching and dyeing them of
various hues, he has succeeded in making his imitations of nature to be very remarkable.
The colouring matters used in flower dyeing are the following: -
For red; carmine dissolved in a solution of carbonate of potash.
For blue: indigo dissolved in sulphuric acid, diluted and neutralised in part by
Spanish whitening.
For bright yellow; a solution of turmeric in spirit of wine.  Cream  of tartar
brightens all these colours.
For violet; archil, and a blue bath.
For lilac; archil.
Some petals are made of velvet, and are coloured merely by the application of the
finger dipped in the dye.
FLUATES, more properly fluorides (Eng. and Fr.;'7ussaure, Germ.); compounds
of fluorine and the metals; as fluor spar, for example, which consists of fluorine and
calcium.
FLUOR  SPAR. (Chaux fluatee, Fr.; Spath  fluor, Germ.)  This mineral often
exhibits a variety of vivid colours. It crystallizes in the cubic system; with regular
octahedral and tetrahedral cleavages; spec. grav. 3 1 to 3'2; scratches cale spar, but
is scratched by a steel point; usually phosphorescent with heat; fusible at the blowpipe into an opaque head; acted on by the acids, with disengagement of a vapour
which corrodes glass; its solution affords precipitates with the oxalates, but not with
ammonia. Its constituents are, fluorine, 48'13; calcium, 51'87 in 100.
Fluor spar occurs subordinate to metallic veins; as to those of lead, in Derbyshire;
of tin, in Saxony and Bohemia; but it is found also in masses of veins, either in crystalline rocks, associated with quartz, heavy spar, &c., as in Auvergne, Forez Vosges,
Norberg in Sweden; Norway; Petersburg; near Hall; Gourock, in Scotland, &c.; or
among secondary limestones, slates, and sandstones, in Derbyshire, Cumberland, Cornwall, and New Jersey. It exists also in the amygdaloids of Scotland, and in the volcanic products of Mount Somma at Vesuvius. The variously coloured specimens,
called Derbyshire spar, are worked upon the turning lathe into vases and other ornamental objects.
FLUX, (Eng. and Fr.; Pluss, Germ.) signifies any substance capable of promoting
the fusion of earths or metallic ores by heat. White flux is the residuum of the deflagration in a red hot crucible, of a mixture of two parts of nitre, and one of cream of
tartar. It is in fact merely a carbonate of potash. Black flux is obtained when equal
parts of nitre and tartar are deflagrated. It owes its colour to the carbonaceous matter
of the tartaric acid, which remains unconsumed; the quantity of nitre being too small
for that purpose. The presence of the charcoal renders this preparation a convenient
flux for reducing calcined or oxidized ores to the metallic state. Limestone, fluor-spar,
borax, and several earthy or metallic oxides are employed as fluxes in metallurgy.
FLY  POWDER; the black coloured powder obtained by the spontaneous oxidizement of metallic arsenic in the air.




798                       FORMULA, CHEMICAL.
FODDER; is the name of a weight by which lead and some other metals are sold
in this country. Its varies in its amount in different parts of the kingdom; being in
Northumberland estimated at 21 cwts., and in other counties 22, 23 or even more cwts.
FONDUS; is the name given by the French to a particular style of calico printing
resembling the rainbow, in which the colours are graduated or melted (fondus) into
one another, as in the prismatic spectrum.  See Pa R  HANIN, for a description of
the process.
FORGE; (Eng. and Fr.; Feuer, Germ.) is the name either of the furnace, where
wrought iron is hammered and fashioned with the aid of heat, or the great workshop
where iron is made malleable. The former is called a smith's forge, the latter a
shingling mill. See IRON.
Fig. 649. represents a portable                 649f
truck forge of a very commodious
construction. A is the cylindricX] 
leather bellows, pressed down byf 
a helical spring, and worked by/ 
means of the handle at B, which[
moves the horizontal shaft c, with 
its two  attached  semi-circular         L
levers and chains.  D, is the pipe       K 
which conducts the blast to the I
nozzle at E. The hearth may be       l
covered with a thin fire-tile or 
with cinders. F, is a vice fixed to 
the  strong  rectangular trame.}
This apparatus answers all the or-!
dinary purposes of a smith's forge;
and is peculiarly adapted to ships,  I           S!
and to the execution of engineer-,                                        0
ing jobs upon railways, or in the 
country.  The height is 2 feet 6
inches; the length is 2 feet 9
inches; the width 2 feet. Weight
about 2 cwt.
FORGERY, PREVENTION.-Forgeries of Bank cheques and other cash documents
are -proposed to be prevented under the patent recently agranted to Messrs. Henry
Glynn and Rudolph Appel. They prepare paper by mixing its pulp with solution of
nitrate or sulphate of copper, to which mixture alkaline saline matter is added, to
produce a cup-reous prkcipitate (phosphate of sode being preferred), so that reddened
litimus paper will be re~ndered blue by it. One ounce of nitrate of copper is sufficient
for two gallons of the pulp, or even more if the cupreous colour is objectionable.
The pulp is to be then washed with water. A mixture of equal parts of white
soft soap and old palm oil is to be dissolved in boiling water, using half a pound of
soap to one gallon of water. Into this saponaceous solution, the paper impregnated
with the said pulp is to be dipped, and then sized. They also prevent a transfer
being taken with paper, by washing it with solution of sulphate of copper, drying
it, and dipping it in phosphate of soda strong enough to convert the sulphate into a
phosphate.
FORMIATES; are compounds of formic acid, with the salifiable bases. Many of
them are susceptible of crystallization.
FORMIC ACID; (Acide Formique, Fr.; Ameisansaure, Germ.) exists in the bodies
of wood ants, associated with the malic, or acid of apples. The artificial formation
of this animal secretion, is one of the most remarkable triumphs of modern chemistry.
If 10 parts of tartaric acid, 14 of black oxdeof manganese, 15 of concentrated sulphuric acid, and from 20 to 30 of water be mixed and distilled in a retort, formic acid
will be the liquid product; while carbonic acid will be disengaged. It may also he
generated from other mixtures. This acid is transparent and colourless, of a pungent
sour smell, a strongly acid taste, of specific gravity 1l1ll68 at 60' F., and may be
re-distilled without suffering any change. It contains in its most concentrated form
149 per cent. of water. The dry acid, as it exists in the forrniates, is composed of
32-54 carbon, 2,68 hydrogen, and 64-78 oxygen: or of two volumes carbonic oxide
gas, and one volume of vapour of water. It reduces the oxides of. mercury and silver
to the metallic state. It has not hitherto been applied to any use in the arts.
FORMULIE, CHEMICAL, are symbols representing the different substances, simple
and compound.




FORMULA, CHEMICAL.                                 801
Name.                      Formula.         Oxygen=100- Hydrogen=l.
Oxygen...              0              100I000      16-026
Hydrogen...              H                6-2398      1-000
2H               12-4796     2-000
Nitrogen...              N               88-518      14-186
2N              177-086     28-372
Phosphorus..                     p               196-155     31-436
2P              392-310     68-872
Chlorine...              CI              221-325     35-470
2CI             442-650     70-940
Iodine...              1               768-781   123*206
21            1537-562   246-412
Carbon..      ~              C                76-437     12-250
2C              152-875     24-500
Boron..              B               135-983     21-793
2B             271-966      43-586
Silicon..                            S Si            277-478     44-469
Selenium..              Se              494-582     79-263
Arsenic...             As              470-042      75-329
2As             940-084    150-659
Chromium    ~..             Cr              351-819      56-383
2Cr             703-638   112-766
Molybdenum.        ~                    Mo              598-525    95-920
Tungstenium...           T  or W          1183-200    189-621
Antimony.        ~.             Sb              806-452    129-243
2Sb            1612-904   258-486
Tellurium   ~.      ~             Te              806-452    129-243
Tantalum      ~.      ~              Ta            1153715    184-896
2Ta            2307-430   369792
Titanium..                    Ti              389-092      62-356
Gold (aurum)..      ~             Au             1243-013   199-207
2Au            2486-026   398-415
Platina...              Pt            1215-220    194-753
Rhodium...              R              750-680    120-305
2R             1501-360   240-610
Palladium...             Pd              714-618    114-526
Silver (argentum)..             Ag             1351-607   216-611
Mercury (hydrargyrus).             Hg             1265-822   202-863
2Hg            2531-645   405-725
Copper (cuprum)..             Cu              395-695     63-415
2Cu             791-390    126-829
Uranium..                     U             2711-360   434-527
2U            5422-720   869-154
Bismuth...             Bi             1330-376   213-208
2Bi            2660-752   426-416
Tin (stannum)..             Sn              735-294    117-839
Lead (plumbum)..             Pb             1294-498   207-458
2Pb            2588-996   414-917
Cadmium..             Cd              696-767    111-665
Zinc....             Zn              403-226     64-621
Nickel...             Ni              369-675     59-245
Cobalt...             Co              368-991    59-135
2Co             737-982    118-270
Iron (ferrum)..                    Fe              339-213     54-363
*                                    2Fe              678-426   108-725
Manganese..             Mn              355-787    57-019
2Mn             711-575    114-038
Cerium...             Ce              574-718     92-105
2Ce            1149-436    184-210
Zirconium...             Zr              420-238    67-348
2Zr             840-476   134-696
Yttrium...              Y              401-840     64-395
Beryllium (glucinum).             Be              331-479    53-123
2Be             662-958    106-247




802                       FORMULA, CHEMICAL.
Name.                       Formula.        Oxygen= 100. Hydrogen= 1.
Aluminum...             Al              171-167     27-431
2AI             342-234     54*863
Magnesium...             Mg              158-353     25-378
Calcium...             Ca              256-019     41-030
Strontium...             Sr              547-285     87-709
Barytum.      *.             Ba              856-88     137-325
Lithium...             L               127-757     20-474
Natrium (sodium)..             Na              290-897     46-620
2Na             581-794     93-239
Kalium (potassium)..             K               489-916     78-515
Ammonia...           2N 2H3            214-474     34-372
Cyanogen...            2NC             329-911      52-872
Srlphureted hydrogen..            2HS              213-644     34-239
Hydrochloric acid..           211 Cl            455-129     72-940
Hydrocyanic acid..           2HNC              342-390     54-872
Water...             21              112-479     18*026
Protoxyde of nitrogen,.            2N               277-036     44-398
Deutoxyde of nitrogen.N                            188-518     30-212
Nitrous acid..             2N              477-036     76-449
Nitric acid.                           2N              677-03.6   108-503
Hyposulphurous acid.        ~              S              301-165     48-265
Sulphurous acid                                          401*165      64-291
Hyposulphuric acid.       ~             2S              902-330    144*609
Sulphuric acid'.             S              501*165      80*317
Phosphoric acid..             2P              892-310    143*003
Chloric acid.                          2CI             942-650    151-071
Perchloric acid     *.            2CI             1042-650    167-097
lodic acid..      *             21             2037-562    326*543
Carbonic acid..       *             C               276-437     44-302
Oxalic acid..      *             2C              452-875     72-578
Boracic acid..       *             2B              871*966    139-743
Silicic acid...             si              577-478     92-548
Selenie acid.                           g.  Se        694*582    111*315
Arsenic acid.      *.             2As            1440-084    230-790
Protoxyde of chrome ~      ~             2Cr            1003*638    160-840
Chromic acid...              Cr             651*819    104-462
Molybdic acid.      *              Mo             898-525    143-999
Tunstic, or wolfram acid    *             W              1483*200    237*700
Oxyde of antimony..             2Sb            1912-904    306*565
Antimonious acid    *       *             Sb             1006*452    161*296
2Sb           2012-904    322*591
Antimonic acid.                    2Sbh           2112-904    338*617




FORMULE, CHEMICAL.                              808
Name.                     Formula.        Oxygen= 100. Hydrogen= I
Oxyde of tellurium..            Te            1006-452    161296
Tantalic acid..               2Ta           2607-430    417-871
Titanic acid...            Ti             589-092     94-409
Protoxyde of gold..            2Au.          2586-026    414-441
Peroxyde of gold..            2Au           2786-026   446-493
Oxyde of platina..            Pt            1415-220    226-086
Oxyde of rhodium..            2R            1801-360    228-689
Oxyde of palladium..            Pd             814-618   130-552
Oxyde of silver..            Ag            1451*607   232-637
Protoxyde of mercury                   2Hg           2631-645   421-752
Peroxyde of mercury..            Hg            1365-822    218-889
Protoxyde of copper..            2Cu            801-390    142-856
Peroxyde of copper..            Cu             495-695     79-441
Protoxyde of uranium.     *             U            2811-360   450-553
Peroxyde of uranium..            2U            5722-720   917-132
Oxyde of bismuth..            2Bi           2960-752    474-49
Protoxyde of tin..             Sn            835-294    133-866
Peroxyde of tin..             Sn            935-294    149-892
Oxyde of lead...            Pb            1394-498    223*484
Minium...            2pb           2888-996   462-995
Brown oxyde of lead*.            Pb            1494-498    239-511
Oxyde of cadmium..            Cd             796-767    127-691
Oxyde of zinc.                   i Zn           503-226    80-649
Oxyde of nickel..            Ni             469-675     75-271
Oxyde of cobalt..             Co            468-991    75-161
Peroxyde of cobalt..            200           1037-982    166-349
Protoxyde of iron..            Fe             439-213    70-389
Peroxyde of iron.      *            2F             978*426    156-804
Protoxyde of manganese    *            Mn             455-787     73-045
Oxyde of manganese..           2Mn            1011-575    162-117
Peroxyde of manganese.            Mn             555-787     89-071
Manganesic acid.                  2Mn            1211-575    194-169
Protoxyde of cerium  *    *            Ce             674-718   108-132
Oxyde of cerium    ~.            2Ce           1449-436   232-289
Zirconia...            2Zr           1140-476    182-775
Yttria..                    Y             501-840     80-425
Glucina, or berryllia..2Be                        962-958    154*325




804                               FOUNDING.
Name                         Formula.         Oxygen= 100. Hydrogen-= 1.;
Alumina...              2A1             642'334    109-942
Magnesia..                     Mg              258-353      41-404
Lime..                                    Ca              356-019      57-056
Strontia...              Sr              647-285    103-735
Baryta...              Ba              956-880    153-351
Lithia....              227-757      36-501
Natron, or soda..              Na              390-897      62-646
Peroxyde of sodium..              2Na             881-794    141-318
Kali, or potassa..               K              589-916      94-541
Peroxyde of potassium.               K              789916    126-593
Sulphate of potassa..              KS             1091081    174-859
Protosulphate of iron..             Fe S             940-378    150-706
Persulphate of iron..            2Fe S3           2481906    397-754
Protochloride of iron..            Fe 2C             781863    125303
Perchloride of iron.               2Fe 2Cl           2006-376    321-545
Protochloride of mercury                 2Hg 2Cl          2974-295    476-666
Perchloride of mercury.            Hg 2C1           1708-472    273-803
Ferrocyanide of iron..       Fe 2NC-2K 2NC         2308-778    370-008
Alum....         KS+2Al S3-24 2H        5936406    951-378
Feldspar..                          k Si+2AI Si3        3.542-162    567-673
FOUNDING of metals, chiefly of Iron. The operations of an iron foundry consist in
re-melting the pig-iron of the blast furnaces, and giving it an endless variety of forms,
by casting it in moulds of different kinds, prepared in appropriate manners. Coke is the
only kind of fuel emplcyed to effect the fusion of the cast-iron.
The essential parts of a well-mounted iron foundry are,
1. Magazines for pig-irons of Aifferent qualities, which are to be mixed in certain proportions, for producing castings cf peculiar qualities; as also for coal, coke, sands, clay,
powdered charcoal, and cow-hair for giving tenacity to the loam mouldings.
2. One or more coke ovens.
3. A workshop for preparing the patterns and materials of the moulds. It should
contain small edge millstones for grinding and mixing the loam, and another mill for
grinding coa/ \nd charcoal.
4. A vast area, called properly the foundry, in which the moulds are made and filled
with the melted metal. These moulds are in general very heavy, consisting of two parts
at least, which must be separated, turned upside down several times, and replaced very
exactly upon one another. The casting is generally effected by means of large ladles
or pots, in which the melted iron is transported from the cupola, where it is fused.
Hence, the foundry ought to be provided with cranes, having jibs moveable in every
direction.
5. A stove in which such moulds may be readily introduced as require to be entirely
deprived of humidity, and where a strong heat may be uniformly maintained.
6. Both blast and air furnaces, capable of melting speedily the quantity of cast-iron to
be em'ployed each day.
7. A blowing machine to urge the fusion in the furnaces.
Fig. 650 represents the general plan of a well-mounted foundry.
a is a cupola furnace, of which the section and view will be afterwards given; it is
capable of containing 5 tons of cast-iron.
a is a similar furnace, but of smaller dimensions, for bringing down 1I tons.
a" is a furnace like the first, in reserve for great castings.




FOUNDING.                                       805
b, b, b, b, a vast foundry apartment, whose floor, to a yard in depth, is formed of san.'
and charcoal powder, which have already been used for castings, and are ready for heap.
650                                   ing up into a substratum, or to be scooped out
when depth is wanted for the moulds. There are
besides several cylindrical pits, from five to seven
yards in depth, placed near the furnaces.  They
are lined with brick work, and are usually left fuL
46  ^1 Ulf            of' moulding sand.  They are emptied in order tc
6    receive large moulds, care being had that their top
o pT     )     is always below the orifice from which the melted
metal is tapped.
I ar    I^Bs   g These moulds, and the ladles full of melted
metal, are lifted and transported by the arm of one
or more men, when their weight is moderate; but
v    if it be considerable, they are moved about by
-,           cranes whose vertical shafts are placed at c, d, e,
6 5 6  6 1 "          in correspondence, so that they may upon occasion
transfer the load from one to another. Each crane
is composed principally of an upright shaft, embraced at top by a collet, and turning
below upon a pivot in a step; next of a horizontal beam, stretched out from nearly the
top of the former, with an oblique stay running downwards, like that of a gallows. The
horizontal beam  supports a moveable carriage, to which the tackle is suspended for
raising the weights.  This carriage is made to glide backwards or forwards along the
beam  by means of a simple rack and pinion mechanism, whose long handle desceids
within reach of the workman's hand.
By these arrangements in the play of the three cranes, masses weighing five tons may
be transported and laid down with the greatest precision upon any point whatever in the
interior of the three circles traced upon fig. 650 with the points c, d, e, as centres.
c, d, e, are the steps, upon which the upright shafts of the three cranes rest and turn.
Each shaft is 16 feet hiah., f, is the drying stove, having its floor upon a level with that of the foundry.
f'),f' is a supplementary stove for small articles.
g, g, g, are the cokins ovens.
h) is the blowing machine or fan.
i, is the steam-engine, for driving the fan, the loam-edge stones,
k, and the charcoal mill.
i", are the boiler and the furnace of the engine.
k, workshop for preparing the loam and other materials of moulding.
1, is the apartment for the patterns.
The pig-iron, coals, &c. are placed either under sheds or in the open air, round the
above buildings; where are also a smith's forge, a carpenter's shop, and an apartment
mounted with vices for chipping and rough cleaning the castings by chisels and files.
Such a foundry may be elected upon a square surface of about 80 yards in each side,
and will be capable, by casting in the afternoon and evening of each day, partly in large
and partly in small pieces, of turning out from 700 to 800 tons per annum, with an establishment of 100 operatives, including some moulding boys.
Of waking the moulds,~1. Each mould ought to present the exact form of its object.
2. It should have such solidity that the melted metal may be poured into it, and fill it
entirely without altering its shape in any point.
3. The air which occupies the vacant spaces in it, as well as the carbureted gases
generated by the heat, must have a ready vent; for if they are but -partially confined,
they expand by the heat, and may crack, even blow up the moulds, or at any rate become
dispersed through the metal, making it vesicular and unsound.
There are three distinct methods of making the moulds
1. In green sand; 2. In baked sand; 3. In loam.
To enumerate the different means employed to make every sort of mould exceeds the
limits prescribed to this work.  I shall merely indicate for each species of moulding,
what is common to all the operations; and I shall then describe the fabrication of a few
such moulds as appear most proper to give general views of this peculiar art.
Moulding in green sand.-The name green is given to a mixture of the sand as it comes
from its native bed, with about one twelfth its bulk of coal reduced to powder, and damped in such a manner as to form a porous compound, capable of preset ving the forms of
the objects impressed upon it. This sand ought to be slightly argillaceous, with particles
not exceeding a pin's head in size. When this mixture has once serve(l for a mould, and
been filled with metal, it cannot be employed again except for the coarsest castings, and
is generally used for filling up the bottoms of fresh moulds.
For moulding any piece in green sand, an exact pattern of the object must be pre



3806                               FOUNDING.
pared in wood or metal; the latter being preferable, as not liable to warping, swelling,
or shrinkage.
A couple of iron frames form a case or box, which serves as an tvelope to the mould.
Sutch boxes constitute an essential and very expensive part of the furniture of a foundry.
It is a rectangular frame, without bottom or lid, whose two largest sides are united b7 a
series of cross bars, parallel to each other, and placed from 6 to 8 inches apart.
The two halves of the box carry ears corresponding exactly with one another; of
which one set is pierced with holes, but the other has points which enter truly into these
holes, and may be made fast in them by cross pins or wedges, so that the pair becomes
one solid body. Within this frame there is abundance of room for containing the pattern
of the piece to be moulded with its incasing sand, which being rammed into the frame,
is retained by friction against the lateral faces and cross bars of the mould.
When a mould is to be formed, a box of suitable dimensions is taken asunder, and
each half, No. I and No. 2, is laid upon the floor of the foundry. Green sand is thrown
with a shovel into No. 1, so as to fill it; when it is gently pressed in with a rammer.
The object of this operation is to form a plain surface upon which to lay in the pattern
with a slight degree of pressure, varying with its shape. No. I being covered with sand,
the frame No. 2 is laid upon it, so as to form the box. No. 2 being now filled carefully with the green sand, the box is inverted, so as to place No. I uppermost, which is
then detached and lifted off in a truly vertical position; carrying with it the body of
sand formed at the commencement of the operation. The pattern remains imbedded in
the sand of No. 2, which has been exactly moulded upon a great portion of its surface.
The moulder condenses the sand in the parts nearest to the pattern, by sprinkling a little
water upon it, and trimming the ill-shaped parts with small iron trowels of different
kinds. He then dusts a little well-dried finely-sifted sand over all the visible surface of
the pattern, and of the sand surrounding it; this is done to prevent adhesion when he
replaces the frame No. 1.
He next destroys the preparatory smooth bed or area formed in this frame, covers the
pattern with green sand, replaces the frame 1 upon 2, to reproduce the box, and proceeds
to fill and ram No. 1, as he had previously done No. 2. The object of this operation is
to obtain very exactly a concavity in the frame No. 1, having the shape of the part
of the model impressed coarsely upon the surface formed at the beginning, and which
was meant merely to support the pattern and the sand sprinkled over it, till it got
imbedded in No. 2.
The two frames in their last position, along with their sand, may be compared to a box
of which No. I is the lid, and whose interior is adjusted exactly upon the enclosed
pattern.
If we open this box, and after taking out the pattern, close its two halves again, then
pour in melted metal till it fill every void space, and become solid, we shall obviously
attain the wished-for end, and produce a piece of cast iron similar to the pattern. But
many precautions must still be taken before we can hit this point. We must first lead
through the mass of sand in the frame No. I one or more channels for the introduction
of th la-slted metal; and though one may suffice for this purpose, another must be made
for letting the air escape. The metal is run in by several orifices at once, when the
piece has considerable surface, but little thickness, so that it may reach the remotest
points sufficiently hot and liquid.
The parts of the mould near the pattern must likewise be pierced with small holes, by
means of wires traversing the whole body of the sand, in order to render the mould more
porous, and to facilitate the escape of the' air and the gases. Then, befor! lifting off
the frame No. I, we must tap the pattern slightly, otherwise the sand enclosing it would
stick to it in several points, and the operation would not succeed. These gentle jolts
are given by means of one or more pieces of iron wire which have been screwed vertically
into the pattern before finally ramming the sand into the frame No. I, or which enter
merely into holes in the pattern. These pieces are sufficiently long to pass out through
the sand when the box is filled; and it is upon their upper ends that the horizontal
blows of the hammer are given; their force being regulated by the weight and magnitude of the pattern. These rods are then removed by drawing them straight out; after
which the frame No.' I may be lifted off smoothly from the pattern.
The pattern itself is taken out, by lifting it in all its parts at once, by means of screw
pins adjusted at the moment. This manceuvre is executed, for large pieces, almost
always by several men, who, while they lift the pattern with one hand, strike it with the
other with small repeated blows to detach the sand entirely, in which it is generally more
engaged than it was in that of the frame No. 1. But in spite of all these precautions,
there are always some degradations in one or other of the two parts of the mould; which
are immediately repaired by the workmtan with damp sand, which he applies and presses
gently with his trowel, so as to restore the injured forms.
Hitherto I have supposed all the sand rammed into the box to be of one kind; but




FOUNDING.                                    807
from economy, the green sand is used only to form the portion of the mould next the
pattern, in a stratum of about an inch thick; the rest of the surroundin     s filled
with the sand of the floor which has been used in former castings. The interior layer
round the pattern is called, in this case, new sand.
It may happen that the pattern is too complex to be taken out without damaging the
mould, by two frames alone; then 3 or more are mutually adjusted to form the box.
When the mould, taken asunder into two or more parts, has been properly repaired, its
interior surface must be dusted over with wood charcoal reduced to a very fine powder,
and tied up in a small linen bag, which is shaken by hand. The charcoal is thus sifted
at the moment of application, and sticks to the whole surface, which has been previously
damped a little. It is afterwards polished with a fine trowel. Sometimes, in order to
avoid using too much charcoal, the surfaces are finally dusted over with sand, very finely
pulverized, from a bag like the charcoal. The two frames are now replaced with great
exactness, made fast together by the ears, with wedged bolts laid truly level, or at the
requisite slope, and loaded with considerable weights. When the casting is large the
charcoal dusting, as well as that of fine sand, is suppressed. Everything is now ready
for the introduction of the fused metal.
IMoulding in baked or used sand.-The mechanical part of th's process is the same as
of the preceding. But when the castings are large, and especially if they are tall, the
hydrostatic pressure of the melted metal upon the sides of the mould cannot be counteracted by the force of cohesion which the sand acquires by ramming. We must in that
case adapt -to each of these frames a solid side, pierced with numerous small holes to give
issue to the gases. This does not form one body with the rest of the frame, but isattached,extemporaneously to it by bars and wedged bolts. In general, no ground coaris mixed
with this sand. Whenever the mould is finished, it is transferred to the drying stove,
where it may remain from 12 to 24 hours at most, till it be deprived of all its humidity.
The sand is then said to be baked or annealed. The experienced moulder knows how
to mix the different sands placed at his disposal, so that the mass of the mould as it
comes out of the stove may preserve its form, and be sufficiently porous. Such moulds
allow the gases to pass through them much more readily than those made of green
sand; and in general the castings they turn out are less vesicular, and smoother upon
the surface.  Sometimes in a large piece, the three kinds of moulding that in green
sand, in baked sand, and in loam, are combined to produce the best result.
Moulding in loam.-This kind of work is executed from drawings of the pieces to be
moulded, without being at the expense of making patterns.  The mould is formed of a
pasty mixture of clay, water, sand, and cow's-hair, or other cheap filamentous matter,
kneaded together in what is called the loam mill. The proportions of the ingredients are
varied to suit the nature of the casting. When the paste requires to be made very light,
horse dung or chopped straw is added to it.
I shall illustrate the mode of fabricating loam moulds, by a simple case, such as that
of a sugar pan. Fig. 651 is the pan. There is laid upon the floor of the foundry an
annular platform of cast-iron, a bfig. 652; and upon its centre c, rests the lower extremity of a vertical shaft, adjusted so as to turn freely upon itself, while it makes a wooden
pattern, e f, fig. 653, describe a surface of revolution identical with the internal surface
reversed of the boiler intended to be made. The outline, e g, of the pattern is fashioned
so as to describe the surface of the edge of the vessel. Upon the part a d b d, fig. 652,
of th. flat cast-iron ring, there must next be constructed, with bricks laid either flat or
on their edge, and clay, a kind of dome, h i k, fig. 653, from two to four inches thick,
652
according to the size and weight of the piece to be moulded. The external surface of
the bricic dome ought to be everywhere two inches distant, at least, from the surface described by the arc e f. Before building up the dome to the point i, coals are to be placed
in its inside upon the floor, which may be afterwards kindled for drying the mould. The
top is then formed, leaving at i, round the upright shah of revolution, only a very small
outlet. This aperture, as also some others left under the edges of the iron ring, enable
the moulder to light the fire when it becomes necessary, and to graduate it so as to make
it last long enough without needing more fuel, till the mould be quite finished and dry.
The combustion should be always extremely slow.
Over the brick dome a pasty layer of loam is applied, and rounded with the mould




808                                 FOUNDING.
g ef; this surface is then coated with a much smoother loam, by means of the concave
edge of the same mould. Upon the latter surface, the inside of the sugar pan is cast;
the line' g having traced, in its revolution, a ledge m. The fire is now kindled, and as
the surface of the mould becomes dry, it is painted over by a brush, with a mixture of
water, charcoal powder, and a little clay, in order to prevent adhesion between the surface already dried and the coats of clay about to be applied to it. The board g e f is
now removed, and replaced by another, g' e' J, fig. 654, whose edge e' f  describes the
outer surface of the pan. Over the surface e, f, a layer of loam is applied, which is
turned and polished so as to produce the surface of revolution e' f, as was done for the
suirface e fj; only in the latter case, the line e' g' of the board does not form a new shoulder,
but rubs lightly against m.
The layer of loam included between the two surfaces e f, e' f', is an exact representation of the sugar pan. When this layer is well dried by the heat of the interior fire, it
must be painted like the former. The upright shaft is now removed, leaving the small
vent hole through which it passed to promote the complete combustion of the coal
There must be now laid horizontally upon the ears of the platform d d, fig. 652, anrother annular platform p q, like the former, but a little larger, and without any cross-bar.
P
654                  655                    656(
4
The relative position of these two platforms is shown in fig. 656. Upon the surface
e' f' fig. 655, a new layer of loam is laid, two inches thick, of which the surface is
smoothed by hand. Then upon the platform p q, fig. 656, a brick vault is constructed,
whose inner surface is applied to the layer of loam. This contracts a strong adherence
with the bricks which absorb a part of its moisture, while 1he coat of paint spread over
the surface e' f', prevents it from sticking to the preceding layers of loam. The brick
dome ought to be built solidly.
The whole mass is now  to be thoroughly dried by the continuance of the fire, the
draught of which is supported by a small vent left in the upper part of the new dome; and
when all is properly dry, the two iron platforms are adjusted to each other by pin points,
and p q is lifted off, taking care to keep it in a horizontal'position. Up( i this platform
are removed the last brick dome, and the layer of loam which had been applied next to
it; the latter of which represents exactly by its inside the mould of the surface e'f', that
is, of the outside of the pan. The crust contained between e f and e' f is broken away,
an operation easily done without injury to the surface e f, which represents exactly the
inner surface of the pan; or only to the shoulder m, corresponding to the edge of the
vessel. The top aperture through which the upright shaft passed must be now closed;
only the one is kept open in the portion of the mould lifted off upon p q; because through
this opening the melted metal is to be poured in the process of casting. The two platforms being replaced above each other very exactly, by means of the adjusting pin points,
the mould is completely formed, and ready for the reception of the metal.
When the object to be moulded presents more complicated forms than the one now
chosen fur the sake of illustration, it is always by analogous processes that the workman
construct- his loam moulds, but his sagacity must hit upon modes of executing many
things which at first sight appear to be scarcely possible. Thus, when the forms of the
interior and exterior do not permit the mould to be separated in two pieces, it is divided
into several, which are nicely fitted with adjusting pins. More than two cast-iron
rings or platforms are sometimes necessary. When ovals or angular surfaces must be
traced instead of those of revolution, no upright shaft is used, but wooden or cast-iron
guides made on purpose, along which the pattern cut-out board is slid according to the
drawing of the piece. Iron wires and claws are often interspersed through the brick
work to give it cohesion. The core, kernel, or inner mould of a hollow casting is frequently fitted in when the outer shell is moulded. I shall illustrate this matter in the
case of a gas-light retort, fig. 657. The core of the retort ought to have the form e e e e,
and be very tolid, since it cannot be fixed in the outer mould, for the casting, except in
the part standing out of the retort towards m m. It must be modelled in loam, upon
a piece of cast-iron called a lantern, made expressly for this purpose. The lantern is a
cylinder or a truncated hollow cone of cast-iron, about half an inch thick; and differently shaped for every different core. The surface is perforated with holes of about
half an inch in diameter. It is mounted by means of iron cross-bars, upon an iron axis,




FOUNDING.                                       809
which traverses it in the direction of its length.  Fig. 668 represents a horizontal
section through the axis of the core; g h is the axis of the lantern, figured itself at i k
658
k i; o i i o is a kind of disc or dish, perpendicular to the axis, open at i i, forming one
piece with the lantern, whose circumference o o presents a curve similar to the section
of the core, made at right angles to its axis. We shall see presently the two uses for
which this dish is intended. The axis g h is laid upon two gudgeons, and handles are
placed at each of-its extremities, to facilitate the operation in making the core. Upon
the whole surface of the lantern, from the point h to the collet formed by the dish, a hay
cord as thick as the finger is wound. Even two or more coils may be applied, as occasion requires, over which loam is spread to the exact form of the core, by applying with
the hand a board, against the dish o o, with its edge cut out to the desired shape; as also
against another dish, adjusted at the time towards h; while by means of the handles a
rotatory movement is given to the whole apparatus.
The hay interposed between the lantern and the loam, which represents the crust of
the core, aids the adhesion of the clay with the cast-iron of the lantern, and gives passage
to the holes in its surface, for the air to escape through in the casting.
When the core is finished, and has been put into the drying stove, the axis g h is taken
out, then the small opening which it leaves at the point h, is plugged with clay. This is
done by supporting the core by the edges of the dish, in a vertical position. It is now
ready to be introduced into the hollow mould of the piece.
This mould executed in baked sand consists of three pieces, two of which, absolutely
o t' ^,0     6  similar, are represented, fig. 659, at p q, the third is
P"U   U~siP I  p^   ^ shown at r s.  The two similar parts p q, present each
E is'.1 ill.  the longitudinal half of the nearly cylindrical portion
of the outer surface of the gas retort; so that when
659        1   660                  they are brought together, the cylinder is formed; r s
contains in its cavity the kind of hemisphere which
forms the bottom of the retort. Hence, by adding this
part of the mould to the end of the two others, the
resulting apparatus presents in its interior, the exact
mould of the outside of the retort; an empty cylin(q  "l~ll  "^   drical portion t t, whose axis is the same as that of the
ra~i~"^^T  \         cylinder u u, and whose surface, if prolonged, would be
everywhere distant from the surface u u, by a quans^~S~         tity equal to the desired thickness of the retort. The
diameter of the cylinder t t is precisely equal to that of the core, which is slightly conical,
in order that it may enter easily into this aperture t t) and close it very exactly when it
is introduced to the collet or neck.
The three parts of the mould and the core being prepared, the two pieces p q, must
first be united, and supported in an upright position; then the core must be let down
into the opening t t, fig. 660. When the plate or disc o o of the core il supported upon
the mould, we must see that the end of the core is everywhere equally distant from the
edge of the external surface u u, and that it does not go too far beyond the line q q.
Should there be an inaccuracy, we must correct it by slender iron slips placed under the
edge of the disc o o; then by means of a cast-iron cross, and screw bolts v v, we fix the
core immoveably. The whole apparatus is now set down upon r s, and we fix with screw
bolts the plane surface q q upon r r; then introduce the melted metal by an aperture z,
which has been left at the upper part of the mould,
When, instead of the example now selected, the core of the piece to be cast must go
beyond the mould of the external surface, as is the case with a pipe open at each end,
the thing is more simple, because we may easily adjust and fix the core by its two ends.
In rastine a retort, the metal is poured into the mould set upright. It is important to
maintain this position in the two last examples of casting; for all the foreign matters
which may soil the metal during its flow, as the sand, the charcoal, gases, scoria, being
less dense than it, rise constantly to the surface. The hydrostatic pressure produced by
a high gate, or filling-in aperture, contributes much to secure the soundness and solidity
of the casting. This gate-piece being superfluous, is knocked off almost immediately




810                               FOUNDING.
alfter, or even before the casting cools. Very long, somewhat slender pieces, are usually
cast in moulds set up obliquely to the horizon. As the metal shrinks in cooling, the
mould should always be somewhat larger than the object intended to be cast. The iron
founder reckons in general upon a linear shrinkage of a ninety-sixth part; that is, one eighth
of an inch per foot.
Melting of the cast iron. -- The metal is usually melted in a cupola furnace, of which
the dimensions are very various. Fig. 661 represents in plan, section, and elevation,
one of these furnaces of the largest size; being capable of founding 5 tons of cast iron at
a time. It is kindled by laying a few chips of wood upon its bottom, leaving the orifice
c open, and it is then filled up to the throat with coke. T he fire is lit at c, and in a
quarter or half an hour, when the body of fuel is sufficiently kindled, the tuyere blast is
set in action. The flame issues then by the mouth as well as the orifice c, which has
been left open on purpose to consolidate it by the heat. Without this precaution, the
sides, which are made up in argillaceous sand after each day's work, would not present
the necessary resistance. A quarter of an hour afterwards, the orifice c is closed with a
lump of moist clay, and sometimes, when the furnace is to contain a great body of melted
metal, the clay is supported by means of a small plate of cast iron fixed against the
furnace. Before the blowing machine is set a going, the openings g g g had been kept
shut. Those of them wanted for the tuyeres are opened in succession, beginning at the
lowest, the tuyeres being raised according as the level of the fused iron stands higher in
the furnace. The same cupola may receive at a time from one to six tuyeres, through
which the wind is propelled by the centrifugal action of an eccentric fan or ventilator.
It does not appear to be ascertained whether there be any advantage in placing more
than two tuyeres facing each other upon opposite sides of the furnace. Their diameter
at the nozzle varies from 3 to 5 inches. They are either cylindrical or slightly conical.
A few minutes after the tuyeres have begun to blow, when the coke sinks in the furnace,
alternate charges of coke and pig iron must be thrown in. The metal begins to melt in
about 20 minutes after its introduction; and successive charges are then made every
10 minutes nearly; each charge containing from 2 cwts. to 5 cwts. of iron, and a quantity
proportional to the estimate given below. The amount of the charges varies of course
with the size of the furnace, and the speed required for the operation. The pigs must
be previously broken into pieces weighing at most 14 or 16 pounds. The vanes of the
blowing fan make from 625 to 650 turns per minute. The two cupolas represented
fig. 661, and another alongside in the plan, may easily melt 6j tons of metal in 21 hours;
do     __    ____ ao\d,    do'
~od                   da\
that is,,2 tons per hour. This result is three or four times greater than what was




FOUNDING.                                    811
formerly obtained in similar cupolas, when the blast was thrown in from s.all nozzles
with cylinder bellows, moved by a steam engine of 10 horse power.
In the course of a year, a considerable foundry like that represented in the plan,
fig. 650, will consume about 300 tons of coke in melting 1240 tons of cast iron; consisting
of 940 tons of pigs of different qualities, and 300 tons of broken castings, gate-pieces,
&c. Thus, it appears that 48 pounds of coke are consumed for melting every 2 cwt.
of metal.
Somewhat less coke is consumed when the fusion is pushed more rapidly to collect a
great body of melted metal, for casting heavy articles; and more is consumed when, as in
making many small castings, the progress of the founding has to be slackened from time
to time; otherwise, the metal would remain too long in a state of fusion, and probably
become too cold to afford sharp impressions of the moulds.
It sometimes happens that in the same day, with the same furnace, pieces are to be
cast containing several proportions of different kinds of iron; in which case, to prevent
an intermixture with the preceding or following charges, a considerable bed of coke is
interposed.  Though there be thus a little waste of fuel, it is compensated by the
improved adaptation of the castings to their specific objects. The founding generally begins
at about 3 o'clock, P. M., and goes on till 6 or 8 o'clock. One founder, aided by four
laborers for charging, &c., can manage two furnaces.
The following is the work of a well-managed foundry in Derby.
200 lbs. of coke are requisite to melt, or bring down (in the language of the founders),
ton of cast-iron after the cupola has been brought to its proper heat, by the combustiot
in it of 9 baskets of coke, weighing, by my trials, 40 pounds each, = 360 lbs.
The chief talent of the founder consists in discovering the most economical mixtures
and so compounding them as to produce the desired properties in the castings. One
piece, for example, may be required to have great strength and tenacity to bear heavy
weights or strains; another must yield readily to the chisel or the file; a third must resist
sudden alternations of temperature; and a fourth must be pretty hard.
The filling in of the melted metal is managed in two ways. For strong pieces, whose
moulds can be buried in the ground at 7 or 8 yards distance from the furnace, the metal
may be run in gutters, formed in the sand of the floor, sustained by plates or stones. The
clay plug is pierced with an iron rod, when all is ready.
When from the smaller size, or greater distance of the moulds, the melted metal
cannot be run along the floor from the furnace, it is received in cast-iron pots or ladles,
lined with a coat of loam. These are either carried by the hands of two or more men,
or transported by the crane. Between the successive castings, the discharge hole of the
furnace is closed with a lamp of clay, applied by means of a stick, having a small disc of
iron fixed at its end.
After the metal is somewhat cooled, the moulds are taken asunder, and the excrescences upon the edges of the castings are broken off with a hammer. They are afterwards
more carefully trimmed or chipped by a chisel when quite cold. The loss of weight in
founding is about 61 per cent. upon the pig iron employed. Each casting always requires
the melting of considerably more than its own weight of iron. This excess forms the
gates, false seams, &c.; the whole of which being deducted, shows that I cwt. of coke
is consumed for every 3 cwts. of iron put into the furnace; for every 138 cwts. of crude
metal, there will be 100 cwts. of castings, 32 of refuse pieces, and 6 of waste.
Explanation of the plates.
Manner of constructing the Mould of a Sugar-pan.
Fig. 651. View of the pan.
-  652. Flat ring of cast-iron for supporting the inner mould.
-  653. Construction of the inner mould.
-  654. Formation of the outer surface of the pan.
-  655. Finished mould.
-  956. Position of the two flat cast-iron rings, destined to sustain the moulds of the
inner and the outer surface.
Gas-retort Moulding.
-  657. Vertical projection, perpendicular to the axis of the retort; and two sections,
the one upright, the other horizontal.
-  658. Construction of the core of the retort.
-  659. Disposition of the outer mould.
-  660. Adjustment of the core in the mould.
-  661. Cupola furnace. It is 3 feet wide within, and 131 high.
TO m, solid body of masonry, as a basis to the furnace.




812                                 FOUNDING.
b b, octagonal platform of cast iron, with a ledge in which the plates a a a a are ena a, eight plates of cast iron; 1 inch thick, absolutely simnilar; only one of them  is
notched at its lower part in c, to allow the melted metal to run out, and two of the others
have six apertures g g g, &c. to admit the tuyeres.
c, orifice for letting the metal flow out. A kind of cast iron gutter, e, lined with loam,
is fitted to the orifice.
d, hoops of hammered iron, 41 inches broad; one half of an inch thick for the bottom
ones, and a quarter of an inch for the upper ones. The intermediate hoops decrease in
thickness from below upwards between these limits.
e, cast iron gutter or spout, lined with loam, for running off the metal.
f f, cylindrical piece of cast iron, for increasing the height and draught of the
furnace.
g, side openings for receiving the tuyeres, of which there are six.pon each side of the
furnace. Each of them may be shut at pleasure, by means of a small cast iron plate h,
made to slide horizontally in grooves sunk in the main plate, pierced with the holes
k k, interior lining of the surface, made of sand, somewhat argillaceous, in the following
way.'Afterhaving  laid  at
the bottom  of the furnace a
bed of sand a few inches thick,
662                                     >        lhtly  sloped  towards  the
\\E\\\~ \\~  W    orifice of discharge, there is
set upright, in the axis of the
cupola, a wooden cylinder of
its whole  height, and of  a
diameter a little less than that
of the vacant snace belonging
~/ /y < (l\X~       to  the top  of  thefurnace.
Sand is to be then rammed in
so as to fill the whole of the
furnace;   after  which  the
wooden   cylinder  is  with-;  ~    ^BBBBB~^^ ^    drawn, and the lining of sand
is cut or shaved away, till it has
received the proper form.
This lining lasts generally
5 or 6 weeks, when there are
6 meltings weekly.
1P                          i i, cast iron circular plate,
through which the mouth of
the furnace passes, for protecting the lining in k during the
introduction of the charges.
N N, level of the floor of the
foundry.   The portion of it
below the running out orifice
consists of sand, so that it may
be readily sunk when it is wished to receive the melted metal
in ladles or pots of large dimensions.
The fan distributes the blast
from  the main pipe to three
principal  points, by   three
branch tubes of distribution.
A   register, consisting  of a
cast-iron  plate  sliding  with
friction in a frame, serves to
intercept the blast at any moicnct, when it is not desirable
^*^^/   ftA"~""'~' III" i'               to  stop  the  moving  power.
A large main pipe -of zinc or
sheet iron is fitted to the orifice of the slide valve.  It is
square at the beginning, oi
only rounded at the angles




FOUNDIM.                                       813
but at a little distance it becomes cylindrical, and conducts the blast to the divaricating
points. There, each of the branches turns up vertically, and terminates at bb, fig. 662,
where it presents a circular orifice of 7. inches. Upon each of the upright pipes b, the
ine end of an elbow-tube of zinc c c c c, fig. 662, is adjusted rather loosely, and the
other end receives a tuyere of wrought iron d d, through the intervention of a shifting
hose or collar of leather c c d, hooped with iron wire to noth the tube and the tuyere.
The portion c c c c may be raised or lowered, by sliding upon the pipe b, in order to
bring the nozzle of the tuyere d d, to the requisite point of the furnace. The portion
c c c c may be made also of wrought iron. A power of 4 horses is adequate to drive this
fan, for supplying blast to 3 furnaces.
The founders have observed the efflux of air was not the same when blown into the
atmosphere, as it was when blown into the furnaces; the velocity of the fan, with the
same impulsive )power, being considerably increased in the latte:ase. They imagine that
this circumstance arises from the blast being sucked in, so to speak, by the draught of the
furnace, and that the fan then supplied a greater quantity of air.
The following experimental researches show the fallacy of this opinion. Two water
sypons, e e e, f f f, made of glass tubes, one fifth of an inch in the bore, were inserted
into the tuyere, containing water in the portions, g g g, h h h. The one of these tnometers for measuring the pressure of the air was inserted at k, the other in the centreof
the nozzle. The size of this glass tube was too small to obstruct in any sensible degree
the outlet of,he air. It was found that when the tuyeres of the fan 2charged into the
open air, the expenditure by a nozzle of a constant diameter was proportional to the
number of the revolutions of the vanes. It was further found, that when the speed of the
vanes was constant, the expenditure by one or by two nozzles was proportional to the total
area of these nozzles. The following formulae give the volume of air furnished bv the
fan, when the number of turns and the area of the nozzles are known.
25-32 S n
Volume =  (1)
1-000,000
0'86'6'7 S n
Volume =                   (2)
1,000,000
The volume is measured at 320 Fahr., under a pressure of 29-6 inches barom.
S = is the total area of the orifices of the tuyeres in square inches.
n = the number of turns of the vanes in a minute.
After measuring the speed of the vanes blowing into the atmosphere, if we introduce
the nozzle of discharge into the orifice of the furnace, we shall find that their speed, immediately augments in a notable degree. We mieht, therefore, naturally suppose that
the fan furnishes more air in the second case than in the first; but a little reflection will
show  that it is not so.  In fact, the air which issues in a cold state from the tuyere
encounters instantly in the furnace a very high temperature, which expands it, and
contributes, along with the solid matters with which the furnace is filled, to diminish
the facility of the discharge, and consequently to retard the efflux by the nozzles. The
oxygen gas consumed is replaced by a like volume of carbonic acid gas, equally expansible by heat. Reason leads us to conclude that less air flows from the nozzles into the
furnace than into the open atmosphere.
The increase in the velocity of the vanes takes place precisely in the same manner,
when after having made the nozzles blow into the atmosphere, we substitute for these
nozzles others of a smaller diameter, instead of directing the larger ones into the furnace.
Hence we may conceive that the proximity of the charged furnace acts upon the blast
iike the contraction of the nozzles. When the moving power is uniform, and the velocity
of the vanes remains the same, the quantity of air discharged must also be the same in the
two cases.
Two tuyeres, one 5 inches in diameter, the other 44, and which, consequently, presented a total area of 35j square inches, discharged air into one of the furnaces, from a
fan whose vanes performed 654 turns in the minute. These two nozzles being briskly
withdrawn from the furnace, and turned round to the free air, while a truncated pasteboard cone of 31 inches diameter was substituted for the nozzle of 44 inches, whereby
the area of efflux was reduced to 29'3 square inches, the velocity of the vanes continued
exactly the same. The inverse operation having been performed, that is to say, the two
original nozzles having been smartly replaced in the furnace, to discover whether or not
the moving power had changed in the interval of the experiment, they betrayed no perceptible alteration of speed. From the measures taken to count the speed, the error
could not exceed 3 revolutions per minute, which is altogether unimportant upon the
number 654.




814                                FREEZING.
It follows, therefore, that when the vanes of the fan have the velocity of 654 turns per
minute, the expenditure by two nozzles, whose joint area is 352 square inches, both
blowing into a furnace, is to the expenditure which takes place, when the same nozzles
blow into the air, as 35'5 is to 29'3; that is, a little more than four fifths.
If this be, as is probable, a general rule for areas and speeds considerably different
from.the above, to find the quantity of air blown into one or more furnaces by the fan,
we should calculate the volume by one of the above formulae (1) or (2), and take four fifths
of the result as the true quantity.
The fan A c here represented is of the best eccentric form, as constructed by Messrs.
Braithwaite and Ericsson.  D is the circular orifice round the axis by which the air is
admitted; and c c B is the eccentric channel through which the air is wafted towards
the main discharge pipe E.
FOUNTAIN; a stream of water rising up through the superficial strata of the earth.
See ARTESIAN WELLS.
FOXING  is a term  employed by brewers to characterize the souring of beet in the
process of its fermentation or ripening.
FRANKFORT BLACK is made by calcining vine branches, and the other refuse
lees of the vinegar vats in Germany.  They must be previously washed.
FREEZING. (Congelation, Fr.; Gefrierung, Germ.)  The three general forms, solid,
liquid, and gaseous, under one or other of which all kinds of matte" exist, seem to be
immediately referable to the influence of heat; modifying, balancing, or subduing the
attraction of cohesion. Every solid may be liquefied, and every liquid may be vaporized,
by a certain infusion of caloric, whether this be regarded as a moving power or an elastic essence.  The converse of this proposition is equally true; for many eases, till lately
styled permanent, may be liquefied, nay, even solidified, by diminution of their temperature, either alone, or aided by a condensing force, to bring their particles within the
sphere of aggregative attraction. When a solid is transformed into a liquid, and a liquid
into a gas or vapor, a quantity more or less considerable of heat is absorbed, or becomes
latent, to use the term of Dr. Black, the celebrated discoverer of this great law of nature.
When the opposite transformation takes place, the heat absorbed is again emitted, or
what was latent becomes sensible caloric. Upon the first principle, or the absorption of
heat, are founded the various artificial methods of producing cold and congelation.
Tables exhibiting a collective view of all the Frigorific Mixtures contained in
Mr. Walker's publication, 1808.
I.-Table consisting of Frigorific Mixtures, composed of ice, with chemical salts and
acids.
Frigorific Mixtures with Ice.
MIXTURES.                      Thermometer sinks.       Degree f old
produced.
Snow, or pounded ice       -  2 parts     (        to -  50
Muriate of soda    -       -                _
Snow, or pounded ice       - 5 parts  =
Muriate of soda    -       - 2                    to-  12~
Muriate of ammonia -          1_                                    
Snow, or pounded ice       - 24 parts  
Muriate of soda    -         10                   to           18 
Muriate of ammonia         -5                     o 
Nitrate of potash   -      -  5 
Snow, or pounded ice       - 12 parts     
Muriate of soda    -       -5                     to-25
Nitrate of ammonia-        -  5 
Snow        _                 3 parts I   From + 320 to -  23             55
Diluted sulphuric acid     -  2        __
Snow                       - 8 parts      From 4- 32~ to -270              59
Muriatic acid       -      - 5        1 
Snow                -      - 7 parts     From + 32~ to    30~              62
Diluted nitric acid  -     - 4
Snow                -      - 4 parts      From +320 to -400                72
Muriate of lime        -  - 5.
Snow.'2 parts J   From + 32~ to —  50~  82
Cryst. muriate of lime     - 3_  
Snow                - -    - 3 parts|   From + 32 to-51~                   83
Potash             -         - 4 




FREEZING.                                    815
N. B.-The reason for the omissions in the last column of the preceding table is, the
thermometer sinking in these mixtures to the degree mentioned in the preceding column.
and never lower, whatever may be the temperature of the materials at mixing.
II.-Table, consisting of Frigorific Mixtures, having the power of generating or creating cold, without the aid of ice, sufficient for all useful and philosophical purposes, in
any part of the world at any season.
Frigorific Mixtures without Ice.
MIXTURES.                      Thermometer sinks.      Degree ofcold
Muriate of ammonia -       - 5 parts
Nitrate of potash   -      -  5           From + 50~ to +  10~           40~
Water              -  -   - 16
Muriate of ammonia         - 5 parts
Nitrate of potash   -      -              From +50 to - 4O                46
Sulphate of soda    -      -8
Water       -       -      - 16
Nitrate of ammonia     -  -1part          From + 50 to + 4               46
From + 50~ to +4~              46
Water       -      -      - 1
Nitrate of ammonia -       -  I part
Carbonate of soda  -       -  1           From + 50~ to-  7~             57;
Water       -      -       - 1
Sulphate of soda    -      - 3 parts      From+50  to3 
Diluted nitric acid -  - 2   _____  _____m + 50 to 3    53
Sulphate of soda    -      -  6 parts T
Muriate of ammonia         -4       4,   t o 
Nitrate of potash    -        2           From+50~ to-10~                 60
Diluted nitric acid  -     - 4
Sulphate of soda    -      -  6 parts
Nitrate of ammonia -       - 5            From + 50~ to - 14~             64
Phosphate of soda  -       - 9 parts      From + 50 to   12              62
Diluted nitric acid  -     - 4
Phosphate of soda  -       - 9 parts
Nitrate of ammonia -       - 6            From + 50~ to -  21~,          71
Diluted nitric acid  -     - 4
Sulphate of soda. -       *  8 parts     From +500 to 00                50
Muriatic acid      -       - - 5
Sulphate of soda    -      - 5 parts     From +50 to +   0               47
Diluted sulphuric acid     - 4         
N. B.-If the materials are mixed at a warmer temperature than that expressed in the
table, the effect will be proportionably greater; thus, if the most powerful of these
mixtures be made when the air is + 85~, it will sink the thermometer to + 2~.
III.-Table consisting of Frigorific Mixtures selected from the foregoing Tables, and
combined so as to increase or extend cold to the extremest degrees.
Combinations of Frgorific Mixtures.
MIXTURES.                       Thermometer sinks.      Degree of cold
Phosphate of soda  -       - 5 parts
Nitrate of ammonia -       - 3            From 0~ to -  340~             34
Diluted nitric acid  -     -     4   l                              _
Phosphate of soda  -       - 3 parts
Nitrate of ammonia -       - 2            From - 34~ to -  50~           16
Diluted mixed acids -      - 4       [
Snow                         3 parts    From 00 to -  46"                46
Diluted nitric acid    -                                        46




816                                     FUEL.
TABLE III.-continued.
MiXTURES.                        Thermometer sinks.          Deg. of cold
produced.
Snow        -    -          -  8 parts
Diluted sulphuric acid      -  3            From -  10 to -56                46
Diluted nitric acid    -    -  3
Sno  s c  part   From -20~ to-  60~          40
Diluted sulphuric acid -    -1                -
I Snow-    3 parts     From +  200 to-  48                                      68
Muriate of lime        -                                ______4 
at.o fu imeo3 parts T    From +  100 to-540                                  64
-                              - 4
Snow- -                                       - 2 parts  From150 to- 680 
Muriateof lime                  3 l   -  3
~~~Snow                 I part | From 0~ to - 660~
Cryst. muriate of lime -    -  2 
Cryst. muriate of lime -   3       1
Dilutedsulphuric acid-        10            From -68 to -91                  23
N. B.-The materials in the first column are to be cooled, previously to mixing, to the
temperature required, by mixtures taken from either of the preceding tables.
Water absorbs 1000 degrees of heat in becoming vapor; whence, if placed in a saucer
within an exhausted receiver, over a basin containing strong sulphuric acid, it will freeze
by the rapid absorption of its heat into the vapor so copiously formed under these circumstances.
But the most powerful means of artificial refrigeration is afforded by the evaporation
of liquefied carbonic acid gas; for the frozen carbonic acid thus obtained has probably a
temperature 100~ under zero; so that when a piece of it is laid upon quicksilver, it instantly congeals this metal.  The more copious discussion of this subject belongs to
chemical science.
FRENCH BERRIES; Berries of Avignon.
FRICTION, counteraction of; see LUBRICATION.
FRIT; see ENAMEL and GLASS.
FUEL (Combustible, Fr.; Brennstoff, Germ.)
Such combustibles as are used for fires or furnaces are called fuel, as wood, turf, pitcoal. These differ in their nature and in their power of giving heat.
1. Wood, which is divided into hard and sort. To the former belong the oak, the
beech, the alder, the birch, and the elm; to the latter, the fir, the pine of different sorts,
the larch, the r linden, the willow, andc thie poplar.
Under like dryness and weight different woods are found to afford equal degrees of'
heat in combustion. Moisture diminishes the heating power in three ways; by diminishing the relative weight of the ligneous matter, by wasting heat in its evaporation, and
by causing slow and imperfect combustion. If a piece of wood contain, for example, 25
per cent. of water, then it contains only 75 per cent. of fuel, and the evaporation of that
water will require L part of the weight of the wood. Hence the damp wood is of less
value in combustion  by J or 2 than the dry. The quantity of moisture in newly felled
wood amounts to from 20 to 50 per cent.; birch contains 30, oak 35, beech and pine 39,
alder 41, fir 45. According to their different natures, woods which have been felled and
cleft for 12 months contain still from 20 to 25 per cent. of water. There is never less
than 10 per cent. present, even when it has been kept long in a dry place, and though it
be dried in a strong heat, it will afterwards absorb 10 or 12 per cent. of water. If it be
too strongly kiln dried, its heating powers are impaired by the commencement of carbonization, as if some of its hydrogen were destroyed. It may be assumed as a mean of
many experimental results, that I pound of artificially dried wood will heat 35 pounds
of water from the freezing to the boiling point; and that a pound of such wood as contains from 20 to 25 per cent. of water will heat 26 pounds of ice-cold water to the same
iegree. It is better to buy wood by measure than by weight, as the bulk is very little
increased by moisture. The value of different woods for fuel is inversely as their moisture, and this may easily be ascertained by taking their shavings, drying them in a heat
of 1400 F., and seeing how much weight they lose.
From every combustible the heat is diffused either by radiation or by direct communication to bodies in contact with the flame. In a wood fire the quantity of radiating heat
is to that diffused by the air as 1 to 3; or it is one fourth of the whole heating power




FUEL.                                       817
HII. Charcoal. The different charcoals afford, under equal weights, equal quantities ol
heat. We may reckon, upon an average, that a pound of dry charcoal is capable of
heating 73 pounds of water from the freezing to the boiling point; but when it has been
for some time exposed to the air, it contains at least 10 per cent. of water, which is par.
tially decomposed in the combustion into carbureted hydrogen, which causes flame,
whereas pure dry charcoal emits none.
A cubic foot of charcoal from soft wood weighs, upon an average, from 8 to 9 pounds,
and from hard wood 12 to 13 pounds; and hence the latter are best adapted to maintain
a high heat in a small compass. The radiating heat from charcoal fires constitutes one
third of the whole emitted.
III. Pilcoal. The varieties of this coal are almost indefinite, and give out very various quantities of heat in their combustion. The carbon is the heat-giving constituent,
and it amounts, in different coals, to from 75 to 95 per cent. One pound of good pitcoal
will, u~pon an average, heat 60 pounds of water from the freezing to the boiling point.
Small coal gives out three fourths of the heat of the larger lumps. The radiating heat
emitted by burning pitcoal is greater than that by charcoal.
IV. The coke of pitcoal.-The heating power of good coke is to that of pitcoal as 75
to 69.  One pound of the former will heat 65 pounds of water from 32~ to 212~; so that
its power is equal to nine tenths of that of wood charcoal.
V. Turf or peat.-One pound of this fuel will heat from 25 to 30 pounds of water
from freezing to boiling. Its value depends upon its compactness and freedom from
earthy particles; and its radiating power is to the whole heat it emits in burning as 1 to 3.
VI. Carbureted hydrogen or coal gas.-One pound of this gas, equal to about 24 cubic
feet, disengages, in burning, as much heat as will raise 76 pounds of water from the
freezing to the boiling temperature.
In the following table the fourth column contains the weight of atmospherical air,
whose oxygen is required for the complete combustion of a pound of each particular
substance.
Pounds of water    Pounds of boiling Weight of atmospheric
Species of combustible.    which a pound can  water evaporated by  air at 32~, to burn
heat from 0~ to 212~.  1 pound.           1 pound.
Perfectly dry wood  -      35 00              6-36              5-96
Wood in its ordinary state        26-00              4-72              4-47
Wood charcoal  -         -           73-00            13-27              11-46
Pitcoal  -       -       -           60-00            10-90               9-26
Coke    -        -       -           65-00            11-81              11-46
Turf    -        -       -           30-00             5-45               4-60
Turf charcoal   -        -           64-00            11-63               9-86
Carbureted hydrogen gas -            76-00            13-81              14-58
Oil      )
Wax              -       -           78-00            14-18              15-00
Tallow
Alcohol of the shops    -            52-60             9-56              11-60
The quantity of air stated in the fourth column is the smallest possible required to
burn the combustible, and is greatly less than would be necessary in practice, where
much of the air never comes into contact with the burning body, and where it consequently never has its whole oxygen consumed. The heating power stated in the second
column is also the maximum effect, and can seldom be realized with ordinary boilers.
The draught of air usually carries off at least I of the heat, and more if its temperature be very high when it leaves the vessel. In this case it may amount to one half
of the whole heat or more; without reckoning the loss by radiation and conduction,
which., however, may be rendered very small by enclosing the fire and flues within proper non-conducting and non-radiating materials.
It appears that, in practice, the quantity of heat which may be obtained from any combustible in a properly mounted apparatus must vary with the nature of the object to be
heated. In heating chambers by stoves, and water boilers by furnaces, the effluent heat
in the chimney which constitutes the principal waste may be reduced to a very moderate
quantity, in comparison of that which escapes from the best constructed reverberatory
hearth. In heating the boilers of steam engines, one pound of coal is reckoned adequate
to convert 7^ pounds of boiling water into vapor; or to heat 411 pounds of water from
the freezing to the boiling point. One pound of fir of the usual dryness will evaporate
4 pounds of water, or heat 22 pounds to the boiling temperature; which is about two
thirds of the maximum effect of this combustible. According to Watt's experiments upon
the great scale, one pound of coal can boil off, with the best built boiler, 9 pounds of
water; the deficiency from the maximum effect being here i 0 or nearly one sixth.
In many cases, the hot air which passes into the flues or chimneys may be bene.




818                            FULLER'S EARTH.
ficially applied to the heating, drying, or roasting of objects; but care ought to be takec
that the draught of the fire be not thereby impaired, and an imperfect combustion of the
fuel produced. For at a low smothering temperature both carbonic oxyde and carburet.
ed hydrogen may be generated from coal, without the production of much heat in the
fire-place.
To determine exactly the quantity of heat disengaged by any combustible in the act
of burning, three different systems of apparatus have been employed: 1. the calorimeter
of Lavoisier and Laplace, in which the substance is burned in the centre of a vessel, whose
walls are lined with ice; and the amount of ice melted, measures the heat evolved; 2. the
calorimeter of Watt and Rumford, in which the degree of heat communicated to a given
body of water affords the measure of temperature; and 3. by the quantity of water evaporated by different kinds of fuel in similar circumstances.
If our object be to ascertain the relative heating powers of different kinds of fuel, we
need not care so much about the total waste of heat in the experiments, provided it be
the same in all; and therefore they should be burned in the same furnace, and in the
-tme way. But the more economically the heat is applied, i.e greater certainty will
there be in the results. The apparatusf. 480,
is simple and well adapted to make such corn
668          parative trials of fuel. The little furnace is
covered at top, and transmits its burned ar by c,
through a spiral tube immersed in a cis ern of
water, having a thermometer inserted near its
top, and another near its bottom, into little side
orifices a a, while the effluent air escapes from the
upright end of the tube b. Here also a thermometer bulb may be placed. The average indication of the two thermometers gives the mean
temperature of the water. As the water evaporates from the cistern, it is supplied from a vessel
placed alongside of it. The experiment should be
begun when the furnace has acquired an equability of temperature. A throttle valve at c serves to regulate the draught, and to
equalize it in the different experiments by means of the temperature of the effluent
air. When the water has been heated the given number of degrees, which should be
the same in the different experiments, the fire may be extinguished, the remaining fuel
weighed, and compared with the original quantity. Care should be taken to make the
combustion as vivid and free from smoke as possible.
On the measurement of heat, and the qualities of different kinds of coal, I made an
elaborate series of experiments, a few years ago. of which the following is an outline.
The first and most celebrated, though probably not the most accurate apparatus for
measuring the quantity of heat transferable from a hotter to a colder body, was the
calorimeter of Lavoisier and Laplace. It consisted of three concentric cylinders of tin
plate, placed at certain distances asunder; the two outer interstitial spaces being filled
with ice, while the innermost cylinder received the hot body, the subject of experiment.
The quantity of water discharged from the middle space by the melting of the ice in it,
served to measure the quantity of heat given out by the body in the central cylinder.
A simpler and better instrument on this principle would be a hollow cylinder of ice of
proper thickness, into whose interior the hot body would be introduced, and which
would indicate by thd quantity of water found melted within it the quantity of heat
absorbed by the ice. In this case, the errors occasioned by the retention of water among
the fragments of ice packed into the cylindric cell of the tin calorimeter, would be
avoided. One pound of water at 1720 F., introduced into the hollow cylinder above
described, will melt exactly one pound of ice; and one pound of oil heated to 1720 will
melt half a pound.
The method of refrigeration, contrived at first by Meyer, has been in modern times
brought to great perfection by Dulong and Petit. It rests on the principle, that two
surfaces of like size, and of equal radiating force, lose in like times the same quantity
of heat when they are at the same temperature. Suppose for example, that a vessel of
polished silver, of small size, and very thin in the metal, is successively filled with different pulverized substances, and that it is allowed to cool from the same elevation of
temperature; the quantities of heat lost in the first instant of cooling will be always
equal to each other; aud if for one of the substances, the velocity of cooling is double
of that for another, we may conclude that its capacity for heat is one half, when its
weight is the same; since by losing the same quantity of heat, it sinks in temperature
double the number of degrees.
The method of mixtures.-In this method, two bodies are always employed; a hot
body which becomes cool, and a cold body, which becomes hot, in such manner that all




FUEL.                                      819
the caloric which goes out of the former is expended in heating the latter.  Suppose
for example, that we pour a pound of quicksilver at 21~ F., into a pound of water at
32;$ the quicksilver will cool and the water will heat, till the mixture by stirring acquires a common temperature. If this temperature was 122~, the water and mercury
would have equal capacities, since the same quantity of heat would produce in an equal
mass of these two substances equal changes of temperature, viz., an elevation of 90~ in
the water and a depression of 900 in the mercury. But in reality, the mixture is found
to have a temperature of only 3710, showing that while the mercury loses 174-~ the
water gains only 5 1~0; two numbers in the ratio of about 32 to 1; whence it is concluded,
that the c- acity of mercury is _J  of that of water.  Corrections must be made for the
influence of the vessel and for the heat dissipated during the time of the experiment.
The following calorimeter, founded upon the same principle as that of Count Rumford, but with certain improvements, may be considered as an equally correct instrument
for measuring heat, with any of the preceding, but one of much more general application, since it can determine the quantity of heat disengaged in combustion, as well as
the latent heat of steam and other vapors.
664
(Scale about j inch to the foot.)
It consists of a large copper bath, ef (fig. 6 64), capable of holding 100 gallons of
water. It is traversed four times, backward and forward, in four different levels, by
a zig-zag horizontal flue, or flat pipe d, c, nine inches broad and one deep, ending below
in a round pipe at c, which passes through the bottom of the copper bath e, f, and
receives there into it the top of a small black lead furnace b. The innermost crucible
contains the fuel. It is surrounded at the distance of one inch by a second crucible,
which is enclosed at the same time by the sides of the outermost furnace; the strata
of stagnant air between the crucibles serving to prevent the heat from being dissipated
into the atmosphere round the body of the furnace. A pipe a, from a pair of cylinder
double bellows, enters the ash-pit of the furnace at one side, and supplies a steady but
gentle blast, to carry on the combustion, kindled at first by half an ounce of red-hot
charcoal, So completely is the heat which is disengaged by the burning fuel absorbed
by the waier in the bath, that the air discharged at the top orifice g, has usually the
same temperature as the atmosphere.
The vessel is made of copper, weighing two pounds per square foot; it is 51 feet long,
1j wide, 2 deep, with a bottom 51 feet long, and lI broad, upon an average. Including
the zig-zag tin plate flue, and a rim of wrought iron, it weighs altogether 85 pounds.
Since the specific heat of copper is to that of water as 94 to 1,000; the specific heat of
the vessel is equal to that of 8 pounds of water, for which, therefore, the exact correction is made by leaving 8 pounds of water out of the 600, or 1,000 pounds used in each
experiment.
In the experiments made with former calorimeters of this kind, the combustion was
maintained by the current or draft of a chimney, open at bottom, which carried off at
the top orifice of the flue a variable quantity of heat, very difficult to estimate.
When the object is to determine the latent heat of steam and other vapors, they may
he introduced through a tube into the orifice g, the latent heat being deduced from the
elevation of temperature in the water of the bath, and the volume of vapor expended




820                                   FUEL.
from the quantity of liquid discharged into a measure glass from the bottom outlet c
In this case, the furnace is of course removed.
Thile heating power of the fuel is measured by the number of degrees of temperature
which the combustion of one pound of it, raises 600 or 1,000 pounds of water in the
bath, the copper substance of the vessel being taken into account. One pound of dry
wood charcoal by its combustion causes 6,000 pounds of water to become 200 hottea.
For the sake of brevity, we shall call this calorific energy 12,000 unities. In like circumstances, one pound of Llangennoek coal will yield by combustion 11,500 unities of
caloric. One pound of charcoal after exposure to the air gives out in burning only
10,500 unities; but when previously deprived of the moisture which it so greedily imbibes from the atmosphere, it affords the above quantity. One pound of Lambton's
Wall's-end coals, affords 8,500 unities; and one of anthracite 11,000.
It must be borne in mind that a coal which gives off much unburnt carburetted hydrogen gas, does not afford so much heat, since in the production of the gas a great
deal of heat is carried off in the latent state. I have no doubt, that by this distillatory
process, from one third to one fourth of the total calorific effect of many coals is dissipated in the air. But by means of such a furnace as the patent Argand invention of
Mr. C. W. Williams, the whole heat produceableby the hydrogen as well as the carbon
is obtained; and it should be borne in mind that a pound of hydrogen in burning generates as much heat as three pounds of carbon.
Mr. Berthier proposes to determine the proportion ofcarbon in coals and other kinds
of fuel, by igniting in a crucible a mixture of the carbonaceous matter with litharge,
both finely comminuted, and observing the quantity of lead which is reduced. For
every 34 parts of lead, he estimates 1 part of carbon, apparently on the principle, that
when carbon is ignited in contact with abundance of litharge, it is converted into carbonic acid. Each atom of the carbon is therefore supposed to seize two atoms of
oxygen, for which it must decompose two atoms of litharge, and revive two atoms of
lead. Calling the atom of carbon 6, and that of lead 104, we shall have the following
ratio:-6: 104X2:: 1: 34.66, being Berthier's proportion, very nearly.
On subjecting this theory to the touchstone of experiment, I have found it to be en
tirely fallacious. Having mixed very intimately 10 grains of recently calcined charcoal with 1,000 grains of litharge, both in fine powder, I placed the mixture in a crucible
which was so carefully covered, as to be protected from all fuliginous fumes, and exposed it to distinct ignition. No less than 603 grains of lead were obtained; whereas
by Berthier's rule, only 340 or 346.6 were possible. On igniting a mixture of 10 grains
of pulverized anthracite from Merthyr Tydfil, with 500 grains of pure litharge (previously fused and pulverized), I obtained 380 grains of metallic lead. In a second
similar experiment with the same anthracite and litharge, I obtained 450 grains of lead;
and in a third only 350 grains. It is therefore obvious that this method of Berthier is
altogether nugatory for ascertaining the quantity of carbon in coals, and is worse than
useless for judging of the calorific qualities of different kinds of fuel.
In my researches upon coals, I have also made it one of my principal objects to determine the quantity of sulphur which they may contain; a point which has been
hitherto very little investigated in this country at least, but which is of great consequence, not only in reference to their domestic combustion, but to their employment
by manufacturers of iron and gas. That good iron can not be produced with a sulphureous coal, however well coked, has been proved in France by a very costly experience. The presence of a notable proportion of sulphur in a gas coal is most injurious
to the gaseous products, because so much sulphuretted hydrogen is generated as to require an operose process of washing or purification, which improverishes the gas, and
impairs its illuminating powers by the abstraction of its olefiant gas, or bicarburetted
hydrogen. In proof of this proposition, I have only to state the fact, that I found in
a specimen of coal gas as delivered from the retorts of one of the metropolitan companies, no less than 18 per cent. of olefiant gas, while in the same gas, after being passed
through the purifiers, there remained only 11 per cent. of that richly-illuminating gas.
By using a gas-coal, nearly free from sulphur, such as No. 4, in the subjoined list, I
think it probable that 10 per cent. of more light may be realized than with the common
more sulphureous coal. This is an important circumstance which the directors of gasworks have hitherto neglected to investigate with analytical precision, though it is one
upon which their success and profits mainly depend.
How little attention indeed has been bestowed updi the sulphureous impregnation
of pit-coal may be inferred from the fact that one of our professional chemists of note,
in a public report, upon a great commercial enterprise, stated that a certain coal analyzed
by him was free from sulphur, which coal I found by infallible chemical evidence to
contain no less than 7 per cent. of sulphur, being about the double of what is contained
in English coals of average quality. The proportion of sulphur may in general be inferred from the appearance and quantity of the ashes. If these be of a red or ochrey
color, and amount to above 10 per cent., we may be sure that the coal is eminently




FUEL.
sul~phureous. The coal above referred to afforded from 15 to 16 per cent. of ferruginous ashes. I believe that sulphur exists in coal generally, though not always in the state
of pyrites, either in manifest particles, or invisibly disseminated through their substance.
The readiest method of determining rigidly the quantity of sulphur in anv compound,
is to mix a given weight of it with a proper weight of carbonate of potassa, nitre, and
common salt, each chemically pure, and to ignite the mixture in a platinum  crucible.
A whitish mass is obtained, in which all the sulphur has been converted into sulphate
of potassa. By determining with nitrate of baryta the amount of sulphuric acid produced, that of the sulphur becomes known.  By means of this process applied to different samples of coals, I obtained the following results:Gas                       Sulphur in            Gas                        Sulphur in
Coals.                     100 parts.           Coals.                      100 parts.
No.1I    -    -    -    -  3-00                 No. 5    -    -    -    -  2-50
2    -    -    -    -  3-90                     6    -    -           -
3    -    -    -    -  2-42                     7    -    -40
4    -    -    -    -  3-80                     8-                       3-50
Coals for puddling cast iron,                                         Sulphur in
to be converted into steel,                                           100 parts.
No. 1, hard foliated or splent coal, specific gravity   1-258         080
2, ditto -    --                         -    -   1-290           0-96
3, ditto -    - -                                  1-273          310
4, cubical and rather soft    -    -    -    -   1267             080
Thi lasi coal being rich in bitumen, would prove an excellent one for the production
of a pure coal gas. See PITCOAL.
FUEL, ECONOMY  OF.  In the report of the Transactions of the Institution of
Civil Engineers for February, 1838, the results of exact comparisons between the performance of different steam-engines exhibit this economy in a remarkable manner. It
is there shown that a condensing engine of the most perfect construction, and in perfect
condition, ot the common low pressure crank-kind, not working expansively, performs
a duty of not more than 20 or 21 millions of lbs. raised one foot high, by 90 or 94 lbs.
of coal; or ten lbs. of coal per horse power per head.
The following table exhibits the relative value of different engines in lbs. of coal per
horse power per hour:Cornish Pumping Engine   -                                  1-57
Bolton and Watt's Single Engine -      -     -    -    - 4-82
Cornish Double Engine             -- - - -325
Bolton and Watt's Double Engine         -    -    -    -10-5
The greatest duty performed by the measured bushel of 84 lbs. was 86g millions of
lbs.  There was raised by the Huel Towan engine in Cornwall 1,085 tons (of water)
one foot high for one farthing. Hence the weight of a man (14 cwt.) would be raised
ten miles for one penny!
In order to raise steam with economy, the surface of water in the boiler, exposed to
the fire, ought not to be less thon 10 square feet per horse power; but the usual allowance in Lancashire is only 74; and by Messrs. Boulton and Watt, 5 square feet.
The values of the mean of the Cornish, Warwick, London, Lancashire, and locomotive experiments, as reported by Mr. Josiah Parkes, were respectively 21, 18, 134,
and 10 cubic feet of water evaporated by 112 lbs. of coals, from  water heated to
2120 F.
FUEL, GRANT'S PATENT.  This fuel is composed of coal-dust and coal-tar
pitch; these materials are mixed together, under the influence of heat, in the following
proportions:-20 lbs. of pitch to I cwt. of coal-dust, by appropriate machinery
consisting of crushing-rollers for breaking the coal in the first instance sufficiently
small, so that it may pass through a screen the meshes of which do not exceed a quarter
of an inch asunder; 2dly, of mixing-pans or cylinders, heated to the temperature of
2200, either by steam or heated air; and, 311y, of moulding machines, by which the
fuel is compressed, under a pressure equal to five tons, into the size of a common brick.
the fuel bricks are then whitewashed, which prevents their sticking together, either ir.
the coal bunkers or n hot climates. The advantages of Grant's fuel over even the
best coal may be stated to consist, first, in its superior efficacy in generating steam,
which may be thus stated-200 tons of this fuel will perform the same work as 301.
tons of coal, such as are generally used; secondly, it occupies less space; that is to say,
500 tons of it may be stowed in an area which will contain only 4CO tons of coal;
thirdly, it is used with much greater ease by the stokers or firemen than coal, and it
creates little or no dirt or dust, considerations of some importance when the delicate
machinery of a steam-engine is considered; fourthly, it produces a very small propor
tion of clinkers, and thus it is far less liable to choke and destroy the furnace bars and




822                                       FUEL.
boilers than coal; fifthly, the ignition is so complete that comparatively little snoke, and
only a small quantity of ashes, are produced by it; sixthly, from the mixture of the patent
fuel, and the manner of its manufacture, it is not liable to enter into spontaneous ignition.
FUEL CHIEFLY  PIT COAL.  " Considering the vast importance of the subject, it is
somewhat remarkable that no exact mode of determining the true value of coal as a fuel
has ever yet been invented.  Of the methods hitherto in use there is not one which
deserves the title even of an approximation to the truth. The plan of Berthier, as has
been well shown by Dr. Ure, is beyond all things fallacious, though this very plan is that
most relied on by the experimenters connected with the late Admiralty investigation respecting the coals best suited for the steam navy. It needs, however, but a moment's
reflection to see that this process of Berthier can never afford a correct result, for the agent
employed is litharge, a substance not acted on                              heat more than
sufficient for the expulsion of the volatile constituents of coal, and moreover a substance
capable of being reduced at high temperatures by the carbonic oxide gas of the fire
employed to effect the assay. Here then are two enormous sources of error; for in the
first place the hydrogenous constituents of the coal can never be estimated at all, and in
the second the litharge by mere exposure in a crucible to the action of the fire will give
metallic lead exactly the same as if coal existed in it, so that not the least dependence in
the world can be placed in this method. Numerous and carefully conducted experiments
have fully confirmed the original observations of Dr. Ure upon this matter, and, in fact,
the results from four crucibles, each charged with the same quantities of coal and litharge,
taken from the same massive powder, and placed side by side in the same furnace, and
treated in all respects exactly alike, have shown a discordance equal to the numbers
117, 142, 166, and 163.  To think of attaching any value to any of these, or to the
average which they present, is to lose sight of the most important province of chemistry
in its relation to the arts.
" Another, and certainly a preferable method, is to consume a given amount of each
coal in a calorimeter, so as to measure the total heat disengaged during combustion.
But here, again, we meet with difficulties more than enough to destroy all confidence in
the results. Thus it is not possible thoroughly to consume the whole of the fuel in this
way. Of the volatile constituents of the coal, a portion always passes off unburnt in the
shape of carburetted hydrogen, tar, and soot, whilst of the carbon or fixed constituents,
part is constantly lost in the form of carbonic oxide gas. So that no real estimate
of the calorific value of a coal can be arrived at in this way, and even comparative
experiments are worthless from  the great inequalities which  prevail in the ratio
of the volatile and fixed ingredients in different coals, as well as from the changes
induced by accidental variations of draught through the body of the fueL Of course
the same objections apply to what are called practical experiments, conducted with any
one particular form of furnace or setting of a boiler. The form of furnace, as is well
known, requires to be adapted to the fuel, and not the fuel to the furnace: nevertheless,
in the Admiralty experiments already alluded to, the only form of furnace and boiler
employed was that called the Cornish setting, though this particular form was expressly
invented for, and will, as is notorious, do justice to no other kind of coal than anthracite.
Hence the parliamentary reports which chronicles the results of the Procrustean theorem,
though yet almost wet from the press, is even now rapidly on its road to the buttershop, there to expiate, by the humblest of services, its previous utter inutility to the
public. To know  the precise amount of heat evolved from  coals during their combustion, must, as has been before remarked, be a subject of the greatest possible
interest, for until the total calorific power be taken into account, it is impossible for us
to appreciate the loss which ensues under the existing modes of consuming fuel. At
present it seems generally agreed, that ordinary Newcastle coal will evaporate about
8 times its weight of water, or in other words, that a ton of such coal will boil off or con
vert into steam 17,920 lbs. of water. If, however, we proceed to a practical analysis of
this very coal, by examining the heating power of its gaseous and fixed constituents,
after these have been separated from each other, we shall find that the above is very far
short of.the most moderate estimate that can be formed of the beat which must be disengaged; and whether the difference be lost by imperfect combustion, or by tile action
of the chimney, or in what other way, remains still to be decided by those who seek to
improve our present modes of consuming fuel. The following table represents the actual
heat evolved, and of water evaporated, by the different constituents, of one ton of the
Newcastle coal called Pelton; and it must be remembered, that so far as chemical
research has yet gone, the heat evolved from  a combustible is in proportion to the
amount of oxygen consumed, and has no connection with the particular mechanical state
of the combustible. For instance, there is no reason to suppose that gaseous carbon,
if we possessed  such a substance, would evolve either more or less heat than its
equivalent weight of solid carbon, in combining with the same quantity of oxygen gas.
Whether, therefore, we regard the constituents of coal as existing in the solid or gaseous




FUEL.                                        823
form, does not, according to our present knowledge, alter the proportion of heat which
these constituents would give out during  their perfect oxidation.  Now  one ton of
Pelton coal affords
10,000 cubic feet of gaseous matters,
10 gallons or about 125 lbs. of tar,
and 41 bushels or 1680 lbs. of coke;
and, by experiment, it has been found that the above gas before purification will boil off
for every cubic- foot consumed 101 ounces of water; that 3 gallons of tar are equal to
about one bushel of coke; and that the coke will boil off 10 times its weight of water
Hence we have the total amount of water evaporated as under:
10,000 cubic feet of gas at 10} ounces per foot  =   6537 lbs.
10 gallons of tar equal to 333 bushels of coke  =   1365 lbs.
1680 lbs. of coke at 10 lbs. per lb.    -      -  =  16800 lbs.
Total 24702
or upwards of 11 lbs. of water for every lb. of coal. It happens, however, that even this
estimate is too low, and that actual experiments on this very coal shows its true heating
power to be not less than 12. To elucidate this it becomes necessary, however, to enter
into an explanation of the means employed for ascertaining the precise amount of heat
evolved by any combustible during its complete oxidation, and which is perhaps the only
approach to accuracy that has yet been proposed with this view.  A  copper vessel,
shaped like a  parallelogram, and having in its ends two small openings provided
with stopcocks, has also in its lower surface a large opening of two inches in diameter,
terminating in a tube or neck of about two inches in length and fitted with an earthenware plug or stopper. This parallelogram is enclosed in another and larger one, capable
of holding in addition 20 lbs. of water. The smaller vessel should have an internal
capacity of about half a cubic foot, or 800 cubic inches, and the different openings must
pass out of and through the larger vessel. The earthenware stopper is to be provided,with two small openings, in which pass two insulated copper wires, and on the top of the
stopper is a cavity capable of holding 50 grains of coal in coarse powder, through which
a fine platinum  wire passes connected with the terminal ends of the two copper wires,
and over the whole a cage of stout platinum wire is placed so as to prevent the coal from
being thrown out during tlhe experiment, and also to insure the complete combustion of
all the volatile and fuliginous matter.  To use this apparatus, 50 grains of the coal in
question are placed in the cavity of the stopper, and the necessary connections being
made by means of a fine platinum  wire, the cage is applied, and the whole inserted in
the neck or opening left for it, and which it hermetically closes: as soon as this is completed, a current of oxygen gas is made to traverse the smaller vessel by means of the
stop-cocks in the sides, and this is continued until the atmospheric air being almost
wholly expelled, the vessel remains full of oxygen gas; when this is the case water must
be poured into the larger vessel, and a piece of ice introduced into it until the temperature has fallen about 50 below that of the apartment, when the ice must be withdrawn,
and the coal lighted by means of a small galvanic battery, the poles of which need be
applied but for a moment to the copper wires which pass through the earthenware
stopper. Ignition instantly ensues, and is finished in two or three seconds, when the heat
of the water in the larger vessel must be ascertained by a delicate thermometer, after
proper agitation. It is of course necessary to take the usual precautions followed in
experiments of this kind, and to surround the whole of the larger vessel by non-conductors of caloric, having carefully determined beforehand the absorption of heat due to
the apparatus, so that this may be added to that of the water; the water itself should
either be actually weighed or measured with great accuracy at a mean temperature, and
the ice must also be weighed before and after immersion. The accompanying sketch in
section will perhaps facilitate the comprehension of this instrument.
A                _                "A, cover made of wood; B, larger
__~______                                   vessel of copper; c, smaller vessel of
copper; D, entrance for oxygen gas;
B3                  l      E, exit for atmospheric air; F, platinum   cage; G, earthenware  stopper
with cavity in top; H H, copper wires
for conveying electricity, between the
upper extremities of which a fine plaAk'In              I       tinum  wire is loosely stretched which
passes through the mass of powdered
The  results  hitherto  obtained  by
Jthis apparatus are not very extensive,
but nevertheless they  embrace sub



'824                                     LFUEL.
stantially many of the best established coals, and as might d priori be imagied, they
moreover demonstrate in an undeniable manner the superiority of bituminous over anthracitic coals and coke,-a position directly the reverse of the absurd assumptions and
foregone conclusions contained in the parliamentary report of Sir H. de la Beche and
Dr. Playfair. The following is a tabular view of these results, with a column showing
the evaporative power of each, deduced by assuming 980 as the latent beat of steam.
Lbs. of Water
Unities of Caloric,    capable of being
evaporated by I lb.
of Coal.
NEWCASTLEE:
Pelton -...-..                                      14800               151 lbs
Garesfield       ) -      -    -     -    -          15200              155 -
Hastings y   -    -                            16175              165 -
West Hartley                                          16280              16'6 -
Bates Hartley-15985                                                      163 
Newcastle Hartley -    -    -    -    -               16330              16-6
Heaton —-..    15075    156 
Gosford                                              15000               153 
Killingworth.                                         14875              151 
DURHAM:
Hetton  -      -.                                     15660              160 
Lambton-.  15450    15-7
Rainton -           -14995                                               153 
YORKSHIRE:
Woodthorpe                                            13780              140 -
Mortemly -                                            14010    143 -
NORTH WAL1ES:
Brymbo -       --                                     13875             141 -
Ruabon  -      -                                      14200              14-5
SOUTH WALES:
Anthracite No. 1.-        -     -     -     -         13090              13-3 -
Anthracite No. 2.-    -                               12875              13-1 
Neath (Bituminous)        -    -    -    -            13845              14'0 -
IRELAND:
Anthracite -12990                                                        13-2 -
WIGAN:
Cannel Ince Hall   -    -    -    -    -              14340              14-6 
Lesmahago- Cannel -                                   12285              12'5 -
NEWCASTLE:
Ramsev's Cannel   -                                  14420              14-7 -
Comparing these results with the actual working of most of the above bituminous
coals, it appears that very nearly one half of all the heat evolved is lost in practice, and
either passes off in the shape of unconsumed fuel, or is wasted in the chimney.  With a
view to ascertain how much of the loss is due to this latter circumstance, Mr. F. J. Evans,
the eminent engineer of the Westminster station of the Chartered Gas Company, made
some time ago an experiment bearing upon this subject, and in which the loss of heat is
necessarily very high, from the fact that the substance heated by the furnace was almost
white hot, whereas in a steam boiler the temperature never exceeds 300~ of Fahr. Mr.
Evans's experiment, which shows no trifling amount of ingenuity, nevertheless demonstrates that not more than 3 per cent. of the fuel passes off by the heat of the chimney;
consequently at least 15 times this amount must be lost by imperfect combustion, and fly
away in the shape of carburetted hydrogen, tarry vapour, or carbonic oxide; thus leaving a wide field.for improvement in burning and applying fuel. We give the following
in Mr. Evans's own words.




FUEL.                                           825'Experiments on waste heat: to determine the quantity of heat going away to the
chimney from a setting of 8 retorts. A deal box was constructed of the following dimensions; length 5 feet 6 inches, width 11 inches, and depth 7 inches, and quite watertight.
Within this box, and running through it, was placed an iron tube of the following dimensions; length 81 inches, width 9 inches, depth 3 inches. This tube formed by subsequent
arrangement a portion of the flue through which the air from the furnace passed to the
chimney, as is shown in the sketch below, where A represents an iron plate closing the
main flue, and compelling the hot air to pass through the iron tube contained in th3
wooden box, into which water was ultimately placed, as will be explained..MAIN   FLU E 
s,.,,.,....  i,..I..,.I II........
WOODEN  BOX FOR WATER
I  I     IRON TUBE OR TEMPORARY FLUE            _~'Matters being thus arranged, and the iron plate at A securely fixed, it necessarily
followed that all the heat from the setting of 8 retorts passed through the 81 inches of
iron tube contained in the box, and would therefore impart heat to the water placed in
that box, which was filled with this fluid at 71~ Fahr. to the extent of 112 lbs. This
water being kept in constant motion afforded the annexed thermometric indications.
Temperature of water.
Commenced experiment at 6-45                                    -       -    710
Observation made at 6-48    -            -       -                -    82
"'         6-51             -        -       -       -    94
"'         6-54     -       -        -       -       - 110
i"               6-57     -       -        -       -       -   114
t"               7-01     -        -       -       -        -   132
6"               7-06     -       -        -       -        -   148
"                7 07     -       -        -       -        -   150
Thus showing that 112 lbs. of water were raised 890 in 22 minutes, which is equal to
2-52 lbs. of water at 320 made to boil in each minute.  Consequently in 24 hours
3628-8 lbs. of such water might be made to boil, or 604'1 lbs. of water be converted
into steam in the same period of time, and as coke will evaporate, according to Lavoisier,
more than 10 times its weight of water, this implies the consumption of nearly 60j lbs.
of coke, the heat of which is entirely lost in the chimney. And if this be compared
with the total coke consumed for 24 hours in the same setting of retorts, it amounts to
about 3 per cent. only, and is therefore under the circumstances remarkably trifling.'
Hence it would  appear, as has been  before remarked, that some very considerable
improvements are needed in the present mode of consuming bituminous coals. The probability is, that a flat boiler surface exposed freely to a single sheet of flame from such
coals is the best form, for it is certain that long narrow flues act like the meshes of wire
gauze upon the volatile constituents, and cool them  down below  the point at which
ignition can go on.  In  support of this view  we have only to recollect that though
the gases from a blast furnace will burn freely when they first issue from the furnace and are white hot, yet after being once cooled down to the ordinary temperature they refuse altogether to burn or afford  heat.  The use of lonu  and  narrow
flues, with combustibles of low accendibility, is therefore highly improper, and sufficiently explains the miserable results arrived at by the Admiralty coal investigators
with a Cornish boiler."-Mr. L. Thompson.
FULGURATION; designates the sudden brightening of the melted gold and silver
in the cupel of the assayer, when the last film of vitreous lead and copper leaves
their surface.
FULLER'S  EARTH, (Terre d foulon, Argile Smectique, Fr.; Walkererde, Germ.)
is a soft, friable, coarse or fine grained mass of lithomarge clay. Its colour is greenish,
or yellowish gray; it is dull, but assumes a fatty lustre upon pressure with the fingers,
feels unctuous, does not adhere to the tongue, and has a specific gravity varying from
182 to 2'19. It falls down readily in water, into a fine powder, with extrication of air
bubbles, and forms a non-plastic paste.  It melts at a high heat into a brown slag.  Its
constituents are 53'0 silica; 10-0 alumina; 9'75 red oxide of iron; 125 magnesia; 0'5
lime; 24 water, with a trace of potash.  Its cleansing  action  upon woollen stuffs
depends upon its power of absorbing greasy matters.  It should be neither tenacious
nor sandy; for in  the first case, it would not diffuse  itself well through  water,




826                              FULLING MILL.
and in the second it would abrade the cloth too much. The finely divided silica is one
of its useful ingredients.
Fuller's earth is found in several counties of England; but in greatest abundance i
Bedfordshire, Berkshire, Hampshire, and Surry.
In the county of Surry there are great quantities of fuller's earth found about Nutfield, Ryegate, and Blechingley, to the south of the Downs, and some, but of inferior
quality, near Sutton and Croydon, to the north of them. The most considerable pits
are near Nutfield, between which place and Ryegate, particularly on Redhill, about a
mile to the east of Ryegate, it lies so near the surface as frequently to be turned up by
the wheels of the wagons. The fuller's earth to the north of the road between Redhill and Nutfield, and about a quarter of a mile from the latter place, is very thin; the
seam in general is thickest on the swell of the hill to the south of the road. It is not
known how long this earth has been dug in Surry; the oldest pit now  wrought is said
to have lasted between 50 and 60 years, but it is fast wearing out. The seam of fuller's
earth dips in different directions. In one, if not in more cases, it inclines to the west.vith a considerable angle. There are two kinds of it, the blue and the yellow; the
former, on the eastern side of the pit, is frequently within a yard of the surface, being
covered merely with the soil-a tough, wet, clayey loam. A few  yards to the west,
the blue kind appears with an irony sand-stone, of nearly two yards in thickness, between
it and the soil. The blue earth in this pit is nearly 16 feet deep. In some places the
yellow kind is found lying upon the blue; there seems, indeed, to be no regularity either
in the position or inclination of the strata where the fuller's earth is found, nor any mark
by which its presence could be detected. It seems rather thrown in patches than laid in
any continued or regular vein. In the midst of the fuller's earth are often found large
pieces of stone of a yellow color, translucent and remarkably heavy, which have been
found to be sulphate of barytes, encrusted with quartzose crystals. These are carefully
removed from  the fuller's earth, as the workmen say they often spoil many tons of it
which lie about them.  There is also found with the yellow fuller's earth a dark brown
crust, which the workmen consider as injurious also. In Surry the price of fuller's earth
seems to have varied very little, at least for these last 80 years. In 1730, the price at
the pit was 6d. a sack, and 6s. per load or ton. In 1744, it was nearly the same. It is
carried in wagons, each drawing from three to four tons, to the beginning of the iron
railway near Westham, along which it is taken to the banks of the Thames, where it is
sold at the different wharves for about 25s. or 26s. per ton. It is then shipped off either
to the north or west of England.
The next characteristic stratum, owing to its forming a ridge of conspicuous hills through
the country, is the Woburn land, a thick ferruginous stratum, which below its middle contains a stratum of fuller's earth. This is thicker and more pure in Aspley and Hogstyeend, two miles north-west of Woburn, than in any known place.
Fuller's earth is found at Tillington, and consumed in the neighboring fulling mills.
Mode of preparing fuller's earth
After baking it is thrown into cold water, where it falls into powder, and the separation of the coarse from the fine is effectually accomplished, by a simple method used in
the dry color manufactories, called washing over. It is done in the following manner:
Three or four tubs are connected on a line by spouts from their tops; in the first the
earth is beat and stirred, and the water, which is continually running from the first to
the last through intermediate ones, carries with it and deposites the fine whilst the coarse
settles in the first. The advantages to be derived from this operation are, that the two
sdnds will be much fitter for their respective purposes of cleansing coarse or fine cloth;
for without baking the earth they would be unfit, as before noticed, to incorporate so
minutely with the water in its native state; it would neither so readily fall down, nor so
easily be divided into different qualities, without the process of washing over. When fuel
is scarce for baking the earth, it is broken into pieces of the same size, as mentioned
above, and then exposed to the heat of the sun.
The various uses of fuller's earth may be shortly explained. According to the above
method, the coarse and fine of one pit being separated, the first is used for cloths of
an inferior, and the second for those of a superior quality. The yellow and the blue
earths of Surry are of different qualities naturally, and are, like the above, obtained artificially, and used for different purposes. The former, which is deemed the best, is
employed in fulling the kerseymeres and finer cloths of Wiltshire and Gloucestershire,
whilst the blue is principally sent into Yorkshire for the coarser cloths. Its effect on
these cloths is owing to the affinity which alumine has for greasy substances; it unites
readily with them, and forms combinations which easily attach themselves to different
stuffs, and thereby serve the purpose of mordants in some measure. The fullers generally
apply it before they use the soap.
FULLING; for the theory of the process, see FELTING and WOOL.
FULLING MILL. Willan and Ogle obtained a patent in 1825 for improved ful



FULMINATES.
667            ling machinery, designed to act in a similar way to the ordinary stocks, in which
cloths are beaten, for the purpose of washing and thickening them; but the standard
c11         < ^^^^and the bed of the stocks are made of iron
instead of wood as heretofore; and a steam
a \d   Id-:       vessel is placed under the bed, for heating
\  /'117  /  the cloths during the operationoffulling;
\ \, f1I whereby their appearance is said to be greatly improved.
Fig. 667  is a section of the fulling
machine or stocks; a is a cast-iron pillar,
made hollow  for the sake of lightness; b
is the bed of the stocks, made also of iron,
and polished smooth, the side of the stock
being removed to show  the interior; cis
the lever that carries the beater d. The
cloths are to be placed on the bed b, at
bottom, and water allowed to pass through the stock, when by the repeated blows of the
beater d., which is raised and let fall in the usual way, the cloths are beaten, and become
cleansed and fulled.
A part of the bed at e, is made hollow, for the purpose of forming a steam box, into
which steam from a boiler is introduced by a pipe with a stop-cock. This steam heats
the bed of the stock, and greatly facilitates, as well as improves the process of cleansing
and fulling the cloths.
The smoothness of the surface of the polish-1 metal, of which the bed of the stock is
constituted, is said to be very much preferable to the roughness of the surface of wood
of which ordinary fullinr stocks are made, as by these iron stocks less of the nap or felt
of the cloth is removed, and its appearance when finished is very much superior to cloths
fulled in ordinary stocks.
In the operation of fulling, the cloths are turned over on the bed, by the falling of the
beaters, but this turning over of the cloths will depend in a great measure upon the form
of the front or breast of the stock. In these improved stocks, therefore, there is a contrivance by which the form of the front may be varied at pleasure, in order to suit cloths
of different qualities; f, is a moveable curved plate, constituting the front of the stock;
its lower part is a cylindrical rod, extending along the entire width of the bed, and being
fitted into a recess, forms a hinge joint upon which the curved plate moves; g, is a rod
attached to the back of the curved plate f, with a screw thread upon it; this rod passes
through a nut h, and by turning this nut, the rod is moved backward or forward, and consequently the position of the curved plate altered.
The nut h, is a wheel with teeth, taking into two other similar toothed wheels, one on
each side of it, which are likewise the nuts of similar rods jointed to the back of the
curved plate f; by turning the central wheel, therefore, which may be done by a winch,
the other two wheels are turned also, and the curved plate moved backward or forward.
At the upper part of the plate there are pins passing through curved slots, which act as
guides when the plate is moved.
The patentees state in conclusion, that steam has been employed before for heating
cloths while fulling them, they therefore do not exclusively claim its use, except in the
particular way described; the advantages arising from the construction of iron stocks,
with polished surfaces in place of wooden ones, together with the moveable curved plates
described, are in their opinion " sufficiently important to constitute a patent right."
FULMINATES, or fulminating powders.  Of these explosive compounds, there are
several species; such as fulminating gold, mercury, platinum, silver; besides the old
fusible mixture of nitre, sulphur, and potash. The only kind at all interesting in a manufacturing point of view is the fulminate of mercury, now so extensively used as a priming to the caps of percussion locks. Having published a paper in the Journal of the
Royal Institution for 1831, upon gunpowder (see GUNPOWDER), the result of an elaborate
suite of experiments, I was soon afterwards requested by the Hon. the Board of Ordnance
to make such researches as would enable me to answer, in a satisfactory practical manner,
a series of questions upon fulminating powders, subservient to the future introduction of
percussion muskets into the British army. The following is a verbatim copy of my report upon the subject
To the Secretary of the Board of Ordnance.
C SIR,-I have the honor of informing you, for the instruction of the Honorable the
Master General and the Board of Ordnance, that the researches on fulminating mercury,
%which I undertook by their desire, have been brought to a satisfactory conclusion, after




828                                FULMINATES.
a numerous, diversified, and somewhat hazardous series of experiments. The following
are the questions submitted to me, with their respective answers:Qaestlion 1.  What proportions of mercury, with nitric acid and alcohol of certain
strengths, will yield the greatest quantity of pure fulminate of mercury?
a.nlswer. One hundred parts, by weight, of mercury, must be dissolved with a gentle
heat, in 1000 parts (also by weight) of nitric acid, spec. gr. 1'4; and this solution, at
the temperature of about 130~ Fahr., must be poured into 830 parts by weight of alcohol,
spec. Sr. 0'330.-Note. 830 parts of such alcohol, by weight, constitute 1000 by measure;
and 1000 parts of such nitric acid, by weight, constitute 740 by measure.  Hence, in
round numbers, one ounce weight of quicksilver must be dissolved in 74 oz. measures of
the above designated nitric acid, and the resulting solution must be poured into 10 oz.
measures of the said alcohol.
Question 2. What is the most economical and safe process for conducting the manipulation, either as regards the loss of nitrous gas and residqum, or as respects danger to
the operator; also, what is the readiest and safest mode of mixing the fulminate intimately with its due proportions of common gunpowder.
answer. The mercury should be dissolved in the acid in a glass retort, the beak of
which is loosely inserted into a large balloon or bottle of glass or earthenware, whereby
the offensive fumes of the nitrous gas disengaged during the solution, aie, in a consider
able measure, condensed into liquid acid, which should be returned into the retort.  As
soon as the mercury is all dissolved, and the solution has acquired the prescribed temperature of about 130~, it should be slowly poured, through a glass or porcelain funnel
into the alcohol contained in a glass matrass or bottle capable of holding fully 6 times
the bulk of the mixed liquids.  In a few minutes bubbles of gas will proceed from  the
bottom of the liquid; these will gradually increase in number and magnitude till a general fermentative commotion, of a very active kind, is generated, and the mixture assumes
a somewhat frothy appeara'nce.  A white voluminous gas now issues from  the orifice of
the matrass, which is very combustible, and must be suffered to escape freely into the
air, at a distance from any flame.  These fumes consist of an ethereous gas, holding
mercury in suspension or combination.  I have made many experiments with the view
of condensing this gas, or, at least, the mercury, but with manifest disadvantage to the
perfection of the process of producing fulminate.  When the said gas is transmitted,
through a glass tube, into a watery solution of carbonate of soda, a little oxyde of
mercury is, no doubt, recovered; but the pressure on the fermentative mixture, though
slight, necessary to the displacement of the soda solution, seems to obstruct or impair
the generation of the fulminate; this effect is chiefly injurious towards the end of the
operation, when the gaseous fumes are strongly impregnated with nitrous gas.  When
this is not allowed freely to come off, a portion of subnitrate or nitrate of mercury is apt
to be formed, to the injury of the general process and the product.
As soon as the effervescence and concomitant emission of gas are observed to cease,
the contents of the matrass should be turned out upon a paper double filter, fitted into a
glass or porcelain funnel, and washed by the affusion of cold water till the drainings no
longer redden litmus paper.  The powder adhering to the matrass should be washed out
and thrown on the filter by the help of a little water. Whenever the filter is thoroughly
drained, it is to be lifted out of the funnel, and opened out on plated copper or stone
ware, heated to 2129 Fahr. by steam or hot water. The fulminate, being thus dried, is to
be put up in paper parcels of about 100 grains each; the whole of which may be afterwards packed away in a tight box, or a bottle with a cork stopper.  The excellence of
the fulminate may be ascertained by the following characters.  It consists of brownish.
gray small crystals which sparkle in the sun, are transparent when applied to a slip of
glass with a drop of water, and viewed by transmitted light.  These minute spangles
are entirely soluble in 130 times their weieht of boiling water; that is to say, an imperial
pint of boiling water will dissolve 67 grs. of pure fulminate. Whatever remains indicates
impurity.  From that solution beautiful pearly spangles of fulminate fall down as the
liquid cools.
It may now be proper to show within what nice and narrow limits the best proportions
of the ingredients used in making the fulminate of mercury lie.  The following are
selected from among many experiments instituted to determine that point, as well as the
most economical process.
1. According to the formula given by the celebrated chemist Berzelius, in the 4th
vol. of his "Trait6 de Chimie," recently published (p. 383), the mercury should be
dissolved in 12 times its weight of nitric acid, sp. gr. 1375; and alcohol of sp. gr.
0-850, amounting to 16-3 times the weight of the mercury, should be poured at intervals into the nitric solution. The mixture is then to be heated till effervescence with th(
characteristic cloud of gas appears. On the action becoming violent, alcohol is to be
poured in from time to time to repress it, till additional 16.3 parts have been em.
ployed.
On this process I may remark, that it is expensive, troublesome, dangerous, and unproductive of genuine pure fulminate.  One fifth more nitric acid is expended very




FULMINATES.                                      829
nearly than what is necessary, and almost four times the weight of alcohol which is
beneficial.  Of alcohol at 0'83, 8'3 parts by weight are sufficient; whereas Berzelius
prescribes nearly 4 times this quantity in weight, though the alcohol is somewhat weaker,
being of sp. gr. 0850.  By using such an excess of alcohol, much of the fulminate is
apt to be revived into globules of quicksilver at the end of the process, as I showed
in my paper on this subject published in the Journal of the Royal Institution two years
ago.  There is no little hazard in pouring the alcohol into the nitric solution; for at
each affusion an explosive blast takes place, whereas by pouring the solution into the
alcohol, as originally enjoined by the Hon. Mr. Howard, the inventor of the process, no
danger whatever is incurred.   100 parts of mercury treated in the way recommended
by Berzelius afforded me only 112 parts of fulminate, instead of the 130 obtained by my
much more economical and safe proportions and process from the same weight of quicksilver.
2. If 10 parts of nitric acid of sp. gr. 1-375 be used for dissolving I of quicksilver,
and if 14 parts of alcohol of sp. gr. 0*85 be thereafter mixed with the solution, the. product of such proportions will either be not granular, and therefore not fulminating, or
it will be partially granular and partially pulverulent, being a mixture of fulminate and
subnitrate of mercury ill adapted for priming detonating caps. Instead of 130 parts of
genuine fulminate, as I do obtain, probably not more than 10 parts of powder will be
produced, and that of indifferent quality. In fact, whenever the ethereous fermentation
is defective, or not vigorous, little true fulminate is generated; but much of the mercury
remains in tfhe acidulated alcoholic liquid.
3. If the alcohol be poured in successive portions, and of proper strength (sp. gr. 083),
into a proper nitric solution of mercury, the explosive action which accompanies each
affusion dissipates much of the alcohol, and probably impairs the acid, so that the subsequent ethereous fermentation is defective, and little good fulminate is formed. From
100 parts of mercury submitted to this treatment, I obtained in one experiment, carefully
made, only 51 parts of a powder, which was impalpable, had a cream color, and was not
explosive either by heat or percussion.
4. When, with 100 parts of mercury. 800 of nitric acid of sp. gr. 1-375, are employed
With 650 of alcohol of sp. gr. -846. no fulminate whatever is generated.
5. When, with the proper proportions of mercury, acid, and alcohol, the process is
advanced into a proper energy of fermentative commotion, if the matrass be immersed it
cold water so as materially to repress that action, the process will be impaired, and will
turn out ultimately defective both as to the quantity and quality of the fulminate. It is
therefore evident that a certain energy or vivacity of etherization is essential to the full
success of this curious process, and that anything which checks it, or obstructs its taking
place, is injurious and to be avoided.
When my proportions are observed in making fulminating mercury, somewhat less
than one fourth of the nitric acid used in making the solution remains in the alcoholic
mixture along with the fulminate.  When other proportions are taken, much more acid
remains.  This acid is not recoverable to any useful or economical purpose, nor is the
alcohol that is associated with it. Many distillations, with various reagents, have led me
to this practical conclusion. In fact, when the process is most complete, as described in
the first paragraph, the alcohol is entirely and profitably employed in etherization, an
generating fulminic acid.
I have made a series of analytical experiments on the pure fulminate of mercury, with
the view of determining its composition, the quantity of quicksilver present in it, and
consequently the loss of mercury in the operation. I have stated that my maximum product of fulminate from 100 grs. of quicksilver is 130 grs. Occasionally, from slight differences in the temperature of the mixture, or the ambient atmosphere, 2 grs. less may
be obtained.
A. I dissolved 130 grs. with a gentle heat in muriatic acid contained in a small matrass,
adding a few drops of the nitric to quicken the solution. On evaporating it to dryness,
with much care to avoid volatilization of the salt, I obtained 125 grs. of corrosive sublimate or bi-chloride of mercury.  But 125 grs. of this bi-chloride contain only 91lgrs. of quicksilver.  Therefore, by this experiment, 130 grs. (if fulminate contain no
more than 91'1 of mercury, indicating an exhalation of 8-9 parts in the form of fumes,
or a retention in the residuary liquid of some of these 8'9 parts, out of the 100 originally
employed.
B. In another experiment for analysis, 130 grs. dissolved as above, were thrown
down by carbonate of soda. 95 grs. of black oxyde of mercury were obtained, which
are equivalent to 91-2 grs. of quicksilver; affording a confirmation of the preceding
result.
C. 130 grs. of fulminate were dissolved in strong muriatic acid, and the solution was
decomposed by crystals of proto-muriate of tin at a boiling temperature. The mercury
was precipitated in globules to such amount as to verify the two preceding experiments.
Regarding fulminate of mercury as a bicyanate, that is, as a compound of one atom




830                                FULMINATES.
or one equivalent prime of deutoxyde of mercury, and two primes of cyanic acid, weshall
find its theoretical composition to be as follows, hydrogen being the radix, or 1.
2 primes of Cyanic or Fulminic Acid =  34 X 2 =  68                24
Deutoxyde of Mercury =              216               76
284             100
As these 284 parts of fulminate contain 200 of quicksilver, so 142 parts of fulminate
will contain 100 of quicksilver. Whence it appears, that when only 130 parts of fulminate can be obtained in practice from 100 of quicksilver, 8~ parts of quicksilver out
of the 100 are unproductive, that is, are expended in the etherized gas, or left in the
residuary acidulous liquid.  By the above experimental and theoretical analysis 916
parts of quicksilver enter into the composition of 130 parts of true crystalline fulminate.
The complete accordance here exhibited between theory and practice removes every
shadow  of doubt as to the accuracy of the statements.  100 parts of fulminate conOxyen    56           ye 
Fulminic acid -    -       24
100'0
Question 3. May the gas or vapor produced by the inflammation of the fulminate of
mercury, when combined with a portion of gunpowder, be considered in its nature corro.
sive of iron or brass?
aJnswer.  I have suggested to Mr. Lovell, of Waltham  Abbey works, that the fulminate may be probably diluted most advantageously with spirit varnish made of a
proper consistence by dissolving sandarach in alcohol.  When well mixed with this
varnish, a small drop of the mixture will suffice for priming each copper cap or disc;
and as the spirit evaporates immediately, the fulminate will be fixed to the copper
beyond the risk of shaking or washing away.  On the Continent, tincture of benjamin
is used for the same purpose; but as that balsamic resin leaves in combustion a voluminous coal, which sandarach does not, the latter, which is the main constituent of
spirit varnish, seems better adapted for this purpose. It is sufficiently combustible, and
may be yet made, by a due proportion, to soften the violence of the explosive mercury
on the nipple of the touch-hole.  Fulminate prepared by my formula has no corrosive
influence whatsoever on iron or steel; and, therefore, if such a medium of applying it, as
I have now taken leave to suggest, should be found to answer, all fears on the score of
corrosion may for ever be set at rest.
Queslion 4. How far is the mixture (of fulminate and gunpowder) liable to be affected
by the moisture of the atmosphere, or by the intrusion of water; and will such an accident adect its inflammability when dried again?.answer.  Well made fulminate, mixed with gunpowder and moistened, undergoes no
change, nor is it apt to get deteriorated by keeping any length of time in a damp climate
or a hazy atmosphere. Immersion in water would be apt to wash the nitre out of the
pulverine; but this result would be prevented if the match or priming mixture were
liquefied or brought to the pasty consistence, not with water, but spirit varnish. Such
detonating caps would be indestructible, and might be alternately moistened and dried
without injury.
Question 5. Is it at all probable that the composition would be rendered more inflammable or dangerous of use by the heat of tropical climates?
ansvwer. No elevation of temperature of an atmospheric kind, compatible with human existence, could cause spontaneous combustion of the fulminating mercury, or the
detonating matches made with it. In fact, its explosive temperature is so high as 367w
of Fahrenheit's scale, and no inferior heat will cause its detonation.
Question 6. Is the mercurial vapor or gas arising from the ignition of a great number
of primers, and combined with the smoke of gunpowder in a confined space (as in the
case of troops in close bodies, squares, casemates, &c.), likely in its nature to be found
prejudicial to human health?.4nswer. I have exploded in rapid succession of portions, 100 grains of fulminate of
mercury (equivalent to 300 or 400 primers), in a close chamber of small dimensions,
without experiencing the slightest inconvenience at the period, or afterwards, though my
head was surrounded by the vapors all the time of the operation. These vapors are, in
fact, so heavy that they subside almost immediately. When the fulminate mixed with
pulverine is exploded in the primers by condensed masses of troops, the mercury will
cause no injury to their health, nor 100th part of the deleterious impression on weak
lungs which the gases of exploded gunpowder might by possibility inflict. These gases
are all, theoretically speaking, noxious to respiration; such as carbonic acid gas, azote,
carbureted hydrogen, and sulphureted hydrogen, a deadly gas.  Yet the soldier who
should betray any fear of gunpowder smoke would be an object of just ridicule."




FULMINATES.                                    831
In the following September, I executed for the Board of Ordnance a set of experiments, complementary to those of the memoir, with the view of ascertaining the best
manner of protecting the fulminate when applied to the copper caps, from  being
detached by carriage, or altered by keeping. The following were my results and conclusions.
" 1. Fulminate of mercury moistened upon copper is speedily decomposed by the
superior affinity of the copper over mercury, for oxygen and fulminic acid. Dryness
is, therefore, essential to the preservation of the fulminate; and hence charcoal, which
is apt to beci.me moist, should not be introduced into percussion caps destined for distant
service.
2. An alcoholic solution of sandarach, commonly called spirit varnish, acts powerfully on copper, with the production of a green efflorescence, which decomposes ful.
minate of mercuiy. Indeed, sandarach can decompose the salts of copper.  It is therefore ill adapted for attaching the fulminate to copper caps.
3. An alcoholic solution of shellac acts on copper, though more feebly than the
sandarach.
4. A solution of mastic in spirits of turpentine, whether alone or mixed with fulminate, has no action whatever on bright copper, but protects it from being tarnished. Such
a varnish is very cheap, dries readily, adheres strongly, screens the fulminate from damp,
and does not impair or counteract its detonating powers. This, therefore, is, in my opinion, the fittest medium for attaching the fulminate, and for softening the force of its impulsion in any degree preportional to the thickness of the varnish."
Fulminate of mercury is obtained in white grains, or short needles, of a silky lustre,
which become gray upon exposure to lig'ht, and detonate either by a blow or at a heat undler 3700 F.; with the disengagement of azote, carbonic acid, as also of aqueous and mer-'
curial vapors; to the sudden formation of which gaseous products the report is due.  It
detonates even in a moist condition; and when dry it explodes readily when struck between
two pieces of iron, less so between iron and bronze, with more difficulty between marble
and glass, or between two surfaces of marble or glass.  It is hardly possible to explode
it by a blow with iron upon lead; and impossible by striking it with iron upon wood. It
fulminates easily when rubbed between two wooden surfaces; less so between two of
marble, two of iron, or one of iron against one of wood or marble. The larger its crystals, the more apt they are to explode. By damping it with 5 per cent. of water, it becomes less fulminating; the part of it struck still explodes with a proper blow, but will
not kindle the adjoining portion. Though moistened with 30 per cent. of water, it will
occasionally explode by trituration between a wooden muller and a marble slab, but only
to a small extent, and never with any danger to the operator. When an ounce of it, laid
upon the bottom of a cask, is kindled, it strikes a round hole down through it, as if it
had been exposed to a four-pound shot, without splintering the wood. If a train of fulminate of mercury be spread upon a piece of paper, covered with some loose gunpowder,
in exploding the former the latter will not be kindled, but merely scattered. When gunpowder, however, is packed in a cartridge, or otherwise, it may be certainly kindled by a
percussion cap of the fulminate, and more completely than by a priming of gunpowder.
81 parts of gunpowder exploded by a percussion cap, have an equal projectile force as 10
exploded by a flint lock.  If we add to this economy in the charge of the barrel, the
saving of the powder for priming, the advantage in military service of the percussion
system will become conspicuous.
The French calculate that 1 kilogramme of mercury will furnish 1  kil. (2^ lbs. nearly)
of fulminate, which will be sufficient to charge 40,000 percussion caps. For this purpose they. grind the crystalline salt along with 30 per cent. of water upon a marble table
with a wooden muller; mixing with every 10 parts of the fulminate 6 of gunpowder. A
consistent dough is thus obtained, which, being dried in the air, is ready for introducing
into the bottoms of the copper caps. One quarter of a grain of the fulminate is said to
be fully sufficient for one priming.
Mr. Lovell, of the Royal Manufactory of Arms, has lately executed a series of experiments upon priming powders. His trials, which occupied nearly 18 months, were made
for the purpose of ascertaining what is the advantage in point of force obtained by using
percussion primes.  He had anticipated some extra energy would be imparted to the
charge of powder in the barrel, because he had repeatedly proved that a good strong cap,
exploded by itself on the nipple of the musket (without any charge of gunpowder), will
exert sufficient force upon the air within the barrel to blow a candle out at a distance of
12 feet from the muzzle.  He concluded also that stopping the escape of fluid from the
vent, as is done by the cap, would have some effect, but he attributed most to the quickness and energy with which the powder of the charge is ignited by the vivid stream of
flame, generated by the percussion prime. The trials were made from one and the same
barrel, having a percussion lock on one side and a flint lock on the other. The balls were
fired against Austen's recoiling target, a very delicateplegometer, beginning with a charge
of 150 grains (the present musket charge), and descending by 10 grains at a time (firing




832                                  FURNACE
descending by 10 grains at a time (firing 30 rounds with each weight), down to 60
grains. The machine marked the decrease of force at each reduction in the charge very
satisfactorily, and the result of the whole average was that 884 parts of gunpowder
fired by percussion are equal to 10 parts fired by the flint.
To find out what sort of liberties might be taken with fulminate of mercury in
handling it, he placed 8 grains on an anvil, putting the end of a steel punch gently on
the top of it, and while so placed he covered the fulminate over with a drachm of dry
gunpowder. He then ignited the fulminate by a blow on the punch with the hammer,
but not a grain of the gunpowder was lighted, though it was blown about in all
directions. He then placed a train of fulminate as thick as a quill, and about 3 feet long,
on a table, and covered it over entirely with gunpowder except about an inch at one
end; this he lighted with hot iron, when the whole train went off without blazing a
grain of the gunpowder, which he swept together and blew  up afterwards with a
match.  He then took a tin box containing 500 copper caps, made a hole in the top of
the box, and through this hole ignited one of the caps in the middle, by means of the
punch and hammer on the outside; only two other caps besides the one struck exploded;
no injury was sustained by the remainder, except being discoloured.  This he tried
repeatedly, and always with the same kind of result, never more than 3 or 4 caps exploding. He then made a steel rammer red hot, and passed it through the hole in the
box right in amongst the caps, but it only ignited them where the iron came in actual
contact with the priming composition; when, however, he placed a few grains of gunpowder loose among the caps, the hot iron lighted this, and produced a flame that blew
off the whole of them.
The same thing has been tried at Woolwich, where large packages of percussion caps
(some thousands) have been fired at with musquet balls, and only a few of the caps actually
hit by the ball exploded; but when any cartridges were connected with the packages,
the whole, caps and all, were blown up. The flame of the fulminate is therefore hazardous, but being so very ethereal, it requires for making primes an admixture of some
combustible matter, as a little gunpowder, to condense or modify the flame.
FULMINIO  ACID; (Acid fulminique, Fr.; Knallsaure, Germ.) is the explosive
constituent of the fulminating mercury of
668                           Howard, and the fulminating silver of
68  c                    Brugnatelli, being generated by the reaction of alcohol and the acid nitrates of
_these metaL. It is a remarkable chemical
\'C71          fact, that fulminic acid has exactly the
a                         same composition as cyanic acid; though
the' salts of the latter possess no detonating property, and afford, in their decomposition by an oxygen acid, ammonia with
carbonic acid; while those of the former
afford ammonia and prussic acid.  All
attempts to insulate fulminic acid have.2 ^.    (0)   proved unsuccessful, as it explodes with
the slightest decomposing force.  It con-.~1;    sists, by weight, of 2 primes of carbon,
-/"Io <g1 of azote, and I of oxygen; or of two
volumes of carbonic acid, and one of azote,
/(B)   0s\   j ^~^\ \                  When two different bodies, like the above,
0       0a) <i~ (j>^/   ^ 1    I         have the same composition, they are said
\        0 ^,J (A _______ Ito be isHomeric.
0^J^   ^/"~~~\   U  ^                    FUMIGATION, is the employment of
d^  L/2i \fumes or vapours to purify articles of apparel, and goods or apartments supposed
to be imbued with some infectious or contagious poison or fumes. The vapours of
vinegar, the fumes of burning sulphur, explosion of gunpowder, have been long prescribed and practised, but they have in all
probability little or no efficacy. The diffusion of such powerful agents as chlorine
gas, muriatic acid gas, or nitric acid vapour, should alone be trusted to for the
destruction of morbific effiluvia.
FURNACE   OF   ASSAY.   Under
ASSAY, I have referred to a furnace con'
- ~ i~ ~ ~ structed by Messrs. Anfrye and d'Arcet




FUSEL OIL.                                          833
whbich gives some peculiar facilities and economy to the ancient process by fire. It had
originally a small pair of bellows attached to it, for raising the heat rapidly to the proper
vitrifying pitch. The furnace, 171 inches high, and 7j inches wide, made of pottery or
fine clav, is represented fig. 481., supported upon a table, having a pair of bellows
beneath~ it.  The laboratory is at b, the blow-pipe of the bellows at d, with a stop-cock,
and the dome is surmounted by a chimney a, c, in whose lower part there is an opening
with a sliding door, for the introduction of the charcoal fuel. The furnace is formed in
three pieces; a dome, a body, and an ash-pit.  A  pair of tongs, a stoking-hook, and
cupel, are seen to the right hand, and the plan of the stone-ware grate, pierced with
conical holes, and a poker, are seen to the left.  This grate suits the furnace represented under ASSAY.  The following are comparative experiments made by means of
this furnace:
ver employed. Lead employed. Time of Assay.   Standards.    Charcoal used.
Nubes    S rI Grain         4 Grains.    12 minutes.  947 milliemes.  173 Grains.
2-  -~                      11             950                86
3-                          13             949                93
-4               ~-         10             949                60
Each assay was therefore performed at an average in 11- minutes, and not much more
than a quarter of a pound of charcoal was used. An experiment of verification in the
ordinary assay furnace showed the standard to be 949 thousandths.
This furnace becomes a very convenient one for melting small quantities of metals in
analyses, by removing the muffle, and closing the several apertures with their appropriate
stoppers. A  small pedestal may be then set in the middle of the grate, to support
a crucible, which may be introduced through the opening h.  Coke may also be used
as fuel, either by itself or mixed with charcoal. For descriptions of various furnaces, see
ASSAY; BEER; COPPER; EVAPORATION; IRON; METALLURGY; ORES; SILVER; TIN, &c
FU'R-SKISN  DRESSING.  Fur-skins are usually dressed by placing them  in their
dried state in tubs, where they undergo a treading operation with men's feet, until they
are sufficiently soft and bend easily. The skins if large are sewn up, the fur being turned
inwards; but if small skins, such as ermine, are being dressed, they require no sewing
This sewing is preparatory to the greasing with butter or lard, and is intended to protect
the fur from the grease, and  to promote the softening in the succeeding treading operation.  The skins are next wetted, and their flesh is removed; or they are fleshed and
then hung up to dry.  They are again subjected to treading in tubs containing sawdust;
and afterwards in tubs containing plaster of Paris, or whitening, sprinkled between the
skins.  They are then beaten with a stick, and combed; when the dressing is completed.
M. Pierre Thirion proposes, in his patent of June, 1845, to soften the skins, not by treading, but by beating stocks, of a construction like the fulling mill. They are next sewn up,
and again fulled in a strong vessel, where they are forced upwards by the beaters, turned
over and over, and thus speedily softened.  They are now fleshed, and then returned
to the beating stocks, and mahogany or other sawdust is sprinkled upon the fur, before
the beating is renewed.  They are next placed in a heated barrel, furnished within with
radial pins for turning the goods over and over, in order that they may be acted upon by
various dry substances, which are thrown into the barrel, and absorb the fat from  th<.
skins.  Througli the hollow  shaft of the barrel, steam  is introduced, which heats the
skins, softening the fat, which is then absorbed by sand, flour, or any other desiccative
powder.  It is proper to take the skins out of the barrel from  time to time to comb
them. Such as lhave been sufficiently acted upon may then be set aside. They are lastly
freed from the (lust by being subjected to a grated cylinder in a state of rotation, and
then combed by hand.
FUSEL  OIL  is the German  name of the offensive smelling oil which exists in
alcohol, as distilled from the fermented infusions of malt, and corn meal of all kinds, as
also from  the fermented wash of potatoes, and of beets, &c.  A  like oil occurs in
the alcohol distilled from  the fermented must of grapes, and the juices of many sweet
fruits. This oil is not, however, identical from these several sources; as may indeed be
inferred from the diversity in the flavours of the different liquors.  But they all agree in
being somewhat less volatile than water, and therefore make their appearance chiefly in
the spirits towards the end of the distillation process. It is to the presence of this oil that
the milkiness of the last, and also sometimes of the first, portions of the spirit that come
over, called feints, owe their opalescence and their penetrating odour. When the milky
fluid is redistilled, alcohol ana water first pass over with very little oil, but if the heat
of the still be moderate, the oil may be made a residuum, and obtained in a tolerably
concentrated state. The oil from potatoes was first analyzed by Dumas, and was shown
by him  to be composed of 68-2 per cent. of carbon, 13-6 of hydrogen, and 18-2 of
oxygen; according to the formula CGoH11O, HO.  It belongs therefore to the class of
63




834                                   FUSTIAN.
alcohols, one whose radical is C0oHu, or amyle, and is an amyl oxyhydrate; just as
common alcohol is an oxyhydrate of ethyle.  The potato amyle spirit is a colourless fluid
of an acrid burning taste, and of a most offensive, penetrating, durable smell. When
the vapour of it is inhaled it produces an oppressive nausea, headache, giddiness, and
retching. It has a poisonous action on the animal system. By oxydizing agents it is
converted into valerianic (Baldrian) acid. According to Balard the amyle spirit occurs
along with the venanthic ether in the oil, which contaminates brandy, and is probably
derived from the husks of the grapes. This noxious spirit exists most abundantly in
the whisky of malt, and especially in that from raw grain; and is now an article of considerable sale, being used to burn in lamps, to dissolve copal and other resins for varnish
making and other purposes.
Besides this liquid amyle spirit corn spirits contain a concrete fatty matter, of a brown
colour, an acid reaction, and an offensive smell and taste. It has a green tinge, which
I believe is derived from the copper worm of the still. Mulder has shown that this fatty
product consists of an easily fusible and a difficultly fusible portion. The former he
regards as the ether of aenanthic acid; consisting of 85 carbon, 103 hydrogen, and 48
oxygen, and is therefore quite different from the amyle spirit. Margaric acid is mixed
with the less fusible portion. He says that one million parts of malt whisky contain
30 of aenanthic acid, 9 of aenanthic ether, and 5 of corn oil (amyle spirit). There are
probably many varieties of these oils of crude alcohol
FUSIBILITY. That property by which solids assume the fluid state.
Some chemists have asserted that fusion is simply a solution in caloric; but this opinion
includes too many yet undecided questions, to be hastily adopted.
Fusibility of Metals, as given by M. Thenard.
Centigr.
1. Fusible below a        Mercury         -390
red heat.           Potassium        +58~
Sodium             90
Tin              210      Newton.
Bismuth          256
Lead             260      Biot.
Tellurium        A little less fusible than lead.-Kaproth.
Arsenic          Undetermined.
Zinc             3700    Brongniart.
Antimony         A little below a read heat.
Cadmium                   Stromeyer.
Pyrometer of Wedgewood.
2. Infusible below a      Silver             20      Kennedy.
red heat.           Copper              27 )   Wd3 od
Gold               32 s  Wedgewood.
Cobalt             A little less difficult to melt than iron.
Iron              1        Wedgewood.
Manganese         160     Guyton.
Nickel          *         As manganese.-Richter.
Palladium
Ur dnium           Nearly infusible; and to be obtained at a
Tnunt           J    forge heat only in small buttons.
Chromium
Titanium
Cerium
Osmium             Infusible at the forge furnace. Fusible at
Iridium              the oxyhydrogen blowpipe.  See Blow.
Rhodium.             PIPE.
Platinum
Columbium
FUSIBLE METAL. See ALLoY.
FUSTET.  (Fustec, Fr.)  The wood of the rhus cotinus, a fugitive yellow dye.
FUSTIAN is a species of coarse thick tweeled cotton, and is generally dyed of an
olive, leaden, or other dark color. Besides the common fustian, which is known by the
name of pillow (probably pilaw), the cotton stuffs called corduroy, velverett, velveteen,
thicksett, used for men's wearing apparel, belong to the same fabric. The commonest
kind is merely a tweel of four, or sometimes five leaves, of a very close stout texture,
and very narrow, seldom exceeding 17 or 18 inches in breadth. It is cut from the loom
in half pieces, or ends, as they are usually termed, about 35 yards long, and after undergoing the subsequent operations of dyeing, dressing, and folding, is ready for the
market




FUSTIAN.                                     835
The draught and cording of common fustian is very simple, being generally a regular
or unbroken tweel of four or five leaves. Below are specimens of a few different kinds,
selected from those most general in Lancashire.
The number of leaves of heddles are represented by the lines across the paper, and the
cording by the ciphers in the little squares, those which raise every leaf being distinguished by these marks, and those which sink them left blank, as more particularly
explained in the article TEXTILE FABRIC.
Of velvet, there are properly only two kinds, that with a plain, and that with a tweeled,
or, as it is here called, a Genoa ground, or back. When the material is silk, it is called
velvet, when cotton, velveteen; and this is the sole difference. In the same way a common tweeled cloth, when composed of silk is called satin; when of cotton, fustian or
jean - of woollen, plaiding, serge, or kerseymere; and in the linen trade is distinguished
by a variety of names according to the quality or fineness, or the place where the article
is manufactured.
No. l.-Pillow Fustian.                       No. 2.-Plain Velveret.
JO1   I    I    I   4   5       I     4    I 1 01    I   I 1         3.   1
1    101    I    I  3  6              ~    101    I   I   I   1  5
I 10 I  16     2         3         ~    1  1 I 10101           0       2
I      I    101    5  1   4     _          I      I 1  1 01     I  6  4
2431                                       46231
5
Of the above, each contains four leaves of heddles or healds; that represented by No. 1
is wrought by four treddles, and that which is distinguished by No. 2 by five; the succession of inserting the threads of warp into the heddles will be discovered by the figures
between the lines, and the order in which the treddles are to be successively pressed
down by the figures below.
No. 3.-Double Jean.                         No. 4.-Plain Thickset.
101   I    101   1                   4    I   101    I   I 1   8
11 I     1l 1   2                          I 10t 1O101  1        6  4
1    1010l1 I  3                      4    I    I    I    101    I  5   2
I 101 101 4                                l0 I    1010 I   Oll 7    3 1
4 2 3 1                                    4 6 2 3 1
5    7
These, like the former, are wrought with leaves.  No. 3 requires four, and No. 4 five
treddles. The succession of inserting the threads of warp, and of working the treddles,
are marked by the respective numbers between and under the lines, as in the former
example. Both are fabrics of cloth in very general use and estimation as low priced
articles.
No. 5.-Best Thickset.                        No. 6.-Velvet Tuft.
0i1 I  010             3   I             I10    I I 3    5   3  1
I   I   I   I 1Il   5   3             4   I   IO O 1 t   I              4  2
I   i0  I   I   I         2           4     I1   1   1  10  l   4  2
I 1001 1I I       6  4                4   I I I 101           {....5  3  1
64231                                      6 423 — 1
5
These are further specimens of what may be, and is, executed with four leaves, and in
both examples five treddles are used. With two other specimens we shall conclude our
examples of this description of work, and shall then add a very few specimens of the
more extensive kinds.
No. 7.-Cord and Velveret.                    No. 8.-Thickset Cord.
I 101  I I I       3  1         3  14    101   101   01               5  3  1
I 10101 I   I  5         7   5                   1 01 I                 4  2
l I 1101 6             8          2  4        I I I I I I          9  7
I 1    101    4  2    6   4             I 10 101 I I          10  8  6
4    2 3 1                                 5 4 3 2 1
6 5
In these the succession of drawing and working are marked like the former. The next
are examples of patterns wrought with six leaves. No. 9 has eight, and No. 10 five
heddles.




836                                      FUSTIAN.
No. 9.-Double Corduroy.                            No. 10.-Genoa Thickset.
I I I   10l  1lt   i0l                           I  I II     10101       _
l101 I I    1O   I I                 2              I 1    0 1l  I01              2
101010o1010   I I 1                3             lo1   1010o   1                3
I I      l Ol IOl  I  1         4               1  010101 4ol'1     lo    I        I     1 l  i   5             1    0 01       10       5
I   01  1 01          I              I               I6  1  101 Il         6 
2  4 6 8 10123  1                                4 2 5 3  1
75                              861197
119                             1 210
In both these the warp is inserted into the heddles the same way.  The difference is
entirely  in the application of the cords, and in the succession of pressing d-wn the
treddles. We now give four specimens of the flushed and cut work, known by the name
of velveteen. They are also upon six leaves, and the difference is solely in the cording
und in the treading.
No. 11.                Queen's Velveteens.                        No. 12.
1 10   1010      1                  1               I I      i  101
i   1)0 I1l   1                  2              I        1l1 10101l                2
I  1o0 1       1               3                       I    1     1010    1      3
11 101001                  4             0       101  101l 10                4
I  I    1 1    1           5 I                  I I  I I 101 1               5
1o    10101 I I           6                       101 1o 0o1                6
1212 8 4 2                                       243            1
57            6                                   687        5
911           10                                 10 12 119
No. 13.-Plain Velveteen.                       No. 14.-Genoa Velveteen.
I I   I  I         ol            i                I   IO{l_ _ I O l_   i12
I     I         _o l_ I  _ 4                  I    I I  IO0 II                  4
I I  111l                5                        I 1O0101    l l 
-   1    1 1   01   3 0                           1~ 1      10)   1   1       5   3
I 101  101             6                          I 101 o0   I              6
1 3    4                                         2 4 82 31
576                                               6          75
10         11 9
The additional varieties of figure which might be given are almost endless, but the
limits of this article will not admit a further detail. Those already given are the articles
in most general use. The varieties of fancy may be indulged to a great extent; but it is
universally found, that the most simple patterns in every department of ornamental
weaving are those which attract attention and command purchasers. We shall therefore
only add two examples of king's cord or corduroy, two of Genoa and common velvet, and
two more of jean. These will be found below.
No. 15.-King's Cord.                                 No. 16.-Dutch Cord.
I11 I   I 10                                     I I  O 1   101              4   1
1 I   11l 1   l                a 2                110  I  o1              5    2
1I   10101l           7      3                     0   I101              6   3
1_  1 1010 I i             4                      I  4  001  I         7
I 1     1o   I 10101     5                         01  11  11  8
1o l   101   I   I I   6                         10101   10101    9
138642                                           6 4231
5 7                                                    5
No. 17.-Genoa Velvet.                              No. 18.-Plain Velvet.
_       0   I  01                1I   I                           I I I  
I  1010101   1                 2           4    I I I  I                     2
IOloll I I   I              3                     I   I  I 1I            3
I  I      \OO\ 1 I         4 1                   I I I  I  I             4
I       1 0'l l   I      5                        I   I   I   I  I     5
J     1     l    i     6 II I I ii                                   6
2  4  8123 1i1 342 8
6          75                                     75
10         11 9
After the fustian cloth is taken from  the loom-beam, it is carried to the cutter, who
nps up the surface-threads of weft, and produces thereby a hairy-looking stuff.




FUSTIC.                                      837
Preparatory to its being cut, the cloth is spread evenly upon a table about six feet long
upon each end of which a roller mounted with a ratchet-wheel is fixed; the one to give
off, and the other to wind up the piece, in the above six-feet lengths.
The knife is a steel rod about two feet long, and three eighths of an inch square, having a square handle at the one end; the other end is tapered away to a blade, as thin as
paper. To prevent this point from turning downwards and injuring the cloth, its under
side is covered by a guide which serves to stiffen it, as well as to prevent its lower edge
from cuttineg the fustian.
The operative (male or female) grasps the handle in the right hand, and insinuating
the projecting point of the guide under the weft, pushes the knife smaitly forward through
the whole length of six feet, with a certain dexterous movement of the shoulder and
right side balancing the body meanwhile, like a fencer, upon the left foot. This process
is repeated upon every adhesive line of the weft.
The next process to which fustians are exposed is steeping in hot water, to take out
the dressing paste.  They are then dried, reeled, and brushed by a machine, &c.
From twenty to thirty pieces, each eighty yards long, may be brushed in an hour.  The
breadth of the cloth is twenty inches.  The maceration is performed by immersing the
bundled pieces in tanks of water, heated by waste steam; and the washing by means of
a reel or winch, kept revolving rapidly under the action of a stream of cold water, for
an hour or longcr.
After being thus ripped up, it is taken to the brushing or teazling machine, to make it
shaggy.
This consists of a series of wooden rollers, turning freely upon iron axles, and covered
with tin-plate, rough with the burs of punched holes; and blocks of wood, whose concave under surfaces are covered with card-cloth or card-brushes, and which are made to
traverse backwards and forwards in the direction of the axes of the revolving rollers
during the passage of the cloth over them.
After they are brushed in the machine, the goods are singed by passing their cut surface
over a cylinder of iron, laid in a horizontal direction, and kept red hot by a flue.  See
SINGEING. They are now brushed again by the machine, and once more passed over the
singeincg surface.  The brushing and singeing are repeated a third, or even occasionally
a fourth time, till the cord acquires a smooth polished appearance.
The goods are next steeped, washed, and bleached, by immersion in solution of chloride
of lime.  They are then dyed by appropriate chemical means.  After which they are
padded (imbued by the padding machine of the calico printers) with a solution of glue,
and passed over steam cylinders to stiffen them.
Smooth fustians, when cropped or shorn before dyeing, are called moleskins; but when
shorn after being dyed, are called beaverteen: they are both tweeled fabrics. Cantoon is
a fustian with a fine cord visible upon the one side, and a satiny surface of yarns running
at right angles to the cords upon the other side.  The satiny side is sometimes smoothed
by singeing.  The stuff is strong, and has a very fine aspect.  Its price is one shilling
and sixpence a yard.
Common plain fustian, of a brown or drab color, with satin top, is sold as low as
sevenpence a yard.
A fustian, with a small cord running in an oblique direction, has a very agreeable appearance. It is called diagonal.  Moleskin shorn, of a very strong texture, and a drab
dyed tint, is sold at 20d. per yard.
The weight of 90 yards of the narrow velveteen, in the green or undressed state, is
about 24 pounds.  The goods made for the German, Italian, and Russian markets are
lighter, on account of the peculiarity in the mode of levying the import duty in these
countries.
Velveteens as they come from the loom, are sold wholesale by weight, and average a
price of 20d. per pound. They are usually woven with yarns of Upland and Brazil cotton
wool, spun together for the warp; or, sometimes, New Orleans alone. The weft is usually Upland, sometimes mixed with East India cotton wools.
Trouser velveteens are woven 19 inches wide, if they are to be cut up; if not, they
are woven 30 inches, and called beaverteen.
Cutting or cropping fustians by hand is a very laborious and delicate operation.
The invention of an improved apparatus for effecting the same end with automatic precision and despatch, was therefore an object of no little interest to this peculiar manufacture of Manchester. An ingenious machine, apparently well calculated for this purpose,.
was made the subject of a patent by Messrs. William Wells and George Scholefield, of
Salford, in November, 1834.
FUSTIC.  (Bois jaune, Fr.; Gelbholz, Germ.)  The old fustic of the English dyer,
as the article fustet is their yellow fustic. It is the wood of the Morus tinctoria. It is
light, not hard, and pale yellow with orange veins; it contains two coloring matters, one
resinous, and another soluble in water.  The latter resembles weld, bat it has more of
an orange cast, and is not so lively.




838                                 GALL-NUTS.
Its decoctions in water are brightened by the addition of a little glue, and more by curdled milk. This wood is rich in color, and imparts permanent dyes to woollen stuffs,
when aided by proper mordants.  It unites well with the blue of the indigo vat, and
Saxon blue, in producing green of various shades.  Alum, tartar, and solution of tin,
render its color more vivid; sea salt and sulphate of iron deepen its hue. From 5 to 6
parts of old fustic are sufficient to give a lemon color to 16 parts of cloth. The color of
weld is however purer and less inclining to orange; but that of fustic is less afected by
acids than any other yellow dye. This wood is often employed with sulphate of iron in
producing olive and brownish tints, which agree well with its dull yellow. For the same
reason it is much used for dark greens.
G.
GABRONITE is a yellowish stony substance, of a greasy lustre and spec. gr.=2'74;
affording no water by calcination; fusible at the blowpipe into an opaque glass; soluble
in muriatic acid; solution affords hardly any precipitate by oxalate of ammonia. This
mineral is distinguished by the large quantity of soda which it contains; its constituents
being-silica, 54; alumina, 24; soda, 17-25; magnesia, 1'5; oxyde of iron, 1'25; water,
2. It belongs to the species Nepheline.
GADOLINITE, called also Yttrite and Ytterbite, is a mineral of a black, brownish,
or yellowish color, granular, or compactly vitreous, and conchoidal fracture; of spec.
grav. 4'23; readily scratching glass; fusible at the blowpipe into an opaque glass, sometimes with intumescence.  It affords, with acids, a solution that lets fall, with caustic
soda, a precipitate partly re-soluble in carbonate of ammonia. It is remarkable for containing from 45 to 55 per cent. of the earth Yttria; its remaining constituents being silica, 25-8; oxyde of cerium, 17-92; oxyde of iron, 11-43.  This mineral is very rare, having been hitherto found only in tlie neighborhood of Fahlon and Ytterby, in Sweden; its
peculiar constituent was discovered by Professor Gadolin.
GALACTOMETER, or LACTOMETER, is an instrument to ascertain the quality
of milk; an article often sophisticated in various ways. Fresh milk, rich in cream, has a
less specific gravity than the same milk after it has been skimmed; and milk diluted with
water becomes proportionably lighter.  Hence, when our purpose is to determine the
quantity of cream, the galactometer may consist merely of a long graduated glass tube
standing upright upon a sole. Having filled 100 measures with the recent milk, we shall
see, by the measures of cream  thrown up, its value in this respect.  A delicate longranged glass hydrometer, graduated from 1-000 up to l'060, affords the most convenient
means of detecting the degree of watery dilution, provided the absence of thickening materials has been previously ascertained by filtration. Good fresh milk indicates from 1-030
to 1-032; when the cream is removed, -035 to 1-037. When its density is less than 1028,
we may infer it has been thinned with water.
GALBANUM is a gum-resin, which occurs sometimes in yellow, shining tears, easily
agglutinated; of a strong durable smell; an acrid and bitter taste; at other times in lumps.
It exudes either spontaneously or from incisions made into the stem of the bubon galbanum,
a plant of the family of umbelliferce, which grows in Africa, particularly in Ethiopia. It
contains 67 of resin; 19-3 of gum; 6-4 of volatile oil and water; 7-5 of woody fibres and
other impurities; with traces of acid malate of lime.
GALENA, (Plomb sulfurg, Fr.; Bleiglanz, Germ.;) is a metallic looking substance of
a lead-gray color, which crystallizes in the cubical system, and is susceptible of cleavages
parallel to the faces of the cube; spec. gr. 7*7592; cannot be cut; fusible at the blowpipe with exhalation of sulphureous vapors; is easily reduced to metallic lead.  Nitric
acid first dissolves it, and then throws down sulphate of lead in a white precipitate; the
solution affording, with plates of zinc, brilliant laminae of lead (arbor Saturni.) It consists of sulphur, 13; lead, 85; with a little iron, and sometimes a minute quantity of silver.
This is the richest ore of lead, and it occurs in almost every geological formation, in
veins, in masses, or in beds. It is almost always accompanied by sulphuret of zinc, different salts of lead, heavy spar, fluor spar, &c.  Galena in powder, called Alquifoux, is
employed as a glaze for coarse stoneware.
GALIPOT is a name of a white semi-solid viscid rosin found on fir-trees; or an inferior sort of turpentine, poor in oil.
GALLATES; salts consisting of gallic acid combined with bases; the most important
being that with oxyde of iron, constituting a principal part of the black dye.
GALLIC ACID is the peculiar acid extracted from gall-nuts; which see.
GALLIPOLI OIL is a coarse olive oil, containing more or less mucilage; imported from
a seaport so named, of the province of Otranto, in the kingdom of Naples.
GALL-NUTS, or GALLS, (Noix de Galle, Fr.; Galldpfel, Germ.;) are excrescences
found upon the leaves and leaf-stalks of a species of oak, called Quercus infectoria, which grows in the Levant.  They are produced in consequence of the puncture
of the female of the gall wasp (Cynips folii quercus), made in order to deposite her




GALL-.NTS.                                     839
eggs;' round which the juice of the tree exudes, and dries in concentric portions. When
the insect gets fully formed, it eats through the nut, and flies off.,The Levant galls are of two different appearances and qualities; the first are heavy
compact, imperforated, the insect not having been sufficiently advanced to eat its way
through the shell; prickly on the surface; of a blackish or bluish green hue; about the
size of a musket-ball.  These are called black, blue, or Aleppo galls.  The second are
light, spongy, pierced with one or more holes; smooth upon the surface, of a pale grayish
or reddish yellow color, generally larger than the first, and are called white galls.  Besides the galls of the Levant, others come from Dalmatia, Illyria, Calabria, &c.; but they
are of inferior quality, being found upon the Quercus Cerris; they are smaller, of a browns'h color, and of inferior value. The further south the galls are grown, they are reckoned
the better.
Galls consist principally of three substances; tannin or tannic acid; yellow extractive;
and gallic acid. Their decoction has a very astringent and unpleasant bitter taste. The
following are their habitudes with various reagents.Litmus paper is powerfully reddened.
Stannous chloride (protomuriate of tin) produces an isabel yellow precipitate.
Alum; a yellowish gray precipitate.
Acetate of lead; a thick yellowish white precipitate.
Acetate of copper; a chocolate brown precipitate.
Ferric sulphate (red sulphate of iron); a blue precipitate.
Sulphuric acid; a dirty yellowish precipitate.
Acetic acid brightens the muddy decoction.
The galls of the Quercus Cerris and common oak (Galles a l'epine, Fr.; Knoppern,
Germ.)( are of a dark brown color, prickly on the surface, and irregular in shape and size.
They are used chiefly for tanning in Hungary, Dalmatia, and the southern provinces of
the Austrian states, where they abound.
Tannin or tannic acid is prepared as follows: Into a long narrow glass adopter tube,
shut at its lower orifice with a cotton wick, a quantity of pounded galls are put, and
slightly pressed down.  The tapering end of the tube being inserted into a matrass or
bottle, the vacant upper half of the tube is filled with sulphuric ether, and then closed with
a ground-glass stopper.  Next day there will be found in the bottle a liquid in two distinct strata; of which the more limpid occupies the upper part, and the other, of a sirupy
consistence and amber color, the lower. More ether must be filtered through the galls,
till the thicker liquid ceases to augment. Both are now poured into a funnel, closed with
the finger, and after the dense liquor is settled at the bottom, it is steadily run off into a
capsule. This, after being washed repeatedly with ether, is to be transferred into a stove
chamber, or placed under the receiver of an air pump, to be evaporated. The residuary
matter swells up in a spongy crystalline form of considerable brilliancy, sometimes colorless, bat more frequently of a faintly yellowish hue.
This is pure tannin, which exists in galls to the amount of from 40 to 45 per cent. It
is indispensable that the ether employed in the preceding process be previously agitated
with water, or that it contain some water, because by using anhydrous ether, not a particle of tannin will be obtained.
Tannic acid is a white or yellowish solid, inodorous, extremely astringent, very soluble
^n water and alcohol, much less so in sulphuric ether, and uncrystallizable.  Its watery
solution, out of contact of air, undergoes no change; but if, in a very dilute state,
*t be left exposed to the atmosphere, it loses gradually its transparency, and lets fall a
slightly grayish crystalline matter, consisting almost entirely of gallic acid. For procuring
this acid in a perfectly pure state, it is merely necessary to treat that solution thus
changed with animal charcoal, and to filter it, in a boiling state, through paper previously washed with dilute muriatic acid.  The gallic acid will fall down in crystals as
the liquid cools.
If the preceding experiment be made in a graduated glass tube containing oxygen over
mercury, this gas will be absorbed, and a corresponding volume of carbonic acid gas will'be disengaged.  In this case the liquor will appear in the course of a few weeks as if
traversed with numerous crystalline colorless needles of gallie acid.
Tannin or tannic acid consists of carbon 51-56; hydrogen 4'20; oxygen 44-24.
From the above facts it is obvious that gallic acid does not exist ready formed in gallnuts, but that it is produced by the reaction of atmospheric oxygen upon the tannin of
these concretions.
Gallic acid is a solid, feebly acidulous and styptic to the taste, inodorous, crystallizing
in silky needles of the greatest whiteness; soluble in about 100 times its weight of cold,
and in a much smaller quantity of boiling water; more soluble in alcohol than in-water,
Hut little so in sulphuric ether.
Gallic acid does not decompose the salts of protoxyde of iron, but it forms, with the
sulphate of the perovyde, a dark blue precipitate, much less insoluble than the tannate
of iron. Gallic acid takes the oxyde from the acetate and nitrate of lead, and throws




840                            GALL OF ANIMALS.
down a white gallate unchangeable in the air, when it is mixed with that acetate and
nitrate. It occasions no precipitate in solutions of gelatine (isinglass or glue), by which
criterion its freedom from tannin is verified.
Gallic acid occurs but seldom in nature; and always united to brucine, veratrine, or
lime. Its constituents are carbon 49-89; hydrogen 3-49; oxygen 46'62. Ia the crystal.
line state it contains one atom of water, which it loses by drying.
Scheele obtained gallic acid by infusing pounded galls for 3 or 4 days in 8 times their
weight of water, and exposing the infusion to the air, in a vessel covered loosely with
paper. At the end of two months, the liquor had almost all evaporated, leaving some
mouldiness mixed with a crystalline precipitate. The former being removed, the deposite was squeezed in a linen cloth, and then treated with boiling water. The solution,
being gradually evaporated, yielded crystals of gallic acid, granular or star-like, of a
grayish color. These crystals might be whitened by boiling their solution along with a
little animal charcoal. About one fifth of gallic acid may be obtained by Scheele's process from good gall-nuts.
From a decoction of 500 parts of galls, Sir H. Davy obtained 185 parts of solid extract;
which consisted of 130 parts of tannin; 31 parts of gallic acid with extractive; 13 parts
of mucilage; 12 parts of lime and salts. Hence gall-nuts would seem to contain, by
this statement, more than two thirds of their weight of tannin. This result is now seen,
from the above experiments of Pelouze, to have been incorrect, in consequence of the
admixture of yellow extractive in Davy's tannin.
The use of galls in many processes of dyeing, and in making black ink, is detailed
under their respective heads.
GALL OF ANIMALS, or OX-GALL, purification of.  Painters in water colors,
scourers of clothes, and many others, employ ox-gall or bile; but when it is not purified,
it is apt to do harm from the greenness of its own tint. It becomes therefore an important object to clarify it, and to make it limpid and transparent like water. The following
process has been given for that purpose. Take the gall of newly killed oxen, and after
having allowed it to settle for 12 or 15 hours in a basin, pour the supernatant liquor off
the sediment into an evaporating dish of stone ware, and expose it to a boiling heat in a
water bath, till it is somewhat thick. Then spread it upon a dish, and place it before a
fire till it becomes nearly dry. In this state it may be kept for years in jelly pots covered with paper, without undergoing any alteration. When it is to be used, a piece of
it of the size of a pea is to be dissolved in a table spoonful of water.
Another and probably a better mode of purifying ox-gall is the following. To a pint
of the gall boiled and skimmed, add one ounce of fine alum in powder, and leave the
mixture on the fire till the alum be dissolved. When cooled, pour into a bottle, which
is to be loosely corked. Now take a like quantity of gall, also boiled and skimmed, add
an ounce of common salt to it, and dissolve with heat; put it when cold into a bottle,
which is likewise to be loosely corked. Either of these preparations may be kept for
several years without their emitting a bad smell.  After remaining three months, at a
moderate temperature, they deposite a thick sediment, and become clearer, and fit for
ordinary uses, but not for artists in water colors and miniatures, on account of their
yellowish-green color. To obviate this inconvenience, each of the above liquors is to
be decanted apart, after they have become perfectly settled, and the clear portion of both
mixed together in equal parts. The yellow coloring matter still retained by the mixture coagulates immediately and precipitates, leaving the ox-gall perfectly purified and
colorless. If wished to be still finer, it may be passed through filtering paper; but it
becomes clearer with age, and never acquires a disagreeable smell, nor loses any of its
good qualities.
Clarified ox-gall combines readily with coloring matters or pigments, and gives them
solidity either by being mixed with or passed over them upon paper. It increases the
brilliancy and the durability of ultramarine, carmine, green, and in general of all delicate
colors, whilst it contributes to make them spread more evenly upon the paper, ivory,
&c. When mixed with gum-arabic, it thickens the colors without communicating to
them  a disagreeable glistering appearance; it prevents the gum  from  cracking, and
fixes the colors so well that others may be applied over them  without degradation.
Along with lamp black and gum, it forms a good imitation of China ink. When a coat
of ox-gall is put upon drawings made with black lead or crayons, the lines can no longer
be, effaced, but may be painted over safely with a variety of colors previously mixed up
with the same ox-gall.
Miniature painters find a great advantage in employing it; by passing it over ivory,
it removes completely the unctuous matter from its surface; and when ground with the
colors, it makes them spread with the greatest ease, and renders them fast.
It serves also for transparencies. It is first passed over the varnished or oiled paper,
and is allowed to dry. The colors mixed with the gall are then applied, and cannot
afterwards be removed by any means.
It is adapted finally for taking out spots of grease and oil.




GARNET.                                        841
GALL OF GLASS, called also sandiver, is the neutral salt skimmed off the surface
of melted crown glass; which, if allowed to remain too long, is apt to be reabsorbed
in part, and to injure the quality of the metal, as the workmen call it.
GALVANIZED IRON, is the somewhat fantastic name newly given in France to iron
tinned by a peculiar patent process, whereby it resists the rusting influence of damp
air, and even moisture, much longer than ordinary tin plate. The following is the prescribed process.  Clean the surface of the iron perfectly by the joint action of dilute
acid and friction, plunge it into a bath of melted zinc, covered with sal-ammoniac, and
stir it about till it be alloyed superficially with this metal; when the metal thus prepared is exposed to humidity, the zinc is said to oxidise slowly by a galvanic action,
and to protect the iron from rusting within it, whereby the outer surface remains for a
long period perfectly white, in circumstances under which iron tinned in the usual way
would have been superficially browned and corroded with rust.
GALVANO-PLASTIC is the German name of Electro-Metallurgy.
GAMBOGE; (Gomme Gutte, Fr.; Gutti, Germ.) is a gum resin, concreted in the air,
from the milky juice which exudes from several trees. The gambogia gutta, a tree which
grows wild upon the coasts of Ceylon and Malabar, produces the coarsest kind of ganboge; the guttcafera vera (Stalagmites cambogioides) of Ceylon and Siam affords the
best.  It comes to us in cylindrical lumps, which are outwardly brown yellow, but
reddish yellow within, as also in cakes; it is opaque, easily reducible to powder of
specific gravity 1'207, scentless, and nearly devoid of taste, but leaves an acrid feeling
in the throat. Its powder and watery emulsion are yellow. It consists of 80 parts of a
hyacinth red resin, soluble in alcohol; and 20 parts of gum; but by another analysis, of
89 of resin, and 105 of gum. Gamboge is used as a pigment, and in miniature painting,
to tinge gold varnish; in medicine as a powerful purge. It should never be employed
by confectioners to colour their liqueurs, as they sometimes do.
GANGUE.  A word derived from the German gang, a vein or channel  It signifies
the mineral substance which either encloses or usually accompanies any metallic ore in
the vein. Quartz, lamellar carbonate of lime, sulphate of baryta, sulphate and fluate of
lime, generally form the gangues; but a great many other substances become such when
they predominate in a vein. In metallurgic works the first thing is to break the mixed
ore into small pieces, in order to separate the valuable from the useless parts, by processes called stamping, picking, sorting. See METALLURGY and MINES.
GARANCINE, is a dyeing substance prepared from  madder, called in the French
language garance.
A patent was granted in August, 1843, to Mr. F. Steiner, for the manufacture of
Gararwcine from used madder, formerly thrown away, as being exhausted of its dyeing
principle.  His process is as follows:-" A  large filter is constructed outside the
building in which the dye-vessels are situated, formed by sinking a hole in the ground,
and lining it at the bottom and sides with bricks without any mortar to unite them.
A quantity of stones or gravel is placed upon the bricks, and over the stones or gravel
common wrappering, such as is used for sacks.  Below the bricks is a drain to take
off the water which passes through the filter. In a tub adjoining the filter is kept a
quantity of dilute sulphuric acid, of about the specific gravity of 105, water being 100.
Hydrochloric acid will answer the several purposes. but sulphuric acid is preferred as
more economical. A  channel is made from  the dye-vessels to the filter. The madder
which has been employed in dyeing is run from  the dye-vessels to the filter; and
while it is so running, such a portion of the dilute sulphuric acid is run in and mixed
with it as changes the colour of the solution and the undissolved madder to an orange
tint or hue. This acid precipitates the colouring matter which is held in solution, and
prevents the undissolved madder from  fermenting or otherwise decomposing.  When
the water has drained from  the madder through the filter, the residuum is taken from
off the filter and put into bags. The bags are then placed in an hydraulic press, to have
as much water as possible expressed from their contents. In order to break the lumps
which have been formed by compression, the madder or residuum  is passed through a
sieve. To 5 cwt. of madder in this state, placed in a wood or lead cistern, I cwt. of
sulphuric acid of commerce is sprinkled on the madder through a lead vessel similar
in form to the ordinary watering-can used by gardeners. An instrument like a garden
spade or rake is next used, to work the madder about, so as to mix it intimately with
the acid.  In this stage the madder is placed upon a perforated lead plate, which is
fixed about five or six inches above the bottom of a vessel. Between this plate and
the bottom of the vessel is introduced a current of steam by a pipe, so that it passes
through the perforated plate and the madder which is upon it.  During this process,
which occupies from one to two hours, a substance is produced of a dark brown colour
approaching to black.  This substance is garancine and insoluble carbonized matter.
When cool, it is placed upon a filter and washed with clear cold water until the water




842                                     GAS.
passes from it without an acid taste. It is then put into bags and pressed with an
hydraulic press. The substance is dried in a stove and ground to a fine powder under
ordinary madder stones, and afterwards passed through a sieve. In order to neutralize
any acid that may remain, from 4 to 5 lbs. of dry carbonate of soda for every hundred
weight of this substance is added and intimately mixed. The garancine in this state is
ready for use."
GARNET (Grenat, Fr.; Granat, Germ.); is a vitreous mineral of the cubic system,
of which the predominating forms are the rhomboidal dodecahedron and the trapeezohedron; specific gravity varying from 3-35 to 4-24; fusible at the blowpipe. Its constituents are, silica, 42; alumina, 20'0; lime, 34 0; protoxide of iron, 4.  Garnets are
usually disseminated, and occur in all the primitive strata from gneiss to clay slate.
The finer varieties, noble garnet or Almandine, and the reddish varieties of Grossulaire
(Essonite), are employed in jewelry; the first are called the Syrian or oriental; the
others, hyacinth.  In some parts of Germany garnets are so abundant as to be used
as fluxes to some iron ores: in others, the garnet gravel is washed, pounded, and employed as a substitute for emery.  The garnets of Pegu are most highly valued.  Factitious garnets may be made by the following composition:-Purest white glass, 2
ounces; glass of antimony, 1 ounce; powder of cassius, 1 grain;  manganese, 1 grain.
GAULTHERIA  OIL; an aromatic oil, called in commerce wintergreen oil.  It
is obtained from a shrub of the Ericeen family, (Gaultheria procumbens L., Canadian tea.)
The oil occurs in all parts of the plant, but mostly in the flowers, and may be extracted
by alcohol, but not by water from the dried or scentless plant. The same oil is obtained
from the bark of sweet birch, by distilling it with water, whereby it results from the
mutual action of a body like emulsion upon a body like amygdalin. The oil is colourless,
but becomes reddish in the air, as it is found in commerce.  Its specific gravity is 1"173,
and its boiling point 211~ C.; it distils at the constant heat of 220~,; it has then a
gravity 1'18: the watery solution of the oil produces with the red salts of iron a violet
tint, which becomes with excess of oil very deep and rich. Its constituents are
C,,, =  1200      63'16
Hs =   100         5-26
OB =   600        31'58
1900      100-00
If we distil the oil with an excess of caustic potash, wood spirit comes over, and the
remainder consists of salicylate of potash. The oil is a natural compound wood ether,
which may be prepared artificially by distilling together two parts of salicylic acid)
with two parts of dry wood spirit, and one part of oil of vitriol. The ether is separable*
from the distilled liquor by means of chlorcalcium. Bromine and chlorine act violently,
upon the oil. The gaultheria oil combines without decomposition into a peculiar class
of salts.
GAULTHERINE.  When the pulverized dried bark of betula lenta is exhausted
with cold alcohol of 95~, it can afford no more oil. The fluid which contains the
gaultherine has a slight bitterish taste, and by evaporation it forms a dry gummy mass,
which at a high heat leaves a coaly residual.
Oil of vitriol dissolves the gaultherine with a red colour and a flavour of the oil.
GAS (Eng. and Fr.; Gaz, Germ.) is the generic name of all those elastic fluids which
are permanent under a considerable pressure, and at the temperature of zero of Fahrenheit. In many of them, however, by the joint influence of excessive cold and pressure,
the repulsive state of the particles may be balanced or subverted, so as to transform the
elastic gas into a liquid or a solid. For this most interesting discovery, we are indebted
to the fine genius of Mr. Faraday.
The following table exhibits the temperatures and pressures at which certain gases are
liquefied.
Becomes liquid
Name of the gas.' Calculated boiling point;'     -TT 1          e   Barom. =- 30 inches.
At    Under a pressure of
Sulphurous acid       -       -    590 F.   3 atmospheres.       -    4~ Fahr.
Chlorine.              -    60        4                   -   22
Ammonia        -      -       -    50        6'5                 -   64
Sulphureted hydrogen  -       -    50       17                   -  142
Carbonic acid -           -   -    32       36                   -  229
Hydrochloric or muriatic acid  -    50      50                   -  249
Deutoxide of azote    -       -    45       50                   -  254




GAS-LIGHT.                                      843
Liquid carbonic acid becomes solidified, into a snowy-looking substance, by its own
rapid evaporation. Oxygen, hydrogen, and azote, have hitherto resisted all attempts to
divest them of their elastic form. For this purpose, it is probable that a condensing force
equal to that of 650 atmospheres, will be required.
The volume of any gas is, generally speaking, inversely as the pressure to which it is
exposed; thus, under a double pressure its bulk becomes one half; under a triple pressure, one third; and so on. For the change of volume in gaseous bodies by heat, see
EXPANSION.
Ammonia, carbonic acid, carbureted hydrogen, chlorine, muriatic acid, sulphurous
acid, sulphureted hydrogen, are the gases of most direct interest in the arts anD manufactures. Their detailed examination belongs to a work on chemistry.
GAS-LIGHT.  (Eclairage par gas, Fr.; Gaslicht, Germ.)  Dr. Clayton  lemonstrated, by numerous experiments in 1737 and 1738, that bitumin.o-E pit-coal subjected to
a red heat in close vessels, afforded a great deal of an air similar to the fire-damp of
mines, but which burned with a brighter flame. It does not appear that this species
of factitious air was ever produced from pit-coal for the purpose of artificial illumination
till 1792, when Mr. William Murdoch, engineer to Messrs. Bolton and Watt, employed
loal gas for lighting his house and offices, at Redruth in-Cornwall. The gas was generated in an iron retort, whence it was received in a gasometer, distributed in different situations by pipes, and finally burned at small apertures which could be opened
and stopped at pleasure. He moreover made this light moveable, by confining the gas
in portable tin-plate vessels, and burning it wherever he pleased. Between this period
and 1802, Mr. Murdoch continued at intervals to make similar experimens; and
upon occasion of the national illumination in the spring of the latter year, at the
peace of Amiens, he lighted up part of the Soho manufactory with a public display of gaslights.
The earliest application of this artificial light, on a large systematic scale, was made
at Manchester; where an apparatus for lighting the great cotton mills of Messrs.
Philips and Lee, was fitted up in 1804 and 1805, under the direction of Mr. Murdoch.
A quantity of light, nearly equal to 3000 candles, was produced and distributed in this
building. This splendid pattern has been since followed very generally in Great Britain,
and more or less in many parts of the continents of Europe and America. By the yeat
1822, gas-lighting in London had become the business of many public companies. At
the Peter street station, for example, 300 retorts had been erected, supplying 15 gasometers, having each an average capacity of 20'626 cubic feet, but, being never quite filled,
their total contents in gas might be estimated at 309,385 cubic feet. The extent of main
pipes of distribution belonging to this station was then about 57 miles, with two separate
mains in some of the streets. The product of gas was from 10,000 to 12,000 cubic feet
from a chaldron of coals. The annual consumption of coals was therefore altogether 9282
chaldrons, affording 11,384,000 cubic feet of gas, allowing 153 retorts to be in constant
daily action, upon an average of the year; and illuminating 10,660 private lamps, 2248
street lamps, and 3894 theatre lamps.
At the Brick-lane works, 371 retorts were fixed in 1822, 133 being worked on an aver
age of summer and winter. There were 12 gasometers, charged with an average quantity
of gas amounting to 197,214 cubic feet. Of coals, 8060 chaldrons were annually consumed; 96,720,000 cubic feet of gas were generated; for the supply of 1978 public lamps,
and 7366 private ones, connected with main pipes 40 miles long.
At the Curtain-road gas establishment, there were 240 retorts; but the greatest number
worked in 1821 was only 80, and the lowest 21. The six gasometers had an average
contents of 90,467 cubic feet. Of coals, 3336 chaldrons were annually consumed, yielding 40,040,000 cubic feet of gas, that supplied 3860 private lamps, and 629 public ones,
by means of mains 25 miles long. The above three stations belonged to the London GasLight and Coke Company.
The City of London Gas-Light Company, Dorset street, had built up 230 retorts, and
6 gasometers, while two were preparing; having a total capacity of 181,282 cubic feet.
Of private lamps 5423 were lighted, and 2413 public ones, from mains extending 50 miles.
The quantity of coals carbonized amounted to 8840 chaldrons; producing 106,080,000
cubic feet of gas.
The South London Gas-Light and Coke Company had mounted at Bankside 143 retorts,
with 3 gasometers; the contents of the whole being 41,110 cubic feet, connected with
mains from 30 to 40 miles long. At their other station, in Wellington street, 9 large
gasometers were then erecting, with a capacity of 73,565 cubic feet, which were to be
supplied with gas from Bankside, till retorts were mounted for them.
- The Imperial Gas-Light and Coke Company had at that time 6 gasometers in progress
at their Hackney station.
In 1822 there were thus four great companies, having in all 47 gasometers at work,
capable of containing 917,940 cubic feet of gas, supplied by 1315 retorts, which generated




844                                 GAS-LIGHT.
per annum. upwards of 397,000,000 cubic feet of gas, by which 61,203 private lamps, and
7268 public or street lamps, were lighted in the metropolis. Besides these public companies, there were likewise several private ones.
1. Of the generation of illuminating gases.-Pure hydrogen gas buns with too feeble
a flame to be employed for illumipation. But carbureted hydrogen having the property
of precipitating its carbon in the act of burning, its solid particles become incandescent,
and diffuse a vivid light. The more carbon it contains, the more brightly does it burn.
This gas exists in two distinct states of combination. In the first, two measures of hydrogen gas are combined with one measure of the vapor of carbon, forming together one
measure whose specific gravity is of course the sum of the weights of the constituents,
oi0'559'; atmospherical air being 1'000. This is the gas which is found in mines, and
is also evolved in ditches frpm decomposing vegetable matter. In the second, two measures of hydrogen gas are combined with two of gaseous carbon, forming also one volume
or measure whose weight or specific gravity is 0'985.  This was at one time called the
olefiant gas, because when mixed with chlorine an oily looking compound was produced.
It may be called as well oil gas, because it is generated in considerable quantities by the
igneous decomposition of oil. Thus the olefiant gas contains in the same volume double
the quantity of carbon of common carbureted hydrogen, and it burns with a proportionably brighter flame. The gaseous oxyde of carbon, as well as sulphureted hydrogen gas,
burns with a feeble blue light, bat the latter produces in combustion sulphurous acid, an
offensive and noxious gas.
By dry distillation or carbonization in close vessels, all bodies of vegetable and animal
origin disengage carbureted hydrogen gas; even charcoal, when placed in ignition in
contact with steam, by decomposing the water, produces abundance of carbonic acid,
carbureted hydrogen, hydrogen, and carbonic oxyde. After separating the carbonic acid
with lime water, that mixed gas contains in 100 measures, 20 of carbureted hydrogen
the rest being hydrogen and carbonic oxyde, so that the gaseous mixture cannot be used
for illumination. The best substances for furnishing a gas rich in luminiferous materials
are, pitcoal, especially the cannel coal, resin, oil, fats of all kinds, tar, wax, &c. In some
cases the gases evolved during the igneous decomposition of bones and other animal matters for the production of ammonia, may be employed for procuring light, but they are
apt to emit a fetid odor.
When coals are heated in a cast-iron retort to ignition, the progress of decomposition
is as follows. First, and before the retort becomes red hot, steam issues along with the
atmospheric air. When the retort begins to redden, tar distils in considerable quantity
with some combustible gas, of which hydrogen mixed with ammoniacal gas forms a part.
The evolution of gas increases as the retort becomes hotter, with a continual production
of tar and ammoniacal liquor as well as sulphurous acid from the pyrites of the coal, which
unites with the ammonia. When the retort has come to a bright cherry red heat, the
disengaaement of gas is most active. By and by the gaseous production diminishes, and
eventually ceases entirely, although the heat be increased. In the retort a quantity of
carbonized coal or coke remains, while tar is found at the bottom of the receiver, covered
with the ammoniacal liquor, and combined with carbonic and sulphurous acids, and sulphureted hydrogen.
If, during this distillation, the combustible gas be collected and examined at the
several stages of the process, it is found to differ extremely in its luminiferous powers.
That which comes off before the retort has acquired its proper temperature, gives a
feeble light, and resembles the gas obtained by the ignition of moist charcoal, consisting
chiefly of hydrogen. That evolved when the retort has just acquired throughout a vivid
red heat, is the best of all, consisting chiefly of bi-carbureted hydrogen or olefiant gas.
From good coal, it consists, for example, in 100 measures, of 13 of olefiant gas, 82'5 of
carbureted hydrogen, 3'2 carbonic oxyde, 13 azote; the mixture having a specific gravity
of 0650. At a later period, as after 5 hours, it contains 7 measures of olefiant gas, 56
of carbureted hydrogen, 11 of carbonic oxyde, 21*3 of hydrogen, 4'7 of azote; the specific gravity of the whole being 0O500. Towards the end of the operation, as after 10 hours,
it contains twenty measures of carbureted hydrogen, 10 of carbonic oxyde, 60 of hydrogen, 10 of azote, with a specific gravity of only 0345. The hydrogen becomes sulphureted hydrogen, if there be much pyritous matter in the coal. The larger proportion of
the gas is disengaged during the first hour, amounting to about one fifth of the whole; in
the, three following hours the disengagement is tolerably uniform, constituting in all fiftyfour hundredths; in the sixth hour, it is one tenth; in the seventh and eighth hours.
sixteen hundredths.
From these observations are derived the rules for the production of a good light gas
from coals.  They show that the distillation should commence with a retort previously
heated to a cherry red, since thereby good gas is immediately produced, and a portion
of the tar is also converted into gas, instead of being simply distilled over into the condenser pit; that this heat should be steadily continued during the whole opemation,
from 5 to 8 hours; that it should not be increased, especially towards the end, for feat




GAS-LIGHT.                                       845
of generating carbonic oxyde and hydrogen gases, as well as of injuring the retort when
the cooling agency of gasefication has become feeble; and that the operation should be
stopped some time before gas ceases to come over, lest gases with feeble illuminating power
should impoverish the contents of the gasometer. Upon the average, a pound of good coai
affords four cubic feet of gas, or a chaldron=-26 cwts. London measure, affords from 12,000
to 15,000 cubic feet, according to the form of the retort, and the manner of firing it.
When oil, fats, rosin, tar, &c. are employed for the production of a light gas, it is not
sufficient to introduce these substances into the retorts, and to heat them, as is done
with coals. In this case, the greater part of them would distil over in the state of volatile oils, and very little gas be generated, only as much as corresponded to the quantity
of fat, &c. in immediate contact with the retort. It becomes therefore necessary to
fill the retorts with pieces of brick cr coke; and to keep them in ignition, while the
oil, &c. is slowly introduced into their interior. The fats instantly assume the vaporous
state, and thus coming into contact upon an extensive surface with the ignited bricks,
are decomposed into combustible gases. A  small portion of carbonaceous matter remains in the retort, while much olefiant gas is formed, possessing a superior illuminating power to common coal gas, and entirely free from  sulphureous impregnation.
The best oil gas is generated at a dull red, a heat much below what is requisite for the
decomposition of coal. A more intense heat would indeed produce a greater volume
of gas, but of a poorer quality, because the olefiant gas thereby deposites one half of
its carbon, and is converted into common carbureted hydrogen. Oil affords at a lively
red heat, gases which contain in 100 measures, 19 of olefiant gas, 32-4 of carbureted
hydrogen, 12-2 of carbonic oxyde gas, 32-4 of hydrogen, and 4 of azote; the mean specific
gravity being only 0'590.  At a more moderate temperature it yields 225 of the
olefiant, 503 carbureted hydrogen, 15'5 carbonic oxyde, 7'7 hydrogen, and 4 azote,
with a specific gravity of 0'758.  It contains when generated by dull ignition, as is
usual in works on the manufacturing scale, in 100 parts from 38 to 40 of olefiant gas
and besides the carbureted hydrogen, a few  per cent. of carbonic oxyde and azote
with a specific gravity of 0900, and even upwards. One pound of oil or fluid fat affords
15 cubic feet of gas; of tar affords about 12 cubic feet; of rosin or pitch, 10 cubic feet.
When the oil gas is compressed by a force of from 15 to 20 atmospheres, as was the
practice of the Portable Gas Company, about one fifth of the volume of the gas becomes
liquefied into an oily, very volatile fluid, having the specific gravity 0821.  It is a
mixture of three fluids (consisting of carbureted hydrogen), of different degrees of
volatility. The most volatile of these boils even under 320 F. Some of the vapor of
this gas-oil is mixed with the olefiant gas in the general products of decomposition; in
consequence of which they are sometimes richer in carbon than even olefiant gas, and
have a higher illuminating power. Oil gas contains about 22 per cent. and coal gas
about 3^ per cent. of this oily vapor. In the estimations of the composition of the
gases given above, this vapor is included under olefiant gas. This vapor combines
readily with sulphuric acid, and is thus precipitated from the gaseous mixture. The
amount of olefiant gas is shown, by adding to the gas, contained over water, one half of
its volume of chlorine, which, in the course of an hour or two, condenses the olefiant gas
into an oily looking liquid (chloride of hydrocarbon.) After the mixture, the gases
must be screened from the light, otherwise the common carbureted hydrogen would also
combine with the chlorine, while water and carbonic acid would make their appearance.
The oil employed for affording gas is the crudest and cheapest that can be bought; even
the blubber and sediment of whale oil are employed with advantage. After all, however,
coal is so much cheaper, and the gas produced from it is now so well purified, that oil
and rosin are very little used in gas apparatus..apparatus for Coal Gas.-Coal gas, as it issues from the retort, cannot be directly
employed for illumination; for it contains vapors of tar and coal oil, as also steam
impregnated with the carbonate, sulphite, and hydrosulphuret of ammonia.   These
vapors would readily condense in the pipes through which the gas must be distributed, and would produce obstructions; they must therefore be so far removed by
previous cooling, as to be liable to occasion no troublesome condensation at ordinary
temperatures. The crude coal gas contains moreover sulphureted hydrogen, whose combustion for light would exhale an offensive sulphureous odor, that ought to be got
rid of as much as possible. Carbonic acid and carbonic oxyde gases, generated at first
from the decomposition of the steam by the ignited coal, enfeeble the illuminating power
of the gas, and should be removed. The disengagement of gas in the retorts is never
uniform, but varies with the degree of heat to which they are exposed; for which
reason the gas must be received in a gasometer, where it may experience uniform pressure, and be discharged uniformly into the pipes of distribution, in order to ensure a
steady discharge of gas, and uniform intensity of light in the burners. A coal gas apparatus ought therefore to be so constructed as not only to generate the gas itself, but to fulfil
the above conditions.




846                                 GAS-LIGHT,
In fig. 669, such an apparatus is represented, where the various parts are shown con
nected with each other, in section.
A is the furnace with its set of cylindrical or elliptical retorts, five innumber. From
each of these retorts, a tube b proceeds. perpendicularly upwards, and then by a curve
669                            or saddle-tube, it turns down
wards, where it enters a long::::         horizontal cylinder under B, shut
at each end with a screw cap, and
Z Y...~..........L.   descends to beneath its middle,
~   ~\g.&"^\^.? ^~:_1        so as to dip about an inch into
I   _ _ _ __,, =,  - -^Ei Xj'< III >the water contained in it. From: 1-__-_-_1_1_~_  iiI    one end of this cylinder the tube. _ -   l       d passes downward to connect
itself with a  horizontal tube
which enters into the tar pit or
cistern c, by means of the verti.oT____-Le=-e  _S:, I ~ I1   cal branchf. Teach1 _     -Tl ^^ iI'I"'  es to near the bottom of the cy-"-.  -_"_-_U _^ _       lil      lindrical vessel,whichsitsonthe
-j_  K_-_l  ^^"1    sole of the tar cistern. From the
- -_~_~_"_"_l  ^ il     other side of the vertical branch
the main pipe proceeds to the
*-~r~i^    l -1^1^'i                  condenser D, and thence by the
0ll^X  sBpipe 1, into the purifier E; from
67 2                                    which  the gas is immediately
^- JI"               transmitted by the pipe pinto the
g' o  ~ b. t       agasometer P.?    jl    1^    WW  The operation proceeds in the
following way:-As soon as gas
begins to be disengaged from the
ignited retort, tar and ammoni1 -11"  -iacal liquor are deposited in the
(- Ir~;~ 1  41[ \II 11l 1  cylindrical receiver, and fill it
up till the superfluity runs over
by the piped, the level being con_______ -~-g~ ji,          stantly  preserved  at the line
shown in the figure. By the same
tarry liquid, the orifices of the
several pipes b, issuing from the
- ^sjJ^ ^-j   ^    retorts, are closed; whereby the
-\ -lll^ Hul   ^                    municatiori cut off with the gas
in the retorts. Hence if one of
the retorts be opened and emptied, it remains shut off from the
J. /l 1 ^^l      o                 rest of the apparatus. This insulation of the several retorts is
the function of the pipe under B,
and therefore the recurved tubeb
must be dipped as far under the
surface of the tarry liquid, as to
be in equilibrio with the pressure
of the gas upon the water in the
purifier. The tube b is closed at
top with a screw cap, which can
be taken off at pleasure, to perll. ^1111 mit the interior to be cleansed.
Both by the overflow from the
receiver-pipe B, and by subsequent condensation in the tube d, tar and ammoniacal liquor collect progressively in the
cistern or pit under c, by which mingled liquids the lower orifice of the vertical tubef is
closed, so that the gas cannot escape into the empty space of this cistern. These liquids
flow over the edges of the inner vessel when it is full, and may from time to time be
drawn off by the stopcock at the bottom of the cistern.
Though the gas has, in its progress hitherto, deposited a good deal of its tarry and
ammoniacal vapors, yet, in consequence of its high temperature, it still retains a considerable portion of them, which must be immediately abstracted, otherwise the tar




GAS-LIGHT.                                       847
would pollute the lime in the vessel E, and interfere with its purification.  On this ac
count the gas should, at this period of the process, be cooled as much as possible, in order
to condense the-se vapors, and to favor the action of the lime in the purifier E, upon the
sulphureted hydrogen, which is more energetic the lower the temperature of the gas.
The coal gas passes, therefore, from the tube f into the tube h of the condenser D, which
is placed in an iron chest g filled with water, and it deposites more tar and ammoniacal
liquor in the underpart of the cistern at t, t. When these liquids have risen to a certain
level, they overflow into the tar-pit, as shown in the figure, to be drawn off by the stopcock as occasion may require.
The refrigerated gas is now conducted into the purifier E, which is filled with milk of
lime, made by mixing one part of slaked lime with 25 parts of water.  The gas, as it
enters by the pipe 1, depresses the water in the wide cylinder n, thence passes under the
perforated disc in the under part of that cylinder, and rising up through innumerable
small holes is distributed throughout the lime liquid in the vessel m.  By contact with
the lime on this extended surface, the gas is stripped of its sulphureted hydrogen and
carbonic acid, which are condensed into the hydro-sulphuret and carbonate of lime; it now
enters the gasometer ri in a purified state, through the pipe p t, and occupies the space A.
The gasometer, pressing with a small unbalanced force over the counterweight s, expels
it through the main u u, in communication with the pipes of distribution through the
buildings or streets to be illuminated.
The parts A    c D CE andF, of which this apparatus consists, are essential constituents
of every good coal-gas wvork.  Their construction rests upon peculiar principles, is susceptible of certain modifications, and therefore deserves to be considered in detail.
The Retorts. - These are generally made of cast iron, though they have occasionally
been made of baked clay, like common earthenware retorts.  The original form was a
cylinder, which was changed to an ellipse, with the long axis in a horizontal direction,
then into the shape of the letter D with the straight line undermost, and lastly into a
semi-cylinder, with its horizontal diameter 22 inches, and its vertical varying from 9 to
12. The kidney form was at one time preferred, but it has been little used of late.
The form of retort represented in ig. 6670 has been found to yield the largest quantity
of good gas in the shortest time, and with
the least quantity of firing. The length is
72, and the transverse area, from one foot
to a foot and a half square.  The arrows
show the direction of the flame and draught
in  this excellent bench  of retorts, as
mounted by Messrs. Barlow.
The charge of coals is most conveniently
^  /U' "'IT^   ^              introduced in a tray of sheet iron, made
somewhat like a grocer's scoop, adapted to
the size of the retort, which is pushed home
to its further end, inverted so as to turn
Out the contents, and then immediately
The duration of the process, or the time
of completing a distillation, depends upon
the nature of the coal and the form of the
retort.  With cylindrical retorts it cannot
be finished in less than 6 hours, but with
elliptical and semi-cylindrical retorts, it may
be completed in 4 or 5 hours.  If the distillation be continued in the former for 8
hours, and in the'latter for 6, gas will continue to be obtained, but during the latter period
of the operation, of indifferent quality.
The Receiver. - If the furnace contains only 2 or 3 retorts, a simple cylindrical vessel
standing on the ground half filled with water, may serve as a receiver; into which the
tube from the retort may be plunged. It should be provided with an overflow pipe for the
tar and ammoniacal liquor.  For a range of several retorts, a long horizontal cylinder is
preferable, like that represented at B in fig. 671.  Its diameter is from 10 to 15 inches.
This cylinder may be so constructed as to separate the tar from the ammoniacal liquor,
by means of a syphon attached to one of its ends.
The Condenser.- The condenser, represented in fig. 669, consists of a square chest g,
made of wrought iron plates open at top, but having its bottom  pierced with a row of
holes, to receive a series of tubes.  To these holes the upright four-inch tubes h h are
secured by flanges and screws, and they are connected in pairs at top by the curved ot
saddle tubes. The said bottom  forms the cover of the chest t, t, which is divided by vertical iron partitions, into half, as many compartments as there are tubes.




848                                  GAS-LIGHT.
These partition plates are left open at bottom, so as to place the liquids of each compartment in communication.  Thereby the gas passes up and down the series of tubes;
in proceeding from one compartment to another.  The condensed liquids descend into the
671'      1 1cistern, when they rise above the level
t it.  The tar may be drawn off from
time to time by the stopcock. Through
-cubic n   ~ U~^~^~J~U                 ~ 7       the tube i, cold water flows into the
surface of the                                condenser chest, and the warm water
d   {I________                               ^    passes away by a pipe at its upper
gas                                                The extent of surface which the gas
requires for its refrigeration before it
\     \           i den sings admitted into the washing-fime apThe  urifier.  paratus. depends upon the  emperature of the milk of lime, and the
c^^'^^yin^icquantity of gas generated in a certain
time.
It may be assumed as a determination
sufficiently exact, that 10 square feet
\n is also\fixed air-ih.           of surface of the condenser can cool
_nrmin_ so 4a      -==_i ^^^=a cubic foot of gas per minute to the
temperature of the cooling  water.
For example, suppose a furnace or
mT       nEL 7                    arch with 5 retorts of 150 pounds of
coal each, to produce in 5 hours 3000
cubic feet of gas, or 10 cubic feet per minute, there would be required, for the cooling
surface of the condenser, 100 square feet =10 X  10.  Suppose 100,000 cubic feet of
gas to be produced in 24 hours, for which 8 or 9 such arches must be employed, the condensing surface must contain from 800 to 900 square feet.
The Purifier. -The apparatus represented in the preceding figure is composed of a
cylindrical iron vessel, with an air-tight cover screwed upon it, through which the cylinder
n is also fixed air-tight.  The bottom of this cylinder spreads out like the bim of a hat,
forming a horizontal circular partition, which is pierced with holes.  Through a stuffing
box, in the cover of this interior cylinder, the vertical axis of the agitator passes, whicb
is turned by wheel and pinion work, in order to stir up the lime from the bottom of the
water in the purifier. The vessel o serves for introducing fresh milk of lime, as also for
letting it off by a stopcock when it has become too foul for further use.
The quantity of lime should be proportioned to the quantity of sulphureted hydrogen
and carbonic acid contained in the gas.  Supposing that in good coal gas there is 5 per
cent. of these gases, about one pound and a half of lime will be requisite for every hundred cubic feet of coal gas generated, which amounts to nearly one sixteenth of the
weight of coal subjected to decomposition. This quantity of lime mixed with the proper
quantity of water will form about a cubic foot of milk of lime.  Consequently, the
capacity of the purifier, that is, of the interior space filled with liquid, may be taken at
four sevenths of a cubic foot for every hundred cubic feet of gas passing through it in
one operation; or for 175 cubic feet of gas, one cubic foot of liquor.  After every
operation, that is, after every five or six hours, the purifier must be filled afresh.  Sup.
pose that in the course of one operation 20,000 cubic feet of gas pass through the
machine, this should be able to contain~-2000 =  114 cubic feet of milk of lime; whence
its diameter should be seven feet, and the height of the liquid three feet. If the capacity
of the vessel be less, the lime milk must be more frequently changed.
In some of the large gas works of London the purifier has the following construction,
whereby an uninterrupted influx and efflux of milk of lime takes place.  Three single
purifiers are so connected together, that the second vessel stands higher than the first,
and the third than the second; so that the discharge tube of the superior vessel, placed
somewhat below its cover, enters into the upper part of the next lower vessel; consequently, should the milk of lime in the third and uppermost vessel rise above its ordinary level, it will flow over into the second, and thence in the same way into the first;
from which it is let off by the eduction pipe.  A tube introduces the gas from the condenser into the first vessel, another tube does the same thing for the second vessel, &c.,
and the tube of the third vessel conducts the gas into the gasometer.  Into the third
vessel, milk of lime is constantly made to flow from a cistern upon a higher level.
By this arrangement, the gas passing through the several vessels in proportion as it
is purified, comes progressively into contact with purer milk of lime, whereby its purification becomes more complete.  The agitator c, provided with two stirring paddles, is




GAS-LIGHT.                                      849
kept in continual rotation. The pressure which the gas has here to overcome is naturally
three times as great as with a single purifier of like depth.
Fig. 672 is a simple form of purifier, which has been found to answer well in practice.
Through the cover of the vessel A B, the wide cylinder e d is inserted, having its lower
end pierced with numerous holes. Concentric with that cyl.nder is the narrower one s z,
bound above with the flange a b, but open at top and bottom.  The under edge g h of
this cylinder descends a few inches below the end c d of the outer one. About the middle
of the vessel the perforated shelf m n is placed.  The shaft of the agitator 1, passes
through a stuffing box upon the top of the vessel.  The gas-pipe g, proceeding from the
condenser, enters through the flange a b in the outer cylinder, while the gas-pipe h goes
from the cover to the gasometer. A stopcock upon the side, whose orifice of discharge is
somewhat higher than the under edge of the outer cylinder, serves to draw off the milk
of lime. As the gas enters through the pipe g into the space between the two cylinders,
it displaces the liquor till it arrives at the holes in the under edge of the outer cylinder,
through which, as well as under the edge, it flows, and then passes up through the apertures of the shelf m n into the milk of lime chamber; the level of which is shown by
the dotted line. The stirrer, 1, should be turned by wheel work, though it is here shown
as put in motion by a winch handle.
In order to judge of the degree of purity of the gas aftet its transmission through the
lime machine, a slender syphon tube provided with a stopcock may have the one end
inserted in its cover, and the other dipped into a vessel containing a solution of acetate
of lead. Whenever the solution has been rendered turbid by the precipitation of sulphuret of lead, it should be renewed.   The saturated and fetid milk of lime is evaporated
in oblong cast-iron troughs placed in the ash-pit of the furnaces, and the dried lime
is partly employed for luting the apparatus, and partly disposed of for a mortar or
manure.
By this purifier, and others of similar construction, the gas in the preceding parts of
the apparatus, as in the retorts and the condenser, suffers a pressure equal to a column
of water about two feet high; and in the last described purifier even a greater pressure.
This pressure is not disadvantageous, but is of use in two respects; 1. it shows by a
brisk jet of gas when the apparatus is not air-tight, and it prevents common air from
entering into the retorts; 2. this compression of the gas favors the condensation of the
tar and ammoniacal liquor.  The effect of such a degree of pressure in expanding the
metal of the ignited retorts is quite inconsiderable, and may be neglected.  Two contrivances have, however, been proposed for taking off this pressure in the purifier.
In fig. 673, m m are two similar vesseLs of a round or rectangular form, furnished at
their upper border with a groove filled with water, into which the under edge of the
cover fits, so as to make the vessel air-tight. The cover is suspended by a cord or chain,
which goes over a pulley, and may be raised or lowered at pleasure.  The vessels themselves have perforated bottoms, r r', covered with wetted moss or hay sprinkled over with
slaked and sifted quicklime.  The gas passes through the loosely compacted matter of
the first vessel, by entering between its two bottoms, rises into the upper space 1, thence
it proceeds to the second vessel, and, lastly, through the pipe u, into the gasometer.
a~   674    This method, however, requires
twice as much lime as the former,
without increasing the purity of
The second method consists in
compressing the gas by the action of an Archimedes screw, to
such a degree, before it is admitdpl       lted into the purifier, as that it
nil  - iIP may overcome the pressure of
the column  of water in  that
-vessel.  Fig. 674 exhibits this
apparatus in section. D D is the
Archimedes worm, the axis of
- =i  ^                            ^       which revolves at bottom  upon
the gudgeon e; it possesses a
three-fold spiral, and is turned
-- IU    7- ~- ~'   - ~-^ in    in the opposite direction to that
in which it scoops the water.
^ ^1 ~ ~~^ljE^I-  ~^"c ^^~- ~_ ~~~ in- The cistern which contains it has
be purified  passes through the
pipe c into the space D, over the
water level d; the upper cells of the worm  scoop in the gas at this point, and




850                                 GAS-LIGHT.
carry it downwards, where it enters at g into the cavity z of a second cistern.  In ordet
that the gas, after it escapes from the bottom of the worm, may not partially return
through g into the cavity D, an annular plate g h is attached to its tinder edge, so as to
turn over it.  The compressed gas is conducted from the cavity E through the pipe G
into the purifying machine; a is a manometer, to indicate the elastic tension of the gas
in D.  On the top of the worm  a mechanism  is fitted for keeping it in constant
rotation.
A perfect purification of light-gas from sulphureted hydrogen, either by milk of lime
or a solution of the green sulphate of iron, is attended with some difficulty, when carried
so far as to cause no precipitation of sulphuret in acetate of lead, because such a degree
of washine is required as is apt to diminish its illuminating power, by abstracting the
vapor of the rich oily hydrocarburet which it contains. Moreover, the coal gas obtained
towards the end of the distillation contains some sulphuret of carbon, which affords sulphurous acid on being burned, and can be removed by no easy method hitherto known.
The lime in the purifier disengages from the carbonate and hydro-sulphuret of ammonia
carried over with the gas, especially when it has been imperfectly cooled in the condenser,
a portion of ammoniacal gas, which, however, is not injurious to its illuminating power.
The best agent for purifying gas would be the pyrolignite of lead, were it not rather ex
pensive, because it would save the trouble of stirring, and require a smaller and simpler
apparatus.
The Gasometer.-The gasometer serves not merely as a magazine for receiving the
gas when it is purified, and keeping it in store for use, but also for communicating to
the gas in the act of burning such a uniform pressure as may secure a steady unflick
ering flame.  It consists of two essential parts; 1. of an under cistern, open at top and
filled with water; and 2. of the upper floating cylinder or chest, which is a similar
cistern inverted, and of somewhat smaller dimensions, called the gas-holder; see F,
fig. 6 6 9. The best form of this vessel is the round or cylindrical; both because under
equal capacity it requires least surface of metal, and it is least liable to be warped by its
own weight or accidents.  Since a cylindrical body has the greatest capacity with a
given surface when its height is equal to its semi-diameter, its dimensions ought to be
such that when elevated to the highest point in the water, the height may be equal to
the radius of the base.  For example, let the capacity of the gas-holder in cubic
feet be k, the semi-diameter of its base be x, the height out of the water be h
h is =x =  V   k   This height may be increased by one or two feet, according to its
magnitude, to prevent the chance of any gas escaping beneath its under edge, when it is
raised to its highest elevation in the water.. The size of the gasometer should be proportional to the quantity of gas to be con
sumed in a certain time.  If 120,000 cubic feet be required, for instance, in 10 hours
for street illumination, and if the gas retorts be charged four times in 24 hours, 30,000
feet of gas will be generated in 6 hours.  Hence the gasometer should have a capacity
of at least 70,000 cubic feet, supposing the remaining 50,000 cubic feet to be produced
during the period of consumption. - If the gasometer has a smaller capacity, it must be
supplied from  a greater number of retorts during the lighting period, which is not
advantageous, as the first heating of the supernumerary retorts is wasteful of fuel.
Some engineers consider that a capacity of 30,000 cubic feet is the largest which can
with propriety be given to a gasometer; in which case they make its diameter 42 feet,
and its height 23.  When the dimensions are greater, the sheet iron must be thicker
and more expensive; and the hollow cylinder must be fortified by strong internal cross
braces.
The water cistern is usually constructed in this country with cast-iron plates bolted together, and made tight with rust-cement.
In cases where the weight of water required to fill such a cistern might be inconvenient
to sustain, it may be made in the form represented in fig. 6T5; which, however, will cost
nearly twice as much. Parallel with the side of the cistern, a second cylinder c, of the
same shape, but somewhat smaller, is fixed in an inverted position to the bottom of the
first, so as to leave an annular space BnB between them, which is filled with water, and
in which the floating gasometer A plays up and down. The water must stand above the
cover of the inverted cylinder,  a and b are the pipes for leading the gas in and out.
Through an opening in the masonry upon which the gasometer apparatus rests, the
space c may be entered, in order to make any requisite repairs.
The water cistern may also be sunk in the ground, and the sides made tight with
hydraulic mortar, as is shown in fig. 675, and to make it answer with less water, a concentric cylindrical mass of masonry may be built at a distance of 2 or 3 inches within it.
Every large gasometer must be strengthened interiorly with cross iron rods, to stiffen
both its top and bottom. The top is supported by rods stretching obliquely down to




GAS-LIGHT.                                      851
the sides and to the under edge an iron ring is attached, consisting of curved cast iron
bars bolted together; with which the oblique rods are connected by perpendicular ones.
676                                   675
_      li I     ~ I  I    I lH,
_ _ _ I -t         __, 
_    I =,                                     a I r  _ i  _   _
E                                     C
Other vertical rods stretch directly from the top to the bottom edge.  Upon the periphery
of the top, at the end of the rods, several rings are made fast, to which the gas-holder
is suspended by means of a common chain which runs over a pulley at the centre
Upon the other end of the chain there is a counterpoise, which takes off the greater part
of the weight of the gas-holder, leaving-only so much as is requisite for the expulsion of
the gas. The inner and outer surfaces of the gas-holder should be a few times rubbed
over with hot tar, at a few days' interval between each application. The pulley must be
made fast to a strong frame.
If the water cistern be formed with masonry, the suspension of the gas-holder may be
made in the following way. A A, fig. 676, is a hollow cylinder of cast iron, standing up
through the middle of the gasometer, and which is provided at either end with another
small hollow  cylinder G, open at both ends and passing through the top, with its axis
placed in the axis of the gas-holder. In the hollow cylinder G, the counterweight moves
up and down, with its chain passing over the three pulleys B, B, B, as shown in fig. 676.
E F are the gas pipes made. fast to a vertical iron rod. Should the gasometer be made to
work without a counterweight, as we shall presently see, the central cylinder A A, serves
as a vertical guide.
In proportion as the gas-holder sinks in the water of the cistern, it loses so much of
its weight, as is equal to the weight of the water displaced by the sides of the sinking
vessel; so that the gas-holder when entirely immersed, exercises the least pressure upon
the gas, and when entirely out of the water, it exercises the greatest pressure. In order
to counteract this inequality of pressure, which would occasion an unequal velocity in
the efflux of the gas, and of course an unequal intensity of light in its flame, the weight of
the chain upon which the gas-holder hangs is so adjusted as to be equal, throughout the
length of its motion, to one half of the weight which the gas holder loses by immersions
In this case, the weight which it loses by sinking into the water, is replaced by the portion of the chain which, passing the pulley, and hanging over, balances so much of the
chain upon the side of the counterweight; and the weight which it gains by rising out
of the water, is counterpoised by the links of the chain which, passing over the pulley,
add to the amount of the counterweight. The pressure which the gas-holder exercises
upon the gas, or that with which it forces it through the first main pipe, is usually so regulated as to sustain a column of from one to two inches of water; so that the water will
stand in the cistern from one to two inches higher within, than without the gas-holder.
The following computation will place these particulars in a clear light.
Let the semi-diameter of the gas-holder, equal tc the vertical extent of its motion into
and out of the water, = x; let the weight of a foot square of the side of the gas-holder,
including that of the strengthening bars and ring, which remain plunged under the water,
be = p; thea




852                                GAS-LIGHI.
1. the weight of the gas-holder in its highest position = 3 p r xg;
2. the weight of the sides of the gas-holder which play in the water = 2 p   x;
q. the cubic contents of the immersed portion of the gas-holder   2 p r x;
4. its loss of weight in water =       p 
5. the weight of the gas-holder in its lowest position
p r x2 (3 ~112  
\    400 -)=272p TX2;
56
6. the weight of n inches, height of water =
7. the amount of the counterweight =  r x2) 3 p8. the weight of the chain for the length x =
If we reduce the weight of the gas-holder in its highest and lowest positions to th
height of a stratum of water equal to the surface of its top, this height is that of the
column of water which would press the gas within the gasometer were no counterweight
employed; it consists as follows:
9. for the highest position =3 p 
56
10. for the lowest =272 I
50
For the case, when the height of the gas-holder is different from its semi-diameter,
let this height = m x; then the height of the water level is/1+2 m
11. for the highest position = p    6 m;
12. for the lowest = P + 6       );
13. the counterweight =   xr 2( (I -- 2m)   5614. the weight of the equalizing chain=  ~ p r m aX2.
For example, let the diameter of the gas-holder be 30 feet, the height 15 (the contents
in cubic feet will be 10,597), p = 4 pounds; then the counterweight for a height of an
inch and a half of water pressure = 3532 pounds; the weight of the chain for a length of
15 feet = 395 pounds. Were no counterweight employed, so that the gas-holder pressed
with its whole weight upon the gas, then the height of the equivalent column of water
in its highest position = 2-56 inches; and in its lowest, 2'33. The counterweight may
hence be lessened at pleasure, if the height of the pressing water-column n be increased.
The weight of the equalizing or compensating portion of the chain remains the same.
When n   2 inches, for instance, the counterweight = 1886 pounds.
The velocity with which the gas passes along the mains for supplying the various jets
of light, may be further regulated by opening the main-cock or slide-valve in a greater
or less degree. Gasometers whose height is greater than their semi-diameter, are not only
more costly in the construction, but require heavier counterweights and equilibration chains.
The above estimate is made on the supposition of the gas in the gas-holder being of the
same specific gravity as the atmospherical air, which would be nearly true with regard to
oil gas under the ordinary pressure. But coal gas, whose specific gravity may be taken
on an average at about 0*5, exercises a buoyancy upon the top of the gas-holder, which
of course diminishes its absolute weight. Supposing the cubic foot of gas to be = 00364
pounds, the buoyancy will be =  0'0364 r x3 pounds; a quantity which deserves to be
taken into account for large gasometers. Hence,
15. the weight of the gas-holder in its highest position = 3 p ir x2-0*1143 x3;
16. the counterweight = r x2 (3 P -         0       x2;
17. the weight of the chain for the length x= —-P  ir  __~
800            2
18. The height of the water pressure for the highest position, without the counterweight-^3pr-O311i43 
56                     2*72 n
19. the same for the lowest position =       in feet
56




GAS-LIGHT.                                      853
The preceding values of p and x are,
(16) = 3147; (17) = 203; (18) = 2'44 inches; (19) = 2-33 inches.
rhe water columns in the highest and lowest situations of the gas-holder here diffei
about 0-1 of an inch, and this difference becomes still less when p has a smaller value,
for example, 3 pounds, or when the diameter of the gas-holder is still greater.
It would thus appear that for coal-gas gasometers, in which the height of the gas-holder
does not exceed its semi-diameter, and especially when it has a considerable size, neither
a compensation chain nor a counterweight is necessary. The only thing requisite, is to
preserve the vertical motion of the gas-holder by a sufficient number of guide rods or
pillars, placed either within the water cistern, or round about it. Should the pressure
of the gas in the pipe proceeding from the gasometer, be less than in the gasometer itself,
this may be regulated by the main valve. or by water valves of various kinds. Or a small
intermediate regulating gasometer may be introduced between the great gas-holder, and
the main pipe of distribution. With a diameter of 61 feet in the gas-holder, the pressure
in the highest and lowest positions is the same.
The gasometers employed in storing up gas until required for use, occupy, upon the
old plan, much space, and are attended with considerable expense in erecting. The
water tank, whether sunk in the ground or raised, must be of equal dimensions with
the gasometer, both in breadth and depth.  The improved construction which we are
about to describe, affords a means of reducing the depth of the tank, dispensing with the
bridge of suspension, and of increasing at pleasure the capacity of the gasometer upon a
given base; thus rendering a small apparatus capable, if required, of holding a large
quantity of gas, the first cost of which will be considerably less than even a small gasometer constructed upon the ordinary plan.
Mr. Tait, of Mile-End Road, the inventor, has, we believe, been for some years
connected with gas establishments, and is therefore fully aware of the practical defects
617              e            -i        or advantages of the different constructions of
^1^)1  ^^ gasometers now in use. Fig. 617 is a section
of Mr. Tait's improved contrivance; a a is the
ct  v^~  tank, occupied with water, b   two ironcole          umns, with pulley-wheels on the top, c c,
I    chains attached to a ring of iron, d d, extendCc'  ing round the gasometer, which chains pass
over the pulley-wheels, and are loaded at their
l/"   f\    extremities, for the purpose of balancing the
71                             ^      weight of the materials of which the gasometer.    -.-t____________    is composed.
sliding one within the other, like the tubes
of a telescope; e, e, e, is the first or outer cyl
I? ^                      l~i ^        inder closed at the top, and having the ring
i ^                      ll J   of iron d, passing round it, by which the whole
\ ll                          1^~ \   is suspended; ff, is the second cylinder, sliding
7 F~  f^-                              freely within the first, and there may be a thiri
and fourth within these if necessary.
When there is no gas in the apparatus, all the cylinders are slidden down, and remain
one within the other immersed in the tank of water; but when the gas rises through the
water pressing against the top of the gasometer, its buoyancy causes the cylinder e to ascend. Round the lower edge of this cylinder a groove is formed by the turning in of the
plate of iron, and as it rises, the edge takes hold of the top rim of the cylinderf, which is
overlapped for that purpose.  The groove at the bottom of the cylinder fills itself with
water as it ascends, and by the rim of the second cylinder falling into it, an air-tight hydraulic joint is produced.
Thus, several cylinders may be adapted to act in a small tank of water, by sliding one
within the other, with lapped edges forming hydraulic joints, and by supporting the apparatus in the way shown, the centre of gravity will always be below the points of suspension. A gasometer may be made upon this plan of any diameter, as there will be no
need of frame-work, or a bridge to support it; and the increasing weight of the apparatus, as the cylinders are raised one after the other, may be counterpoised by loading the
ends of the chains c c.
The water in the gasometer need not be renewed; but merely so much of it as
evaporates or leaks out, is to be replaced. Indeed, the surface of the water in the cistern
gets covered with a stratum of coal oil, a few inches deep, which prevents its evaporation,
and allows the gas to be saturated with this volatile substance, so as to increase its illuminating powers.
The gasometer may be separated from the purifier by an intermediate vessel, such
as is represented fig. 678, with which the two gas pipes are connected. A is the




854                                GAS-LIGHT.
cylindrical vessel of cast iron a, the end of the gas pipe which comes from the purifier
i                    a              immersed a few inches deep into the liquid with
l    ~^1 b  /, m =.         which the vessel is about two thirds filled; b is
the gas-pipe which  leads into the gasometer;
c is a perpendicular tube, placed over the bottom
of the vessel, and reaching to within one third of
the top, through which the liquid is introduced
678 into the vessel, and through which it escapes when
it overflows the level d.  In this tube the liquid
stands towards the inner level higher, in propord                 c     tion to the pressure of the gas in the gasometer.
A                   |_   l7      The fluid which is condensed in the gas-pipe b, and
in its prolongation from  the gasometer, runs off
into the vessel,A; and therefore the latter must be
laid so low that the said tube may have the requisite
declivity. A straight stopcock may also be attached
_______  J~  to the side over the bottom, to draw off any sediment.
II. APPLICATION OF LIGHT-GAS.
1. Distribution of the pipes.-The pressure by which the motion of the gas is maintained in the pipes, corresponds to a certain height of water in the cs.tern of the gasometer. From the magnitude of this pressure, and the quantity of gas which in a given
time, as an hour, must be transmitted through a certain length of pipes, depends the
width or the diameter that they should have, in order that the motion may not be retarded
by the friction which the gas, iike all other fluids, experiences in tubes, and thereby the
gas might be prevented from issuing with the velocity required for the jets of flame.
The velocity of the gas in the main pipe increases in the ratio of the square root of the
pressing column of water upon the gasometer, and therefore by increasing this pressure,
the gas may be forced more rapidly along the remoter and smaller ramifications of the
pipes. Thus it happens, however, that the gas will be discharged from the orifices near
the gasometer, with superfluous velocity.  It is therefore advisable to lay the pipes in
such a manner, that in every point of their length the velocity of discharge may be nearly
equal. This may be nearly effected as follows:From experiment it appears that the magnitude of the friction, or the resistance which
the air suffers in moving along the pipes, under a like primary pressure, that is, for equal
initial velocity, varies with the square root of the length. The volume of gas discharged
from the end of a pipe is directly proportional to the square of its diameter, and inversely as the square root of its length; or, calling the length L, the diameter D, the cubic
D2
feet of gas discharged in an hour k; then k =  --      Experience likewise shows, that
for a pipe 250 feet long, which transmits in an hour 200 cubic feet of gas, one inch is
a sufficient diameter.
1       D2
Consequently, 200: k         -: -; and D= v k V-~
144 I/V 250  4VL~ ~
455,000
From this formula the following table of proportions is calculated.
Number of cubic feet per hour.   Length of pipe, in feet.  Diameter, in inches
50                          100                     0'40
250                          200                      1-00
500                          600                      1-97
700                         1000                     2-65
1000                         1000                     3-16
1500                         1000                     3-87
2000                         1000                     4-47
2000                         2000                      5-32
2000                         4000                      6-33
2000                         6000                      7-00
6000                          1000                     7-75
6000                         2000                     9-21
8000                         1000                     8-95
8000                         2000                     16-65
These dimensions are applicable to the case where the body of gas is transmitted through




GAS-LIGHT.                                     855
pipes without being let off in its way by burners, that is, to the mains which conduct the
gas to the places where it is to be used.  If the main sends off branches for burners,
then for the same length the diameter may be reduced, or for like diameter the length
may be greater. For example, if a pipe of 5'32 inches, which transmits 2000 cubic feet
through a length of 2000 feet, gives off, in this space, 1000 cubic feet of gas; then the
remainder of the pipe, having the same diameter, can continue to transmit the gas through
a lenth of 2450 feet =  (450 00) 2 with undiminished pressure for the purposes of lighting. Inversely, the diameter should be progressively reduced in proportion to the number
of jets sent off in the length of the pipe.
Suppose, for instance, the gasometer to discharge 2000 cubic feet per hour, and the lat
point of the jets to be at a distance of 4000 feet. Suppose also that from the gasometer
to the first point of lighting, the gas proceeds through 1000 feet of close pipe, the
diameter of the pipe will be here 4-47 inches; in the second 1000 feet of length, suppose the pipe to give off, at equal distances, 1000 cubic feet of gas, the diameter in
this length (calculated at 1500 cubic feet for 1000 feet long) = 3-87 inches; in the
third extent of 1000 feet, 600 cubic feet of gas will be given off, and the diameter
(reckoning 700 cubic feet for 1000 feet long) will be 2'65 inches; in the fourth and
last space (for 200 cubic feet in 1000 feet long) the pipe has a diameter of only an
inch and a half, for which, in practice, a two-inch cast iron pipe is substituted; this
being the smallest used in mains, into which branch pipes can be conveniently inserted.
The same relations hold with regard to branch pipes through which th? gas is transmitted into buildings and other places to be illuminated.  If such pipes  ake frequent
angular turnings, whereby they retard the motion of the gas, they must be a third or a
half larger in diameter.  The smallest tubes of distribution are never less than one
fourth of an inch in the bore.
Where, from one central gas work, a very great quantity of light is required in particular localities, there ought to be placed near these spots gasometers of distribution, which,
being filled during the slack hours of the day, are ready to supply the burners at night,
without making any considerable demand upon the original main pipe. Suppose the first
main be required to supply 8000 cubic feet in the hour, for an illumination of 8 hours, at
the distance of 2000 feet, a pipe 101 inches in diameter would be necessary; but if two
or three gasometers of distribution, or station gasometer  be had recourse to, into which
the gas during the course of 24 hours would flow through che same distance continuously
from the central gas works, the quantity required per hour from them would be only one
third of 8,000 = 2666'6 cubic feet; consequently the diameter for such a pipe is only 6-15
inches.
All the principal as well as branch pipes, whose interior diameter exceeds an inch and
a half, are made of cast iron from 6 to 8 feet long, with elbow pipes cast in them where
it is necessary.  These pipe lengths are shown in fig. 679, having at one end a wide
socket a, and at the other a nozzle 6, which fits the former.  After inserting the one it
the other in their proper horizontal position, a coil of hemp soaked with tar is driven
home at the junction; then a luting of clay is applied at the mouth, within which a ring
of lead is cast into the socket, which is driven tight home with a mallet and blunt chiseL,
The pipes should be proved by a force pump before being received into the gas works;
two or three lengths of them should be joined before laying them down, and they should
be placed at least two feet below the surface, to prevent their being affected by changes
of temperature, which would loosen the joints. The tubes for internal distribution, when
of emai size, are made of lead, copper, wrought iron, or tihL




856                                  GAS-LIGHT
Instead of a stopcock for letting off the gas in regulated quantities from the gasometer, a peculiarly formed water or mercurial valve is usLally employed. Fig. 680
shows the mode of construction for a water trap or lute, and is, in fact, merely a gasometer in miniature. c D E F is a square cast iron vessel, in the one side of which a pipe
A is placed in communication with the gasometer, and in the other, one with the main B
The moveable cover or lid H G I K has a partition, L. M. in its middle.  If this cover be
raised by its counterweight, the gas can pass without impediment from A to B; but if the
counterweight be diminished so as to let the partition plate L I sink into the water, the
communication of the two pipes is thereby interrupted.  In this case the water-level
stands in the compartment A so much lower than outside of it, and in the compartment
B, as is equivalent to the pressure in the gasometer; therefore the pipes A and B must
project thus far above the water. In order to keep the water always at the same height,
and to prevent it from flowing into the mouths of these pipes, the rim c B of the outer
vessel stands somewhat lower than the orifices A B; and thence the vessel may be kept
always full of water.
If a quicksilver valve be preferred, it may be constructed as shown in fig. 681. A B are
C  68     __             the terminations of the two gas pipes,
which are made fast in the rectangular
iro  vessel.       is an iron vessel.of th
same form, which is filled with quicksilver
684.^^=^          I I               up to the level a, and which, by means of
A^\\  j   ~ S~ ^the screw  G, which presses against its
^(d n  P )0l ~LJ@         ~-a     bottom, and works in the fixed female screw
c c, may be moved up or down, so that the
vessel M may be immersed more or less into
the quicksilver.  The vessel M is furnisher
with a vertical partition m; the passage of
the gas from A to Bis therefore obstructed
f              when this partition dips into the quickM                       silver, and from the gradual depression of
-f__681              \\       __       the vessel E by its screw, the interval be
_ ~: ~  ~      tween the quicksilver and the lower edge
f   ~~B "~A 2 iof the partition, through which the gas
j                       l ^^^^^^^^_    must enter, may be enlarged at pleasure
whereby the pressure of the gas in B may
I    ___    n    I   be regulated to any degree.  The trans
verse section of that interval is equal to
pE,      E             the area of the pipe or rather greater; the
breadth of the vessel M  from  A to 
_- -~V _ _; -               amounts to the double of that space, and
H            l{              its length to the mere diameter of A or B.
~ —~-_..'"\'~..  The greatest height to which the partition
m ean rise out of the quicksilver, is also
equal to the above diameter, and in this
e                   c             case the line a comes to the place of b.
The vertical movement of the outer vessel
E, is secured by a rectangular rim or hoop
3)t                = ____which surrounds it, and is made fast to the...... [, — ~'t upper part of the vessel M, within which
{;                      guide it moves up and down.  Instead of
the lever D D, an index with a graduated
plate may be employed to turn t   screw,
and to indicate exactly the magnitude in
t, 8'         &      \    ^^                ^the opening of the valve.
IIIn order to measure the quantity of gas
which passes through a pipe for lightirg a
factory, theatre, &c., the gas-meter is employed, of whose construction a sufficiently
precise idea Emay be formed from the con-lllll~^ ~^~'^l^l  sideration of fig. 682, which shows the ina           -    b —^=~^-_-l/         strument in a section perpendicular to its
Within the cylindrical case a, there is
=a shorter cylinder b b, shut at both ends,
and moveamle round an axis, which is
ditded  into four compartments, that communicate  by  the  opening  d, with the
inteival between  this cylinder andi the outer case         The  mode  in which  this




GAS-LIGHT.                                    857
cylinder turns round its axis is as follows:-The end of the tube c, which is made fast to
the side of the case, and by which the gas enters, carries a pivot or gudgeon, upon which
the centre of its prop turns; the other end of the axis runs in the cover, which here forms
the side of a superior open vessel, in which, upon the same axis, there is a toothed wheel.
The vessel is so far filled with water, that the tube c just rises above it, which position
is secured by the level of the side vessel. When the gas enters through the tube c, by
its pressure upon the partition e (fig. 682), it turns the cylinder from right to left upon
its axis, till the exterior opening d rises above the water, and the gas expands itself in
the exterior space, whence it passes off through a tube at top. At every revolution, a
certain volume of gas thus goes through the cylinder, proportional to its known capacity. The wheel on the axis works in other toothed wheels, whence, by means of an
index upon a graduated disc or dial, placed at the top or in front of the gas-meter,
the number of cubic feet of gas, which pass through this apparatus in a given time, is
registered.
B. Employment of the gas for lighting.-The illuminating power of different gases
burned in the same circumstances, is proportional, generally speaking, to their specific
gravity, as this is to the quantity of carbon they hold in combination. The following
table exhibits the different qualities of gases in respect to illumination.
Density or specific gravity.
L  ________________________    Proportion of light afforded by coal
gas to oil gas.
Coal gas.               Oil gas.
0-659                   0'818                        100: 140
0-578                   0'910                        100: 225
0-605                   1'110                        100: 250
0-407                   0-940                        100: 354
0-429                   0-965                        100: 356
0'508                   1'175                        100: 310
Mean 0.529                    0-96                         100: 272
In the last three proportions, the coal gas was produced from coals of middle quality;
in the first three proportions, from coals of good quality; and therefore the middle proportion of 100 to 270 may be taken to represent the fair average upon the great scale.
On comparing the gas from bad coals, with good oil gas, the proportion may become
100 to 300. Nay, coal gas of specific gravity 0-4, compared to oil gas of 1-1, gives the
proportion of I to 4.  A mould tallow candle, of 6 in the pound, burning for an hour,
is equivalent to half a cubic foot of ordinary coal gas, and to four tenths of a foot of
good gas. The flame of the best argand lamp of Carcel, in which a steady supply of oil
is maintained by pump-work, consuming 42 grammes = 649 grains English in an hour,
and equal in light to 9-38 such candles, is equivalent to 3-75 cubic feet of coal gas per
hour. The sinumbra lamp, which consumes 50 grammes = 772 grains English, of oil
per hour, and gives the light of 8 of the above candles, is equivalent to the light emitted
by 3-2 cubic feet of coal gas burning for an hour. A common argand lamp, equal to 4
candles, which consumes 30 grammes = 463 grains English per hour, is represented by
1*6 cubic feet of gas burning during the same time. A common lamp, with a flat wick
and glass chimney, whose light is equal to 1-13 tallow candles, and which consumes 11
grammes = 169-8 grains English per hour, is represented by 0-452 of a cubic foot of
gas burning for the same time.
Construction of the Burners.-The mode of burning the gas as it issues from the jets
has a great influence upon the quantity and quality of its light.  When carbureted
hydrogen gas is transmitted through ignited porcelain tubes, it is partially decomposed
Wvith a precipitation of some of its carbon, while the resulting gas burns with a feebler
flame.  Coal gas, when kindled at a small orifice in a tube, undergoes a like decomposition and precipitation. Its hydrogen, with a little of its carbon, burns whenever it
comes into contact with the atmospherical air, with a bluish colored flame; but the
carbonaceous part not being so accendible, takes fire only when mixed with more air;
therefore it a greater distance from the beak, and. with a white light from the vivid
ignition of its solid particles. Upon this principle pure hydrogen gas may be made tc
burn with a white instead of its usual blue flame, by dusting into it particles of lamp
black, or by kindling it at the extremity of a tube containing finely pulverized zinc.
The metallic particles become ignited, and impart their bright light to the pale blue
flame. Even platinum wire and asbestos, when placed in the flame of hydrogen gas,
serve to whiten it.  Hence it has been concluded, that the intensity of light which a
gas is capable of affording is proportional to the quantity of solid particles which it




858                                 GAS-LIGHT
contains, and can precipitate in the act of burning. Carbonic oxyde gas burns with the
feeblest light next to hydrogen, because it deposites no carbon in the act of burning
Phosphureted hydrogen gives a brilliant light, because the phosphoric acid, into which
its base is converted during the combustion, is a solid substance, capable of being
ignited in the flame.  Olefiant gas, as also the vapor of hydrocarbon oil, emits a
more vivid light than common coal gas; for the first is composed of two measures of
hydrogen and two measures of the vapor of carbon condensed into one volume; while
the last contains only one measure of the vapor of carbon in the same bulk, and
combined with the same proportion of hydrogen.  Olefiant gas may therefore be expected to evolve a double quantity of carbon in its flame, which should emit a double
light.
The illuminating power of the flame of coal gas is, on the contrary, impaired, when,
by admixture with other species of gas which precipitate no carbon, its own ignited particles are diffused over a greater surface. This happens when it is mixed with hydrogen,
carbonic oxyde, carbonic acid, and nitrogen gases, and the diminution of the light is proportional to the dilution of the coal gas.
In like manner the illuminating power of coal gas is impaired, when it is consumed
too rapidly to allow time for the separation and ignition of its carbonaceous matter; it
burns, in this case, without decomposition, and with a feeble blue flame.  1. This
occurs when  the light-gas is previously mixed with atmospherical air, because the
combustion is thereby accelerated throughout the interior of the flame, so as to prevent
the due separation of carbon. A large admixture of atmospherical air makes the flame
entirely blue.  2. When it issues, with considerable velocity, from a minute orifice,
whereby the gas, by expansion, gets intimately mixed with a large proportion of atmospherical air. If the jet be vertical, the bottom part of the flame is blue, and the more
so the less carbon is contained in the gas. The same thing may be observed in the flame
of tallow, wax, or oil lights.  The burning wick acts the part of a retort, in decomposing the fatty matter. From the lower part of the wick toe gases and vapors of the
fat issue with the greatest velocity, and are most freely mixed with the air; while the
gases disengaged from the upper part of the wick compose the interior of the flame, and
being momentarily protected from the action of the atmosphere, acquire the proper high
temperature for the deposition of carbon, which is then diffused on the outer surface in
an ignited state, and causes its characteristic white light. Hence with coal gas, the light
increases in a certain ratio with the size of the flame as it issues from a larger orifice,
because the intermixture of air becomes proportionately less. 3. If by any means too
great a draught be given to the flame, its light becomes feebler by the rapidity and completeness with which the gas is burned, as when too tall a chimney is placed over an
argand burner, see fig. 683. Fig. 684, c, is a view of the upper plate, upon which the
glass chimney b rests, The gas issues through the smallei openings of the inner ring,
and forms a hollow cylindrical flame, upon the outside as well as the inside of which the -
atmospherical air acts. The illuminating power of this flame may be diminished at
pleasure, according as more or less air is allowed to enter through the orifices beneath.
With a very full draught the light almost vanishes) leaving only a dull blue flame of
great heating power, like that of the blowpipe, corresponding to the perfect combustion
of the gas without precipitation of its carbon. 4. On the other hand, too small a draught
of air is equally prejudicial; not merely because a portion of the carbon thus escapes
unconsumed'in smoke, but also because the highest illuminating power of the flame is
obtained only when the precipitated charcoal is heated to whiteness; a circumstance
which requires a considerable draught of air.  Hence the flame of dense oil gas, or of
oil in a wick, burns with a yellow light without a chimney; but when it is increased in'ntensity by a chimney draught, it burns with a brilliant white flame.
From the consideration of the preceding facts, it is possible to give to coal gas its
highest illuminating power.  The burners are either simple beaks perforated with a
small round hole, or circles with a series of holes to form an argand flame, as shown in
fig, 684, or two holes drilled obliquely, to make the flame cross, like a swallow's tail, or
with a slit constituting the sheet of flame called a bat's wing, like most of the lamps in
th!! streets of London. These burners are mounted with a stopcock for regulating the
quantity of gas.
The height of the flame, which with like pressure depends upon the size of the orifice,
and with like orifice upon the amount of pressure, the latter being modified by the stopcock, is, for simple jets in the open air, as follows:~
Length of'he flame              2       3       4          5          6 inches.
Intensity of the light     -   55-6    100       150      197-8      247.4
Volume of gas consumed  -   60-5  101-4   126-3           143-7       182-2
Light with equal consumption   100    109        131        150        150
When the length exceeds five inches, nothing is gained in respect to light.  For ofl




GAS-LIGHT.                                     859
gas the'ame statements will serve, only on account of its superior richness in carbon, it
does not bear so long a flame without smoke. Thus:
Length of the flame       -     1       2          3         4         5 inches.
Intensity of the light   -    22    63-7         96-5       141       178
Gas consumed        -    -  33-1    78-5           90       118       153
Light with equal consumption 100       122        159       181        174
The diameter of the orifice for single jets, or for several jets from the same beak, is
one twenty-eighth of an inch for coal gas, and one forty-fifth for oil gas.
When several jets issue from the same burner, the light is improved by making all the
flames unite into one. In this case the heat becomes greater, for the combined flame
presents a smaller surface to be cooled, than the sum of the smaller flames. The advantage gained in this way may be in the ratio of 3 to 2, or 50 per cent.  In an argand
burner the distances of the orifices for coal gas should be from JJL to      of an inch,
and for oil gas -12-. If the argand ring has 10 orifices, the diameter of the central openincg should be = 4- of an inch; if 25 orifices, it should be one inch for coal gas; but
for oil gas with 10 orifices, the central opening should have a diameter of half an inch,
and for 20 orifices, one inch. The pin holes should be of equal size, otherwise the larger
ones will cause smoke, as in an argand flame with an uneven wick. The glass chimney
is not necessary to promote the combustion of an argand coal gas flame, but only to prevent it from flickering with the wind, and therefore it should be made so wide as to
exercise little or no influence upon the draught. A narr(w chimney is necessary merely
to prevent smoke, when a very strong light with a profusion of gas is desired. Oil gas
burned in an argand beak requires a draught chimney, like a common argand lamp, on
account of the large quantity of carbon to be consumed.  The most suitable mode of
regulating the degree of draught can be determined only by experiment, and the best
construction hitherto ascertained is that represented in fig. 685. Fig. 686 exhibits the
l~^c  ~l,        view from above, of the rim or ring c, upon which
/^"~'^\ b I ^ Ithe chimney b stands, and which surrounds the perforated beak.  The ring is made of open fretwork,
to permit the free passage of air upwards to strike
the outside of the flame. The thin annular dsic d,
686                   e  A,,   a 6685 which is laid over its fellow disc c,in the bottom
of the chimney-holder, being turned a little one way
or other, will allow more or less air to pass through
cs7p    __I ill Ifor promoting, more or less, the draught or ventilation. The draught in the central tube of the
burner may be regulated by the small disc e, whose
diameter is somewhat smaller than that of the ring
f              of the burner, and which, by turning the milled
headf, of the screw, may be adjusted with the greatest nicety, so as to admit a greater
or smaller body of air into the centre of the cylindrical flame.
In mounting gas-lights, and in estimating beforehand their illuminating effects, we
must keep in mind the optical proposition, that the quantity of light is inversely as the
square of the distance from the luminous body, and we must distribute the burners
accordingly. When, for example, a gas-light placed at a distance of ten feet, is required
for reading or writing to afford the same light as a candle placed at a distance of twa
feet; squaring each distance, we have IOO4; therefore 100
Such lights will be necessary at the distance of 10 feet.
Concerning portable gas-light, with the means of condensing it, and carrying it from
the gas woiis to the places where it is to be consumed, we need say nothing, as by the
improvements lately made in the purification and distribution of coal gas, the former
system has been superseded.
It is well known that light gas deteriorates very considerably by keeping, especially
when exposed to water over an extensive surface; but even to a certain degree over oil,
or in close vessels. An oil gas which when newly prepared has the specific gravity of
1-054, will give the light of a candle for an hour, by consuming 200 cubic inches; will,
after two days, give the same light by consuming 215 cubic inches per hour; and after
foun lays, by consuming 240 cubic inches in the like time. With coal gas the deterioration appears to be more rapid. When newly prepared, if it affords the light of a candle
with a consumption of 400 cubic inches per hour, it will not give the same light after
being kept two days, except with a consumption of 430 inches; and after four days, of
460. Oil gas three weeks old has become so much impaired in quality that 600 inches
of it were required per hour to furnish the light of a candle. All light gas should be
used therefore as soon as possible after it is properly purified.
Economical consideratioas.-The cost of gas-light depends upon so many local cir
eumstances, that no estimate of it can be made of general application; only a fei




860                                  GAS-LIGHT.
leading points may be stated. The coals required for heating the retorts used to constiute
one half of the quantity required for charging the retorts themselves. When five retorts
are heated by one fire, the expenditure for fuel is only one third of that when each retort
has a fire. The coke which remains in the retorts constitutes about 60 per cent. of the
weight of the original coal; but the volume is increased by the coking in the proportion
of 100 to 75. When the coke is used for heating the retorts, about one half of the whole
is required. If we estimate the coke by its comparative heating power, it represents 65
per cent. of the coals consumed. One hundred pounds of good coal yield in distillation
10 pounds of ammoniacal liquor, from which sulphate, or muriate of ammonia may be
made, by saturation with sulphuric or muriatic acid, and evaporation. The liquor contains likewise some cyanide of ammonia, which may be converted into Prussian blue by
the addition of sulphate of iron, after saturation wih muriatic acid.
Two hundred pounds of coal afford about 17 pounds of tar.  This contains in 100
pounds 26 pounds of coal oil, and 48 pounds of pitch. The tar is sometimes employed as
a paint to preserve wood and walls from the influence of moisture but its disagreeable
smell limits its use. The coal oil, when rectified by distillation, is extensively employed
for dissolving caoutchouc in making the varnish of waterproof cloth, and also for burning
in a peculiar kind of lamps under the name of naptha. Oil of turpentine, however, is
often sold and used for this purpose, by the same name. If the coal oil be mixed with
its volume of water, and the mixture be made to boil in a kettle, the mingled vapors when
passed through a perforated nozzle may be kindled and employed as a powerful means
of artificial heat. The water is not decomposed, but it serves by its vapor to expand the
bulk of the vqlatile oil, and to make it thereby come into contact with a larger volume
of atmospherical air, so as to burn without smoke, under a boiler or any other vessel.
The pitch may be decomposed into a light-gas.
The relative cost of light from coal gas and oil gas may be estimated as one to six at
least. Rosin gas is cheaper than oil gas. See ROSIN.
I shall conclude this article with a summary of the comparative expense of different
modes of illumination, and some statistical tables.
One pound of tallow will last 40 hours in six mould candles burned in succession, and
costs 8d.; a gallon of oil, capable of affording the light of 15 candles, for 40 houm
costs 5s.; being therefore  of the price of  ould candles, and of the price of mdio
The cost of wax is about 3  timeas that of tallow; and coal gas, as-sold at the rate of
9s. for 1000 cubic feet, will be one sixth the price of mould candles; for 500 cubic inches
of coal gas give a light equal to the above candle for an hour; therefore 40 X 500
20,000 cubic inches = 1157 cubic feet, worth 1d., which multiplied by 6 gives 71d-,
the average, price of mould candles per pound..,
The author of the article Gas-light in the Encyclopedia Britannica, observes, in refer
ence to the economy of this mode of illumination, that while the price of coal, in consequence of the abundant and regular supply of that article, is liable to little fluctuation,
the cost of wax, tallow, and oil, on account of the more precarious nature of the sources
from which they are obtained, varies exceedingly in different seasons. "Assuming that
a pound of tallow candles, which last when burned in succession forty hours, costs-'nwhpence" (seven-pence halfpenny is the average price), " that a gallon qfo.il, yielding, the
light of 600 candles for an hour, costs two shillings" (five shillings is the' owest price of
a gallon of such oil as a gentleman would'choose to burs. in his lamp), " that the expense
of the light from wax is three times as great as from tallow, and that,.,thousand cubic
feet of coal gas cost nine shillings;" he concludes the relative cost to be forqhe same
quantity of light,-from wax, 100; tallow, 25; oil, 5; and coal-gas, 3.  I conceive the
estimate given above to be much nearer the truth; when referred to wax called 100, it
becomes, for tallow, 28-6; oil, 14-3; coal-gas, 4-76.
Ggs-lighting has received a marvellous development in London. In the year 1834, the
number of gas lamps in this city was 168,000, which consumed daily about 4,200,000
cubic feet of gas. For the purpose of generating this gas, more than 200,000 chaldrons,
or..0,800,000 cubic feet of coals were required.
For  the  following  valuable  statistical details upon gas-light, my readers are
indebted to Joseph Hedley, Esq., engineer, of the Alliance Gas Works, Dublin; a
gentlemt nwho to asound knowledge of chemistry, joins such mechanical talent and
indefn tigable diligence, as qualify him to conduct with success any great undertaking
committed to his care. Ife has long endeavored to induce the directors of the London
gas-works to employ a better coal,.and generate a more richly carbureted gas, which.much smaller quantity would give as brilliant a light, without heating the apartmeftB
unpleasantly, as their highly hydrogenated gas now does. Were his judicious views
adopted, coal gas would soon supersede oil, and even wax candles, for illuminating pAR
rate mansions.




GAS-LIGHT.                                            861
Copy of a paper laid before a Committee of the House of Commons, showing not only
the relative values of the Gases produced at the undermentioned places, but showing in
like manner the relative economy of Gas, as produced at the different places, over candles.  By Joseph Hedley, Esq.
30 33     3 ~3e-      35. ~                            A'     s
ofthePla572ces                 M12            i704    100       - 7      0    9
3254'85                    489                
where experiments i    1       US                              ^  I Q    s  f
2.were made.                    Coo                   1 6                           S
4'408' 9           1164     10 0 0   11  8    6I'190   1A    2          3123      9C0  181   125
2 970         8553       1644     8050 1"12 Cn co   W
1'645 1'3               4200              17      15
Equal to
Candles.   Cubic Feet. Cubic Feet. s. d. L. s. d. PerCeni  L. s. d.
Birmingham;  I
Birmingham and       2-572         1-22       2704     10       0        9      15  4  7    541
two CompaniesJ
Stockport -.-     3-254         185        1489    10 0    1411   12          0 13  0    539
Manchester   -       3-060 0        825       1536      8 0 0       120 1 1            0    534
es are estimateOld               to369  11    2646 15700 hours.   6  5    6      1 4 candles9    462
~L~~~ iverpoo l New       Com pany il illuminating power.
Gas Company       and   thee exeriment  the  in                                   91t and  i
Bradford -   -       2-190        1-2         3123      9 0  18  1   121         1 4  6    420
Leeds    -   -       2-970         -855       1644      80  013 2    64          012 4    -530
Sheffield -   -      2-434       104         2440      80  019 6    64          018  3    -466
Leicester -   -      2-435        1-1         2575      7 6  019 3   15         0 16 5    -528
Nottingham    -      1-645        1-3         4200      9 0  117 9   15          111 3    -424
Derby    -   -       1937         1-2         3521    100  115 4   15            110 0    -448
Preston  -   -       2-136        115         3069    10 0  110 8   15           1 6  2    -419
London  -   -        2-083        1-13        3092    10 0  110 11I allowed. 1 10 11   -412
* 100 lbs. of candles are estimated to burn 5700 hours. t The candles cost 31. 2s. 6d.
t The Liverpool Old Company have since resorted to the use of Cannel coal, and consequently very nearly
assimilate to the Liverpool New Company in illuminating power.
MEMORANDUM.-It will not fail to be observed that in deducing the comparative value
between candles and gas by these experiments, the single jet (and in every instance,
of course, it was the same) has been the medium. This, however, though decidedly
the most correct way of making the comparative estimate of the illuminating power of
the several gases, is highly disadvantageous in the economical comparison, inasmuch
as gas burnt in a properly regulated argand burner, with its proper sized glass, air
aperture, and sufficient number of holes, gives an advantage in favor of gas consumed
in an argand, over a jet burner, of from 30 to 40 per cent. At the same time it must
not be overlooked, that in many situations where great light is not required, it will be
found far more economical to adopt the use of single jets, which, by means of swing
brackets and light elegant shades, become splendid substitutes for candles, in banking
establishments, offices, libraries, &c. &c.
NOTE.-In Glasgow, Edinburgh, Dundee, Perih, and the Scotch towns generally, the
Parrot or Scotch Cannel coal is used; in illuminating power and specific gravity the
gas produced is equal to that from  the best description of Cannel coal in England.
The price per 1OuQ cubic feet ranges about 9s., with from 5 to 30 per cent. off for dis.
counts, leaving the net price about 9s. to bi: equal in the above table to 100 lbs. of
candles.
Epitome of Experiments made in Gas prcductsd from  different qualities of Coal, and
consumed in different kinds of Burners:
Tried at the Sheffield Gas Light Company's Works, and laid before a Committee of the
House of Commons.  By Joseph Hedley, Esq.
Date Description   Speciesof  beD    5 1      a~ 11.= 1 3              J            0
1835.  of Burner.    Coal.                M e  ~~    ea'     -     00 b~               1"1
Cubic                    Cubic
May                                  Inches Feet. Inches  Candles.   Feet.  L. s. d.  L. a. d
8  Single Jet   Deep Pit   -410   75    1-         4      2-36      2415  0 19 341
9   Ditto        Mortormley  -450   74    -95   4         2-434     2224  0 17 941
9   Ditto        Cannel       -660   614   -7    4        3-54       1127  0 9  0    3
8    Argan       Deep Pit   -410   31   3-3    34    11-53           1631  0 13 041
9   Ditto        Mortormley  -450   33    3-1   3A    12-24          1443  0 11 641'
9   Ditto        Cannel       -6f0   29   2-6    34    15-85          935  0 7  54 J




862                                  GAS-LIGHT.
Copy of Experiments made at the Alliance Gas Company's Works in Dublin, during the
past year 1837. By Joseph Hedley, Esq.
Results of experiments on the qualities of various coals for the production of gas; its
value in illuminating power; produce of coke, and quality; and other particulars important in gas-making:1st Experiment, Saturday, May 27, 1837.-Deane coal (Cumberland), 2 cwts. of 112
lbs. each (or 224 lbs.) produced 970 cubic feet of gas; 4 bushels of coke of middling
quality; specific gravity of the gas, 475.  Consumed in a single-jet burner, flame 4
inches high, 1 4ths cubic feet per hour; distance from  shadow  76 inches, or 2(3
mould candles.^ "Average quantity of gas made from the charge (6 hours) 433 cubic feet
per lb., or 9,700 cubic feet per ton of 20 cwts. Increase of coke over coal in measure, not
quite 30 per cent. Loss in weight between coal, coke, and breize 56 lbs., converted
into eas, tar, ammonia, &c.
2d Experiment, May 28.-Carlisle coal (Blenkinsopp). 224 lbs. produced 1010 cubic
feet of gas, 4 bushels of coke of good quality though small; increase of coke over coal in
measure not quite 30 per cent. Loss in weight, same as foregoing experiment. Average
quantity of gas made from the charge (6 hours) 4'5 cubic feet per lb. or 10,080 per ton.
Illuminating power of the Gas.
Consumed
per hour,    Distance     Equal       Specific
single jet.  from candle.  to candles.    gravity.
feet.      inches.
At the end of the first hour    -       11          70          2-72       -475
Ditto      ditto     with 20-hole  25                          2.'33
argand burner                       5            25         2133          475
When charge nearly off   -    -  85                              1-84       -442
When charge quite off, with 20-                      1 0       o n  1
hole argand burner    -    - $n                                           26
3d Experiment, May 29.-Carlisle coal (Blenkinsopp).  112 lbs. produced 556 cubic
feet of gas. Other products, loss of weight, &c., same proportion as foregoing experiment. Average quantity of gas made from the charge (6 hours) 4-96 cubic feet per lb.,
or 11,120 per ton
In this experiment the quantity of gas generated every hour was ascertained; the
illuminating power, the specific gravity, and the quantity of gas consumed by the single
jet with a flame 4 inches high, was tried at the end of each hour, with the respective
gases generated at each hour; and the following is a table of results.
RESULTS.
Consumed                    Distance of    Illuminating
Hour.   Gas produced.   per houl je,   Specific gravity.  candle from    power equal to
4 inches high.                   shadow.    mould candles.
cubic feet.    cubic feet.                    inches.
1st.        150    S  1l-  h              -534             70           2-72
2d.         120              11           -495             75           2-36
3d.          95              12'344             75           2-36
4th.'       95              15           -311             80           2-08
5th.         80              17           -270             85           1-81
6th.         16             29            *200            100         not one
Total      556 or           92- or 21feet 9 inches.       _        _____
Average of the above gas, 6-hour charge.
921       16-lOths, nearly    -359             81          2-03
Average of the above gas at 4-hour charge.
115       121-10ths,           -421             75          2*36
rroduction of gas in 6 hours 556 feet, or at he rate of 11,120 cubic feet per ton.
Ditto      in 4 hours 460 feet, or at the rate of  9,200      ditto




GAS-LIGHT.                                         863
The relative value of these productions of gas is as follows, viz.:
11,120 at 16-1Oths per hour nearly (or 1'5916 accurately), and equal to 203 candles;
the 11,120 feet would be equal to and last as long as 1597 candles, or 266k lbs. of
candles.
9200 at 12k-10ths per hour (or 1-2375 accurately), and equal to 236 candles; the
9200 feet would be equal to 1949 candles, or 3245. lbs. candles.
Now 2661 lbs. of mould candles, at 7s. 6d. per6dozen lbs., will cost 81. 6s. 4Qd., whilst
324) lbs. of  do.    do.    at 7s. 6d. per  do.           do.      101. as.
Showing6 the value of 4-hour charges over 6-hour charges; and of 9,200 cubic feet
over 11,120 cubic feet.
Note.-9500 cubi' feet of Wigan cannel coal gas are equal in illuminating power to 859 1-6th lbs of candles, which at 7s. 6d. per dozen lbs. will cost 251. 10s. 5-d.  It is also found that any burner with superior
gas will consume only about half the quantity it would do with common gas.
4th Experiment, May 30th.-Cannel and Cardiff coal mixed 2 and -, together 112 lbs.,
produced 460 feet of gas; 2 bushels of coke of good quality; increase of coke over coal
in measure, about 30 per cent.; loss in weight, 41 lbs.; coke weighed 71 lbs., no breize.
Average quantity of gas made from the  L.arge (4 hours), 4'1 cubic feet per lb., or 9'200
per ton.
Illuminating power.-At the end of the first hour.
Candles.                                    Cubic feet.
Distance of candle from           o         Consumed per hour sin-le) h
shadow    -    -    -   jet, 4 inches high                            -  12-ths
At end of 2d hour, do.   70 or 2-72   Do.    do.    do.                     11-10ths.
At end of 3d hour.    This gas very indifferent.
Average of the three   -  70 or 2-72   Do.    do.    do.                    11-10ths.
Specific gravity 3'44; 5 feet per hour, with a 20-hole argand burner, equal to 14'66
candles.
5th Experiment, May 31st.-Carlisle coal, 112 lbs. produced 410 feet of gas; other
products, same as in former experiments with this coals but heat very low.
Illuminating power and produce of gas.
Average of this gas: specific gravity, 540;
(1st hour 120 cubic feet                  distance of candle from shadow, 55 inches,
410 ft.  2d         100                           or 4'4 candles consumed per single jet,
1 3d         90                           9-lOths of a cubic foot per hour. 20-hole
[4th       100                            argand burner, 4 feet per hour, equal to.  21-33 candles.
It is possible, from the superior quality of this gas, that a little of the cannel gas made
for a particular purpose, may have got intermixed with it in the experimental gasholder
and apparatus.
A variety of other experiments were tried on different qualities of coal, and mixtures
of ditto, too tedious to insert here, though extremely valuable, and all tending to show
the superior value of gas produced at short over long charges; and also showing the importance and value of coal producing gas of the highest illuminating power; among
which the cannel coal procured in Lancashire1 Yorkshire, and some other counties of
England and Wales, and the Parrot or splent coal of Scotland, stand pre-eminent.
Note.-In all the foregoing experiments the same single-jet buiner was used; its flame in all instance#
exactly 4 inches high.
The coal when drawn from the retort was slaked with water, and after allowing some short time iot
drying, was weighed.
A TABLE of the number of hours Gas is burnt in each month, quarter, and year..0 I M           I'        0
Time of Burnaing,                   I.                               V  ^          c   C7
J^  ho s, ^   >   oo        5 ^                 5   ^.8   8       5.
o'clock.
From dusk to 6          2 31 62  80  65  33   4  --    _   _    2  173 102 277
-_      7 -   14226292 111  96  61  31   4 — _    4  36  265 188 4934
-       8 -   40 52 93122 142 127  89  62  28   4 -    32  92  357 278 759.
-       9  13 71 82 124 152 173 158 117  93  58  29   8  95 166  449 368 1078 W
-      10  44 102 112 155 182 204 189 145 124  88  60  38 180 258  541 458 1443 FtF
-      11  75 133 142 186 212 235 220 173 155 118  91  68 277 350  633 548 1808,
-      12 106 164 172 217 242 266 251 201 186 148 112  98 368 442  725 638 2173 Cs
AU night     - 217 307 345 421 473 527 512 411 382 295 241 195 732 869 1421 1305 4327    a
Moruing from 4 -   16 48 80110 137 137  98  71  28   2              30  64  327 306 727 ~
-       5          18 49 80 106 106  70  40   3                318  235 216 472
-       6 -           18 50  75  75  42   9   -                         143 126 269
-       7   -    -        20  44  44  14                                 64  58 122
I              I....       I        I  __J




864                                                               GAS-LIGHT.
Copy of a Paper submitted to a Committee of the House of Commons in the Session of 1837,
of England; and procured by actual Survey and
~1J5                                                No. of
Name of. thePrice of Coal,                                           i                    Mu-   Quaii   Publit                       Price
Place where Price of Gas per Meter, De  Cad  C.   made from                                                                   o          por*rcW         s,
are situated.                                Toe.         o                                                   p  ied
Cu.ft.. d.
Birmingham   10s. per meter cub. feet.  Lump coal   6,500            32     2s. Id  per Slack.  About            490  Batswins.  1 10  OComanyand
Gas Com-             Discounts           from West               bushels.   quarter               5 cwt.                   460      2  0 0  provi           ts,
pany.          101.  to   301. d 2.    Bromwich                            delivered,           of slack,                  30                 ervice, &
301.  to   501. "  5-     pits, risen                        or about               at 6s.
501.  to   751.'  7  u lsnuch of late.                       3d. per             per ton,
751.  to  100..10       1837, Itls. 10d.                     bushel.               25 per
001. & upwards 15                                                                    cent.
Birmingham   10s. per metercub. feet. From  West   6,500  24 bush.   2s d.   Slack.                 5 cwt.    1,500  Batswings. average             Ditto.
and Staf-       Discounts as above.    Bromwich                but larg-er per sack       and   of slack,                            11   0
fordshire.                                pits, 1837,           measure        of 8       Tar.    at 4s.
9s. 3d.             than Bir-  bushels.               25 per
minsolham.                         cet.
Macclesfield. lO. per meter cub. feet. Common, 8s.  6,720  12 cwt.              lOs.      Coke.      No          220      Ditto.      210  0    Company.
Discounts          average 1834.                        per ton.            account
501.       751.  5                                                               kept.
751.   o 1001.  7J
1001. o-  1251. 10 
1251.     1501. 121JQ
~1501.  g  1751. 15 
1751.   * 2001. 1780
2001. &upwards 20O
Stockport.   l0s. per meter cub. feet. Coal 10s. 6d.  7,800   7 cwt.           6a. 8d.    Coal,   Ditto.         230     Ditto               OComr. provide
Disco'ntssame as Mac- cannel 19s.6d.                          per ton.   coke,                                          1..  lamps &  posts.
clesfield. Macclesfield abouthalfand                                    and tar.                                     2  0  0   Company's
discounts taken from    half used.                                                                                    1837.   service light,
Stockport card.         Average 15s.                                                                                           repair, clean,
1834.                                                                                            and extioguish.
Manchester.  10s. per m.cub.ft. 1834.   15s. 2d.          9,500  14 cwt.    Ditto.    Coke.  4,2-3ds   2,375  Sionlejets   1  2  OCommissioners
9s. and 8s.  -    1837.   average.                                                   cwt.                anI flat    2  0          of police.
Discounts          Oldham                                                                         flames,
501.      1001.  2H      Water-    o                                                                   about half
1001.      150/.   5       gate    (                                                                    and half.
1501.  1   2oO.   7  5  Wio-an  )
2000.  ~   225/.  10       Mixed, 1834.
2251. "   2501.  121 f
2501.  g   3001.  15.
3001.      4001.  17J
4001. &  upwards 20'
Liverp'i Old lOs.permetercub. feet. 7s.3d.perton  8,200  ll} cwt.   8s. 4d.   Siack, 61 cwt.    1,700  Batswings.  410  0                         Company
Company,             Discounts          of 112 lbs. per                    per ton of  7s. 3d.                   30          jet,    2  5    lit clan, put
1834.          101. &  under 501. 2. cwt.  Orms-                           112 lb.   per to.                           2  -       213  0out, and repair
301.  to     100/1. 5 $    kirk or Wig-                      per cwt.                                     3          3  2  9
o100.  to     2001. 7,      an slack.                                                                      4  -       3 13
3001. and upwards 10 
Ditto, ditto,  In 1835, this Compsny resortedtothe use of cannel co at similar to the L iverpool New  Gas and Coal Company, producing
Liverpoo lto1. permeter cub. feet. 18s.all cannel  9,500  13 cwt.    7s. 6d.    Coke   5J cwt.  Only a   Argarsds.   4  8  0 Commissioners.
New K           os and Discounts same as Liv-    Wig"an.                      per ton.    and                  few.
Coke, 1833.   erpoolOldComp'ny.                                                          slack.
Bradford,    9s. per meter cubic feet 8s.6d.perton.  8,000  12 cwt.             12s.      Coke.  8J cwt.         220  Batswienga   2 12  41Company light,
14 4.         to lacre consumers.   3 sorts used                           per ton.                                                            ropair, &c.
iiscounts             averaoe.
201.  to   30   5        Slack 5s. 6d.
301.   to   40   71        Low moor
400.   to   60  10  S    8s. l0d.
600.   to   80  121       Catherine
870.   to  100  15         slack 8*.
1001. & upwards 20.
Small Consumers,
10s. per meter cub. feet.
an   5 per  cent. off
from  100. to 200.
Leeds,.834. 8s. per meter cudio feet. 8s. per ton    6,500   12 cwt.    7,. 6d.   Dittos. 5i.,wl.              217      D its.    2 12  6Commissioners,
Discounts             averaga.                          per ton.                                                          except extin2.) per cent. (  150. 2-3ds. cos s                                                                                              guish ing, for
5. on half-       301.       7s.                                                                                            which Cop'sny
7(   yearly         501. 1-3d cannel                                                                                          pay 3s.10t  per
10  J payments.  1000.         tog.                                                                                                 lamp.
Sheffield,     8s. per meter cubic feet. 7s.9d. per Ion  8,000  10 cwt.         10s.      Ditto.   J cwt.       600      Ditto.      2 10  0    Company
1835.         Disc'ntssameas Leeds.   average,                 of saleable  uer ton.                                                         prt vide lotnpa,:
3 sorts lised,           coke.                                                                       tb  n, repair,
1, 2-I0ths                                                                                           pu. out, &..
can'elat 16s.
8, 2-IOths
deep      7s.
silkstone, log.
Leicester,    7. 6d. per meter cub.ft.    13s. 6d.        7,500 4 quarters  IOu. 8d.   Coke,   About             4 4      Ditto.      2 1S  Compan) lig-ht,
1837.         Disc'nts on half-yearly   average,                            or 2s. Sd. tar, &c. 1-3d of                                         put out, std
rental, not exceeding  Derbyshire                            per qr.                cehe.                                          clean.
10/., 5 per cent.         soft coal.
101., ae 201.  71
201..50  301.0 0
p301.       401. 18 
0400.       50/. 15
50/.      600. 20  S
60/.dotspwards25
Derby, 1834. tOo. per metercub. feet.  Same coal   7,000   Ditto.              Ditto.    Coke.  Ditto.           219      Ditto.      2  2  OCommissioners
Discounts            used as at                                                                                 2  7  0 light, put out,
5 to 35 per cent.      Leicester.                                                                               I                &c.
Nottingham, 9s. per meter cubic feet.    Ditto.           7,000   Ditto.       Ditto.    Ditto    Ditto.         300     S9itto.      3  3  0 Commissioners
1834.        Discounts as above.                                                                                                               light, clean,
London, 1834. 16s. permetercub. feet. 17s. average.  8,500  36 bush.    12?. per   Ditto. 12 bush.  26,280               Ditto        4  0       ve"^pany li-ht,
No discounts.            Newcastle.                        chaldron.                                                         clean, put on.
bho 90a* repair
xittu, 1887.            Ditto                Ditto.       8,500   Ditto.      Ditto.    Ditto.  Ditto.   20,408          Ditto.      4  0           ft's
I______________




GAS-LIGHT.                                                                         865
b<ig a Synopsis of the proceedings of the undermentioned principal Gas-Light Establishmenta
Experiments between the Years 1834 and 1837. By Joseph Hedley, Esq.
^   Ga,   at   ^ ^"                                                                             t.ll'I IGreatest
s. dsth.ed.                         Cubicao.et. Iao.A. c"iidlfs Cu.at. Cu.Lf. Inch.
234 Timeghts, oritto.   131 each           ReceivesOnetf85millions    Ditto.   oi               to.   6,      7   *455    72    1,929  1-22       *8 - 
s                                              DuGts ion  ho.  Nmer bou                        
mond.1  minOeE s.
30    1 8 0  Receives n  48 millios   6 hours.  Dry lime. I4,  1anu  2 i t    534    7     1,29   *2              2
2938  sours, 9  Dpee   40 18            about so. 5             5,000.. peei  the year.4as the town,
tiig  n-tights                                                                                       holders
dfor snmostation.s sat ai
234 nsights, or Ditto.   1  31   18  0    Receives itet    5 millions    Ditto.          Ditto.   6,aDitd          455    72    1,929, 122 8a
80moths,   4 feet   3  5    12  0   Could sot say.           80,000.      8 hours.    Ditto.        3 go       -Not    70       204  Not        8    21
3 fn1hours.a  clpal h      l......, 10g
omittios~2 f5 per                                            Total for                              holders.   taket                 takes
rights irt hour.                             year                                      s theo
ho urons.                  et                   millions        me.
8 months, 4   Ditto.  2  6    12  6           Ditto.          65tla 3,000.  8Ditto.    Ditto.        4 gas        8539    64    2,4471'85     5  2 5,
pnights omit-ith                                         Total fory lime,   holders in.
uted.ormo omrs.                                           year about          ts,
~~~237 n ~isights-                           12 tmillions.wn, 1000
per                      hot 7w.                                         dry4. per   yeards off100  2 i the
hour.                    meter cbic feet,  millionsa towsr.
private.
3600 hosro.   5 feet   4  4    12  0  Could sat learn    360,000.    8 hours,  Wet ad               8' gas      862    75    1,777'Il'9  2
omittin^   per        in the abience of   Total for       large    dry lime,  holders in
ho'ur.                    the manager.         year 72      retorts,     prii-    all, 4 n ib
millions.    holong    cipatly    town1, 1000
6 tct,      dry.   yards off the
emoh.                   worhs.
8 mosths,       feet   3  1    12  6   Receive 8o. per    42,500.         8 hours.  Dry lime.    45 gas'420    78    1,6423    12 8     9'
armittisgi 7    per                     meter cubit trot,  Total for                                holders.
ihgts.  3800  hour.                      less Si per cout.      year
hours to 4                                                   8,61 9,08.
2330 hours.   4 feet t      2    3 10 Receive for public   176,000.    6 hours.    Ditto.            S gas'530    67    2,228.855    751    2j
and private 6Is. 8.  Total for                              holdera*
~otg.                   per meter cubic       year 31
eet.  Public S.   millionss.
private7s.. meters
used 5 to I for
2200 hours.   Ditto.  3  24   18  0 Receive forpublic   220,000.            Ditto.      Ditto.       4 gas'468    74    1,826  1I04    755    21
aind private Its. 6S.  Total far                            holders,
feet.  Public      millions.                             erecting-.
3s.2od., private
motors used.
From  Aogust  5 feet   3  4        7  2  Not uoifficiently   Total for       Ditto.      Ditto.        3 gas'528    74    1,826   1-1'73    S1
14th to       per                      Iog, at 7. 6d.    year 15                              holders, and
September    hour.                                           millions.                            1 erectiirg.
pst, omitting8
I sights for
2173 hours,  Ditto.  4  0   -            Lose about 171       Ditto.        Ditto.  Wet lime.    4 gas          -448   83    1,453   12    3825    3
from  Argisyt nearly                          per cent,                                              holders.




00
^_______________________________________________________________ _______________ ^___________________________________ 03
A TABLE showing the rate per Thousand Cubic feet received for any Burner consuming from I a Cubic foot to 10 Cubic feet per hour, at any given
price per annum, PMd to the times below  stated.  By Joseph Hedley, Esq.
Fancy and extra-vaSingle Jets.            2 Jets.                3 Jets.           Small Argand.         Large Argand.               Burners.
Time of Burning per annum.                  of             ~                      ~                                 -                              ~                       ~
hours* Cu. ft. Cu. ft. Cu. ft. Cu. ft. Cu. ft Cu. ft. Cu. ft. Cu. ft. Cu. ft. Cu. ft Cu. ft. Cu. ft. Cu. ft Cu. ft. Cu. ft. Cu. ft. Cu. ft. Cu. ft.
*  *  1  p~~~~~~   ii  Pt      2 ~~~~~ 21     3      3.      4     41      5       6      7       8      9      10
From Dusk to 8 o'clock      -.    -         -    781  2-56   1-706  1-28   1-026   -853   -731   -64   -5139  -4268  -3658  -3201 -2846  -2561  -2134  -1829'16    -1423'128
dittoand Sundays    -    -    -    902  2-216  1-478  1-108   -887'739   -633   -554.4434  -3695  -3168  -2771  -2464  -2217  -184!"  -1584  -1383  -1232  -1108
ditto and from 6 o'clock mornings    1050  1-904  1-27    -952   -762   -635   -544   -476  -381   -3174  -272   -2381  -2116  -1905'1587  -136   -119    1058  -0952
dittoand Sundays and from ditto    1172  1-706  1-138   -853   -682   -569   -487   -426  -3412'2844  -2438  -2133  -1896  -1706  -1422  -1219   1067  -0948  -0853
9 o'clock    -...       1054  1-896  19-64   -948   -759   -632   -542    474'3791  -3162  -271   -2371  -2108  -1897  -1581  -1355  -1185   1054  -0948
ditto and Sundays   -    -    -    1221  1-638  1-092   -819'675   -546   -463   -409  -3376  -273   -234   -2047  -182   -1638  -1365  -117   -1024.  091   -0819
ditto and from 6 o'clock mornings    1323  1-510  1-006    755   -604   -503   -431   -378  -3022  -2519  -2158   1889  1678  -1511  -1259  -1079  -0945  -0839  -0755
ditto and Sundays and from ditto    1490  1-342   894   -671   -536   -447   -383    335'2684  -2236  -1918'1675'1492  -1312  -1118  -0959   0839  -0746'0671
10 o'clock                              1367  1-462   -974'731'585   -487   -418   -366'2926  -2438  -209   -1829  -1626  -1463  1219   1045  -0914  -0813  -0731
ditto and Sundays    -    -    -   1586  1-26    -84    -63'504   -42    -36    -315  -2522  -2101  -1802  -1576'14    -1261 -1051  -0901  -0789  -07    -0630
ditto and from 6 o'clock mornings    1636  1-222   814   -611   -489   -407   -349   -305  -2444  -2037  -1746  -1528  -1358  -1222  -1019  -0873  -0764'0679  -0611
ditto and Sundays and from ditto    1855  1-078   718'539   -431   -359   -308   -269  -2156  -1796'154'1347'1198  -1078  -0898  -077   -0674  -0599'0539
11 o'clock    -    -  -.   -        1680  1-19    -794   -595'476   -397   -34'297'238'1984  -17'1488  -133   -119   -0992  -085   -0744  -0665'0595              ^
ditto and Sundays    -.      1951  1-024'682'512   -409   -341   -293'256'2048'1707  -1466  -1281  -1138  -1024  -0854  -0733  -064'0569'0512               ^
ditto and from 6 o'clock mornings    1949  1-026   684'513   -41    -342   -294   -256'2052'171   -1466  -1282  -114   -1026  -0855  -0731  -0641  -057'0513
ditto and Sundays and from ditto    2220'9'6         -45    -36    -3    -257   -225'1802'1501  -1286  -1126  -1          -0981  -0751  -0643  -0563  -05    -045
12 o'clock    -    -.    -    -    1993  1   -'668   -502   -4'334   -287   -251  -2006  -1672  -1434  -1254  -1114  -1003  -0836  -0717'0627  -0557  -0502
iitto and Sundays    -    -    -    2316  -'62'574   -432'345   -287   -247   -215  -1726  -1439  -1236  -1079  -0958  -0863  -0719  -0618'0539  -0479  -0432
ditto and from 6 o'clock mornings    2262   -884   -59'442'353  -295   -255   -221  -1768  -1476'1274  -1105'0982  -0884  -0737  -0637' -0552  -0491  -0442
ditto and Sundays and from ditto    2585   -772'514   -387'309   -257   -221   -193  -1546  -1289  -1104  -0967  -0858'(773  -0645'0552  -0483  -0429  -0387
1 o'clock.2306   -866   -578   -434'347   -289   -247   -217  -1734  -1445  -1238  -1080  -0962  -0867  0723  -0619'0542'0481  -0434
ditto and Sundays    -.      2681   -746   -498   -373'298   -249   -213   -186  -1492  -1243  -1066  -0932  -0828  -0746  -0621  -0533'0466  -0414  -0373
ditto and from 6 o'clock mornings    2575   -776   -518'388   -31    -259   -222   -194  -1552'1294  -111   -0971  -0862  -0776  -0647  -0555  -0185'0431  -0388
ditto and Sundays and from ditto    2950   -678  -452   -339'271   -226   -193   -169  -1356  -113   -0968'0847  -0754  -0678  -0565  -0484  -0424  -0377  -0339
All night   -     -    -     -.        4327   -462  -308   -231   -185   -154   -132   -115  -6924  -077   -066   -0578  -0515  -0462  -0385  -033   -0289  -0257  -0231
To use the Table.-~Select the hour to which it is agreed the gas is to burn,-9, 10, Il o'clock, Sundays, &c., as the case may be, and the description of the burner.-Multiply the
decimal number opposite to it by the amount in shillings agreed to be paid per annum, and the product will be the sum received per m. cubic feet for the gas.
Ex ~mple.-Suppose a small argand, which should burn 3l feet per bour, is agreed for till 9 o'clock at 2;. per annum. Look along the line of 9 o'clock till you arrive at the column
of 3j feet per hour, and you find the number, 271.  Multiply this number by 40s. and the result gives 10s. lQd. per m. cubic feet.  But suppose instead of keeping to 9 o'clock
the party burns till 1 o'clock, Sundays and mornings, and by enlarging the holes or height of flame consumes 8 cubic feet of gas per hour; then you have the number, -0424.
which multiplied by 40s., still the price paid, gives Is. 8d. per m. cubic feet only, and so on for any greater or lesser variation of the agreement.
* The " number of hours" includes I of an hour allowed for shutting shops, and I hour's extra burning on Saturday nights




GAS-LIGHT.                                                867
TRIALS of, and Experiments on, various Kinds of Coal as regards the Production  of
Gas from  each, and its Quality or Illuminating Power; by Joseph Hedley, Esq., Consulting Gas Enginteer, London.
NOTE-.In all the experiments the gas was passed through a governor, on a pressure of 5 IOths of an
inch.
1.  2.  3.  4.  5.  6.             7..        9 10. 11.  12  13. 14. 15.        17.
6       -2       5      6-o          7-5.'.47  1,
4 6 6-  1O  21O 16                6-5i 023               0!
Ic ^  I   i^ Candles Cubic Feet. Cubic  F et
N6   60  15- 111  1-81        5'            7.      *52  100 3 S 20 
lamel a  2    i  9   12n1  71 3'           2'            3''737 low02 cadls
A6   5-' 7'5                444  1023   292 
BickerssafLi-  - a
Ierpoot d.21t  19   14   Coode1s204  4C 6    6e 5      476 1023   30b4c8e61 
Wneln Can2eto22  12  8S  131  7.2  2'             23           3'.606 100e j392         211 24
Nwcastlecoal  2718  6 6 1    56 1  111 1187   4'   6           75.521104 3   32        1815815
NOTE~Thecnle her    e used was a compos ditio 19n6h plaited wick, req11   20 
giving at least one third more light than mould tallow candles.
Attention to the preceding tabular statement of experiments is important, as exhibitequal  quantities  of gas, notwithstanding  the variable characters and  qualities of the
20 cwt., th    smallest 1 1' 200  cubic  feet.   All these experiments were performed with the
five feet to be equal to the same.




868                                      GAS-LIGHT.
inferior gas, to be equal to the 3 feet of good gas, should have given light equal to
sixty-two and a half candles, whereas they only gave light equal to twentyfive candles,
so great is the difference in the QUALITIES of gas for producing light.
Whilst on the subject of the illuminating  power and  the value of one gas over
another, it will not fail to be observed, by the table, that another great difference
also exists, caused by the use of particular burners; as, for example, the best gas in
column No. 6., where the single jet was used, required seven-tenths of a cubic foot to
be equal to three candles, whilst the same gas in column No. 7., where a 20-hole
argand burner was used, required only two feet to be equal to twelve candles; and in
column  No. 8., where  a  30-hole  argand  burner was used, only  three feet were
required to be equal to twenty-five candles; demonstrating the fact that a great and
extraordinary improvement in the quantity of illuminating  power is effected by the
simple increase or enlargement of the  burner, affording, where great light in one
position is required, a most extraordinary economy in the use of gas, shown in fact
practically by the recent introduction of the celebrated "Bude" light, patented by
Mr. Goldsworthy Gurney.
TABULAR  STATEMENT, deduced from  the foregoing Experiments, showing the Cost of
Candles to produce as much light as 9,000 Cubic Feet of Gas would afford, being
the Product of One Ton of Coal.  (The  candles are  moulds, 6 to the pound, 9
inches long, and each candle is calculated to burn 91 hours. Cost of Candles lid.
per pound, or 7s. 6d. per dozen pounds.)
Where a Bude
Where a single  Where a 20-hole  Where a 30-hole  Burner is used,
Candles would cost, to be equivalent to  Jet Burner is    Argand Burner   Argand Burner    according to
used.         is used.      is used.     Statement of. ________  _ ___ ~ _    Company.
~  s. d.      ~  s. d.  d.             ~  s. d.
Common coalgas  - -                    10 18 6        1515 8         21 18 0        59 2 
Good       do.-            - -         25 18 4       39 9 6         5416 T         1486 709
TABLE, also  deduced from  the foregoing, showing  the Cost of Gas at the several
Prices  undermentioned, and  equivalent to  100 lbs. of Mould  Candles, costing
31. 2s. 6d.
If burnt                      If burnt in                If burnt in
in a                         a 20-hole                  a 30-hole
Desrip    Single Jet    Gas would cost at  Argand   Gas would cost at   Argand    Gas would cost at
ef Gas.1  Gam equal     per thousand     Burner,    per thousand    Burner,     per thousabd
Ms'  to 100 lbs.        Cubic Feet.     Gau eqoal    Cubic Feet.    Gas equal    Cubic Feet.
of Mould                      to 100 lbs.                to 100 lbs.
Candles,                      of Candles,                of Caudles.
Cubic seet.  56.    Is.   9s.   Cubic feet.  5s.  1s.  9,. Cubic Feet.  5s.   Is.   9*.
~. d.  s. d.  8.              s. d. s. d. s. d.          s.d. s. d. s. d.
Common    2,687    13 5  18 9  242    1,781   81012 5 160   1,282    65  811  116
Good  -    1,072      5 4   7 5   9 7        712   8641164              513    27  37   47
I have received from  Mr. Hedley, an engineer of great eminence and  experience,
plans and drawings of gas works and of apparatus of the most approved and modern
construction, and on the very largest scale as to extent of business or manufacture: also
plans and drawings of a gas work on a smaller scale, with its corresponding apparatus.
In the first, or large work, purification by wet lime, before described, is used; in the
latter, by dry lime.
The large work referred to is calculated for and is arranged to contain 400 retorts, 12
wet-lime purifiers, and 2 washers; 12 large double or telescopic gas-holders, capable of
storing 1,000,000 cubic feet of gas; and coal stores capable of holding 10,000 tons of
coal.
The smaller work is calculated for and will contain 40 retorts, 2 dry-lime purifiers,
and a wash vessel; 2 gas-holders capable of storing 50,000 cubic feet of gas; and coal
stores sufficient for 1000 tons of coal.
Fig. 687. is the side elevation (front view) of a gas work capable of containing 400
retorts, and all their dependencies.
Fig. 688. is the plan of the retort house, coal stores, tanks, gas-holders, &c., on the
largest scale and most approved form, viz., A the retort house, 300 feet long, 56 feet
wide; B, retort beds; c, chimney  stack; D, flues; E, hydraulic mains; F, coal
stores, each 300 feet long, 30 feet wide; G, condensers; H, engine houses; J, wash
vessels; K, purifiers and connections; L, lime  store and mixing  tub; M, smiths'
and fitters' shop; N, refuse lime pits; o, meter houses; p, tar tank; Q, tanks, gasholders, bridges, columns, valves, and  connections; R, governors; s, coke stores;
T, inlet pipes; v, outlet pipes; w, house and offices; x, stores.




GAS-LIGHT.                                    869
Fig. 689. Transverse section and elevation of a bed of 5 D retorts; A, transverse
section; B, elevation.
y       ~           ~^1 68I
jl:




~~~870    ~GAS-LIGHT.
Fig. 690. Longitudinal section of a bed of 5 D retorts.
fig. 691. Elevation of an upright air condenser consisting of 5 chambers, with a
series of 10-inch pipes.
ig. 692. Elevation of a double or telescopic gas-holder, of a modern and approved
form, with part of tank.
688
A: 




GAS-LIGHT.                                     871
Fig. 693. End elevation and plan of air condenser; A, end elevation; B, plan.
Fig. 694. Set of 3 wet-lime purifiers and wash-vessels in elevation and section, with
feed-heads, agitators, valves, and connections, raised for the lime liquor to run from one
purifier to the next below it, and ultimately into the refuse lime-pits, ViZ. A, section of
wash-vessel;, B, section of purifier; c, elevation of purifier.
Fig.~6fFront elevation of gas works on a smaller scale, where dry lime is used.
4           ~ ernor; Q, smith's shop; a, office; s, coke store.
~~~I\^                      ^a         a      ___
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~i " ^1^ 




872                                  GAS-LIGHT.
Fig. 697. Elevations and sections of dry-lime purifiers; A, longitudinal elevation; s
ditto section; c, transverse elevation; D, ditto section.
I am well convinced that a distribution and arrangement of gas-works, combining
effectiveness, economy, convenience, and elegance, at all equal to the preceding, have
never before met the public eye, in this or any other country.
In the brief description of the meter given in this Dictionary, I omitted to state,
that this most ingenious scientific contrivance for measuriug aeriform. or gaseous fluids
as they flow through pipes is the invention of Samuel Clegg, Esq., Civil Engineer, of




GAS-LIGHT.                                     873
L~ondon, Manchester, Liverpool, Birmingham, Chester, Bristol, &c. &c., in all which
places he has erected gas-works.  To this gentleman's genius and skill the public
are mainly indebted for many valuable improvements in the application of gas from
coal to purposes of illumination.
693                                              69
i'( ~ ~       ~ ~ ~                   ~~ 




874                              GAS-LIGHT.
Brought up in the great engineering establishment of Messrs Boulton and Watt,
at Soho, near Birmingham, he became connected with Mr. Wm. Murdoch, who most
undoubtedly was the author and originator of gas-lighting, as the evidence given before
a Committee of the House of Commons in the year 1809 abundantly verified.  He




GAS-LIGHT.                                     875
demonstrated that the light produced from gas was superior in economy to all other
modes of artificial illumination; and by that evidence, though so long back as 1809,
it will be seen that all the information of the present day was even then known to him,
clearly pointed out, and illustrated by his experiments, which strangely contrasted




876                                 GAS-LIGHT.
Fig. 62. Elevations and sections of dry-lime purifiers; A, longitudinal elevation
B. ditto section; C, transverse elevation; D, ditto section.
al  B   B     B n    e   n o        o  |
A
697       i. 
B.B
D
with the statements put forward by the parties then attempting to introduce this mode
of lighting into the metropolis. All the ephemeral plans of those parties, have, however, long since disappeared, or nearly all. One, unfortunately, remains, and that a
most unlucky one-the unprofitable manufacture of coke in gas-making-an article
worthless in the scale of value, which should never have been sought for.  Messrs.
Watt and Murdoch predicted that when the parties became incorporated by Parliament, they would resort to their apparatus, notwithstanding their repudiation of it
at the time, alleging their own schemes to be so much superior; and they verified this
prediction a very few years afterwards by engaging the services of Mr. Clegg, to extricate them from their manifold and egregious errors. He began by introducing the very
apparatus of Messrs. Murdoch and Watt, so inconsiderately condemned by them.
Mr. Clegg put up the first gas-holder ever erected in London.
To Mr. Clegg is due also the introduction of lime for the purification of the gas,
without which  gas-lighting would  to this day have  afforded  little comfort and
economy.  The hydraulic main, for separating the gas making from  the gas made,
valves, lutes, and many other admirable contrivances, are peculiarly due to Mr. Clegg.
But the crowning performance of all his inventions, was that for measuring out the gas
to the several parties requiring it exactly according to their demands. The manufacture of gas having by this time been so far mechanically perfected as to be brought
to our doors, it became at once apparent that some contrivance should be found by the
use of which every person might consume as much or as little gas as he pleased, paying
only for what he really used, thus making science subservient to fair dealing.
Mr. Clegg took out a patent for the gas meter about the year 1814; but great as
its merits were, he soon found that serious difficulties remained to be overcome, in inducing parties to support and encourage its use, even where their interests should have
prompted them to adopt it. Mr. Clegg had, however, fortunately associated with him,
towards the completion of the apparatus, Mr. Samuel Crosley; and by their joint
labours it acquired its present precision.
The value of the meter is primarily to the gas companies, next to the public. By
its use, the gas companies are enabled to supply gas to all places where light is required, at a rate proportioned to its just value. The public thereby see the economy
afforded by gas over candles, oil, or other material; but they gain also in another most
important way-by the use' of the meter, gas companies, being duly paid, are enabled
to reduce the price of gas, and yet realise equal profits, thus bringing it within the reach




GAS-LIGHT.                                        877
of a much larger class of the community; and it is a well established fact that in towns
where gas is sold by meter, gas companies can and do sell at nearly one half the price
they otherwise could do.
Reduction of price increases demand; increased demand increases profits; increased
profits again enable prices to be reduced; and again, reduced prices increase the demand
thus benefiting reciprocally companies and consumers.
Notwithstanding, however, all these advantages, there are not wanting persons whe
have set up an outcry against the use of the meter, by impugning its accuracy, and accusing the gas companies with fraud in charging by it. It would be idle to follow these
parties in their baseless allegations. An action for pirating it was brought and tried in
the Court of King's Bench, in which not only the novelty of the machine was fully established, but its accuracy and usefulness proved by the ablest mathematicians, mechanicians,
and chemists of the day; and a verdict in its favour obtained. Subsequently very large
damages have been given for the infringement-in one case as much as 50001, and in another, in the Court of Chancery, a decree was made referring it to the Master, to take an
account of the profits made by the use of the meter; this is not yet finally settled, the
Master's report finding 60001. to be due; but this is excepted to by the parties infringing: the Chancellor, however, allowed the exceptions to be argued, only on payment by
the infringers of 40001. into court to meet the patentee's law costs. These exceptions
have no reference whatever to the question of the accuracy of the meter, but are simply
as to whether the advantages of the meter were as great as allowed by the Master.
The patent for the meter expired about the year 1828; since that period numerous
competitors have commenced making the machine.
Mr. Clegg has recently obtained a patent for a dry gas-meter, of which the following
are its advantages and construction, as described by the very meritorious inventor
1. Working without water.
2. W orking without membranes or valves.
3. Working without requiring the least pressure.
4. Working without interference with the perfect steadiness of the lights.
5. Registering more accurately than any other meter.
6. Occupying only one-tenth of the space of the common meters.'T. Being subject to little or no wear and tear.
8. And being cheaper.
Prices-.For plain meters.~   &  d.
Three-light meter              1  12  0
Six-light     do.              2   4  0
Twelve-light do.               3   3  0
The highest numbers will be still cheaper in proportion.
Ornamental meters, appearing like handsome time pieces, for halls, living-rooms, com
mittee-rooms, offices, counting-houses, &c., are charged extra, at ten shillings each and up
wards, according to pattern.
Description of Cleggs patent dry Gas-meter.
The two figs. 698,9. are half the full size of the apparatus, and the letters of reference
are the same in both.
B, B, fig. 698., represents a cylindrical vessel, about three inches and three quarters
diameter, and four inches deep, being the dimensions of a meter capable of measuring
gas for three burners, called a three-light meter. In this vessel are two glass cylinders F,
F, connected together by the bent tube d. The cylinders being perfectly exhausted of air,
and half filled with alcohol, are made to vibrate on centres e and e, and are balanced by
the weight!.
This instrument accurately indicates the excess of heat to which either cylinder may
be exposed, upon the principle of Leslie's differential thermometer.
C is a hollow brass box, called the heater, about four inches long, and half an inch
broad, projecting out of the meter about one inch. At a issues a small jet of gas, which,
when inflamed, gives motion to the cylinders.
The gas enters the meter by the pipe A, and circulates throughout the double case B:
having passed round the case B, a portion of it enters the top of the box C, by the pipe
D, and passes out again at the bottom by the tube c, into the meter; the rest of the gas
enters the body of the meter through holes in the curved faces of the hoods EE, and,
after blowing on the glass cylinders, passes to the burners by the outlet pipe.
To put the meter in action, let the jet a be lighted abdut an hour before the burners
are wanted. In most cases this jet will be lighted all day iw a useful flame. The




878                              GAS-LIGHT.
hole a i' so situated on the box C, that whatever be the size of the jet, a fixed tem.
perature is given to the box, that temperature depending on the quantity of flame in
a ^        /^^\ X98        X  x^^^ — - -
contact with the box, and not at all on the length of the jet. The jet being lighted,
and the box C thereby heated, the gas which passes through it is raised to the same
temperature, and, flowing out at the tube c, impinges oa the glass cylinder which
happens for the time to be lowest; the heated gas soon raises a vapor in the
lower cylinder, the expansion of which drives the liquid into the upper one, until it
becomes heavier than the counterpoisef, when the cylinders swing on their centre, the
higher one descends, and comes in the line of the current of hot gas, and the lower one
ascends; the same motion continues as long as the jet a burns. The same effect on
the cylinder is maintained, however the outward temperature may change, by the
cold gas, which, issuing from the curved side of the hood EE, impinges on the uppei
cylinder, asrd hastens the condensation of the vapor which it contains.
The coL gas and the heater vary in temperature with the room, and thus counteract
each other.
The lighting of the jet a is essential to the action of the meters; in order to insure
this, the supply of gas to the burners is made to depend on it in the following manner.
The pipe G, by which the gas leaves the meter, is covered by a slide valve, which is
opened and shut by the action of the pyrometer g; the pyrometer is in communication
with and receives heat from the jet, and opens the valve when hot, closing it again
when cold.
The speed at which the cylinders vibrate is an index of the quantity of heat communicated to them, and is in exact proportion to the quan~tity of gas blowing on them
through the pipe c and curved side of the hoods EE.
The gas passed through the heater is a fixed proportion of the whole gas passing the
meter; therefore the number of vibrations of the cylinders is in proportion to the gas
consumed.
A train of wheel-work, with dials similar to that used in the common meter, registers the vibrations.
Simplicity, accuracy, and compactness, are the most remarkable features of this
instrument, and the absence of all corrosive agents will insure its durability.




GAS-LIGHT.                                   879
Directions for fixing and using Clegg's patent dry Gas-meter.
Choose a situation for fixing the meter, where the small jet of flame will be of the
such as an office-desk or counter, taking care to screw the same firm and
level on its base. When the jet at the top of the meter is required to be kept con.
stantly burning as a useful flame, press in the brass knob at the front of the meter, and
before lighting the burners pull it out; when the small flame is not required, let it be
lighted about an hour before you want the burners lighted. Adjust the size of the
small flame at pleasure by the screw b.
On the back of each meter is marked the number of lights it will supply.
The inlet and outlet pipes are marked at the bottom of the meter.
The quantity of gas consumed is recorded by the index in the usual way.
For testing Clegg's patent dry Gas-meters.
Pass the gas through two meters at least, and take the mean. Vary the number of
lights at pleasure, not exceeding the number marked on the meter, and when one or
two hundred cubic feet of gas have been consumed, compare the indices.
These meters are not for measuring small fractional parts; but taking the average
for any periodical consumption, are more accurate than any other meter.
Mr. Thomas Edge, of Great Peter Street, Westminster, has contrived the following
meter, of which drawings are annexed.
Fig. 700 is a front view of a three-light meter, the front plate being removed, and
some of the parts shown in section 65.
700             CUBIC    FEET          K
Fig. 701 is a transverse section of the same.
The gas enters at A into the small chamber B, in the bottom  of which is a lever
valve (part of Mr. Edge's patent improvements), moving upon its axis and attached
by the rod to a metal float c, which in the present drawing is buoyant. The object
of this arrangement is to intercept the passage of the gas into the meter, unless a
sufficient quantity of water is in it, that being necessary to its proper action; the gas
then passes through the inverted syphon or tunnel into the convex cover, whence it
passes into the chambers of the drum.
Another of Mr. Edge's improvements consists in the cutting down of this syphon pipe
or tunnel to the proper water level, and connecting the bottom of it to a waste waterbox., into which any surplus water must fall. The importance of this precaution will be
seen on investigating the drum, as an excessive height of the water will materially
interfere with the measurement, the quantity of gas delivered per revolution being
considerably less. This, in connexion with the lever valve and float, confines the




880                                 GAS-LIGHT.
variation of the water levels within such narrow limits, that the measurement may be
considered perfectly just on all occasions.
The last patent by Mr. Edge is for an improved
index, which is composed of a series of moving
dials, with 10 figures upon each, one figure only ap.
pearing of each series at a time.
This contrivance is very ingenious, and will no
doubt be applied to other machines, where indexes
(indices) of quantity are required.
Recurring to Mr. Clegg he is also the inventor
of an instrument of great value-appropriately
called a "governor."   Its purpose is to render
equal the heiht of flame of the several burners in
any house or establishment, and to keep them  so,
)~i-l^    =notwithstanding any, and whatever alteration may
be made in the pressure at the works or elsewhere.
This instrument is perfected, and successfully ap~ r=- _ -| -_l                   plied, though it is not so generally in use as it
ought to be. By the use of this instrument a light
\   ~ — -Ul WASTE                once set athat
WATER             height unify
xWATE             height uniformly, and without the least variation
_~ -~_-.    BX   ja    the whole evening; and continue to do so till
altered.
-~~:'~_^.   j  8=          Without this instrument, it is necessary to pay'~^^-r —  I    ~       attention to  the burning of gas-lights, as their
heights are frequently affected by the most trifling
circumstance, such, for example, as their extinction
at the hour of closing the shops, which makes a sensible difference in the neighborhood.
All these works have prodigiously increased in the quantity of gas made and supplied. Since the account in the former edition of this work, large additional manufactories have been erected by new companies, and great additions made by the old ones.
There are now  in the metropolis alone 15 public gas companies, having among them
23 gas establishments. The quantity of gas manufactured by these 23 gas-works, and
supplied to the public was during the past year three thousand one hundred millions
of cubic feet of gas; and the coal used to produce this quantity of gas was at the least
400,000 tons!
Baked clay retorts are very generally used in Scotland, and found to be most economical as regards wear and tear; in London, however, they are mostly of cast iron.
The pressure upon the retorts is caused principally by the use of wet lime, used in
London, because the process is less expensive and less cumbersome than dry lime.
Wet lime can not be used with clay retorts, owing to this excess of pressure.
Merit is due, for enlarging the capacities of double  gas-holders, to the late
Mr. Joshua Horton, of West Bromwich, near Birmingham; and to Mr. Stephen
Hutchinson, engineer of the New London Gas-Works, Vauxhall, where they were first
successfully introduced, and manufactured by Ar. Horton. They have now come very
generally into u&s throughout the kingdom, and are manufactured by all gas-holder
makers.
Separate gas-holders are advisable and advantageous, but they are not generally
used, except in Glasgow, Manchester, Birmingham, Sheffield, and a few other places.
The annexed drawing represents Mr. Croll's vessels for the purification of gas from
ammonia, which is effected by means of dilute sulphuric acid applied between the condensers with the ordinary lime purifiers. The vessels are made of either wood or iron,
and lined with lead; have a wash-plate similar to the wet lime purifiers. The radiating bottom formed of wooden bars, as shown in the drawing, is for the purpose of
supporting the wash-plate and distributing the gas.
Fig. 102: a, is the inlet pipe; b, the outlet pipe; c, c, the tube with funnel for
introducing the sulphuric acid; d, the first purifying vat; e, the second ditto, both
lined with lead, and which are filled up to the dotted line with the dilute acid; ff,
the water supply-pipe; g, g, the discharging cocks.
Fig. 703 represents a ground-plan of the vats, each 10 feet in diameter; A, the
bottom of the middle; B, the inlet of the gas; C, the outlet of ditto.
In commencing the process, these vessels are charged with water and sulphuric acid,
in the proportion of seven pounds, or thereabouts, of the latter, to 100 gallons of the
former.  As the acid is neutralized by the ammonia contained in the gas passing
through the vessels, the above proportion, as near as may be, is kept up by a continuous
dropping or running of acid, regulated according to the quantity of ammonaa contained




GAS-LIGHT.                                       881
in the gas, from a reservoir placed on the top of the saturator. This mode of supplying
the acid is continued until the specific gravity of the solution arrives at 1170, or close
rystallization, after which the supply of acid is disco:
n the vessel until neutral, when it is drawn off and
lphate of ammonia.
T  as been introduced at several of the provincial gasstations of the Chartered, the Imperial, Phoenix, &c., &c. Mr. Croll is also now in
treaty with several other companies for its introduction.
The produce-sulphate of ammonia-from the process, by the gas-companies using
it, now amounts to several tons per week-and it may be here mentioned, as one of the
advantages of science, that the ammonia so produced before the adoption of this process
passed along with the gas to the consumer, destroying rapidly the main pipes, fittings,
and metres, through which it was transmitted, as well as deteriorating the illuminating
power of the gas, and producing a choky effect when consumed in close apartments. It is
now employed as a manure, and found to be superior in its effects as a fertilizer, as well
as comparatively cheaper than any of the other artificial manures; so that whether
Mr. C.'s invention be looked upon as affecting improvements in the manufacture of
gas, hitherto unknown, or as producing a valuable manure, the results are alike of the
utmost importance.
(When Mr. Croll's process is employed before the lime purifiers, dry lime can be
used without creating the nuisance hitherto complained of, and a much less quantity is
required for this purification.)
Mr. Croll has recently patented another invention, connected also with the manufacture of gas, which consists in the combination of clay and iron retorts, so that the heat
of the furnace first acts on the clay retorts and then passes to those of iron.
The annexed drawing is a transverse section
A is the fireplace.
B B are piers of fire-bricks, placed at intervals to form nostrils or flues, and the fire
tile resting upon them in conjunction with the front and back wall, form the bed or
support of the clay retort 1, and the clay retort 2 is also supported by the front and
back brickwork, and a lump, or fire-brick, E, placed midway on the crown of the
retort 3.
F is a wall which separates the clay retorts I and 2, and the iron retorts 10 and 20; a
space being left between the top of the said wall F, and the under surface of the arch,
to allow the fire or heated air to pass freely from the clay to the iron retorts.
G G is the bed, and H H is the flue under the iron retort 10. The retort 20 is supported by the front wall and pieces or lumps.
J, placed at the back and crown of the retort 10, in connexion with the horizontal
flue. H is a vertical flue, forming a passage thence into the shaft or chimney.
The heat passes from the furnace or fireplace A, through the spaces or nostrils formed
by the piers B B, and around the clay retorts I and 2, over the wall F, descends between
and around the iron retorts and along the flue H, and escapes by the vertical flue into
the chimney. The advantages of this mode of setting retorts are the small quantity of




882                                    GAS-LIGHT.
brickwork necessary for the erections, the increased durability of the retorts, and the
economy in fuel. From adopting this mode of setting a brick lump, it has been found
that 12 tons of coke will carbonize 100 tons of coal.
I,      s,   n  d i   d            o r         p           l           t'"A
draught.
Before dismissing Mr. Croll's patent improvements, it is proper to state, that the sulphuric acid used for condensing the ammonia should be free from iron, otherwise the
s-dphuretted hydrogen of the coal gas is apt to give rise to sulphuret of that metal which
will blacken the sulphate of ammonia and reduce its value in the market. An occur.
rence of this kind was recently brought professionally before me for investigation. The
sulphuric acid had been made from pyrites.
Mr. Kirkham, engineer, obtained a patent, in June, 1837, for an improved TMole of
removing the carbonaceous incrustation from the internal surfaces of gas retorts. He
employs a jet or jets of heated atmospheric air or other gases containing oxygen, which
he impels with force into the interior of such retorts as have become incrusted in consequence of the decomposition of the coal. The retort is to be kept thoroughly red
hot during the application of the proposed jets. An iron pipe, constructed with several




GAS-LIGHT.                                       883
flexible joints, leading from a blowing machine, is bent in such a way as to allow its
nozzle end to be introduced within the retort, and directed to any point of its surface.
I should suppose that air, even at common temperatures, applied to a retort ignited to
the pitch of making gas, would burn away the incrustations; but hot air will, no doubt,
be more powerful.
Bude-light. -  This brilliant mode of illumination  has been so called  from  the
name of the residence in  Cornwall of Mr. Goldsworthy  Gurney, who  obtained a
patent for it in the year 1838. In its first form it consisted of a common Argand oil
flame or lamp of rather narrow circular bore, into the centre of whose wick a jet of
oxygen gas was admitted through a tube inserted in the middle of the burner. This
contrivance was not, however, new in this country, for a similar lamp, similarly suplied with oxygen gas, was employed  by the celebrated  Dr. Thomas Young in his
lectures at the Royal Institution of Great Britain for the purpose of illuminating a
solar microscope, or gas microscope, about 40 years ago, and I had done the same thing
in Glasgow in the year 1806 or 1807.  When used  as a light for lighthouses or for
other continuous illumination, it has been found to be too expensive and difficult to
manage. It was tried upon a good scale a few  years ago both by the Trinity House
in Tower Hill, and in one of their lighthouses on the coast, as well as by the House
of Commons. The Masters of the Trinity did not find it to be essentially superior for
the use of their lighthouses to their old and ordinary plan of illumination with a
number of Argand lamps placed in the focus, or near the focus, of reflecting mirrors.
It was, after several expensive trials by them, and in the House of Commons, abandoned by both.
In  the course of numerous experiments in  the Trinity  House, Tower Hill, Mr.
Gurney had occasion to examine the structure and see the performance of Mr. Fresnel's
compound Argand  lamps which are used in the French lighthouses, furnished with
refracting lenses of peculiar forms which surround these lamps, and transmit their concentrated light in any desired horizontal direction along the surface of the sea. Two of
Mr. Fresnel's lamps are placed  in the lamp apartment of the Trinity House. Each
consists of a serie of 4, 5, or 6 concentric wicks in the same plane, supplied with oil
from  the fountain below  by means of a pumping mechanism, as in the well-known
Parisian lamps of Carcel and Gagneau.  The effect of 4, 5, or 6 concentric flames thus
placed in close proximity to each other, with suitable supply of air through the interior
of the innermost tube anct the interstices between the exterior ones, is, to increase the
heat in a very remarkable degree, and by this augmentation of the heat to increase proportionably the light. For it has been long known that a piece of even incombustible
matter, such as a lump of brick, intensely heated, sends forth a most brilliant irradiation of light. This fact was applied first to the purpose of illuminating objects by Professor Hare, of Philadelphia, fully 40 years ago. By directing the very feebly luminous flame of the compound jet of hydrogen and oxygen upon a bit of clay, such as one
of Wedgwood's pyrometer pieces, a most vivid illumination was sent forth from  it as
soon as it became intensely heated. More lately, a piece of lime has been used instead
of a bit of clay, as it is not so apt to change by the ignition, and affords, therefore, a
more durable effect. It is used in our modern gas microscopes. Mr. Gurney suggested
the use of lime for the above purpose in a work on chemistry which he published
more than twenty years ago. It was afterwards adopted by Mr. Drummond, in order
to make signal lights in the trigonometrical survey of the Board of Ordinance, and was
therefore called the Drummond light, though he had no share whatever in the merit of
the invention.
The structure of the Fresnel lamp would naturally suggest to Mr. Gurney the idea
of trying the effect of a similar construction of an Argand gas lamp. But prior to the
execution of this scheme, he obtained a second patent in the year 1839, for increasing
the illuminating power of coal gas by feeding its flame in a common Argand burner
with a stream of oxygen. But here a serious difficulty occurred. The stream of oxygen,
when admitted into the centre of such a flame, instead of augmenting its quantity of
light, destroys it almost entirely. This result might have been predicted by a person
well versant in the principles of gas illumination, as long ago expounded in Sir Humphry Davy's admirable Researches on Flame. This philosopher demonstrated that
the white light of gas-lamps, as also of oil lamps, was due to the vivid ignition of solid
particles of carbon evolved by the igneous decomposition of the hydro-carburet, either
in the state of gas or vapour; and that if, by any means, these particles were not deposited, but burned more or less completely in the moment or act of their evolution
from the hydro-carburet, then the illumination would be more or less impaired. Mr.
Gurney, on observing this result, sought to obviate the evil, by charging the coal gas
with the vapour of naphtha. Thus a larger supply of hydro-carburet, and of carbon of
course, being obtained, the flame of the naphthalized gas, admitted with advantage
the application of oxygen gas, for the increase of its light; on the principle of greater




884                                  GAS-LIGHT.
intensity of ignition, and consequently of light, being produced by the burning of carbon
in oxygen than in common air, as had been long known to the chemical world. But
an obstruction to the permanent employment of naphthalized gas was experienced by
Mr. Gurney, from  the deposition of liquid naphtha in the pipes of distribution. He
was therefore induced to renounce this project. He then resorted to the use of coal-gas,
purified in a peculiar way, and burned in compound Argand lamps, consisting of two
or more concentric metallic rings, perforated with rows of holes in their upper surfaces,
having intervals between the rings for the admission of a proper quantity of air, the
burner being enclosed in a glass chimney at the level of the flame, surmounted by a
tall iron chimney. Between these two chimneys, a certain space is left for the admission of air, and to favour draught and ventilation. The intensity and whiteness of the
cylinder of light produced by the combustion of coal-gas in this lamp are truly admirable, and form  such an improvement in illumination for streets, churches, public
rooms and private houses, as to merit the protection of a patent, and the encouragement of the public at large.
General Estimate of Sizes, Number of Concentrics, Consumption ofGas, and
Comparative Light.
Size.     Number of   Bude Consump-  Height of    Comparative Light  Cons t
Concentrics.   tion per hour.   Flame.                            per hour.
Inches.                   Feet. Inches.   Inches.        15-hole Argands.    Cubic Feet.
22         10      6         3                  5               30
3             2           16      4         3                 8                48
312        21      6         3                10                60
4             2           26      4         3                12                72
412        33      7         3                15                90
5             3           40      0         3                18               108
61  3      43      5         31                20              120
6             3           56      4         4                24               144
Laming and Evans's Invention.-The first part of this invention consists of an improvement in retorts for making gas, and for other uses; and in making pots, crucibles,
muffles, stoves, fire-bricks and lumps, and other articles of clay, required to stand the
action of fire without cracking. The improvement consists in mixing with the fire-clay,
which is to enter into the composition of any of the aforesaid articles, about 0-25 per
cent. of its weight of asbestos or fibrous silicate of magnesia; the vessels are then to
be constructed and burned in the usual manner. The patentees state that they do
not confine themselves to any particular forms of the articles, each of which may be
made of one or more pieces, as at present; and the proportion of silicate of magnesia may be varied to meet the exigencies of particular cases, its introduction being
for the purpose of giving greater tenacity to the materials used, and thus diminishing
their tendency to become cracked under the influence of change of temperature.
They claim  under this head of the invention, the introduction of asbestos or fibrous
silicate of magnesia among the materials used for making articles of clay, intended to
be submitted to a great heat; and the use of all such articles, made with asbestos or
fibrous silicate of magnesia in their composition.
Another part of this invention consists in an arrangement of apparatus for making
gas from oil, tar, melted pitch, resin, fat, or other analogous material, in conjunction
or not with water. The apparatus consists of an iron or clay retort, composed of two
horizontal chambers, one above the other, and communicating at the back only. The
ends of the chambers are closed by three man-hole doors; two of which are secured
over the front end of the chambers; and the third, which is a large door, serves to
close the hind ends of both chambers;-the three doors all projecting beyond the brickwork setting of the retort. Upon the upper chamber, near the front end thereof, is an
inverted funnel of large diameter, closed by a cover, the edge of which is turned down,
and dips into a hydraulic joint, or into a joint filled with metal, fusible at the temperature to which it is exposed, or else it is secured in the same manner as the ordinary
man-hole doors. The cover is fitted with a double syphon, furnished with a stop-cock.
The eduction-pipe, leading to the hydraulic main, is connected with the front end of
the lower chamber of the retort. To use this apparatus, previously raised to the usual
temperature, the patentees charge the upper chamber with coke, heaping it somewhat just beneath the funnel, and allowing  some pieces to fall over against the
large man-hole door at the back, and they charge the lower chamber either with coal
or coke. A stream  of oil, tar, melted pitch, resin, fat, or other analogous matter, in




GAS-LIGHT.                                      885
conjunction or not with water, is then allowed to fall from the double syphon through
the large funnel, on to the red-hot coke beneath; it passes thence, partly as gas and
partly as liquid, through the upper chamber to the back of the lower one, along which
it next proceeds, chiefly in the state of gas, and escapes, mixed with the gaseous products
of the lower chamber, through the eduction pipe into the hydraulic main.  When the
lower chamber of this apparatus is charged with coal, the liquid should not be permitted
to flow from the double syphon, till the coal has had time to give off the greater part of its
richer gas, and to become heated throughout; but when coke is used in both chambers,
the liquid is admitted from  the commencement, and without intermission, until the
passages of the gas apparatus need to be opened and cleaned out.
The patentees do not claim  the making of gas from  tar, or any other form  of
hydrocarbon, or water, by means of red-hot coke, or the combining of any materials
affording gas. What they claim is, the combination and arrangement of the apparatus,
particularly of the large funnel, with the double chambers, and back and front man-hole
doors, for making gas by the decomposition of any suitable hydro-carbon, or water, by
bringing it, in a fluid state, into contact with red-hot coke or other suitable material.
Another part of the invention consists in elongating the eduction pipes of retorts,
used for making gas for illumination, into their interior, and arranging them in lines
near their axes. The further ends of these pipes are left open, and they are supported
by bearers. Holes should be made along the pipes, but only in sufficient number to
permit of the free escape of the gas as it is generated; or a longitudinal slit may be
made in tlhe under side of the horizontal pipe, from its further end to near its ascending
portion; and this arrangement is preferred, because it admits of the passage being
cleared out by a proper tool, in the event of its becoming choked. The improvement
is applicable to retorts of any material, and of the ordinary forms; but it will be found
more easy to charge the retorts, to which this improvement is applied, when they are
made large enough to receive a charging-scoop on either side of the horizontal eduction
pipes. The object of the improvement is to diminish the contact of a gas with a surface
heated high enough to cause it to deposit some portion of its carbon; and thus to
produce a richer gas, or a larger quantity of equally rich gas, from  a given quantity
of coal.
The claim made under this head is for the elongation of the eduction-pipes of retorts,
used for making gas for illumination, along or near their axes.
Another part of the invention consists in a process for obtaining light by means of
platinum, heated to whiteness by coal gas or peat gas. It is known, that when water
is decomposed, and the resulting hydrogen burnt within a small cage, made of platinum
wire or platinum foil, in such a manner as to heat the metal to whiteness, the platinum
becomes luminous, and remains so as long as its temperature is maintained; but it is
equally well known that hydrogen gas, resulting from the decomposition of water, is
not readily obtainable under the generality of circumstances when light is required.
The improvement consists in replacing hydrogen gas from water by coal gas (which is
to be obtained almost universally, and which answers the purpose) or by peat gas. In
carrying out this improvement, it is preferred to burn the gas either by itself, or mixed
with atmospheric air, within a platinum wire cylinder, greater in height and diameter
and made of coarser material, as the quantity of gas burned within it in a given time
is greater,-the only practical rule that it is necessary to give being, that all the metal
be placed, with respect to the flame, in the best position for becoming white-hot. The
advantages which result from  this part of the invention are, first, with respect to
ordinary coal gas, that more light is obtained in proportion to the quantity of coal gas
consumed, than is the case when platinum  is not used; and, secondly, that, by its
means, a good light is obtained by the combustion of peat gas, or of coal gas of inferior
quality.
Under this head, the patentees state, that they neither claim nor restrict themselves
to the use of any particular form or dimensions of the platinum apparatus; but what
they claim is, the use of coal or peat gas, mixed or not with air, for heating platinum
wire or foil to whiteness, and thereby producing light.
A  previous patent has been obtained by one of the patentees (Mr. Laming), for
purifying coal gas by a solution of muriate of iron, mixed with porous materials; and also
by muriate of iron, decomposed by lime into chloride of calcium and oxide of iron, and
made porous by suitable materials. Now, one part of the present invention consists in
combining known processes, so as to obtain the last-named purifying materials. The
patentees decompose sulphate of iron, in solution, by its equivalent quantity of chloride
of sodium; and, having separated, by known means, the resulting sulphate of soda,
they add to the solution of muriate of iron concentrated by evaporation, first, enough
dry sawdust, or other suitable matter, to absorb it, and then enough hydrate of lime
to decompose it into chloride of calcium and precipitated oxide of iron. Coal gas is
purified with this mixture, disposed in dry purifiers; and, afterwards, sulphur, cyanogen,




886                                   GAS-LIGHT.
and muriate of ammonia, are extracted from the used materials by any ordinary processes adapted for that purpose.  Sometimes the purifying material is modified in the
following manner: an equivalent quantity of ground or granulated sulphate of iron, or
chloride of sodium, is mixed with the other of these salts in solution, absorbed into
sawdust or other suitable matter; and then an equivalent of hydrate of lime is stirred
in. This modified material, after being used in dry purifiers for purifying coal gas,
affords by lixiviation a mixed solution of sulphate of soda and muriate of ammonia;
sulphur and cyanogen also may be extracted from it, as in the former case. Sometimes
the sulphate of iron is replaced by sulphate of copper; and then the resulting oxi
course, is the oxide of that metal instead of the oxide of iron.
The patentees claim, under this head, the combination of processes above described
for making a purifying material, containing chloride of calcium, and precipitated oxide
of iron or copper; and likewise the composition of the modified material,'as described.
They also claim the use of both kinds of materials for purifying coal gas.
Another part of the invention consists in purifying coal gas by means of a cheap
material, made by mixing refuse sulphate of lime or gypsum, in a finely divided state,
with sulphate of iron. The sulphate of iron should be either ground fine or granulated,
and mixed with sawdust, or other matter, suitable for separating its particles; or it may
be merely mixed, in a divided state, with the earthy salt, or absorbed into its mass, or
into sawdust, or other porous matter.  The gypsum  should be previously baked at a
red heat, to prevent its tendency to solidify with water. The material, thus prepared,
is used in dry purifiers, in the way well understood for purifying by hydrate of lime.
For the sulphate of iron other metallic salts maybe substituted with similar results;
such, for example, as muriate of iron, sulphate or muriate of zinc, sulphate or muriate
of manganese, or even sulphate or muriate of copper; but sulphate of iron is preferred.
The resulting mass is either used as a manure, or else it is subjected to certain known
chemical processes for obtaining from it an ammoniacal salt, or salts, sulphur, and
cyanogen.
The claim under this head is for the purificatien of coal gas by the use of sulphate of
lime, mixed with any of the metallic salts above named; and the use of the spent
purifying material as a manure.
Another improvement consists in causing impure coal gas to pass through dry purifiers charged with a porous solid material, which is made by mixing, in about equivalent proportions, hydrated or precipitated oxide of iron, with carbonate of lime, magnesia, carbonate of magnesia, or magnesian limestone, in fine powder, or else burned or
slaked, either by thenmselves, or rendered more pervious to the gas by sawdust, or
other suitable matter. A mixture of precipitated oxide of iron and lime answers the
same purpose, and was claimed by Mr. Laming, under a former patent.  In each of the
above cases oxide of copper may be substituted for the oxide of iron. All the several
compounds, when they begin to act on the impure gas, purify it from  sulphuretted
hydrogen and cyanogen; and any one of them, having  been once made foul, and
afterwards placed in contact with atmospheric air for a few hours, acquires the property
of purifying coal gas from  ammonia also. The spent materials afford, by processes
well known, cyanogen, sulphur, and ammoniacal products.
The patentees claim, under this head, the purification of coal gas, by mixtures made
as described, whether with hydrated or precipitated oxide of copper or of iron.
Another part of the invention consists in a particular way of using chloride of mag.
nesium, or sulphate of magnesia, for withdrawing from coal gas ammonia and carbonic
acid. Sawdust or other solid matter calculated to expose an extensive surface to the
gas, without opposing great resistance to its passage, is caused to absorb a saturated
solution of one or both of the above named salts; or those salts may be mixed, singly
or together, in a divided and solid state, with sawdust or other suitable matter, in a
damp state; and then the mixture is placed in dry purifiers, through which the gas is
made to pass in its way from the condensers to the gas-holders. When the gas ceases
to be purified from its ammonia, the contents of the purifier are taken out and washed,
to obtain an ammoniacal solution; and a new charge of similar purifying materials is
introduced into the purifier.
The claim  made under this head is for the extraction of ammonia and carbonic acid
from coal gas, by chloride of magnesium, or sulphate of magnesia and water, diffused
through sawdust or other solid matter, capable of exposing an extensive surface of the
re-agents to the gas, without materially impeding its passage.
A further improvement consists in purifying coal gas by the use of a solid material,
containing chloride of magnesium or of calcium, or sulphate of magnesia, mixed with
hydrated or precipitated oxide of copper.  To make this purifying material, the
patentees take sawdust, or other suitable matter, wetted with a strong solution of
suitable matter, wetted with a strong solution of muriate or sulphate of copper, or else
either of those salts of copper in a finely-divided state, and mixed with moistened




GAS-LIGHT.                                        887
sawdust or other suitable matter, and they mix therewith enough lime, magnesia, or its
carbonate, or magnesian limestone, burned and slaked with water or powdered, to
decompose the salt of copper into precipitated oxide of the metal, and a salt of lime or
magnesia, or both. Or, instead of making extemporaneously both or either of the salts
of magnesia and lime and oxide of copper, they mix sulphate of magnesia or chloride of
magnesium  or of calcium, ready formed and in a state of mechanical division, or in
solution, with oxide of copper and sawdust, or other suitable matter. These purifying
materials are used in dry purifiers, like hydrate of lime. They can be employed for
removing ammonia, carbonic acid, and sulphuretted hydrogen from  the gas; or they
may be used for the latter impurity without the two former. In the first case, it is found
useful to add to therm about half an equivalent of fine carbonate of lime, or of carbonate
of magnesia, or of both; and in the latter case it is preferred to make either the
same addition, or, in lieu thereof, to add about the same quantity of caustic lime or
magnesia, or of both of them. When the used material will no longer purify the gas
from sulphuretted hydrogen, either it is taken out of the purifier and exposed to the
atmosphere, or else a current is directed through it while in that vessel; a vent-hole in
the purifier, below the level of the foul purifying matter being open, or not, at the same
purifying energy of the material is. thus restored,
and this alternate expenditure and restoration of energy can be repeated a number of
times, until the material becomes sufficiently charged with sulphur and with ammoniacal
and cyarnogen products, or either of them, to render it worth while to extract it or them
in any known way.
The patentees claim under ~this head, the purifying coal gas by the repeated use of a
solid material, containing sulphate of magnesia, or chloride of magnesium, or calcium, or
more than one of those re-agents, in combination with oxide of copper, and mixed or not
with lime or magnesia, or both, or either, or both of the carbonates of those earths.
The next part of the invention consists in a process for converting the ammoniacal
liquor, produced in making gas, or by distilling animal matters, into sulphate of
ammonia. By. repeatedly using the same portion of hydrated or precipitated oxide of
iron or copper, in conjunction with lime, magnesia, carbonate of lime, carbonate of magnesia,
or any compound of lime or magnesia, susceptible, under the circumstances in which it is
used, of being decomposed by carbonate of ammonia,-for purifying coal gas, with subsequent exposure to atmospheric air, the spent material eventually becomes in great part
changed into sulphate of lime or sulphate of magnesia, mixed with oxide of a metal.
When this has taken place, the spent material is mixed in a vat for an hour or two,,with
nearly as much of the ammoniacal liquor as it will decompose; the fluid is next drawn off
and filtered; the saturation of any ammonia which it may contain in a volatile state is
effected by sulphuric acid; and then it is evaporated to obtain crystals of ammoniacal
sulphate. The same process is followed by another good result; for the decomposition
of the carbonate of ammonia by the sulphate of lime, or sulphate of magnesia, reproduces
in the spent material a carbonate of the earth, which fits it for beginning anew the work
of purifying coal gas.
The patentees claim the use of the spent materials, above described, for converting
solutions of carbonate of ammonia, mixed or not with hydrosulphate of ammonia, inte
solutions of ammoniacal sulphate; by which use, also, the sulphate of lime or sulphate
of magnesia, in the said mixtures, is changed into carbonate of lime, or carbonate of
magnesia.
When solid or porous mixtures, containing hydrated or precipitated oxide of iron or
copper, or a salt of either of those metals, decomposable into hydro-sulphuret of the
metal are employed to absorb sulphuretted hydrogen from coal gas, and are afterwards
brought into contact with atmospheric air, the mixture rapidly absorbs oxygen, and
thereby acquires an elevated temperature, greater in proportion as it is free from
moisture. In certain cases, when the materials are at first, or become by use, dry to the
touch, their temperature during  the subsequent absorption of oxygen rises much
higher than is desirable. One way of preventing this injurious accession of heat is by
communicating humidity to the mixture of materials, at a proper time; and this constitutes another part of the invention. This improvement is put into practice, either by
sprinkling the used purifying materials with water, on removing the cover from the
vessel, which contains them; or by pipes, properly disposed within the vessel, distribute
ing water over the surface of the materials, without the cover being removed; or by
sprinkling the materials with water, after they have been thrown out of the vessel; or
lastly, by placing the purifier in communication with a steam-boiler, and directing
through the used materials a sufficient quantity of the vapour of water to moisten them
and subsequently submitting them to the influence of a current of atmospheric air, also
directed through them. The patentees state, that they know it to be necessary that the
metallic oxides used for purifying coal gas from  sulphuretted hydrogen should be
hydrated; that is to say, combined with a certain portion of water in a dry state; but




888                                 GAS-LIGHT.
experience has proved to them, contrary to common opinion, that the said oxides act less
energetically on the sulphuretted hydrogen in the gas, and also that they regain their
expended energy less suddenly, when they contain water in a liquid state, than when
they are free from hygrometric water.
The patentees do not claim  the regeneration of the purifying energy of any spent
purifying mixtures, by exposing them to atmospheric air; but what they claim is, the
means, above described, for checking the rapidity of the regenerating action, and, consequently, preventing the temperature of the materials from rising to a pernicious height
viz., by wetting them with water, or by condensing steam in their mass, either in or out
of the purifier, at any time after they commence to purify the gas, and before they are
put in communication with the atmosphere.
The patentees have found that mixtures containing hydrated or precipitated oxide of
iron, changed into hydro-sulphuret of iron, by purifying coal gas from sulphuretted
hydrogen, do not readily re-absorb oxygen, and, consequently, do not readily recover
their purifying energy at temperatures below 82~ Fahr.
Now, another improvement consists in applying to such used mixtures, during frosty
weather, atmospheric air, artificially warmed to about 60~ Fahr.: by the ordinary operations of the "retort house," or in any other convenient manner. The warmed air may be
used there, or conducted thence to the purifiers, by suitable pipes, in which a draft is
established by any known means.
The claim under this head is for the use of air, artificially warmed, for promoting, in
cold weather, the regeneration of hydrated oxide of iron, in mixtures which have been
used for purifying coal gas from sulphuretted hydrogen,-whether the warmed air be
conveyed to the used purifying mixtures, or the latter be carried to the warm air.
Another part of the invention consists in the use of phosphate of lime, dissolved in
hydrochloric acid, for purifying coal gas, and for decomposing the ammoniacal liquors
produced in making gas, and in the distillation of animal matters, and the application of
the products as manures. In carrying out the improvement, bones, or other form  of
phosphate of lime, are dissolved in hydrochloric acid. This solution is prepared for purifying gas by mixing it with sawdust or other suitable solid matter; and thus itis exposed
to the impure gas in dry purifiers. To use the solution for decomposing ammoniacal
liquors, one of the fluids is added to the other, until the hydro-sulphuric and carbonic
acids combined with the ammonia have escaped. To facilitate the transport of the product, and its application as a manure, it is heated in pans until it becomes dry. The
product of the purification of gas is also a good manure, mixed as it is with the sawdust
or other absorbent matter used.
The patentees claim under this head the use of a solution of phosphate of lime in
hydrochloric acid, for purifying coal gas and for saturating ammoniacal solutions; and
also the use of the products as manure.
Another part of the invention relates to certain processes for obtaining, in an economical manner, one of the re-agents which the patentees use for purifying gas,-namely
chloride of calcium. In certain chemical works, hydrochloric acid gas is a residuary product,-not only of no value, but even costly to get rid of without nuisance to the neighbourhood. One of the processes consists in causing hydrochloric acid gas to pass, in a
heated state, over beds of lime, or carbonate of lime, in its way from the furnaces, where
it is generated, to the condensers, where it would else become absorbed into water.
The beds of lime, or carbonate of lime, are formed on the bottom of the ordinary
conduits; two conduits being arranged in a line, and worked and discharged alternately.
When the lime in one passage has been converted into chloride, the draft through
it is diverted into the neighbouring passage by means of dampers arranged for that purpose; and the finished charge is withdrawn through doors made at convenient distances.
When this is done, the bed is re-charged with lime or its carbonate, in readiness to
receive the current of hydrochloric acid, after it shall have saturated the lime in
the second conduit. When this saturation is completed, the dampers are reversed,
so as to divert the acid gas again into the first conduit, while the charge of the
second is being withdrawn, preparatory to re-charging it a second time; and so on continually. By the second process, hydrochloric acid is obtained in a concentrated state,
preparatory to its saturation in a fluid form by lime or its carbonate, or to its application
to other uses. This process is carried on with only one conduit leading from the furnaces where the hydrochloric acid is generated. The conduit is lined with hard glazed
bricks, or tiles, or sandstone; and its bottom  is so constructed, that any fluid formed
within it shall escape by a pipe adjusted to its lowest part. Along this conduit a
number of porous earthenware vessels are arranged in a line or lines, standing on its
floor, and built into its arch or cover up to their necks. These vessels are filled with
water, and made to communicate, by means of syphons, with one another, and with a
reservoir of water placed with its highest part on the same level as the mouths of the
earthenware vessels. By well-known arrangements, the water is kept at a constant level




GAS-LIGHT.                                      889
in the reservoir, and consequently at a constant level in the earthenware vessels which
communicate with it.  The consequences of this arrangement are, that the water contained in the vessels within the heated conduit is speedily raised to a temperature of
2120 F.; that the gaseous contents of the conduit are reduced to that temperature, or
that the water which exudes from the porous earthenware absorbs as
r ic acid gas as it can combine with.  Now, as strong hydrochloric acid
it a temperature above 2120 Fahr.; and as the vapour of water is not
condensable at that temperature, the strong acid flows down the outsides of the porous
vessels and runs in a stream to the most depending part of the passage, where it escapes
by the pipe placed for that purpose. By treating the acid so obtained with lime or its
carbonate, chloride of calcium or muriate of lime is obtained, with hardly any cost for
evaporation.
The patentees claim, under this head, making chloride of calcium, by causing the
hydrochloric acid gas, which results from the decomposition of common salt by sulphuric
acid, to act on lime or carbonate of lime in its passage from the furnace where the
decomposition is effected; and also the collecting of concentrated hydrochloric acid, for
making chloride of calcium or other purposes, by condensing hydrochloric acid gas in
water by means of earthen vessels built into a conduit or flue, conducting from furnaces
in which chloride of sodium is decomposed by sulphuric acid, and containing water kept
at about 2120 Fahr. by the heated products of the said furnaces.
The next part of the invention is a new way of using certain forms of carbon for
purifying coal gas and obtaining ammonia therefrom. It consists in alternately causing
the material to absorb impurities from the gas, and to discharge them under the influence
either of heat or of a current of air, or steam directed through the purifying material
In carrying out this improvement, a dry lime purifier, or other convenient vessel, is filled
with animal charcoal in coarse powder, and impure coal gas is directed through it, until
it no longer issues from the vessel pure. The gas is then sent in another direction, and a
current of steam or air, heated or otherwise, is passed through the foul material; the
volatile products being received into any desirable acid or other substance calculated to
fix the ammonia, or else the ammonia, combined with carbonic and hydro-sulphuric acids,
is condensed by water, or by the abstracting of heat, in any suitable apparatus. If steam
be used, it brings away nearly the whole of the ammonia, but it damps the purifying
material, which then needs to be dried by a current of hot air or otherwise; and if air
be used, in the first instance, to bring away the ammonia, part of it becomes sulphate of
that base, and must be removed by washing. In addition to, or without the introduction
of air or steam among the purifying material, it may be heated by steam or hot water
contained in a jacket around the vessel, or in pipes within it; or the foul material may
be removed from the purifier and heated to about 2120 Fahr. in any suitable close vessel.
Coke, wood, charcoal, or peat charcoal may be substituted for animal charcoal, in the process above described, but with inferior results.
The patentees do not claim the exclusive use of any form of carbon for absorbing the
impurities of coal gas; their claim being for the means above described, for making coke
and charcoal repeatedly useful for purifying coal gas, and for obtaining its ammonia by
their agency.
Another part of the invention consists of certain processes by which prussiate of potash,
prussiate of soda, and prussiate of ammonia, are obtained from prussiate of lime. With
respect to prussiate of potash, the process is to mix well together equivalent quantities of
prussiate of lime and sulphate of potash, or carbonate of potash, previously dissolved in
separate portions of water; and then, after subsidence of the sulphate or carbonate of
lime which is formed, to evaporate and crystallize the clear solution. The prussiates of
soda and of ammonia are made in like manner, by substituting the sulphates or carbonates
of the respective bases for the sulphate or carbonate of potash.
The claim under this head is for the manufacture of the prussiates of potash, soda, and
ammonia, by decomposing solutions of the sulphates or carbonates of those bases by solu.
tions of prussiate of lime.
Another improvement consists in a process for obtaining carbonic acid gas for converting
the hydrosulphate of ammonia in gas liquor into carbonate of ammonia, and for other
useful purposes to which carbonic acid gas is applicable. It is known that hydrosulphate
of ammonia is decomposable by carbonic acid, and that hydrosulphate of ammonia exists
in gas liquor. To change it into carbonate of ammonia, the patentees proceed as follows:They make a mixture of deutoxide of copper and charcoal, or other., form of carbon, in
fine powder, in the proportion of twelve parts, by weight, of the former to one part of
the latter, and introduce the mixture into a retort, made red hot, and furnished with an
eduction pipe which passes through cold water and finally enters into gas liquor. The
formation of carbonic acid gas soon takes place, by the union of the carbon with the
oxygen of the metal: and this gas, combining with the base of the hydrosulphate of
ammonia, combined in the gas liquor, converts it into carbonate, causing hydrosulphuric




890                                  GAS-LIGHT.
acid to escape.  When the carbonic acid ceases to come away, nearly all the carbon
will have disappeared from the retort, and the copper which it contains become reduced
to the metallic state. The charge is then drawn and left to cool, while a second charge,
of similar materials, is being worked off; during which time the copper re-absorbs oxygen
from the air, and becomes again deutoxide of copper, which may then be used anew with
fresh carbon.
The patentees claim making carbonic acid gas for converting hydrosulphate of ammonia into carbonate of ammonia, and for all other purposes in the arts, by exposing a
proper mixture of deutoxide of copper and carbon in powder to a red heat in suitable
vessels.
The last part of this invention is a process for consilidating peat to be used in furnishing gas or charcoal, or for feul. The process is as follows:-The peat, without being
previously dried, is treated with water in a mill in a way similar to that in which chalk
is treated for the manufacture of whitening, and which is well understood. The resulting
liquor is made to pass through a strainer of wire-work (fine enough to prevent the passage of the large fibres) into tanks or backs, cut in the earth, or built upon the surface of
the ground if necessary; where it is left to deposit the finer parts of the peat. When
this is effected, the supernatent liquor is run off from the deposit, and the magma
taken out from the tanks or backs and dried, either by the air, by the sun, or on arches
of brick or other absorbent material, heated by flues underneath.
The patentees claim under this head the separation of the grosser from the finer parts
of the peat, and the consolidation of the latter by the process above described.
Gas-light, Purification of. The purification of coal gas has lately received one of those
important improvements, which constitute an era in the practical application of science to
the arts. From  the commencement of the manufacture of gas up to a very recent
period, the only agent in use for the removal of the impurities of coal-gas was the
hydrate of lime. The impurities in question are, as is well known, carbonic acid and
sulphuretted hydrogen united to ammonia, and held in the gas more by a principle of
diffusion than from  their own proper volatility.  Hence mere condensation by cold, or
the application of water, unless both of these are employed to an injurious excess, will
not combine with or precipitate the bicarbonate and hydrosulphate of ammonia present
in impure coal gas.  The hydrate of lime, however, readily decomposes both of these
salts, with the production of carbonate and hydrosulphate of lime and the liberation of
free ammonia, the greater part of which may subsequently be removed by the use of a
dilute acid, or the application of cold water in an apparatus similar to thie " cascade
chemique" of Clement Desormes. Thus, then, it was possible by lime to remove the
whole, or at least nearly the whole, of the impurities of coal-gas, and as we have before
stated, this, up to within a very recent date, was the general practice whenever coal-gat
was manufactured. But the use of lime in this way entailed many and serious dis
advantages in a sanitary point of view, to obviate or rather to diminish which considerable
outlay was incurred in large towns, for it is a property of the hydrosulphate of lime too
be decomposed with singular rapidity by carbonic acid, and as the atmosphere, more
especially in crowded localities, always contains a notable proportion of this latter gas, it
follows that the hydrosulphate of lime begins to decompose the moment it comes in con-.
tact with the air, and, consequently, an intolerable nuisance and pestilential effluvium
were thus originated, not only in the neighbourhood of the gas-works themselves, but
also in those localities to which this gas-lime refuse happened to be transported; of which
a lamentable illustration occurred not long ago in Pimlico, where a sewer had been
covered over by this kind of refuse; and though three or four years had intervened
between the deposition of this matter and the accident we now relate, yet no less than
five healthy individuals were struck dead, as if by lightning, on entering the sewer
beneath the spot where the refuse lime had been placed. With so terrific a proof of the
deleterious action of the hydrosulphate of lime, even after many years had. elapsed, it
becomes superfluous to dwell upon the necessity which existed for discontinuing the
formation of this poisonous substance, and, fortunately, science has stepped in at the
eleventh hour to the relief of the public.
About the year 184&, a Mr. Laming, of Paris, took out a patent for the employment
of various metallic oxides in lieu of lime for the purification of gas, which oxides
were used at the same time or in combination with muriate of lime. The effect of this.
arrangement was two-fold, for as we have seen that the impurities to be taken away
consist of ammonia, carbonic acid, and sulphuretted hydrogen, then by the use of
muriate of lime, Mr. Laming was able to remove the carbonic acid and ammonia,,
whilst by the metallic oxide he removed the sulphuretted hydrogen; producing in
the first case muriate of ammonia and carbonate of lime, and in the second a metallic
sulphuret and water.  The oxides patented were those of manganese, iron, zinc, and
lead; but there was this' insuperable difficulty connected with their employment, that
as they could be formed only by the decomposition of a metallic salt and its equivalent




GAS-LIGHT.                                        891
of lime, they necessarily cost, for an equal amount of work done, the whole value of the
lime plus that~of the metallic salt. The expense of purification by this plan, therefore,
stood as an insurmountable barrier to its introduction, though the peculiar defect of lime
was entirely got rid of in the use of the metallic oxide, as this did not suffer decomposition by atmospheric carbonic acid, and therefore evolved no sulphuretted hydrogen.
Nevertheless, the process languished, and threatened to die out on the score of cost  Mr.
Laming's first essays with this patent seem to have been made almost entirely with the
oxides of manganese and lead, and oxide of iron does not appear to have been employed
or tried on a large scale until about three years ago, when, in conjunction with Mr.
F. J. Evans, of the Chartered  Gas Works, it was put in use by Mr. Laming at
Westminster. The success of the experiment was complete as to purification, but the
question of expense could only be decided by a few  consecutive  trials, and therefore, fresh materials were sent for this purpose, whilst the old, or as it was called
"spent" material was cast on one side.  During the progress of the ensuing experiments it was, however, observed by Mr. Evans, that this spent material consisting as it
did of black sulphuret of iron, rapidly regained its original red colour, and looked like
oxide of iron. This induced him to give it another trial in the purifier, when, to his
astonishment, he discovered that its purifying power was completely restored, and that,
in fact, it might be used over and over again, 10, 15, or 20 times, or even more in succession, nothing being required to restore its power but a few hours' exposure to the air.
From that moment the practical employment of oxide of iron in the purification of coalgas became un fait accompli; for the question of expense was altogether done away
with by a material which, though costly in the first instance, soon ceased to be so from
repeated and continuous usage without additional outlay. And it is here worthy of
remark, that oxide of iron is the only oxide yet discovered which fully answers this
purpose, for the sulphurets of manganese, zinc, and lead, do not become reconverted
into oxides by simple exposure at ordinary temperatures to the action of the air. And
as oxide of iron is contained in the blood of all animals, it opens out an ihteresting
question in physiology, how far this gas purification process may be analogous to that
of the blood, through the agency of the pulmonary system.  We shall now, however,
merely give a condensed view of the oxide of iron method, as practised at the Westminster and other gas works, without offering more than a few brief theoretical remarks
by way of explanation.
Impure coal-gas, as it leaves the condenser, contains about two per cent. in bulk of
carbonic acid, and one per cent. of sulphuretted hydrogen, with a quantity of ammonia,
generally insufficient to saturate these two acids, though this varies much with the
variations of the weather and the state of the condenser. For the most part, however,
the amount of ammonia is equal to the carbonic acid, and in this case the new process is
perfect; but if the ammonia be less than will saturate the carbonic acid, then the excess
of this acid remains in the gas, and to this extent the coalgas may be said to be impure.
Taking the normal condition of gas as it quits the condenser, it is first made to traverse
a quantity of sawdust, saturated with a very strong  solution of muriate of lime.
Here double decomposition goes on, accompanied by the formation of carbonate of
lime and muriate of ammonia, and the gas becomes deprived of its carbonic acid and
ammonia, consequently it now  contains only sulphuretted hydrogen; and when the
muriate of lime in the sawdust is totally decomposed, the muriate of ammonia which
it then contains is dissolved out by lixiviation, and crystallised as a marketable product.
The impure gas is next transmitted through a mixture of the hydrated peroxide of iron
and sawdust, damped with a solution of muriate of lime, by which the whole of the
sulphuretted hydrogen is absorbed, and also any traces of carbonate of ammonia which
may have escaped the first purifier. In this way the peroxide of iron is reduced to the
state of protoxide, with the formation of water and deposition of half an atom of
sulphur, whilst the protoxide of iron as it is produced reacts upon the remaining
sulphuretted hydrogen, and yields a hydrated proto-sulphuret of iron of a black colour,
so that the resulting products are water, sulphur, and hydrated protosulphate of iron.
So soon, however, as these are exposed to the air, the iron of the protosulphuret combines with oxygen and liberates free sulphur, whilst it nevertheless retains the water of
combination belonging to the protosulphuret, thus generating a mixture of hydrated
and anhydrous peroxide of iron; and as it is the former of these alone which is useful in purification, there is after each renewal a slight loss of power, and this slowly
increasing ultimately renders the whole mass inefficacious after from 18 to 20 exposures.  At the same time the free sulphur in the material goes on augmenting, and
at last a period arrives in which the mixture becomes pyrophoric, and it is almost impossible to prevent it from  catching fire.  The effect of the muriate of lime is to
diminish this tendency; but this gives rise to the presence of carbonate of lime, as
we have seen above, and when much carbonate of lime has made its appearance, then
the disposition of the sulphur to form sulphuric acid is increased by the readiness for its
absorption by the carbonate of lime, and therefore the proneness to inflammation is




892                                   GAS-LIGHT.
again manifested; so that in practice a small specimen of this material is seldom used
more than twenty times in succession before it is removed from the gas works. It is,
however, now very far from being valueless, as it not only contains a vast amount of free
sulphur, but also of ferrocyanic acid: a product scarcely to have been expected in a commercial sense. Nevertheless, it is found that one ton of Newcastle coals gives off in
distillation sufficient cyanogen to produce from 5 to 8 lbs. of Prussian blue with the
hydrated oxide of iron; and it is part of the process now carried on by Mr. Laming at
Mill Wall, to extract this ferrocyanic acid from the spent material, and convert it into
prussiate of potash or Prussian blue at pleasure. The great advantage of this invention
is not therefore confined to its sanitary details, but extends into the merit of having discovered a new and fertile source for the production of an article of great commercial
value, and rendered both useful and profitable that which was previously a pestilential
waste threatening to interfere very seriously with the progress of gas manufacturing.Mr. L. Thompson.
Lowe and Evans's Improvements. On the 20th January, 1852, a patent was granted to
George Lowe, of Finsbury-circus, in the city of London, civil engineer, and Frederick
John Evans, of Horseferry Road, in the city of Westminster, civil engineer, for improvements in the manufacture of gas for the purpose of illumination, and of improvements in
the purification of gas.
The first part of this invention refers to certain means of enriching or improving the
quality of gases, so as to render them fit for the purposes of illumination.
In carrying out this improved manufacture of gas, the patentees pass gas, obtained
from any of the sources hereinafter specified, through heated retorts containing cannel
coal, coal, lignite, resin, pitch, tar, oil, retinite, or other substance or substances capable
of yielding carburetted hydrogen gas: by which means such a combination of rich and
poor gases may be produced as will be exactly suited to the              ses of illumination.
For this purpose, it is proposed to use retorts open at both ends, as shown in the drawing given' in fig. 705., which represents a longitudinal vertical section of the apparatus
employed in carrying out this part of the invention.  Only  one  retort is exhibited; but
05'a  similar  arrangement  of  retorts  may  be
adopted to that in general use in gas-works.
a is the retort, set in  a suitable furnace for
heating  the same; and b, b are mouthpieces
and lids, fitted to both ends of the retorts.  c
is the pipe for carrying off the gaseous products generated in the retort; and, is a pipe
ml I =?    for introducing into the retort the gas which
b,      5                  1        is intended to combine with the gaseous pro-........... a ~-*  _~  E-~_.    ducts of the substances under  distillation in
"M m        ^*" 8:the retort.  As soon as the retort is charged
with coal or other carbonaceous matter, a cock
e, in the pipe d, is opened, which allows the
gas to flow  into the retort; and it then passes
in the direction  of the  arrows, and  mingles
with the gas that is evolved from  the carbonaceous matters contained in the retort: whereby a compound gas is formed, possessing
a much higher illuminating power than could have been obtained had the combination
taken place after instead of at the time of the generation of the gas in the retort a. The
gas, which is brought to the retort by means of the pipe d, may be forced into the retort,
so as to overcome the internal pressure put on the retort by means of the hydraulic
main; or, instead thereof, an exhauster may be applied to draw  off the gas from  the
retort. Should tar, oil, resin (previously melted), or any liquid hydrocarbon be employed
for the generation of the gas, it is to be run into the retort in the way generally adopted
for making oil or resin gas.
The sources from  which the patentees propose to obtain inflammable gases, to be
applied as above indicated, are wood, sawdust in a damp or dry state, spent tanner's
bark, and other like substances capable of yielding an inflammable gas. These substances
must be put into a red-hot retort, and distilled like coal. The resulting gases may be
either purified at once, or passed directly to the retort containing the coal or other carbonaceous materials. As a general rule, however, these gases are preferred to be stored
in gas-holders for use; as, in that case, a more uniform and constant supply to the coal
retort may be relied on.
Another source of inflammable gas is from  coal of an inferior description, or from
peat. These substances having been distilled in a retort, the resulting gas can be then
employed as above indicated. It is also proposed to conduct carbonic oxide gas into
retorts containing carbonaceous matters under distillation.  This gas the patentees
obtain from carbonic acid, by passing the latter gas (which may be obtained from any




GAS-LIGHT.                                        893
convenient source) through a retort or furnace containing red or white hot coke. Or,
they utilize a portion of the gases generated in furnaces, by collecting these gases and
converting the carbonic acid they contain into carbonic oxide, by passing them through
a retort or furnace, as described for treating carbonic acid; or the gases may be conducted directly into retorts, wherein carburetted hydrogen is beinggenerated, for the
purpose of effecting the desired combination.
From the foregoing description, it will be understood, that the object of this part of
the invention is to obtain gas of a uniform quality,-that is, possessing a definite amount
of illuminating power. Now, it is well known that if the gas be too rich in carbon it
will burn with a dull flame, and give off a large amount of smoke; and that, if deficient
in carbon, it will burn with a blue flame, and possess very little illuminating power.
It is therefore proposed to mix the rich and poor gases, obtained as above described, in
such proportions as will be needful to produce a highly illuminating quality of gas.
As the proportions will depend entirely on the quality of the gases to be combined, no
rule can be laid down for the amount of the gas required to be passed into the retorts,
wherein the distillation is proceeding. The mode, however, in which the gas burns, on
issuing from the retort, will be a sufficient test for the workmen in attendance.
The second part of this invention refers to the purification of coal-gas from suiphuretted hydrogen; and consists in effecting this operation by the use of what has been
considered by chemists to be the ferrate of potash, but what is now found to be a peroxide of iron in a peculiar state, and such as results from the employment of the following means:-First the patentees heat together peroxide of iron and caustic potash or
soda to a dull red heat, by which a kind of ferrate or ferrite of potash or soda is produced; and when this substance is washed in water, it undergoes decomposition, with
the reproduction of caustic potash or soda (which remains in solution), and the precipitation of peroxide of iron in the state fit for the purification of gas. All or any of the
peroxides of iron may be used for the above purposes, and will, by its means, become
useful for purifying gas, though previously inert; and the solution of potash or soda,
when evaporated to dryness, may be again and again employed upon fresh  ortions of
peroxide of iron, so as to communicate to them  the peculiar property desire. Or per
oxide of iron may be heated with a smaller quantity of caustic potash or soda, and a
portion of common salt, in order to economize the potash or soda: the heat in this case
should be, as before, a dull red; and the same measures must be adopted for recovering
the potash or soda and common salt, which may be used over and over again with fresh
portions of peroxide of iron. Or the patentees heat the common hydrated peroxide of
iron, to about 6000 Fahr.,-taking care that the heat never reaches a bright red; and
in this way they obtain a peroxide of iron, having the requisite properties. Or they
heat in the same way, and with the same precautions, such of the native ochres or ferruginous compounds as will, after such treatment, become rapidly black upon being subjected to the action of a stream of sulphuretted hydrogen.
A quantity of peroxide of iron, fit for purifying gas, having been procured, by any
of the means thus indicated, the oxide is next to be mixed with sawdust or other con.
venient material, and  damped  slightly with water; and  the mixture is then to be
spread in a dry lime purifier, and used in the way adopted with hydrate of lime; or it
may be mixed with water, and run into a wet lime purifier, and used in the way adopt.
ed with regard to lime when employed in this kind of apparatus. In both cases it will
be necessary, after the peroxide of iron has ceased to act upon the gas, to expose it to
the air, by which its energies are renewed, so that it may be again and again used for
the purification of gas. With the dry lime purifier, simple exposure is all that is required.  With the wet lime purifier, the mixture must be run out and left at rest for
some time; then, when the fluid has entirely separated from the solid part, it may be
allowed to escape; and as the solid portion dries, its power will become renewed: after
which it may be mixed with water and employed as before. The renewal of the peroxide
of iron, in both these cases, is known by its changing from black to red or deep brown.
Another part of the invention relates to the use of the sulphite and bisulphite of lead
for the removal of the sulphuretted hydrogen from coal-gas.
These substances are to be employed singly or together, mixed with water, in a wet
lime purifier, exactly as is practised with regard to lime. When they cease to purify
the gas, the mixture is run out of the purifier; and after the water has been removed
by subsidence and decantation, or by a filter, the residue is dried and burned, so as to
make sulphurous acid, which is employed in the manufacture of fresh sulphite or bisulphite of lead, or in the production of sulphuric acid. The matter which remains,
after this burning process, is carefully roasted, and thus converted into oxide of lead or
litharge, from which sulphite or bisulphite of lead may be again produced.
The patentees claim the combining of gases which possess different degrees of illuminating power, by the introduction of gas, obtained in any of the ways above indicated
into retorts or vessels containing carbonaceous matters under distillation. They also




894                                   GELATINE.
claim, as their improvements in the purification of gas, First,-the use of anhydrous peroxide of iron prepared as above described; and, Secondly,-the use of sulphite andbisuipbite
of lead, for the removal of sulphuretted hydrogen from coal-gas.-Newton's Journal.
We are indebted to Mr. Thomas G. Barlow, an eminent engineer, for a vast body of
information on coal-gas, contained in his excellent Journal of Gas Lighting, commenced
on the 10th of February, 1849, and continued in monthly numbers ever since. His first
number presented a list of the London Gas Companies, and the value of their shares at
the Stock Exchange, to which we have added the ruling rates in the present year.
Paid up.              Name.                January, 1848.  January, 1849.  September, 1852.
~                              ~~~    ~    ~    ~    ~    ~
25      Commercial   -   -  -   -    25 to  26           25 to  26        30  to  32
150      City of London   -       -       285-290    240-  245            124  -126
50      Chartered  ------    58-   59                    48-   49         36       37
50      Equitable  -  -  -                38-   39       33-  35          25       26
50      Imperial  -    -  -               80-   84       62-   64          5 -   80
50      Independent                      --                      62 60-   62       47
50      London (Vauxhall) -  -  -                                  10-   20  2-    3
50      Ditto (preference)   -  --    -   -   -          20- 30           15- 18
49      Phmenix  -  -  -  -  -  -  -    35  to 36        28-   30         26       27
90      Ratcliff  -  -  -78 -  80                        72-   74         60       65
25      South Metropolitan  -  -  -    28-  30           21-  23          20       22
GENERAL SUMMARY.
For lighting London and its suburbs with gas, there are -
18 public gas works.
12     do.    companies.
2,800,0001. capital employed in works, pipes, tanks, gas-holders, apparatus.
450,0001. yearly revenue derived.
134,300 private burners supplied to about 40,000 consumers.
30,400 public or street do. N. B. about 2650 of these are in the city of London.
380 lamplighters employed.
176 gas-holders; several of them double ones, capable of storing 5,500,000 cubic feet.
890 tons of coal used in the retorts on the shortest day, in 24 hours.
7,120,000 cubic feet of gas used in the longest night, 24th December.
About 2500 persons are employed in the metropolis alone, in this branch of manufacture.
Between 1822 and 1827 the quantity nearly doubled itself, and that in 5 years.
Between 1827 and 1837 it doubled itself again.
The consumption of coals of all kinds for the supply of gas to the metropolis during
the year ending June, 1852, is almost exactly 408,000 tons, which on an average would
yield about 4,000 millions of cubic feet of gas.
GAS-HOLDER; a vessel for containing and preserving gas, of which various forms
are described by chemical writers.
GASOMETER, means properly a measurer of gas, though it is employed often to
denote a recipient of gas of any kind. See the article GAs-LIGHT.
GAUZE  WIRE CLOTH, is a  textile fabric, either plane or tweeled, made of
brass, iron, or copper wire, of very various.degrees of fineness and openness of textures.
Its chief uses are for sieves and safety lamps.
GAY-LUSSITE, is a white mineral of a vitreous fracture, which crystallizes in
oblique rhomboidal prisms; specific gravity from  1-93 to 1'95; scratches gypsum, but
is scratched  by calcspar; affords water by calcination; it consists of carbonic acid
28-66; soda, 20-44; lime, 17-70; water, 32-20; clay, 1-00. It is in fact, by my analysis, a hydrated soda-carbonate of lime in atomic proportions. This mineral occurs
abundantly in insulated crystals, disseminated through the bed of clay which covers the
urao, or native sesquicarbonate of soda, at Lagunilla in Columbia.
GELATINE; (Eng. and Fr.; Gallert, Leim, Germ.) is an animal product which is
never found in the humours, but it may be obtained by boiling with water the soft and
solid parts; as the muscles, the skin, the cartilages, bones, ligaments, tendons, and membranes. Isinglass consists almost entirely of gelatine. This substance is very soluble in
boiling water; the solution forms a tremulous mass of jelly when it cools. Cold water
has little action upon gelatine. Alcohol and tannin (tannic acid, see GALL-NUTS) precipitate gelatine from its solution; the former by abstracting the water, the latter by
combining with the substance itself into an insoluble compound, of the nature of leather.
No other acid, except the tannic, and no alkali, possesses the property of precipitating




GELATINE.                                         895
gelatine. But chlorine and certain salts render its solution more or less turbid; as the
nitrate and  bi-chloride of mercury, the  proto-chloride  of tin, and a few  others.
Sulphuric acid converts a solution of gelatine at a boiling heat into sugar.  See
LIGNEoUs FIBRE.  Gelatine consists of carbon, 47'88; hydrogen, 7'91; oxygen, 2721.
See GLUE and ISINGLASS.
This substance is produced by boiling the skin of animals in water, which in its
crude but solid  state is called glue, and when a tremulous semi-liquid, size. The
latter preparation is greatly used by the paper-makers, and was much improved by the
following process, for which Mr. William Rattray obtained a patent in May, 1838. The
parings and scrows of skins are steeped in water till they begin to putrefy; they are
then washed repeatedly in fresh water with the aid of stampers, afterwards subjected, in
wooden or leaden vessels, to the action of water strongly impregnated with sulphurous
acid for from  12 to 24 hours; they are now  drained, washed with stampers in cold
water, and next washed with water of the temperature of 120~ F., which is poured upon
them and run off very soon to complete their purification. The scrows are finally converted into size, by digestion in water of 120~ for 24 hours; and the solution is made
perfectly fine by being strained through several thicknesses of woollen cloth. They must
be exhausted of their gelatinous substance, by repeated digestions in the warm water.
The claim is for the sulphurous acid which, while it cleanses, acts as an antiseptic.Newton's Journal, xiv. 173.
A fine gelatine for culinary uses, as a substitute for isinglass, is prepared by Mr.
Nelson's patent, dated March, 1839.  After washing the parings, &c., of skin, he scores
their surfaces, and then digests them in a dilute caustic soda lye during ten days.
They are next placed in an air-tight vat, lined with cement, kept at a temperature of
100 Fahr.; then washed in a revolving cylinder apparatus with plenty of col water, and
afterwards exposed to the fumes of burning sulphur (sulphurous acid) in a wooden
chamber.  They are now  squeezed to expel the moisture, and finally converted into
soluble gelatine, by water in earthen vessels, enclosed in steam cases. The fluid gelatine
is purified by straining it at a temperature of 100~ or 120~ Fahr. I have examined this
patent gelatine, and found it to be remarkably good, and capable of forming a fine
calf's-foot jelly.
Very redently a very beautiful sparkling gelatine has been prepared under a patent
granted to Messrs. J. and G. Cox, of Edinburgh.  By their process the substance is
ren~dered perfectly pure, while it possesses a gelatinizing force superior even to isinglass.
It makes a splendid calves'-feet jelly and a milk-white blanc-mange. The patentees also
prepare a semi-solid gelatine, resembling jujubes, which  readily dissolves in warm
water, as also in the mouth, and may be employed to make an extemporaneous jelly.
The gelatine of bones may be extracted  best by  the combined action of steam
and a current of water trickling over their crushed  fragments in a properly constructed apparatus.  When the gelatine is to be used as an alimentary article, the
bones ought to be quite fresh, well preserved in brine, or to be dried strongly by a
stove.  Bones are best crushed by passing them  between grooved  iron rolls.  The
cast-iron cylinders in which they are to be steamed, should be three times greater in
length than in diameter.  To obtain 1000 rations of gelatinous soup daily a charge
of four cylinders is required; each being 3j feet long, by 14 inches wide, capable of
A.  __ —--   B    M
t706




896                                  GELATINE.
holding 10 lbs. of bones.  These will yield each hour about 20 gallons of a strong
jelly, and will require nearly I gallon of water in the form of steam, and 5 gallons
of water to be passed through them  in the liquid state. The 5 quarts of jelly produced hourly by each cylinder, proceeds from the I quart of steam-water and 4 quarts
of percolating water.
The boiler should furnish steam  of about 223~ Falr., at a pressure of about 4 lbs.
on the square inch.
In fig. 106. A, B, C, D, represents a vertical section of the cylinder; G, H, I, X, a
section of the basket or cage, as filled with the bruised bones, inclosed in the cylinder;
E, c, c, the pipe which conducts the steam  down to the bottom  of the cylinder; L, s,
a pipe for introducing  water into the interior; M, a stopcock for regulating  the
quantity of water (according to the force of the steam  pressure within the apparatus),
which should be 31 quarts per hour; N is a tube of tin plate fitting tightly into the
part s of the pipe L; it is shut at R, and perforated below  with a hole; it is
inserted in its place, after the cage full of bones has been introduced. Fig. 707. is an
707
h           h   g 
a       rIn         DQ         r IT Ff _I       P
e          e           e         e c
A           B          C         D.__                   __3_ ~f__ 5_
elevation of the apparatus.  A, B, C, D, represent the four cylinders, raised about
20 inches above the floor, and fixed in their seats by screws; h h, are the lids 
g, g, tubulures or valves in the lids; i, ring junction of the lid; p, a thermometer;
f, f, stop-cocks for drawing off the jelly; n, n small gutters of tin-plate; m, the
general gutter of discharge into the cistern b; o, a block and tackle for hoisting the
cageful of bones in and out.  Fig. 708. is an end view  of the apparatus; a, the main
steam-pipe; a, b, c, c, branches that conduct that
steam  to the bottom  of the cylinder; o, the
o            < N -      tackle for raising the cage; s, stopcock; i, small
gutter; m, main conduit; b, cistern of reception.
When a strong and pure jelly is wished for,
the cylinder charged with the bones is to be
wrapped  in  blanket stuff; and whenever the
grease ceases to drop, the stopcock which admits
the cold water is to be shut, as also that at the
bottom of the cylinder, which is to be opened only
at the end of every hour, and so little as to let
708                              the gelatinous solution run out, without allow
ing any of the steam to escape with it.
5b               Butchers' meat contains on an average in 100
pounds, 24 of dry flesh, 56 of water, and 20 of
bones.  These 20 pounds can furnish 6 pounds!I| I   l          11 gIIof alimentary substance in a dry state; whence
II i                     ll    t appears that, by the above means, one fourth
X4"    j ^lwL rc \  more nutritious matter can be obtained than is...~~il. 7 \        j    usually got. I am  aware that a keen dispute
has been carried on for some time in Paris, beci.^i,..l, i..711)11'    I      tween the partisans and adversaries of gelatine,1~JU,11lklI?     l    l~as an article of food.  It is probable that both
parties have pushed their arguments too  far.
Calf's-foot jelly  is still deemed  a  nutritious
article by the medical men of this country, at least, though it is not to be trusted




GERHARDT'S ACETIC ACID.                                       897
to alone, but should' have a due  admixture or interchange of fibrine, albumine,
caseum, &c.
GEMS, are precious stones, which, by their colour, limpidity, lustre, brilliant polish,
purity, and rarity, are sought after as objects of dress and decoration. They form the
principal part of the crown jewels of kings, not only from their beauty, but because they
are supposed to comprise the greatest value in the smallest bulk; for a diamond, no
larger than a nut or an acorn, may be the representative sign of the territorial value of a
whole country, the equivalent in commercial exchange of a hundred fortunes acquired by
severe toils and privations.
Among these beautiful minerals mankind have agreed in forming a select class, to
which the title of gems or jewels has been appropriated; while the term precious stone is
more particularly given to substances which often occur under a more considerable
volume than fine stones ever do.
Diamonds, sapphires, emeralds, rubies, topazes, hyacinths, and chrysoberyls, are reckoned the most valuable gems.
Crystalline quartz, pellucid, opalescent or of various hues, amethyst, lapis lazuli,
malachite, jasper, agate, &c., are ranked in the much more numerous and inferior class of
ornamental stones. These distinctions are not founded upon any strict philosophical
principle, but are regulated by a conventional agreement, not very well defined; for it is
impossible to subject these creatures of fashion and taste to the rigid subdivisions of
science. We have only to consider the value currently attached to them. and take care
not to confound two stones of the same colour, but which may be very differently prized
by the virtuoso.
Since it usually happens that the true gems are in a cut and polished -tate, or even set
in gold or silver, we are thereby unable to apply to them  the criteria of mineralogical
and chemical science. The cuttinog of the stone has removed or masked its crystalline
chlaracter, and circumstances rarely permit the phenomena of double or single refraction
to be observed; while the test by the blowpipe is inadmissable.  Hence the only
scientific resources that remain are the trial by electricity, which is often inconclusive;
the degree of hardness, a criterion requiring great experience in the person who employs
it; and, lastly, the proof by specific gravity, unquestionably one of the surest means of
distinguishing the really fine gems from ornamental stones of similar colour. This proof
can be applied only to a stone that is not set; but the richer gems are usually dismounted when offered for sale.
This character of specific gravity may be applied by any person of common intelligence,
with the aid of a small hydrostatic balance. If, for example, a stone of a fine crimson-red
colour, be offered for sale, as an oriental ruby, the purchaser must ascertain if it be not
a Siberian tourmaline, or ruby spinel. Supposing its weight in air to be 100 grains, if he
finds it reduced to 69 grains, when weighed in water, he concludes that its bulk is equal
to that of 31 grains of water, which is its loss of weight. Now, a real sapphire which
weighs 100 grains in air, would have weighed 76'6 in water; a spinel ruby of 100 grains
would have weighed 72'2 in water, and a Siberian tourmaline of 100 grains would
have weighed only 69 grains in water.  The quality of the stone in question is,
therefore, determined beyond all dispute, and the purchaser may be thus protected from
fraud.
The sard of the English jewellers (Sardoine, French) is a stone of the nature of agate,
having an orange colour more or less deep, and passing by insensible shades into yellow,
reddish, and brown; whence it has been agreed to unite under this denomination all the
agates whose colour verges upon brown. It should be remarked, however, that the sard
presents, in its interior and in the middle of its ground, concentric zones, or small
nebulosities, which are not to be seen in the red cornelian, properly so called. The
ancients certainly knew our sard, since they have left us a great many of them engraved,
but they seem to have associated under the title sarda both the sardoine of the French,
and our cornelians and calcedonies. Pliny says that the sarda came from the neighbourhood of a city of that name in Lydia, and from  the environs of Babylon. Among the
engraved sards which exist in the collection of antiques in the Bibliotbeque Royale of
Paris, there is an Apollo remarkable for its fine colour and, great size. When the stone
forms a part of the agate-onyx, it is called sardonyx. For further details upon Gems, and
the art of cutting and engraving them, see LAPIDARY.
GEOGNOSY, means a knowledge of the structure of the earth; GEOLOGY, a description
of the same. The discussion of this subject does not come within the province of this
GERHARDT'S ANHYDROUS ACETIC ACID. Mix perfectly dry fused acetate
of potash with about half its weight of chloride of benzoyle, and applying a gentle
heat, a limpid liquid distils over, which after being rectified has a constant boiling point of 279~ Fahr., is heavier than water, with which it does not mix till after
it has been agitated with it for some time. It dissolves at once in hot water, forming




898                                         GIN.
a hydrated acetic acid.  Its composition agrees perfectly with the atomic numbers.
See ACID, ACETIC.
GERMAN SILVER.  See the latter end of the article COPPER.
CGERMINATION; (Eng. and Fr.; Das Keimen, Germ.) is the first sprouting of a
seed after it is sown, or when, after steeping, it is spread upon the malt floor. See BEER.
GIG  MACHINES, are rotatory drums, mounted with  thistles or wire teeth  for
teazling cloth. See WOOLLEN MANUFACTURE.
GILDING  (Dorure, Fr.; Vergoldung, Germ.); is the art of coating surfaces with
a thin film of gold. For a full discussion of this subject, see GOLD. Mr. Elkington,
gilt toy maker, obtained a patent, in June, 1836, for gilding  copper, brass, &c., b
means of potash or soda combined with  carbonic acid, and with a solution of gold.
Dissolve, says he, 5 oz. troy of fine gold in 52 oz. avoirdupois of nitro-muriatic acid of
the following proportions; viz. 21 oz. of pure nitric acid, of spec. grav. 145, 17 oz.
of pure muriatic acid, of spec. grav. 1-15; with 14 oz. of distilled water.
Thie gold being put into the mixture of acids and water, they are to be heated in
a glass or other convenient vessel till the gold is dissolved; and it is usual to continue
the application of heat after this is effected, until a reddish or yellowish vapour ceases
to rise.
The clear liquid is to be carefully poured off from  any sediment which  generally
appears and results from a small portion of silver, which is generally found in alloy with
gold. The clear liquid is to be placed in a suitable vessel of stone; pottery ware is
preferred. Add -to the solution of gold 4 gallons of distilled water, and 20 pounds of bicarbonate of potash of the best quality; let the whole boil moderately for two hours, the
mixture will then be ready for use.
The articles to be gilded having been first perfectly cleaned from scale or grease, they
ate tc be suspended on wires, conveniently for a workman to dip them in the liquid, which
is kept boiling.  The time required for gilding any particular article will depend on circumstances, partly on the quantity of gold remaining in the liquid, and partly on the size
and weight of the article; but a little practice will readily give sufficient guidance to the
workman.
Supposing the articles desired to be gilded be brass or copper buttons, or smal
articles for gilt toys, or ornaments of dress, s;.:,h as ear-rings or bracelets, a considerable
number of which may be strung on a hoop, r_ bended piece of copper or brass wire, and
dipped into the vessel containing the boiling liquid above described, and moved therein,
the requisite gilding will be generally obtained in from a few seconds to a minute; this
is when the liquid is in the condition above described, and depending on the quality of
the gilding desired; but if the liquid has been used some time, the quantity of gold will
be lessened, which will vary the time of operating to produce a given eflect, or the
color required, all which will quickly be observed by the workman; and by noting
the appearance of the articles from time to time, he will know when the desired object
is obtained, though it is desirable to avoid as much as possible taking the articles out of
the liquid.
When the operation is completed, the workman perfectly washes the articles so gilded
with clean water; they may then be submitted to the usual process of coloring.
If the articles be cast figures of animals, or otherwise of considerable weight, compared
with the articles above mentioned, the time required to perform the process will be
greater.
In case it is desired to produce what is called a dead appearance, it may be performed
by several processes: the one usually employed is to dead the articles in the process of
cleaning, as practised by brass-founders and other trades; it is produced by an acid, prepared for that purpose, sold by the makers under the term " deading aquafortis," which
is well understood.
It may also be produced by a weak solution of nitrate of mercury, applied to the
articles previous to the gilding process, as is practised in the process of gilding with
mercury, previous to spreading the amalgam, but generally a much weaker solution; or
the articles having been gilded may be dipped in a solution of nitrate of mercury, and
submitted to heat to expel the same, as is practised in the usual process of gilding.
It is desirable to remark, that much of the beauty of the result depends on the well
cleaning of the articles, and it is better to clean them by the ordinary processes, and at
once pass them into the liquid to be gilded. See GOLD, towards the end.
GIN, or Geneva, from Genievre (juniper), is a kind of ardent spirits manufactured in
Holland, and hence called Hollands gin in this country, to distinguish it from British
gin.  The materials employed in the distilleries of Schiedam, are two parts of unmalted
rye from  Riga, weighing about 54 lbs. per bushel, and one part of malted bigg,
weighing about 37 lbs. per bushel.  The mash tun, which serves also as the fermenting
tun, has a capacity of nearly 700 gallons, being about five feet in diameter at the mouth,




GLASS.                                         899
rather narrower at the bottom, and 41 feet deep; the stirring apparatus is an oblon
rectangular iron grid made fast to the end of a wooden pole. About a barrel, =  36
gallons of water, at a temperature of from 162~ to 168~ (the former heat being best for
the most hi~ghly dried rye), are put into the mash tun for every 1l cwt. of meal, after
which the malt is introduced and stirred, and lastly the rye is added. Powerful agitation
is given to the magma till it becomes quite uniform; a process which a vigorous workman piques himself upon executing in the course of a few minutes. The mouth of the
tun is immediately covered over with canvas, and further secured by a close wooden lid
to confine the heat; it is left in this state for two hours. The contents being then stirred
up once more, the traneparent spent wash of a preceding mashing is first added, and next
as much cold water as will reduce the temperature of the whole to about 850 F. The
best Flanders yeast, which had been brought, for the sake of carriage, to a doughy consistence by pressure, is now introduced to the amount of one pound for every 100 gallons
of the mashed materials.
The gravity of the fresh wort is usually from 33 to 38 lbs. per Dicas' hydrometer; and
the fermentation is carried on from 48 to 60 hours, at the end of which time the attenuation is from 7 to 4 lbs., that is, the specific gravity of the supernatant wash is from 1007
to 1004.
The distillers are induced, by the scarcity of beer-barm in Holland, to skim off a quantity of the yeast from the fermenting tuns, and to sell it to the bakers, whereby they
obstruct materially the production of spirit, though they probably improve its quality, by
preventing its impregnation with yeasty particles; an unpleasant result which seldom fails
to take place in the whiskey distilleries of the United Kingdom.
On the third day after the fermenting tun is set, the wash containing the grains is
transferred to the still, and converted into low wines. To every 100 gallons of this liquor,
two pounds of juniper berries, from 3 to 5 years old, being added along with about one
quarter of a pound of salt, the whole are put into the low wine still, and the fine Holland
spirit is drawn off by a gentle and well-regulated heat, till the magma becomes exhausted;
the first and the last products being mixed together; whereby a spirit, 2 to 3 per cent.
above our hydrometer proof, is obtained, possessing the peculiar fine aroma of gin. The
quantity of spirit varies from 18 to 21 gallons per quarter of grain; this large product being
partly due to the employment of the spent wash of the preceding fermentation; an addition ~which contributes at the same time to improve the flavour.
For the above instructive details of the manufacture of genuine Hollands, I am
indebted to Robert More, Esq., formerly of Underwood, distiller, who, after studying the
art at Schiedam, tried to introduce that spirit into  general consumption  in  this
country, but found  the palates of our gin-drinkers too much  corrupted to relish so
pure a beverage.
GINGER BEER   Boil 65 gallons of river water, 11 cwt. of the best loaf sugar, and
5 lbs. of the best race ginger, bruised, half an hour; then add the whites of 10 eggs,
beaten to a froth with 2 ounces of dissolved isinglass.  Stir it well in, and boil 20
minutes longer, skimming it the whole time. Then add the thin rinds of 50 lemons,
boiling them 10 minutes more. Cut 28 lbs. of good Malaga raisins in half, take away the
stones and stalks, and put them, with the juice of the lemon, strained, into the hogshead.  Strain  the hot liquor into a cooler, and when it has stood two hours and is
settled, draw it off the lees, clear, and put it into the cask; filter the thick and fill
up with it.  Leave the bung out, and when at the proper temperature, stir 3 quarts
of thick fresh ale yeast well into it; put on the bung lightly, and let it ferment 6 or 7
days, filling up with liquor as it ferments over. When the fermentation has ceased, pour
in 6 quarts of French brandy, and 8 ounces of the best isinglass, dissolved in a gallon of
the wine; then secure the bung effectually, and paste paper over it, &c. Keep it 2
years in a cool cellar, then bottle it, using the best corks, and sealing them; and
when it is 4 years old commence using it.
GINNING-, is the name of the operation by which  the filaments of cotton  are
separable from the seeds. See COTTON MANUFACTURE.
GLANCE  COAL, or anthracite, of which  there are two varieties, the slaty and
the conchoidal.  See ANTHRACITE and PITCOAL.
GLASS (Verre, Fr.; Glas, Germ.); is a transparent solid formed by the fusion of
siliceous and alkaline matter.  It was known to the Phoenicians, and constituted for
a long time an exclusive manufacture of that people, in consequence of its ingredients,
natron, sand, and fuel, abounding upon their coasts.  It is probable that the more
ancient Egyptians were unacquainted with glass, for we find no mention of it in the
writings of Moses. But according to Pliny and Strabo, the glass works of Sidon and
Alexandria were famous in their times, and produced beautiful articles, which were
cut, engraved, gilt, and stained of the most brilliant colours, in imitation of precious
stones.  The Romans employed glass for various purposes; and have left specimens
in Herculaneum of window-glass, which must have been blown by methods analogous to




900                                         GLASS.
the moderm.  The Phoenician processes seem to have been learned by the Crusaders, and
transferred to Venice in the 13th century, where they were long held secret, and formed
a lucrative commercial monopoly. Soon after the middle of the 17th century, Colbert
enriched France with the blown mirror glass manufacture.
Chance undoubtedly had a principal share in the invention of this curious fabrication,
but there were circumstances in the most ancient arts likely to lead to it; such as the
fusing and vitrifying heats required for the formation of pottery, and for the extraction of
metals from their ores. Pliny ascribes the origin of glass to the following accident. A
merchant ship laden with natron being driven upon the coast at the mouth of the river
Belus, in tempestuous weather, the crew were compelled to cook their victuals ashore,
and having placed lumps of the natron upon the sand, as supports to the kettles, found
to their surprise masses of transparent stone among the cinders. The sand of this small
stream of Galilee, which runs from the foot of Mount Carmel, was in consequence supposed to possess a peculiar virtue for making glass, and continued for ages to be sought
after and exported to distant countries for this purpose.
Agricola, the oldest author who has written technically upon glass, describes furnaces
and processes closely resembling those employed at the present day. Neri, Kunckel,
Henckel, Pott, Achard, and some other chemists, have since then composed treatises
upon  the subject; but Neri, Bosc, Antic, Loysel, and  Allut, in the Encyclopodie
Methodique, are the best of the older authorities.
The window-glass manufacture was first begun in England in 1557, in Crutched Friars,
London; and fine articles of flint-glass were soon afterwards made in the Savoy House,
Strand.  In 1635 the art received a great improvement from Sir Robert Mansell, by the
use of coal fuel instead of wood. The first sheets of blown glass for looking-glasses and
coach windows were made in 1673 at Lambeth, by Venetian artisans employed under the
patronage of the Duke of Buckingham.
The casting of mirror-plates was commenced in France  about the year 1688, by
Abraham Thevart; an invention which gave rise soon afterwards to the establishment of
the celebrated works of St. Gobain, which continued for nearly a century the sole place
where this highly-prized object of luxury was well made. In cheapness, if not in excellence, the French mirror-plate has been for some time rivalled by the English.
The analysis of modern chemists, which will be detailed in the course of this article,
and the light thrown upon the manufacture of glass in general by the accurate means
now possessed of purifying its several ingredients, would have brou. ht the art long since
to the highest state of perfection in this country, but for the vexatious interference and
obstructions of our excise laws.
The researches of Berzelius having removed all doubts concerning the acia character
of silica, the general composition of glass presents now no difficulty of conception.
This substance consists of one or more salts, which are silicates with "bases of potash,
soda, lime, oxide of iron, alumina, or oxide of lead; in any of which compounds we can
substitute one of these bases for another, provided that one alkaline base be left. Silica
in its turn may be replaced by the boracic acid, without causing the glass to lose its
principal characters.
Under the title glass are therefore comprehended various substances fusible at a high
temperature. solid at ordinary temperatureb, brilliant, generally more or less transparent,
and always brittle. The following chemical distribution of glasses has been proposed.
1. Soluble glass; a simple silicate of potash or soda; or both of these alkalis.
2. Bohemian or crown glass; silicate of potash and lime.
3. Common window and mirror glass -. silicate of soda and lime; sometimes also of potash.
4. Bottle glass; silicate of soda, lime, alumina and iron.
5. Ordinary crystal glass; silicate of potash and lead.
6. Flint glass; silicate of potash and lead; richer in lead than the preceding.
7. Strass; silicate of potash and lead; still richer in lead.
8. Enamel; silicate and stannate or antimoniate of potash or soda, and lead.
The glasses which contain several bases are liable to suffer different changes when
they are uelted or cooled slowly. The silica is divided among these bases, forming new
compounds in definite proportions, which by crystallizing separate from  each other, so
that the general mixture of the ingredients which constitute the glass is destroyed. It
becomes then very hard, fibrous, opaque, much less fusible, a better conductor of electricity and of heat; forming what Reaumur styled devitrified glass; and what is called after
him Reaumur's porcelain.
This altered glass can always be produced in a more or less perfect state, by melting
the glass and allowing it to cool very slowly; or merely by heating it to the softening
pitch, and keeping it at this heat for some time. The process succeeds best with the
most complex vitreous compounds, such as bottle glass; next with ordinary window
glass; and lastly with glass of potash and lead.
This property ought to be kept constantly in view in manufacturing glass. It shows




GLASS-MAKING.                                          901
why in making bottles we should fashion them as quickly as possible with the aid of a
mould and reheat them as seldom as may be absolutely necessary. If it be often heated
and cooled, the glass loses its ductility, becomes refractory, and exhibits a multitude of
stony granulations throughout its substance. When coarse glass is worked at the enameller's lamp, it is apt to change its nature in the same way, if the workman be not quick and
expert at his business.
JFrom these facts we perceive the importance of making a careful choice of the glass
intended to be worked in considerable masses, such as the large object glasses of telescopes; as their annealing requires a very slow process of refrigeration, which is apt to
cause devitrified specks and clouds. For such purposes, therefore, no other species of
glass is well adapted except that with basis of potash and lead; or that with basis of
potash and lime. These two form the best flint glass, and crown glass; and they should
be exclusively employed for the construction of the object glasses of achromatic telescopes.
Crystal glass is rapidly corroded by the sulphate of ammonia at a heat of 600~ Fahr.
The following is an account of the exports of British manufacture:Quantities.             Declared Value.
1851.        1852.        1851.         1S52.
Flint glass  ------ -            cwts.       23,870       25,755    ~106,500   ~110,519
Window glass-         -          cwts.       15,517       16,460        20,077       22,234
Bottles, green or common  -  cwts.    296,065            825,804       162,843    172,880
Plate glass      -  -  -      - value       -     -             -       18,335       20,929
Imports and exports of Glass of Foreign and Colonial produce in the years ending
respectively 5th January, 1851 and 1852:Window  glass, not exceeding ~ of an inch thick, and shades and cylinders: imports,
21,015 cwts. and 12,358 cwts.; exports, 11,604 cwts. and 2,059 cwts.; duty on imports,
1,6561. and 1,8771.
All glass exceeding } of an inch thick, all silvered or polished glass of whatever thickness: imports, 122,394 sq. ft. and 173,935 sq. ft.; exports, 32,388 sq. ft. and 36,550
sq. ft.; duty received, 1,8451. and 2,8411.
White flint glass goods (except bottles) not cut, engraved, or otherwise ornamented:
imports, 95,240 lbs. and 102,002 lbs.; exports, 70,660 lbs. and 66,738 lbs.; duty received,
1011. and 108l.
All flint cut glass, flint coloured glass, and fancy ornamental glass: imports, 880,981
lbs. and 68,2,011 lbs.; exports, 187,209 lbs. and 166,948 lbs.; duty received, 5,5421.
and 4,4541.
GLASS-MAKING, general principles of.  Glass may be defined in technical phraseology, to be a transparent homogeneous compound formed by the fusion of silica with
oxides of the alkaline, earthy, or common metals.  It is usually colourless, and then
resembles rock crystal, but is occasionally stained by accident or design with coloured
metallic oxides.  At common temperatures it is hard and brittle, in thick pieces; in thin
plates or threads, flexible and elastic; sonorous when struck; fracture conchoidal, and
of that peculiar lustre called vitreous; at a red heat, becoming soft, ductile and plastic.
Besides glass properly so called, other bodies are capable of entering into vitreous fusion,
as phosphoric acid, boracic acid, arsenic acid, as also certain metallic oxides, as of lead,
and antimony, and several chlorides; some of which are denominated glasses. Impure
and opaque vitriform masses are called slags; such are the production of blast iron furnaces and many metallurgic operations.
Silica, formerly styled the earth of flints, which constitutes the basis of all commercial
glass, is infusible by itself in the strongest fire of our furnaces; but its vitreous fusion is
easily effected by a competent addition of potash or soda, either alone or mixed with lime
or litharge. The silica, which may be regarded as belonging to the class of acids, combines at the heat of fusion with these bases, into saline compounds; and hence glass may
be viewed as a silicate of certain oxides, in which the acid and the bases exist in equivalent.proportions. Were these proportions, or the quantities of the bases which silica
requires for its saturation at the melting point, exactly ascertained, we might readily
determine beforehand the best proportions of materials for the glass manufacture.  But
as this is far from being the case, and as it is, moreover, not improbable that the capacity
of saturation of the silica varies with the temperature, and that the properties of glass
also vary with the bases, we must, in the present state of our knowledge, regulate the
proportions rather by practice than by theory, though the latter may throw an indirect
light upon the subject. For example, a good colourless glass has been found by analysis
to consist of 72 parts of silica, 13 parts of potash, and 10 parts of lime, in 95 parts. If
we reduce these numbers to the equivalent ratios, we shall have the follbwing results;
taking the atomic weights as given by Berzelius.




902                                  GLASS-MAKING.
I atom potash =   590        14.67
1      lime       356         884)
3      silica     1722       42-79  71-49
2      silica     1155       28-70)
3823        95-00
This glass would therefore have been probably better compounded with the just atomic
proportions, to which it nearly approaches, viz. 71*49 silica, 14*67 potash, and 884 lime,
instead of those given above as its actual constituents.
The proportions in which silica unites with the alkaline and other oxydes are modified by the temperature as above stated; the lower the heat, the less silica will enter
into the glass, and the more of the base will in general be required. If a glass which
contains an excess of alkali be exposed to a much higher temperature than that of its
formation, a portion of the base will be set free to act upon the materials of the earthen
pot, or to be dissipated in fumes, until such a silicate remains as to constltute a permanent glass corresponding to that temperature. Hence the same mixture of vitrifiable
materials will yield very different results, according to the heats in which it is fused and
worked in the glass-house; and therefore the composition should always be referrible to
the going of the furnace.  When a species of glass which at a high temperature formed
a transparent combination with a considerable quantity of lime, is kept for some time in
fusion at a lower temperature, a portion of the lime unites with the silica into another
combination of a semi-vitreous or even of a stony aspect, so as to spoil the transparency
of the glass altogether. There is probably a supersilicate and a sub-silicate formed in
such cases; the latter being much the more fusible of the two compounds. The Reaumur s porcelain produced by exposing bottle glass to a red heat for 24 hours, is an example of this species of vitreous change, in which new affinities are exercised at a lower
temperature. An excess of silica, caused by the volatilization of alkaline matter with
too strong firing, will bring on similar appearances.
The specific gravity of glass varies from 2-3 to 3'6. That of least specific gravity consists of merely silica and potash fused together; that with lime is somewhat denser, and
with oxyde of lead denser still. Plate glass made from silica, soda, and lime, has a specific gravity which varies from 2'50 to 2-6; crystal or flint glass from 3*0 to 36.
The power of glass to resist the action of water, alkalis, acids, air, and light, is in
general the greater, the higher the temperature employed in its manufacture, the smalles
the proportion of its fluxes, and the more exact the equivalent ratios of its constituents.
When glass contains too much alkali, it is partially soluble in water. Most crystal glass
is affected by having water boiled in it for a considerable time; but crown glass being
poorer in alkali, and containing no lead, resists that action much longer, and is therefore
better adapted to chemical operations. The affinity of glass for water, or its hygrometric
attraction, is also proportional to the quantity of alkali which it contains. In general
also potash glass is more apt to become damp than soda glass, agreeably to the respective
hygrometric properties of these two alkalis, and also to the smaller proportion of soda
than of potash requisite to form glass.
Air and light operate upon glass probably by their oxydizing property. Bluish or
greenish colored  glasses become by exposure  colorless, in  consequence  undoubtedly of the peroxydizement of the iron, to whose protoxyde they owe their tint;
other glasses become purple red from the peroxydizement of the manganese. The glasses
which contain lead, suffer another kind of change in the air, if sulphureted hydrogen
be present; the oxyde of lead is converted into a sulphuret, with the effect of rendering
the surface of the glass opaque and iridescent. The more lead is in the glass, the
quicker does this iridescence supervene. By boiling concentrated sulphuric acid in a
glass vessel, or upon glass, we can ascertain its power of resisting ordinary menstrua. Good glass will remain smooth and transparent; bad glass will become rough
and dim.
The brittleness of unannealed glass by change of temperature is sometimes very
great. I have known a thick vessel to fly by vicissitudes of the atmosphere alone. This
defect may be corrected by slowly heating the vessel in salt water or oil to the highest
pitch consistent with the nature of these liquids, and letting it cool very slowly. Within
the limits of that range of heat, it will, in consequence of this treatment, bear alternations
of temperature without cracking as before.
It has been said that glass made from silica and alkalis alone will not resist the action
of water but that the addition of a little lime is necessary for this effect. In general
100 parts of quartzose sand require 33 parts of dry carbonate of soda for their vitrification, and 45 parts of dry carbonate of potash. But to make unchangeable alkaline glass,
especially with potash, a smaller quantity of this than the above should be used, with a
very violent heat. A small proportion of lime increases the density, hardness, and lustre
of glass; and it aids in decomposing the alkaline sulphates and muriates always present
in the pearlash of commerce.  From 7 to 20 parts of dry slaked lime have been added
Sir 100 of silica, with advantge, it is said, in some German glass manufactories, where




GLASS-MAKING.                                      903
the alkaline matter is soda; for potash does not assimilate well with the calcareous
earth.
In many glass works on the Continent, sulphate of soda is the form ander which alkalne
matter is introduced into glass.  This salt requires the addition of 8 per cent. of charcoal to decompose and dissipate its acid; a result which takes place at a high heat, without the addition of any lime.  88 pounds of quartz-sand, 44 pounds of dry glauber salt,
and 3 pounds of charcoal, properly mixed and fused, afford a limpid, fluent, and workable
glass; with the addition of 17 pounds of lime, these materials fuse more readily into a
plastic mass. If less carbon be added, the fusion becomes more tedious. The two following formulae afford good glauber salt glass.
1.      2.
Sand.-...     100      60'2
Calcined sulphate of soda    -    -        50      26-8
Lime   -      -    -     -    -     -      20      108
Charcoal      -    -    -    -    -   2-65          2-1
The first mixture has been proved in the looking-glass manufactory of Ne.haus near
Vienna, and the second by the experiments of Kirn.  The fusion of the first requires
IS, of the second 21 hours. The bluish green tinge which these otherwise beautiful and
brilliant glasses possess, is not removeable by the ordinary means, such as manganese or
arsenic, which decolor alkaline glass. When the sulphate of soda and charcoal are used
in smaller proportions, the glass becomes more colorless.  The tinge is no doubt owing
to the sulphur combining with the oxyde of sodium, in some such way as in the pigment
ultramarine.
By a proper addition of galena (the native sulphuret of lead), to glauber salt and quartz
sand, without charcoal, it is said a tolerably good crystal glass may be formed.  The
sulphuric acid of the salt is probably converted by the reaction of the sulphuret of lead
into sulphurous acid gas, which is disengaged.
One atom of sulphuret of lead = 1495-67, is requisite to decompose 3 atoms of sulphate
of soda == 2676.  It is stated, on good authority, that a good colorless glass may be obtained by using glauber salt without charcoal, as by the following formula.
Quartz-sand  -      ---             100 pounds
Calcined glauber salt    -    -      24
Lime  -— 20
Cullet of soda glass     -    -      12
The melting heat must be continued for 261 hours.  A small quantity of the sand is
reserved to be thrown in towards the conclusion of the process, in order to facilitate the
expulsion of air bubbles.  The above mixture will bear to be blanched by the addition
of manganese and arsenic. The decomposition of the salt is in this case effected by the
lime, with wuich the sulphuric acid first combines, is then converted into sulphurous acid,
and dissipated. Glass made in this way was found by analysis to consist of 79 parts of
silica, 12 lime, and 9'6 soda, without any trace of gypsum or sulphuric acid.
Glauber salt is partially volatilized by the heat of the furnace, and acts upon the arch
of the oven and the tops of the pots. This is best prevented by introducing at first into
the pots the whole of the salt mixed with the charcoal, the lime, and one fourth part of
the sand; fusing this mixture at a moderate heat, and adding gradually afterwards the
remainder of the sand, increasing the temperature at the same time.  If we put in the
whole ingredients together, as is done with potash glass, the sand and lime soon fall to
the bottom, while the salt rises to the surface, and the combination becomes difficult and
unequal.
Sulphate of potash acts in the same way as sulphate of soda.
Muriate of soda also, according to Kirn, may be used as a glass flux with advantage.
The most suitable proportions are 4 parts of potash, 2 of common salt, and 3 of lime,
agreeably to the following compositions:~
1.                       2.
Quartz-sand    -      -                     60-0                       75-1
Calcined carbonate of potash                 17*8                      19-1
Common salt ---                        - 89                             9.5
Lime       — ~              --               13.3                      14'3
For No. 1., the melting heat must be 10 hours, which turns out a very pure, solid, good
glass; for No. 2., 23 hours of the furnace are required. Instead of the potash, glauber
salt may be substituted; the proportions being then 19'1 glauber salt) 9'5 muriate of soda,
14-3 lime, 75'1 sand, and 13 charcoal
The oxide of lead is an essential constituent of the denser glasses, and may be regarded
as replacing the lime, so as to form with the quartz-sand a silicate of lead. It assimilates
best with purified pearl ash, on account of the freedom of this alkali from iron, which is
present in most sodas.




904                                       GLASS.
Its atomic constitution may be represented as follows:CoMputation.   Analysis.
Silicic acid   — 5 —          -      5 atoms  =    2877'            5919          59-20
Oxide of lead-      -1                          =    1394-5         2868          28.20
Potash-  -------                     1          =     590'0         12-13          9-00
Oxides of iron and manganese                           -             -             140
4861-5        100-00        100-0
The above analysis by Berthier relates to a specimen of the best English crystal glass,
perfectly colourless and free from air-bubbles. Thlis kind of glass may however take
several different proportions of potash and silica to the oxide of lead.
The composition of mirror-plate, as made on the Continent, is as follows
White quartz-sand          -        --                               300 pounds
Dry carbonate of soda                               -       -        100
Lime slaked in the air    -                                 -         43
Cullet, or old glass       -                                -        300
The manganese should not exceed one-half per cent. of the weight of soda.
Optical glass requires to be made with very peculiar care. It is of two different kinds;
namely, crown glass and flint glass. The latter contains a considerable proportion of lead,
in order to give it an increased dispersive power upon the rays of light, in proportion to
its mean refractive power.
Optical crown glass should be perfectly limpid, and have so little colour, that a pretty
thick piece of it may give no appreciable tinge to the rays of light. It should be exempt
from strive or veins as well as air-bubbles, and have not the slightest degree of milkiness.
It should moreover preserve these qualities when worked in considerable quantities.
Potash is preferable to soda for making optical crown glass, because the latter alkali is
apt to make a glass which devitrifies and becomes opalescent, by long exposure to heat
in the annealing process. A simple potash silicate would be free from this defect, but
it would be too attractive of moisture, and apt to decompose eventually by the humidity
of the atmosphere. It should therefore contain a small quantity of lime, and as little
potash as suffices for making a perfect glass at a pretty high temperature. It is probably
owing to the high heats used in the English crown glass works, and the moderate quantity
of alkali (soda) which is employed, that our crown glass has been found to answer so well
for optical purposes.
The following recipe for crown glass is excellent:5 atoms of silica (2j-?)      -       -       -       -  80
1 carbonate of soda   -       -       -       -       -  54
5 silica       -       -      -       -       -       -  80
I carbonate of lime   -       -       -       -       -  50
1 atom of carbonate of baryta         -       -       -  98
5 atoms of silica     -       -       -       -       -  80
Silicates of lime and baryta per se, or even combined, are very refractory; but they
vitrify well along with a third silicate, such as that of soda, or potash.
PRACTICAL DETAILS OF THE MANUFACTURE OF GLASS.
The Venetians were the first in modern times who attained to any degree of excellence
in the art of working glass, but the French became eventually so zealous of rivalling
them, particularly in the construction of mirrors, that a decree was issued by the court
of France, declaring not only that the manufacture of glass should not derogate from the
dignity of a nobleman, but that nobles alone should be masters of glass-works.  Within
the last 30 or forty years, Great Britain has made rapid advances in this important art,
and at the present day her pre-eminence in every department hardly admits of dispute.
There are five different species of glass, each requiring a peculiar mode of fabrication,
and peculiar materials: 1. The coarsest and simplest form of this manufacture is bottle
glass.  2. Next to it in cheapness of material may be ranked broad or spread window
glass. An improved article of this kind is now made near Birmingham, under the name
of British or German plate.  3. Crown glass comes next, or window glass, formed in
large circular plates or discs.  This glass is peculiar to Great Britain.  4. Flint glasr,
crystal glass, or glass of lead. 5. Plate or fine mirror glass.
The materials of every kind of glass are vitrified in pots made of a pure refractory
clay; the best kind of which is a species of shale or slate clay dug out of the coal-formation near Stourbridge.  It contains hardly any lime or iron, and consists of silica
and alumina in nearly equal proportions.  The masses are carefully picked, brushed,
and ground under edge iron wheels of considerable weight, and sifted through sieves




GLASS-MAKING.                                       905
having 20 meshes in the square inch. This powder is moistened with water (best hot),
and kneaded by the feet or a loam-mill into a uniform smooth paste. A large body of
this dough should be made up at a time, and laid by in a damp cellar to ripen. Previously to working it into shapes, it should be mixed with about a fourth of its weight of
cement of old pots, ground to powder.  This mixture is sufficiently plastic, and being
less contractile by heat, forms more solid and durable vessels. Glass-house pots have
the figure of a truncated cone, with the narrow end undermost; those for bottle and
window-glass being open at top, about 30 inches diameter at bottom, 40 inches at the
mouth, and 40 inches deep; but the flint-glass pots are covered in at top with adome-cap,
having a mouth at the side, by which the materials are introduced, and the glass is extracted. Bottle and crown-house pots are from 3 to 4 inches thick; those for flint-houses
are an inch thinner, and of proportionally smaller capacity.
The well-mixed and kneaded dough is first worked upon a board into k cake for
the bottom; over this the sides are raised, by laying on its edges rolls of clay above
each other with much manual labor, and careful condensation.  The clay is made
into  lumps, is equalized, and  slapped  much  in  the  same  way  as for making
POTTERY.   The pots  thus fashioned must be dried very prudently, first in  the
atmospheric temperature, and finally in a stove floor, which usually borrows its heat
directly from the glass-house. Before setting the pots in the furnace, they are annealed
during 4 or 5 days, at a red heat, in a small reverberatory vault, made on purpose.
Whena completely annealed, they are transferred with the utmost expedition into their
seat in the fire, by means of powerful tongs supported on the axle of an iron-wheel
carriage frame, and terminating in a long lever for raising them and swinging them
rou nd. The pot-setting is a desperate service, and when unskilfully conducted without
due mechanical aids, is the forlorn hope of the glass-founder.-Queque ipse miserrima
vidi. The celebrated chemist, Dr. Irvine, caught his last illness by assisting imprudently
at this formidable operation. The working breast of the hot furnace must be laid bare
so as to open a breach for the extraction of the faulty pot, and the insertion of the fresh
one, both in a state of bright incandescence. It is frightful to witness the eyes ane
fuming visages of the workmen, with the blackening and smoking of their scorched woollen clothes, exposed so long to the direct radiations of the flame. A light mask and sack
dress coated with tinfoil, would protect both their faces and persons from any annoyance,
at a very cheap rate.
The elass-houses are usually built in the form of a cone, from 60 to 100 feet high,
and from 50 to 80 feet in diameter at the base. The furnace is constructed in the centre
of the area, above an arched or groined gallery which extends across the whole space, and
terminates without the walls, in large folding doors. This cavern must be sufficiently high
to allow laborers to wheel out the cinders in their barrows. The middle of the vaulted
top is left open in the building, and is covered over with the grate-bars of the furnace.
1. Bottle glass.-The bottle-house and its furnace resemble nearly fig. 505. The furnace is usually an oblong square chamber, built of large fire-bricks, arrd arched over with
fire-stone, a silicious grit of excellent quality extracted from the coal measures of Newcastle. This furnace stands in the middle of the area; and has its base divided into three
compartments. The central space is occupied by the grate-bars; and on either side is
the platform or fire-brick siege (seat), raised about 12 inches above the level of the ribs
upon which the pots rest. Each siege is about 3 feet broad.
In the sides of the furnace, semi-circular holes of about a foot diameter are left opposite to, and a little above the top of, each pot, called working holes, by which the workmen shovel in the materials, and take out the plastic glass. At each angle of the furnace
there is likewise a hole of about the same size, which communicates with the calcining
furnace of a cylindrical form, dome-shaped at top. The flame that escapes from the founding or pot-furnace is thus economically brought to reverberate on the raw materials of the
bottle-glass, so as to dissipate their carbonaceous or volatile impurities, and convert them
into a frit. A bottle-house has generally eight other furnaces or fire-arches; of which
six are used for annealing the bottles after they are blown, and two for annealing the
pots, before setting them in the furnace.
The laws of this country till lately prohibited the use for making common bottles of
any fine materials. Nothing but the common river sand, and soap-boilers' waste, was
allowed.  About 3 parts of waste, consisting of the insoluble residuum of kelp, mixed
with lime and a little saline substance, were used for 1 part of sand. This waste was first
of all calcined in two of the fire arches or reverberatories reserved for that purpose, called
the coarse arches, where it was kept at a red heat, with occasional stirring, from 24 to 30
hours, being the period of a journey or journie, in which the materials could be melted
and worked into bottles. The roasted soap-waste was then withdrawn, under the name
of ashes, from its arch, coarsely ground, and mixed with its proper proportion of sand.
This mixture was now  put into the fine arch, and calcined during the working journey, which extended to 10 or 12 hours.  Whenever the pots were worked out, that frit




906                              GLASS-MAKING.
was immediately transferred into them  in its ignited state, and the founding
proceed d with such despatch that this first charge of materials was completely melted
down in 6 hours, so that the pots might admit to be filled up again with the second charge
of frit, which was founded in 4 hours more. The heat was briskly continued, and in the
course of from 12 to 18 hours, according to the size of the pots, the quality of the
fuel, and the draught of the furnace, the vitrification was complete. Before blowing the
bottles, however, the glass must be left to settle, and to cool down to the blowing consistency, by shutting the cave doors and feeding holes, so as to exclude the air from the
fire-rate and the bottom of the hearth.  The glass or metal becomes more dense, and
by its subsidence throws up the foreign lighter earthy and saline matters in the form of
a scum  on the surface, which is removed with skimming irons.  The furnace is now
charged with coal, to enable it to afford a working heat for 4 or 5 hours, at the end of
which time more fuel is cautiously added, to preserve adequate heat for finishing the
journey.
It is hardly possible to convey in words alone a correct idea of the manipulations necessary to the formation of a wine bottle; but as the manufacturers make no mystery of this
matter, any person may have an opportunity of inspecting the operation. Six people are
employed at this task; one, called a gatherer, dips the end of an iron tube, about five feet
long, previously made red-hot, into the pot of melted metal, turns the rod round so as to
surround it with glass, lifts it out to cool a little, and then dips and turns it round again;
and so in succession till a ball is formed on its end sufficient to make the required bottle.
He then hands it to the blower, who rolls the plastic lump of glass on a smooth stone or
cast-iron plate, till he brings it to the very end of the tube; he next introduces the
pear-shaped ball into an open brass or cast-iron mould, shuts this together by pressing a
pedal with his foot, and holding his tube vertically, blows through it, so as to expand the
cooling glass into the form of the mould. Whenever he takes his foot from the pedal-lever,
the mould spontaneously opens out into two halves, and falls asunder by its bottom hinge.
He then lifts the bottle up at the end of the rod, and transfers it to the finisher, who,
touching the glass tube at the end of the pipe with a cold iron, cracks off the bottle
smoothly at its mouth-ring. The finished bottles are immediately piled up in the hot annealing arch, where they are afterwards allowed to cool slowly for 24 hours at least. See
BOTTLE MOULD.
2. Broad or spread window-glass.-This kind of glass is called inferior window-glass,
in this country, because coarse in texture, of a wavy wrinkled surface, and very cheap,
but on the Continent spread window-glass, being made with more care, is much
better than ours, though still far inferior in transparency and polish to crown glass,
which has, therefore, nearly superseded its use among us. But Messrs. Chance and
Hartley, of West Bromwich near Birmingham, have of late years mounted a spread-glass
work, where they make British sheet glass, upon the best principles, and turn out an article quite equal, if not superior, to anything of the kind made either in France or Belgium. Their materials are those used in the crown-glass manufacture. The vitrifying
mixture is fritted for 20 or 30 hours in a reverberatory arch, with considerable stirring
and puddling with long-handled shovels and rakes; and the frit is then transferred by
shovels, while red hot, to the melting pots to be founded. When the glass is rightly
vitrified, settled, and brought to a working heat, it is lifted out by iron tubes, as will be
described under the article CROWN GLASS, blown into pears, which being elongated
into cylinders, are cracked up along one side, parallel to the axis, by touching them with
a cold iron dipped in water, and are then opened out into sheets. Glass cylinders
are spread in France, and at West Bromwich, on a bed of smooth stone Paris-plaster,
ar laid on the bottom of a reverberatory arch; the cylinder being placed on its side
horizontally, with the cracked line uppermost, gradually opens out, and flattens on the
hearth. At one time, thick plates were thus prepared for subsequent polishing into mirrors; but the glass was never of very good quality; and this mode of making mirror-plate
has accordingly been generally abandoned.
The spreading furnace or oven is that in which cylinders are expanded into talbles or
plates. It ought to be maintained at a brisk red heat, to facilitate the softening of the
glass. The oven is placed in immediate connexion with the annealing arch, so that the
tables may be readily and safely transferred from the former to the latter. Sometimes
the cylinders are spread in a large muffle furnace, in order to protect them from being
tarnished by sulphureous and carbonaceous fumes.
Fig. 709 represents a ground plan of both the spreading and annealing furnace; fig.
710 is an oblong profile in the direction of the dotted line x xfig. 709,
a is the fire-place; b b the canals or flues through which the flame rises into both
furnaces; c the spreading furnace, upon whose sole is the spreading slab. d is the cooling and annealing oven; e e iron bars which extend obliquely across the annealing arch,
and serve for resting the glass tables against, during the cooling. f f the channel
along which the previously cracked cylinders are slid, so as to be gradually warmed;




GLASS-MAKING.                                      907
g the opening in the spreading furnace, for enabling the workmen to regulate the pro.
710
3   3
cess; h a door in the annealing arch, for introducing the tools requisite for raising ur,
and removing the tables.
In forming glass-plates by the extension of a cylinder into a plane, the workman first
blows the lump of glass into the shape of an oblong pear, the length of which must be
nearly equal to the length of the intended plate, and its diameter such, that the circumference, when developed, will be equal to the breadth of the plate. He now rests the
blowving iron on a stool or iron bar, while an assistant, with a pointed iron, pierces a hole
into the extreme end of the pear, in the line of the blowing-pipe. This opening is then
enlarged, by introducing the blade of a pair of spring-tongs, while the glass is turned
round; and by skilful management, the end of the pear is eventually opened out into a
cylindrical mouth. The workman next mounts upon a stool, and holds the blowing-iron
perpendicularly. The blown cylinder is now cracked off; a punto rod of iron having been
previously stuck to its one end, to form a spindle for working the other by. This rod has
a flat disc on its end, or three prongs, which being dipped in melted glass, are applied to
the mouth of the cylinder. By this as a handle, the glass cone is carried to the fire, and
the narrow end being heated, is next opened by spring tongs, and formed into a cylinder
of the same size as the other end.  The cylinder, thus equalized, is next cracked or slit
down in its side with a pair of shears, laid on a smooth copper plate, detached from the
iron rod, spread out by heat into a plane surface, and finally annealed. This series of
transformations is represented in fig.'721, at A, B, c, D, E, F, G, H.
Figs.'712 and 713 represent a Bohemian furnace in which excellent white window
glass is founded. Fig. 712 is a longitudinal section of the glass and annealing furnace.
Fig. 1713 is the ground plan. a is the ash-pit vaulted under the sole of the furnace; the
fire-place itself is divided into three compartments; with a middle slab at d, which is hollowed in the centre, for collecting any split glass, and two hearth tiles or slabs b b. c c
A   1ii D'712                 are the draught or air holes; e e are
A       ^                                    <     arches upon which the bearing slabs
6J     )1          is'                             ff  partly rest. In the middle beI III                       tween these arches, the flame strikes
B                                                  upwards upon the pots g g, placed
as closely together as possible, for
economy of room. h is the breast
wall of the furnace; i,fig.'713, the
c                                                  opening through which the pots are
H713                          introduced; it is bricked up as soon
as they are set. k k, is the base of
4   the cone or dome of the furnace;
f F                                         1 ^ ^ ~^1 1 the working orifices, which
1Sll  H tftare ma de larger or smaller according to the size of the glass articles
18'7              /   leads to the annealing stove n, with
II/   an arched door.  Exterior to this,
there is usually a drying kiln not
shown in the figure; and there are
adjoining stoves called arches, for
drying and annealing the new pots before they are set.
The cooling or annealing arch, or leer, is often built independent of the glass-house
furnace, is then heated by a separate fire-place, and constructed like a very long reverberatory furnace. See COPPER.
The leer pans or trays of sheet-iron, are laid upon its bottom in an oblong series, and
hooked to each other.
3. Crown-glass.-The crown-glass house with its furnace is represented in fig. 714,
where the blowing operation is shown on the one side of the figure, and the flashing on
the other. The furnace is usually constructed to receive 4 or 6 pots, of such dimen.
sions as to make about a ton of glass each at a time. There are, however, several sub



908                                GLASS-MAKING.
sidiary furnaces to a crown-house. 1. A reverberatory furnace or calcar, ior calcining oI
fritting the materials; 2. a tow
f \ $^^^^&^ \\\\\i        ing furnace, for blowing the pear.
/q14   /  ^^^  ^^\\\\Wll^              shaped balls, made  at the  potholes, into  large  globes;  3. a
flashing  furnace, and bottoming
hole for communicating a softening heat, in expanding the globe
into  a  circular  plate;  4. the
\'  (\  annealing  arch for  the finished
4lw  ^ ^1      /1^           I u      tables; 5. the reverberatory oven
14li' 11    t /!L If   | u              for annealing the pots prior to
their being set upon the founding
siege.:~f                 -.t We    jSThe materials of crown  glass
used to be, fine sand, by measure
5 parts, or by weight 10; ground
ji"^l ^P   Jkelp by measure 11 parts, or by
weight 161; but instead of kelp,
soda ash is now generally employed.
Ki li lJttis,  _       From  6 to 8 cwts. of sand, lime,
and soda-ash, mixed together in
wooden boxes with a shovel, are thrown on the sole of a large reverberatory, such as is
represented in the article COPPER. Here the mixture is well worked together, with iron
paddles, flat shovels, and rakes with long handles; the area of this furnace being about
6 feet square, and the height 2 feet. The heat soon brings the materials to a pasty consistence, when they must be diligently turned over, to favor the dissipation of the carbon,
sulphur, and other volatile matters of the kelp or soda ash, and to incorporate the fixed
ingredients uniformly with the sand. Towards the end of three hours, the fire is considerably raised, and when the fourth hour has expired, the fritting operation is finished.
The mass is now shovelled or raked out into shallow cast-iron square cases, smoothed
down, and divided, before it hardens by cooling, into square lumps, by cross sections with
the spade. These frit-bricks are afterwards piled up in a large apartment for use; and
have been supposed to improve with age, by the efflorescence of their saline constituents
into carbonate of soda on their surface.
The founding-pots are filled up with these blocks of frit, and the furnace is powerfully
urged by opening all the subterranean passages to its grate, and closing all the doors
and windows of the glass-house itself. After 8 or 10 hours the vitrification has made
such progress, and the blocks first introduced are so far melted down, that another charge
of frit can be thrown in, and thus the pot is fed with frit till the proper quantity is used.
In about 16 hours the vitrification of the frit has taken place, and a considerable quantity, amounting often to the cwt. of liquid saline matter, floats over the glass. This salt is
carefully skimmed off into iron pots with long ladles. It is called Sandiver or Glass-gall,
and consists usually of muriate of soda, with a little sulphate. The pot is now ready for
receiving the topping of cullet, which is broken pieces of window glass, to the amount of
3 or 4 cwts. This is shovelled in at short intervals; and as its pressure forces up the
residuary saline matter, this is removed; for were it allowed to remain, the body of the
glass would be materially deteriorated.
The heat is still continued for several hours till the glass is perfect, and the extrication
of gas called the boil, which accompanies the fusion of crown glass, has nearly terminated,
when the fire is abated, by shutting up the lower vault doors and every avenue to the
grate, in order that the glass may settle fine. At the end of about 40 hours altogether,
the fire being slightly raised by adding some coals, and opening the doors, the glass is
carefully skimmed, and the working of the pots commences.
Before describing it, however, we may state that the marginal figure 715 shows the
^15                                             base of the crown-house cone, with the
four open pots in two ranges on opposite
sides of the furnace, sitting on their raised
sieges, at each side of the grate. At one
side of the base the door of the vault is...""""^^.  sP.      shown, and its course is marked by the
Detailed description of the crown-glass furnace, figs. 716, 717.-It is an oblong square,
built in the centre of a brick cone, large enough to contain within it, two or three pots
at each side of the grate room, which is either divided as shown in the plan, or runs the
whole length of the furnace, as the manufacturer chooses. Fig. 716 is a ground plan, and
fig. 717 a front elevation, of a six-pot furnace.  1, 2, 3,fig. 717, are the working holes




GLASS-MAKING.                                 909
for the purposes of ventilation, of putting in the materials, and of taking out the metal
to be wrought. 4, 5, 6, 7, are pipe holes for warming the pipes before beginning to work
with them. 8, 9, 10, are foot holes for mending the pots and sieges.  11 is a bar of iron
for binding the furnace, and keeping it from swelling.
7167
The arch is of an elliptic form; though a barrel arch, that is, an arch shaped like the
half of a barrel cut longwise through the centre, is sometimes used. But this soon gives
way when used in the manufacture of crown glass, although it does very well in the clayfurnace used for bottle houses.
The best stone for building furnaces is fire-stone, from Coxgreen in the neighborhood of Newcastle.  Its quality is a close grit, and it contains a greater quantity of
talc than the common fire-stone, which seems to be the chief reason of its resisting the
fire better. The great danger in building furnaces is, lest the cement at the top should
give way with the excessive heat, and by dropping into the pots, spoil the metal. The top
should therefore be built with stones only, as loose as they can hold together after the centres are removed, and without any cement whatever. The stones expand and come quite
close together when annealing; an operation which takes from eight to fourteen days at
most. There is thus less risk of any thing dropping from the roof of the furnace.
The inside of the square of the furnace is built either of Stourbridge fire-clay annealed,
or the Newcastle fire-stone, to the thickness of sixteen inches. The outside is built of
common brick about nine inches in thickness.
The furnace is thrown over an ash-pit, or cave, as it is called, which admits the atmospheric air, and promotes the combustion of the furnace. This cave is built of stone
until it comes beneath the grate room, when it is formed of fire-brick. The abutments
are useful for binding and keeping the furnace together, and are built of masonry. The
furnaces are stoutly clasped with iron all round, to keep them tight. In four-pot furnaces
this is unnecessary, provided there be four good abutments.
Fig. 718 is an elevation of the flashing furnace. The outside is built of common brick,
the inside of fire-brick, and the mouth or nose of Stourbridge fire-clay.
Fig. 719 is the annealing kiln. It is built of common brick, except round the grate
room, where fire-brick is used.
Few tools are needed for blowing and flashing crown-glass.  The requisite ball of
plastic glass is gathered, in successive layers as for bottles, on the end of an iron tube, and
rolled into a pear-shape, on a cast-iron plate; the workman taking care that the air
blown into its cavity is surrounded with an equal body of glass, and if he perceives any
side to be thicker than another, he corrects the inequality by rolling it on the sloping
iron table called marver, (marbre). He now heats the bulb in the fire, and rolls it so a,




910                             1 GLASS-MAKING.
to form  the -gass upon the end of the tube, and by a dexterous swing or two he
lengthens it, as shown in x, fig. 720. To extend the neck of that pear, he next rolls it
over a smooth iron rod, turned round in a horizontal direction, into the shape, fig. 720.
By further expansion at the blowing-furnace, he now brings it to the shape L. represented in fig. 720.
719                                                              L 
~   ~          tC'718
I4 ~~~''~L %, I -" 
^5 __     X-                                  i  r',','-" I,',
This spheroid having become cool and somewhat stiff, is next carried to the bottoming
hole (like fig. 718\ to be exposed to the action of flame. A slight wall erected before
one half of this hole, screens the workman from the heat, but leaves room for the globe to
pass between it and the posterior wall. The blowing-pipe is made to rest a little way from
the neck of the globe, on a hook fixed in the front wall; and thus may be made easily to revolve on its axis, and by giving centrifugal force to the globe, while the bottom of it, or
part opposite to the pipe, is softened by the heat, it soon assumes the form exhibited in
ml fig. 720.
In this state the flattened globe is removed from the fire, and its rod being rested on
the casherbox covered with coal cinders, another workman now applies the end of a solid
iron rod tipped with melted glass, called a punto, to the nipple or prominence in the
middle; and thus attaches it to the centre of the globe, while the first workman cracks
off the globe by touching its tubular neck with an iron chisel dipped in cold water. The
workman having thereby taken possession of the globe by its bottom or knobbed pole
attached to his punty rod, he now carries it to another circular opening, where he exposes
it to the action of moderate flame with regular rotation, and thus slowly heats the thick
projecting remains of the former neck, and opens it slightly out, as shown at N, in
fig. 720. He next hands it to the flasher, who, resting the iron rod in a hook placed
near the side of the orifice A, fig. 718, wheels it rapidly round opposite to a powerful
flame, till it assumes first the figure o, and finally that of a flat circular table.
The flasher then walks off with the table, keeping up a slight rotation as he moves
along, and when it is sufficiently cool, he turns down his rod into a vertical position,
and lays the table flat on a dry block of fire-clay, or bed of sand, when an assistant
nips it off from the punto with a pair of long iron shears, or cracks it off with a toucl
of cold iron. The loose table or plate is lastly lifted up horizontally on a double prongeL
iron fork, introduced into the annealing arch fig. 719 and raised on edge; an assistant with
a long-kneed fork preventing it from falling too rapidly backwards. In this arch a great
many tables of glass are piled up in iron frames, and slowly cooled from a heat of about
6000 to 1000 F., which takes about 24 hours; when they are removed. A circular plate
or table of about 5 feet diameter weighs on an average 9 pounds.
4. Flint glass.-This kind of glass is so called because originally made with calcined
flints, as the silicious ingredient. The materials at present employed in this country
for the uinest flint glass or crystal, are first, Lynn sand, calcined, sifted, and washed;
second, an oxyde of lead, either red lead or litharge; and third, pearlash. The pearlash of commerce must however be purified by digesting it in a very little hot water,
which dissolves the carbonate of potash, and leaves the foreign salts, chiefly sulphate of
potash, muriate of potash, and muriate of soda.  The solution of the carbonate being
allowed to cool and become clear in lead pans, is then run off into a shallow iron boiler,
and evaporated to dryness. Nitre is generally added as a fourth ingredient of the body
of the glass; and it serves to correct any imperfections which might arise from
accidental combustible particles, or from the lead being not duly oxydized. The above
four substances constitute the main articles; to which we may add arsenic and manganese, introduced in  very small quantities, to purify the color and clear up the
transparency of the glass. The black oxyde of manganese, when used in such quantity
only as to peroxydize the iron of the sand, simply removes the green tinge caused by the
iron; but if more manganese be added than accomplishes that purpose, it will give a
purple tinge to the glass; and in fact, most manufacturers prefer to have an excess
rather than a defect of manganese, since cut glass has its brilliancy increased by a faint
lilach hue. The arsenic is supposed to counteract the injury arising from excess of manganese, but is itself very apt on the other hand to communicate some degree of opalescence,




GLASS-MAKING.                                  911
or at least, to impair the lustre of the glass.  When too much manganese has been
added, the purple tinge may indeed be removed by any carbonaceous matter, as by
thrusting a wooden rod down into the liquid glass; but this cannot be done with good
effect in practice, since the final purple tinge is not decided till the glass is perfectly
formed, and then the introduction of charcoal would destroy the uniformity of the whole
zontents of the pot.
The raw materials of flint glass are always mixed with about a third or a fourth of
their weight of broken crystal of like quality; this mixture is thrown into the pot
with a shovel; and more is added whenever the preceding portions by melting subside; the
object being to obtain a pot full of glass, to facilitate the skimming off the impurities
~21                               and sandiver. The mouth of the pot
is now shut, by applying clay-lute round
the stopper, with the exception of a
small orifice below, for the escape of
/  ^ili  n                   the liquid saline matter.  Flint glass
requires about 48 hours for its complete
//~~~~ flir   II W)vitrification, though the materials be
more fusible than those of crown glass;
in consequence of the contents of the
pot being partially screened by its cover
T  from the action of the fire, as also from
Snl  /  n n  E I_  the lower intensity of the heat.
Fig. 121 represents a flint glass
house for 6 pots, with the arch or leer
on one side for annealing the crystal
-  ware.  In fig. 722, the base of the
"     cone is seen, and the glass pots in situ;1        _              I_|  ^     Pon their platform ranged round the central fire grate. The dotted line denotes
the contour of the furnace,fig. 721.
Whenever the glass appears fine,
and is freed from its air bubbles, which
it usually is in about 36 hours, the
___~II^^Yttdl~^^^^        heat is suffered to fall a little by closing'722                                              the bottom valves, &c., that the pot
may settle; but prior to working the
1111111,    -          --—' —-" \\.............  metal the heat is somewhat raised again.
It would be useless to describe the
manual operations of fashioning the
various articles of the flint-glass manufacture, because they are indefinitely varied to suit
the conveniences and caprices of human society.
Every different flint-house has a peculiar proportion of glass materials. The following
have been offered as good practical mixtures.
1. Fine white sand   -       -       -       -      -       -       300 parts.
Red lead or litharge       -...      -       200
Refined pearlashes        -       -       -.      -        80
Nitre      -                                                      20
Arsenic and manganese, a minute quantity.
In my opinion, the proportion of lead is too great in the above recipe, which is given
on the authority of Mr. James Geddes, of Leith.  The glass made with it would be
probably yellowish and dull.
2. Fine sand               -.-                             -      -       50*5
Litharge -       -       -      -       -       -      -       -       27*2
Refined pearlashes (carbonate of potash, with 5 per cent. of water)   17-5
Nitre...-.-                                  -        4-8
100*0
To these quantities from 30 to 50 parts of broken glass or cullet are added; with about
a two-thousandth part of manganese, and a three-thousandth part of arsenic. But manganese varies so extremely in its purity, and contains often so much oxyde of iron, that
nothing can be predicated as to its quantity previously to trial.
M. Payen, an eminent manufacturing chemist in France, says that the composition of
crystal does not deviate much from the following proportions
Wood fire.      Coal fire
Silicious sand   - - - 3                                  3
Minium  --- 2                                             24
Carbonate of potash --                     1              I1f




-912                              GLASS-MAKING.
I conceive that this glass contains too much lead and potash. Such a mixture will prcx
duce a dull metal, very attractive of moisture; defects to which the French crown-glass
also is subject.
The flint-glass leer for annealing glass, is an arched gallery or large flue, about 36 feet
long, 3 feet high, 4 wide; having its floor raised above 2 feet above the ground of the
glass-house.  The hot air and smoke of a fire-place at one end pass along this gallery,
and are discharged by a chimney 8 or 10 feet short of the other end. On the floor of the
vault, large iron trays are laid and hooked to each other in a series, which are drawn from
the fire end towards the other by a chain, wound about a cylinder by a winch-handle projecting through the side.  The flint-glass articles are placed in their hot state into the
tray next the fire, which is moved onwards to a cooler station whenever it is filled, and
an empty tray is set in its place.  Thus, in the course of about 20 hours, the glass advances to the cool end thoroughly annealed.
Besides colorless transparent glass, which forms the most  mnportant part of this
manufacture, various colored glasses are made to suit the taste of the public.  The
taste at Paris was lately for opaline crystal; which may be prepared by adding to the
above composition (No. 2) phosphate of lime, or well burnt bone ash in fine powder,
washed and dried.   The article must be as uniform  in thickness as possible, and
speedily worked into shape, with a moderate heat.  Oxyde of tin, putty, was formerly
used for making opalescent glass, but the lustre of the body was always impaired by its
means.
Crystal vessels have been made recently of which the inner surface is colorless, and al
the external facets colored.  Such works are easily executed.  The end of the blowingrod must be dipped first in the pot containing colorless glass, to form a bulb of a certain
size, which being cooled a little is then dipped for an instant into the pot of colored glass.
The two layers are associated without intermixture; and when the article is finished in
its form, it is white within and colored without. Fluted lines, somewhat deeply cut, pass
through the colored coat, and enter the colorless one; so that when they cross, their ends
alone are colored.
For some time past, likewise, various crystal articles have been exhibited in the market
with colored enamel-figures on their surface, or with white incrustations of a silvery
lustre in their interior.  The former are prepared by placing the enamel object in the
brass mould, at the place where it is sought to be attached. The bulb of lass being put
into the mould, and blown while very hot, the small plate of enamel gets cemented to the
surface.  For making the white argentine incrustations, small figures are prepared with
an impalpable powder of dry porcelain paste, cemented into a solid by means of a little
gypsum plaster.  When these pieces are thoroughly dried, they are laid on the glass
while it is red hot, and a large patch of very liquid glass is placed above it, so as to encase
it and form one body with the whole. In this way the incrustation is completely enclosed;
and the polished surface of the crystal, which scarcely touches it, gives a brilliant aspect,
pleasing to the eye.
A uniform flit-glass, free from strim, or wreath, is much in demand for the optician.
It would appear that such an article was much more commonly made by the English
manufantrers many years ago, than at present; and that in improving the brilliancy of
crystal-glass they have injured its fitness for constructing optical lenses, which depends
not so rouch on its whiteness and lustre as on the layers of different densities being parallel
to each other. The oxyde of lead existing in certain parts of a potful of glass in greater
proportion than in other parts, increases the density unequally in the same mass, so that
the adjoining strata are often very different in this respect.  Even a potful of pretty
uniform -lass, when it stands some time liquid, becomes eventually unequable by the subsidence of the denser portions; so that striae and gelatinous appearances begin to manifest
themselves, and the glass becomes of little value. Glass allowed to cool slowly in mass in
the pot is particularly full of wreath; and if quickly refrigerated, that is, in two or three
hours, it is apt to split into a multitude of minute splinters, of which no use can be made.
For optical purposes, the glass must be taken out in its liquid state, being gathered on
the end of the iron rod from the central portion of a recently skimmed pot, after the upper
layers have been worked off in general articles.
M. Guinand, of Brennets near Geneva, appears to have hit upon processes that fur.
nished almost certainly pieces of flint-glass capable of forming good lenses of remarkable
dimensions, even of 11 inches diameter; of adequate density and transparency, and
nearly free from stria,.  M. Cauchoix, the eminent French optician, says, that out of
ten object glasses, 4 inches in diameter, made with M. Guinand's flint glass, eight or
nine turned out very good, while out of an equal number of object glasses made of the
flint glass of the English and French manufactories, only one, or two ar most, were found
serviceable. The means by which M. Guinand arrived at these results have not been
published. He has lately died, and it is not known whether his son be in possession of
his secret.




GLASS-MAKING.                                    913
An achromatic object glass for telescopes and microscopes consists of at least two
lenses; the one made with glass of lead, or flint-glass, and the other with crown-glass;
the former possessing a power of dispersing the colored rays relatively to its mean refractive power, much greater than the latter; upon which principle the achroatism or the
image is produced, by reuniting the different colored rays into one focus. Flint-glass to
e fit for this delicate purpose must be perfectly homogeneous, or of uniform density
throughout its substance, and free from wavy veins or wreaths; for every such inequality would occasion a corresponding inequality in the refracti.n and dispersion of the
lit; like what is perceived in looking throuoh a thick and thin solution of gm-arabic
imperfectly mixed. Three plans have been prescribed for obtaining homogeneous pieces
of optical glass: 1. to lift a mass of it in larce ladles, and let it cool in them; 2. to
pour it out from the pots into moulds; 3. to allowit to cool in the pots, and afterwards
to cut it off in horizontal strata. The last method, which is the most plausible, seldom
affords pieces of uniform density, unless peculiar precautions have been adopted to settle
the flint glass in uniform strata; because its materials are of such unequal density, the
oxyde o lead having a specific gravity of 8, and silica of 2-7, that they are apt to stand
at irreular heits in the pots.
One main cause of these inequalities lies in the construction of the furnace whereby
the bottom of the pot is usually much less heated than the upper part. In a plate glass
furnace the temperature of the top of the pot has been found to be 130~        while
that of the bottom was only 110~, constituting a difference of no less than 2610 F.
The necessary consequence is that the denser particles which subside to the bottom,
during the fusion of the materials, and after the first extrication of the gases, must
remain there, not being duly agitated by the expansive force of caloric, acting from
below upwards.
The preparation of the best optical glass is now made a great mystery by one or two
proficients. The following suggestions, deduced from a consideration of principles, may
probably lead to some improvements, if judiciously applied. The great object is to counteract the tendency of the glass of lead to distribute itself into strata of different densities; which may be effected either by mechanical agitation or by applying the greatest
heat to the bottom of the pot. But however homogeneous the glass may be thereby ade,
its subsequent separation into strata of different densities must be prevented by rapid
coolin and solidification. As the deeper the pots, the greater is the chance of unequal
specific gravity in their contents, it would be advisable to make them wider and shallower than those in use for making ordinary glass.  The intermixture may be effected
either by lading the glass out of one pot into another in the furnace, and back again, with
copper ladles, or by stirring it up with a rouser, then allowing it to settle for a short
time, till it becomes clear and free from air bubbles. The pot may now be removed from
the furnace, in order to solidify its contents in their homogeneous state; after which the
glass may be broken in pieces, and be perfected by subjecting it to a second fusion; or,
what is easier and quicker, we may form suitable discs of glass without breaking down
the potful, by lifting it out in flat copper ladles with iron shanks,, and transferring the
lumps after a little while into the annealing leer.
723                To render a potful of glass homogeneous by agitation, Is a
more difficult task, as an iron rod would discolor it, and a
copper rod would be apt to melt. An iron rod sheathed in
laminated platinum would answer well, but for its expense.
A stone-ware tube supported within by a rod of iron, might
also be employed for the purpose in careful hands; the stirring being repeated several times, till at last the glass is
I           ~~~~suffered to stiffen a little by decrease of temperature.  It
must then be allowed to settle and cool, after which the pot.,
being of small dimensions, may be drawn out of the fire.
2. The second method of producing the desired uniformity
of mixture, consists in applying a greater heat to the bottom
than to the upper part of the melting, pot. Fig. 72.3 repreC         B      ~~~~~sents in section a furnace contrived to effect this object.  It
is cylindrical, and of a diameter no greater than to allow the
A               flames to play round the pot, containing from  three to four
cwts. of vitreous materials.  A is the pot, resting upon the
6   o         ~~~~arched grid b a, built of fire-bricks, whose apertures are wide
enough to let the flames rise freely, and strike the bottom and
sides of the vessel.  From 1.1 to 2 feet under that arch, the
fuel grate c d is placed. a c are the two working openings
F~~~7 ~for introducing the materials, and inspecting the progress of
-- the fusion; they must be closed with fire-tiles and luted with
fire-clay at the beginning of the process. At the back of the furnace, opposite the mouth




914                              GLASS-MAKING.
of the fire-place there is a door-way, which is bricked up, except upon occasion of putting in and taking out the pot. The draught is regulated by means of a slide-plate upon
the mouth of the ash-pit f. The pot being heated to the proper pitch, some purified
pearlash, mixed with fully twice its weight of colorless quartz sand is to be thrown into
it, and after the complete fusion of this mixture, the remaining part of the sand along with
the oxyde of lead (fine litharge) is to be strown upon the surface.  These silicious particles in their descent serve to extricate the air from the mass. Whenever the whole is
fused, the heat must be strongly urged, to ensure a complete uniformity of combination
by the internal motions of the particles. As soon as the glass has been found, by making
test vials, to be perfectly fine, the fire must be withdrawn, the two working holes must
be opened, as well as the mouths of- the fire-place and ash-pit, to admit free ingress to
cooling currents of air, so as to congeal the liquid mass as quickly as possible; a condition essential to the uniformity of the glass. It may be worth while to stir it a little
with the pottery rod at the commencement of the cooling process. The solidified glass
may be afterwards detached by a hammer in conchoidal discs, which, after chipping off
their edges, are to be placed in proper porcelain or stone-ware dishes, and exposed to a
softening heat, in order to give them a lenticular shape. Great care must be taken that
the heat thus applied by the muffle furnace be very equable, for otherwise wreaths
might be very readily reproduced in the discs.  A  small oven, upon the plan of a
baker's, is best fitted for this purpose, which being heated to dull redness, and then
extinguished, is ready to soften and afterwards anneal the conchoidal pieces.
Guinand's dense optical flint glass, of specific gravity 3,616, consists, by analysis, of
oxyde of lead, 43-05; silica, 44'3; and potash, 11*75; but requires for its formation the
following ingredients: 100 pounds of ground quartz; 100 pounds of fine red lead; 35
pounds of purified potash; and from 2 to 4 pounds of saltpetre. As this species of glass
is injured by an excess of potash, it should be compounded with rather a defect of it,
and melted by a proportionably higher or longer heat. A good optical glass has been
made in Germany with 7 parts of pure red lead, 3 parts of finely ground quartz, and 2
parts of calcined borax.
5. Plate glass.
This, like English crown-glass, has a soda flux; whereas flint-glass requires potash,
and is never of good quality when made with soda. We shall distribute our account of
this manufacture under two heads.
1. The different furnaces and principal machines, without whose knowledge it would
be impossible to understand the several processes of a plate-glass factory.
2. The materials which enter into the composition of this kind of glass, and the series
of operations which they undergo; devoting our chief attention to the changes and improvements witich long experience, enlightened by modern chemistry, has introduced into
the great manufactory of Saint-Gobin, in France, under the direction of M. Tassaert. It
may however be remarked, that the English plate-glass manufacture derives peculiar
advantages from the excellence of its grinding and polishing machinery.
The clay for making the bricks and pots should be free from lime and iron, and very
refractory. It is mixed with the powder of old pots passed through a silk sieve. If the
clay be very plastic it will bear its own weight of the powder, but if shorter in quality,
it will take only three fifths. But before mingling it with the cement of old pots, it must
be dried, bruised, then picked, ground, and finally elutriated by agitation with water,
decantation through a hair sieve, and subsidence. The clay fluid after passing the sieve
is called slip (coulis).
The furnace is built of dry bricks, cemented with slip, and has at each of its four
angles a peculiar annealing arch, which communicates with the furnace interiorly, and
thence derives sufficient heat to effect in part, if not wholly, the annealing of the pots,
which are always deposited there a long time before they are used.  Three of these
arches, exclusively appropriated to this purpose, are called pot-arches.  The fourth is
called the arch of the materials, because it serves for drying them before they are founded.
Each arch has, moreover, a principal opening called the throat, another called bonnard,
by the French workmen, through which fire may be kindled in the arch itself, when it
was thought to be necessary for the annealing of the pots; a practice now abandoned.
The duration of a furnace is commonly a year, or at most 14 months; that of the arches
is 30 years or upwards, as they are not exposed to so strong a heat.
In the manufacture of plate-glass two sorts of crucibles are employed, called the
pots and the basins (cuvettes).  The first serve for containing the materials to be
founded, and for keeping them a long time in the melted state. The cuvettes receive the
melted glass after it is refined, and decant it out on the table to be rolled into a plate.
Three pots hold liquid glass for six small basins, or for three large ones, the latter being
employed for making mirrors of great dimensions, that is, 100 inches long and up



GLASS-MAKING.                                    915
wards. Furnaces have been lately constructed with 6 pots, and 12 cuvettes, 8 of which
are small, and 4 large; and cuvettes of three sizes are made, called small, middling, and
large. The small are perfect cubes, the middling and the large ones are oblong parallel
opipeds. Towards the middle of their height, a notch or groove, two or three inches
broad, and an inch deep, is left, called the girdle of the cuvette, by which part they are
grasped with the tongs, or rather are clamped in the iron frame. This frame goes round
the four sides of the small cuvettes, and may be placed indifferently upon all their sides
in the other cuvettes, the girdle extends only over the two large sides, because they can.
not be turned up. See m T, fig. 724, p. 918.
The pot is an inverted truncated cone, like a crown glass pot. It is about 30 inches
high, and from 30 to 32 inches wide, including its thickness. There are only a few inches
of difference between the diameter of the top and that of.he bottom. The bottom is
3 inches thick, and the body turns gradually thinner till it is an inch at the mouth of the
pot.
The large building or factory, of which the melting furnace occupies the middle space,
is called the halle in French. At Ravenhead in Lancashire it is called the foundry, and
is of magnificent dimensions, being probably the largest apartment under one roof in
Great Britain, since its length is 339 feet, and its breadth 155. The famous halle of St.
Gobin is 174 feet by 120. Along the two side walls of the halle, which are solidly constructed of hewn stone, there are openings like those of common ovens. These ovens.
destined for the annealing of the newly cast plates, bear the name of carquaises. Their
soles are raised two feet and a half above the level of the ground, in order to bring them
into the same horizontal plane with the casting tables. Their length, amounting sometimes to 30 feet, and their breadth to 20, are required in order to accommodate 6, 8, or
even 10 plates of glass, alongside of each other. The front aperture is called the throat,
and the back door the little throat (gueulette). The carquaise is heated by means of a
fire-place of a square form called a tisar, which extends along its side.
The founding or melting furnace is a square brick building laid on solid foundations,
being from 8 to 10 feet in each of its fronts, and rising inside into a vault or crown about
10 feet high. At each angle of this square, a small oven or arch is constructed, likewise
vaulted within, and communicating with the melting furnace by square flues, called lunettes, through which it receives a powerful heat, though much inferior to that round the
pots. The arches are so distributed as that two of the exterior sides of the furnace stand
wholly free, while the two other sides, on which the arches encroach, offer a free space
of only three feet. In this interjacent space, two principal openings of the furnace, of
equal size in each side, are left in the building. These are called tunnels. They are
destined for the introduction of the pots and the fuel.
On looking through the tunnels into the inside of the furnace, we perceive to the right
hand and the left, along the twofree sides, two low platforms or sieges, at least 30 inches
in height and breadth. See figs. 715,'717.
These sieges (seats) being intended to support the pots and the cuvettes filled with
heavy materials, are terminated by a slope, which ensures the solidity of the fire-clay
mound. The slopes of the two sieges extend towards the middle of the furnace so near
as to leave a space of only from 6 to 10 inches between them for the hearth. The end
of this is perforated with a hole sufficiently large to give passage to the liquid glass of a
broken pot, while the rest is preserved by lading it from the mouth into the adjoining
cuvette.
In the two large parallel sides of the furnace, other apertures are left much smaller
than the tunnels, which are called ouvreaux (peep holes). The lower ones, or the ouvreaux
en bas, called cuvette openings, because, being allotted to the admission of these vessels,
they are exactly on a level with the surface of the sieges, and with the floor of the halle.
Plates of cast-iron form the thresholds of these openings, and facilitate the ingress and
egress of the cuvettes. The apertures are arched at top, with hewn stone like the tunnels, and are 18 inches wide when the cuvettes are 16 inches broad.
The upper and smaller apertures, or the higher ouvreaux called the lading holes, beeause they serve for transvasing the liquid glass, are three in number, and are placed 31
or 32 inches above the surface of the sieges. As the pots are only 30 inches high, it
becomes easy to work through these openings either in the pots or the cuvettes. The
pots stand opposite to the two pillars which separate the openings, so that a space is left
between them for one or more cuvettes according to the size of the latter. It is obvious
that if the tunnels and ouvreaux were left open, the furnace would not draw or take the
requisite founding heat. Hence the openings are shut by means of fire-tiles. These are
put in their places, and removed by means of two holes left in them, in correspondence
with the two prongs of a large iron fork supported by an axle and two iron wheels, and
terminated by two handles which the workmen lay hold of when they wish to move
the tile.
The closing of the tunnel is more complex. When it is shut or ready for the firing,




916                               GLASS-MAKING.
the aperture appears built up with bricks and mortar from the top of the arch to the
middle of the tunnel.  The remainder of the door-way is closed; 1. on the two sides
down to the bottom, by a small upright wall, likewise of bricks, and 8 inches broad,
called walls of the glaye; 2. by an assemblage of pieces called pieces of the glaye, because the whole of the closure of the tunnel bears the name of glaye. The upper hole,
4 inches square, is called the tisar, through which billets of wood are tossed into the
fire. Fuel is also introduced into the posterior openings. The fire is always kept up on
the hearth of the tunnel, which is, on this account, 4 inches higher. than the furnacehearth, in order that the glass which may accidentally fall down on it, and which does
not flow off by the bottom hole, may not impede the combustion. Should a body of glass,
however, at any time obstruct the grate, it must be removed with rakes, by opening the
tunnel and dismounting the fire-tile stoppers of the glaye.
Formerly wood fuel alone was employed for heating the melting-furnaces of the
mirror-plate manufactory of Saint Gobin; but within these few years, the Dipector of
the works makes use with nearly equal advantage of pit-coal. In the same establishment,
two melting furnaces may be seen, one of which is fixed with wood, and the other with
coals, without any difference being perceptible in the quality of the glass furnished by
either. It is not true, as has been stated, that the introduction of pit-coal has made it
necessary to work with covered pots in order to avoid the discoloration of the materials,
or that more alkali was required to compensate for the diminished heat in the covered
pots. They are not now covered when pit-coal is used, and the same success is obtained
as heretofore by leaving the materials two or three hours longer in the pots and the cuvettes. The construction of the furnaces in which coal is burned, is the same as that
with wood, with slight modifications. Instead of the close bottomed hearth of the wood
furnace, there is an iron grate in the coal-hearth through which the air enters, and the
waste ashes descend.
When billets of wood were used as fuel, they were well dried beforehand, by being
placed a few days on a frame-work of wood called the wheel, placed two feet above the
furnace and its arches, and supported on four pillars at some distance from the angles of
the building.
Composition of plate-glass.-This is not made now, as formerly, by random  trials.
The progress of chemistry, the discovery of a good process for the manufacture of soda
from sea salt, which furnishes a pure alkali of uniform power, and the certain methods
of ascertaining its purity, have rendered this department of glass-making almost entirely
new, in France. At Saint Gobin no alkali is employed at present except artificial
crystals of soda, prepared at the manufactory of Chauny, subsidiary to that establishment. Leaden chambers are also erected there for the production of sulphuric acid
from sulphur.  The first crop of soda crystals is reserved for the plate-glass manufacture, the other crystals and the mother-water salts are sold to the makers of inferior
glass.
At the mirror-plate works of Ravenhead, near St. Helen's in Lancashire, soda crystals, from the decomposition of the sulphate of soda by chalk and coal, have been also
tried, but without equal success as at Saint Gobin; the failure being unquestionably due
to the impurity of the alkali. Hence, in the English establishment the soda is obtained
by treating sea-salt with pearl-ash, whence carbonate of soda and muriate of potash result. The latter salt is crystallized out of the mingled solution, by evaporation at a moderate heat, for the carbonate of soda does not readily crystallize till the temperature of the
solution falls below 600 Fahr. When the muriate of potash is thus removed, the alkaline
carbonate is evaporated to dryness.
Long experience at Saint Gobin has proved that one part of dry carbonate of soda is
adequate to vitrify perfectly three parts of fine silicious sand, as that of the mound of
Aurnont near Senlis, of Alum  Bay in the Isle of Wight, or of Lynn in Norfolk.  It
is also known that the degree of heat has a great influence upon the vitrification, and
that increase of temperature will compensate for a certain deficiency of alkali; for it is
certain that a very strong fire always dissipates a good deal of the soda, and yet the glass
is not less beautiful. The most perfect mirror-plate has constantly afforded to M. Vauquelin in analysis, a portion of soda inferior to what had been employed in its formation.
Hence, it has become the practice to add for every 100 parts of cullet or broken plate
that is mixed with the glass composition, one part of alkali, to make up for the loss that
the old glass must have experienced.
To the above mentioned proportions of sand and alkali independently of the cullet
which may be used, dry slaked lime carefully sifted is to be added to the amount of one
seventh of the sand; or the proportion will be, sand 7 cwts.; quicklime I cwt.; dry
carbonate of soda 2 cwts. and 37 lbs.; besides cullet. The lime improves the quality of
the glass; rendering it less brittle and less liable to change. The preceding quantities
of materials, suitably blended, have been uniformly found to afford most advantageous
results. The practice formerly was to dry that mixture as soon as it was made, in tht




GLASS-MAKING.                                      917
arch for the materials, but it has been ascertained that this step may be dispensed with,
and the small portion of humidity present is dissipated almost instantly after they are
thrown into the furnace. The coat of glaze previously applied to the inside of the pot,
prevents the moisture from doing them  any harm.  For this reason, when the demand
for glass at Saint-Gobin is very great, the materials are neither fritted nor even dried,
but shovelled directly into the pot; this is called founding raw.   Six workmen are
employed in shovelling-in the materials either fritted or otherwise, for the sake of expedition, and to prevent the furnace getting cooled. One third of the mixture is introduced
at first; whenever this is melted, the second third is thrown in, and then the last. These
three stages are called the first, second, and third fusion or founding.
According to the ancient practice, the founding and refining were both executed in
the pots, and it was not till the glass was refined, that it was laded into the cuvettes,
where it remained only 3 hours, the time necessary for the disengagement of the ail
bubbles introduced by the transvasion, and for giving the metal the proper consistence
for casting. At present, the period requisite for founding and refining, is equally divided
between the pots and the cuvettes.  The materials are left 16 hours in the pots, and as
imany in the cuvettes; so that in 32 hours the glass is ready to be cast.  During the last
two or three hours, the fireman or tiseur ceases to add fuel; all the openings are shut,
and the glass is allowed to assume the requisite fluidity; an operation called stopping the
glass, or performing the ceremony.
The transfer of the glass into the cuvettes, is called lading, (trejetage). Before this is
done, the cuvettes are cleared out, that is, the glass remaining on their bottom is removed,
and the ashes of the firing.   They are lifted red hot out of the furnace by the
method presently to be described, and placed on an iron plate, near a tub filled
with water. The workmen, by means of iron paddles 6 feet long, flattened at one end
and'hammered to an edge, scoop out the fluid glass expeditiously, and throw it into water;
the cuvettes are now returned to the furnace, and a few minutes afterwards the lading
begins.
In this operation, ladles of wrought iron are employed, furnished with long handles,
which are plunged into the pots through the upper openings or lading holes, and immedi.
ately transfer their charge of glass into the buckets. Each workman dips his ladle only
three times, and empties its contents into the cuvette. By these three immersions (whence
the term lrjejer is derived), the large iron spoon is heated so much that when plunged
into a tub full of water, it makes a noise like the roaring of a lion, which may be heard
to a very great distance.
The founding, refining, and ceremony, being finished, they next try whether the glass
be ready for casting. With this view, the end of a rod is dipped into the bucket, which
is called, drawing the glass; the portion taken up being allowed to run off, naturally
assumes a pear-shape, from the appearance of which, they can judge if the consistence be
proper, and if any air bubbles remain. If all be right, the cuvettes are taken out of the
furnace, and conveyed to the part of the halle where their contents are to be poured out.
This process requires peculiar instruments and manipulations.
Casting.-While the glass is refining, that is, coming to its highest point of perfection,
preparation is made for the most important process, the casting of the plate, whose
success crowns all the preliminary labors and cares. The oven or carquaise destined to
receive and anneal the plate is now heated by its small fire or tisar, to such a pitch that
its sole may have the same temperature as that of the plates, being nearly red-hot at the
moment of their being introduced. An unequal degree of heat in the carquaise would
cause breakage of the glass. The casting table is then rolled towards the front door or
throat, by means of levers, and its surface is brought exactly to the level of the sole of
the oven.
The table T, fig. 724, is a mass of bronre, or now preferably cast iron, about 10 feet
long, 5 feet broad, and from 6 to 7 inches thick, supported by a frame of carpentry, which
rests on three cast iron wheels. At the end of the table opposite to that next to the front
of the oven, is a very strong frame of timber-work, called the puppet or standard, upon
which the bronze roller which spreads the glass is laid, before and after the casting. This
is 5 feet long by I foot in diameter; it is thick in the metal but hollow in the axis. The
same roller can serve only for two plates at one casting, when another is put in its place,
and the first is laid aside to cool; for otherwise the hot roller would at a third casting
make the plate expand unequally, and cause it to crack. When the rollers are not in
action, they are laid aside in strong wooden trestles, like those employed by sawyers. On
the two sides of the table in the line of its length, are two parallel bars of bronze, t, t,
destined to support the roller during its passage from end to end; the thickness of these
bars determines that of the plate. The table being thus arranged, a crane is had recourse
to for lifting the cuvette, and keeping it suspended, till it be emptied upon the table.
This raising and suspension are effected by means of an iron gib, furnished with pulleys,
held horizontally, and which turns with them.




918                              GLASS-MAKING.
The tongs T, fig. 724, are made of four iron bars, bent into a square frame in their
liddle, for embracing the bucket. Four chains proceeding from the corners of the frame
v are united at their other ends into a ring which fits into the hook of the crane.
724
Things buing thus arranged, all the workmen of the foundry co-operate in the manipulations of the casting. Two of them fetch, and place quickly in front of one of the lower
openings, the small cuvette-carriage, which bears a forked bar of iron, having two prongs
corresponding to the two holes left in the fire-tile door. This fork, mounted on the axle
of two cast-iron wheels, extends at its other end into two branches terminatedby handles,
by which the workmen move the fork, lift out the tile stopper, and set it down against
the outer wall of the furnace.
The instant these men retire, two others push forward into the opening the extremity of the tongs-carriage, so as to seize the bucket by the girdle, or rather to clamp it.
At the same time, a third workman is busy with an iron pinch or long chisel, detaching
the bucket from its seat, to which it often adheres by some spilt glass; whenever it is
free, he withdraws it from  the furnace.  Two powerful branches of iron united by a
bolt, like two scissor blades, which open, come together, and join by a quadrant near the
other end, form the tongs-carriage, which is mounted upon two wheels like a truck.
The same description will apply almost wholly to the iron-plate carriage, on which
the bucket is laid the moment it is taken out of the furnace; the only difference in its
construction is, that on the bent iron bars which form the tail or lower steps of this carriage (in place of the tongs) is permanently fastened an iron plate, on which the bucket
is placed and carried for the casting.
Whenever the cuvette is set upon its carriage, it must be rapidly wheeled to its station
n.ear the crane. The tongs T above described are now applied to the girdle, and are then
hooked upon the crane by the suspension chains. In this position the bucket is skimmed by means of a copper tool called a sabre, because it has nearly the shape of that
weapon. Every portion of the matter removed by the sabre is thrown into a copper
ladle (poche de gamin), which is emptied from time to time into a cistern of water. After
being skimmed, the bucket is lifted up, and brushed very clean on its sides and bottom;
then by the double handles of the suspension-tongs it is swung round to the table, where
it is seized by the workmen appointed to turn it over; the roller having been previously
laid on its ruler-bars, near the end of the table which is in contact with the annealing
oven. The cuvette-men begin to pour out towards the right extremity E of the roller, and
terminate when it has arrived at the left extremity D. While preparing to do so, and
at the instant of casting, two men place within the ruler-bar on each side, that is, between
the bar and the liquid glass, two iron instruments called hands, m, m, m, m, which prevent the glass from spreading beyond the rulers, while another draws along the table the
wiping bar c, c, wrapped in linen, to remove dust, or any small objects which may interpose between the table and the liquid glass.
Whenever the melted glass is poured out, two men spread it over the table, guiding
the roller slowly and steadily along, beyond the limits of the glass, and then run it smartly
into the wooden standard prepared for its reception, in place of the trestles v, v.
The empty bucket, while still red-hot, is hung again upon the crane, set on its plateiron carriage, freed from its tongs, and replaced in the furnace, to be speedily cleared
out anew, and charged with fresh fluid from the pots. If while the roller glides along,
the two workmen who stand by with picking tools, perceive tears in the matter in advance of the roller, and can dexterously snatch them out, they are suitably rewarded,
according to the spot where the blemish lay, whether in the centre, where it would
have proved most detrimental, or near the edge.  These tears proceed usually from




GLASS-MAKING.                                    919
emall portions of semi-vitrified matter which fall from the vault of the furnace, and from
their density occupy the bottom of the cuvettes.
While the plate is still red-hot and ductile, about 2 inches of its end opposite to the
carquaise door is turned up with a tool; this portion is called the head of the mirror;
against the outside of this head, the shovel, in the shape of a rake without teeth, is applied, with which the plate is eventually pushed into the oven, while two other workmen
press upon the upper part of the head with a wooden pole, eight feet long, to preserve
the plate in its horizontal position, and prevent its being warped. The plate is now left
for a few moments near the throat of the carquaise, to give it solidity; after which it is
pushed farther in by means of a very long iron tool, whose extremity is forked like the
letter y, and hence bears that name; and is thereby arranged in the most suitable spot for
allowing other plates to be introduced.
However numerous the manipulations executed from the moment of withdrawing the
cuvette from the furnace, till the cast-plate is pushed into the annealing oven, I have seen
them all performed in less than five minutes; such silence, order, regularity, and despatch
prevail in the establishment of Saint-Gobin.
When all the plates of the same casting have been placed in the carquaise, it is sealed
up, that is to say, all its orifices are closed with sheets of iron, surrounded and made tight
with plastic loam. With this precaution, the cooling goes on slowly and equably in every
part, for no cooling current can have access to the interior of the oven.
After they are perfectly cooled, the plates are carefully withdrawn one after another,
keeping them all the while in a horizontal position, till they are entirely out of the carquaise. As soon as each plate is taken out, one set of workmen lower quickly and
steadily the edge which they hold, while another set raise the opposite edge, till the glass
be placed -upright on two cushions stuffed with straw, and covered with canvass. In
this vertical position they pass through, beneath the lower edge of the plate, three girths
or straps each four feet long, thickened with leather in their middle, and ending in
wooden handles; so that one embraces the middle of the plate, and the other two, the
ends. The workmen, six in number, now seize the handles of the straps, lift up the
glass closely to their bodies, and convey it with a regular step to the warehouse. Here
the head of the plate is first cut off with a diamond square, and then the whole is attentively examined, in reference to its defects and imperfections, to determine the sections
which must be made of it, and the eventual size of the pieces. The pairings and small
cuttings detacheL are set aside, in order to be ground and mixed with the raw materials
of another glass-pot.
The apartment in which the roughing-down and smoothing of the plates is performed,
is furnished with a considerable number of stone tables truly hewn and placed apart like
billiard tables, in a horizontal position, about 2 feet above the ground. They are rectangular, and of different sizes proportional to the dimensions of the plates, which they
ought always to exceed a little. These tables are supported either on stone pillars or
wooden frames, and are surrounded with a wooden board whose upper edge stands somewhat below their level, and leaves in the space between it and the stone all round an interval of 3 or 4 inches, of which we shall presently see the use.
A cast plate, unless formed on a table quite new, has always one of its faces, the one
next the table, rougher than the other; and with this face the roughing-down begins.
With this view, the smoother face is cemented on the stone table with Paris-plaster. But
often, instead of one plate, several are cemented alongside of each other, those of the same
thickness being carefully selected. They then take one or more crude plates of about one
third or one fourth the surface of the plate fixed to the table, and fix it on them with
liquid gypsum to the large base of a quadrangular truncated pyramid of stone, of a weight
proportioned to its extent, or about a pound to the square inch. This pyramidal muller,
if small sized, bears at each of its angles of the upper face a peg or ball, which the
grinders lay hold of in working it; but when of greater dimension, there is adapted to it
horizontally a wheel of slight construction, 8 or 10 feet in diameter, whose circumference
is made of wood rounded so as to be seized with the hand. The upper plate is now
rubbed over the lower ones, with moistened sand applied between.
This operation is however performed by machinery. The under plate being fixed or
imbedded in stucco, on a solid table, the upper one likewise imbedded by the same
cement in a cast-iron frame, has a motion of circumrotation given to it closely resembling that communicated by the human hand and arm, moist sand being supplied
between them. While an eccentric mechanism imparts this double rotatory movement
to the upper plate round its own centre, and of that centre round a point in the lower
plate, this plate, placed on a moveable platform, changes its position by a slow horizontal
motion, both in the direction of its length and its breadth. By this ingenious contrivance, which pervades the whole of the grinding and polishing machinery, a remarks
able regularity of friction and truth of surface is produced. When the plates are sufficiently worked on one face, they are reversed in the frames, and worked together on




920                               GLASS-MAKING.
the other. The Paris plaster is usually colored red, in order to show any defects in the
glass.
The smoothing of the plates is effected on the same principles by the use of moist
emery washed to successive degrees of fineness, for the successive stages of the operation;
and the polishing process is performed by rubbers of hat-felt and a thin paste of colcothar
and water.  The colcothar, called also crocus, is red oxyde of iron prepared by the ignition of copperas, with grinding and elutriation of the residuum.
The last part or the polishing process is performed by hand. This is managed by females, who slide one plate over another, while a little moistened putty of tin finely levigated is thrown between.
Large mirror-plates are now the indispensable ornaments of every large and sumptuous
apartment; they diffuse lustre and gayety round them, by reflecting the rays of light in a
thousand lines, and by multiplying indefinitely the images of objects placed between opposite parallel planes.
The silvering of plane mirrors consists in applying a layer of tin-foil alloyed with mercury to their posterior surface. The workshop for executing this operation is provided
with a great many smooth tables of fine freestone or marble, truly levelled, having round
their contour a rising ledge, within which there is a gutter or groove which terminates by
a slight slope in a spout at one of the corners. These tables rest upon an axis of wood
or iron which runs along the middle of their length; so that they may be inclined easily
into an angle with the horizon of 12 or 13 degrees, by means of a hand-screw fixed below. They are also furnished with brushes, with glass rules, with rolls of woollen stuff,
several pieces of flannel, and a great many weights of stone or cast-iron.
The glass-tinner, standing towards one angle of his table, sweeps and wipes its surface
with the greatest care, along the whole surface to be occupied by the mirror-plate; then
taking a sheet of tin-foil adapted to his purpose, he spreads it on the table, and applies
it closely with a brush, which removes any folds or wrinkles. The table being horizontal, lie pours over the tin a small quantity of quicksilver, and spreads it with a roll
of woollen stuff; so that the tin-foil is penetrated and apparently dissolved by the mercury. Placing now two rules, to the right and to the left, on the borders of the sheet, he
pours on the middle a quantity of mercury sufficient to form everywhere a layer about
the thickness of a crown piece; then removing with a linen rag the oxyde or other impurities, he applies to it the edge of a sheet of paper, and advapces it about half an inch.
Meanwhile another workman is occupied in drying very nicely the surface of the glass
that is to be silvered, and then hands it to the master workman, who, laying it flat,
places its anterior edge first on the table, and then on the slip of paper; now pushing
the glass forwards, he takes care to slide it along so that neither air nor any coat of
oxyde on the mercury can remain beneath the plate. When this has reached its position,
he fixes it there by a weight applied on its side, and gives the table a gentle slope, to
run off all the loose quicksilver by the gutter and spout. At the end of five minutes he
covers the mirror with a piece of flannel, and loads it with a great many weights which
are left upon it for twenty-four hours, under a gradually increased inclination of the table.
By this time the plate is ready to be taken off the marble table, and laid on a wooden one
sloped like a reading desk, with its under edge resting on the ground, while the upper is
raised successively to different elevations by means of a cord passing over a pulley in the
ceiling of the room. Thus the mirror has its slope graduated from  day to day, till
it finally arrives at a vertical position. About a month is required for draining out
the superfluous mercury from  large mirrors; and from  18 to 20 days from  those of
moderate size. The sheets of tin-foil being always somewhat larger than the glass
plate, their edges must be paired smooth off, before the plate is lifted off the marble
table.
Process for silvering concave mirrors.-Having prepared some very fine Paris plaster by
passing it through a silk sieve, and some a little coarser passed through hair-cloth, the
first is to be made into a creamy liquor with water, and after smearing the concave surface
of the glass with a film of olive oil, the fine plaster is to be poured into it, and spread by
turning about, till a layer of plaster be formed about a tenth of an inch thick. The
second or coarse plaster, being now made into a thin paste, poured over the first, and
moved about, readily incorporates with it, in its imperfectly hardened state. Thus an
exact mould is obtained of the concave surface of the glass, which lies about three quarters of an inch thick upon it, but is not allowed to rise above its outer edge.
The mould, being perfectly dried, must be marked with a point of coincidence on the
glass, in order to permit of its being exactly replaced in the same position, after it has
been lifted out. The mould is now removed, and a round sheet of tin-foil is applied to it,
so large that an inch of its edge may project beyond the plaster all round; this border
being necessary for fixing the tin to the contour of the mould by pellets of white wax
softened a little with some Venice turpentine. Before fixing the tin-foil, however, it
must be properly spread over the mould, so as to remove every wrinkle; which the




GLASS-MAKING.                                      921
pliancy of the foil easily admits of, by uniform and well-directed pressure with the
fingers.
The glass being placed in the hollow bed of a tight sack filled with fine sand, set in a
well-jointed box, capable of retaining quicksilver, its concave surface must be dusted
with sifted wood-ashes, or Spanish white contained in a small cotton bag, and then well
wiped with clean linen rags, to free it from  all adhering impurity, and particularly the
moisture of the breath. The concavity must be now filled with quicksilver to the very
lip, and the mould, being dipped a little way into it, is withdrawn, and the adhering
mercury is spread over the tin with a soft flannel roll, so as to amalgamate and brighten
its whole surface, taking every precaution against breathing on it.  Whenever this
brightening seems complete, the mould is to be immersed, not vertically, but one edge
at first, and thus obliquely downwards till the centres coincide; the mercury meanwhile
being slowly displaced, and the mark on the mould being brought finally into coincidence with the mark on the glass. The mould is now left to operate by its own weight,
in expelling the superfluous mercury, which runs out upon the sand-bag and thence
into a groove in the bottom of the box, whence it overflows by a spout into a eather bag
of reception.  After half an hour's repose, the whole is cautiously inverted, to drain ^fl
the quicksilver more completely.  For this purpose, a box like the first is provided
with a central support rising an inch above its edges; the upper surface of the support
being nearly equal in diameter to that of the mould.  Two workmen are required to
execute the following operation. Each steadies the mould with the one hand, and raises
the box with the other, taking care not to let the mould be deranged, which they rest
on the (convex) support of the second box. Before inverting the first apparatus, however, the reception bag must be removed, for fear of spilling its mercury. The redundant quicksilver now drains off; and if the weight of the sandbag is not thought sufficient, supplementary weights are added at pleasure. The whole is left in this position
for two or three days. Before separating the mirror from its mould, the border of tinfoil, fixed to it with wax, must be pared off with a knife.  Then the weight and
sandbag  being  removed, the glass is lifted  up with  its interior coating of tinamalgam.
For silvering a convex surface.-A concave plaster mould is made on the convex glass,
and their points of coincidence are defined by marks. This mould is to be lined with
tinfoil, with the precautions above described; and the tin surface being first brightened
with a little mercury, the mould is then filled with the liquid metal. The glass is to be
well cleaned, and immersed in the quicksilver bath, which will expel the greater part of
the metal. A sandbag is now to be laid on the glass, and the whole is to be inverted as
in the former case on a support; when weights are to be applied to the mould, and the
mercury is left to drain off for several days.
If the glass be of large dimensions, 30 or 40 inches, for example, another method is
adopted. A circular frame or hollow ring of wood or iron is prepared, of twice the diameter of the mirror, supported on three feet. A circular piece of new linen cloth of close
texture is cut out, of equal diameter to the ring, which is hemmed stoutly at the border,
and furnished round the edge with a row of small holes, for lacing the cloth to the ring,
so as to leave no folds in it, but without bracing it so tightly as to deprive it of the elasticity necessary for making it into a mould. This apparatus being set horizontally, a
leaf of tinfoil is spread over it, of sufficient size to cover the surface of the glass; the
tin is first brightened with mercury, and then as much of the liquid metal is poured on as
a plane mirror requires. The convex glass, weli cleaned, is now set down on the cloth,
and its own weight, joined to some additional weights, gradually presses down the cloth.
and causes it to assume the form of the glass which thus comes into close contact withthe tin submersed under the quicksilver. The redundant quicksilver is afterwards drained
off by inversion, as in common cases.
The following recipe has been given for silvering the inside of glass globes. Melt in
an iron ladle or a crucible, equal parts of tin and lead, adding to the fused alloy one part
of bruised bismuth. Stir the mixture well, and pour into it as it cools, two parts of dry
mercury; agitating anew and skimming off the drossy film from the surface of the amalgam. The inside of the glass globe, being freed from all adhering dust and humidity, is
to be gently heated, while a little of the semi-fluid amalgam is introduced. The liquidity
being increased by the slight degree of heat, the metallic coating is applied to all the
points of the glass, by turning round the globe in every direction, but so slowly as to
favor the adhesion of the alloy. This silvering is not so substantial as that of plane mirrors: but the form of the vessel, whether a globe, an ovoid, or a cylinder, conceals or
palliates the defects by counter reflection from the opposite surfaces.
Colored Glasses and Artificial Gems.-The general vitreous body preferred by Fontanieu in his treatise on this subject, which he calls the Mayence base, is prepared in
the following manner. Eight ounces of pure rock-crystal or flint in powder, mixed
with 24 ounces of salt of tartar, are baked and left to cool. This is afterwards poured




922                             GLASS-MAKING.
into a basin of hot water, and treated with dilute nitric acid trll it ceases to effervesce,
when the frit is to be washed till the water comes off tasteless. The frit is now dried
and mixed with 12 ounces of fine white lead, and the mixture is to be levigated and elutriated with a little distilled water. An ounce of calcined borax is to be added to about
12 ounces of the preceding mixture in a dry state, the whole rubbed together in a porce
lain mortar, then melted in a clean crucible, and poured out into cold water. This vitreous matter must be dried, and melted a second and a third time, always in a new crucible,
and after each melting poured into cold water as at first, taking care to separate the lead
that may be revived. To the last glass ground to powder, five drachms of nitre are to be
added, and the mixture being melted for the last time, a mass of crystal will be found in
the crucible with a beautiful lustre. The diamond is well imitated by this Mayence
base. Another very fine white crystal may be obtained, according to M. Fontanieu, from
eight ounces of white lead, two ounces of powdered borax, half a grain of manganese,
and three ounces of rock-crystal, treated as above.
The colors of artificial gems are obtained from metallic oxydes. The oriental topaz is
prepared by adding oxyde of antimony to the base; the amethyst from manganese, with
a little purple precipitate of Cassius; the beryl from antimony and a very little cobalt;
yellow artificial diamond and opal from horn-silver (chloride of silver); blue stone from
cobalt. See PASTES and PIGMENTS VITRIFIABLE.
The following are recipes for making the different kinds of glass
1. Bottle glass.-11 pounds of dry glauber salts; 12 pounds of soaper salts; a half
bushel of waste soap ashes; 56 pounds of sand; 22 pounds of glass skimmings; I
cwt. of green broken glass; 25 pounds of basalt. This mixture affords a dark green
glass.
2. Yellow or white sand, 100 parts; kelp, 30 to 40; lixiviated wood ashes, from 160
to 170 parts; fresh wood ashes, 30 to 40 parts; potter's clay, 80 to 100 parts; cullet or
broken glass, 100. If basalt be used, the proportion of kelp may be diminished.
In two bottle-glass houses in the neighborhood of Valenciennes, an unknown ingredient, sold by a Belgian, was employed, which he called spar. This was discovered
by chemical analysis to be sulphate of baryta.  The glass-makers observed that the
bottles which contained some of this substance were denser, more homogeneous, more
fusible, and worked more kindly, than those formed of the common materials. When
one prime equivalent of the silicate of baryta = 123, is mixed with three primes of the
silicate of soda = (3 X 77*6) 232'8, and exposed in a proper furnace, vitrification
readily ensues, and the glass may be worked a little under a cherry red heat, with as
much ease as a glass of lead, and has nearly the same lustre. Since the ordinary run
of glass-makers are not familiar with atomic proportions, they should have recourse to
a scientific chemist, to guide them in using such a proportion of sulphate of baryta as
may suit their other vitreous ingredients; for an excess or defect of any of them will
injure the quality of the glass.
3. Green window glass, or broad glass.-II pounds of dry glauber salts; 10 pounds of
soaper salts; half a bushel of lixiviated soap waste; 50 pounds of sand; 22 pounds of
glass pot skimmings; 1 cwt. of broken green glass.
4. Crown glass.-300 parts of fine sand; 200 of good soda ash; 33 of lime; from
250 to 300 of broken glass; 60 of white sand; 30 of purified potash; 15 of saltpetre
(I of borax); " of arsenious acid.
5. Nearly white table glass.-20 pounds of potashes; II pounds of dry glauber salts;
16 of soaper salt; 55 of sand; 140 of cullet of the same kind. Another.-100 of sand;
235 of kelp; 60 of wood ashes; 1 of manganese; 100 of broken glass.
6. While table glass.-40 pounds of potashes; 11 of chalk; 76 of sand; I of manga
nese; 95 of white cullet.
Another.-50 of purified potashes; 100 of sand; 20 of chalk; and 2 of saltpetre.
Bohemian table or plate glass is made with 63 parts of quartz; 26 of purified pot
ashes; 11 of sifted slaked lime, and some cullet.
7. Crystal glass.-60 parts of purified potashes; 120 of sand; 24 of chalk; 2 of salt
petre; 2 of arsenious acid; I of manganese.
Another.-70 of purified pearlashes, 120 of white sand; 10 of saltpetre; I of arse
nious acid; j of manganese.
A third.-67 of sand; 23 of purified pearlashes; 10 of sifted slaked lime; ^ of man
ganese; (5 to 8 of red lead).
A fourth.-120 of white sand; 50 of red lead; 40 of purified pearlash; 20 of salt,
petre; ^ of manganese.
A fifth.-120 of white sand; 40 of pearlash purified; 35 of red lead; 13 of saltpetre;
12 of manganese.
A sixth.-30 of the finest sand; 20 of red lead; 8 of pearlash purified; 2 of salt.
petre; a little arsenious acid and manganese.




GLASS-CUTTING.                                  923
A seventh. — 100 of sand; 45 of red lead; 35 of purified pearlashes; -1 of manganese;
i of arsenious acid.
8. Plate glass.-Very white sand 300 parts; dry purified soda 100 parts; carbonate
of lime 43 parts; manganese 1; cullet 300.
Another.-Finest sand 720; purified soda 450; quicklime 80 parts; saltpetrre 25
parts; cullet 425.
A little borax has also been prescribed; much of it communicates an exfoliating pro.
perty to glass.
Tabular view of the composition of several kinds of Glass...... ~       No. 1. No. 2.  No. 3.  No. 4.  No. 5.  No. 6.  No. 7.  No. 8.  No. 9.
Silica -    -      71-7 69-2   62-8   69-2   60-4  53'55   59-2  51-93  42-5
Potash      -      12-7 15-8   22'1    8'0    3-2    5-48    9-0  13-77   11-7
Soda  -    -        2-5  3-0            3-0  S. pot.
Lime -    -        10-3  7-6  12-5   13-0   20-7   29-22                      0-5
Alumina   -         0-4  1-2            3-6   10-4    601                     1-8
Magnesia  -              2-0  )         0-6    0-6
Oxyde of iron       0-3  0-5    2.6    1-6    3-8    5-74    0-4
-  manganese   0-2                                           1.0
-lead  -                                                   28-2  33-28  43-5
Baryta      -                                   09                           43
No. I is a very beautiful white wine glass of Neuwelt in Bohemia.
No. 2. Glass tubes, much more fusible than common wine glasses.
No. 3. Crown glass of Bohemia.
No. 4. Green glass, for medicinal vials and retorts.
No. 5. Flask glass of St. Etienne, for which some heavy spar is used.
No. 6. Glass of Sevres.
No. 7. London glass employed for chemical and physical purposes.
No. 8. English flint glass.
No. 9. Guinand's flint glass.
The manufacture of Glass beads at Murano near Venice, is most ingeniously simple.
Tubes of glass of every color are drawn out to great lengths in a gallery adjoining the
glass-house pots, in the same way as the more moderate lengths of thermometer and
barometer tubes are drawn in our glass-houses. These tubes are chopped into very small
pieces of nearly uniform length on the upright edge of a fixed chisel. These elementary
cylinders, being then put in a heap into a mixture of fine sand and wood ashes, are stirred
about with an iron spatula till their cavities get filled.  This curious mixture is now
transferred to an iron pan suspended over a moderate fire and continually stirred about
as before, whereby the cylindrical bits assume a smooth rounded form; so that when removed from the fire and cleared out in the bore, they constitute beads, which are packed
in casks, and exported in prodigious quantities to almost every country, especially to
Africa and Spain.
GLASS CUTTING AND GRINDING, for common and optical purposes.  By this
mechanical process the surface of glass may be modified into almost any ornamental or
useful form.
1. The grinding of crystal ware.  This kind of glass is best adapted to receive
polished facets, both on account of its relative softness, and its higher refractive power,
which gives lustre to its surface.  The cutting shop should be a spacious long apartment, furnished with numerous sky-lights, having the grinding and polishing lathes
arranged right under them, which are set in motion by a steam-engine or water-wheel at
725     E           one end of the building.  A shaft is fixed as usual
ii 5  ^E   in gallowses along the ceiling; and from the pulleys
a              a   of the shaft, bands descend to turn the different
lathes, by passing round the driving pulleys near
their ends.
bds         SC    The turning lathe is of the simplest construction.
Hibf -, ^^p J    Fig. 725, D is an iron spindle with two well-turned
prolongations, running in the iron puppets a a,
\HIIfl       I!B    I    between two concave bushes of tin or type metal,
lL_\ }I F~u I I Il|I   \        which may be pressed more or less together by the
*"}~ 1 J I m'  ___I illI -thumb-screws shown in the figure.  These two
A     L.... LJ      puppets are made fast to the wooden support B,
~ ~-~~~r^~          ~which is attached by a strong screw and bolt to the
longitudinal beam of the workshop A.  E is the fast and loose pulley for putting the




924                              GLASS-CUTTING.
lathe into and out of gear with the driving shaft.  The projecting end of the spindle il
furnished with a hollow head-piece, into which the rod c is pushed tight.  This rod car1
ries the cutting or grinding disc plate.  For heavy work, this rod is fixed into the head
by a screw.  When a conical fit is preferred, the cone is covered with lead to increase
the friction.
Upon projecting rods or spindles of that kind the different discs for cutting the glass
are made fast. Some of these are made of fine sandstone or polishing slate, from 8 to 10
inches in diameter, and from I to I inch thick. They must be carefully turned and polished at the lathe, not only upon their rounded but upon their flat face, in order to grind and
polish in their turn the flat and curved surfaces of glass vessels.  Other discs of the
same diameter, but only j of an inch thick, are made of cast tin truly turned, and serve
for polishing the vessels previously ground; a third set consist of sheet iron from i to 
an inch thick, and 12 inches in diameter, and are destined to cut grooves in glass by the
aid of sand and water.  Small discs of well-hammered copper from ]         to 3 inchesin
diameter, whose circumference is sometimes flat, and sometimes concave or convex, serve
to make all sorts of delineations upon glass by means of emery and oil.  Lastly, there
are rods of copper or brass furnished with small hemispheres from       to  of an inch in
diameter, to excavate round hollows in glass. Wooden discs are also employed for polishing, made of white wood cut across the grain, as also of cork.
The cutting of deep indentations, and of grooves, is usually performed by the iron
disc, with sand and water, which are allowed constantly to trickle down from a wooden
hopper placed right over it, and furnished with a wooden stopple or plug at the apex, to
regulate by its greater or less looseness the flow of the grinding materials.  The same
effect may be produced by using buckets as shown in fig. 26.  The
7 26  sand which is contained in the bucket F, above the lathe has a spigot
A,^^n         and faucet inserted near its bottom, and is supplied with a stream of
F   g           water from the stopcock in the vessel, which, together running down
II ff   the inclined board, are conducted to the periphery of the disc as shown
in the figure, to whose lowest point the glass vessel is applied with
\\^^     pressure by the hand.  The sand and water are afterwards collected in
the tub  H.  Finer markings, which are to remain without lustre, are
f    a t ^\^ made with the small copper discs, emery, and oil.  The polishing is
effected by the edge of the tin disc, which is from time to time moistenb          ed with putty (white oxyde of tin) and water.  The wooden disc is
also employed for this purpose with putty, colcothar, or washed tripoli.
For fine delineations, the glass is first traced over with some colored
varnish, to guide the hand of the cutter.
H^='i jy       In grinding and facetting crystal glass, the deep grooves are first
cut, for example the cross lines, with the iron disc and rounded edge,
by means of sand and water. That disc is one sixth of an inch thick
and 12 inches in diameter.  With another iron disc about half an inch thick, and more
or less in diameter, according to the curvature of the surface, the grooves may be widened.  These roughly cut parts must be next smoothed down with the sandstone disc and
water, and then polished with the wooden disc about half an inch thick, to whose edge
the workman applies, from time to time, a bag of fine linen containing some ground pumice
moistened with water.  When the cork or wooden disc edged with hat felt is used for
polishing, putty or colcothar is applied to it.  The above several processes in a large
manufactory, are usually committed to several workmen on the principle of the division
of labor, so that each may become expert in his department.
2. The grinding of optical glasses.-The glasses intended for optical purposes, being
spherically ground, are called lenses; and are used either as simple magnifiers and spectacles, or for telescopes and microscopes. The curvature is always a portion of a sphere,
and either convex or concave.  This form ensures the convergence or divergence of the
rays of light that pass through them, as the polishing does the brightness of the
image.
The grinding of the lenses is performed in brass moulds, either concave or convex,
formed to the same curvature as that desired in the lenses; and may be worked either by
hand or by machinery.  A gauge is first cut out out of brass or copper plate to suit the
curvature of the lens, the circular arc being traced by a pair of compasses. In this way
both a convex and concave circular gauge are obtained.  To these gauges the brass
moulds are turned.  Sometimes, also, lead moulds are used.  After the two moulds are
made, they are ground face to face with fine emery.
The piece of glass is now roughed into a circular form by a pair of pincers, leaving
It a little larger than the finished lens ought to be, and then smoothed round upon the
stone disc, or in an old mould with emery and water, and is next made fast to a holdfhst.  This consists of a round brass plate having a screw in its back; and is somewhat
smaller in diameter than the lens, and two thirds as thick. This as turned concave upon




GLASS-CUTTING.                                     925
the lathe, and then attached to the piece of glass by drops of pitch applied to several
points of its surface, taking care, while the pitch is warm, that the centre of the glass
coincides with the centre of the brass plate. This serves not merely as a holdfast, by
enabling a person to seize its edge with the fingers, but it prevents the glass from bending by the necessary pressure in grinding.
The glass must now be ground with coarse emery upon its appropriate mould, whetheconvex or concave, the emery being all the time kept moist with water. To prevent the
heat of the hand from affecting the glass, a rod for holding the brass plate is screwed to
its back. For every six turns of circular motion, it must receive two or three rubs across
the diameter in different directions, and so on alternately. The middle point of the glass
must never pass beyond the edge of the mould; nor should strong press
time applied. Whenever the glass has assumed the shape of the mould, and touches it
in every point, the coarse emery must be washed away, finer be substituted in its place,
and the grinding be continued as before, till all the scratches disappear, and a uniform
dead surface be produced.  A commencement of polishing is now to be given with pumice stone powder. During all this time the convex mould should be occasionally worked
in the concave, in order that both may preserve their correspondence of shape between
them. After the one surface has been thus finished, the glass must be turned over, and
treated in the same way upon the other side.
Both surfaces are now to be polished. With this view equal parts of pitch and rosin
must be melted together, and strained through a cloth to separate all impurities. The
concave mould is next to be heated, and covered with that mixture in a fluid state to the
thickness uniformly of one quarter of an inch. The cold convex mould is now to be
pressed down into the yielding pitch, its surface being quite clean and dry, in order to
give the pitch the exact form of the ground lens; and both are to be plunged into cold
water till they be chilled.  This pitch impression is now the mould upon which the
glass is to be polished, according to the methods above described, with finely washed
colcothar and water, till the surface become perfectly clear and brilliant. To prevent the
pitch from changing its figure by the friction, cross lines must be cut in it about aninch
asunder, and 1-12th of an inch broad and deep.  These grooves remove all the superfluous parts of the polishing powder, and tend to preserve the polishing surface of the
pitch clean and unaltered. No additional colcothar after the first is required in this part
of the process; but only a drop of water from time to time. The, pitch gets warm as the
polishing advances, and renders the friction more laborious from the adhesion between
the surfaces. No interruption must now be suffered in the work, nor must either water
or colcothar be added; but should the pitch become too adhesive, it must be merely
breathed upon, till the polish be complete. The nearer the lens is brought to a true and
fine surface in the first grinding, the better and more easy does the polishing become. It
should never be submitted to this process with any scratches perceptible in it, even
when examined by a magnifier.
As to small lenses and spectacle eyes, several are ground and polished together in a
mould about 6 inches in diameter, made fast to a stiffening plate of brass or iron of a
shape corresponding with the mould. The pieces of glass are affixed by means of drops
of pitch, as above described, to the mould, close to each other, and are then all treated as
if they formed but one large lens. Plane glasses are ground upon a surface of pitch
rendered plane by the pressure of a piece of plate glass upon it in its softened state.
Lenses are also ground and polished by means of machinery, into the details of which
the limits of this work will not allow me to enter.
GLAss IN THE EXHIBITION.-So far as may be inferred, from the analysis of ordinary
commercial samples of window-glass, this substance lhas not only a very variable composition, but, worse than this, is out of all keeping with anything like definite proportion.
That it should be full of strive, and, therefore, refract the rays of light equally, as it does,
so as to produce the most hideous appearances of distortion, is a mere natural consequence
of its mechanical composition, which might, and must one day, be corrected; but that whole
nations should have come to view this defect as an unavoidable peculiarity, is precisely
one of those surprising facts which demonstrate the influence of habit over the powers of
the mind, and show how easily human reason can reconcile itself to the most gross inconsistencies.- If window-glass had one uniform  atomic composition, the tendency to form
these strias would nowhere exist in excess; and, therefore, their production would
diminish as the skill of the workmen increased; but, with the present variable compound, the glass stretches unequally in different parts, by an equal application of force,
and, in spite of human skill, presents a result alternately thick or thin, as accident
determines. That these strive have not the same composition as the parts surrounding
them  is very obvious, from  the circumstance that, if striated glass be cut to an uniform
thickness, and polished on both sides, the optical defects remain but little changed, and
occasionally they are found to be increased.   Again it is known, that the more
complex the composition of any glass may be, the greater the liability to this striated




926                                      GLASS.
structure-,of which flint glass offers an opposite illustration; for here, in addition to
the ordinary components of glass, the silicate of lead is superadded. Now the specific
gravity of silicate of lead is very high compared with that of silicate of soda, potash,
or lime; hence, unless employed in the exact quantity to form a chemical combination
with the  other silicates, a mere mechanical mixture is produced of very different
densities throughout; and the product, under the action of light, displays, permanently,
that peculiar fugitive appearance, seen when syrup and water, or alcohol and water, are
mixed together: that is to say, a series of curved lines are formed by the unequal
refraction of the two fluids, which entirely disappear, so soon as perfect admixture has
taken place, but which remain in the case of flint glass, from the utter impossibility of
affecting the necessary union between its various parts.  Although, however, this cannot be done mechanically, yet, in a chemical way, nature performs such operations with
ease and unerring fidelity. The French chemist, Berthier, long ago proved that many
neutral salts combine together by fusion in atomic proportions, and form  new, and
definite compounds.  Thus, carbonate of potash and carbonate of soda when mixed,
atom  for atom, unite and produce a compound  more easy of fusion than the most
fusible of the two:-similarly, either of these carbonates will act with carbonate of
baryta or stronchia, and  again, flour-spar  and  sulphate of lime, two remarkably
infusible substances, when mixed, melt readily, at a low red heat, into a fluid as mobile
and transparent as water.  It is useless to multiply examples of this kind, for thousands exist; and the alkaline and earthy silicates form no exception to this almost
universal rule. A mixture of silicate of potash and silicate of soda, will, if in atomic
ratios, fuse much more readily than either of them alone. But now, let us imagine an
attempt to fuse these two bodies together, in any other proportion than that in which
they are naturally disposed to combine;-say that the silicate of soda is in excess;
then the silicate of potash would unite with exactly sufficient of the silicate of soda to
produce the extremely fusible compofnd above spoken of: whilst the less easily fusible
silicate of soda, added in excess, would form  a kind of network throughout the mass.
It may be said, that a higher heat would overcome this difficulty, by  thoroughly
liquifying the silicate of soda; and this is really the plan now used with that view;
but, independent of the fact, that the mixed silicate of potash and soda would also
undergo a corresponding liquefaction, and, therefore, favour the separation of the silicate
of soda; yet, as chemical union is impossible, from  the very conditions of the experiment, even the most perfect mechanical mixture, under the greatest advantages of
fluidity, would never generate a homogeneous body.  The striae might, indeed. be
diminished in size; but this would imply a corresponding increase in their number;
and, if carried very far, complete opacity would result from  such  an endeavour to
subvert the laws of nature.  The power of the workmen to remedy this defect is therefore limited to the capability of modifying its more salient features; he can neither
remove nor destroy it.  What we have here illustrated by the simplest of all assumptions, gathers and accumulates into a formidable evil, when several silicates are fused
together, having considerable differences of specific weight. Thus, in the case of flintglass before alluded to, there are generally three, and sometimes five, of these silicates
fused together, into, probably, one of the most antagonistic compounds that could be
conceived, refracting and dispersing the ray of light in fifty different directions, and
demonstrating the unfriendly nature of its coerced union, by flying in pieces from the
most trivial applications of heat or violence. Yet in flint-glass we are not surpassed,
nor indeed  equalled, by any other nation; and  so thoroughly has this beautiful
substance become associated with our industrial reputation, that the name, flint-glass,
has been  adopted  into several continental languages.   Nevertheless, it cannot be
doubted that a wide field of improvement is open in this quarter, and that some more
solid foundation is needed by our manufacturers in this line, than the prestige of a name,
or the force of capital.
In our concluding remarks we shall point out the direction in which improvement is
practicable; and at present it may not be uninteresting to examine the contents of the
Great Exhibition in respect to this kind of glass. The display of goods by Messrs.
Apsley, Pellatt and Co., is alone sufficient to exhaust the entire subject of flint-glass;
and the mere inquirer into this branch of manufacture need go no farther to get a perfect
conception of the wonders that can be achieved by the manipulation of this material. The
coup d'meil is certainly most beautiful; but, supported as it is and multiplied by the rival
exhibitions of Messrs. Osler, Harris, Bacchus, Powell, Lloyd and Summerfield, and a
host of others, the effect is positively dazzling and gorgeous. At a distance sufficient to
cover the faults of refraction, not even the diamond itself has a more pleasing appearance; and indeed, the glass koh-i-noor of Mr. Pellatt, displayed in the gallery, might be
substituted for the real gem, shown in the main avenue, without the least risk of detection on the part of the million, or any great loss of brilliancy to the most practised eye,so perfect is the imitation. Is it not then to be deplored, that science has had no hand in




GLASS.                                        927
mingling its constituents together?  But we must turn from  this glittering assortment
and descend to a lower level, where we shall find Great Britain in disgrace, and suffering severely from comparison with a rival inferior in capital and natural resources, but
conscious of power through the aid of real knowledge, and triumphantly asserting a claim
to supremacy in the very perfection of the glass-maker's art. The plate-glass of France
casts that of England far into the shade. The productions of St. Gobain stand alone in
the Exhibition; they have no competitors; and we are in a condition to prove that
chemistry has done this. The plate-glass of Montlu!on, too, adds to the defeat. In examining the refractive aberrations of a mirror, the spectator will find his task facilitated by
standing so that the rays of light from any geometrically shaped body fall upon the glass,
at an angle of 250; when, of course, they will be reflected towards his eye at the same
angle. Now gazing intently on the figure in question-and which, in the Exhibition, may
be one of the parallelograms formed by the rafters of the roof, let him gently move his
head from one side to the other. If the glass be of English manufacture, he will immediately perceive a tumultuous movement in the lines of the figure, as if this were subjected
to an undulatory action,-the lines, before straight and parallel, become crooked and convergent in places, and minute objects lose entirely their outline and definition.  In
the case of the St. Gobain glass, shown in the French department, nothing of this kind
rtakes place. As it can serve no good purpose to dwell upon each individual example
of imperfection, we refrain from entering further into the comparative merits of the
British exhibitors. They are all surpassed by the French makers, both in respect to
uniformity of composition and fineness of polish.  The St. Gobain Company having had
the good sense to place a number of small samples of their glass for the acceptance of
those visitors who may feel an interest in the manufacture, we have selected and analyzed
one of these little squares, and shall presently detail the result; but our object in alluding to them here is, that glass-makers themselves may procure one of these specimens
and contrast it with a like morsel of English plate-glass. If the two be laid side by side
uponD any moderately light-coloured ground, and a distant object, as a chimney for example, be subjected to reflection, it will be found, that whilst the French glass gives a
clear sharp outline, the English reflects either two or more images in a hazy and imperfect manner. There is no getting over this fact; and therefore improvement is imperative.
The mode of making plate-glass being, so to say, identical in the two countries, the difference here remarked can arise from nothing else than a difference in composition.
In France, as in England, the ingredients are mixed with some care, and introduced
into a crucible, heated by a powerful furnace. These ingredients are sand or silica,
carbonate of soda, and carbonate of lime, with perhaps a little ground felspar in some
cases. The carbonate of soda is first attacked by the silica, and its carbonic acid driven
off, whilst the remaining silica and carbonate of lime becomes imbedded in the vitrifying
mass. As the heat increases, a more perfect fusion takes place; and then the carbonic
acid of the carbonate of lime makes its way through the fused materials by which they
are mechanically mingled together during the'effervescence, which is technically termed
the "boil;" and, provided no after separation ensues from the process of " settling," the
whole crucible or "pot" of glass will have a uniform composition,  But, as we have seen,
this depends altogether upon the relative proportion of the materials towards each other,
for an excess of either one or other of the bases will destroy the homogeneous character
of the whole, and introduce a plexus of striae. Now the plate-glass of St. Gobain is
almost exactly an atomic compound, and consists of one atom of the trisilicate of soda
and one atom of the trisilicate of lime, with a small per-centage of alumina. The union
is therefore complete; and when it is remembered that the celebrated French chemist,
Gay Lussac, was regularly employed as an adviser to this company, and that his son,
M. Jules Lussac, retains that appointment to this day, it is not very surprising that our
manufacturers are defeated in the article of plate-glass. Science must ever take the lead
of prejudice and custom.
The examination of English plate-glass fully corroborates the general result deduced
from  the action of light.  There is no  approach to an  atomic arrangement.  The
principal constituent is trisilicate of soda, but variable quantities of lime, alumina,
and even magnesia, exist in it.  Potash is sometimes present, and oxide of iron is
invariably so; but in not one single instance, out of 17 samples examined with great
care, could so much as a surmise of the doctrine of combining proportions be gathered
from the result of the analyses. Similarly fruitless was a research instituted upon flintglass, both British and foreign.   Of 35 samples analyzed, no satisfactory evidence
could be adduced to favour the opinion that science had been a helpmate to industry,
or was at all concerned in this branch of manufacture.  There are, however, some
points of vast interest associated with the practical working out of this matter. Potash
is known to give a more brilliant and harder glass than soda, and alumina seems to tend
in the same direction.   The Bohemian glass, so celebrated throughout Europe, is a
glass of this description, and contains silicate of alumina, silicate of lime, and silicate of




928                                      GLASS.
potash, but not in chemical proportions. This glass is therefore striated, as may be
seen by examining that in the Austrian department; but it seems to permit of a more
perfect decoration by metallic oxides than can be developed in glass of lime and soda.
This very probably depends upon the alumina contained in it.  From  some singular
oversight, the use of carbonate of baryta has not yet found its way into the composition of glass, though we can scarcely conceive a more hopeful material. This substance may be had in large quantity in the North of England, of great purity, and at
a merely nominal cost as compared with its value for such a purpose as glass-making.
That it would fuse readily with a due amount of soda, and give "a boil" as well as
chalk, there can be no doubt; whilst its great density will certainly improve the refractive power of the resulting product, and thus rival the brilliancy of lead or flintglass, -without imparting that softness and liability to receive scratches which are so
objectionable in the latter variety. One difficulty may perhaps reside in the want of
information concerning the quantity to be employed.  But this is easily adjusted; for
it has been demonstrated that, during vitrification, the silicic acid unites to bases in the
proportion of three atoms to one: consequently three atoms, or 138 parts, will always
require one atom of each base.  Therefore, this weight of good dry sand may be set
against 54 of dry carbonate of soda, 70 of carbonate of potash, 50 of pure marble or
chalk, 99 of carbonate of baryta, and 112 of oxide of lead or litharge. Suppose, then,
that the object is to employ carbonate of baryta for the first time, here 6 atoms or 276
parts of sand, I atom or 54 parts of dry carbonate of soda, and 1 atom or 99 parts of
carbonate of baryta, may be mixed and fused together with every prospect of obtaining
a good result; or 9 atoms of silica, 1 of carbonate of potash, 1 of carbonate of soda,
and 1 of carbonate of baryta, might be tried without fear of failure. Again, in the
case of flint-glass, 112 of litharge, 54 of soda, and 276 of sand, would probably succeed,
or an additional atom  of trisilicate of potash might be used.  For many years past,
M. Dumas, now, perhaps, the first chemist in France, has been in the habit of demonstrating to his pupils that glass of all kinds, when properly made, must necessarily
be an atomic compound; and yet we scarcely expect to find a single British glass.
maker wlho will admit that his art is susceptible of such decisive and beautiful simplification.
To assist as far as we can in the attainment of tlTis end, we shall proceed to describe
a simple means for the analysis of glass, which will enable any person, possessed of even
very trifling chemical skill, to determine the composition of any given sample of glass
in a comparatively short time. From the nature of the material, it becomes necessary
to divide the analysis into two distinct portions; one of which has for its object the
estimation of its alkaline ingredients, the other that of the earthy, metallic, and siliceous
matters.  Having heated a sufficient quantity of the sample in question to dull redness,
it must be suddenly thrown, whilst still hot, into a basin containing cold water. In this way
it becomes cracked and flawed in all directions, so as to favour its reduction into powder.
When dry it must, therefore, be carefully ground in an agate or steel mortar, until it
has the appearance of fine flour.  Nor is it a matter of indifference whether this takes
place in contact with water or not; for glass, in this extreme state of comminution,
readily gives up a part of its alkali to water; and hence, if ground in the presence of
that fluid, the resulting analysis would prove incorrect. But we will suppose that a
quantity of finely powdered glass has been obtained as above indicated, and the amount
of its alkali is desired; then weigh out 100 grains of the glass, and carefully mix with
it 200 grains of pure fluor spar in a similarly powdered condition. Place the mixture
in a platinum or leaden vessel, and pour over it 500 grains of strong sulphuric acid,stirring the whole well together with a silver spoon; but taking care not to remove
any portion of the materials.  Next, apply a heat of about 2120 Fahr.; and as the
process draws to a conclusion, this may be raised as high as 3000. When all evolution
of gaseous fumes has ceased, water may be poured on the residuary mass to the extent
of four or five ounces, and the mixture thrown on a filter. After the clear fluid has
passed through, a little more water must be added to the filter, so as to wash out the
whole of the soluble matter; these washings being joined to the original clear fluid,
which consists of sulphate of soda or potash, or both, with a quantity of sulphate of
lime, and perhaps also of magnesia and alumina. To this an excess of carbonate of
ammonia must now  be added, to admit of the separation of the earthy salts being
effected by filtration. The clear solution is next boiled down to dryness, and the residue
is heated red-hot for a minute or two. This residue is the soda or potash, or both, formerly contained in 100 grains of the glass, but now united to sulpliuric acid. Having
ascertained its weight, the relative proportions of potash and soda may be found by
testing its content of sulphuric acid with a barytic solution, and calculating the result
by the well-known Archimedean equation; or by dissolving the mixed salt in a small
quantity of water, and, after adding an excess of tartaric acid, leaving the whole for a
few hours covered up in a cool place. Almost the whole of the potash will separate in




GLASS.                                           929
this way as bitartrate of potash.  The quantity of alkali may be determined from  the
atomic constitution of the alkaline salts. Thus, supposing the dry residue altogether composed of sulphate of soda, then as'72 grains of it indicate 32 of pure soda, the result may
be obtained by the rule of proportion. The amount of alkali being known, another portion of the po~wdered glass must be employed for ascertaining the remainder of the
ingredients. That is to say, 100 grains of the sample must be mixed with 200 grains of
pure potash, and the whole fused together in a silver crucible, at a red heat, until perfect
liquefaction ensues, when the crucible and its contents may be withdrawn from the fire,
and, as soon as cool enough, boiled in half-a-pint of pure water, so as thoroughly to dissolve the fused mass from the crucible. An excess of nitric acid being poured into the
solution, the mixture is then evaporated to dryness, by which means the silicic acid is
rendered insoluble; consequently, on the application of water, this remains, and may be
dried and weighed, whilst the lime, alumina, and lead of the glass may be separated
from  the soluble  portion  by  tlhe addition, first, of sulphuretted  hydrogen, which
separates the lead, then of ammonia, which throws down the alumina, and, next, by
pouring- in carbonate of ammonia, which precipitates the lime as a carbonate.  Thus,
therefore, the alkaline matters are found by one process, and the silica, earthy, and
metallic constituents by another, both of which may be conducted at the same time.  It
has been recommended to employ carbonate of baryta in the analysis of glass; but the
high temperature required with this substance dissipates a portion of the alkaline components, and thus leads to serious errors.  Even mere fusion in a glass furnace expels
soda from  glass, and renders it more and more infusible; but this expulsion is much
favoured by the presence of baryta.  Tlhe above method of analyzing glass is, therefore,
to be preferred to the baryta plan, by individuals not habitually engaged in manipulative
chemistry.   Until manufacturers adopt the  custom  of examining  every  specimen
of glass they make, the chances of improvement are extremely limited; for success
one day  is constantly  followed by failure in another, without any means of checking or controlling the manufacture. It is generally said that the best glass is made
during cold weather, as at this time the furnaces give most heat, from  the increased
activity of the draught, through the augmented barometrical pressure.  The assertion
itself is most likely true; but the explanation of its cause leaves much to be elucidated,
even if a higher heat prevails at the period in question.  Admitting the beneficial
agency of a high temperature, or " sharp fire," as it is termed, this perhaps depends
upon the sudden fusion of the materials before the carbonic acid of either of the
carbonates has had time to escape; consequently, a much more active "boil" and
thorough intermixture must occur under such circumstances than where this gas has
been suffered to pass off in great part before fusion. This, however, would only diminish
the individual size of the strite by multiplying their number; and such glass must,
even under the most favourable circumstances, suffer greatly by comparison with that
of St. Gobain. Nor can improvement be hoped for until, as in France, in this particular
case, science is linked hand in hand with manufacturing industry.  Since the grand
discovery made by Dalton, that Nature works in definite proportions, there can be
no excuse for continuing to follow the doctrine of chance, with its occasional successes
and frequent failures-the alternations of hope and -despair.  The laws which regulate the' entire universe are not more immutable than those which tend to unite silica
and soda in  equivalent proportions.  It is, therefore, simply futile to battle with
such a power; for even  when success seems on the point of attainment, we find
Nature  reasserting  her dominion, and  stamping  those works of man  which  have
been pursued in defiance of her laws with the indelible impress of imperfection and
error.
That glass of all kinds may be made in this country quite equal to that of St. Gobain,
is saying no more than that Nature's laws are universal. But, remembering the great
facilities we possess as a glass manufacturing nation, the attainment even of such a
result is but a sorry flight of ambition.  We are placed in a position which demands
from  us something more than mediocrity or successful competition, as no nation in the
world possesses the same amount of natural advantages.  In fuel, in soda, in sand, in
chalk, in litharge, we are naturally rich to overflowing.  Our capital and commerce give
us the command of every market; our manufacturers need only ask and have. So long
as a miserable fiscal impost sat like an incubus upon the back of the glass-making
interest, inferiority was unavoidable; but the humiliating aspect of the British plate
glass throughout the Great Exhibition is scarcely palliated by this excise reminiscenced
and we refrain from  terming it a national disgrace only under a belief that already
improvement has begun, which will thrust these specimens into the oblivious records of
the past.
AN AcHRoMATIc TELESCOPE of gigantic ditneosions and powers, which is now  being
constructed for the Rev. Mr. Craig, Vicar of Leamington, under the superintendence of
W. Cravatt, Esq. F.R.S., has been the occasion of the manufacture of some admirable




930                                      GLASS.
optical flint object glasses at the great works of Messrs. Chance, of Birmingham. It is
24 inches in diameter, and is perfectly clear and homogeneous in structure. The crown
glass lens, of like size, is of plate glass, cast by the Thames Plate-glass Company. The
total length of the telescope in use will be 85 feet, but the real focal length of the lens is
much less, being probably about 76 feet. A quarter of an inch letter can be read with
this telescope, even in its imperfect state, at the distance of half a mile. It promises to be
as powerful as Lord Rosse's colossal reflector, and it is mounted, in its observatory, on
Wandsworth Common on such mechanical principles, as to be moveable in any direction
with the slightest touch of the finger, while it can be directed to objects at 80~ of elevation above the horizen. The weight of the tube is 3 tons; it is quite inflexible and free
from tremor or vibration. The chain by which the tube is lowered or raised, is capable
of raising a weight of 13 tons. A gentle touch on the wheel of the iron railway, on which
it moves, lifts 20 cwt.
GLASS FROM  ALKALINE SULPHATES.  Messrs. Balmain  and Parnell have patented
a process for making glass from alkaline sulphates, in which they first make a silicate
by igniting sulphate of soda with sand and charcoal powder, for example, so as to
contain from  about 12 to 20 per cent. of alkali.  To make a silicate of about 20
per cent. of soda, they mix 3 cwt. of sand, 2 cwt. of dry sulphate of soda in fine
powder, and from  16 to 18 lbs. of finely ground charcoal, and heat the mixture to
whiteness in a furnace.  As the silicate falls from  the furnace it is received into a
vessel of water, which renders it more easy to grind, and by dissolving the excess
of sulphate, presents that substance in a convenient form  for being recovered.  To
make a silicate of soda of 12 per cent. of soda, 3 parts of sand and 1 part of sulphate of
soda are mixed, and the mixture is heated, with occasional stirring, in the furnace. By
exposure to a low red heat for from 6 to 10 hours, a perfect silicate of soda will be
formed. A silicate of potash of 26 per cent. is made by heating 31 cwt. of sand, 2v  cwt.
of sulphate of potash, and 18 pounds of charcoal.  Sometimes both a sulphate and
carbonate of a base are used together; and sometimes two bases are used to make a
double silicate.
In all cases, chemical equivalents are observed; a single equivalent of charcoal to one
of sulphate. To make a double silicate of soda and barytes, either of the following mixtures may be used -~
No. 1., 273 parts of sand, 72 sulphate of soda, 117 sulphate of barytes, and 12 charcoal.
No. 2., 273 sand, 72 sulphate of soda, 99 carbonate of barytes, and 6 charcoal. A flow of
sulphate indicates want of charcoal, and a brown colour in the result an excess of charcoal; but both of these accidents may be produced by too low a heat in the furnace.
The highest working temperature is a fair white heat. The addition of 5 or 10 per cent.
of common salt aids the fluxing, and is not hurtful to the result. The sulphate should be
in fine powder. The patentees also use a sulphuret or hyposulphite as a decomposing
agent for the sulphates instead of charcoal. Half an equivalent proportion of sulphuret,
or a single equivalent of hyposulphite, should be used in the place of each equivalent of
the charcoal; as, for example, 20 parts of sulphuret of sodium for 6 parts of charcoal.
These decompositions and combinations are effected by means of a peculiar reverberatory
furnace, with two inclined beds or flues through which the fire passes and plays.Newton's Journal, xxxv. 223.
The duties payable in the United Kingdom, upon the different descriptions of glass
are, for
~ 8. d.
Window glass, any kind, not exceeding - inch
thickness   -       -       -       -       -0  3  6 per cwt.
All glass exceeding ^ inch thickness, and all
silvered or polished glass, superficial measure:      -       -       -       -        -
Not exceeding 9 square feet    -          -  0  0  3 per square foot.
Exceeding      9 and not 14 square feet -  0  0  6 
-         14,,   36,,       -  0  0  7         -
~         36 and upwards   -          -  0  0  9 
Painted or ornamented         -        -       -  0  0  9 per superficial foot.
All white flint glass bottles, not cut, engraved,
or otherwise ornamented, and beads and
bugles      -       -       -       -       -0  0  01 per lb.
Wine glasses, tumblers, and all other white
flint glass goods not cut, engraved, or otherwise ornamented   -         -       -       -0  0  1
All flint cut glass, flint coloured glass, and fancy
ornamental glass  -         -       -       -0  0  2 per lb.




GLASS (BOHEMIAN).                                        931
~  s. d.
Bottles of glass covered with wicker (not being
flint or cut glass), or of green or common
glass      -      -        -          -      -  0  0  9 per cwt.
Unenumerated, and old broken glass                 0  3  6 per cwt.
GLASS, AUSTRIAN. M. Peligot states that the hard glass of Bohemia is composed of
100 parts of silica, 12 parts of quicklime, and only 28 parts of carbonate of potash.
These proportions give a glass quite unmanageable in ordinary furnaces; but the addition of a comparatively small quantity of boracic acid is capable of determining
fusion, and the result is a glass having all the requisite limpidity at a high temperature
and possessing at the same time a great brilliancy and hardness.
GLASS, BOILEMIAN. Glasses are silicates which must contain at least 50 per cent. of
silica; the more there is of it, the more perfect, unalterable, hard, and infusible is the
glass. The hardest, most beautiful, and most perfect glass, is found in nature in the state
of pure silica in rock- crystal. To render silica fusible, certain fluxes must be added:
these fluxes are potassa, soda, lime, and oxide of lead.
Silica fuses very well with the alkalis, but the resulting glass is rapidly changed by
absorbing moisture from the air. To prevent this alteration, it is always necessary, in
the manufacture of glass, to introduce a certain quantity of lime or of oxide of lead.
In the following table is given the analyses of a certain number of Bohemian glasses,
which will indicate their composition with precision.
(1.)   (2.)    (3.)   (4.)    (65.)    (6.)    (.)    (8.)
Silica-  -'- --  - 71'6   71-7    69-4   62-8    75-9    7885   70-                  571
Potassa  -  -  --  -   11-0   12-7    11'8   22-1   -                55    20-    25'
Soda --           -.-. -    2-3. -   -                 -   17-5    12-05
Lime -  -  -  -  -  -    10-    10-3         9-2   12-5      3-8     5-6      4-     12-5
Magnesia   -  -  -  -    2-3
Alumina    -  -  -  -       2-2    0-4       9-6     2-6     2-8     3.5      5-      3.
Oxide of Iron  -  -  -       3-9                         0-3-0-6                      1-3
Oxide of Manganese -        0-2    0.2 - --                                   04      0-4
101-2   981   100-   100-   100-   100-5   100-            992
(1.) Bohemian glass from  Neufeld, (M. Grus); its composition is represented, nearly,
by the formula, Ca Sr, + (Al F) S5 + (K Mg Mn) S~.
(The reader will remember, that these are mineralogical, and not chemical, symbols,
since the letters signify the oxides, or acids, and not the elementary bases, as they would
in chemistry.-Trans.)
(2.) A fine table glass from Neuwelt (M. Berthier); it is exceedingly beautiful, and
is prepared, according to M. Perdonnet, with a mixture of 100 quartz, 50 caustic lime, 75
carbonate of potassa, and a very small quantity of nitre, arsenious acid, and oxide of
manganese. The presence of arsenic cannot be detected by analysis. The composition
of this glass is expressed by the formula C S6 + (K N) S ~.
(3.) Old Bohemian glass, (M. Dumas); its formula is (Al C K) S4.
(4.) Crown glass of German manufacture, (M. Dumas); its composition is expressed
by the formula (K C) S 5
(5.) Glass for mirrors, (M. Dumas); it is represented by the formula (N Al C) S \.
(6.) Another glass for mirrors, (M. Dumas); its formula lies between B S 5 and
B S.
(7.) White table glass, from Silberberg near Gratzen; its composition is exactly expressed by the formula, 2 (K Ca) S 5 +  (Al F) S 
(8.) Mirror glass from  New-Hurkenthal, for the manufacture of cast mirrors. It
shows a greenish tint in section, and softens at a gentle heat. Its composition is nearly
represented by the formula (Al F) S3 + 6 (K C M) S3, or more simply (K C Al) S3.
Properties of Glass, Transparence, Colourlessness.-Transparence and colourlessness
are the first properties of glass: to obtain them, the materials must be employed extremely pure, and the least possible flux added; an excess of potassa gives the glass a
greenish tint; soda and its salts give it a yellow tint, and lime renders it milky.  A
very small quantity of the sulphate of potassa, or soda, gives it a yellowish, or blackish,
brown green; iron colours it strongly bottle green; and an excess of the manganese
employed to remove the coloration due to the oxide of iron, gives it a bluish tint, which
becomes a decided violet by the action of the solar light. If the minium employed in*
6 0 2




932                        GLOVE MANUFACTURE.
the manufacture of crystal contains a little copper, which very often happens, the crystal
takes a slight emerald green tint; this, however, is not to be feared in Bohemia, where
there is but a single establishment which makes lead glass.
Charcoal colours glass of a topaz yellow, more or less dark, and sometimes reaching
a purple, so that it is impossible to obtain a perfectly colourless glass in furnaces which
smoke, or in those which are heated by turf, lignite, or bituminous coal; and in these
cases it is necessary to employ covered crucibles, as is done in the manufactory of crystal
at Choisy-le-Roi; it is also necessary on this account, when in tbe fabrication of glass
the alkaline carbonates are replaced by sulphate of soda, to add in the crucible a little
(about 4 —) less of carbon than would be necessary to reduce the sulphate completely,
and even thus but common glass is obtained by this process, since the slight excess of
sulphate of soda, which must be left, gives a blackish brown tint.
Hardness, Elasticity.-The Bohemian glass is, within certain limits, perfectly elastic.
and very sonorous; when well made, it is sufficiently hard to strike fire with steel, and
is scratched with difficulty. The lead glasses, on the other hand, have but little hardness, and less in proportion as they contain more oxide of lead; besides which they
rapidly lose their brilliancy by use.
Fusibility, Cooling, Annealing, Devitrification.-All glass is more or less fusible; when
it is softened by the action of heat, it may be worked with the greatest ease, and may
be drawn out into threads as fine as those of the cocoon of the silkworm. Glass, when
it is submitted to rapid cooling, becomes very fragile, and presents several very remarkable phenomena, among which I will cite as an example Prince Rupert's drops. Glass
supports variations of temperatures better in proportion as it has been more slowly
cooled; thus, when it has been but slightly annealed, or not at all, its fragility may
be considerably diminished by annealing it in water, or better, in boiling oil.
All glass exposed during a longer or shorter time to a heat sufficiently elevated, loses
its transparency, and becomes extremely hard, and much less brittle than before.
There takes place a phenomenon precisely similar to that which we see taking place
every day, by the slow cooling of the slags of our smelting furnaces, and especially in
volcanic lavas. Glass with a soda base is more fusible and less bard than that whose
base is potassa.
Density.-Below is given the density of several glasses without lead
Old Bohemian glass (Dumas)                        -       -       -       -  2-896
Bohemian bottle glass             -       -       -       -       -       -  3782
do.     window glass                    --             -       -        -  2'642
Fine glass, called Bohemian crystal               -       -       -       -  2'892
Mirror glass of Cherbourg, (Dumas)    -..       -       -  2-506
do.    St. Gobain      -       -       -       -.       -       -  2-488
do.    Newhaus 1812, (Scholz)           -       -       -       -       -2-551
do.         do.  1830.          -       -       -       -       -       -  2653
Action of Atmospheric and Chemical Agents.-The harder and more infusible a glass is,
the less is it alterable by the action of atmospheric and chemical agents, with the exception
of hydrofluoric acid. Glass which is too alkaline attracts gradually the moisture of the
air and loses its lustre and polish. Many glasses are perceptibly attacked by a prolonged
boiling with water, and &fortiori by acid and alkaline solutions; thus, the bottle glass
is frequently attacked by the tartar which is found in the wine. According to Guyton
Morveau all glass which is attacked by prolonged boiling with concentrated solutions
of alum, common salt, sulphuric acid, or potassa, is of bad quality.
The silica which is employed in Bohemia in the manufacture of glass, is obtained by
calcining crystalline quartz, and afterwards pounding it while dry. When the quartz
has been heated to a cherry-red, it is withdrawn from the fire, and thrown immediately
into cold water.
Almost all the Bohemian glass is a potash glass, because soda and its salts give to
glass a sensible yellowish tint. The limestone which is used is as white as Carrara
marble.  The clay employed for the crucibles is very white, and consists of silica 45-,
alumina 404, and water 13-4.
GLAUBER SALT is the old name of sulphate of soda.
GLAZES. See POTTERY.
GLAZIER, is the workman who cuts plates, or panes of glass, with the diamond, and
fastens them by means of putty in frames or window casements. See DIAMOND, for an
explanation of its glass-cutting property.
GLOVE  MANUFACTURE.  In February, 1822, Mr. James Winter of Stokeunder-Uambdon, in the county of Somerset, obtained a patent for an improvement upon




GLOVE-SEWING.                                    933
a former patent machine of his for sewing and
v,_ A add J                     pointing leather gloves.  Fig. 727 represents
A^\28  i                          a pedestal, upon which the instrument called
(I28t b             732          the jaws is to be placed. Fig. 728 shows the
^aL~ agrd ff    /^\               jaws, which instead of opening and closing by
/  "TT*      //    \\s           a circular movement upon a joint as described
in the former specification, are now made to
igggrl ptggggB q k^   ^open and shut by a parallel horizontal move-i^^^-[~~ ~ment, effected by a slide and screw; a a is the
127        p                   733 fixed jaw, made of one piece, on the under
lt~  o         0          side of which is a tenon, to be inserted into
the top of the pedestal.  By means of this
tenon the jaws may be readily removed, and
another similar pair of jaws placed in their,HiO               stead, which aflfords the advantage of expediting
/   \ 0\            the operation by enabling one person to prepare the work whilst another is sewing; b b is
731          the moveable jaw, made of one piece.  The
two jaws being placed together in the manner
shown atfig. 728, the moveable jaw traverses
backwards and forwards upon two guide-bars,
c, which are made to pass through holes exactly fitted to them, in the lower parts of the
jaws. At the upper parts of the jaws are
729        what are called the indexes, d d, which are
pressed tightly together by a spring, shown at
fig. 729, and intended to be introduced between the perpendicular ribs of the jaws at
e.  At f is a thumbscrew, passing through
the ribs for the purpose of tightening the jaws, and holding the leather fast between the
indexes while being sewn; this screw, however, will seldom, if ever, be necessary if the
spring is sufficiently strong; g is an eye or ring fixed to the moveable jaw, through which
the end of a lever, h, in fig. 727 passes; this lever is connected by a spring to a treadle,
i, at the base of the pedestal, and by the pressure of the right foot upon this treadle,
the moveable jaw is withdrawn; so that the person employed in sewing may shift the
leather, and place another part of the glove between the jaws. The pieces called indexes
are connected to the upper part of the jaws, by screws passing through elongated holes
which render them capable of adjustment.
The patentee states, that in addition to the index described in his former patent, which
is applicable to what is called round-seam sewing only, and which permits the leather to
expand but in one direction when the needle is passed through it, namely, upwards, he
now makes two indexes of different construction, one of which he calls the receding
index, and the other the longitudinally grooved index. Fig. 730 represents an end view,
and fig. 731 a top view of the receding index, which is particularly adapted for what are
called "drawn sewing, and prick-seam sewing;" this index, instead of biting to the top,
is so rounded off in the inside from the bottom of the cross grooves, as to permit the
needles, by being passed backwards and forwards, to carry the silk thread on each side
of the leather without passing over it. Fig. 732 represents an end view of the longitudinally grooved index, partly open, to show the section of the grooves more distinctly;
and fig. 733 represents an inside view of one side of the same index, in which the longitudinal groove is shown passing from k to I. This inaex is more particularly adapted to
round seam sewing, and permits the leather to expand in every direction when the needle
is passed through it, by which the leather is less strained, and the sewing consequently
render ed much stronger.
It is obvious that the parallel horizontal movement may be effected by other mechanical means besides those adopted here, and the chief novelty claimed with respect to that
movement, is its application to the purpose of carrying the index used in sewing and
pointing leather gloves.
Importation of leather gloves for home consumption; and amount of duty in
1836.           1837.           1836.           1837.
1,461,769.  l  1,221,350.       ~27,558.         ~22,923.
GLOVE-SEWING. The following simple and ingenious apparatus, invented by
an Englishman, has been employed extensively in Paris, and has enabled its proprietors
to realize a handsome fortune. The French complain that "it has inundated the world
with gloves, made of excellent quality, at 30 per cent. under their former wholesale




934                                     GLUE.
ismade fasttot     tA  Ai  bprices."  The  instruthment is
I734         shown in profile ready for ac^..-.     ~     -^                                   l ^   tion infig. 734. It resembles
by meas ofan iron vice, having the upper
used                                                 portion of each jaw made of'735 \        I             ff ^l   1brass, and tipped with a kind
of comb of the same metal. The
I        I            ffscrwIs.    n\teeth of this comb, only one
Ijaw, by te t e s s.twelfth of an inch long, are
perfectly regular and equal.
^pcomb~~,Change combs are provided for
The leverKA                  different styles of work. The
woman's                          B foot,.whenevice A A is made fast to the
hem  the parallel                                       edge of the bench or table Bsewed.
1         Qjaws jo    I th~jforcof the proper height, by a
I  ~UP                    thumb-screw  c, armed with a
{\stationaryncramp which lays hold of the
lol                 wood. Of the two jaws com~After              posing the machindouble, the to be in i
is made fast to the foot A A, butll   the other E is moveable upon th base of the machine,omb,
by means of a hinge at the point F. At i i is shown how the upper brass portion is adjusted to the lower part made of iron; the two being secured to each other by two stout
screws. The comb, seen separately in fig.'36, is made fast to the upper end of each
jaw, by the three screws n n n. Fig. 735 is a front view of the jaw mounted with its
comb, to illustrate its construction.
The lever K corresponds by the stout iron wire L, with a pedal pressed by the needlewoman's foot, -whenever she wishes to separate the two jaws, in order to insert between
them the parallel edges of leather to be sewed. The instant she lifts her foot, the two
jaws join by the force of the spring G, which pushes the moveable jaw E against the
stationary one D. The spring is made fast to the frame of the vice by the screw H.
After putting the double edge to be sewed in its place, the woman passes her needle
successively through all the teeth of the comb, and is sure of making a regular seam in
every direction, provided she is careful to make the needle graze along the bottom of the
notches. As soon as this piece is sewed, she presses down the pedal with her toes,
whereby the jaws start asunder, allowing her to introduce a new seam, and so in quick
succession.
The comb may have any desired shape, straight or curved; and the teeth may be
larger or smaller, according to the kind of work to be done. With this view, the combs
might be changed as occasion requires; but it is more economical to have sets of vices
ready mounted with combs of every requisite size and form.
GLUCINA (G6lucine, Fr.; Berryllerde, Germ.), is one of the primitive earths, originally
discovered by Vauquelin, in the beryl and emerald. It may be extracted from either of
these minerals, by treating their powder successively with potash, with water, and with
muriatic acid. The solution by the latter, being evaporated to dryness, is to be digested
with water, and filtered. On pouring carbonate of ammonia in excess into the liquid, we
form soluble muriate of ammonia, with insoluble carbonates of lime, chrome, and iron, as
also carbonate of glucina, which may be dissolved out from the rest by an excess of carbonate of ammonia. When the liquid is filtered anew, the glucina passes through, and may
be precipitated in the state of a carbonate by boiling the liquid, which expels the excess
of ammonia. By washing, drying, and calcining the carbonate, pure glucina is obtained.
It is a white insipid powder, infusible in the heat of a smith's forge, insoluble in
water, but soluble in caustic potash and soda; as also, especially when it is a hydrate,
in carbonate of ammonia. It has a metallic base called glucinum, of'which 100 parts
combine with 45-252 of oxygen to form the earth.  It is too rare to be susceptible
of application in manufactures.
GLUCOSE. The name given to grape and starch sugar by M. Dumas.
GLUE (Colle forte, Fr.; Leim, Tischlerleim, Germ.) is the chemical substance gelatine in a dry state. The preparation and preservation of the skin and other animal
matters employed in the manufacture of glue, constitute a peculiar branch of industry.
Those who exercise it should study to prevent the fermentation of the substances, and
to diminish the cost of carriage by depriving them of as much water as can conveniently
be done. They may then be put in preparation by macerating them in milk of lime,
renewed three or four times in the course of a fortnight or three weeks. This process
is performed in large tanks of masonry. They are next taken out with all the adhering
lime, and laid in a layer, 2 or 3 inches thick, to drain and dry, upon a sloping pavement,
where they are turned over by prongs two or three times a day. The action of the




GLUE.                                        935
lime dissolves the blood and certain soft parts, attacks the epidermis, and disposes the
gelatinous matter to dissolve more readily. When the cleansed matters are dried, they
may be packed in sacks or hogsheads, and transported to the glue manufactory at any
distance. The principal substances of which glue is made are the parings of ox and
other thick bides, which form the strongest article, the refuse of the leather dresser;
both afford from  45 to 55 per cent. of glue.  The tendons, and many other offals of
slaughter-houses, also afford materials, though of an inferior quality, for the purpose.
The refuse of tanneries, such as the ears of oxen, calves, sheep, &c., are better articles;
but parings of parchment, old gloves, and, in fact, animal skin in every form, uncombine  with tannin, may be made into glue.
The manufacturer who receives these materials is generally careful to ensure their
purification by subjecting them to a weak lime steep, and rinsing them by exposure
in baskets to a stream of water. They are lastly drained upon a sloping surface, as above
described, and well turned over till the quicklime gets mild by absorption of carbonic
acid; for, in its caustic state, it would damage the glue at the heat of boiling water. It
is not necessary, however, to dry them before they are put into the boiler, because they
dissolve faster in their soft and tumefied state.
The boiler is made of copper, rather shallow in proportion to its area, with a uniform
flat bottom, equably exposed all over to the flame of the fire.  Above the true bottom
there is a false one of copper or iron, pierced with holes, and standing upon feet 3 or 4
inches high; which serves to sustain the animal matters, and prevent them from being
injured by the fire. The copper being filled to two-thirds of its height with soft water,:_s then heaped up with the bulky animal substances, so high as to surmount its brim.
But soon after the ebullition begins they sink down, and, in a few hours, get entirely
immersed in the liquid.  They should be stirred about from  time to time, and well
pressed down towards the false bottom, while a steady but gentle boil is maintained.
The solution must be drawn off in successive portions; a method which fractions the
products, or subdivides them  into articles of various value, gradually decreasing from
the first portion drawn off to the last. It has been ascertained by careful experiments
that gelatine gets altered over the fire very soon after it is dissolved, and it ought therefore to be drawn off whenever it is sufficiently fluid and strong for forming a clear
gelatinous mass on cooling capable of being cut into moderately firm slices by the wire.
This point is commonly determined by filling half an egg-shell with the liquor, and
exposing it to the air to cool The jelly ought to get very consistent in the course of a
few minutes; if not so, the boiling must be persisted in a little longer. When this term
is attained, the fire is smothered up, and the contents of the boiler are left to settle for a
quarter of an hour. The stop-cock being partially turned, all the thin gelatinous liquor
is run off into a deep boiler, immersed in a warm water bath, so that it may continue
hot and fluid for several hours. At the end of this time the supernatant clear liquid is
to be drawn off into congealing boxes, as will be presently explained.
The grounds, or undissolved matters in the boiler, are to be again supplied with a
quantity of boiling water from an adjoining copper, and are to be once more subjected to
the action of the fire, till the contents assume the appearance of dissolved jelly, and
afford a fresh quantity of strong glue liquor, by the stop-cock.  The grounds should be
subjected'a third time to this operation, after which they may be put into a bag, and
squeezed in a press to leave nothing unextracted. The latter solutions are usually too
weak to form glue directly, but they may be strengthened by boiling with a portion of
fresh skin-parings.
Fig. S*37. represents a convenient apparatus for the boiling of skins into glue, in which
there are three coppers upon three different levels; the uppermost being acted upon by
the waste heat of the chimney, provides warm water in the most economical way; the
second contains the crude materials, with water for dissolving them; and the third
receives the solution to be settled. The last vessel is double, with water contained
between the outer and inner one; and discharges its contents by a stop-cock into buckets
for filling the gelatinizing wooden boxes. The last made solution has about one-fivehundredth part of alum in powder usually added to it, with proper agitation, after which
it is left to settle for several hours.
The three successive boils furnish three different qualities of glue.
Flanders or Dutch glue, long much esteemed on the Continent, was made in the
manner above described, but at two boils, from animal offals well washed and soaked, so
as to need less boiling. The liquor being drawn off thinner, was therefore less coloured,
and being made into thinner plates was very transparent. The above two boils gave
two qualities of glue.
By the English practice, the whole of the-animal matter is brought into solution at
once, and the liquor being drawn off, hot water is poured on the residuum, and made to
boil on it for some time, when the liquor thus obtained is merely used instead of water




936                                      GLUE.
upon a fresh quantity of glue materials. The first drawn off liquor is kept hot in a
settling copper for five hours, and then the clear solution is drawn off into the boxes.
These boxes are made of deal, of a square form, but a little narrower at bottom than
at top. When very regular cakes of glue are wished for, cross grooves of the desired
square form are cut in the bottom of the box. The liquid glue is poured into the boxes
placed very level, through funnels furnished with filter cloths, till it stands at the brim
of each. The apartment in which this is done ought to be as cool and dry as possible,
to favour the solidification of the glue, and should be floored with stone flags kept very
clean, so that if any glue run through the seams, it may be recovered. At the end of
12 or 18 hours, or usually in the morning if the boxes have been filled overnight, the
glue is sufficiently firm for the nets, and they are at this time removed to an upper story,
mounted with ventilating windows to admit the air from all quarters.   Here the boxes
are inverted upon a moistened table, so that the gelatinous cake thus turned out will
not adhere to its surface; usually the moist blade of a long knife is insinuated round
the sides of the boxes beforehand, to loosen the glue. The mass is first divided into
horizontal layers by a brass wire stretched in a frame, like that of a bow-saw, and guided
by rulers which are placed at distances corresponding to the desired thickness of the
cake of glue. The lines formed by the grooves in the bottom  of the box define the
superficial area of each cake, where it is to be cut with a moist knife. The gelatinous
layers thus formed, must be dexterously lifted, and immediately laid upon nets stretched
in wooden frames, till each frame be filled. These frames are set over each other at
distances of about three inches, being supported by small wooden pegs, stuck into mortise holes in an upright, fixed round the room; so that the air may have perfectly free
access on every side. The cakes must moreover be turned upside down upon the nets
twice or thrice every day, which is readily managed, as each frame may be slid out like
a drawer, upon the pegs at its two sides.
The drying of the glue is the most precarious part of the manufacture. The least
disturbance of the weather may injure the glue during the two or three first days of its
exposure; should the temperature of the air rise considerably, the gelatine may turn so
soft as to become unshapely, and even to run through the meshes upon the pieces below,
or it may get attached to the strings that surround them, so as not to be separable without plunging the net into boiling water. If frost supervene, the water may freeze and
form  numerous cracks in the cakes. Such pieces must be immediately re-melted and
re-formed. A slight fog even produces upon glue newly exposed a serious deterioration;
the damp condensed upon its surface occasioning a general mouldiness.  A  thunderstorm sometimes destroys the coagulating power in the whole laminae at once; or causes
the glue to turn on the nets, in the language of the manufacturer. A wind too dry or
too hot may cause it to dry so quickly, as to prevent it from  contracting to its proper
size without numerous cracks and fissures. In this predicament, the closing of all the
flaps of the windows is the only means of abating the mischief. On these accounts it
is of importance to select the most temperate season of the year, such as spring and
autumn, for the glue manufacture.
After the glue is dried upon the nets it may still preserve too much flexibility, or
softness at least, to be saleable; in which case it must be dried in a stove by artificial
heat. This aid is peculiarly requisite in a humid climate, like that of Great Britain.
When sufficiently dry it next receives a gloss, by being dipped cake by cake in hot




GLUTEN.                                      937
water, and then rubbed with a brush also moistened in hot water; after which the glue
is arranged upon a hurdle, and transferred to the stove room, if the weather be not
sufficiently hot. One day of proper drought will make it ready for being packed up in
casks.
The pale-colored, hard, and solid article, possessing a brilliant fracture, which is made
from the parings of ox-hides by the first process, is the best and most cohesive, and is
most suitable for joiners, cabinet-makers, painters, &c. But many workmen are influencedl by such ignorant prejudices, that they still prefer a dark-colored article, with somewhat of a fetid odor, indicative of its impurity and bad preparation, the result of bad
materials and too long exposure to the boiling heat.
There is a good deal of glue made in France from bones, freed from the phosphate of
lime by muriatic acid. This is a poor article, possessing little cohesive force. It dissolves almost entirely in cold water, which is the best criterion of its imperfection. Glue
should merely soften in cold water, and the more considerably it swells, the better, generally speaking, it is.
Some manufacturers prefer a brass to a copper pan for boiling glue, and insist much
on skimming it as it boils; but the apparatus I have represented renders skimming of
little consequence. For use, glue should be broken into small pieces, put along with some
water into a vessel, allowed to soak for some hours, and subjected to the heat of a boilbath, but not boiled itself. The surrounding hot water keeps it long in a fit state
for joiners, cabinet-makers, &c.
Water containing only one hundredth part of good glue, forms a tremulous solid.
When the solution, however, is heated and cooled several times, it loses the property of
gelatinizing, even though it be enclosed in a vessel hermetically sealed. Isinglass or fishglue undergoes the same change.  Common glue is not soluble in alcohol, but is precipitated in a white, coherent, elastic mass, when its watery solution is treated with that
fluid. By transmitting chlorine gas through a warm  solution of glue a combination
is very readily effected, and a viscid mass is obtained like that thrown down by alcohol.
A little chlorine suffices to precipitate the whole of the glue. Concentrated sulphuric
acid makes glue undergo remarkable changes; during which are produced, sugar of gelatine, leucine, an animal matter, &c. Nitric acid, with the aid of heat, converts glue into
malic acid, oxalic acid, a fat analogous to suet, and into tannin; so that, in this way,
one piece of skin may be made to tan another.  When the mixture of glue and nitric
acid is much evaporated, a detonation at last takes place. Strong acetic acid renders
glue first soft and transparent, and then dissolves it. Though the solution does not
gelatinize, it preserves the property of gluing surfaces together when it dries. Liquid
glue dissolves a considerable quantity of lime, and also of the phosphate of lime recently
precipitated.  Accordingly glue is sometimes contaminated with that salt.  Tannin
both natural and artificial combines with glue; and with such effect, that one part of
glue dissolved in 5000 parts of water affords a sensible precipitate with the infusion of
nutgalls. Tannin unites with glue in several proportions, which are to each other as
the numbers 1, 1l, and 2; one compound consists of 100 glue and 89 tannin; another
of 100 glue and 60 tannin; and a third of 100 glue and 120 tannin. These two substances cannot be afterwards separated from  each other by any known chemical
process.
Glue may be freed from the foreign animal matters generally present in it, by softening it in cold water, washing it with the same several times till it no longer gives out
any color, then bruising it with the hand, and suspending it in a linen bag beneath the
surface of a large quantity of water at 600 F. In this case, the water loaded with the
soluble impurities of the glue gradually sinks to the bottom of the vessel, while the pure
glue remains in the bag surrounded with water. If this softened glue be heated to 920
without adding water, it will liquefy; and if we heat it to 1220, and filter it, some albuminous and other impurities will remain on the filter, while a colorless solution of glue
will pass through.
Experiments have not yet explained how gelatine 6 formed from skin by ebullition.
It is a change somewhat analogous to that of starch into gum and sugar, and takes place
without any appreciable disengagement of gas, and even in close vessels.  Gelatine, says
Berzelius, does not exist in the living body, but several animal tissues, such as skin,
cartilages, hartshorn, tendons, the serous membranes, and bones, are susceptible of being
converted into it.
GLUTEN  (Colle Vegetale, Fr.; Kieber, Germ.) was first extracted by Beccaria from
wheat flour, and was long regarded as a proximate principle of plants, till Einhof, Taddei, and Berzelius succeeded in showing that it may be resolved by means of alcohol into
three different substances, one of which resembles closely animal albumine, and has been
called Zymome, or vegetable albumine; another has been called Gliadine; and a third,
Mucine. The mode of separating gluten from the other constituents of wheat flour has
been described towards the end of the article BREAD.
Gluten, when dried in the air or a stove, diminishes greatly in size, becomes hard, brit



938                                 GLYCERINE.
brittle, glistening, and of a deep yellow colour.  It is insoluble in ether, in fat and
essential oils, and nearly so in water. Alcohol and acetic acid cause gluten to swell and
make a sort of milky solution. Dilute acids and alkaline lyes dissolve gluten. Its
ultimate constituents are not determined, but azote is one of them, and accordingly
whlen moist gluten is left to ferment, it exhales the smell of old cheese.
Some years since, M. E. M. Martin, of Vervins, proposed to extract the starch
without injuring the gluten, which then becomes available for alimentary purposes.
His process is a mechanical one (resembling that long practised in laboratories for
procuring gluten), and consists in washing wheat flour, made into a paste, with water,
either by the hand or machinery.
The gluten thus obtained is susceptible of numerous useful applications for alimentary
purposes. Mixed with wheat flour, in the proportions of 30 parts of flour, 10 of fresh
gluten. and' of water, it has been employed to produce a superior sort of macaroni,
vermicelli, and other kinds of Italian pastes; and MM. V6ron frres, of Paris, have
made with it a new sort'of paste, which they have termed granulated gluten (gluten
granule).
Mr. 1. P. Gentile, of the Habertonford works, near Totness, in  Devonshire, has
for some time past been engaged in the manufacture of gluten for alimentary purposes,
and placed in the Exhibition samples of several dietetical substances made with gluten:
such as macaroni, vermicelli, a sort of gluten chocolate, and a kind of meal biscuit
powder.
Madame St. Etienne, the wife of Mr. Gentile's foreman, also placed in the Exhibition a very complete collection of alimentary preparations, made with gluten.
To the same category belongs Mr. Bullock's Semola, of which he has given an
account in the Lancet of December 15, 1849, and March 9, 1850. It is, in fact, wheat
gluten made into a paste with wheat flour, and granulated.
In all the above preparations, the gluten employed is that extracted from wheat by a
mechanical process (hand working), as practised by M. E. M. Martin.
Messrs. Orlando Jones and Co., manufacturers of rice starch, also placed in the Exhibition a specimen of rice gluten. But, as it is extracted from rice by a solution of
caustic soda, and precipitated from its alkaline solution by an acid, it is obvious that it
must have suffered deterioration, and be less proper for alimentary purposes than gluten
extracted from the grain by a mechanical process.
We hail with much satisfaction these attempts to introduce into use, as alimentary
substances, preparations of gluten.  No one has hitherto succeeded in making in
England macaroni and vermicelli equal to the Italian pastes; for, although the Englishmade article presented a tolerably good appearance, it failed in cooking, either running
into a mass, or falling to pieces; whereas it should simply expand and retain its form,
even after long boiling. With Mr. Gentile's gluten it is to be hoped that good pastes
may be made, even with English wheat. Hitherto, hundreds of tons of a most valuable
and important article of food have been annually lost, and the prevention of this by the
economic application of the gluten deserves, therefore, every encouragement.
By mixing gluten with wheat flour, Mr. Gentile prepares what he calls gluten flour,
containing 42 per cent., or four times the normal quantity of gluten. This preparation
is susceptible of several very useful applications. It yields a very nutritious and
digestible gluten biscuit; mixed with cocoa it forms an agreeable and nutritious gluten
chocolate; and mixed with beef or mutton it furnishes a highly-condensed nutritive
food. Bread made with gluten flour might be advantageously employed by diabetic
patients as a substitute for Bouchardat's gluten bread.
GLYCERINE, is a sweet substance which may be extracted from fatty substances.
If we take equal parts of olive oil and finely-ground litharge, put them  iuto a basin
with a little water, set this on a sand bath moderately heated, and stir the mixture constantly, with the occasional addition of hot water to replace what is lost by evaporation,
we shall obtain, in a short time, a soap or plaster of lead. After having added more
water to this, we remove the vessel from the fire, decant the liquor, filter it, pass sulphuretted hydrogen through it to separate the lead, then filter afresh, and concentrate
the liquor as much as possible without burning upon the sand-bath. What remains
must be finally evaporated within the receiver of the air-pump. Glycerine thus prepared is a transparent liquid, without colour or smell, and of a syrupy consistence. It
has a very sweet taste. Its specific gravity is 127 at the temperature of 600. When
thrown upon burning coals, it takes fire and burns like an oil. Water combines with
it in almost all proportions; alcohol dissolves it readily; nitric acid converts it into
oxalic acid; and according to Vogel, sulphuric acid transforms it into sugar, in the
same way iss it does starch. Ferment or yeast does not affect it in any degree.
Its constituents are, carbon 40, hydrogen 9, oxygen 51, in 100.
The employment of glycerine as an application in the treatment of deafness, and also
for other purposes as a medicinal agent, has given rise to enquiries on the Subject, on




GOLD.                                        939
which account a few  practical remarks may probably be interesting to some of our
readers.
Glycerine is one of the products of the saponification of fat oils.  It is produced in
large quantities in the soap manufactories in a very impure state, being contaminated
with saline and empyreumatic matters, and' having a very strong disagreeable odour.
In order to obtain glycerine from this source, the residuary liquors are evaporated and
treated with alcohol, which dissolves out the glycerine.  The alcohol having  been
separated by evaporation, the glycerine is diluted with water, and boiled with animal
charcoal. This process must be repeated several times, or until the result is sufficiently
free from smell. It is, however, extremely difficult to obtain pure glycerine from this
source, on account of the nature and condition of the ingredients usually employed in
making soap, which it is almost impossible to deprive of rancid odour.
The best method of obtaining glycerine for medicinal purposes is to evaporate the
water used in malking emplastrum  plumbi.  When the oil employed is fresh, and the
process is carefully conducted, the result is easily made fit for use, and is almost without
odour.  Any lead with which it may be contaminated is separated by passing a stream
of sulphuretted hydrogen through it when in a dilute state. The excess of gas escapes
during the process of evaporation. If requisite, it may be boiled with animal charcoal,
filtered, and evaporated. The specific gravity, when reduced to the proper consistence,
is 127.
It is now  about twelve months since an announcement appeared in the medical
journals, respecting a new cure for deafness, discovered by Mr. Yearsley. The remedy
was reported to be perfectly simple, remarkably safe and very effectual. Several papers
by Mr. Yearsley appeared in the Lancet during July and August, 1848; and from  the
statements therein contained, it appeared that the novelty consisted in the insertion of
a piece of moistened cotton wool into the ear in a particular manner. In answer to
the intimation that he "had not so fully described the modus operandi as to enable
others to adopt it with more than a mere chance of success," Mr. Yearsley observes
"in answer, I have only to say, that the experience of several years has taught me that
it is impossible to convey to others, in words, such explicit directions as shall enable
them  to manipulate with any degree of certainty.  In fact, it was on this account that
I have so long held back from  publishing any account of the remarkable fact I bad
observed in my practice."
IGNEISS, is the name of one of the great mountain formations, being reckoned the
oldest of the stratified rocks. It is composed of the same substances as granite, viz.
quartz, mica, and felspar. In gneiss, however, they are not in granular crystals, but in
scales, so as to give the mass a slaty structure. It abounds in metallic treasures.
GOLD.  (Eng. and Germ.; Or, Fr.)  This metal is distinguished by its splendid
yellow  colour; its great density's 19'3 compared to water 10; its fusibility at the
82d degree of Wedgewood's pyrometer; its pre-eminent ductility and malleability,
whence it can be beat into leaves only 1-282,000th of an inch thick; and its insolubility in any acid menstruum, except the mixture of muriatic and nitric acids, styled
by the alchemists aqua regia, because gold was deemed by them  to be the king of
metals.
Gold is found only in the metallic state, sometimes crystallized in the cube, and its
derivative forms. It occurs also in threads of various sizes, twisted and interlaced into
a chain of minute octahedral crystals; as also in spangles or roundish grains, which
when of a certain magnitude are called pepitas. The small grains are not fragments
broken from  a greater mass; but they show  by their flattened ovoid shape and their
rounded outline that this is their original state. The spec. grav. of native gold varies
from  13-3 to lii. Humboldt states that the largest pepita known was one found in
Peru weighing about 12 kilogrammes (261 lbs. avoird.); but masses have been quoted
in the province of Quito which weighed nearly four times as much.
Another ore of gold is the alloy with silver, or argental gold, the electrum of Pliny,
so called from its amber shade. It seems to be a definite compound, containing in 100
parts, 64 of gold and 36 of silver.
The mineral formations in which this metal occurs are the crystalline primitive rocks,
the compact transition rocks, the trachytic and trap rocks, and alluvial grounds.
It never predominates to such a degree as to constitute veins by itself. It is either
disseminated, and as it were impasted in stony masses, or spread out in thin plates or
grains on their surface, or, lastly, implanted in their cavities, under the shape of filaments or crystallized twigs. The minerals composing the veins are either quartz, calespar, or sulphate of baryta. The ores that accompany the gold in these veins are chiefly
iron pyrites, copper pyrites, galena, blende, and mispickel (arsenical pyrites).
In the ores called auriferous pyrites, this metal occurs either in a visible or invisible
form, and though invisible in the fresh pyrites becomes visible by its decomposition; as
the hydrated oxide of iron allows the native gold particles to shine forth on their reddish



940                                    GOLD.
Drown ground, even when tne precious metal may constitute culy the five mlionth part
of its weight, as at PRammelsberg in the Hartz. In that state it has been extracted with
profit; most frequently by amalgamation with mercury, proving that the gold was in the
native state, and not in that of a sulphuret.
Gold exists among the primitive strata, disseminated in small grains, spangles, and
crystals. Brazil affords a remarkable example of this species of gold mine. Beds of
granular quartz, or micaceous specular iron, in the Sierra of Cocies 12 leagues beyond
Villa Rica, which form a portion of a mica-slate district, include a great quantity of
native gold in spangles, which in this ferruginous rock replace mica.
Gold has never been observed in any secondary formation, but pretty abundantly in
its true and primary locality among the trap rocks of igneous origin; implanted on the
sides of the fissures, or disseminated in the veins.
The auriferous ores of Hungary and Transylvania, composed of tellurium, silver
pyrites or sulphuret of silver, and native gold, lie in masses or powerful veins in a rock
of trachyte, or in a decomposed feldspar subordinate to it.  Such is the locality of the
gold ore of K6nigsberg, of Telkebanya, between Eperies and Tokay in Hungary, anc
probably that of the gold ores of Kapnick, Felsobanya, &c. in Transylvania; an arrange.
menent nearly the same with what occurs in Equatorial America. The auriferous veins
of Guanaxuato, of Real del Monte, of Villalpando, are similar to those of Schernitz in
Hungary, as to magnitude, relative position, the nature of the ores they include, and of
the rocks they traverse. These districts have impressed all mineralogists with the evidences of the action of volcanic fire. Breislak and Hacquet have described the gold
mines of Transylvania as situated in the crater of an ancient volcano. It is certain that
the trachytes which form the principal portions of the rocks including gold, are now
almost universally regarded as of igneous or volcanic origin.
It would seem, however, that the primary source of the gold is not in these rocks, but
rather in the sienites and greenstone porphyries below them, which in Hungary and
Transylvania are rich in great auriferous deposites; for gold has never been found in
the trachyte of the Euganean mountains, of the mountains of the Vicentin, of those
of Auvergne; all of which are superposed upon granite rocks, barren in metal.
Finally, if it be true that the ancients worked mines of gold in the island of Ischia, it
would be another example, and a very remarkable one, of the presence of this metal in
trachytes of an origin evidently volcanic.
Gold is, however, much more common in the alluvial grounds than among the primitive and pyrogenous rocks just described.  It is found disseminated under the form of
spangles, in the silicious, argillaceous, and ferruginous sands of certain plains and rivers,
especially in their re-entering angles, at the season of low water, and after storms and
temporary floods.
It has been supposed that the gold found in the beds of rivers had been torn out
by the waters from the veins and primitive rocks, which they traverse.  Some have
even searched, but in vain, at the source of auriferous streams, for the native bed of this
precious metal. The gold in them belongs, however, to the grounds washed by the waters
as they glide along. This opinion, suggested at first by Delius, and supported by Deborn,
Guettard, Robitant, Balbo, &c., is founded upon just observations. 1. The soil of these
plains contains, frequently, at a certain depth and in several spots, spangles of gold,
separable by washing.  2. The beds of the auriferous rivers and streamlets contain
more gold after storms of rain upon the plains than in any other circumstances. 3. It
happens almost always that gold is found among the sands of rivers only in a very circumscribed space; on ascending these rivers their sands cease to afford gold; though
did this metal come from the rocks above, it should be found more abundantly near the
source of the riveis. Thus it is known that the Orco contains no gold except from
Pont to its junction with the Po. The Ticino affords gold only below the Lago Maggiore, and consequently far from the primitive mountains, after traversing a lake, where
its course is slackened, and into which whatsoever it carried down from these mountains
must have been deposited. The Rhine gives more goua near Strasburg than near Basle,
though the latter be much closer to the mountains. The sands of the Danube do not contain a grain of gold, while this river runs in a mountainous region; that is, from the
frontiers of the bishopric ot Passau to Efferding; but its sands become auriferous in the
p ains below. The same thing is true of the Ems; the sands of the upper portion of this
river, as it flows among the mountains of Styria, include no gold; but from its entrance
into the plain at Steyer, till its embouchure in the Danube, its sands become auriferous,
and are even rich enough to be washed with profit.
The greater part of the auriferous sands, in Europe, Asia, Africa, and America.
are black or red, and consequently ferruginous; a remarkable circumstance in th<
geological position of alluvial gold. M. Napione supposes that the gold of these ferru.
ginous grounds is due to the decomposition of auriferous pyrites. The auriferous
sand occurring in Hungary almost always in the neighborhood of the beds of lignites.




GOLD.                                       941
and the petrified wood covered with gold grains, found buried at a depth of 55 yards in
clay, in the mine of Vorospatak near Abrabanya in Transylvania, might lead us to presume that the epoch of the formation of the auriferous alluvia is not remote from that
of the lignites. The same association of gold ore and fossil wood occurs in South
America, at Moco.  Near the village of Lloro, have been discovered at a depth of 20
feet, large trunks of petrified trees, surrounded with fragments of trap rocks interspersed
with spangles of gold and platinum.  But the alluvial soil affords likewise all the characters of the basaltic rocks; thus in France, the Ceze and the Gardon, auriferous
rivers, where they afford most gold, flow over ground apparently derived from the
destruction of the trap rocks, which occur in situ higher up the country. This fact had
struck Reaumu r, and this celebrated observer had remarked that the sand which more
immediately accompanies the gold spangles in most rivers, and particularly in the Rhone
and the Rhine, is composed, like that of Ceylon and Expailly, of black protoxyde of iron
and small grains of rubies, corindon, hyacinth, &c. Titanium has been observed more
recently. It has, lastly, been remarked that the gold of alluvial formations is purer than
that extracted from rocks.
Principal Gold Mines.
Spain anciently possessed mines of gold in regular veins, especially in the province of
Asturias; but the richness of the American mines has made them  to be neglected.
The Tagus, and some other streams of that country, were said to roll over golden sands.
France contains no workable gold mines; but it presents in several of its rivers auriferous sands. There are some gold mines in Piedmont; particularly the veins of auriferous pyrites of Macugnagna, at the foot of Monte Rosa, lying in a mountain of gneiss;
and although they do not contain 10 or 11 grains of gold in a hundred weight, they have
long defrayed the expense of working them. On the southern slope of the Pennine Alps,
from the Simplon and Monte Rosa to the valley of Aoste, several auriferous districts and
rivers occur. Such are the torrent Evenson, which has afforded much gold by washing;
the Orco, in its passage from the Pont to the Po; the reddish grounds over which this
little river runs for several miles, and the hills in the neighborhood of Chivasso, contain
gold spangles in considerable quantity.
In the county of Wicklow, in Ireland, a quartzose and ferruginous sand was discovered
not long ago, containing many particles of gold, with pepitas or solid pieces, one of which
weighed 22 ounces. No less than 1000 ounces of gold were collected.
There are auriferous sands in some rivers of Switzerland, as the Reuss and the Aar.
In Germany no mine of gold is worked, except in the territory of Salzburg, amid the
chain of mountains which separates the Tyrol and Carinthia.
The mines of Hungary and Transylvania are the only gold mines of any importance in
Europe; they are remarkable for their position, the peculiar metals that accompany them,
and their product, estimated at about 1430 pounds avoird. annually. The principal ones
are in Hungary.  1. Those of Konigsberg. The native gold is disseminated in ores of
sulphuret of silver, which occur in small masses and in veins in a decomposing feldspar
rock, amid a conglomerate of pumice, constituting a portion of the trachytic formation.
2. Those of Borson, Schemnitz. And, 3. of Felsobanya; ores also of auriferous sulphuret of silver, occur in veins of sienite and greenstone porphyry. 4. Those of Telkebanya, to the south of Kaschau, are in a deposite of auriferous pyrites amid trap rocks
of the most recent formation.
In Transylvania the gold mines occur in veins often of great magnitude, 6, 8, and sometimes 40 yards thick. These veins have no side plates or wall stones, but abut without
intermediate gangues at the primitive rock. They consist of carious quartz, ferriferous
limestone, heavy spar, fluor spar, and sulphuret of silver. The mine of Kapnik deserves
notice, where the gold is associated with orpiment, and that of Verospatak in granite
rocks; those of Offenbanya, Zalatna, and Nagy-Ag, where it is associated with tella
nium. Thelast is in a sienitic rock on the limits of the trachyte.
In Sweden, the mine of Edelfors in Smoland may be mentioned, where the gold
occurs native and in auriferous pyrites; the veins are a brown quartz, in a mountain
of foliated hornstone.
In Siberia, native gold occurs in a hornstone at Schlangenberg or Zmeof, and at
Zmeino-garsk in the Altai mountains, accompanied with many other ores.
The gold mine of Berezof in the Oural mountains has been long known, consisting of
partially decomposed auriferous pyrites, disseminated in a vein of greasy quartz. About
1820, a very rich deposit of native gold was discovered on the eastern side of the Oural
mountains, disseminated at some yards depth in an argillaceous loam, and accompanied
with the debris of rocks which usually compose the auriferous alluvial soils, as greenstone,
serpentine, protoxide of iron, corundum, &c.  The rivers of this district possess auriferous sands. The product of the gold mines of the Oural, in 1845, was 11,808 pounds




942                                       GOLD.
avoirdupois, and in 1846, 11,327 pounds; that of Siberia, in 1846, 38,576 pounds, and
in 1846, 48,863 pounds. In these accounts the pood has been reckoned at 36 lbs. It is
believed that in 1847 and  1849 the yield was still larger, but it must since have
materially fallen off, as it is stated in Erman's Archives that the yield in 1851 will not
exceed 20,000 pounds troy.
In Asia, and especially in its southern districts, there are many mines, streams, rivers,
and wastes, which contain this metal. The Pactolus, a small river of Lydia, rolled over
such golden sands, that it was supposed to constitute the origin of the wealth of Croesus.
But these deposits are now poor and forgotten. Japan, Formosa, Ceylon, Java, Sumatra,
Borneo, the Philippines, and some other islands of the Indian Archipelago, are rich in
gold mines.  Those of Borneo are worked by the Chinese in an alluvial soil on the
western coast, at the foot of a chain of volcanic mountains.
Little or no gold comes into  Europe from  Asia, because its servile inhabitants
place their fortune in treasure, and love to hoard up that precious metal
Numerous gold mines occur on the two slopes of the chain of the Cailas mountains in
the Ound's, a province of Little Thibet. The gold lies in quartz veins which traverse a
very crumbling reddish granite.
Africa was, with Spain, the source of the greater portion of the gold possessed by
the ancients.  The gold which Africa still brings into the market is always in dust,
showing that the metal is obtained by washing the alluvial soils. None of it is collected in the north of that continent; three or four districts only are remarkable for
the quantity of gold they produce.
The first mines are those of Kordofan, between Darfour and Abyssinia. The negroes
transport the gold in quills of the ostrich or vulture. These mines seem to have been
known to the ancients, who considered Ethiopia to abound in gold. Herodotus relates
that the king of that country exhibited to the ambassadors of Cambyses all their
prisoners bound with golden chains.
The second and chief exploitation of gold dust is to the south of the great desert of
Zaara, in the western part of Africa, from the mouth of the Senegal to the Cape of
Palms.  The gold occurs in spangles, chiefly near the surface of the earth, in the
bed of rivulets, and always in a ferruginous earth. In some places the negroes dig wells
in the soil to a depth of about 40 feet, unsupported by any props. They do not follow
any vein; nor do they construct a gallery. By repeated washings they separate the
gold from the earthy matters.
The same district furnishes also the greater part of what is carried to Morocco Fez,
and Algiers, by the caravans which go from Timbuctoo on the Niger, across the great
desert of Zaara. The gold which arrives by Sennaar at Cairo and Alexandria comes from
the same quarter. From Mungo Park's description, it appears that the gold spangles are
found usually in a ferruginous small gravel, buried under rolled pebbles.
The third spot in Africa where gold is collected is on the south-east coast, between the
twenty-fifth and the twenty-second degree of south latitude, opposite to Madagascar, in
the country of Sofala. Some persons think that this was the kingdom of Ophir, whence
Solomon obtained his gold.
In modern times, the richest gold mines are found in South America. It occurs there
principally in spangles among the alluvial earths, and in the beds of rivers; more rarely
in veins. See California, infra.
There is little gold in the northern part of America. In 1810, a mass of alluvial gold,
weighing 28 pounds, was found in the gravel pits of the creeks of Rockhole, district of
Lebanon, in North Carolina.
Previously to the important discoveries in California, Brazil, Choco, and Chili, were the
regions which furnished most gold. The only contributor of Chilian objects to the Great
Exhibition was one who forwarded a lump of gold ore weighing 3,cwt., which was
brought up from a deep mine on the back of a miner, from a depth of 45 yards beneath
the surface.
The gold of Mexico is in a great measure contained in the argentiferous veins, so
numerous in that country, whose principal localities are mentioned under the article
SILVER. The silver of the argentiferous ores of Guanaxuato contains one 360th of its
weight of gold;. the annual product of the mines being valued at from 2640 to 3300
pounds avoirdupois.
Oaxaco contains the only auriferous veins exploited as gold mines in Mexico; they
traverse the rocks of gneiss and mica slate.
All the rivers of the province of Caracas, to ten degrees north of the line, flow
over golden sands.
Peru is not rich in gold ores.  In the provinces of Huailas and Pataz, this metal
is mined in veins of greasy quartz, variegated with red ferruginous spots, which traverse
primitive rocks. The mines called pacos de oro, consist of ores of iron and copper oxides,
containing a great quantity of gold.




GOLD.                                         943
All the gold furnished by New Grenada (New Columbia) is the product of washings
established in alluvial grounds. The gold exists in spangles and in grains, disseminated
among fragments of greenstone and porphyry.  At Choco, along with the gold and
platinum, hyacinths, zircons, and titanium occur. There has been found, as already
stated, in the auriferous localities, large trunks of petrified trees. The gold of Antioquia
is 20 carats fine, that of Choco 21, and the largest lump or pepita of gold weighed about
27h pounds avoirdupois. The gold of Chili also occurs in alluvial formations.
Brazil does not contain any gold mine, properly so called; for the veins containing
the metal areseldom worked.
It is in the sands of the Mandi, a branch of the Rlo-Dolce, at Catapreta, that the auriferous ferruginous sands were first discovered in 1682.  Since then they have been
found almost everywhere at the foot of the immense chain of mountains, which runs
nearly parallel with the coast, from the 5th degree south to the 30th. It is particularly
near Villa Rica, in the environs of the village Cocaes, that the numerous washings for
gold are established. The pepitas occur in different forms, often adhering to micaceous
specular iron. But in the province of Minas Geraes, the gold occurs also in veins, in
beds, and in grains, disseminated among the alluvial loams. It has been estimated in
annual product, by several authors, at about 2800 pounds avoirdupois of fine metal.
We thus see that almost all the gold brought into the market comes from alluvial
lands, and is extracted by washing.
The gold coin of the ancients was made chiefly out of alluvial gold, for in these early
times the metallurgic arts were not sufficiently advanced to enable them to purify it. The
gold dust from Bambouk in Africa is of 221 carats fine, and some from Morocco is even
23.
The gold of Giron, in New Grenada, is of 231 carats; being the purest from America.
" For those who traffick in gold," says Humboldt, "it is sufficient to learn the place where
the metal has been collected, to know its title."
Californian Gold Mines.-The accident which first revealed the golden treasures of the
soil of California is thus related by a writer of Article VII. of the Quarterly Review,
for September, 1852. Captain Suter, the first white man who had established himself
in the district where the Americanos joins the Sacramento, having erected a saw-mill on
the former river, whose tail race turned out to be too narrow, took out the wheel, and
let the water run freely off. A great body of earth having been carried away by the
torrent, laid bare many shining yellow spangles, and on examination, Mr. Marshall, his
surveyor, picked up several little lumps of gold. He and Captain Suter then commenced a search together and gathered an ounce of the ore from the sand without any
difficulty; and with his knife the captain picked out a lump of an ounce and a half from
the rock. A  Kentuckian workman employed at the mill had espied their supposed
secret discovery, and when after a short absence the gentlemen returned, he showed them
a handful of the glittering dust.  The captain hired a gang of fifty Indians, and set
them to work. The news spread, but the announcement of the discovery was received
with incredulity beyond the immediate neighbourhood.  But presently when large and
continuous imports of gold from San Francisco placed the matter beyond doubt, there
ensued such a stir in the States, as even in that go-a-head region is wholly without parallel: numbers of every age and of every variety of occupation pushed for the land
of promise. Many were accompanied by their families, and most under the excitement
of the hour overlooked their physical unfitness, and their inability to procure necessaries.
The waters of the Humboldt, from  their head to their " sink," a space of nearly 300
miles, are in the dry season strongly impregnated with alkali: and it was here that they
first began to faint. Some died from thirst, others from ague, others fell beneath the
burdens they attempted to carry when their last animal dropped into the putrid marsh,
which grew thicker at every step. Beyond the " sink" the diminished bands had to
encounter sixty or seventy miles of desert, where not a blade of herbage grew, and not
a drop of pure water could be procured; and those who pushed safely through this
ordeal had still to ascend the icy slopes of Sierra Nevada, when the rigours of winter
were added to all other difficulties.  At different points, one being almost in sight of the
golden land, overwearied groups had formed encampments, in case perhaps some help
might reach them. It is to the credit of the settlers that on hearing this, they strained
their resources to the utmost to afford relief. Yet when all was done, a sick, destitute,
most wretched horde of stragglers, was all that remained of the multitude, who, full of
hope and spirits, had commenced the prairie journey.
Enterprise and energy have now overcome or smoothed the worst difficulties of the
route.  A great central railroad has been projected, and will probably at no distant
time be formed.
To this time, the stream of life flowing into California has kept continually increasing.
Upwards of 20,000 souls, and about 50,000 animals, forming a scattered train of about
700 miles in length, passed Fort Kearney in the month of May last. In this multitude




944                                      GOLD.
the strangest contrasts were seen; ladies on spirited steeds, in full Bloomer costume, or
in the more modest equestrian habit to which we are accustomed, and men gallantly
mounted with Kossuth hat and plume, swept by the humble pedlar driving ass or mule,
and toil-worn women, leading their children by the hand. Some had their little stock
of provisions strapped on their backs; others trusted to hand-carts and wheelbarrows.
"The journey would be pleasant," writes one of the company, "but for the vast number
of graves along the road.   There are about 80 graves to 100 miles so far; that is
new ones, the old ones are nearly obliterated, and their places no longer known by man."
This passage depicts well the recklessness with which in the States life is squandered in
the pursuit of gain. By sea, the arrivals are even more numerous; upwards of 10,000
landed at the port of San Francisco in May, and about an equal number in June. In
the first six months of the year 10,000 Chinamen had arrived to claim part in the golden
harvest; 400 more followed in the first fortnight of July, and eighteen women, in the
costume of the Celestial Empire, had come infrom  Hong Kong. The population of
California was about 200,000 at the commencement of the present year; it will be
300,000 by its close. Already the sea-board of California is brought within a month's
passage of England; and its exports now amount in value to one fourth the exports of
the United Kingdom. The produce of California up to the 10th of January, 1851, is
stated by Mr. Scheer at about 62 millions sterling; but these figures taken from a gold
circular published at San Francisco must be much too high. From 35 to 40 millions
would probably be nearer the mark. 17,339,5441. is the amount for last year, as carefully computed by Mr. Birkmyre.  See Times, May 21.  The exports this year are
known to have been during the three first months, 3,900,000 dollars more than those of
the three corresponding months of the preceding year, 1851.
Report of Deposits of Goldfrom California, at the several United States Mints,
dollars.
in 1848                                                 - 44,177
1849        -       -       -       -       -       6,14,509
1850                         -       -       -     36,074.062
1851         -       -       -       -      -      55,938,232
Hussey & Co.'s Circular, San Francisco, July 30, 1852.
Australian Gold Mines.-The discovery of a great gold field in Australia to the
westward of Bathurst, about 150 miles from  Sydney, was officially made known in
Great Britain, by a despatch from Sir C. A. Fitzroy to Earl Grey, on the 18th September, 1851, many persons with a tin dish having obtained from one to two ounces per
day.  On the 25th of May, he writes that lumps have been obtained varying in weight
from an ounce to four pounds. On the 29th May, he writes that gold has been found
in abundance, that people of every class aje proceeding to the locality, that the field
is rich, and from  the geological formation of the country of immense area.  By
assay the gold was found to consist of 91.1 of that metal and about 8.333 of silver, with
a little base metal; or of 22 carats in fineness. July 17th, a mass of gold weighing
106 pounds was found imbedded in the quartz matrix, about 53 miles from Bathurst;
and much more, justifying the anticipations formed of the vast richness and extent of
the gold field in this colony. This magnificent treasure, the property of Dr. Kerr, surpasses the largest mass found in California, which was 28 pounds; and that in Russia,
which was 70 pounds, now  in the museum  at Petersburg. One party of six persons
got at the same time 4001. in ten days, by means of a quicksilver machine; and a party
of three, who were unsuccessful for seven days, obtained in five days more, 200 ounces. A
royalty of 10 per cent. was ordered to be paid on gold in matrix if found in Crown lands,
and 5 per cent. if found in private property. Four armed men travel in the carriage
that conveys the gold from  the diggings to Sydney, accompanied by two armed constables, in general weekly, or oftener if required.  The licence fee is 30s. a month.
August 19th, 1851, the Governor Sir C. Fitzroy reports to Earl Grey, that gold to the
value of 70,0001. had been already collected; and on the 21st, that 3,614 ozs. had that
morning arrived at Sydney from Bathurst, worth upwards of 12,6001.
August 25th, 1851, Lieutenant Governor C. J. Latrobe announced to Earl Grey from
Melbourne, the discovery of large deposits of gold in that district of the colony. In a
second Parliamentary blue book, issued February 3, 1852, it is stated that 79,340 ounces
of gold, worth 257,855/. 7s. had been previously forwarded to England; and that the gold
fields of the colony of Victoria rival, if they do not exceed in value, the first discovered
gold fields of New South Wales; the total value being now 300,0001.; and a little time
afterwards about half a million sterling. Mr. E. Hargraves, commissioner for Crown
lands, announces from Bathurst, that no part of California which he had seen has produced gold  so generally and to such an extent as Summerhill Creek, the Turon




GOLD.                                         945
River and its tributaries. A letter from Sir J. F. W. Herschel, Bart., dated Royal Mint,
London, February 7th, 1852, says, "it is believed that in California, gold to the value of
18 millions sterling had been found during each of the two last years; and prior to the
discovery of that gold region, the whole annual produce throughout the world was supposed to be only about one-fifth of that amount.
Taking the actual amount shipped from  Melbourne to the end of March last, and
allowing for the quantity supposed to be at the diggings, and waiting shipment, it would
appear that about 700,000 ounces had been raised in Victoria. At 31. per oz. this would
be worth 2,100,0001. The licences up to the same date were 49,386; equivalent to 421.
10s. as the average monthly earnings of each licensed digger. The amount raised in
New South Wales to the end of March may be taken at 320,000 ounces, and the value at
960,0001.; being at the rate of 311. 3s. monthly per individual; probably about Il. daily
for each digger. Australia will soon be supplied with silver coin. The shipments on
board (September 13) are understood to amount to 2,000,0001. and estimating the additional sum. taken out by emigrants, it is probable that the value of the total quantity
exported equals that of the gold received. The diggers must be largely benefited by
these shipments of coin, as the gold, which in London would realize 41. per oz., has not
always brought them 31. The gold fields discovered in Australia stretch over 1000 miles,
in a south-westerly direction from Moreton district to Ballarat.
Up to the first week in June last, it is certain from the actual exports, that the total
gold raised in Australia must have amounted in value to 4,000,0001. sterling; and the
produce was still on the increase.  The number of diggers at present hardly reaches
20,000.  It seems moderate to assume that 50,000 labourers will be scattered over
the Australian gold fields before the end of the present year; and taking their earnings at only 201. per month, we shall have a yield then of 12,000,0001. yearly.
Mr. Birkmyre supposes that in 1846 there were raised from,North and South America                      -                       1,301.500
Russia..r-                    -       -       -        -  3,414,42Austria    -      -      -       -       -.      -             282,150
Piedmont, Spain, and North Germany               -        -       -     20,696
Africa...       -       -       -        -       -    203,900
Borneo.       -      -       -       -        -       -       -    305,900
Ava, Malacca and other countries         -       -       -       -    317.519
~ 5,846 692
This total is exclusive of China and Japan.
Metallurgic treatment of gold.-The gold found in the sands of rivers, or in auriferous
soils, needs not be subjected to any metallurgic process, properly speaking.   The
Orpaillers separate it from  the sands, by washing them  first upon inclined tables,
sometimes covered with a cloth, and then by hand in wooden bowls of a particular form.
Amalgamation is employed to carry off from the sand the minuter particles of gold they
may contain. The people called Bohemians, Cigans, or Tehinganes, who wash the
auriferous sands in Hungary, employ a plank with 24 transverse grooves cut in its
surface. They hold this plank in an inclined position, and put the sand to be washed
in the first groove; they then throw water on it, when the gold mixed with a little sand
collects usually towards the lowest furrow.  They remove this mixture into a flat wooden
basin, and by a peculiar sleight of hand,' separate the gold entirely from the sand. The
richest of the auriferous ores consist of the native gold quite visible, disseminated in a
gangue, but the veins are seldom  continuous for any length. The other ores are auriferous metallic sulphurets, such as sulphurets of copper, silver, arsenic, &c., and particularly iron.
The stony ores are first ground in the stamping mill, and then washed in hand-basins,
or on wooden tables.
The auriferous sulphurets are much more common, but much poorer than the former
ores; some contain only one' 200,000th part of gold, and yet they may be worked with
advantage, when treated with skill and economy.
The gold of these ores is separated by two different processes; namely, by fusion and
amalgamation.
The auriferous metallic sulphurets are first roasted; then melted into mattes, which
are roasted anew; next fused with lead, whence an auriferous lead is obtained, which
may be refined by the process of cupellation.
When the gold ores are very rich, they are melted directly with lead, without preliminary calcination or fusion. These processes are, however, little practised, because
they are less economical and certain than amalgamation, especially when the gold ores
are very poor.
If these ores consist of copper pyrites, and if their treatment has been pushed to the point




946                                   GOLD.
of obtaining auriferoas rose copper, or even black copper including gold, the precious
metal cannot be separated by the process of liquation, because the gold, having more affinity for copper than for lead, can be but partially run off by the latter metal. For these
reasons the process of amalgamation is far preferable.
This process being the same for silver, I shall reserve its description for this metal.
The rich ores in which the native gold is apparent, and merely disseminated in a stony
gangue, are directly triturated with quicksilver, without any preparatory operation. As
to the poor ores, in which the gold seems lost amid a great mass of iron, sulphuret of
copper, &c., they are subjected to a roasting before being amalgamated. This process
seems requisite to lay bare the gold enveloped in the sulphurets. The quicksilver with
which the ore is now ground, seizes the whole of its gold, in however small quantity this
metal may be present.
The gold procured by the refining process with lead, is free from copper and lead, but
it may contain iron, tin, or silver. It cannot be separated from iron and tin without
great difficulty and expense, if the proportion of gold be too small to admit of the employ
ment of muriatic acid.
By cupellation with lead, gold may be deprived of any antimony united with it.
Tin gives gold a remarkable hardness and brittleness; a piece of gold, exposed for
some time over a bath of red hot tin, becomes brittle. The same thing happens more
readily over antimony, from the volatility of this metal. A two thousandth part of antimony, bismuth, or lead, destroys the ductility of gold. The tin may be got rid of by
throwing some corrosive sublimate or nitre into a crucible, containing the melted alloy.
By the first agent, perchloride of tin is volatilized; by the second, stannate of potash
forms, which is carried off in the resulting alkaline scorie.
Gold treated by the process of amalgamation, contains commonly nothing but a little
silver. The silver is dissolved out by nitric acid, which leaves the gold untouched; but
to make this parting with success and economy on the great scale, several precautions
must be observed.
If the gold do not contain fully two thirds of its weight of silver, this metal, being
thoroughly enveloped by the gold, is partially screened from the action of the acid. When.
ever, therefore, it is known by a trial on a small scale, that the silver is much below this
proportion, we must bring the alloy of gold and silver to that standard by adding the requisite quantity of the latter metal.  This process is called quartation.
This alloy is then granulated or laminated; and from twice to thrice its weight of sulphuric or nitric acid is to be boiled upon it; and when it is judged that the solution has
been pushed as far as possible by this first acid, it is decanted, and new acid is poured on.
Lastly, after having washed the gold, some sulphuric acid is to be boiled over it, which
carries off a two or three thousandth part of silver, which nitric acid alone could not dissolve. Thus perfectly pure gold is obtained.
The silver held in solution by the sulphuric or nitric acid is precipitated in the metallic
state by copper, or in the state of chloride by sea-salt. See PARTING.
Not only has the ratio between the value of gold and silver varied much in different
ages of the world; but the ratio between these metals and the commodities they represent has undergone variations, owing to the circumstances in which their mines have
been successively placed; since they have always poured a greater quantity of the metals
into the market than has been absorbed by use. This quantity has greatly increased
since the discovery of America, a period of little more than 300 years. The mines of
that continent, rich, numerous, and easily worked, by augmenting the mass of gold and
silver, necessarily lessened the value of these metals compared with that of the objects
of commerce represented by them, so that everything else being equal, there is now
required for purchasing the same quantity of commodities, much more gold or silver
than was necessary in the reign of Henry VII., before the discovery of America. This
productiveness of the American mines has had an influence on those of the ancient continent; many of whose silver and gold mines have been abandoned, not because the
veins or auriferous sands are less rich than they were, but because their product no
longer represents the value of human labor, and of the goods to be furnished in return
for their exploitation.
In the 3d vol. of the Mining Journal, p. 331, we have the following statement as to
the produce of the precious metals.-" In 40 years, from 1790 to 1830, Mexico produced
6,436,4531. worth of gold, and 139,818,0321. of silver. Chili, 2,768,4881. of gold, and
1,822,9241. of silver.  Buenos Ayres, 4,024,8951. of gold, and 27,182,6731. of silver.
Russia, 3,703,7431. of gold, and 1,502,9811. of silver. Total, 1880 millions sterling, or
47 millions per annum.
The following table shows what proportion the product of the mines of America bears
to that of the mines of the ancient continent.




GOLD.                                      947
Table of the Quantities of Gold which may be considered as having been brought into
the European Market, every Year on an.dverage, from 1790 to 1802.
Continents.                       Gold.
ANCIENT CONTINENT.                     lbs. Avoir.
Asia:               _....
Siberia                              -           3740
Africa   -                   -.   3300
Europe: -....-     -
Hungary         -                    -           1430
Salzbourg  -        -.- -.            165
Austrian States  -    -    -    -    - 
Hartz and Hessia     -    - 
Saxony    -     -    -...
Norway    ---...                                 165
France               -     -    -
Spain, &cc.          -    -              J -
Total of the Ancient Continent     -    -           8800
NEW CONTINENT.
North America      -     -..           2860
South America -.          -
Spanish dominions  -    -    -              22,000
Brazil  -    -.             15,400
Total of the New Continent   -    -.          40,260
The mines of America have sent into Europe three and a half times more gold, and
twelve times more silver, than those of the ancient continent.  The total quantity of
silver was to that of gold in the ratio of 55 to 1; a very different ratio from that which
holds really in the value of these two metals, which is in Europe as 1 to 15.  This
difference depends upon several causes, which cannot be investigated here at length;
but it may be stated that gold, by its rarity and price, being much less employed in the
arts than silver, the demand for it is also much less; and this cause is sufficient to
lower its price much beneath what it would have been, if it had followed the ratio of its
quantity compared to that of silver.  Thus also bismuth, tin, &c., though much rarer
than silver, are, nevertheless, very inferior in price to it.  Before the discovery of
America, the value of gold was not so distant from that of silver, because since that era
silver has been distributed in Europe in a far greater proportion than gold.  In Asia
the proportion is now actually only I to 11 or 12; the product of the gold mines in that
quarter, being not so much below that of the silver mines as in the rest of the
world.
The total annual production of Gold at present has been estimated as follows.
From the ancient Spanish colonies of America -    -    -    10,400 kilogrammes
Brazil                      -                              600
Europe and Asiatic Russia     -     -    -    -    -      6,200
The Indian Archipelago -                                  4,700
Africa   -     -    -         --      -    --      -    14,000?
35,900=36 tons nearly
without taking into account the quantity of gold now extracted from silver.
Gold has less affinity for oxygen than any other metal.  When alone, it cannot be
oxydized by any degree of heat with contact of air, although in combination with other
oxydized bodies, it may pass into the state of an oxyde, and be even vitrified. The purple smoke into which gold leaf is converted by an electric discharge is not an oxyde,
for it is equally formed when the discharge is made through it in hydrogen gas.  There
are two oxydes of gold; the first or protoxyde is a green powder, which may be obtained by pouring, in the cold, a solution of potash into a solution of the metallic
chloride.  It is not durable, but soon changes in the menstruum  into metallic gold,




948                                      GOLD.
and peroxyde. Its constituents are 96-13 metal, and 3'87 oxygen. The peroxyde is best
prepared by adding magnesia to a solution of the metallic chloride; washing the precipitate with water till this no longer takes a yellow tint from muriatic acid; then digesting
strong nitric-acid upon the residuum, which removes the magnesia, and leaves the per.
oxyde in the form of a black or dark brown powder, which seems to partake more of the
properties of a metallic acid than a base.  It contains 10-77 per cent. of oxygen. For
the curious combination of gold and tin, called the PURPLE PRECIPITATE OF CASSIus, see
this article, and PIGIENTS VITRIFIABLE.
Gold beating.-This is the art of reducing gold to extremely thin leaves, by beating
~with a hammer.  The processes employed for this purpose may be applied to other
metals, as silver, platinum, and copper.  Under tin, zinc, &c., we shall mention such
modifications of the processes as these metals require to reduce them o thin leaves. The
Romans used to gild the ceilings and walls of their apartments; and Pliny tells us, that
from an ounce of gold forming a plate of 4 fingers square, about 600 leaves of the same
area were hammered.  At the present day, a piece of gold is exteqded so as to cover a
space 651,590 times greater than its primary surface when cast.
The gold employed in this art ought to be of the finest standard. Alloy hardens gold,
and renders it less malleable; so that the fraudulent tradesman who should attempt to debase the gold, would expose himself to much greater loss in the operations, than he could
derive of profit from the alloy.
Four principal operations constitute the art of gold beating.   1. The casting of the
gold ingots. 2. The hammering.  3. The lamination; and 4, the beating.
1. The gold is melted in a crucible along with a little borax.  When it has become
iquid enough, it is poured out into the ingot-moulds previously heated, and greased on
the inside. The ingot is taken out and annealed in hot ashes, which both soften it and
free it from grease.  The moulds are made of cast iron, with a somewhat concave internal surface, to compensate for the greater contraction of the central parts of the metal
in cooling than the edges.  The ingots weigh about 2 ounces each, and are I of an inch
broad.
2. The forging.-When the ingot is cold, the French gold-beaters hammer it out on
a mass of steel 4 inches long and 3 broad.  The hammer for this purpose is called the
forging hammer. It weighs about 3 pounds, with a head at one end and a wedge at the
other, the head presenting a square face of 12 inches. Its handle is 6 inches long. The
workman reduces the ingot to the thickness of l of an inch at most  and during this operation he anneals it whenever its substance becomes hard and apt to crack. The English
gold-beaters omit this process of hammering.
3. The lamination.-The rollers employed for this purpose should be of a most perfectly cylindrical figure, a polished surface, and so powerful as not to bend or yield in the
operation. The ultimate excellence of the gold leaf depends very much on the precision
with which the riband is extended in the rolling press.  The laminating machine represented under the article MINT, is an excellent pattern for this purpose. The gold-beater
desires to have a riband of such thinness that a square inch of it will weigh 61 grains.
Frequent annealings are requisite during the lamination.
4. Beating.-The riband of gold being thus prepared uniform, the gold-beater cuts it
with shears into small squares of an inch each, having previously divided it with compasses, so that the pieces may be of as equal weight as possible. These squares are piled
over each other in parcels of 150, with a piece of fine calf-skin vellum interposed between
each, and about 20 extra vellums at the top and bottom. These vellum leaves are about
4 inches square, on whose centre lie the gold laminae of an inch square. This packet is
kept together by being thrust into a case of strong parchment open at the ends, so as to
form a belt or band, whose open sides are covered in by a second case drawn over the
packet at right angles to the first.  Thus the packet becomes sufficiently compact to
bear beating with a hammer of 15 or 16 pounds weight, having a circular face nearly 4
inches diameter, and somewhat convex, whereby it strikes the centre of the packet most
forcibly, and thus squeezes out the plates laterally.
The beating is performed on a very strong bench or stool framed to receive a heavy
block of marble, about 9 inches square on the surface, enclosed upon every side by woodwork, except the front where a leather apron is attached, which the workman lays before him to preserve any fragments of gold that may fall out of the packet. The hammer
is short-handled, and is managed by the workman with one hand; who strikes fairly on
the middle of the packet, frequently turning it over to beat both sides alike; a feat dexterously done in the interval of two strokes, so as not to lose a blow. The packet is occasionally bent or rolled between the hands, to loosen the leaves and secure the ready
extension of the gold; or it is taken to pieces to examine the gold, and to shift the central leaves to the outside, and vice versa, that every thing may be equalized. Whenever
the gold plates have extended, under this treatment, to nearly the size of the vellum,
they are removed from the packet, and cut into four equal squares by a knife. Thev




GOLD.                                        949
are thus reduced to nearly the same size as at first, and are again made up into packets
and enclosed as before, with this difference, that skins prepared from ox-gut are now
interposed between each gold leaf instead of vellum. The second course of beating is
performed with a smaller hammer, about 10 pounds in weight, and is continued till the
leaves are extended to the size of the skins. During this period the packet must be often
folded, to render the gold as loose as possible between the membranes; otherwise the
leaves are easily chafed and broken. They are once more spread on a cushion, and subdivided into four square pieces by means of two pieces of cane cut to very sharp edges,
and fixed down transversely on a board. This rectangular cross being applied on each
leaf, with slight pressure, divides it into four equal portions. These are next made up into
a third packet of convenient thickness, and finally hammered out to the area of fine gold
leaf, whose average size is from 3 to 3- inches square. The leaves will now have obtained an area 192 times greater than the plates before the hammering begun. As these
were originally an inch square, and 75 of them weighed an ounce (- 6  X 75 = 487),
the surface of the finished leaves will be 192 X 75 = 14,400 square inches, or 100 square
feet per ounce troy. This is by no means the ultimate degree of attenuation, for an
ounce may be hammered so as to cover 160 square feet; but the waste incident in this
case, from the number of broken leaves, and the increase and nicety of the labor, make
this an unprofitable refinement; while the gilder finds such thin leaves to make less
durable and satisfactory work.
The finished leaves of gold are put up in small books made of single leaves of soft
paper, rubbed over with red chalk to prevent adhesion between them. Before putting
the leaves in these books, however, they we lifted one by one with a delicate pair of pincers out of the finishing packet, and spread out on a leather cushion by blowing them flat
down. They are then cut to one size, by a sharp-edge square moulding of cane, glued
on a flat board. When this square-framed edge is pressed upon the gold it cuts it to the
desired size and shape. Each book commonly contains 25 gold leaves.
I shall now describe some peculiarities of the French practice of gold beating. The'workman cuts the laminated ribands of an inch broad into portions an inch and a half
long. These are called quartiers. He takes 24 of them, which he places exactly over
each other, so as to form a thickness of about an inch, the riband being   of a line, or
of an inch thick; and he beats them  together on the steel slab with the round face
(panne) of the hammer, so as to stretch them truly out into the square form. He begins
by extending the substance towards the edges, thereafter advancing towards the middle;
he then does as much on the other side, and finally hammers the centre. By repeating
this mode of beating as often as necessary, he reduces at once all the quartiers (squares)
of the same packet, till none of them is thicker than a leaf of gray paper, and of the
size of a square of 2 inches each side.
When the quartiers are brought to this state, the workman takes 56 of them, which
he piles over each other, and with which he forms the first packet (caucher) in the manner already described; only two leaves of vellum are interposed between each gold leaf.
The empty leaves of vellum at the top and bottom of the packet are called emplures.
They are 4 inches square, as well as the parchment pieces.
The packet thus prepared forms a rectangular parallelepiped; it is enclosed in two
sheaths, composed each of several leaves of parchment applied to each, and glued at the
two sides, forming a bag open at either end.
The block of black marble is a foot square at top, and 18 inches deep, and is framed
as above described. The hammer used for beating the first packet is called the flat,
or the enlarging hammer; its head is round, about 5 inches in diameter, and very slightly
convex. It is 6 inches high, and tapers gradually from its head to the other extremity,
which gives it the form of a hexagonal truncated pyramid.   It weighs 14 or 15
pounds.
The French gold-beaters employ, besides this hammer, three others of the same form;
namely, 1. The commencing hammer, which weighs 6 or 7 pounds, has a head 4 inches
in diameter, and is more convex than the former. 2. The spreading hammer (marteau
a chasser); its head is two inches diameter, more convex than the last, and weighs only
4 or 5 pounds. 3. The finishing hammer; it weighs 12 or 13 pounds, has a head four
inches diameter, and is the most convex of all.
The beating processes do not differ essentially from the English described above. The
vellum is rubbed over with fine calcined Paris plaster, with a hare's foot.  The skin of
the gold-beater is a pellicle separated from the outer surface of ox-gut; but before
being employed for this purpose, it must undergo two preparations. 1. It is sweated, in
order to expel any grease it may contain. With this view, each piece of membrane is
placed between two leaves of white paper; several of these pairs are piled over each
other, and struck strongly with a hammer, which drives the grease from the gut into the
paper.
2. A body is given to the pieces of gut; that is, they are moistened with an infusion




950                                       GOLD.
of cinnamon, nutmeg, and other warm  and aromatic ingredients, in order to preserve
them; an operation repeated after they have been dried in the air. When the leaves of
skin are dry, they are put in a press, and are now ready for use. After the parchment,
vellum, and gut membrane have been a good deal hammered, they become unfit for work,
till they are restored to proper flexibility, by being placed leaf by leaf between leaves
of white paper, moistened sometimes with vinegar, at others with white wine. They are
left in this predicament for 3 or 4 hours, under compression of a plank loaded with weights.
When they have imbibed the proper humidity, they are put between leaves of parchment
12 inches square, and beat in that situation for a whole day. They are then rubbed
over with fine calcined gypsum, as the vellum was originally. The gut-skin is apt to
contract damp in standing, and is therefore dried before being used.
The average thickness of common gold leaf is'- 6- of an inch.
The art of Gilding.-This art consists in covering bodies with a thin coat of gold;
which may be done either by mechanical or chemical means.  The mechanical mode is
the application of gold leaf or gold powder to various surfaces, and their fixation by various means.  Thus gold may be applied to wood, plaster, pasteboard, leather; and to
metals, such as silver, copper, iron, tin, and bronze; so that gilding, geneially speaking,
includes several arts, exercised by very different classes of tradesmen.
1. Mechanical Gilding.-Oil gilding is the first method under this head, as oil is the
fluid most generally used in the operation of this mechanical art. The following process
has been much extolled at Paris.
1. A coat of impression is to be given first of all, namely, a coat of white lead paint,
made with drying linseed oil, containing very little oil of turpentine.
2. Calcined ceruse is to be ground very well with unboiled linseed oil, and tempered
with essence of turpentine, in proportion as it is laid on. Three or four coats of this
hard tint are to be applied evenly and dryly on the ornaments and the parts which are to
Se rmost carefully gilded.
3. The Gold color is then to be smoothly applied. This is merely the dregs of the
colors, ground and tempered with oil, which remain in the little dish in which painters:lean their brushes. This substance is extremely rich and gluey; after being ground
up, and passed through fine linen cloth, it forms the ground for gold leaf.
4. When the gold color is dry enough to catch hold of the leaf gold, this is spread on
the cushion, cut into pieces, and carefully applied with the palette knife, pressed down
with cotton, and in the small ornaments with a fine brush.
5. If the gildings be for outside exposure, as balconies, gratings, statues, &c., they
must not be varnished, as simple oil gilding stands better; for when it is varnished, a
bright sun-beam, acting after heavy rain, gives the gilding a jagged appearance. When
the objects are inside ones, a coat of spirit varnish may be passed over the gold leaf, then
a glow from the gilder's chafing dish may be given, and finally a coat of oil varnish. The
workman who causes the chafing dish to glide in front of the varnished surface, must
avoid stopping for an instant opposite any point, otherwise he would cause the varnish
to boil and blister.  This heat brings out the whole transparency of the varnish and
lustre of the gold.
Oil Gilding is employed, with varnish polish, upon equipages, mirror-frames, and other
furniture. The following method is employed by eminent gilders at Paris.
1. White lead, with half its weight of yellow ochre, and a little litharge, are separately ground very fine; and the whole is then tempered with linseed oil, thinned with
essence of turpentine, and applied in an evenly coat, called impression.
2. When this coat is juite dry, several coats of the hard tint are given, even so many
as 10 or 12, should the surface require it, for smoothing and filling up the pores. These
coats are given daily, leaving them to dry in the interval in a warm sunny exposure.
3. When the work is perfectly dry, it is first softened down with pumice stone and water,
afterwards with worsted cloth and very finely powdered pumice, till the hard tint give
no reflection, and be smooth as glass.
4. With a camel's hair brush, there must be given lightly and with a gentle heat, from
4 to 5 coats at least, and even sometimes double that number, of fine lac varnish.
5. When these are dry, the grounds of the panels and the sculptures must be first
polished with shave-grass (de la prele); and next with putty of tin and tripoli, tempered
with water, applied with woollen cloth; by which the varnish is polished till it shines
like a mirror.
6. The work thus polished is carried into a hot place, free from dust, where it receives
very lightly and smoothly a thin coat of gold color, much softened down. This coat is
passed over it with a clean soft brush, and the thinner it is the better.
7. Whenever the gold color is dry enough to take the gold, which is known by laying
the back of the hand on a corner of the frame work, the gilding is begun and finished
as usual.
8. The gold is smoothed off with a very soft brush, one of camel's hair, for example,
of three fingers' breadth; after which it is left to dry for several days.




GOLD.                                        951
9. It is then varnished with a spirit of wine varnish; which is treated with the chafing
dish as above described.
10. When this varnish is dry, two or three coats of copal or oil varnish are applied, at
intervals of two days.
11. Finally, the panels are polished with a worsted cloth, imbued with tripoli and
water, and lustre is given by friction with the palm of the hand, previously softened with
a little olive oil, taking care not to rub off the gold.
In this country, burnished gilding is practised by first giving a ground of size whiting,
in several successive coats; next applying gilding size; and then the gold leaf, which is
burnished down with agate, or a dog's tooth.
Gilding in distemper of the French, is the same as our burnished gilding. Their process seems to be very elaborate, and the best consists of 17 operations; each of them
said to be essential.
1. Encollage, or the glue coat.  To a decoction of wormwood and garlic in water,
strained through a cloth, a little common salt and some vinegar are added. This composition, as being destructive of worms in wood, is mixed with as much good glue; and the
mixture is spread in a hot state, with a brush of boar's hair. When plaster or marble is
to be gilded, the salt must be left out of the above composition, as it is apt to attract humidity in damp places, and to come out as a white powder on the gilding. But the salt
is indispensable for wood. The first glue coating is made thinner than the second.
2. White preparation. This consists in covering the above surface with 8, 10, or 12
coats of Spanish white, mixed up with strong size, each well worked on with the brush,
and in some measure incorporated with the preceding coat, to prevent their peeling off
in scales.
3. Stopping up the pores, with thick whiting and glue, and smoothing the surface with
dog-skin.
4. Polishing the surface with pumice-stone and very cold water.
5..Reparation; in which a skilful artist retouches the whole.
6. Cleansing; with a damp linen rag, and then a soft sponge.
7. Priler. This is rubbing with horse's tail (shave-grass) the parts to be yellowed, in
order to make them softer.
8. Yellowing. With this view yellow ochre is carefully ground in water, and mixed
with transparent colorless size. The thinner part of this mixture is applied hot over the
white surface with a fine brush, which gives it a fine yellow hue.
9. Ungraining consists in rubbing the whole work with shave-grass, to remove any
granular appearance.
10. Coat of assiette; trencher coat. This is the composition on which the gold is to
be laid. It is composed of Armenian bole, 1 pound; bloodstone (hematite), 2 ounces;
and as much galena; each separately ground in water. The whole are then mixed to.
gether, and ground up with about a spoonful of olive oil. The assiette well made and applied gives beauty to the gilding. The assiette is tempered with a white sheep-skin glue,
very dlear and well strained. This mixture is heated and applied in three successive
coats, with a very fine long-haired brush.
II. Rubbing, with a piece of dry, clean linen cloth; except the parts to be burnished,
which are to receive other two coats of assiette tempered with glue.
12. Gilding. The surface, being damped with cold water (iced in summer), has then
the gold leaf applied to it. The hollow grounds must always be gilded before the prominent parts. Water is dexterously applied by a soft brush, immediately behind the
gold leaf, before laying it down, which makes it lie smoother. Any excess of water is
then removed with a dry brush.
13. Burnishing with bloodstone.
14. Deadening. This consists in passing a thin coat of glue, slightly warmed, over the
parts that are not to be burnished.
15. Mending; that is, moistening any broken points with a brush, and applying bits
of gold leaf to them.
16. The vermeil coat. Vermeil is a liquid which gives lustre and fire to the gold; and
makes it resemble or moulu. It is composed as follows: 2 ounces of annotto, I ounce
of gamboge, 1 ounce of vermilion, half an ounce of dragon's blood, 2 ounces of salt of
tartar, and 18 grains of saffron, are boiled in a litre (2 pints English) of water, over a
slow fire, till the liquid be reduced to a fourth. The whole is then passed through a
silk or muslin sieve. A little of this is made to glide lightly over the gold, with a very
soft brush.
17. Repassage is passing over the dead surfaces a second coat of deadening glue,
which must be hotter than the first. This finishes the work, and gives it strength.
Leaf gilding, on paper or vellum, is done by giving them a coat of gum water or fine
size, applying the gold leaf ere the surfaces be hard dry, and burnishing with agate.




952                                   GOLD.
Gold lettering, on bound books, is given without size. by laying the gold leaf on the
leather, and imprinting it with hot brass types.
The edges of the leaves of books are gilded while they are in the press, where they have
been cut smooth, by applying a solution of isinglass in spirits, and laying on the gold
when the edges are in a proper state of dryness. The French workmen employ a ground
of Armenian bole, mixed with powdered sugar-candy, by means of white of egg. This
ground is laid very thin upon the edges, after fine size or gum water has been applied;
and when the ground is dry it is rubbed smooth with a wet rag, which moistens it sufficiently to take the gold.
Japanner's gilding is done by sprinkling or daubing with wash leather, some gold powJer, over an oilzed surface, mixed with oil of turpentine.  This gives the appearance
of frosted gold. The gold powder may be obtained, either by precipitating gold from its
solution in aqua regia by a solution of pure sulphate of iron, or by evaporating away the
mercury from somelgold amalgam.
NI. Chemical gilding, or the application of gold by chemical affinity to metallic sur
faces.
A compound of copper with one seventh of brass is the best metal for gilding on; copper by itself being too soft and dark colored. Ordinary brass, however, answers very
well. We shall describe the process of wash gilding, with M. D'Arcets late improvements, now generally adopted in Paris.
Wash gilding consists in applying evenly an amalgam of gold to the surface of a copper alloy, and dissipating the mercury with heat, so as to leave the gold film fixed. The
surface is afterwards burnished or deadened at pleasure. The gold ought to be quite
pure, and laminated to facilitate its combination with the mercury; which should also
be pure.
Preparation of the amalgam. After weighing the fine gold, the workman puts it in a
crucible, and as soon as this becomes faintly red, he pours in the requisite quantity
of mercury; which is about 8 to 1 of gold. He stirs up the mixture with an iron rod,
bent hookwvise at the end, leaving the crucible on the fire till he perceives that all the
gold is dissolved. He then pours the amalgam into a small earthen dish containing water,
washes it with care, and squeezes out of it with his fingers all the running mercury that
he can. The armalgam that now remains on the sloping sides of the vessel is so pasty as
to preserve the impression of the fingers. When this is squeezed in a shamoy leather
bag, it gives up much mercury; and remains an amalgam, consisting of about 33 of mercury, and 57 of gold, in 100 parts. The mercury which passes through the bag, under
the pressure of the fingers, holds a good deal of gold in solution; and is employed in making fresh amalgam.
Preparation of the mercurial solution. The amalgam of gold is applied to brass, through
the intervention of pure nitric acid, holding in solution a little mercury.
100 parts of mercury, and 110 parts by weight of pure nitric acid, specific gravity 133,
are to be put into a glass matrass. On the application of a gentle heat the mercury dissolves with the disengagement of fumes of nitrous gas, which must be allowed to escape
into the chimney. This solution is to be diluted with about 25 times its weight of pure
water, and bottled up for use.
I. annealing.-The workman anneals the piece of bronze after it has come out of the
hands of the turner and engraver. He sets it among burning charcoal, or rather peats,
which have a more equal and lively flame; covering it quite up, so that it may be oxydized
as little as possible, and taking care that the thin parts of the piece do not become hotter
than the thicker. This operation is done in a dark room, and when he sees the piece of
a cherry red color, he removes the fuel from about it, lifts it out with long tongs, and sets
it to cool slowly in the air.
2. The decapage.-The object of this process is to clear the surface from the coat of
oxyde which may have formed upon it. The piece is plunged into a bucket filled with
extremely dilute sulphuric acid; it is left there long enough to allow the coat of oxyde to
be dissolved, or at least loosened; and it is then rubbed with a hard brush. When the
piece becomes perfectly bright, it is washed and dried. Its surface may however be still
a little variegated; and the piece is therefore dipped in nitric acid, specific gravity 1'33,
and afterwards rubbed with a long-haired brush. The addition of a little common salt
to the dilute sulphuric acid would probably save the use of nitric acid, which is so apt to
produce a new coat of oxyde. It is finally made quite dry (after washing in pure water),
by being rubbed well with tanners' dry bark, saw-dust, or bran. The surface should
now appear somewhat de-polished; for when it is very smooth, the gold does not adhere
so well..application of  the amalgam.-Thc  gilder's scratch-brush  or pencil, made  with
fine brass wire, is to be dipped into the solution of nitrate of mercury, and is
then to be drawn over a lump of gold amalgam, laid on the sloping side of an earthen
vessel, after which it is to be applied to the surface of the brass. This process is to be




GOLD.                                        953
repeated, dipping the brush into the solution, and drawing it over the amalgam, till the
whole surface to be gilded is coated with its just proportion of gold. The piece is then
washed in a body of water, dried, and put' to the fire to volatilize the mercury. If one
coat of gilding be insufficient, the piece is washed over anew with amalgam, and the operation recommenced till the work prove satisfactory.
4. Volatilization of the mercury.-Whenever the piece is well coated with amalgam,
the gilder exposes it to glowing charcoal, turning it about, and heating it by degrees
to the proper point; he then withdraws it from the fire, lifts it with long pincers, and,
seizing it in his left hand, protected by a stuffed glove, he turns it over in every direction, rubbing and striking it all the while with a long-haired brush, in order to equalize
the amalgam. He now restores the piece to the fire, and treats it in the same way till
the mercury be entirely volatilized, which he recognises by the hissing sound of a drop
of water let fall on it. During this time he repairs the defective spots, taking care to
volatilize the mercury very slowly.  The piece, when thoroughly coated with gold, is
washed, and scrubbed well with a brush in water acidulated with vinegar.
If the piece is to have some parts burnished, and others dead, the parts to be burnished
are covered with a mixture of Spanish white, bruised sugar-candy, and gum ^ssolved in
water. This operation is called in French epargner (protecting). When the gilder has
protected the burnished points, he dries the piece, and carries the heat high enough to
expel the little mercury which might still remain on it. He then plunges it, while still
a little hot, in water acidulated with sulphuric acid, washes it, dries it, and gives it the
burnish.
5. The burnish is given by rubbing the piece with burnishers of hematite (bloodstone).  The workman dips his burnisher in water sharpened with vinegar, and rubs the
piece always in the same direction backwards and forwards, till it exhibits a fine polish,
and a complete metallic lustre. He then washes it in cold water, dries it with fine linen
cloth, and concludes the operation by drying it slowly on a grating placed above a chafing
dish of burning charcoal.
6. The deadening is given as follows. The piece, covered with the protection on those
parts that are to be burnished, is attached with an iron wire to the end of an iron rod,
and is heated strongly so as to give a brown hue to the epargne by its partial carbonization. The gilded piece assumes thus a fine tint of gold; and is next coated over with
a mixture of sea salt, nitre, and alum, fused in the water of crystallization of the latter
salt. The piece is now restored to the fire, and heated till the saline crust which covers
it becomes homogeneous, nearly transparent, and enters into true fusion. It is then taken
from the fire and suddenly plunged into cold water, which separates the saline crust, carrying away even the coat of epargne. The piece is lastly passed through very weak nitric
acid, washed in a great body of water, and dried by exposure either to the air, over a
drying stove, or with clean linen cloths.
7. Of or-moulu color. -When it is desired to put a piece of gilded bronze into ormoulu color, it must be less scrubbed with the scratch-brush than usual, and made to
come back again by heating it more strongly than if it were to be deadened, and allowing
it then to cool a little. The or-moulu coloring is a mixture of hematite, alum, and
sea salt. This mixture is to be thinned with vinegar, and applied with a brush so as to
cover the gilded brass, with reserve of the burnished parts. The piece is then put on
glowing coals, urged a little by the bellows, and allowed to heat till the color begins
to blacken. The piece ought to be so hot that water sprinkled on it may cause a hissing
noise. It is then taken from the fire, plunged into cold water, washed, and next rubbed
with a brush dipped in vinegar, if the piece be smooth, but if it be chased, weak nitric
acid must be used. In either case, it must be finally washed in a body of pure water, and
dried over a gentle fire.
8. Of red gold color.-To give this hue, the piece, after being coated with amalgam
and heated, is in this hot state to be suspended by an iron wire, and tempered with the
composition known under the name of gilder's wax; made with yellow wax, red ochre,
verdigris, and alum. In this'state it is presented to the flame of a wood fire, is heated
strongly, and the combustion of its coating is favored by throwing some drops of the wax
mixture into the burning fuel. It is now turned round and round over the fire, so that the
flame may act equally. When all the wax of the colo'ring is burned away, and when the
flame is extinguished, the piece is to be plunged in water, washed, and scrubbed with the
scratch-brush and pure vinegar. If the color is not beautiful, and quite equal in shade,
the piece is coated with verdigris dissolved in vinegar, dried over a gentle fire, plunged
in water, and scrubbed with pure vinegar, or even with a little weak nitric acid if the
piece exhibit too dark a lie. It is now washed, burnished, washed anew, wiped with
linen cloth, and finally dried over a gentle fire.
The following is the outline of a complete gilding factory, as now fitted up at
Paris.
Fig. 738. Front elevation and plan of a complete gilding workshop.




954                                GOLD.
P. Furnace of appel, or draught, serving at the same time to heat the deadening paz
(poelon au mat).'38;.  I
i      ri     ll::
0          A_
Chimney  L 1Z, 1117 TE
nB'                          "' -"      g,.. 
F. Ashpit of this furnace.
N. Chimney of this furnace constructed of bricks, as far as the contraction of the
great chimney s of the forge, and which is terminated by a summit pipe rising 2 or 3
yards above this contraction.
B. Forge for annealing the pieces of bronze; for drying the gilded pieces, &c.
c. Chimney of communication between the annealing forge B, and the space D below
the forge. This chimney serves to carry the noxious fumes into the great vent of the
factory.
u. Bucket for the brightening operation.
A. Forge for passing the amalgam over the piece.
R. Shelf for the brushing operations.
E: E. Coal cellarets.
o. Forge for the deadening process.
G. Furnace for the same.
hM. An opening into the furnace of appet, by which vapors may be let off from any operation by taking out the plug at M.
i. Cask in which the pieces of gilded brass are plunged for the deadening process.
The vapors rising thence are carried up the general chimney.
J J. Casement with glass panes, which serves to contract the opening of the hearths,
without obstructing the view. The casement may be rendered moveable to admit larger
objects.
H H. Curtains of coarse cotton cloth, for closing at pleasure, in whole or part, one or
several of the forges or hearths, and for quickening the current of air in the places where
the curtains are not drawn
Q. Opening above the draught furnace, which serves for the heating of the poelon an
mat (deadening pan).
Gilding on polished srod and steel. -If a nearly neutral solution of gold in muriatic
acid be mixed with sulphuric ether, and agitated, the ether will take up the gold, and
float above the denser acid. When this auriferous ether is applied by a hair pencil to
brightly polished iron or steel, the ether flies off, and the gold adheres. It must be fixed
by polishing with the burnisher. This gilding is not very rich or durable. In fact, the
affinity between gold and iron is feeble, compared to that between gold and copper or
silver.  But polished iron, steel, and copper, may be gilded with heat, by gold leaf.
They are first heated till the iron takes a bluish tint, and till the copper has attained to
a like temperature; a first coat of gold leaf is now applied, which is pressed gently




GRADUATOR.                                       955
down with a burnisher, and then exposed to a gentle heat.  Several leaves either single
or double are thus applied in succession, and the last is burnished down cold.
Cold gilding.-Sixty grains of fine gold and 12 of rose copper are to be dissolved in
two ounces of aqua regia.  When the solution is completed, it is to be dropped on clean
linen rags, of such bulk as to absorb all the liquid. They are then dried, and burned into ashes. These ashes contain the gold in powder.
When a piece is to be gilded, after subjecting it to the preliminary operations of softening or annealing and brightening, it is rubbed with a moistened cork, dipped in the
above powder, till the surface seems to be sufficiently gilded.  Large works are thereafter burnished with pieces of hematite, and small ones with steel burnishers, along with
soap water.
In gilding small articles, as buttons, with amalgam, a portion of this is taken equivalent
to the work to be done, and some nitrate of mercury solution is added to it in a wooden
trough; the whole articles are now put in, and well worked about with a hard brush, till
their surfaces are equably coated. They are then washed, dried, and put altogether iAto
an iron frying-pan, and heated till the mercury begins to fly off, when they are turned out
into a cap, in which they are tossed and well stirred about with a painter's brush. The
operation must be repeated several times for a strong gilding.  The surfaces are finally
brightened by brushing them along with small beer or ale grounds.
Gold wire is formed by drawing a cylindrical rod of the metal, as pure as may be,
through a series of holes punched in an iron plate, diminishing progressively in size. The
gold, as it is drawn through, becomes hardened by the operation, and requires frequent
annealing.
Gold thread, or spun gold, is a flatted silver-gilt wire, wrapped or laid over a thread of
yellow silk, by twisting with a wheel and iron bobbins. By the aid of a mechanism like
the Braiding Machine, a number of threads may thus be twisted at once by one master
wheel.  The principal nicety consists in so regulating the movements that the successive
volutions of the flatted wire on each thread may just touch one another, and form a
continuous covering.  The French silver for gilding is said to be alloyed with 5 or 6
pennyweights, and ours with 12 pennyweights of copper in the pound troy.  The gold
is applied in leaves of greater or less thickness, according to the quality of the gilt wire.
The smallest proportion formerly allowed in this country by act of parliament, was 100
grains of gold to one pound, or 5760 grains of silver; but more or less may now be used.
The silver rod is encased in the gold leaf, and the compound cylinder is then drawn into
round wire down to a certain size, which is afterwards flatted in a rolling mill such as is
described under MINT.
The liquor employed by goldsmiths to bring out a rich color upon the surface of their
trinkets, is made by dissolving I part of sea salt, I part of alum, 2 parts of nitre, in 3 or
4 of water. This pickle or sauce, as it is called, takes up not only the copper alloy, but
a notable quantity of gold; the total amount of which in the Austrian empire, has been
estimated annually at 47,000 francs.  To recover this gold, the liquor is diluted with at
least twice its bulk of boiling water; and a solution of very pure green sulphate of iron
is poured into it. The precipitate of gold is washed upon a filter, dried, and purified by
melting in a crucible along with a mixture of equal parts of nitre and borax.
Gold refining.-The following process has been patented as a foreign invention by
Mr. W. E. Newton in January, 1851.
It consists, 1., in reducing argentiferous or any other gold bullion to a granulated,
or spongy, or disintegrated molecular condition by fusion therewith of zinc, or some
other metal baser than silver, and the subsequent removal of the zinc by dilute sulphuric
or other acid; that is, the reducing of the gold bullion to a state to allow of the removal by acids of the silver and other impurities contained therein, so as to fit it for
coinage and other purposes without quartation with silver or any other intermediate
process. And
2., in pulverizing by grinding or concussion gold bullion, rendered brittle by union
with lead, solder, or other suitable metal, the silver and other impurities being removed
by acids in this as in the preceding case, and recovered from the acid solution by any of
the known chemical means.
This operation, if properly conducted, will produce fine ductile gold in a state of
great purity; that is, containing from 98-5 to 99-5 per cent. of pure gold.
GONG-GONG; or tam-tam  of the Chinese; a kind of cymbal made of a copper
alloy, described towards the end of the article COPPER.
GONIOMETER, is the name of a little instrument made either on mechanical or
optical principles, for measuring the angles of crystals. It is indispensable to the mineralogist.
GRADUATOR, called by its contriver M. Wagenmann, Essigbilder, which means,
in German, vinegar-maker, is represented in fig. 739. It is an oaken tub, 56 feet high,
38 feet wide at top, and 3 at bottom, set upon wooden beams, which raise its bottom




956                                GRAUWACKE.
about 14 inches from  the floor. At a distance of 15 iches
above the bottom, the tub is pierced with a horizontal row
"39                     of 8 equidistant round holes, of an inch in diameter. At 5
inches beneath the mouth of the tub, a thick beech-wood
hoop is made fast to the inner surface, which supports a
circular oaken shelf, leaving a space round its edge of If
inches, which is stuffed water-tight with hemp or tow. In
this shelf, 400 holes at least must be bored, about -1 of an
\  inch in diameter, and 1r   inches apart; and each of these
must be loosely filled with a piece of packthread, or cotton
E~Il   wick, which serves to filter the liquid slowly downwards.
I n the same shelf there are likewise four larger holes of
_t   i IY)        1W1   1- inches diameter, and 18 inches apart, each of which receives air-tight a glass tube 3 or 4 inches long, having its
ends projecting above and below the shelf.  These tubes serve to allow the air that
enters by the 8 circumferential holes, to circulate freely through the graduator.  The
mouth of the tube is covered with a wooden lid, in whose middle is a hole for the insertion
of a funnel, when the liquor of acetification requires to be introduced.  One inch above
the bottom, a hole is bored for receiving a syphon-formed discharge pipe, whose upper
curvature stands one inch below the level of the holes in the side of the tub, to prevent
the liquor from rising so high as to overflow through them. The syphon is so bent as to
retain a body of liquor 12 inches deep above the bottom of the tub, and to allow the ex
cess only to escape into the subjacent receiver.  In the upper part of the graduator, but
under the shelf, the bulb of a thermometer is inserted through the side, some way into
the interior, having a scale exteriorly.  The whole capacity of the cask from the bottom
up to within one inch of the perforated shelf, is to be filled with thin shavings ofbeech
wood, grape stalks, or birch twigs, previously imbued with vinegar. The manner of using
this simple apparatus is described under ACETIC ACID.
GRANITE  is a compound rock, essentially composed of quartz, feldspar, and mica
each in granular crystals.  It constitutes the lowest of the geological formations, and
therefore has been supposed to serve as a base to all the rest.  It is the most durable
material for building, as many of the ancient Egyptian monuments testify.
The obelisk in the place of Saint Jean de Lateran at Rome, which was quarried at
Syene, under the reign of Zetus, king of Thebes, 1300 years before the Christian era;
and the one in the place of Saint Pierre, also at Rome, consecrated to the Sun by a son
of Sesostris, have resisted the weather for fully 3000 years. On the other hand there are
many granites, especially those in which feldspar predominates, which crack and crumble
down in the course of a few years.  In the same mountain, or even in the same quarry,
granites of very different qualities as to soundness and durability occur.  Some of the
granites of Cornwall and Limousin readily resolve themselves into a white kaolin or
argillaceous matter, from which pottery and porcelain are made.
Granite, when some time dug out of the quarry, becomes refractory, and difficult to cut.
When this rock is intended to be worked it should be kept under water; and that variety
ought to be selected which contains least feldspar, and in which the quartz or gray crystals predominate.
GRANULATION is the process by which metals are reduced to minute grains. It is
effected by pouring them, in a melted state, through an iron cullender pierced with small
holes, into a body of water; or directly upon a bundle of twigs immersed in water.  In
this way copper is granulated into bean shot, and silver alloys are granulated preparatory
to PARTING; which see.
GRAPHITE (Plombagine,Fr.; Reissblei, Germ.) is a mineral substance of a lead or
iron gray color, a metallic lustre, soft to the touch, and staining the fingers with a lead
gray hue. Spec. grav. 2-08 to 2-45. It is easily scratched, or cut with a steel edge, and
displays the metallic lustre in its interior.  Burns with great difficulty in the outward
flame of the blow-pipe. It consists of carbon in a peculiar state of aggregation, with an
extremely minute and apparently accidental impregnation of iron. Graphite, called also
plumbago and black lead, occurs in gneiss, mica slate, and their subordinate clay slates
and lime stones; in the form of masses, veins, and kidney-shaped disseminated pieces;
as also in the transition slate, as at Borrodale in Cumberland, where the most precious
deposite exists, both in reference to extent and quality, for making pencils. It has been
found also among the coal strata, as near Cumnock in Ayrshire.  This substance is employed for counteracting friction between rubbing surfaces of wood or metal, for making
crucibles and portable furnaces, for giving a gloss to the surface of cast iron, &c.  See
PLUMBAGO, for some remarks concerning the Cumberland mine.
GRAUWACKE, or GREYWACKE, is a rock formation, composed of pieces of quartz,
flinty slate, feldspar, and clay slate, cemented by a clay-slate basis; the pieces varying in
size from small grains to a hen's egg.




GREEN PAINTS.                                    957
GRAY DYE.  (Teinture grise, Fr.; Graufdrbe, Germ.)  The gray dyes, in their
numerous shades, are merely various tints of black, in a more or less diluted state, from
the deepest to the lightest hue.
The dyeing materials are essentially the tannic and gallic acid of galls or other
astringents, along with the sulphate or acetate of iron, and occasionally wine stone.
Ash gray is given for 30 pounds of woollen stuff, by one pound of gall-nuts, 4 lb. of wine
stone (crude tartar), and 21 lbs. of sulphate of iron. The galls and the wine stone being
boiled with from 70 to 80 pounds of water, the stuff is to be turned through the decoction at a boiling heat for half an hour, then taken out, when the bath being refreshed with cold water, the copperas is to be added, and, as soon as it is dissolved, the
stuff is to be put in and fully dyed.  Or, for 36 pounds of wool; 2 pounds of tartar,
4 pound of galls, 3 pounds of sumach, and 2 pounds of sulphate of iron are to be
taken.  The tartar being dissolved in 80 pounds of boiling water, the wool is to be
turned through the solution for half an hour, and then taken out.  The copper being
Blled up to its former level with fresh water, the decoction of the galls and sumach is to
be poured in, and the wool boiled for half an hour in the bath. The wool is then taken
out, while the copperas is being added and dissolved; after which it is replaced in the
bath, and dyed gray with a gentle heat.
If the gray is to have a yellow cast, instead of the tartar, its own weight of alum is to
be taken; instead of the galls, one pound of old fustic; instead of the copperas, A of a
pound of Sailzburg vitriol, which consists, in 221 parts, of 17 of sulphate of iron, and 51
of sulphate of copper; then proceed as above directed. Or the stuff may be first stained
in a bath of fustic, next in a weak bath of galls with a little alum; then the wool being
taken out, a little vitriol (common or Saltzburg) is to be put in, previously dissolved in
a decoction of logwood; and in this bath the dye is completed.
Pearl gray is produced by passing the stuff first through a decoction of sumach and
logwood (2 lbs. of the former to cne of the latter), afterwards through a dilute solution
of sulphate or acetate of iron; and finishing it in a weak bath of weld containing a little
alum. Mouse-gray is obtained, when with the same proportions as for ash-gray, a small
quantity of alum is introduced.
For several other shades, as tawny-gray, iron-gray, and slate-gray, the stuff must receive a previous blue ground by dipping it in the indigo vat; then it is passed first
through a boiling bath of sumach with galls, and lastly through the,ame bath at a lower
temperature after it has received the proper quantity of solution of iron.
For dyeing silk gray, fustet, logwood, sumach, and elder-tree bark, are employed
instead of galls. Archil and annotto are frequently used to soften and beautify the
tint.
The mode of producing gray dyes upon cotton has been sufficiently explained in the
articles CALICO PRINTING and DYEING.
GREEN DYE is produced by the mixture of a blue and yellow  dye, the blue
being first applied. See DYEING; as also BLUE and YELLOW  DYES, and CALICO
PRINTING.
GREEN PAINTS. (Couleurs vertes, Fr.; Griine pigmente, Germ.)  Green, which is
so common a color in the vegetable kingdom, is very rare in the mineral. There is only
one metal, copper, which affords in its combinations the various shades of green in
general use. The other metals capable of producing this color are, chromium in its protoxyde, nickel in its hydrated oxyde, as well as its salts, the seleniate, arseniate, and sulphate; and titanium in its prussiate.
Green pigments are prepared also by the mixture of yellows and blues; as, for example, the green of Rinman and of Gellert, obtained by the mixture of cobalt blue, and
flowers of zinc; that of Barth, made with yellow lake, Prussian blue, and clay; but
these paints seldom appear in the market, because the greens are generally extemporaneous
preparations of the artists.
Mountain green consists of the hydrate, oxyde, or carbonate of copper, either factitious,
or as found in nature.
Bremen or Brunswick green is a mixture of carbonate of copper with chalk or lime,
and sometimes a little magnesia or ammonia. It is improved by an admixture of white
lead. It may be prepared by adding ammonia to a mixed solution of sulphate of copper
and alum.
Frise green is prepared with sulphate of copper and sal ammoniac.
Mittis green is an arseniate of copper; made by mixing a solution of acetate or sulphate of copper with arsenite of potash. It is in fact Scheele's green.
Sap green is the inspissated juice of buckthorn berries. These are allowed to.ferment for 8 days in a tub, then put in a press, adding a little alum to the juice, and con
centrated by gentle evaporation. It is lastly put up in pigs' bladders, where it becomes
dry and'iard




958                                  GUANO.
Schweinfurt green; see SCHWEINFURT.
Verona g3reen is merely a variety of the mineral called green earth,
1REEN'VITBIOL is sulphate of iron in green crystals.
GROWAN. ITheename given by the Cornish miners to granite, and to rocks of like
structure.
G-UAIAC, (Gaiac, Fr.; G'uajaharz, Germ.) is a resin which  exudes from  the
trunk of the Guaiacum officinale, a tree which grows in the West India islands. It
comes to us in large greenish-brown, semi-transparent lumps, having a conchoidal or
splintery fracture, brittle and easy to pulverize. It has an aromatic smell, a bitterish,
acrid taste, melts with heat, and has a spec. grav. of from 1'20 to 122. It consists of
6788 carbon; 705 hydrogen; and 25'07 oxygen; and contains two different resins,
the one of which is soluble in all proportions in ammonia, and the other forms, with
water of ammonia, a tarry consistenced mixture. It is soluble in alkaline lyes, in alcohol, incompletely in ether, still less so in oil of turpentine, and not at all in fat oils.
Its chief use is in medicine.
GUANO. This extraordinary excrementitious deposite of certain sea-fowls, which
occurs in immense quantities upon some parts of the coasts of Peru, Bolivia, and
Africa, has lately become an object of great commercial enterprise, and of intense
interest to our agricultural world. Four or five years ago it was exhibited and talked
of merely as a natural curiosity. No one could then have imagined that in a short
period it would be imported from the coasts of the Pacific in such abundance, and at
such a moderate price, as to cheer by its fertilizing powers the languid and depressed
spirits of the farmers throughout the United Kingdom. Such, however, is now the
result, as attested by the concurring reports of almost all the agricultural societies
of Great Britain and Ireland. No less than 28,500 tons of guano have been already
imported from Peru and Bolivia, 1,500 from Chili, and 8,000 from Africa, altogether
38,000 tons, while more is on the way. The store of it, laid up from time immemorial
in the above localities, seems to be quite inexhaustible; especially since it is receiving
constant accessions from myriads of cormorants, cranes, &c.
Having been much occupied with the chemical analyses of guano during the last
two years for Messrs. Gibbs, of London, and Messrs. Myers, of Liverpool, who are the
co-agents of the Peruvian and Bolivian governments, I have enjoyed favorable opportunities of examining samples of every description, and hope to show that many of the
analyses of guano hitherto published have been made upon specimens not in their normal or sound state, like the best imported by the above houses from Chincha and Bolivia,
but in a certain state of eremacausis and decay.
Huano, in the language of Peru, signifies dung; a word spelt by the Spaniards guano.
The natives have employed it as a manure from the remotest ages, and have by its means
given fertility to the otherwise unproductive sandy soils along their coasts. While Peru
was governed by its native incas, the birds were protected from violence by severe laws.
The punishment of death was decreed to persons who, dared to land on the guaniferous islands during the breeding period of the birds, and to all persons who destroyed
them at any time. Overseers were appointed by the government to take care of the
guano districts, and to assign to each claimant his due share of the precious dung. The
celebrated Baron Von Humboldt first brought specimens to Europe in 1804, which he
sent for examination to Foureroy, Vauquelin, and Klaproth, the best analytical chemists of the day; and he spoke of it in the following terms: " The guano is deposited in
layers of 50 or 60 feet thick upon the granite of many of the South sea islands off the
coast of Peru. During 300 years the coast birds have deposited guano only a few
lines in thickness. This shows how great must have been the number of birds, and
how many centuries must have passed over in order to form the present guano-beds."
The strata have undergone many changes, according to the length of time they have
been deposited. Here and there they are covered with silicious sand, and have thus
been protected from the influence of the weather; but in other places, they have lain
open to the action of light, air, and water, which have produced important changes
upon them. Fresh guano is of a whitish or very pale drab color, but it becomes progressively browner and browner by the joint influence of the above three atmospherical agents. Only one guano examined by Foureroy and Vauquelin was found to contain a fourth of its weight of uric acid combined with ammonia, whence that appears
to have been well selected by Baron Von Humboldt. They also found phosphates of
ammonia, of lime, with urate and oxalate of ammonia, and some other constituents of
little value in agriculture. Klaproth's analysis reported 16 per cent. of urate of ammonia, no less than 12-75 of oxalate of lime, 10 of phosphate of lime, 32 of clay and sand,
Nith 28-75 of water and indeterminate organic matter. From the great proportion of
slay and sand, Klaproth's sample of guano was obviously not genuine. I have met
vith no specimen of Peruvian guano that contained any appreciable quantity of clay,
and none that contained above 4 or 5 per cent. of silicious sand.




GUANO.                                     959
To Mr. Bland, of the firm of Messrs. Myers and Co., I am indebted for the following
valuable information:The Chincha islands, which afford the best Peruvian guano, are three in number, and
lie in one line from north to south, about half a mile apart. Each island is from five to
fix miles in circumference, and consists of granite covered with guano insome places to
a height of 200 feet, in successive horizontal strata, each stratum being from 3 to 10
inches thick, and varying in color from  light to dark brown. No earthy matter
whatever is mixed with this vast mass of excrement. At Mr. Bland's visit to these
islands in 1842, he observed a perpendicular surface of upward of 100 feet of perfectly
uniform aspect from top to bottom. In some parts of these islands, however, the deposite
does not exceed 3 or 4 feet in thickness. In several places, where the surface of the
guano is 100 feet or more above the level of the sea, it is strewed here and there with
masses of granite, like those from the Alpine mountains, which are met with on the slopes
of the Jura chain. These seem to indicate an ancient formation for the guano, and terraqueous convulsions since that period. No such granite masses are found imbedded'within the guano, but only skeletons of birds.
The good preservation of the Chincha guano is to be ascribed to the absence ofrain;
which rarely, if ever, falls between the latitude of 14~ south, where these islands lie,
about 10 miles from the main land, and the latitude of Paquica, on the island of Bolivia, in 210 S. L. By far the soundest cargoes of guano which I have analysed have
come from Chincha and Bolivia. Beyond these limits of latitude where rain falls in
greater or less abundance, the guano is of less value-and what has been imported from
Chili has been found by me far advanced in decay-most of the ammonia and azotised
animal substances having been decomposed by moisture, and dissipated in the air (by the
eremacausis of Liebig), leaving phosphate of lime largely to predominate along with
effete organic matter. The range of the American coast from which the guano is taken
must therefore be well considered; and should not extend much beyond the Chincha
islands as thenorthern limit, and Paquica, in Bolivia, as the southern.
The relative estimation of guano and nitrate of soda among the Peruvians is well
shown by the following fact communicated to me by Mr. Bland: "Near the coast of
Peru, about 45 miles from Iquique (the shipping port of guano) there is the chief deposite
of nitrate of soda. The farmers, who collect and purify this natural product, carry it
to the place of shipment, and always require to be paid in return with an equivalent
quantity of guano, with which they manure their land, to the exclusion of the far
cheaper nitrate of soda. We can not be surprised at this preference, when we learn
that in the valley of Chancay, about 40 miles distant from Lima, the soil produces,
when farmed with irrigation in the natural way, a return upon maize of only 15 for 1;
whereas, with the aid of guano, it produces 500 for I! Hence the Peruvian proverb:
Huano, though no saint, works many miracles.
In the pamphlet recently published by Messrs. Gibbs and Myers, entitled "Peruvian
and Bolivian Guano, its nature, properties, and results," we have a very interesting
view of the best established facts with regard to its operation and effects upon
every variety of soil, and in every variety of circumstance, as ascertained by the most
intelligent agriculturists of the United Kingdom. The general conclusion that may
be fairly deduced from the whole evidence is, that good guano will, under judicious
application, increase the crops of grain, turnips, potatoes, and grass, by about 33 per
cent.; and with its present price of 101. per ton, at a cost considerably under the average cost of all other manures, whether farm-yard dung and composts, or artificial compounds. Guano is, moreover, peculiarly adapted to horticultural and floricultural improvement, by its relative cleanliness and facility of application.
The following observations upon guano, by Dr. Von Martius, of Munich, addressed
to the agricultural society of Bavaria, deserve attention. Among animal manures,
says he. it clearly claims the first place. It is uncommonly rich in ammoniacal salts,
which act very favorable on vegetation. The ease with which these salts are decomposed, and exhale their ammonia into the air, is by him assigned as the reason why
plants manured with guano generally present early in the morning accumulations of
dew on the points of their leaves. The guano absorbs the atmospheric vapor, as well
as carbonic acid; whereby it becomes so valuable a manure in dry barren regions. If
we compare guano with other excrementitious manures,.we shall find it far preferable
to those afforded by man or other mammalia, which do not generally contain more than
20 per cent. of food that can be appropriated by plants. It is therefore five times better
than night-soil, and also very superior to the French poudrette, which, being dried nightsoil, loses, through putrefaction and evaporation, the greater proportion of its ammoniacal elements. In birds, the excretions both of the kidneys and intestines are contained
in the cloaca; whereby thq volatile elements of the former get combined with the more
fixed components of the latter. The guano is also a richer manure, on account of its
being produced bv sea-fowl, which live entirely on fish, without admixture of vegetable




960                                    GUANO.
matter. The exposure also of the guano as soon as deposited to the heat of a tropical
sun, in a rainless climate, prevents the components from fermenting, and mummifies
them, so to speak, immediately into a concrete substance not susceptible of decomposition
till it gets moisture; whereas the dung of our dove-cotes suffers a considerable loss by
exposure to our humid atmosphere. But in their action on vegetation, and in their
chemical composition, these two bird excrements are analogous. Davy found in fresh
dove-cote manure 23 parts in 100 soluble in water, which yielded abundance of carbonate of ammonia by distillation, and left carbonaceous matter, saline matter, principally common salt, and carbonate of lime as a residuum. Pigeons' dung readily ferments, but after fermentation afforded only 8 per cent. of soluble matter, which gave
proportionably less carbonate of ammonia in distillation than the dung recently voided.
Dr. Von Martius proceeds to compare the proportion of soluble salts in guano and
pigeons' dung, and thinks that by that comparison alone he can establish the superiority
of the former; but he should have considered that the insoluble urate of ammonia,
which is so powerful and copious a constituent of good guano, and is present in much
smaller proportion in pigeons' dung, is sufficient of itself to turn the balance greatly in
favor of the Peruvian manure. His general estimate, however, that the manuring power
of genuine guano is four times greater than that of pigeons' dung, is probably not wide
of the truth. Besides the above-mentioned constituents, guano derives no small portion of its fertilizing virtue from the great store of phosphoric acid which it contains,
in various states of saline combination, with lime, magnesia, and ammonia. Of all the
principles furnished to plants by the soil, the phosphates are, according to Liebig, the
most important. They afford, so to speak, the bones and sinews of vegetable bodies, while
ammonia supplies them with their indispensable element, azote. Their carbon, hydrogen,
and oxygen, are derived from the air and water. Those products of vegetation which
are most nutritious to man and herbiverous animals, such as bread-corn, beans, peas, and
lentils, contain the largest proportion of phosphates. The ashes of these vegetable
substances afford no alkaline carbonates. A soil in which phosphates are not present,
is totally incapable of producing the above cereals. Agreeably to these views, Liebig
believes that the importation of 1 cwt. of guano is equivalent to the importation of 8
cwts. of wheat; so that 1 cwt. of that manure assumes, with due culture, the form of
8 cwts. of substantial foodsfor man.
Since all these testimonies concur to place this remarkable excrementitious product in
such high estimation, it becomes a paramount duty of the chemist to investigate its composition, and to discover certain means of distinguishing what maybe termed the sound
or normal state of guano, from the decomposed, decayed, and effete condition. The
analysis by Fourcroy and Vauquelin of a sample of guano presented to them by Baron
Von Humboldt, gave the following composition in 100 parts:~
Urate of ammonia       -      -       -       -      -       -        9.0
Oxalate of ammonia   -        -       -       -      -       -       10-6
Oxalate of lime        -7 —                                  -        70
Phosphate of ammonia              - -         -      -                6'0
Phosphate of ammonia and magnesia -           -      -       -        2g6
Sulphate of potash    -        -      -       -       --              5.
~   soda    -       -      -       -      -       -        3*3
Sal ammoniac  -        -       -      -       -      -       -        4*2
Phosphate of lime      -       -      -       -      -       -       14-3
Clay and sand          -      -       -       -.       -        4.7
Water and organic matters    -        -       -       -      -       32-3
How different are these constituents from those assigned by Klaproth-a no less skilful analyst than the French chemists! and how much this difference shows not only the
complexity of the substance, but its very variable nature!
The general results of an analysis by Professor Johnston, published in his paper on
guano, in the 3d part of the 2d vol. of the Journal of the Royal Agricultural Society
of England, are as follows:~
Ammonia        -       -      -       -.      -       -        7-0
Uric acid      -       -      -       -      -       -       -        0o8
Water and carbonic and oxalic acids, &c., expelled by a red heat    515
Common salt, with a little sulphate and phosphate of soda   -        114
Phosphate of lime, &c.        -       -       -      -               29.3
00-0
The specimen of guano represented by this analysis must have been fai advanced in
decomposition, as shown by the very scanty portion of uric acid; and must have been
originally impure (spurious?) from the large proportion of common salt, of which I have




GUANO.                                      961
not found above 4 or 5 per cent. in any of the genuine guanos which I have had occasion
to analyze. In another sample, Professor Johnston found 44'4 of phosphate of lime,
with a little phosphate of magnesia, and carbonate of lime. These results resemble,
to a certain degree, those which I have obtained in analyzing several samples of Chilian
and African guanos, especially in the predominance of the earthy phosphates. The proportion of ammonia which can be extracted by the action of hydrate of soda and quicklime, at an elevated temperature, is the surest criterion of the soundness of the guano;
for by this process we obtain not only the ready formed ammonia, from its several saline
compounds, but also the ammonia producible from its uric acid, and undefined animal
matter.  These two latter quantities have been hitherto too little regarded by most
analysts, though they constitute the most durable fund of azote for the nutrition of
lants. Uric acid, and urate of ammonia, which contains 10-11ths of uric acid, being
both nearly insoluble in water, and fixed at ordinary temperatures, continue to give
out progressively to plants in the soil, the azote, of which they contain fully one-third
of their weight. Under the influence of oxygen and a certain temperature, uric acid
passes through a very remarkable series of transformation; producing allantoin, urea,
and oxalic acid, which eventually becomes carbonic acid. These changes are producible immediately by the action of boiling water and peroxide of lead.  From  these
metamnorphoses, we can readily understand how much oxalate of ammonia and of lime is
reported in many analyses of guano, though none, I believe, is to be found in the normal
state, as it is occasionally imported from the Chincha Islands and Bolivia; nor were any
oxalates found in the dung of the gannet, as analyzed by Dr. Wollaston, or of the sea
eagle, according to the following analysis of Coindet: ammonia, 9-21 per cent.; uric acid,
84'65; phosphate of lime, 6'13=100. The Peruvian sea-fowl, by feeding exclusively on
fish, would seem to swallow a large proportion of earthy phosphates; since, in the purest
guano that has come in my way, I have found these salts to amount to from 10 to 15 per
cent.
Dr. Von Martins proposes to use the degree of solubility of the guano in water as a
good criterion of its quality; but this is a most fallacious test. Sound guano contains
from 15 to 25 per cent. of insoluble urate of ammonia; nearly as much undefined animal
matter, along withfrom 15 to 20 of earthy phosphates, leaving no more than 50 or 55 per
cent. of soluble matter, exclusive of moisture; whereas decayed guano yields often 60 or
70 per cent. of its weight to water, in consequence of the uric acid and animal matter
being wasted away, and the large portion of mnoisture in it, the latter amounting very
often to from 25 to 35 per cent. The good Peruvian guano does not lose more than from
I7 to 9 per cent. by drying, even at a heat of 2120 Fahr.; and this loss necessarily includes
a little ammonia. Each analysis of guano executed for the information of the farmer
should exhibit definitely and accurately to at least 1 per cent.:~
1. The proportion of actual ammonia.
2. The proportion of ammonia producible also from  the uric acid and azotized
animal matter present; and which may be called the potential ammonia.  This is a
most valuable product, which is, however, to be obtained only from well-preserved dry
guano.
3. The proportion of uric acid, to which, if I 10th of the weight be added, the quantity of urate of ammonia is given.
4. The proportion of the phosphates of lime and magnesia.
5. The proportion of fixed alkaline salts, distinguishing the potash from the soda
salts; the former being more valuable, and less readily obtainable, than the latter can
be Vy the use of common salt. Wheat, peas, rye, and potatoes, require for their successful caltivation, a soil containing alkaline salts, especially those of potash.
6. The proportion of sandy or other earthy matter, which, in genuine guano, carefully collected, never exceeds 2 per cent. and that is silica.
7. The proportion of water, separable by the heat of 2120 F.
The farmer should never purchase guano except its composition in the preceding
particulars be warranted by the analysis of a competent chemist. He should cork up
in a bottle a half-pound sample of each kind of guano that he buys; and if his crop
shall disappoint reasonable expectation, he should cause the samples to be analyzed;
and should the result not correspond to the analysis exhibited at the sale, he is fairly
entitled to damages for the loss of his labor, rent, crop, &c. The necessity of following this advice will appear on considering the delusive if not utterly false analyses,
under which cargoes of guano have been too often sold. In a recent case which came
under my cognizance, in consequence of having been employed professionally to analyze
the identical cargo, I found the guano to be nearly rotten and effete; containing altogether only 24  per cent. of ammonia, ^ per cent. of urate of ammonia, nearly 9 of sea
salt, 24 of water, and 451 of earthy phosphates. Now, this large cargo, of many
hundred tons, fetched a high price at a public sale, under the exhibition of the following analysis by a chemist of some note:~




962                                   GUANO.
Urate of ammonia, ammoniacal salts, and decayed animal matter   17*4
Phosphate of lime, phosphate of magnesia, and oxalate of lime - 48 1
Fixed alkaline salts                                                10-8
Earthy and stony matter -- 
Moisture                                       -          -    -   22.3
100-0
rhe purchasers, I was told by the broker, bought it readily under a conviction that
the guano contained 17*4 of ammonia, though the proportion of ammonia is not stated,
but merely mystified, and adroitly confounded with the decayed animal matter.
By the following hypothetical analysis, much guano has been well sold
" Bone earth, 35; lithic acid, &c., 15; carbonate of ammonia, 14; organic matter, 36
= 100."  I am quite certain that no sample of guanocancontain 14 perentofarbonate
of ammonia-a very volatile salt. We shall see presently the state of combination in
which the ammonia exists. It may contain at the utmost 4 or 5 per cent. of the carbonate; but such guano must have been acted upon powerfully by humidity, and will
therefore contain little or no uric acid.
In the very elaborate examination of guano by T. Oellacher, apothecary at Innsbruck, published in a recent number of Buchner's Repertorium of Pharmacy, it is said,
that if a glass rod dipped into muriatic acid be held over guano, strong fumes are developed; and the solution of guano has an alkaline reaction with litmus-paper. These
phenomena evidently indicate the presence of carbonate of ammonia, and of course a
partially decomposed guano; for sound Chincha and Bolivian guanos have an acid reaction, proceeding from the predominance of phosphoric acid. Farmers frequently
judge of the goodness of guano by the strength of the ammoniacal odor; but in this
judgment they may egregiously err, for the soundest guano has no smell of ammonia
whatever; and it begins to give out that smell only when it is more or less decomposed
and wasted.
Oellacher could find no evidence of urea in his guano; I have obtained fully 5 per
cent. of this substance from good Peruvian guano.
I shall now describe my own system of analysis
1. In every case I determine, first of all, the specific gravity of the guano; which I
take by means of spirits of turpentine, with a peculiar instrument contrived to render
the process easy and precise.  If it exceeds 175 in density, water being 1*0, it must
contain sandy impurities, or has an excess of earthy phosphates, and a defect of azotized
animal matter.
2. I triturate and digest 200 grains of it with distilled water, filter, dry the insoluble
matter, and weigh it.
3. The -above solution, diffused in 2,000 gr. measures, is examined as to its specific
gravity, and then with test paper, to see whether it be acid or alkaline.
4. One half of this solution is distilled along with slaked lime in a matrass connected
with a small quintuple globe condenser, containing distilled water, and immersed in a
basin of the same. As the condensing apparatus terminates in a water-trap, no part
of the ammonia can be lost; and it is all afterward estimated by a peculiar meter, whose
indications make manifest one hundredth part of a grain.
5., The other half of the solution is mixed with some nitric acid, and divided into 3
equal portions.
a, the first portion, is treated with nitrate of barytes, and the resulting sulphate of
barytes is collected, ignited, and weighed.
b, the second portion, is treated with nitrate of silver, and the resulting chloride of
silver ignited and weighed.
c, the. third portion, has a certain measure of a definite solution of ferric nitrate mixed
with it, and then ammonia in excess. From the weight of the precipitated subphosphate
of iron after ignition, the known amount of oxide used being deducted, the quantity of
phosphoric acid in the soluble portion of the guano becomes known.
d, the three above portions are now mixed, freed by a few drops of dilute sulphuric
and hydrochloric acids from any barytes and silver left in them, and then tested by
nitrate of lime for oxalate of ammonia. The quantity of oxalate of lime obtained, determines that point.
6. The last liquor filtered, being freed from any residuary particles of lime by oxalate
of ammonia, is evaporated to dryness and ignited, to obtain the fixed alkaline matter.
This being weighed, is then dissolved in a little water, neutralized with acid, and treated
with soda-chloride of platinum. From the quantity of potash-chloride of platinum, which
precipitates, after being filtered, dried, and weighed, the amount of potash present is
deducted-the rest is soda. These bases may be assigned to the sulphuric, hydro-chloric,
and phosphoric acids, in proportions corresponding to their respective affinities.
7. The proportion of organic matter in the above solution of guano, is determined
directly by evaporating a certain portion of it to dryness, and igniting.  The loss of




GUANO.                                       963
weight, minus the ammonia and oxalic acid, represents the amount of organic matter.
8. A second portion of a solution of the guano is evaporated to dryness by a getle
steam heat, weighed, enclosed in a stout well-closed phial along with alcohol of 0-85,
and heated to 2120. After cooling, the alcoholic solution is decanted or filtered clear,
evaporated to dryness by a gentle h at, and weighed. This is urea, which may be tested
by its conversion into carbonate of a amonia, when heated in a test tube or small retort.
In this way, I have obtained from Bo vian guano, 5 per cent. of urea; a certain proof
of its entire soundness.
9. analysis of the insoluble matter. One third of it is digested with heat in abundance
of Borax-water, containing ~   of the salt, filtered, and the filter dried by a steam heat.
The loss of weight indicates the amount of uric acid, which is verified by supersaturating
the filtrate with acetic or hydrochloric acid, thus precipitating the uric acid, throwing it
upon a filter, drying, and weighing it. This weight should nearly agree with the above
loss of weight, the small difference being due to soluble organic matter sometimes called
geine and ulmic acid. The uric acid is evidenced, 1, by its specific gravity, which I
find to be only 1 25, as also that of the urate of ammonia; 2, by its affording fine purple
murexide when heated in a capsule alongwith nitric acid, and then exposed to the vapor
of ammonia from a feather held over it; 3, by its dissipation when heated, without
emitting an empyreumatic odor.
10. Another third of the solid matter is distilled along with half its weight of slaked
lime, and 10 times its weight of water, in the apparatus already described, and the ammonia obtained from it estimated.
I1. The remaining third having been ignited, is digested with a gentle heat in weak
hydrou-loric acid, and the undissolved silica and alumina washed on a filter, dried, and
weighed. To the hydrochloric solution, dilute sulphuric acid is added, and the mixture
is heated till all the hydrochloric acid be expelled, with the greater part of the water.
Alcohol of 0-850 is now poured upon the pasty residuum, and the whole, after being well
stirred, is thrown upon a filter. The phosphoric acid passes through, as also the magnesia
in union with sulphuric acid.  The sulphate of lime, which is quite insoluble in spirits
of wine, being washed with them, is dried, ignited, and weighed. From the weight of
sulphate of lime, the quantity of phosphate of that earth, that was present, becomes
known.
12. Ammonia in excess is now added to the filtrate, which throws down the granular
phosphate of ammonia and magnesia. After washing and drying this powder at a heat
of 1r0^, its weight denotes the quantity of that compound in the guano.
13. To the filtered liquor (of 12), if a little ammonia be added, and then muriate of
magnesia be slowly dropped in, phosphate of ammonia and magnesia will precipitate,
from the amount of which the quantity of phosphoric acid may be estimated.
14. The proportion of oxalate of lime is determined by igniting the washed residuum
(of 9) and placing it in an apparatus for estimating the quantity of carbonic acid given
off in dissolving carbonate of lime. The apparatus, either fig. 1 or 2, described in my
little Treatise on Alkalimetry, will serve that purpose well. I have rarely obtained
more than ^ gr. of carbonic acid from the insoluble residuum of 100 gr. of good guano,
and that corresponds to less than 11 per cent. of oxalate of lime in the guano. Sometimes no effervescence at all is to be perceived in treating the washed residuum with
acid after ignition.
15. The carbonate of ammonia in guano is readily determined by filtering the solution
of it in cold water, and neutralizing the ammonia with a test or alkalimetrical acid.
(See the Treatise on Alkalimetry, above referred to.)
16. Besides the above series of operations, the following researches must be made to
complete our knowledge of guano. The insoluble residuum (of 10) which has been
deprived by two successive operations of its uric acid and ammonia, may contain azotized organic matter. It is to be therefore well dried, mixed with 5 times its weight of
the usual mixture of hydrate of soda and quicklime, and subjected to gentle ignition in
a glass or iron tube closed at one end, and connected at the other with an ammonia
condensing apparatus. The amount of ammonia being estimated by a proper ammonia
meter, represents the quantity of azote, allowing 14 of this element for 17 of ammonia,
being the potential ammonia corresponding to the undefined animal matter. In a sample
of Peruvian guano I obtained 6 per cent. of ammonia from this source.
17. The whole quantity of ammonia producible from guano is to be determined by
gently igniting 25 gr. of it well dried, and mixed with ten times its weight of the mixture of hydrate of soda and quicklime (2 parts of the latter to I of the former;. The
ammonia disengaged is condensed and measured, as described above.
18. The ready-formed ammonia is in all cases determined by distilling a mixture ot
100 gr. of it with 50 gr. of slaked lime, condensing the disengaged ammonia, and esti
mating it exactly by the meter.
19. The relation of the combustible and volatile to the incombustible and fixed constituents of guano, is determined by igniting 100 gr. of it in a poised platinum capsule.




964                                  GUANO.
The loss of weight denotes the amount of combustible and volatile matter, including
the moisture, which is known from a previous experiment.
20. The insoluble matter is digested in hot water, thrown upon a filter, dried, and
weilghed. The loss of weight is due to the fixed alkaline salts, which, after concentrating their solutions, are investigated by appropriate tests: 1, nitrate of barytes for the
sulphates; 2, nitrate of silver for the chlorides and sulphates; and 3, soda-chloride of
platinum, for distinguishing the potash from the soda salts.
21. The insoluble matter (of 20) is digested with heat in dilute nitric or hydrochloric acid, and the whole thrown upon a filter. The silica which remains on the
filter is washed ignited, and weighed. The lime, magnesia, and pho
be determined as already pointed out.
22. I have endeavored to ascertain if muriate of ammonia be present in guano, by
evaporating its watery solution to dryness, and subliming the residuum, but I have
never obtained a satisfactory portion of sal ammoniac; and therefore I am inclined to
think there is little of it. The quantity of chlorine to be obtained from guano is too inconsiderable to lead to a suspicion of its presence, except in combination with sodium
and potassium. Phosphate of soda is also a doubtful product-but if present, it may be
obtained from the saline matter (of 20), by acidulating it with nitric acid; precipitating first with nitrate of barytes, next with nitrate of silver, taking care to use no excess of these two re-agents, then supersaturating the residuum with ammonia, and adding acetate of magnesia, when the characteristic double phosphate of this earth should
fall, in case phosphate of soda be present.
By the preceding train of researches, all the constituents of this complex product may
be exactly disentangled and estimated; but they manifestly require much care, patience,
time, and dexterity, and also a delicate balance, particularly in using the appropriate
apparatus for generating the potential ammonia, and for measuring the whole of this
volatile substance separated in the several steps of the process. It may be easily imagined how little confidence can be reposed in many of the analyses of guano, framed,
I fear, too often with the view of promoting the sale of an indifferent or even spurious
article of commerce.
A. I shall now give in detail my analytical results upon three different samples of
a good South American guano; and next the general results upon three samples of
African and Chilian guanos:
I. Guano from  Bolivia, imported by the Mary and Anne. This sample was taken
by myself, as an average out of several bags in the lighter, before the cargo was landed.
Pale yellow brown color, dry, partly pulverulent, partly concreted, in small lumps,
with a few small fragments of granite interspersed, and which, being obvious, were
separated prior to the analysis. Specific gravity of the pulverulent portion without
the granite, 1 60;  of the concretions, 166; mean 163. Water digested on the former
portion is neutral to litmus, that on the latter is faintly acid.
2. 100 parts lose 6'5 by the heat of boiling water, and exhale no ammonia. When
digested and triturated with cold water, 30-5 parts dissolve, and 69-5 are obtained after
drying, at 2120 F. Of those 30-5 parts, 6'5 are therefore water, easily separable, and
24'5 parts are solid matter.
3. 100 parts, mixed with 9 times their weight of water, and 50 of lime, being distilled
in an alembic connected with the five-globe condenser, &c., afforded exactly 4-2 of ammonia. 20 grains in fine powder, along with 200 of a mixture, consisting of 2 parts of
dry lime and 1 of hydrate of soda, were gently ignited in a combustion-tube connected
with the ammonia-condensing apparatus, and they produced 4'25 grains of ammoniaequivalent to 21-25 from 100 grains of the guano. Thus only 4-2 per cent. of ammonia
were ready formed; while 17*05 lurked, so to speak, in their azotized elements.
From its aspect, and its want of ammoniacal odor, this guano, the first cargo received from Bolivia, was imagined by the importers to be of bad quality; and, accordingly, my very favorable report of its analysis surprised them not a little, and rather
unsettled the little faith they at that time (January, 1843) had in chemistry. But about
a fortnight after the date of my report they received a letter from Peru, apprizing them
of the excellence of that cargo of Bolivian guano, and of its being prized by the Americans, as possessing fertilizing powers in a pre-eminent degree. I consider this guano,
therefore, as a type of the substance in its best state.
II. The soluble matter was analyzed, in the manner already detailed, and was found
to consist of1. Urea       -      -       -      -       -      5-00
2. Sulphate of potash        -       -      -       7-90
3. Chloride of sodium        -      -       -       500
4. Biphosphate of ammonia            -      -       5*50
5. Oxalate of ammonia        -       -      -       0'60
24-0




GUANO.                                      965
In these ammo-niacal salts there are only 1'65 parts of ammonia; but I obtained 255
grains in distilling the soluble matter of 100 grains of the guano. The remaining 09
parts, therefore, must have proceeded from the partial decomposition of the urea during
the long ebullition necessary to extract every particle of ammonia, in distilling the
guano along with lime.
III. The insoluble matter =69'5 parts, was found to consist of1. Silica  -       -       -      -       -      -       -      -   2-25
2. Subphosphate of lime                                         -   9.00
3. Phosphate of magnesia and ammonia             -       -      -      25
4. Urate of ammonia                                              -  15'27
5. Undefined azotized organic matter, affording, with the 14 parts
of uric acid, by ignition with hydrate of soda, 17-05 parts
of ammonia                  -.       -      -          4173
69-50
This result as to the large proportion of organic matter in the dried insoluble residuuim was verified by igniting a given quantity of it, when it was found to lose, out of
69*5 parts, 57; corresponding to the 15'27 urate of ammonia, 41'73 of undefined organic
matter, and 008 of ammonia, in the double magnesian phosphate. In the urate and
double phosphate are 1-35 of ammonia, which, with the 2'55, make 3-9 parts; the other
0'3 parts may be traced to the urea.
As these results differ very considerably in many respects from those of the analyses
made by respectable German chemists, I was careful to verify them by manifold variations of the process, as follows:1. The soluble matter, with acid reaction, of 100 parts of the lumps of the Bolivian
guano, was examined by per-acetate of iron and ammonia, for phosphoric acid, and
afforded 4 parts of it, which is more than had been found in the neutral pulverulent
guano. After the phosphoric acid was separated by that method, chloride of calcium
gave no cloud with the filtered liquor, proving that no oxalic acid was present in these
nodules. The washed insoluble matter, when gently ignited, and treated with dilute
uitric acid, afforded no effervescence whatever, and therefore showed that no oxalateof
lime had been present, for it would have become a carbonate.
It is necessary to determine from time to time the quantity of ferric oxide in ine
acetate or nitrate, as it is liable to be deposited from the solution when this is kept for
some time. If this point be not attended to, serious errors would be committed in the
estimation of the phosphoric acid.
2. The quantity of uric acid was verified, by several repetitions, and found to be 14
per cent.
3. The undefined organic matter, when deprived of the uric acid by prolonged digestion with weak borax, being subjected to ignition along with hydrate of soda, yielded
the quantity of ammonia requisite to constitute the whole sum, that producible from the
uric acid also being taken into account.
4. The little lumps of the guano afforded, by distillation along with quicklime, 5*27
per cent. of ready-formed ammonia, probably from the uric, acid having been partially
decomposed by the moisture which had caused them to concrete. It is a curious fact,
that the solution of borax, from being of an alkaline, becomes of an acid reaction,' after
digestion with the Bolivian guano.
5. For distinguishing and separating the soda salts from those of potash, I tried the
antimoniate of potash, according to Wackenroder's prescription, but I found reason to
prefer very much the crystallized soda-chloride of platinum, for that purpose.
From another specimen of the Bolivian guano, I extracted 3'5 per ct. of the ammoniaphosphate of magnesia.
B. A sample of guano from the Chincha islands, of nearly the same light color as
the preceding, and the same dryness, being an early importation of 250 tons in the
present year, was subjected by me to a careful analysis.
1. The solution in water of this guano had an alkaline reaction from caibonate of
ammonia, which, being neutralized by test acid, indicated 0-34 per cent. of ammonia,
equivalent to about I of the smelling sesqui-carbonate.
2. Of this guano, 47 per cent. were soluble in water, and 53 per cent. remained, after
drying at a heat of 212D F.  Of the above 47 parts, 8-5 were moisture in the guano.
3. The solution being acidulated with nitric acid, was treated with acetate of barytes,
in a quantity equivalent to the sulphuric acid present, and it afforded 12 parts of sulphate of barytes. With the filtered liquor, 700 water grain measures of ferric acetate
were mixed, and then ammonia in excess; 18*5 parts of washed and ignited sub-phosphate
of iron were obtained, from which deducting 8-8 parts present in the acetate, 9-7 remain as the quantity of phosphoric acid; but 9*7 of acid produce 13'25 of bi-phosphate of ammonia, which contain only 2*3 of ammonia, combined with 0'95 of water,




966                                  GUANO.
or its elements. From the alkaline excess in the guano, there can be no doubt, however, that it contained the sub-phosphate (found in the urine of Carnivora), and not the
bi-phosphate of that base. In this case, 9-7 of acid produce 14-32 of dry saline compound, containing 4-62 of ammonia, which, with the 0'34 of ammonia in the carbonate,
constitute a sum of 4'96. To the liquor freed from the phosphate of iron, and acidulated with nitric acid, acetate of lime being added, 3'33 parts of oxalate of this base
were obtained, which are equivalent to 3'23 oxaIate ammonia, containing 089 of ammonia.
4. Nitrate of silver now produced from the filtered residual solution 8 parts of chloride, corresponding to nearly 3 of sal ammoniac, which contain nearly 0*95 of ammonia.
5. The 53 parts insoluble in water were digested with weak solution of borax at a boiling heat, thrown on a filter, and the uric acid being precipitated from the filtrate by
means of a little hydrochloric acid, washed and dried, was found to weigh 13'5 parts.
There were left on the filter 36-5 parts, dried at 2120 F., so that 3 parts of soluble organic matter had passed through the filter. These 36-5 parts lost by ignition only 9*7
parts in organic matter, became white, and afforded a very faint effervescence with
hydro-chloric acid, showing that a very little oxalate of lime had been present. 125
parts of silica were left after the action of the acid. To the solution of the 26-55 parts,
sulphuric acid was added, and the mixture being heated to expel the hydro-choric acid
and the excess of the sulphuric, the residuary matter was digested and washed with dilute alcohol, and thrown on a filter; the solution of magnesia passed through, while the
sulphate of lime remained. After ignition, this weighed 27'5 parts, equivalent to 22 of
sub-phosphate of lime. On supersaturating the filtrate with ammonia, 4*5 parts of the
malgnesian ammonia phosphate were precipitated, containing 0.32 of ammonia. With
the 13*5 parts of uric acid, 1'23 of ammonia had been originally combined, forming 14'73
of urate.
6. 25 grains of the dry guano afforded, by ignition in the combustion-tube along with
200 grains of the mixed lime and hydrate of soda, 4'165 of ammonia, which correspond
to 16-66 in 100 parts of the dry, or to 15-244 in the natural state; leaving therefore 5
parts for the quantity of potential ammonia, or of ammonia producible from the de
composition of its azotized organic matter. This guano is, therefore, well adapted to
promote permanently the fertility of a soil. It yields besides to alcohol a notable
quantity of urea, which I did not think it worth while to determine quantitively, and
from which undoubtedly a portion of the ammonia proceeded, in the distillation Vitt
milk of lime.
7. 100 parts afforded by distillation with milk of lime, 102 of ammonia.
8. The total constituents of that guano, being tabulated, are1. Matter soluble in water         -      -       -      47-00
consisting ofAmmonia.
1. Sulphate of potash, with a little sulphate of soda  -   6-00
2. Muriate of ammonia           -      --                 3-00    0.95
3. Phosphate of ammonia         -      -       -      -  14-32    4-62
4. Sesqui-carbonate of ammonia         -       -      -   1-00    0-34
5. Sulphate of ammonia          -      -       -      -   2-00    0-50
6. Oxalate of ammonia           -      -       -      -   3-23    0-89
7. Water         -       -      -      -.      -   8-50
8. Soluble organic matter and urea    -        -      - 8-95
47-00
II. Matter insoluble in water          -       -         53-00
consisting of1.   Silica........  1.25
2. Undefined organic matter    -       -       -      - 9-52
3. Urate of ammonia         --.      -      -  14-73    1*23
4. Oxalate of lime              -      -       -      -   1-00?
5. Sub-phosphate of lime        -      -       -      -22-00
6. Phosphate of magnesia and ammonia           -      - 4-50    0-32
53-00    9-80
The remaining 1.25 of actual ammonia may be fairly traced to the partial decomposi
lion of the urea during the distillation with lime; whereas the 5 per cent. of potential
ammonia proceeded from the transforming decomposition of the uric acid.
C. Foliated guano, from Peru, in caked pieces, the layers very thin, parallel, and in.
terspersed with white streaks. This guano was somewhat dense for a pure specimen,
having a specific gravity of 1-7. The insoluble matter afforded by digestion with borax




GUANO.                                      967
water, no less than 25X2 per ct. of pale yellow uric acid; 9 of other combustible organic
matter, and 15 of earthy matter; consisting of silica, 3-5; phosphate of magnesia and
amnionia, 6'5; and only 5 of sub-phosphate of lime or bone earth. It lost 10 per cent.
when dried in a heat of 212~ F. The remaining 30-8 parts soluble in water, had a
strong acid reaction, and afforded, by ferric acetate and ammonia, 6 of phosphoric acid,
equivalent to 9'7 of crystallized bi-phosphate of ammonia, after acetate of barytes had
separated the sulphuric acid. No less than 17 parts of chloride of silver were obtained,
by precipitating with nitrate of silver the liquor filtered from the phosphate of iron, and
acidulated with nitric acid. As the present is an accidental sample, and not an average
of any importation, I did not prosecute the research further.
D1. Chincha guano, of a somewhat darker color than the preceding, and alkaline reaction; specific gravity, 1'62. Digested with water and strained, 5675 parts remained
after dryin it at 2120 F. The solution, evaporated and dried also at 2120, afforded
31-25 of saline matter. This saline mass being mixed with four fifths of its weight of
slaked lime, nine times its weight of water, and distilled, afforded of ammonia 14*28
per cent. Some chemists have prescribed potash instead of lime, for separating the ammonia in distillation; but no person of intelligence who has made the experiment once
will choose to repeat it, because the potash forms with the organic matter of the guano
a viscid compound, that froths up like a mass of soap-bubbles, and coming over with
the vapors, obstructs and vitiates the result.
2. When dried altogether by a steam heat, 100 parts lost 12 in moisture; whereas by
evaporating and drying the soluble matter by itself, the loss amounted to 16-3, no
doubt by the dissipation of some of the ammoniacal salts; for 100 parts of the entire
guano afford, by distillation with quicklime, 9 parts of ammonia, and by the transforming decomposition with hydrate of soda and lime, 16-25, indicating 7-25 of potential
ammonia, in addition to the 9 of ready formed.  The insoluble matter of 100 parts
afforded to borax-water a solution containing 16-5 of uric acid, corresponding to 18 of
urate of ammonia. There remained on the filter, after drying it at 212~ F., only 33i8
parts; so that about 5 parts of soluble organic matter had passed through the filter in
the borax water. These 33-8 consisted of subphosphate of lime 17, magnesian phosphate of ammonia 5*5, silica 0'7, and combustible organic matter 10*6.
The ammonia in the soluble portion was in the state chiefly of phosphate; there was
merely a faint trace of oxalate of ammonia..  irican Guano.-Among the many samples of African guano which I have had
occasion to analyze for the importers, none has contained any appreciable quantity
of uric acid, or by consequence of potential ammonia. The best afforded me 10 per
cent. of ready-formed ammonia, existing chiefly in the state of a phosphate, though they
all contain carbonate of ammonia, and have of consequence an alkaline reaction. The
said sample contained 21*5 of moisture, separable by a heat of 212' F. Its specific
gravity was so low as 157, in consequence of the large proportion of moisture in it.
It contained 23 per cent. of subphosphate of lime, 3 of magnesian phosphate of ammonia, 1 of silica, and 1-5 of alkaline sulphate and muriate. The remaining 50 parts
consisted of decayed organic matter, with phosphate of ammonia, and a little carbonate,
equivalent to half a grain of ammonia, which is the largest quantity in such guanos.
Other African guanos have afforded from 24 to 36 of moisture, no uric acid; no potential ammonia; but decayed organic matter; from 5 to 7 of ready-formed ammonia in
the state of phosphate, with a little carbonate; from 25 to 35 per cent. of subphosphate
of lime; 5 or 6 of the magnesian phosphate of ammonia; more or less oxalates from
the decomposition of the uric acid, and 3 to 5 per cent. of fixed alkaline salts.
F. The Chilian Guano gathered on the coast, already adverted to, contained a remarkable proportion of common salt, derived probably from the sea spray.
The following is the general report of the chemical examination of several
samples of guano, which I made for Messrs. Gibbs of London, and Messrs. Myers of
Liverpool:
" In these various analyses, performed with the greatest care, and with the aid of the
most complete apparatus for both inorganic and organic analysis, my attention has been
directed, not only to the constituents of the guano which act as an immediate manure,
but to those which are admitted by practical farmers to impart durable fertility to the
grounds. The admirable researches of Professor Liebig have demonstrated that AZOTE,
the indispensable element of the nourishment of plants, and especially of wheat and
others abounding in gluten (an azotized product), must be presented to them in the state
of ammonia, yet not altogether ammonia in the pure or saline form, for, as such, it is
too readily evaporated or washed away; but in the dormant, or as one may say, in the
potential condition in contradistinction from the actual. Genuine Peruvian and Bolivian
guanos, like those which I have minutely analyzed, surpass very far all other species
of manure, whether natural or artificial, in the quantity of potential ammonia, and,
therefore, in the permanency of their action upon the roots of plants, while, in conse
quence of the ample store of actual ammonia which they contain ready formed, they




968                                   GUANO.
are qualified to give immediate vigor to vegetation.  Urate of aimonia constitutes a
considerable portion of the azotized organic matter in well-preserved guano; it is
nearly insoluble in water, not at all volatile, and is capable of yielding to the soil, by
its slow decomposition, nearly one third of its weight of ammonia. No other manure
can rival this animal saline compound. One of the said samples cf guano afforded me
no less than 17 per cent. of potential ammonia, besides 4' per cent. of the actual or
ready formed; others from 7 to 8 per cent. of ammonia in each of these states respectively. These guanos which I have examined are the mere excrement of birds,
and are quite free from the sand, earth, clay, and common salt, reported in the analyses
of some guanos, and one of which (sand) to the amount of 30 per cent. I found myself
n a sample of guano from Chile.
" The Peruvian guano, moreover, contains from 10 to 25 per cent. of phosphate of
lime, the same substance as bone-earth, but elaborated by the birds into a pulpy consistence, which, while it continues insoluble in water, has been thereby rendered more
readily absorbable and digestible (so to speak) by the roots of plants. I have therefore no doubt, that by the judicious application of these genuine guanos, mixed with
twice or thrice their weight of a marly or calcareous soil, to convert their phosphate of
ammonia into phosphate of lime and carbonate of ammonia, as also to dilute all their
amnmoniacal compounds-such crops will be produced, even on sterile lands, as the
farmer has never raised upon the most improved soil by the best ordinary manure. To
the West India planter, guano will prove the greatest boon, sirce it condenses in a
portable and inoffensive shape the means of restoring fertility to his exhausted canefields, a benefit it has long conferred on the poorest districts of Peru.
I respectfully observe, that no analysis of guano hitherto n ade public at all exhibits the value of tne cargoes referred to above, while none gives the quantity of
ammonia dormant in the azotized animal matter of the birds' dung,which, called into
activity with the seeds in the soil, becomes the most valuable of its constituents, as a
source of perennial fertility.  In the detailed account of my anslyses of this complex
excretion (now preparing for publication), all the above statements will be biought
within the scope of general comprehension. I shall also describe my'ammonia gene.
rator,' based on the process invented in the laboratory of Professor Li-big, and also my'ammonia metes,' which, together, can detect and measure one hundredth part of a
grain weight of absolute ammonia, whether potential or actual, in any sample of
guano.
" Meanwhile the following may be offered as the average result of my analyses of
genuine guano in reference to its agricultural value
" 1. Azotized animal matter, including urate of ammonia, together capable of affording from 8 to 16 per cent. of
ammonia by slow decomposition in the soil        -       - 50
2. Water        -       -       -      -       -       -   8 to 11
3. Phosphate of lime   -       -       -       -      -   12 to 25
4. Phosphate of ammonia, sulphate of ammonia, ammoniaphosphate of magnesia, together containing from 5 to
9 parts of ammonia        -       -       -      -       -13
5. Siliceous sand       -       -      -       -                  I -1
100
"Very moist guano has in general more actual and less potential ammonia than the
d:y guano.
"ANDREW  URE.
"London, 13 Charlotte street, Bedford square,
"February 14, 1843."
Oellacher's analysis of a brownish yellow guano is as follows   [see top  of next
I am satisfied from its large proportion of oxalate of ammonia, that the sample thri
analyzed was by no means a fair or normal specimen of guano; and it is in fact widely
different from  all the fresh samples which have passed through my hands. It is
described as " knobby, being mixed with light laminated crystalline portions, in white
grains, from the size of a pea to that of a pigeon's egg."  Having some lumpy concre
tions of a similar aspect in my possession, I submitted them to chemical examination.
G. 1,000 grains being digested in boiling water and strained, afforded a nearly colorless solution. This was concentrated till crystals of oxalate of ammonia appeared. It
was then acidulated with hydrochloric acid, to protect the phosphoric acid from precipitation, and next treated carefully with a solution of nitrate of lime equivalent to the
oxalic acid present. The oxalate of lime thus obtained being converted into carbonate
weighed 80-5 grains, corresponding to 100 of oxalate of ammonia, being 10 per cent.,or the weight of the guano.




GUMS.                                     969
Ammonia.. Urate of ammonia            -              -      -1220    1-06
2. Oxalate of ammonia         -       -      -       -17-73    6-50
3. Oxalate of lime    -       -       -       -         1-30
4. Phosphate of ammonia       -       -      -       - 90 6        79
5. Phosphate of ammonia and magnesia         -       - 11-63    168
6. Phosphate of lime  -       -       -      -       - 2016
7. Muriate of ammonia         -       -      -       -  2-25    072
8. Chloride of sodium (common salt) -        -       -  040
9. Carbonate of ammonia    -          -              -     0    023
10. Carbonate of lime..-  -          -  165
21. Sulphate of potash         -       -              -  4-00
12. Sulphate of soda           -       -              -  4-'92
13. Humate of ammonia          -.               -'6        9
14. Substance resembling wax -        -       -      -  0' 7
15. Sand       -       -       -      -              -  168
16. Water (hygroscopic)        -      -       -      -4-31
17. Undefined organic matter -        -       -      -  826
100-00    12-0 7
The liquor filtered from  the oxalate was precipitated by nitrate of bartes, )nd
afforded 112 grains of sulphate of barytes=38 sulphuric acid; and the  ast ftrate
being mixed with a given measure of ferric acetate, -and the mixture supersaturated
with ammonia, yielded subphosphate of iron, equivalent to 5 per cent of plosphoric
acid. I digested with heat other 500 grains of the same guano in a weak solution of
borax, filtered, acidulated the liquid, but obtained merely a trace f uric acid. It is
clear therefre that the oxalate of ammonia had been formed in this guano at the
expense of the uric acid, and that its coacreted state, and the erystalline aodules disseminated through it, were the result of transformation by moisture in a hot climate,
which had agglomerated it to a density of 1*75; whereas clean fresh guano, friable and
dry like the above, is seldom denser than 1-65. The guano contained only 3'23 of
ammonia,; 65 of insoluble matter, 53 of earthy phosphates, 5 silica, 3 alkaline salts
(fixed), and 7 organic matter.
Oxalate of ammonia, being readily washed away, it is a bad substitute for the urate
of ammonia, urea, and azotized animal matter, which it has replaced. Oellacher
could find no urea in the guano which he analyzed.; another proof of its disintegration.
Bartel's analysis of a brown-red guano is as follows:~
1. Muxiate of ammonia    -      -                         -   6500
2. Oxalate of ammonia                 -    --  13-351
3. Urate of ammonia   ----— 3244
4. Phosphate of ammonia           - - - -    6450
5. Substances resembling wax and resin    — 600
46. Sulphate of potash2 1277
7. Sulphate of soda -1119
S. Phosphate of soda             -5291
~9. Phosphate of lime-                                          9-940
10. Phosphate of ammonia and magnesia                       -   4*196
11. Common salt                        -       -        - 0*100
12. Oxalate of lime         - - - -                            16360
13. Alumina                    - - - -0*104
14. Sand insoluble in nitric acid, and iron                     5-800
15. Loss (water and volatile ammonia and undefined organic
matter)   ----                                          22-718
100-000
Voelckel, in his analysis of guano, states 7 per cent. of oxalate of lime-a result quite
at variance with all my experience-for I have never found so much as 2 per cent. of
carbonate of lime in the washed and gently ignited insoluble matter; whereas, according
to Bartels and Voelckel, from 10 to 5 per cent. of carbonate should be obtained, as the
equivalents of the proportions of the oxalate assigned by them.
All these analyses are defective moreover in not showing the total quantity of ammonia
which the guano is capable of giving out in the soil; and since it appears that the freshest
guano abounds most in what I have called potential ammonia, it must nosseas of consequence, the greatest fertilizing virtue.




97&D                                  GUM RESINS.
A  sample of decayed dark-broen moist guano from  Chile, being examined as above
described, for oxalate of ammonia, was found to contain none whatever; and it contained
less than I per cent. of uric acid.
H. An article offered to the public, by advertisement, as Peruvian guano, was lately
sent to me for analysis. I found it to be a spurious composition; it consisted of1. Common salt                                                   32-0
2. Common siliceous sand  -          -       -       -           280
3. Sulphate of iron or copperas    -         -        -       -     2
4. Phosphate of lime                         -                      0, with
5. Organic matter from bad guano, &c. (to give it smell)         233
6. Moisture                 -        -       -       -       -.
100-0
Genuine guano, when burned upon a red hot shovel, leaves a white ash of phos
phate of lime and magnesia; whereas this factitious substance left a black fused mass
of sea salt, copperas, and sand. The specific gravity of good fresh guano is seldom more
than 166, water being 100; whereas that of the said substance was so high as 217,
prodluced by the salt, sand, and copperas.
GULM  (Gomme, Fr.; Gummi, Pflanzenschleim, Germ.) is the name of a proximate
vegetable product, which forms with water a slimy solution, but is insoluble in alcohol
ether, and oils; it is converted by strong sulphuric acid into oxalic and mucic acids.
There are six varieties of gum: 1. gum arabic; 2. gum senegal; 3 gin of the cherry
and other stone fruit trees: 4. gum tragacanth; 5. gum of Bassora *6. the gum of seeds
and roots. The first five spontaneously flow from the branches and trunks of their trees,
and sometimes from the fruits, in the form of a mucilage which dries and hardens in the
air.  The sixth kind is extracted by boiling water.
Gum arabic and gum senegal consist almost wholly of the purest gum Called arabine by
the French chemists; our native fruit trees contain some cerasine, along with arabine;.the gum of Bassora and gum tragacanth consist of arabine and bassorine.
Gum arabic flows from the acacia arabica, and the acacia vera, which grow upon the
banks of the Nile and in Arabia. It occurs in commerce in the form of small pieces,
rounded upon one side and hollow  upon the other.  It is transparent, without smell,
brittle, easy to pulverize, sometimes colorless, sometimes with a yelk; or brownish
tint. It may be bleached by exposure to the air and the sun-beams, at the temperature
of boiling water. Its specific gravity is 1-355. Moistened gum arabic reddens litmus
paper, owing to the presence of a little supermalate of lime, which may be removed by
boiling alcoliQl; it shows also traces of the chlorides of potassium and calcium, and the
acetate of potash.  100 parts of good gum  contain 70-40 of arabine, 17-60 of water,
with a few per cents. of saline and earthy matters. Gum arabie is used in medicine, as
also to give lustre to crapes and other silk stuffs,
Gum  senegal is collected by the negroes during the month of November, from  the
acacia senegal, a tree 18 or 20 feet high. It comes to us in pieces about the size of a
partridge egg, but sometimes larger, with a hollow centre. Its specific gravity is 1436.
It consists of 81-10 arabine; 16-10 water; and from 2 to 3 of saline matters. The
chemical properties and uses of this gum are the same as those of gum arabic. It is
much employed in calico-printing.
Cherry-tree gum  consists of 52- 10 arabine; 54-90 cerasine; 12 water; and I saline
matter.
Gum  tragacanth is gathered about the end of June, from the astragalus tragacantha
of Crete and the surrounding islands. It has the appearance of twisted ribands; is white
or reddish; nearly opaque, and a little ductile. It is difficult to pulverize, without heating the mortar. Its specific gravity is 1-384. When plunged in water, it dissolves in
part, swells considerably, and forms a very thick mucilage. 100 parts of it consist of
53'30 arabine; 33-30 bassorine and starch; 11-0 water; and from 2 to 3 parts of saline
matters. It is employed in calico printing, and by shoemakers.
Gum of Bassora; see BASSORINE.
Gum of seeds, as linseed, consists of 52*70 arabine; 28'9 of an insoluble matter; 10'3
water; and 711 saline matter. Neither bassorine nor cerasine seems to be present in
seeds and roots. For British Gum, see STARCH.
GUM  RESINS.  (Gomme-resines, Fr.; Schleimharze, Germ.)  When incisions are
made in the stems, branches, and roots of certain plants, a milky juice exudes, which
gradually hardens in the air; and appears to be formed of resin and essential oil, held
suspended in water charged with gum, and sometimes with other vegetable matters,
such as caoutchouc, bassorine, starch, wax, and seveial saline matters. TLe said concrete juice is called a gum-resin; an improper name, as it gives a false idea of the nature
of the substance. They are all solid; heavier than water; in general opaque and brittle;




GUNPOWDER.                                        971
many have an acrid taste, and a strong smell; their colour is very variable. They are
partiall soluble in water, and also in alcohol; and the solution in the former liquid
seldom becomes transparent.  Almost all the gum  resins are medicinal substances, and
little employed in the arts and manufactures. The following is a list of them: assafetida; gum  aunmmoniac; bdellium; euphorbium; galbanum; gamboge; myrrh; olibanum or frankincense; opoponax; and scammony.  Some of these are described in this
work under their peculiar names.
GUMS. Under the generic name Gum  several substances have been classed, which
differ essentially, though they possess the following properties in common; viz. forming a thick mucilaginous liquid with water, and being precipitable from that solution
by alcohol. Properly speaking, we should style gums only such substances as are transformed into mucic acid by nitric acid; of which bodies there are three: 1. Arabine,
which constitutes almost the whole of gum arabic; 2. Bassorine, which forms the chief
part of gum  tragacanth; and 3. Cerasine, which occurs in cherry-tree gum, and is convertible into gum arabic by hot water.
I 1. Gum arabic, in its ordinary state, contains 17 per cent. of water, separable from it
by a heat of 2120 Fahr.
2. Cherry-tree gum  consists of 52 per cent of arabine, and 35 of a peculiar gum,
which has been called Cerasine.  This latter substance is convertible into grape sugar
Dy boiling it with very dilute sulphuric acid.
GUNPOWDER.  The following memoir upon this subject was published by me in
the Journal of the Royal Institution for October, 1830.  It contains the results of
several careful analytical experiments, as also of observations made at the Roval
Gunpowder Works at Waltham  Abbey, and at some similar establishments in the
neighbourhood of London.
GUNPOWDER is a mechanical combination of nitre, sulphur, and charcoal; deriving
the intensity of its explosiveness from the purity of its constituents, the proportion in
which they are mixed, and the intimacy of the admixture.
1. On the nitre.-Nitre may be readily purified, by solution in water and crystallization, from the muddy particles and foreign salts with which it is usually contaminated.
In a saturated aqueous solution of nitre, boiling hot, the temperature is 240~ F.; and
the relation of the salt to its solvent is in weight as three to one, by my experiments: not
five to one, as MM. Bottee and Riffault have stated.  We must not, however, adopt the
general language of chemists, and say that three parts of nitre are soluble in one of boiling water, since the liquid has a much higher heat and greater solvent power than this
expression implies.
Whter at 600 dissolves only one fourth of its weight of nitre; or, more exactly, this
saturated solution contains 21 per cent. of salt. Its specific gravity is l114l5; 100 parts
in volume of the two constituents occupy now 97-91 parts.  From  these data we may
perceive that little advantage could be gained in refining crude nitre, by making a boilinghot saturated solution of it; since on cooling, the whole would concrete into a moist
saline mass, consisting by weight of 21 parts of salt, mixed with I part of water, holding
* of salt- in solution, and in bulk of 17 of salt, with about 1 of liquid; for the specific
gravity of nitre is 2'005, or very nearly the double of water., It is better, therefore, to
use equal weights of saltpetre and water in making the boiling-hot solution.  When the
filtered liquid is allowed to cool slowly, somewhat less than three fourths of the nitre will
separate in regular crystals; while the foreign salts that were present will remain with
fully one fourth of nitre in the mother liquor.  On redissolving these crystals with heat,
in about two thirds of their weight of water, a solution will result, from which crystalline
nitre, fit for every purpose, will concrete on cooling.
As the principal saline impurity of saltpetre is muriate of soda (a substance scarcely
more soluble in hot than in cold water), a ready mode thence arises of separating that
salt from  the nitre in mother waters that contain them in nearly equal proportion.
Place an iron ladle or basin, perforated with small holes, on the bottom of the boiler in
which the solution is concentrating. The muriate, as it separates by the evaporation of
the water, will fall down and fill the basin, and may be removed from time to time.
When small needles of nitre begin to appear, the solution must be run off' into the crystallizing cooler, in which moderately pure nitre will be obtained, to be refined by another
similar operation.
At the Waltham Abbey gunpowder works the nitre is rendered so pure by successive
solutions and crystallizations, that it causes no opalescence in a solution of nitrate of
silver.  Such crystals are dried, fused in an iron pot at a temperature of from 500~ to
6000 F., and cast into moulds. The cakes are preserved in casks.
About the period of 1794 and 1795, under the pressure of the first wars of their
revolution, the French chemists employed by the government contrived an expeditious,
economical, and sufficiently effective mode of purifying their nitre. It must be observed
that this salt, as brought to the gunpowder-works in France, is in general a much cruder




972                                GUNPOWDER.
article than that imported into this country from  India.  It is extracted from  the
nitrous salts contained in the mortar-rubbish of old buildings, especially those of the
lowest and filthiest descriptions.   By their former methods, the French could not refine
their nitre in less time than eight or ten days; and the salt was obtained in great lumps,
very difficult to dry and divide; whereas the new process was so easy and so quick, that
in less than twenty-four hours, at one period of pressure, the crude saltpetre was converted into a pure salt, brought to perfect dryness, and in such a state of extreme division
as to supersede the operations of grinding and sifting, whence also considerable waste
Was avoided.
The following is a brief outline of this method, with certain improvements, as now
practised in the establishment of the.dministration des poudres et sallpetres, in France.
The refining boiler is charged over night with 600 kilogrammes of water, nd 1200
kilo~grammes of saltpetre, as delivered by the salpetriers.  No more fire is applied than
is adequate to effect the solution of this first charge of saltpetre. It may here beobserved,
that such an article contains several deliquescent salts, and is much more soluble than
punt3 nitre.  On the morrow morning the fire is increased, and the boiler is charged at
different intervals with fresh doses of saltpetre, till the whole amounts to 3000 kilogrammes., During these additions, care is taken to stir the liquid very diligently, and to
skim off the froth as it rises. When it has been for some time in ebullition, and when it
may be presumed that the solution of the nitrous salts is effected, the muriate of soda is
scooped out from the bottom of the boiler, and certain affusions or inspersions of cold
water are made into the pot, to quicken the precipitation of that portion which the boiling
motion mavy have kept afloat. When no more is found to fall, one kilogramme of Flanders
glue, dissolved in a sufficient quantity of hot water, is poured into the boiler; the mixture is thoroughly worked together, the froth being skimmed off, with several successive
inspersions of cold water, till 400 additional kilogrammes have been introduced constituting altogether 1000 kilogrammes.
W~hen the refining liquor affords no more froth, and is grown perfectly clear, all manipulation must cease. The fire is withdrawn, with the exception of a mere kindling, so a
to maintain the temperature till the next morning at about 88~ C. = 190~4 F.
This liquor is now transferred by hand-basins into the crystallizing reservoirs, taking
care to disturb the solution as little as possible, and to leave untouched the impure
matter at the bottom.  The contents of the long crystallizing cisterns are stirred backwards and forwards with wooden paddles, in order to quicken the cooling, and the
consequent precipitation of the nitre in minute crystals. These are raked, as soon as they
fall, to the upper end of the doubly-inclined bottom of the crystallizer, and thence removed to the washing chests or boxes. By the incessant agitation of the liquor, no large
crystals of nitre can possibly form. When the temperature has fallen to within 7~ or 80
F., of the apartment, that is, after seven or eight hours, all the saltpetre that it can yield
will have been obtained. By means of the double inward slope given to the crystallizer,
the supernatant liquid is collected in the middle of the breadth, and may be easily laded
out.
The saltpetre is shovelled out of the crystallizer into the washing chests, and heaped
up in them so as to stand about six or seven inches above their upper edges, in order to
allow for the subsidence which it must experience in the washing process. Each of these
chests being thus filled, and their bottom holes being closed with plugs, the salt is besprinkled from the rose of a watering-can, with successive quantities of water saturated
with saltpetre, and also with pure water, till the liquor, when allowed to run off, indicates
by the hydrometer, a saturated solution. The water of each sprinkling ought to remain
on the salt for two or three hours; and then it may be suffered to drain off through the
plug-holes below, for about an hour.
All the liquor of drainage from the first watering, as well as a portion of the second,
is set aside, as being considerably loaded with the foreign salts of the nitre, in order to
be evaporated in the sequel with the mother waters.  The last portions are preserved,
because they contain almost nothing but nitre, and may therefore serve to wash another
dose of that salt. It has been proved by experience, that the quantity of water employed
in washing need never exceed thirty-six sprinklings in the whole, composed of three
waterings, of which the first two consist of fifteen, and the last of six pots = 3 gallons E.;
or in other words, of fifteen sprinklings of water saturated with saltpetre, and twentyone of pure water.
The saltpetre, after remaining five or six days in the washing chests, is transported into
the drying reservoirs, heated by the flue of the nearest boiler; here it is stirred up from
time to time with wooden shovels, to prevent its adhering to the bottom, or running into
lumps, as well as to quicken the drying process.  In the course of about four hours, it
gets completely dry, in which state it no longer sticks to the shovel, but falls down into a
soft powder by pressure in the hand, and is perfectly white and pulverulent.  It is now




GUNPOWDER.                                        973
passed through a brass sieve, to separate any small lumps or foreign particles accidentally
present, and is then packed up in bags or barrels. Even in the shortest winter days, the
drying basin may be twice charged, so as to dry 700 or 800 kilogrammes.  By this opetation, the nett produce of 3000 kilogrammes (3 tons) thus refined, amounts to from
1750 to 1800 kilogrammes of very pure nitre, quite ready for the manufacture of gunpowder.
The mother waters arc next concentrated; but into their management it is needless to
enter in this memoir.
On reviewing the above process as practised at present, it is obvious that, to meet the
revolutionary crisis, its conductors must have shortened it greatly, and have been content
with a brief period of drainage.
2. On the sulphur.-The sulphur now imported into this country, from the volcanic
districts of Sicily and Italy, for our manufactories of sulphuric acid, is much purer than
the sulphur obtained by artificial heat from any varieties of pyrites, and may, therefore,
by simple processes, be rendered a fit constituent of the best gunpowder.  As it is not
my purpose here to repeat what may be found in common chemical compilations, I shal
say nothing of the sublimation of sulphur; a process, moreover, much too wasteful for
the gunpowder-maker.
Sulphur may be most easily analyzed, even by the manufacturer himself; for I find it
to be soluble in one tenth of its weight of boiling oil of turpentine, at 3160 Fahrenheit,
forming a solution which remains clear at 180~. As it cools to the atmospheric tempera.
ture, beautiful crystalline needles form, which may be washed sufficiently with cold alcohol, or even tepid water. The usual impurities of the sulphur, which are carbonate and
sulphate of zinc, oxyde and sulphuret of iron, sulphuret of arsenic and silica, will remain
unaffected by the volatile oil, and may be separately eliminated by the curious, though
such separation is of little practical importance.
Two modes of refining sulphur for the gunpowder works have been employed; the
first is by fusion, the second by distillation.  Since the combustible solid becomes as
limpid as water, at the temperature of about 230~ Fahrenheit, a ready mode offers of
removing at once its denser and lighter impurities, by subsidence and skimming. But
I may take the liberty of observing, that the French melting pot, as described in the
elaborate work of MM. Bott6e and Riffault, is singularly ill-contrived, for the fire is
kindled right under it, and plays on its bottom. Now a pot for subsidence ought to be
cold set; that is, should have its bottom part imbedded in clay or mortar for four or six
inches up the side, and be exposed to the circulating flame of the fire only round its
middle zone. This arrangement is adopted in many of our great chemical works, and
is found to be very advantageous. With such a boiler, judiciously heated, I believe
that crude sulphur might be made remarkably pure; whereas by directing the heat
against the bottom of the vessel, the crudities are tossed up, and incorporated with the
mass. See EVAPORATION.
The sulphur of commerce occurs in three prevailing colors; lemon yellow verging on
green, dark yellow, and brown yellow. As these different shades result from the different degrees of heat to which it has been exposed in its original extraction on the great
scale, we may thereby judge to what point it may still be heated anew in the refinery
melting. Whatever be the actual shade of the crude article, the art of the refiner consists in regulating the heat, so that after the operation it may possess a brs2iant yellow
hue, inclining somewhat to green.
In seeking to accomplish this purpose, the sulphur should first be sorted according to
its shades; and if a greenish variety is to be purified, since this kind has been but little
heated in its extraction, the fusion may be urged pretty smartly, or the fire may be kept
up till everything is melted but the uppermost layer.
Sulphur of a strong yellow tinge cannot bear so great a heat, and therefore the fire
must be withdrawn whenever three fourths of the whole mass have been melted.
Brown-colored brimstone, having been already somewhat scorched, should be heated
as little as possible, and the fire may be removed as soon as one half of the mass is
fused.
Instead of melting, separately, sulphurs of different shades, we shall obtain a better result by first filling up the pot to half its capacity, with the greenish-colored article, putting
over this layer one quarter volume of the deep yellow, and filling it to the brim with
the brown-colored. The fire must be extinguished as soon as the yellow is fused. The
pot must then be closely covered for some time; after which the lighter impurities will be
found on the surface in a black froth, which is skimmed off, and the heavier ones sink
to the bottom. The sulphur itself must be left in the pot for ten or twelve hours, after
which it is laded out into the crystallizing boxes or casks.
Distillation affords a more complete and very economical means of purifying sulphur,
which was first introduced into the French gunpowder establishments, when  their
importation of the best Italian and Sicilian sulphur was obstructed by the British
navy. Here the sulphur need not come over slowly in a rare vapor, and be deposited




974                               GUNPOWDER.
in a pulverulent form called flowers; for the only object of the refiner is to bring over
the whole of the pure sulphur into his condensing chamber, and to leave all its crudities
in the body of the still. Hence a strong fire is applied to elevate a denser mass of
vapors, of a yellowish color, which passing over into the condenser, are deposited in
a liquid state on its bottom, whilst only a few lighter particles attach themselves to the
upper and lateral surfaces. The refiner must therefore give to the heat in this operation very considerable intensity; and, at some height above the edge of the boiler, he
should provide an inclined plane, which may let the first ebullition of the sulphur overflow into a safety recipient. The condensing chamber should be hot enough to maintain the distilled sulphur in a fluid state-an object most readily procured by leading
the pipes of several distilling pots into it; while the continuity of the operations is secured, by charging each of the stills alternately, or in succession. The heat of the receiver must be never so high as to bring the sulphur to a sirupy consistence, whereby its
color is darkened.
In the sublimation of sulphur, a pot containing about 4 cwts. can be worked off only
once in twenty-four hours, from the requisite moderation of its temperature, and the precaution of an inclined plane, which restores to it the accidental ebullitions. But, by distillation, a pot containing fully ten cwts. may complete one process in nine hours at most,
with a very considerable saving of fuel. In the former plan of procedure, an interval
must elapse between the successive charges; but in the latter, the operation must be
continuous to prevent the apparatus from getting cooled; in sublimation, moreover, where
communication of atmospheric air to the condensing chamber is indispensable, explosive
combustions of the sulphurous vapors frequently occur, with a copious production of sulphurous acid, and correspondent waste of the sulphur; disadvantages from which the distillatory process is in a great measure exempt.
I shall here describe briefly the form and dimensions of the distilling apparatus
employed at Marseilles in purifying sulphur for the national gunpowder works, which
was found adequate to supply the wants of Napoleon's great empire. This apparatus
consists of only two still-pots of cast iron, formed like the large end of an egg, each
about three feet in diameter, two feet deep, and nearly half an inch thick at the bottom,
but much thinner above, with a horizontal ledge four inches broad. A  pot of good
east iron is capable of distilling 1000 tons of sulphur before it is rendered unserviceable,
by the action of the brimstone on its substance, aided by a strong red heat. The pot is
covered in with a sloping roof of masonry, the upper end of which abuts on the brickwork
of the vaulted dome of condensation. A large door is formed in the masonry in front
of the mouth of the pot, through which it is charged and cleared ont; and between the
roof-space over the pot, and the cavity of the vault, a large passage is opened. At the
back of the pot a stone step is raised to prevent the sulphur boiling over into the condenser. The vault is about ten feet wide within, and fourteen feet from the bottom up to
the middle of the dome, which is perforated, and carries a chimney about twelve feet high,
and twelve feet diameter inside.
As the dome is exposed to the expansive force of a strong heat, and to a very considerable pressure of gases and vapors, it must possess great solidity, and be therefore
bound with iron straps. Between the still and the contiguous wall of the condensing
chamber, a space must be left for the circulation of air; a precaution found by experience
indispensable; for the contact of the furnaces would produce on the wall of the chamber
such a heat as to make it crack and form  crevices for the liquid sulphur to escape.
The sides of the chamber are constructed of solid masonry, forty inches thick, surmounted by a brick dome, covered with a layer of stones. The floor is paved with
tiles, and the walls are lined with them up to the springing of the dome; a square
hole being left in one side, furnished with a strong iron door, at which the liquid
sulphur is drawn off at proper intervals. In the roof of the vault are two valve-holes
covered with light plates of sheet-iron, which turn freely on hinges at one end, so as
to give way readily to any sudden expansion from within, and thus prevent dangerous
explosions.
As the chamber of condensation is an oblong square, terminating upwards in an oblong
vault, it consists of a parallelepiped below, and semi-cylinder above, having the following dimensions:~
Length of the parallelepiped                           161 feet.
Width.... 10^
Height                                                 71
Radius of the cylinder                                 52
Height or length of semi-cylinder     ~    ~    ~    16k
Whenever the workman has introduced into each pot its charge of ten or twelve hundred weight of crude sulphur, he closes the charging doors carefully with their iron plates
and cross-bars, and lutes them tight with loam. He then kindles his fire, and makes the




GUNPOWDER.                                     975
sulphur boil. One of his first duties (and the least neglect in its discharge may occasion
serious accidents) is to inspect the roof-valves and to clean them, so that they may play
freely and give way to any expulsive force from within. By means of a cord and chain,
connected with a crank attached to the valves, he can, from time to time, ascertain their
state, without mounting on the roof. It is found proper to work one of the pots a certain
time before fire is applied to the other. The more steadily vapors of sulphur are seen to
issue from the valves, the less atmospherical air can exist in the chamber, and therefore
the less danger there is of combustion. But if the air be cold, with a sharp north wind,
and if no vapors be escaping, the operator should stand on his guard, for in such circumstances a serious explosion may ensue.
As soon as both the boilers are in full work the air is expelled, the fumes cease, and
every hazard is at an end. He should bend his whole attention to the cutting off all corn.
munication with the atmosphere, securing simply the mobility of the valves, and a steady
vigor of distillation. The conclusion of the process is ascertained by introducing his
sounding-rod into the pot, through a small orifice made for its passage in the wall. A
new charge must then be given.
By the above process, well conducted, sulphurs are brought to the most perfect statt
of purity that the arts can require; while not above four parts in the hundred of the sulphur itself are consumed; the crude, incombustible residuum varying from five tc eight
parts, according to the nature of the raw material. But in the sublimation of sulphur, the
frequent combustions inseparable from this operation carry the loss of weight in flowers to
about twenty per cent. See SULPHUR, for a figure of the subliming apparatus.
The process by fusion, performed at some of the public works in this country, does
not afford a return at all comparable with that of the above French process, though a
much better article is operated upon in England. After two meltings of rough sulphur (as imported from Sicily or Italy), eighty-four per cent. is the maximum amount
obtained, the average being probably under eighty; while the product is certainly inferior
in quality to that by distillation.
3. On the charcoal.-Tender and light woods, capable of affording a friable and porous
charcoal, which burns rapidly away, leaving the smallest residuum of ashes, and containing therefore the largest proportion of carbon, ought to be preferred for charring in
gunpowder works.
After many trials made long ago, black dogwood came to be preferred to every plant
for this purpose; but modern experiments have proved that many other woods afford an
equally suitable charcoal.: The woods of black alder, poplar, lime-tree, horse-chestnut,
and chestnut-tree, were carbonized in exactly similar circumstances, and a similar gunpowder was made with each, which was proved by the same proof-mortar. The following results were obtained:Toises.           Feet.
Poplar-mean range             -  -       -          113                2
Black alder                --.10                4
Lime        -I-.-  I(                                                  3
Horse-chestiat     -       -      -      -          110                3
Chestnut-tree... -         --                       109
By subsequent experiments, confirmatory of the above, it has been further found that
the willow presents the same advantages as the poplar, and that several shrubs, such as
the hazel-nut, the spindle-treee, the dogberry, the elder-tree, the common sallow, and
some others, may be as advantageously employed.  But whichever wood be used, we
should always cut it when full of sap, and never after it is dead; we should choose
branches not more than five or six years old, and strip them carefully, because the old
branches and the bark contain a larger proportion of earthy constituents. The branches
ought not to exceed three quarters of an inch in thickness, and the larger ones should be
divided lengthwise into four, so that their pith may be readily burned away.
Wood is commonly carbonized in this country into gunpowder-charcoal in cast-iron
cylinders, with their axes laid horizontally, and built in brick-work, so that the flame of
a furnace may circulate round them. One end of the cylinder is furnished with a door,
for the introduction of the wood and the removal of the charcoal; the other end terminates in a pipe, connected with a worm-tub for condensing the pyroligneous acid, and giving vent to the carbureted hydrogen gases that are disengaged. Towards the end of the
operation, the connexion of the cylinder with the pyroligneous acid cistern ought to be
cut off, and a very free egress opened for the volatile matter, otherwise the charcoal is
apt to get coated with a fuliginous varnish, and to be even penetrated with condensable
matter, which materially injure its qualities.




976                                GUNPOWDER.
In France, the wood is carbonized for the gunpowder works either in oblong vaulted
ovens, or in pits, lined with brick-work or cylinders of strong sheet-iron. In either case,
the heat is derived from the imperfect combustion of the wood itself to be charred.' In
general, the product in charcoal by the latter method is from 16 to 17 parts, by weight,
from 100 of wood.  The pit-process is supposed to afford a more productive return, and
a better article; since the body of wood is much greater, and the fuliginous vapors are
allowed a freer escape. The surface of a good charcoal should be smooth, but not glistening. See CHARCOAL.
The charcoal is considered by the scientific manufacturers to be the ingredient most
influential, by its fluctuating qualities, upon the composition of gunpowder; and,
therefore, it ought always to be prepared under the vigilant and skilful eye of the
director of the powder establishment. If it has been kept for some time, or quenched
at first with water, it is unsuitable for the present purpose. Charcoal extinguished in a
close vessel by exclusion of air, and afterwards exposed to the atmosphere, absorbs only
from three to four per cent. of moisture, while red-hot charcoal quenched with water may
lose by drying twenty-nine per cent. When the latter sort of charcoal is used for gunpowder, a deduction of weight must be made for the water present. But charcoal which
has remained long impregnated with moisture, constitutes a most detrimental ingredient
of gunpowder.
4. On mixing the Constituents and forming the Powder.
The three ingredients thus prepared are ready for manufacturing into gunpowder.
They are, 1. Separately ground to a fine powder, which is passed through sorted silk
sieves or bolting machines.  2. They are mixed together in the proper proportions
Which we shall afterwards discuss. 3. The composition is then sent to the gunpowder
mill, which consists of two edge-stones of a calcareous kind, turning by means of a horizontal shaft, on a bed-stone of the same nature; incapable of affording sparks by collision with steel, as sand-stones would do.  On this bed-stone the composition is spread,
and moistened with as small a quantity of water as will, in conjunction with the weight
of the revolving stones, bring it into a proper body of cake, but by no means into a pasty
state.  The line of contact of the rolling edge-stone is constantly preceded by a hard
copper scraper, which goes round with the wheel, regularly collecting the caking mass,
and bringing it into  the track of the stone. From 50 to 60 pounds of cake are usually
worked at one operation, under each millstone.  When the mass has been thoroughly
kneaded and incorporated, it is sent to the corning-house, where a separate mill is employed to form the cake into grains or corns. Here it is first pressed into a hard firm
mass, then broken into small lumps; after which the corning process is performed, by
placing these lumps in sieves, on each of which is laid a disc or flat cake of lignum vitae.
The sieves are made of parchment skins, or of copper, perforated with a multitude of
round holes. Several such sieves are fixed in a frame, which, by proper machinery, has
such a motion given to it as to make the lignum vitte runner in each sieve move about
*with considerable velocity, so as to break down the lumps of the cake, and forves its substance through the holes, in grains of certain sizes. These granular -particles are afterwards separated from the finer dust by proper sieves and reels.
The corned powder must now be hardened, and its rougher angles removed, by causing
it to revolve in a close reel or cask turning rapidly round its axis. This vessel resem., leg
somewhat a barrel-churn, and is frequently furnished inside with square bars parallel to
its axis, to aid the polish by attrition.
The gunpowder is finally dried, which is now done generally with a steam heat, or in
some places by transmitting a current of air, previously heated in another chamber, over
canvass shelves, covered with the damp grains.
5. On the proportion of the Constituents.
A very extensive suite of experiments, to determine the proportions of the constituents
for producing the best gunpowder, was made at the Essonne works, by a commission of
French chemists and artillerists, in 1794.
Powders in the five following proportions were prepared:Nitre.       Charcoal.      Sulphur.
1          76             14          10     Gunpowder of BAle.
2          76             12          12    Gunpowder works of Grenelle.
3          76             15           9    M. Guyton de Morveau.
4          77-32          13-44        9-24 Idem.
5          77-5           15           7-5   M. Riffault.




GUNPOWDER.                                     977
The result of more than two hundred discharges with the proof-mortar showed that
the first and third gunpowders were the strongest; and the commissioners in consequence recommended the adoption of the third proportions. But a few years thereafter
it was thought proper to substitute the first set of proportions, which had been found
equal in force to the other, as they would have a better keeping quality, from containing
a little more sulphur and less charcoal. More recently still, so strongly impressed have
the French government been with the high value of durability in gunpowders, that they
have returned to their ancient dosage of 75 nitre, 121 charcoal, and 121 sulphur.  In
this mixture, the proportion of the substance powerfully absorbent of moisture, viz., the
charcoal, is still further reduced, and replaced by the sulphur, or the conservative ingredient.
If we inquire how the maximum gaseous volume is to be produced from the chemical
reaction of the elements of nitre on charcoal and sulphur, we shall find it to be by the
generation of carbonic oxyde and sulphurous acid, with the disengagement of nitrogen.
This will lead us to the following proportions of these constituents.
Hydrogen = 1.        Per cent
I prime equivalent of nitre -    -      -          102               75-00
I                    sulphur      -       -           16              11-77
3                    charcoal     -       -           18              13-23
136             100-00
The nitre contains five primes of oxygen, of which three, combiningwith the three of
charcoal, will furnish three of carbonic oxyde gas, while the remaining two will convert
the one prime of sulphur into sulphurous acid gas. The single prime of nitrogen is,
therefore, in this view, disengaged alone.
The gaseous volume, on this supposition, evolved from 136 grains of gunpowder, equi
valent in bulk to 75- grains of water, or to three tenths of a cubic inch, will be, at the
atmospheric temperature, as follows:Grains.  Cubic Inches.
Carbonic oxyde  -    -           -    42  =   141-6
Sulphurous acid-    -    -    -        32  =    47-2
Nitrogen    -    -     -    -    -    14  =    47-4
236-2
being an expansion of one volume into 787-3. But as the temperature of the gases at
the instant of their combustive formation must be incandescent, this volume may be
safely estimated at three times the above amount, or considerably upwards of two thousand times the bulk of the explosive solid.
But this theoretical account of the gases developed does not well accord with,he
experimental products usually assigned, though these are probably not altogether exact.
Much carbonic acid is said to be disengaged, a large quantity of nitrogen, a little oxyde
of carbon, steam of water, with carbureted and sulphureted hydrogen. From experiments
to be presently detailed, I am convinced that the amount of these latter products printed
in italics must be very inconsiderable indeed, and unworthy of ranking in the calculation;
for, in fact, fresh gunpowder does not contain above one per cent. of water, and can
therefore yield little hydrogenated matter. Nor is the hydrogen in the carbon of any
consequence.
It is obvious that the more sulphur is present, the more of the dense sulphurous acid
will be generated, and the less forcibly explosive will be the gunpowder. This is sufficiently confirmed by the trials at Essonne, where the gunpowder that contained 12 of
sulphur and 12 of charcoal in 100 parts, did not throw the proof-shell so far as that
which contained only 9 of sulphur and 15 of charcoal. The conservative property is,
however, so capital, especially for the supply of our remote colonies and for humid climates, that it justifies a slight sacrifice of strength, which at any rate may be compensated by a small addition of charge.




978                                GUNPOWDER.
Table of Composition of different Gunpowders.
Nitre.   | Charcoal.     Sulphur.
Royal Mills at Waltham Abbey -    -    -          75            15           10
France, national establishment    -               75            125          125
French, for sportsmen..-     -      78            12           10
French, for mining -    -     -     -     -       65            15           20
United States of America  -                       75            12-5         125
Prussia.... 75           135          11.5
Russia    -.                                      73-78         13-59        12-63
Austria (musquet) -     -     -     -     -       72            17           16
Spain- -                   -.-..   76-47   10-78   1275
Sweden --                                         76            15            9
Switzerland (a round powder)  -    -    -         76            14           10
Chinese -_                                        75            144           99
Theoretical proportions (as a'bove)   -    -      75            13-23        11.77
6. On the Chemical Examination of Gunpowders.
I have treated five different samples: 1. The government powder made at Waltham
Abbey; 2. Glass gunpowder made by John Hall, Dartford; 3. The treble strone gun.
powder of Charles Lawrence and Son; 4. The Dartford gunpowder of Pigou and Wilks;
5. Superfine treble strong sporting gunpowder of Curtis and Harvey.  The first is
coarse-grained, the others are all of considerable fineness. The specific gravity of each
was taken in oil of turnentine: that of the first and last three was exactly the same
being 1*80; that of the second was 1-793, all being reduced to water as unity.
The above density for specimen first, may be calculated thus:75 parts of nitre, specific gravity = 2-000
15 parts of charcoal, specific gr. =  1-154
10 parts of sulphur, specific gr.  - 2-000
The volume of these constituents is 55-5 (the volume of their weight of water tieing
100); by which if their weight 100 be divided, the quotient is 1-80.
The specific gravity of the first and second of the above powders, including the interstices of their grains, after being well shaken down in a vial, is 1-02. Thes is a curiqus
result, as the size of the grains is extremely different. That of Pigou and Wilks, similarly tried, is only 0-99; that of the Battle powder is 1-03; and that of Curtis and Harvey is nearly 1-05. Gunpowders thus appear to have nearly the same weight as water,
under an equal bulk; so that an imperial gallon will hold from 10 pounds to 10 pounds
and a half, as above shown.
The quantities of water which 100 grains of each part with on a steam bath, and
absorb when placed for 24 hours under a moistened receiver standing in water, are as
follows:~
100 grains of Waltham Abbey, lose 1-1 by steam heat, gain 0-8 over water.
of Hall       -       - 0-5    -       -       -2-2
Lawrence -         -1-0      -       -      -1*1
Pigou and Wilks  - 0-6       -      -       - 2-2
Curtis and Harvey - 0-9      -      -       -1-7
rhus we perceive that the large grained government powder resists the hygrometric
influence better than the others; among which, however, Lawrence's ranks nearly as
high. These two are therefore relatively the best keeping gunpowders of the series.
The process most commonly practised in the analysis of gunpowder, seems to be tolerably exact. The nitre is first separated by hot distilled water, evaporated and weighed.
A minute loss of salt may be counted on, from its known volatility with boiling water.
I have evaporated always on a steam bath. It is probable that a small portion of the
lighter and looser constituent of gunpowder, the carbon, flies off in the operations of
corning and dusting. Hence, analysis may show a small deficit of charcoal below the
synthetic proportions originally mixed. The residuum of charcoal and sulphur left on
the double filter-paper, being well dried by the heat of ordinary steam, was estimated, as
usual, by the difference of weight of the inner and outer papers. This residuum was
cleared off into a platina capsule with a tooth-brush, and digested in a dilute solution
of potash at a boiling temperature. Three parts of potash are fully sufficient to dissolve out one of sulphur. When the above solution is thrown on a filter, and washed




GUNPOWDER.                                     979
first with a very dilute solution of potash boiling hot, then with boiling water, and after.
wards dried, the carbon will remain; the weight of which deducted from that of the mixed
powder, will show the amount of sulphur.
I have tried many other modes of estimating the sulphur in gunpowder more directly,
but with little satisfaction in the results. When a platina capsule, containing gunpowder
spread on its bottom, is floated in oil, heated to 4000 Fahrenheit, a brisk exhalation of
sulphur fumes rises, but, at the end of several hours, the loss does not amount to more
than one half of the sulphur present.
The mixed residuum of charcoal and sulphur digested in hot oil of turpentine gives
up the sulphur readily; but to separate again the last portions of the oil from the charcoal or sulphur, requires the aid of alcohol.
When gunpowder is digested with chlorate of potash and dilute muriatic acid, at a moderate heat in a retort, the sulphur is acidified; but this process is disagreeable and slow,
and consumes much chlorate. The resulting sulphuric acid being tested by nitrate of
baryta, indicates of course the quantity of sulphur in the gunpowder. A curious fact
occurred to me in this experiment. After the sulphur and charcoal of the gunpowder
had been quite acidified, I poured some solution of the baryta salt into the mixture, but
no cloud of sulphate ensued. On evaporating to dryness, however, and redissolving, the
nitrate of baryta became effective, and enabled me to estimate the sulphuric acid generated; which was of course 10 for every 4 of the sulphur.
The acidification of the sulphur by nitric or nitro-muriatic acid is likewise a slow and
unpleasant operation.
By digesting gunpowder with potash water, so as to convert its sulphur into a sulphuret, mixing this with nitre in great excess, drying and igniting, I had hoped to convert
the sulphur readily into sulphuric acid.  But on treating the fused mass with dilute
nitric acid, more or less sulphurous acid was exhaled.  This occurred even though
chlorate of potash had been mixed with the nitre to aid the oxygenation.
The following are the results of my analyses, conducted by the firct described
method:
100 grains afford, of    Nitre.       Charcoal.      Sulphur.       Water.
Waltham Abbey  - -          74-5          14-4           10'0       1'1
Hall, Dartford - - -        76-2          14-0           9'0        0-5 loss 0-'3
Pigou and Wilks -  -        77-4          13-5            8'o       0*6
Curtis and Harvey  -        76-7          12-5           9'0        1-1 loss 0-7
Battle gunpowder   -        77-0          13-5            8'0       0-8 loss 0-7
It is probable, for reasons already assigned, that the proportions mixed by the manufacturers may differ slightly from the above.
The English sporting gunpowders have long been an object of desire and emulation in
France. Their great superiority for fowling pieces over the product of the French national
manufactories, is indisputable. Unwilling to ascribe this superiority to any genuine cause,
M. Vergnaud, captain of French artillery, in a little work on fulminating powders lately
published, asserts positively, that the English manufacturers of' poudre de chasse' are
guilty of the' charlatanisme' of mixing fulminating mercury with it. To determine what
truth was in this allegation, with regard at least to the above five celebrated gunpowders,
I made the following experiments.
One grain of fulminating mercury, in crystalline particles, was mixed in water with
200 grains of the Waliham  Abbey gunpowder, and the mixture was digested over a
tamp with a very little muriatic acid. The filtered liquid gave manifest indications of
the corrosive sublimate, into which fulminating mercury is instantly convertible by ma
riatic acid; for copper was quicksilvered by it; potash caused a white cloud in it that
oecame yellow, and sulphureted hydrogen gas separated a dirty yellow white precipitate of bisulphuret of mercury. When the Waltham Abbey powder was treated alone
with dilute muriatic acid, no effect whatever was produced upon the filtered liquid by the
sulphureted hydrogen gas.
200 grains of each of the above sporting gunpowders were treated precn~'y in the
same way, but no trace of mercury was obtained by the severest tests. Since by this
process there is no doubt but one 10,000th part of fulminating mercury could be detected, we may conclude that Captain Vergnand's charge is groundless. The superiority
of our sporting gunpowders is due to the same cause as the superiority of our cotton
fabrics -the care of our manufacturers in selecting the best materials, and their skill in
combining them.
I shall subjoin here some miscellaneous observations upon gunpowder.




980                                 GYPSUM.
In Bengal, mixing is performed by shutting up the ingredients in barrels, which are
turned either by hand or machinery; each containing 50 lbs. weight, or more, of small
brass balls. They have ledges on the inside, which occasion the balls and composition
to tumble about and mingle together, so that the intermixture of the ingredients, after
tne process has been gone through, cannot fail to be complete. The operation is continued two or three hours; and I think it would be an improvement in Her Majesty's
system of manufacture if this method of mixing were adopted.
In England two or three pints of water are used for a 42 lb. charge: but the quantity
is variable; both the temperature and the humidity of the atmosphere influence it.
Bramah's hydrostatic press, or a very strong wooden press working with a powerful
screw, lever, and windlass, constitutes the description of mechanism by which density is
imparted to gunpowder. The incorporated or mill-cake powder is laid on the bed or
follower of the press, and separated, at equal distances, by sheets of copper, so that when
the operation is over, it comes out in large thin solid cakes, or strata, distinguished by
the term press-cake. The mill-cake powder at Waltham Abbey, is submitted to a mean
theoretic pressure of 70 to 75 tons per superficial foot.
Gunpowder should be thoroughly dried, but not by too high a degree of heat; that
of 140~ or 150~ of Fahrenheit's thermometer is sufficient. It appears to be of no consequence whether it be dried by solar heat, by radiation from red-hot iron, as in the gloom
stove, or by a temperature raised by means of steam. Her Majesty's gunpowder is dried
by the last two methods. The grain should not besuddenlyexposedtothe ighestdegree
of heat, but gradually.
The method of trial best adapted to show the real inherent strength and goodness of
gunpowder, appears to be an eight or ten inch iron or brass mortar, with a truly spherical
solid shot, having not more than one tenth of an inch  indage, and fired with a low
charge. The eight-inch mortar, fired with two ounces of powder, is one of the established
methods of proof at Her Majesty's works. Gunpowders that range equally in this mode
of trial, may be depended on as being equally strong.
Another proof is by four drachms of powder laid in a srall neat heap, on a clean, polished
copper plate; which heap is fired at the apex, by a red hot iron. The exploion should
be sharp and quick; not tardy, nor lingering; it should produce a sudden concussion in
the air; and the force and power of that concussion ought to be judged of by comparison
with that produced by powder of known good quality. No sparks should fly off, nor should
beads, or globules of alkaline residuum, be left on the copper. - If the copper be left
clean, i. e. without gross foulness, and no lights, i. e. sparks, be seen, the ingredients
may be considered to have been carefully prepared, and the powder to have been well
manipulated, particularly if pressed and glazed; but if the contrary be the result, there
has been a want of skill or of carefulness manifested in the manufacture.
"Gunpowder," says Captain Bishop, " explodes exactly at the 600~ of heat by Fahrenheit's thermometer; when gunpowder is exposed to 5000 it alters its nature altogether; not only the whole of the moisture is driven off, but the saltpetre and sulphur are
actually reduced to fusion, both of which liquefy under the above degree. The powder,
on cooling, is found to have changed its color from a gray to a deep black; the grain has
oecome extremely indurated, and by exposure even to very moist air, it then suffers no
alteration by imbibing moisture."
The mill for grinding the gunpowder cake may be understood from  the following
representation (fig.'40); p, is the water wheel, which may drive several pairs of
stones; q, q, two vertical bevel wheels, fixed upon the axis of the great wheel' r, r, two




GUTTA PERCHA.                                           981
horizontal bevel wheels working in q, q, and turning the shafts s, s; t, t, two horizontal
spur wheels fixed to the upper part of the vertical shafts, and driving the large wheels
u, u. To the sshafts of these latter wheels are fixed-the runners v, v, which traverse upon
the bed stone w, w; x, x, are the curbs surrounding the bed stone to prevent the powder
from falling off; o is the scraper. Mill A represents a view, and mill B a section of the
bed stone and'curb.
GuNPOWDER, Analysis of.  M. Bolley dissolves out the sulphur from charcoal in gunpowder (previously freed from its nitre by water) by digesting it, at a boiling beat for 2
hours, with the solution of 20 times its weight of sulphite of soda, which is thereby
converted into hyposulphite. To the mixture water must be added, as it is wasted by the
boiling. If the residum be heated on platinum foil, it will exhale sulphur, if this had
not been all removed by the sulphurous salt.
GUTTA  PERCHA (NATIVE). "Although the trees yielding this substance abound
in the forests of the Indian Archipelago, the first notice taken of it appears to have been
by Dr. W. Montgomerie, in a letter to the Bengal Medical Board, in the beginning of
1843, wherein he recommends the substance as likely to prove useful for some surgical
purposes, and. supposes it to belong to the fig tribe. In April, 1843, the substance was
taken to Europe by Dr. D'Almeida, who presented it to the Royal Society of Arts of
London, but it did not at first attract much attention, as the Society simply acknowledged
the receipt of. the gift; whereas shortly after they thought proper to award a gold medal
to Dr. W. Montgomerie for a similar service.  Now, as the discovery of both of these
gentlemen rested pretty much upon' the same foundation, the accidental falling in with
itin. the  ands of some Malays, who had found out its greatest peculiarity, and availed
themselves thereof, manufactured it into whips, which were brought into town for ale,
there does not appear any plausible reason'for the passing over the first, and rewarding
the second. Both gentlemen are highly to be commended for endeavourin  to introduce
to public notice a substance which has proved so useful and interesting.  The gutta
percha having of late-attracted much attention, and as yet but little being known or
published about it, I would now propose to supply, to the best of my ability, this desideratum, and give a description of the tree, its product and- uses, so far as it has been
made available for domestic and other purposes in the place of its origin.
"The gutta percha, tree, or gutta tuban, as it ought more properly to be called, the
percha producing a spurious article, belongs to the natural family Sapotece, but differs so
much from all described genera, having alliance with both Achras and Bassia, but differing
in some essentials from both, that I am disposed to think it is entitled to rank as a new
genus. I shall, therefore, endeavour to give its general character, leaving the honour of
naming it to some. more competent botanist, especially as I have not quite satisfied myself
regarding the stamens, from want of specimens for observations,
"The.tree is of a large size, from'60 to 70 -feet in height, and from  2 to 3 feet in
diameter.- Its general appearance -resembles the genus Durio, or well known Doorian,
so much so as to strike the most superficial observer. The under surface of the leaf, however, is of a more reddish and decided brown'than in' the Durio, and the shape is somewhat different.
"It is quite extraordinary how difficult it is to obtain specimens of either the Rower or
the fruit of this tree, and this is probably the reason of its not having been earlier
recognised and described by some of the many botanists who have visited these parts.
"Only a short time ago the tuban tree was tolerably abundant on the island of Singapore; but already all the large timber has been felled, and few, if any, other than small
plants are now to be found. The range of its growth, however, appears to be considerable, it being found all up the Malayan Peninsula, as far as Penang, where I have
ascertained it to be abundant; although, as yet, the inhabitants do not seem to be aware
of the fact, several of the mercantile houses there having sent down orders to Singapore
for supplies of the article, when they have the means of supply close at band. The tree
is also found in Borneo, and, I have little doubt, is to be-found in most of the islands
adjacent.
" The localities it particularly likes are the alluvial tracts along the foot of hills, where
it flourishes luxuriantly, forming, in many spots, the principal portion of the jungle. But,
notwithstanding the indigenous character of the tree, its apparent abundance and widespread diffusion, the gutta will soon become a very scarce article, if some more provident
means be not adopted in its collection than those at present in use by the Malays and
Chinese.
"The mode in which the natives obtain the gatta is by cutting down the trees of full
growth, and ringing the bark at distances of about 12 to 18 inches apart, and placing a
cocoa-nut shell, spathe of a palm  or such like receptacle, under the fallen trunk,
to receive the milky sap that immediately exudes upon every fresh incision.  This
sap is collected in bamboos, taken to their houses, and boiled, in' order to drive off
the watery particles and inspissate it to the consistence it finally assumes. Although




982                              GUTTA PERCHA.
the process of boiling appears necessary when the gutta is collected in large quantities,
if a tree be freshly wounded, a small quantity allowed to exude, and it be collected and
moulded in the hand, it will consolidate perfectly in a few minutes, and have all the
appearance of the prepared article.
" When it is quite pure the colour is of a grayish white; but, as brought to market, it
is more ordinarily found of a reddish hue, arising from chips of bark that fall into the sap
in the act of making the incisions, and which yield their colour to it. Besides these accidental chips there is a great deal of intentional adulteration by sawdust and other
materials. Some specimens I have lately seen brought to market could not have contained much less than i lb. of impurities; and even in the purest specimens I could
obtain for surgical purposes, one pound of the substance yielded on being cleansed one
ounce of impurities; fortunately, it is neither difficult to detect or clean the gutta of
foreign matter, it being only necessary to boil it in water until well softened, roll out the
substance into thin sheets, and then pick out all impurities, which is easily done as the
gutta does not adhere to anything, and all foreign matter is merely entangled in its
fibres, not incorporated in its substance. The quantity of gutta obtained from each tree
varies from 5 to 20 catties, so that, taking the average at 10 catties, which is a tolerably
liberal one, it will require the destruction of ten trees to produce one picul. Now, the
quantity exported from Singapore to Great Britain and the continent, from 1st January
1845 to the present date, amounted to 6,918 piculs, to obtain which 69,180 trees must
have been sacrificed. How much better would it, therefore, be to adopt the method of
tapping the tree, practised by the Burmese in obtaining the caoutchouc from the Ficus
elastica (viz. to make oblique incisions in the bark, placing bamboos to receive the sap
which runs out freely), than to kill the goose in the manner they are at present doing!
True, they would not at first get so much from  a single tree, but the ultimate gain
would be incalculable, particularly as the tree seems to be one of slow  growth; by no
means so rapid as the Ficus elastica.  I should not be surprised, if the demand increases,
and the present method of extermination be persisted in, to find a sudden cessation of the
supply.
Properties of the Gutta.-This substance when fresh and pure is, as already mentioned, of a dirty white colour, and of a greasy feel, with a peculiar leathery smell. It is
not affected by boiling alcohol, but dissolves readily in boiling spirits of turpentine, also
in naphtha and coal-tar. A good cement for luting bottles and other purposes is formed
by boiling together equal parts of gutta and coal-tar and resin.  I am  indebted for this
hint to Mr. Little, surgeon, and the above were his -proportions. I have, however,
found it necessary to put two parts of the gutta, that is, one-half instead of one-third, to
enable the cement to stand the heat of this climate. When required for use, it can
always be made plastic by putting the pot containing it over the fire for a few minutes.
The gutta itself is highly inflammable; a strip cut off takes light, and burns with
a bright flame, emitting sparks, and dropping a black residuum in the manner of sealing wax, which in its combustion it very much resembles. But the great peculiarity
of this substance, and that which makes it so eminently useful for many purposes,
is the effect of boiling water upon it. When immersed for a few  minutes in water
above 1500 Fahr., it becomes soft and plastic, so as to be capable of being moulded
to any required shape or form, which it retains upon cooling. If a strip of it be cut off
and plunged into boiling water, it contracts in size both in length and breadth. This
is a very anomalous and remarkable phenomenon, apparently opposed to all the laws of
heat.
"' It is this plasticity when plunged into boiling water that has allowed of its being
applied to so many useful purposes, and which first induced some Malays to fabricate it
into whips, which were brought into town, and led to its further notice. The natives have
subsequently extended their manufactures to buckets, basins, and jugs, shoes, traces,
vessels for cooling wines, and several other domestic uses; but the number of patents
lately taken out for the manufacture of the article in England, proves how much attention it has already attracted, and how extensively useful it is likely to become. Of all
the purposes, however, to which it may be adapted, none is so valuable as its applicability to the practice of surgery. Here it becomes one of the most useful auxiliaries
to that branch of the healing art which of all is the least conjectural.  Its easy
plasticity and power of retaining any shape given to it when cool, at once pointed
it out as suitable for the manufacture of bougies; and accordingly my predecessor,
Dr. W. Montgomerie, availed himself of this, made several of the above instruments, and
recommended the use of it to the Bengal Medical Board. But, like many other good
hints, for want of sufficient inquiry, I fear it was disregarded. The practice, however, has been continued by me, and I find many advantages in the use of this substance. It also answers very well for the tubes of syringes, which are always getting
out of order in this country, when made of caoutchouc. But my late experiments have
given it a much higher value, and proved it the best and easiest application ever yet




GUTTA PERCHA.                                            983
discovered in the management of fractures, combining ease and comfort to the patient,
and very much lessening the trouble of the surgeon.  When I think of the farrago of
bandages and splints got rid of, the lightness and simplicity of the application, the gutta
would be no trifling boon to mankind, were it to be used splely for this and no other purpose. The injuries coming under my observation, wherein I have tested its utility, have,
as yet, only been two compound fractures of the leg, and one of the jaw; but so admirably has it not only answered, but exceeded my expectations, that I should think myself
culpable in not giving the facts early publicity.  Its utility in fracture of the lower jaw
must at once strike any surgeon.  So well does it mould itself to every sinuosity, that it
is more like giving the patient a new bone than a mere support.  A man lately brought
into hospital, who had his lower jaw broken by the kick of a horse, and which was so
severe as to cause haemorrhage from the ears, smashing the bone into several fragments,
was able to eat and speak three days after the accident, and felt so well with his gutta
splint that he insisted on leaving the hospital within ten days. My mode of applying
this substance to fractures of the leg is as follows:"- The gutta having been previously rolled out into sheets of convenient size, and about
one-fourth of an inch in thickness, is thus kept ready for use. When required, a piece of
the necessary length and breadth is plunged into a tub of boiling water. The limb of
the patient is then gently raised by assistance, making extension in the usual manner.
The surgeon, having ascertained that the broken bone is in its place, takes the sheet of
gutta out of the hot water, and allows it to cool for a couple of minutes.  It is still soft
and pliable as wash leather.  Place it whilst in this state under the limb, and gently
lower the latter down on it. The gutta is then to be brought round and moulded carefully to the whole of the back and sides of the leg, bringing the edges close together, but
not uniting them.  If there be any superfluous substance, it can be cut off with scissors,
leaving an open slit down the front of the leg. You have now the leg in a comfortable,
soft, and smooth case, which in ten minutes will be stiff enough to retain any shape the
surgeon may have given it, and which will also retain the bone in situ.  Place the leg
so done up on a double incline plane, and secure it thereto by passing three of the
common loop bandages around the whole; that is, one at the top, one in the middle,
and one at the lower end.  Let the foot be supported by a foot-board, and a case of
gutta put over the dorsum, of the foot, to bear off the pressure of the small bands
generally used to secure it to the board.  Having done this, the surgeon need not cause
the patient another twinge of pain until he thinks he can use the leg, or he deems
the bone sufficiently united to bear the weight of his patient. If it be a compound
fracture, it will be only necessary to untie the loop bandages, separate the edges of the
gutta splint to the required distance, wash and cleanse the limb without shifting anything except the dressings, and, having done so, shut it up again. The most perfect
cleanliness can be maintained, as the gutta is not affected by any amount of ablution;
neither is it soiled -or rendered offensive by any discharge, all which washes off as easily
from the gutta case as from  oil-cloth.  I have had a patient where the tibia protruded
through the integuments fully two inches, walking about in six weeks from the injury,
with a leg as straight and well formed as ever it had been. It is quite obvious, therefore, that if it answers so well for compound, it will answer equally, if not better, for
simple fractures; and that any broken bone capable of receiving mechanical support can
be supported by the gutta better than by any other contrivance; for it combines lightness, and smoothness, and durability, and a capability of adjustment not possessed by
any other known substance.  All new  experiments have to run the gauntlet of opposition; and I do not suppose that these recommendations will prove any exception to the
rule; but all I ask of any surgeon is, to try thre experiment ere he argues on its propriety, and I feel fully convinced that all other splints and bandages will be consigned
to the tomb of the Capulets. There are some other uses for which I have tried this substance, viz., as capsules for transmission of the vaccine virus, which ought to keep well
when thus protected, for it is most perfectly and hermetically sealed; but I have not
had sufficient experience in this mode of using it to pronounce decidedly on its merits.
I am at present trying the effects of it on ulcers, by enclosing the ulcerated limb in a
case of gutta, so as to exclude all atmospheric air; and so far, the experiment promises
success.
" Since writing the foregoing observations, I have had an official intimation from
Penang, of the vaccine virus transmitted in the gutta capsules having been received in
good order, and of its having succeeded satisfactorily. I have also opened a capsule
containing a vaccine crust that bad been kept here for one month, and it also seems to
have lost none of its efficacy, as the case inoculated has taken. This will appear the
more striking when it is recollected that, to preserve the vaccine virus hitherto in
Singapore, even for a few days, has been almost impossible; that this settlement, notwithstanding every exertion on the part of both private and public practitioners, has
been without the benefit of this important prophylactic for an interval sometimes of two




984                              GUTTA PERCHA.
years; and that, at all times, the obtaining and transmitting this desirable remedy has
been a cause of trouble and difficulty to all the medical officers I have ever met with in
the Straits."-Mr. T. Oxley, Surgeon, Prince of Wales Island and Malacca.
I observed in the Mechanics' Magazine for March, 1847, a notice of several patents
taken out for the working of the article by Mr. Charles Hancock, in which an elaborate
process is described for cleaning the gutta, as also mention of its havinga disagreeable
acid smell. The gutta, when pure, is certainly slightly acid, that is, it will cause a very
slight effervescence when put into a solution of soda, but is unaffected by liquor potasse.
The smell, although peculiar, is neither strong nor unpleasant, so that the article experimented upon must have been exceedingly impure, and possibly derived a large portion
of its acidity from  the admixture and fermentation of other vegetable substances.
Again; it appears to me that, if the gutta be pure, the very elaborate process described
as being necessary for cleaning it, is superfluous. The gutta can be obtained here in a
perfectly pure state by simply boiling it in hot water until well softened, and then
rolled out into thin sheets, when, as I have before said, all foreign matter can be easily
removed. I would recommend that the manufacturers at home should offer a higher
price for the article if previously strained through cloth at the time of being collected,
when they will receive the gutta in a state that will save them a vast deal more in
trouble and expense than the trifling addition necessary to the original prime cost."
Mr. Oxley.
In February, 1847, Mr. Charles Hancock obtained a patent for improvements in the
manufacture of gutta percha, consisting, in the first place, in the construction of a slicing
machine, consisting of a circular iron plate, formed with three radial slots, in which
knives are fixed in a similar manner to the irons of an ordinary plane or spoke shave
the shaft which carries the plate is caused to rotate by steam or other power. The
lumps of gutta percha drop against the knives, a plate by which they are cut into slices,
of a degree of thickness corresponding to the projection given to the knives. These slices
are then soaked in a vessel of hot water till they become pliable. Instead of a circular
revolving cutter, a vertical cutter or chopper may be used; curved knives may be had
recourse to for refractory lumps. The softened slices are next subjected to the action of
breakers or rollers with serrated blades, which are mounted transversely over the tank.
In front of each breaker there is a pair of fluted feeding rollers; and the pieces of gutta
percha are passed to the rollers of the first breaker. There is an incline endless web
mounted upon two rollers, the front one of which is immersed in the water, and the
other is situated opposite the space between the feeding rollers of the second breaker.
There is a second inclined web placed before the third breaker. There is also a mincing
cylinder with radial blades working partly in the water. The feeding-rollers, and the
carrying-rollers of the endless webs, are made to revolve in a forward direction, while the
breakers, the mincing cylinder, and the agitator, are made to revolve in the opposite
direction. The breakers and mincing cylinder should revolve at the rate of from 600 to
800 revolutions per minute, but the feeding rollers and endless webs need not move
faster than about one-sixth of that rate. Thus, the substance is reduced to small fragments and washed in the water, the heavy impurities falling to the bottotri of the tanks,
and the lighter and purer matter floating. The water should be used cold. When the
gutta perchia has a fetid smell, it is treated with carbonate of soda or chloride of lime.
The said apparatus may be used also for purifying caoutchouc and jintawan;
Mr. Hancock now considers the use of sulphur to be altogether objectionable by itself
on account of its offensive smell and efflorescing property as a means of vulcanizing
caoutchouc. He has found that if a minute portion of sulphur be used along with a
sulphuret the best result is obtained; the proper proportions being 6 parts of sulphuret
of antimony, or hydrosulphuret of lime, and I part of sulphur to 48 parts of gutta percha
or caoutchouc. When these materials have been mixed, the compound is put into a
boiler and heated under pressure to a temperature of from 2600 to 3000 F. and is to be
left in this state for a period varying from half an hour to two hours, according to the
thickness of the materials. He prefers for effecting the union of the sulphurous constituent the following method to the masticating machine. 1st. He subjects the purified
gutta percha to the conjoined action of steam and the fumes of orpiment and sulphur
mixed in the proportions stated, in a metal chamber, provided with a steam-tight cover
secured by screw-bolts. There is also a steam boiler connected therewith, and when the
heat in it is raised to about 2800 Fahr., a fire is lighted beneath the pot containing the
sulphuring materials. But the gutta percha, &c. should be heated with the steam before
it is sulphured. In from half an hour to two hours the sulphuring is finished. Or, the
gutta percha may be rubbed strongly over with the sulphurous mixture and then
heated, either dry or with the aid of steam, or coated in the form of a paste along with
gutta percha.
Another of Mr. Hancock's inventions is to expose the gutta percha to the deutoxide
of azote. or chloride of zinc, concentrated and boiling hot, and then washed with an




UTTA. PERCHA.                                         985
alkaline solution or mere water. Gutta percha thus treated by the action of nitrous gas,
as it is evolved from nitric acid and copper, iron, or zinc, becomes exceedingly smooth,
and of a lustre approaching to metallic; so also does common unsulphured caoutchouc.
It is thus also freed from  all stickiness; while the sulphured acquires under this
treatment the d/wny softness of velvet. Chloride of zinc and nitrous gas remove
the smell of vulcanized caoutchouc in a great measure, especially if it be afterwards
washed.
Other new inventions are practised by masticating either gutta percha, caoutchouc, or
jintawan, in the proportion of 6 parts with 1 of chloride of zinc; all which compounds
may be afterwards sulphured.  A further modification consists in producing a spongy
gutta percha, caoutchouc, or jintawan, for stuffing sofas, &c. 48 parts of one of these,
moistened with oil of turpentine, coal naphtha, bisulphuret of carbon, or other proper
solvent, 6 parts of hydrosulphuret of lime, sulphuret of antimony, or other analogous
sulphuret, 10 parts of carbonate of ammonia, carbonate of lime, or other substance that
is either volatile or capable of yielding a volatile product, and 1 part of sulphur. He
mixes these materials together in a masticator, and then subjects them to a high degree
of heat, observing the same conditions which are stated in the former description, except
only that the heat may be pushed with advantage several degrees higher, say from 260~
to 3000 Fahr.. Articles are manufactured of ordinary gutta percha, caoutchouc, or jintawan, such as
single and double texture waterproof fabrics, boots, galoshes, belts, bandages, trousers'
and other straps, capes, life-preservers, tubes, knapsacks, caps, cups, and other vessels of
capacity, hammer cloths, cotton spinning rollers, backs of cards for carding wool, pianoforte hammers, paper holders, springs, trusses, &c. By taking the gutta percha, caoutchouc, or jintawan, after it has been sulphured, and brushing it with a solution of resin
in boiling oil (linseed), placing it in a chamber heated to from 15~ to 1000 Fahr., and
afterwards polishing it by the means usually employed by the japanners, it acquires the
lustre of japanned wares.
Mr. Hancock has also contrived a machine for cutting gutta percha into strips or ribands,
thread', or cord of any required shape. It consists of two grooved rollers of iron or
steel, mounted in a suitable framework. The grooves of each roller are semicircular,
and the projecting divisions between the grooves are made with knife edges, so as to
divide readily any sheet or mass of gutta percha presented to them. The under roller
is flanged at both ends, and the upper roller is'made to fit inside of these flanges, in
order to keep the cutting edges from shifting or being damaged. To cut thin sheets of
gutta percha with this machine into strips or ribands, the material is passed through it ia
a cold state, and only the cutting edges are brought into operation. To make round cord
or thread by means of it, either a sheet of gutta percha of a thickness equal to the
diameter of the holes formed by the grooves, and at a temperature of 2000 Fahr. (produced by supplying it from a feeding-chamber heated to that degree) is passed through
the machine, and the threads or cords are received in a tank of cold water, from which
they are led away to be wound on reels or drums; or the gutta percha is employed in a
plastic state, and passed under a gauge before it enters the machine. If it be desired to
produce a cord of a semicircular form in the transverse section, a plane roller is substituted for the lower grooved roller; or should cord of a square, triangular, or hexangular,
or any other form be required, the two rollers must be shaped to suit.-Newton's Journal,
xxxv. 96.
Gutta Perefha Letters. Gutta Pereha has been patented for making letters for shop
signs by Mr. Moore, Barrister.
Gutta Percha Tubes; strength of.  A series of interesting experiments have just been
concluded at the Birmingham Waterworks, relative to the strength of Gutta Percha
Tubing, with a view to its applicability for the conveyance of water. The experiments
were made (under the direction of Henry Rofe, Esq., engineer,) upon tube I of an inch
diameter, and one eighth of gutta percha. These were attaced to the iron main, and
subjected for two months to a pressure of 200 feet head of water, without being in the
slightest degree deteriorated. In order to ascertain if possible the maximum strength of
the tubes, they were connected with the Water Company's hydraulic proving pump, the
regular load of which is 250 lbs. on the square inch. At this point the tubes were unaffected, and the pump was worked up to.337 lbs., but to the astonishment of every one
the tubes still remained perfect. It was then proposed to work the pump up to 500 lbs.,
but it was found that the lever of the valve would not bear this weight. The utmost
power of the hydraulic pump could not break the tubes.
The gutta percha being somewhat elastic, allowed the tubes to become slightly expanded by the extraordinary pressure which was applied, but on its withdrawal they resumed their former size.
Gutta Pereha Tubing.  This tubing is such an extraordinary conductor of sound, that
its value, nwotonly to deaf persons, but to the public generally, will speedily be appre



986                               GUTTA PERCHA.
ciated. It has already been fitted up in dwelling houses, in lieu of bells;-as speaking
tubes for giving and receiving messages in mines, railway stations, prisons, workhouses,
hotels, and all large establishments, it is invaluable.
GUTTA PERCiHA-its Properties, Analysis, Elementary Composition and Applications,
by M. Payen.  Without possessing any exact information regarding the extraction of the
substance which comes to us from  the Eastern Archipelago under the name of gutta
perclha, we know that this substance is contained in the descending sap of the Isonandra
Gntta, Hooker, belonging to the natural order Sapotacece. This tree attains a great size,
being sometimes as much as a yard in diameter, and 60 or 70 feet in height; its soft and
fibrous wood is useless for industrial purposes; its fruit furnishes a fatty oil.
It is said that a tree, when cut down, will yield 18 kilogrammes of gutta percha or
solid gum. The juices, dried in thin strata laid one upon another, form irregular masses
of greater or less thickness, of a reddish or grayish colour, of which a gradually increasing
quantity has been annually imported into Europe and America since 1845.
During many years the natives of the countries where it is produced have employed it
almost solely in the formation of handles for axes, which possess when cold a certain
degree of flexibility with great toughness. At present, the gutta percha is purified by
rasping it in cold water, which removes the greater part of the soluble organic matter and
salts, and also facilitates the separation of any portions of wood or earthy matters. The
purification is completed by means of warm water in several basins; the gutta percha is
afterwards dried, and formed into a pasty mass by heating it to about 230' F. in a vessel
with a steam jacket.
The gutta percha thus prepared becomes sufficiently soft to be readily joined, stretched
out into sheets or straps of any thickness, drawn into tubes of various diameters, and
moulded into any form, whilst, on being slowly cooled, it acquires great tenacity and
solidity. It is necessary, however, to remark, that the presence of a small quantity of
water is sufficient to prevent the adhesion of its parts.
Properties of common Gutta Percha.-The gutta percha thus purified for manufacturing purposes, is of a reddish-brown colour; it readily becomes electrical by friction and is
a bad conductor of both electricity and heat. At the ordinary temperature of our climate,
say from 320 to 77~, it possesses about as much tenacity as thick leather, with rather less
flexibility; it softens and becomes sensibly doughy towards 1200, although still very
tough. Its ductility is such, at a temperature of from 110~ to 241~, that it is readily
extended into thin sheets, or drawn into threads or tubes; its flexibility and ductility
diminish as the temperature becomes lower. It does not possess at any temperature the
peculiar elastic extensibility which characterizes caoutchouc. Exposed for an hour to a
temperature of 140, its flexibility is slightly diminished.
In its various forms, gutta percha possesses a peculiar porosity, as may be shown in
the following manner:-A drop of its solution in sulphuret of carbon is to be placed on
a glass slip; the spontaneous evaporation soon reduces this solution to a whitish plate;
if it be then examined with the microscope, the numerous cavities with which it is pierced
may be distinctly perceived.  These cavities may be rendered still more visible by means
of a drop of water; the liquid gradually insinuates itself, the mass appears more opake,
and by means of the microscope the cavities are seen to be enlarged.
Similar results are obtained by keeping immersed in water for a considerable time
thin transparent laminae, obtained by the evaporation by heat of a solution of gutta
percha.
The preceding observations led me to think, that this substance retaining, in consequence of its porosity, a great many minute particles of air, owed to this circumstance its
appearance of possessing a less density than that of water, namely 0-979.  In fact, on
stretching gutta percha under strong pressure, and immediately cutting the strips thus
produced into very small pieces under water, the greater part of the fragments fell to the
bottom  of the vessel-some immediately, others after absorbing a certain quantity of
water. The same result was also obtained by keeping very thin leaves of gutta percha,
prepared by different methods, immersed for a month in water deprived of air; their pores
becoming gradually filled with the liquid, they became heavier than the water, and then
ceased to float. Gutta percha is also heavier in proportion to the length of time it has
been exposed to the air, particularly in thin leaves.
The porous structure of gutta percha becomes changed into a fibrous texture when it is
drawn out so as to double its length; then retaining but little extensibility, it supports,
without breaking, the action of a force equal to double that required for its elongation in
the first instance.
Common gutta percha resists cold water, damp, and also the various influences which
excite fermentation; but it can be softened, and experience a sort of superficial doughy
fusion by the action of the solar rays in summer.
It is not attacked by alkaline solutions, even when caustic and concentrated; ammonia, saline solutions, water containing carbonic acid, the various vegetable and




GUTTA PERCHA.                                             987
mineral acids, do not act upon it; alcoholic liquors (wines, beer, &c.) do not touch it;
even brandy scarcely dissolves a trace of it. Olive-oil does not appear to attack gutta
percha when cold; when hot, it dissolves a small portion of it, which is again precipitated on cooling.
Sulphuric acid with one equiv. of water colours it brown, and disintegrates it with a
sensible evolution of sulphurous acid.
Muriatic acid, in its saturated solution in water at a temperature of 680 F., attacks
gutta percha slowly, and gives it a more or less deep brown colour, at length rendering
it brittle.
Monolhydrated nitric acid attacks it rapidly, with effervescence and an abundant evolution of fumes of hyponitrous acid; the substance is decomposed, and coloured of a
browvnishorange red; it becomes doughy, and afterwards solidifies by degrees and remains friable.
In the cold, and even by heat, only a part of the gutta percha (0'15 to 0-22) is dissolved by anhydrous alcohol or ether.   Benzine and  spirits of turpentine dissolve it
partially when cold, but nearly completely by heat. Sulphuret of carbon and chloroform
dissolve gutta percha when cold; the solutions may be' filtered beneath a bellglass to
prevent evaporation; the filter retains the foreign matters of a reddish-brown colour,
whilst the solution passes perfectly clear and almost colourless. The filtered liquid,
exposed to the air in a saucer, allows the solvent to escape, and deposits the white gutta
percha in a plate of greater or less thickness, which shrinks gradually in proportion to
the evaporation of the liquid.
Except the colour, which has disappeared, the gutta percha offers then the characters
and properties mentioned above as belonging to the commercial substance. Submitted
to a gradually-raised temperature, it softens and melts, and may be made to boil without acquiring a sensible colour; the transparent fluid gives abundant vapours which are
condensable into a nearly colourless oily liquid.  The portions last distilled have a
brownish-orange colour, and a thin layer of carbonaceous deposit remains adherent to
the sides of the vessel..Analysis.-We have said above that alcohol and ether can dissolve only a portion of
gutta percha; this is because that substance consists, in fact, of three proximate principles, the separation of which has required very delicate observation, although they are
very clearly distinguished by several of their properties.*
When  gutta perca i  thin leaves is brought into contact, in a close vessel,   with
15 to 20 vols. of cold anhydrous alcohol, and the temperature raised slowly by means of
the water-bath to the point of ebullition (1120 F.), and kept at this point during several hours, the liquid, if filtered whilst boiling and left in a closed flask, will, at the
end of from 12 to 36 hours, begin to deposit on the sides of the vessel and on the surface
of the solution whii9 opaline granules, distant from one another, but some of them in
groups.; their sip Iwill gradually increase for some days. These granules, carefully
examined under tih. microscope, will be found to have the form of spherules truncated
by the sides of theivessel. Their surface is either smooth or bristling, with very small
transparent, elongated, lamellar crystals. Some superficial fissures appear to indicate
that these spherules are formed of a sort of transparent yellow kernel covered with a
white pellicle.
Such is really their singular crystalline structure, of which perhaps no other example
is known.  In fact, cold anhydrous alcohol dissolves the whole of the yellow, subjacent
spheroidal substance, while the superficial pellicle, in the interior of which the alcohol
has substituted itself for the solid globule, appear whiter and less transparent.
The alcoholic solution which has been for some days depositing this complex spheroidal crystallization, can again take up by heat a portion of the two proximate principles remaining in the substance, allowing a fresh quantity to crystallize on cooling.
The extraction is completed by returning the boiling alcohol several times upon the
gutta percha until it no longer dissolves anything.
The solid substance which has resisted the action of the solvent, possesses, with some
modifications, the principal properties of crude gutta percha; we shall here call it purgutta or gutta.  As to the two other organic principles, one is a yellow resin, which is
much more soluble in cold alcohol than the other, the white crystalline resin.
By taking advantage of these different degrees of solubility, we are enabled, with time
and patience, to effect the complete purification of these three principles. The separation may also be effected by treating finely-divided gutta percha with cold ether, which
dissolves the mixture of the two resins more abundantly than alcohol; they are afterwards separated from one another by the same treatment already described for alcohol.
The tendency of the white resin to form itself into groups of radiated lamelle is manifested in a rather remarkable circumstance, which it is easy to reproduce. Narrow
* The author appears to be unacquainted with the researches of M. Arppe on this subject. See Chem.
Gaz. vol. ix. p. 471.




988                               GUTTA PERCHA.
ribbons cut from a thin leaf of ordinary gutta percha are to be placed in a tube, and
immersed in anhydrous alcohol. The tube is then closed, and left for twenty or thirty
days, when a few whitish points appear here and there on the ribbons, and afterwards on
the sides of the tube. These points, which become gradually larger, are formed of crystalline tufts of the white resin. Thus this proximate principle is separated directly, and
in the cold, even when the atmospheric temperature is gradually rising, for instance
during the spring or early summer.
The crystalline white resin, when completely purified by washings with alcohol, and
then redissolved in anhydrous alcohol, is deposited by slow spontaneous evaporation in
the air, in radiated lamellar crystals, forming sometimes symmetrical tufts arranged in
stars, and then presenting the appearance of a sort of efflorescence.
Distinctive Characters and Properties of the Three Proximate Principles which constitute common Gutta Percha.-The most abundant of these three principles, forming at
least from 75 to 82 per cent. of the whole mass, is the pure gutta, which presents the
principal properties of the commercial substance; it is white, transparent at a temperature of 212~ F., when all its parts are melted together; opake or semitransparent when
cold, from its then acquiring a structure which causes the interposition of air, or of a
liquid possessing a different refraction from its own. This structure appears still more
distinct than in the natural substance containing all three principles.
In thin sheets, and at a temperature of 50~ to 680 F. it is supple, tough, extensible but
not very elastic. At 112~ F., it softens and turns back upon itself, and becomes more and
more adhesive and translucent in proportion to the elevation of temperature, undergoing
a sort of doughy fusion, which becomes more distinct towards 2120 to 2300. Heated
beyond this point, it melts, boils and distils, furnishing a pyrogenous oil and carburetted
gases.
Pure gutta, like the other two proximate principles, is quickly rendered electrical by
friction, and is.a bad conductor of heat; it generally floats on water but sinks to the
bottom as soon as its pores are filled with this liquid. It is insoluble in alcohol and
ether, almost completely insoluble in benzine at 320 F., it is soluble at 70, and becomes
more and more so in proportion as the temperature is raised. The saturated solution at
86~ forms itself into a semi-transparent mass when cooled below 320; alcohol precipitates
the gutta from its solution in benzine.
At 32~, spirits of turpentine dissolves very like gutta, whilst it disintegrates and dissolves it readily when hot.
Chloroform and sulphuret of carbon dissolve the gutta in the cold.
After the extraction by means of ether of the two resins interposed in the thin leaves
of white gutta percha, leaving the last portion of ether with which they were impregnated
to evaporate in the open air, these leaves, enclosed in a flask, experienced, after remaining there for two months at a temperature of from 68~ to 820 F., an alteration which
appeared to depend on their porosity, the action of the air, and perhaps the ether
retained in their pores. However it be, these leaves had then acquired new properties;
they were brittle;' exhaled a very distinct sharp odour; brought into contact with an
excess of anhydrous ether, they were partially dissolved; the soluble portion, obtained
by the evaporation of the ether and desiccation at 1940 F., was glutinous and translucent;
it became opake and hard by cooling down to 140 F.
Sulphuret of carbon' renewed three times in six days, and evaporated each time after
two days' contact, left as residue a white flexible leaf. The portion not dissolved, swelled
and transparent, did not appear to undergo any change when left in sulphuretd of carbon
for ten days.
This kind of spontaneous transformation would perhaps become complete if more
prolonged; its study will require much time; it will perhaps put us in the way of ascertaining the causes of certain changes observed in some small objects formed of gutta
percha. I have already been able to ascertain, that thin leaves, exposed for eight consecutive days to the action of the sun in moist air, were discoloured, and that their substance had become in great part' soluble in ether.
Monohydrated sulphuric acid disintegrates, and communicates a brown colour to the
pure gutta, with evolution of sulphurous acid; after eight days' contact, the deep brown
liquid, on dilution with water, becomes turbid, and furnishes a brown flocculent precipitate. Nitric acid, with a single equivalent of water, attacks the pure gutta with a lively
effervescence, and the evolution of orange vapours of hyponitrous acid. Muriatic acid, in
its saturated solution, slowly attacks the thin leaves of gutta, giving them a deep brown
colour; at the end of eight days it becomes friable. The reaction of muriatic acid establishes an additional distinctive character between this proximate principle and the two
others.
Crystalline White Resin.-Obtained pure by means of the operations above described;
it presents itself as a light pulverulent mass, apparently opake, which  under the
microscope exhibits the transparent lamellar crystals. From 320 to 2120 F. it does not




GYPSUM.                                          989
experience any sensible change; its fusion commences at 3200; at 347  to 3560 it
acquires an oleiform fluidity and complete transparency, without any noticeable colour;
it solidifies on cooling, shrinks, which causes it to split, and remains transparent and a
little heavier than water.
The crystallized resin is very soluble in spirits of turpentine, in benzine, sulphuret of
carbon, ether and chloroform; on the spontaneous evaporation of the two last solvents,
it crystallizes in long, narrow, thin, pearly laminae, forming separate groups radiating
from common centres.
Anhydrous alcohol dissolves it pretty readily at the temperature of 160 F.: on
cooling, groups of crystals separate, which increase during several days; the cold solution, decanted after crystallization, and left to spontaneous evaporation, yields similar
crops of more voluminous lamellae.
These crystals are not attacked or readily moistened by either cold or boiling water,
as is also the case with hot or cold caustic alkaline solutions, ammonia, and the various'dilute acids.  Monohydrated sulphuric and nitric acids attack  it rapidly, producing
similar phenomena to those observed in their action upon pure gutta. Muriatic acid,
on the contrary, does not act upon the white resin; in several of these characters it approaches to the breane extracted by M. Scribe from  the resin of Icica.*  It would be
well to submit these two principles to a comparative study.
Yellow Resin,-This amorphous transparent resin of a lemon or orange colour according to its thickness, is a little heavier than water, solid, and even hard and brittle, at
320.F.;it gradually becomes more flexible in proportion as the temperature is raised;
at 122  F. it becomes pasty; it does not become completely fluid below 2120 to 2300.
Heated beyond this point, it boils, but then gradually undergoes considerable alteration,
becomes brown, and evolves acid fumes and carburets of hydrogen.
This resin strongly retains the alcohol in which it has been dissolved; it is separated
from it by beating in vacuo to 212~ F. until bubbling entirely ceases.
It is soluble in the cold in alcohol, ether, benzine, essential oil or turpentine, sulphuret of carbon and chloroform; all these liquids, when evaporated, leave as residue
the amorphous resin.
Dilute acids, concentrated alkaline solutions, and ammonia do not attack the yellow
resin. Monobydrated sulphuric and nitric acids act upon it rapidly, producing phenomena analogous to those exhibited with the other two principles.  Muriatic acid, even
in its saturated solution at 68^  F., is without action upon it.  But the most remarkable
character of this resin is the power of forming, under the circumstances already indicated, those globose crystals covered with a white pellicle of another resin, and offering
in their complex form the appearance of opaline spherules.
We see thus that the gutta pereha, as it occurs in commerce, consists of three distinctly
characterized proximate principles, besides some other matters in small quantities; the
most abundant of these principles possesses the properties of the original substance; I
give it the name of pure gutta or gutta; the two other principles are neutral resins.
In order to recal their characteristic properties, I will give the name of crystalhane or
albane to that which is obtained without.difficulty in white crystals; and that offluavile
to the third, which is yellow, and becomes sensibly fluid at a low temperature.
The commercial varieties which I have examined have given me the following proGutta         -       -       -       -  15         82
Albane        -       -       -        -  16        14
Fluavile      -.                       -   6         4
GYPSUM, Sulphate of Lime, Alabaster, or Paris Plaster.  This substance is found
in three geological positions in the crust of the.earth; among transition rocks; in the
red marl formation.; and above the chalk, in the tertiary beds..
1. The alpine gypsums are ranged by M. Brochant among the transition class, and
are characterized by the presence of anthracite or stone coal; some of them are white
and pure, others gray or yellowish, and mixed with mica, talc, steatite, black oxide of
iron, pyrites, compact carbonate of lime, sulphur, and common salt. Examples of such
localities are found in the gypsum of Vat-6Canaria at the foot of Saint Gothard, that of
Brigg in the upper Valais; of the Grilla in the valley of Chamouni, and of Saint Gervais-les-Bains, near Sallenches in Savoy.
2. The secondary gypsum, or that of the salt mine districts, belongs to the red ground,
immediately beneath the lias in the order of stratification, and therefore a rock relatively
ancient. Near Northwick, the red marl beds above the great deposit of rock salt, are
irregularly intersected with gypsum, in numerous laminae or plates. At Newbiggin in
Cumberland, the gypsum lies in red argillaceous marl, between two strata of sandstone;
and a mile south of Whitehaven, the subterraneous workings, for the alabaster extend
* Chem. Gaz. vol. iv. p. 151.




990                                       GYPSUM.
S0 yards in a direct line; with two or three lateral branches extending about 10 yards,
at whose extremities are large spaces where the gypsum is blasted with gunpowder. It
is generally compact, forming a regular and conformable bed, with crystals of selenite
(crystallized gypsum) in drusy cavities. Gypsum occuls in the red marl in the isle of
Axholme, and various other places in Nottinghamshire.  In Derbyshire some considerable deposits have been found in the same red sandstone, several of which are mined,
as at Chellaston hill, which would exhibit a naked and water-worn rock of gypsum,
were it not for a covering of alluvial clay.  It appears in  general to present itself
chiefly in particular patches, occasioning a sudden rise, or an insulated hill, by the
additional thickness which it gives to the stratum of the red ground in these places.
The principal demand for the pure white gypsum, or that faintly streaked with red, is by
the potters in Staffordshire, who form their moulds with the calcined powder which it
affords; only particularly fine blocks are selected for making alabaster ornaments on
the turning lathe. In one of the salt pits near Droitwich, the strata sunk through were
vegetable mould, 3 feet; red marl, 35 feet; gypsum, 40 feet; a river of brine, 22 inches;
gypsum, 75 feet; a rock of salt, bored into only five, but probably extending much
deeper.  On the Welsh side of the Bristol Channel, gypsum  occurs in the red marl
cliffs of Glamorganshire, from Pennarth to Lavernock. No organic remains or metallic
minerals have hitherto been found in the gypsum of this formation.
3. The most interesting gypsums in a general point of view, are certainlythe tertiary,
or those of the plains, or hills of comparatively modern formation. They are characterized
by the presence of fossil bones of extinct animals, both mammifera and birds, by shells,
and a large proportion of carbonate of lime, which gives them the property of effervescing with acids, and the title of limestone gypsums. Such are the gypsums of the
environs of Paris, as at the heights of Montmartre, which contain crystallized sulphate
of lime in many forms, but most commonly the lenticular and lance-shaped.
Sulphate of lime occurs either as a dense compound without water, and is called
anhydrite from that circumstance; or with combined water, which is its most ordinary
state. Of the latter there are 6 sub-species; sparry gypsum or selenite in a variety of
crystalline forms; the foliated granular; the compact; the fibrous; the scaly foliated;
the earthy.
The prevailing colour is white, with various shades of gray, blue, red, and yellow.
More  or les's translucent.  Soft, sectile, yielding  to  the nail.  Specific gravity 22.
Water dissolves about one five-hundredth part of its weight of gypsum, and acquires
the quality of hardness, with the characteristic selenitic taste. When exposed on red
hot coals, it decrepitates, becomes white, and splits into a great many brittle plates. At
the heat of a baker's oven, or about 4000 Fahr., the combined water of gypsum  escapes with a species of ebullition; at a higher temperature the particles get indurated.
When rightly calcined and pulverized, gypsum  is mixed with water to the consistence
of cream, and  poured  into moulds by  the manufacturers of stucco ornaments and
statues. A species of rapid crystallization ensues, and the thin paste soon acquires a
solid consistence, which is increased by drying the figure in proper stoves.  During
the consolidation of the plaster, its volume expands into the finest lines of the mould,
so as to give a sharp and faithful impression.
The plaster stone of the Paris basin contains about 12 per cent. of carbonate of lime.
This body, ground and mixed with water, forms an adhesive mortar much  used  in
building, as it fixes very speedily. Works executed with pure gypsum never become so
hard as those made with the calcareous kind: and hence it might be proper to add a
certain portion of white slaked lime to our calcined gypsum, in order to give the stucco
this valuable property. Coloured stuccos of great solidity are made by adding to a
clear solution of glue, any desired colouring tincture, and mixing in the proper quantity of the calcined calcareous gypsum.
The compact, fine-grained gypseous alabaster is often cut into various ornamental
figures, such as vases, statuary groups, &c., which take a high polish and look beautiful, but
from their softness are easily injured, and require to be kept enclosed within a glass shade.
In America and France, the virtues of gypsum in fertilizing land have been highly
extolled, but they have not been realized in the trials made in this kingdom.
Pure gypsum  consists of lime 28; sulphuric acid 40; water 18; which are the respective weights of its prime equivalent parts.
M. Gay Lussac, in a short notice, in the Annales de Chimie for April 1829, on the
setting of gypsum, says that the purest plasters are those that harden least, and that the
addition of lime is of no use towards promoting their solidity, nor can the heat proper
for boiling gypsum  ever expel the carbonic acid  gas from  the  calcareous carbonate
present in the gypsum of Montmartre. He conceives that a hard plaster-stone having
lost its water, will resume more solidity in returning to its first state, than a plaster.
stone naturally tender or soft; and that it is the primitive molecular arrangement which
is regenerated. See ALABASTER, and STONE ARTIFICIAL.




HAD.                                      991
H.
HADE signifies, among English miners, the inclination, or deviation from the vertical
of any mineral vein.
HAIR (Cheveu, Crin, Fr.; Haar, Germ.) is of all animal products, the one least
liable to spontaneous change. It can be dissolved in water only at a temperature somewhat above 230~ F., in a Papin's digester, but it appears to be partially decomposed by
this heat, since some sulphureted hydrogen is disengaged. By dry distillation, hair gives
off several sulphureted gases, while the residuum contains sulphate of lime, common
salt, much silica, with some oxyde of iron and manganese. It is a remarkable fact that
fair hair affords magnesia, instead of these latter two oxydes. Horse-hair yields about 12
per cent. of phosphate of lime.
Hairs are tubular, their cavities being filled with a fat oil, having the same color with
themselves. Hair plunged in chlorine gas, is immediately decomposed and converted into
a viscid mass; but when immersed in weak aqueous chlorine, it undergoes no change,
except a little bleaching. The application of nitrate of mercury to hairy skins in the
process of secretage, is explained under PELTRY.
For the dyeing of horse-hair, see the next article.
Living hairs are rendered black by applying to them, for a short time, a paste made by
mixing litharge, slaked lime, and bicarbonate of potash, in various proportions, according
to the shade of color desired.
We have no recent analysis of hair. Vauquelin found nine different substances in black
hair; in red hair, a red oil instead of a greenish-black one.
The salts of mercury, lead, bismuth, as well as their oxydes, blacken hair, or make it
of a dark violet, by the formation, most probably, of metallic sulphurets.
Hair as an object of manufactures is of two kinds, the curly and the straight. The
former, which is short, is spun into a cord, and boiled in this state, to give it the tortuous
springy form. The long straight hair is woven into cloth for sieves, and also for ornamental purposes, as in the damask-hair cloth of chair bottoms. For this purpose the hair
may be dyed in the following way.
Forty pounds of tail hair about 26 inches long are steeped in lime water during twelve
hours. Then a bath is made with a decoction of 20 pounds of logwood, kept boiling for
three hours, after which time the fire is withdrawn from the boiler, and ten ounces of
copperas are introduced, stirred about, and the hair is immersed, having been washed from
the lime in river water. The hair should remain in this cooling bath for 24 hours, when
the operation will be finished. For other colors, see the respective dyes.
The looms for weaving hair differ from the common ones, only in the templet and the
shuttle. Two templets of iron must be used to keep the stuff equably, but lightly
stretched. These templets, of which one is represented in fig. 741, are constructed in
the shape of flat pincers; the jaws c c being furnished with teeth inside. A screw D,
741               binds the jaws together, and hinders the selvage
oD                                from going inwards. Upon the side cross beam
F            of the loom, seen in section at i a bolt is fixed
E'mn'B:j1    ^,-.J~L              which carries a nut F at its end, into which a
Cd {r ~         J ~iM.j~j    screwed iron rod E enters, on one of whose ends
11~-. L! is the handle B. The other extremity of the
B   screw E is adapted by a washer and pin to the
r     back of the pincers at the point H, so that by
turning the handle to the right or the left, we
draw onwards or push backwards the pincers
and the stuff at pleasure. The warp of the web is made of black linen yarn. The weft
is of hair, and it is thrown with a long hooked shuttle; or a long rod, having a catch
hook at its end. The length of this shuttle is about 3 feet; its breadth half an inch, and
its thickness one sixth. It is made of box-wood. The reed is of polished steel; the
thread warps are conducted through it in the usual way. The workman passes this
shuttle between the hairs of the warp with one hand, when the shed or shuttle way is
opened by the treddles; a child placed on one side of the loom presents a hair to the
weaver near the selvage, who catches it with the hook of his shuttle, and by drawing it
out passes it through the warp. The hairs are placed in a bundle on the side where the
child stands, in a chest filled with water to keep them moist, for otherwise they would not
have the suppleness requisite to form a web. Each time that a hair is thrown across, the
batten is driven home twice. The warp is dressed with paste in the usual way. The
hair cloth, after it is woven, is hot calendered to give it lustre.




992                                 HARDNESS.
HAIR PENCILS OR BRUSHES for painting. Two sorts are made; those with coarse
nair, as that of the swine, the wild boar, the dog, &c., which are attached usually to short
wooden rods as handles; these are commonly called brushes; and hair pencils, propely
so called, which are composed of very fine hairs, as of the minever, the marten, the
badger, the polecat, &c. These are mounted in a quill when they are small or of moderate size, but when larger than a quill, they are mounted in white-iron tubes.
The most essential quality of a good pencil is to form a fine point- so that all the hairs
without exception may be united when they are moistened by laying them upon the
tongue, or drawing them through the lips. When hairs present the'form of an elongated
cone in a pencil, their point only can be used. The whole difficulty consists after the
hairs are cleansed, in arranging them together so that all their points may lie in the same
horizontal plane. We must wash the tails of the animals whose hairs are to be used,
by scouring them in a solution of alum till they be quite free from grease, and then steeping them for 24 hours in luke-warm water.  We next squeeze out the water by pressing
them strongly from the root to the tip, in order to lay the hairs as smooth as possible.
They are to be dried with pressure in linen cloths, combed in the longitudinal direction,
with a very fine-toothed comb, finally wrapped up in fine linen, and dried. When perfectly dry, the hairs are seized with pincers, cut across close to the skin, and arranged in
separate heaps, according to their respective lengths.
Each of these little heaps is placed separately, one after the other, in small tin pans
with flat bottoms, with the tips of the hair upwards. On striking the bottom of the pan
slightly upon a table, the hairs get arranged parallel to eath other,'and their delicate
points rise more or less according to their lengths. The longer ones are to be picked out
and made into so many separate parcels, whereby each parcel may be composed of equally
long hairs. The perfection of the pencil depends upon this equality; the tapering point
being produced simply by the attenuation of the tips.
A pinch of one of these parcels is then taken, of a thickness corresponding to the intended size of the pencil; it is set in a little tin pan, with its tips undermost, and is shakes
bv striking the pan on the table as before. The root end of the hairs being tied by'the
fisnerman's or seaman's knot, with a fine thread, it is taken out of the pan, and then
hooped with stronger thread or twine; the knots being drawn very tight by means of two
little sticks. The distance from the tips at which these ligatures are placed, is of course
relative to the nature of the hair, and the desired length of the pencil. The base of the
pencil must be trimmed flat with a pair of scissors.
Nothing now remains to be done but to mount the pencils in quill or tin-plate tubes as
above described.'The' quills are those of swans, geese' ducks, lapwings, pigeons, or larks,
according'to the size of the pencil. They are steeped during 24 hours in water, to swell.
and soften them, and to prevent the chance of their splitting when the hair brush is pressed
into them. The brush of hair is introduced by its tips into the large end of the cut quill,
having previously drawn them to a point with the lips, when it is pushed forwards with
a wire of the same diameter, till it comes out at the other and narrower end of the quill.
The smaller the pencils, the finer ought the hairs to be. In this respect, the manufacture
requires much delicacy of tact and experience. It is said that there are only four first-rate
hands among all the dexterous pencil-makers of Paris, and that these are principally women.
HALOGENE is a term employed by Berzelius to designate those substances which
form  compounds of a saline nature, by their union with. metals; such are Bromine,
Chlorine, Cyanogene, Fluorine, Iodine. Haloid is his name of the salt thereby formed.
HANDSPIKE is a strong wooden bar, used as a lever to move the windlass and capstan in heaving up the anchor, or raising any heavy weignts on board a ship. The
handle is smooth, round, and somewhat taper; the other end i^ squared to fit the holes in
the head of the capstan or barrel of the windlass.
HARDNESS (Duret, Fr.; HdrieFestigkeit, Germ.) is that modification of cohesive
attraction which enables bodies to resist any effort made to abrade their surfaces. Its relative intensity is measured by the power they possess ox cutung or scratching other substances.  The following table exhibits pretty nearly inc successive hardnesses of the
several bodies in the list:



HARTSHORN.                                     993
Substances.                      Hardness.     Specific Gravity.
Diamond from Ormus  -         -       -      -          20              3'7
Pink diamond                                            19              3'4
Bluish diamond         -~                               19              3.3
Yellowish diamond -              -       -              19              3*3
Cubic diamond -                                         18              3'2
Ruby....              17              4-2
Pale ruby from Brazil.       -       -      -          16              3-5
Deep blue sapphire -      -      -       -              16              3'8
Ditto, paler..      -       -      -          17              3-8
Topaz..   -..              15              4'2
Whitish topaz  -       -      -       -      -          14              3-5
Ruby spinell              -      -                      13              3'4
Bohemian topaz -       -      -       -      -          11              2'8
Emerald   -        -              -      -12                            2'8
Garnet -                      -                         12              4-4
Agate      -.              12              2-6
Onyx           -       -      -       -.                12              2'6
Sardonyx   -      -                      -              12              2-6
Occidental amethyst   -       -      -       -          11              2*7
Crystal....                            11              2-6
Cornelian      -      -.                         11              2*7
Green jasper       -      --                            1               2-7
Reddish yellow do.     -      -       -      -           9              2'6
Schoerl    -       -      -      -       -              10              36
Tourmaline    -           -  -           -              10              30
Quartz    -       -       -                             10              2-7
Opal.                         10              2-6
Chrysolite -      -       -      -       -              10              3-7
Zeolite -      -       -      -..                        8              2-1
Fluor      -      -  -.               7              3-5
Calcareous spar.      -.        -           6              2,7
Gypsum.-        -       -      -       -               5              2'3
Chalk  -       -       -              -      -           3              2-7
HARTSHORN, SPIRIT OF, is the old name for water of ammonia.
HATCHING OF CHICKENS. See INCUBATION, ARTIFICIAL.
HAT MANUFACTURE. (L'art de Chapelier, Fr.; Hutmacherkunst, Germ.)  Hat
is the name of a piece of dress worn upon the head by both sexes, but principally by the
men, and seems to have been first introduced as a distinction among the ecclesiastics in
the 12th century, though it was not till the year 1400 that it was generally adopted by.
respectable laymen.
As the art of making common hats does not involve the description of any curious machinery, or any interesting processes, we shall not enter into very minute details upon
the subject. It will be sufficient to convey to the reader a general idea of the methods
employed in this manufacture.
The materials used in making stuff hats are the furs of hares and rabbits freed from
the long hair, together with wool and beaver. The beaver is reserved for the finer hats.
The fur is first laid upon a hurdle made of wood or wire, with longitudinal openings;
and the operator, by means of an instrument called the bow (which is a piece of elastic
ash, six or seven feet long, with a catgut stretched between its two extremities, and made
so vibrate by a bowstick), causes the vibrating string to strike and play upon the fur, so
as to scatter the fibres in all directions, while the dust and filth descend through the grids
of the hurdle.
After the fur is thus driven by the bow from the one end of the hurdle to the other, it
forms a. mass called a bat, which is only half the quantity sufficient for a hat. The
bat or capade thus formed is rendered compact by pressing it down with the hardening
sktn (a piece of half-tanned leather), and the union of the fibres is increased by covering
them with a cloth, while the workman presses them together repeatedly with his hands.
The eloth being taken off, a piece of paper, with its corners doubled in, so as to give it
a triangular outline; is laid above the bat. The opposite edges of the bat are then folded
over the paper, and being brought together and pressed again with the hands, they form
a conica. cap. This cap is next laid upon another bat, ready hardened so that the joined




994                           HAT MANUFACTURE.
edges of the first bat rest upon the new one. This new bat is folded over the other, and
its edes *joined by pressure as before; so that the joining of the first conical cap is
opposite to that of the second. This compound bat is now wrought with the hands for a
considerable time upon the hurdle between folds of linen cloth, being occasionally sprinkled
with clear water, till the hat is basined or rendered tolerably firm.
The cap is now taken to a wooden receiver, like a very flat mill-hopper, consisting of
eight wooden planes, sloping gently to the centre, which contains a kettle filled with
A42  ^~ ~^  water acidulated with  sulphuric acid.   The
technical name of this vessel is the battery.  It
consists of a kettle A; and of the planks, B
1s 0  ^ ~ 7^  ^ which are sloping planes, usually eight in number, one being allotted to each workman.  The
half of each plank next the kettle is made of
lead, the upper half of mahogany.  In this liquor
the hat is occasionally dipped, and wrought by
the hands, or sometimes with a roller, upon the
sloping planks.  It is thus fulled or thickened
l during four or five hours; the knots or hard sub/Vm l i  A S stances are picked out by the workman, and fresh
felt is added by means of a wet brush to those
parts that require it.  The beaver is applied at
the end of this operation.  In the manufacture
of beaver hats, the grounds of beer are added to
~ c =' —'~                 the liquor in the kettle.
Stopping, or thickening the thin spots, seen by looking through the body, is performed
by daubing on additional stuff with successive applications of the hot acidulous liquor
from a brush dipped into the kettle, until the body be sufficiently shrunk and made
uniform. After drying, it is stiffened with varnish composition rubbed in with a brush;
the inside surface being more copiously imbued with it than the outer; while the brim is
peculiarly charged with the stiffening.
When once more dried, the body is ready to be covered, which is done at the battery.
The first cover of beaver or napping, which has been previously bowed, is strewed equably
over the body, and patted on with a brush moistened with the hot liquor, until it gets in
corporated;' the cut ends towards the root, being the points which spontaneously intrude.
The body is now put into a coarse hair cloth, then dipped and rolled in the hot liquor,
until the root ends of the beaver are thoroughly worked in.  This is technically called
rolling off, or roughing. A strip for the brim, round the edge of the inside, is treated in
the same way; whereby every thing is ready for the second cover (of beaver), which is
incorporated in like manner; the roiling, &c. being continued, till a uniform, close, and
well-felted hood is formed.
The hat is now ready to receive its proper shape. For this purpose the workman turns
up the edge or brim to the depth of about 1' inch, and then returns the point of the cone
back again through the axis of the cap, so as to produce another inner fold of the same
depth.  A third fold is produced by returning the point of the cone, and so on till the
point resembles a flat circular piece having a number of concentric folds.  In this state
it is laid upon the plank, and wetted with the liquor. The workman pulls out the point
with his fingers, and presses it down with his hand, turning it at the same time round on
its centre upon the plank, till a flat portion, equal to the crown of the hat, is rubbed out.
This flat crown is now placed upon a block, and, by pressing a string called a commander,
down the sides of the block, he forces the parts adjacent to the crown, to assume a cylindrical figure.  The brim now appears like a puckered appendage round the cylindrical
cone; but the proper figure is next given to it, by working and rubbing it. The body is
rendered waterproof and stiff by being imbued with a varnish composed of shellac,
sandarach, mastic, and other resins dissolved in alcohol or naptha.
The hat being dried, its nap is raised or loosened with a wire brush or card, and sometimes it is previously pounced or rubbed with pumice, to take off the coarser parts, and
afterwards rubbed over with seal-skin.  The hat is now tied with pack-thread upon its
block, and is afterwards dyed. See HAT-DYEING, infra.
The dyed hats are now removed to the stiffening shop. Beer grounds are next applied
on the inside of the crown, for the purpose of preventing the glue from coming through;
and when the beer grounds are dried, glue (gum Senegal is sometimes used) a little
thinner than that used by carpenters, is laid with a brush on the inside of the crown, and
the lower surface of the brim.
The hat is then softened by exposure to steam, on the steaming basin, and is brushed
and ironed 11 it receives the proper gloss. It is lastly cut round at the brim by a knife
fixed at the end of a gauge, which rests against the crown. The brim, however, is not
41




HAT MANUFACTURE.                                    995
cut entirely through, but is torn off so as to leave an edging of beaver round the external
rim of the hat.  The crown being tied up in a gauze paper, which is neatly ironed
down, is then ready for the last operations of lining and binding.
The furs and wools of which hats are manufactured contain, in their early stage of preparation, hemps and hairs, which must be removed in order to produce a material for the
better description of hats.  This separation is effected by a sort of winnowing machine,
which wafts away the finer and lighter parts of the furs and wools from the coarser.
Messrs. Parker and Harris obtained a patent in 1822 for the invention and use of such
an apparatus, whose structure and functions may be perfectly understood, from its analogy
to the blowing and scutching machine of the cotton manufacture; to which I therefore
refer my readers.
I shall now proceed to describe some of the recent improvements proposed in the manufacture of hats, but their introduction is scarcely possible, on account of the perfectly
organized combination which exists among journeyman hatters throughout the kingdom,
by which the masters are held in a state of complete servitude, having no power to take a
single apprentice into their works beyond the number specified by the Union, nor any sort
of machine which is likely to supersede hand labor in any remarkable degree.  Hence
the hat trade is, generally speaking, unproductive to the capitalist, and incapable of receiving any considerable development.  The public of a free country like this, ought to
counteract this disgracefill state of things, by renouncing the wear of stuff hats, a branch
of the business entirely under the control of this despotic Union, and betake themselves
to the use of silk hats, which, from recent improvements in their fabric and dyeing, are
not a whit inferior to the beaver hats, in comfort, appearance, or durability, while they
may be had of the best quality for one fourth part of their price.
The annexed figures represent Mr. Ollerenshaw's machine, now generally employed
or ironing hats.  Fig. 743 is the frame-work or standard upon which three of these
744;45                     746
1i 43             ___     ____                    ~ v 
lathes are mounted, as A, a, c.  The lathe A is intended to be employed when the
crown of the hat is to be ironed. The lathe B, when the flat top, and the upper side of
the brim is ironed, and lathe c, when its under side is ironed; motion being given to the
whole by means of a band passing from any first mover (as a steam-engine, water-wheel,
&c.) to the drum on the main shaft a a. From this drum a strap passes over the rigger
bwhich actuates the axle of the lathe A. On to this lathe a sort of chuck is screwed, and
to the chuck the block c is made fast by screws, bolts, or pins. This block is represented in section, in order to show the manner in which it is made, of several pieces held
fast by the centre wedge-piece, as seen at fig.'744.
The hat-block being made to turn round with the chuck, at the rate of about twenty
turns per minute, but in the opposite direction to the revolution of an ordinary turning
lathe, the workman applies his hot iron to the surface of the hat, and thereby smooths
it, giving a beautiful glossy appearance to the beaver; he then applies a plush cushion,
and rubs round the surface of the hat while it is still revolving.  The hat, with its
block, is now removed to the lathe B, where it is placed upon the chuck d, and made to
turn in a horizontal direction, at the rate of about twenty revolutions per minute, for
the purpose of ironing the flat-top of the crown.  This lathe B moves upon an upright
shaft e, and is actuated by a twisted band passing from the main shaft, round the




996                            HAT MANUFACTURE.
riggerf. In order to iron the upper surface of the brim, the block c is reroved from
the lathe, and taken out of the hat, when the block fig. /45, is mounted upon the cluck
d, and made to turn under the hand of the workman, as before.
The hat is now to be removed to the lathe c, where it is introduced in an inverted
position, between the arms g g supporting the rim h h, the top surface of which is
shown at fig. 746. The spindle i of the lathe turns by similar means to the last, but
slower; only ten turns per minute will be sufficient.  The workman now smooths the
under side of the brim, by drawing the iron across it, that is, from the centre outwards.
The hat is then carefully examined, and all the burs and coarse hairs picked out, after
which the smoothing process is performed as before, and the dressing of the hat is conplete.
Messrs. Gillman and Wilson, of Manchester, obtained a patent in 1823, for a peculiar
kind of fabric to be made of cotton, or a mixture of cotton and silk, for the covering of
hats a~nd bonnets, in imitation of beaver. The foundation of the hat may be of felt, hemp,
wool, which is to be covered by the patent fabric. This debased article does not seem to
have got into use; cotton, from its want of the felting property and inelasticity, being
very ill-adapted for making hat-stuff.
A more ingenious invention of John Gibson, hatter, in Glasgow, consisting of an elastic
fabric of whalebone, was made the subject of a patent, in June, 1824. The whalebone,
being separated into threads no larger than hay stalks, is to be boiled in some alkaline
liquid for removing the oil from it, and rendering it more elastic. The longest threads
are to be employed for warp, the shorter for weft; and are to be woven in a hair-cloth
loom. This fabric is to be passed between rollers, after which it is fit to be cut out into
forms for making hats and bonnets, to be sewed together at the joints, and stiffened with
a preparation of resinous varnishes, to prevent its being acted upon by perspiration or
rain. A very considerable improvement in the lightness and elasticity  f silk hats has
been the result of this invention.
The foundation of men's hats, upon whose outside the beaver, down, or other fine fur
is laid to produce a nap, is, as I have described, usually made of wool felted together
by hand, and formed first into conical caps, which are afterwards stretched and moulded
upon blocks to the desired shape.  Mr. Borradaile, of Bucklersbury, obtained a patent
in November, 1825, for a machine, invented by a foreigner, for setting up hat bodies,
which seems to be ingeniously contrived; but I shall decline describing it, as it has
probably not been suffered by the Union to come into practical operation, and as I shall
presently give the details of another later invention for the same purpose.
Silk hats, for several years after they were manufactured, were liable to two objections; first, the body or shell over which the silk covering is laid, was, from its hardness,
apt to hurt the head; second, the edge of the crown being much exposed to blows, the
silk nap soon got abraded, so as to lay bare the cotton foundation, which is not capable
of taking so fine a black dye as the silk; whence the hat assumed a shabby appearance.
Messrs. Mayhew and White of London, hat-manufacturers, proposed in their patent of
February, 1826, to remedy these defects, by making the hat body of stuff or wool, and
relieving the stiffness of the inner part round, the brim, by attaching a coating of beavel
upon the under side of the brim, so as to render the hat pliable. Round the edge of
the tip or crown, a quantity of what is called stop wool is to be attached by the ordinary
operation of bowing, which will render the edge soft and elastic. The hat is to be afterwards dyed of a good black color, both outside and inside; and being then properly stiffpned and blocked, is ready for the covering of silk.
The plush employed for covering silk hats, is a raised nap or pile woven usually upon
a cotton foundation; and the cotton, being incapable of receiving the same brilliant
black dye as the silk, renders the hat apt to turn brown whenever the silk nap is partially
worn off. The patentees proposed to counteract this evil, by making the foundation of
the plush entirely of silk. To these two improvements, now pretty generally introduced,
the present excellence of the silk hats may be, in a good measure, ascribed.
The apparatus above alluded to, for making the foundations of hats by the aid of mechanism, was rendered the subject of a patent, by Mr. Williams, in September, 1826; but,
I fear it has never obtained a footing, nor even a fair trial in our manufactures, on ac
count of the hostility of the operatives to all labor-saving machines.
~Fig, 747 is a side view of the carding engine, with a horizontal or plan view of the
lower part of the carding machine, showing the operative parts of the winding apparatus,
as connected to the carding engine.  The doffer cylinder is covered with fillets of
wire cards, such as are usually employed in carding engines, and these fillets are
divided into two, three, or more spaces extending round the periphery of the cylinder,
the object of which division is to separate the sliver into two, three, or more breadths,
which are to be conducted to, and wound upon Distinct blocks, for making so many separate hats or caps.




HAT MANUFACTURE.                                   997
The principal cylinder ot the carding engine is made to revolve by a rigger upon it
axie, actuated by a band from any first mover as usual, and the subordinate rollers oi.~ ^^^J~i^.____..               a7__I.::l................ 
748
cylinders belonging to the carding engine, are all turned by pulleys, and bands, and gear,
as in the ordinary construction.
The wool or other material is supplied to the feeding cloth, and carried through
the engine to the doffer cylinder, as in other carding engines; the doffer comb is
actuated by a revolving crank in the common way, and by means of it the slivers are
taken from the doffer cylinder, and thence received on to the surfaces of the blocks e e.
These blocks, of which two only are shown to prevent confusion, are mounted upon
axles, supported by suitable bearings in a carriage ff, and are made to revolve by means
of a band g g, leading from a pulley on the axle of a conical drum beneath. The band g
passes over a pulley h, affixed to the axle of one of the blocks, while another pulley i,
upon the same axle, gives motion, by means of a band, to as many other blocks as are
adapted to the machine.
As it is necessary, in winding the slivers on to the blocks, to cross them in different
directions, and also to pass the sliver over the hemispherical ends of the blocks, in
order that the wool or other material may be uniformly spread over the surface in
forming the cap or hood for the shell or foundation of the intended hat, the carriage f,
with the blocks, is made to traverse to and fro in lateral directions upon rollers at each
end.
This alternating motion of the carriage is caused by a horizontal lever 11 (seen in
the horizontal view fig. X47), moving upon a fulcrum pin at m, which lever is attached
to the carriage at one extremity n, and at the other end has a weighted cord which
draws the side of this lever against a cam wheel o. This cam is made to revolve by
means of a band and pulley, which turns the shaft and endless screw q, and this
endless screw taking into a toothed wheel r, on the axle of the cam o, causes the cam
to revolve, the periphery of which cam running against a friction roller on the side of
the lever 1, causes the lever to vibrate, and the carriage ff attached to it, to traverse to
and fro upon the supporting rollers, as described.  By these means the slivers are
laid in oblique directions (varying as the carriage traverses), over the surface of the
blocks.
The blocks being conically formed, or of other irregular figures, it is necessary, in
order to wind the slivers with unifornm tension, to vary their speed according to the
diameter of that part of the block which is receiving the sliver. This is effected by
giving different velocities to the pulley on the axle of the conical drum s, corresponding
with e. There is a similar conical drum t, placed in a reverse position in the loweT




998                          HAT MANUFACTURE.
part of the frame, which is actuated by a band from any convenient part of the machine
passing over a pulley u, upon the axle of t. From the drum t, to the drum s, there is a
band v, which is made to slide along the drums by the guidance of two rollers at the end
of the lever 1.
It will now be seen that when the larger diameter of the cam wheel o forces the lever
outwards, the band v will be guided on to the smaller part of the conical drum t and the
larger part of s, consequently the drum s will at this time receive its slowest motion, and
the band g will turn the blocks slower also; the reverse end of the lever 1 having, by the
same movement, slidden the carriage into that position which causes the slivers to wind
upon the larger diameter of the blocks.
When the smaller diameter of the cam  is acting against the side of the lever, the
weighted cord draws the end of the lever to the opposite side, and the band v will be
guided on to the larger part of the cord t, and the smaller part of the cone; consequently,
the quicker movement of the band g will now cause the blocks e e to revolve with a corresponding speed. The carriagef will also be moved upon its rollers, to the reverse side,
and the sliver of wool or other material be now wound upon the smaller p.rts and ends
of the blocks, at which time the quicker rotation of the blocks is required. It may be
here observed, that the cam wheel o should be differently formed according to the different shaped blocks employed, so as to produce the requisite movements of the lever and
carriage suited thereto.
It only remains to state, that there are two heavy conical rollers w  v, bearing upon
the peripheries of the blocks e e, which turn loosely upon their axles by the fiction
of contact, for the purpose of pressing the slivers of wool or other material on the
blocks as it comes from the doffer cylinder of the carding engine, and when the blocks
have been coated with a sufficient quantity of the sliver, the smaller end of the pressing
rollers is to be raised, while the cap is withdrawn from the block. The process being
continued as before, the formation of other bodies or caps is effected in the manner above
described.
After the caps or bodies of hats, &c. are formed in the above described machine, they
are folded in wet cloths, and placed upon heated plates, where they are rolled under
pressure, for the purpose of being hardened. Fig. 748 represents the front of three
furnaces a a a, the tops of which are covered with iron plates b b b. Upon these plates,
which are heated by the furnace below, or by steam, the bodies wrapped in the wet
cloths c c c, are placed, and pressed upon by the flaps or covers d d d, sliding upot
guide rods, to which flaps a traversing motion is given, by means of chains attached to
an alternating bar e e. This bar is moved by a rotatory crank f, which has its motion
by pulleys from  any actuating power. When any one of the flaps is turned up to
remove the bodies from  beneath, the chains hang  loosely, and the flap remains
stationary.
These caps or hat bodies, after having been hardened in the manner above described,
may be felted in the usual way by hand, or they are felted in a fulling mill, by the usual
process employed for milling cloths, except that the hat bodies are occasionally taken out
of the fulling mill, and passed between rollers, for the purpose of rendering the felt more
perfect.
749                       752                    Mr. Carey, of Basford, ob~       ~        — i        tained a patent in October, 1834,
I      for an invention of certain mai =   = ^         <^^       chinery to be employed in the
manufacture of hats, which is
ingenious, and seems to be worthy
of notice in this place. It con0 == ='/^  ^^^' ^ ^^          sists in the adaptation of a sys____________,_____         tem of rollers, forming a machine,
by means of which the operation
of roughing or plaiting of hats
may be performed; that is, the
beaver or other fur may be made
to attach itself, and work into
-. I __________ L__ I I___  t ~ the felt or hat body, without the
operations.
The accompanying drawings represent the machine in several views, for the purpose
of showing the construction of all its parts. Fig. 749 is a front elevation of the machine;
fig. 750 is a side elevation of the same; fig. 71 is a longitudinal section of the machine; and fig.'752 is a transverse section; the similar letters indicating the same parts
in all the figures.




HAT MANUFACTURE.                                       999
Upon a brick or other suitable base, a furnace or fire-place a, is made, having a descending flue b, for the purpose of carry.
ing away the smoke.  A  pan or
shallow vessel c c, formed of lead,
is placed over the furnace; which
vessel is intended to contain a sour.i^^==^ a o.      I d               liquor, as a solution of vitriolic acid
and water.   On the edge of this
pan is erected  a wooden casing
d d d, which encloses three sides,
I  II      leaving the fourth  open for the, l I i~S~ purpose of obtaining access to the
working apparatus within. A series
of what may be termed  lantern
I~  I 5     rollers, e e e, is mounted on axles
turning in the side casings; and
another series of similar lantern
rollers, f f f, is in like manner
mounted  above.   These  lantern
rollers are made to revolve by means
of bevel pinions, fixed on the ends
/k.of their axles, which are turned
by similar bevel wheels on the late ll            eral shafts g and h, driven by a
winch i, and gear, as shown in
figs. 749 and 750.
/   -  Having prepared the bodies of
1   the hats, and laid upon their sur.
111,  faces the usual coatings of beaver,
or other fur, when so prepared they
~  ~'are to be placed between hair cloths,
and these hair cloths folded within
& canvass or other suitable wrapper.  Three or more hats being thus enclosed in each
wrapper, the packages are severally put into' bags or pockets in an endless band of sackcloth, or other suitable material; which endless band is extended over the lantern rollers
in the machine.
In the first instance, for the purpose of merely attaching the furs to the felts (which if
called slicking, when performed by hand), Mr. Carey prefers to pass the endless band k k k,
with the covered hat bodies, over the upper series I ff, of the lantern rollers, in ordei
to avoid the inconvenience of disturbing the fur, which might occur from subjecting them
to immersion in the solution contained in the pan, before the fur had become attached to
the bodies.
After this operation of slicking has been effected, he distends the endless band k k k,
over the lower series of lantern rollers e e e, and round a carrier roller 1,'as shown in fig,
*71; and having withdrawn the hat bodies for the purpose of examining them, and changing their.ifolds, he packs them again in a similar way in flannel, or other suitable cloths,
and introduces them into the pockets or bags of the endless bands, as before.
On putting the machinery in rotatory motion in the way described, the hats will be
carried along through the apparatus, and subjected to the scalding solution in the pan, as
also to the pressure, and to a tortuous action between the ribs of the lantern rollers, as they
revolve, which will cause the ends of the fur to work into the felted bodies of the hats,
and by that means permanently to attach the nap to the body; an operation which, when
performed by hand, is called rolling off.
The improved stiffening for hat bodies proposed by Mr. Blades, under his patent of
January, 1828, consists in making his solution of shellac in an alkaline ley, instead of
spirits of wine, or pyroxylic spirit, vulgarly called naptha.
He prepares his water-proof stiffening by mixing 18 pounds of shellac with 1 pounds
of salt of tartar (carbonate of potash), and 51 gallons of water. These materials are to
be put into a kettle, and made to boil gradually until the lac is dissolved; when the
liquor will become as clear as water, without any scum  upon the top, and if left to
cool, will have a thin crust upon its surface of a whitish cast, mixed with the light impurities of the gum.  When this skin is taken off, the hat body is to be dipped into
the mixture in a cold state, so as to absorb as much as possible of it; or it may be
applied with a brush or sponge.  The* hat body, being thus stiffened, may stand till it
become dry, or nearly so; and after it has been brushed, it must be immersed in very
4ilute sulphuric or acetic acid, in ordt- to neutralize the potash, and cause the shellac to




1000                        HAT MANUFACTURE.
set. If the hats are not to be napped immediately, they may be thrown into a cistern of
pure water, and taken out as wanted.
Should the hat bodies have been worked at first with sulphuric acid (as usual), they
must be soaked in hot water to extract the acid, and dried before the stiffening is applied
care being taken that no water falls upon the stiffened body, before it has been immersed
in the acid.
This ingenious chemical process has not been, to the best of my knowledge, introduced into the hat manufacture. A varnish made by dissolving shellac, mastic, sandarach, and other resins in alcohol, or the naptha of wood vinegar, is generally employed
as the stiffening and water-proof ingredient of hat bodies. A solution of caoutchouc is
often applied to whalebone and horse-hair hat bodies.
The following recipe has been prescribed as a good composition for stiffening hats;
four parts of shellac, one part of mastic, one half oC a part of turpentine, dissolved in
five parts of alcohol, by agitation and subsequent repose, without the aid of heat. This
stiffening varnish should be applied quickly to the body or foundation with a soft oblong brush, in a dry and rather warm workshop; the hat being previously fitted with its
inside turned outwards upon a block. The body must be immediately afterwards taken
off, to prevent adhesion.
Hat-Dyeing.-The ordinary bath for dyeing hats, employed by the London manufacturers,
consists, for 12 dozen, of144 pounds of logwood;
12 pounds of green sulphate of iron, or coppras;
7- pounds of verdigris.
The copper is usually made of a semi-cylindrical shape, and should be surrounded with
an iron jacket or case, into which steam may be admitted, so as to raise the temperature
of the interior bath to 190~ F., but no higher, otherwise the heat is apt to affect the
stiffening varnish, called the gum, with which the body of the hat has been imbued.
The logwood having been introduced and digested for some time, the copperas and
verdigris are added in successive quantities, and in the above proportions, along with
every successive two or three dozens of hats, suspended upon the dipping machine.
Each set of hats, after being exposed to the bath with occasional airings during 40
minutes, is taken off the pegs, and laid out upon the ground to be more completely
blackened by the peroxydizement of the iron with the atmospheric oxygen. In 3 or 4
hours the dyeing is completed. When fully dyed, the hats are well washed in running
water.
Mr. Buffum states that there are four principal objects accomplished by his patent invention for dyeing hats.
1. in the operation;
2. the production of a better color;
3. the prevention of any of the damages to which hats are liable in the dyeing;
4. the accomplishment of the dyeing process in a much shorter time than by the usual
methods, and consequently lessening the injurious effects of the dye-bath upon the texture
of the hat.
Fig. 753 shows one method of constructing the apparatus. a a is a semi-cylindrical
753                                        754
shaped copper vessel, with flat ends, in which the dyeing process is carried on. b b b is
a wheel with several circular rims mounted upon arms, which revolve upon an axle c.
In the face of these rims a number of pegs or blocks are set at nearly equal distances
apart, upon each of which pegs or blocks it is intended to place a hat, and as the wheel




HAT MAINUFACTURE.                                     1001
revolves, to pass it into and out of the dyeing liquor in the vat or copper. This wheel
may be kept revolving with a very slow motion, either by gear connecting its axle, c,
with any moving power, or it may be turned round by hand, at intervals of ten minuteswhereby the hats hung upon the pegs, will be alternately immersed for the space of ten
minutes in the dyeing liquor, and then for the same space exposed to the atmospheric
air. In this way, the process of dyeing, it is supposed, may be greatly facilitated and
improved, as the occasional transition from the dye vat into the air, and from the air
again into the bath, will enable the oxygen of the atmosphere to strike the dye more per
fectly and expeditiously into the materials of which the hat is composed, than by a continued
immersion in the bath for a much longer time.
A variation in the mode of performing this process is suggested, and the apparatus
ig. 54 is proposed to be employed,  a a is a square vat or vessel containing the dyeing
liquor; b b is a frame or rack having a number of pegs placed in it for hanging the hats
upon, which are about to be dyed, in a manner similar to the wheel above described.
This frame or rack is suspended by cords from a crane, and may in that way be lowered
down with the hats into the vat, or drawn up and exposed in the air; changes which may
be made every 10 or 20 minutes.
I have seen apparatus of this kind doing good work in the hat-dyeing manufactories
of London that being a department of the business with which the Union has not thought
it worth their while to interfere.
Mr. William Hodge's patent improvements in hat dyeing, partly founded upon an
invention of Mr. Bowler consist, first in causing every alternate frame to which the
suspenders or blocks are to be attached, to slide in and out of grooves, for the purpose
76'7         7585             75^6              of more easily removing the said
suspenders when required.  Fig.'755 represents the improved dyeing frame, consisting of two circular rims, a a, which are connected togetherat top and bottom,
C\       i   j)  ^~~1 ^ by three fixed perpendicular bars
^i \^/  g )  lor the frame-work b b b.  Two
other perpendicular frames c c,
similar to  the former, slide  in
grooves, d d d d, fixed to the upper
and lower rims. These grooves
-,^'   ^  ~  ^  ^^^" ^          have anti-friction rollers in them,
]  II  1]  I ]cI^^^     frames c c, to slide in and out
more freely. The suspenders or
substitutes for blocks, by these
by.  drawin  out te fmeans, may be more easily got at
by drawing out the frames c c,
about half way, when the suspenders, which are attached to the
frames with the hats upon them,
may be easily reached, and either
a                                removed or altered in position;
and when it is done on one side, the sliding frame may be brought out on the other, and
the remaining quantity of "suspenders" undergo the same operation.
The patentee remarks, that it is well known to all hat dyers, that after the hats have
been in the dyeing liquor some time, they ought to be taken out and exposed to the
action of the atmospheric air, when they are again immersed in the copper, that part of
the hat which was uppermost in the first immersion, being placed downwards in the
second. This is donl for the purpose of obtaining a uniform and regular dye. The
patentee's mode of carrying this operation into effect, is shown in the figure: e e are
pivots for the dyeing-frame to turn upon, which is supported by the arms f, from a crane
above.  The whole apparatus may be raised up or lowered into the copper by means of
the crane or other mechanism. When the dyeing-frame is raised out of the copper, the
whole of the suspenders or blocks are reversed, by turning the apparatus over upon the
pivots e e, and thus the whole surfaces of the hats are equally acted upon by the dyeing
material.
It should be observed, that when the dyeing-frame is raised up out of the copper, it
should be tilted on one side, so as to make all the liquor run out of the hats, as also to
eause the rims of the hat-s to hang down, and not stick to the body of the hat, or leave
A bad place or uneven dye upon it. The second improvement described by the patentee,
is the construction of "suspenders," to be substituted instead of the ordinary blocks.




1002                                     HATS.
These " suspenders" are composed ot thin plates of copper, bent into the reqaired
form, that is, nearly resembling that of a hat block, and made in such a manner as to be
capable of contraction and expansion to suit different sized hats, and keep them
distended, which may be altered by the workmen at pleasure, when it is required to
place the hats upon them, or remove them therefrom. The dyeing-frame at fig. 546 is
shown with only two of these "suspenders," in order to prevent confusion. One of these
suspenders is represented detached at fig. 547, which exhibits a side view; andfig. 548
a front view of the same. It will be seen by reference to the figure, that the suspenders
consist of two distinct parts, which may be enlarged or collapsed by a variety of means,
and which means may be suggested by any competent mechanic. The two parts of the
suspenders are proposed to be connected together by arms g g, and at the junction of
these arms a key is connected for turning them round when required. It will be seen on
reference to the front view, fig. 548, that the " suspenders" or substitutes for blocks, are
open at the top or crown part of the hat; this is for the purpose of allowing the dyeing
liquor to penetrate.
From  the mixture of copperas and verdigris employed in the hat-dye, a vast quantity
of an ochreous muddy precipitate results, amounting to no less than 25 per cent. of the
weight of the copperas. This iron mud forms a deposite upon the hats, which not only
corrodes the fine filaments of the beaver, but causes both them and the felt stuff to turn
speedily of a rusty brown. There is no process in the whole circle of our manufactures
so barbarous as that of dyeing stuff hats. No ray of chemical science seems hitherto to
have penetrated the dark recesses of their dye shops. Some hatters have tried to remove
this corrosive brown ochre by a bath of dilute sulphuric acid, and then counteract the
evil effect of the acid upon the black dye by an alkaline bath; but with a most unhappy
effect. Hats so treated are most deceptions and unprofitable; as they turn of a dirty
brown hue, when exposed for a few weeks to sunshine and air.
HATS. The body of a beaver hat is made of fine wool and coarse fur mixed and
felted together, then stiffened and shaped; the covering consists of a coat of beaver fur
felted upon the body. Cheap hats have their bodies made of coarse wool, and their
coverings of coarse fur or fine wool. The body or foundation of a good beaver hat, is
at present made of 8 parts of rabbit's fur, 3 parts of Saxony wool, and 1 part of lama,
vicunia, or red wool. About two ounces and a half of the above mixture are sufficient
for one hat, and these are placed in the hands of the bower; his tool is a bow or bent
ashen staff, from 5 to 7 feet long, having a strong catgut string stretched over a bridge
at each end, and suspended at its middle by a cord to the ceiling, so as to hang nearly
level with thes work-bench, and a small space above it. The wool and coarser fur are
laid in their somewhat matted state upon this bench, when the bower, grasping the bent
rod with his left hand, and by means of a small wooden catch plucking the string with his
right, makes it vibrate smartly against the fibrous substances, so as to disentangle them,
toss them up in the air, and curiously arrange themselves in a pretty uniform layer or
fleece. A skilful bower is a valuable workman. The bowed materials of one hat are
spread out and divided into two portions, each of which is compressed, first with a light
wicker frame, and next under a piece of oil cloth or leather, called a hardening skin,
till by pressing the hands backward and forward all over the skin, the filaments are
linked together by their serrations into a somewhat coherent fleece of a triangular shape.
The two halves or " bats" are then formed into a cap; one of them is covered in its
middle with a 3-cornered piece of paper, smaller than itself, so that its edges may be
folded over the paper, and by overlapping each other a little, form a complete envelope
to the paper; the junctions are then partially felted together by rubbing them hard,
care being taken to keep the base of the triangle open by means of the paper; the second bat being made to enclose the first by a similar process of folding and friction.
This double cap, with its enclosed sheet of paper, is next rolled up in a damp cloth and
kneaded with the hands in every direction, during which it is unfolded and creased up
again in different forms, whereby the two layers get thoroughly incorporated into one
body; thus, on withdrawing the paper, a hollow cone is obtained. The above operations have been partially described in the body of the Dictionary, and the remaining
steps in making a hat are there sufficiently detailed.
In a great hat factory women are employed, at respectable wages, in plucking the
beaver skins, cropping off the fur, sorting various qualities of wool, plucking and cutting
rabbit's fur, shearing the nap of the blocked hat, picking out unseemly filaments of fur,
and in trimming the hats; that is, lining and binding them.
The annual value of the hats manufactured at present in the United Kingdom  is
estimated at 3,000,0001. sterling. The quantity exported in 1840, was 22,522 dozens,
valued at 81,5831.
With regard to the stiffening of hats, I have been furnished ay a skilful operator with
the following valuable information: " All the solutions of gums which I have hitherto
seen prepared by hatters, have not been perfect, but, in a certain degree, a mixture, more
or less, of the gums, which are merely suspended, owing to the consistency of the composition. When this is thinned by the addition of spirit, and allowed to stand, it lets




HATS.                                          1003
fall a curdy-looking sediment, and to this circumstance may be ascribed the frequent
breaking of hats. My method of proceeding is. first to dissolve the gums by agitation in
twice the due quantity of spirits, whether of wood or wine, and then, after complete solution, draw off one-half the spirit in a still, so as to bring the stiffening to a proper
consistency. No sediment subsequently appears on diluting this solution, however much
it may be done.
" Both the spirit and alkali stiffenings for hats made by the following two recipes,
have been tried by  some of the first houses in  the trade, and have been much
approved of:~
Spirit Stiffening.
7 pounds of orange shellac.
2 pounds of gum sandarac.
4 ounces of gum mastic.
Half a pound of amber rosin.
1 pint of solution of copal.
1 gallon of spirit of wine or wood naphtha.
"The shellac, sandarac, mastic, rosin, are dissolved in the spirit, and the solution of
copal is added last.
Alkali Stiffening.
7 pounds of common block shellac.
1 pound of amber rosin.
4 ounces of gum thus.
4 ounces of gum mastic.
6 ounces of borax.
Half a pint of solution of copal.
The borax is first dissolved in a little warm water (say 1 gallon); this alkaline liquor
is now put into a copper pan (heated by steam), together with the shellac, rosin, thus, and
mastic, and allowed to boil for some time, more warm water being added occasionally
until it is of a proper consistence; this may be known by pouring a little on a cold slab
somewhat inclined, and if the liquor runs off at the lower end, it is sufficiently fluid; if,
on the contrary, it set before it reaches the bottom, it requires more water. When the
whole of the gums seem dissolved, half a pint of wood naphtha must be introduced, and
the solution of copal; then the liquor must be passed through a fine sieve, and it will be
perfectly clear and ready for use. This stiffening is used hot. The hat bodies, before
they are stiffened, should be steeped in a weak solution of soda in water, to destroy any
acid that may have been left in them (as sulphuric acid is used in the making of the
bodies). If this is not attended to, should the hat body contain any acid when it is dipped
into the stiffening, the alkali is neutralized, and the gums consequently precipitated.
After the body has been steeped in the alkaline solution, it must be perfectly dried in
the stove before the stiffening is applied; when stiffened and stoved it must be steeped
all night in water, to which a small quantity of sulphuric acid has been added; this sets
the stiffening in the hat body, and finishes the process. A good workman will stiffen 15
or 16 dozen hats a day. If the proof is required cheaper, more shellac and rosin must
be introduced."
HEALDS, is the harness for guiding the warp threads in a loom; that is, for lifting a
certain number of them alternately to open the shed, and afford passage to the decussating
weft threads of the shuttle. See WEAVING.
HEARTH; (Foyer, Fr.; Heerde, Germ.) is the flat or hollow  space in a smelting furnace upon which the ore and fluxes are subjected to the influence of flame. See COPPER,
IRON, METALLURGY, &c.
HEAT, is that power or essence called caloric, the discussion of whose habitudes with
the different kinds of matter belongs to the science of chemistry.
HEAT-REGULATOR. The name given by M. Bonnemain to an ingenious apparatus
for regulating the temperature of his incubating stove rooms. See INCUBATION, ARTiFICIAL,
for the manner of applying the Heat-Regulator.
The construction of the regulator is founded upon the unequal dilatations of different
metals by the same degree of heat. A rod of iron x, fig. 758., is tapped at its lower end
into a brass nut y, enclosed in a leaded box or tube, terminated above by a brass collet z.
This tube is plunged* into the water of the boiler, alongside of the smoke-pipe.
(Fig. 759. is a bird's-eye view  of the dial, &c.)  The expansion of the lead being
more than the iron for a like degree of temperature, and the rod enclosed within
the tube being less easily warmed, whenever the heat rises to the desired pitch, the
elongation of the tube puts the collet z in contact with the heel a, of the bent lever




1004                              HEAT-REGULATOR.
US,,^       a, b, d; thence the slightest increase
of heat lengthens the tube anew.       ~  eand the collet lifting  the heel of
9 h 3e^  the lever, depresses the other end,  1                759            d  through  a much  greater space,
on account of the relative lengths
of its legs.  This movement operates near the axis of a balance-bar
e, sinks one end of this, and thereby increases the extent ofthemovement which is transmitted directly
to the iron  skewer v.  This pushing  down  a swing  register diminishes or cuts off the access of air
to the fire-place.  The combustion
is thereby obstructed, and the temperature falling by degrees, the tube shrinks and disengages the heel of the lever. The
counterpoise g, fixed at the balance-beam e, raises the other extremity of this beam  by
raising the end d of the lever as much as is necessary to make the heel bear upon the
collet of the tube.  The swing register acted upon by this means, presents a greater
section to the passage of the air; whence the combustion is increased. To counterbalance the effect of atmospheric changes, the iron stem which supports the regulator
is terminated by a dial disc, round the shaft of the needle above h,fig. 759.; on turning
this needle, the stem below it turns, as well as a screw at its under end, which raises or
lowers the leaden tube. In the first case, the heel falls, and opens the swing register,
whence a higher temperature is required to shut it, by the expansion of the tube. We
may thus obtain a regularly higher temperature.  If, on the contrary, we raise the tube
by turning the needle in the other direction, the register presents a smaller opening, and
shuts at a lower temperature; in this case, we obtain a regularly lower temperature.
It is therefore easy, says M. Bonnernain, to determine d priori the degree of temperature
to be given to the water circulating in the stove pipes. In order to facilitate the regulation of the apparatus, he graduated the disc dial, and inscribed upon its top and bottom,
the words, Strong and Weak heat.  See THERMOSTAT, for another HEAT-REGULATOR.
HEAVY-SPAR, sulphate of Baryta, or Cawk; ({Spath pesant, Fr.; Schwerspath,
Germ.) is an abundant mineral, which accompanies veins of lead, silver, mercury, &C.,
but is often found, also, in large masses. Its colour is usually white, or flesh coloured.
It occurs in many crystalline forms, of which the cleavage is a right rhomboidal prism.
It is met with also of a fibrous, radiated, and granular structure. Its spec. gray. varies
from 4'1 to 4-6. It has a strong lustre, between the fatty and the vitreous. It melts at
S50 Wedgw. into a white opaque enamel.  Its constituents are 65'63 baryta, and
34'37 sulphuric acid.  It is decomposed by calcination in contact with charcoal at a
white heat, into a sulphuret of baryta; from which all the baryta salts may be readily
formed.  Its chief employment in commerce is for adulterating white lead; a purpose
which it readily serves on account of its density. Its presence here is easily detected by
dilute nitric acid, which dissolves the carbonate of lead, and leaves the heavy spar. It
is also a useful ingredient in some kinds of pottery, and glass.
HECKLE; (Seran, Fr.; Hechel, Germ.) is an implement for dissevering  the filaments of flax, and laying them in parallel stricks or tresses. See FLAX.
HELIOGRAPHY  may be regarded as the appropriate title of the new and elegant
art of making sun pictures; an art which originated with Niepce and Daguerre, and
which has been much improved by Mr. Fox Talbot.  See the articles CALOTYPE and DAGUERREOTYPE.  It has been called photography, being a picture produced by the action
of light; but as the sunbeams are essential to a good result, I have called it Heliography.
Iodide of silver is the principal agent applied to paper, to make it very sensible to the
impressions of the sunbeam. The bromide has also been used, and preferably in mixture.   Le Gray in his new  treatise of photography, lately published, recommends a
mixture of the Iodide, cyanide and fluoride, as the excitable fluid; this compound being
used in union with potassium. The paper thus impregnated, is laid on the aceto-nitrate
of silver, and then exposed to the light. A picture may thus be obtained in the focus
of the camera obscura in 30 seconds in fine weather; a circumstance of great consequence in taking living portraits, on account of the mobility of the human countenance.
Waxed paper applied dry possesses a like sensibility.
One of the main difficulties in heliography lies in the choice of the paper. The post
paper of Whatman of London, is preferred for the preliminary trials, when it is slightly
glazed. Thin paper is better for portraiture, and thick for landscapes. Well sized paper
is to be preferred, and of equal texture.
The first step in preparing the paper, is to fill up all its pores with fine white-wax,




HELIOGRAPHY.                                        1005
and thus give it the aspect of parchment. Provide a large plate of silver-plated, as for
the daguerreotype process, place it on a tripod horizontally, heat it by passing the flame
of a spirit of wine lamp to and fro under it, or rather set it over a water bath, while with
the other hand a piece of white wax is rubbed over it.  The coat 6f wax being equally
fused, lay the paper upon it, and cause it to apply evenly by putting a card on it. It is
then to be removed, and laid between two or three folds of blotting paper, and gently
pressed over with a hot smoothing iron, to remove the excess of wax. It is indispensable
that no wax remain on the surface, but only in the texture of the paper; which should
have no glistening spot, and be perfectly transparent. Thin paper should be preferred
for waxing. Well prepared paper should allow  the proof of the picture to develop
itself in the gallic acid for a considerable time, without spotting either the proof or the
acid. Its principal quality is, to permit the aceto-nitrate of silver to be prepared beforeland, and thus have a store of ready waxed paper. This preparation affords very intense
blacks upon thin papers.
The bath of iodide of potassium completely penetrates the wax, and deprives it of its
greasy aspect, by a sort of decomposition, which causes the subsequent preparations to
apply uniformly. This paper should be left from half an hour to an hour, in the solution
of the iodide, according to the thickness of the paper; to ensure the decomposition of the
wax, care must be taken to keep the waxed paper cool.  The iodized paper assumes a
violet tint when completely dry. This hue, resulting from the union of the wax with the
iodine, is beneficial, because it affords sufficient time to leave the paper on the acetonitrate of silver, till the violet tint disappears. The preparations that follow may be
applied to either the waxed or plain paper; but in the latter case, the paper should be
somewhat thick.
First Preparation.-Negative Paper.-Boil in a porcelain or earthen pan, 3 litres of
distilled water, with 250 grammes of rice, till this merely bursts, lest the water becomes
too glutinous. Strain through calico. This forms an excellent size, and affords a good
body and fine blacks.  In a litre of the above rice water, dissolve 40 grammes of sugar
of milk; 15 of iodide of potassium; 80 centigrammes of cyanide of potassium, and 50 centigrammes of fluoride of potassium. Filter the solution, and set aside for use in a bottle.
To prepare the paper, pour this solution into a large plate, and plunge the waxed paper
into it, leaf by leaf over each other, taking care to expel the air bubbles. Take them out,
return them for about half an hour; then hang them up to dry, by means of a bent pin
hooked to the corner; and favour their drainage by placing a bit of blotting paper on
their lower point. This process is to be repeated. French and English papers should
not be mixed in the same cistern. The English paper is said to contain a free acid, which
precipitates iodide of starch in the French paper, and gives it a deep violet tint. The
paper is to be cut down to the size of the camera obscura, and put up for use in a portefeuille. The liquid which has been used will serve again. The paper thus prepared, is
called iodized.
Paper specially for Portraiture-is prepared as follows. Take 400 grammes of distilled water, 20 of iodide of potassium, 2 of cyanide of potassium, 0650 centigrammes of
fluoride of potassium;-dissolve. Pour 2 or 3 millimetres of this solution into a flat plate
of porcelain, or on a flat glass, quite horizontal. Take a piece of glazed paper by the
two corners, the rough side uppermost, and apply the smooth face upon the liquid in
the plate; beginning the immersion with thbe side next your body, and pushing the leaf
before you, so that it may always fall at right angles upon the liquid. This movement is
to be repeated two or three times, so as to press out any air bubbles. Take care that the
liquid does not pass to the other side of the paper. It is to remain on the bath not more
than two minutes at most. It is then to be lifted and perfectly dried between folds of
blotting paper, of a fine tissue, rubbing it in all directions with the hands, and changing
its place, that it may be perfectly dry. Remove the paper and smooth it with a soft
brush. Lay the same side upon the bath of aceto-nitrate of silver (about to be indicated);
leaving it there not more than 8 or 10 seconds at most, and then place it upon the slate
in the camera, (which has been previously furnished with a leaf of blotting paper well
soaked in water, as will be described further on. It is requisite to make immediate use
of this paper, because its great sensibility depends chiefly on the nascent state of the
iodide of silver that it operates upon. In summer, from 4 to 10 seconds are required for
an impression; in winter, from 18 to 40.
The second operation is to give sensibility to the iodized papers, either in the dry or
humid way. Take of
Distilled water    -        -       -       -150 grammes
Crystallized nitrate of silver      -       -   5
When this is dissolved, add of crystallizable acetic acid 12 grammes. Care must be
taken to prepare this solution by the light of a feeble taper, and to surround the phial
with a case of blackened paper. No more of this mixture should be put into the cap.




1006                                HELIOGRAPHY.
sule than is sufficient for once. If not to be kept more than 4 days upon the paper, the
following mixture may be used:
Distilletl water     -                            150 grammes
Acetate of silver    -       -       -        -    10
Crystallizable acetic acid   -       -       -    12     "
For the humid operation the paper may preferably be employed moist. At the moment
of commencing, pour one of those mixtures of aceto-nitrate of silver upon a plate of
porcelain or glass, quite horizontal, to about one millimetre in depth. A pipette or small
sucking glass tube is convenient for this purpose, as its fine point prevents any drops
from being spilled irregularly. And the surface of the liquid may be skimmed if necessary with a piece of white paper. The leaf of iodized paper is now to be seized by the
two corners on the side only which was iodized, and to be laid down and raised several
times so as to expel the air. This may be done with the thumb by the help of a pallet
ivory knife to save staining the fingers. Take care that none of the nitro-acetate of silver
goes on the other side of the paper. Allow the paper to receive the chemical action till
the formation of a very sensible layer of cyano-iodo-fluoride of silver. Five minutes may
suffice for the French paper, and a little longer for the English; both being imbued with
the sugar of milk preparations. Time should be given for the violet hue to disappear,
4 or 5 minutes; but with the portrait paper, 9 or 10 seconds should be sufficient. The
lon-ger this interval the less is the sensibility.
Apply the paper quite moist upon a slate, on which there has been previously spread
to receive it, a well soaked leaf of unsized paper. The sole of the camera may also be
made use of, if it has been well covered with a coat of white wax.  But the slate is
preferable; care being had to lay the surface with the aceto-nitrate uppermost to receive
the radiations of light. The undermost piece of paper should be free from iron stains.
The slate should be marked so as to be preserved always in one posture, both when the
are applied and when put up in the frame.   If these precautions be neglected, the
liquid collects below  and falls upon the prepared paper, and may cause spots. The
paper, when thus put on the slate, may be left there for three or four hours without
being removed, and may be placed during this interval in the camera.  On going a
little way off to take a proof, the fold of the leaf may be dipped in thick mucilage of
gum-arabic, which serves to preserve the moisture and the adhesion. Two panes of glass
may also be used for laying the papers between.; not sparing blotting paper in cleaning
them.
In the dry way, waxed paper is to be used. It will require more time to develop the
image with the gallic acid; but this comes out equally well, only there will be a pretty
strong contrast between the whites and the blacks. The aceto-gallic acid, and the acetonitric, which are added should be fresh, extremely pure, and well filtered. Two porcelain
basins of some depth are to be taken; into the first put from 5 to 6 millimetres of acetonitric acid (noted above) and into the second put distilled water. Plunge completely on
the two sides the waxed and iodized paper, into the bath of the aceto-nitrate of silver of
the first cistern, and leave it there 4 or 6 minutes, then transfer it immediately into the
bath of distilled water in the second cistern, and leave it at least 4 minutes or more if you
wish to keep the paper some time before using it. You may prepare next in the same
baths, ten leaves one after the other. Lastly, the paper is to be taken from the water to
be dried between folds of blotting paper, and laid by in a blotting-book equally dry.
The paper is not to be dried by suspension in the air. Kept in the dark the paper will
thus keep its qualities fully 6 days, before going into the camera. The aceto-nitrate of
silver deteriorates after 8 days. It is good not to put at once more than one or two proofs
into the same bath of gallic acid. The period of exposure in the camera is not longer in
the dry than in the humid way, but the proof must stand a little longer in the gallic
acid, which may have 15 or 20 drops added to it of the nitro-acetate of silver filtered, and
fresh made, or not previously used. The granular and soiled look of the paper under the
gallic acid when it becomes dry, should give no concern, as it disappears completely on
re-melting the.wax, of the proof on the exposure of its negative to a suitable heat. This
precaution should never be neglected, for it is superior to any varnish. These operations
being finished, invert the aceto-nitrate of silver into a phial, but don't reserve any for
fresh proofs, which would prove a constant cause of failures. It may be thrown down
by common salt, in the state of chloride of silver, which serves to give to hyposulphite of
soda, the quality necessary for producing fine tones. The aceto-nitrate may be decoloured
and revived by means of bone black, with which it is to be boiled a short time and then
filtered.
Third Operation: Exposure in the Camera.-Place the point of the image in the depolished glass most scrupulously in the middle of the lens. After the exposure to the
luminous rays the image in the camera has little appearance, being developed only by




HELIOGRAPHY.                                   1007
the subsequent operation, which may be performed some hours afterwards, on the moist
paper, or even some days with the waxed paper in the dry state.
Development of the Image.-This is effected by the gallic acid diluted with pure water,
in the proportion of 1 litre of the latter and 4 grammes of the former. Pour out of this
solution into a horizontal flat shallow plate, to the thickness of 3 or 4 millimetres.
Plunge the proof completely into it, so that it may be covered all round. Watch its
development, which is readily perceived across the thickness of the paper. It may be
left here from 10 minutes for an hour or two, till it be arrived at perfection. The
development is much quickened by adding 20 or 21 drops of aceto-nitrate of silver,
when the image begins to appear.  Very intense blacks are thus obtained, but theaction
must then be followed up, because it is rapid, and it gives such intense blacks, as to be
disagreeable if the time be prolonged. When it is sufficiently deep, withdraw it smartly,
and pour several streams of water over it, upon a plate or dish, rubbing the back of the
paper at the sarme time with a finger to remove any crystalline grains which might spoil
it. The gray hue of'the waxed paper need cause no alarm as it disappears, and leaves
beautiful whites and blacks. The tone which the image takes from the gallic acid will
enable you to judge whether the exposure to the light has been adequate. If it becomes
immediately of a gray black everywhere (looked well through), it shows it to have been
too long under the light. If the greatest lights, which should be the greatest blacks
of the negative, do not become deeper than the semi-tints, the exposure has also been
too long. A first proof serves to regulate the time of exposure in the camera for the
rest. Its period may be shortened by warming the gallic acid, for which a little apparatus has been used, consisting of a little square copper basin filled with water, supported
over a small spirit lamp, which communicates heat to the shallow dish containing the
gallic acid, &c.
The picture taken as above described will not be permanent.  It must be fixed by
the
Fifth Operation, or that of the Negative Proof.-Dissolve in a bottle 100 grammes of
hyposulphite of soda in 800 grammes of filtered water. Put the solution into a basin to
the depth of half a centimetre, and plunge the negative proof completely in it, taking
care to free it from air bubbles. The hyposulphite takes possession of the cyano-iodofluoride of silver, and the proof remains clear; but it does not affect the gallate of silver,
which on the contrary continues black. Never put more than one proof at a time in this
bath; but you may put several proofs in it one after the other. The hyposulphite of soda
which has been already used is to be collected, and when kept, lets fall flocks of gallate
of iron and sulphuret of silver. When filtered it serves well for fixing weak proofs. On
examining the proof after it has remained some time in the bath, we might be tempted
to believe that it has lost its strength from its transparency, because the iodide of silver,
which has a straw yellow tint, being completely removed from its place and resting at
other spots, annihilates the image in appearance. But if we consider that the whole
iodide of silver is removed, as is recognized when the yellow tint of the proof is also
gone-one becomes astonished at the whiteness and the transparency of the paper; as
well as the beauty of the blacks of the image.
For these effects it requires from half an hour to three quarters of an hour with the
ordinary papers. An abode of too much length in the bath weakens the blocks of the
proof; and, therefore, this process should be looked after. With waxed papers, from 10
to 15 minutes are sufficient for fixing.  The proof is to be next washed with several
waters, and left to drain off its hyposulphite into a basin for the space of half an hour. It
is then dried by hanging it up by a corner; and is now inalterable at the light, since there
does not remain any more in the paper than the bla k gallate of iron.
Sixth Operation: Waxing of the Negative Proof~When the negative proof is weak
and the paper very transparent, counterproofs should be made with it without waxing.
The proofs obtained from paper previously waxed should not be waxed anew, but only
approached near the fire to restore their transparency, which they had lost by their suc.
cessive baths. Before this operation they have a granular aspect. The negative proof
should be waxed, which counteracts the ill effect of any of the nitrate of silver remaining
on the surface of the positive paper. The waxing of the negative proof is done by melting
with'a spirit lamp a layer of white wax on a piece of plated copper like that of a
daguerreotype, laying the negative upon it, and promoting its adhesion by the weight of
a card. When it is equally soaked, place it between folds of smooth writing paper, and
glide a hot smoothing iron over all to remove the excess of wax. The iron should not be
too hot.
Seventh Preparation; that of Positive Paper.-Saturate a bottle of water with sea
salt. Dilute 1 part of this solution with 3 parts of water. Put into a plate this brine to
the depth of 4 or 5 millimetres. Into another bottle put of distilled water 100 grammes;
crystallized nitrate of silver 20 grammes. Dissolve. Of which pour out into a plate to
the above thickness.




1008                                  HELIOGRAPHY.
Take stout paper weighing about 15 kilogrammes the ream, previously cut of a suitable size, and free from iron stains or any impurities. Mark a cross on the side of the
paper which bears the metallic mark of the manufacturer.  Le Gray says the English
paper should not be used unless a red tone be wanted in the pictures. Place the paper
upon. a plate of porcelain or glass moistened (as formerly directed) with the dilute brine,
and leave it there from 2 to 4 minutes; dry it between folds of pink blotting paper,
rubbing it at the same time with the hand. Prepare thus 3 leaves before beginning, to
put them in the bath of nitrate of silver, in order that all traces of humidity may be removed.  Take the dried leaves and clear them by a somewhat hard flat brush from  all
particles of salt or other impurities. Put a leaf of the pink blotting paper upon the
nitrate of silver of the salted side only, and leave it there the time requisite to prepare
another leaf upon the salt. By leaving it for a little on the nitrate of silver, red tones
are obtained; but, by leaving it longer, blacker tones. The paper is then to be dried,
hanging it up by a corner; but all must be done by candlelight.  The positive paper
should be very dry before laying a negative upon it, for fear of staining it with nitrate
of silver. On this account it is good to dry it well the previous night, but not too many
days beforehand, lest the silver should darken..Eighth Operation: Tlaking the Positive Proof.-Put the negative upon one of the
glasses of the frame of reproduction, lay above it a leaf of glazed paper, then one of
positive paper prepared by the preceding operation, the side of the preparation upon the
place of the negative, then lay above it a leaf of black paper, and the second glass of the
frame.  Shut the cover of the frame, which will exert a slight pressure upon the glasses,
and secure their contact. A sheet of transparent and waxed paper, or a piece of papier
glape in gelatine, should be placed between the negative proof and the leaf of the positive
paper.  Tihis does not hurt the nicety of the proof, and preserves the negative from
contact with the nitrate of silver, which would spoil it. It is proper to allow one of the
sides of the positive paper to overlap on the side of the negative, in order to judge of the
action of the light.  Expose the frame to the solar or diffuse light, so that the rays fall
vertically upon the surface of the proof. Trace the progress of the proof by the tone of
the folded over-part of the paper, as per the following gradations of tint: Gray blue,neutral tint, violet blue, black blue, black, bistre, coloured sepia, yellowish sepia, dead leaf
colour, greenish-gray; always wearing away, till the oxide of silver be at last reduced
to the state of a metallic oxide. It, is proper to stop at some one of these tones, accordto the greater or less vigour of the negative, and the deptlh of the proof that is desired.
Once we have obtained a proof with a negative, we may be sure when we stop at
the same tint of the overlapping edge, we shall have the same result.  To have a proof
of a black tint, for example, after the fixing of the hyposulphite, the deep parts should
have the tone of sepia, and the parts which should form the whites, have a blue gray, on
withdrawing it from beneath the frame, in order to repair the loss of tone given by the
hyposulphite.  The precise time of the exposure to the light cannot, therefore, be fixed,
and is subordinate to the intensity both of the negative, and also of the proof which is
desired.
Ninth and last Operation: Fixing of the Positive Proof.-This proof would not be
permanent without being immediately fixed by the following process:
Dissolve in a bottle 100 grammes of hyposulphite of soda, with 600 of filtered water;
and in another bottle dissolve 5 grammes of nitrate of silver in a couple of glasses of
water, and add a solution of common salt, till no more white precipitate falls.  After
letting it settle to the bottom of the vessel, collect the chloride of silver in a piece of
calico, and put it into the preceding solution of the hyposulphite. Thus, black tones
may be obtained with this new hyposulphite.  The older this hyposulphite is the better.
When it becomes turbid, a little more fresh solution need only be added to it. We must
also beware of filtering it to remove the black deposit which is formed; we have only to
let it remain at rest in a large bottle, and decant the clear liquor for use, so as not to lose
the black deposit, and to redissolve it by means of fresh hyposulphite. By means of
a stay shorter or longer in this bath, almost all the tones may be obtained from the red
to the black, and the pale yellow; so that, with a little practice, any desired tint may be
secured.  The proof should be left in the bath at least an hour to be sufficiently fixed;
and it may remain in it from 3 to 4 hours to bring out the sepia and the yellow tones.
By heating the hyposulphite, we may quicken the operation, but we must not leave the
proof an instant to itself, because the action is rapid, and the picture might become
effaced. In this case it is good to add a little acetic acid to the hyposulphite, in order to
preserve the whites.
On adding to tIme preceding solution of the hyposulphite 25 grammes of ammonia, very
pretty bistre tones are obtained along withi very pure whites. English paper suits these
effects very well. Very fine velvety tones are obtained by putting the proof (on taking
out of the hyposulphite) upon a bath of salt of gold (1 gramme of the salt into a litre of
water), sharpened with 5 grammes of nitro-muriatic acid.




HEPAR.                                          1009
Very fine yellow tones have been obtained by putting a proof pretty strong at first
into the hyposulphite, then into a bath composed of a litre of water, and 50 grammes of
hydrochloric acid; finally rinsing it with water. Water of ammonia used in the same
dose, without putting the proof previously in the hyposulphite of soda, gives also
remarkable tones.  When the proof is of the desired tone, wash it with several waters,
and leave it two or three hours in a basin, taking it out only when the proof has no
longer a sweet taste on the tongue, characteristic of the hyposulphite of silver. It is to
be then dried by hanging by a corner; when it is finished. The hyposulphite bath may
contain as many proofs as we please at a time. But great care must be taken to entangle
no air bubbles among the leaves, which would produce indelible black spots. A longhaired pencil is useful for clearing away these bubbles. The taking of the positive proofs
requires all the attention of a skilful operator, and it must not be disregarded. It is
necessary to calculate rightly the shade of a proof with the subject, and the effect wished
to be produced. A superior fine proof should be put by itself in the hyposulphite of soda.
Heliographs or Photographs have been recently taken of extreme accuracy and fineness of delineation, upon glass coated with albumen, by the following recipe:Put the
whites of ten eggs into a large basin; dissolve in them, by beating them with a box-wood
fork, 4 grammes of iodide of potassium; A gramme of bromide of ammonia, and as much
chloride of sodium. Reduce it to a white thick froth, leave it to settle for a night, and
next morning decant the viscid liquor which has fallen, and keep it for use. This glairy
compound is best when applied to depolished glass. A film of collodium on glass is now
preferred. For the remaining minute precautions and directions, I refer to the publication
of M. Le Grey, entitled Nouveau Traite Theorique et Pratique de Photographie.
HELIOTROPE; is a variety of jasper, mixed with chlorite, green earth, and diallage;
occasionally marked with blood-red points; whence its vulgar name of blood-stone.
HEMATINE; is the name given by its discoverer Chevreul to a crystalline substance,
of a pale pink colour, and brilliant lustre when viewed in a lens, which he extracted
from  logwood, the hcematoxylon Campechianum  of botanists.  It is, in fact, the characteristic principle of this dye-wood. To procure hematine, digest during a few hours
ground logwood in water heated to a temperature of about 130~ Fahr,
evaporate it to dryness by a steam bath, and put the extract in alcohol of 0835 for a day.
Then filter anew, and after having inspissated the alcoholic solution by evaporation,
pour into it a little water, evaporate gently again, and then leave it to itself in a cool
place. In this way a considerable quantity of crystals of hematine will be obtained,
which may be readily purified by washing with alcohol and drying.
When subjected to dry distillation in a retort, hematine affords all the usual products
of vegetable bodies, along with a little ammonia; which proves the presence of azote.
Boiling water dissolves it abundantly, and assumes an orange-red colour, which passes
into yellow by cooling, but becomes red again with heat. Sulphurous acid destroys the
colour of solution of hematine.  Potash and ammonia convert into a dark purple-red
tint, the pale solution of hematine; when these alkalis are added in large quantity, they
make the colour, violet blue, then brown-red, and lastly brown-yellow. By this time the
hematine has become decomposed, and cannot be restored to its pristine state by neutralizing the alkalis with acids.
The waters of baryta, strontia, and lime exercise an analogous power of decomposition;
but they eventually precipitate the changed colouring matter.
A red solution of hematine subjected to a current of sulphuretted hydrogen becomes
yellow; but it resumes its original hue when the sulphuretted hydrogen is removed by a
little potash.
The protoxide of lead, the protoxide of tin, the hydrate of peroxide of iron, the hydrate
of oxides of copper and nickel, oxide of bismuth, combine with hematine, and colour it
blue with more or less of a violet cast.
Hematine precipitates glue from its solution in reddish flocks. This substance has not
hitherto been employed in its pure state; but as it constitutes the active principle of
logwood, it enters as an ingredient into all the colours made with that dye stuff.
These colours are principally violet and black. Chevreul has proposed hematine as an
excellent test of acidity.
HEMATITE; (Fer Oligiste, Fr.; Rotheisenstein, Germ.) is a native reddish-brown
peroxide of iron, consisting of oxygen 30'66; iron 60'34. It is the kidney ore of Cumberland which is smelted at Ulverstone with charcoal, into excellent steel iron.
HEMP; (Chanvre, Fr.; Hanf, Germ.) is the fibrous rind of the bark of the cannabis
sativa, which is spun into strands or yarn for making rope, sail-cloth, &c. It is prepared
for spinning in the same way as flax, which see. Hemp-seed contains an oil which is
employed for making soft soap, for painting, and for burning in lamps. See OILS.
The importation of undressed hemp for home consumption in 1851 and 1852, was
respectively 1,048,635 cwts. and 1,293,412 cwts.
HEPAR; which signifies liver in Latin, was a name given by the older chemists to
64




1010                    HOMBOURG MINERAL WATERS.
some of those compounds of sulphur with the metals which had a liver-brown colour.
Thus the sulphuret of potassium was called liver of sulphur.
HEPATIC AIR; sulphuretted hydrogen gas.
HERMETICAL SEAL, is an expression derived from  Hermes, the fabulous parent
of Egyptian chemistry, to designate the perfect closure of a hollow vessel, by the
cementing or melting of the lips of its orifice; as in the case of a glass thermometer, or
matrass.
HIDE; (Peau, Fr.; Haut, Germ.) the strong skin of an ox, horse, or other large animal.
See LEATHER.
Imports.                 Exports.
1851.       1852.        1851.       1852.
Untanned, dry    -        -   cwts.    150.57         18,091    83,99         113,727
wet    -      -   cwts.    441,346    485,076    29,779            43,200
Tanned, tawed, curried or
dressed (except Russia
hides)    -      -     -   lbs.    1,876,557   2,275,107   105,924          79,817
HIRCINE; from hircus, a ram; is the name given by Chevreul to a liquid fatty substance, which is mixed with the oleine of mutton suet, and gives it ts peculiar rank
smell. Hircine is much more soluble in alcohol than oleine. It produces hircic acid by
saponification.
HOG'S LARD; see FATS.
HOLLOW   FOUNDING.  Candlesticks are cast in sand and made hollow, by the
introduction into the mould of what is called a "core," viz., a piece of sand corresponding
in size to the hollow of the pillar. Upon his skill in making this in such a ma1nner
as to produce uniform thickness of metal throughout, depends the success of the workman; the metal must also be of a proper temperature, or the casting is rendered
useless by the presence of flaws. Candlesticks are finished by being turned and polished
by friction, when in a state of motion in the lathe; the bottoms, when round, are also
turned; when square, they are filed and polished. The composition of metal in this case
is copper and zinc, in the proportion of 10 ounces of the former to 8 ounces of the latter.
HOMBOURG; MINERAL WATERS OF.  The city of Hombourg near Frankfort,
is situated at the bottom and to the east of the mountains of Taunus, 600 ft. above the
level of the sea, in a picturesque position.
The Elizabeth spring consists by Liebig's analysis in 16 ozs. ofGrains.
Cblor. sodium            -       -..       79-1547
Sulphate of soda         -      -       -                        0-3809
Chlor. calcium           -      -       -       -       -        7-7568
Chlor. magnesium        -       -       -                        7-7670
Silica        -          -       -          -    -               0-3157
Carbonate of lime       -       -       -       -       -       10-9824
Do. of magnesia         -        -.       -       -        2-0111
Proto-carbonate of iron -        -      -       -       -        0-4608
Free carbonic acid      -       -       -       -       -       21-4808
130-3102
THE BATH  SPRING. Contains for 16 oz. of water, 22-728 cubic in. of carbonic acid
combined withGrains.
Sulphate of lime        -       -       -       -       -         0-212
Chlor. calcium          -       -       --                       15-285
Brom. magnesium         -       -       -       -       -         0-002
Chlor.     do....                      -         5-904
Chlor. potassium..-                             -         0-384
Do.   sodium...       -       -       108-392
Silica       -          -.-                                0-164
Proto-carbonate of iron -       -       -               -         0-480
Alumina         -       -       -       -       -       -         0-054
Carbonate of lime.           -..       -         9-698
Do.  magnesia           -       -       -       -       -         2-485
143.060




HOP.                                       IOi
To this water are added occasionally some of the salt springs of Bingen which contain
considerable quantities of the compounds of bromine and iodine.
Mother Water, is the name given to the clear liquor which remains in the boiler,
when, after evaporating the water, the common salt has been crystallized and separated.
This residuum is greasy to the touch, but a little thinner than oil, and when applied to
the skin covers it with small scales, as if it had been washed with chlor-calcium. Iodine
and bromine exist in it, and are supposed to give it efficacy against scrofulous and chronic
diseases.
HONEY; (Mel, Fr.; Honig, Germ.) is a sweet viscid liquor, elaborated by bees from
the sweet juices of the nectaries of flowers, and deposited by them in the waxen cells of
their combs. Virgin honey is that which spontaneously flows with a very gentle heat
from  the comb, and common honey is that which is procured by the joint agency of
pressure and heat. The former is whitish or pale yellow, of a granular texture, a
fragrant smell, and a sweet slightly pungent taste; the latter is darker coloured, thicker,
and not so agreeable either in taste or smell. Honey would seem  to be simply collected by the bees, for it consists of merely the vegetable products; such as the sugars
of grape, gum, and manna; along with mucilage, extractive matter, a little wax and
acid.
HONEY-STONE; (Mellite, Fr.; Honigstein, Germ.) is a mineral of a yellowish or reddish colour, and a resinous aspect, crystallizing in octahedrons with a square base; specific
gravity 1'58. It is harder than gypsum, but not so hard as calc-spar; it is deeply
scratched by a steel point; very brittle; affords water by calcination; blackens, then burns
at the flame of the blowpipe, and leaves a white residuum which becomes blue, when it
is calcined after having been moistened with a drop of nitrate of cobalt. It is a mellate
of alumina, and consists of:
Melliticacid..46                                        4       44
Alumina -                                                     16            145
Water....                                       81            411
100           100-0
The honey-stone, like amber, belongs to the geological formation of lignite. It has
been hitherto found clearly in only one locality, at Artern in Thuringia.
HOP; (Houblon, Fr.; Iopfen, Germ.) is the name of a well-known plant of the natural
family of Urticee, and of the dicecia pentandria of Linnaeus. The female flowers, placed
upon different plants from the male, grow in ovoid cones formed of oval leafy scales, concave, imbricated, containing each at the base an ovary furnished with two tubular open
styles, and sharp pointed stigmata. The fruit of the hop is a small rounded seed, slightly
compressed, brownish coloured, enveloped in a scaly calyx, thin but solid, which contains,
spread at its base, a granular yellow substance, appearing to the eye like a fine dust, but
in the microscope they seem to be round, yellow, transparent, grains; deeper coloured,
the older the fruit. This secretion, which constitutes the useful portion of the hop, has
been examined in succession by Ives, Planche, Payen, and Chevallier. I have given a
pretty full account of the results of their researches in treating of the hop under the
article BEER.
Annual Amount of Hop Duty, Average Price per Cwt., and Number of Acres.
Year.                 Duty.              Average Price.          No. of Acres.
~                  ~   s.  d.
1838                171,556                5  1   0                 55,045
1839                205,537                4  10  0                 52,305
1840                  34,091              13  11  0                44,805
1841                146,159                6   6  0                45,769
1842                169,773                4  18  0                43,720
1843                133,508                8   0  0                43,156
1844                140,322                7  15  0                44,485
1845                158,003                7  10  0                48,058




1012                                             HORN.
Pounds Weight of Hops which paid Duty from 1840 to 1845.
Lbs.
1840               -         -         -        -                7,14,917
1841      -                  -         -        -              30,504,106
1842           -             -                  -         -    35,432,142
1843      -         -        -         -        -         -    27,862,725
1844......    29,285,092
1845           -             -         -        -              32,974,749
Number of Acres under the Cultivation of Hops ii England.
1807    38,218   1813    39,521    1819    51,014   1825   46,718  1831   47,129   1837   56,323
1808    38,436    1814    40,571   1820    50,148   1826   50,471   1832   47,101   1838   55,045
1809    38,357   1815    42,150    1821    45,662   1827   49,485   1833   49,187   1839   52,305
1810    38,265   1816    44,219   1822   43,766   1828   48,365   1834   51,273   1840   44,805
1811    38,401    1817    46,493    1823   41,458   1829   46,135   1835   53,816   1841   45,769
1812    38,700   1818    48,593    1824    43,449   1830   46,726   1836   55,422   1842
Annual amount of hop duty.
Yrs. Amount. Yrs. Amount. Yrs. Amount. Yrs. Amount. Yrs. Amount. Yrs. Amount.
1711  ~43,437  1733   ~70,215  1755   ~82,157  1777   ~43.581  1799   ~73,279  1821  ~154,609
1712    30,278  1734    37,716.1756    48,106  1778   159,891  1800           72,928  1822    203,724
1713   -23,018  1735    42,745  1757    69,713  1779    55,800  1801   241,227  1823              26,058
1714  14,457  1736    46,482  1758          72,896  1780   122,724  1802        15,463  1824    148,832
1715    44,975  1737      56,492  1759      42,115  1781    120,218  1803    199,305  1825        24,317
1716    20,354  1738    86,575  1760   117,992  1782    14,895  1904   177,617  1826    269,331
1717    54,669  1739    70,742  1761    79,776  1783    75,716  1805    32,904  1827    140.848
1718    15,005  1740      37.875  1762      79,295  1784    94,359  1o06   153,102  1828    172,027
1719    90,317  1741    65,222  1763    88,315  1785   112,684 IS07   100,071  1829               38,398
1720    38,169  1742    45,550  1764        17.178  1786    95,973  1808   251,089  1830          88,047
1721    61,362  1743    61,072  1765        73,778  1787    42,227  1609    63,452  1831    174,864
1722    49,443  1744    46,708  1766   116,445  1788   143,168  1810    73,514  1832    139,018
-1723    30,279  1745    34,635  1767    25,997. 1789   104,063  1811   157,025  1833    156,905
1724    61,271  1746    91,879  1768   114,002  1790   106,841  1812            30,633  1834    189,713
1.725    6,526  1747    62,993  1769        16,201  1791    90,059  1813   131,482  1835    235,207
1726   -80,031  1748    87,155  1770   101,131  1792   162,112  1814   140,202  1836    200,332
1727    69,409  1749    36,805  1771    33,143  1793    22,619  1815   123,878  1837   I 78,578
1728    41,494  1750    72,138  1772   102,650  1794   203,063  1816    46,302  1838    171,556
1729    48,441  1751    73,954  1773    45,847  1795    82,342- 1817    66,522  1839    205,537
1730    44,419  1752    82,163  1774   138,887  1796    75,223  1818   199,465  1840              34,091
1731    22,600  1753    91,214  1775    41,597  1797   157,458  1819   242,476  1841    146,1591
1732    35,135  1754   -102,012  1776   125,691  1798    56,032  1820   138,330  1842    169,776
Hop duties of particular districts.
1839.              1840.              1841.              1842.
Rochester                      X -   ~60,802 16  6  ~23,256 198        ~51,490  3  8    ~58,812  4  7
Canterbury    -      -    -      50,649  3  0         5,757  0 4        33,960 14 10        31,019 13  5
Kent    -...    111,451 19  6         29,014  0 0        85,450 18  6       90,731 18  0
Sussex   -   -       -    -     65,026 19  7          3,080 12 9        38,086 13 10       43,561 10  0
Worcester    -                   1 -  36,639 16  4      239 19 0        12,076 19  8       19,815  2 11
Farnham        -    -    -       7,730  7  2          1,643 18 7         7,702 10  2       11,678 18  4
North Clays  -    -    -         2,005 13 10             57  4 1          1,159  7 10       1,724  2  7
Essex    -           -            1,624  5  9            35171             977  3  Q        2,05019 11
Sundries       -    -    -       1,058 11  5             20  4 8           705  8  7          203 14  3
_____         ____________________205,538 12 7   34,091 17 2  146,159 1 7  169,776 6 0
HORDEINE  is the name given by Proust to the peculiar starchy matter of barley.  It
seems to be a mixture of the starch, lignine, and husks, which constitutes barley meal.
See BEER.
HORN  (Eng. and Germ.; Corne, Fr.), particularly of oxen, coWs, goats, and sheep, is
a substance soft, tough, semi-transparent, and susceptible of being cut and pressed into a
varitcy of forms; it is this property that distinguishes it from bone. Turtle or tortoise




HORN.                                      1013
shell seems to be of a nature similar to horn, but instead of being of a uniform color, it
is variegated with spots.
These valuable properties render horn susceptible of being employed in a variety
of works fit for the turner, snuff-box, and comb maker.  The means of softening
the horn need not be described, as it is well known to be by heat; but those of cutting,
polishing, and soldering it, so as to make the plates of large dimensions, suitable to
form  a variety of articles, may be detailed.  The kind of horn to be preferred is
that of goats and sheep, from its being whiter and more transparent than the horn
of any other animals.  When horn is wanted in sheets or plates, it must be steeped
min water, in order to separate the pith from the kernel, for about fifteen days in sum
mer, and'a month in winter; and after it is soaked, it must be taken out by one end,
well shaken and rubbed, in order to get off the pith; after which it must be put for
half an hour into boiling water, then taken out, and the surface sawed even, lengthways; it must again be put into the boiling water to soften it, so as to render it caqable
of separating; then, with the help of a small iron chisel, it can be divided into sheets or
leaves. The thick pieces will form three leaves, those which are thin will form only
two, whilst young horn, which is only one quarter of an inch thick, will form only one.
These plates or leaves must avain be put into boiling water, and when they are sufficiently
soft, they must be scraped with a sharp cutting instrument, to render those parts that are
thick even and uniform; they must be put once more into the boiling water, and finally
carried to the press.
At the bottom of the press employed, there must be a strong block, in which is
formed a cavity, of nine inches square and of a proportionate depth; the sheets of horn
are to be laid within this cavity, in the following manner at the bottom   first a sheet of
hot iron, upon this a sheet of horn, next again a sheet of hot iron, and so on taking care
to place at the top a plate of iron even with the last. The press must then be screwed
down tight.
There is a more expeditious process, at least in part, for reducing the horn into
sheets, when it is wanted very even. After having sawed it with a very fine and sharp
saw, the pieces must be put into a copper made on purpose, and there boiled, until sufficiently soft, so as to be able to split with pincers; the sheets of horn must then be put i
the press, where they are to be placed in a strong vice, the chaps of which are of iron
and larger than the sheets of horn, and the vice must be screwed as quick and tight as
possible; let them cool in the press or vice, or it is as well to plunge the whole into cold
water. The last mode is preferable, because the horn does not shrink in cooling. Now
draw  out the leaves of horn, and introduce other horn to undergo the same process.
The horn so enlarged in pressing, is to be submitted to the action of the saw, which
ought to be set in an iron frame, if the horn is wanted to be cut with advantage, in
sheets of any desired thickness, which cannot be'done without adopting this mode. The
thin sheets thus produced must be kept constantly very warm between plates of hot
iron to preserve their softness; every leaf being loaded with a weight heavy enough to
prevent its warping. * To join the edges of these pieces of horn together, it is necessary
to provide strong iron moulds suited to the shape of the article wanted, and to place the
pieces in contact with copper-plates or with polished metal surfaces against them; when
this is done, the whole is to be put into a vice and screwed up tight, then plunged into
boiling water, and after some time it is to be removed from thence and immersed in cold
water. The edges of the horn will be thus made to cement together and become perfectly united.
To complete the polish of the horn, the surface must be rubbed with the subnitrate of
bismuth by the p'ldm of the hand. The process is short, and has this advantage, that it
makes the horn dry promptly.
When it is wished to spot the horn in imitation of tortoise-shell, metallic solutions
must be employed as follows:-To spot it red, a solution of gold, in aqua regia, must be
employed; to spot it black, a solution of silver in nitric acid must be used; and for
brown, a hot solution of mercury in nitric acid. The right side of the horn must be
impregnated with these solutions, and they will assume the colors intended. The
brown spots can be produced on the horn by means of a paste made of red lead, with a
solution of potash, which must be put in patches on the horn, and subjected some time to
the action of heat.  The deepness of the brown shades depends upon the quantity of
potash used in the paste, and the length of time the mixture lies on the horn. A decoction of Brazil wood, or a solution of indigo, in sulphuric acid, or a deoction of saffron.
and Barbary wood may also be used.  After having employed these materials, the horn
may be left for half a day in a strong solution of vinegar and alum.
In France, Holland, and Austria, the comb-maker and horn-turners use the clippings
of horn, which are of a whitish yellow, and tortoise-shell skins, out of which they make
snuff-boxes, powder-horns, and many curious and handsome things. They first soften
the horn and shell in boiling water, so as to be able to submit them to the press in iron




1:14                                  HORNSTONE.
moulds, and by means of heat form  them  into one mass.  The degree of beat necessary
to join the horn clippings must be stronger than that for shell skins, and it can only be
found out by experience.  The heat must not however be too great, for fear of scorching
the horn or shell. Considerable care is required in these operations, not to touch the
horn with the fingers, or with any greasy body, because the grease will prevent the
perfect joining.  Wooden instruments should be used to move them, while they are at
the fire, and for carrying them to the moulds.
In mnaking a ring of horn for bell-pulls, &c., the required piece is to be first cut out
in the flat of its proper dimensions, and nearly in the shape of a horse-shoe; it is then
pressed in a pair of dies to give its surface the desired pattern; but previous to the pressure,
both the piece of horn and the dies are to be heated: the piece of horn is to be introduced between the dies, squeezed in a vice, and when cold, the impression or pattern
will be fixed upon the horn.  One particular condition, however, is to be observed in
the construction of the dies, for forming a ring. They are to be so made, that the open
ends of the horse-shoe piece of horn, after being pressed, shall have at one end a nib,
and at the other a recess of a dovetailed form, corresponding to each other; and the
second operation in forming this ring of horn is to heat it, and place it in another pair
of dies, which shall bring its open ends together, and cause the dovetailed joints to be
locked fast into each other, which completes the ring, and leaves no appearance of the
junction.
In forming the handles of table knives and forks, or other things which require to be
made of two pieces, each of the two pieces or sides of the handle is formed in a separate
pair of dies; the one piece is made with a counter-sunk groove along each side, and the
other piece with corresponding leaves or projecting edges.  When these two pieces are
formed, by the first being cut out of the flat horn, then pressed in the dies in a heated state,
for the purpose of giving the pattern, the two pieces are again heated and put together,
the leaves or edges of the one piece dropping into the counter-sunk grooves of the other
piece, and being introduced between another pair of heated dies, the joints are pressed
together and the two pieces formed into one handle.
In making the knobs for drawers which have metal stems or pins to fasten them into
the furniture, the face of the knob is to be first made in a die, as above described, and then
the back part of the knob with a hole in it; a metal disc of plate-iron is next provided
in which the metal stem  or screw  pin is fixed, and the stem  being passed through
the aperture in the back piece, and the two, that is, the back and the front pieces of horn
put together, they are then heated and pressed in dies as above described; the edge of
the back piece falling into the counter-sunk groove of the front piece, while by the heat
they are perfectly cemented together.
Mr. J. James has contrived a method of opening up the horns of cattle, by which lie
avoids the risk of scorching or frizzling, which is apt to happen in heating them over an
open fire.  He takes a solid block of iron pierced with a conical hole, which is fitted
with a conical iron plug, heats them in a stove to the temperature of melting lead, and
having previously cut up the horn lengthwise on one side with a saw, he inserts its
narrow end into the hole, and drives the plug into it with a mallet.  By the heat of the
irons, the horn gets so softened in the course of about a minute, as to bear flatting out in
the usual way.
HORNSILVER; (Argent Corne', or Kerargyre, Fr.; Hornsilber, Germ.) is a white
or brownish mineral, sectile like wax or horn; and crystallizing in the cubic system.
Its specific gravity varies from 4'75 to 5-55.  Insoluble in water; not volatile; fusible
at the blowpipe, but difficult of reduction by it.  It deposits metallic silver when
rubbed with water upon a piece of clean copper or iron.  It consists of 24-67 chlorine,
and 75-32 silver.
Hornsilver is rare in the European mines, but it occurs in great quantity in the districts
of Zacatecas, Fresnillo, and Catarce, in Mexico: and in Huantajaya, Yauricocha, &(c., in
Peru;i where it is abundantly mixed with the ores of hydrate of iron, called Pacos and
Colorados, interspersed with veins of metallic silver, which form considerable deposits in
the pencean limestones. There it is profitably mined as an ore of silver.
HORNSTONE; is a variety of rhomboidal quartz.  Being both hard and tough, it
is well adapted to form the stones of pottery mills for grinding flints; it is called chert
in Derbyshire, where it abounds.
Hornstone occurs under three modifications: splintery hornstone, conchoidal hornstone, and woodstone.  The colours of the first two are gray, white and red; they are
all massive; dull, or of a glimmering lustre. Translucent only on the thin edges. Difficult
to break. Hornstone is less brittle than flint; and by its infusibility before the blowpipe
it may be distinguished from petrosilex, which it resembles in external appearance. The geological locality of hornstone is remarkable; for it occurs in both ancient and modern formations.   It is found frequently in the veins that traverse primitive crystalline rocks,
filling up the interstices, and enveloping their metallic ores.  In the lead mine of Huel



HORSE POWER.                                        1015
gout in Brittany it is whitish; but its prevailing colour is gray. It occurs likewise in the
middle beds of the coarse limestone (calcaire grossier) in the Paris basin, which is a comparatively modern formation, as well as in the sand beds of the upper parts of this district,
near Saint Cloud, Neuilly &c.  The hornstone which occurs in secondary limestone is
called chert by the English miners. It is valuable for forming the grinding blocks of
flint mills in the pottery manufacture.
HORSE  POWER, in steam  engines, is estimated by Mr. Watt at 32,000 pounds
avoirdupois lifted one foot high per minute, for one horse. Mr. D'Aubuisson, from an
examination of the work done by horses in the whims, or gigs (machines   molottes) for
raising ore from  the mines at Freyberg, the horses being of average size and strength,
has concluded that the useful. effect of a horse yoked during eight hours, by two relays
of four hours each, in a manege or mill course, may be estimated at 40 kilogrammes
raised 1 metre per second; which is nearly 16,440 pounds raised one foot per minute:
being very nearly one-half of Mr. Watt's liberal estimates for the work of his steam
engines.
Results of the Application of Horse Power to ra'sing Water from the worinq Shafts
at Stattwood Tunnel, on the South Eastern Railway, in 1842. By Frederick William
Simms, M. Inst. C. E.-This tunnel is driven in the middle bed of the lower green sand,
between which and the surface of the ground is interposed only the upper bed of the
same stratum; but in sinking the eleven shafts for the work, it was found that the level of
the top of the tunnel, the ground assumed the character of a quicksand, saturated with
water, in such quantity that it could not be reduced by manual labour. Under these
circumstances horse gins were erected for drawing the water by barrels, containing one
hundred gallons each, weighing when full about 1310 lbs.
The engineer's intention was, to dive simultaneously from these shafts, in the direction
of the tunnel, an adit or heading to carry off the water; but the earth, which was sand
mixed with fine particles of blue clay, was so filled with water as to become a mass of
semifluid mud, great exertions were therefore necessary to overcome the water, without
erecting pumps.  At first this was accomplished by making each horse work for 12
hours and then for 8 hours per day, allowing one hour for food and rest: as the water
increased it became necessary to work night and day, and the time of each borse's working was reduced generally to 6 hours, and sometimes to 3 hours. As all the horses were
hired at the rate of seven shillings per day, the author, who had the direction of the
works, ordered a daily register to be kept of the actual work done by each horse, for
the double purpose of ascertaining whether they all performed their duty, and also
hoping to collect a body of facts relative to horse power, which might be useful hereafter.
This detailed register, which was kept by Mr. P. N. Brockedon, is appended to the
communication.
The author gives as a proposition, " that the proper estimate of horse power would be
that which measures the weight that a horse would draw up out of a well; the animal
acting by a horizontal line of traction turned into the vertical direction by a simple pulley,
whose friction should be reduced as much as possible." He states that the manner in
which the work was performed, necessarily approached very nearly to these conditions;
and after giving the principal dimensions of the horse gins, he analyzes each set of experiments, and by taking the mean of those, against which no objections could be urged, he
arrives at the following results:~
The power of a horse for 8 hours =  23,412 lbs. raised 1 foot high in one minute.
do.         do.      6         = 24,360              do.
do.         do.       4-J     =  27,056               do.
do.         do.      3. 32,943             do.
Of these results, he thinks the experiments for 6 hours and for 3 hours alone should be
adopted as practical guides, all the others being in some degree objectionable.
As a means of comparison, the following table of estimates of horse power is given:
Pounds raised   flours of
Name.              1 Foot high       Wr                    Authority.
in a Minute.     WA o
Boulton and Watt -   -   -    33,000             8         Robinson's Mech. Phil., ii. 145.
Tredgold    -     -    -        27,500           8        Tredgold on Railroads, p. 69.
Desaguliers   - - -             44,000           8
Ditto  ---          ---         27,500      Not stated       Dr. Gregory's Mathematics
More, for Society of Arts       21,120      Not stated          f     actalMen,p 183
Smeaton -22,000   Not stated




1016                               HORSE POWER.
These are much higher results than the average of his experiments, and would more
nearly accord with the extremes obtained by him; but under such excessive fatigue, the
horses were speedily exhausted, and died rapidly. Nearly one hundred horses were
employed; they were of good quality; their average height was 15 hands + inch, and
their weight about 104 cwts., and they cost from 201. to 401. each. They had as much
corn as they could eat, and were well attended to.
The total quantity of work done by the horses, and its cost, was as under
tons.
Registered quantity of water drawn 104 feet, the average height, 
28,220,800 gallons      -       -       -       -       -       - 
do. earth, 3,500 yds. 1 ton 6 cwt. per yard           -       -           4550.Total weight drawn to the surface       -          -3,955
~. d.
Total cost of horse labour, including a boy to drive each horse  -  1,585  15  3
Or 2-86d. per ton the average height of 104 ft.
As soon as the adit was driven, all the water was carried off by it, and the works are
stated to be perfectly dry.
Mr. Palmer said, it should be understood, that in stating 32,000 lbs. raised one foot
high in a minute, as the measure of the power of a horse, Boulton- and Watt had not
intended to fix that as the average work which horses were capable of performing: they
had taken the highest results of duty performed by powerful horses, in order to convince
the purchasers of their steam-engines that they received all that had been contracted
for.
He had made some experiments on the amount of work performed by horses tracking
boats on canals; on the upper end of the mast of the boat a pulley was hung; over this
the towing rope was passed, with the means of suspending to its extremity given
weights, so as exactly to balance the power exerted by the horse.
The results arrived at by these means were so various, that he could not deduce any
average conclusions; as the power exerted varied between 30 lbs. and 120 lbs., the power
diminishing as the speed was increased; he thought that 2_ miles was too high an average
estimate, and that it should not exceed 2 miles per hour.
Mr. Field remarked that in all estimates of horse power, the speed was considered
to be at an average of 24 miles per hour, and all experiments were reduced to that
standard.
Mr. Hawkins said, that some years since, he had made numerous inquiries respecting
the work done by horses in drawing upon common turnpike roads, and found that four
good horses could draw an ordinary stagecoach, with its complement of passengers, 8
miles a day, at the rate of 10 miles an hour; that if they ran stages 10 miles in the hour,
the horses must rest one day in each week; that good horses, so worked, would last only
five years, each horse drawing about half a ton: he had been informed by waggoners,
that good horses would walk at the rate of 24 miles per hour, for twelve hours out of
twenty-four, making 30 miles a day; and that they would continue to do such work day
by day, each horse drawing one ton, for many years, provided they had not been worked
hard when young.
Mr. Gravatt observed, that although there might exist some hesitation in receiving
these results of work actually performed, as a general measure of a horse's power, yet as
engineers frequently required to know what could be performed by horses, when employed.for short periods, in works of haste or difficulty, he thought that the experiments were
useful, and wQuld form good data for reference: he was sorry to observe that in too
many cases, an idea was prevalent, that it was cheaper to work a small number of horses
to death,'than' to keep a large number, and to work them fairly; the results which he
had been enabled to arrive at, were perhaps not a fair value of a horse's work, continued
for any length of time, at the best rate of economy, for both the contractor and the
employer.
The President believed that however, in cases of emergency, which he allowed did
occur iin engineering works, the forced system of labour mentioned by Mr. Gravatt might
be tolerated, he was convinced that it was not the most economical, but, on the contrary,
humanity and economy would be found to go hand in hand.
It would be desirable to know the average speed at which the different rates of work
had been performed; this was essential in order to found any calculation upon the results
given. Coach proprietors calculated that at a speed of 10 miles per hour, a horse was
required for every mile going and returning, so that one horse was kept for every mile
of road.  Now  supposing a four-horse coach, with an average load to weigh 2 tons,




HORSE POWER.                                      1017
the load for each horse was 10 cwts.; whereas in the case of a horse drawing a cart, the
gross load frequently amounted to 2 tons, but the speed was reduced to 21 miles per
hour, at which pace he conceived that 16 miles per day might be considered a fair day's
work; this therefore was double the distance with four times the load, or eight times
the coach work, but with a heavier horse.
The law that the quantity of work done was as the square root of the velocity, or
as the cube root of the velocity, in equal times, was confined to work upon canals, or
bodies moving through the water.
Mr. Rennie had trie" d some experiments on the force of traction of the boats on the
Grand Junction Canal. The towing rope was attached to a dynamometer, which had
previously been tested by weights.
The horse, although, urged at first starting, was afterwards allowed to fall into his
natural speed, which was 24 miles per hour on the average of 20 miles. The maximum
speed was 4 miles, and the minimum 2 miles, per hour. The dynamometer indicated
an ave rage of 108 lbs., which was capable of overcoming the resistance of the loaded
barge of 25 tons, being in the ratio of 15-00. The weight of the horse was about 11
cwts.
He also tried many experiments upon a fast boat, lent to him  in 1833 by the late
Colonel Page. These experiments were principally made in order to ascertain the comparative resistance of vessels moving through water at different velocities, and the Grand
Junction Canal afforded a convenient opportunity of undertaking them.
The boat was 70 feet in length, 4 feet in breadth, and drew 9 inches of water.
The traction indicated by the dynamometer the following resistance:
Miles per hour.             lbs.
At 2- the resistance was 20
3           "         27
U3        "           30
4           "         50
41        "           60
5         ^"        70 to 75
One horse was employed in these experiments.
Miles per hour.            lbs.
At 6 the resistance was 97 to 214'7        "         250
8                   336
9-69      "        411
10        "        375
114       "        892
Average 336
Two horses were employed in these experiments.
Stakes were fixed near the margin of the canal, so as to ascertain the rise and fall of
the wave caused by the boat in passing; and it was observed that when a boat passed
with a velocity of from 4 to 6 miles per hour, the rise of the wave was 5 inches, and
the fall 5 inches, making a wave of 10 inches in depth; and when the velocity was l1j
miles, the rise was reduced to 24 inches, and the fall to 24 inches.
Great difference existed in the power of horses, their weights and structure; and the
large dray horses used  by Messrs. Barclay, Perkins, & Co. did a full average duty
as assumed by Boulton an'd Watt; but considering the average power of strong and
weak animals, he had adopted 22,009 lbs. raised I foot high as the standard; much, how-,ever, depended on the nature of the work performed.
Mr. Charles Wood remarked, that although on an emergency it might be necessary
to work horses to the extent which had been mentioned, it had always been found more
economical to feed them well, and not unduly to force the speed, the weight drawn, or
the hours of labour. By the recorded experiments on ploughing, which were tried at
Lord Ducie's and by Mr. Pusey, it was shown that any increase of speed diminished the
amount of work done, in a greater ratio than it was affected by an increase of the load.
In drawing loads the weight of the animal was a point of consideration and importance,
and when extra exertions and muscular action were required, the nearer horses ap.
proached to "' thorough bred," the greater was the result.
Mr. Davidson gave the following statement of the work performed by a London
brewer's horse per day; the cost of feed and of wear and tear per horse per annumi being
derived from  actual experience among a large number of horses at Messrs. Truman,
Hanbury, & Co.'s brewery. The feed, &c. is supposed to have cost the same per quarter
per truss, &c. each year.




1018                               HORSE POWER.
Pounds Weight Pounds Weight Average Pounds   Cost of Feed    Difference per
drawn 6} Miles  drawn 61 Miles   Weight drawn   and Straw per  Horse of Horses
per Horse per  per Horse return-  13 Miles per    Horse per    bought and sold
Day.        ing per Day.   Horse per Day.      Annum,        per Annum.
Lbs.            Lbs.            Lbs.          ~  &  d.        ~  8. d.
1835          5,148            1,716           3,342         4327           10  0  3
1836           5,072           1,767           3,389         43 16  6        9180
1837
1838          5,057            1,698           3,377         41180           9159
1839          5,287            1,740           3,513         42911           9  7  1
1840          5,786            1,820           3,803         46117           71711
1841          5,311            1,750           3,530         4501           101611
1842           5,263           1,740           3,501         4709           10  8  0
Total      36,924           12,171          24,455        309195          68311
Average 7
years
nearly -       5,275           1,738            3,506         4457            91410
Mr. Horne stated that Messrs. Tredwell had a contract on the South Eastern Railway, near where Mr. Simms' experiments were made; they had upwards of 100 horses,
whose average cost was about 301.; they were worked 10 hours per day, and were well
fed, so that their value was but little reduced, and they were eventually sold for nearly
the same prices as they originally cost. These contractors had about 400 horses on the
Southampton Railway, which  cost them  about 251. each.  The same course of not
over-working, and of feeding them well, was pursued from motives of economy, and they
found it answer.
It was Mr. Jackson's practice to keep so many horses for his work as not to be under
the necessity of working them more than 10 hours per day; he gave to each a peck of
corn a-day  by this means he had been able to keep up their value.
On the Chester and Crewe Railway he had about 300 horses at work, and towards
the end of the contracts owing to circumstances over which he had no control, he was
obliged to work them 14 or 15 hours per day; and in the course of four months horses
that had been worth 251. were so reduced as not to be valued at above 7l. He is a great
advocate for steady work and good keep.
On the Tame Valley Canal there had been sometimes between 300 and 400 horses'
hut as the work was nearly finished, many had been sold. Those sub-contractors whbo
had kept a sufficient number of horses for the work, so as not to have them in harness
more than i2 hours per day, had realized nearly the same prices they had given for
them in the first instance.
The horses belonging to Mr. Edwards, the sub-contractor for the  excavation of
Newton Hill, and those of Mr. W. Tredwell, sub-contractor for the Friar Park Farm
cuttings, were purchased from the same parties at prices varying from 201. to 351. The
Former had been acting on the principle of getting out of the horses all he could, working them frequently 15 and 16 hours at a time; and the consequences were, that all his
stock was in bad condition, and he would be glad to get 61. or 71. a-piece for them. Oa
the other hand, Mr. W. Tredwell, who was an excellent horse master, and who did not
work his horses beyond their strength, would be able to sell them for about as much as
he gave for them,-indeed he had done so already for those that he had parted with.
Having been a good many years in the service of the late Mr. Mcintosh, Mr. Home
could state that it never was his system to over-work his horses. It did sometimes hap.
pen that there was no alternative, but the deviation from  the regular rule in every instance showed that his system was founded on right principles. The over-worked horses
were most liable to disease, and the time lost by illness formed an important item;
whereas there were plenty of instances in which horses that had worked their regular
10 hours per day, and had been properly fed, had worked for five or six years without
losing a single day by illness. On the whole he felt convinced, that both on the score
of humanity and economy, the horse was the more valuable servant when treated with
kindness.
Mr. Beardmore said that a case had occurred in a work near Plymouth, which he believed would give the fair value of the work actually performed daily by a horse for a
considerable period.
A quarry-wagon, weighing 2j tons, carrying an average load of stone of 51- tons, waa
drawn by one horse along a railway 960 feet in length, 260 of it being level, and the remaining 700 feet having an inclination of 1 in 138.  During48 working days. the numbei




HOSIERY.                                      1019
of trips was 1,302, or an average of 271 trips each day; the time of performing each
trip was 4 minutes, or at a speed of 272 miles per hour; and the total weight drawn,
including that of the waggons, was 23,959,600 lbs.
Repeated experiments proved, that upon the incline of 1 in 138 the waggons in their
ordinary working state would just remain stationary; the friction was therefore assumed
to be 162 lbs. per ton; by calculation it was found that the horse raised 39,320 lbs. 1
foot high perk minute during the 8 working hours each day: the useful effect, or net
amount of stone carried, being 21,38 lIbs. raised 1 foot high per minute. This difference
between the work done and the useful effect arose from  the necessary strength and
weight of the waggons.
The animal employed was a common Devonshire cart-horse, 8 years old, 15 hands
high, and weighed 10- cwts.; he continued doing the same work throughout a whole
summer, remaining in good condition; but a lighter horse was found unequal to it.
HOSIERY (Bonniterie, Fr.; Strurmpfweberei, Germ.).  The stocking frame, which is
the great implement of this business, though it appears at first sight to be a complicated
machine, consists merely of a repetition of parts easily understood, with a moderate degree of attention, provided an accurate conception is first formed of the nature of the
hosiery fabric.  This texture is totally different from  the rectangular decussation which
constitutes cloth, as the slightest inspection of a stocking will show;  i-r this, instead of
having two distinct systems of thread, like the warp and the weft, which are woven
together, by crossing each other at right angles, the whole piece is composed of a single
thread united or looped together in a peculiar manner, which is called stocking-stitch,
and sometimes chain-work.
This is best explained by the view  in fig.  60.  A  single thread is formed into
a number of loops or waves, by arranging it
760'            8            R over a number of parallel needles, as shown at
R: these are retained or kept in the form of
loops or waves, by being  drawn  or looped
through similar loops or waves formed by the
thread of the preceding course of the work, s.
The fabric thus formed by the union of a num
ber of loops is easily unravelled, because the
stability of the whole piece depends upon the
ultimate fastening of the first end of the thread;
and if this is undone, the loops formed by that
551                                     end will open, and release the subsequent loops,
one at a time, until the whole is unravelled, and drawn out into the single thread from
which it was made. In the same manner, if a thread in a stocking-piece fails, or breaks
at any part, or drops a stitch, as it is called, it immediately produces a hole, and the extension of the rest can only be prevented by fastening the end. It should be observed
that there are many different fabrics of stocking-stitch for various kinds of ornamental
hosiery, and as each requires a different kind of frame or machine to produce it, we
should greatly exceed our limits to enter into a detailed description of them all. That
species which we have represented in fig. 160 is the common stocking-stitch used for
plain hosiery, and is formed by the machine called the common stocking-frame, which is
the groundwork of all the others. The operation, as we see, consists in drawing the
loop of a thread successively through a series of other loops, so long as the work is
continued, as is very plainly shown for one stitch in fig. 761.
There is a great variety of different frames in use for producing various ornamental
kinds of hosiery. The first, which forms the foundation of the whole, is that for knitting
plain hosiery, or the common stocking-frame.
Of this valuable machine, the invention of Mr. Lee, of Cambridge, a side elevation is
given in fig. 762, with the essential parts. The framing is supported by four upright
posts, generally of oak, ash, or other hard wood. Two of these posts appear at A A, and
the connecting cross rails are at c c. At B is a small additional piece of framing, which
supports the hosier's seat. The iron-work of the machine is bolted or screwed to the
upper rails of the frame-work, and consists of two parts. The first rests upon a sole of
polished iron, which appears at D, and to which a great part of the machinery is
attached. The other part, which is generally called the carriage, runs upon the iron
sole at D, and is supported by four small wheels, or trucks, as they are called by the
workmen. At the upper part of the back standard of iron are joints, one of which
appears at Q; and to these is fitted a frame, one side of which is seen extending to H.
By means of these joints, the end at H may be depressed by the hosier's hand, and it
returns, when relieved, by the operation of a strong spring of tempered steel, acting
between a cross bar in the frame and another below.  The action of this spring is
very apparent in fig. 763.  In the front of the frame, immediately opposite to where
the hosier sits, are placed the needles which form  the'cops.  These needles, or rathei




1020                                 HOSIERY.
hooks, are more or  less numerous, according to the coarseness or fineness of the
stocking; and this, although unavoidable, proves a very considerable abatement of
762    ^^' "^^                       the value of a stocking-frame. In
D o,^^^    /         / ^^B^^^\                     almost every other machine (for
WHQ //  \\   J  example, those employed in spin/  _P                                           ning or weaving), it is easy to
adapt any one  either to work
coarser or finer work, as it may
be wanted.  But in the manaOF ~   I *      facture of hosiery, a frame once
_____|_______ -    -? ^ },.finished, is limited for ever in its
C     -                            C!          operation to the same quality of
^    _________ __________         work, with this exception, that
by changing the stuff, the work
may be made a little more dense
A             |HL                                oi flimsy; but no alteration in
l  A          the size or quantity of loops "an
take place.   Hence where the
manufacture is extensively prosecuted, many  frames  may  be
B   thrown idle by every vicissitude
of demand; and where a poor
mechanic does purchase his own
frame, he is for ever limited to
the same kind of work.   The
gauge, as it is called, of a stocking-frame  is  regulated  by  the
-     number of  loops  contained  in
three inches of breadth, and varies very much; the coarsest frames in common use being
about what are termed Fourteens, and the finest employed in great extent about
Forties. The needles are of iron wire, the manufacture of which is very simple; but
long practice in the art is found necessary before a needle-maker acquires the dexterity
which will enable him both to execute his work well, and in sufficient quantity.to render
his labor productive.
The process of making the needles is as follows:-Good sound iron wire, of a proper
fineness, is to be selected; that which is liable to split or splinter, either in filing,
punching, or bending, being totally unfit for the purpose. The wire is first to be cut
into proper lengths, according to the fineness of the frame for which the needles are
designed, coarse needles being considerably longer than fine ones.  When a sufficient
number (generally some thousands) have been cut, the wire must be softened as much
as possible. This is done by laying them in rows in a flat iron box, about an inch
deep, with a close cover; the box being filled with charcoal between the strata of wires.
This box, being placed upon a moderate fire, is gradually heated until both the wires
and charcoal have received a moderate red heat, because, were the heat increased to what
smiths term the white heat, the wire would be rendered totally unfit for the subsequent
processes which it has to undergo, both in finishing and working. When the box has
been sufficiently heated, it may be taken from  the fire, and placed among hot ashes,
until both ashes and box have gradually cooled; for the slower the wires cool, the
sofler and easier wrought. they will be. When peifectly cool, the next process is to
punch a longitudinal groove in the stem of every needle, which receives the point or
barb, when depressed. This is done by means of a small engine worked by the power
of a screw and lever.  The construction of these engines is various; but a profile
elevation of one of the most simple and com-'63. monly used will be found in fig. 763.  It
consists of two very strong pieces of malleE                                    able iron, represented at A and c, and these
A                          two pieces are connected by a strong wellfitted joint at B. The lower piece, or sole of
the engine at c, is screwed down by bolts to
F   ^^T^\^  ^B   a strong board or table, and the upper piece
A Will then rise or sink at pleasure, upon the
joint B. In order that A may be very steady
in rising and sinking, which is indispensable
H-        C                 to its correct operation, a strong bridle of
iron, which is shown in section at E, is added to confine it, and direct its motion. In
the upper part of this bridle is a female screw, through which the forcing screw passei,
which is turned by the handle or lever D. To the sole of the engine c is fixed a bolster




HOSIERY.                                   1021
of tempered steel, with a small groove to receive the wire, which is to be punched; and
in the upper or moving part A, is a sharp chisel, which descends exactly into the groove,
when A is depressed by the screw. These are represented at F, and above H. At G is a
strong spring which forces up the chisel when the pressure of the screw is removed. The
appearance of the groove, when the punching is finished, will be rendered familiar by
inspecting fig. 764, p. 1022. When the punching is finished, the wires are to be brought
to a fine smooth point by filing and burnishing, the latter of which should be very completely done, as, besides polishing the wire, it tends greatly to restore that spring and
elasticity which had been removed by the previous operation of softening. The wire is
next to be bent, in order to form the hook or barb; and this is done with a small piece
of tin plate bent double, which receives the point of the wire, and by its breadth regulates the length of the barb. The stem of the needle is now flattened with a small
hammer, to prevent it from turning in the tin socket in which it is afterwards to be cast;
and the point of the barb being a little curved by a pair of small pliers, the needle is
completed.
In order to fit the needles for the frame, they are now cast into the tin sockets, or leads,
as they are called by the workmen; and this is done by placing the needles in an iron
mould, which opens and shuts by means of a joint, and pouring in the tin while in a
state of fusion. In common operations, two needles are cast into the same socket. The
form of the needle, when complete and fitted to its place in the frame, will be seen in
fig.'65, which is a profile section
~FA ^ll^ of the needle-bar, exhibiting one
765                           needle. In this figure a section of
I                                              the pressure is represented at F;
B      d'~=' ~ 1  G  ~^=====^      the needle appears at G, and the
_JL__%~  K  ~.... ~socket or level at K. At H, is a
IH                            section of the needle-bar, on the
fore part of which is a small plate
of iron called a verge, to regulate the position of the needles. When placed upon the
bar resting against the verge, another plate of iron, generally lined with soft leather, is
screwed down upon the sockets or leads, in order to keep them all fast. This plate and
the screw appear at I. When the presser at F is forced down upon the barb, this sinks
into the groove of the stem, and the needle is shut; when the presser rises, the barb opens
again by its own elasticity.
The needles or hooks being all properly fitted, the next part of the stocking-frame to
which attention ought to be paid, is the machinery for forming the loops; and this consists of two parts. The first of these, which sinks between every second or alternate
needle, is represented at o, fig. 762, and is one of the most important parts of the whole
machine. It consists of two moving parts; the first being a succession of horizontal
levers moving upon a common centre, and called jacks, a term applied to vibrating levers
in various kinds of machinery as well as the stocking-frame. One only of these jacks
can be represented in the profile fig.'62; but the whole are distinctly shown in a horizontal position in fig. 766; and a profile upon a very enlarged scale is given in fig. 167.
11' 7i66                                        767.-=_   I             4
0 -        I
z




1022                                  HOSIERY.
The jack shown in fig. 762, extends horizontally from o to r, and the centre of motion
is at R. On the front, or right hand part of the jack at o, is a joint suspending a very
thin plate of polished iron, which is termed a sinker.  One of these jacks and sinkers is
allotted for every second or alternate needle.  The form of the sinker will appear at s,
fig. 767; and in order that all may be exactly uniform in shape, they are cut out and
finished between two stout pieces of iron, which serve as moulds or gauges to direct the
frarme-smith. The other end of the jack at I, is tapered to a point; and when the jacks
are in their horizontal position, they are secured by small iron springs, one of which is
represented at i, fig. 762, each spring having a small obtuse angled notch to receive the
point of the jack, against which it presses by its own elasticity.  In fig. 76  the centre is
at it; the pointed tail is omitted for want of roxom, the joint is at o, and the throat of the
sinker, which forms the loop, is at s.  The standards at R, upon which the jack moves,
are called combs, and consist of pieces of flat smooth brass, parallel to, and equidistant
from each other.  The cross-bar R, which contains the whole, is of iron, with a perpendicular edge or rim on each side, leaving a vacancy between them, or a space to receive
the bottom part or tails of the combs. The combs are then placed in the bar, with a flat
piece of brass called a countercomb, between each, to ascertain and preserve their distances
from each other.  These countercombs are exactly of the same shape as the combs, buL
have no tails.  When both combs and countercombs are placed in the bar, it is luted
with clay so as to form a mould, into which is poured a sufficient quantity of melted tin.
When the tin has had time to cool, the countercombs having no tails are easily taken out,
and the combs remain well fastened and secured by the tin, which has been fused entirely
round them.  Thus they form a succession of standards for the jacks; and a hole being
drilled through each jack and each comb, one polished wire put through, serves as a com
mon centre for the whole.
The jack sinkers being only used for every alternate or second needle, in order to
complete this part of the apparatus, a second set of sinkers is employed.  These are, in
form and shape, every way the same as the jack sinkers, but they are jointed at the top
into pieces of tin, all of which are screwed to the sinker bar H, fig. 762; and thus a
sinker of each kind descends between the needles alternately.  By these sinkers the
loops are formed upon all the needles, and the reason of two sets different in operation
being employed, will be assigned in describing the mode of working the frame.  The
presser of the operation, of which something has already been said, appears at F; and
of the two arms which support and give motion to it, one appears very plainly at E, its
centre of motion being at c.  The circular bend given to these arms, besides having an
768                             ornamental effect, is very useful,
in order to prevent any part from
^ ______________^______.______________ \Q interfering with the other parts
which are behind, by elevating
them entirely above them. The
II                                                 extremities of these arms at the
are connected by a cross bar,
which has also a circular bend
in the middle, projecting downwards, for a reason similar to that
at          X^^^^^                 ^already assigned.  This bend is
concealed in fig. 762, but visible
in the front elevation, fig. 768.
From  the middle of the bend,
the presser is connected with the
____________________________ ____^ middle treadle by a depending
wire appearing at M, fig.'762, and
thus, by the pressure of that
treadle, the presser is forced down
to close the barbs of the needle.
The re-ascent of the presser is
sometimes effected by means of
a counterpoising weight passing
over a pulley behind; and some__JBj      times by the reaction of a wooden
spring, formed of a strong hoop' ^'                                            like that represented at K. The
latter of these is preferred, espeh64                             cially by the Nottingham hosiers,'764____________                because, as they assert, it makes




HOSIERY.                                      1023
rapidity, and co.sequently saves time in working.  I-ow far this may be practic'lly the
case, it would be superfluous here to investigate; but it is obvious that the wooden spring,
if very stiff, must add much to the hosier's exertion of his foot, already exercised against
the united spring of all his barbs; and this inconvenience is much complained of by those
who have been accustomed to work with the counterpoise.
At L are two pulleys or wheels, of different diameters, moving upon a common centre,
by which the jack sinkers are relieved from the back springs, and thrown downwards to
form the loops upon the needles.  About the larger wheel is a band of whipcord, passing twice round, the extremities of which are attached to what is called the slur, which
disengages the jacks from the back springs. The smaller pulley, by another band,
communicates with the right and left treadle; so that these treadles, when pressed
alternately, turn the pulleys about in an inverted order.  The directions of these bands
also appear more plainly in the front elevation, fig. 768.  The construction of the slur,
and its effect upon the jacks, will also be rendered apparent by fig.'769.  In this
figure, eight jacks are represented in section, the tail part of three of which, 1, 2, 3, are
thrown up by the slur in its progress from  left to right; the fourth is in the act of
rising, and the remaining four, 5, 6, 7, and 8, are still unacted upon, the slur'not yet
having reached them.  As the slur acts in the direction of the dotted line x, x, fig.'766,
behind the centres of the jacks, it is hardly necessary to remark, that this forcing up of
the tails must of course depress the joints by which the sinkers in front are suspended.
The jack sinkers falling successively from the loops on every alternate needle, in the way
A                                             ^^B  represented at fig. 770, where both
kinds of sinkers appear in section, the
light part expressing what is above'P70                                               the point at which the throat of the
sinker operates upon the thread, and
the dark part what is below.  The
CS  li~ff~l  8  iffli~ffl  1^D                    second set, or, as they are called, the
I  -— lead sinkers, from  the manner of
jointing them, and suspending them from the bar above, appear still elevated; the
position of the bar being represented by the line A, B. But when these are pulled down
to the level of the former by the operator's hands, the whole looping will be completed,
and the thread c, D, which is still slack, will be brought to its full and proper degree of
tension, which is regulated by stop screws, so as to be tempered or altered at pleasure.
The sinking of this second set of
AC           sinkers, may be easily explained by'71                                                 fig.'771. The direction of the sinkI ^        ^"^~"^^                     ers is expressed by the line E; the
IC                                      bar from which they are suspended
I             ^^~-^^                    will be at A; the top frame is in the
E                             F           direction from  A  to B; the back
standards at D, and the joint at B, is
the centre of motion. If E is pulled
perpendicularly downwards, the spring c will be contracted, and its upper extreme point
G, will be brought nearer to its lower extreme point F, which is fixed. Again, when the
force which has depressed E is removed, the spring c will revert to its former state, and
the sinkers will rise. The raising of the jack sinkers and jacks takes place at the same
time, by the hosier raising his hands; and for the cause of this we must revert to fig.
766.  The lead sinkers in rising lay hold of notches, which raise the extreme parts of
the set of jacks z, z, which are called half-jacks. Between the extremities of these at z, z,
is a cross bar, which, in descending, presses all the intermediate jacks behind the common
centre, and restores them to their original posture, where they are secured by the back
springs, until they are again relieved by the operation of the slur recrossing at the next
course.
Working of the frame.-In order to work a frame, the whole apparatus being previously put into complete order, the hosier places himself on the seat B in front, and provides himself with a bobbin of yarn or stuff. This bobbin he places loosely on a vertical
pin of wire, driven into one side of the frame contiguous to the needles, so that it may
turn freely as the stuff is unwound from it. Taking the thread in his hand, he draws it
loosely along the needles, behind the barbs, and under the throats of the sinkers.  He
then presses down one of the treadles to pass the slur along, and unlock the jacks from
the back springs, that they may fall in succession.  When this is done, the number of
loops thus formed is doubled by bringing down the lead sinkers, and the new formed
loops are lodged under the barbs of the needles by bringing forward the sinkers.  The
preceding course, and former fabric, being then again pushed back, the barbs are shut
by depressing the middle treadle, and forcing down the presser upon the needles.  The
former work is now easily brcught over the shut needles, after which by raising the




1024                                  HOSIERY.
hands, both sets of sinkers are raised; the jacks are locked by the back springs, and the
hosier goes on to another course.
From this it will be apparent, that the remark made in the outset is well founded,
that there are, in reality, no complicated or difficult movements in the stocking-frame.
Almost the. whole are merely those of levers moving upon their respective fulcra, excepting
that of the carriage which gives the horizontal motion to the sinkers, and that is merely
an alternate motion on four wheels. Yet the frame is a machine which requires considerable experience and care, both to work it to advantage, and also to keep it in good
order. This circumstance arises greatly from the small compass in which a number of
moving parts mutst be included.  Owing to this, the needles, unless cautiously and delicately handled, are easily bent or injured. The same circumstance applies with equal
or greater force to the sinkers, which must be so very thin as to be easily injured. But
as these must work freely, both in a perpendicular and horizontal direction between the
needles, in a very confined and limited space, the slightest variation in either, from being
truly and squarely placed, unavoidably injures the others. When a hosier, either ignorant of the mechanical laws, of their relation to each other, or too impatient to wait for
the assistance of another, attempts to rectify defects, he in most cases increases them tenfold, and renders the machine incapable of working at all, until repaired by some more
experienced person. This circumstance has given rise to a set of men employed in this
trade, and distinguished by the name of upsetters; and these people, besides setting new
frames to work, have frequently more employment in repairing old ones injured by want
of care or skill, than many country apothecaries, who live in unhealthy parishes, find in
tampering with the disorders of mankind.
It seeims unnecessary to go further into detail respecting a machine so well known,
and which requires practical attention even more than most others. It may, therefore
be sufficient to describe shortly some of its varieties, the most simple and common of
which is the rib stocking-frame.
Rib stocking-frame. - This frame, which, next to the common frame, is most extensively in use, is employed for working those striped or ribbed stockings, which are very
common in all the different materials of which hosiery is formed.  In principle it does
not differ from the common frame, and not greatly in construction. The preceding general description will nearly apply to this machine with equal propriety as to the former;
that part, however, by which the ribs or stripes are formed, is entirely an addition, and
to the application of this additional machinery it may be proper to pay the chief attention, referring chiefly to fig. 768, which is a front elevation.
This figure has been already referred to for the illustration of those parts of
the machinery which are common to both, and those parts therefore require no recapitulation. The principle of weaving ribbed hosiery possesses considerable affinity to
that which subsists in the weaving of that kind of cloth which is distinguished by the
name of tweeling, for the formation of stripes, with some variation arising merely from
the different nature of the fabric. In cloth weaving, two different kinds of yarn intersecting each other at right angles, are employed; in hosiery only one is used. In the
tweeling of cloth, striped as dimity, in the cotton or kerseymere, and in the woollen manufacture, the stripes are produced by reversing these yarns. In hosiery, where only one
kind of yarn is used, a similar effect is produced by reversing the loops. To effect this
reversing of the loops, a second set of needles is placed upon a vertical frame, so that
the bends of the hooks may be nearly under those of the common needles. These
needles are cast into tin moulds, pretty similar to the former, but more
P72  7 p    oblique or bevelled towards the point, so as to prevent obstructions in
working them. They are also screwed to a bar of iron, generally lighter
than the other, and secured by means of plates: this bar is not fixed,
but has a pivot in each end, by means of which the bar may' have a kind
of oscillatory motion on these pivots. The two frames of iron support this
~\    bar; that in which it oscillates being nearly vertical, but inclined a little
towards the other needles.  Fig.,72, which is a profile', elevation, will
serve to illustrate the relative position of each bar to the other. The
Q   lower or horizontal frame, the ends only of which can be seen in fig.
~ 768 under a a, appears in profile in fig. P72, where it is distinguished
by d. The vertical frame at a is attached to this by two centre screws,
which serve as joints for it to move in. On the top of this frame is the
rib-needle bar at f, in figs.'762 and 772, and one needle is represented
in fig. P72 at f. At g is a small presser, to shut the barbs of the ribneedles, in the same manner as the large one does those of the frame.
At h is one of the frame needles, to show the relative position of the one
set to the other. The whole of the rib-bar is not fitted with needles
like the other; for here needles are only placed where ribs or stripes
are to be formed, the intervals being fillel up with blank leads, that is




HOT-FLUE.                                   1025
to say, with sockets of the same shape as the others, but without needles; being merely
designed to fill the bar and preserve the intervals. Two small handles depend from the
needle bar, by which the oscillatory motion upon the upper centres is given. The rising
and sinking motion is communicated to this machine by chains which are attached tc
iron sliders below, and which are wrought by the hosier's heel when necessary. The
pressure takes place partly by the action of the small presser, and partly by the motion
of the needles in descending. A small iron slider is placed behind the rib-needles, which
rises as they descend, and serves to free the loops perfectly from each other.
In the weaving of ribbed hosiery, the plain and rib courses are wrought alternately.
When the plain are finished, the rib-needles are raised between the others, but no additional stuff is supplied. The rib-needles, intersecting the plain ones, merely lay hold of
the last thread, and, by again bringing it through that which was on the rib-needle before, give it an additional looping, which reverses the line of chaining, and raises the rib
above the plain intervals, which have only received a single knitting.
HOT-FLUE is the name given in England to an apartment heated by stoves or
steam pipes, in which padded and printed calicoes are dried hard.  Fig. 73 represents
the simplest form of such a flue, heated Ly the vertical round iron stove c, from whose
top a wide square pipe proceeds upwards in a slightly inclined direction, which receives
the current of air heated by the body and capital of the stove. In this wide channe.
there are pulleys, with cords or bands which suspend by hooks, and conduct the web of




1026                               HOT-FLUE.
calico, from the entrance at B, where the operative sits, to near the point A, and back
again. This circuit may be repeated once or oftener till the goods are perfectly dried.
At D the driving pulley connected with the main shaft is shown.  Near the feet of the
operative is the candroy or reel upon which the moist goods are rolled in an endless web;
so that their circulation in the hot-air channel can be continued without interruption, as
long as may be necessary.
Fig. 774 is a cross section of the apparatus of the regular hot-flue, as it is mounted'774                     in the most scientific calico works of
England, those of James Thomson, Esq.,
of Primrose, near Clitheroe, Lancashire.
a    a a a a, is an arched apartment, nearly 30
yards long, by 13 feet high, and 10 feet
wide.  Through about one half of this
gallery there is a horizontal floor sup/l r  III  ported on arches, above which is the driest
space, through which the goods are finally
4   _ ~,,passed before they escape from the hot-flue,
m  k.                   ^1., _  -: P k   Z' U after they have been previously exposed to
the hot but somewhat moist air of the
lower compartment.  A large scuare flue
covered with cast-iron plates runs along
the whole bottom  of the gallery. It is
divided  into  two  loi., parallel vaults,
~ X ~ aiW^ l  ~~  III     whose sections are seen at u, u, fig. 74,
covered  with  the cast-iron  plates v v,
4    grooved at their ends into one another. The
thickness of these plates is increased progressively as they come nearer to the fireplace or furnace. There are dampers which regulate the draught, and of course the heat
of the stove. h h are the air-passages or vent-holes, left in the side walls, and which by
means of a long iron rod, mounted with iron plates, may be opened or closed together
to any degree.  k k are the cast-iron supports of the tinned brass rollers which guide
the goods along, and which are fixed to the cross pieces represented by r r, fig. 74.
11 are iron bars for supporting the ventilators or fans (see the fan under FOUNDRY).
These fans are here enclosed within a wire grating.  They make about 300 turns per
minute, and expel the moist air with perfect effect. s indicates the position of the windows, which extend throughout the length of the building. t is a gas-light jet, placed at
the side of each window to supply illumination for night work.
The piece is stretched along the whole extent of the gallery, and runs through it in
the course of one minute and a half; being exposed during its passage to the heat of
212~ Fahr.
In fig. 775, A is the iron door of entrance to the hot-flue gallery; at b is the padding machine, where the goods are imbued with the general mordant.  The speed of




JAOQUARD.                                      1027
the padded calicoes requires for each piece of 28 yards, 3 pounds of coals for the furnace
when a fan is employed, and four pounds without it.
HYDRATES; are compounds of the oxides, salts, &c. with water in definite or equivalent proportions. Thus slaked lime consists of one atom of quick-lime = 28, + one atom
of water = 9, of which the sum is 37 on the hydrogen scale.
HYDRAULIC PRESS. See OIL, PRESS, and STEARINE.
HYDRYODIC ACTD; (Acide Hydriodique, Fr.; Hydriodsaure, Germ.) is an acid formed
by the combination of 9921 parts of iodine, and 0'79 hydrogen. When pure, it occurs in
the gaseous state, but it combines with water, like the hydrochloric or muriatic acid gas,
into a liquid acid.
HYDROCHLORIC ACID; the new chemical name of muriatic acid, which see.
HYDROGEN; (Eng. and Fr.; Wasserstoff, Germ.) an undecompounded gaseous body;
the lightest of all ponderable matter, whose examination belongs to chemistry.
HYDROMETER; an instrument for ascertaining the specific gravities of liquids.
Bauimn's hydrometer, which is much used in France, and other countries of the continent
of Europe, when plunged in pure water, at the temperature of 58~ Fahr., marks 0 upon
its scale; in a solution containing 16 per cent. of common salt (chloride of sodium), and
85 of water by weight, it marks 15~0; so that each degree is meant to indicate a density
corresponding to one per cent. of that salt. See AREOMETER, for comparative tables of
hydrometers.
HYDROSULPHTURETS; chemical compounds of bases with  sulphuretted  hydrogen.
HYMENOEA  COURBARIL; a tree growing in South America, from which the resin
animg exudes.
HYOSCIAMUS NIGER. Henbane is a plant used in medicine, from which modern
chemistry has extracted a new crystalline vegetable principle called hyosciamine, which
is very poisonous, and when applied in solution to the eye, determines a remarkable
dilatation of the pupil; as belladonna also does.
HYPOSIULPHATES; HYPOSULuHITEs; saline compounds of the hyposulphuric or
hyposulphurous acid with bases.
HYPEROXYMURIATES; the old and incorrect name for CHLORATES.
HYPOSULPHATE OF SODA. Pure crystallized carbonate of soda is dried as much
as possible, and reduced to a fine powder; 1 lb. of it is then mixed with 10 ozs. of flowers
of sulphur, and the mixture is heated in a glass or porcelain dish, gradually, until the
sulphur melts.  The mass which cakes together is kept at this temperature and is
divided, stirred and mixed, in order that each part may be brought into contact with the
atmosphere. The sulphuret of sodium formed passes, under these circumstances, by the
absorption of oxygen from the atmosphere, with a slight incandescence, gradually into
sulphite of soda. It is dissolved in water; filtered, the liquid immediately boiled with
flowers of sulphur; the filtered, nearly colourless, strongly concentrated liquid affords
hyposulphate of soda in very pure and beautiful crystals, and in large quantity.
When the mixture is heated too quickly, some sulphur is easily burnt; there then
remains a portion of undecomposed carbonate of soda, which contaminates the hyposulphite in the first crystallization, but which may very readily be separated from it.
HYPOSULPHITE OF SODA. This salt, so extensively used in the practice of
Daguerreotyping, may be easily prepared in quantities by the following process:-Mix
one pound of finely pulverised ignited carbonate of soda with ten ounces of flowers of
sulphur, andh eat the mixture slowly in a porcelain dish till the sulphur melts. Stir the
fused mass so as to expose all its parts freely to the atmosphere, whereby it passes from
the state of a sulphuret, by the absorption of atmospherical oxygen, into that of a
sulphite, with the phenomenon of very slight incandescence.  Dissolve in water,
filter the solution, and boil it immediately along with flowers of sulphur. The filtered
concentrated saline liquid will afford, on cooling, a large quantity of pure and beautiful
crystals of hyposulphite of soda.
J.&J.
JACK, called also jack in a box, atid hand-jack, is a portable, mechanical instrument,
consisting of a rack and pinion, or a pair of claws and ratchet bar, moved by a winch
handle for raising heavy weights a little way off the ground.
JACK and JACK-SINKERS, are parts of a stocking frame. See HOSIERY.
JACK-BACK, is the largest jack of the brewer.
JACQUARD. A  peculiar and most ingenious mechanism, invented by M. Jacquart
of Lyons, to be adapted to a silk or muslin loom for superseding the employment
6 P 2




1028                              JACQUARD LOOM.
of draw-boys, in weaving figured goods. Independently of the ordinary play of the
warp threads for the formation of the ground of such a web, all those threads which
should rise simultaneously to produce the figure, have their appropriate healds, which a
child formerly raised by means of cords, that grouped them together into a system, in
the order, and at the time desired by the weaver. This plan evidently occasioned no
little complication in the machine, when the design was richly figured; but the apparatus
of Jacquart, which subjects this manceuvre to a regular mechanical operation, and derives
its motion from a simple pedal put in action by the weaver's feet, was generally adopted
soon after its invention in 1800.  Every common loom  is susceptible of receiving this
beautiful appendage. It costs in France 200 francs, or 81. sterling, and a little more in
this country.
Fig. 776. is a front elevation of this mechanism, supposed to be let down. Fig. 777.
is a cross section, shown in its highest position. Fig. 778. the same section as the preceding, but seen in its lower position.
A, is the fixed part of the frame, supposed to form a part of the ordinary loom; there
are two uprights of wood, with two cross-bars uniting them at their upper ends, and
leaving an interval x y between them, to place and work the movable frameB, vibrating
round two fixed points a a, placed laterally opposite each other, in the middle of the
space x y, fig. 776.
c, is a piece of iron with a peculiar curvature, seen in front, fig. 776., and in profile,
figs. 777. and 778. It is fixed on one side upon the upper cross-bar of the frame B, and
on the other, to the intermediate cross-bar b of the same frame, where it shows an
inclined curvilinear space c, terminated below by a semicircle.
D, is a square wooden axis, movable upon itself round two iron pivots, fixed into its
two ends; which axis occupies the bottom of the movable frame B. The four faces of this
square axis are pierced with three round, equal, truly-bored holes, arranged in a quincunx. The teeth a, fig. 780., are stuck into each face, and correspond to holes a, fig. 783.,
made in the cards which constitute the endless chain for the healds; so that in the successive application of the cards to each face of the square axis, the holes pierced in one
card may always fall opposite to those pierced in the other.
The right-hand end of the square axis, of which a section i shown in double size,
fig. 779., carries two square plates of sheet iron d, kept parallel to each other and a little
apart, by four spindles e, passed opposite to the corners. This is a kind of lantern in
whose spindles, the hooks of the levers ff, turning round fixed points g g' beyond the
right hand upright A, catch hold, either above or below at the pleasure of the weaver,
according as he merely pulls or lets go the cord z, during the vibratory movement of the
frame B.
E is a piece of wood shaped like a T, the stem of which prolonged upwards, passes
freely through the cross-bar 6, and through the upper cross-bar of the frame B, which
serves as guides to it. The head of the T piece being applied successively against the
two spindles e, placed above in a horizontal position, first by its weight, and then by the
spiral spring h, acting from above downwards, keeps the square axis in its position, while
it permits it to turn upon itself in the two directions. The name press is given to the
assemblage of all the pieces which compose the movable frame B B.
F is a cross-bar made to move in a vertical direction by means of the lever G, in the
notches or groovesi, formed within the fixed uprights A.
a, is a piece of bent iron, fixed by one of its ends with a nut and screw, upon the crossbar F, out of the vertical plane of the piece c. Its other end carries a friction roller J,
which working in the curvilinear space c of the piece c, forces this, and consequently the
frame B, to recede from the perpendicular, or to return to it, according as the cross-bar F
is in the top or bottom of its course, as shown in figs. 777. and 778.
i, cheeks of sheet iron attached on either side to the cross-bar F, which serves as a safe
to a kind of claw K, composed here of eight small metallic bars, seen in section fig. 777.
and 778., and on a greater scale in fig. 780.
J, upright skewers of iron wire, whose tops bent down hook-wise naturally place
themselves over the little bars K. The bottom of these spindles likewise hooked in the
same direction as the upper ones, embraces small wooden bars l, whose office is to keep
them in their respective places, and to prevent them from twirling round, so that the
uppermost hooks may be always directed towards the small metallic bars upon which
they impend. To these hooks from below are attached strings, which after having crossed
a fixed board m n, pierced with corresponding holes for this purpose, proceed next to be
attached to the threads of the loops destined to lift the warp threads. K K, horizontal
spindles or needles, arranged here in eight several rows, so that each spindle corresponds
both horizontally and vertically to each of the holes pierced in the four faces of the
square axis D. There are therefore as many of these spindles as there are holes in one
of the faces of the square.
Fig. 781. represents one of these horizontal spindles. n is an eyelet through which




JACQUARD LOOM.                                             1029.............;.....  "...............................................  -......'}/   { 1~                              I                -
the corresponding vertical skewer passes. o another elongated eyelet, through which a
small fixed spindle passes to serve as a guide, but which does not hinder it from moving
lengthwise, within the limits of the length of the eyelet. p, small spiral springs placed
in each hole of the case q q,.fig. 780. They serve the purpose of bringing back to its
primitive position every corresponding needle, as soon as it ceases to press upon it.




1030                           JACQUARD LOOM.
8     7   6 5  4 8  2 1         780
_,,               ___x__i.tL _ _  *,  It  -T  -d - D  ___
D1.- __1                           I-  II             11 78
~"P                                                    0 -
Fig. 7&2. represents the plan of the upper row of horizontal needles. Fig. 783. is a
fragment of the endless chain, formed with perforated cards, which are made to circulate
or travel by the rotation of the shaft D. In this movement, each of the perforated cards,
whose position, form, and number, are determined by the operation of tying-up of the
warp, comes to be applied in succession against the four faces of the square axis or drum,
782                                          783'-:w  ~ooo o 0 8.  _o_~ 0     ~o o00.0 0    0 **.o   0 ~ 0000.0'      ~o 888  o~iB            "ooo oo  S.eOo       oo oo 0oo  o  o 00,5
leavin  open the corresponding holes, and covering those upon the face of the axis. which
have no coesponding holes upon the card...
g 0   1 0 0TI0 c 0  00   0 Ja
holes, but pushes back those which are opposite to the unpierced part of the card * thereby
the corresponding upright skewers, 3, 5, 6, and 8, for example, pushed out of the perpenOCP    Oc Po 00   0    00   0,.000  0 0 0
dicular, unhook themselves from above the bars of the claw, and remain in their place,
leaving ope n th e corresponding holes, by mean g those upon the   face of the     axis, which
hav    e no corresponding holes up     on    the card.
Nothem. let us suppose  at ssage  press   is let down into the   vertical position shown in
fig. an a; then the card  applied against the left face of t he axis, leaves  at rest or untouched the whole of the horizontal spindles (skewers), whose ends correspond to these
holes, but pushes back those which are opposite to the unpierced part of the cards all; thereby
t    he corres ponding uprigh t skewe rs, 3, 5, 6, and 8, f or example, pushed     out of the perpendicular, unhook     them selv es from above the bars of the   claw, a nd remain    in their place,
when this claw comes to be raised by means of the lever G; and the skewers 1, 2, 4, and
7, which have remained hooked on, are raised along with the warp threads attached to
them. Then by the passage across of a shot of the color, as well as a shot of the common
weft and a stroke of the lay after shedding the warp and lowering the press to rise an element
or point in the                 pattern is  completed.
The followin g card, brought round by a  quarter revolution of  the axis,   finds all the
needles in their first position, and as it is necessarily perforated differently from the preceding card, it will lift another series of warp threads; and thus in succession for all the
other c ards, w hich   compos e a complete system o  f a  f        igured  the pattern.
This machine, complicated in appearance, and which requires some pains to be understood, acts  however in a very simple manner. Its who  le play is dependa nt   upon the
movement of the lever subje which thto make mistakehimself causes to rise and fall, by means of
a peculiar pedal; so that with out the  aid of a ny person, after the     piece  is properly read
in and mounted, he can execute the most complex patterns, as easily as he could weave
plain goods; only attending to    the   order   of his  weft yarns, when th ese happen  to be of
different colors.
If some warp yarns should happen to break without the weaver observing them, or
should he mistake his colored shuttle yarns, which would so far disfigure the pattern,
he must undo his work. For this purpose, he makes use of the lower hooked lever fi,
whose purpose is to make the chain of the card go backwards, while working the loom
as usual, withdrawing at each stroke the shot both of the ground and of the figure. The
weaver is the more subject to make mistakes, as the figured side of the web is downwards,
and it is only with the aid of a bit of looking-glass that he takes a peep of his work from
time to time. The upper surface exhibits merely loose threads in different points, according as the pattern requires them to lie upon the one side or the other.
Thus it must be evident, that such a number of paste-boards are to be provided and
mounted as equal the number of throws of the shuttle between the beginning and end of
any figure or design which is to be woven; the piercing of each paste-board individually,
will depend upon the arrangement of the lifting rods, and their connexion with the warp)




JACQUARD LOOM.                                     1031
which is according to the design and option of the workman; great care must be taken
that the holes come exactly opposite to the ends of the needles; for this purpose two large
holes are made at the ends of the paste-boards, which fall upon conical points, by which
means they are made to register correctly.
It will be hence seen, that, according to the length of the figure, so must be the
number of paste-boards, which may be readily displaced so as to retnount and produce
the figure in a few minutes, or remove it, or replace it, or preserve the figure for future
use. The machine., of course, will be understood to consist of many sets of the lifting
rods and needles, shown in the diagram, as will be perceived by observing the disposition
of the holes in the paste-board; those holes, in order that they may be accurately
distributed, are to be pierced from a gauge, so that not the slightest variation shall take
place.
To form these card-slips, an ingenious apparatus is employed, by which the proper steel
punches required for the piercing of each distinct card, are placed in their relative situations preparatory to the operation of piercing, and also by its means a card may be punched
with any number of holes at one operation.  This disposition of the punches is effected
by means of rods connected to cords disposed in a frame, in the nature of a false simple,
on which the pattern of the work to be performed is first read in.
These improved pierced cards, slips, or paste-boards, apply to a weaving apparatus,
which is so arranged that a figure to be wrought can be extended to any distance along
the loom, and by that means the loom is rendered capable of producing broad figured
works; having the lonig, lever G placed in such a situation that it affords power to the
foot of the weaver, and by this means enables him to draw the heaviest morintures and
figured works, without the assistance of a draw-boy.
The machinery for arranging the punches, consists of a frame with four upright
standards and cross-pieces, which contains a series of endless cords passing under a
wooden roller at bottom, and over pulleys at the top. These pulleys are mounted on
axles in two frames, placed obliquely over the top of the standard frame, which pulley
frames constitute the table commonly used by weavers.
In order better to explain these endless cords, fig. 784 represents a single endless
cord 1, 1, which is here shown in operation, and part of another endless cord 2, 2, shown
stationary.  There must be as many endless cords
6^\'o^ 784  \    in this frame as needles in the weaving-loom. a is
the wooden cylinder, revolving upon its axis at the
lower part of the standards; b b, the two pulleys of the
pulley-frames above, over which the individual end1                               less cord passes; c is a small traverse ring. To each
of these rings a weight is suspended by a single thread,
for the purpose of giving tension to the endless cord.
2       C                   d is a board resembling a common comber-bar, which
is supported by the cross-bars of the standard frame,
6P~p^^ll    ^                and is pierced with holes, in situation an' number,
U Ifl  ~corresponding with the perpendicular threads that
D~ \V apass through them; which board keeps the threads
distinct from each other.
At e, the endless cord passes through the eyes of
wires resembling needles, which are contained in a
wooden box placed in front of the machine, and shown
in this figure in section only. These wires are called
the punch-projectors; they are guided and supported
by horizontal rods and vertical pins, the latter of
which pass through loops formed at the hinder part
of the respective wires. At f are two horizontal
rods extending the whole width of the machine, for
o^' the purpose of producing the cross in the cords; g
0 a.  i'    is a thick brass plate, extending along in front of the
machine, and lying close to the box which holds the
punch-projectors; this plate g, shown also in section, is called the punch-holder; it contains
the same number of apertures as there are punch-projectors, and disposed so as to corres-,pond with each other. In each of these apertures, there is a punch for the purpose of
piercing the cards, slips, or pasteboards with holes; h is a thick steel plate of the same
size as g, and shown likewise in section, corresponding also in its number of apertures,
and their disposition, with the punch-projectors and the punch-holder. This plate h, is
called the punch-receiver.
The object of this machine is to transfer such of the punches as may be required for
piercing any individual card from the punch-holder g, into the punch-receiver h; when
they will be properly situated, and ready for piercing the individual card or slip, with




1032                                ICE-HOUSE.
such holes as have been read in upon the machine, and are required for permitting the
warp threads to be withdrawn in the loom, when this card is brought against the ends
of the needles. The process of transferring the patterns to the punches will be effected
in the following manner.
The pattern is to be read in, according to the ordinary mode, as in a false simple,
upon the endless cords below the rodsf, and passed under the revolving wooden cylinder
a, to a sufficient height for a person in front of the machine to reach conveniently. He
there takes the upper threads of the pattern, called the beard, and draws them forward
so as to introduce a stick behind the cords thus advanced, as shown by dots, for the purpose of keeping them separate from the cords which are not intended to be operated
upon. All the punch-projectors which are connected with the cords brought forward,
will be thus made to pass through the corresponding apertures of the punch-holder g,
and by this means will project the punches out of these apertures, into corresponding
apertures of the punch-receiver h. The punches will now be properly arranged for
piercing the required holes on a card or slip, which is to be effected in the following
manner.
Remove the punch-receivers from  the front of the machine; and having placed one
of the slips of card or pasteboard between the two folding plates of metal, completely
pierced with holes corresponding to the needles of the loom, lay the punch-receiver upon
those perforated plates; to which it must be made to fit by mortises and blocks, the
cutting parS of the punches being downwards. Upon the back of the punch-receiver
is then to be placed a plate or block, studded with perpendicular pins corresponding to
the above described holes, into which the pins will fall. The plates and the blocks thus
laid together, are to be placed under a press, by which means the pins of the block will
be made to pass through the apertures of the punch-receiver; and wherever the punch
has been deposited in the receiver by the above process, the said punches will be forced
through the slip of pasteboard, and pierced with such holes as are required for producing
the figured design in the loom.
Each card being thus pierced, the punch receiver is returned to its place in front of
the machine, and all the punches forced back again into the apertures of t.a punch
holder as at first. The next set of cords is now drawn forward by the next beard, as
above described, which sends out the punch-projectors as before, and disposes the punches
in the punch-receiver, ready for the operation of piercing the next card.  The process
being thus repeated, the whole pattern is, by a number of operations, transferred to the
punches, and afterwards to the cards or slips, as above described.
JADE, axe-stone (Nephrite, Ceraunite, Fr.), is a mineral commonly of a greenish
color, compact, and of a fatty lustre. Spec. Grav. 2-95; scratches glass, is very tough;
fuses into a white enamel. Its constituents are, silica, 50-5; alumina, 10; magnesia, 31;
oxyde of iron, 5-50; oxyde of chrome, 0-05; water, 2*75. It comes from China, is used
among rude nations for making hatchets; and is susceptible of being cut into any
form.
JAPANNING, is a kind of varnishing or lackering, practised with excellence by the
Japanese, whence the name. See VARNISH.
JASPER (Jaspe calcedoine, Fr.; Jaspis, Germ.) is a sub species of calcedony quartz,
of which there are five varieties: 1. The Egyptian red and brown, with ring or tendrilshaped delineations. 2. Striped jasper. 3. Porcelain jaspe'r. 4. Common jasper. 5.
Agate jasper.  The prettiest specimens are cut for seals, and for the inieto-r kinds of
jewellery ornaments. See LAPIDARY.
ICE-HOUSE; (Glacilre, Fr.; Eishaus, Germ.)   Under the article FREEZING I have
enumerated the different artificial methods of producing cold.  But for the uses of common life, in these climates, the most economical and convenient means of refrigeration in
hot weather may be procured by laying up a store of ice in winter, in such circumstances
as will preserve it solid during summer.
An ice-house should not be regarded as an object of mere luxury, for pleasing the palates of gourmands with iced creams and orgeats. In the southern countries of Europe
it is considered among people in easy circumstances as an indispensable appendage to a
country mansion.  During the Dog-days, especially at those periods and in those districts where the sirocco blows, a lassitude and torpor of mind and body supervene, with
indigestion or total loss of appetite, and sometimes dysenteries qrYch are obviously oc.
casioned by the excessive heat, and are to be prevented or countesacted chiefly by the use
of cold beverages.  By giving tone to the stomach, iced drinks immediately restore the
functions of the nervous and muscular systems when they are languid; while they enable
persons in health to endure without much inconvenience an atmosphere so close and
sultry as would be intolerable without this remedy.   Ice-houses, moreover, afford to
country gentlemen a great advantage in enabling them to preserve their fish, butcher
meat, dead poultry, and game, which would otherwise, in particular states of the weather.
immediately spoil.  Considering at how little expense and trouble an ice-house can be




ICE PRODUCING MACHINE.                                  1033
constructed, it is surprising that any respectable hanitation in the country should not have
one attached to it.  The simplest and most scientific form is a double cone, that is, two
cones joined base to base; the one being of stones or brickwork, sunk under ground with
its apex at the bottom, into which the ice is rammed; the other being a conical roof of
carpentry coveredwith thatch, andpointed at top. The entrance should be placed always
on the north side; it should consist of a corridor or porch with double doors, and be
screened from the sunbeams by a smsall shrubbery.  Such are, in general, the principles
upon which an ice-house should be formed; but they will be better understood by the
following explanation and figure.
A dry sandy soil should be selected, and, if possible, a spot sheltered by a cliff or other
natural barrier from the direct rays of the sun. Here a cavity is to be dug about 16 feet
in diameter, terminating below like the point of a sugar loaf.  Its ordinary depth, for
a moderate family, may be about 24 feet; but the larger its dimensions are, the longer
will it preserve the ice, provided it be filled.  In digging, the workman should slope the
ground progressively towards the axis of the cone, to prevent the earth falling in. This
conical slope should be faced with brick or stone work about one foot thick, and jointed
with Roman cement so as to be air and water tight.  A well is to be excavated at the
bottom twvo feet wide and four deep, covered at top with an iron grating for supporting
the ice, and letting the water drain away.
The upper cone may likewise be built of brickwork, and covered with thatch; such a
roof would prove the most durable. This is the construction shown in fig. 785. What
ever kind of roof be preferred, there must be left in it an oblong passage into the interior.
This porch should face the north, and be at least 8 feet long by 24 feet wide; and perfectly closed by a well-fitted door at each end. All round the bottom of this conical
cover, a gutter should be placed to carry off the rain to a distance from the ice-house, and
prevent the circumjacent ground from getting soaked with moisture.
Fig. 1785 shows the section of a well-constructed ice-house.  Under the ice-^-hamber A the ice is rammed into the space B.  c is the grate of the drain-sink D. The
portion.E E is built in brick or stone; the base L of the ice-chamber slopes inwards to
wards the centre at c.  The upper part of the brickwork E E is a little way below the
level of the ground.  The wooden frame work
r F F Fforms the roof, and is covered with thick
thatch.  G H is the wooden work of the door I. At
K the bucket is seen for lifting up a charge of ice,
by means of the cord J passing over the pulley M)
F     EW^  1^ ^^  l^^Cll  which enables the servant to raise it easily.
The icehouse should have no window to admit
light; but be, so to speak, hermetically sealed in
every point, except at its cess-pool, which  may
terminate in a water trap to prevent circulation of
A clear day should be selected for charging the
icehouse; but before beginning to fill, a quantity
of long dry straw  should be laid on the bottom
crosswise; and as the ice is progressively introduced,
straw is to be spread against the conical sides, to prevent the ice from coming into contact with the brick
or stone work.  The more firmly compacted the ice
is, the better does it keep; with which view it should
be broken into pieces with mallets before being
thrown in.  No layers of straw should be stratified
among the ice, for they would make its bodl porous.
Some persons recommend to pour in a little water
with the successive layers of ice, in order to fill up its small crevices, and convert the
whole into one mass.
Over the top layer a thick bed of straw should be spread, which is to be covered
with boards surmounted with heavy stones, to close up the interstices in the straw. The
inner and outer doors should never be opened at once; but the one should always be shut
before the other is opened.
Dry snow well rammed keeps equally well with hard ice, if care be taken to leave no
cavities in the mass, and to secure its compactness by sprinkling a little water upon the
successive charges.
To facilitate the extraction of the ice, a ladder is set up against its sloping wall at one
side of the door. aid left there during the season.
ICE PRODUCING MACHINE. It is well known that by the rapid condensation
t air or other elastic fluid, so much heat may be evolved as to ignite tinder, &c. It appears
from  a communication in the Mechanics' Magazine of February, 1851, that Dr. Gorrie




1 0034                       ILLUMINATION, COST OF.
a physician in New Orleans, has on this principle constructed an apparatus for producing
so much cold as to freeze water, by exposure to the condensed air in the act of its
subsequent expansion. Gay Lussac, many years ago, made use of a jet of condensed air
to refrigerate any body such as a glass globe filled with water, upon which the expanding air was allowed to play, and he even caused water contained in the globe to
freeze. Now the American process is quite identical with that of the French chemist,
but on a vastly enlarged scale, for he employs the power of a steam engine acting on a
pump 8 inches in diameter, with a 16 inches stroke, to condense the air into one third
its volume, into a vessel, where it is cooled by water. A pump is made to throw in a
jet of cold water at the same time to quicken the refrigeration. It is said that in this
way a block of ice of 60 lbs. was formed; a circumstance which appears to me quite
incredible,  In fact, the whole statement has a most apocryphal air, and I do not
believe that any such result could have been produced, as the reporter says, by the
labour of two men at a couple of pumps in alternate action.
The inventor's object at first was to ventilate and cool the atmosphere of sick rooms,
where febrile patients lay. " This case is one among the many examples of a useful
scientific invention remaining long dormant or sterile."  The hydrostatic paradox of
Archimedes is a parallel instance, in reference to Bramah's press.
ICE  BY  THE  RED-HOT  PROCESS.   One  of the most singularly  beautiful
experiments perhaps ever devised, has been  recently  published by M. Prevostaire,
illustrative of the repellent power of heat radiating from bodies at a high temperature,
and of the rapid abstraction of heat, produced by evaporation, or generally by such a
change of condition as largely increases the volume of any body. The experiment is
simply this:-A platina crucible is made and maintained red-hot over a large spirit
lamp.  Some sulphurous acid is poured into it from  a pipette.  This acid, though at
common temperatures one of the most volatile of known bodies, possesses the singular
property of remaining fixed in the red-hot crucible and not a drop of it evaporates:
in fact, it is not in contact with the crucible, but has an atmosphere of its own interposed.  A few drops of common water are now added to the sulphurous acid in the
red-hot crucible.  The diluted acid gets into immediate contact with the heated metal,
instantly flashes off into sulphurous acid vapour, and such is the rapidity and energy of
the evaporation that the water remains behind, and is found frozen into alump of ice in
the red-hot crucible, from which, seizing the moment before it again melts, it may be
thrown out before the eyes of the astonished observer.
JELLY, VEGETABLE, of ripe currants  and other berries, is a compound of
mucilage and acid, which loses its power of gelatinizing by prolonged ebullition.
JELLY, ANIMAL; see GELATINE, GLUE and ISINGLASS.
JET; (,Jaiet or jais, Fr.) a species of pitch coal, or glance-coal, which, being found
abundantly in a beautiful compact form, in the valley of Hers, arrondissement of Pamiers, department of the Arriege, has been worked up extensively there, from time itnmemorial, into a multitude of ornamental articles.  With this black lignate, buttons,
crosses, rosaries, necklaces, ear-drops, bracelets, waist-buckels; &c., are made, which were
at one time much worn by ladies for mourning dresses. The greater number of these
ornaments are fashioned upon grindstones which turn in a horizontal direction, and
are kept continually wet; others are turned at the lathe, or shaped by files.
About 40 years ago this manufacture employed from 1000 to 1200 operatives; at
present it gives bread to only 60. This falling off may be ascribed to the successful
imitation of the jet articles by those of black glass, which are equally beautiful, and not
nearly so apt to lose their polish by use.
JET  PUMP. The purpose for whieh this instrument is designed, is to clear the
water out of the pits of submerged water-wheels, when access to them is required for
inspection or repairs. For this special purpose it is likely to prove very useful; though
at the same time, there are very few other cases in which it could not be employed
with advantage.  The action of the jet pump depends on two principles.  One of
these is the same as that of steam blast used in locomotive engines, and in the ventilation of mines. The other is one which was known to the ancient Romans, and was
used sometimes by them for drawing off more water from  the public pipes than they
paid for. The jet pump was first tried at the mill of Messrs. Herdman & Co., Belfast,
when it was found most successful.
ILLUMINATION, COST OF.  The production, diffusion, and economy of light,
are subjects of the highest interest both to men of science and men of the world;
leading the former to contemplate many of the. most beautiful phenomena of Physics
and Chemistry, while they provide the latter with the artificial illumination so indispensable to the business and pleasures of modern society. The great cost of lig ht from
wax, spermaceti, and even stearic candles, as also the nuisance of the light from tallow
ones, have led to the invention of an endless variety of lamps, of which the best hitherto
known is undoubtedly the mechanical or Carcel lamp, so generally used by the opulent




ILLUMINATION, COST OF.                                  1035
families in Paris. In this lamp the oil is raised through tubes by clock-work, so as
continuall to overflow at the bottom of the burning wick; thus keeping it thoroughly
soaked, wle the excess of the oil drops back into the cistern below.  I have possessed
for several years an excellent lamp of this description, which performs most satisfactorily;
but it can hardly be trusted in the hands of a servant; and when it gets at all deranged,
it must be sent to its constructor in Paris to be repaired. The light of this lamp. when
furnished with an appropriate tall glass chimney, is very brilliant, though not perfectly
uniform; since it fluctuates a little, but always perceptibly to a nice observer, with the
alternating action of the pump-work; becoming dimmer after every successive jet of
oil, and brighter just before its return. The flame, moreover, always flickers more or
less, owing to the powerful draughlt, and rectangular reverberatory shoulder of the
chimney.  The mechanical lamp is, however, remarkable for continuing to burn, not
only with unabated but with increasing splendour for seven or eight hours; the vivacity
of the combustion increasing evidently with the increased temperature and fluency of
the oil, which, by its ceaseless circulation through the ignited wick, gets eventually
pretty warm.  In the comparative experiments made upon different fights by the
Parisian philosophers, the mechanical lamp is commonly taken as the standard. I do
not think it entitled to this pre-eminence: for it may be made to emit very different
quantities of light, according to differences in the nature and supply of the oil, as well as
variations in the form and position of the chimney. Besides, such lamps are too rare in
this country to be selected as standards of illumination.
After comparing lights of many kinds, I find every reason to conclude that a large
wax candle of three to the pound, either long or short, that is, either 12 or 15 inches
in length, as manufactured by one of the great wax-chandlers of London, and furnished
with a wick containing 27 or 28 threads of the best Turkey cotton, is capable of furnishing a most uniform, or nearly invariable standard of illumination. Its affords one
tenth of the light emitted by one of the Argand lamps of the Trinity house, and one
eleventh of the light of my mechanical lamp, when each lamp is made to burn with its
maximum flame, short of smoking.
The great obstacle to the combustion of lamps, lies in the viscidity, and consequent
sluggish supply of oil, to the wicks; an obstacle nearly insuperable with lamps of the
common construction during the winter months.  The relative viscidity, or relative
fluency of different liquids at the same temperature, and of the same liquid at different
temperatures, has not, I believe, been hitherto made the subject of accurate researches.
I was, therefore, induced to make the following experiments with this view.
Into a hemispherical cup of platinum, resting on the ring of a chemical stand, I
introduced 2,000 water-grain measures of the liquid whose viscidity was to be measured,
and ran it off through a glass syphon, ^ of an inch in the bore, having the outer leg 3^
inches, and the inner leg 3 inches long. The time of efflux became the measure of the
viscidity; and of two liquids, if the specific gravity, and consequent pressure upon the
syphon, were the same, that time would indicate exactly the relative viscidity of the two
liquids. Thus, oil of turpentine and sperm oil have each very nearly the same density;
the former being, as sold in the shops, =0'876, and the latter from 0876 to 0O8S0,
when pure and genuine. Now I found that 2,000 grain-measures of oil of turpentine
ran off through the small syphon in 95 seconds, while that quantity of sperm oil took
2,700 seconds, being in the ratio of I to 28k; so that the fluency of oil of turpentine is
28- times greater than that of sperm oil. Pyroxilic spirit, commonly called naphtha,
and alcohol, each of specific gravity 0825, were found to run off respectively in 80 and
120 seconds; showing that the former was 50 per cent. more fluent than the latter.
Sperm oil, when heated to 265 Fahr., runs off in 300 seconds, or one ninth of the time
it took when at the temperature of 640. Southern whale oil, having a greater density
than the sperm oil, would flow off faster were it not more viscid.
2,000 grain-measures of water at 600 run off through the said syphon in 75 seconds,
but when heated to 1800, they run off in 61.
Concentrated sulphuric acid, though possessing the great density of 1-840, yet flows
off very slowly at 640, on account of its viscidity; whence its name of oil of vitriol.
2,000 grain-measures of it took 660 seconds to discharge.
Mr. Samuel Parker, long advantageously known to the public for his sinumbral and
pneumatic fountain lamps, as well as other inventions subservient to domestic comfort,
having obtained a patent for a new lamp, in which the oil is heated by a very simple
contrivance, in the cistern, to any desired degree, before arriving at the wick, I instituted an extensive series of experiments to determine its value in the production of
light, and consumption of oil, compared to the value of other lamps, as well as candles,
in these respects.
In fig. 786, A, A, B, B, is a section of the cylinder which constitutes the cistern;
the oil being contained between the inner and outer cylinders, and receiving heat from
the flame of the lamp which passes up through the inner cylinder, and is rever



1036                     ILLUMINATION, COST OF.
berated more or less against its sides by the top of the metal chimney, being notched
and bent back. D is a slide-valve which is opened to allow the oil to descend to the
wick, and is shut when the cistern is to be separated from the pipe of supply, at E,
for the purpose of recharging it with oil. The flame is modified, not by raising or
lowering the wick, as in common lamps, but by raising or lowering the bell-mouthed
glass chimney which rests at its bottom on three points, and is moved by means of the
rack-work mechanism F. The concentric cylindric space A, A, and B,B, contains a
pint imperial, and should be made entirely full before lighting the lamp; so as to leave
no air in the cistern, which, by its expansion with the heat, would inevitably cause an
overflow of the oil.
The following arrangement was adopted in these experiments for determining the
relative illumination of the different lights. Having trimmed, with every precaution,
my French mechanical lamp, and charged it with pure sperm oil, I placed it upon an
oblong table, at a distance of 10 feet from a wall, on which a white sheet of paper was
stuck. One of Mr. Parker's hot-oil lamps, charged with a quantity of the same oil,
was placed upon the same table; and each being made to burn with its maximiu
786      /n                                   t
b eek   method o e p  n     s     w  a; f.e  ih   log..
I I
and of the thickness of a crow-quill, being found suitable for enabling the eye to estimate very nicely the shade of the intercepted light. It was observed in numerous trials,
both by my own eyes and those of others, that when one of the lamps was shifted half
an inch nearer to or further from the paper screen, it caused a perceptible difference
in the tint of the shadow. Professor Wheatstone kindly enabled me to verify the precision of the above method of shadows, by employing, in some of the experiments, a
photometer of his own invention, in which the relative brightness of the two lights was
determined by the relative brightness of the opposite sides of a revolving silvered ball,
illuminated by them.
1. The mechanical lamp was furnished with a glass chimney 1*5 inches in diameter
at the base, and 12 at top; the wide bottom part was 1*8 inches long, and the narrow
upper part 8 inches. When placed at a distance of 10 feet from the wall its light there
may be estimated as the square of this number, or 100. In the first series of experiments, when burning with its maximum flame, with occasioned flickerings of smoke,
it emitted a light equal to that of 11 wax candles, and consumed 912 grains of oil per
hour. The sperm oil was quite pure, having a specific gravity of 0*874 compared to




ILLUMINATION, COST  0F.                                 1037
water at 1,000. In a subsequent series of experiments, when its light was less flickering,
and. equal only to that of 10 wax candles, it consumed only 815 grains, or 0-1164 of a
lb. per hour. If we multiply this number into the price of the oil (8s. per gallon) per
lb. ld.,~ the product 1*2804d. will represent the relative cost of this illumination, estimated at 100.
2. The hot-oil lamp burns with a much steadier flame than the mechanical, which
must be ascribed in no small degree to the rounded slope of the bell-mouthed glass
chimney, whereby the air is brought progressively closer and closer into contact with
the outer surface of the flame, without being furiously dashed against it, as it is by the
rectangular shoulder of the common contracted chimney. When charged with sperm
oil, and made to burn with its maximum flame, this lamp required to be placed one
foot further from the screen than the mechanical lamp, in order that its shadow should
have the same depth of tint. Hence, its relative illumination was, in that case, as the
square of 11 to the square of 10; or as 121 to 100. Yet its consumption of oil was
only 696 grains, or somewhat less than 0-1 of a pound per hour. Had its light been
reduced to 100, it would have consumed only 576 grains per hour, or 0'C82 of a pound.
If we multiply this number by lid., the product 0'902d. will represent the relative cost
of 100 of this illumination.
3. The hot-oil lamp being charged with the southern whale oil, of specific gravity
0-926, at 25. 6d. per gallon, or 3d. per lb., when burning with its maximum flame,
required to be placed 9 feet and I inch from the screen to drop the same tint of shadow
upon it as the flamesof the other two lamps did at 10 and 11 feet with the sperm  oil.
The square of 9 feet and 1 inch = 82 is the relative illumination of the hot-oil lamp
with the southern whale oil. It consumed 780 grains, or 0'  111 of a pound per hour;
but had it given 100 of light it would have consumed 911 grains, or 0'130 of a pound,
which number being multiplied by its price 31d., the product 0'4875d. will represent
the relative cost of 100 of this light.
4. A hot-oil lamp charged with olive oil of specific gravity 0*914, at 5s. 6d. per
gallon, or 71d. per lb. when burning with its maximum flame, required to be placed at
9 feet 6 inches, to obtain the standard tint of shadow upon the screen. It consumed
760 grains per hour. The square of 9-i feet is 90-, which is the relative intensity of the
light of this lamp. Had it emitted a light = 100, it would have consumed 840 grains,
or 0' 12 of a pound per hour-which number multiplied by the price per pound, gives
the product 0'9d. as the relative cost of 100 of this light.
5. A hot-oil lamp charged with Price and Co.'s cocoa-nut oil (oleine), of specific
gravity 0-925, at 45. 6d. per gallon, or 5Md. per lb., had to be placed 9 feet from the
screen, and consumed 1,035 grains per hour. Had its light been 100 instead of 81 (92),
the consumption would have been 1,277 grains, or 0' 182 of a pound per hour! which
number multiplied by its price per pound, the product 1031d. will represent the cost of
100 of this illumination.
6. In comparing the common French annular lamp in general use with the mechanical lamp, it was found to give about one half the light, and to consume two thirds of
the oil of the mechanical lamp.
7. Wax candles from  some of the most eminent wax-chandlers of the metropolis
were next subjected to experiment; and it is very remarkable that, whether they were
threes, fours, or sixes in the pound, each afforded very nearly the same quantity of
light, for each required to be placed at a distance of three feet from the screen to afford
a shadow of the same tint as that dropped from the mechanical lamp, estimated at 100.
The consumption of a genuine wax candle, in still air, is upon an average of many experiments, 125 grains per hour, but as it affords only  111th of the light of the
mechanical lamp, II times 125 = 1,375 grains, or 0' 1064 of a pound is the quantity
that would need to be consumed to produce a light equal to that of the said lamp.
If we multiply that number by the price of the candles per lb. = 30d. the product
= 5-892d. is the cost of 100 of illumination by wax. A wax candle, three in the pound
(short), is one inch in diameter, 12 inches in length, and contains 27 or 28 threads,
each about 1 10th of an inch in diameter. But the quality of the wick depends upon the
capillarity of the cotton fibrils, which is said to be greatest in the Turkey cotton, and:
hence the wicks for the best wax candles are always made with cotton yarn imported
from the Levant. A wax candle, three in the pound (long), is ^ of an inch in diameter,
15 inches long, and has 26 threads in its wick. A wax candle, six to the pound, is 9
inches long, 4 5ths of an inch in diameter, and has 22 threads in its wick. The light of
this candle may be reckoned to be, at most, about   111th less than that of the threes in
the pound. A well-made short three burns with surprising regularity in still air, being
at the rate of an inch in an hour and a half, so that the whole candle will last 18 hours..
A long three will last as long, and a six about 96 hours. Specific gravity of wax
0-960.
8. A spermaceti candle, three in the pound, is 9 IOths of an inch in diameter, 15inches long, and has a plaited wick, instead of the parallel threads of a wax candle. The




1038                     ILLUMINATION, COST OF.
same candles four in the pound, are 8 10ths of an inch indiameter, and 13incheslong.
Each gives very nearly the same quantity of light as the corresponding wax candles:
viz. I1 11th of the light of the above mechanical lamp, and consumes 142 grains per
hour. Multiplying the last number by 11, the product, 1,562 grains = 0'223 of a pound,
would be the consumption of spermaceti requisite to give 100 of illumination. Multiplying the last number by 24d., the price of the candles per pound, the product 5'352d.
is the relative cost of 100 of this illumination.
9. Stearic acid candles, commonly called German wax, consume 1685 grains, or
0'024 of a pound per hour, when emitting the same light as the standard wax candle.
Multiplying the latter number by 11, and by 16d. (the price of the candles per pound),
the product 4-224d. will represent the relative cost of 100 of this illumination.
10. Tallow candles: moulds, short threes, I inch in diameter, and 12' in length; do.
long threes, 9 1Oths of an inch in diameter, and 15 inlength; do., long fours, 8 10thso.f
an inch in diameter, and 134 in length. Each of these candles burns with a most un
certain light, which varies from 1 12th to I 16th of the light of the mechanical lampthe average may be taken at 1 14th. The threes consume each 144 grains, or 0*2 of a
pound, per hour; which number, multiplied by 14, and by 9d. (the price per pound),
gives the product 2'52d. for the relative cost of 100 of this illumination.
11. Palmer's spreading wick candles. Distance from the screen 3 feet 4 inches, with
a shadow  equal to the standard.  Consumption of tallow  per hour 232*5 grains, or
0*0332 of a pound. The square of 3 feet 4 inches == 119 is the relative illumination
of this candle = 11-9:: 0-3332:: 100: 0-28 X 10d. = 11-9 is the relative cost of this
illumination.
12. Cocoa-nut stearine candles consumed each 168 grains per hour, and emitted a
light equal to 1 16th of the standard flame. Multiplying 168 by 16, the product 30-88
grains, or 0-441 of a pound, is the quantity which would be consumed per hour to afford
a light equal to 100. And 0-441 multiplied by IOd., the price per pound, gives the
product 4-441d. as the cost of 100 of this illumination per hour.
A gas argand London lamp, of 12 holes in a circle of' of an inch in diameter, with
a flame 3 inches long, afforded a light = 78- compared to the mechanical lamp: and
estimating the light of the said mechanical lamp as before, at 100, that of the bot-oil
lamp is 121, and that of the above gas flame of 78-57, or in rouid numbers 80, and the
common French lamp in general use 50.
Collecting the preceding results, we shall have the following tabular view of the
cost per hour of an illumination equal to that of the mechanical lamp, reckoned 100, or
that of eleven wax candles, three to the pound.
TABLE of COST per HOUR of ONE HUNDRED of ILLUMINATION.
Pence.         Pence.
1. Parker's hot-oil lamp, with southern whale oil      -  0-4875 or about id.
2. Mechanical or Carcel lamp, with sperm oil           -  1*2804  -    -  1x
3. Parker's hot-oil lamp, with sperm oil               -  0-902   -    -  I
4. Ditto       ditto      common olive oil             -  0-900   -    -  1
5. Ditto       ditto      cocoa-nut oleine or oil      -  1-031   -    -  I
6. French lamp in general use, with sperm oil          -  1-7072  -    -  1^
7. Wax candles   -                -- 5-892 -  - 6
8. Spermaceti candles               --  5-352   -    -5
9. German wax (Stearic acid) ditto    -    -           -  4-224   -    -
10. Palmer's spreading wick candles   -    -            -  2-800   -    -2
11. Tallow (mould) candles        ----                  -  2-520   -    -2
12. Cocoa-nut stearine of Price and Co.                 -  414      -    -4
Since the hot-oil lamp affords sufficient light for reading, writing,.sewing, &c., with
one fifth of its maximum flame, it will burn at that rate for 10 hours at the cost of
about ONE PENNY, and it is hence well entitled to the inventor's designation, "The
Economic."
Sir D. Brewster, in his examination lately before the committee of the house of
commons on lighting the house, stated, that the French light-house lamp of Fresnel
emitted a light equal to that of forty argand flames; whereas, according to other
accounts, it gave much less light. With the view of settling this point, before being
examined by the said committee, I repaired to the Trinity house, and tried one of
the two original Fresnel lamps, which had been deposited there by that eminent French
engineer himself. This lamp consists of four concentric circular wicks, placed in one
horizontal plane; the innermost wick being 7 of an inch in diameter, and the outermost
3- inches. Being carefully trimmed, supplied with the best sperm  oil, surmounted
with its great glass chimney, burning with its n aximum flame, and placed at a distance
of 13 feet 3 inches from the screen, it let fall a shadow of the same tint as that let fall




ILLUMINATION, COST OF.                              1039
by the flame of my mechanical lamp, placed at a distance of 4 feet 6 inches from the
screen. The squares of these two numbers are very nearly as 81 to 1 (1755625 to
20*25); showing that the Fresnel lamp gives less than 9 times the light of my mechanical lamp, and about 9-6 times the light of one of the Trinity house argand lamps.
The Fresnel lamp is exceedingly troublesome to manage, from the great intensity of its
heat, and the frequent fractures of its chimneys-two having been broken in the course
of my experiments at the Trinity house.
Mr. Goldsworthy Gurnsy, the ingenious inventor of the new light-house lamp, in
which a stream of oxygen gas is sent up through a small tube within the burning circular wick of a small argand lamp, having politely sent two of his lamps to my house,
along with a bag of oxygen gas, I made the following experiments, to ascertain their
illuminating poweis compared to those of the mechanical lamp and wax candles.
His larger lamp has a wick I of an inch in diameter, but emits an oxygen flame of
only I of an inch. The flame is so much whiter than that of the best lamp or candle
that it becomes difficult to determine, with ultimate precision, the comparative depths
of the shadows let fall by them. The mean of several trials showed that the above
Bude-light (as Mr. Gurney calls it, from the name of his residence in Cornwall), has
an illuminating power of from 28 to 30 wax candles. His smaller lamp has a flame 
of an inch in diameter, and a wick 2 of an inch. Its light is equal to that of from 18
to 20 wax candles.
The committee of the house of commons on lighting it, having asked me what was
the relative vitiation of air by the breathing of men and the burning of candles, I gave
the following answer:Wax contains 81'75 parts of carbon in 100, which generate by combustion 300 parts
of carbonic acid gas. Now, since 125 grains of wax constitute the average consumption of a candle per hour, these will generate 375 grains of carbonic acil; equivalent
in volume to 800 cubic inches of gas. According to the most exact experiments on
respiration, a man of ordinary size discharges from his lungs 1,632 cubic inches of carbonic acid gas per hour, which is very nearly the double of the quantity produced from
the wax candle. Hence the combustion of two such candles vitiates the air much
the same as the breathing of one man. A tallow candle, three or four in the pound,
generates nearly the same quantity of carbonic acid as the wax candle; for though tallow contains only 79 per cent. of carbon, instead of 81.75, yet it consumes so much
faster, as thereby to compensate fully for this difference.
When a tallow candle of 6 to the lb. is not snuffed, it loses in intensity, in 30 minutes, 80 hundredths; and in 39 minutes 86 hundredths, in which dim state it remains
stationary, yet still consuming nearly the same proportion of tallow. A wax candle
attains to its greatest intensity of light when its wick has reached the greatest length,
and begins to bend out of the flame. The reason of this difference is, that only the
lower part of the wick in the tallow candle is charged with the fat, so as to emit luminiferons vapor, while the upper part remains dry; whereas, in the wax candle, the
combustible substance being less fusible and volatile, allows a greater length of the
wick to be charged by capillary attraction, and of course to emit a longer train of light.
The following table contains, according to P6clet, the illuminating powers of different candles, and their consumption of material in an hour; the light emitted by a Carcel argand lamp, consuming 42 grammes (= 42 X 15- grains) in an hour, being called
100:Intensity of Light. Consumption per Hour.
Tallow Candles 6 in lb.      -      -         10-66               8-51
Stearine, or Pressed Tallow, 8 in lb. -        8-74               7-51
W~x~andlesin lb. -    5 in lb. -              7.50               7-42
Wax Candles, 5 in lb.        -      -          33-61              8-71
Spermaceti ditto, 5 in lb.   -      -         14-40               8-92
Stearic Acid, commonly called Stearine, 5 in lb.-    -       -      -         14-40               9-33
The subjoined table shows the economical ratios of the candles, where the second
column gives the quantity of material in grammes which is requisite to produce as much
light as the Carcel lamp:



1040                     ILLUMINATION, COST OF.
Quality of     Price per Kilo-   Cost of-Light per
Material.        gramme.           Hour.
Tallow candle, 6 per lb.  -  -  -'7035           f. 408 c., 8 per lb.  -  -  -       85'92          1 f. 40 c.         12-0c.
Pressed tallow, 5 pea lb.  -  -  -       98-93          2 f. 40 c.         237 c.
Wax candle, 5 per lb.  -  -  -  -         64-04         7 f.  60 c.        486 c.
Spermaceti ditto, 5 per lb. -  -         61-94: f. 60 c.         478 c.
Stearine, 5 per lb.  -  --  -             65-24         6 f.               371 c.
These results may be compared with mine given above.  A kilogramme, or 1000
graimmes == 15,440 grains =-2+ lbs. avoirdupois.
JINTA-WAN. A compound, elastic, water-repellent substance for manufacturing purposes is made by combining gutta percha with an elastic and water-repellent substanceb
called "jinta-wan," recently imported for the first time from the East Indies, and which
has never heretofore, to the best of my knowledge and belief, been used in the arts and
manufactures of this country; or by combining gutta percha with "jinta-wan" and
caoutchouc. The gutta percha which is intended to be combined in this way should,
if necessary, be cleansed from impurities, and may if desired be previously prepared as
heretofore described.  The jinta-wan, or caoutchouc, should also be cleansed from  its
impurities, if any.  Gutta percha and jinta-wan are combined by placing these two
substances in the intended proportions (cut into pieces) in a masticator, such as is
used for masticating caoutchouc, and then operate upon the two materials by that
machine until they are intimately blended  together.  And the triple  combination
of gutta percha, jinta-wan, and caoutchouc are combined by means of a masticator, in
the same manner. For the  purpose  of making  these combinations, the  proportions of the two, or of the three substances may be combined according to the quality
which it is desired that the combined substance shall possess, employing a larger proportion of any one of the substances to be combined, when it is desired that the peculiar qualities of that substance shall predominate in the combined article.  See GUTTA
PERCHA.
IMPERMEABLE, is the epithet given to any kind of textile fabric, rendered waterproof by one or other of the following substances:1. Linseed oil to which a drying quality has been communicated by boiling with
litharge or sugar of lead, &ec.
2. The same oil holding in solution a little caoutchouc.
3. A varnish made by dissolving caoutchouc in rectified petroleum or naphtha, applied
between two surfaces of cloth, as described under Macintosh's patent. See CAOUTCHOUC.
4. Vegetable or mineral pitch, applied hot with a brush, as in making tarpauling for
covering goods in ships.
5. A solution of soap worked into cloth, and decomposed in it by the action of a
solution of alum; whence results a mixture of acid fats and alumina, which insinuates
itself among all the woolly filaments, fills their interstices, and prevents the passage of
water.
6. A solution of glue or isinglass, introduced into a stuff, and then acted upon by a
clear infusion of galls, whereby the fibres get impregnated with an insoluble, impermeable, pulverulent leather.
1. Plaster work is rendered impermeable by mixing artificial or natural asphaltum
with it.
JEWELLERY, Art of. See GEM and LAPIDARY.
INCOMBUSTIBLE CLOTH; is a tissue of the fibrous mineral called amianthus or
asbestos. This is too rare to form the object of any considerable manufacture. Cotton
and linen cloth may be best rendered incapable of taking fire, or burning with flame, by
being imbued with a solution of sal ammoniac.
INCUBATION, ARTIFICIAL.   The  Egyptians have from  time  immemorial
been accustomed to hatch eggs by artificial warmth, without the aid of hens, in peculiar
stoves, called Mfammals. The inhabitants of the village Berme still travel through the most
distant provinces of Egypt at certain seasons of the year, with a portable furnace, heated
by a lamp, and either hatch chickens for sale, or undertake to hatch the eggs belonging
to the natives at a certain rate per dozen. M. de Reaumur published in France about
a century ago, some ingenious observations upon this subject; but M. Bonnemnain was
the first person who studied with due attention all the circumstances of artificial incubation, and mounted the process successfully upon the commercial scale. So far back as
1777 be communicated to the Academy of Sciences an interesting fact, which he had




INCUBATION, ARTIFICIAL.                                  1041
noticed, upon the mechanism  employed by chicks to break their shells; and for some
time prior to the French revolution he furnished the Parisian market with excellent
poultry at a period of the year when the farmers had ceased to supply it. His establishment was ruined at that disastrous era, and no other has ever since been constructed
or conducted with similar care. As there can be no doubt however of the practicability
and profitableness of the scheme, when judiciously managed, I shall insert a brief
account of his ingenious arrangements. I had the pleasure of making the acquaintance
of this amiable old man at my first visit to Paris, many years ago, and believe all his
statements to be worthy of credit. Some imitations of his plans have been made in this
country, but how far they have succeeded in an economical point of view, it is difficult
to determine. His apparatus derives peculiar interest from the fact, that it was founded
upon the principle of the circulation of hot water, by the intestine motion of its particles,
in a returning series of connected pipes; a subject afterwards illustrated in the experimental researches of Count Rumford. It has of late years been introduced as a novelty into
this country, and applied to warm the apartments of many public and private buildings.
The following details will prove that the theory and practice of hot-water circulation
were as perfectly understood by M. Bonnemain fifty years ago, as they are by any of
our stove doctors at the present day. They were then publicly exhibited at his residence in Paris, and were afterwards communicated to the world at large in the interesting article of the Dictionnaire Technologique, entitled Incubation Artificielle.
The apparatus of M. Bonnemain consisted; 1. of a boiler, and pipes for the circulation of water; 2. of a regulator calculated to maintain an equable temperature; 3.
of a stove-apartment, heated constantly to the degree best fitted for incubation, which
he called the hatching pitch. He attached to one side a poussiniere or chick-room, for
cherishing the chickens during a few days after incubation.
The boiler is represented in vertical section and ground plan. in figs. 7 and    8.
It is composed of a double cylinder of copper or cast iron 1, 1, having a grate b (see
hot,         plan), an ash-pit at d (section).  The water occupies the shaded'87 __ pi  space c, c.  h,g, g, e, e, are five vertical flues, for conducting
n the burnt air and smoke, which first rise in the two exterior
flues e, e, then descend in the two adjoining flues g, g, and
1 l:   finally re-mount through the passages i, i, in the central flue
h. During this upwards and downwards circulation, as shown
i  9    i by the arrows in the section, the products of combustion are
I   lI   made to impart nearly the whole of their beat to the water by
which  they are surrounded.   At the commencement some
e  9eI         ^ -  burning paper or wood shavings are inserted at the orifice m,
l A""    1^  ---  to establish a draught in this circuitous chimney. The air is
admitted into the ash-pit at the side, in regulated quantities,
through a small, square door, moveable round a rod which runs
horizontally along its middle line. This swing valve is acted
c       d~           upon  by  an  expanding  bar (see HEAT-REGULATOR), which
opens it more or less according to the temperature of the
stove apartment in which the eggs are placed.
D is the upper orifice of the boiler, by which the hotter and consequently lighter particles of the water continually ascend, and are replaced by the cooled particles, which
enter the boiler near its bottom, as shown in fig. 789. at a. Into further details relative
to the boiler it is needless to enter; for though its form, as designed by M. Bonnemain,
is excellent and most economical of heat for a charcoal fire, it would not suit one of
pit-coal, on account of the obstruction to the pipes which would soon be occasioned by
its soot.
In fig. l89. the boiler is shown at R, with the rod which regulates the air door of the
ash-pit. D is a stopcock for modifying the opening by which the hotter particles of
water ascend; G is the water-pipe of communication, having the heating pipe of distribution attached between E F, which thence passes backwards and forwards with a very
slight slope from the horizontal direction, till it reaches the poussiniere o p Q. It traverses
this apartment, and returns by N N to the orifice of the boiler, H, where it turns vertically
downwards, and descends to nearly the bottom of the boiler, discharging at that point
the cooled and therefore denser particles of water to replace those which continually issue
upwards at D. L a is a tube surmounted with a funnel for keeping the range of pipes
always full of water; and K is a syphon orifice for permitting the escape of the disengaged
air, which would otherwise be apt to occupy partially the pipes and obstruct the aqueous
circulation.
The faster the water gets cooled in the serpentine tubes, the quicker its circulation
will be, because the difference of density between the water at the top and bottom of the
boiler, which is the sole cause of its movement, will be greater. N represents small
saucers filled with water, to supply the requisite moisture to the heated air, and to place
66




1042                       INCUBATION, ARTIFICIAL.
eggs, arranged along the trays M M, in an atmosphere analogous to that under the body
of the hen.
When we wish to hatch eggs with this apparatus, the fire is to be kindled in the boiler,
and as soon as the temperature has risen to about 1000 F. the eggs are introduced; but
only one twentieth of the whole number intended, upon the first day; next day, a like
number is laid upon the trays, and thus in succession for twenty days, so that upon the
twenty-first day the eggs first placed may be hatched, for the most part, and we may
obtain daily afterwards an equal number of chicks. In this way regularity of care is
established in the rearing of them.
During the first days of incubation, natural as well as artificial, a small portion of the
water contained in the egg evaporates by the heat, through the shell, and is replaced by
a like quantity of air, which is afterwards useful for the respiration of the animal. If the
warm atmosphere surrounding the eggs were very dry, such a portion of the aqueous part
of the eggs would evaporate through the pores of the shells as would endanger the future
life of the chick in ovo. The transpiration from the body of the hen, as she sits upon her
eggs, counteracts this desiccation in general; yet, in very dry weather, many hatching
eggs fail from that cause, unless they be placed in moist decomposing straw. The water
saucers N N are therefore essential to success in artificial incubation.
After the chickens are hatched they are transferred into the nursery, o q, on the front
side of which there is a small grated trough filled with millet seed. Small divisions are
made between the broods of successive days, to enable the superintendent to vary their
feeding to their age.
In order to supply an establishment of the common kind, where 100 eggs are to be
hatched daily, a dozen of hens would be needed, and 150 eggs must be placed under them,
as only two thirds in general succeed. At this rate, 4300 mothers would be required to
sit. Now supposing we should collect ten times as many hens, or 43,000, we should not
be able to command the above number of chickens, as there is seldom a tenth part of
hens in a brooding state. Besides, there would be in this case no fewer than 720 hens
every day coming out with a fresh brood of chickens, which would require a regiment of
superintendents.
artificial Incubation by means of Hot Mineral Waters.-This curious process is
aescribed very briefly in a letter by M. D'Arcet. The following are extracts from this
letter:" In June, 1825, I obtained chickens and pigeons at Vichy, by artificial incubation,
effected through the means of the thermal waters of that place. In 1827 I went to the
baths of Chaudes-Aigues, principally for the purpose of doing the same thing there.
Finding the proprietor a zealous man, I succeeded in making a useful application of this
source of heat to the production of poultry.
" The advantage of this process may be comprehended, when it is known that the
invalids who arrive at Vichy, for instance in the month of May, find chickens only the
size of quails; whereas, by this means, they may be readily supplied six months old.
"The good which may be done by establishing artificial incubation in places where
hot springs exist is incalculable; it may be introduced into these establishments without
at all interfering with the medical treatment of patients, since the hatching would go
on in winter, at a time when the baths for other purposes are out of use.
"There is no other trouble required in breeding chickens, by means of hot baths, than
to break the eggs at the proper time; for, when the apartments are closed, the whole of
the interior will readily acquire a sufficiently elevated and very constant temperature."
In addition to these details by M. D'Arcet, a letter was reveived from M. Felgeris, the




INDlGO.                                     1043
proprietor of the baths at Chaudes-Aigues (Cantal), in which he describes the success
he had in following M. D'Arcet's process. This consists in putting the eggs into a small
basket, suspending it in one of the stove-rooms heated by the hot mineral water, and
turning round the eggs every day. The very first trial was attended with success, and
no failure was experienced in four repetitions of it.
INDIGO. This invaluable blue dye-stuff, for which no tolerable substitute has been
found, was known to the ancients as a pigment under the name of indicum, whence its
present denomination.  In modern Europe, it first came into extensive use in Italy, bit,
about the middle of the 16th century, the Dutch began to import and employ it in considerable quantities. Its general introduction into the dye-houses of both England and
France was kept back by absurd laws. founded upon an opinion that it was a fugitive
substance, and even prejudicial to the fibie of wool. See DYEING, p. 419.
The plants which afford this dye-drug grow in the East and West Indies, in the middle regions of America, in Africa, and Europe. They are all species of the genera Indigofera, Isatis, and Nerium.
The following are cultivated: —Indigofera tinctoria affords in Bengal, Malabar,
Madagascar, the Isle of France, and St. Domingo, an article of middling quality, but
in large quantity.  The indigofera disperma, a plant cultivated in the East Indies
and America, grows higher than the preceding, is woody, and furnishes a superior
dye stuff.  The Guatimala indigo comes from  this species.  Indigofera J nil grows in
the same countries, and also in the West Indies. The Indigofera Argentea, which grows
also in Africa; it yields little indigo, but of an excellent quality.  Indigofera Pseudotinctoria, which is cultivated in the East Indies, furnishes the best of all: the Indigofera
Glauca is the Egyptian and Arabian species. There are also the cerulea, cinerea erecta,
hirsuta, glabra, and several others. The Nerium tinctorium of the East Indies affords
some indigo; as does the Isatis tinctoria, or Woad, in Europe; and the Polygonum
tinctorium.
The districts of Kishenagar, Jessore, and Moorshedabad, in Bengal, ranging from 8
to 90~ E. L. and 220 to 24~ N. L., produce the finest indigo.  That from  the districts
about Burdwan and Benares is of a coarser or harsher grain. Tyroot, in lat. 260, yields
a tolerably good article. The portion of Bengal most propitious to the cultivation of
indigo lies between the river Hoogly and the main stream of the Ganges.
In the East Indies, after having ploughed the ground in October, November, and the
beginning of December, they sow the seed of the indigo plant in the last half of March
and the beginning of April, while the soil, being neither too hot nor too dry, is most propitious to its germination. A light mould answers best; and sunshine, with occasional
light showers, are most favorable to its growth. Twelve pounds of seeds are sufficient
for sowing an acre of land. The plants grow rapidly, and will bear to be cut for the
first time at the beginning of July, nay, in some districts, so early as the middle of June.
The indications of maturity are the bursting forth of the flower buds, and the expansion
of the blossoms; at which period  the plant abounds most in the dyeing principle.
Another indication is taken from the leaves; which, if they break across, when doubled
flat, denote a state of maturity. But this character is somewhat fallacious, and depends
upon the poverty or richness of the soil. When much rain falls, the plants grow too
rapidly, and do not sufficiently elaborate the blue pigment. Bright sunshine is most
advantageous to its production.
The first cropping of the plants is the best; after two months a second is made; after
another interval, a third, and even a fourth; but each of these is of diminished value,
There are only two croppings in America.
Two methods are pursued to extract the indigo from the plant; the first effects it by
fermentation of the fresh leaves and stems; the second, by maceration of the dried'eaves; the latter process being most advantageous.
1. From  the recent leaves.-In the indigo factories of Bengal there are two large
stone-built cisterns, the bottom of the first being nearly upon a level with the top of
the second, in order to allow the liquid contents to be run out of the one into the other.
The uppermost is called the fermenting vat, or the steeper; its area is 20 feet square,
and its depth 3 feet; the lowermost, called the beater or beating vat, is as broad as the
other, but one third longer. The cuttings of the plant, as they come from the field,
are stratified in the steeper, till this be filled within 5 or 6 inches of its brim. In order
that the plant, during its fermentation, may not swell and rise out of the vat, beams of
wood and twigs of bamboo are braced tight over the surface of the plants, after which
water is pumped upon them till it stands within three or four inches of the edge of the
vessel. An active fermentation speedily commences, which is completed within 14 or 15
hours; a little longer or shorter, according to the temperature of the air, the prevailing
winds, the quality of the water, and the ripeness of the plants. Nine or ten hours after
the immersion of the plant, the condition of the vat must be examined; frothy bubbles appear, which rise like little pyramids, are at first of a white color, but soon




1044                                 INDIGO.
become gray-blue, and then deep purple-red.  The fermentation is at this time
violent, the fluid is in constant commotion, apparently boiling, innumerable bubbles
mount to the surface, and a copper-colored dense scum covers the whole. As long as
the liquor is agitated, the fermentation must not be disturbed; but when it becomes
more tranquil, the liquor is to be drawn off into the lower cistern. It is of the utmost
consequence not to push the fermentation too far, because the quality of the whole indigo
is deteriorated; but rather to cut it short, in which case there is, indeed, a loss of weights
but the article is better.  The liquor possesses now a glistening yellow color, which,
when the indigo precipitates, changes to green. The average temperature of the liquor
is commonly 85~ Fahr.; its specific gravity at the surface is 1-0015; and at the bottom,
1'003.
As soon as the liquor has been run into the lower cistern, ten men are set to work to
beat it with oars, or shovels 4 feet long, called busquets. Paddle wheels have also been
employed for the same purpose. Meanwhile two other laborers clear away the compressing beams and bamboos from the surface of the upper vat, remove the exhausted plant,
set it to dry for fuel, clean out the vessel, and stratify fresh plants in it. The fermented
plant appears still green, but it has lost three fourths of its bulk in the process, or from
12 to 14 per cent. of its weight, chiefly water and extractive matter.
The liquor in the lower vat must be strongly beaten for an hour and a half, when the
indigo begins to agglomerate in flocks, and to precipitate.  This is the moment for
judging whether there has been any error committed in the fermentation; which must
be corrected by the operation of beating. If the fermentation has been defective, much
froth rises in the beating, which must be allayed with a little oil, and then a reddish
tinge appears.  If large round granulations are formed, the beating is continued, in
order to see if they will grow smaller. If they become as small as fine sand, and if the
water clears up, the indigo is allowed quietly to subside. Should the vat have been over
fermented, a thick fat-looking crust covers the liquor, which does not disappear by the
introduction of a flask of oil. In such a case the beating must be moderated. Whenever
the granulations become round, and begin to subside, and the liquor clears up, the beating
must be discontinued. The froth or scum diffuses itself spontaneously into separate minute
particles, that move about the surface of the liquor; which are marks of an excessive
fermentation.  On the other hand, a rightly fermented vat is easy to work; the froth,
though abundant, vanishes whenever the granulations make their appearance.  The
color of the liquor, when drawn out of the steeper into the beater, is bright green; but
as soon as the agglomerations of the indigo commence, it assumes the color of Madeira
wine; and speedily afterwards, in the course of beating, a small round grain is formed,
which, on separating, makes the water transparent, and falls down, when all the turbidity
and froth vanish.
The object of the beating is three-fold: first, it tends to disengage a great quantity
of carbonic acid present in the fermented liquor; secondly, to give the newly developed
indigo its requisite dose of oxygen by the most extensive exposure of its particles to
the atmosphere; thirdly, to agglomerate the indigo in distinct flocks or granulations.
In order to hasten the precipitation, lime-water is occasionally added to the fermented
liquor in the progress of beating, but it is not indispensable, and has been supposed
capable of deteriorating the indigo. In the front of the beater a beam is fixed upright,
in which three or more holes are pierced a few inches in diameter.  These are closed
with plugs during the beating, but, two or three hours after it, as the indigo subsides,
the upper plug is withdrawn to run off the supernatant liquor, and then the lower
nlugs in succession. The state of this liquor being examined, affords an indication of
the success of both the processes.  When the whole liquor is run off, a laborer enters
the vat, sweeps all the precipitate into one corner, and empties the thinner part into a
spout which leads into a cistern, alongside of a boiler, 20 feet long, 3 feet wide, and 3 deep.
When all this liquor is once collected, it is pumped through a bag for retaining the
impurities, into the boiler, and heated to ebullition. The froth soon subsides, and shows
an oily looking film upon the liquor.  The indigo is by this process not only freed from
the yellow extractive matter, but is enriched in the intensity of its color, and increased in
weight.  From the boiler the mixture is run, after two or three hours, into a general
receiver called the dripping vat, or table, which, for a factory of twelve pairs of preparation vats, is 20 feet long, 10 feet wide, and 3 feet deep; having a false bottom, 2 feet
under the top edge.  This cistern stands in a basin of masonry (made water tight with
Chunam hydraulic cement), the bottom of which slopes to one end, in order to facilitate
the drainage. A thick woollen web is stretched along the bottom of the inner vessel,
to act as a filter. As long as the liquor passes through turbid, it is pumped back into
the receiver.  Whenever it runs clear, the receiver is covered with another piece of
cloth to exclude the dust, and allowed to drain at its leisure.  Next morning the
drained magma is put into a strong bag, and squeezed in a press.  The indigo is then
carefully taken out of the bag, and cut with a brass wire into bits, about 3 inches cube,




INDIGO.                                     1045
which are dried, in an airy house, upon shelves of wicker work.  During the drying, 9
whitish efflorescence comes upon the pieces, which must be carefully removed with a
brush. In some places, particularly on the coast of Coromandel, the dried indigo lumps
are allowed to effloresce in a cask for some time, and when they become hard they are
wiped and packed for exportation.
Frorh some experiments it would appear that the gas disengaged during the middle
period of the fermentation is composed in 100 parts of 27'5 carbonic acid, 58 oxygen,
and 66-7 azote; and towards its end, of 40'5 carbonic acid, 4-5 oxygen, and 550 azote.
The fermentinsg leaves apparently convert the oxygen of the atmosphere into carbonic
acid gas, and leave its azote; besides the quantity of carbonic acid which they spontaneously evolve.  Carbureted hydrogen does not seem  to be disengaged.  That the
liquor in the beating vat absorbs oxygen from the air in proportion as the indigo becomes
flocculent and granular, has been ascertained by experiment, as well as that sunshine
accelerates the separation of the indigo blue. Out of 1000 parts of the fermented liquor
of specific gravity 1'003, the blue precipitate may constitute 0-75 of a part. Such a proportion upon the great scale is however above the average, which is not more than 05.
When lime water is added, an extractive matter is thrown down, which amounts to from
20 to 47 parts in 1000 of the liquor.  It has a dark brown tint, a viscid appearance, an
unpleasant smell, and a bitter taste.  It becomes moist in damp air, and dissolves in
water without decomposition.  It is precipitated by lime, alkalis, infusion of galls, and
acetate of lead. All indigo contains a little lime derived from the plant, even though
none has been used in its preparation.
2. Indigo from dried leaves.-The ripe plant being cropped, is to be dried in sunshine
from 9 o'clock in the morning till 4 in the afternoon, during two days, and thrashed to
separate the stems from the leaves, which are then stored up in magazines till a sufficient
quantity be collected for manufacturing operations. The newly dried leaves must be free
from spots, and friable between the fingers. When kept dry, the leaves undergo, in the
course of 4 weeks, a material change, their beautiful green tint turning into a pale blue.
gray, previous to which the leaves afford no indigo by maceration in water, but subsequently a large quantity. Afterwards the product becomes less considerable.
The following process is pursued to extract indigo from  the dried leaves.  They are
infused in the seeping vat with six times their bulk of water, and allowed to macerate for
two hours with -'ontinual stirring till all the floating leaves sink. The fine green liquor
is then drawn ol' into the beater vat, for if it stood longer in the steeper, some of the indigo would settle among the leaves and be lost. Hot water, as employed by some manufacturers, is not necessary. The process with dry leaves possesses this advantage, that
a provision of the plant may be made at the most suitable times, independently of the
vicissitudes of the weather, and the indigo may be uniformly made; and moreover, that
the fermentation of the fresh leaves, often capricious in its course, is superseded by a
much shorter period of simple maceration.
The process for obtaining indigo from the Nerium is altogether the same, but hot
water has been generally applied to the dried leaves. For woad, hot water must be employed, and also lime water as a precipitant, on account of the small proportion of indigo
in the plant. Dilute muriatic acid is digested upon the woad indigo to remove the lime,
without which no dye could be precipitated.  According to the warmth of the summer
and the ripeness of the plant, from 2 to 5 ounces of indigo may be obtained from  100
pounds of the dried woad, or upon an average 4 ounces to the hundred weight.
The indigo found in European commerce is imported from  Bengal, Coromandel,
Madras, the Mauritius, Manilla, and Java in the Eastern hemisphere; from Senegal,
Caraccas, Guatimnala, Brazil (South Carolina and Louisiana in small quantity), and for
merly from the West India islands, especially St. Domingo. Its quality depends upon the
species of the plant, its ripeness, the soil and climate of its growth, and mode of manufacture. The East Indian and Brazilian indigo comes packed in chests, the Guatimala
in ox-hides, called surons.
The organ which affords the indigo is confined entirely to the pellicle of the leaves, anti
exists in largest quantity at the commencement of maturation while the plant is in flower.
The indigofera is remarkable for giving a blue tinge to the urine of cows that feed upon
its leaves.
According to some manufacturers, the plants should be cut down in dry weather, an
hour or two before sunset, carried off the field in bundles, and immediately spread upon
a dry floor. Next morning the reaping is resumed for an hour and a half, before the sun
acts too powerfully upon vegetation; and the plants are treated in the same way. Both
cuttings become sufficiently dry by 3 o'clock in the afternoon, so as to permit the leaves
to be separated from the stems by thrashing. They are now thoroughly dried in the
sunshine, then coarsely bruised, or sometimes ground to powder in a mill, and packed up
for the operations of manufacture.
In the spring of 1830 I subjected a variety of specimens of indigo to comparative




1046                                 INDIGO.
analyses, by dissolving a few grains of each in strong sulphuric acid, diluting the solua
tions with an equal volume of water, and determining the resulting shade of color in a
hollow prism of plate glass, furnished with a graduated scale. The following are the
results, compared to the shade produced by a like weight of absolute indigo.
1. East India Indigos; prices as at the last October sales.
No.   Price.   Real Indigo                   Characters by the Brokers.
s. d.
1    3  9       42       Broken, middling violet, and coppery violet spotted.
2    3  6       56-5     Ditto, a little being coppery violet and copper.
3    3  3       46'0     Ditto, middling red violet, dull violet and lean.
4    4  3       54'5     Large broken, and square, even middling red violet.
5    4  2       75-0     Much broken and very small, very crumbly and limy, soft,
good violet.
6    4  9       60'0     Square and large broken, I middling violet) and z    good
coppery violet.
70-0     Large broken, very good; paste a little limy, good violet.
8    6  6       60-0     Square and large broken, soft, fine paste, fine violet.
9661-    Square, ditto, good red violet.
10    7  0       75       Square, ditto, fine purple and blue.
11    2  3       37-5     Middling ordinary Madras.
12    3  6       60'0     Good Madras.
13    4  3       58-0     Very fine ditto.
14    2  0         ~~   Low, pale Oude.
15    2  4       271      Middling, ordinary Oude.
16    3  3       54       Good Oude.
1-17    1  9     29       Lundy, very low quality.
II. American Indigos; wholesale prices at present. (March, 1830.)
Indigo.        No.  Price. i.             Indigo.        No.  Price.         
d.                                            do
Caraccas flor. --    1   6  0    54    Guatimala - -  -            6   5  0    50
Guatimala  -      -    2   6  0    3342                            7   5  3    35
~              332   19                     ~             84846
-              446          321                           9 48    334
______-          _       5   54    50                              10   5  4    50
Properties of Indigo.-It possesses a dark blue color, passing into violet-purple, is void
of taste and smell, dull, but by rubbing with a smooth hard body, it assumes the lustre
and hue of copper. It occurs sometimes less and sometimes more dense apparently than
water, which circumstance depends upon its freedom from foreign impurities, as well
as upon the treatment of its paste in the boiling, pressing, and drying operations. It
is insoluble in water, cold alcohol, ether, muriatic acid, dilute sulphuric acid, cold
ethereous and fat oils; but boiling alcohol and oils dissolve a little of it, which they
deposite on cooling. Creosote has the property of dissolving indigo.
Indigo is a mixture of several dye-stuffs, and other substances. Berzelius found in it a
matter resembling vegetable gluten or. gliadine, a brown, red, and blue pigment, besides
oxyde of iron, clay, lime, magnesia, and silica.
1. Indigo gluten or gliadine is dissolved along with the calcareous and magnesian salts
by acids. If the powder be treated with dilute sulphuric acid, if the solution be saturated
with carbonate of lime, evaporated to dryness, and its residuum treated with alcohol; the
solution thus formed leaves, after being evaporated, a yellow transparent extract, easily
soluble in water, more difficultly in acid liquids; showing that acids extract only a portion
of the gliadine from the indigo. It yields, by dry distillation, much ammonia, a fetid oil,
and comports itself in other respects like vegetable gluten.
2. Indigo-brown occurs in combination with lime, as also with vegetable acid in considerable quantity, and more abundantly in the coarser sorts of indigo than in the finer.
Indigo purified by acids is to be treated with hot strong caustic ley, which dissolves the
indigo-brown; the liquid part of the mixture passes with difficulty through the filter
is black-brown, opaque, and holds some indigo-blue in solution, or diffused in fine powder




iNDIGO.                                      1047
The alkali being neutralized with acetic acid, the liquor is to be evaporated, and alcohol
poured on the residuum, whereby the alkaline acetate is dissolved out from the brown.
This pigment is a dark brown, almost black, but is not yet entirely deprived of the
other constituents of indigo. It is nearly tasteless, is combustible, affords, by dry distillation, ammonia and fetid oil, forms with acids combinations hardly soluble in water, with
alkalis soluble ones, but with earths hardly soluble. Lime possesses the property of precipitating the indigo-brown completely from its alkaline solution. Chlorine occasions a
pale yellow brownish precipitate, which consists of indigo brown and muriatic acid, but
causes no further change.  By drying, it becomes again dark colored. Indigo-brown
seems to exist also in woad.
3. Indigo-red, or more properly red resin of indigo. This may be obtained by boiling
alcohol of sp. gra. 0-830 upon some indigo which has been previously treated with acids
and alkalis; for the red substance is hardly soluble in cold alcohol. The solution is dark
red, opaque, and leaves, by distillation, the indigo-red in the form of a black-brown powder, or a glistening varnish, slightly soluble in alcohol and ether. Alkalis do not dissolve
it, but cone~ntrated sulphuric acid forms with it a dark yellow dye, from which water
causes no precipitation; wool extracts the color from the acid solution, and becomes
of a dirty brown hue. Chlorine does not seem capable of destroying the color, for though
it makes it yellow, it becomes as dark as ever on being dried. Indigo-red melts with
heat, burns with a bright flame, affords, when heated in vacuo, first a white crystalline
sublimate, and then unchanged indigo-red.  That white matter is changed by nitric acid
into indigo-red.
4. Indigo-blue, or pure indigo, remains, after treating the indigo of commerce with
dilute acid, alkalis, and alcohol; it retains, however, still traces of the matters thereby
extracted, along with some earthy substances.  In order to procure indigo-blue in its
utmost parity, we must deoxydize.the above blue residuum, thus form colorless indigo,'which again acquires a blue color from the air, and constitutes the pure pigment. For
this purpose the above moist indigo is to be mixed with slaked lime, green sulphate of
iron, and hot water in an air-tight matrass. The indigo when deoxydized by protoxyde
of iron being soluble in lime-water, the clear yellow solution is to be poured off, and exposed to the air. The indigo absorbs oxygen, and becomes again blue.  By digestion
with dilute muriatic acid the foreign matters are dissolved, and may then be washed away
with distilled water, from the absolute indigo.
The indigo-blue obtained in this manner has a cast of purple red, displaying the
characteristic copper lustre in a high degree, but in powder, it is blue. It is void
of taste and smell, is by my experiments of specific gravity 1l50, affords at 5540
Fahr. a purple vapor, and sublimes in shining purple scales, or slender needles in
an apparatus open to the air, whereby, however, much of it is destroyed.  Some
carbon remains after the sublimation. A quick heat produces most sublimate. These
needles contain a brown oily matter, which may be dissolved out by means of hot alco.
hol. Their specific gravity is 1-35, according to Mr. Crum. The sublimate from common indigo does not contain any oil, but some indigo-red and the above white crystalline
matter. According to Mr. Crum, indigo-blue consists of carbon, 73'22; oxygen, 12-60
azote, 1126; hydrogen, 2'92; while according to Dumas, crystallized indigo consists of
carbon, 73-26; oxygen, 10*43; azote, 13-81; and hydrogen, 2*50; precipitated indigo
consists of carbon, 74'81; oxygen, 7-88; azote, 13*98; and hydrogen, 3-33; sublimed
indigo, of carbon, 71*71; oxygen, 12-18; azote, 13A45; hydrogen, 2-66. My own analysis afforded-carbon, 71'37; oxygen, 14-25; azote, 10-00; hydrogen, 4'38. In another
analysis of Dumas, 3'93 parts of hydrogen were obtained. Hence we must infer that
considerable differences exist in the composition of indigo in its purest state. Reagents
act upon it much as upon common indigo. Chlorine, iodine, and bromine convert it into
a reddish brown soluble substance. Concentrated sulphuric acid, especially the smoking
or anhydrous of Nordhausen, dissolves indigo-blue with the disengagement of heat, but it
makes it suffer some modification; for though it retains an intense dark blue color, it has
become soluble in water, and may be blanched by light, which does not happen with indigo
itself. Nitric acid destroys indigo-blue, forms indigotic (carbazotic) acid, carbonic acid,
artificial resin, and bitter principle.
Indigo-blue may be reduced by substances oxydized, with the co-operation of alkalis
or alkaline earths; for example, by such substances as have a strong affinity for oxygen,
and are imperfectly saturated with this principle, as the sulphurous and phosphorous
acids and their salts, the protoxydes of iron and manganese, the protoxyde salts of tin,
and the corresponding compounds of chlorine, as the proto-cblorides of tin and iron; and
the solution of the former in potash. When in these circumstances, in the presence of
alkali, a deoxydation or reduction of the indigo-blue takes place, the other bodies get
oxydized by absorption of the oxygen of the indigo-blue; the protoxydes become peroxydes, and the acids in ous become acids in ic, &c. Several metallic sulphurets also
reduce the indigo-blue in the same predicament, as the sulphurets of potassium, of cal



1048                                   INDIGO.
cium, of antimony, and of arsenic (orpiment.) A similar influence is exercised by fermenting vegetable substances, such as woad, madder, bran, raw sugar (molasses), starch,
sirup, in consequence of the formation of carbonic and acetic acids, by absorption of the
oxygen of the indigo-blue, for acetic acid and acetic salts are found in the liquor of the
warm blue vat, in which indigo has been reduced by means of woad, madder, and bran.
Form~at ion of colorless reduced indigo-blue, or indigotihe.-Purified indigo-blue is to
be treated with copperas and slaked lime, as above described; or the clear wine-yellow
supernatant liquor of the cold blue-vat mixture is to be taken, run by a syphon into
a materass, a few drops of concentrated acetic or sulphuric acid, deprived of air, are to be
poured into it, and the vessel, being made quite full, is to be well corked. The reduced
indigo soon falls in white flocks, or crystalline scales. They must be edulcorated upon
a filter with water deprived of its air by boiling, then pressed between folds of blottingpaper, and dried under the receiver in vacuo. Indigo-blue may likewise be reduced and
dissolved by solution of hydro-sulphuret of ammonia; and the colorless indigotine maybe
precipitated by muriatic acid.
The reduced indigo is sometimes white at the instant of its elimination, sometimes
grayish, of a silky lustre, but becomes very readily greenish, blue green, and blue, in the
air; in which case it absorbs, according to Berzelius, 4-2 per cent. of oxygen; but according to Liebeg, 11-5 per cent. It is void of taste and smell, is insoluble in water;
well boiled water free from air is not affected by it, but is turned blue by common water.
It dissolves in alcohol and ether into a yellow dye; not in dilute acids, but in concentrated sulphuric acid, whereby probably a portion of this is decomposed, and some hyposulphurous acid formed; the color of this solution is blue.  Solutions of the caustic and
carbonated alkalis, even the alkaline earths, readily dissolve reduced indigo into a wineyellow  liquid; but in contact with air, oxygen is absorbed, and indigo-blue falls,  hile
a purple-colored froth, passing into copper-red, appears -".on the surface, just as in the
indigo vats of the dyer.
The reduced indigo may be combined, by means of complex affinity, with other bases,
with the exception of the oxydes of copper, zinc, and mercury, which oxydize it. These
combinations are white, in part crystallizable, become speedily blue in the air, and afford
by sublimation indigo-blue.  Berzelius formed with lime a two-fold combination; one
easily soluble in water, and another difficultly soluble, of a lemon color, which contained
an excess of lime; this is formed both in the hot and the cold blue vat; in the latter it is
occasioned by an overdose of lime.
When pure indigo-blue is treated with concentrated sulphuric acid, and particularly with
six times its weight of the smoking dry acid, it dissolves completely, and several different
compounds are produced in the solution. There is first a blue sulphate of indigo; secondly,
a similar compound with the resulting hyposulphurous acid; thirdly, a combination of
sulphuric acid with the purple of indigo (called Phlenicin by Crum), a peculiar substance,
generated from indigo-blue. These three compounds are here dissolved in an excess of
sulphuric acid. The more concentrated the sulphuric acid is, the more blue hyposulphite
is formed. The solution in smoking acid, when diluted with water and filtered, affords a
considerable precipitate of indigo purple, which that in oil of vitriol does not. The vapor
of anhydrous sulphuric acid combines with indigo-blue into a purple fluid.
In order to obtain from the dark blue solution each of these blue acids in a pure state,
we must dilute it with forty times its weight of water, and immerse in the filtered
liquor, well washed woo- or flannel, with which the blue acids combine, while most of the
sulphuric acid and some other foreign substances remain free in the liquor. The wool
must be then scoured with water containing about a half per cent. of carbonate of ammonia, or potash, which neutralizes both of the blue acids, and produces a blue compound,
rhis being evaporated to dryness at the temperature of 1400 F., alcohol of 0-833 is to be
poured upon the residuum, which dissolves the blue hyposulphite, but leaves the blue
sulphate undissolved. From either salt, by precipitating with acetate of lead, by acting
upon the precipitate with sulphureted hydrogen water, and evaporation, either of the
two blue acids may be obtained.  They may be both evaporated to dryness, especially
the blue sulphate of indigo; they both become somewhat moist in the air, they are very
soluble in water, and the blue sulphate also in alcohol; they have a not unpleasant smell,
and an acid astringent taste.
From these habitudes, particularly in reference to the bases, it appears that indigo-blue
does not comport itself like a saline base towards the acids, but rather like an acid, since
it enters into the salts, just as the empyreumatic oil of vinegar and oil of turpentine do
into resin soaps. The blue pigment of both acids is reduced by zinc or iron without the
disengagement of hydrogen gas; as also by sulphureted hydrogen, tepid protochloride of
tin, while the liquor becomes yellow.
Indigo-blue sulphate of potash, or ceruleo-sulphate of potash, may be obtained by
extracting the blue color from  the wool by water containing I per cent. of carbonate of potash, evaporating nearly to dryness, treating the extract with alcohol




INDIGO.                                     1049
to  remove the  indigo-blue  hyposulphite, then  with  acetic  acid  and  alcohol to
remove any excess of carbonate of potash.   It is found in commerce under the
name of precipitated indigo, indigo paste, blue carmine, and soluble indigo. To prepare
it economically, indigo is to be dissolved in ten times its weight of concentrated sulphuric
acid; the solution after twenty-four hours is to be diluted with ten times its weight of
water, filtered, and imperfectly saturated with carbonate of potash; whereby a blue pow.
der falls down; for the resulting sulphate of potash throws down the ceruleo-sulphate,
while the hyposulphite of potash remains dissolved.  It is a dark blue copper shining
powder, soluble in 140 parts of cold water, and in much less of boiling water. It is made
use of as a dye, and to give starch a blue tint.  When mixed with starch inst cakes, it is
sold under the name of blue for washerwomen.
Ceruleo-sulphate of ammonia may be formed in the same way.  It is much more
soluble in water. Ceruleo-sulphate of lime is obtained by saturating the above dilute
acid with chalk, filtering to separate the undyed gypsum, and washing with water till
the purple color be extracted.  This liquor, evaporated and decomposed by alcohol,
affords a bluish flocky precipitate, which is more soluble in water than common gypsum,
and dries up in a purple-blue film. Ceruleo-sulphate of alumina may be obtained by
double affinity; it is dark blue while moist, but becomes black-blue by drying, and is soluble in water.
The blue present in all these salts of ceruline is destroyed by sunshine, becomes greenish.
gray by caustic alkalis; and turns immediately yellow-brown by alkaline earths. But
when the solution is very dilute, the color becomes first green, then yellow. The carbonates of alkalis do not produce these changes. Nitric acid decomposes the color quickly.
Mr. Cram considers ceruline to be a combination of indigo-blue with water.
Phenicine, or indigo-purple combined with sulphuric acid, is obtained when the solution
of indiuo-blue in concentrated sulphuric acid has been diluted for a few hours with
water, and then filtered. It seems to be an intermediate body into which the indigo-blue
passes, before it becomes soluble ceruline. Hence it occurs in greater quantity soon after
estin   the indigo with the acid, than afterwards.  It is dark blue,.dissolves gradually
in water, affords after evaporation a blue residuum, of the same appearance as the above
blue acids.  When a salt is added to it a purple precipitate ensues, which is a compound
of indigo-purple, sulphuric acid, and the base of the salt. Indigo-purple is reduced by
bodies having a strong attraction for oxygen, if a free alkali or alkaline earth be present,
and its solution is yellow, but it becomes blue in the atmosphere. According to Mr. Crum,
Phenicine contains half as much combined water as ceruline.
The table which I published in 1830 (as given above) shows very clearly how much
the real quality and value of indigo differ from its reputed value and price, as estimated
from external characters by the brokers. Various test or proof processes of this drug
have been proposed.  That with chlorine water is performed as follows. It is known
that chlorine destroys the blue of indigo, but not the indigo-red or indigo-brown, which
by the resulting muriatic acid is thrown down from the sulphuric solution in flocks, and
the chlorine acts in the same way on the gliadine or gluten of the indigo. Pure indigo-blue
is to be dissolved in 10 or 12 parts of concentrated sulphuric acid, and the solution is to
be diluted with a given weight of water, as, for example, 1000 parts for I of indigo-blue.
If we then put that volume of liquor into a graduated glass tube, and add to it chlorine
water of a certain strength till its blue color be destroyed by becoming first green and
then red-brown, we can infer the quantity of color from the quantity of chlorine water
expended to produce the effect. The quantity of real indigo-blue cannot, however, be
estimated with any accuracy in this way, because the other coloring matters in the drug
act also upon the chlorine; and, indeed, the indigo itself soon changes when dissolved in
sulphuric acid even out of access of light, while the chlorine water itself is very susceptible
of alteration. Perhaps a better appreciation might be made by avoiding the sulphuric
acid altogether, and adding the finely powdered indigo to a definite volume of the chlorine
water till its color ceased to be destroyed, just as Prussian-blue is decolored by solution
of potash in making the ferro-cyanide.
Another mode, and one susceptible of great precision, is to convert 10 or 100 grains
of indigo finely powdered into its deoxydized state, as in the blue vat by the proper
quantity of slaked lime and solution of green sulphate; then to precipitate the indigo,
collect and weigh it. The indigo should be ground upon a muller along with the quicklime, the levigated mixture should be diluted with water, and added to the solution of the
copperas. This exact analytical process requires much nicety in the operator, and can
hardly be practised by the broker, merchant, or manufacturer.
Employment of indigo in dyeing. -As indigo is insoluble in water, and as it can penetrate the fibres of wool, cotton, silk, and flax, only when in a state of solution, the dyer
must study to bring it into this condition in the most complete and economical manner
This is effected either by exposing it to the action of bodies which have an affinity foi
oxygen superior to its own, such as certain metals and metallic oxydes, or by mixing it




1050                                   INDIGO.
with fermenting matters, or, finally, by dissolving it in a strong acid, such as the sulphuric.
The second of the above methods is called the warm blue, or pastel vat; and being the
most intricate, we shall begin with it.
Before the substance indigo was known in Europe, woad having been used for dyeing
blue, gave the name of woad vats to the apparatus. The vats are sometimes made of
copper, at other times of iron or wood, the last alone being well adapted for the employment of steam. The dimensions are very variable; but the following may be considered
as the average size: depth, 7} feet; width below, 4 feet, above, 5 feet. The vats are
built in such a way that the fire does not affect their bottom, but merely their sides half
way lup; and they are sunk so much under the floor of the dyehouse, that their upper
half only is above it, and is surrounded with a mass of masonry to prevent the dissipatior
of the heat. About 3 or 31 feet under the top edge an iron ring is fixed, called the
champagne by the French, to which a net is attached in order to suspend the stuffs out
of contact of the sediment near the bottom.
In mounting the vat the following articles are required: 1. woad prepared by fermen'
tation, or woad merely dried, which is better, because it may be made to ferment in the
vat, without the risk of becoming putrid, as the former is apt to do; 2. indigo, previously
ground in a proper mill; 3. madder; 4. potash; 5. slaked quicklime; 6. bran. In
France, weld is commonly used instead of potash.
The indigo mill is represented in figs. q90 and 791. a is a four-sided iron cistern
790                                 791.f~~ ~
cylindrical or rounded in the bottom, which rests upon gudgeons in a wooden frame; it
has an iron lid b, consisting of two leaves, between which the rod c moves to and fro,
receiving a vibratory motion from the crank d. By this construction, a frame e, which
is made fast in the cistern by two points d 4 is caused to vibrate, and to impart its swing
movement to six iron rollersff f, three being on each side of the frame, which triturate
the indigo mixed with water into a fine paste. Whenever the paste is uniformly ground,
it is drawn off by the stopcock g, which had been previously filled up by a screwed plug,
to prevent any of the indigo from lodging in the orifice of the cock, and thereby escaping
the action of the rollers. The cistern is nearly three "eet long.
The vat being filled with clear river water, the fire is to be kindled, the ingredients
introduced, and if fermented woad be employed, less liae is needed than with the merely
dried plant. Meanwhile the water is to be heated to the temperature of 1600 Fahr.,
and maintained at this pitch till the deoxydizement and solution of the indigo begin
to show themselves, which, according to the state of the constituents, may happen in 12
hours, or not till after several days. The first characters of incipient solution are blue
bubbles, called the flowers, which rise upon the surface, and remain like a head of soap.
suds for a considerable time before they fall; then blue coppery shining veins appear with
a like colored froth. The hue of the liquor now passes from  blue to green, and an
ammoniacal odor begins to be exhaled. Whenever the indigo is completely dissolved,
an acetic smelling acid may be recognised in the vat, which neutralizes all the alkali,
and may occasion even an acid excess, which should be saturated with quicklime. The
time for doing this cannot be in general very exactly defined. When quicklime has been
added at the beginning in sufficient quantity, the liquor appears of a pale wine-yellow
color, but if not, it acquires this tint on the subsequent introduction of the lime.
Experience has not hitherto decided in favor of the one practice or the other.
As soon as this yellow color is formed in the liquor, and its surface becomes blue,
the vat is ready for the-dyer, and the more lime it takes up without being alkaline, the
better is its condition. The dyeing power of the vat may be kept up during six months,
or more, according to the fermentable property of the woad. From time to time, madder
and bran must be added to it, to revive the fermentation of the sediment, along with some
indigo and potash, to replace what may have been abstracted in the progress of dyeing.
The quantity tof indigo must be proportional, of course, to the depth or lightness of the
tints required.




INDIGO.                                     1051
During the operation of this blue vat two accidents are apt to occur; the first, which
is the more common one, is called the throwing back, in French, the cure rebutS, and in
German, the Scharf or Schwartzwerden (the becoming sharp or black); the second is
the putrefaction of the ingredients. Each is discoverable by its peculiar smell, which it
is impossible to describe. The first is occasioned by the employment of too much quicklime, whereby the liquor becomes neutral or even alkaline. This fault may be recognised by the fading of the green, or by the dark green, or nearly black appearance of the
liquor; and by a dull blue froth, owing to a film of lime. The remedy for a slight degree
of this vicious condition, is to suspend in the liquor a quantity of bran tied up in a bag,
and to leave it there till the healthy state be restored. Should the evil be more inveterate, a decoction of woad, madder, and bran must be introduced. Strong acids are rather
detrimental. Sulphate of iron has been recommended, because its acid precipitates the
lime, while'^its oxyde reduces the indigo to the soluble state.
The decomposition or putrefaction of the blue vat is an accident the reverse of the
preceding, arising from the transition of the acetous into the putrid fermentation, whereby
the dyeing faculty is destroyed. Such a misfortune can happen only towards the comnuencement of working the vat, whilst the woad is still powerful, and very little indigo
has been dissolved. Whenever the vat is well charged with indigo, that accident cannot
easily supervene. In both of these distemperatures the elevation of the temperature of
the vat aggravates the evil.
Dyeing in the blue vat is performed as follows:Wool is put into a net, and pressed down into the liquor with rods; but cloth is smoothly
stretched and suspended by hooks upon frames, which are steadily dipped into the vat,
With slight motions through the liquor; yarn-hanks must be dipped and turned about by
hand. All unnecessary stirring of the liquor must however be avoided, lest the oxygen
of the atmosphere be brought too extensively into contact with the reduced indigo, for
which reason mechanical agitation with rollers in the vat is inadmissible. The stuffs to
be dyed take at the first dip only a feeble color, though the vat be strong, but they must
be deepened to the desired shade by successive immersions of fifteen minutes or more each
time, with intervals of exposure to the air, for absorption of its oxygen.
After the lapse of a certain time, if the fermentative power be impaired, which is recognised by the dye stuffs losing more color in a weak alkaline test ley than they ought,
the vat should be used up as far as it will go, and then the liquor should be poured away,
for the indigo present is not in a reduced state, but merely mixed mechanically, and
therefore incapable of forming a chemical combination with textile fibres.  If cotton
goods previously treated with an alkaline ley are to be dyed blue, the vat should contain
very little lime.
Theory of the Indigo vat.-The large quantity of extractive matter in woad and
madder, as also the sugar, starch, and gluten, in the bran and woad, when dissolved
in warm water, soon occasion a fermentation, with an absorption of oxygen from the
air, but especially from the indigo of the woad, and from that introduced in a finely
ground state. When thus disoxygenated, it becomes soluble in alkaline menstrua; the
red-brown of the indigo being dissolved at the same time. When lime is added, the
indigo-blue dissolves, and still more readily if a little potash is conjoined with it; but
whatever indigo-brown may have been dissolved by the potash, is thrown down by the lime.
Lime in too large a quantity, however, forms an insoluble combination with the reduced
indigo, and thus makes a portion of the dye ineffective; at the same time it combines
with the extractive. In consequence of the fermentative action, carbonic acid, acetic
acid, and ammonia are disengaged; the first two of which neutralize a portion of the lime,
and require small quantities of this earth to be added in succession; hence also a considerable quantity of the carbonate of lime is found as a deposite on the sides and bottom
of the vat. In the sound condition of the indigo vat, no free lime should be perceived,
but on the contrary a free acid. Yet when the disengaged carbonic and acetic acids saturate the lime completely, no indigo can remain at solution; therefore a sufficient supply
of lime must always be left to dissolve the dye, otherwise the indigo would fall down
and mix with the extractive matter at the bottom. Goods dyed in the blue vat are occasionally brightened by a boil in a logwood bath, with a mordant of sulpho-muriate of tin,
or in a bath of cudbear.
Another mode of mounting the indigo vat without woad and lime, is by means of madder, bran, and potash. The water of the vat is to be heated to the temperature of 122~
F.; and for 120 cubic feet of it, 12 pounds of indigo, 8 pounds of madder, and as much
bran, are to be added, with 24 pounds of good potashes; at the end of 36 hours, 12
pounds more of potash are introduced, and a third 12 pounds in other 12 hours.  In
the course of 72 hours, all the characters of the reduction and solution of the indigo
become apparent; at which time the fermentation must be checked by the addition of
quicklime.  The liquor has a bright full color, with a beautiful rich froth. In feeding
the vat with indigo, an equal weight of madder and a double weight of potash, should




1052                                      INDIGO.
be added. - The odor of this vat, in its mild but active state, is necessarily different from
that of the woad vat, as no ammonia is exhaled in the present case, and the sediment is
much smaller. The reduced indigo is held in solution by the carbonated potash, while
the small addition of quicklime merely serves to precipitate the indigo-brown.
A potash vat dyes in about half the time of the ordinary warm vat, and penetrates
fine cloth much better; while the goods thus dyed lose less color in alkaline and soap
solutions. This vat may moreover be kept with ease in good condition for several
months; is more readily mounted; and from  the minute proportion of lime present, it
cannot impair the softness of the woollen fibres. It is merely a little more expensive.
It is said that cloth dyed in the potash indigo vat, requires one third less soap in the
washing at the fulling mill, and does not soil the hands after being dressed. At Elbeuf
and Louviers, in France, such vats are much employed.  Wool, silk, cotton, and linen,
may all be dyed in them.
Cold va/s.-The copperas or common blue vat of this country is so named because the
indigo is reduced by means of the protoxyde of iron. This salt should therefore be as
free as possible from the red oxyde, and especially from any sulphate of copper, which
would re-oxydize the indigo. The necessary ingredients are: copperas (green sulphate
of iron), newly slaked quicklime, finely ground indigo, and water; to which sometimes
a little potash or soda is added, with a proportional diminution of the lime. The operation is conducted in the following way: the indigo, well triturated with water or an alkaline ley, must be mixed with hot water in the preparation vat, then the requisite quantity
of lime is added, after which the solution of copperas must be poured in with stirring.
Of this preparation vat, such a portion as may be wanted is laded into the dyeing vat.
For one pound of indigo three pounds of copperas are taken, and four pounds of lime
(or I of indigo, 21 of copperas, and 3 of lime). If the copperas be partially peroxydized,
somewhat more of it must be used.
A vat containir, a considerable excess of lime is called a sharp vat, and is not well
adapted for dyeing. A soft vat, on the contrary, is that which contains too much copperas. In this case the precipitate is apt to rise, and to prevent uniformity of tint in the
dyed goods. The sediment of the copperas vat consists of sulphate of lime, oxyde of
iron, lime with indigo brown, and lime with indigo blue, when too much quicklime has
been employed. The clear, dark wine yellow fluid contains indigo blue in a reduced state,
and indigo red, both combined with lime and with the gluten of indigo dissolved. After
usin it for some time the vat should be refreshed or fed with copperas and lime, upon
which occasion the sediment must first be stirred up, and then allowed time to settle
again and become clear. For obtaining a series of blue tints, a series of vats of different
strengths is required.
Linen and cotton yarn, before being dyed, should be boiled with a weak alkaline ley,
then put upon frames or tied up in hanks, and after removing the froth from the vat,
plunged into and moved gently through it. For pale blues, an old, nearly exhausted
vat is used; but for deep ones, a fresh, nearly saturated vat. Cloth is stretched upon a
proper square dipping frame made of wood, or preferably of iron, furnished with sharp
hooks or points of attachment. These frames are suspended by cords over a pulley, and
thus immersed and lifted out alternately at proper intervals. In the course of 8 or 10
minutes, the cloth is sufficiently saturated with the solution of indigo, after which it is
raised and suspended so as to drain into the vat. The number of dippings determines
the depth of the shade; after the last, the goods are allowed to dry, taken off the frame,
plunged into a sour bath of very dilute sulphuric or muriatic acid, to remove the adhering lime, and then well rinsed in running water. Instead of the dipping frames, some
dyers use a peculiar roller apparatus, called gallopers, similar to what has been described
under CALICO PRINTING; particularly for pale blues.  This cold vat is applicable to
cotton, linen, and silk goods.
When white spots are to appear upon a blue ground, resist pastes are to be used, as
described under CALICO PRINTING.
The urine vat is prepared by digestion of the ground indigo in warmed stale urine,
which first disoxygenates the indigo, and then dissolves it by means of its ammonia.
Madder and alum are likewise added, the latter being of use to moderate the fermentation. This vat was employed more commonly of old than at present, for the purpose of
dyeing woollen and linen goods.
The mode of making the China blue dye has been described under CALICO PRINTING;
as well as the pencil blue, or blue of application.
A blue dye may likewise be given by a solution of indigo in sulphuric acid. This process was discovered by Barth, at Grossenhayn, in Saxony, about the year 1740, and is
hence called the Saxon blue dye. The chemical nature of this process has been already
fully explained. If the smoking sulphuric acid be employed, from 4 to 5 parts are sufficient for I of indigo; but if oil of vitriol, from 7 tc 8 parts. The acid is to be poured
into an earthenware pan, which in summer must be placed in a tub of cold water, to pre



INDIGO.                                                          1053
vent it getting hot, and the indigo, in fine powder, is to be added, with careful stirring,
in   small successive  portions.    If it  becomes  heated, a  part  of  the  indigo  is  decomposed, with the disengagement of sulphurous acid gas, and indigo green is produced.
Whenever all the indigo has been dissolved, the vessel must be covered up, allowed to
stand for 48 hours, and then diluted with twice its weight of clear river water.
The undiluted mass has a black blue color, is opaque, thick, attracts water from the
air, and  is called indigo composition, or chemic blue.    It  must be   prepared  beforehand,
and kept in store. In this solution, besides the cerulin, there are also indigo-red, indigobrown, and gluten, by which admixture the pure blue of the dye is rendered foul, assuming a brown or a green cast. To remove these contaminations, wool is had recourse
to. This is plunged into the indigo previously diffused through a considerable body of
water, brought to a boiling heat in a copper kettle, and then allowed to macerate as it
cools for 24 hours. The wool takes a dark blue dye by absorbing the indigo-blue sulphate
and hyposulphite, while at the same time the liquor becomes greenish blue; and if the
wool be left longer immersed, it becomes of a dirty yellow. It must therefore be taken
out, drained, washed in running water till this runs off colorless, and without an acid
taste. It must next be put into a copper full of water, containing one or two per cent.
of carbonate of potash, soda, or ammonia (to about one third the weight of the indigo),
and subjected to a boiling heat for a quarter of an hour.  The blue salts forsake the
wool, leaving it of a dirty red-brown, and dye the water blue. The wool is in fact dyed
with the indigo-red, which is hardly soluble in alkali. The blue liquor may now be employed as a fine dye, possessed of superior tone and lustre. It is called distilled blue and
soluble blue. Sulphuric acid throws down from it the small quantity of indigo-red which
had been held in solution by the alkali.
When wool is to be dyed with this sulphate of indigo-blue, it must be first boiled in
alum, then treated with the blue liquor, and thus several times alternately, in order to
produce a uniform  blue color.  Too long continuance of boiling is injurious to the
beauty of the dye. In this operation the woollen fibres get impregnated with the indigoblue sulphate of alumina.
With sulphate of indigo, not only blues of every shade are dyed, but also green, olive,
gray, as also a fast ground to logwood blues; for the latter purpose the preparatory boil
is given with alum, tartar, sulphates of copper and iron, and the blue solution; after
which the goods are dyed up with a logwood bath containing a little potash.
Table of STOCKS, DELIVERIES, IMPORTS, &c., through the course of 16 Years.
Arrived
in 2 months.                Crop of                Prices 31st December.
Stock 31st Delivered                                            Bengal in ___
December. 12 Months.                                            course of                   Mddig 
Bengal.*    Madras,        Total.    SIipent. Good and  Fine            ooad Ordinary
Manilta, &c.                               P. V.        Consuming.   Consuming.
inauld-s.           per lb.         per tb.         per tb.
1836    22,342       22,378      21,829         1.672       23,501      115,500     7       8       6  0    6  6   5  4   51 0
1837    25,969       18,544      19,409        2,762        22,171      113,600     74 "8           6    " 6  9   5  6   6  6
183S    21,161)      28,488      21,670        2,812        23,688       8.000      8  6 " 9        6  9 "7  3   5    "0   6  6
1839     15,250      23,271      13 802        3.470        17.352     1'23.00      8  3 " 9        6  0 "7  0   5    " 5  9
1840    16,344       25,811      22,823        4,082        26.95       123,000     7  6 " 8  3   5  3 "6  3   4     " 50
1S41    16,478       26.599      22,687         4.046       26.733      16-,000     6  0 "6 10   3  4" 4  0   2  9 "3  3
1842    21,927       27,820       26,594        6,,75       33,269       78,90      7  9 " 8  3   5    "     9   4  3 " 4  9
1843    21,781       22,954       16.920        5 888       2-2 808     172,000     5  0 5  8   3  6 "310   2 10 "3  4
1844    25,275       32,253      28.228         8.219       36.447      143500      4 10         " 5  610   3  2 "         3   6
1845    33.51-2      29,968       25,458       12,047       37,505      127,800     4 10 " 5  8   3  3 " 3  6   2 10 " "    3
1846    33,118       28,431       19,4:,8       8.659       28.097      101.300     5    " 6  0   3  8" 4  0   3  2 "3  6
1847    31,902       30).428      19,576        9,576       29,152      1,07.200    4  6 " 5  3   2 10 " 3  3   2  4 " 2  8
1848    28.96-2      27,5t3       21,119        3.504       24,62:0     1260.700    4  3 " 5        2 10 " 3  3   6  6 "2  9
1843    29.036       32,773      27,464         5 383       3-.847      122,000     4  6 "5  4   3  6 "3  9   3  3 "3  5
1808    27,205       28,690      202057         6,802       26,859      112,>00     60  0           5 "5       6   4  7 "  5  0
1851    30,332       29,241      22,572         9,796       32,368      122,000     4  8 " 5  9   3     " 3 11  3  1 " 3  6
Stock of E. I. INDIGO, in the chief EUROPEAN PORTS, at the end of the following Years.
St.                                               London      Total
Years.    daR.       Amnter   Antwerp.   bHurg.   Peters-  Trieste.  Genoa.  Bremen. France.    and                      St
burgh.                                               Liverpool.  Europe.
chests. chests.    c   chests.    chests.   chests.   chests.   chests.   chests,   chests.   chests.    chests.
1843     1,500       1,600        100        255       1,707      150        149        20       6,466     2-2.381     341,328
1S4       664       1,342        170        350       1.600      249        235        10       7,172     26.975      39.367
1845       550         650        100         220      2,011      280        2-25       60      10,485     34,512      49.193
1842       337         492        100        215       1,389      400        165        50      10.615     33 978      47,741
1847       938         560         60        150       1.918      230        13:)       20      11,1-27    32 802      47.935
1848      10,2         531         50        450       2,000      200        120        48       7,402     29,412      41.315
1849       595         828        100        550       1,655      150        107        20       4,501     29,240      37.745
1850       395         851        150        340       1,4f0      150         40        50       5,311     27.2 5,'5 962
1851        80         320        100        260       1,681       50         50        20       5,953     30,452      38,969
Imported  for home  consumption, in 1850, 7,893,984  pounds; in 1851, 10,073,728
pounds.




1054                                           INDIGO.
LANDINGS, DELIVERIES, AND STOCKS OF E. L. INDIGO.
Landed.                   Delivered.               Stock lst January, 1852.
n a      l.eMadras, Tt
Bengal.  Mra,  Total.   Consump- Export.  Total.   Bengal.  Madras,           Total.
tioe.
In Dec.    1851     177      273       450       679    1,134    1,813      -                    chests.
1850     673      731     1,404       399      418      817      -                  ~ 
1849    -         -         473       433    1,261    1,694      - 
In 12 inonths 1851   22,572    9,796    32,368  8,344    20,88.7   29.241    26,028    4,304    30,332
1850   20,057    6,802    26,859    8.551    20,139   28,690    23,089    4,116    27,205
1849    -         -      32.799     9,209   23,564   33,773    24,989    4,047    29.036
1848    -         -      21,623    10,468    17,095   27,563    23,732    5.230    28,962
1847    -         -       29.252    9,010    21,418   30,428    24,395    7,507    31.902
1846    -         -      28,10-2   10,546    17,885'28,431    25,333    7,845    83,178
184S    -         -      37,461    10.666    19,302   29,968    26,335    7,177    33,.2
1844    -         -      36.808    11.664   20,589   3'2,53    22,823    3,152    25,975
1843    -         -      22,808     8,253    14,701   22,954                      21,78
Indigo from  Spanish South America has formed a large feature in our importations of
1851. The landings amount to 7,291 serons, being 4,111 more than the greatest quantity
ever before received in one year, and 5,428 more than the average importations of the
last ten years.
The deliveries have been still greater; 7,887 serons-equivalent to about 8,900 chests
of East Indian production.   The parcels, uniformly  brought to  auction upon arrival,
have met with very general attention. The value may be considered relatively as high
as Bengal.
That such quantities of this indigo were directed to this country is not the result of
increased cultivation, but of the high prices current in 1850, offering a better market than
those of the United States or the Mediterranean, the usual destination direct from the
producing countries.
LANDINGS, DELIVERIES, AND STOCKS OF SPANISH INDIGO.
Landed.             Delivered.           Stock 1st January.
In December           1851             13 serons            207 serons                   serons
1850           316    "              127
In 12 months          1851          7,291                 7,887    "               403
1850         3,080    "            2,478                      999
1849         2,352    "            3,027                      397
1848         1,153    "            1,967   "                  965
1847         2,045    "            1,273                    1,779
1846         1,265'            1,414    ".              948
1845         1,083    "            1,047   "               1,097
1844         1,132    "            1,095   "                  889
1843         2,480    "            2,641   "                  891
1842         1,968    "            1,850                    1,052    "
Prices.-Bengal, fine blue, 5s. lOd. to 6s. per lb.; fine purple and violet, 5s. 2d. to 5.
9d.; fine red  violet, 5s. Id. to 5s. 7d.; good purple and  violet, 4s. 8d. to 5s.; middling
violet, 4s. 6d. to 4s. 8d.; middling defective, 4s. to 4s. 5d.  Consuming, fine, 4s. to 4s. 5d.;
middling  and good, 3s. 7Id. to 3s. lid.; ordinary, 3s. 1d. to  3s. 6d.; ordinary  and  trash,
2s. 3d. to 2s. 10d.
Oude, middling and good, 2s. 6d. to 3s.; ordinary, 2s. 2d. to 2s. 5d.
Madras, good  and fine, 4s. to 4s. 6d.; middling, 3s. to 3s. 9d.; ordinary, Is. 4d. to
2s. 9d.
Kurpah, fine, 5s. to 5s. 8d.; good, 4s. to 4s. 9d.; middling, 3s. 3d. to 3s. lid.; ordinary,
2s. 3d. to 2s. 10d.; sweepings, Is. 3d. to Is. 6d.
Spanish: Guatemala, good and fine, 4s. 4d. to 5s.; middling, 3s. 6d. to 4s. 2d; ordinary,
2s. 6d. to 3s. 3d.
Caracca, good, 3s. 8d. to 4s. 6d.; ordinary, 2s. 6d. to 3s. 6d.
Layton, Hulbert d& Co.'s Circular, 7th Jan. 1852.
* Including Coastwise from Liverpool.




INK.                                     1055
INDIGO, tested and valued. Rub one gramme of indigo to a fine powd   i
lain mortar, pour over it 10 grammes of fuming sulphuric acid, cover it and stir occasionally from 6 to 8 hours. Pour the mixture into an evaporating dish, containing 2 lbs. of
water, and add 60 gramnmes of muriatic acid, and heat the whole to boiling, replacing the
water lost in vapour.
Dissolve one-fourth of a gramme of chlorate of potash in 100 grammes of water, in a
graduated glass tube capable of holding 100 cubic centimetres of water. This quantity
of salt suffices even for the very best indigo. This test liquid is to be added to the
boiling hot indigo solution in question by degrees, and the quantity of it is noted,
which is required to make the colour pass from blue into green, and finally to brownish
red. By comparative results with other indigos, and the same test, their relative value
is given.
INDIAN RUBBER, is the vulgar name of caoutchouc in this country.
INDUSTRY. See MANUFACTURING INDUSTRY.
INK (Encre, Fr.; Tinte, Germ.) is a colored liquid for writing on paper, parchment,
linen, &c. with a pen.
Black ink.-Nutgalls, sulphate of iron, and gum, are the only substances truly useful
in the preparation of ordinary ink; the other things often added merely modify the shade,
and considerably diminish the cost to the manufacturer upon the great scale. Many of
these inks contain little gallic acid, or tannin, and are therefore of inferior quality. To
make 12 gallons of ink, we may take12 pounds of nutgalls,
5 pounds of green sulphate of iron,
5 pounds of gum senegal,
12 gallons of water.
The bruised nutgalls are to be put into a cylindrical copper, of a depth equal to its
diameter, and boiled, during three hours, with three fourths of the above quantity of
water, taking care to add fresh water to replace what is lost by evaporation. The
decoction is to be emptied into a tub, allowed to settle, and the clear liquor being
drawn off, the lees are to be drained. Some recommend the addition of a little bullock's
blood or white of egg, to remove a part of the tannin. But this abstraction tends to lessen
the product, an!d will seldom be practised by the manufacturer intent upon a large return
for his capital. The gum  is to be dissolved in a small quantity of hot water, and the
mucilage thus formed, being filtered, is added to the clear decoction. The sulphate of
iron must likewise be separately dissolved, and well mixed with the above. The color
darkens by degrees, in consequence of the peroxydizement of the iron, on exposing the
ink to the action of the air. But ink affords a more durable writing when used in the
pale state, because its particles are then finer, and penetrate the paper more intimately.
When ink consists chiefly of tannate of peroxyde of iron, however black, it is merely
superficial, and is easily erased or effaced. Therefore, whenever the liquid made by the
above prescription has acquired a moderately deep tint, it should be drawn off clear into
bottles, and well corked up. Some ink-makers allow it to mould a little in the casks
before bottling, and suppose that it will thereby be not so liable to become mouldy in the
bottles. A few bruised cloves, or other aromatic perfume, added to ink, is said to prevent the formation of mouldiness, which is produced by the ova of infusoria animalcules.
I prefer digesting the galls to boiling them.
The operation may be abridged, by peroxydizing the copperas beforehand, by moderate
calcination in an open vessel; but, for the reasons above assigned, ink made with such a
sulphate of iron, however agreeable to the ignorant, when made to shine with gum and
sugar, under the name of japan ink, is neither the most durable nor the most pleasant to
write with.
From  the comparatively high  price of gall-nuts, sumach, logwood, and  even
oak bark, are too frequently substituted, to a considerable degree, in the manufacture
of ink.
The ink made by the prescription given above, is much more rich and powerful than
many of the inks commonly sold.  To bring it to their standard, a half more water may
safely be added, or even 20 gallons of tolerable ink may be made from that weight of
materials, as I have ascertained.
Sumach and logwood admit of only about one half of the copperas that galls will take
to bring out the maximum amount of black dye.
Chaptal gives a prescription in his Chimie appliqufe aux arts, which, like many other
things in that book, are published with very little knowledge and discrimination.  He
uses logwood and sulphate of copper, in addition to the galls and sulphate of iron; a pernicious combination, productive of a spurious fugitive black, and a liquor corrosive of
pens. It is, in fact, a modification of the vile dye of the hatters.
Lewis, who made exact experiments on inks, assigned the proportion of 3 parts of galls




1056                                     INK.
to  of sulphate of iron, which, with average galls, will answer very well; but good galls
will admit of more copperas.
Gold ink is made by grinding upon a porphyry slab, with a mu.ler, gold leaves along
with white honey, till they be reduced to the finest possible division.  Te paste i
2ollected upon the edge of a knife or spatula, put into a large glass, and diffused thri gh'water.  The gold by gravity soon falls to the bottom, while the honey dissolves in the
water, wnich must be decanted off. The sediment is to be repeatedly washed till entirely
freed from the honey.  The powder, when dried, is very brilliant, and when to be used
as an ink, may be mixed up with a little gum water.  After the writing becomes dry, it,should be burnished with a wolf's tooth.
Silver ink is prepared in the same manner.
Indelible ink.-A very good ink, capable of resisting chlorine, oxalic acid, and ablution
with a hair pencil or sponge, may be made by mixing some of the ink made by the preceding prescription, with a little genuine China ink. It writes well. Many other formulae have been given for indelible inks, but they are all inferior in simplicity and usefulness to the one now prescribed.  Solution of nitrate of silver thickened with gum, and
written with upon linen or cotton cloth, previously imbued with a solution of soda, and
dried, is the ordinary permanent ink of the shops.  Before the cloths are washed, the
writing should be exposed to the sun-beam, or to bright daylight, which blackens and fixes
the oxyde of silver. It is easily discharged by chlorine and ammonia.
A good permanent ink may be made by mixing a strong solution of chloride of platinum
with a little potash sugar, and gum to thicken. The writing made therewith should be
passed over with a hot smoothing iron, to fix it.
Red ink.-This ink may be made by infusing, for 3 or 4 days in weak vinegar,
Brazil wood chipped into small pieces; the infusion may be then boiled upon the wood
for an hour, strained, and thickened slightly with gum  arabic and sugar.  A  little
alum improves the color.  A decoction of cochineal with a little water of ammonia,
forms a more beautiful red ink, but it is fugitive.  An extemporaneous red ink of the
same kind may be made by dissolving carmine in' weak water of ammonia and adding a
little mucilage.
Green ink.-According to Klaproth, a fine ink of this color may be prepared by boiling
a mixture of two parts of verdigris in eight parts of water, with one of cream of tartai
till the total bulk be reduced one half.  The solution must be then passed through
cloth, cooled, and bottled for use.
Yellow ink is made by dissolving 3 parts of alum in 100 of water, adding 25 parts of
Persian or Avignon berries bruised, boiling the mixture for an hour, straining the liquor,
and dissolving in it 4 parts of gum arabic. A solution of gamboge in water forms a convenient yellow ink.
By examining the different dye-stuffs, and considering the processes used in dyeing with
them, a variety of colored inks may be made.
China ink.-Proust says, that lamp-black purified by potash ley, when mixed with
a solution of glue, and dried, formed an ink which was preferred by artists to that of
China.  M. Merimde, in his interesting treatise, entitled, De la peinture A l'hlmile, says,
that the Chinese do not use glue in the fabrication of their ink, but that they add
vegetable juices, which render it more brilliant and more indelible upon paper.
When the best lamp-black is levigated with the purest gelatine or solution of glue, it
forms, no doubt, an ink of a good color, but wants the shining fracture, and is not so
permanent on paper as good China ink; and it stiffens in cold weather into a tremulous
jelly.  Glue may be deprived of the gelatinizing property by boiling it for a long time,
or subjecting it to a high heat in a Papin's digester; but as ammonia is apt to be generated in this way, M. Merimee recommends starch gum made by sulphuric acid (British
gum) to be used in preference to glue.  He gives, however, the following directions fol
preparing this ink with glue.  Into a solution of glue he pours a concentrated solution
of gall nuts, which occasions an elastic resinous-looking precipitate.  He washes this
matter with hot water, and dissolves it in a spare s. ution of clarified glue. He filters
anew, and concentrates it to the proper degree for being incorporated with the purified;amp-black. The astringent principle in vegetables does not precipitate gelatine when
its acid is saturated, as is done by boiling the nutgalls with limewater or magnesia. The
first mode of making the ink is to be preferred. The lamp-black is said to be made in
China, by collecting the smoke of the oil of sesame. A little camphor (about 2 per cent.)
bos been detected in the ink of China, and is supposed to improve it. Infusion of galls
renders the ink permanent on paper.
Sympathetic ink. The best is a solution of muriate of cobalt.
Printer's ink. See this article.
By decomposing vanadate of ammonia with infusion of galls, a liquid is obtained
of a perfectly black hue, which flows freely from the pen, is rendered blue by acids, is
insoluble in dilute alkalis, and resists the action of chlorine. Whenever the metal vana'




INK.                                        1057
dium  shall become more abundant, as it probably may ere long, we shall possess the
means of making an ink, at a moderate price, much superior to the tannate and gallate
of iron.
To prepare the above vanadic salt cheaply, the cinder or hammerschlag obtained
friom  the iron made at Ekersholm, in Sweden, or other iron which contains vanadium, being reduced to a fine powder, is to be mixed with two thirds of its weight
of nitre, and one third of effloresced soda. The mixture is to be ignited in a crucible;
cooled and lixiviated, whereby solutions of the vanadates of potash and soda are obtained,
not pure, indeed, but sufficiently so for being decomposed, by means of sal ammoniac,
into a vanadate of ammonia.  This being rendered nearly neutral with any acid, constitutes an excellent indelible ink.
Ink, indelible, may be prepared by adding lamp-black and Indigo to a solution of the
gluten of wheat in acetic acid.  This ink is of a beautiful black colour, at the same time
cheap, and cannot be removed by water, chlorine, or dilute acids.  M. Herberger gives
the following directions for its preparation: - Wheat-gluten is carefully freed from the
starch, and then dissolved in a little weak acetic acid; the liquid is now mixed with so
much rain water that the solution has about the strength of wine vinegar, i. e. neutralizes - of its weight of carbonate of soda. 10 grs. of the best lamp-black and 2 grs. of
indigo are mixed with 4 ozs. of the solution of gluten and a little oil of cloves added.
This ink may be employed for marking linen, as it does not resist mechanical force.
Ink, indelible, of Dr. Traill, is essentially the same as the above.
French indelible ink consists of Indian ink diffused through dilute muriatic acid, for
writing with quills, and through weak potash lye for writing with steel pens.
Ink, blue. Mr. Stephen's patent blue ink is made by dissolving Prussian blue in a
solution of oxalic acid. The blue should be washed in dilute muriatic acid.
M. Hornung has given the following, as the best formula for blue ink: -
Mix 4 parts of perchloride of iron, in solution, with 7'50 parts of water, then add 4
parts of cyanide of potassium dissolved in a little water; collect the precipitate formed,
wash it with several additions of water, allow it to drain until it weighs about 200 parts;
add to this one part of oxalic acid, and promote the solution of the cyanide by shaking
the bottle containing the mixture. The addition of gum and sugar is useless, and even
appears to exercise a prejudicial effect on the beauty of the ink. It may be kept without any -addition for a long time.
-Rev. Mr. Reade's inks.-A  series of writing inks of a new  composition have been
made the subject of a patent by the Rev. J. B. Reade, F. R. S., and they seem  to
deserve public patronage. They resist equally acids and alkalis, and are well adapted
to metallic pens.  His inks for marking linen are not acted upon by cyanide of potassium  or chloride of lime.  His process for obtaining a soluble Prussian blue is new to
the chemical world, and inclines to raise'a doubt as to the elementary nature of iodine.
In the course of his researches, he has discovered two new salts of gold, which he has
named ammonia-iodide, and ammonia periodide, of gold. His specification runs thus: -
Istly. I manufacture in manner following, a bfie writing ink, which is wholly free
from acid, and therefore well adapted for use with steel pens. I first obtain a solution of
iodide of iron by the process ordinarily followed for that purpose, and then dissolve
therein half the weight of iodine already employed. I next pour this mixture into a
semi-saturated solution of yellow prussiate of potash, employing a weight of this salt
nearly equal to the whole weight of iodine used in the above iodine solution. A decomposition of the materials, thus brought together, immediately takes place, when the
cyanogen (of the prussiate of potash) and iron combine, and are precipitated in a solid
form, and the potassium (of the prussiate) and iodine combine to form a neutral iodide
of potassium, which remains in solution with a little excess of iodide of iron. I next
filter and wash the solid precipitate of cyanogen and iron (which is soluble Prussian
blue), and finally dissolve it in water, which forms the blue ink required. In this process, it will be observed that neither any acid nor persalt of iron is employed, as is usual
in the formation of Prussian blue.
I was led to these results by a microscopical examination of the metallic colours in
salts of the ashes of plants.  I employed iron and iodine to produce the same effects in
pure salts; and in the course of my experiments, I ascertained that these two substances
(iron and iodine) have so great an affinity for each other, that when placed together
without any water, or when rubbed together, they very speedily form a liquid containing an excess of iodine in solution, which, being added to a solution of prussiate of
potash, gives the compound of cyanogen and iron, or soluble Prussian blue, which has
been just described.  The addition of water alters the character of this iodine solution;
without water, it turns litmus paper green, and with water it has the usual acid
reaction, thus apparently  confirming Davy's original doubt as to the elementary
character of iodine.
67




1058                                       -INK.
2ndly. I form a neutral iodide of potassium, of great purity, and wholly free from
alkaline reaction, in manner following: I take the solution which remained over from
the process first described, after the Prussian blue had been precipitated, which solution
consisted, as before stated, of a neutral iodide of potassium, with iodide of iron in
excess; and I get rid of that excess by the well known processes of fusion and crystallization. The result is an iodide of potassium, which is as pure as when iodine and
potassium are made to act directly on one another, and is perfectly free from the alkaline
reaction on turmeric paper, which invariably characterizes the most careful preparations
of this salt when carbonate of potassa is employed (as usual) in its manufacture. It is
also much less deliquescent than the ordinary iodide of potassium of commerce, and, on
account of its great purity, much to be preferred in medicinal preparations.
3rdly. I manufacture a blue ink of peculiar intensity, and, therefore, particularly
suitable for printing purposes, by using the same materials, and manipulating them in
the same way as first described, with the exception that for the iodine wherever it is
used, I substitute bromine, and rub up the precipitate in oil.
4thly. I form a bromide of potassium of great purity, and wholly free from alkaline
reaction, by treating the bromide of potassium, which remains over in a state of solution
from  the process last before described, in the same way as the iodide of potassium
solution is directed to be used under the second head of this specification.
5thly. I manufacture a very superior black writing ink, by adding to gall ink of a
good quality soluble Prussian blue, described under the first head of this specification.
The addition of this Prussian blue makes the ink, which was already proof against
alkalines, equally proof against acids, and forms a writing fluid, which cannot be erased
from paper by any common method of fraudulent obliteration, without the destruction
of the paper.
6thly. I manufacture in manner following  a red writing ink which is generally
superior to the common solutions from  peach  wood and Brazil wood, not only in
permanent brilliancy of colour, but also in its freedom from acid, and consequentfitness
for use with steel pens.  I first boil cochineal repeatedly in successive quantities of pure
water, till it ceases, or nearly so, to give out any colouring matter. I then boil it in
water containing liquor ammoniac. which combines after the manner of an alkali with
an acid, with the residue of colouring matter, and leaves the insect matter nearly white.
The liquid products of these successive boilings are then  thrown together into an
earthienware vessel, and, in order to get rid of a peculiar element or principle, still combined with the colouring matter, and which has a great affinity for iron, I precipitate
the colouring matter with ammonia-bichloride of tin. The precipitate is afterwards
dissolved in ammonia, and protiodide of tin added, till a sufficient degree of brilliancy
of colour is obtained, which completes the process, water being added ad libitum,
according to the degree of body required to be given to the ink.
7thly. I manufacture by  the improved  process following a marking  ink  which
may be used with steel pens, and is not only of great intensity of colour, but comes out
most readily on the application of hit. I rub together in a mortar nitrate of silver
and the proper equivalent of tartaric acid in a dry state. I then add water, on which
crystals of tartrate of silver are formed and the nitric acid set free.  I next neutralize
this acid by adding liquor ammoniae, which also dissolves the tartrate of silver.  I
finally add gum, colouring matter, and water, in the usual way, and in quantities which
may be varied at pleasure.  By this process the nitric acid, which is essential to a good
marking ink, is retained and the tartrate of silver formed is soluble in less than half
the quantity of liquor ammonia ordinarily required when tartrate of silver is the basis
of the ink. The tedious operation of filtering and washing the carbonate of silver in
order to form the tartrate is also thereby entirely dispensed with.
8thly. I  manufacture in  manner following a  marking  ink, differing  from   the
preceding and all other marking inks containing salts of silver only, in this respect,
that it cannot be acted upon by the common solvents of salts of silver, as cyanide of
potassium, or chloride of lime, and is so far, therefore, more indelible. I take the ink,
as it has been formed by the process last described, and add to it an ammoniacal solution
of an oxide or salt of gold. I have used for this purpose the purple of Cassius, the
hyposulphite of gold, the ammonia-iodide of gold, and ammonia-periodide of gold.
The two last salts, which I believe to be new salts, I obtain by dissolving iodine in
liquor ammonire, under the application of heat; an operation, however, which requires
to be conducted with great caution in order to prevent the formation of the explosive
compound, the teriodide of nitrogen. This iodine solution is a very speedy solvent of
gold. If gold leaf be placed upon it without the addition of water, a black oxide of
gold is formed, which immediately dissolves, but if it be diluted with water, the process
of oxidation is less rapid, and the gold leaf assumes a fine purple colour (not black),
before solution. This salt of gold crystallizes in four-sided-prisms, which are soluble
in  water. A  few  drops of this solution placed on a slip of glass generally form




IODINE.                                      1059
microscopic arborescent crystals, from which, under the application of heat, both the
iodine arnd ammonia may be volatilized, and arborescent metallic gold alone remains. If
a moderate heat only is employed, one equivalent only of iodine is expelled, and white
crystals of ammonia-iodide of gold remain.
9thly. I manufacture a blue printing ink by taking the soluble precipitate of
cyanogen and iron, obtained by the process described under the first head of this
specification, and rubbing up the same in oil, after the manner ordinarily followed in
the manufacture of printing inks; or by boiling down the blue writing ink, produced
by the said process to a sufficient consistence, and then rubbing up the same in oil.
IOthly. I manufacture a black printing ink by boiling down the black writing ink,
produced from the materials, and by the process described under the fifth head of this
specification, and rubbing it up in oil as aforesaid.
11th. I manufacture a red printing ink by taking the ammoniacal solution of
cochineal, obtained by the process described under the sixth head of this specification,
and rubbing it up in oil, adding protiodide of tin according to the degree of lustre
required; or by boiling down the red writing ink, produced by the said process, to a
sufficient consistence, and then rubbing up the same in oil as aforesaid.
And 12th, I manufacture a black printing ink by boiling chips of logwood (for
which an extract of logwood may be substituted), -or other dye woods, containing
colouring matter and tannin, along with as much of proto-salt or persalt of iron or
copper, or other precipitate of tannin, as will be equal to about twice the weight of the
tannin contained in the wood or extract employed; whereby I obtain a black or blueish
black precipitate; the blueness of which I diminish, as may be required, by the
addition of bichromate of potash, more or less. I finally rub up the whole in oil as
aforesaid, adding a small quantity of the lamp-black, or other black colouring matter,
ordinarily employed in the manufacture of black printing inks.
INIULINE (Eng. and Fr.) is a substance first extracted from the root of the Inula-Hellenium, or Elecampane.  It is white and pulverulent like starch; and differs from this
substance chiefly because its solution, when it cools, lets fall the inuline unchanged in
powder, wlhereas starch remains dissolved in the cold, as a jelly or paste.
Inuline is obtained by boiling the root sliced in 3 or 4 times its weight of water, and
setting the strained decoction aside till it cools, when the pulverulent inuline precipitates.
It exists also in the roots of colchicum, and pellitory.
IODINE (lode, Fr.; lod, Germ.) is one of the archbeal undecompounded chemical
bodies, which was discovered accidentally in 1812 by M. Courtois, a manufacturer of
saltpetre, in the mother-waters of that salt. Its affinities for other substances are so
powerful as to prevent it from existing in an insulated state. It occurs combined with
potassium and sodium in many mineral waters, such as the brine spring of Ashby-de-laZouche, and other strongly saline springs. This combination exists~paringly in seawater, abundantly in many species of fucus or sea-weed, and in the kelp made from
them; in sponges; in several marine molluscs, such as the doris, the venus, oysters, &c.;
in several polyparies and sea plants, as the gorgonia, the zostera marina, &c.; particularly in the mother-waters of the salt-works upon the Mediterranean sea; hnd it has
been found in combination with silver, in some ores brought from the neighborhood of
Mexico.
Iodine is most economically procured from the mother-water of kelp, as furnished by
those manufacturers of soap in Scotland and elsewhere who employ this crude alkaline
matter. By pouring an excess of sulphuric acid upon that liquid, and exposing the
mixture to heat in a retort, iodine rises in violet vapors (whence its name), and condenses
in the receiver into black, brilliant, soft, scaly crystals, resembling graphite or plumbago.
An addition of the peroxyde of manganese to the above mixture, favors the production
of iodine. Souberain has proposed as a means of extracting it in greater abundance
from  a given quantity of the said mother-waters, to transform the iodide of potash or
soda, present, into an insoluble iodide of copper, by pouring into them solution of
sulphate of copper, which precipitates first of all one half of the iodine. He then
decants the supernatant liquor, and adds to it a fresh quantity of the sulphate along
with some iron filings. The latter metal seizes the oxygen and sulphuric acid of
the cupreous salt, sets the copper free, which then seizes the other half of the
iodine.  To separate this iodide from  the remaining iron filings, he agitates the
whole with water, and decants the liquor. The filings immediately subside, but the
iodide of copper remains for some time in a state of suspension. This compound,
separated by a filter cloth, is to be mixed with twice its weight of the black peroxyde
of manganese, and as much sulphuric acid as will make the mixture into a paste; which
mixture being introduced into a retort, and distilled, the iodine comes over in its characteristic violet vapors, which are condensed into the glistening black substance in the
receiver.
Iodine is always solid at atmospheric temperatures, though it slowly flies off with a




1060                                      IRON.
peculiar offensive penetrating odor somewhat like chlorine.  Its specific gravity is
4*946 at the temperature of 58~ Fahr.  Its prime equivalent, according to Berzelius is
63-283, one volume of hydrogen being 1'000; but 126'566, if two volumes of hydrogen
be reckoned unity, as most British chemists estimate it, from the composition of water,
It possesses in a high degree electro-negative properties, like oxygen and chlorine; and
therefore makes its appearance at the positive pole, when its compounds are placed in the
voltaic circuit. It stains the skin yellow; and if applied for some time to it, is apt tc
produce painful ulcerations.
Iodine melts only at about 390~ Fahr.; but with the vapor of water it volatilizes at 2120
It has a great affinity for hydrogen, and constitutes by that union hydriodic acid; a compound resembling in some respects muriatic or hydrochloric acid. It also can be combined with oxygen, and forms thereby iodic acid. Its compounds with carbon, phosphorus,
sulphur, chlorine, azote, and many metals, have not been applied to any manufacturing
purpose, and therefore need not be described here.
The chief application of iodine in the arts, is for the detection of starch, which its
watery solution, though containing only one part in 5000, does readily, by the production
of a deep purple color; this vanishes by exposing the starch to the air for some time, or
more quickly by heating it.
As a medicine, iodine and its compounds, such as the iodides of potassium and iron, are
supposed to possess great powers in resolving glandular swellings. The periodide of mercury is a brilliant red pigment, but somewhat evanescent.
Chlorine, bromine, and iodine, are frequently associated; and it has hitherto been
reckoned a difficult problem to separate them from one another.  The following  Ian is
proposed by Mr. Lovig.
Heat the mixture of the dried chloride and bromide (or chloride and iodide) while a
current of chlorine is made to pass over it, till no more bromine is carried off by the
chlorine. Receive the gases in a solution of potash; saturate this fluid mixture of the
chloride of potassium, and the chlorate and bromate of potash with nitric acid, adding
afterwards nitrate of silver., A mixture of bromate and chloride of silver will precipitate.
Dry the precipitate, calcine it, and calculate the proportion of bromine from the volume
of oxygen gas now disengaged.  It would be preferable to digest in a vial, the precipitate while moist, along with water of baryta, which decomposes the bromate of silver
without acting upon the chloride. The excess of baryta being thrown down by carbonic
acid, and the liquid being evaporated, a bromate of baryta is obtained which may be
washed with alcohol of 0840. The solution of bromate of baryta may also be neutralized by nitric acid, and the bromic acid may be precipitated by nitrate of silver. The
same method is applicable to the separation of iodine from chlorine.
After throwing down the solution of the mixed salts by nitrate of silver, Berzelius
digests the washed precipitate in a closed bottle of water of baryta; whence results
bromate of baryta without any chloride of barium. On evaporating the liquor we obtain crystallized bromate of baryta, which may be freed from a small accidental quantity
of chloride, by washing with alcohol at 0-840. By calcination we then obtain bromide
of barium, which, being distilled with sulphuric acid and peroxyde of manganese, affords
bromine.
IRIDIUM  is a metal discovered by Descotils in 1803, as also by Tenant in 1804; and
is so called because its different solutions exhibit all the colors of the rainbow. It occurs
only in the ore of platinum, being found there in two states; 1. united to that metal, and
2. as alloy of osmium and iridium, in the form of small, insulated, hard grains. Iridium
is the most refractory of all the metals; and appears as a gray metallic powder. It is
not fused by the flame of the hydroxygen lamp.
IRON (Fer, Fr.; Eisen, Germ.) is a metal of a bluish-gray color, and a dull fibrous
fracture, but it is capable of acquiring a brilliant surface by polishing. Its specific gravity
is 7'78. It is the most tenacious of metals, and the hardest of all those which are malleable
and ductile. It is singularly suscesible of the magnetic virtue, but in its pure state soon
loses it.  When rubbed it has a slight smell, and it imparts to the tongue a peculiar
astringent taste, called chalybeate.  In a moist atmosphere, iron speedily oxydizes, and
becomes covered with a brown coating, called rust.
Every person knows the manifold vises of this truly precious metal; it is capable of
being cast in moulds of any form; of being drawn out into wires of any desired strength
or fineness; of being extended into plates or sheets; of being bent in every direction; of
being sharpened, hardened, and softened at pleasure. Iron accommodates itself to all
our wants, our desires, and even our caprices; it is equally serviceable to the arts, the
sciences, to agriculture, and war; the same ore furnishes the sword, the ploughshare, the
scythe, the pruning hook, the needle, the graver, the spring of a watch or of a carriage,
the chisel, the chain, the anchor, the compass, the cannon, and the bomb. It is a
medicine of much virtue, and the only metal friendly to the human frame.
The ores of iron are scattered over the crust of the globe with a beneficent profusion.
proportioned to the utility of the metal; they are found under every latitude, and every




IRON.                                       101
zone; in every mineral formation, and ate disseminated in every soil.  Considered in a
purely mineralogical point of view, without reference to their importance for reduction,
they may be reckoned to be 19 in number; namely, 1. native iron of three kinds: pure,
nickeliferous, and steely; 2. arsenical iron; 3. yellow sulphuret of iron; 4. white sulphuret of iron; 5. magnetic sulphuret of iron; 6. black oxyde of iron, either the loadstone, or susceptible of magnetism, and titaniferous; 7. compactfer oligiste, specular iron
ore, as of Elba, and scaly fer oligiste; 8. hematite, affording a red powder; 9. hematite
or hydrate of iron, affording a yellow powder, of which there are several varieties; 10.
pitchy iron ore; 11. siliceo-calcareous iron, or yenite; 12. sparry carbonate of iron, and
the compact clay iron-stone of the coal formation; 13. phosphate of iron; 14. sulphate
of iron, native copperas; 15. chromate of iron; 16. arseniate of iron; 17. muriate of
iron; 18. oxalate of iron; 19. titanate of iron.
Among all these different species, ten are worked by the miner, either for the sake of
the iron which they contain; for use in their native state; or for extracting some principles from them advantageous to the arts and manufactures; such are arsenical iron,
sulphate of iron, sulphuret of iron, and chromate of iron.
1. Native iron A. Pure.-This species is very rare, and its existence was long matter
o)f dispute; though it has been undoubtedly found not only in volcanic formations, but in
veins properly so called.  It is not entirely, like our malleable iron; but is whiter, more
ductile, more permanent or less -oxydizable in the air, and somewhat less dense. Among
the best attested examples of pure native iron is that observed by M. Schreber, in the
mountain of Oulle near Grenoble.  The metal was entangled in a vein running through
gneiss, and appeared in ramifying stalactites, enveloped in fibrous brown-oxyde of iron
mixed with quartz and clay.
iB. The native nickeliferous or meteoric iron is very malleable, often cellular, but sometimes compact, and in parallel plates, which pass into rhomboids or octahedrons.  It is
naturally magnetic, and by its nickel is distinguishable from terrestrial native iron. Macquart, in describing the famous mass found at mount Kemir in Siberia, says that the iron
is perfectly flexible, and fit for making small instruments at a moderate heat; but in too
strong a fire, the metal becomes short, brittle, and falls into grains under the hammer.
Meteoric iron is covered with a sort of varnish which preserves its surface from the rusting action of the air; but this preservative property does not extend to the interior.
Chladni has given a list of masses of meteoric iron, which have been known to fall at
different times from the atmosphere, and of many specimens which indicate their atmospheric origin, by their aspect and composition.  A portion of the mass of meteoric iron
found at Santa-Rosa near Santa-Fe-de-Bogota, was made into a sword and presented to
Bolivar.
c. Native steel-iron.-This substance has all the characters of cast-steel; it occurs in a
kind of small button ingots, with a finely striated surface, and a fracture exceedingly fine
grained. It is hardly to be touched by the file, and will scarcely flatten under the hammer.  M. Mossier' found this native steel at the village of Bouiche, near Nery, department of the Allier, in a spot where there had existed a seam of burning coal.  A mass
of 16 pounds and 6 ounces of native steel was discovered in that place, besides a great
many small globules.
2. arsenical iron, /rsenikkies, or Mispickel, is a tin-white mineral, which emits a garlic
smell at the blowpipe, or even when sparks are struck from it by steel, accompanied with
a small train of white smoke. It contains generally more or less sulphur, and sometimes
a little silver, associated with metallic arsenic and iron.
3. Yellow  sulphuret of iron, commonly called Marcasite, or Martial pyrites.  The
bronze or brass yellow color enables us to recognise this mineral.  At the blowpipe it
giveb off its sulphur, and is converted into a globule attractable by the blowpipe. It is a
bisulphuret of iron containing 32 of sulphur and 28 of metal.
Copper pyrites may be distinguished from it by its golden yellow color, which is frequently iridescent, and by its inferior hardness; for it does not strike fire with steel, like
the preceding persulphuret.  There is no vein, stratum, or mass of metallic ore which
does not contain some iron pyrites; and it is often the sole mineral that fills the veins in
quartz. It sometimes contains gold, and at other times silver.
4. White sulphuret of iron.-This is distinguishable from the preceding species only
by:3 color and form of crystallization, and was hence till lately confounded with it by
mineralogists. Its surface is often radiated.
5. Magnelic sulphuret of iron, the Magnetkies of the Germans.-This ore is attractable by the magnet like common iron.  Its color is reddish-yellow, passing into brown;
its fracture is rough. It consists of 16 of sulphur and 28 of iron.
6. Black oxyde of iron, magnet ore, or native loadstone.-One variety of this species
has two poles in each specimen, which manifest a repulsive action against the corresponding poles of a magnetic needle.  All the varieties furnish a black powder.  Its
external color is a gray approaching to that of metallic iron, but somewhat duller;




1062                                   IRON.
with occasional iridescence of surface.  Neither nitric acid nor the blowpipe has any
action upon it. Its specific gravity varies frofi  4'24 to 5'4; and its constituents are
7186 peroxyde, and 28-14 protoxyde, according to Berzelius; or in 100 parts, 71'74 of
metallic iron, and 28'26 of oxygen.  Assuming the prime equivalent of iron to be 28,
with the British chemists, then an ore consisting, like the above, of two prime proportions of peroxyde, and one of protoxyde, would be represented by the number 116 =80
+  36; and would consist in 100 parts, of iron 72-4, oxygen 27'6.
Magnetic iron-ore belongs to primitive rock formations, and occurs abundantly in
Sweden, Dalecarlia, Norway, Siberia, China, Siam, and the Philippine isles; but itis
rare in England and France.  It is worked extensively in Sweden, and furnishes an excellent iron.
The titaniferous oxyde of iron, or iron sand, is also attractable by the magnet.  Its
color is a deep black, with some metallic lustre; it is perfectly opaque; its fracture is
conchoidal; it is hard and difficult to grind under the pestle into a dull black powder,
which stains the fingers when it is very fine; it melts at a high heat into a black enamel
without lustre. All volcanic rocks contain a greater or less quantity of titanic iron-ore,
disseminated through them, which may be recognised by its brilliant metallic lustre, and
its perfect conchoidal fracture.
7. Fer oligiste, iron-glance, specular iron, and red iron ore.-This ore has the color of
polished steel; and the light transmitted through the thin edges of its crystals appears of
a beautiful red.  Its powder is always of a well marked brown-red hue, passing into
cherry-red, which distinguishes it from the black-oxyde ore.  Its fracture is rough, or
vitreous in certain varieties; it breaks easily; but it is hard enough to scratch glass. It
usually contains from 60 to 70 of metallic iron in 100 parts; the equivalent proportion
of oxygen in the pure red oxyde of iron being 30 parts combined with 70 of metal.  It
is a mistake to suppose any specular iron ore capable of yielding 85 per cent. of iron, for
100 parts of even protoxyde of iron contain only 77-77 parts of metal.
The compact variety comprises the crystals of the island of Elba, and of Framont in
the Vosges, which have a rough-grained fracture. It exists in very great masses, constituting even entire mountains; in the cavities and fissures of these masses, the beautiful
crystals so much prized by collectors of minerals, occur.
The island of Elba is equally celebrated for its inexhaustible abundance of rich specular
iron ore, and for the immemorial antiquity of its mining operations. Fig. 792 is a vertical...-..'..-.".'.."'..........
section passing through the three workings, called Pietamonte (D), Sanguinaccio (E),
Antenna (F), through an ancient excavation a, through the coast o, and the mole p, ending at the canal of Piombino. The total height of the metalliferous mountain above the
level of the sea, is no more than 180 metres, or 600 feet.
The rock which constitutes the body of this little mountain d 1, is called bianchetta by
the workmen. It is a white slaty talc, slightly ochreous, or yellowish, consisting chiefly
of silica and alumina, with some magnesia.
The ore of Antenna (F) is a very hard compact fer oligiste, of a brilliant metallic
aspect. The workable bed has a height of 66 feet, and consists of metalliferous blocks
mixed confusedly with sterile masses of the rock; the whole covered with a rocky detritus, under a brownish mould.  From its metallic appearance and toughness, this bed is
called venaferrata, the iron vein. In Pietamonte the workable bed is composed entirely
of micaceous specular iron ore (fer oligiste), with its fissures filled with yellow ochre.
This bed rests upon the rock called bianchetta; the brilliant aspect of ore in this place
has gained for it the name of vena lucciola.
The metalliferous hill d 1, extends to the north-east, about a mile beyond the workings D E F.  The ore contains about 65 per cent. of iron, and is smelted in Catalan
forges.
The following description of the figure will make the structure of this extraordinary
mine well understood. a, is a great excavation, the result of ancient workings.
1, 1; 2, 2; 3,3, 4, 4, 5, 6, and 7, are roads for carrying off the rubbish, in correspond
ence with the several working levels.




IRON.                                        1063
b, b, b, masses of old rubbish (deblais).
c, c, ditto, from the present workings D, E, F.
d, the rocky mass called bianchetta, against which the ore extracted from a abuts.
e, the surface of a bed of ore, near the streamlet g.
f, J; indication of beds of iron pyrites and fer oligiste.
g a small rivulet proceeding from the infiltration of rains, and which is impregnated
with acidulous sulphate of iron.
h, h, ravine which separates the metalliferous hill d I from the barren bill i
k, masses of slags from ancient smelting operations; such are very common in this
island.  None of any consequence now  exist; nearly the whole of the ore being expoited to Tuscany, the Romagna, the Genoese territories, Piedmont, Naples, and
Corsica.
1, a considerable body of rubbish from ancient workings, towards the summit of the
metalliferous hill d, 1.
nm, m, part of this hill covered with rubbish, the result of, old workings.
a, the site called Vigneria.
o, houses upon the shore called Maries de Rio, where the workpeople live, and the
mineral is kept in store.
p, wooden pier (mole) whence the ore is shipped; terminated by a small tower, q.
Compact fer oligiste occurs also in the Vosges, in Corsica, at Altenberg and Freyburg
in Saxony, Presnitz, in Bohemia, Norberg and Bisberg, in Sweden, &c.
The varieties called specular fer oligiste, and scaly fer oligiste, or iron-glance, do not
differ essentially from the compact. None of them affects the magnetic needle, and their
powder is a red of greater or less vivacity.
8. Red oxyde of iron.-The varieties included under this species afford a red powder,
do not affect the magnetic needle, and are destitute of metallic lustre. At the blowpipe'hey all become black, or deep brown; and then they act on the needle.  The crystalzed variety consists of 70 iron and 30 oxygen in 100 parts.  The concretionary kind,
or hematite, has a brown-red color; is solid, compact, and sometimes very hard; its
surface may be filed and polished so as to acquire a lustre almost metallic; its internal
structure is fibrous, and it exhibits sometimes a resemblance to splinters of wood. Its
outer surface is constantly concretionary, mammelated, and presents occasionally sections
of a sphere, or cylinders attached to each other. This is the blood-stone of the burnisher
of metals. It is a very common mineral. The ochry variety or red.iron-ochre is distinguished from the solid hematite by the brightness of its color.  It is used as a
pigment.
9. Brown oxyde of iron, brown iron-stone.-This affords always a yellow powder,
without any shade of red, which passes sometimes into the bistre brown, or velvet black.
At the blowpipe this oxyde becomes brown, and very attractable by the magnet; but after
calcination and cooling, the ore yields a red powder, which stains paper nearly as red
as hematite does, and which is much employed in polishing metals. All the yellow or
brown oxydes contain a large proportion of water, in chemical combination; and hence
this species has been called hydrate of iron. There are several varieties which assume
globular, reniform, stalactitic, and fruticose shapes. As impure varieties of the species
we must consider some of the clay-iron ores, such as the granular, the common, the pisi.
form, and the reniformn clay-iron ore. According to D'Aubuisson, the present specie?
consists of peroxyde of iron, from 82 to 84 per cent.; water, 14 to 11; oxyde of manganese, 2; silica, I to 2. It is therefore a hydrated peroxyde of iron; and ought by theory
to consist, in its absolute state, of 81-63 peroxyde, and 18-37 water. It occurs both in
beds and veins. The cetites or eagle-stones form a particular variety of this ore. On
breaking the balls, so named, they are observed to be composed of concentric coats, the
outside ones being very hard, but the interior becoming progressively softer towards the
centre, which is usually earthy and of a bright yellow color; sometimes, however, the
centre is quite empty, or contains only a few drops of water. (Etites occur in abundance,
often even in continuous beds in secondary mountains, and in certain argillaceous strata.
These stones are still considered by the French shepherds as amulets or talismans, and
may be found in the small bags which they suspend to the necks of their favorite rams;
and they are in such general use, that a large quantity is annually imported into France
from the frontiers of Germany, for this superstitious purpose. When smelted, they yield
a good iron.
The variety called gratular brown oxyde, or bone ore, is merely a modification of
the preceding. It occurs in grains nearly round, varying in size from a millet seed to a
pea, each being composed of concentric coats, hard outside and soft within. They are
generally agglutinated by a calcareous or argillaceous paste; but are occasionally quite
loose. This ore occurs in calcareous formations, and is sometimes accompanied with
shells, such as terebratulae.  The brittle quality of the iron afforded by it has been
ascribed to the phosphorus derived from  the large quantity of organic bodies, with




1064                                    IRON.
which the ore is frequently mixed. The bog-iron ore and swamp-iron ore belong to thi
species.
10. Pitchy hydrate of iron.-This is a rare mineral of a resinous aspect, found in a
vein ir the mine of Braunsdorf, two leagues from Freyberg, and seems to consist of red
oxyde of iron and water.
11. Yenite is a mineral species, rather rare, composed of red oxyde of iron, silica, and
lime.
12. Carbonate of iron, sparry iron, or brown-spar.-This important species has been
divided into two varieties; spathose iron and the compact carbonate. The first has a
sparry and lamellar fracture; with a color varying from yellowish-gray to isabella yellow, or even to brownish-red.  It turns brown without melting at the blowpipe, and
becomes attractable by the magnet after being slightly roasted in the flame of a candle.
Even by a short exposure to the air, after its extraction from the mine, it also assumes the
same brown tint, but without acquiring the magnetic quality.  It affords but a slight
effervescence with nitric acid, changing merely to a red-brown color. Its specific gravity
varies from 3'00 to 3'67.  Its primitive form is like that of carbonate of lime, an obtuse
rhomboid. Without changing this form, its crystals are susceptible ~f containing variable quantities of carbonate of lime, till it passes wholly into this mininal. Manganese
and illagnesia enter also occasionally into its composition.
Sparry carbonate of iron belongs to primitive formations; forming powerful veins in
mountains of gneiss, and is associated in these veins with quartz, copper pyrites, gray
copper, fibrous brown oxyde of iron, and a variety of ramose carbonate of lime, vulgarly
called  os ferri. Thus it is found at Allevard and Vizille, near Grenoble, at SaintGeorge d'HIuretiere, in the Alps of Savoy; at Baigorry, in the Lower Pyrenees; at Eisenerz, in Styria; at Huttenberg, in Carinthia; at Schwartz, in the Tyrol; in Saxony,
Hungary, other places in Germany, as also in Spain, Sweden, Norway, and Siberia. It
also occurs, along with galena and other ores of lead, in the mines of Lead-Hills and
Wanlockhead, in Scotland; and in the mines of Cumberland, Northumberland, and
Derbyshire; likewise with tin-ore, at Wheal Maudlin, Saint-Just, and other places in
Cornwall.
This ore, viewed as a metallurgic object, is one of the most interesting and valuable
that is known; it affords natural steel with the greatest facility, and accommodates itself
best to the Catalan smelting forge. It was owing in a great measure to the peculiar
quality of the iron which it produces, that the excellence long remarked in the cutlery
of the Tyrol, Styria, and Carinthia, was due. It was called by the older mineralogists
steel ore.
The carbonate of iron of the coal formation, is the principal ore from which iron is
smelted in England and Scotland, and it yields usually from 30 to 33 per cent. of cast
metal.  We are indebted to Dr. Colquhoun for several elaborate analyses of the sparryirons of the Glasgow coal field; ores which afford the best qualities of iron made in that
district. The richest specimen, out of the nine which he tried, came from the neighborhood of Airdrie; it had a specific gravity of 3-0533, and afforded in 100 parts, carbonic
acid, 35-17; protoxyde of iron, 53*03; lime, 3-33; magnesia, 1'77; silica, 14; alumina,
0-63; peroxyde of iron, 023; carbonaceous or bituminous matter, 3-03; moisture and
loss, 1'41. Its contents in metallic iron are 41-25.
The compact carbonate of iron has no relation externally with the sparry variety. It
comprehends most of the clay-iron stones, and particularly that which occurs in flattened
spheroidal masses of various size, among the coal measures. The color of this ore is
often a yellowish-brown, reddish-gray, or a dirty brick-red. Its fracture is close grained;
it is easily scratched, and gives a yellowish-brown powder. It adheres to the tongue,
has an odor slightly argillaceous when breathed upon, makes no effervescence with any
acid, blackens at the blow-pipe without melting, and becomes attractable by the magnet
with the slightest calcination.
This ore affords from 30 to 40 per cent. of iron of excellent quality; and it is the
object of most extensive workings in Great Britain. It occurs in the slaty clay which
serves as a roof or floor to the strata of coal; and also in continuous beds, from 2 to 18
inches thick, among the coal measures, as in Staffordshire, Shropshire, and Wales. It is
remarkable, that the coal-basin of Newcastle contains little clay iron-stone, while the
coal-basin of Dudley is replete with it.
13. Phosphate of iron.-A dull blue color is the most remarkable external charactex
of this species, which occurs in small masses composed of aggregated plates, sometimes
in an excessively fine powder, or giving other bodies a blue tinge. It assumes at the
blowpipe a rusty hue, and is then reduced to a button of a metallic aspect. It dissolves
completely in dilute nitric acid, as well as in ammonia, but it dues not communicale its
color to them, and oil turns it black; characters which distinguish it readily from blue
carbonate of copper, whose color is not altered by ammonia.  It is of no use as a
smelting ore.




IRON.                                      1065
14. Sulphate of iron, native green vitriol.-This is formed by the oxygenation of sul
phuret of iron, and is unimportant in a metallurgic point of view.
15. Chromate of iron.-For the treatment and use of this ore, see CHROME.
16. drseniate of iron, Wurfelerz.
17. Miuriate of iron.
18. Oxalate of iron; Humboldtitfe, found by M. Breithaupt in the lignite of Kolaw. It
consists of protoxyde of iron, 53'86; oxalic acid, 46'14; in 100.
19. Titanate of iron consists of protoxyde and peroxyde of iron, 86; titanic acid, 8;
oxyde of manganese, 2; gangue, 1 -= 97. See Black Oxyde of iron.
Of the assay of iron-ores byfusion.-In the assays by the dry way, the object is to Separate exactly all the iron which the ore may contain, with the view of comparing the result
with the product of smelting on the great scale. In order to succeed in this operation,
we must deoxydize the iron, and produce at the same time such a temperature as will
melt the metal and the earths associated with it in the ore, and obtain the former in a
dense button at the bottom of a crucible, and the latter in a lighter glass or slag, above it.
Sometimes the gangue of the ores, consisting mostly of a single earth, as quartz, alumina,
or lime, is of itself very refractory, and hence some flux must be added to bring about the
fusion. The substance most commonly employed for this purpose is borax; but ordinary
flint glass may be substituted for it. Sometimes, also, instead of adding borax, which
always succeeds, lime or clay may be added to the ore, according to the nature of its
mineralizer; that is, lime for a clay iron-stone, and clay for a calcareous carbonate of
iron; and both, when the gangue is silicious, as occurs with the black oxyde.
The ore, pulverized and passed through a silk sieve, is to be well mixed with the flux,
and the mixture introduced into the smooth concavity made in the centre of a crucible
lined with hard-rammed damp charcoal dust.  Were the mixture diffused through the
charcoal, the reduced iron would be apt to remain scattered in little globules through
the crucible, and no metallic button would be formed at its bottom. The mingled ore and
flux must be covered with charcoal. The crucible thus filled must be shut with an earthen
lid luted on with fire-clay; and it is then set on its base, either in an air furnace, or on
the hearth of a forge urged with a smith's bellows. The heat should be very slowly raised,
not employing the bellows till three quarters of an hour have expired. In this way, the
water of the damp charcoal (brasque) is allowed to exhale slowly, and the deoxydation is
completed before the fusion begins; for by acting otherwise, the slags formed would dissolve some oxyde of iron, and the assay would not indicate the whole of the iron to be
obtained from the ore. At the end of the above period, the fire must be raised progressively to a white heat, at which pitch it must be maintained for a quarter of an hour,
after which the crucible should be withdrawn. Whenever it has cooled, it is to be
opened, the brasque must be carefully removed or put aside, and the button of cast-iron
taken out and weighed. The brasque may sometimes contain a few globules, which must
be collected by washing in water, or the application of a magnetic bar. The quantity
of iron denotes, of course, the richness of the ore. These assays furnish always a gray
cast-iron; and, therefore, the quality of the products can hardly be judged of, except by
an experiment on the large scale. The temperature necessary for the success of an assay
is about 1500 of Wedgewood.
In the assays by the humid way, we may expect to find manganese, silica, alumina,
lime, magnesia, and sometimes carbonic acid, associated with the iron.  100 grains of
the ore in fine powder are to be digested with nitro-muriatic-acid; which will leave only
the silica with perhaps a very little alumina. If an effervescence takes place in the cold
with a dilute acid, the loss of weight will indicate the amount of carbonic acid gas expelled. The muriatic solution contains the iron, the manganese, the lime, magnesia, and
most of the alumina, with a little silica.  On evaporating to dryness, and digesting in
water, all the silica will remain in an insoluble state. If the solution somewhat acidulated be treated with oxalate of ammonia, the lime will fall down in the form of an oxalate; ammonia will now precipitate the alumina and the oxyde of iron together, while
the manganese and magnesia will continue dissolved in the state of triple salts (ammoniamuriates). The alumina may be separated from the ferric oxyde by potash-ley. The
manganese may be thrown down by hydrosulphuret of potash; and, finally, the magnesia
may be precipitated by carbonate of soda. 100 parts of the red oxyde of iron contain
69-34 of metal, and 30-66 of oxygen.
If phosphorus be present in the ore, the nitro-muriatic solution, being rendered nearly
neutral, will afford with muriate of lime a precipitate of phosphate of lime, soluble in an
excess of muriatic acid.
When the sole object is to learn readily the per-centage of iron, the ore maybe treated
with hot nitro-muriatic, the acid solution filtered and supersaturated with ammonia.
which will throw down only the iron oxyde and alumina; because the lime is not precipitable by that alkali, nor is magnesia and manganese, when in the state of ammonia.




1066                                     IRON.
muriates. The red precipitate, being digested with some potash-ley, will lose its alumina,
and will leave the ferric oxyde nearly pure.  The presence of sulphur, phosphorus, oi
arsenic, in iron'ores, may always be detected by the blowpipe, or ustulation in the assay
muffle, as described under FURNACE.
Of the smelting of iron ores.-We shall describe, in the first place, the methods practised in Great Britain, and shall afterwards consider those pursued in other countries, in
the treatment of their peculiar ores.
Iron is divided into three kinds, according to the different metallic states in which it
may be obtained; and these are called crude or cast iron; steel; and bar or malleable
iron. These states are determined essentially by the different proportions of charcoal or
carbon held in chemical combination; cast iron containipg more than steel, and steel more
than malleable iron; which last, indeed, ought to be the pure metal, a point of perfection, however, rarely if ever attained. It is impossible to assign the limits between these
three forms of iron, or their relative proportions of carbon, with ultimate precision  for
bar iron passes into steel by insensible gradations, and steel and cast iron mahe such
mutual transitions as to render it difficult to define where the former commences, and the
latter ceases, to exist. In fact, some steels may be called crude iron, and some east irons
may be reckoned among steels.
Towards the conclusion of the last century the manufacture of iron underwent a very
important revolution in Great Britain, by the substitution of pitcoal for charcoal of
wood, the only combustible previously used in smelting the ores of this metal.  This
improvement served not merely to diminish the cost of reduction, but it furnished a
softer cast iron, fit for many new purposes in the arts. From this era, iron works have
assumed an immense importance in our national industry, and have given birth to many
ingenious and powerful machines for fashioning the metal into bars of every form, with
almost incredible economy and expedition.
The profusion of excellent coal, and its association in many localities with iron-stone,
have procured hitherto for our country a marked superiority over all others in the iron
trade; though now every possible effort is making by foreign policy to rival or to limit
our future operations. In 1802, M. de Bonnard, now divisionary inspector in the royal
corps of mines of France, and secretary of the general council, made a tour in England,
in order to study our new processes of manufacturing iron, and published, on his return,
in the Journal des Mines, tom. 17, a memoir descriptive of them. Since the peace, many
French engineers and iron-masters have exerted themselves in naturalizing in France
this species of industry; and M. de Gallois, in particular, after a long residence in Great
Britain, where he was admitted to see deliberately and minutely every department of th<
iron trade, returned with ample details, and erected at Saint-Etienne a large establishment entirely on the English model. More recently, MM. Dufrdnoy and Elie de Beaumont, and MM. Coste and Perdonnet, have published two very copious accounts of their
respective metallurgic tours in Great Britain, illustrated with plans and sections of our
furnaces, for the instruction of the French nation.
The argillaceous carbonate of iron, or clay iron-stone of the coal measures, is the chief
ore smelted in England. Some red hematite is used as an auxiliary in certain works in
Cumberland and Lancashire; but nowhere is the iron-sand, or other ferruginous matters
of the secondary strata, employed at present for procuring the metal.
Among the numerous coal-basins of England there are two, in particular, which furnish more than three fourths of the whole cast iron produced in the kingdom; namely,
the coal field of Dudley, in the south of Staffordshire; and the coal fields of Monmouthshire, in South Wales, along with those of Gloucestershire and Somersetshire.
Dudley is peculiarly favored by nature.  There are found associated the coal, the
iron ore, the limestone for flux, and the refractory fire-clay for constructing the interior
brick-work of the furnaces.  This famous clay is mined at Stourbridge, and exported
to every part of the kingdom for making cast steel crucibles and glass-house melting
pots.
At Merthyr-Tydvil, the centre of the iron-works of Wales, the iron-stone is extremely
plentiful, forming 16 beds, or rather constituting an integrant portion of 16 beds of
slate-clay. Sometimes it occurs in pretty long tables adjoining each other, so as to
resemble a continuous stratum; but more frequently it forms nodules of various size and
abundance, placed in planes both above and below the coal seam.  Eight varieties of
ore, belonging to different beds, have been distinguished by the following barbarous
names: black balls, black pins, six-inch-wide vein, six-inch jack, blue vein, blue pins,
gray pins, seven pins. The bed containing the first quality of iron-stone is analogous
to the black ore of Staffordshire, called gubbin; it is often cleft within like septaria, and
its cavities are sometimes besprinkled with crystals of carbonate of lime or quartz. In
the superior beds there are nodules decomposing into concentric coats, of which the
middle is clay. Crystals of oxyde of titanium are occasionally found in the middle of




IRON.                                     1067
the balls of clay iron-stone; to which the metallic titanium observed in the inside of the
dome of blast furnaces, may be traced. Both at Dudley and South Wales, casts of shells,
belonging to the genus unio, are observed on the iron-stone.
The average richness of the iron-stones of South Wales is somewhat greater than that oi
those of Staffordshire. The former is estimated at 33 parts of cast iron, while the latter
rarely exceeds 30 parts in 100 of ore; and this richness, joined to the superior quality or
cheapness of the coals, and the proximity of the sea, gives South Wales a decided advantage as a manufacturing district.
The number of blast furnaces in the parish of Merthyr-Tydvil amounts to upwards of
30.  The cast iron produced is, however, seldom brought into the market, but is almost
entirely converted into bar iron, of which, at Mr. Crawshay's works, 600 tons are manufactured in a week.  Numerous iron railways, extending through a length of 220 miles,
facilitate the transport of the materials and the exportation of the products.  That concurrence of favorable circumstances, which we have noticed as occurring at Dudley, prevails in an equal degree in South Wales.
The same economy which the use of coal has introduced into the smelting of cast iron
from the ore, also extends to its refinery into bars. And this process would supersede in
every iron work the use of wood charcoal, were not the iron produced by the latter combustible better for many purposes, particularly the manufacture of steel. In some English
smelting works, indeed, where sheet iron is prepared for making tin plate, a mixed refining
)rocess is employed, where the cavt iron is made into bar iron by wood charcoal, and
iaminated by the aid of a coal fire.
Till 1740, the smelting of iron ores in England was executed entirely with wood charcoal; and the ores employed were principally brown and red hematites. Earthy iron ores
were also smelted; but it does not appear that the clay iron-stones of the coal-basins
were then used, though' they constitute almost the sole smelting material at the present
day. At that era, there were 59 blast furnaces, whose annual product was 17,350 tons
of cast iron; that is, for each furnace, 294 tons per annum, and 56 tons per week.  By
the year 1788, several attempts had been made to reduce iron ore with coked coal; and
there renained only 24 charcoal blast furnaces, which produced altogether 13,000 tons
of cast iron in the year; being at the rate of 546 tons for each per annum, or nearly 11
tons per week.  This remarkable increase of 11 tons for 51, was due chiefly to the substitution of cylinder blowing machines worked with pistons, for the common wooden
bellows. Already 53 blast furnaces fired with coke were in activity; which furnished in
toto 48,800 tons of iron in a year; which raises the annual product of each furnace to
907 tons, and the weekly product to about 17i tons. The quantity of cast iron produced
that year (1788) by means of coal, was    -                                   48,800 tons,
and that by wood charcoal, was       -                                 13,100
Constituting a total quantity of   -61,900 tons.
In 1796, the wood charcoal process was almost entirely given up; when the returns of
the iron trade made by desire of Mr. Pitt, for establishing taxes on the manufacture
afforded the following results:~
121 blast furnaces, furnishing in whole per annum 124,879 tons, constituting an average
amount for each furnace of 1032 tons.
In 1802, Great Britain possessed 168 blast furnaces, yielding a product of about 170,000
tons; and this product amounted, in 1806, to 250,000 tons, derived from 227 coke fur.
naces, of which only 159 were in activity at once. These blast furnaces were distributed
a- follows.
In the principality of Wale- -52
In Staffordshire -42
In Shropshire -42
In Derbyshire -17
In Yorkshire -28
In the counties of Gloucester, Monmouth, Leicester, Lancaster, Cumberland, and Northumberland -18
In Scotland                                                                   28
227
In.820, the iron trade had risen to the amount shown in the following table:~
Tons.
Wales manufactured, per annum -        -     -    -     -    -     -    150,000
Shropshire and Staffordshire     -     -     -    -     -    -     -    180,000
Yorkshire and Derbyshire --  50,000
Scotland, with some places in England -      --                          20,000
Total    -. —                         400 000




1068                                   IRON.
In a statistical view given by M. de Villefosse, of the French and English iron works,
be assigns to the latter, in 1826, 305 blast furnaces, distributed as follows
In the principality of Wales                                                  87
In Staffordshire                                                              78
In Shropshire, Derbyshire, Yorkshire, &c.  --                                 84
In Scotland                 ---  - -56
305
Out of these, 280 were in activity at the same time; and if we suppose their mean
product to have been 50 tons a week, the total product would have been, in 1826, 728,000
tons. But this estimate seems to be somewhat above the truth; for, from the information
communicated by Mr. Philip Taylor to M. Achille Chaper, a considerable French ironmaster, who, in the summer of 1826, inspected two thirds of the blast furnaces of Great
Britain, their product during this year was about 600,000 tons.
The preceding details show the successive increments which the manufacture of cast
iron has received; and a similar progression has taken place in its refinery into wrought
iron. This operation was formerly effected by the agency of wood charcoal in refineries
analogous to those still made use of in France. But when that kind of fuel be-an to be
scarce in this island, it came to be mixed with coke in various proportions. The bar iron
thu-s produced was usually hard, and required much time to convert, so that an establishment which could produce 20 tons of bar iron in a week, was deemed considerable. At
that time, England imported annually from Sweden and Russia the enormous quantity of
70,000 tons of iron.
Mr. Cort, to whom  Great Britain is indebted for the methods now  pursued in this
country, succeeded about that time, after many unsuccessful experiments, in converting
cast iron into bar iron, by exposing it on the hearth of a reverberatory furnace to the flame
of pitcoal. This method, which possessed the advantage of employing this species of combustible alone, likewise simplified the treatment, because it required no blast apparatus.
But this mode of refinery, consisting in the use of a reverberatory furnace alone, did not
produce altogether the desired result.  It was irregular; sometimes the loss of iron was
small, but at others it was very considerable; and there were great variations in the
quality of the iron, as well as in the quantity of fuel consumed. Mr. Cort succeeded in
removing this uncertainty of result, by causing the puddling in the reverberatory furnace
to be preceded by a kind of refinery with coke.  The intent of this operation was to decarburate the iron, and to prepare it for becoming malleable. The metal took in that case
the name of finery metal, called, for the sake of brevity, fine-metal.
He also substituted the drawing cylinders for the extension under the hammer, an improvement which accelerated greatly the manufacture of bar iron. The iron then yielded
by the operation of puddling was of a very inferior quality, and could not be directly employed in the arts. In order to give it more consistence, it was subjected to a second heating
in a reverberatory furnace; and whenever this method had arrived at a high enough degree of perfection to afford products fit for the market, it became exclusively employed in
Great Britain.  This new method of transforming cast iron into malleable iron speedily
gained such an extension, that of late years, a single iron-work, Cyfartha in Wales, manufactured annually more than twice as much as was made annually from 1740 to 1750,
in the whole kingdom.
In surveying the improvements which the iron manufacture has received in England in
the space of the last 60 years, they are seen to be resolvable into two; the first set relating to the smelting of fthe ores; the other, to the conversion of the pigs into bar iron;
hence naturally arise two heads under which the subject of iron must be treated.
1. Manufacture of cast-iron by coke and coal.-The cast-iron produced by the English
and Scotch blast furnaces is in general black and very soft; but yet may be distinguished
into several qualities, of which three are particularly noticed.
No. 1. Very black cast-iron, in large rounded grains, obtained commonly near the commencement of the casting, when an excess of carbon is present; in flowing, it appears
pasty, and throws out blue scintillations. It exhibits a surface where crystalline vegetations develop themselves rapidly in very fine branches; it congeals or fixes very slowly;
its surface when cold is smooth, concave, and often charged with plumbago; it has but a
moderate tenacity, is tender under the file, and susceptible of a dull polish. When melted
ovei again, it passes into No. 2, and forms the best castings.
No. 2. Black cast-iron has a somewhat lighter shade than the preceding, and may
therefore on comparison be called blackish-gray. It presents less large granulations than
No. I; is tenacious, easily turned, filed, and polished; excellent for casting when it approaches to No. 1, and for the manufacture of bar iron when it has on the contrary a
shade somewhat lighter. If repeatedly melted, it passes into the next quality, or
No. 3. White cast iron; this is brittle, and indicates always some derangement in the




IRON.                                        1069
working of the furnace; it flows imperfectly, and darts out, in casting, abundance of
brilliant white scintillations; it fixes very quickly; and on cooling, exhibits q. its surface
irregular asperities, which make it extremely rough. It is easily broken, and presents a
lamellar and radiated fracture; and is so hard that tempered steel cannot act upon it.
It is cast only into weights, bullets, or bombs, but never into pieces of machinery. When
exposed to the refinery processes, it affords a bad bar iron. It is owing probably to the
different nature of the cast iron obtained in different counties in England, that Staffordshire and Shropshire furnish the greater part of the great iron castings, while Wales
manufactures almost exclusively malleable iron.  The lower price of coals in Wales
is perhaps the cause to a certain extent of this difference in the results of these two iron
districts. It will be interesting, at any rate, to describe separately the processes employed
in Staffordshire and Wales..
The blast furnaces of Staffordshire, in the neighborhood of Dudley, Bilston, and
Wednesbury, are constructed almost wholly of bricks.  Their outer form  is frequently
a cone, often also a pyramid with a square base.  They are bound about with a great
many iron hoops, or with iron bars placed at different heights.  This powerful armor
allows the furnaces to be built much less massively than they formerly were; and admits
lighter and more elegant external forms. They are seldom  insulated; but are usually
associated to the number of two or three in the same line.  A narrow passage is left
between them, which leads to the lateral openings where the tuyeres are placed. At the
front of the furnace, a large shed is always raised. The roofs of these sheds present in
general circular profiles, and being made of cast or bar iron, they display a remarkable
lightness of construction. The cast iron columns likewise, which support the joists and
girders, give additional elegance.
In the Dudley field, the furnaces are almost always in the middle of the plain, and an
inclined rail-way must be formed to reach their platform. These inclined planes, composed of beams or rails placed alongside of each other, and sustained by props and crossbars, as indicated in fig. 793, are set up mostly against the posterior face of the furnace.
Two chains or ropes, passing over the drums of gins, moved by a steam engine (commonly
the same that drives the bellows), draw up the wagons of wood or sheet iron a a, which
contain the various materials for supplying the furnace. To facilitate this service, the
platform round the furnace is sometimes enlarged behind by a floor; while a balustrade,
which opens when the wagons arrive at the platform, prevents accidents. This projection is occasionally covered by a roof. For a furnace of the largest size, the force expended by this lifting apparatus is not more than a two-horse power.
Fig. 793 is a vertical section. through the furnace from front to rear, or at right angles
to the line of the lateral tuyeres. The erection of a pair of blast furnaces, of 40 feet
high each, costs, in the Dudley district, 1800 pounds sterling; and requires for building
each, 160,000 common bricks for the outside work, 3900 lire-bricks for the lining or shirt
of the furnace, and 825 for the boshes. The dimensions of the fire-bricks are various; 5
kinds are employed for the lining, and 9 kinds for the boshes. They are all 6 inches
thick, and are curved to suit the voussoirs.
The number of charges given in 12 hours is different in different furnaces; being
sometimes 20, 25, and even so high as 40; but!tO is a fair average. Each charge is




1070                                    iRON.
composed of from 5 to 6 cwts. of coke, (or now of 3 to 4 cwts. of coal with the hot blast);
3, 4, and sometimes 6 cwts. of the roasted mine, according to its richness and the quality
of cast iron wanted; the limestone flux is usually one third of the weight of the roasted
iron stone. There are 2 casts in 24 hours; one at 6 in the morning, and another at 6 in
the evening.
The height of the blast furnaces is veiy variable; some being only 36 feet high
including the chimney, while others have an elevation of 60 feet. These extreme limits
are very rare: so that the greater part of the furnaces are from 45 to 50 feet high.
They are all terminated by a cylindrical chimney of from 8 to 12 feet long; being about
one fifth of the total height of the furnace. The inside diameter of this chimney is the
same as that of the throat or mouth; and varies from 4 to 6 feet.  The chimney is frequently formed of a single course of bricks, and acquires solidity from its hoops of iron,
so thickly placed that one half of the surface is often covered with them. At its lower
end, the mouth presents one or two rectangular openings, through which the chare is
given. It is built on a basement circle of cast-iron, which forms the circumference of the
throat; and a sloping plate of cast-iron b is so placed as to make the materials slide ov]r
into the furnace, as shown in the figure.
The ins~ie of the blast furnaces of Staffordshire is most frequently of A circular form,
except the hearth and working area. The inner space is divided into four portions, different
in their forms, and the functions which they fulfil in the smelting of the ore.
The undermost, called the hearth, or crucible, in which the cast-iron collects, is a right
rectangular prism, elongated in a line prependicular to the axes of the tuydres. The
3ides of the hearth consist in general of refractory sandstone (fire-stone), obtained mostly
7rom the bed of the coal basin, called millstone grit; and the bottom of the hearth is formed of a large block of the same nature, laid on a cast-iron plate.
The second portion is also made of the same refractory grit stone. It has the form of
quadrangular pyramidal, approaching considerably to a prism, from the smallness of the
ingle included between the sides and the alis.
The third portion or lower body of the furnace is conical, but here the interior space
suddenly expands; the slope outwards at this part seems to have a great influence on
the quality of the cast-iron obtained from the furnace. When No. 2 of the blackest kind
is wanted for castings, the inclination of this cavity of the furnace is in general less
considerable than when No. 2 cast iron for conversion into bar iron is required. The
inclination of this conical chamber, called the boshes, varies from 55 to 60 degrees with the
horizon. The diameter of this part is equal to that of the belly, and is from 11 to 13 feet.
The boshes are built of masonry, as shown in figs. 794, 195.
rhe fourth part, which constitutes about two thirds of the height of the furnace from
the base of the hearth up to the throat, presents the figure of a surface of revolution,
generated by a curve whose concavity is turned towards the axis of the furnace, and
vhose last tangent towards the bottom is almost vertical. This surface is sloped off with
that of the boshes (6talages in French), so that no sharp angle may exist at the belly.
In some furnaces of considerable dimensions, as in that with three tuyeres, this portion of
the furnace is cylindrical for a certain height.




IRON.                                       1071
The following  measurements  represent tlh  interior structure of two well-going
farnaces.
No. 1.      No. 2.
Feet.       Feet.
Height from the hearth to the throat or mouth    -                 4     459
Height of the crucible or hearth       -       -       -I                        6
of the boshes      -       -       --                        87
ofthecone    -                -       -                          306
the chimney or mouth  -        -       -       -         8          12
Width of the bottom of the hearth    -         -       -            2            2
Ditto at its upper end     -       -       -                        3            2
Ditto of the boshes                    -       -                   1213
Ditto at one third of the belly    -       -                       1211
Ditto at two thirds of ditto    --                                  8 
Ditto at t th  -..        43
Inclination of the boshes      -       -       -       -           59           5
The conical orifice called the tuyere, in which ihe tapered pipes are placed, for impart
ing the blast, is seen near the bottom of the furnace, fig. 794, at A. Nose tubes of various sizes, from 2 to 4 inches in diameter, are applied to the extremity of the main
blast-pipe. Under A is the bottom of the hearth, which, in large furnaces, may be two
feet square. B is the top of the hearth, about two feet six inches square. A B is the
height of the hearth, about six feet six inches. B shows the round bottom of the conical
or funnel part, called in this country the boshes, standing upon the square area of the
hearth. c is the top of the boshes, which may be about 12 feet in diameter, and 8 feet
in perpendicular height. D is the furnace top or mouth (gueulard in French), at which
the materials are charged. It may be 4k feet in diameter. The line between c, D, is the
height of the internal cavity of the furnace, from the top of the boshes upwards, supposed to be 30 feet. A, D, is the total height of the interior of the furnace, reckoned at
44k feet. E F. is the lining, which is built in the nicest manner with the best fire-bricks,
from 12 to 14 inches long, 3 inches thick, and curved to suit the circle of thecone. A
vacancy of 3 inches wide is left all round the outside of the first lining by the builder;
which is sometimes filled with coke dust, but more generally with sand firmly rammed.
This void space in the brick-work is for the purpose of allowing for any expansion which
might occur, either by an increase in the bulk of the building, or by the pressure and
weight of the materials when descending to the bottom of the furnace. Exterior to E E
is a second lining of fire-bricks similar to the first. At r, on either side, is a cast-iron
lintel, 8k feet long, by 10 inches square, upon which the bottom of the arches is supported. F, G, is the rise of the tuyere arch, which may be 14 feet high upon the outside,
and 18 feet wide. The extreme size of the bottom  or sole of the hearth, upon each
side of A, may be 10 feet square. This part and the boshing stones are preferably made
from a coarse sandstone grit, containing large rounded grains of quartz, united by a siliceo-argillaceous cement.
The bottom of the hearth consists, first, of a course of the said gritstone; beneath
which is a layer of bedding sand, having, in its under
795                      part, passages for the escape of the vapors generated
by damps; the whole being supported upon pillars of
brick.
Fig. 795 represents the hearth and boshes, in a
vertical side section.  a is the tymp stone, and b the
tymp plate for confining the liquid metal in the hearth.
The latter is wedged firmly into the side-walls of the
hearth; c is the dam-stone, which occupies the whole
breadth at the bottom of the hearth, excepting about 6
a Q                     inches, which space, when the furnace is at work, is
filled, before every cast, with a strong binding sand.
This stone is faced outside by a cast-iron plate d, called
the dam-plate, of considerable thickness, and peculiar
shape. The top of the dam-stone, or rather the notch
of the dam-plate, lies from 4 to 8 inches under the
level of the tuyere hole. The space under the tymp plate, for 5 or 6 inches down, is
rammed full, for every cast, with strong loamy earth, or even fine clay; a process called
the tymp stopping. The area of the base of this furnace being 38 feet, its extreme
height is 55 feet.
The blast furnaces of Staffordshire have always two tuye'res, at least, placed on oppo




1072                                      IRON.
site sides, but so pointed that the blast may not pursue directly opposite lines. In a furnace
acting well in the neighborhood of Dudley, the one of the tuyeres was 10 inches distant
from the posterior wall of the hearth, and the other only four inches. In other furnaces
with 3 tuyeres, the side ones are placed, the one 16k inches, and the other 6k inches
from the back.  Three tuyeres are seldom  made to blow  simultaneously.  The third is
brought into action only when the furnace seems to be choked up, and when it
becomes necessary to clear it up by a powerful concussion. Too much pains cannot be
bestowed oil the masonry and brickwork of a blast furnace, and on the solidity of its
foundation. In a soft ground it should rest on piles, so driven that the channel left
beneath for the drainage of the building may be above any water level. Small passages
should likewise be left throughout the body of the work, for the transpiration of moisture.
The blowing machines employed in Staffordshire are generally cast-iron cylinders, in
which a metallic piston is exactly fitted as for a steam engine, and
way.  Towards the top and bottom of the blowing cylinders orifices are left covered
with valves, which open inside when the vacuum is made with the cylinders, and afterwards shut by their own weight. Adjutages conduct into the iron globe or chest, the air
expelled by the piston, both in its ascent and descent; because these blowing machines
have always a double stroke.
The pressure of the air is made to vary through a very considerable range, according
to the nature of the fuel and season of the year; for as in summer the atmosphere is
more rarefied, it must be expelled with a compensating force.  The limits are from  16
pounds to 3A pounds on the inch; but these numbers represent extreme proportions, the
average amount in Staffordshire being 3 pounds.  With this pressure a furnace usually
works, which affords 60 tons of cast-iron in the week; and the pressure may be 2pounds
on an average.  The orifices, or nose-pipes, through which the air issues, also vary with
the nature of the coke and the ore. In Staffordshire they are generally from 2 inches and
5 tenths to 2 inches and 8 tenths in diameter.
The blowing machines of Staffordshire are always impelled by steam engines. At Mr.
Bagn-ill's works, two blast furnaces, 40 feet high, exclusive of the chimney or top, and
two finery furnaces, are worked by a steam engine of 40 horses power; and therefore
the power of one horse corresponds to the production of 2k tons of cast iron per week,
independently of the finery.
In South Wales, especially at Pontypool, there are slighter blast furnaces, whose upper
portion is composed of a single range of bricks, each ef which is 20 inches long, 4 thick,
and 9 broad.  The interior of the chimney represents an inverted cone.  These furnaces
derive solidity, and power to resist the expansions and contractions from change of temperature, by being cased, as it were, in horizontal hoops, placed 3 feet, or, even in some
cases, only 6 inches asunder. These flat rings consist of four pieces, which are joined
by means of vertical bars, that carry a species of ears or rings, into which the hoops enter,
and are retained by bolts or keys. Instead of these ears, screw nuts are also employed
for the junction.  Each hoop is alternately connected to each of the eight vertical bars.
The interior of these furnaces is the same as of the others; being generally from 12 to
14 feet diameter at the belly, and from 50 to 55 feet high. Though slight, they last as
long as those composed of an outer body of masonry and a double lining of bricks; and
have continued constantly at work for three years. In Wales also the blast furnaces are
generally somewhat larger than in Staffordshire; because there the object being to refine
the cast iron, they wish to procure as large a smelting product as possible. But in Staffordshire, a fine quality of casting iron is chiefly sought after, and hence their furnaces
have less height, but nearly the same width.
In a blast apparatus employed at the Cyfartha works, moved by a 90 horse steam
power, the piston rod of the blowing cylinder is connected by a parallelogram mechanism
with the opposite end of the working beam of the steam engine. The cylinder is 9 feet
4 inches diameter, and 8 feet 4 inches high. The piston has a stroke 8 feet long, and it
rises 13 times in the minute. By calculating the sum of the spaces percurred by the
piston in a minute, and supposing that the volume of the air expelled is equal to only 96
per cent. of that sum, which must be admitted to hold with machines executed with so
much precision, we find that 12,588 cubic feet of air are propelled every minute. Hence
a horse power applied to blowing machines of this nature gives, on an average, 137 cubic feet of air per minute. The pressure on the air, as it issues, rarely exceeds two pounds
on the square inch in the Welsh works.
At the establishment of Cyfartha, for blowing seven smelting furnaces, and the seven
corresponding  fineries, three steam  engines are employed, one of 90 horse power,
another of 80, and a third of 40; which constitutes in the whole a force of 210 horses,
or 26 horses and I per furnace, supposing the fineries to consume one eighth of the blast.
In the whole of the works of Messrs. Crawshay, the proprietors of Cyfartha, the power
of about 350 horses is expended in blowing 12 smelting furnaces, and their subordinate
fineries; which gives from 25 to 26 horses for each, allowing as before one eighth for the
fineries. As these furnaces produce each about'60 tons of cast iron weekly, we find




IRON.                                       1073
that a horse power corresponds to 2 tons and a tenth in that time. Each of the furnaces
consumes about 3567 cubic feet of air per minute.  These works have been greatly
increased of late years.
The following analyses of the English coal ironstones have been made by M. Berthier,
at the school of mines in Paris.
Rich Ore of Dudley,
Rich Welsh Ore.   Poor Welsh Ore.       orgun.
Loss by ignition-    -    -           30-00              27-00              21-00
Insoluble residuum      -    -          8-40             22-03               7-66
Lime- --                     -          0-0               6'00               2-66
Peroxyde of iron -    -    -          60-00              42-66              58-33
On calculating the quantities of carbonate of iron, and metallic iron, to which the
above peroxyde corresponds, we have:- 
Carbonate of iron   -  88-77                          65-09             85- 20
Metallic iron     -    -    -         4215               31-38              40-45      l
The mean richness of the ores of carbonate of iron of these coal basins is not far from
33 per cent. About 28 per cent. is dissipated on an average, in the roasting of the ores.
Every ferruginous clay-stone is regarded as an iron ore, when it contains more than 20
per cent. of metal; and it is paid for according to its quality, being on an average at 12
shillings per ton in Staffordshire. The gubbin, however, fetches so high a price as 16
f 1"7 shillings. The ore must be roasted before it is fit for the blast furnace, a process
caiiied on in the open air.  A heap of ore mingled with small coal (if necessary) is
piled up over a stratum of larger pieces of coal; and this heap may be 6 or 7 feet hioh,
by 15 or 20 broad.  The fire is applied at the windward end, and after it has burned a
certain way, the heap is prolonged at the other extremity, as far as the nature of the
ground or convenience of the work requires. The quantity of coal requisite for roasting
the ore varies from one to four hundred weight per ton, according to the proportion of
bituminous matter associated with the iron-stone.  The ore loses in this operation from
25 to 30 per cent. of its weight. Three and a quarter tons of crude ore, or two and a
quarter tons of roasted ore, are required to produce a ton of cast-iron; that is to say, the
crude material yields on an average 30-7 per cent., and the roasted ore 44-4 of pig metal.
In most smelting works in Staffordshire, about equal weights of the rich ore in round
nodules called gubbin, and the poorer ore in cakes called blue flat, are employed together
in their roasted state; but the proportions are varied, in order to have a uniform mixture, capable of yielding from 30 to 33 per cent. of metal.
The transition or carboniferous limestone of Dudley is used as the flux; it is compact
and* contains little clay. The bulk of the flux is made nearly equal to that of the ore.
To treat two tons and a quarter of roasted ore, which furnish one ton of pig iron, 19
hundred weight of limestone are employed; constituting nearly 1 of limestone for 3 of
unroasted ore. The limestone costs 6 shillings the ton.
Carbonized pitcoal or coke was, till within these few years, the sole combustible used
in the blast furnaces of Staffordshire.
The coal is distributed in circular heaps, about 5 feet diameter, by 4 feet high; and
the middle is occupied by a low brick chimney, piled with loose bricks, so open as to leave
interstices between them, especially near the ground. The larger lumps of coal are
arranged round this chimney, and the smaller towards the circumference of the heap.
When every thing is adjusted, a kindling of coals is introduced into the bottom of the
brick chimney; and to render the combustion slow, the whole is covered over with a coat
of coal dross, the chimney being loosely closed with a slab of any kind.  Openings are
occasionally made in the crust and afterwards shut up, to quicken and retard the ignition
at pleasure, during its continuance of 24 hours. Whenever the carbonization has reached
the proper point for forming good coke, the covering of coal dross is removed, and water
is thrown on the heap to extinguish the combustion; a circumstance deemed useful to
the quality of the coke. In this operation the Staffordshire coal loses the half of its
weight, or two tons of coal produce one of coke.
As soon as the blast furnace gets into a regular heat, which happens about 15 days or
three weeks after fires have been put in it, the working consists simply in charging it, at
the opening in the throat, whenever there is a sufficient empty space; the only rule
being to keep the furnace always full. The coke is measured in a basket, thirteen of
which go to the ton. The ore and the flux (limestone) are brought forwards in wheelbarrows of sheet iron. In 24 hours, there are thrown into a furnace such as fir,.
582, 14- tons of coke, 16 tons of roasted ore, and 61 tons of limestone; from which
about 7 tons of pig iron are procured. This is run oft e iery 12 hours; in some works
the blast is suspended during the discharge. The metal intended to be converted into




1074                                    IRON.
bar iron, or to be cast again into moulds, is ran into small pigs 3 feet long, and 4 inches
diameter; weighing each about 2 hundred weight and a half.
The disorders to which blast furnaces are liable have a tendency always to produce
white cast-iron.  The color of the slag or scoria  is the surest test of these derangements, as it indicates the quality of the products. If the furnace is yielding an iron
proper for casting into moulds, the slag has a uniform vitrification, and is slightly translucid. When the dose of ore is increased in order to obtain a gray pig iron, fit for
fabrication into bars, the slag is opaque, dull, and of a greenish-yellow tint, with blue
enamelled zones. Lastly, when the furnace is producing a white metal, the slags are
black, glassy, full of bubbles, and emit an odor of sulphureted hydrogen. The scorie
from a coke are much more loaded with lime than those from a charcoal blast furnace
This excess of lime appears adapted to absorb and carry off the sulphur, which would
otherwise injure the quality of the iron. The slags, when breathed on, emit an argillaceous odor.
A blast furnace of 50 or 60 feet in height gives commonly from 60 to 70 tons of castiron per week; one from 50 to 55 feet high, gives 60 tons; two united of 45 feet produce
together 100 tons; and one of 36 feet furnishes from 30 to 40. A blast furnace should
go for four or five years without needing restoration. From 31 to 4 tons of coal, inclusive of the coal of calcination, are required in Staffordshire to obtain one ton of cast-iron
and the expense in workmen's wages is about 15 shillings on that quantity.
At the Cyfartha works of Messrs. Crawshay in South Wales, the average price of the
lithoid carbonate of iron, ready for roasting, is only 7s. 6d. a ton, and its richness is about
33 per cent. The furnaces for roasting the ore in that country are made in the form of
cylinders, placed above an inverted cone. The cylindrical part is 6 feet high and wide
and the cone is about 4 feet high, with a base equal to that of the cylinder; towards
the bottom or narrowest part of the inverted cone, there is an aperture which terminates
in an outlet on a level with the bottom of the terrace in which the furnace is built.
Sometimes, however, all the roasting furnaces are in a manner combined into one,
which resembles a long pit about 6 feet in width and depth, and whose bottom presents
a series of inverted hollow quadrangular pyramids, 6 feet in each side, and 4 deep. The
bottom or apex of each of these pyramids communicates with a mouth or door-way that
opens on a lower terrace, through which the ore falls in proportion as it is roasted; and
whence it is wheeled and tumbled into the throat of an adjoining blast furnace, on the
same level with the terrace; for in Wales the blast furnace is generally built up
against the face of a hill, which makes one of its fronts. The above roasting furnaces, which closely resemble lime-kilns' after being filled with alternate strata of small
coal and ore, are set on fire; and the roasted ore is progressively withdrawn below, as
already mentioned.
The product of coke from a certain weight of coal is greater in Wales than in Staffordshire, though the mode of manufacture is the same. At Pen-y-Darran, for example,
5 of coal furnish 31 of coke; or 100 give 70; at Dowlais 100 of coal afford 71 of coke,
and the product would be still greater if more pains were bestowed upon the process.
At Dowlais, coal costs only 2 shillings a ton; at Cyfartha, it is worth from 2s. 6d. to 5
shillings. About 2 tons of coke are employed in obtaining I ton of cast-iron.
According to M. Berthier's analysis, the slag or cinder of Dowlais consists of silica,
40-4; lime, 38-4; magnesia, 5-2; alumina, 1l12; protoxyde of iron, 3'8; and a trace of
sulphur. He says that the silica contains as much oxygen as all the other bases united;
or is equivalent to them in saturating power; and to the excess of lime he ascribes the
freedom from sulphur, and the good quality of the iron produced. The specimen examined was from a furnace at Merthyr-Tydvil. Other slags from the same furnace, and one
from Dudley, furnished upwards of 2 per cent, of manganese. Those which he analyzed
from Saint Etienne, in France, afforded about 1 per cent. of sulphur.
The consumption of coal in the Welsh smelting furnaces may be estimated, on an
average, at 3 tons per ton of cast-iron; corresponding to 2'l of their coke. From this
economy in the quantity of fuel, as well as from its cheapness and that of the iron ore,
the iron of South Wales can be brought into the market at a much lower rate than that
of any other district. These blast furnaces remain in action from 5 to 10 years; at the
end of which time, only their interior surface has to be repaired. The lining of the
upper part lasts much longer; for examples are not wanting of its holding good for
nearly 40 years.
One of the greatest improvements ever made by simple means in any manufacture is
the employment of hot air, instead of the ordinary cold air of the atmosphere, in supplying the blast of furnaces for smelting and founding iron. The discovery of the superior power of a hot over a cold blast in fusing refractory lumps of cast-iron was accidentally observed by my pupil, Mr. James Beaumont Neilson, engineer to the Glasgow
gas works, about the year 1827, at a smith's forge in that city, and it was made the
subject of a patent in the month of September of the following year. No particular
construction of apparatus was described by the inventor by which the air was to be




IRON.
heated, arid conveyed to the furnace; but it was merely stated that the air may bc
heated in a chamber or closed vessel, having a fire under it, or in a vessel connected in
any convenient manner with the forge or furnace. From this verssel the air is to be forced
by means of bellows into the furnace.  The quantity of surface which aheating furnaceis
required to have for a forge, is about 1260 cubic inches; for a cupola furnace, about 10,000
cubic inches. The vessel may be enclosed in brickwork, or fixed in any other manner
that may be found desirable, the application of heated air in any way to furnaces or
forges, for the purposes of working iron, being the subject c-aimed as constituting the
invention.
Wherever a forced stream of air is employed for combustion, the resulting temperature
must evidently be impaired by the coldness of the air injected upon the uel. The heat
developed in combustion is distributed into three portions; one is communicated to the
remaining fuel, another is communicated to the azote of the atmosphere, and to the volatile products of combustion, and a third to the iron and fluxes, or other surrounding
matter to be afterwards dissipated by wider diffusion. This inevitable distribution takes
place in such a way, that there is a nearly equal temperature over the whole extent of a
fire-place, in which an equal degree of combustion exists.
We thus perceive that if the air and the coal be very cold, the portions of heat absorbed by them might be very considerable, and sufficient to prevea the resulting temperature from  rising to a proper pitch; but if they were very hot tney would absorb
less caloric, and would leave more to elevate the common temperature. Let us suppose
two furnaces charged with burning fuel, into one of which cold air is blown, and into
the other hot air, in the same quantity. In the same time, nearly equal quantities of fuel.w` be consumed with a nearly equal production of heat; but notwithstanding of this,
there will not be the same degree of heat in the two furnaces, for the one which receives the hot air will be hotter by all the excess of heat in its air above that of the
other, since the former air adds to the heat while the latter abstracts from it. Nor are
we to imagine that by injecting a little more cold air into the one furnace we can raise
its temperature to that of the other. With more air indeed we should burn more coals
in the same time, and we should produce a greater quantity of heat, but this heat being
diffused proportionally among more considerable masses of matter, would not produce a
greater temperature; we should have a larger space heated, but not a greater intensity
of heat in the same space.
Thus, according to the physical principles of the production and distribution of heat
fires fed with hot air should, with the same fuel, rise to a higher pitch of temperature
than fires fed with common cold air. This consequence is independent of the masses,
being as true for a small stove which burns, only an ounce of charcoal in a minute, as
for a furnace which burns a hundred weight; but the excess of temperature produced by
hot air cannot be the same in small fires as in great; because the waste of heat is usually
less the more fuel is burned.
This principle may be rendered still more evident by a numerical illustration. Let
us take, for example, a blast furnace, into which 600 cubic feet of air are blown per
minute; suppose it to contain no ore, but merely coal or coke, and that it has been burn;
ing long enough to have arrived at the equilibrium of temperature, and let us see what
excess of temperature it would have if blown with air of 3000 C. (572~ F.), instead of being blown with air at 00 C.
600 cubic feet of air under the mean temperature and pressure, weigh a little more
than 45 pounds avoirdupois; they contain' 10-4 pounds of oxygen, which would burn very
nearly 4 pounds of carbon, and disengage 16,000 times as much heat as would raise by
one degree Cent. the temperature of two pounds of water. These 16,000 portions of heat,
produced every minute, will replace 16,000 other portions of heat, dissipated by the sides
of the furnace, and employed in heating the gases which escape from its mouth. This
must take place in order to establish the assumed equilibrium of caloric.
If the 45 pounds of air be heated beforehand up to 3000 C., they will contain about
the eighth part of the heat of the 16,000 disengaged by the combustion, and there will
be therefore in the same space one eighth of heat more, which will be ready to operate
upon any bodies within its range, and to heat them one eighth more. Thus the blast
of 3000 C. gives a temperature which is' nine'eighths of the blast at zero C., or at even
the ordinary atmospheric temperature; and as' we may reckon at from 22000 to 27000 F.
(from 12000 to 15000 C.), the temperature of blast furnaces worked in the common way,
we perceive that the hot air blast produces an increase of temperature equal to from 2700
to 3600 F.
Now in'order to appreciate the immense effects which this excess of temperature may
produce in metallurgic operations, we must consider that often only a few degrees mqre
temperature'are required to modify the state of a fusible body, or to determine the play
of affinities dormant at lower degrees of heat. Water is solid at 1~ under 320 F.; it
is liquid at 10 above. Every fusible body has a determinate melting point, a very few




1076                                   IRON.
degrees above which it is quite fluid, though it may be pasty below it. The same ot
servation applies to ordinary chemical affinities charcoal, for example, which reduce!
the greater part of metallic oxydes, begins to do so only at a determinate pitch of temperature, under which it is inoperative, but a few degrees above, it is in general lively
and complete. It is unnecessary, in this article, to enter into any more details to show
the influence of a few degrees of heat, more or less, in a furnace, upon chemical operalions, or merely upon physical changes of state.
These consequences might have been deduced long ego, and industry might thus have
been enriched with a new application of science, but philosophers have been and still
796
are too much estranged from the study of the useful arts, and content themselves too
much with the minutiae of the laboratory or theoretic abstractions. Within the space of
7 years, the use of the hot blast has been so much extended in Great Britain, as to have
enabled many proprietors of iron works to add 50 per cent. to their weekly production of
metal, to diminish the expenses of smelting by 50 per cent., and, in many cases, to produce
a better sort of cast iron from indifferea materials.'797
/  7       n
The figures here given represent the blast furnace, and all the details of the air heating,
800             at one view. Fig. 794 is a vertical section of
the furnace and the apparatus; fig. 796 represents the plan at the height of the line 1, 2, of
fig.'794.  The blowing machine, which is not
shown in this view, injects the air through the
pipe A, into the regulator chamber R, fig. 796;
the air thence issues by the pipe B, proceeds to
Iii)   I will "T^c where it is subdivided into two portions; the
A11 I I ~TT~r^     one passes along the pipe c D to get to the
fill I  I  IT~^ UlK         tuydre T, the other passes behind the furnace,
J 1l j U   ^ ^ U~i   and arrives at the tuyere T' by the pipe c E F.
VAi   I U  -\ \ ^\           These pipes are distributed in a long furnace
j BJ i i' ^ ^'^f    or flue, whose bottom, sides, and top are formed
fig  j D   ~\ \ PT^           with fire-brick, where they are exposed to the
action of the flame of the three fires x, Y, z.
The flame of the fire x plays round the pipe B at
its entrance into the flue, and quits it only to go
into the chimney Hi; that of the fire Y acts from
the point D to the same chimney, passing by the
elbow c; that of the fire z acts equally upon F
and H, in passing by the elbow E.
Disposition of the fires and furnace.-Fig.
797 represents, upon a scale three times larger than fig.'96, the section of the




IRON.                                       1077
fire x, of which thC plan is seen infig. 796, and the elevation in fig.'94; as also in the
outside view of the blast furnace, fig. 800.
The grate is at L; the fuel is introduced by the door P, fig. 794; the flame rises above
the bridge i K, and proceeds along the vaulted flue towards the chimney H. Through a
length of about 13 feet, including the grate, the furnace is on each side supported by
oblong plates of cast-iron, which are bound together by 4 upright ribbed or feathered
bars, also on each side; these bars, n, being bound together by iron rods furnished with
screw nuts at their ends (figs. 794, 796, 797). Beyond this distance, the outside of the
furnace is mere brickwork.
The fires Y and z have exactly a like disposition with the above.
Fig. 797 indicates the dimensions and the curvature of the arch above the grate, near
the bridge; fig. 798 represents the section of the furnace and of the pipe beyond the castiron casing.
I find thatthe furnace is only about 3 feet wide at the bottom, and that the elevation
of the arch above the bottom is no more than 30 inches. Perhaps it might be made a
little wider with advantage; the combustion would be more vigorous and effective; and
if the sides also were a little thicker, the heat would be better confined.
The distance from the fire-place x to the chimney H, is 431 feet.
~- -                    Y to the point c, is    13
-                -       z to the chimney, is   29  -   including  the
turn of the elbow E.
Disribution of the pipes.-At B the pipe is 18 inches diameter outside, and one inch
thick of metal, and it tapers to c; from c to D and from D to c the pipes are only 11 inches
in external diameter, and three fourths of an inch thick; they are 5 feet long, and are
united by two kinds of joints; the ordinary ones, and those of compensation, to give
play for the expansion and contraction. One of these is seen between B and c, one between c and D, one between c and E, and a fourth between E and F.  These pipes and
their adjustment are seen more at large in fig. 799; u v is one of these pipes, its widened
mouth receives the extremity M of the preceding pipe. These pieces are truly bored and
turned to fit each other, and slide out and in like telescope tubes, by the effect of dilatation and contraction of the pipes with changes of temperature.
At certain distances castors or friction-rollers of cast-iron are placed to carry the pipes,
which roll upon oblong plates of cast-iron laid upon the floor of the flues. These castors
are shown at a, b, c, d, e, f, g, fig. 796; one of them  is shown separate upon a larger
scale at G, in fig. 798, as also the plate or rail s, on which it runs.
The tuyhres T T' are adjusted into the pipe behind them; this is truly bored, so as to
allow the thick end of the tuyhre to slide tightly backwards and forwards in it, like a
piston in the barrel of a pump; a diaphragm moreover prevents the tuyere from being
drawn or forced entirely out of its tube. At the side of this tube there is a small orifice,
which may be shut or opened at pleasure with a stopcock or screw-plug: it serves to try
the degree of heat of the air-blast; if a lead wire does not melt when held at this hole,
the temperature is reckoned too low; being under the 612th degree of Fahrenheit. The
nozzles are 2 inches in diameter.
Near the fire-places of the air-heating furnaces the pipes are at a cherry-red heat; and
lest they should be burned, they are there coated with a lute of fire-clay, as shown near
K, in fig. 797. By this means the air is kept up at the heat of 3500 C., or 6620 F., a
little above the boiling point of quicksilver.
Quantity of air and pressure.-The blowing-machine belonging to the above blastfurnace is moved by a water wheel of 22 horse power; the pistons are 4 feet in diameter,
have a 31-feet stroke, work double, and expel 1200 cubic feet of air in the minute; or
600 cubic feet for each nozzle. The pressure of the air is equivalent to no more than
2 or 21 inches of mercury; formerly with cold air it amounted to 31 inches.  This furnace yields, upon an average, 51 tons of cast-iron daily, and consumes 11 cwt. of coke
for each cwt. of cast-iron produced; being 7 tons of coke per diem.
The consumption of the three flue fires is 30 pounds of small coal, for 100 pounds of
cast-iron produced, which may be reckoned equivalent to 15 pounds of coke; hence altogether each ton of cast-iron requires for its production 11 tons of coke.
The same furnace worked with the cold blast, the same pressure, and the same ores,
produced only 31 tons of cast-iron daily, with an expenditure of 2-55 of coke for I of
cast-iron; in which case the coke amounted to 9 tons daily.
The returns by the hot blast compared with those by the cold, are therefore as the
numbers 3 and 2, which shows an advantage by the former plan of 50 per cent.  The
consumption of fuel in the two cases is as 8 to 9, being a saving in this article of about
11 per cent. Coke is used on account of sulphur in the coal.
Hot-blast heated by the flame of the furnace mouth.-This system is mounted in Staffordshire. The heating apparatus is there set immediately upon the mouth of the fur.
nace; and is composed of two large cast-iron cylinders of the same length, the one within




1078                                   IRON.
the other, leaving a space between them. This annular interval amounts to 16 inches
and it is closed at top and bottom: but the innermost cylinder is open at both ends, and
forms, indeed, the vent of the chimney or furnace. It carries nine rows of pipes, three
in each row, which cross its interior, and open into the annular space.
The flame of the furnace passes between the intervals of the cross pipes, heating
them, and also the two upright cylinders with which they are connected.  The air of
the blowinog machine arrives by a vertical pipe, which is placed at the back of the furnace; it enters into the above annular space, and thence circulates, with more or less
velocity, through the 27 cross tubes, upon which the flame is continually playing; lastly,
it is drawn through to the bottom of the annular space; the two tubes which conduct it
to the two tuydres, pass down within the brickwork of the furnace, and thus prevent the
dissipation of its heat.
Below this heating apparatus there is a door for putting the charges into the furnace.
The above arrangement does not seem to be the best for obtaining the greatest possible heat for the blast, nor for favoring the free action of the furnace; but it illustrates
perfectly well the principle of this application. A serpentine movement in a long bent
hot channel would be much better adapted for communicating heat to so bad a conducto:
as air is known to be.
In the month of July, 1836, I paid a visit to Codner Park and Butterly works, in Derbyshire, belonging to the eminent iron-masters, Messrs. Jessop & Co., where I was
kindly permitted not only to study the various processes of the manufacture of cast and
wrought iron, but to inspect the registers of the products of cast iron in their blast
furnaces for several years back.  It appeared that in the year 182
cast-iron were made weekly in each of the blast furnaces at Codner Park.  They
were then worked with coke, and blown with cold air.  Each ton of iron required
for its production, at that time, 6'82 tons of coals, made into coke for smelting; with
2-64 of roasted iron ore (carbonate), called mine; and 0-87 of limestone, the castie of
the French.
In 1835 and 1836, the same furnaces turned out weekly 49 tons of cast-iron each; anc
every ton of iron required for its production only 3 tons of coal (not made into coke);
2'72 tons of mine; and 0'77 of lime.
In 1829, and for many years before, as well as one or two after, each ton of coals is said
to have cost for coking the sum of 6s., whence the 6-82 tons of coals then converted into
coke for smelting one ton of iron, cost fully 40s. in coking alone, in addition to their prime
cost. The saving in this respect, therefore, is 40s. upon each ton of iron, besides the
saving of fully half the coal, and the increased produce of nearly 60 per cent. of metal
per week. The iron-master pays the patentee 1s. upon every ton of iron which he
makes, and, at the prices of 1836, he lessened his expenses by at least 30s. or 40s. per
ton by the patent improvement.
The following tabular view of the progression in the management and results of the
hot blast, is given by M. Dufrenoy, after visiting the various iron works in this country
where it had been introduced.
" At the Clyde iron works, near Glasgow; in 1829, when the combustion was effected
by the cold air blast,-                                                         Coal.
Tons. cwt. lbs
There were consumed, for smelting, 3 tons of coke, equivalent to        -  6  13  0
-      for the blowing engine                           -  1   0  7
Total coal per ton of iron     -  7  13  7
Limestone      -               -  0  101 0
In 1831, with the hot blast at 450P F., coke being still used in smelting,There were consumed, for smelting, I ton, 18 cwt. of coke, equivalent to       -       -       -       -       -       -       -      -4   6  0
-                for heating the air, 5 cwt.       l            -0124
~                for the blowing engine, 7 cwt. 4 Ibs.
Total coal per ton of iron    -  4  18  4
Limestone    -         -      -  0   9  0
In July, 1833, with the hot blast at 6120 F., raw coal alone being used
for smelting,There were consumed: for smelting    -          -       -       -       -  2   0  0
~           for heating the air     -       -       -       -  0   8  0
~           for the blowing engine -        -       -       -  0  11  2
Total coal per ton of iron     -2  19  2
Limestone    -         -       -0   7  0




IRON.                                       1079
"At the last period the use of hot air had increased the make of the furnaces by more
than one third, and had consequently produced a great saving of expense in the article
of labor.  The quantity of blast necessary for the furnaces was also sensibly diminished;
for a blowing engine of seventy-horse power, which, in 1829, served only for three blast
furnaces, was now sufficient for the supply of four.
"C On comparing these several results, we find that the economy of fuel is in proportion
to the temperature to which the air is raised. As for the actual saving, it varies in
every work, according to the nature of the coal, and the care with which the operation
is conducted.
This process, though it has been four years in use in the works near Glasgow
(which it has rescued from certain ruin), has scarcely passed the borders of Scotland;
the marvellous advantages, however, which it has produced, are beginning to triumph
over prejudice, and gradually to extend its use into the different English iron districts.
There are one-and-twenty works, containing altogether sixty-seven blast furnaces, in
which hot air is used. The pig iron run out of these furnaces is generally No. 1, and is
fit for making the most delicate castings. This process is equally applicable to forge
pigs for the manufacture of bar iron; since in order to obtain this quality of iron, it is
only necessary to alter the proportion of fuel and mineral. In the forges of the Tyne ironworks, near Newcastle, and of Codner Park, near Derby, pigs made in furnaces blown by
hot air, are alone used in the manufacture of bar iron.
In the side of the tuyere pipe a small hole is made, by means of which the heat of
the air may be ascertained at any moment. This precaution is indispensable, it being of
importance to the beneficial use of hot air, that it be kept at a uniformly high temperature.
With a proper apparatus the air is raised to 612 degrees Fahr., which is a greater heat,
by several degrees, than is necessary for the fusion of lead."
" At Calder works the consumption of fuel has diminished in the proportion of 7 tons
17 cwts. to 2 tons 2 cwts. There has also been a great diminution of expense in limestone,
of which only     cwts. are now used, instead of 13 cwts., which were used in 1828. This
decrease results as I have already said, from the high temperature which the furnace has
acquired since the introduction of hot air.
" The quantity of blast has been reduced from  3500 cubic feet per mi]ne, to 2627
cubic feet; the pressure also has been reduced from 3- to 2-1 lbs."
Of the refinery of cast-iron, or its conversion into bar-iron, in England.-This peration
is naturally divisible into three distinct parts. The first, or the finery properly speaking,
is executed in peculiar furnaces called running outfires; the second operation completes
the first, and is called puddling; and the third consists in welding several iron I ars together, and working them under forge hammers, and between rolls.
1. The finery furnaces are composed of a body of brickwork, about 9 feet square; rising
but little above the surface of the ground.. The hearth, placed in the middle, is two
feet and a half deep; it is rectangular, being in general, 3 feet by 2, with its greatest
side parallel to the face of the tuybres; and it is made of cast iron in four plates. On the
side of the tuyeres there is a single brick wall. On the three other sides, sheet iron doors
are placed, to prevent the external air from cooling the metal, which is almost always
worked under an open shed, or in the open air, but never in a space surrounded by walls.
The chimney, from 15 to 18 feet high, is supported upon four columns of cast iron; its
lintel is four feet above the level of the hearth, in order that the laborers may work without restraint.
The number of tuyeres is from  two to three; they are placed at the height of the lip
of the crucible or hearth, and distributed so as to divide its length into equal parts;
their axes being inclined towards the bottom, at an angle of from 25" to 30", so as to point
upon the bath of melted metal as it flows. The cast-iron nose-pipe is incased, and water
is made to circulate in the hollow space by means of cylindrical tubes; being introduced
by one tube, and let off by another, so as to prevent the tuyeres from getting burned in
the process.
Two nozzles are usually placed in each tuyere, to render the blast constant and unifbrm; and for the same end, the air impelled by the bellows, is sometimes received at
first in a regulator. The quantity of air blown into the fineries is considerable; being
nearly, 400 cubic feet per minute for each finery; or about the eighth part of the consumption of a blast furnace.
The finery furnace, or running out fire, is represented in figs. 801 and 802. It is a
smelting hearth, in which by first fusing and then cooling gray cast iron in a peculiar
way, it is converted into white cast iron, called fine iron, or fine metal, of the quality of
forge pig, for making malleable iron by the puddling process. The furnace resembles the
forge hearth employed in Germany and France for converting forge pig into wrought
iron; but it differs, particularly in this, that the fused iron is run out into an oblong iron
trough, for sudden congelation.
a is the air-chest, in communication with the tlowing cylinder, or bellows; the air




1080                                   IRON.
Deing conducted through at least two blast pipes to the fire, and sometimes through
even 4 or 6 pipes. b is the side of the furnace, corresponding to the tuyere plater in
e circulation of water throuh the cavity between t —wa h801eu  e, having a strong cast iron plate containing the tap         r
off the melted metal. d d is the exterior wall of the furnace, which corresponds to the
contre-vent and ash-hearth of the French refining forge. e, is the top plate upon which the
coke is piled up in store. ffff, iron props of the chimney, (not shown in this view) g
cast iron trough into which the fine iron is run off in fusion; which is sometimes made
in one piece, but more usually in separate plates joined together. Beneath this mould
a stream of water is made to flow. h is the bottom of the hearth, covered with sand.
In the finery process, the hearth or crucible of the furnace is filled with coke; then six
pigs of cast iron are laid horizontally on the hearth, namely, four of them parallel to
the four sides, and two in the middle above; and the whole is covered up in a domeform  with a heap of coke. The fire is now lighted, and in a quarter of an hour the
blast is applied. The cast iron flows down gradually, and collects in the crucible; more
coke being added as the first quantity burns away. This operation proceeds by itself;
the melted metal is not stirred about, as in some modes of refinery, and the temperature
is always kept high enough to preserve the metal liquid. During this stage the coals
are observed continually heaving up, a movement due in part to the action of the blast,
and in part to an expansion caused in the metal by the discharge of gaseous oxyde of
carbon. When all the pig iron is collected at the bottom of the hearth, which happens
commonly at the end of two hours, or two and a half, the tap hole is opened, and the
fine metal flows out with the slag, into the loam-coated pit, on a plate 10 feet long,
3 broad, and from 2 inches to 2^ thick. A portion of the slag forms a small crust on the
surface of the metal; but most part of it collects in a basin scooped out at the bottom of
the pit, into which the fine metal is run.
A large quantity of water is thrown on the fine metal, with the view of rendering it
brittle, and perhaps of partially oxydizing it. This metal suddenly cooled, is very white,
and possesses in general a fibrous radiated texture; or sometimes a cellular, including a
considerable number of small spherical cavities, like a decomposed amygdaloid rock. If
the cast iron be of bad quality, a little limestone is occasionally used in the above
operation.
Three samples of cinder, analyzed by Berthier, gave.
Silica 0-276; protox. of iron, 0-612; alumina, 0-040; phosp. acid, 0-072, Dudley.
~ 0-368           -        0-610    -      0-015; puddling of Dowlais.
0-424                  0-520    -       0-033; ditto.
The remarkable fact of the presence of phosphoric acid, shows how important this operation is to the purification of the iron. The charge varies from a ton and a quarter to a
ton and a half of pigs; and the loss by the process varies from 12 to 17 per cent.
The fine metal is broken into fragments, and sent to the puddling furnace after the
product of each operation has been weighed. The coal consumed in the fine metal
process is from 4 to 5 hundred weight for the ton of cast iron. About 10 tons may be
refined per diem, a quantity somewhat greater than the supply from a blast furnace; but
the fineries are not worked on the Sundays; and therefore a smelting furnace just keeps
one of them in play.  Whatever care be taken in this process, the bar iron finally
resulting is never so good as if wood charcoal had been used in the refinery; and hence
in making sheet iron for the tin p'ate manufacture, wood charcoal is substituted for
coke in one Welsh establishment. The cast iron treated with charcoal, gets into clots




IRON.                                    1081
)r lumps in the finery furnace, which are lifted out, set under the hamner, and rattered
into thin cakes.
The main effect of the finery process, is probably the separation of the plumbaginous part of the charcoal, which is disseminated through the gray cast iron in a state
of imperfect chemical combination. When that is removed the metal becomes more
homogeneous, having no crystalline carbon present to counteract its transition into pure
iron; much of the silica and manganese are also vitrified together, and run off in the finery
cinder.
2. The puddling furnace is of the reverberatory form. It is bound generally with iron
as represented in the side view, fig. 803, by means of horizontal and vertical bars, which
803
^n            3
are joined together and fixed by wedges, to prevent them from starting asunder.  Very
frequently, i the reverberatory furnaces are armed with cast-iron plates over their
whole surface.. These are retained by upright bars of cast iron applied to the side walls,
and by horizontal bars of iron, placed across the arch or roof. The furnace itself is
divided interiorly into three parts; the fire-place, the hearth, and theflue. Thefire-place
-varies from 3j to 42 feet long, by from 2 feet 8 inches to 3 feet 4 inches wide. The door
way by which the coke is charged, is 8 inches square, and is bevelled off towards the outside of the furnace. This opening consists entirely of cast iron, and
coal gathered round it. The bars of the fire grate are moveable, to admit of more readily
clearing them from ashes.
Fig. 804 is a longitudinal section referring to the elevation, fig. 803, and fig. 805,
as aground plan. When the furnace is a single one, a square hole is left in the side of
the fire-place opposite to the door, through which the rakes are introduced, in order to be
heated.
a is the fire door; b, the grate; c, the fire bridge.; d d, cast-iron hearth plates, resting
upon cast-iron beams e e, which are bolted upon both sides to the cast-iron binding
plates of the furnace. f is the hearth covered with cinders or sand; g, is the main
working door, which may be opened and shut by means of a lever g', and chain to
smove it up and down.  In this large door there is a hole 5 inches square, through
whlich the iron.may be worked with the paddles or rakes.; it may also be closed air



1082                                   IRON.
tight. There is a second working door h, near the flue, for introaucing the cast iro
so that it may soften slowly, till it be ready for drawing towards the bridge. i, is the
chimney, from 30 to 50 feet high, which receives commonly the flues of two furnaces, each
806                         provided with a damper plate or register.  Fig. 806,
shows the main damper for the top of the common
chimney, which may be opened or shut to any degree by
means of the lever and chain.  k, fig. 804, is the tap or
floss hole for running off the slag or cinder.
________l 6- The sole is sometimes made of bricks, sometimes of
cast iron.  In the first case it is composed of fire-bricks
set on edge, forming a species of flat vault.  It rests
immediately on a body of brickwork either solid or
arched below. When it is made of cast iron, which is
now  beginning to be the general practice, it may be
made either of one piece or of several. It is commonly
in a single piece, which, however, causes the inconvenience of reconstructing the furnace
entirely when the sole is to be changed. In this case it is a little hollow, as is shown in the
preceding vertical section; but if it consists of several pieces, it is usually made flat.
The hearths of cast iron rest upon cast iron pillars, to the number of four or five;
which are supported on pedestals of cast iron placed on large blocks of stone. Such an
arran gement is shown itf the figure, where also the square hole a, fig. 803, for heating the
rake irons, ipay be observed. The length of the hearth is usually six feet; and its breadth
varies from one part to another. Its greatest breadth, which is opposite the door, is four
feet. In the furnace, whose horizontal plan is given above, and which produces good results, the sole exhibits, in this part, a species of ear, which enters into the mouth of the door.
At its'origin towards the fireplace, it is 2 feet 10 inches wide; from the fire it is
separated, moreover, by a low wall of bricks (the fire-bridge) 10 inches thick, and from
3 inches to 5 high.  At the other extremity its breadth is 2 feet.  The curvature
presented by the sides of the sole or hearth is not symmetrical; for sometimes it makes
an advancement, as is observable in the plan. At the extremity of the sole furthest from
the fire there is a low rising in the bricks of 21 inches, called the altar, for preventing
the metal from running out at the floss-hole when it begins to fuse. Beyond this shelf
the sole terminates in an inclined plane, which leads to the floss, or outlet of the slag
from the furnace. Thisfloss is a little below the level of the sole, and is hollowed out of
the basement of the chimney. The slag is prevented from concreting here, by the flame
being made to pass over it, in its way to the sunk entry of the chimney; and there is also
a plate of cast iron near this opening, on which a moderate fire is kept -up to preserve the
fluidity of the scoriae, and to burn the gases that escape from the furnace, as also to quicken
the draught, and to keep the remote end of the furnace warm. On the top of this iron
plate, and at the bottom of the inclined plane, the cinder accumulates in a small cavity,
whence it afterwards flows away; whenever it tends to congeal, the workman must clear
it out with his rake.
The door is a cast iron frame filled up inside with fire-bricks; through a small hole in
its bottom the workmen %an observe the state of the furnace. This hole is at other times
shut with a stopper. The chimney has an area of from 14 to 16 inches.
The hearth stands 3 feet above the ground. Its arched roof, only one brick thick, is
raised 2 feet above the fire-bridge, and above the level of the sole, taken at the middle of
the furnace. At its extreme point near the chimney, its elevation is only 8 inches; and
the same height is given to the opening of the chimney.
In most iron works the sole is covered with a layer of refractory sand from 24 to 3 inches
thick, which is lightly beat down with a shovel. At each operation a portion of the sand
is carried away; and is replaced before another. Within these few years, there has been
substituted for the sand a body of pounded slags; a substitution which has occasioned, it
is said, a great economy of iron and fuel.
The fine metal obtained by the coke is puddled by a continuous operation, which calls
for much care and skill on the part of the workmen. To charge the puddling furnace,
pieces of fine metal are successively introduced with a shovel, and laid one over another on
the sides of the hearth, in the form of piles rising to the roof; the middle being left open
for puddling the metal; as it is successively fused. Indeed, the whole are kept as far separate as possible, to give free circulation to the air round the piles. The working door of
the furnace is now closed, fuel is laid on the grate, and the mouth of the fireplace, as well
as the side opening of the grate, are both filled up with coal, at the same time that the
damper is entirely opened.
The fine metal in about twenty minuses comes to a white-red heat, and its thin-edged
fragments begin to melt and fall in drops on the sole of the furnace. At this period the
workman opens the small hole of the furnace door, detaches with a rake the pieces of
fine metal that begin to melt, tries to expose new surfaces to the action of the heat, awd




IRON.                                       1083
in order to prevent the metal from running together as it softens, he removes it from the
vicinity of the fire-bridge. When the whole of the fine metal has thus got reduced
to a pasty condition, he must lower the temperature of the furnace, to prevent it from
becoming more fluid.  He closes the damper, takes out a portion of the fire and the
ribs of the grate, and also throws a little water sometimes on the semi-fused mass. He
then works about with his paddle the dotty metal, which swells up, with the discharge
of gaseous oxyde of carbon, burning with a blue flame, as if the bath were on fire. The
metal becomes finer by degrees, and less fusible; or in the language of the workmen, it
begins to get dry.  The disengagement of the oxyde of carbon diminishes and soon
stops. The workmen continue meanwhile to puddle the metal till the whole charge be
reduced to the state of incoherent sand; and at that time, the ribs of the grate are
replaced, the fire is restored, and the register is progressively opened up.  With the
return of the heat, the particles of metal begin to agglutinate, the charge becomes more
difficult to raise, or in the laborers' language, it works heavy.  The refining is now
finished and nothing remains but to gather the iron into balls. The founder with his
paddle takes now a little lump of metal, as a nucleus, and makes it roll about on the
surface of the furnace, so as to collect more metal, and form a ball of about 60 or 70
pounds weight.  With a kind of rake, called in England a dolly, and which he heats
beforehand, the workman sets this ball on that side of the furnace most exposed to the
action of the heat, in order to unite its different particles; which he then squeezes
together to force out the scoriae. When all the balls are fashioned, (they take about
20 minutes work,) the small opening of'the working door is closed with a brick to cause
the heat to rise, and to facilitate the welding. Each ball is then lifted out, either with
tongs, if roughing rollers are to be used, as in Wales, or with an iron rod welded to the
lump as a handle, if the hammer is to be employed, as in Staffordshire. Thus we see
that the operation lasts in whole from  2 hours to 2-; in a quarter of an hour, the fine
metal melts at its edges, when the puddling begins, in order to effect its division; at the
end of an hour or an hour and a half, the metal is entirely reduced to a sand; a state
that is kept up forhalf an hour by continual stirring; and finally, theballing operation
takes nearly the same time.
The charge for each operation is from.32 to 4 hundred weight; and sometimes the
cuttings of bar-ends are introduced, which are puddled apart. The loss of iron is here
very variable, according to the degree of skill in the workman, who by negligence
suffer a considerable body of iron to scorify or to flow into the hearth and raise the bottom. In good working, the loss is from 8 to 10 per cent. In Wales, the consumption
of coal is estimated at one ton for every ton of fine metal. About five puddling furnaces
are required for the service of one smelting furnace and one finery. The hearth of the
puddling furnace should be exposed to heat for 12 hours before the work begins on the
Mondays; and on the Saturdays, the old sole must be cleared out, by melting it off, and
running it out by the floss-hole.
Mr. Schafthault obtained, in May, 1835, a patent for the conversion of cast into
wrought iron, by adding a mixture of black oxyde of manganese, common salt, and
potter's clay, in certain small portions, successively, to the melting iron in the puddling
furnace.
The'reheating furnaces, balling furnaces, or mill furnaces, are analogous to the puddling
furnaces, but only of larger dimensions.
The wood charcoal forge hearth is employed for working up scrap iron into boiler plate,
&c. He-c 22 bushels of charcoal are consumed in making one ton of iron of that descrip.
tion, from boiler plate parings.
Machines for forging and condensing the iron.-In England there are employed for the
forging'and drawing out of the iron, cast-iron hammers of great weight, and cylinders ot
different dimensions, for beating out the balls, or extending the iron into bars, as also
powerful shears. These several mechanisms are moved either by a steam engine, as in
Staffordshire, and in almost all the other counties of England, or by water-wheels when
the localities are favorable, as in many establishments in South Wales. We shall here
offer some details concerning these machines.
The main driving shaft usually carries at either end a large toothed wheel, which
communicates motion to the different machines through smaller toothed wheels. Of
these, there are commonly six, four of which drive four different systems of cylinders,
and the two others work the hammer and the shears. The different cylinders of an iron
work should never be placed on the same arbor, because they are not to move together,
and they must have different velocities, according to their diameter. In order to economize time and facilitate labor, care is taken to associate on one side of the motive machine the hammer, the shears, and the reducing cylinders; and on the other side to place
the several systems of cylinders for drawing out the iron into bars. For the same reason
the puddling furnaces ought to be grouped on the side of the hammer; and the reheating
furnaces on the other side of the works.




1084                                    IRON.
The hammers, fig. 807, are made entirely of cast iron; they are nearly 10 feet long
and consist usually of two parts, the helve c, and the head or pane d. The latter enters
807
b
with friction into the former, and is retained in its place by wedges of iron or wood.
The head consists of several faces or planes receding from each other; for the purpose
of giving different forms to the ball lumps. A ring of cast-iron a, called the cam-ring bag,
bearing moveable cams b b, drives the hammer d, by lifting it up round its fulcrum f, and
then letting it fall alternately. In one iron work, this ring was found to be 3 feet in diameter, 18 inches thick, and to weigh 4 tons. The weight of the helve (handle) of the
corresponding hammer was 3 tons and a half, and that of the head of the hammer, 8 hundred weight.
The anvil e consists also of two parts; the one called the pane of the anvil, is the counterpart of the pane of the hammer; it likewise weighs 8 hundred weight. The second, g,
named the stock of the anvil, weighs 4 tons. Its form is a parallelepiped, with the edges
rounded. The bloom  or rough ball, from the puddle furnace, is laid and turned about
upon it, by means of a rod of iron welded to each of them, called a porter. Since the
weight of these pieces is very great, and the shocks very considerable, the utmost precautions should be taken in setting the hammer and its anvil upon a substantial mass of
masonry, as shown in the figure, over which is laid a double, or even quadruple flooring
of wood, formed of beams placed in transverse layers close to each other. Such beams
possess an elastic force, and thereby partially destroy the injurous reaction of the shock.
In some works, a six-feet cube of cast iron is placed as a pedestal to the anvil.
Forge hammers are very frequently mounted as levers of the first kind, with the centre
of motion about one third or one fourth of the length of the helve from the cam wheel.
The principle of this construction will be understood by inspection offig. 605. The short
end of the lever which is struck down by the tappet c, is driven against the end of an elastic
beam a, and immediately rebounds, causing the long end to strike a harder blow upon the
anvil s.
The shears are composed of two branches, the one fixed and the other moveable, each
formed of two pieces. The fixed branch is a cast-iron plate, which forms one mass with
a horizontal base fixed to a piece of wood or cast iron buried in the ground. A sharpened chisel is fastened to its upper part by screws and nuts. The moveable branch is
likewise of cast iron; it bears an axis round which it turns, and this axis passes through
the fixed part. It is also furnished with a cutting chisel, fixed on by nuts and screws.
An eccentric or an ellipse, moved directly by a toothed wheel, lifts the moveable branch
of the shears, and forces it to cut the iron bars presented to it. The pressure exerted by
these scissors is such, that they can cut without difficulty, iron bars, one half or two thirds
of an inch thick.
Cylinders.-The compression between cylinders now  effects, in a few seconds, that
condensation and distribution of the fibres, which, 40 years ago, could not be accomplished till after many heats in the furnace, and many blows of the hammer.  The
cylinders may be distinguished into two kinds; 1. those which serve to draw out the
ball, called puddling rolls, or roughing rolls, and which are, in fact, reducing cylinders;
2. the cylinders of extension, called rollers, for drawing into bars the massive iron after
it has received a welding, to make it more malleable. This second kind of cylinders is




IRON.                                      1085
subdivided into several varieties, according to the patterns of bar iron that are required.
These may vary from 2 inches square to less than one sixth of an inch.
Beneath the cylinders there is usually formed an oblong fosse, into which the scoriae
and the scales fall when the iron is compressed.  The sides of this fosse, constructed of
stone, are founded on a body of solid masonry, capable of supporting the enormous load
of the cylinders.  Beams of wood form in some measure the sides of this pit, to which
cylinders may be made fast, by securing them with screws and bolts.  Massive bars of
cast iron are found, however, to answer still better, not only because the uprights and
bearers may be more solidly fixed to them, but because the basement of heavy metal is
more difficult to shatter or displace, an accident which happens frequently to the
wooden beams.  A rill of water is supplied by a pipe to each pair of cylinders, to
hinder them from getting hot; as also to prevent the hot iron from adhering to the
cylinder, by cooling its surface, and perhaps producing on  it a slight degree of
oxydizement.
The shafts are one foot in diameter for the hammer and the roughing rolls; and six
inches where they communicate motion to the cylinders destined to draw the iron into
bars.
The roughing rolls are employed either to work out the lump or ball immediately
after it leaves the puddling furnace, as in the Welsh forges, or only to draw out the
piece, after it has been shaped under the hammer, as is practised in most of the Staffordshire establishments.  These roughing cylinders are generally 7 feet long, including
the trunnions, or 5 feet between the bearers, and 18 inches diameter; and weigh in the
whole from 4 to 41 tons.  They contain from 5 to 7 grooves, commonly of an elliptical
form, one smaller than another in regular progression, as is seen in fig. 597. The small
axis of each ellipse, as formed by the union of the upper and under grooves, is always
placed in the vertical direction, and is equal to the great axis, or horizontal axis of the
succeeding groove; so that intransferring the bar from one groove to another, it must
receive a quarter of a revolution, whereby the iron gets elongated in every direction.
Sometimes the roughing rolls serve as preparatory cylinders, in which case they bear
towards one extremity rectangular grooves, as the figure exhibits.  Several of these
large grooves are bestudded with small asperities analogous to the teeth of files, for
biting the lump of iron, and preventing its sliding.  On a level with the under side of
the grooves of the lower cylinder, there is a plate of cast iron with notches in its edge
adapted to the grooves. This piece, called the apron, rests on iron rods, and serves to
support the balls and.bars exposed to the action of the rollers, and to receive the fragments
of ill-welded metal, which fall off during the drawing. The housing frames in which the
rollers are supported and revolve, are made of great strength.  Their height is 5 feet;
their thickness is 1 foot in the side perpendicular to the axis of the cylinders, and 10
inches in the other. Each pair of bearers is connected at their upper ends by two iron
rods, on which the workmen rest their tongs or pincers for passing the lump or bar from
one side of the cylinders to the other.
The cods or bushes are each composed of two pieces; the one of hard brass, which
presents a cylindrical notch, is framed into the other which is made of cast iron, as is
clearly seen in fig. 597.
The iron bar delivered from the square grooves, is cut by the shears into short lengths,
which are collected in a bundle in order to be welded together.  When this bundle of
bars has become hot enough in the furnace, it is conveyed to the rollers; which differ
in their arrangement according as they are meant to draw iron from a large or small
piece.  The first, fig. 597, possess both elliptical and rectangular grooves; are 1 foot
in diameter and 3 feet long between the bearers. The bar is not finished under these
cylinders, but is transferred to another pair, whose grooves have the dimensions proper
for the bar, with a round, triangular, rectangular, or fillet form.  The triangular grooves
made use of for square iron, have for their profile an isosceles triangle, slightly obtuse,
so that the space left by the two grooves together may be a rhombus, differing little
from a square, and whose smaller diagonal is vertical.  When the bar is to be passed
successively through several grooves of this kind, the larger or horizontal diagonal of
each following groove is made equal to the smaller or upright of the preceding one,
whereby the iron must be turned one fourth round at each successive draught, and thus
receive pressure in opposite directions.  Indeed, the bar is often turned in succession
through the triangular and rectangular grooves, that its fibres may be more accurately
worked together.  The decrement in the capacity of the grooves follows the proportion
of 15 to 11.
When it is intended to reduce the iron to a small rod, the cylinders have such a diam.
eter, tha.t three may be set in the same housing framime.  The lower and middle cylinders
are employed as roughing rollers, while the upper and middle ones are made to draw out
the rod.  When a rod or bar is to be drawn with a channel or gutter in its face, the
grooves of the rollers are suitably formed.




1086,                                    IRON.
To draw out square rode of a very small size, as nail-rods, a system of small rollers ia
employed, called slitters.  Their ridges are sharp-edged, and enter into the opposite
808                     grooves 21 inches deep; so that the flat bar in
vN                 passing between such rollers is instantaneously
divided into several slips.  For this purpose
the rollers represented in fig. 809 may be
<K            The                                  809
put on and removed from  the shaft at plea
sure.
The velocity of the cylinders varies with
their dimensions. In one work, cylinders for
o   drawing out iron of from one third to twc.c-j^'.1@i  Wthirds of an inch thick, make 140 revolutions
\^  Trrl[ i   _ X per minute; while those for iron of from  two
thirds of an inch to 3 inches, make only 65.
In another work, the cylinders for two inch
iron, make 95 revolutions per minute; those
for iron from  two thirds of an inch to an inch
and a third, make 128; and those for bars
from one third to two thirds of an inch, 150.
The roughing rollers move with only one third
4>     Q   the velocity of the drawing cylinders.
The shingling and plate-rolling mill is repj (I l{I) 111111111 ^ I  t resented in fig. 808.  The shingling mill, for
converting the blooms from  the balling furu  1^ IP'....    nace into bars, consists of two sets of grooved
cylinders, the first being called puddling rolls
or roughing rolls; the second are for reducing
or drawing the iron into mill-bars, and are'j     called simply rolls.
a, a, a, a, are the powerful uprights or stand.
pIT) {>                 ards called housingframes, of cast iron, in which
the gudgeons of the rolls are set to revolve;
b, b, b, b, are bolt rods for binding these frames
together at top and bottom; c, are the roughing
rolls, having each a series of triangular grooves,
such that between those of the upper and
___    u~       M'        tinder cylinder, rectangular concavities are
___^   \^^~ -      formed  in  the circumference with  slightly
sloping sides.  The end groove to the right
of c, should be channelled like a rough file, in
order to take the better hold of the blooms, or
to bite the metal, as the workmen say; and give
Ki i^    ^   it the preparatory elongation for entering into
and passing through the remaining grooves
1^11  <~ ~    1^till it comes to the square ones, where it becomes a mill-bar.  d, d, are the smooth cylinders, hardened upon the surface, or chilled
as it is called, by being cast in iron moulds,
for rolling iron into plates or hoops. e, e, e, e, are strong screws with rectangular threads,
which work by means of a wrench or key, into the nuts e' e' e' e', fixed in the standards;
they serve to regulate the height of the plummer blocks or bearers of the gudgeons, and
thereby the distance between the upper and under cylinders. f is a junction shaft; g.
g, g, are solid coupling boxes, which embrace the two separate ends of the shafts, and make
them turn together.  h, h, are junction pinions, whereby motion is communicated from the
driving shaft f, through the under pinion to V~ie upper one, and thus to both upper and
under rolls at once.  i) i) are the pinion standards in which their shafts run;' they arc
smaller than the uprights of the rolls. k, k, are screws for fastening the head pieces 1 tc
the top of the pinion standards.  All the standards are provided with sole plates m,




IRON.                                        1087
whereby they are screwed to the foundation beams n, of wood or preferably iron, as
shown by dotted lines; o o are the binding screw bolts.  Each pair of rolls at work is
kept cool by a small stream of water let down upon it from a pipe and stop-cock.
In the cylinder drawing, the workman who holds the ball in tongs, passes it into the
first of the elliptical grooves; and a second workman on the other side of the cylinders,
receives this lump, and hands it over to the first, who re-passes it between the rollers,
after bringin-g themsomewhat closer to each other, by giving a turn to the adjusting pressure screws. After the lump has passed five or six times through the same groove, it has
got an elliptical form, and is called in England a bloom. It is next passed through a
second groove of less size, which stretches the iron bar.  In this state it is subjected to
a second pair of cylinders, by which the iron is drawn into flat bars, 4 inches broad and
half an inch thick.  Fragments of the ball or bloom fall round about the cylinders;
which are afterwards added to the puddling charge. In a minute and a half, the rude lump
is transformed into bars, with a neatness and rapidity which the inexperienced eye can
hardly follow. A steam engine of thirty-horse power can rough down in a week, 200 tons
of coarse iron.
This iron, called mill-bar iron, is however of too inferior a quality to be employed in
any machinery; and it is subjected to another operation, which consists in welding
several pieces together, and working them into a mass of the desired quality. The iron
bars, while still hot, are cut by the shears into a length proportional to the size of iron
bar that is wanted; and four rows of these are usually laid over each other into a heap
or pile, which is placed in the'e-heating furnace above described, and exposed to a free
circulation of heat; one pile being set crosswise over another.  In a half or three
quarters of an hour, the iron is hot enough, and the pieces now sticking together, are
carried in successive piles to the bar-drawing cylinders, to be converted into strong bars,
which are reckoned of middle quality. When a very -uagh iron is wanted, as for anchors,
another welding and rolling must be given. In the re-heating ovens, the loss is from 8
to 10 per cent. on the large bar iron, and from 10 to 12 in smaller work. A ton of iron consumes in this process about 150 lbs. of coals.
It is thought by many that a purer iron is obtained by subjecting the balls as they
come out of the puddling furnace, to the action of the hammer at first, than to the
roughing rollers; and that by the latter process vitrified specks remain in the metal, which
the hammer expels. Hence, in some works, the balls are first worked under the forgehammer; and these stampings being afterwards heated in the form of pies or cakes piled
over each other, are passed through the roughing rollers.
Having given ample details concerning the manufacturing processes used in England
for making cast iron, it may be proper to subjoin a few observations upon its chemical
constitution. It has been generally believed and taught that the dark gray cast iron,
No. 1 or No. 2, contains more carbon than the white cast iron; and that the superior
quality of the former in tenacity and softness, is to be ascribed to that excess. But
the distinguished German metallurgist, M. Karsten, in his instructive volume, " Handbuch der Eisenhittenkunde," or manual of the art of smelting iron ores, has proved, on
the. contrary, that the white cast iron contains most charcoal; that this substance exists
in it in a state of combination with the whole body of the iron; that the foliated or lamellar white cast iron contains as much carbon as iron can absorb in the liquid state; and
that this constitutes a compound of 4 atoms of iron combined with 1 of charcoal, or 112~6;
or 5^ per cent.; whereas the dark gray cast iron contains generally from 3 to 4 per
cent., in the state of plumbago merely dispersed through the metal. He has further
confirmed his opinion, by causing the white variety to pass into the gray, and reciprocally. Thus, dark gray cast metal melted and suddenly cooled, gives a silvery white
metal, hard and brittle.  On the other hand, when the white cast iron is cooled very
slowly after fusion, the condition of the carbon in it changes, and a dark gray cast iron
is obtained.. These phenomena show that the graphite or plumbago, which requires a
high temperature for its formation, cannot be produced but by a. slow cooling, which allows the carbon to agglomerate itself in the iron in the state of graphite; while under a
rapid congelation, the carbon remains dissolved in the mass, and produces a white metal.
Hence we may understand how each successive fusion of dark gray iron hardens and whitens
it, though in contact with coke, by completing that chemical dissolution of the carbon on
which the white state depends.
In the manufacture of the blackest No. 1 cast iron, it sometimes happens that a considerable quantity of a glistening carburet of iron appears, floating on the top of the
metal as it is run out into t e sand-moulds. This substance is called kish by the
English workmen; and it affords a sure test of the good state of the furnace and quality
of the iron.
The most remarkable fact relative to the smelting of cast iron, is the difference of product between the workings of the summer and the winter season, though all the materials
and machinery be the same. In fact, no cold-blast furnace will carry so great a burder




1088                                    IRON.
in summer as in winter, that is, afford so great a product of metal, or bear so great a
charge of ore with the same quantity of. coke. This difference is undoubtedly due to the
dilated and humid state of the atmosphere in the warm season. A very competent judge
of this matter, states the diminution in summer at from one fifth to one seventh, indepen
dently of deterioration of quality.
Some of the foreign irons, particularly certain Swedish and Russian bars, are im.
ported into Great Britain in large quantities, and at prices much greater than those of
the English bars, and therefore the modes of manufacturing such excellent metal deserve
examination. All the best English cast steel, indeed, is made from the hoop L iron from
Dannemora, in Sweden.
The processes pursued in the smelting works of the Continent have frequently in view
to obtain from the ore malleable iron directly, in a pure or nearly pure state. The furnaces
used for this purpose are of two kinds, called in French, 1. Feux de Loupes, or Forges
Catalanes; and 2. Fourneaux Z piece, or Forges.llemaides.
In the Catalan, or French method, the ore previously roasted in a kiln is afterwards
strongly torrefied in the forge before the smelting begins; operations which follow in
immediate succession. Ores treated in this way should be very fusible and very rich;
such as black oxyde of iron, hematites, and certain spathose iron ores.  From  100
parts of ore, 50 of metallic iron have been procured, but the average product is 35.
The furnaces employed are rectangular hearths, figs. 811, and 811, the water-blowing
810                                811
machine being employed to give the blast.   See METALLURGY.  There are three
varieties of this forge; -the Catalan, the Navarrese, and the Biscayan. The dimensions
of the first, the one most generally employed, are as follows: 21 inches long, in the
irection p f, fig. 811; 181 broad, at the bottom of the hearth or creuset, in the line
A B; and 17 inches deep,fig. 810. The tuyere, q p, is placed 91 inches above the bottom,
so that its axis is directed towards the opposite side, about 2 inches above the bottom.
But it must be moveable, as its inclination needs to be changed, according to the stage
of the operation, or the quantity of the ores. It is often raised or lowered with pellets
of clay; and even with a graduated circle, for the workmen make a great mystery of
this matter.   The hearth is lined with a layer of brasque (loam  and charcoal dust
worked together), and the ore after being roasted is sifted; the small powder being set
aside to be used in the course of the operation. The ore is piled up on the side opposite
to the blast in a sharp saddle ridge, and it occupies one third of the furnace. In the remaining space of two thirds, the charcoal is put. To solidify the small ore on the hearth,
it is covered with moist cinders mixed with clay.
The fire is urged with moderation during the first two hours, the workman being
continually employed in pressing down more charcoal as the former supply burns
away, so as to keep the space full, and prevent the ore from crumbling down. By a
blast so tempered at the beginning, the ore gets well calcined, and partially reduced in
the way of cementation.  But after two hours, the full force of the air is given;
at which period the fusion ought to commence. It is easy to see whether the torrefaction be sufficiently advanced, by the aspect of the flame, as well as of the ore,
which becomes spongy or cavernous; and the workman now completes the fusion, by
detaching the pieces of ore from the bottom, and placing them in front of the tuyere.
When the fine siftings are afterwards thrown upon the top, they must be watered,
to prevent their being blown away, and to keep them evenly spread over the whole
surface of the light fuel. They increase the quantity of the products, and give a propel
fusibility to the scoriae. When the scorie are viscid, the quantity of siftings -must be
diminished; -but if thin, they must be increased. The excess of slag is allowed to run off
by the chio or floss hole. The process lasts from five to six hours, after which the pasty
mass is taken out, and placed under a hammer to be cut into lumps, which are afterwards
forged into bars.
Each mass presents a mixed variety of iron and steel; in proportions which may
be modified at pleasure; for by using much of the siflings, and making the tuyere dip
towards the sole of the hearth, iron is the chief product; but if the operation be coP




IRON.                                    1089
ducted slowly, with a small quantity of siftings, and an upraised tuyire, the quantity
of steel is more considerable.  This primitive process is favorably spoken of by M.
lBrongniart. The weight of the lump of metal varies from 200 to 400 pounds. As the
consumption of charcoal is very great, amounting in the Palatinate or Rheinkreis to
seven times the weight of iron obtained, though in the Pyrenees it is only thrice, the
Catalan forge can be profitably employed only where wood is exceedingly cheap and
abundant.
The Foiurneaux a piece of the French, or Stuck-ofen of the Germans, resemblesfig. 885
(CoPPER); the tuyhre (not shown there) having a dip towards the bottom of the hearth,
where the smelted matter collects.  When the operation is finished, that is, at least
once in every 24 hours, one of the sides of the hearth must be demolished, to take
out the pasty mass of iron, more or less pure. This furnace holds a middle place in the
treatment of iron, between the Catalan forge and the cast-ironfloss-ofen, or high-blast
furnaces.  The stuck-ofen are from 10 to 15 feet high, and about 3 feet in diameter at
the hearth. Most usually there is only one aperture for the tuyre and for working;
with a small one for the escape of the slag; on which account, the bellows are removed
to make way for the lifting out of the lump of metal, which is done through an opening
left on a level with the sole, temporarily closed with bricks and potters' clay, while the
furnace is in action.
This outlet being closed, and the furnace filled with charcoal, fire is kindled at the
bottom. Whenever the whole is in combustion, the roasted ore is introduced at the top
in alternate charges with charcoal, till the proper quantity has been introduced. The ore
falls down; and whenever it comes opposite to the tuyere the slag begins to flow, and the
iron drops down and collects at the bottom of the hearth into the mass or stuck; and in
proportion as this mass increases, the floss-hole for the slag and the tuyere is raised
higher. When the quantity of iron accumulated in the hearth is judged to be sufficient,
the bellows are stopped, the scorim are raked off, the little brick wall is taken down, and
the mass of iron is removed by rakes and tongs. This mass is then flattened under the
hammer, into a cake from 3 to 4 inches thick, and is cut into two lumps, which are submitted to a new operation; where it is treated in a peculiar refinery, lined with charcoal
basque, and exposed to a nearly horizontal blast. The above mass, seized in the jaws
f a powerful tongs, is heated before the tuyere; a portion of the metal flows down to the
bottom of the hearth, loses its carbon in a bath of rich slags or fused oxydes, and forms
thereby a mass of iron thoroughly refined. The portion that remains in the tongs furnishes steel, which is drawn out into bars.
This process is employed in Carniola for smelting a granular oxyde of iron. The mass
or stuck amounts to from 15 to 20 hundred weight, after each operation of 24 hours.
Eight strong men are required to lift it out, and to carry it under a large hammer, where
it is cut into pieces of about I cwt. each. These are afterwards refined and drawn into
bars as above described.  These furnaces are now almost generally abandoned on the
Continent, in favor of charcoal high or blast furnaces.
Fig. 385 represents a shachtofen (but without the tuyere, which may be supposed to be
in the usual place), and is, like all the continental Hauts Fourneaux, remarkable for the
excessive thickness of its masonry. The charge is put in at the throat, near the summit
of the octagonal or square concavity, for they are made of both forms.  At the bottom
of the hearth there is a dam-stone with its plate, for permitting the overflow of the slag,
while it confines the subjacent fluid metal; as well as a tymp-stone with its plate, which
forms the key to the front of the hearth; the boshes are a wide funnel, almost flat, to
obstruct the easy descent of the charges, whereby the smelting with charcoal would proceed too rapidly.  The bottom  of the hearth is constructed of two large stones, and
the hinute part of one great stone, called in German, rickstein (black stone), which the
French have corrupted into rustine. In other countries of the Continent, the boshes are
frequently a good deal more tapered downwards, and the hearth is larger than here represented. The refractory nature of the Hartz iron ores is the reason assigned for this
peculiarity.
In Sweden there are blast-furnaces, schachtofen, 35 feet in height, measured from the
boshes above the line of the hearth, or creuset. Their cavity has the form of an elonga
ted ellipse, whose small diameter is 8 feet across, at a height of 14 feet above the bottom
of the hearth; hence, at this part, the interior space constitutes a belly, corresponding
with the upper part of the boshes. In other respects, the details of the construction of
the Swedish furnaces resemble the one figured above. Marcher relates that a furnace of
that kind, whose height was only 30 feet, in which brown hydrate of iron (hematite) was
smelted, yielded 47 per cent. in cast-iron, at the rate of 5 hundred weight a day, or 36
hundred'weight one week after another; and that in the production of 100 pounds of
cast-iron, 130 pounds of, charcoal were consumed. That furnace was worked with forge
bellows, mounted with leather.




1090                                    IRON.
The decarburation of cast-iron is merely a restoration of the carbon to the surf ce, in
tracing inversely the same progressive steps as had carried it into the interior during the
smelting of the ore. The oxygen of the air, acting first at the surface of the cast metal,
upon the carbon which it finds there, burns it: fresh charcoal, oozing from the interior,
comes then to occupy the place of what had been dissipated; till, finally, the whole car.
bon is transferred from the centre to the surface, and is there converted into either carbonic acid gas, or oxyde of carbon; for no direct experiment has hitherto proved which
of these is the precise product of this combustion.
This diffusibility of carbon through the whole mass of iron constitutes a movement by
means of which cast-iron may be refined even without undergoing fusion, as is proved by
a multitude of phenomena.  Every workman has observed that steel loses a portion of
its steely properties every time it is heated in contact with air.
On' the above principle, cast-iron may be refined at one operation. Three kinds of iron
are susceptible of this continuous process:-1. The speckled cast-iron, which contains
such a proportion of oxygen and carbon as with the oxygen of the air and the carbon of
the fuel may produce sufficient and complete saturation, but nothing in exces.   2. The
dark gray cast-iron. 3. The white cast-iron. The nature of the crude metM riequires
variations both in the forms of the furnaces, and in the manipulations.
Indeed, malleable iron may be obtained directly from the ores by one fusion. This
mode of working is practised in the Pyrenees to a considerable extent. All the ores of
iron are not adapted for this operation. Those in which the metallic oxyde is mixed with
much earthy matter, do not answer well; but those composed of the pure black ox) 
red oxyde, and carbonate, succeed much better. To extract the metal from such ores, it
is sufficient to expose them to a high temperature, in contact either with charcoal, or
with, carbonaceous gases; the metallic oxyde is speedily reduced.  But when several
earths are present, these tend continually, during the vitrification which they suffer, to
retain in their vitreous mass the unreduced oxyde of iron. Were such earthy ores as
our ironstones, to be put into the low furnaces called Catalan, through which the charges
pass with great rapidity, and in which the contact with the fuel is merely momentary,
there would be found in the crucible or hearth merely a rich metallic glass, instead of a
lump of metal.
In smelting and refining by a continuous operation, three different stages may be distinguished: 1. The roasting of the ore to expel the sulphur, which would be less
easily separated afterwards.  The roasting dissipates likewise the water, the carbonic
acid, and any other volatile substances which the minerals may contain. 2. The deoxydizement and reduction to metal by exposure to charcoal or carbureted vapors. 3. The
melting, agglutination, and refining of the metal to fit it for the heavy hammers where
it gets nerve. There are several forges in which these three operations seem to be con
founded into a single one, because, although still successive, they are practised at one
single heating without interruption. In other forges, the processes are performed separately, or an interval elapses between each stage of the work.  Three systems of this
kind are known to exist:-1. The Corsican method; 2. The Catalan with wood charcoal; and 3. The Catalan with coke.
The furnaces of Corsica are a kind of semicircular basins, 18 inches in diameter, and
6 inches deep. These are excavated in an area, or a small elevation of masonry, 8 or 10
feet long by 5 or 6 broad, and covered in with a chimney. This area is quite similar to
that of the ordinary hearths of our blast-furnaces.
The tuyere stands 5 or 6 inches above the basin, and has a slight inclination downwards. In Corsica, and the whole portion of Italy adjoining the'Mediterranean shores,
the iron ore is an oxyde similar to the specular ore of the Isle of Elba.  This ore contains a little water, some carbonic acid, occasionally pyrites, but in small quantity. Before deoxydizing the ore, it is requisite to expel the water and carbonic acid combined
with the oxyde, as well as the sulphur of the pyrites.
The operations of roasting, reduction, fusion, and agglutination, are executed' in the
same furnace. These are indeed divided into two stages, but the one is a continuation
of the other.  In the first, the two primary operations are performed at once;-the
reduction of a portion of the roasted ore is begun at the same time that a portion of
the raw ore is roasted: these two substances are afterwards separated. In the second
stage, the deoxydizement of the metal is continued, which had begun in the preceding
stage; it is then melted and agglutinated, so as to form a ball to bs submitted to the
forge-hammer.
The roasted pieces are broken down to the size of nuts, to make the reduction of the
metal easier. In executing the first step, the basin and area of the furnace must be
lined with a brasque of charcoal dust, 3, 4, or even 5 inches thick: over this brasque a
mound is raised with lumps of charcoal, very hard, and 4 or 5 inches high.  A  semicircle is formed round the tuyere, the inner radius of which is 5 or 6 inches. This mass
of charcoal is next surrounded with another pile of the roasted and broken ores, which




IRON.                                     1091
must be covered with charcoal dust. The whole is sustained with large blocks of the
raw ore, which form externally a third wall.
These three piles of charcoal, with roasted and unroasted ore, are raised in three successive beds, each 7 inches thick: they are separated from each other by a layer of charcoal dust of about an inch, which makes the whole 24 inches high. This is afterwards
covered over with a thick coat of pounded charcoal.
The blocks of raw ore which compose the outward wall form a slope; the larger and
stronger pieces are at the bottom, and the smaller in the upper part. The large blocks
are sunk very firmly into the charcoal dust, to enable them better to resist the pressure
from within.
On the bottom of the semicircular well formed within the charcoal lumps, kindled pieces
are thrown, and over these, pieces of black charcoal; after which the blast of a waterblowing machine (trompe) is given. The fire is kept up by constantly throwing charcoal into the central well. At the beginning of the operation it is thrust down with
wooden rods, lest it should affect the building; but when the heat becomes Loo intense
for the workmen to come so near the hearth, a long iron rake is employed for the purpose. At the end of about 3 hours, the two processes of roasting and reduction are commonly finished: then the raw ore no longer exhales any fumes, and the roasted ore, being
softened, unites into lumps more or less coherent.
The workman now removes the blocks of roasted ore which form the outer casing,
rolls them to the spot where they are to be broken into small pieces, and pulls down the
brasque (small charcoal) which surrounds the mass of reduced ore.
The second operation is executed by cleaning the basin, removing the slags, covering
the basin anew with 2 or 3 brasques (coats of pounded charcoal), and piling up to the
right and the left, two heaps of charcoal dust. Into the interval between these conical
piles two or three baskets of charcoal are cast, and on its top some cakes of the reduced
crude metal being laid, the blast is resumed. The cakes, as they heat, undergo a sort
of liquation, or sweating, by the action of the earthy glasses on the unreduced black
oxyde present. Very fusible slags flow down through the mass; and the iron, reduced
and melted, passes finally through the coals, and falls into the slag basin below. To the
first parcel of cakes, others are added in succession. In proportion as the slags proceeding from these run down, and the melted iron falls to the bottom, the thin slag is run
off by an upper overflow or chio hole, and the reduced iron kept by the heat in the pasty
condition, remins in the basin: all its parts get agglutinated, forming a soft mass, which
is removed by means of a hooked pole in order to be forged. Each lump or bloom of
malleable iron requires 3 hours and a half for its production.
The iron obtained by this process is in general soft, very malleable, and but little
steely. In Corsica four workmen are employed at one forge. The produce of their
labor is only about 4 cwts. of iron from 10 cwts. of ore and 20 of charcoal, mingled
with wood of beech and chestnut. Though their ore contains on an average 65 per cent.
of iron, only about 40 parts are extracted; evincing a prodigious waste, which remains
in the slags.
The difference between the Corsican and the Catalonian methods consists in the latter
roasting the ore at a distinct operation, and employing a second one in the reduction,
agglutination, and refining of the metal. In the Catalonian forges, 100 pounds of iron
are obtained from 300 pounds of ore and 310 pounds of charcoal; being a produce of
only 33 per cent. It may be concluded that there is a notable loss, since the sparry iron
ores, which are those principally smelted, contain on an average from 54 to 56 per cent.
of iron. The same ores, smelted in the ordinary blast furnace, produce about 45 per cent,
of cast iron.
On the Continent, iron is frequently refined from the cast metal of the blast furnaces by three operations, in three different ways.  In one, the pig being melted,
with aspersion of water, a cake is obtained, which is again melted in order to form
a second cake. This being treated in the refinery fire, is then worked into a bloom. In
another system, the pig iron is melted and cast into plates: these are melted anew in
order to obtain crude balls, which are finally worked into blooms. In a third mode of
manufacture, the pig-ironis melted and cast into plates, which are roasted, and then strongly
heated, to form a bloom.
The French fusible ores, such as the silicates of iron, are very apt to smelt into white
cast iron. An excess of fluxes, light charcoals, too strong a blast, produce the same results.
A surcharge of ores which deranges the furnace and affords impure slags mixed with
much iron, too rapid a slope in the boshes, too low a degree of heat, and too great condensation of the materials in the upper part of the furnace; all tend also to produce a
white cast iron. In its state of perfection, white cast iron has a silver color, and a
bright metallic lustre. It is employed frequently in Germany for the manufacture of
steel, and is then called steel floss, or lamellar floss, a title which it still retains, though it
be hardly silver white, and have ceased to be foliated. When its color takes a bluish



1092                                   IRON.
gray tinge, and its fracture appears striated or splintery, or when it exhibits gray spots
it is then styled flower floss. In a third species of white cast iron we observe still much
lustre, but its color verges upon gray, and its texture is variable. Its fracture has been
sometimes compared to that of a broken cheese. This variety occurs very frequently.
It is a white cast iron, made by a surcharge of ore in the furnace. If the white color
becomes less clear and turns bluish, if its fracture be contorted, and cohtains a great many
empty spaces or air-cells, the metal takes the name of cavernous-floss, or tender-floss. The
whitest metal cannot be employed for casting. When the white is mixed with the gray
cast iron, it becomes riband or trout cast iron.
The German refining forge.-Figs. 812, 813 represent one of the numerous refinery
813
furnaces so common in the Hartz. The example is taken from the Mandelholz works,
in the neighborhood of Elbingerode. Fig. 813 is an elevation of this forge. Dis the
refinery hearth, provided with two pairs of bellows.  Fig. 812 is a vertical section,
showing particularly the construction of the crucible or hearth in the refinery forge D.
c is an overshot water wheel, which gives an alternate impulsion to the two bellows a b
by means of the revolving shaft e, and the cams or tappets df e g.
D, the hearth, is lined with cast iron plates. Through the pipe 1, cold water may be
introduced, under the bottom plate m, in order to keep down, when necessary, the temperature of the crucible, and facilitate the solidification of the loupe or bloom. An orifice
TO, figs. 812, 813, called the chio (floss hole), allows the melted slag or cinder to flow
off from the surface of the melted metal. The copper pipe or nose piece p, fig. 811,
conducts the blast of both bellows into the hearth, as shown at b x, fig. 813, and D g p,
fig. 811.
The substance subjected to this mode of refinery, is a gray carbonaceous cast iron,
from the works of Rothehutte. The hearth D, being filled and heaped over with live
charcoal, upon the side opposite to the tuyere x, figs. 812, 813, long pigs of cast iron are
laid with their ends sloping downwards, and are drawn forwards successively into the
hearth by a hooked poker, so that the extremity of each may be plunged into the middle of
the fire, at a distance of 6 or 8 inches from the mouth of the tuyere. The workman proceeds in this way, till he has melted enough of metal to form a loupe. The cast iron, on
melting, falls down in drops to the bottom of the hearth; being covered by the fused slags,
or vitreous matters more or less loaded with oxyde of iron. After running them off by
the orifice n, he then works the cast iron by powerful stirring with an iron rake (ringard),
till it is converted into a mass of a pasty consistence.
During this operation, a portion of the carbon contained in the cast iron combines
with the atmospherical oxygen supplied by the bellows, and passes off in the form of
carbonic oxyde and carbonic acid. When the lump is coagulated sufficiently, the workman
turns it over in the hearth, then increases the heat so as to melt it afresh, meanwhile
exposing it all round to the blast, in order to consume the remainder of the carbon, that
is, till the iron has become ductile, or refined. If one fusion should prove inadequate to
this effect, two are given.  Before the conclusion, the workman runs off a second
stratum of vitreous slag, but at a higher level, so that some of it may remain upon the
metal.
The weight of such a loupe or bloom is about 2 cwts., being the product of 2 cwts. and
f  of pig iron; the loss of weight is therefore about 26 per cent.  149 pounds of charcoal
are consumed for every 100 pounds of bar iron obtained. The whole operation lasts
about 5 hours. The bellows are stopped as soon as the bloom is ready; this is immediately transferred to a forge hammer, such as is represented fig. 816; the cast iron head
of which weighs 8 o0 9 cwts. The bloom is greatly condensed thereby, and discharges
a considerable quantity of semi-fluid cinder. The lump is then divided by the hammer




IRON.                                     1093
anna a chisel into 4 or 6 pieces, which are reheated, one after another, in the same refinery
fire, in order to be forged into bars, while another pig of cast iron is laid in its place, to
prepare for the formation of a new bloom. The above process is called by the Germans
klump-frischen, or lump-refining. It differs from the durch-brech-frischen, because in the
latter, the lump is not turned over in mass, but is broken, and exposed in separate pieces
successively to the refining power of the blast near the tuyere. The French callthis afinage par portions; it is much lighter work than the other.
The quality of the iron is tried in various ways; as first, by raising a bar by one end
with the two hands over one's head, and bringing it forcibly down to strike across a narrow anvil at its centre of percussion, or one third from the other extremity of the bar; after
which it may be bent backwards and forwards at the place of percussion several times;
2. a heavy bar may be laid obliquely over props near its end, and struck strongly with a
hammer with a narrow pane, so as to curve it in opposite directions; or while heated
to redness, they may be kneed backwards and forwards at the same spot, on the edge of
the anvil. This is a severe trial, which the hoop L, Swedish iron, bears surprisingly,
emitting as it is hammered, a phosphoric odor, peculiar to it and to the bar irn of
Ulverstone, which also resembles it, in furnishing a good steel. The forging of a horseshoe is reckoned a good criterion of the quality of iron. Its freedom  from flaws is
detected by the above modes; and its linear strength may be determined by suspending
a scale to the lower end of a hard-drawn wire, of a given size, and adding weights till
the wire breaks. The treatises of Barlow and Tredgold may be consulted with advantage on the methods of proving the strength of different kinds of iron, in a great variety
of circumstances.
Steel of cementation, or blistered steel and cast steel, are treated under the article STEEL.
But since in the conversion of cast iron into wrought iron, by a very slight difference in
the manipulations, a species of steel may be produced called natural steel, I shall describe
this process here.
Fig. 814 is a view of the celebrated steel iron works, called K6nigshuiitte, (king's-forge),
in Upper Silesia, being one of the best arranged in Germany, for smelting iron ore by
means of coke. The front shown here is about 400 English feet long. a a are two blast
furnaces. A third blast furnace, all like the English, is situated to the left of one of the
towers fb. b b are the charging towers, into which the ore is raised by machinery from
the level of the store-houses I 1, up to the mouth of the furnaces a a; c c point to the
positions of the boilers of the two steam engines, which drive two cylinder bellows at f.
n n n n are arched cellars placed below the store-houses 11, for containing materials and
tools necessary for the establishment.
Figs. 810, 815, are vertical sections of the forge of Konigshiitte, for making natural
steel; fig. 810 being drawn in the line A B of
_815         the plan, fig. 811. a is the bottom of the hearth,
consisting of a fire-proof gritstone; b is a space
filled with small charcoal, damped with  water,
~- i  _l - D I under which, at a, in fig. 815, is a bed of well
I II1~1 I           rammed clay; d is a plate of cast iron, which lines
the side of the hearth called ruckstein (backstone)
in German, and  corrupted by the French  into
rustine; f is the plate of the counter-blast; g the
plate of the side of the tuyere; behind, upon the
face d, the fire-place or hearth is only 5j inches deep; in front as well as upon the
lateral faces, it is 18 inches deep. By means of a mound made of dry charcoal, the posterior face d is raised to the height of the face f. i, fig. 811, is the floss-hole, by which
the slags are run off from the hearth during the working, and through which, by removing
some bricks, the lump of steel is taken out when finished.
k I m are pieces of cast iron, for confining the fire in front, that is, towards the side where
the workman stands; o is the level of the floor of the works; p a copper tuyere; it is
situated 41 inches above the bottom a, slopes 5 degrees towards it, and advances 4 inches
into the hearth or fire-place, where it presents an orifice, one half inch in horizontal
length, and one inch up and down; q the nose pipes of two bellows, like those represented




1094                                 JIIRON.
infig. 813, and under SILVER; the round orifice of each of them within the tuydre being
one inch in diameter. r is the lintel or top arch of the tuyere, beneath which is seen the
cross section of the pig of cast iron under operation.
For the production of natural steel, a white cast iron is preferred, which contains little
carbon, which does not flow thin, and which being cemented over or above te wind falls
down at once through the blast to the bottom of the hearth in the state of steel. With
this view, a very flat fire is used; and should the metal run too fluid, some malleable
lumps are introduced to give the mass a thicker pasty consistence.
If the natural steel be supposed to contain too little carbon, which is   very rare case,
the metal bath covered with its cinder slag, is diligently stirred with a wonden pole, or it
may receive a little of the more highly carbureted iron. If it contains the right dose of
carbon, the earthy and other foreign matters are made progressively to sweat out into the
supernatant slag. When the mass is found by the trial of a sample to be completely converted, and has acquired the requisite stiffness, it is lifted out of the furnace, by the opening in front, subjected to the forge hammer, and drawn into bars. In Sweden, the cast
iron pigs are heated to a cherry-red, and in this state broken to pieces under the hammer
before they are exposed in the steel furnace. These natural steels are much employed on
the Continent in making agricultural implements, on account of their cheapness. The
natural steel of Styria is regarded as a very good article.
Wootz is a natural steel prepared from a black ore of iron in Hindostan, by a process
analogous to that of the Catalan hearth, but still simpler. It seems to contain a minute
portion of the combustible bases of alumina and silica, to which its peculiar hardness
when tempered may possibly be ascribed. It is remarkable for the property of assuming
a damask surface, by the action of dilute sulphuric acid, after it has been forged and
polished. See DAMASCUS and STEEL.
Fig. 816 is the German forge-hammer; to the left of 1, is the axis of the rotatory
cam, 2, 3, consisting of 8 sides,."'..................  each formed of a strong broad bar
816  /'            \         of cast iron, which are joined together to make the octagon wheel.
4, 5, 6, are cast iron binding rings
z,l ^  ^^"^            or hoops, made fast by wooden
wedges. b, b, are standards of the
1^816    6                    frame-work e, 1, m, in which the
helve of the forge-hammer has its
/'                         I ^fulcrum  near u. h, the sole part
of the frame.  Another cast iron
]    "7   ~      z       base or sole is seen at m. n is a
/^^i-^ 1./        strong  stay, to  strengthen  the
In[.QJX^,^^    ^^^           frame-work.  At r two parallel
hammers are placed, with  castiron heads and wooden helves. s is the anvil, a very massive piece of cast iron. t is the
end of a vibrating beam, for throwing back the hammer from it forcibly by recoil. x y is
the outline of the water-wheel which drives the whole. The cams or tappets are shown
mounted upon the wheel 6, g, 6.
Analysis of irons.-Oxydized substances cannot exist in metallic iron, and the foreign
substances it does contain are present in such small quantities, that it is somewhat
difficult to determine their amount.  The most intricate point is, the proportion of
carbon. The free carbon, which is present only in gray cast iron, may, indeed, be determined nearly, for most of it remains after solution of the metal in acids. The combined
charcoal, however, changes by the action of muriatic acid into gas and oil; sulphuric acid
also occasions a great loss of carbon, and nitric acid dissipates it almost entirely. Either
nitre or chloride of silver may be employed to ascertain the amount of carbon; but when
the iron contains chromium and much phosphorus, the determination of the carbon is attended with many difficulties.
The quantity of sulphur is always so small, that it can scarcely be ascertained by the
weight of the precipitate of sulphate of barytes from the solution of the iron in nitromurnatic acid. The iron should be dissolved in muriatic acid; and the hydrogen, as it
escapes charged with the sulphur, should be passed through an acidulous solution of
acetate of lead. The weight of the precipitated sulphuret shows the amount of sulphur,
allowing 13-45 of the latter for 100 of the former. In this experiment the metal should
be slowly acted upon by the acid. Cast iron takes from 10 to 15 days to dissolve, steel
from 8 to 10, and malleable iron 4 days. The residuum of a black color does not contain
a trace of sulphur.
Phosphorus and chromium  are determined in the following way. The iron must be
dissolved in nitro-muriatic acid, to oxygenate those two bodies. The solution must be
evaporated cautiously to dryness in porcelain capsules, and the saline residuum heated




IRON.                                    1095
to redness. A little chloride of iron is volatilized, and the remainder resembles the
red-brown oxyde. This must be mixed with thrice its weight of carbonate of potash,
and fused in a platinum crucible; the quantity of iron being from 40 to 50 grains at
most.
The mixture, after being acted upon by boiling water, is to be left to settle, to allow
the oxyde to be deposited, for it is so fine as to pass through a filter. If the iron contained manganese, this would be found at first in the alkaline solution; but manganese spontaneously separates by exposure to the air. The alkaline liquor must be
supersaturated with muriatic acid, and evaporated to dryness. The liquor acidulated,
and deprived of its silica by filtration, is to be supersaturated with ammonia; when
the alumina will precipitate in the state of a subphosphate. When the liquor is now
supersaturated with acetic acid, and then treated with acetate of lead, a precipitate
of phosphate of lead almost always falls. There is hardly a bit of iron to be found
which does not contain phosphorus. The slightest trace of chrome is detected by the
yellow color of the lead precipitate; if this be white there is none of the coloring metal
present.
100 parts of the precipitated phosphate of lead contain, after calcination, 19'4 parts of
phosphoric acid. The precipitate should be previously washed with acetic acid, and then
with water. These 19'4 parts contain 8'525 parts of phosphorus.
Cast iron sometimes contains calcium  and barium, which may be detected by their
well-known reagents, oxalate of ammonia. and sulphuric acid. In malleable iron they.are seldom or never present.
The charcoal found in the residuum of the nitro-muriatic solution is to be burned away
under -a muffle. The solution itself contains along with the oxyde of iron, protoxyde of
manganese, and other oxydes, as well as the earths, and the phosphoric and arsenic acids.
Tartaric acid is to be added to it, till no precipitate be formed by supersaturation with
caustic ammonia. The ammoniacal liquor must be treated with hydrosulphuret of ammonia as lon  as i is clouded, then thrown upon a filter. The precipitate is usually very
voluminous, and must be well washed. The liquor which passes through is to be saturated with muriatic acid, to decompose all the sulphurets.
The solution still contains all the earths and the oxyde of titanium, besides the phosphoric acid. It is to be evaporated to dryness, whereby the ammonia is expelled, and
the carbonaceous residuum must be burned under a muffle. If the iron contains much
phosphorus, the ashes are strongly agglutinated.   They are to be fused as already
described along with carbonate of potash, and the mass is to be treated with boiling
water. The residuum may be examined for silica, lime, barytes, and oxyde of titanium.
Muriatic acid being digested on it, then evaporated to dryness, and -the residuum treated
with water, will leave the silica. Caustic ammonia, poured into the solution, will separate the alumina, if any be present, and the oxyde of titanium; but the former almost
never occurs.
Manganese is best sought for by a distinct operation. The iron must be dissolved
at the heat of boiling water, in nitro-muriatic acid; and the solution, when very
cold, is to be treated with small successive doses of solution of carbonate of ammonia. If the iron has been oxydized to a maximum, and if the liquor has been
sufficiently acid, and diluted with water, it will retain the whole of the manganese.
This process is as good as that by succinate of ammonia, which requires many
precautions.
The liquor is often tinged yellow by carbon, after it has ceased to contain a single trace
of iron oxyde. As soon as litmus paper begins to be blued by carbonate of ammonia, we
should stop adding it; immediately throw the whole upon a filter, and wash continuously
with cold water. What passes through is to be neutralized with muriatic acid, and concentrated by evaporation. It may contain, besides manganese, some lime or barytes. It
should therefore be precipitated with hydro-sulphuret of ammonia, the hydrosulphuret of
manganese should be collected, dissolved in strong muriatic acid, filtered, and treated, at
a boiling heat, with carbonate of potash. The precipitate, well washed and calcined,
contains, in 100 parts, 72-75 parts of metallic manganese.
The copper, arsenic, lead, tin, bismuth, antimony, or silver, are best separated by a
stream of sulphureted hydrogen gas passed through the solution in nitro-muriatic acid,
after it is largely diluted with water. The precipitate must be cautiously roasted in a
porcelain test, to burn away the large quantity of sulphur which is deposited in consequence of the conversion of the peroxyde of iron into the protoxyde. If nothing
remains upon the test, none of these metals is present. If a residuum be obtained, it
must be dissolved in nitro-muriatic acid, and subjected to examination. But, in fact,
carbon, sulphur, phosphorus, silicon, and manganese, are the chief contaminators of
iron.
Chloride of silver affords the means of determining the proportion of carbon contained
in iron and of ascertaining the state in which that substance exists in the metal. Fused




1096                                 IRON.
chloride of a pale yellow  color must be employed. The operation is to be performed
in close vessels, with the addition of a great deal of water, and a few drops of muriatic
acid.  The carbonaceous residuum  is occasionally slightly acted upon.   We may
judge of this circumstance by the gases disengaged, as well as by the appearance of the
charcoal.
Ductile iron and soft steel, as well as white cast-iron which has been rendered gray
bv roasting, when decomposed by chloride of silver, afford a blackish-brown unmagnetic
charcoal, and a plumbaginous substance perfectly similar to what is extracted from the
same kinds of iron, by solution in acids. A portion of this plumbago is also converted
into charcoal of a blackish brown color, by the action of the chloride. Hence this
agent does not afford the means of obtaining what has been called the poly-carburet, till
it has produced a previous decomposition. But we obtain it, in this manner, purer and in
greater quantity than we could by dissolving the metal in the acids. The only subject
of regret is, that we possess no good criterion for judging of the progress of this analytical
operation.
Gray cast iron leaves, besides the poly-carburet, a residuum of plumbago, and carbon
which was not chemically combined with the iron; while tempered steel and white cast
iron afford merely a blackish brown charcoal; but the operation is extremely slow with
the latter two bodies, because a layer of charcoal forms upon the surface, which obstructs their oxydizement. For this reason the white cast iron ought to be previously
changed into gray by fusion in a crucible lined with charcoal, before being subjected to the
chloride of silver; if this process be emrloyed for tempered steel, the combined carbon
becomes merely a poly-carburet. It would not be possible to operate upon more than
15 grains, which require from 60 to 80 times that quantty of the chloride, and a period
of 15 days for the experiment.
The residuum, which is separable from the silver only by mechanical means, should be
dried a long time at the heat of boiling water. It contains almost always iron and silica.
After its weight is ascertained, it is to be burned in a crucible of platinum till the ashes
no longer change their color, and are not attractable by the magnet. The difference be.
tween the weights of the dried and calcined residuum is the weight of the charcoal. The
oxyde of iron is afterwards separated from the silica by muriatic acid.
In operating upon gray cast iron, we should ascertain separately the proportion of
graphite or plumbago, and that of the combined charcoal. To determine the former,
we dissolve a second quantity of the cast iron in nitric acid, with a little muriatic; the
residuum, which is graphite, is separated from the silica and the combined carbon by the
action of caustic potash. After being washed and dried, it must be weighed. The weight
of the graphite obtained being deducted from the quantity of carbon resulting from the decomposition elfected by the chloride of silver, the remainder is the amount of the chenic^1y combined carbon.
By employing muriatic acid, we could dissipate at once the combined carbon; but thi
method would be inexact, because the hydrogen disengaged would carry off a portion of
the graphite.
According to Karsten, Mushetvs table of the quantities of carbon contained in different
steels and cast irons is altogether erroneous. It gives no explanation why, with equal
proportions of charcoal, cast iron constitutes at one time a gray, soft, granular metal, and
at another, a white, hard, brittle metal in lamellar facets. The incorrectness of Mushet's
statement becomes most manifest when we see the white lamellar cast iron melted in a
crucible lined with charcoal, take no increase of weight, while the gray cast iron treated
in the same way becomes considerably heavier.
Analysis has never detected a trace of carbon unaltered or of graphite in white cast iron,
if it did not proceed from small quantities of the gray mixed with it; while perfect gray
cast iron affords always a much smaller quantity of carbon altered by combination, and a
much greater quantity of graphite. Neither kind of cast iron, however, betrays the presence of any oxygen. Steel affords merely altered carbon, without graphite; the same
thing holds true of malleable iron; while the iron obtained by fusion with 25 per cent. of
scales of iron contains no carbon at all.
The graphite of cast iron is obtained in scales of a metallic aspect, whereas the combined carbon is obtained in a fine powder. When the white cast iron has been roasted,
and become gray, and is as malleable as the softest gray cast iron, it still affords no graphite as the latter does, though in appearance both are alike. Yet in their properties
they are still essentially dissimilar.
With 41 per cent. of carbon, the white cast iron preserves its lamellar texture; but
with less carbon, it becomes granular and of a gray color, growing paler as the dose
of carbon is diminished, while the metal, after passing through an indefinite number
of gradations, becomes steely cast iron, very hard steel, soft steel, and steely wrought
iron.
The steels of the forge and the cast steels examined by Karsten, afforded him from




IRON.                                      1097
^2* to 1-1 per cent. of carbon; in the steel of cementation (blistered steel), he never
found above l1 of carbon.  Some wrought irons which ought to contain no charcoal hold
per cent. and they then approach to steel in nature.  The softest and purest
Tons contain still 0-2 per cent. of carbon.
The quantity of graphite which gray cast-iron contains, varies, according to Karstens
experiments, from 2-57 to 3-75 per cent.; but it contains, besides, some carbon in a state
of alteration. The total contents in carbon varied from 3-15 to 4-65 per cent. When
the congelation of melted iron is very slow, the carbon separates, probably in consequence of its crystallizing force, so as to form a gray cast-iron replete with plumbago.
If the gray do not contain more charcoal than the white from which it has been formed,
and if it contain the charcoal in the state of mechanical mixture, then it can have little
or none in a state of combination, even much less than what some steels contain. Hence
we can account for some of its peculiarities in reference to white cast-iron; such as its
granular texture, its moderate hardness, the length of time it requires to receive annealing colors, the modifications it experiences by contact of air at elevated temperatuies, the
high degree of heat requisite to fuse it, its liquidity, and finally its tendency to rust by
porosity, much faster than the white cast-iron.
We thus see that carbon may combine with iron in several masters; that the gray
cast-iron is a mixture of steely iron and plumbago; that the white, rendered gray and soft
by roasting is a compound of steely iron and a carburet of iron, in which the carbon predominates;' and that untempered steel is in the same predicament.
For the following analyses of cast-irons, we are indebted to MM. Gay Lussac and
Wilson.
TABLE.-In 100 parts.
Cast-iron.         Iron.  Carbon. Silica.  Phos-  Maga         Remarks.
White cast from Siegen  94-338  2-690  0.230  0-162  2-590  By wood charcoal.
Do.        Coblentz  -  94-654  2-441  0-230  0-185  2-490                do.
Do.        a. d. Champ  96-133  2-324  0-840  0-703 a trace               do.
Do.        Isire   -  -  94-687  2-636  0-260  0-280  2-137               do.
Gray       Nivernais -  95-673  2-254  1-030  1-043 a trace               do.
Do.        Berry  -  -  95-573  2-319  1-920  0-188   do.  Mixt'e of coke & do.
Do.        a. d. Champ  95-971  2-100  1-060  0-869   do.              Charcoal.
Do.        Creusot   -  93-385  2-021  3-490  0-604   do.                Coke.
Do.        a. d. Franche
Comt6  -  95-689  2-800  1-160  0-351   do.                  do.
Do.        Wales -  -  94-842  1-666  3-000  0-492   do.                   do.
Do.        Do. ---  95-310  2-550  1-200  0-440    do.                    do.
Do.        Do. -          95-150  2-450  1-620  0-780   do.                do.
Karsten has given the following results as to carbon, in 100 parts of gray cast-iron.
Combined    Free     Total.
Gray cast-iron.          carbon.   carbon.   carbon.         Remarks.
Siegen, from brown iron stone  -    0-89       3-71      4-60    By wood charcoal.
Siegen (Widderstein), from brown
and sparry iron -      -         1-03      3-62      4-65             do.
Malapane, from spherosiderite  -   0-75        3-15      8-90             do.
Konigshiitte, from brown ore   -    0-58       2-57      3-15            coke.
Do. at a lower smelting heat -  -    0-95      2-70      3-65             do.
IRON, Cast, Strength of.-In the following Table each bar is reduced to exactly
one square inch; and the transverse strength, which may be taken as a criterion of
the value of each iron, is obtained from  a mean between the experiments upon it,
(Memoirs of Brit. Ass.) first on bars 4 ft. 6 in. between the supports, and next on
those of half the length, or 2 ft. 3 in. between the supports.  All the other results
are deduced from the 4 ft. 6 in. bars. In all cases the weights were laid on the middle
of the bar.




1098                                                       IRON.
Table of Results obtained from Experiments on the Strength and other Properties of
Cast Iron, from the principal Iron Works in the United Kingdom. By Mr. Win.
Fairbairn.'!~ ~i                         ii i        ~  ~ ~.a...0.....      ~ so     ~i   ~
a0~~~~~~
f —~~~~~~~~~~~~~~~I                                               -               --
D e Namoes of Irons                                - 71.51 {47l..[              1    -1     Color.        Quality.
3  Oldberry, No. 3. Hot Blast   - -'7300 ~227334001 543  I517   ]  i01 1-005 ]549 White  - -  Hard.
4Carton, No. 3. Hot Blast* -    -        27'0,'6 1178731001 620  [534    527[ 1'365 [710 WVhitish gray  Hard.
5   Beaufort, No. 3. Hot Blast - - -       57'069 J1680-2000J 506    529   J5171 1'599  807 Bullish gray   Hard.
6 Butterley.........                   4'7038 ~15379500[ 489   515   502I 1-815  889 ]Dark gray -  S~oft.
7Bute, No. 1. Cold Blast.   -.  4  7'066 ]1516.30001 495  ]487   [491 1-764  872 Bluish gray ~ ISoft.
8  Wind Mill End, No. 2. Cold Blast       4  7-071 {16490000i 48.3    495   [489  -'581  765 Dark giay - IHard.
9g  Old Park, No. 2. Cold Blast  -         5'7049 I14607000~ 441  [529   [48.5 -'621  718 Gray - - - ~Soft.
10 Beaufort, No. 2. Hot Blast   - -      4'7108 16.3010001 478  ]470   [474[ -612 I7~29;Dull gray  -  [Hard.
12 Bufbry, No. 1. Cold Blast*..     5'-7  15381200 463 ~8[ 463'             I a -5          - -.Rather hRd
~~   4..:.eo~~~~bo.  M M 
0                            ii                                   a ~~~~~~~~~~~~~~~~~00
1  Ponkey, No. 2. Cold Blast   -      -        70122 17214911000666  466    453    45981 1-748  92815 WLighti  gray  Hard.
Apedaleo, No. 32. Hot Blast    -        2  7-017 14852004750 45.37       4 55   4  730 79 1 Light gr ayrd-.Stif
3   Oldberry, No. 3. Hot Blast             5  7-300 22733400 543       517    4530 1-85  549 Whie e      -   RHard.
4  Carroyn, No. 3. Hot Blast      -           7-056 17873100 5         534     527 1'3484  650 WBluhish gray  Hard.
5   Beaufort, No. 3. Hot Blast..          5  7069 1680200 505        529      517 1599  8071 ullisar gray   Hard.
6   ButMaesterleyNo. 2.  - - - - - -         7038 1395379500 489      515    4540 1957  889 Dark gray -  Rather s.
7   BMuirkirkte,  No. 1. Cold Blast  - -    4  706113 114035000 44953    487   4911'764  8 772 Bluright gray    SoFluid.
8  Wiad  Mll Endpi, No. 2. Cold Blast   -  - 4  7'071 164 00 441 3    45     449 1-7591  777L Darght gray  HardSoft.
9  Old Parknia, No. 3. Cold Blast          5  704159 148146600  43    464    4485 1-2621  74718Bright gray    Hard.  Soft.
10  BDevonrt, No. 3. Cold  Blast           4  7-1285 229077000  448    470      448 1-70  753 Light gray      Hard.
11   owarts Mooerrie, No. 3. Hotld Blast -  4  7051  13894000 462    4673    4472 1557  851D998arLight gray -  Soft.
12   Bfl~ery, No. 1. Cold Blaut*           5  7-079 15.381209  463    -        46.3 1,55   721 Gray...  Rallier hard.
13   Froodimbo, No. 2. Cold Blast.-. -   5  7031 134911666 460       4.534    44759 1'8745  841 jLight gray -Rather hard.
124  Lane  Endale, No. 2. Hot Blast - -    3  70178 1405       457    455      4456   730  791 29LightDark gray -  Soft.
25  OldCaerroy, No. 3. Cold Blast -   -        7094 59 14307500966 463  437    44355 181336  822 Dark gray -  - -  RaS er oft.
26  Pentwyn, No. 2. C    B                 4  7-038 10513000 438    473         4551 1464  650Bluiuls gray    Hard.
17  Maesteg, (Marked Red)2.                5  7.038 13971500 440 3    44455     454 1'95887  830 Bluishark gray  RalFluid.
18  Miorbynkirk Hall, No. 1 2. Cold Bl-.  4  7-1 13 18458660 44.3    454      4453 1'68734  77027 Brigligray - - -  Soft.
19  AdePontypoolphi, No. 2. Cold Blast     5  7080 131536500 439 44   1 457     449 1759  777816 Duit blue  - g Ra ther So.
20   Ballaarook, No. 3. Cold Blt -         5  7159 14281466 43.3    464    448 14726  7473 625Light gray-  HRard.
31  DevMilton, No. 3. Hotld Blast*         4  7-28051 158.72500 47 4    498  -  438  1368 790  7585 G ray - -  Rather hd.
22   GartBufferrie, No. 1. Hot Blast  -   5      98 1373894000 47.36  467      44367 1-654 7 21 Dullt gray -  Soft.
23   FrooLevel, No. 1. Hotld Blast...   5  7031 154531125006 460    4034    447-32 18516  8469 Light gray -  Open.
24  Pane Et d, N o. 23782.1 -          -78 72 1578             444 -            4144 14251  9511L D tark gray  -  SoRather.
325   CarrLevelon, No. 3. Hotld Blast. -   5  7031 15624 1000       419  43     42943 1.3583  570 Dull gray    -.    Soft.
26      S.S.Dandivan, No. 3. Cold Blast.- -  4  7041 1465.33  4136   4.30    446 3429 14339  674 D54Light gray  -   S oft.
37  Ea gle Fou(Mary, Noed. 2. Hot Blast    5  7038 13971100  408    446         442  1-87512  6183 Bluish gray    Soft.
38   ElCoryns Hall, No. 2. Cold Blast - - -  5  7007 13845     43046    40854   447 1 2-6724  7 992 Gray..-   Soft.
29  VarPontypooleg, No. 2. Hot Blast  - -  5  700 1313        4       4        4   150        Dull blue      Rather soft.
30  Wallbrookam, No. 1. Hot Blast -        5  67128 15394510066 432 4 49 385    4240 144532  71625 LWhitish gray  Rather hard.
41  MiCarrollton, No. 3. Hotd Blast  - -   4  701 15570362500 427    449       43819 1-3168  5085 Gray  - -   Rather hard.
32   Muirkirk, No. 1. Hot Blast*               6-9.8 1373(5294400 43176  -     4319   418   721 Dullush gray  Soft.
33   Bierel, No. 1. Hot Blast                        1 5  7080  1 615 33   404 3 4 32 2418 1-222  494 LighDark gray.  Soft.
44  Coed-Ta lon, No.   2.   Hot Blast -        6975 14322500  409 8    455     4316 1288 1  771 Bright gray   RaSofter hard.
35  LCoed-Talon, No. 2. Co ld B last       6  70315 152430400 408 419 439       429 1358 1 5470 D 600   gray -  - -  SoRatler s.
36  W. S. S., No. L. —       --- 5  7,041 14 95333.3 413   446      429 1P339  5.54 Light gray.Soft.
37  EMonklae Foundry, N o. 2. Hot Blast -      7 03896 1421159000 408    404    40327 1-76512  617098 Bluish gray    Soft.
3847  Ley's Wor ks, No.   1. Hotld Blast.  4  69578 11539.3500 443             392  18   90  742Bluish gray   Soft.
39  Varteg, No.-2. Hot Blast.            4  7,007 1301201 422        430      426 1-4.50  621 Gray...Hard.
40   Coltbamn, No. 1iHot Blast.         5  7,108 1551   2464        385     424 25.32  716 Whitish gray  Rather soft.
48  Miltonll, No. 1. Hotld Blast  - - -    4    976 11974500 430       408     419 1-5231  5380 Gray - -.  Soft and.
49  MPlaskynirkton, No. 2. Hot Blast       -  4  6916 13324400 416 7   419     418 1570  656 Bluish gray    Rather Soft.
4 u BierleyTo find from        the  above  table the  breaking weight in  rectangul44 Dark gray             Soft.
rally, calling b and d the  breadth  and  depth  in  inches, and l lhe  distance betwee:  h
supp44  Coed-Talon, No. feet2. and   putting   4'       3225 for 409    424 ft.  416 i n.,   771 Bright gray    Soft.bre
I4.5  Coed-Talon, No. 2. Cold Blast*        5  60055 14304(   408       418     413 1-470.600 Gray._ -     Rallier soft.
46  Monkland, No. 2. Hot Blast -           3  6-916 122-58900 402      404     403 1-702  709 Bloish gray    Soft.
147  ILey's Works, No. 1. Hot Blast         3  6%. 7 1 1539C.3.31 3.q   -       392 1-890  340 Bluish gray    Soft.
48Milton, Na. 1. Hot Blast  - -          4  6-976 119745001 353      386     369 15025  ft3 Gray - -     Soil and fluid.
49  Plaokyniston, Nii. 0. Hot HIast.      5  6-916 1334163.31 378     37      357 1,366  517 Light gray       Rallier soft.I
Rule.-To find from the above table the breaking weight in rectangular bars, gene.
rally, calling b and  d the  breadth  and  depth  in  inches, and. I the  distance between  the
supports  in   feet,  and   putting   4-5  for  4   ft.  6  in.,  we  hav                                         breaking
weight in lbs., the value of S being taken from the table above.
For example:-What weight would be necessary to break a bar of Low Moor
iron, 2 inches broad, 3 inches deep, and 6 feet oetween the supports? According to
Analyses of Ten Specimens of Cast Iron made from South Staffordshire Iron Ore, West
of Dudley.
Iron from Hot Blast.
I.               II.              III.              IV.                V.            VI.
Iron -  -  -  -  -                 89.53             92-98            93-84             92-90       C(a)95-23        95-80
Carbon -  -  -  -         C 32T  7-93    C 3-11  6-51   C 2-98  5-54   CO-8T  6-83                 C(b) I-TT          272
Carbon -               -   -    -                                    -                 -     -            0-49        0-26
Silica, &c. ---                                         -                                                 0-31        0.11
Manganese -  -  -                   1-71              1-30              072              0-62             0-34        0-54
Calcium         -  -  -             0-11         trace                  0.34             0-06             0-10        0-06
Sodium        -  -  -               0-41              0.37              0.39             0-30             0-19        0-14
Potassium  ---                        -                           trace             trace
Sulpliur   -  -  -                 0-07          trace       minute trace           trace             trace         trace
Phosphorus  -  -                   0-54          lost                   0-07             0-40             0-12        0-37
100-39            100-19            100-90           101.11            98-55      100-00
* The irons with  asterisks are taken from  the experiments on hot and cold blast iron, made by Mr.
Hodgkinson and myself for the British  Association for the Advancement of Science.-See Seventh
Rteport, vol. vi.
1- The modulus of elasticity was usually taken from the deflection caused by 112 lbs. on the 4 ft.
to. bars.




IRON.                                        1099
Iron from  Cold Blast.
I.          III.        IV.V.
Iron -  -   -  ----              94'10      9657              94'5i       -       9442
Combined carbon (a)  -  -         1-87        0 95
Uncombined carbon (b)  -          1'92        167     0 1-98 371       23          4.05
Silica - -                        130  0'51
Manganese  -             -        1'12        1'16             083   -   -          094
Cobalt --        ----            trace                          -     -   -       trace
Chromium --  -  -  -  -          trace
Calcium   -  -  -  -  -  -        0'05        trace            0'25   - -          0-16
Sodium    -   --   ---            0'15        trace            0'30   -   -        034
Potassium ------                 trace        0'42
Sulphur  --      ----     trace               0'11             0'05 - -           trace
Phosphorus  - ----                0-21        0-36             0-03   -            036
100-73     10175              99-201  -   -      10027
the rule given above, we have b =  2 inches, d=  3 inches, I = 6 feet, S    472 from  the
b d2 S    4-5 X 2 X 32 X 472
table.  Then   ~6 —6                           -   =  6372 lbs., the breaking weight.
A very small amount of phosphorus is found to impart to iron a great degree of
brittleness, when bar iron contains but 0'5 per cent..Fig. 818. represents in section, and fig. 817. in plan, the famous cupola furnace for casting iron employed at the Royal Foundry in Berlin. It rests upon a foundation a, from 18
to 24 inches high, which supports the basement plate of cast iron, furnished with ledges,
for binding the lower ends of the upright side plates or cylinder, e. Near the mouth
there is a top-plate d, made in several pieces, which serves to bind the sides at their
upper end, as also to cover in the walls of the shaft. These plates are most readily secured in their places by screws and bolts. Within this iron case, at a little distance
from it, the proper furnace-shaft e, is built with fire-bricks, and the space between this
and the iron is filled up with ashes. The sole of the hearth f. over the basement-plate,
is composed of a mixture of fire-clay and quartz-sand firmly beat down to the thickness
of 6 or 8 inches, with a slight slope towards the discharge-hole for running off the
metal. g is the form  or the tuy~re (there are sometimes one on each side); h tho
nose pipe; the discharge aperture i is 12 inches wide and 15 inches' high; across
which the sole of the hearth is rammed down.  Du'ring the melting operation this
opening is filled up with fire-clay; when it is completed, a small hole merely is pierced
through it at the lowest point, for running off the liquid metal. The hollow shaft should
be somewhat wider at bottom than at top. Its dimensions vary with the magnitude of
the foundry.  When 5 feet high, its width at the level of the tuyere or blast hole may
be from 20 to 22 inches. From 250 to 300 cubic feet of air per minute are required
for the working of such a cupola. For running down 100 pounds of iron, after the
furnace has been brought to its heat, 48 pounds of ordinary coke are used; but with the
hot blast much less will suffice. The furnace requires feeding with alternate charges
of coke and iron every 8 or 10 minutes. The waste of iron by oxidation and slag
amounts in most foundries to fully 5 per cent. For carrying off the burnt air, a chimney-hood is commonly erected over the cupola. See FOUNDRY.




1100                                    IRON.
The double-arched air or wind-furnace used in the foundries in Staffordshire for melting
cast iron, has been found advantageous in saving fuel, and preventing waste by slag. It
requires fire-bricks of great size and the best composition.
The main central key-stone is constructed of large fire-bricks made on purpose; against
that key-stone the two arches press, having their abutments at the sides against the walls.
The highest point of the roof is only 8 inches above the melted metal. The sole of the
hearth is composed of a layer of sand 8 inches thick, resting upon a bed of iron or of
brickwork. The edge of the fire-bridge is only 3 inches above the fluid iron.
In from  2 to 4 hours from  I to 3 tons of metal may be founded in such a furnace,
according to its size; but it ought always to be heated to whiteness before the iron is
introduced. 100 pounds of cast iron require from 1 to 1~ cubic foot of coal to melt them.
The waste varies from 5 to 9 per cent.
I shall conclude the subject of iron with a few miscellaneous observations and statistical tables. Previously to the discovery by Mr. Cort, in 1785, of the methods of puddling
and rolling or shingling iron, this country imported 70,000 tons of this metal from
Russia and Sweden; an enormous quantity for the time, if we consider that the cotton
and other automatic manufactures, which now consume so vast a quantity of iron, were
then in their infancy. From  the following table of the prices of bar iron in successive years, we may infer the successive rates of improvement and economy, with slight
vicissitudes.
Years.              Per Ton.               Years.                Per Ton.
~  8.   ~  s.                               ~  8.   ~  s.
1824            9  0 to 10  0              1830             5  5 to 6  0
1825           10  0-14  0                 1831             5  5 -5  10
1826            810-  10  0                1832              5  0-  5 10
1827            8  0-    9  0              1833              510-  6  0
1828-           8 10-   8  0               1834              6  0-6  10
1829            5 10-    7  0              1835              510-  7  0
The export of iron in 1836, in bars, rods, pigs, castings, wire, anchors, hoops, nails, and
old iron, amounted to 189,390 tons; in unwrought steel to 3,014, and in cutlery to 21,072;
in whole to 213,478; leaving apparently for internal consumption 776,522 tons, from
which however one-tenth should probably be deducted for waste, in the conversion of the
bar iron. Hence 700,000 tons may be taken as the approximate quantity of iron made
use of in the United Kingdom, in the year 1836.
The years 1835 and 1836 being those of the railway mania over the world, produced
a considerable temporary rise in the price of bar iron; but as this increased demand
caused the construction of a great many more smelting and refining furnaces, it has tended
eventually to lower the prices; an effect also to be ascribed to the more general use of
the hot blast.
The exports of foreign produce in 1850 amounted to 5,996 tons, in 1851 to 4,813
tons; of British produce of all kinds (except steel) in 1850, 772,830 tons, in 1851
908,955 tons; the declared value being respectively 4,956,3081. and 5,414,1211. The
imports in bars unwrought amounted in 1850 to 34,066 tons, and in 1851 to 40,279.
The relative cost of making cast iron at Merthyr Tydvil in South Wales, and at
Glasgow, was as follows, eight or nine years ago.
At Merthyr.
s            Tons. Cwts. Qrs.                             ~   &  d.
Raw mine at 10 per ton,    3    7    0                   -      -         1  136
Coal        at 6                2   16    0    -         -      -       -0  16  6
Limestone                       1    5    2                  - -0   1  4
Other charges    -                                              -       - 0   9  1
Total Cost      -              -       -                                3   0  5
At Glasgow.
s. d.   Tons. Cwts.                                        ~   s. d.
Raw mine at 4  6    3    10              -       -       -      -       - 0  16  3
Splint coal at 2  5    5    15           -       -       -      -       -0  14  0
Limestone at 0  3    0        14         -       -       -              -0   3  6
Coals for the engine  1    10            -       -       -      -         0   3  0
Other charges    -        -                      -..       - 1   1  0
Total Cost      -       -              -       -       -.       - 2  17  9




IRON.                                        1101
The cost is still nearly the same at Merthyr, but it has been greatly decreased at
Glasgow.
The saving of fuel by the hot-blast is said to be in fact so great, that blowing
cylinders, which were adequate merely to work three furnaces at the first period, were
competent to work four furnaces at the last period.  The saving ofmaterials has moreover been accompanied by an increase of one-fourth in the quantity of iron, in the same
time; as a furnace which turned out only 60 tons a week with the cold blast now turns
out no less than 80 tons. That the iron so made is no worse, but probably better, when
judiciously smelted, would appear from the following statement. A considerable order
was not long since given to four iron-work companies in England, to supply pipes to
one of the London water companies.   Three of these supplied pipes made from  the
cold-blast iron; the fo.urth, it is said, supplied pipes made with the hot-blast iron. On
subjecting these several sets of pipes to the requisite trials by hydraulic pressure, the
last lot was found to stand the proof far better than any of the former three.That
iron wvas made with raw coal.
I have been since told by eminent iron-masters of Merthyr, that this statement stands
in need of confirmation, or it is probably altogether apocryphal, and that as they find
the hot blast weakens the iron, they will not adopt it.
Between the cast irons made in different parts of Great Britain, there are characteristic differences. The Staffordshire metal runs remarkably fluid, and makes fine sharp
castings. The Welsh is strong, less fluent, but produces bar iron of superior quality.
The Derbyshire iron also forms excellent castings, and may be worked with care into
very good bar iron. The Scotch iron is very valuable for casting into hollow wares, as
it affords a beautiful smooth skin from the moulds, so remarkable in the castings of the
Carron company, in Stirlingshire, and of the Phcenix foundry, at Glasgow. The Shropshire iron resembles the Staffordshire in its good qualities.
Thle average quantity of fine metal obtainable from the forge-pigs at Merthyr Tydvil,
from the finery furnace, is one ton for 223 cwt. of cast iron, with a consumption of about
9J cwt. of coal per ton.
Estimate of the average cost of erecting three blast furnaces.
BUILDING EXPENSES.
Foundations       - -.. —-..             ~480
Masonry of hewn gritstones.-.-.       -      600
Common bricklayers' work              -.         -.       -.       -    1200
Lining of the furnace, hearth, &c., in fire-bricks -      -       -       -       -    1140
Fire-clay for building    -       -       -       -       -       -       -        -       80
Lime and sand   -         -       -       -       -       -       -       --              800
CAST IRON.
Cast-iron pieces, such as dam-plates, tymp-plates, beams, tuy~re-plates, &c.,
weighing about 24 tons for each furnace;-in whole  -            -       -       -    1140
WROUGHT IRON.
For the binding-hoops, l-eys, &e.; 5 tons for each           3-           -        -       00
COST OF LABOUR.
Bricklayers, masons, and labourers in building  -         -       -       -       -    1080
VARIOUS EXPENSES.
Scaffolding       -       -       -       ---                     -.       -       48
Tools    -        ---                     -       -       --.                    -      160
Shed in front of each furnace   -         -       -       -       -       -       -      480
Terracing, cost of ground, &c.  -         -       -       -       -       -       -    2400
Total cost of erecting the furnaces   -                                              9908
INCIDENTAL CHARGES.
Blowing machinery, and steam engine of 80-horse power                     -       -    6400
Inclined railway for mounting the charges         -       -       -       -       -      120
Gallery for charging      -       -       -       -       -       -       -       -      160
Steam engine house.       -       --.            -       -.              400
Carried forward       -                   16,988




1102                                        IRON.
Brought forward                         - ~ 16,988
Chimneys, boilers, &c(f.           -        -       -       -                -        -      480
Roasting kilns   ~         -       -.        -       -..        -      480
Coke kilns.       -...        -       -        -      800
Dwelling houses for workmen                                                           -      800
Total cost of 3 furnaces complete        -        -       -                           ~19,548
Estimate from the Neath-Abbey Works in S. Wales, of the cost of machines requisitefor
aforge and shingling mill, capable of turning out 120 tons of bar iron per week.
1. Steam-engine upon Bolton and Watt's construction; of 40 inches diameter
in the cylinder, and 8-feet stroke; with boilers, pipes, grate, bars, firedoors, &c. &c., complete.-  ~1,600
2. System of great-geering for transmitting the crank-motion of the engine to
the mill-work, with fly-wheel, &c. -             -        -1,090.3. A  system  of roughing rolls, with pinions, uprights, and every thing else
necessary  -             --                   -       -       -        -       -      525
4. Two pairs of finisher rolls, with all their accessories                                 525
5. Two pairs of shear-machines, at 170I. a-piece           -        -340
6. One pair of rolls of 10 inches diameter, for making  small bar iron, with all
their accessories                                                              -      230'7. Forge hammer, including the anvil, the cam-shafts, and all the other requisites    -       -        -       -       -        -       -       -        -      185
8. A complete turning lathe                                                                 200
~4,695
9. To the above must be added, spare cylinders weighing about 60 tons                      960
10. Duplicate articles for the steam-engine         -       -        -               -
11. 150 tons of cast-iron plates, to cover the floor of the mill  -900
12. Eight tons of cast-iron pieces for a reverberatory furnace  -            -       -        52
13. Tools of malleable iron; rakes, oars, &c.    -          -        -28
14. Castings for mounting a cupola furnace          -       -        -50
15. Blowing machine for the cupola          -       -       -        -80
16. Pieces of iron for a small forge, with two fires, two bellows, two anvils,
iron tools faced with steel, and common iron tools, &c.               -       -       100
17. Eight tons of cast-iron pieces, and wrought-iron pieces for 14 puddling
furnaces   -        -       -        -       -       -        -       -       -       983
18. Seven tons of cast-iron pieces, and wrought-iron for 4 re-heating furnaces              252
19. Tools for the puddlers and other workmen  -             -        -       -       -        15
20. Iron mountings for two cranes, partly made of wood               -       -       -        50
Total cost of machines, and pieces of iron    -           -       -        -       -     8165
To the above, the cost of the steam  engine house is to be added, that of another forge
hammer, and incidental expenses.
In Staffordshire the following estimate has been given:
A  steam-engine of 60-horse power           -       -       -        -       -       -    2016
Rolls, with the iron-work of the furnaces, &c., to make 120 tons of bar iron
weekly    -             --...       -             2572
4588
The Neath-Abbey estimate is greater, but that company has a high character for
making substantial well-finished machinery.
Bar iron made entirely from ore without admixture of cinder, or vitrified oxide, is
always reckoned worth 10s. a ton more than the average iron in the market, which is
frequently made by smelting 25 per cent. of cinder with 75 of ore or mine, as it is called.
M. Virlet's Statistical Table of the Produce of Iron in Europe.
Quintals.
England (1827)          -.-                       -       -       -',098,000
France (1834)           -        -       -       -       -        -       - 2,200,000
Russia (1834)           -.        -       -.        -       -1,150,000
Austria (1829)          -       -        -       -        -       -           850.000
Sweden (1825)           -        -,       -        -       -.  850,000
Prussia                 -       -        -       -       -        -       -  800,000




IRON.                                        1103
The Hartz Mountains             -       -       -       -       -       -  600,000
Holland and Belgium....       -  600,000
Elba and Italy                  -       --  280,000
Piedmont                                             Britain is now up 200,000
Spain                    South Wales furnishes 70180,000
Norway                         Scotland 60150,000
Denmark         -       -       -       -       -       -       -       -  135,000
Bavaria                                                causes of the ad 130,000
Saxony         -       -       -        -       -       -       -       -   80,000
Poland          -      -        -n      -       -n-             -       -   75,000
Switzerland   -         -       -       - fi  n -       -       -            30,000
Savoy           -       -       -       -       -'       -       -   25,000
Total              -               -       -       -               13,433,000 (equal to
about 672,000 tons.)
The gross annual production of iron in Great Britain is now upwards of 2,250,000
tons. Of this quantity South Wales furnishes 700,000, South Staffordshire, including
Worcestershire, 600,000,            and 600,000 tons. The remainder is divided among
the several smaller districts. Onof the  principal causes of the advantages possessed
by Great Britain in the manufacture of iron arises from the number and variety of the
measures of argillaceous and black band ironstones which alternate with the beds of
coal in almost all the coal fields; and in consequence of which, the same localities, and
in many instances the same mineral workings, frequently furnish both the ore and the
fuel to smelt it. So extensive are the ironstone beds of the coal measures that they
furnish in themselves the greater part of the iron produced in Great Britain; but the
iron-making resources of the kingdom are by no means confined to them. The carboniferous or mountain limestones of Lancashire, Cumberland, Durham, the Forest of
Dean, Derbyshire, Somersetshire and South Wales, all furnish important beds and veins
of haematite; those of Ulverstone, Whitehaven and the Forest of Dean, are the most
extensively worked, and seem  to be almost exhaustless.  The brown haematites and
white carbonates of Alston Moor and Weardale also exist in such large masses, that
they must ultimately become of vast importance.  In the older rocks of Devon and
Cornwall are found important veins of black haematite, and in the granite of Dartmoor
numerous veins of magnetic oxide and specular iron ore.  The new red sandstone
furnishes in its lowest measures beds of hlematitic conglomerate. In the lias and
oolites are important beds of argillaceous ironstones, now becoming extensively worked;
and the iron ores of the green sand of Sussex, once the seat of a considerable manufacture of iron, will in all probability soon again become available by means of the
facilities of railway communication.
In the following classification the number of the blast furnaces in each district is
given, and the ironstone of the coal measures are arranged in the definite order in
which they occur in the different coal fields; so that their position in reference to the
beds of coal alternating with them is at once seen. The more important of the coal
fields are also subdivided into districts showing the changes which occur in each, and
thus giving a concise view of their general character.
The produce of the iron manufacture in Great Britain in 1750 was only about
30,000 tons; in 1800 it had increased to 180,000 tons; in 1825 to 600,000 tons. See
METALLIC STATISTICS.
IRON, PRODUCTION OF.
SOUTH WALES.  (Eastern Outcrop.)
Blast Furnaces.
Principal Works:-                                                       In.   Out.
Cwm Bran         -        -       -      -                -  0     1
Pontypool        -       *       -       -       -           2     1
Abersychan       *       -       -       -               -  2      4
Pentwyn                  -               -       -       -  0     3
Vateg   -        -       -       -       -.  2     0
Gelynos -                -       -           -           -  3      0
Blaenavon                -       -       -       -       -  3      2
23 Furnaces   -        -       -        -      -12   11




1104                                      IRON.
SOUTH WALES. (North Eastern Outcrop.)
Blast Furnaces.
Principal Works:-                                                       In.   Out.
Clydach          -       -                                      -  -  -4 0
Nant-y-glo       -       -       -       -       -       -
Coalbrook Vale -         -       -       -       -       -  2
Blaina  -        -       -       -       -       -        -2       1
Cwm Celyn        -       -       -       -       -       -         1
eauft            -               -       -       -        -        0
Ebbw Vale        -       -       -       -        -       -        0
Victoria -               -               -        -       -        2
Sirhowey         -       -       -       -        -       -_       0
Tredegar         -       -       -        -           -   -        0
50 Furnaces   -        -       -        -       -42      8
The beds of coal in this division of the coal-field are all bituminous. The principal
coals only are given in this section. The iron stones are principally  argillaceous,
although some important beds of blackband or carbonaceous ironstone exist locally.
The total thickness of the coal measures, in this series, from the Soap Vein Mine to the
bottom coal, is about 150 yards.
SOUTH WALES. (Northern Outcrop.)
Blast Furnaces.
Principal Works:-                                                       In.   Out.
Rhymney          -.. 2
Dowlais.        -       -                -                 11     3
Ivor     -       -       -       -.  3     1
Penydarren       -       -       -        -       -       -        2
Cytharfa-        -       -        -                          6     1
Hirwain -         -       -       -                   -            0
Duffryn and Furnace Ycha          -       -       -       -  8     0
Ynysfach         -       -                                -  4     0
Aberdare                 -        -               -       -  6     0
Aberammon        -       -       -       -        -       -  2     1
Gadlys  -                                                -  3      0'70 Furnaces   -       -                       - 60   10
SOUTH WALES. (Central Anticlinal District.)
Blast Furnaces.
Principal Works:-                                                       In.   Out.
Cwm Avon          -       -       -       -       -       -  4     2
Oakwood           -      -        -       -               -2       0
Garth    -       -       -       -        --  0                    3
Maesteg -            -       -    -         -         -      0     3
Llynvi  -        -       -       -        -       -          4     0
Neath Abbey    -          -       -       -      -.  0      2
20 Furnaces   -        -                -       - 10    10
SOUTH WALES. (Western or Anthracite District.)
Blast Furnaces.
Principal Works:-                                                       In.   Out.
Venalt  -        -       -       -       -       -       -  0      2
Yqtalyfera       -       -       -        -       -      -  5      6
Yniscedwin       -       -       -               -       -3        4
Banwen -          -       -       -       -      -       -  0      2
Onlluyn or Brin -        -               -       -       -2        0
Cwm Ammon   -            -       -       -       -       -  2      0
Trim Saren        -       -       -       -      -       -  0      3
Gwendrarth       -        -      -       -       -       -  0      3
Branere -         -       -       -       -       -          0     2
34 Furnaces   -         -       -       -       -12   22




IRON.                                        1105
SOrTH WALES.  (Southern Outcrop.)
Blast Furnaces.
Principal Works:                                                         In.   Out.
Pentyrch         -2    0
Toudu   -        -       -                -       -       -  1      1
Cefn Cusc        -       -                -       -       -  1      2
Cefn Cribbur    -        -       -        -       -       -  0      1
Dinas   -        -       -        -       -                  3     0
11 Furnaces   -        -       -        -       -7    4
The iron ore principally used at the Pentyrch works is haematite, from  the carboniferous limestone on the south of the South Welsh coal-field. The annual production
of iron on the south outcrop is about 25,000 tons.
NORTH WALES.
Blast Furnaces.
Principal Works:-                                                       In.   Out.
Rhuabon-          -       -       -       -       -          2      1
Brymbo  -         -       -       -       -       -       -  1 
5 Furnaces    -         -       -       -       -  3      2
SHROPSEHRE.
Prin  l Works*''    nrBlast Furnaces.
Principal Works:-                                                       In.   Out.
Madeley Wood  -          -        -       -       -       -  3     0
Madeley Court -           -       -       -       -       -  2     1
The Castle       -1                                                1
Light Moor        -       -       -       -       -       -  2     0
Horse-hay                 -       -       -       -       -  2      1
Lawley  -         -      -        -       -       -       -  1     0
HIinkshay        -        -       -       -       -       -0        2
Stirchley        -        -.       -                  4     0
Dark Lane                 -       -               -       -  0      2
New Lodge        -                -       -       -       -1       1
Donnington       -       -       -        -                  3     0
Sneds Hill       -       -   -       -        -       -      2     0
Langley-         -        -       -       -       -       -1       1
Ketley  -        -        -       -       -       -       -1        1
33 Furnaces   -         -       -       -         23   10
SOUTH STAFFORDSHIRE.
Blast Furnaces.
In.   Out.
148 Furnaces                                             105   43
NORTH STAFFORDSHIRE.
Blast Furnaces.
Principal Works:                                                        In.   Out.
Silverdale       -        -       -       -               -  1     4
Apedale -                 -       -       -       -       -  2     2
Kidsgrove        -        -       -       -       -          3      0
Goldendale                -       -       -       -       -  2     1
Etruria  -       -        -       -       -       -          3     0
Longton                                                   -  2      1
21 Furnaces   -         -       -       -       -13      8
YORKSHIRE.  (iVorthern District.)
Blast Furnaces.
In.   Out.
Bowling          -       -                        -          3     2
Low Moor         -       -       -                           1     2
New Begin        -       -                   -               2     0
Shelfe   -       -       -       -       -        -       -  0     1
Bierley  -       -       -       -       -        -   -      3     1
Farnley -        -       -       -       -        -       -  1    0
16 Furnaces       -       -       -       -       -10       6
10




1106                                      IRON.
Annual production of iron about 25,000 tons.  The quality of iron made is very
superior. The Low Moor and Bowling marks are especially celebrated. The beds of
coal in this district are exceedingly thin. The Better Bed coal is the only one used for
iron making purposes. The White Bed and Black Bed mines of this district probably
correspond with the Thorncliffe White mine and the Clay Wood mine of the southern
division of this field.
YoRKSHIRE.  (Southern District.)
Blast Furnaces.
Principal Works:~                                                      In.   Out.
Worsbro' Dale  -                                            0     1
Elsecar -.                       -.  0     3
Milton   -       -                       -       -       -  1
Thorncliffe      -       -       -       -       -       -  1
Chapeltown       -       -       -       -       -       -  1
Holmes --                                                -  1
Parkgate         -       -       -       -       -       -  1     0
13 Furnaces   -        -.       -  5     8
Annual production of iron  about 20,000 tons,  Thickness of measures from  the
Hobbimer to Mirtomley beds of coal about 430 yards.  The entire thickness of the
coal series is however much more. The measures thin out rapidly towards the north.
DERBYSHIRE.
Blast Furnaces.
Principal Works:-                                                      In.   Out.
Unston  -        -       -                       -          1     0
Reinshaw                                 -                  1     1
Staveley.-              -       -               -          2     2
Duckmanton.-..                                       1
Birmington Moor                  -       -       -       -  1     0
Newbold.       -       -       -       -       -        0
Wingerworth    -         -                                     1 -  -
Clay Cross               -         -             -       -I1
Morley Park              -       -       -       -       -2    0
Alfreton         -       -       -       -       -       -2       1
Butterley        -       -       -       -       -          2     1
Codnor Park    -         -       -       -                  2    0
West Hallam                                                 I -  -  -  -  -  I
Stanton                                                     2 -  -  -  -   2 1
29 Furnaces       -       -       -       -      -19   10
Annual production of iron about 60,000 tons; average thickness of coal measures,
from magnesian limestone to Kilburne or lowest worked coal, 600 yards. Many of the
beds of ironstone lie in such a thickness of measure as only to be workable to advantage
by open work or bell pits. Where these means of working can be adopted the produce
per acre is oftentimes very targe; in the Honeycroft Rake it is 6,000 tons per acre;
in the black shale 8,000 tons.
NORTHUMBERLAND, CUMBERLAND, AND DURHAM.
Blast Furnaces.
Principal Works:-                                                      In.   Out.
Walker -         -       -       -       -       -          2    0
Tyne    -        -       -       -       --  2    0
Wylam-                   -       -       -       -      -1        0
Hareshaw         -       -       -       -       -          0     3
Redesdale        -       -       -       -                  0     3
Birtley  -       -       -       -       -                  1     2
Witton Park                      -       -       -       -  3     1
Taw Law          -       -       -       -.  2                    3
Consett and Crookhead  -7 -7
Stanhope                                                    I -  - -  -   1 0
38 Furnaces   -        -       -       -       -19   19




IRON.                                        1107
Annual production of iron about 90,000 tons.  The iron works of this district are
gradually increasing in importance, the cost of fuel being so low as to permit ores to be
brought from many different localities. The bands of Scotland and of Haydon Bridge,
the brown bhematites and white carbonates of Alston and Weardale, and the argillaceous
ironstones of the lias of Whitby and Middlesborough, are all used for the supply of the iron
works of this district.
The brown hbematites deserve especial attention.  They are found associated in very
large masses with the lead veins of this district, and occasionally they occur as distinct,
and regular beds. They contain from 20 to 40 per cent. of iron.  Sometimes they exist
as "riders" to the vein, sometimes they form its entire mass, and in this case they occasionally attain a thickness of 20, 30, and even 50 yards. Their employment for iron
making purposes is only recent, but the supply of ore which they can furnish is almost
unlimited, and when some better means of separating the zinc and lead associated with
them shall have been discovered, they will doubtless be found to be of great importance
Remarkable changes sometimes occur in the character of the metalliferous veins of this
district; the same vein which at one point bears principally lead-ore changing to a calamine vein, and then again to brown haematites.
LANCASHIRE AND WEST CUMBERLAND.
Blast Furnaces.
Principal Works:-                                                          In. Out.
Cleator Iron Company             -         -          -         0
3 Furnaces.
The production of iron in this district is very limited, being confined to the Cleator
works and one or two small charcoal works in the Ulverstone district. The quality of
the latter, charcoal being used for fuel, is very superior, and the produce commands the
highest prices, as it combines with the fluidity of cast-iron a certain malleability,
especially after careful annealing. The iron of the Cleator works is smelted with coal,
and though in consequence not equal to the other, is yet superior in quality. The ore
both of the Whitehaven and the Ulverstone and Furness districts is raised most extensively for shipment to the iron works of Yorkshire, Staffordshire, and North and South
Wales. In quality these ores may be considered as the finest in this kingdom, and the
supplies which these districts are calculated to produce are very great. The large percentage of iron which they contain, from 60 to 65 per cent., and their superior quality,
also enable them to bear the cost of transport, and they are becoming every day of
greater importance. They are found both as beds traversing the beds of mountain limestone formation transversely to the lines of stratification, and also as beds more or less
regular. The former is the general character of the Ulverstone and Furness ores, no
clearly defined bed being as yet known in that district, whilst at Whitehaven there
are two, if not more, beds of irregular thickness, but with clearly defined floors and
roofs, and oftentimes subdivided by regular partings. These beds attain a considerable thickness, occasionally 20 or 30 feet.  The area over which they extend is not
as yet well known; but they have been worked extensively for many years, and the
workings upon them  are rapidly increasing. They lie beneath and close to the coal
measures, which both furnishes the necessary fuel, and also important beds of argillaceous ironstones for admixture.
FOREST or DEAN.
Blast Furnaces.
Principal Works:-                                                        In. Out.
Cinderford           -                     -          -     2  0
Forest of Dean Company          -          -         -      3  0
5 Furnaces                             5  0
Annual production of iron about 30,000 tons. The ores of the Forest of Dean are
carboniferous, or mountain limestone ores lying beneath the coal measures, which are
not here productive in argillaceous ironstones, as in other principal coal fields of the
kingdom. Besides the limestone ore there is a bed in the millstone grit measures; but
which is only worked very locally. The limestone ore occupies a regular position in
the limestone measures, although in itself exceedingly irregular, assuming rather the
character of a series of chambers than a regular bed. These chambers are sometimes
of great extent and contain many thousand tons of ore, which is generally raised at an
exceedingly low cost, no timbering or other supports for the roof being required. The
supply of ore producible in the Forest of Dean is almost unlimited. The iron made
from it is of a red short nature, and especially celebrated for the manufacture of tin




1108                                       IRON.
plates. Its superior quality always commands a high price. This ore is raised extensively for shipment to the iron works of South Wales. It was worked at a very ancient
date, either by the Romans or the Britons, as is evident from the remains of old workings
along the outcrop of the ore bed. This ore averages from 30 to 40 per cent.
For certain new processes for making malleable iron, Mr. W. N. Clay has obtained two
successive patents. Under the first, of December, 1837, he mixed bruised hematite with
one-fifth of its weight of clean carbonaceous matter in coarse powder, and subjected the
mixture in a fi shaped retort to a bright red heat for twelve or more hours, till the ore
be reduced to the metallic state, as is easily ascertained by applying a file to one of the
fragments.  When discharged, the metal is to be transferred into a balling or puddling
furnace, along with about five per cent. of ground coke or anthracite, and worked therein
in the usual way.  He also proposes to use a conical kiln, like that for burning lime,
instead of the retorts.
In his second patent, dated March, 1840, Mr. Clay prescribes above 28 per cent. (from
30 to 40) of carbonaceous matter to be mixed with the ground-iron ore, containing
at least 45 per cent. of metal, which mixture is to be directly treated in a puddling
furnace.  He also proposes to use a mixture of pig or scrap iron and ore, in equal
quantities.
The application of the waste gases (carbonic oxide chiefly) of the blast furnace to the
purpose of heating the puddling or balling furnace, was made the subject of a patent in
June, 1841, by a foreigner not named. The process had been previously practised in
Germany, and was fully described in the Annales des Mines some years ago.
In fig. 819. the manner of conveying the waste carbonic oxide from a blast furnace is
shown.  a, a, a, are openings leading into the vertical channels or passages b, and from
thence into the chamber c.  There is a top to this
chamber, with openings corresponding to the pas81  l ll I   F~iR~lsages b. These openings are closed with cast-iron
plates that can be taken off for the purpose of
clearing out the passages b, and the chamber c.
From the chamber c, the gas may be conducted in
any direction, and to a distance of several hundred
feet.
In some localities, and in cases where it is
I   il  111/1   required to take the gas from  a blast furnace in
operation, a metal cylinder, of a smaller diameter
than the top of the furnace, and of a depth equal to
alllll     a           its diameter, is suspended vertically within the top
of the blast furnace the whole of its length. The
space between the cylinder and the furnace at the
top or mouth is to be hermetically sealed, and the
furnace is to be charged through the cylinder which
I~[~~\~^j~j~ L               must be kept full of minerals and combustibles.
Thus the space between the cylinder and the
interior of the furnace remains vacant, but the
gas may be conducted out of that part laterally,
if required. The gases led off from  the blast
furnace may, if need be, pass through heated
pipes, as for the hot blast.
Figs. 820. and 821. represent a refining furnace for iron, with the necessary apparatus
for working it with the gases, without the use of other fuel; fig. p5. being a vertical
section, and fig. 821. a sectional plan view.
The gas from the blast furnace is brought into the chamber a a, and, passing through
an opening b b, it enters the furnace.  c c are a series of blow  pipes, through which the
heated air is forced into the furnace. In the space between the part marked b and the
tubes c, the gas becomes mixed with the heated atmospherical air.
This combustible gas from *the blast furnace, mixed with the heated air, produces an
intense heat in the furnace, adequate to the refining of iron. The warm air for burning
the gas is usually obtained from the blowing machine and hot blast pipes.




IRON.                                      1109
For giving a still greater heat, the air may be carried through the tube f, into the
iron chambers g g, or a system  of pipes, whence it is led through the tube A into the
semi-circular chamber i, and then through the small pipes c, c, c, into the furnace.
The metal to be refined is placed, in the space d d, in a liquid state, if the arrangement of the furnaces will admit of its being so taken from the blast furnace; if not, it
may be nearly melted by the waste heat in the chamber e e. In order to decarbonize
the metal, a quantity of warm air, from the pipe A, is conducted through the pipe k,
which is divided into two nozzles or tuyires II, and blown upon the fluid metal in the
space d d. After having been thus exposed for an hour or two, it is run off through
the opening m, and will be found in arefined state.
Figs. 823,824, show the application to a puddling furnace. The openings n is admit
a stream of cold water to flow through the cast-iron piece o o, to preserve it from injury
by the fire.
824                                         823
Fig.824is a welding furnace; the interior dimensions and the casing of the hearth
being different, as well as the fire bridge, from those of the puddling furnace. The
pipes for conducting the gases are made of cast-iron, and must have at least a sectional
area of one foot for every furnace that is to be heated.
Figs. 825, 826, 827, 828, 829. show the application of this invention to the generation
of steam. A chimney is here employed only at the commencement of the operation. The
822
d
829                        825
828                                  826
827
air is forced into the furnace by any sort of blowing machine, or in any other con.
venient way. The fuel is introduced into the fireplace, upon the grate n n, through
the door a, which can be closed. The fireplace must contain as much fuel as will last
for several hours. When the fire is first lighted, the combustion takes place in the
ordinary way, on opening the door d, and the slide-valve b, and carrying through them
a current of air by the chimney draught. This is continued till the steam-engine
furnace, or any working (power) engine is in operation, after which a blowing apparatus
is employed to force the air through the tube c, as shown in fg. 826. The openings d




1110                                     IRON.
and b are then closed; the air forced in now  passes through the flues f f,f,  placed
round and beneath the boiler.  The air, on arriving at the point g, is divided, one
portion passes through the opening h, regulated by a valve, into the open space beneath
the grate n n, to assist in the slow combustion of the fuel. The other part of the air
asses through g, into h h, round the fire-place, in order to heat the air to an intense
degree. After the second portion of the air has passed into the chamber h hit enters
another i i, thence through a series of blowpipes, or through o, into p p, beneath the
boiler. The burnt air goes off through p p, into a small chimney, through the opening
b b, which is regulated by a valve.
TIRON.  Hot Blast.  To the account of this interesting innovation in the smelting
of iron ores, given in the dictionary, I have now the pleasure of representing in
accurate plans, the complete system mounted at the Codner Park Works belonging to
William  Jessop, Esq.  For the drawings, from  which the woodcuts are faithfully
copied, I am iadebted to Mr. Joseph Glynn, F.R.S., the distinguished engineer of the
Butterly Iron Works.
Figs. 830, 831, 832, exhibit the apparatus of the hot blast in every requisite detail.
The smelting furnaces have now generally three tuveres, and three sets of air heating
~ IS__, ~,. _
section infg. 831, and passes through these pipes to the horizontal pipe, B, on the
laterally, their section being a parallelogram, to give more heating surface, and also
more depth of pipe (in the vertical plane), so as to make it stronger, and less liable to




IRON.                                    111
bend by its own weight when softened by the red heat. This system of arched pipe
apparatus is set in a kind of oven, from which the flue is taken out at the top of it;
but it thence again descends, before it reaches the chimney, entering it nearly at the
level of the fire grate (as with coal gas retorts). By this contrivance, the pipes are
kept in a bath of ignited air, and not exposed to the corroding influence of a current of
flame. The places and directions of these oven flues are plainly marka4 in the
drawing.
Fig. 87 is a plan of the blast furnace, drawn to a smaller scale than th~ r  the
sreceding figures.
The three sets of hot-blast apparatus, all communicate with one line of conducting
pipes, A, which leads to the furnace. Thus in case of repairs being required in one
set, the other two may be kept in full activity, capable of supplying abundance of hot
air to the blast, though of a somewhat lower temperature. See SMELTING for constructions of different blast furnaces; also PUDDLING.
During a visit which I have recently made to Mr. Jessop, at Butterley, I found thii




1112                                    IRON.
A'
5    10         15         20
eminent and very ingenious iron-master had made several improvements upon nis hotblast arrangements, whereby he prevented the alteration of form to which the arched
pipes were subject at a high temperature, as also that he was about to employ five
tuyeres instead of three.  For a drawing and explanation of his furnace-feeding
apparatus, see SMELTING.
IRON CAST, improved by combination with wrought iron. This improvement, invented
and patented by Mr. Morries Stirling, has been reported upon by the Government
Commissioners on the application of iron to railway purposes. It is applicable to both
cast and wrought iron.  A mixture of the two in certain proportions has the effect of
giving a fibrous nature to the cast metal, and thereby greatly increasing its strength and
tenacity. For all kinds of beams, girders, and other castings where strength is required,
its use is found very advantageous and economical. Beams cast of such toughened iron
may be made of less dimensions to support the same load; and they have the advantage
of deflecting to a greater extent, and are therefore not so liable to sudden failure. At
page 101. of the Commissioners' Report, an abstract is given of a series of trials, from
which it will be seen that Mr. Stirling's alloy is nearly 50 per cent. superior to 16 other
sorts of iron experimented upon. Various other experiments have been made by Mr.
Owen for the Admiralty, and by Messrs. Rennie and others, all with the same results,
sbowing the increase of strength in the patent iron.  Common Scotch pig iron thus
toughened can be had now (1851) for about 21. 10s. per ton; and it is at least 50 per
cent. stronger than the best Blaenavon iron, which costs 31. 3s. per ton.
The improvements in the manufacture of wrought iron are, first, the admixture of a
certain alloy in the puddling furnace, by which all malleable iron is rendered much
more fibrous and tougher than common wrought iron, so much so that common or
merchant bar becomes equal to best bar, thus saving one process to the manufacturer.
Also very ordinary iron, which can scarcely be used at all, is made equal to the best. The
following abstracts of experiments are given in the Report of Commissioners (p. 417.'




IRON ORES.                                         1113
Breaking Strain
in Tons per
Square Inch.
Average of Mr. Jesse Hartley's experiments at Liverpool on many
sorts of malleable iron             -       -        -       -        -     2323
Average of S. C. Crown Iron from  numerous trials at Woolwich
Dockyard                   -        -        -       -                      24-47
Average of best Dundyvan bar           -       -        -       -       -     24-33
Average of Mr. Sterling's best quality         -.                        -    21i81
Do.    another quality        -        -       -        -       -        -    27081
The cost of the process is only a few shillings per ton.  When Mr. Stirling's toughened
pig is used in the puddling furnace instead of common pig, and the alloy added, an iron
is produced of a very superior quality, of a very fibrous nature, and much finer in the
fibre than the iron mentioned above; this will be found very advantageous in the manufacture of thin plates and sheets.
Second, the admixture of a different alloy in the puddling furnace, whereby a quantity
of iron is produced quite opposite in its character to the last; instead of being fibrous,
it becomes hard and  crystalline, approaching  to  the nature of steel.  The average
strength of common round bars, I inch diameter, is about 3 inches per foot; whereas the
average of Mr. Stirling's hardened iron is from one-eighth to three-eighths of an inch
per foot.  This shows the great stiffness obtained by' this method.  The crystalline
nature of this description of iron causes it to resist compression, lamination, and abrasion.
Thus for the top  portions of wrought iron  girders, it is precisely what is required
to resist the compression force, the fibrous iron being used for the bottom portion, to
resist the tension. For rails and tyres for wheels this sort of iron is peculiarly adapted;
the top of the rails and the outside of the tyres being made with it, will resist the wear
and tear and lamination so universally complained of; and rails made of the patent iron
are found to answer remarkably well. They have been ufsed on the East Lancashire,
Caledonian, Edinburgh and Glasgow, and other railways, with great success; the extra
cost of rails made of this iron being only from 7s. 6d. to 10s. per ton.
The first of these improvements in the manufacture of metallic sheets is the use
of polished rolls to such sheets as are either intended for being coated with other metals,
or after such sheets have been so coated; and this improvement is more particularly
applicable to iron plate either coated or to be coated with tin, zinc, or other of the more
fusible metals. After the plates or sheets of iron have been cleaned by pickling or otherwise in the usual way, they are to be passed between polished rollers, using sufficient
pressure to smooth the surface without injuring the quality by producing brittleness;
and as iron is of such different qualities as regards its ductility, both when hot and cold
(according to the district from whence the ore is produced, and peculiarities of make,)
no absolute rule respecting the amount of pressure can be given, but a little practice
will enable a workman to judge, and care is to be taken that the rolls are clean.  The
plates so polished are then to be dipped in the usual manner into the metal or alloy intended for the coating. After the plates or sheets have been coated with any metal or
alloy, they are, where a high degree of smoothness is desired, again passed between
polished rolls, the degree of pressure being carefully regulated so as to avoid producing
brittleness.  It is not essential that the sheets of metal should be passed between the
smooth rolls before coating, but it is preferred that such should be the case.
IRON CAST, ENAMELLED.  The Great Exhibition contained the following examples.
Model of an enamelled tank-or cistern composed of cast iron plates, screwed together
with gutta percha joint.
Model of enamelled water or gas pipes and watercloset pan, with trap pipe; dry
trough, poultry trough, and spittoon.
The application of enamel for the protection of water cistern pipes, (e. from  oxidation and for the lining of cooking utensils is of comparatively recent date. The various
materials of which the coating is composed (silex being the principal) are reduced to a
fluid state; the article to be coated is dipped in the mass; a portion of the fluid
adheres; it is then subjected to the beat of a muffle, and the whole becomes vitrified or
reduced into a glossy covering, affording an excellent defence against oxidation, and a
substitute for the protection afforded by tinning.
IRON, ZINKING OF. See ZINKING.
IRON  ORES (Analysis of, by Bichromate of Potash).  A  convenient quantity  of
the specimen is reduced to coarse powder, and one-half at least of this still further pulverized, until it is no longer gritty between the fingers.  The test solution of bichromate of potash is next prepared.  44-4 gr. of the salt in fine powder are weighed out,
and put into an alkalimeter (graduated into 100 divisions), and tepid distilled water
afterwards poured in until the instrument is filled to 0. The palm of the hand is then
securely placed on the top, and the contents agitated by repeatedly inverting- the in



1114                                  IRON  ORES.
strument until the salt is dissolved, and the solution rendered of uniform density
throughout. It is obvious that each division of the solution thus prepared contains
0-444 gr. of bichromate, which corresponds to - a grain of metallic iron. The bichromate of potash used in this process must of course be purchased pure, or made so by
repeated crystallization, and it should be thoroughly dried by being heated to incipient
infusion.
100 grains of the pulverized ironstone are now introduced into a Florence flask, with
1J. oz. by measure of strong hydrochloric acid, and ~ an ounce of distilled water. Heat
is cautiously applied, and the mixture occasionally agitated, until the effervescence
caused by the escape of the carbonic acid ceases; the heat is then increased and the
mixture made to boil, and kept at moderate ebullition for ten minutes or a quarter of
an hour.  During these operations it will be advisable to incline the flask, in order to
avoid the projection  and  consequent loss of any portion of the liquid by spirting.
About 6 oz. of water are next added, and mixed with the contents of the flask, and the
whole rapidly transferred to an evaporating basin. The flask is rinsed several times with
water to remove all adhering solution.
Several small portions of a weak solution of pure red prussiate of potash (containing
1 part of the salt to 40 of water) are now dropped upon a white porcelain slab, which is
conveniently placed for testing the solution in the basin during the next operation.
The prepared solution of bichromate of potash in the alkalimeter is then added very
cautiously to the solution of iron, which must be repeatedly stirred, and as soon as it
assumes a dark greenish shade, it should be occasionally tested with the red prussiate of
potash. This may be easily done by taking out a small quantity on the end of a glass
rod, and mixing it with a drop of the solution on the porcelain slab. When it is noticed
that the last drop communicates a distinct red tinge, the operation is terminated. The
alkalimeter i allowed to drain for a few minutes, and the number of divisions of the test
liquor consumed read off. This number multiplied by 2 gives the amount of iron per
cent. in the specimen of ironstone, assuming that, as directed, 100 grs. have been used
for the experiment. The necessary calculation for ascertaining the corresponding quantity of protoxide is obvious.
When black-band ironstone is the subject of analysis, or when the ore affords indications by its appearance, or during the treatment with hydrochloric acid, that it contains an appreciable quantity of carbonaceous matter, then the hydrochloric acid solution must be filtered before being transferred to the basin, and the filter, with the insoluble ingredients, must be washed in the usual way with warm distilled water, slightly
acidulated with hydrochloric acid, until the filtrate ceases to give a blue colour with red
prussiate of potash. In those cases, also, where the presence of iron pyrites in the
ironstone is suspected, it will be necessary to remove the insoluble matter by filtering
before using the bichromate solution; but with ironstones in which the insoluble ingredients are merely clay and silica, filtration is not essential.
Now it is evident that the foregoing process, so far as I have described it, serves for
the determination of that portion of iron only which exists in the ore in the state of
protoxide. But many specimens of the common ironstone of this country contain appreciable quantities of peroxide of iron, which, being unacted upon by the bichromate of
potash, would escape estimation by the present method. By an additional and easy
operation, however, the amount of metallic iron in this ingredient may be likewise determined. It is only necessary to reduce it to the minimum state of oxidation, and then
to add the bichromate, as previously directed.
The best and most convenient agent for effecting the reduction of the persalts of iron,
is sulphite of soda. The only  precaution to be observed is to use it in sufficient
quantity, and at the same time to take care that the iron solution contains excess of
acid.  When the reduction is complete, a few minutes' ebullition suffices to decompose
the excess of sulphite of soda, and effectually to expel every trace of sulphurous acid.
In order to test the exactness of this mode of estimating the iron in the peroxide, I
made several experiments with peroxide prepared from  known quantities of pure iron
wire. The peroxide was thoroughly washed, dissolved in hydrochloric acid, reduced
with sulphite of soda, and after complete expulsion of the excess of sulphurous acid, the
solution was diluted with water and treated with bichromate of potash. I select three
of the experiments:~
Exp. 1.   10 grs. of iron consumed  887 of bichromate.
Exp. II.  18        do.    do.       15-94      do.
Exp. III. 25        do.    do.       22-15      do.
The mean of all my experiments on this point gives the ratio of 100 of iron to 88-6 of
bichromate, which is in close accordance with the former results.
Whenever, therefore, the ore of iron contains peroxide, it will be necessary to add
sulphite of soda to the hydrochloric acid solution before the addition of the test liquor




ISINGLASS.                                      1115
from the alkalimeter. The sulphite should be dissolved in distilled water, and added
to the solution of iron in small successive portions, until a drop of the liquor gives
merely a rose pink colour with sulpho-cyanide of potassium, which indicates that the
reduction of the persalt of iron is sufficiently perfect. The liquid is now heated till the
odour of sulphurous acid is no longer perceptible.  These operations should be performed while the solution is in the flask, and before it is filtered or transferred to the
basin.
I will here mention, for the guidance of those who may not be fully aware of the
reactions of the oxides of iron, that the existence of an appreciable quantity of peroxide
in the ironstone may be readily discovered by dissolving (as directed in the process) 30
or 40 grs. of the ore in hydrochloric acid, diluting with about 8 oz. of water, filtering
and testing a portion of the solution with sulpho-cyanide of potassium. If a decided
dark blood-red colour is produced, the quantity of peroxide in the stone must be determined; but if the colour is only light red or rose pink, the proportion is exceedingly
small, and for practical purposes not worth estimating. Of course, when the specimen
of ironstone has an ochrey or a reddish appearance on the surface or in the fracture, the
presence of a large proportion of peroxide is indicated, and its exact quantity must be
determined.
In conclusion, I must not omit to notice one or two circumstances which appear at
first to militate against the accuracy of this process. It may be questioned whether
solutions of the protosalts of iron do not absorb oxygen so rapidly from the air as to influence the results obtained by this method. Marguerite has shown, and my own observations completely confirm his statement, that protosalts of iron, in an acid solution,
become peroxydized very slowly; and, in a particular experiment, I found that contact
with the air during several hours caused no diminution in the quantity of bichromate
of potash required.  As the process may be completed in a few  minutes, it is certain
that no inaccuracy can arise from this cause.
It is also important to inquire whether the chromic acid in the chromates of potash
may not be partially deoxydized by hydrochloric acid alone without the presence of a
protosalt of iron.  Such a reaction would obviously give rise to a serious error.  It is
well known that concentrated hydrochloric acid rapidly decomposes the chromic acid of
the chromates when aided by the application of heat. But I have satisfied myself by
numerous experiments, that this acid exerts very little appreciable action upon dilute
solutions of the chromates of potash, either cold or warm, and that the action is only
partial even after continued ebullition; so that the present method is free from inaccuracy on this account.-Dr. Penney.
Bronzing of polished iron.-The barrels of fowling-pieces and rifles are occasionally
bronzed and varnished, to relieve the eye of the sportsman from the glare of a polished
metal, and to protect the surface from rusting. The liquid used for browning the barrels
is made by mixing nitric acid of specific gravity 1.2, with its own weight of spirit of nitric
ether, of alcohol, and tincture of muriate of iron; and adding to that mixture a quantity
of sulphate of copper equal in weight to the nitric acid and ethereous spirit taken together. The sulphate must be dissolved in water before being added; and the whole being
diluted with about 10 times its weight of water, is to be bottled up for use. This liquid
musthbe applied by friction with a rag to the clear barrel, which must then be rubbed
with a hard brush; processes to be alternated two or three times. The barrel should be
afterwards dipped in boiling water, rendered feebly alkaline with carbonate of potash or
soda, well dried, burnished, and heated slightly for receiving several coats of tin-smith's
lacquer, consisting of a solution of shellac in alcohol, coloured with dragon's blood.
ISINGLASS, or Fish glue, called in Latin ichthyocolla, is a whitish, dry, tough, semitransparent substance, twisted into different shapes, often in the form  of a lyre, and
consisting of membranes rolled together. Good isinglass is unchangeable in the air, has
a leathery aspect, and a mawkish taste, nearly insipid; when steeped in cold water it
swells, softens, and separates in membranous laminae.  At the boiling heat it dissolves
in water, and the solution, on cooling, forms a white jelly, which is semi-transparent,
soluble in weak acids, but is precipitated from them by alkalis. It is gelatine nearly
pure; and if not brittle, like other glue, this depends on its fibrous and elastic texture.
The whitest and finest is preferred in commerce. Isinglass is prepared from the airbladders of sturgeons, and especially the great sturgeon, the accipenser huso; which is
fished on the shores of the Caspian Sea, and in the rivers flowing into it, for the sake
chiefly of its swim bladder.
The preparations of isinglass in this part of Russia, and particularly at Astracan,
consists in steeping these bladders in water, removing carefully their external coat, and
the blood which often covers them, putting them  into a hempen bag, squeezing them,
softening them  between the hands, and twisting. them into small cylinders, which are
afterwards bent into the shape of a lyre. They are ready for the market immediately
after being dried in the sun, and whitened with the fumes of burning sulphur.




1116                              ISLAND  MOSS.
In some districts of Moldavia, another process is followed.  The skin, the stomach,
the intestines, and the swim bladder of the sturgeon are cut in small pieces, steeped in
cold water, and then gently boiled.' The jelly thus obtained is spread in thin layers to
dry, when it assumes the appearance of parchment. This being softened in a little water
then rolled into cylinders, or extended into plates, constitutes an inferior article.
The swim bladder of the cod and many other fishes also furnishes a species of isinglass, but it is much more membranous, and less soluble, than that of the sturgeon.
The properties of isinglass are the same as those of gelatine or pure glue; and its uses
are very numerous. It is employed in considerable quantities to clarify ale, wine, liqueurs,
wand coffee. As an article of food to the luxurious in the preparation of creams and jelit is in great request.  Four parts of it convert 100 of water into a tremulous jelly,
/nich is employed to enrich many soups and sauces. It is used along with gum as a
dressing to give lustre to ribands and other silk articles. The makers 6 artificial pearls
employ it to fix the essence d'Orient on the glass globules which form these pearls, and
the Turks set their precious stones or jewellery by means of isinglass dissolved in alco.
hol along with gum ammoniac; a combination which is also employed in this country to
join broken pieces of China and glass, under the name of diamond cement. That setting
preserves its transparency after it solidifies, if it be well made.
It is by covering taffety or thin silk with a coat of isinglass that court plaster is made.
A solution of isinglass colored with carmine forms an excellent injection liquor to the
anatomist. M. Rochen has made another pretty application of isinglass.  He plunges
into a limpid solution of it, made by means of a water bath, sheets of wire gauze set in
window or lamp frames, which, when cold, have the appearance of glass, and answer instead of it for shades and other purposes. If one dip be not sufficient to make a proper
transparent plate of isinglass, several may be given in succession, allowing each film to
harden in the interval between the dips. The outer surface should be varnished to protect it from damp air. These panes of gelatine are now generally used for lamps instead
of horn, in the maritime arsenals of France.
Isinglass imported for home consumption, and duties paid, in
1835.           1836.          1835.           1836.
1,814 cwts.  {  1,735 cwts. j  ~4,290             ~4,125
ISLAND MOSS (Lichen d'Islande, Fr.; Flechte Isl., Germ.) is a lichen, the Cetraria
islandica, which contains a substance soluble in hot water, but forming a jelly when it
cools, styled lichenine by M. Guerin. Lichenine has a yellowish tint in the dry state, is
transparent in thin plates, insipid, inodorous, and difficult to pulverize. Cold water makes
it swell, but does not dissolve it.  It is precipitated in- white flocks by alcohol and ether.
Iodine tihges it of a brownish-green.  Sulphuric, acid converts it into sugar; and the
nitric into oxalic acid. Lichenine is prepared by extracting first of all from the plant a
bitter coloring matter, by digesting I pound of it in 16 pounds of cold water, containing
1 ounce of pearlash; then draining the lichen, edulcorating with cold water, and boiling
it in 9 pounds of boiling water till 3 pounds be evaporated. The jelly which forms, upon
cooling the filtered solution, is dark colored, but, being dried and redissolved in hot water,
it becomes clear and colorless. Lichenine consists of 39*33 carbon, 7'24 hydrogen, and
55*43 oxygen. With potash, lime, oxyde of lead, and tincture of galls, the habitudes of
lichenine and starch are the same.  The mucilage of island moss is preferred in Germany to common paste for dressing the warp of webs in the loom, because it remains
soft, from its hygrometric quality. It is also mixed with the pulp for sizing paper in
the vat.
IVORY (Ivoire, Fr.; Elfewbein, Germ.) is the osseous matter of the tusks and
teeth of the elephant, the hippopotamus, or morse, wild boar, several species of phoce,
as well as the horn or tooth of the narwhal.  Ivory is a white, fine-grained, dense sub.
stance, of considerable elasticity, in thin plates, and more transparent than paper of equal
thickness.  The outside of the tusk is covered by the cortical part, which is softer and
less compact than the interior substance, with the exception of the brown plate that
sometimes lines the interior cavity. The hardest, toughest, whitest, and most translucent
ivory, has the preference in the market; and the tusks of the sea-horse are considered
to afford the best.  In these, a rough glassy enamel covers the cortical part, of such
hardness, as to strike sparks with steel.  The horn of the narwhal is sometimes ten feet
long, and consists of an ivory of the finest description, as hard as that of the elephant,
and susceptible of a better polish; but it is not in general so much esteemed as the
latter.
Ivory has the same constituents as the teeth of animales three fourths being phosphate,
with a little carbonate of lime; one fourth cartilage. See BONES.
It is extensively employed by miniature painters for their tablets; by turners, in
making numberless useful and ornamental objects; by cutlers, for the handles of knives
and forks; by comb-makers; as also by philosophical instrument makers, for constructing




IVORY                                       1117
the scales of thermometers, &c.  The ivory of the sea-horse is preferred by dentists for
making artificial teeth; that of the East India elephant is better than of the African.
~When it shows cracks or fissures in its substance, and when a splinter broken off has a
dull aspect, it is reckoned of inferior value. Ivory is distinguishable from bone by its
peculiar semi-transparent rhombohedral net-work, which may be readily seen in slips of
ivory cut transversely.
Ivory is very apt to take a yellow-brown tint by exposure to air. It may be whitened
or bleached, by rubbing it first with pounded pumice-stone and water, then placing it moist
under a glass shade luted to the sole at the bottom, and exposing it to sunshine.  The
sunbeams without the shade would be apt to occasion fissures in the ivory   The moist
rubbing and exposure may be repeated several times.
For etching ivory, a ground made by the following recipe is to be applied tu the polished surface:-~Take of pure white wax, and transparent tears of mastic, each one ounce;
asphalt, half an ounce.  The mastic and asphalt having been separately reduced to fine
powder, and the wax being melted in an earthenware vessel over the fire, the mastic is
to be first slowly strewed in and dissolved by stirring; and then the asphalt in like manner. This compound is to be poured out into lukewarm water, well kneaded, as it cools,
by the hand, into rolls or balls about one inch in diameter. These should be kept wrapped round with taffety. If white rosin be substituted for the mastic, a cheaper composition
will be obtained, which answers nearly as well; 2 oz. asphalt, 1 oz. rosin,   o. white
wax, being good proportions.  Callot's etching ground for copper plates, is made by dissolving with heat 4 oz. of mastic in 4 oz. of very fine linseed oil; filtering the varnish
through a rag, and bottlingit for use.
Either of the two first grounds being applied to the ivory, the figured design is
to be traced through it in the usual way, a ledge of wax is to be applied, and the
surface is to be then covered with strong sulphuric acid.  The effect comes better out
with the aid of a little heat; and by replacing the acid, as it becomes dilute by absorption of moisture, with concentrated oil of vitriol. Simple wax may be employed instead
of the copperplate engraver's ground; and strong muriatic acid instead of sulphuric. If
an acid solution of silver or gold be used for etching, the design will become purple or
black, on exposure to sunshine.  The wax may be washed away with oil of turpentine.
Acid nitrate of silver affords the easiest means of tracing permanent black lines upon
ivory.
Ivory may be dyed by using the following prescriptions
1. Black dye.-If the ivory be laid for several hours in a dilute solution of neutral
nitrate of pure silver, with access of light, it will assume a black color, having a slightly
green cast. A still finer and deeper black may be obtained by boiling the ivory for some
time in a strained decoction of logwood, and then steeping it in a solution of red sulphate
or rea acetate of iron.
2. Blue dye.-When ivory is kept immersed for a longer or shorter time in a dilute solution of sulphate of indigo (partly saturated with potash), it assumes a blue tint of greater
or less intensity.
3. Green dye.-This is given by dipping blued ivory for a little while in solution of
nitro-muriate of tin, and then in a hot decoction of fustic.
4. Yellow dye is given by impregnating the ivory first with the above tin mordant, and
then digesting it with heat in a strained decoction of fustic.  The color passes into
orange, if some Brazil wood has been mixed with the fustic. A very fine unchangeable
yellow may be communicated to ivory by steeping it 18 or 24 hours in a strong solution
of the neutral chromate of potash, and then plunging it for some time in a boiling hot
solution of acetate of lead.
5. Red dye-may be given by imbuing the ivory first with the tin mordant, then
plunging it in a bath of brazil wood, cochineal, or a mixture of the two. Lac-dye may
be used with still more advantage, to produce a scarlet tint. If the scarlet ivory be
plunged for a little in a solution of potash, it will become cherry red.
6. Violet dye-is given in the logwood bath, to ivory previously mordanted for a
short time with solution of tin. When the bath becomes exhausted, it imparts a lilac
hue. Violet ivcry is changed to purple-red by steeping it a little while in water containing a few drops of nitro-muriatic acid.
With regard to dyeing ivory, it may in general be observed, that the colours penetrate
better before the surface is polished than aferwards. Should any dark spots appear,
they may be cleared up by rubbing them with chalk; after which the ivory should be
dyed once more to produce perfect uniformity ef shade.  On taking it out of the boiling
hot dye bath, it ought to be immediately plunged into cold water, to prevent the chance
of fissures being caused by the heat.
If the borings and chips of the ivory-turner, caled ivory dust, be boiled in water,
a kind of fine size is obtained.




1118                             IVORY BLACK.
The importation of elephants' teeth amounts to about 5000 cwts. per annum.
Ivory made flexible. Ivory articles may be made flexible and semi-transparent, by
immersing them in a solution of pure phosphoric acid of sp. gr. 1,180, and leaving them
there till they lose their opacity; they are then to be taken out, washed with water,
and dried with a soft cloth; it thus becomes as flexible as leather. It hardens on
exposure to dry air, but resumes its pliancy when immersed in hot water. Necks of
children's sucking bottles are thus made.
IVORY  BLACK  (Noir d'ivoire, Fr.; Kohle voni Elfenbein, Germ.) is prepared
from ivory dust, by calcination in the very same way as is described under BooNE
BLACK.
The calcined matter being ground and levigated on a porphyry slab affords a beautiful velvety black, much used in copperplate printing. Ivory black may be prepared
upon the small scale by a well regulated ignition of the ivory dust in a covered
crucible.
END OF THE FIRST VOLUME.