3 = 1 = 
 
 nS"' 
 
 w 
 
 DUKE UNIVERSITY 
 MEDICAL CENTER LIBRARY 
 HISTORICAL COLLECTIONS 
 
 Gift of 
 
 Perkins Library 
 
 LIBRARY 
 
 DURni{vii I 
 
 DDK] 
 
 

 
■ mpf: n&m-u, u 
 
 r-f. 
 
 
 - ■:- I . > • 
 
 ^Llf ' 'y^ \.l '■>•./' 
 
 
 n, t 
 
 ^l. 
 
 Digitized by the Internet Archive 
 
 in 2016 
 
 
 
 r-'. ' 
 
 ‘h 
 
 
 Wf$ ' V 3 
 
 Vi' ‘■i«*4 
 
 https://archive.org/details/anatomyphysiolog11bell 
 
THE 
 
 ANATOMY AND PHYSIOLOGY 
 
 OP 
 
 iB©iDirc 
 
 CONTAINING 
 
 THE ANATOMY 
 
 OP THE BONES, MUSCLES, AND JOINTS, AND THE 
 HEART AND ARTERIES, 
 
 BY JOHN BELL ; 
 
 AND 
 
 THE ANATOMY AND PHYSIOLOGY 
 OP THE BRAIN AND NERVES, THE ORGANS OP THE 
 SENSES, AND THE VISCERA, 
 
 BY CHARLES BELL, E. R. S. E. 
 
 SURGEON TO THE MIDDLESEX HOSPITAL, AND READER »P ANATOMY 
 IN THE CHAIR OP DR. HUNTER, &.C. &C. 
 
 THE THIRD AMERICAN, FROM THE FOURTH ENGLISH EDITION. 
 
 IN THREE VOLUMES. 
 
 VOL. I. 
 
 V) === 
 
 NEW- YORK: 
 
 PRINTED AND SOLD BY COLLINS AND CO. NO. 189 , PEARL-STREET. 
 
 1817 . 
 

 m 
 
 
 •lie 
 
 
 ;,V . 
 
 * 5r i/v » ’ A '* 4 
 
 ' . * •* 
 
 .Vtiua ?r/.Mnj 
 
 
 -Tfe-'S “ 
 
 . - ^ 
 
 *’R/,an «MT‘-rr'-;r- ty/j -Xiirnm .tUT 
 
 ./•HXfJ J a54A 
 
 ‘ '^ -:*n 
 
 
 
 
 
THE 
 
 ANATOMY 
 
 OF THE 
 
 HUMAN BODY. 
 
 VOL. I. 
 
 CONTAINING 
 
 THE ANATOMY 
 
 OF 
 
 THE BONES, MUSCLES, AND JOINTS, THE HEART 
 AND CIRCULATION, 
 
 AND 
 
 THE LUNGS. 
 
> . 
 
 % 
 
 I 
 
TO 
 
 ALEXANDER WOOD, 
 
 SURGEON, 
 
 WHOSE ABILITIES AND SKILL, AND DISINTERESTED 
 CONDUCT, HAVE RAISED HIM, BY 
 COM»ION CONSENT, 
 
 TO THE FIRST RANK, IN A MOST USEFUL 
 PROFESSION; 
 
 CONDUCTING HIM, IN HONOUR, TO THAT PERIOD 
 OF LIFE, IN WHICH HE MUST FEEL WITH 
 PLEASURE, HOW COMPLETELY HE ENJOYS THE 
 CONFIDENCE OF THE PUBLIC, 
 
 AND THE ESTEEM OF ALL GOOD MEN, 
 
 THIS BOOK OF ANATOMY, 
 
 IS PRESENTED, 
 
 BY HIS PUPIL, 
 
 JOHN BELL. 
 

 .ii;i ifit m ’ik ,mout<r 
 
 ,, ■ . i; 'Yi-'(W. ^V ''s‘^fll|p^a'*' •••' ■ 
 
 '.«! i •. Wiri) ;.J -;•<•»/ 'I'lllH I iJi'.rtt ,'S^Hf- *J»I 
 
 ' ! ibsb 
 
 i-lj ■’?>(■? '^Vv^ #■/, r ^ 1 "*'' '**'^ M* '-!•■■ 
 
 . t WfW: •‘^1 
 
 I f *M'-.ir* r, siii Stiif ^ '< 
 
 f , ' _-'»»■ T-'t 4 »* 'r 4 U«' '.'.'•'V li *. r,-' ".'.,'\' 1 ’ \ ‘ 
 
 ^ J- t« ^»b-;reiiwf .4 V^lttr 
 
 ,;:» j ^m,.: tf«] ^ h 
 
 ,H|t -;mm 
 
 ,T#'>^r< 3 iA 4 »«if i»T 
 
 ©] i/i‘ : j»|rt'i i ^,‘:)t'i.;<?(|^ 7 , It- ^ 
 
 ■■'Y - .tS<»';f{J 6) '^'.«lu>^ioiJf.rV^!^fi; «^V;<:-,r '>'•' .^ 
 
 . .*» ar.v “I 'l‘:»' » ''•■■- 'tm 
 ; 4fMrt 
 :"'-v 
 
 m*lM;--r o ^ •■».;: 
 
 ’ 4 ( 8 ^ : aer" 
 
 i^fnjirnr J AIM' Iilltw 
 
 
 ..:i iiK^fclMl 
 
 '■ '* 
 
 ^■.'/■)< ft'j^'fn '‘'"‘I 
 
 
 T 
 
 •♦O'-. <^ •.. 
 
 r . v*.-v-S .■• 
 
 
PREFACE. 
 
 To those, who are at all acquainted with books on 
 anatomy, the appearance of a new one on the sub- 
 ject will not be surprising. To those, who are 
 not yet acquainted with such writings, I have only 
 to say, that I have written this book, because I be- 
 lieved that such a one was needed, and must be use- 
 ful. I have endeavoured to make it so plain and sim- 
 ple as to be easily understood ; I have avoided the te- 
 dious interlarding of technical terms, (which has been 
 too long the pride of anatomists, and the disgrace of 
 their science,) so that it may read smoothly, com- 
 pared with the studied harshness, and, I may say, 
 obscurity of anatomical description. If an author 
 may ever be allowed to compare his book with others, 
 it must be in the mechanical part ; and I may ven- 
 ture to say, that this book is full and correct in the 
 anatomy, free and general in the explanations, not 
 redundant, I hope, and yet not too brief. 
 
 If, in the course of, this volume, I shall appear to 
 have given a place and importance to theories far 
 higher than they really deserve, my reader uill natu- 
 rally feel how useful they are in preserving the due 
 balance between what is amusing, and what is useful ; 
 between the looser doctrines of functions, and the 
 close demonstration of parts. He will be sensible, 
 how much more easily these things can be read in 
 the closet, than taught in any public course ; he will, 
 I think, be ready to acknowledge, that I introduce 
 
Vlll 
 
 PREFACE. 
 
 such theories only, as should connect the whole, and 
 may be fairly chstinguished as the physiology of 
 acts ; and he will perceive, that in this too, I feel a 
 deference for the public opinion, and a respect for the 
 established course of education, which it is natural 
 to feel and to comply with. 
 
 Thus, perhaps it is less immodest for an author to 
 put down what he thinks he may honestly say con- 
 cerning his own book, than to omit those apologies 
 which custom requires, which give assurance, that he 
 has not entered upon his task rashly, nor performed 
 it without some labour and thought, and which are 
 the truest signs of his respect for the public, and of 
 his care for that science to which he has devoted his 
 iife. 
 
 With these intentions and hopes, I offer this book 
 to the public ; and more particularly to those in 
 whose education I have a chief concern ; not with- 
 out a degree of satisfaction at having accomplished 
 what I think cannot fail to be useful, and surely not 
 without an apprehension of not having done (in this 
 wide and difficult subject) all that may be expected 
 or wished for. 
 
 Every book of this kind should form a part of some 
 greater system of education : it should not only be 
 entire in its own plan, but should be as a part of 
 some greater whole; without which support and 
 connection, a book of science is insulated and lost. 
 This relation and subserviency of his own particular 
 task to some greater whole, is first in an author’s 
 mind : he ventures to look forward to its connection 
 with the general science, and common course of 
 education; or he turns it to a correspondence and 
 harmony with his own notions of study ; and if these 
 notions are to give the complexion and character to 
 any book, it should be when it is designed for those 
 entering upon their studies, as yet uncertain where to 
 begin, or how to proceed. 
 
 Hardly any one has been so fortunate as to pursue 
 the study of his own science under any regular and 
 
PREFACE, 
 
 ix 
 
 Jjerfect plan ; and there aie very few with whom a 
 consciousness of this does not make a deep and se- 
 rious impression at some future period, accompanied 
 with severe regret for the loss of time never to 
 be retrieved. In medicine, perhaps, more than in 
 any other science, we begin our studies thoughtless 
 and undecided, following whatever is delightful, (as 
 much is delightful,) neglecting the more severe and 
 useful parts : but as we advance towards that period 
 in which we are to enter upon a most difficult profes- 
 sion, and to take our place and station in life, and 
 when we think of the hesitation, anxiety, and appre- 
 hension with which we must move through the first 
 years of practice, we begin to look back with regret 
 on every moment that is past; with a consciousness 
 of some idle hours ; and (what is more afflicting still) 
 with an unavailing sense of much ill-directed, unpro- 
 fitable labour : — for there is no study Avhich a young 
 man enters upon with a more eager curiosity ; but, 
 not instructed in what is really useful, nor seriously 
 impressed with the importance of his future profes- 
 sion, he thinks of his studies rather as the amusement, 
 than as the business, of life ; slumbers through his 
 more laborious and usefiil tasks, and soon falls off to 
 the vain pursuit of theories and doctrines. 
 
 If I were not persuaded of the important con- 
 sequences, of the infinite gain or loss, which must 
 follow the first steps in every profession, I should 
 not feel, but, above all, I should not venture to 
 show, an anxiety, which may be thought affected 
 by those who cannot know how sincere it must be ; 
 for, in our profession, this is the course of things, 
 that a young man, who, by his limited fortune, or 
 the will of his friends, by absence fi-om his native 
 country, or by the destination of his future life, is re- 
 stricted to a feAV years of irregular, capricious, ill-di- 
 rected study, throws himself at once into the practice 
 of a profession, in which, according to his ignorance 
 or skill, he must do much good or much harm. Here 
 there is no time for his excursions into that region of 
 
 b 
 
X 
 
 PREFACE. 
 
 airy and fleeting visions, and for his returning again 
 to sedate and useful labour : there is no time for his 
 discovering, by the natural force of his own reason, 
 how vain all speculations are : — in but a few years, 
 at most, his education is determined ; the limited 
 term is completed, ere he have learnt that most use- 
 ful of all lessons — the true plan of study ; his^oppor- 
 ' tunities come to be valued (like every other happiness) 
 only Avhen they are lost and gone. 
 
 Of all the lessons which a young man entering 
 upon our profession needs to learn, this is, perhaps, 
 the first, — that he should resist the fascinations of 
 doctrines and hypotheses, till he have won the privi- 
 lege of such studies by honest labour, and a faithful 
 pursuit of real and useful knowledge. Of this know- 
 ledge, anatomy surely forms the greatest share. — 
 Anatomy, even w^hile it is neglected, is universally 
 acknowledged to be the very basis of all medical 
 skill. — It is by anatomy that the physician gfjesses 
 at the seat, or causes, or consequences, of any inter- 
 nal disease : without anatomy, the surgeon could not 
 move one step in his great operations : and those 
 theories could not even be conceived, which so often 
 usurp the place of that very science, from which they 
 should flow as probabilities and conjectures only, 
 drawn from its store of facts. 
 
 A consciousness of the high value of anatomical 
 knowledge never entirely leaves the mind of the stu- 
 dent. He begins with a strong conviction that this 
 is the great study, and with an ardent desire to mas- 
 ter all its difficulties : if he relaxes in the pursuit, it 
 is from the difficulties of the task, and the seduction 
 of theories too little dependent on anatomy, and too 
 easily accessible without its help. His desire for 
 real knowledge revives, only when the opportunity is 
 lost ; when he is to leave the schools of medicine ; 
 when he is to give an account of his studies, with an 
 anxious and oppressed mind, conscious of his igno- 
 rance in that branch which is to be received as the 
 chief test of his professional skill ; or when, perhaps. 
 
PREFACE. 
 
 XI 
 
 he feels a more serious and manly impression, the 
 difficulty and importance of that ait which he is 
 called to practise. 
 
 Yet, in spite of feeling and reason, the student en- 
 courages in himself a taste for speculations and theo- 
 ries, the idle amusements of the day, which even in 
 his own short course of study, he may observe sinking 
 in quick succession into neglect and oblivion, never 
 to revive ; he aspires to the character of a physiolo- 
 gist, to Avhich want of experience and a youthful 
 fancy, have assigned a rank and importance which it 
 does not hold in the estimation of those who should 
 best know its weakness or strength. The rawest stu- 
 dent, proud of his physiological knowledge, boasts of 
 a science and a name which is modestly disclaimed 
 by the first anatomist, and the truest physiologist of 
 this or any age : Dr. Hunter speaks thus of his phy- 
 siology, and of Iris anatomical demonstration : “ Phy- 
 “ siology, as fai' as it is known or has been explained 
 “ by Haller, and the best of the moderns, may be 
 “ easily acquired by a student without a master, pro- 
 “ vided the student is acquainted with philosophy 
 “ and chemistry, and is an expert and ready anato- 
 “ mist ; for with these qualifications he can read any 
 “ physiological book, and understand it as fast as he 
 “ reads. 
 
 “ In this age, when so much has been printed up- 
 “ on the subject, there is almost as little inducement 
 “ to attend lectures upon physiology, as there would 
 “ be for gentlemen to attend lectures upon govern- 
 “ ment, or upon the history of England. Lectures 
 “ upon subjects which are perfectly intelligible in 
 “ print, cannot be of much use, except when given 
 “ by some man of great abilities, who has laboured 
 “ the subject, and who has made considerable im- 
 “ provements either in matter or in arrangement. 
 
 “ In our branch, those teachers who take but little 
 “ pains to demonstrate the parts of the body with 
 “ precision and clearness, but study to captivate 
 “ young minds ^vith ingenious speculation, Avill not 
 
PREFACE. 
 
 yii 
 
 “leave a reputation that will outlive them half a 
 “ century. 
 
 “ I always have studied, and shall continue my en- 
 “ deavours, to employ the time that is given up to 
 “ anatomical studies as usefully to the students as I 
 “ can possibly make it — and therefore shall never 
 “ aim at showing what I know, but labour to show and 
 “ describe, as clearly as possible, what they ought to 
 “ know. This plan rejects all declamation, all parade, 
 “ all wrangling, all subtilty : to make a show, and 
 “ to appear learned and ingenious in natural know- 
 “ ledge, may flatter vanity ; to know facts, to sepa- 
 “ rate them from suppositions, to range and connect 
 “ them, to make them plain to ordinary capacities, 
 “ and above all, to point out the useful applications, 
 “ is, in my opinion, much more laudable, and shall 
 
 be the object of my ambition.”* 
 
 * Introductory Lecture published by Dr, Hunter. 
 
 Edinburgh, Sept. 1793. 
 
PREFACE 
 
 TO THE 
 
 FOURTH EDITION. 
 
 Xn giving this edition of the Anatomy of the Human 
 Body to the public, I have been careful to revise 
 the descriptions, and have made some additions ; so 
 that I hope it will be found to have fewer errors, and 
 to present a more perfect system. 
 
 Of the first part of the work by my brother, I may 
 speak more treely. And I may recommend it to 
 those who superintend the education of students, to 
 consider whether they have not in it a work calcu- 
 lated to open the minds of the pupils to the right 
 understanding of the important subjects of their 
 studies, and to give them conect and liberal views of 
 their profession. It will not be soon surpassed in 
 correctness and minuteness of description. 
 
 I have not dared to touch the History of the Ar- 
 teries ", the rapid improvement in the surgery of the 
 arteries, which followed as a consequence of the first 
 publication of this part of the Anatomy, has, with 
 me, made it sacred. What is delivered on the com- 
 pression of the great arteries, is an error on the safe 
 side. I may add, that without the necessity of mak- 
 ing experiments on so serious a subject, I have 
 found the strength of my thumb quite sufficient to 
 compress the main artery at the groin, both in 
 wounds of the femoral artery, and in circumstances 
 where I found it necessary to amputate the thigh, 
 without the possibility of using the tourniquet. I 
 must, however, acknowledge, that I have seen too 
 much loss of blood from trusting to compression in 
 
XIV 
 
 PREFACE. 
 
 amputating at the shoulder-joint. I think, in one 
 instance, the patient died from the loss of blood. 
 Few assistants have strength and dexterity to accom- 
 plish the entire compression of the artery in this 
 operation, and such have been my fears of haemo- 
 rrhage, that having had occasion to amputate at the 
 shoulder-joint, in order to avoid that danger, I 
 thought myself obliged to deviate from the common 
 manner of performing the operation. 
 
 On the subject of the Nerves, my reader will find 
 an account of that system, which I have delivered 
 in my Lectures for ten years past. That I have been 
 so long of placing my own particular views in a 
 systematic work, will only prove my respect for the 
 received opinions : but the manner in which so 
 many of my professional brethren have allowed them- 
 selves to be assailed by new and fantastic doctrines, 
 showing little respect for the old, makes me hesitate 
 less in substituting opinions different from those 
 hitherto admitted. 
 
 Considerable additions have been made to the 
 Anatomy and Physiology of the Viscera. 
 
 CHARLES BELL. 
 
 Soho-Square, London, 
 
 Jan. 1816 . 
 

 OF 
 
 THE FIRST VOLUME. 
 
 ANATOMY 
 
 OF THE 
 
 BONES, MUSCLES, AND JOINTS. 
 
 BOOK I. 
 
 OF THE BONES. 
 
 CHAP. I. 
 
 OF THE FORMATION AND GROWTH OF BONES, 1. 
 
 Page 
 
 History of the Doctrines of Ossification, 
 
 Phenomena of ossification. 
 
 Blood Vessels and Absorbents of Bones, and Proofs of 
 
 the Deposition and Re-absorption of the Bony Matter, 7 
 Nerves of Bones, and Proofs of the Sensibility of Bones, 11 
 
 The Process of Ossification described, . . 13 
 
 1. The various Forms, and numerous Points of Ossi- 
 
 fication, ..... 14 
 
 2. The Heads and Processes of Long Bones. 
 
 3. The Cavity of Long Bones, . . 15 
 
 4. The CanceHi. 
 
 5. The Marrow. 
 
 6. The Lammellae, or Bony Plates. 
 
 7. The Holes of Bones, ... 17 
 
 8. The Vessels, . . . .18 
 
 9. The Periosteum. 
 
 to 
 
XVi. CONTENTS. 
 
 Page 
 
 10. The Cartilages, • ... 20 
 
 The Callus and Regeneration of Broksn Bones, . 21 
 
 CHAP. II. 
 
 OF THE SKULL IN GENERAL, 24. 
 
 Importance of the Anatomy of the Skull, . . 24 
 
 The Tables and Diploe of the Bones of the Skull. 
 Enumeration and short Description of the Bones of the 
 Cranium, . . . . • .26 
 
 The Sutures, ..... 27 
 
 Remarks on the Formation, Nature, and Use of Sutures, 29 
 
 CHAP. HI. 
 
 DESCRIPTION OF THE INDIVIDUAL BONES OF 
 THE SKULL, 35 . 
 
 Os Fkontis, . .... 35 
 
 \ 1. Superciliary Ridge, ... 36 
 
 2. Artery and Nerve. 
 
 3. Angular Processes. 
 
 4. Nasal Process. 
 
 5. Frontal Sinuses. 
 
 6. Frontal Ridge or Spine. 
 
 7. Orbitary Process. 
 
 Os Parietale, . . ... .40 
 
 Os OcciPiTis, ..... 42 
 
 I. External Surface. 
 
 1. Transverse Spines. 
 
 2. Crucial Spine. 
 
 3. Posterior Tuberosity. 
 
 II. Internal Surface. 
 
 1. Greal Internal Ridge and Tentorium Ce- 
 
 rebello Superextensum. 
 
 2. Hollows of the Occipital Bone. 
 
 Processes of the Occipital Bone. 
 
 1. Cuneiform 
 
 2. Condyles. 
 
 Holes. 
 
 1. Foramen Magnum. 
 
 2. Hole for the ninth Pair of Nerves. 
 
 3. Hole for the Cervical Vein of the Neck. 
 
 4. Common hole. 
 
 Os Temporis, , , . ., . 44 
 
 Squamous part. . 
 
CONTENTS. XVll 
 
 Page 
 
 Petrous Pai’tj .... 44 
 
 Processes. 
 
 1. Zygomatic. 
 
 2. Styloid. 
 
 3. Vaginal. 
 
 4. Mastoid or Mamillarj’. 
 
 5. Auditojy. 
 
 Holes. 
 
 For the Ear. 
 
 1. Meatus Auditorius Externus. 
 
 2. Internus. 
 
 3. Small Hole Receiving a Branch 
 
 from the fifth Pair of Nerves. 
 
 4. Stylo-Mastoid Hole. 
 
 5. Hole for the Eustachian Tube. 
 
 For Blood Vessels. 
 
 1. For the Carotid Artery. 
 
 2. For the Great Lateral Sinus, call- 
 
 ed the Common Hole, as formed 
 partly by the Temporal, partly 
 by the Occipital Bone. 
 
 3. Small Hole on the outside of the 
 
 Temporal Bone. 
 
 Os CEthmoides, ..... 50 
 
 1. Cribriform Plate. 
 
 2. Crista Galli. 
 
 3. Nasal Plate, or Azygous Process. 
 
 4. Spongy Bones. 
 
 5. Orbitary Plate, or Os Planum. 
 
 6. Os Unguis. 
 
 7. Cells. 
 
 Os Sphenoides, ..... 52 
 
 Processes. 
 
 1. Alae. 
 
 2. Orbitary process. 
 
 3. Spinous process. 
 
 4. Styloid process. 
 
 5. Pterygoid processes. 
 
 6. Azygous process. 
 
 7. Clynoid processes. 
 
 Anterior. 
 
 Posterior. 
 
 Celia Turcica, and its Cells. 
 
 Holes. 
 
 1. Foramen Opticum 
 c 
 
 von. 1 . 
 
xvm 
 
 CONTENTS. 
 
 Page 
 
 2. Foramen Lacerum . . 56 
 
 3. 
 
 Rotundum. 
 
 4. 
 
 Ovale. 
 
 5. 
 
 Spinale. 
 
 6. Pterygoid, or Vidian Hole. 
 CHAP IV. 
 
 BONES OF THE FACE AND JAWS, 58. 
 Ossa Nasi, . . . ' . 
 
 OaSA MAXILLARIA SuPERlORA, 
 
 Processes. 
 
 1. Nasal. 
 
 2. Orbitary. 
 
 3. Malar. 
 
 4. Alveolar. 
 
 ' 5. Palate process. 
 
 Antrum Maxiilai’e, or Higbmorianum. 
 
 Holes. 
 
 1. Infra Orb itary. 
 
 2. Foramen Incisivuin, or Anterior Pala- 
 
 tine Hole. 
 
 3. Posterior Palatine Hole. 
 
 OssA Palati, ..... 
 Processes. 
 
 1. Palatal Plate or Process. 
 
 Middle Palatal Suture. 
 
 Transverse Palatal Suture. 
 
 2. Pterygoid Process. 
 
 3. Nasal Plate or Process. 
 
 4. Orbitary Process, 
 
 Palatine Cells. 
 
 Ossa Spongiosa or Turbinata Inperiora, 
 
 VOMCH, . . . . 
 
 Os Mal^, . . 
 
 Processes. 
 
 1. Upper Orbitary. 
 
 2. Inferior Orbitary. 
 
 3. Maxillary. 
 
 4. Zygomatic. 
 
 5. Internal Orbitary. 
 
 Os Maxillss Infkkioris, 
 
 Processes. 
 
 1. Coronoid. 
 
 2. Condyloid. 
 
 3. Alveolar. 
 
 58 
 
 59 
 
 64 
 
 65 
 
 66 
 67 
 
 6T 
 
CONTENTS. 
 
 XIX 
 
 Page 
 
 Holes, ... .70 
 
 1. Large Hole on the inner Side for the 
 
 Entry of the lower Maxillary Nerve 
 and Artery. 
 
 2. Mental Hole. 
 
 CHAP. V. 
 
 OF THE BONES OF THE TRUNK ; OF THE SPINE, 
 THORAX, AND PELVIS, 70. 
 
 I. Of the spine General View of the Spine its 
 
 Motions and the Division t»f the Vertebrie, 70 
 
 General Description of a Vertebra, . 71 
 
 1. Body of the Vertebra. 
 
 2. Articulating, or Oblique Processes. 
 
 6. Spinous Processes. 
 
 4. Transverse Processes. 
 
 Vertebrse of the Loins, ... 73 
 
 Vertebrca of the Back, ... 74 
 
 VertebriB of the Neck, . . .75 
 
 Atlas, ..... 76 
 
 Dentatus, . . . .76 
 
 Medullary Tube and the Passage of the Nerves, 79 
 Intervertebral Substance, . . 79 
 
 Motions of the Vertebra;, . . SO 
 
 II. Ribs and Sternum, . . .. .81 
 
 i. Of the Ribs. 
 
 General Description of a Rib — Division of 
 the ribs into true and false — Form of a 
 Rib, and place of the Intercostal Artery. 
 
 The parts of the Rib, as the Head, Neck 
 — Surface for articulating with the 
 Transverse Process — Nature of the 
 Joint and Motion of the Rib — Angle of 
 
 Rib, .... 82* 
 
 Size and Length of the Ribs — The Car- 
 tilages of the Ribs, . . 83 
 
 ii. Of the Sternum and its three parts, . 84 
 
 III. Of the Pelvis, .... 86 
 
 i. Os Sacrum, ... 87 
 
 ii. Os CoccYGis, ... 89 
 
 iii. Ossa Innominata, . . 89 
 
 1. Os Ilium, or Haunch-Bone 
 
 1. Ala — Spine — Spinous Process 
 es, anterior and posterior — • 
 
XX 
 
 COIN TENTS. 
 
 2. Dorsum — 3. Costa — 4. Linea 
 Innominata, 
 
 ii. Os iscHiDBi, or Hip-Bone- 
 
 1. Body — 2. Tuber — 3. Ra- 
 mus, - - _ 
 
 iii. Os Pubis, or Share-Bone 
 
 Body Crest Ramus, 
 
 Recapitulation of the chief Points of the 
 Anatomy of the Pelvis, 
 
 Size of the Pelvis in Man and Woman, 
 Remarks on the Separation of the Bones 
 of the Pubes during Labour. 
 
 CHAP. VI. 
 
 BONES OF THE THIGH, LEG, AND FOOT, 98. 
 
 I. Femur, - - - * - 
 
 1. Body. 
 
 2. Head. 
 
 3. Neck. 
 
 4. Trochanter major. 
 
 5. Trochanter minor. 
 
 6. Linea aspera. 
 
 7. Condyles. 
 
 II. Tibia, 
 
 1. Upper Head. 
 
 2. Body. 
 
 3. Lower Head — Inner Ankle. 
 
 III. Fibula, _ . _ _ _ 
 
 1. Upper Head. 
 
 2. Lower Head — Outer Ankle. 
 
 IV. Rotula, Patella, or Knee-pan, 
 
 V. Tarsus, or Instep, - - - - 
 
 1. Astragalus. 
 
 2. Os Calcis. 
 
 3. Os Naviculare. 
 
 4. ^ 
 
 5. V Cuneiforme Bones. 
 
 6 . ) 
 
 7. Os Cuboides. 
 
 VI. Toes, — S esamoid Bones, - 
 
 VII. Metatarsus and its five Bones, 
 
 Page 
 
 90 
 
 91 
 
 92 
 
 93 
 
 94 
 
 95 
 98 
 
 102 
 
 104 
 
 105 
 
 106 
 
 109 
 
 110 
 
CONTENTS. 
 
 XXI 
 
 CHAP. VII. 
 
 Page 
 
 BONES OF THE SHOULDER, ARM, AND HAND, 111 . 
 
 I. Shoulder. 
 
 i. Scapula or Shoulder-blade, - 111 
 
 1. The flat Side of the Scapula. 
 
 2. The upper flat Surface. 
 
 3. The Triangular Form of the Scapu- 
 
 la, — Costa — Basis. 
 
 4. The Glenoid, or Articulating Cavity. 
 
 5. The Neck. 
 
 6. The Spine. 
 
 7. The Acromion Process. 
 
 8. The Coracoid Process. 
 
 ii. Clavicle, or Collar-bone, - 115 
 
 1. The Thoracic End and Joint. 
 
 2. The Outer End, and its Union with 
 
 the Scapula. 
 
 II. Arm. 
 
 Os Humeri, - - - - 116 
 
 1. Head. 
 
 2. Neck. 
 
 3. Tuberosities. 
 
 4. Groove for the Tendon of the Biceps 
 
 Muscle. 
 
 5. Ridges leading to the Condyles. 
 
 6. Condyles. 
 
 7. Articulating Surface for the Elbow- 
 
 joint, and general Explanation of 
 the Joint. 
 
 8. Hollows for the Olecranon and Cord- 
 
 noid Process of the Ulna. 
 
 III. Ulna and Radius, ... - H'8 
 
 I. Ulna. 
 
 1. Greater Sigmoid Cavity, formed by 
 
 1. Olceranon. 
 
 2. Coronoid Process. 
 
 2. Lesser Sigmoid Cavity for receiving 
 
 the Head of the Radius. 
 
 3. Ridges. 
 
 4. Lower Head of the Ulna. 
 
 5. Styloid Process of the Ulna. 
 
 II. Radius, 
 
 I. Body. 
 
 120 
 
XXU CONTENTS. 
 
 Page 
 
 2. Upper Head, - - 120 
 
 3. Necir. 
 
 4. Point for the Implantation of the Biceps. 
 
 Flexor Cubiti. 
 
 5. Lower Head. 
 
 IV. Hand and Fingers. - - . 121 
 
 General Explanation of the Hand and Wrist, 
 Carpus, Metacarpus, and Fingers. 
 
 ' I. Carpus or Wrist, - - 122 
 
 1. Rovv forming the Wrist, - 123 
 
 1. Os Scaphoides. 
 
 2. Os Lunare. 
 
 3. Os Cuneiforme. 
 
 4. Os Pisiforme. 
 
 2. Row supporting the Metacarpal 
 
 Bones, - - - 124 
 
 1. Trapezium. 
 
 2. Trapezoides. 
 
 3. Os Magnum. 
 
 4. OsUnciforme. 
 
 H. Metacarpus, - - . 125 
 
 HI. Fingers, - 126 
 
 Of the Teeth, by Mr. Charles Bell, - - 127 
 
 Description of the Human Adult Teeth. 
 
 1. The Incisores. 
 
 2. The Cuspidati, or Canine Teeth. 
 
 3. The Bicuspides. 
 
 4. The Molares or Grinding Teeth. 
 
 Of the first Set of the Teeth, the Milk, or Deciduous 
 
 Teeth, 130 
 
 Of the Structure of the Teeth, - - 131 
 
 Of the central bony Part of the Teeth, - 133 
 
 Of the Vascularity and Constitution of the bony Part 
 of the Tooth, . _ _ _ 134 
 
 Of the Formation and Growth of the Teeth, - 138 
 
 Of the Growth of the second Set of Teeth, and the 
 shedding of the first, - - - 14] 
 
CONTENTS. 
 
 XXIU 
 
 BOOK II. 
 
 OF THE MUSCLES. 
 
 CHAP. I. 
 
 MUSCLES OF THE FACE, EYE, AND EAR. 
 
 Page 
 
 I. Muscles of the Face, . - - - 145 
 
 1 . Occipito Frontalis. 
 
 2. Corrugator Supercilii, - _ _ 140 
 
 3. Orbicularis Oculi, or, Palpebrarum, - 147 
 
 4. Levator Palpebraa Superioris. 
 
 II. Muscles of the Nose and Mouth, - - 14S 
 
 5. Levator Labii Superioris, et Alse Nasi. 
 
 7. Levator Anguli Oris, or, Levator Com- 
 munis Labiorum, - . . 149 
 
 S. Zygomaticus major. 
 
 9. — minor. 
 
 10 . Buccinator. 
 
 11 . Depressor Anguli Oris, - - - 150 
 
 12 . Depressor Labii Inferioris, or, Quadratus 
 
 Gense. 
 
 13. Orbicularis Oris, _ _ _ 151 
 
 14. Depressor Labii Superioris, et Alas Nasi, 152 
 
 15. Constrictor Nasi. 
 
 16. Levator Men ti. 
 
 III. Muscles of the External Ear. - - 152 
 
 17. Superior Auris, - - - - 153 
 
 18. Anterior Auris. 
 
 19. Posterior Auris. 
 
 20 . Helicis major. 
 
 21 Helicis minor, - - - - 154 
 
 22 . Tragic us. 
 
 23. Antitragicus. 
 
 24. Trans versus Auris. 
 
 IV. Muscles of the Eye-ball. - - - 154 
 
 General Explanation of these Muscles. 
 
 25 Rectus Superior, _ _ . 155 
 
 26. Rectus Inferior. 
 
 27 . Rectus Internus. 
 
 28. Rectus Externus. 
 
 29. Obliquus Superior, . . _ 150 
 
 30. Obliquus Inferior.* 
 
XXiV 
 
 CONTENTS. 
 
 CHAP. n. 
 
 MUSCLES OF THE LOWER JAW, THROAT, AND TONGUE. 
 
 Page 
 
 I, Muscles of the Lower Jaw, - - _ 157 
 
 31. Temporalis. 
 
 32. Masseter, 
 
 33. Pterygoideus Internus, or Major, - 158 
 
 34. Pterygoideus Externus, or Minor. 
 
 II. Muscles of the Throat and Tongue. 
 
 Explanation of certain Bones and Cartilages form- 
 ing the Basis of the Throat and Tongue, and the 
 Centre of their Motions. 
 
 1. Os Hyoides. — Its Cornua. — Its Appen- 
 dices or perpendicular Processes. 
 
 2. Larynx, Trachea, or Windpipe, - - 159 
 
 1. Scutiform, or Thyroid Cartilage, - 160 
 
 2. Cricoid Cartilage. 
 
 3. Arytenoid Cartilages, and Riraa Glottidis 
 
 formed by them. 
 
 4. Epiglottis, - - - - 161 
 
 Recapitulation and View of the Constitution of 
 
 the Larynx. 
 
 i. Muscles of the Throat. - 161 
 
 1. Muscles which pull the Throat down, - 162 
 
 34. Sterno-hyoideus. 
 
 35 Sterno-thyroideus. 
 
 36. Orno hyoideus. 
 
 Action of these Muscles. 
 
 2. Muscles which move the Throat upwards. 
 
 37. Blylo- hyoideus. 
 
 38. Genio-hyoideus, - - - 163 
 
 39. ''tylo-hyoideus. 
 
 40. Digastricus, or Biventer Maxillae Inferio- 
 
 ris. 
 
 3. Muscles moving the Parts and Cartilages of 
 
 the Larynx upon each other. - - 164 
 
 41. Hyo-thyroideus. 
 
 42. Crico-thyroideus. 
 
 43. Musculus Arytenoideus Transversus, 165 
 
 44. Musculus Arytenoideus Obliquus. 
 
 45. Crico Arytenoideus Posticus. 
 
 46. Crico Arytenoideus Obliquus. 
 
 47. Thyreo Arytenoideus. 
 
 4. Muscles of the Palaje and Pharynx. 
 
 48. Azygos Uvulae, 
 
 166 
 
CONTENTS. 
 
 XXV 
 
 Page 
 
 49. Levator Palati Mollis. - - 166 
 
 50. Circumfiexus Palati, or Tensor Palati 
 
 Mollis. 
 
 51. Constrictor Isthmi Fauscium, - 167 
 
 52. Palato Pharyngeus. 
 
 Pharynx explained. 
 
 53. Stylo-pbaryngeus, - - - 168 
 
 54. Constrictor Superior. 
 
 55. Constrictor Medius. 
 
 56. Constrictor Inferior, - - 169 
 
 57. (Esophagus. 
 
 58. Vaginalis Gulae. 
 
 ii. Muscles of the Tongue. 
 
 59. Hyo-glossus. 
 
 60. Genio-glossus. 
 
 61. Lingualis. 
 
 Motions of the Tongue performed by these 
 Muscles. 
 
 CHAP. III. 
 
 OF THE MUSCLES OF THE ARM, INCLUDING THE MUS- 
 CLES OF THE SCAPULA, ARM, FORE-ARM, AND HAND. 
 
 I. Muscles of the Scapula, - - 171 
 
 i. Muscles moving the Scapula upwards and 
 
 backwards. 
 
 62. Trapezius. 
 
 63. Levator Scapulae, or Levator Proprius 
 
 Angularis, - - - 172 
 
 64. and 65. Rhomboides. 
 
 1. Minor, - - 173 
 
 2. Major. 
 
 ii. Muscles which move the Scapula downwards 
 
 and forwards. 
 
 66. Serratus Major Anticus. 
 
 
 
 
 67. Pectoralis Minor, 
 
 68. Subclavius. 
 
 Motions of the Scapula. 
 
 II. Muscles moving the Os Humeri, 
 
 OR Arm-Bone. 
 
 174 
 
 69. Pectoralis Major, 
 
 70. Latissimus Dorsi. 
 
 • 
 
 - 
 
 175 
 
 71. Deltoides, 
 
 ■ - 
 
 - 
 
 176 
 
 72. Coraco-brachialis, 
 
 - 
 
 - 
 
 177 
 
 78. Supra Spinatus, 
 VoL. I. d 
 
 
 - 
 
 178 
 
XXVI 
 
 CONTENTS. 
 
 74. Infra Spinatus, - - - - J78 
 
 75. Teres Minor, - - _ - 179 
 
 76. Teres Major. 
 
 77. Subscapularis. 
 
 Motions of the Humerus, and Use and Effect 
 of each of these Muscles in forming and 
 strengthening the Joint, - - . JSO 
 
 III. Muscles moving the Fore- arm. 
 
 i. Muscles bending the Fore-arm, - - 181 
 
 78. Biceps Brachii Flexor. 
 
 79. Brachialis Internus, - - _ 192 
 
 ii. Muscles extending the Fore-arm. 
 
 80. Triceps Extensor. 
 
 81. Anconeus, _ - - . 184 
 
 IV. Muscles situated on the Fore-arm moving the 
 
 Radius, Carpus, and Fingers. 
 
 Fascia of the Arm. 
 
 Arrangement of these Muscles, the Points of 
 Origin and Insertion, and the Motions of Pro- 
 nation and Supination, Flexion and Exten- 
 sion, explained, - - - - 185 
 
 i. Flexors, arising from the Inner Condyle, 186 
 
 82. Pronator Teres Radii. 
 
 83. Palmaris Longus, _ - _ 137 
 
 84. Palmaris Brevis, or Cutaneus, 188 
 
 85. Flexor Carpi Radialis. 
 
 86. Flexor Carpi Ulnaris, - - 189 
 
 87. Flexor Digitorum Sublimis. 
 
 88. Flexor Digitorum Profundus, vel Perfo- 
 
 rans, _ - - - _ 190 
 
 89. Lumbricales, - - - 191 
 
 90. Flexor Longus Pollicis, - - 192 
 
 91. Pronator Quadratus. 
 
 ii. Extensors arising from the Outer Condyle, 193 
 
 92. Supinator Radii Longus. 
 
 93. Extensor Carpi Radialis Longior, - 194 
 
 94. Extensor Carpi'Radialis Brevior. 
 
 95. Extensor Carpi Ulnaris, - - 195 
 
 96. Extensor Digitorum Communis. 
 
 97. Extensor Minimi Digiti, or Auricularis, 196 
 
 98. Extensor Primus Pollicis, ^ - 197 
 
 99. Extensor Secundus Pollicis, > - 198 
 
 100. Extensor Tertius Pollicis. J 
 
 101. Indicator, . _ _ - 199 
 
 102. Supinator Brevis. 
 
CONTENTS. 
 
 V, Muscles seated on the Hand. 
 
 Table of these Muscles, 
 
 103. Abductor Pollicis. 
 
 104. Opponens Pollicis, 
 
 105. Flexor Brevis Pollicis. 
 
 106. Adductor Polliois, 
 
 107. Abductor Minimi Digiti 
 
 108. Flexor Parvus Minimi Digiti. 
 
 109. Adductor Minimi Digiti, 
 
 110. Abductor Indicis. 
 
 111. Interossei Interni. 
 
 112. Interossei Externi. 
 
 CHAP. IV. 
 
 MUSCLES OF RESPIRATION, OR OF THE RIBS. 
 
 General Explanation and Table of these Muscles. 
 
 113. Serratus Superior Posticus 
 
 114. Serratus Inferior Posticus. 
 
 115. Levatores Costarum, 
 
 116. Intercostales. 
 
 117. Triangularis Sterni, or, Stemo-costalis 
 
 CHAP. V. 
 
 MUSCLES OF THE HEAD, NECK, AND TRUNK. 
 
 I. Muscles of the Head and Neck. 
 
 118. Splenius. 
 
 119. Complexus. 
 
 120. Trachelo mastoideus. 
 
 121. Rectus Minor. 
 
 122. Rectus Major. 
 
 123. Obliquus Superior, _ 
 
 124. Obliquus Inferior. 
 
 II. Muscles of the Trunk. 
 
 125. Quadratus Lumborum. 
 
 126. Longissimus Dorsi, 
 
 127. Sacro Lumbalis, - - - 
 
 128. Cervicalis Descendens. 
 
 129. Transversalis Colli, . - 
 
 Arrangement of the intricate Set of 
 Muscles filling up the Hollows and 
 Interstices among the Spines and 
 Processes of the Vertebra^, 
 
 xxvii 
 
 Page 
 
 199 
 
 200 
 
 201 
 
 202 
 
 203 
 
 204 
 
 205 
 
 206 
 
 207 
 
 208 
 
 210 
 
 211 
 
 212 
 
 213 
 
 214 
 
 214 
 
xxvm 
 
 CONTENTS. 
 
 130. Spinalis Cervicis, - - - 315 
 
 131. Spinalis Dorsi. 
 
 132 Semi-spinalis Dorsi, - - - 216 
 
 133. Multifidus Spinie. 
 
 134. Inter-spinalis Colli, Dorsi, et Lumborum, 217 
 
 135. Inter-transversales. 
 
 III. MrSCl.KS ON THK' FORK PART OF THE HeAD AND 
 
 Neck, completing the Catalogue of those belong- 
 ing to the Spine. 
 
 136. Platysma Myoides. 
 
 137. Mastoideus, - - _ . 218 
 
 136. Rectus Internus Capitis Major. 
 
 139. Rectus Internus Capitis Minor. 
 
 140. Rectus Capitis Lateralis. 
 
 141 Longus Colli. 
 
 142. Scaleni, - - - - 219 
 
 CHAP. VI. 
 
 OF THE MUSCLES OF THE ABDOMEN, AND OP THE 
 DIAPHRAGM. 
 
 I. Muscles of the Abdomen - _ - 220 
 
 Importance of the Anatomy of the Abdominal 
 Muscles, — General Explanation of these 
 Muscles, — their Uses, — Arrangement. 
 
 143 Obliquus Externus, _ _ - 221 
 
 144. Obliquus Internus, - - 222 
 
 145 Transversalis Abdominis. 
 
 146 Recti, - - - - 223 
 
 147- Pyramidalis. 
 
 Explanation of the Lines, Rings, &zc. of the 
 Abdominal Muscles. 
 
 1 Linea Alba. 
 
 2. Linea Semilunaris, - - 224 
 
 3. Sheath for the Rectus. 
 
 4. Umbilicus. 
 
 5. Ring of the Abdominal Muscles, 225 
 
 148. Cremaster Muscle of the Testicle, 226 
 
 6. Ligament of the Thigh, 
 
 Explanation of the different Kinds of Hernia, 
 
 and the Points at which the Bowels are pro- 
 truded. - - - - 227 
 
 Uses of the Abdominal Muscles. 
 
CONTENTS. 
 
 XXIX 
 
 Page 
 
 II. Diaphbagm, - 227 
 
 149. The Diaphragm. 
 
 1. The Greater, or Upper Muscle of the 
 
 Diaphragm, - - - 228 
 
 2. The Lesser Muscle of the Diaphragm. 
 
 3. The Tendon in the Centre of the Dia- 
 
 phragm. 
 
 Vessels perforating the Diaphragm, - 229 
 
 1. Aorta. 
 
 2. (Esophagus. 
 
 3. The Great Vena Cava. 
 
 The Tendon of the Diaphragm. 
 
 Uses of the Diaphragm, - - 230 
 
 CHAP. VII. 
 
 THE MUSCLES OF THE PARTS OF GENERATION, AND 
 OF THE ANUS AND PERINEUM. 
 
 General Idea of these Muscles, - - _ 231 
 
 Structure of the Penis. 
 
 150. Erector Penis. 
 
 151. Transversalis Perinaei, - - 232 
 
 152. Accelerator. 
 
 153. Sphincter Ani, - . . 233 
 
 154. Levator Ani. 
 
 155. Musculus Coccygseus, - - 234 
 
 Perinaeum, — the Point where All these Muscles are united. 
 Course of the Incision in Lithotomy. 
 
 CHAP. VIII. 
 
 MUSCLES OF THE THIGH, LEG, AND FOOT. 
 
 I. Muscles moving the Thigh-bone, - - 235 
 
 General Description of these Muscles, — Classifi- 
 cation and Arrangement of them, — and Table 
 of their Implantations, and of the Motions which 
 they perform. 
 
 Fascia of the Thigh, . _ _ 237 
 
 156. Musculus Fascialis, or. Tensor Vaginae Fe- 
 
 moris, - - - 238 
 
 157. Psoas Magnus. 
 
 158. Psoas Parvus. 
 
 159. Iliacus Inlernus, ... 289 
 
 160. Pectineus, or Pectinalis. 
 
XXX 
 
 CONTENTS. 
 
 Tags 
 
 161. Triceps Femoris, _ - - 240 
 
 1. Adductor Longus. 
 
 2. Adductor Brevis. 
 
 3. Adductor Magnus, - - 241 
 
 162. Obturator Externus. 
 
 163. Glutfeus Maximus, _ - . 242 
 
 164. Glutaeus Medius, or Minor. 
 
 165. Glutaeus Minimus, . - - 243 
 
 167 I 
 
 168. Pyriformis. 
 
 169. Obturator Internus, - - - 244 
 
 170. Quadratus Femoris. 
 
 Motions of the Thigb, and Action of these Muscles. 
 
 >11. Muscles of the Leg, - - - 245 
 
 Arrangement of these Muscles. 
 
 i. Extensors of the Leg. 
 
 171 . Rectus Femoris, or, Rectus Cruris, - 246 
 
 172. Cruraeus, - 247 
 
 Sub cruraei, being Slips only of the Cru- 
 raeus. 
 
 173. Vastus Externus. 
 
 174. Vastus Internus. 
 
 Uses of these Muscles, _ _ - 248 
 
 ii. Flexors of the Leg, - - - 249 
 
 175. Sartorius. 
 
 176. Gracilis, or, Rectus Internus Femoris. 
 
 177. Seraitendinosus, - - - 250 
 
 178. Semimembranosus. 
 
 179. Poplitaeus, - - - - 251 
 
 180. Biceps Cruris. 
 
 III. Muscles of the Foot, - - - 252 
 
 Arrangement. 
 
 i. Extensors. 
 
 181- Gastrocnemius. 
 
 182. Soleus, - - - ■ 253 
 
 183. Plantaris. 
 
 184- Peronseus Longus, - - - 254 
 
 185. Peronaeus Brevis, - - - 255 
 
 186. Peronaeus Tertius. 
 
 187. Tibialis Posticus, _ - - 256 
 
 ii. Flexor. 
 
 188. Tibialis Anticus. 
 
 IV. Muscles of the Toes, _ - - 257 
 
CONTENTS. 
 
 XXXI 
 
 Page 
 
 189. Flexor Longus Pollicis. - - 257 
 
 190. Flexor Longus Digitorum Pedis Perforans, 258 
 
 191. Massa Carnea J. Silvii, or, Plantae Pedis, 259 
 
 192. Flexor Brevis Digitorum. 
 
 193. Lumbricales, - - _ 260 
 
 194. Extensor Longus Digitorum Pedis. 
 
 195. Extensor Digitorum Brevis, - - 261 
 
 196. Extensor Pollicis Proprius. 
 
 Crucial Ligament, _ - - 262 
 
 197. Abductor Pollicis. ^ 
 
 198. Flexor Brevis Pollicis, > - - 263 
 
 199. Adductor Pollicis. } 
 
 200. Transversalis Pedis. 
 
 201. Abductor Mintmi Digiti. 
 
 202. Flexor Brevis Minimi Digiti, - - 264 
 
 203. Interossei Interni. 
 
 204. Interossei Externi. 
 
 205. Plantaris Aponeurosis. 
 
 CHAP. IX. 
 
 OF THE MUSCULAR POWER, 266 
 
 CHAP. X. 
 
 OF THE TENDONS, LIGAMENTS, BURS^, AND ALL THE 
 PARTS WHICH BELONG TO THE BONES OR MUSCLES, 
 OR WHICH ENTER INTO THE CONSTITUTION OF A 
 JOINT. - _ - _ . 277 
 
 General Explanation of the Tendons, Ligaments, &c. 
 
 Of the Forms of the Cellular Substance, - 278 
 
 1. Its Cells, and their Use. 
 
 2. Bursas Mucosas. 
 
 3. Vagin®, or Fasciae. 
 
 4. Tendons. 
 
 5. Periosteum. 
 
 6. Vagina, or Sheaths of Tendons. 
 
 7. Capsules of the Joints. 
 
 8. Ligaments of Joints. 
 
 Recapitulation and Review of the Connections of these 
 Parts, _ - - - - - - 282 
 
 Constitution and Nature of those less feeling Parts 
 — almost insensible in Health, — slcw^to inflame— = 
 their Inflammation very violent, though slow — Dis- 
 eases to which they are liable. 
 
xxxn 
 
 CONTENTS. 
 
 BOOK m. 
 
 OF THE JOINTS. 
 
 CHAP. I. 
 
 Tagt 
 
 JOINTS OF THE HEAD AND TRUNK. 286 . 
 
 I. Joints of the Head and Spine. 
 
 The Motions of the Head and Spine. 
 
 The Provisions of these Motions. 
 
 i. Joint of the Head with the Neck. 
 
 1. Articulation of the Occiput and Atlas. 
 
 Form of the Joint and Capsules for the 
 Condyles. 
 
 2. Flat membranous Ligament from the Ring 
 
 of the Atlas to the Ring of the Occipi- 
 tal Hole. - - - 287 
 
 3. Articulation of the Atlas with the Den- 
 tatus. 
 
 Capsules betwixt the Condyles of the 
 Vertebrse. 
 
 Transverse Ligament embracing the 
 Neck of the Tooth-like Process — Cap- 
 sular Ligament. 
 
 Ligament betwixt the Tooth-like Process 
 and Occipital Hole. 
 
 ii. Joints of the Common Vertebrae with each 
 other. 
 
 Intervertebral Substance, and Intervertebral 
 Ligaments. 
 
 External or Anterior Vagina, or Ligament of 
 the Spine, - 288 
 
 Internal Ligaments, - - _ 289 
 
 Ligamenta Subflava Crurum Processuum 
 Spinosorum — Membranae Interspinales— 
 Ligamenta Processuum Transversorum. 
 Posterior or Internal Ligament of the Spine. 
 Apparatus Ligamentosus Colli. 
 
 II. Joint of the Lower Jaw, _ - - 290 
 
 III. Joints of the Ribs, . - - _ 291 
 
 Ligamenta Capitelli Costarum. 
 
 Ligamentum Transversarium Externum. 
 
 1 — Internum. 
 
 Capsule and Ligaments belonging to the 
 Cartilages. 
 
CONTENTS. 
 
 xxxiii 
 
 CHAP. II. 
 
 JOINTS OF THE SHOULDER, ARM, AND HAND. 
 
 Page 
 
 I. Joints of the Clavicle, _ - > 292 
 
 With the Sternum. 
 
 With the Scapula. 
 
 II. Joint of the Shouluek, » - _ 293 
 
 III. Joint of the Et.bow, _ - - - 295 
 
 The General Capsule of the whole Joint. 
 
 The Lateral Ligaments, External and 
 Internal, - - - - 296 
 
 The Coronary Ligament of the Ulna. 
 
 Accessory Ligaments. 
 
 IV. Whist, - 297 
 
 Articulation of the Scaphoid and Lunated Bones 
 with the Scaphoid Cavity of the Radius. 
 
 Articulation of the Radius with the Ulna for the 
 turning Motions of the Hand, - - 298 
 
 Articulation of the Bones of the Carpus with 
 each other. 
 
 Articulations of the Metacarpus. 
 
 V. Joints of the Fingers, . - - 299 
 
 CHAP III. 
 
 JOINTS OF THE THIGH, LEG, AND ANKLE, 300 
 I. The Hip-Joint. 
 
 The Ligamentum Labri Cartilaginei Transver- 
 sale, ----- 301 
 
 The Capsule of the Joint. 
 
 The Internal Ligaments. 
 
 II. Knee Joint, ----- 303 
 
 1. The External Ligaments. 
 
 Capsule — and Ligamentum Posticum Win- 
 slowii. 
 
 Lateral Ligaments, - - . 304 
 
 Ligamentum Laterale Internum. 
 
 Externum Longior. 
 
 Brevior. 
 
 2. The Internal or Crucial Ligaments of the 
 
 Knee, 
 
 Posterior Crucial Ligament. 
 
 Anterior . - - 305 
 
 VoL I. 
 
 e 
 
xxxiy 
 
 CONTENTS. 
 
 Page 
 
 Semilunar, or^raoveable Cartilages. - 305 
 
 Ligamentum Mucosum — and Ligamentura 
 
 Alare Majus et Minus, ... 306 
 
 Bursae Mucosa of the Knee Joint. 
 
 Recapitulation, explaining the Constitution of 
 this Joint, and Uses of its several Parts, - 307 
 
 III. Articulation of the Fibula with the Tibia, - 308 
 
 IV. Ankle Joint, ..... 309 
 
 Ligamentum Superius Anticum. 
 
 Posticum. 
 
 Inferius Posticum. 
 
 Capsule. 
 
 • Ligamentum Deltoides, - - 310 
 
 Fibulae Anterius. 
 
 Perpendiculare. 
 
 Inter Fibulam et Astragalum 
 
 Posterius. 
 
 V. Joints of the Foot. 
 
 Articulations of the Bones of the Tarsus 
 with each other. 
 
 Joints of the Metatarsus and Toes, - 311 
 
 Aponeurosis Plantaris Pedis. 
 
 Bursaj Mucosae of ihe Ankle and Foot, - 312 
 Conclusion and Enumeration of the Joints. 
 
 ANATOMY 
 
 OF THE 
 
 HEART AND ARTERIES. 
 
 BOOK I. 
 
 OF THE HEART. 
 
 CHAP. I. 
 
 OF THE MECHANISM OF THE HEART, 316 
 
 General View of the Circulating System, - - 316 
 
 Of the Parts of the Heart, 
 
 Venae Cavae, 
 
 ~ 321 
 
CONTENTS. 
 
 XXXV 
 
 Page 
 
 Right Sinus of the Heart, - - 322 
 
 Tuberculum Loweri. 
 
 Auricle, - - - - 323 
 
 Auricular Valv'es. 
 
 Right Ventricle, ... 324 
 
 Pulmonic Artery, ... 325 
 
 Sigmoid Valves, _ . - _ 326 
 
 Left Auricle, .... 327 
 
 Semilunar Valves of the Aorta, - - 328 
 
 Aorta. 
 
 Of the Coronary Vessels, .... 330 
 
 Eustachian Valve, _ . . 333 
 
 Irritability and Action of the Heart, - 338 
 
 Posture of the Heart, ... 343 
 
 Pericardium, .... 345 
 
 Conclusion, - 349 
 
 CHAP. II. 
 
 ON THE APPEARANCE AND PROPERTIES OF THE BLOOD, 
 OF THE CHEMISTRY OF OUR FLUIDS, AND OF THE 
 
 INFLUENCE WHICH AIR HAS UPON THEM, 355 
 
 History of Opinions concerning the Blood. 
 
 Life of the Blood, ..... 301 
 Qualities of the Blood, .... 357 
 
 Of the Red Globules, .... 303 
 
 Coagulable Lymph, ... 371 
 
 Serum, ..... 372 
 
 General View of the Nature of the Blood. 
 
 Chemistry of the Blood, .... 373 
 
 Influence of Air upon the Blood, - - - ^ 377 
 
 1. In reddening the Blood, ... 331 
 
 2. In communicating its stimulant Powers, - 382 
 
 3. In communicating Heat to the Body. - 383 
 
 Of the Respiration of Animals, ... 334 
 
 Of the Membranes of Cavities, and particularly of the 
 
 Membranes of the Thorax, - . - 330 
 
 Of the Pleura, - . . . . 339 
 
 Of the Mediastinum, .... 391 
 
 Of the Pericardium, .... 394 
 
 Of the Thymus Gland, .... 395 
 
 Of the Lungs. 
 
 1'rachea and Bronchi, .... 390 
 
 Bronchial Cells, - - . . . 393 
 
 Course of the Blood in the Lungs, - - . 399 
 
\ 
 
rr- I6'<r''» 
 ...V'eJT" 
 
 IPlate I . 
 
 

Plate H= 
 
]Plat(E HI. 
 
 C. .&/- rf^L 
 
 .'io. 
 
 ' fl 
 
EXPLANATION 
 
 OF 
 
 THE PLATES. 
 
 PLATE I. 
 
 This plate illustrates the description of the manner in which 
 ossification takes place in cartilage. 
 
 Fig. 1. 
 
 The tibia of the foetus cut through after injection of the ar- 
 teries. 
 
 A. The body of the bone, the centre of which is soft and 
 very vascular. 
 
 BB. The CARTILAGES, which are as yet in place of the heads 
 of the bone. 
 
 cc. Vessels seen to penetrate the cartilage from the vascular 
 extremity of the bone itself. 
 
 D. A centra] nucleus of bone forming in the cartilage. 
 
 EE. Vessels penetrating from perichondrium into the carti- 
 lage : small specks of bony matter are seen to be formed 
 by their extremities. 
 
 Fig. 2 
 
 A section of the bones forming the knee joint of a child, show- 
 ing how the apophysis is formed. 
 
 A, Section of the femur, where the bone is complete. 
 
 B. The cartilaginous extremity, as in fig. 1. 
 
 c. A larger mass of bone formed in the cartilage, and which 
 extending, in a short time would have occupied the place 
 of the whole cartilage. The tract of vessels supplying 
 the bone, and which were not visible in the cartilage, are 
 also represented here. 
 
 D. The patella, as yet a cartilage. 
 
 E. The Upper extremity of the tibia, yet a cartilage. 
 
 F. The bone forming in the cartilage. 
 
XXXVUl 
 
 EXPLANATION OP THE PLATES. 
 
 FiC. 3. 
 
 Represents a section of the apophysis of a young bone ; the 
 bony nucleus separated from the cartilage by maceration. 
 
 A. The cartilage. 
 
 B. The bone. 
 
 Explanation op Plate II. 
 
 Explaining the obscure subject of necrosis, or death of a bone, 
 and regeneration of a new one in its stead. 
 
 Fig. 1. 
 
 The bone of a cock’s leg which was perforated, and a fea- 
 ther introduced into the cavity of the bone — the consequence 
 necrosis. 
 
 AA. The old bone dark yellow, and not partaking of the in- 
 jection, because, though retained in its place, dead, 
 c. The new bone formed around the old cylinder of bone, 
 and uniting with the end of the old bone. 
 
 B. The end of the feather, which as a foreign body within the 
 bone, first caused the bone to inflame and throw out new 
 matter, and still continuing a source of irritation, killed 
 the bone. 
 
 Fig. 2 . 
 
 Example of the process of necrosis in the human bone. 
 This is the thigh bone of a stump remaining after amputation 
 of the knee. 
 
 A. The old bone where it was sawn through in operation. 
 
 B B. The old bone seen through the interstices of the new 
 bone. 
 
 c c. The new bone inclosing the old shaft. 
 
 D. The head of the bone in a natural state. 
 
 The process here was similar to that in the experiment on 
 the cock. The wound going v/rong, a bad suppuration comes 
 upon the stump, a wasting discharge comes from within the 
 bone, the bone is inflamed ; the disease of the marrow pro- 
 ceeds, the bone dies, but not till new bone has been formed 
 around the old. 
 
 During such a process it is not wonderful that the continued 
 irritation destroys the patient. 
 
 Fig. 3. 
 
 But sometimes it happens that after these injuries are sus- 
 
EXPLANATION OF THE PLATES. 
 
 xxxix 
 
 tained, the old bone comes away as in this example ; and the 
 stump may yet do well. 
 
 Explanation op Plate III. 
 
 This plate illustrates the chapter on the formation of the 
 teeth. 
 
 Fig I. 
 
 A tooth cut through and burnt. 
 
 A. The enamel not affected by the heat. 
 
 B. The body of the bone black. 
 
 c. The caned of the tooth, in which solely the sensible nerve 
 lies. 
 
 Fig. 2. 
 
 Shows the saccular pulp and rudiments of a tooth. 
 
 A. The pulp of the form of the tooth hanging out of its proper 
 
 place. 
 
 B. The sac which contains the pulp and tooth, but being slit 
 
 open they have fallen out of it. 
 
 c. The shell of this bony part of the tooth which was fojmed 
 on the pulp a ; but being a secretion from it, and not con- 
 nected otherways with it, it has fallen off. 
 
 Fig. 3. and 4. 
 
 The rudiments of a bony part of a tooth, when beginning 
 to form on the projecting parts of the pulp. 
 
 Fig 5. 
 
 A common example of a ball found in the centre of an ele- 
 phant’s tooth. 
 
 A. A part of the iron ball discovered. 
 
 B B. Bone formed in circles round the tooth, 
 c. The common matter of the tooth. 
 
 D. Lesser nuclei of bone marking the irregular action of se- 
 cretion near the ball. 
 
 Fig., 6. 
 
 The bag containing the tooth and pulp, from the human 
 subject. 
 
 A. The bag, or sacculiis. 
 
 B. The lower part of the pulp when it can be seen without 
 
 opening the sac. 
 
xl EXPLANATION OP THE PLATES. 
 
 c. The sac a contains the rudiments of the milk-tooth, and 
 here appended is already the rudiments of the second 
 tooth. • 
 
 FIG. 7 . 
 
 Section of the jaw of a child. 
 
 A. The incisores of the first set of teeth. 
 
 B. c. D. £. The rudiments of the eye tooth. 
 
 B. The pulp, having a connection with the sacculus, and re- 
 ceiving arteries from the bone. 
 
 G. The soft pulp within the sac, and in situ. 
 
 D. The connection of the sacculus with the gum. 
 
 The bone of the tooth forming. — And now it will be per- 
 ceived how it increases : how successive layers of bone are 
 deposited by the pulp beneath; and how in due time the 
 enamel is deposited upon the bone of the tooth by the sac 
 which surrounds it. 
 
THE 
 
 OF THE 
 
 BONES, MUSCLES, AND JOINTS. 
 
 BOOK I. 
 
 OF THE BONES. 
 
 ■ 
 
 CHAP. I. 
 
 OP THE FORMATION AND GROWTH OF BONES.* 
 
 It is not easy to explain in their natural order, the various 
 parts of which the human body is composed ; for they have 
 that mutual dependence upon each other, that continual cir- 
 cle of action and re-action in their various functions, and that 
 intricacy of connection, and close dependence, in respect of 
 the individual parts, that as in a circle there is no point of 
 preference from which we should begin to trace its course, 
 there is in the human body no function so insulated from the 
 other functions, no part so independent of other parts, as to 
 determine our choice. We cannot begin without hesitation, 
 nor hope to proceed in any perfect course ; yet, from what- 
 ever point we begin, we may so return to that point, as to 
 represent truly this consent of functions, and connection of 
 parts, by which it is composed into one perfect whole. 
 
 The bones are framed as a basis for the whole system, fitted 
 to support, defend, and contain the more delicate and noble 
 organs. They are the most permanent, unchangeable parts 
 of all the body. We see them exposed to the seasons, with- 
 out suffering the smallest change ; remaining for ages the 
 
 * I have arranged the preparations illustrative of the growth and structure of bone, so 
 as to correspond with this dissertation. They form the first series in tlie GalJery. C. B. 
 
 voii. I. A 
 
OF THK FORMATION 
 
 memorials of the dead ; the evidence of a former race of meia 
 exceeding ours in strength and stature ; the only remains of 
 creatures w-hich no longer exist ; the proofs of such changes 
 on our globe, as vve cannot trace but by these uncertain marks. 
 Thus we are apt to conceive, that even in the living body, 
 bones are hardly organized, scarcely partaking of life, not 
 liable, like the soft parts, to disease and death. But minute 
 anatomy, the most pleasing part of our science, unfolds and 
 explains to us the internal structure of the bones ; shows their 
 myriads of vessels, and proves them to be as full of blood as 
 the most succulent and fleshy parts ; having, like them, their 
 periods of growth and decay ; as liable to accidents, and as 
 .subject to internal disease. 
 
 The phenomena of fractured bones first suggested some in- 
 distinct notions of the way in which bone might be formed. 
 It was observed, that in very aged men, a hard crust was often 
 formed upon the surface of the bones ; that the fluid exuding 
 into the Joints of gouty people, sometimes coagulated into 
 a chalky mass. Le Dran had seen in a case of spina ventosa, 
 or scrophulous bone, an exudation which flowed out like wax, 
 and hardened into perfect bone. Daventer had seen the 
 juice exuding from a split in a bone, coagulate into a bony 
 crust ; and they thought it particularly well ascertained, that 
 callus was but a coagulable juice, which might be seen exuding 
 directly from the broken ends, and which gradually coagulated 
 into hard bone. The best physiologists did not scruple to be- 
 lieve, that bones, and the callus of broken bones, were formed 
 of a bony juice, which was deposited by the vessels of the 
 part, and which, passing tlu’ough all the successive conditions 
 of a thin uncoagulated juice, of a transparent cartilage, and 
 of soft and flexible bone, became at last, by a slow coagula- 
 tion, a firm, hard, and perfect bone, depending but little upon 
 vessels or membranes, either for its generation or growth, or 
 for nourishment in its perfect state. But this coagulation is a 
 property of dead matter, which has noplace in the living sys- 
 tem ; or if blood or mucus do coagulate within the body, it 
 is only after they are separated from the system. Coagula- 
 tion is a sort of accident in the living body, and it is not to be 
 believed that the accidental concourse of parts should form 
 the perfect system of a living bone ; nor that coagulation, an 
 irregular, uncertain process, should keep pace with the growth 
 of the living parts ; that a bone which is completely organized, 
 and a regular part of the living system, should in all its pro- 
 gress towards this perfect state, be mere inanimate, inorganized 
 matter : yet this opinion once prevailed ; and if other theories 
 were at that time proposed, they did not vary in any very es- 
 
AND GROWTH OF BONES. 
 
 eential point from this first notion. De Heide, a surgeon of 
 Amsterdam, believed that bone or callus was not formed 
 from acoagulable juice, but from the blood itself. He broke 
 the bones of animals, and, examining them at various points of 
 time, he never failed (like other speculators) to find exactly 
 what he desired to find. In “ every experiment,” he found a 
 great effusion of blood among the muscles, and round the bro- 
 ken bone ; and he as easily traced this blood through all the 
 stages of its progress. In the first day red and fluid ; by and 
 by coagulated ; then gradually becoming white, then carti- 
 laginous, and at last (by the exhalation of its thinner parts) 
 hardening into perfect bone. 
 
 It is very singular, that those who abjure theory, and appeal 
 to experiments, who profess only to deliver facts, are least of 
 all to be trusted ; for it is theory which brings them to try ex- 
 periments, and then the form and order, and even the result 
 of such experiments, must bend to meet the theories which 
 they were designed to prove : it is by this deception that the 
 authors of two rival doctrines arrive at opposite conclusions, 
 by facts directly opposed to each other. Du Hamel believed, 
 that as the bark formed the wood of a tree, adding, by a sort 
 of secretion, successive layers to its growth, the periosteum* 
 formed the bone at the first, renewed it when spoiled, or cut 
 away, and, when broken, assumed the nature of bone, and repair- 
 ed the breach. He broke the bones of pigeons, and, allowing 
 them to heal, he found the periosteum to be the chief organ 
 for re-producing bone. He found that the callus had no ad- 
 hesion to the broken bone, was easily separated from the bro- 
 ken ends wdiich remained rough and bare ; and, in pursuing 
 these dissections, he found the periosteum fairly glued to the 
 external surface of the new bone ; or he found rather the cal- 
 lus or regenerated bone to be but a mere thickening of the 
 periosteum, its layers being separated, and its substance swel- 
 led. On the first days he found the periosteum thickened, in- 
 flamed, and easily divided into many lamella, or plates ; but 
 while the periosteum was suffering these changes, the bone 
 was in no degree changed. On the following days, he found 
 the tumour of the periosteum increased at the place of the 
 fracture, and extending further along the bone ; its internal 
 surface already cartilaginous, and always tinged with a little 
 blood, which came to it through the vessels of the marrow. 
 He found the tumour of the periosteum spongy, and divisible 
 into regular layers, while still the ends of the bone were un- 
 changed, or only a little roughened by the first layer of the 
 
 * The periosteum is the membrane wliich surrounds and is attached to the sorfacg of the 
 Iwne, and which conveys the blood vessels to it. 
 
4 
 
 OP THE FORMATION 
 
 periosteum being already converted into earth, and deposited 
 upon the surlace of the bone : and in the next stage of its 
 progress, he found the periosteum firmly attached to the sur- 
 face of the callous mass. By wounding, not breaking the 
 bones, he had a more flattering appearance still of a proof; 
 for, having pierced them with holes, he found the holes fil ed 
 up with a sort of tompion, proceeding from the periosteum, 
 which was thickened all round them. In an early stage, this 
 plug could, by drawing the periosteum, be pulled out from its 
 hole : in a more advanced stage, it was inseparably united ta 
 tbe bone so as to supply the loss. 
 
 Haller, doubting whether the periosteum, a thin and deli- 
 cate membrane, could form so large a mass of bone or callus, 
 repeated the proofs, and he again found quite the reverse of 
 all this : That the callus, or the original bone, w’ere in no de- 
 gree dependent on the periosteum, but were generated from 
 the internal vessels of the bone itself : That the periosteum 
 did indeed appear as early as the cartilage which is to pro- 
 duce the bone, seeming to bound the cartilage, and give it 
 form ; but that the periosteum was at first but a loose tissue of 
 cellular substance, without the appearance of vessels, or any 
 mark of blood, adhe ing chiefly to the heads or processes, 
 while it hardly touched the body of the bone. He also found 
 that the bone grew, became vascular, bad a free circulation of 
 red blood, and that then only the vessels of the periosteum 
 began to carry red blood, or to adhere to the bone. We 
 know that the bones begin to form in small nuclaei, in the very 
 centre of their cartilage, or in the very centre of the yet flex- 
 ible callus, far from the surface, where they might be assisted 
 by the periosteum. 
 
 Thus has the formation of bone been falsely attributed to a 
 gelatinous effusion, giadually hardened; or to that blood which 
 must be poured out from the ruptured vessels round the frac- 
 tured bone ; or to the induration and change of the periosteum, 
 depositing layer after layer, till it completed the form of the 
 bone. 
 
 But when, neglecting theory, we set ourselves to examine^ 
 with an unbiassed judgment, the process of nature in form- 
 ing the bones, as in the chick, or in restoring them, as in 
 broken limbs, a succession of phenomena present themselves^ 
 the most orderly, beautiful, and simple of any that are record- 
 in the philosophy of the animal" body : for if bones were but 
 condensed gluten, coagulated blood, or a mere deposition from 
 the periosteum, they were then inorganized, and out of the 
 system, not subject to change, nor open to disease ; liable, in- 
 deed, to be broken, but without any means of being healed 
 
AND GROWTH OF BONES. 
 
 5 
 
 again ; while they are, in truth, as fully organized, as permeable 
 to the blood, as easily hurt, and as easily healed, as sensible t® 
 pain,* and as regularly changed as the softer parts are. We 
 are not to refer the generation and growth of bone to any 
 other part. It is not formed by that jelly in which the bone 
 is layed, nor by the blood which is circulating in it, nor by the 
 periosteum which covers it, nor by the medullary membrane 
 with which it is lined ; but the whole system of the bone, of 
 which these are parts only, is designed and planned, is laid out 
 in the very elements of the body, and goes on to ripeness, by 
 the concurring action of all its parts. The arteries, by a de- 
 termined action, deposite the bone ; which is formed common- 
 ly in a bed of caitilage, as the bones of the leg or arm are; 
 sometimes betwixt two layers of membrane, like the bones of 
 the skull, where true cartilage is never seen. Often the se- 
 cretion of the bony matter is performed in a distinct bag, and 
 there it grows into form, as in the teeth ; for each tooth is 
 formed in its little bag, which, by injection, can be filled and 
 covered with vessels.f Any artery of the body may assume 
 this action and deposite bone, w’hich is formed also where it 
 should not be, in the tendons, and in the joints, in the great ar- 
 teries, and in their valves, in the flesh of the I eart itself, or 
 even in the soft and pulpy substance of the brain. | 
 
 In the human foetus, and in other animals, before the time 
 of birth, instead of bones, there are only cartilages of the 
 form of the future bone. The whole foetus appears to the eye 
 like a mere jelly : the bones are a pure, almost transparent, 
 and tremulous jelly ; they are flexible, so that a long bone 
 can be bended into a complete ring ; and no opacity nor spot 
 of ossification is seen. 
 
 This cartilage never is hardened into bone ; but, from the 
 first, it is in itself an organized mass. It has its vessels, 
 which are at first transparent, but which soon dilate; and when- 
 ever the red colour of the blood begins to appear in them, 
 ossification very quickly follow's, the arteries being so far en- 
 larged as to carry the coarser parts of the blood. The first 
 mark of ossification is an artery, which is seen running into the 
 centre of the jelly, in which the bone is to be formed. Other 
 arteries soon appear, overtake the first, mix with it, and form 
 a net work of vessels ; then a centre of ossification begins, 
 stretching its rays according to the length of the bone, and 
 
 * The ob'curitv on this subject is from the neglect of defined terms. W> siiall present- 
 ly see that t!ie sensibility posse«sed by the bones, and tlie kind of pain to wliich they are 
 subject, differs from the sensibility and pain of the .skin and soft parts. C. B. 
 
 f The bone of the tooth is formed in a manner very different from common hone. C. B. 
 
 t The structure of the tnie and natural bone is difiereHt from the preternatural bony 
 fOncretioDs ia the vessels and membranes. C, B. 
 
OF THE FORMATION 
 
 6 ‘ 
 
 then the cartilage begins to grow opaque, yellow, brittle ; if, 
 will no longer bend, and the small nucleus of ossification is 
 felt in the centre of the bone, and when touched with a sharp 
 point, is easily known by its gritty feel. Other points of ossi- 
 fication are successively formed ; always the ossification is fore- 
 tohl by the spreading of the artery, and by the arrival of red 
 blood. Every point of ossification has its little arteries, and 
 each ossifying nucleus has so little dependence on the carti- 
 lage in which it is formed, that it is held to it by vessels only ; 
 and when the ossifying cartilage is cut into thin slices, and 
 steeped in water till its arteries rot, the nucleus of ossification 
 drops spontaneously from the cartilage, leaving the cartilage 
 like a ring, with a smooth and regular hole where the bone 
 lay. 
 
 The colour of each part of a bone is proportioned exactly 
 to the degree in which its ossification is advanced. When os- 
 sification begins in the centre of the bone, redness also ap- 
 pears, indicating the presence of those vessels by which the 
 bony matter is to be poured out. When the bony matter be- 
 gins to accumulate, the red colour of those arteries is obscur- 
 ed, the centre of the bone becomes yellow or white, and the 
 colour removes towards the ends of the bone. In the centre, 
 the first colouring of the bone is a cloudy, diffused, and general 
 red, because the vessels are profuse. Beyond that, at the 
 edges of the first circle, the vessels are more scattered and 
 asunder, distinct trunks are easily seen, forming a circle of 
 I’adiated arteries, which point towards the heads of the bone. 
 Beyond that, again, the cartilage is transparent and pure, as 
 yet untouched with blood ; the arteries have not reached it, 
 and its ossification is not begun. Thus, a long bone, while 
 forming, seems to be divided into seven various coloured 
 zones. The central point of most perfect ossification is yel- 
 low and opaque. On either side of that, there is a zone of 
 red. On either side of that, again, the vessels being more 
 sparse, form a vascular zone, and the zone at either end is 
 transparent or white.* The ossification follows the vessels, 
 
 * It is curious to observe how completely vaseular the bone of a chicken is before the 
 ossification liave fairly begun ; liow the ossification being begun, overtakes the arteries, and 
 hides them, changing tlie transparent and vascular part of the bone into an opaque 
 white ; how, by pealing off the periosteum, bloody dots are seen, which show a living con- 
 nection and commerce of vessels betwixt the periosteum and tile bone ; how b^ tearing up 
 the outer layers of the tender bone, the vascularity of the inner layers is again expos^ ; 
 and the most beautiful proof of all is that of our common preparations, where, by filling 
 with injection the arteries of an adult hone, by its nutritious vessels, and then corroding 
 the hone with mineral acids, we dissolve the eaitji, leaving notliing but the transparent jel- 
 ly, which restores it to its original cartilaginous state; and then tlie vessels appear in suclr 
 profusion, that the bone may be compared in vascularity with the soft parts, and it is seen 
 that its arteries were not annihilated, but its high vascularity only concealed by the depo« 
 sition of the bony part. 
 
AND GROWTH OR BONES. 
 
 -and buries and hides those vessels by which it is formed : 
 The yellow and opaque part expands and spreads along the 
 bone : The vessels advance towards the heads of the bones : 
 The whole body of the bone becomes opaque, and there is 
 left only a small vascular circle at either end ; the heads are 
 separated from the body of the bone by a thin cartilage, and 
 the vessels of the centre, extending still towards the extremi- 
 ties of the bone, perforate that cartilage, pass into the head of 
 the bone, and then its ossification also begins, and a small 
 nucleus of ossification is formed in its centre. Thus the heads 
 and the body are, at the first, distinct bones, formed apart, join- 
 ed by a cartilage, and not united till the age of fifteen or 
 twenty years. 
 
 The vessels are seen entering in one large trunk (the nutri- 
 tious artery) into the middle of the bone: From that centre 
 they extend in a radiated form towards either end, and the 
 fibres of the bone are radiated in the same direction ; there 
 are furrows betwixt the rays, and the arteries run along in the 
 furrows of the bone, as if the arteries' were forming these 
 ridges, secreting and pouring out the bony matter, each artery 
 piling it up on either side to form its ridge. f The body of the 
 bone is supplied by its own vessels ; the heads of the bone are 
 in part supplied by the extremities of the same trunks which 
 perforate the dividing cartilage like a sieve ; the periosteum 
 adhering more firmly to the heads of the bone brings assist- 
 ant arteries from without, which meet the internal trunks, and 
 assist the ossification ; which, with every help, is not accom- 
 plished in many years. 
 
 It is by the action of the vessels that all the parts of the hur 
 man body are formed, fluids and solids, each for its respective 
 use : the blood is formed by the action of the vessels, and all 
 the fluids are in their turn formed from the blood. We see in 
 the chick, where there is no external source from which its 
 red blood can be derived, that red blood is formed within its 
 own system. Every animal system, as it grows, assimilates its 
 food, and converts it to the animal nature, and so increases 
 the quantity of its red blood : and as the red blood is thus pre- 
 pared by the actions of the greater system, the actions of par- 
 ticular vessels prepare various parts : some to be added to the 
 mass of solids, for the natural growth ; others to supply the 
 continual waste ; others to be discharged from the body as 
 effete and hurtful, or to allow new matter to be received j 
 
 * The arteries of a hone branch rrith freedom, and with the same seeming irregularity as 
 in other parts of the body. The arteries do not exude their secretion from their aides, so 
 aa to pile up the ridge of bone in their course. Tlis secretion seems to be performed ii 
 their very extremities, C. B. 
 
8 
 
 OF THE FORMATION 
 
 Others again to perform certain offices within the body, as 
 semen, saliva, bile, or urine. Thus the body is furnished with 
 various apparatus for performing various offices, and for re- 
 pairing the waste. These are the secretions, and the forma- 
 tion of bone is one of these. The plan of the whole body 
 lies in the embryo, in perfect order, with all its forms and parts. 
 Cartilage is laid in the place of bone, and preserves its form 
 for the future bone, with all its apparatus of surrounding mem- 
 branes, its heads, its processes, and its connection with the soft 
 parts The colourless arteries of this pellucid but organized 
 mass of cartilage keep it in growth, extend, and yet preserve 
 its form, and gradually enlarging in their own diameter, at last 
 receive the entire blood.* Then the deposition of earthy 
 matter begins- The bone is deposited in specks, which spread 
 and meet and form themselves into perfect bone. While the 
 bone is laid by arteries, the cartilage is conveyed away by the 
 absorbing ves.sels ; and while they convey away the super- 
 fluous cartilage, they model the bone into its due form, shape 
 out its cavities, cancelli, and holes, remove the thinner parts 
 of the cartilage, and harden it into due consistence. 
 
 If such organization of arteries to deposite bone, and ab- 
 sorbents to take up the cartilage, and make room for the 
 osseous matter, be necessaiy in the formation and growth, it 
 is no less necessary for the life and health of the full formed 
 bone. Its health depends on the regular deposition and re- 
 absorption. moulding and forming the parts; and by various 
 degrees of action, bone is liable to inflame, ulcerate, to rot 
 and spoil, to become brittle by too much secreted earth, or 
 to become soft by a greedy diseased absorption of its earthy 
 parts. The earth, which constitutes the hardness, and all the 
 useful properties of bone, is dead, inorganized, and lies in the 
 interstices of the bone, w'here it is made up with mucus, to 
 give it consistence and strength ; furnished with absorbents to 
 keep it in health, and carry off its wasted parts; and pervaded 
 by vessels to supply it wdth new patter. The cartilage is in 
 itself a secretion, to which the full secretion ol bone succeeds, 
 as the arteries grow stronger in their secreting office : for in a 
 broken limb there is first a thin effusion, then a tremulous 
 jelly, then radiated vessels, then ossifying spots, and these 
 
 * Previous to the forraaflon of bone (or the preparation for it) in the cartilaffe, there is 
 no proof of there jjeing vessels in it. But we presume that the cartilage must have vessels, 
 becauseit grows willi the growth of the animal, previous to the formation of bone in it. 
 
 However, the change, previou-^ to the deposition of bone, has not been noticed- the firm 
 cartilage sufflTs a change ; theri? is a tract from the circumi’erence to the centre of it, in 
 which the firm cartilage is dis-so’^-ed j and in the spot where the first particle of bone h to 
 be deposited, there is a lilde soft well of matter, different from the firm substance «f the 
 cartilage. C. B. 
 
AND GROWTH OF BONES. 
 
 running together, form a perfect bone.* If the broken limb 
 be too much moved during the cure, then are the secreting ar- 
 teries interupted in their office, perfect bone is never formed, it 
 remains a cartilage, and an unnatural joint is produced ; the 
 vessels are opened again, the process is renewed, and the 
 bones unite ; or even by rubbing, by stimulating, by merely 
 cutting the surrounding parts, the vessels are made active, 
 and their secretion is renewed. During all the process of 
 ossification, the absorbents proportion their action to the sti- 
 mulus which is applied to them ; they carry away the serous 
 fluid, when jelly is to take its place ; they remove the jelly, 
 as the bone is laid ; they continue removing the bony particles 
 also, which (as in a circle) the arteries continually renew. 
 
 Nothing can be more curious than this continual renovation 
 and change of parts, even in the hardest bones. We are 
 accustomed to say of the whole body, that it is daily changed ; 
 that the older particles are removed, and new ones supply 
 their place ; that the body is not now the same individual 
 body that it was ; but it could not be easily believed that we 
 speak only by guess concerning the softer parts, what we 
 know for certain of the bones. It was discovered by chance 
 that animals fed upon the refuse of the dyer’s vats, received 
 so much of the colouring matter into the system, that the 
 bones were tinged by the madder to a deep red, while the 
 softer parts were unchanged ; no tint remaining in the liga- 
 ments nor cartilages, membranes, vessels, nor nerves, not 
 even in the delicate vessels of the eye. It was easy to distin- 
 guish by the microscope, that such colour was mixed with 
 the bony matter, resided in the interstices only, but did not 
 remain in the vessels of the bone, which, like those of all 
 the body, had no tinge of red ; while our injections again fill 
 the vessels of the bone, make all their branches red, but do 
 not affect the colours of the bony part. When madder is 
 given to animals, withheld for some time, and then given 
 again, the colour appears in their bones, is removed, and 
 appears again wth such a sudden change as proves a rapidity 
 of deposition and absorption, exceeding all likelihood or 
 belief. All the bones are tinged in twenty-four hours; in 
 two or three days their colour is very deep ; and if the mad- 
 
 * The matter may be thus stated : the extravasated blood being absorbed, an eflheion is 
 poured out by the vessels of the broken bone. This matter is a regular secretion, it ap-- 
 pears to the eye like a uniform jeUy ; but so does the embryo itself. It is bone in embryo, 
 the membranes and vessels, arteries, veins, and absorbents are in if ; the arteries of the sur- 
 rtMnding parts do not shoot into it, but veins, as well as arteries and absorbents, inosculate 
 with the vessels of this new formed matter ; and whatever vessels may, by accidental con- 
 tMt, inosculate with this substance, whether coming from bone, muides, or membrane, 
 still bone is form^, because it is the destined constitution of the new fonoed naa.ss. or rather 
 «f the vessels which are already in it to form bone. C. B. 
 
 B 
 
10 
 
 OF THE FORMATION. 
 
 der be left off but for a few days, the red colour is entirely 
 removed. 
 
 This tinging of the bones with madder, was the great in- 
 strument in the hands of Du Hamel, for proving by demon- 
 stration, that it was by layers from the periosteum that the 
 bone was formed ; and how very far the mind is vitiated by 
 this vanity of establishing a doctrine on facts, is too easily 
 seen here. Du Hamel, believing that the periosteum deposi- 
 ted successive layers, which were added to the bone, it was 
 his business to prove that the successive layers would be de- 
 posited alternately red, white, and red again, by giving a 
 young animal madder, withholding it for a little while, and 
 then beginning again to give it. Now, it is easy to forsee that 
 this tinging of the lamellse should correspond with the succes- 
 sive times in which the periosteum is able to deposite the lay- 
 ers of its substance, but Du Hamel very thoughtlessly makes 
 his layers correspond only with the weeks or months in which 
 his madder was given or withheld. It is easy to foresee also, 
 that if madder be removed from the bones in a few days, 
 (which he hiinself has often told us,) then his first layer, viz. of 
 red bone, could not have waited for his layer of white to be 
 laid above it, nor for a layer of red above that again, so 
 that he should have been able to show successive layers : And 
 if madder can so penetrate as to tinge all the bones that are 
 already formed, then, though there might be first a tinged 
 bone, then a white and colourless layer, whenever he proceed- 
 ed to give madder for tinging a third layer, it would pervade 
 all the bone, tinge' the layer below, and reduce the whole into 
 one tint. If a bone should increase by layers, thick enough 
 to be visible, and of a distinct tint, and such layers be conti- 
 nually accumulated upon each other every week, what kind 
 of a bone should this gi'ow to ? Yet such is the fascinating na- 
 ture of a theory, that Du Hamel, unmindful of any interrup- 
 tions like -those, describes boldly his successive layers, carry- 
 ing us through regular details, experiment after experiment, 
 till at last he brings up his report to the amount of five succes- 
 sive layers, viz. two red layers, and three white ones. And 
 in one experiment he makes the tinge of the madder continue 
 in the bones for six months, forming successive layers of red 
 and white, although in an earlier experiment (which he must 
 have forgotten in hishurr)-) he tells us, that by looking through 
 the transparent part of a cock’s wing, he had seen the tinge of 
 the madder gradually leave the bones in not many days. 
 
 These experiments are as gross and palpable as the occa- 
 sion of them, and should stand as a warning to us, showing 
 how severely and honestly we must question our own judg- 
 
AND GROWTH OF BONES. 
 
 11 
 
 rnent, when trying to confirm our preconceived theories by 
 experiments and facts.* 
 
 Yet, by these experiments with madder, one most impor- 
 tant fact is proved to us ; that the arteries and absorbents, 
 acting in concert, alternately deposite and re-absorbthe earthy 
 pai tides, as fast as can be conceived, of the soft parts, or even 
 of the most moveable and fluctuating humours of the body. 
 The absorption of the hardest bones is proved by daily obser- 
 vation ; when a carious bone disappears before the integu- 
 ments are opened ; when a tumour, pressing upon a bone, 
 destroys it ; when an aneurism of the temporal artery destroys 
 the skull ; when an aneurism of the heart beats open the tho- 
 rax, destroying the sternum and ribs ; when an aneurism of 
 the ham destroys the tbigh-bone, tibia, and joint of the knee ; 
 when a tumour coming from within the head, forces its way 
 through the bones of the skull ; — in all these cases, since the 
 bone cannot be annihilated, what can happen, but that it must 
 be absorbed and conveyed away ^ If we should need any 
 stronger proofs than these, we have molities ossium, a dis- 
 ease by which, in a few months, the bony system is entirely 
 broken up, and conveyed away, by a high action of the ab- 
 sorbents, with continual and deep-seated pain ; a discharge of 
 the earthy matter by the urine ; a gradual softening of the 
 bones, so that they bend under the weight of the body ; jhe 
 heels are turned up behind the head ; the spine is crooked ; 
 the pelvis distorted ; the breast crushed and bent in : and the 
 functions beginning to fall low, the patient, after a slow hectic 
 fever, long and much suffering of pain and misery, expires, 
 with all the bones distorted in a shot king degree, gelatinous, 
 or nearly so, robbed of all their earthy parts, and so thoroughly 
 softened as to be cut with the knife.f 
 
 Thus, every bone has, like the soft parts, its arteries, veins, 
 and absorbent vessels ; and every bone has its nerves too. 
 We see them entering into its substance in small threads, as 
 on the surfaces of the frontal and parietal bones: We see 
 them entering for particular purposes, by a large and peculiar 
 hole, as the nerves which go into the jaws to reach the teeth : 
 We find delicate nerves going into each bone along with its 
 nutritious vessels; and yet we dare hardly believe the demon- 
 stration, since bones seem quite insensible and dead : We 
 have ho pain when the periosteum is rasped and scraped from 
 
 * However just this criticism is upon the reasoning of Du Hamel, yet I believe in tire 
 facts stated. In my Collection may be seen the bone of a pig showing three distinct layers, 
 distinguishable in colour. C. B. 
 
 + See the examples of distortion in the Museum, Windmill Street, and in particular the 
 skeleton of a woman who died in consequence of the Caesarean operation. C. B 
 
12 
 
 OP THE FORMATION 
 
 a bone : We have no feeling when bones are cut in amputa- 
 tion; or when, in a broken limb, we cutoff with pincers, the 
 protruding end of a bone : We feel no pain when a bone is 
 trepanned, or when caustics are applied to it ; and it has been 
 always known, that the heated irons which the old surgeons 
 used so much, made no other impression than to excite a par- 
 ticular titillation and heat, rather pleasant than painful, run- 
 ning along the course of the bone. But there is a deception in 
 all this. A bone may be exquisitely sensible, and yet give no 
 pain ; a paradox which is very easily explained. A bone may feel 
 acutely and yet not send its sensation to the brain. It is not 
 fit that parts should feel in this sense, which are so con- 
 tinually exposed to shocks and blows, and all the accidents of 
 life ; which have to suffer all the motions which the other 
 parts require. In this sense, the bones, the cartilages, liga- 
 mints, bursse, and all the parts that relate to joints, are quite 
 insensible and dead. A bone does not feel, or its feelings are 
 not conveyed to the brain : but, except in the absence of pain, 
 it shows every mark of life. Scrape a bone and its vessels 
 bleed ; cut or bore a bone, and its granulations sprout up ; 
 break a bone, and it will heal ; or cut a piece of it away, and 
 more bone will readily be produced ; hurt it any way, jind it 
 inflames ; burn it, and it dies : take any proof of sensibility, 
 but the mere feeling of pain, and it will answer to the proof. 
 In short, these parts have a sensibility which belongs to them- 
 selves, but have no feelings in correspondence with the gene- 
 ral system.* 
 
 A bone feels stimuli, and is excited to re-act ; injuries pro- 
 duce inflammation in tbe bones, as in the soft parts ; and then 
 swelling and spongy looseness, and a fullness of blood, suppu- 
 ration, ulcer, and the death and discharge of the diseased bone 
 ensue. When the texture of a bone is thus loosened by in- 
 flammation, its feeling is roused ; and the hidden sensibility 
 
 * Prom the consideration of these facts, together with this most essential one, viz. that 
 bones, ligaments, and tendons are actually capable of receiving and propagating painful im- 
 pressions to the sensorium, I liave come to tlie following conclusion : — The sensation of pain 
 is bestowed as a safeguard to the frame, forcing us to^avoid whatever is hurtful. To this 
 effect, sensibility varira in different parts, and in general the sensibility of tlie more superfi- 
 cial parts, being sufficient protection to the parts beneath, the deep parts are but little sensi- 
 ble. The sensibility possessed by the skin would not he sufficient protection to the eye; 
 such parts differ in kind of sensibility as well as in degree. Experiments have been made 
 by cutting and burning the bones and tendons, and the conclusion has been, that they were 
 insensible. But when a man sprains his ankle-joint, he is in extreme pain, though he can 
 easily satisfy himself that the pain he feels is not in the skin, but must be in the joint and 
 tendons. It appears then, that such parts usually thought insensible, feel pain and can pro- 
 pagate that pain to the sensorium ; and further, that the peculiar sensibilities are so suited as 
 to allow of the free and natural motion and of the necessary degree of attrition, but are bo- 
 stowed for the purpose of making us avoid that degree of violence, which would endanger 
 the texture or healthy function of the part. C. B. 
 
AND GKOWTH OF BONES. 13 
 
 of the bone rises up like a new property of its nature : and as 
 the eye, the skin, and all feeling parts have their sensibility in- 
 creased by disease, the bones, ligaments, bursae, and all the 
 parts whose feeling during health, is obscure and hardly known, 
 are roused to a degree of sensibility far surpassing the soft 
 parts. The wound of a joint is indeed less painful at first, 
 but when the inflammation comes, its sensibility is raised to a 
 dreadful degree : the patient cries out with anguish. No 
 pains are equal to those which belong to the bones and joints. 
 
 This ossification is a process of a truly animal nature : no 
 coagulation will harden cartilage into bone ; no change of con- 
 sistence will form the blood into it ; no condensation of the 
 periosteum can assimilate it to the nature of a bone. Bone 
 is not the inorganic concrete which it was once supposed, but 
 is a regularly organized part, whose form subsists from the 
 first, which is perfected by its secreting arteries, balanced, as 
 in every secretion, by the absorbents of the part; it lives, 
 grows, and feels, is liable to accidents, and subject to disease. 
 Ossification is a process which, at first, appears so rapid, that 
 we should expect it to be soon complete ; but it becomes 
 in the end, a slow and difficult process. It is rapid at first ; it 
 advances slowly after birth ; it is not completed till the 
 twentieth year ; it is forwarded by health and strength, retard- 
 ed by weakness and disease. In scrophula it is imperfect ; 
 and so children become rickety, when the bones soften and 
 swell at their heads, and bend under the weight of the body. 
 And why should we be surprised, that carelessness of food or 
 clothing, bad air, or languid health, should cause that dread- 
 ful disease, when more or less heat, during the incubation of a 
 chick, prevents the growth of its bones; when the sickness of 
 a creature, during our experiments, protracts the growth of 
 callus ; when, in the accidents of pregnancy, of profuse suppu- 
 ration, or of languid health, the knitting of broken bones is 
 delayed, or prevented quite ? 
 
 This process, so difficult and slow, is assisted by every pro- 
 vision of nature. The progress of the whole is slow, that so 
 long as the body increases in stature, the bones also may grow ; 
 but it is assisted in the individual parts, where some are slow, 
 some rapid in their growth, some delayed, as the heads of joints, 
 that their bones may be allowed to extend, and others hasten- 
 ed, as the pelvis, that it may acquire its perfect size early in 
 life. Ossification is assisted by the softness of the cartilagi- 
 nous bed in which the bone is formed ; by those large and per- 
 meable vessels which carry easily the grosser parts of the 
 blood ; by a quick and powerful absorption, which all along 
 
14 
 
 OF THE FORMATION 
 
 is modelling the bone; and, most of all, by being formed in 
 detached points, multiplied and crowded together, wherever 
 much bone is required. 
 
 There is one central ring first ossified in a long bone, as of 
 the leg or arm ; the heads or ends of the bone are at first 
 mere cartilage, but they also soon begin to ossify ; the body 
 stretches in a radiated form towards either head ; the heads 
 ossifying each in its centre, also stretch towards the bone ; the 
 heads meet the body, and join to it ; a thin cartilage only 
 is interposed, which grows gradually thinner till the twentieth 
 year, and then disappears, the body, heads, and processes, be- 
 coming one bone. In fiat bones, as in the skull, ossification 
 goes from one or more central points, and the radiated fibres 
 meet the radii of other ossifying points, or meet the edges of 
 the next bone. See plate I. fig. 3 and 4. The thick round 
 bones which form the wrist and foot, have one ossification in 
 their centre, which is bounded by cartilage all round. The 
 processes are often distinct ossifications joined to the bones, 
 like their heads, and slowly consolidated with them into firm 
 bones f 
 
 While the bone is forming, various parts, essential to its sys- 
 tem, gradually rise into view. At first we cannot in the long 
 bone perceive any heads, processes, cavities, or cells; these 
 parts are very slowly formed, and are perfected only in the 
 adult bone. 
 
 At first, the whole length of a long bone is represented by 
 a transparent jelly, where there is no distinction of heads nor 
 processes ; it is all of one mass. After the red blood has be- 
 gun to tinge this cartilage, the ossification begins, and one ring 
 is formed in the middle of the bone : from this ring the fibres 
 
 * The csBification of the Hat bones is a subject too curious to be omitted in this disserta- 
 tion. The brain of the foetus wliile of the size of a liazle-nut is invested with a membrane 
 in wliich there is as yet no speck of bone. In the third month, the ossification of the cra- 
 nial bones commence, and the fiist process exhibits a very beautiful net of ossific wire-work. 
 In a circle, t!ie diameter of wliicli is half an incli, we see a perfect net work, resembling a 
 fine lace or the meslies of a spider’s web. Upon this first layer another is deposited, and 
 this superimposed net-work of bone is finer than the first ; the meshes being smaller and the 
 bony matter more abundant. The holes of the second net arc not opposite to tliose of the 
 first, so that the eye no longer penetrates the bone, although the structure be quite light 
 and porous. While the .second and third layer of bone is deposited on the outside of tlie 
 first, the inner layer is extending in threads diver^ng from the centre, betwixt which deli- 
 cate processes of bone, intervening ribs are formed irregularly, still resembling the texture of 
 tlie spider’s web; and the diverging line of hone being tlie stronger, it appears as if the cra- 
 nial bones formed in diverging radii, while the edge of the bone extends in fine net work, 
 like to the first formed speck of ossification. 
 
 It is further worthy of remark, that this is the texture of true hone, and that what are 
 called morbid ossifications, as of the coats of arteries and other membranes are merely the 
 deposite of earth, y matter without organic structure. C. B. 
 
 _ t The proce.sses apd heads are named the epiphysis an:l apophysis of hones. The apophy- 
 siss a process which projects from the bone and grows from it. The epiphysis is that por- 
 tion which growing by a distinct centre of ossification is afterwards unitra to the body of 
 tile bone. C. B. 
 
AND GROWTH OF BONES. 
 
 16 
 
 stretch towards either end, and stop there (fig. I. plate I.) ; 
 then it begins to appear that the heads and body are distinct 
 parts ; the fibres of the growing bone have extended til) the 
 cartilage is annihilated, and only a small plate remains, separa- 
 ting the knobs of the heads from the long body of the bone. 
 Thus there is no distinction betwixt the heads and the body, 
 while the heads are cartiliginous ; they begin to appear, as 
 distinct parts, at that stage in which the body of the bone is 
 ossified, and each of the heads is beginning to form ; they con- 
 tinue three distinct bones, during all the early part of life, 
 and are easily separated, by soaking the bone in water ; when 
 they are separated, there is seen a rough hollow, on the sur- 
 face of the epiphysis, or separated head, and a rough convexi- 
 ty on the end of the body : they are finally united into one 
 bone, about the twentieth year. 
 
 In die original cartilage, there is no hollow nor cavity ; it is 
 all one solid mass. Fig. 1. plate II. When the ossification 
 first appears, the cavity of the bone also begins, and extends 
 with the ossification : at first the cavity is confined chiefly to 
 the middle of the bone, and extends very slowly towards the 
 ends. This cavity, in the centre of the bone, is at first smooth, 
 covered with an internal membrane, containing the trunks and 
 branchings of the nutritious vessels, which enter by a great 
 hole, in the middle of the bone ; and the cavity is traversed, 
 with divisions of its lining membrane, which, like a net-work 
 of partitions, conduct its branches to all parts of the interna] 
 surface of the bone; and its nets, or meshes, are filled witij a 
 reddish and serous fluid in the young *bone, but secrete and 
 contain a perfect marrow in the adult bone. 
 
 The whole substance of a bone is not only fibrous, as ap- 
 pears outwardly, but is truly lamellated, consisting of many 
 distinct and delicate plates of bone, which lie over each other, 
 in regular order, and might suggest the notion of successive 
 ossifications of the periosteum forming the bone. These 
 lamelliE, or plates, are more condensed and firm, towards the 
 outer surface, and are more loose, separate and spongy, to- 
 wards the internal surface of the bone ; and it is easily seen, 
 during the growth of a young bone, that the inner and more 
 delicate plates are separating from the walls of the bone, and 
 receding tow'ards its cavity : and these plates, being again 
 crossed by small bony partitions, form a net-work, or spengy 
 mass, w'hich fills the whole cavity of the bone. In the middle 
 of the bone, the cavity is small, the- walls thick, and having 
 all their bony plates ; the cells of net-work few, and large ; 
 but towards the ends, the bone swells out, the cavity aKo is 
 large ; but it is not like that in the middle, a large tubular 
 
16 
 
 OF THE FORMATION 
 
 cavity : it is so crossed with lattice-work, with small interstices 
 and cells, that it seems all one spongy mass of bone ; and so 
 many of the inner layers are separated, to form this profusion 
 of cells, that the whole substance of the bone has degenerated 
 into this lattice-work, leaving only a thin outward shell.* 
 Th is reticular form is what anatomists call the cancelli, 
 lattice-work, net-work, or alveolar part of the bone : it is all 
 lined with one delicate membrane, and inward partitions of 
 the same lining membrane cover each division of the lattice- 
 work, forming each cell into a distinct cavity. In these 
 cavities, or cells, the marrow is secreted. The secretion is 
 thin and bloody in children ; it thickens as we advance in 
 years ; it is a dense oil, or marrow in the adult. The mar- 
 row is firmer, and more perfect in the middle of the bone, 
 and more thin and serous towards the spongy ends. The 
 whole mass, when shaken out of the bone, is like a bunch of 
 grapes, each hanging by its stalk. The globules, when seen 
 with the microscope, are neat, round, and white, resembling 
 small pearls, and each stalk is seen to be a small artery, which 
 comes along the membrane of the cancelli, spreads its 
 branches beautifully on the surface of the bag, and serves to 
 secrete the marrow, each small twig of artery filling its pecu- 
 liar cell. To this, an old anatomist added, that they had 
 their contractile power, like the urinary bladder, for expel- 
 ling their contents ; that they squeezed their marrow, by 
 channels of communication, through and among the bony 
 layers ; and that their (pi exuded into the joint, by nearly the 
 same mechanism, by which it got into the substance of the 
 bone. 
 
 White the constitution of a bone was not at all understood, 
 anatomists noted with particular care every trifling peculiarity 
 in the forms or connections of its parts, and these lamellae 
 attracted particular notice. That a bone is formed in succes- 
 sive plates, is easily seen, as in whalebone ; or in the horns 
 and bones of the larger animals; in church-yard bones, 
 which have been long buried, or long exposed to the air. 
 It is demonstrated by a careful picking, and separation of the 
 scales in a young bone, or by burning a bone, which melts and 
 consumes its jelly, and leaves the bony parts entire. It is 
 seen in the common diseases of bones ; for they cast off by 
 successive plates or leaves, whence the process is named 
 exfoliation ; and one plate is thoroughly spoiled and cast off, 
 
 * That it is merely an expansion of the layers wlrich forms the cancelli, and a mere swell- 
 ing and spnngiiies? of the same quantity of bony substance, which makes the ends so mucii 
 thicker than the middle, is proved by this, tliat an inch of the smaller bony tube, cut from 
 the middle, weighs equally with an inch of the large spongy tube, cut out from the ends. 
 
AND GROWTH OP BONES. 
 
 1 ? 
 
 while another is entire and sound. Malphighi had first ob- 
 served the lainellated structure of bones, likening them to the 
 leaves of a book. Gagliardi, who, like Hippocrates, went 
 among the burial places of the city, to observe the bones, 
 there, found in a tomb, where the bones had been long ex- 
 posed, a skull, the os frontis of which he could dissect into 
 many layers, with the point of a pin.* He afterwards fou .d 
 various bones, from all parts of the body, thus decomposed ; 
 and he added to the doctrine of plates, that they were held 
 together by minute processes, which, going from plate to 
 plate, performed the ofiSces of nails : these appeared to his 
 imagination to be of four kinds, straight and inclined nails, 
 crooked or hook-like, an I some with small round heads, of 
 the forms of bolts or pins.f 
 
 Another notable discovery, was the use of the holes which 
 are very easily seen througli the substance of bones, and 
 among their plates. They are, indeed, no more than the 
 ways by which the vessels pass into the bones ; but the older 
 anatomists imagined them to be still more important, allow- 
 ing the matter to transude through all the substance of the 
 bone, and keep it soft. Now this notion of lubricating the 
 earthy parts of a bone, like the common talk of fomentations 
 to the internal parts of the body, is very mechanical, and 
 very ignorant; for the internal parts of the body are both 
 hot and moist of themselves, and neither heat nor moisture 
 can reach them from without : the bone is already fully wa- 
 tered with arteries ; it is moist in itself, and cannot be further 
 moistened nor lubricated, unless by a fuller and quicker cir- 
 culation of its blood. It must be preserved by that moisture 
 only which exists in its substance, and must depend for its 
 consistence upon its own constitution; upon the due mixing 
 up of its gluten and earth. Ever^ part is preserved in its due 
 consistence by the vessels which form its subsistence ; and I 
 should no more suppose fat necessary for preserving the moist- 
 ness of a bone, than for preventing brittleness in the eye. — 
 
 * Notwithstanding what is here delivered, there is no proof of the bones being lanst lla- 
 ted ; as to the exfoliation of bone, the dead [.ortion is more generally irregular in its thick- 
 ness, and rngg^ on its inner surface. This exfoliation of bone is a proce.«.s of tlie living 
 ^ne, and the inner living surface recedes from the outer one, because tliat outer surface is 
 injured or dead. The nature of tlie injury, or the depth to which the bone lias become dead, 
 determines the extent and foim of the [iortion cast off. When a scale only is thrown off, 
 it is because the bone is only dead upon the surface In regard to the breaking up of the 
 surface of the cranial hones, when they lie exposed, the .scales are similar to those from 
 atones or metals ex(xised to the influenee of the air, and moisture, and varying temperature: 
 the thickness and succession of exfoliations depends on the operation of the weather, not ou 
 the original formation of the bone. I have never seen heat produce a lamellated decompo- 
 sition of bone. C. B. 
 
 + These nails Gagiiardi imagined were no more than the little irregularities, risings, and 
 hollows of the adjoining plates, by which they are connected. 
 
 VOL. I. C 
 
18 
 
 OF THE FORMATION 
 
 This marrow is, perhaps, more an accidental deposition than 
 we, at first sight, believe. We indeed find in it such a regu- 
 larity of structure, as seems to indicate some very particular 
 use ; but we find the same structure exactly in the common 
 fat of the body. When, as we advance in years, more fat is 
 deposited in the omentum, or round the heart, we cannot 
 entertain the absurd notion, of fat being needed in our old 
 age, to lubricate the bowels or the heart ; no more is the mar- 
 row (which is not found in the child,) accumulated in old age, 
 for preventing brittleness of the bones.* 
 
 The blood vessels of a bone are large, in proportion to the 
 mass of the bone. For first one great trunk enters commonly 
 about the middle of the bone, as in the thigh-bone, leg or arm, 
 and it is called the nutritious or medullary artery : it goes in 
 the central cavity of the bone, spreads upwards and down- 
 wards, supplies all the substance of the bone itself, and gives 
 those delicate arteries which seci’ete the marrow. Other arte- 
 ries enter from without at the spongy ends of the bones, where 
 the bones are not visible only, but very large in the adult ; par- 
 ticularly large arteries enter into the heads of the holes, as of 
 the shoulder or of the thigh bones ; and there the periosteum 
 adheres very strongly ; and every where on its surface the 
 bone is supplied by numerous vessels from the periosteum (and 
 this seems indeed to be the chief use of that membrane ;) so that 
 in tearing off the periosteum, the surface of the membrane, 
 and of the bone, are seen covered with bloody points j all the 
 vessels are conducted to the substance of the bone by its two 
 membranes : the internal vessels by the membrane which lines 
 the cavity, and which is known b\ the absurd name of inter- 
 nal periosteum j the external one by the outer membrane, the 
 proper or external periosteum. 
 
 The internal periosteum is that membrane which surrounds 
 the marrow, and in the bags of which the marrow is formed 
 and contained. It is more connected with the fat than with 
 the bone ; and in animals, can be drawn out entire from the 
 cavity of the bone ; but its chief use is to conduct the vessels 
 which are to enter into the substance of the bone; and this con- 
 nection and office is so essential to the life and health of the 
 bone, that the spina ventosa, or scrophulous bone, is merely a 
 
 * If we look to tlie difference there is in the adipose membrane, we shall find it more 
 apparent than real. The fat on the soles of the feet and palms of the hands is particularly 
 firm, but this firmness results from the strong intertexture of filaments of a tendinous 
 strength. The fat in the exposed parts of the limbs is less firm, in the orbits of the eyes 
 more delicate, but in the bones it lies in transparent membranes, and is quite soft and 
 compressible. The difference, however, is only in the manner in which the bags containing 
 the fat are bound up and protected ; where the substance is exposed lo pressure, it is firm j 
 where it lies concealed, it is less so ; but where it is altogether within the iirotection of the 
 bones, tire membranes are very delicate, and the fat takes the appearance of marrow. C. B. 
 
AND GROWTH OF BONES, 
 
 19 
 
 failure of the internal circulation, a total corruption of the mar- 
 row, and a consequent loss of the medullary vessels; by 
 which the whole bone dies, is thrown out by nature, or oftener 
 the limb must be cut off,* The same effect is produced in 
 otir experiments, where, by piercing into the medullary cavity, 
 and destroying the marrow, the shaft of the bone dies, while 
 the heads and processes live, only because they are supplied 
 more fully by their external vessels. 
 
 The periosteum, which was once referred to the dura ma- 
 ter, is merely condensed cellular substance ; of which kind of 
 matter we now trace many varied forms and-uses, for so close 
 is the connection of the periosteum, tendons, ligaments, fasciae, 
 and bursas, and so much are these parts alike in their nature 
 and properties, that we reckon them but as varied forms of one 
 common substance, serving for various uses in different parts. 
 The periosteum consists ol many layers, accumulated and con- 
 densed one above another : it adheres to the body of the bone 
 by small points or processes, which dive into the substance of 
 the outer layer, giving a firm adhesion to it, so as to bear the 
 pulling of the great tendons, which are fixed rather into the 
 periosteum than into the bone. It is also connected with the 
 bone by innumerable vessels. The layers of the periosteum 
 nearest to the bone are condensed and strong, and take a strong 
 adhesion to the bone, that the vessels may be transmitted safe, 
 and the fibres of this inner layer follow the longitudinal direc- 
 tions of the bony fibres. The periosteum is looser in its tex- 
 ture outwardly, where it is reticulated and lax, changing im- 
 perceptibly into the common cellular substance. There the 
 fibres of the periosteum assume the directions of the muscles, 
 tendons, or other parts which run over it. The periosteum 
 is not for generating bone ; and therefore it adheres but slight- 
 ly to the growing bone : it is for nourishing the external plates ; 
 and therefore, as the bone grows, and as the external plates 
 are further removed from the medi 41 ary vessels, the adhesion 
 of the periosteum becomes closer, its arteries are enlarged, 
 and the dependence of the outer layers on the periosteum is 
 as well proved as the dependence of the body of the bone 
 upon its medullary artery ; for, as piercing the medulla kills 
 the whole bone, hurting the periosteum kills the outer layers 
 of the bone. Any accident which spoils the bone of its pex’i- 
 osteum has this effect; the accidental wounds of the peri- 
 osteum, deep ulcers of the soft parts, as on the shin, the beat- 
 ing of aneurisms, the growth of tumours, the pressure even of 
 
 * This disease is rather what we call necrosis, in which the bone dies. _ The spina ven- 
 tosa is the consequence of abscess in the cavifv of the bone. See the specihrens in ray col- 
 lection. C. B. 
 
20 
 
 OF THE FORMATIOI? 
 
 any external body, will, by hurting the periosteum, cause ex- 
 foliation, which is, in plain terms, the death of the external 
 layer, by the injury of the outward vessels ; and an active in- 
 flammation of the deeper layers, which being fully nourished 
 by the internal arteries, inflame, swell, become porous and 
 spongy, form granulations, and these granulations push olT the 
 mortified plate, and form themselves into new bone, which 
 supplies its place.*' 
 
 The cartilages are also a part of the living system of the 
 bone ; and we see too well, in the question of the bones them- 
 selves, how unphilosophical it must be to deny organization 
 and feeling to any part of the living body, however dead or 
 insulated it may appear; for every part has its degree of life: 
 the eye, the skin, the flesh, the tendons, and the bones, have 
 successive degrees of feeling and circulation. We see, that 
 where even the lowest of these, the bone, is deprived of its 
 small portion of life, it becomes a foreign body, and is thrown 
 off from the healthy parts, as a gangrened limb is separated 
 from the sound body; and we speak as familiarly of the death 
 of a bone, as of the gangrene of soft parts. How, then, 
 should we deny organization and life to the cartilages.^ though 
 surely, in respect of feeling, they must stand in the very last 
 degree. 
 
 The periosteum goes from the bone over the surface of the 
 cartilage also, where it is named perichondrium : It still pre- 
 serves its own vascular nature; the vessels can be injected; 
 and it is not to be believed that the perichondrium has these 
 vessels, without communicating them to the cartilage to which 
 it belongs. We see red arteries in the centre of an ossifying 
 cartilage, and therefore we know that the trunk of the artery 
 may be red, as in the ossifying part of the cartilage, and yet 
 the extremity of the same artery be pellucid, as in the unossi- 
 fied part. Since vessels run through tiie cartilage to generate 
 bone, we cannot in reasonesuppose that these vessels are pro- 
 duced in the instant in which they appear : they had existed 
 before ; they are but dilated now ; the increasing action di- 
 lates them, and the dilatation makes them red ; this enables 
 them to secrete bone, and, in many cases, as in the accidental 
 joint formed by a fracture ill cared for, we can, by paring the 
 cartilage, set the vessels free again, and make them begin to 
 secrete.f 
 
 * It is the injury to the surface of the bone which causes the exfoliation, not the loss of 
 vessels by tlie separation of the periosteum ; and when the hone dies, as in necrosis, Irom 
 the injury to the marrow, inflaraation precedes the death. C. B. 
 
 t This is true as a physiological fact, but it is not the proper method of curing this de- 
 lict of mrion in a bone. Seetlie 2d vol. of Operative Surgery by Charles Bell. 
 
AND GROWTH OF BONES. 
 
 21 
 
 Wherever we find a vascular membrane surrounding and 
 nourishing any part, as the vitreous or crystalline humours in the 
 eye, we must not suppose that such are insulated parts, main- 
 tained there by mere adhesion ; but must consider them as 
 parts regularly organized, their vascular membrane being part 
 of their living system ; and though the transparent humours of 
 the eye, the cartilages and ligaments over all the body, and 
 all the system of the bones, have been considered as mere 
 concretes, and insulated parts, they are now known lo be 
 regular parts of the living whole. The cartilages have no very 
 active circulation ; it is such as to keep them in life, but not 
 so active as to endanger inflammation, in the continual shocks 
 which they must endure ; their feeling must be very obscure, 
 for feeling also would have been inconsistent with their offices, 
 which is to cover and defend the bones; to yield to the weight 
 of the body, and to restore themselves when that weight is re- 
 moved ; to bear all the shocks of leaps or falls ; to perform all 
 the motions of the body, and the continual workings of the 
 joints, where they rub, and even crackle upon each other with- 
 out danger or pain. 
 
 We now understand the constitution of a bone, and can com- 
 pare it fairly with the soft parts in vascularity, and in feeling j 
 in quickness of absorption ; in the regular supply of blood 
 necessary to the life of the bony system ; in the certain death 
 of a bone, when deprived of blood by any injury of its marrow, 
 or of its periosteum, as a limb dies of gangrene, when its ar- 
 teries are cut or tied ; in the continual action of its absorbents, 
 forming its cavity, shaping its processes and heads, keeping 
 it sound and in good health, and regulating the degree of bo- 
 ny matter, that the cotnposition may neither be too brittle nor 
 too soft. From this constitution of a bone, we could easily 
 foresee how the callus for uniting broken bones must be form- 
 ed ; not by a mere coagulation of extravasated juice, but by a 
 new organization resembling the original bone. 
 
 The priinordium of all the parts of the body is a thin gelati- 
 nous mucus, in which the forms of the parts are laid ; and the 
 preparation for healing wounds, and for every new part that 
 needs to be formed, is a secretion of mucus which is soon ani- 
 mated by vessels coming into it from every point. In every 
 external wound, in every internal inflammation, wherever ex- 
 ternal parts are to be healed, or internal viscera are about to 
 adhere, a mucous matter is secreted, which serves as a bed or 
 nidus, in which the vessels spreatl from point to point, till the 
 mucus is animalized and converted into a membrane : and 
 thoB the heart, the intestines, the testicle, and other part?, ad- 
 
22 
 
 OF THE FORMATION 
 
 here by inflammation to the coats which suiTound them, and 
 which are naturally loose. It is a mucus of the same form 
 which unites the ends of a broken bone; and, by breaking the 
 bones of animals, and attending to the progress of the callus, 
 we find first a thin mucus ; then that thickened into a transpa- 
 rent jelly ; that jelly growing vascular, and these vessels gradu- 
 ally depositing nucleei of ossification in the centre of the mass ; 
 and by madder or by fine injections, we can make the jelly 
 appear vascular, and make the nuclsei of ossification quite red. 
 The colours of our injections begin to tinge the cartilage as it 
 begins to ossify, and as soon as the ossification is general, it 
 receives a general tinge. 
 
 When we find the substance of the oldest bone thus full of 
 vessels, why should we doubt its being able, from its own pe- 
 culiar vessels, to heal a breach, or to repair any loss '' We 
 have no reason to refer the generation of callus to the marrow, 
 to the periosteum, nor to the substance of the bone itself, for 
 they are but parts of the common system of a bone ; and each 
 part of this system is of itself capable of regenerating the 
 whole. How little the constitution of a bone has been under- 
 stood, we may know from the strange debates which have 
 subsisted so long about the proper organ for generating callus- 
 Some have pronounced it to be the periosteum ; others, the 
 medullary vessel, and internal membrane ; others, the substance 
 of the bone Itself : but I have been employed in explaining, 
 that not only part of the bone, periosteum, or marrow, but 
 even any artery in all the system, may assume that action 
 which generates bone In the heat of this dispute, one of the 
 most eminent anatomists produced a diseased bone, where a 
 new bone was formed surrounding a carious one, and the spoil- 
 ed bone rattled within the cavity of the sound one : here we 
 should have been ready to pronounce, that bone could be 
 formed by the periosteum only. But presently another ana- 
 tomist produced the very reverse, viz. a sound young bone, 
 forming in the hollow cylinder of a bone which had been long 
 dead ; where, of course, the callous matter must have been 
 poured into the empty cavity of the spoiled bone, from the 
 ends which still remain sound, or must have been secreted by 
 the medullary vessels. But the truth is, that callus may be 
 thus produced from any part of the system of a bone ; from 
 its periosteum, from its medulla, or from the substance of the 
 bone itself.* If we pierce the bone of any animal, and de- 
 
 * The term, system of a bone, is incorrect, if by it is meant the periosteum which sur- 
 rountls the bone, and the marrow within. In the experiments and observations which I 
 have made, neither tile periosteum or marrow seemed to have formed the bone ; and 1 con- 
 clude, tlint nothing but bone can form hone, by the continuation of natural actions ; and 
 that in tlie case of necrosis, the old bone inflames and begins the new formation, before the 
 continued irritation in the centre kills it. C. B. 
 
AND GROWTH OF BONES. 
 
 23 
 
 sti’oy the marrow, the old bone dies, and a new one is formed 
 from the periosteum : if we kill the creature early, we find the 
 new bone to be a mere secretion from the inner surface of the 
 periosteum ; and if we wait the completion of the process, we 
 find the new bone beautiful, white, easily injected, and thick, 
 loose in its texture, and vascular and bloody, but still firm 
 enough for the animal to walk upon ; and in the heart of it, 
 we find the old bone dead and black. If we reverse this ope- 
 ration, and destroy the periosteum only, leaving the nutritious 
 vessels entire, then the new bone is formed fresh and vascular 
 by the medullary vessels, and the old one quite black and dead, 
 surrounds it and in fractures of the patella or knee-pan, 
 where there are no medullary vessels, the pieces are united by 
 a callus, which is secreted from the vessels of the bone itself. 
 
 The diseases of the bones are the most frequent in surgery ; 
 and it is impossible to express how much the surgeon is con- 
 cerned in obtaining true ideas of the structme, constitution, 
 and diseases of bones ; how tedious, how painful, and how 
 loathsome they are ; how often the patient must lose his limb, 
 or endanger his life; how very useful art is; but above all, 
 what wonders nature daily performs in recovering bones from 
 their diseased state. 
 
 * When I injure the marrow of the bone, necrosis is the consequence, see plate Ilf. 
 fig. 1. 1 divide the bone of its periosteum and surround it with a bit of bladder, I 
 
 find the whole surface exfoliates, and the cavity of the bone fills up ; but this is not a con- 
 sequence of the destruction of the vessels of the periosteum,but of the contact of foreign matter 
 with the surface of the bone. An effect precisely similar is the consequence cf the slough- 
 ing of the soft parts over a hone, for the dead slough lying on the surface ofthe bone causes 
 an exfoliation. 
 
 The effect of injury to a living bone is very curious. But the manner in which the hone 
 resumes its pristine form is still more worthy of obseiwation. At first the outward exfolia- 
 tion is attended with a proportionate filling up of the cavity of the bone. And the injury to 
 the centre and body of the bone produces a new bone around the old one, and the old one 
 at last dies and is absorbed or discharged. But after years these changes are again reversed, 
 and the new hone contracts its diameter, and the cavity becomes of its narurai dimentions, 
 M that the evidence of the clianges which the bone ha.s undergoneare quite removed. This 
 is a very beautiful example of the influence of that principle which coetiohs t.be growth of all 
 the parts ofthe body, which may have its operation deranged by violent injuiy or by disease ; 
 but which will at last by slow degrees restore the part to its natural form and action. C. B. 
 
( 24 ) 
 
 CHAP. II. 
 
 OP THE SKULL IN GENERAL THE BONES OF WHICH IT IS 
 
 COMPOSKU THMR TABLES DIPLOE SUTURES THEIR 
 
 ORIGINAL UONOITION, ANU THEIR PERFECT FORM, REPRE- 
 SENTED AND EXPLAINED. 
 
 W illLE the bones in general serve as a basis for the soft 
 parts, and supporting and directing the motions of the body, 
 cenain bones have a higher use in containing those organs 
 whose offices are the most essential to life The skull de- 
 fends the brain ; the ribs and sternum defend the heart and 
 lungs ; the spine contains that prolongation of the brain which 
 gives out nerves to all the body : and the injuries of each of 
 these are important in proportion to the value of those parts 
 which they contain. 
 
 How much tlie student is interested in obtaining a correct 
 and perfect knowledge of the skull, he must learn by slow de- 
 grees. For the anatomy of the skull is not important in itself 
 only ; it provides for a more accurate knowledge of the brain ; 
 explains, in some degree, the organs oi sense} instructs us in 
 all those accidents of the head which are so often fatal, and so 
 often require the boldest of all our operations. The marks 
 which we take of the skull, record the entrance of arteries ; the 
 exit of veins and nerves ; the places and uses of those muscles 
 which move the jaws, the throat, the spine. Indeed, in all 
 the human body, there is not found so complicated and diffi- 
 cult a study as this anatomy of the head; and if this fatiguing 
 study can be at all relieved, it must be by first establishing a 
 very regular and orderly demonstration of the skull. 
 
 For this end, we distinguish the face, where the irregular, 
 suriace is composed of many small bones, from the cranium 
 or skull-cap, where a few broad and fiat-shaped bones form 
 the covering of the brain. It is these chiefly which inclose 
 and defend the brain, which are exposed to injuries, and are 
 the subject of operation. It is these also that transmit the 
 nerves : so that the cranium is equally the object of attention 
 with the anatomist and with the surgeon 
 
 All the bones of the cranium, are of a flattened form, con- 
 sisting of two tables, and an intermediate diploe, which an- 
 swers to the cancelli of other bones. The tables of the skull 
 are two flat and even plates of bone : the external is tho ight 
 to be tuicker, more spongy, less easily broken ; the inner tar 
 
OF THE SKULL IN GENERAL. 
 
 25 
 
 ble, again, is dense, thin, and brittle, very easily broken, and 
 is sometimes fractured, while the external table remains en- 
 tire : thence it is named tabula vitrea, or the glassy table. 
 These tables are parted from each other by the distance of a 
 few lines and this space is filled up with the diploe, or can- 
 celli. The caneclli, or lattice-work, is a net of membranes, 
 covered with vessels, partly for secreting marrow, and partly 
 for nourishing the bone ; and by the dura mater adhering to 
 the internal surface, and sending in arteries, which enter into 
 the cancelli by passing through the substance of the bone, and 
 by the pericranium covering the external plate, and giving ves- 
 sels from witliout, which also enter into the bone, the whole is 
 connected into one system of vessels. The pericranium, dura 
 mater, and skull, depend so entirely, one upon the other, and 
 are so fairly parts of the same system of vessels, that an injury 
 of the pei’icranium spoils the bone, separates the dura mater, 
 and causes effusion upon the brain : a separation of the dura 
 materis, in like manner, followed by separation of the pericra- 
 nium, which had been sound and unhurt ; and every disease 
 of the cancelli, or substance of the bone, is communicated both 
 ways ; inward to the brain, so as^ to occasion very imminent 
 danger ; outwards towards the integuments, so as to warn us 
 that there is disease. The general thickness of the skull, and 
 the natural order of two tables, and an intermediate diploe, is 
 very regular in all the upper parts of the head. In perforating 
 with the trepan, we first cut with more labour, through the ex- 
 ternal table ; when we arrive at the cancelli, there is less re- 
 sistance, the instrument moves with ease, there is a change of 
 sound, and blood comes from the tearing of these vessels, 
 which run in the cancelli, betwixt the tables of the skull. Sur- 
 geons thought themselves so well assured of these marks, that, 
 it became a rule to cut freely and quickly through the outer 
 table, to expect the change of sound, and the flow of blood, as 
 marks of having reached the cancelli, and then to cut more 
 deliberately and slowly through the inner table of the skull. 
 But this shows an indiscreet hurry, and unpardonable rashness 
 in operation. The patient, during this sawing of the skull, is 
 suffering neither danger nor pain ;f and many additional rea- 
 sons lead us to refuse altogether this rule of practice : for the 
 skull of a child consists properly of one table only : or 
 tables are not yet distinguished, nor the cancelli formed : in 
 youth, the skull has its proper arrangement of cancelli and ta- 
 
 * In anatomy, there is occasion in almost every description, for a scale of smaller parts. 
 The French divide their inch into twelve parts, each of which is a line. The French line, 
 or twelfth of an inch, is a measure which 1 shall often have occasion to use. 
 
 t There is a state of inflammation, either under the dead bone or in the surrounding bone, 
 which gives extreme pain, eyen when the silver probe touches the dead bone. C. B. 
 
 D 
 
26 
 
 OP THE SKULL IN GENERAL. 
 
 bles ; but still, with such irregularities, and exceptions, as make 
 a hurried operation unsafe : in old age, the skull declines to- 
 wards its original condition, the cancelli are obliterated, the ta- 
 bles approach each other, or are closed and condensed into 
 one ; the skull becomes irregularly thick at some points, and at 
 others thin, or almost transparent ; so that there can hardly be 
 named any period of life in which this operation may be per- 
 formed quickly and safely at once. But, besides this gradual 
 progress of a bone increasing in thickness and regularity, as 
 life advances, and growing irregular and thinner in the decline 
 of life, we find dangerous irregularities, even in younger skulls. 
 
 There are often at uncertain distances, upon the internal sur- 
 face of the skull, hollows and defects of the internal table, 
 deep pits, or foveas, as they are called, produced, perhaps, by 
 the impressions of contorted veins. These foveae increase in 
 size and in number, as we decline in life : they are more fre- 
 quent on the inner surfaces of the parietal and frontal bones j 
 so that in those places where the skull should be most regular, 
 we are never sure, and must, even in the safest places, perforate 
 gradually and slowly. 
 
 The BONES of the skull are divided into those of the 
 cranium ; the bones of the face ; and common, or interme- 
 diate bones.* 
 
 * The head is divided into the cranium and face. For the cranium we find in old authors 
 tlie words calva or calvaria from calvis, hald, or sometimes cerebri galea, as being like a 
 helmet to protect the brain. 
 
 We-diid some terms distinguishing certain parts of ttie cranium as glabella, the smooth 
 part in the centre and lower part of the forehead. Occiput, the ulmo.st convexity of the 
 head backward. Vertex, the crown of the head where the hairs turn. Bregma, or fon- 
 tanelle, which are terms derived from very false notions, but which mean the interstices left 
 in a child’s skull betwixt the cranial bones. 
 
 The student ought to know these terms, but good taste rejects them even from medical 
 language, when the de.scription can he given in plain English. 
 
 The following is the usual division of the bones of the head. 
 
 In the adult head there are thirty bones and thirty-two teeth. 
 
 Of the Cranium, 
 Six Bones. 
 
 1 Os Frontis 
 
 2 Ossa Parietalia 
 2 Ossa Temporalia 
 I Os Occipitis 
 
 Intermediate or 
 Common Bones, Two. 
 1 Os Sphenoides 
 1 Os Ethmoides 
 
 Bones of the Face, 
 Fourteen. 
 
 2 O.ssa Maxillaria Supra. 
 2 Ossa Malarum 
 2 Ossa Nasi 
 2 Ossa Palati 
 2 O.ssa Unguis 
 2 Ossa Turbinata Infa- 
 1 Vomer 
 
 1 O.ssa Maxillaria Infe. 
 
 Bones of the Ear, 
 Four on each Side. 
 Maleus 
 Incus 
 
 Os Orbiculare 
 
 Stapes 
 
 Teeth, Thirty-two. 
 
 8 Incisorcs 
 4 Cuspidati 
 8 Bicuspideg 
 12 Molares 
 
 32 
 
OP THE SKULL IN GENERAL. 
 
 27 
 
 The bones of which the cranium, or skull-cap is formed, 
 are eight in number. 1. The frontal-bone, or bone of the 
 forehead, forms the upper and fore part of the head, — extends 
 a little towards the temples, and forms also the upper part of 
 the socket for the eye. 2. The parietal bones, are the two 
 large and flat bones which form all the sides, and upper pari of 
 the head ; and are named parietalia, as they are the walls or 
 sides of the cranium. 3. The os occipitis, is named from 
 its forming all the occiput or back of the head, though much 
 of this bone lies in the neck, and is hidden in the basis of the 
 skull. 4. The ossa temporum form the lower parts of the 
 sides of the cranium : they are called temporal, from the hair 
 that covers them being the first to turn grey, marking the time 
 of life. 5. The os 3:thmoides, and, 6. the os sphenoioes, 
 are quite hidden in the basis of the skull : they are very irre- 
 gular and very difiicultly described or e^xplained. The os mtu- 
 MOiuEs, is a .'fmall square bone, hollow, and with many cells 
 in it ; it hangs over the nose, and constitutes a great and im- 
 portant part of that organ, and at the same time supports the 
 brain. The olfactory nerves, by passing through it at 
 many points, perforate it like a sieve ; and it takes its name 
 from this perforated or athraoid plate. The os sphenoides 
 is larger and more irregular still ; placed further back ; locked 
 in betwixt the occipital and sethmoidal bones ; lies over the 
 top of the throat, so that its processes form the back of the 
 nostrils, and roof of the mouth ; and it is so placed, as to sup- 
 port the very centre of the brain, and transmit almost all its 
 nerves. 
 
 SUTURES. — All these bones are joined together by seams, 
 which, from their indented, or dove-tailed appearance, are na- 
 med sutures.* 
 
 * Suture is a common term for the line of contact of tlie flat hones. It is a form of union 
 admitting of no motion, and is somewhat varied according to to the degree of pressure they 
 have to sustain They may be arranged thus ; 
 
 JUNCTURA ImMOBILTS. 
 
 1. Sulurn Vera — Serrata. — Dentata. 
 
 2. Sutura Spuria — Linea — Harmonia. 
 
 3. Sutura Squarrmsa. — Limbosa. 
 
 4 Gamphosis. 
 
 Monro [Jmtrmiy of the Human Bones) expresses the common opinion, that “ the suture 
 “ is formed by the two bones meeting while they are tims flexible and yielding, and have 
 “ not yet come to their full extent of growth, so that they mutually force into the inter- 
 “ slices of each other, till meeting with such resistance as they are not able to overcome 
 “ they are stopt from sprouting out further or are reflected, &c.” 1 object to this, because 
 St represents the suture to be an accident. Are not all Imnes pushrf together as here 
 described f yet the true suture is not universal. 
 
 It is acknowledged, that there is an object and intention in having the bones of the child’s 
 head in separate pieces. The cons^uence of this is, that sutures are formed when their 
 Jnargins unite But why is there this variety in the form of the juncture Certainly this 
 is not accidental. We must notice that when a hone is light and weak it is united by the 
 simple line of contact, or what !.■' called by harmonia. On the contrary, where the bone has 
 to bear pressure, or where it has a more important organ to protect, it is thick and firm 
 
28 
 
 OF THE SKULL IN GENERAL. 
 
 1. The CORONAL SUTURE, IS that whlcli joins the frontal to 
 the parietal bones ; extends almost directly across the head, 
 from ear to ear ; descends behind the eye, into the deep part 
 of the temple ; and there loosing its serrated appearance, be-, 
 comes like the squamous or scaly suture, which joins the tem- 
 poral bones. It is named coronal, because the ancients wore 
 their garlands on this part of the head. But the suture had 
 been better entitled to this name, had it surrounded the head, 
 than as it crosses it. 
 
 2. The LAMBJ)ou)AL SUTURE, is that One which joins the pa- 
 rietals to the occipital bone. It begins behind one ear, ascends 
 and arches over the occiput, and descends behind the other 
 ear. It thus strides over the occiput, in a form somewhat re- 
 sembling the letter lambda (A), of the Greeks, whence its 
 name. 
 
 3. The SAGITTAL SUTURE, joins the parietal bones to each 
 other ; runs on the very top of the head ; extends forwards 
 from the lambdoid suture till it touches, or sometimes passes, 
 the coronal suture ; and from lying betwixt these two sutures, 
 like an arrov/ betwixt the string and the bow, it has been 
 named sagittal. 
 
 4. The TEMPORAL SUTURES, join the temporal bones to the 
 parietal, occipital, and frontal bones ; the sphenoid bone also 
 enters into the temporal suture, just behind the eye. The 
 temporal suture makes an arch corresponding almost with the 
 arch of the external ear ; it meets the coronal suture an inch 
 before the ear, and the lambdoidal an inch behind it. This 
 back part belongs as much to the occipital as to the temporal 
 bone ; and so has been named sometimes, additamentum su- 
 turge lambdoidalis ; sometimes additamentum suturae squamo- 
 sae : for this temporal suture is, on account of the edge of the 
 temporal and occipital bones being tbin, and like scales of ar- 
 mour laid over each other, often named the squamous or scaly 
 suture. 
 
 5. The SPHENOIDAL and ethmoidal sutures, are those 
 which surround the many irregular processes of these two 
 bones, and join them to each other and to the rest. 
 
 I'iidit is joined by the indented suture, which is a union by a more perfect mcclianisin, and 
 gives strength proportioned to the bone. Thus we see that the bones of the cranium are 
 united by the true suture. But the most perfect specimen of the tiue suture will be found 
 ill the skulls of horned cattle, because tliis instrument of defence must be reared on a firm 
 foundation. 
 
 Further, the anatomist repeats from day to day and year to year, that the squamous su- 
 ture is made by the pressure of the temporal muscle ; an accident again. No ; it is formed 
 lor a purpose, it is the kind of suture the best calculated to bind in the ci-anial bones, and_ 
 to prevent the starling of the parietal bones. He does not contemplate the structure of 
 the body in a proper temper of mind, who looks upon these adaiirablc provisions as the effect 
 of accident. C. B. 
 
OF THE SKULL IN GENERAL. 
 
 29 
 
 6. The TRANSVERSE SUTURE, is One which, running across 
 the face, and sinking down into the orbits, joins the bones of 
 the skull to the bones of the face ; but with so many irregula- 
 rities and interruptions, that the student will hardly recognize 
 this as a suture. 
 
 7. The ZYGOMATIC SUTURE, is one which joins a branch of 
 the temporal bone, to a process of the cheek bone ; forming 
 an arch, zygoma, or yoke ; but this suture has no extent, it is 
 a serrated appearance at one single point only. 
 
 To mark and know these sutures, and to be able to trace 
 them in imagination, upon the naked head, to foresee where a 
 suture will present, and how far it runs, may be a matter of 
 great importance to the surgeon. Hippocrates, who has had 
 more to praise his honesty than to follow his example, ac- 
 knowledges his having mistaken a suture for a fracture of the 
 skull ; and since this warning, various contrivances and marks 
 have been thought of, for preventing the like mistake. It 
 may be useful to remember that the suture has its serr:u or in- 
 dentations, is firmly covered by the pericranium, is close, and 
 does not bleed : but that a fissure, or fracture of the skull, 
 runs in one direct line, is larger and broader at the place of 
 the injury, and grows smaller as you recede from that, till it 
 vanishes by its smallness ; and that it always bleeds. Indeed, 
 the older surgeons, observing this, poured ink upon the sus- 
 pected part, which, if the skull was hurt, sunk into the fissure, 
 and made it black and visible ; but left the suture untouched. 
 They also directed to make the patient take a wire betwixt 
 his teeth, which being struck like the string of an instrument, 
 he would feel the twang produce a painful and particular sen- 
 sation in the fractured part of the head. But after all these 
 observations, in place of any true and certain marks, we find 
 a number of accidents w'hich may lead us into a mistake. 
 
 Sutures cannot be distinguished by their serrse or teeth, for 
 the temporal sutures want this common character, and rather 
 resemble capillary fractures of the skull nor even by their 
 places, for we know that there are often insulated bones (ossa 
 Wormiana) surrounded with peculiar joinings, which so de- 
 range the course of the common sutures, that the joinings 
 may be mistaken for fractures of the skull, and the ossa Wor- 
 miana for broken parts. Sometimes the squamous suture is 
 double, with a large arch of bone intercepted betwixt the true 
 and the false suture ; or the sagittal suture, descending beyond 
 its usual extent, and quite to the nose, has been mistaken for a 
 fracture, and trepanned ; and oftener in older skulls, the su- 
 
 * Viz. Fractures as small as a hair, thence named capillary. 
 
30 
 
 OF THE SKULL IN GENERAL. 
 
 tures are entirely obliterated, all over the head. If the sur- 
 geon should pour ink upon the skull, he would have reason to 
 be ashamed of an experiment so awkward and unsuccessful ; 
 and for the old contrivance of a wire or cord held in the 
 mouth, it cannot be done, since the patient is commonly in- 
 sensible ; and even, though less hurt, his feelings, after such 
 an accident, must be very confused ; he must be too liable to 
 be deceived : and we cannot on such slender evidence as this, 
 perform so cruel an operation as cutting up the scalp, or so 
 dangerous a one as the trepan. 
 
 For various reasons, we are careful to trace the bones from 
 their original soft and gristly state, to their perfect condition of 
 hard bone : and most of all, we are concerned to do so in the 
 head, where, in childhood the appearances are not singular 
 and curious only, but have always been supposed to indicate 
 some wise and useful purpose. It is in this original condition 
 of the soft and growing bones, that anatomists have sought to 
 find a theory of the sutures, how they are formed, and for 
 what uses. It has been remarked, that the number of pieces 
 in the skull, is infinitely greater in the child than in the man. 
 These bones ossifying from their centi’e towards their circum- 
 ference, it happens, of course, that the fibres are close at the 
 centre of ossification, and are more scattered at the extremities 
 of the bone : when these scattered fibres of opposite bones 
 meet, the growing fibres of one bone shoot into the interstices 
 of that which is opposed : the fibres still push onwards, till 
 they are stopped at last, and the perfect suture, or serrated line 
 of union is formed. 
 
 In dilating this proposition, we should observe, that in the 
 boy, all the bones in the head are membranous and imperfect. 
 The membranous interstices begin to be obliterated ; the 
 sutures are beginning to close ; the distinction of two tables is 
 not yet established ; the cancelli are not yet interposed be- 
 tween the plates, the sinuses, or caverns of the bones, as in 
 the forehead, the nose, and the jaw, are not formed ; and each 
 bone is not only incomplete towards its edges and sutures, but 
 consists often of many parts. The os frontis is formed of 
 two pieces, which meet by a membranous union in the middle 
 of the bone. The ossa farietalia have one great and promi- 
 nent point of ossification in the very centre of each, from 
 which diverging rays of ossification extend towaids the edges 
 of the bone. The os occipitis is formed in four distinct 
 pieces : and the temporal bones are so fairly divided into 
 two, that their parts retain in the adult the distinct names of 
 petrous and squamous bones. Although these are all the 
 regular points of ossification, yet sometimes there occur small 
 
OF THE SKULL IN GENERAL. 
 
 31 
 
 and distinct points, which form irregular bones, uncertain in 
 number or size, found chiefly in the lambdoid suture, some- 
 times numerous and small, more commonly they are few in 
 number, and sometimes of the full size of a crown, always 
 distorting more or less the course of the suture, and being thus 
 a subject of caution to the surgeon : these are named ossa 
 TK 1Q.UKTKA, Or Tiu angularia, from their angular shape, or, 
 woKMiANA, from Olaus Worrai^is, who remarked them first. 
 Now the os frontis being formed into two larger pieces, their 
 edges meet early in life, and they form a suture ; but the 
 bones continuing to grow, their opposite points force deeper 
 and deeper into each other, till at last the suture is entirely 
 obliterated, and the bones unite ; and so this suture is found 
 always in the child, seldom in the adult, almost never in old 
 age. The occipital bone having four points, they are closer 
 upon each other, they meet early, are soon united j and, al- 
 though very distinct in the child, no middle suture has ever 
 been found in the adult, but always the four pieces are united 
 into one firm and perfect bone. The parietal bones have their 
 rays most of all scattered ; the rays of ossification run out to a 
 great distance, and diverge from one single point, so that at 
 their edges they are extremely loose, and they never fail to 
 form sutures, by admitting into their interstices the points and 
 edges of the adjoining bones. The surest and most constant 
 sutures are those formed by the edges of the parietal bones; 
 the sagittal in the middle, the coronal over the forehead, the 
 lambdoidal behind, and the squamous suture, formed by their 
 lower edges. But another phenomenon results at the same 
 time, from this meeting and opposition of the fibres and inter- 
 stices of the growing bones : that when the opposite fibres 
 meet too early, they are not fairly admitted into the open 
 spaces of the opposite bone ; but the fibres of each bone being 
 directly opposed point to point, they both turn inwards, and 
 form a ridge or spine, such as is seen on the inner surfaces of 
 the frontal and occipital bones. Such is the common theory, 
 which I suspect is imperfect, and wliich should be received 
 with some reserve, for all the phenomena are not yet explain- 
 ed; we find each suture always in its appointed place ; we 
 find nothing like a suture formed betwixt the head and body 
 of a long bone, though they are formed in distinct points, and 
 are not united till after the years of manhood ; we find no 
 sutures when bones are broken and reunited, when they have 
 been spoiled and are replaced, when a piece of spoiled bone 
 has been cut away, nor when a new shaft of a bone is formed 
 by the secreting vessels, and is united to the heads of the old 
 bone. These are accidents which hold us at least in doubt. 
 
32 OF THE SKULL IM GENERAL. 
 
 It has been supposed, and with much appearance of truth, 
 that the sutures limit the extent of fractures, leave a free com- 
 munication of the internal with the external parts ; that they 
 must serve as drains from the brain ; that they are even capa- 
 ble of opening at times, so as to give relief and ease in the 
 most dreadful diseases of the head. But I fear we are not yet 
 able to see the meaning of this peculiarity of structure ; for 
 the sutures are regular and uniform to a wonderful degree, 
 while these uses of them are far from being proved. 
 
 The sutures surely were not intended by nature for limiting 
 the extent of fractures ; for fractures traverse the skull in all 
 directions ; cross the sutures with ease ; and very often, pas- 
 sing all the sutures, they descend quite to the basis of the 
 skull, where we dare not follow them with the knife, nor ap- 
 ply the trepan. Indeed we do not even know that limiting the 
 extent of factures could be a gracious provision of nature, since 
 it would rather appear by the common accidents, that the 
 more easily the b-one yields, the less is the injury to the brain; 
 and that where the fracture is wide and large, the symptoms 
 are milder, and the danger less. 
 
 Neither were they intended as drains; for surely it is a bold 
 position to assume, that nature has carefully provided for our 
 making issues upon the sutures. When the original openness 
 of the head and the membranous condition of the sutures was 
 first observed, it was thought to be an observation of no small 
 importance. The ancients believed that the membranes of 
 the brain came out by the sutures, to form the pericranium, 
 and going from that over the several joints, formed the peri- 
 osteum for all the bones. They saw a close connection betwixt 
 the external and internal membranes of the skull, and they 
 thought that nature had intended there a freer communication, 
 and an occasional drain. They found the sutures particularly 
 wide and membranous in a child, which they attributed to the 
 watery state of its brain, requiring a freer outlet than in the 
 adult ; and accordingly they named the opening of the child’s 
 head the the bregma, fons, fontanelle, the fountain, by which 
 they believed there was a continual exudation of moisture 
 from the brain. 
 
 We might have expected these notions to have vanished 
 with the doctrines of humours and revulsion which gave rise 
 to them ; but both the doctrines and the practice, have been 
 revived of late years; and a surgeon of some eminence has 
 been at pains to examine various skulls, trying to find which 
 of all the sutures remains longest open, and which should form 
 the readiest and surest drain ; and after a curious examination 
 of each, he decidedly condemns the fontanelle ; finds the ad- 
 
OP THE SKULL IN GENERAL. 
 
 33 
 
 ditamentura of the squamous suture always open, and expects 
 this superior advantage from placing his issues there, that he 
 will command at once a drain both from the cerebellum and 
 from the brain. But these notions of derivation and revulsion, 
 of serous humours falling upon the brain, of drains of pituita 
 by the nose, and through the sutures, were much cherished 
 by the ancients, had been long forgotten, and have not been 
 effectually revived by this attempt. 
 
 It cannot be denied, that, in some instances, the sutures 
 have continued quite open in those grown in years, or have 
 opened after a most wonderful manner, in some diseases of 
 the head. 
 
 A young man having been brought into an hospital ill of a 
 fever, the physicians observed with surprise, a very strong pul- 
 sation behind the ear: upon applying the finger, a strong beat- 
 ing was felt ; the part was soft and yielding ; and upon open- 
 ing his head, after death, there was found a large membra- 
 nous space. Diemorbrock found the fontanelle open in a 
 woman of forty years of age. Bauhin says, that in his own wife, 
 twenty-six years of age, the sutures were not yet closed. 
 
 This fontanelle, or opening at the meeting of the coronal 
 and sagittal sutures, was once thought to be a sure mark for the 
 accoucheur to judge by, both of the life of the child, and of 
 the direction in which its head presents. It is large and soft 
 in a child, and the good women lay a piece of firm cloth upon 
 it, and defend it with particular care- It begins to contract 
 from the time of birth ; and in the second and third year, it 
 is entirely closed. Its closing is delayed by weakness, scro- 
 phulous complaints, and indeed by any lingering disease ; it 
 closes very late in rickets, and in hydrocephalic children the 
 bones never close, but continue soft, yield to the watery swell- 
 ing of the brain, and separate in a wonderful degree, so as to 
 hold ten or twelve pounds. 
 
 As the sutures continue open in a hydrocephalic child, they 
 are said to open again in the few in.:tances where adults are 
 seized with the same disease. We are told that it opens in 
 those dreadful head-aches which are sometimes fatal, and that 
 the celebrated Paschal having died after terrible torments, was 
 found to have the sutures opened again : it is even said that 
 they open during disease, and close after the cure. “ That 
 “ a man of forty years of age, being, in the dog-days, seized 
 “ with a raging fever, delirium, watching, and dreadful pains 
 “ of the head, his sutures opened on the seventh day, were 
 “ a^ wide as in a child, n&t only so as to be distinguished by 
 “ the finger, but that the attendants could see the pulsations 
 “ of the brain ; the fever, after some time, abated ; the 
 
 E 
 
34 
 
 OF THE SKULL IN GENERAL. 
 
 “ pains ceased; the sutures closed, and this man lived many 
 “ years in perfect health.” So Hildanus reports the case, 
 and he also says, in another instance, that the sutures had part- 
 ed in a violent hemicrania, with an audible noise. 
 
 Yet if this were a regular design of nature, the relief should 
 be perfect ; perhaps the opening of the sutures should be 
 more easy, and the accident almost as common as diseases of 
 the head ; or perhaps it bad been the more merciful order, to 
 have determined a quick and sudden period for such dreadful 
 and incurable diseases as these. 
 
 The sutures of the cranium are accidental merely, and of 
 little use. The result, perhaps, of this well known law, that 
 nature seeks to facilitate ossification, by beginning the process 
 in many points ; and she establishes as many distinct points in 
 healing a broken limb as in forming the skull. But however 
 they may be formed, their uses cannot be of that importance 
 which has been supposed ; for there are twenty separate bones, 
 and twenty sutures in the face, where they can neither stop 
 fractures, nor serve as drains, nor open so as to give relief. 
 
 But if the sutures of the cranium have any thing peculiar and 
 different from those of the face, in that, perhaps, their pecu- 
 liar uses may be found. We cannot pass unnoticed their loose- 
 ness and flexibility in the new-born child ; how wonderfully 
 the head of the child is increased in length, and reduced in 
 breadth in the time of delivery, and how much this conduces 
 to an easy and happy labour. 
 
 The most eminent anatomists have condescended to remark, 
 that in the various nations of Europe, the head has various 
 forms, which they ascribe to so slight a pressure as that which 
 dress, or even the posture of the head might produce. But 
 how very far Vesalius was deceived in calculating thus, is easi- 
 ly proved. The Turks, says he, have their heads flattened 
 by wearing the turban. But the turban is an eastern dress : 
 the Turks or Tartars are a northern people, who assume this 
 dress only when conquest brings them into a W'armer climate, 
 and the prominent cheek-bones, parted eyes, and flat heads, 
 continue in the Tartars, who have but newly assumed the tur- 
 ban, while the conquered nations which have worn it long, are 
 distinguished by their regular and beautiful features. Perhaps 
 by contrivance and force, we may distort the head of a child ; 
 and we may almost believe what is told of the negroes of the 
 Caribbee islands, who had contrived, by pressure, to flatten 
 their children’s heads, that their race might be in future distin- 
 guished from those who had submitted to the, Spanish yoke; 
 or of what is told so often of eastern nations, i r' ., Srey some- 
 times mould the heads of children into monstrous and uncouth 
 
OF THE SKULL IN GENERAL. 
 
 35 
 
 librms, to extort charity, or as an act of religion. Were I to 
 assign a reason for the flexible bones, and wide sutures, and 
 the yielding condition of the head of the child, I should say 
 that it were meant hy nature to stand in the place of that se- 
 paration of the bones of the pelvis which has been supposed, 
 but which cannot exist ; for the child’s head is moulded with 
 little injury, is evolved again without help ; and it seems a 
 provision of nature, since the child scarcely feels the change: 
 but no woman has been known to have the joinings of the pel- 
 vis relaxed or dissolved without pain and danger, confinement 
 for many months, a temporary lameness, and sometimes she 
 is rendered unable for life. 
 
 CHAP. III. 
 
 DESCRIPTION OP THE INDIVIDUAL BONES OF THE SKULL. 
 
 Os FRONTIS. This bone is compared with a clam- 
 shell. It is of a semicircular shape, hollowed like a shell. 
 It is marked on the inside by a spine, or prominent line, 
 which divides the hollow of the bone into two equal parts, 
 and gives rise to a membranous partition, which divides and 
 supports the hemispheres of the brain. It is marked on its 
 external surface by those high ridges on which the eye-brows 
 are placed, and by two prominences, which are hollow ca- 
 verns, named the sinus (or cavites) of the frontal bone. Its 
 orbitary plates are the two thin and delicate lamellae that de- 
 part from the general direction of the bone, and stand out 
 horizontally, so as to form a part of the socket for the eye, or, 
 as it were, a roof defending the upper part of the eye, and a 
 floor for supporting the lower part of the brain ; and these 
 two orbitary plates leave an open space, in which is incased 
 the chief part of the aethmoid bone, viz. incissura sethmoidea. 
 
 The frontal bone stands connected with the parietal bones 
 by tbe coronal suture ; it is connected to the great ala of the 
 sphenoid bone by the sutura spheno frontalis ; while its or- 
 bitary plates are united to the lesser ala by the linea spheno 
 frontalis. The nasal bones are attached to it by part of the 
 transverse suture of the face. The cribriform plate of the 
 aethmoid bone is united to the orbitary plates by the linea 
 sethmoidea frontalis, and looking into the orbits the same or- 
 
36 
 
 description of the 
 
 bitaiy plates are seen to be contiguous to the ossa plana and 
 ossa unguis ; and, lastly, the ossa inalarum are attached to 
 the frontal bone by the extremities of the transverse suture of 
 the face. 
 
 The first point to be remarked, is the superciliary ridge, 
 on which the eye-brows are placed : it is a prominent arched 
 line, corresponding in size and length with tiie eye-brow which 
 it supports : over this line the integuments are loose : here 
 many arteries perforate the bone, which are properly the nu- 
 tritious arteries of this part of the bone ; and we find all over 
 the superciliary ridge many small holes through which these 
 arteries had passed. Among these, there is one hole which is 
 larger, and which is distinguished from the rest ; for its use is 
 not like the others, to transmit arteries to the bone, but to give 
 passage to the frontal nerve and a small artery which comes 
 out from the orbit, to mount over tbe forehead. Sometimes 
 the nerve turns freely over the border of the orbit, and makes 
 no mark, or but a slight. one : often lying closer upon tbe bone, 
 it forms a notch ; but most commonly, in place of turning fair- 
 ly over the edge of the orbit, it passes obliquely through the 
 superciliary ridge, and by perforating the bone, makes a hole : 
 this hole is named the superciliary hole. The artery 
 wliir h comes from the eye to go out upon the forehead is 
 named, where it passes, the superciliary artery; and higher up 
 upon the lorehead, the frontal artery : it establishes a commu- 
 nication betwixt tlie internal arteries of the eye, and external 
 arteries of the forehead and temple. We are always warned 
 of the danger of wounding arteries where they pass through 
 bones ; and strange stories are told of the terrible bleedings 
 which have risen from this artery, wounded near its hole, and 
 of the convulsions, palsies, and loss of sight, which have arisen 
 from the accidents, wounds or lacerations of this frontal nerve ; 
 stories deliv^ered on such authorities as we dare not refuse, and 
 yet cannot easily believe. 
 
 The second foramen is the foramen orbitale internum, 
 which transmits a branch of the ophthalmic division of the fifth 
 nerve into the cranium, and finally into the nose. There is 
 frequently another foramen in the orbital plate, which trans- 
 mits a small vessel from the orbit to the nose. 
 
 The orbitary, or superciliary ridge, ends by two processes, 
 which, forming the angles of tbe eye, are named the angular 
 PROCESSES. The frontal bone has, therefore, four angular 
 processes: 1. The two internal angular processes, forming 
 
 the internal angles of the eyes ; and 2. The two external an- 
 gular processes which form the external angles of each eye. 
 
 Betwixt the two internal angular processes there is the na- 
 
INDIVIDUAL BONES OF THE SKULL. 37 
 
 SAL POINT or puocEss. This nasal process is a small sharp 
 projecting point, occupying that space which is exactly in the 
 midfile of the bone, and is betwixt the two internal angular 
 pr »cesses. It is very irregular and rough all round its root, 
 for supporting the two small nasal bones ; and this gives them 
 a firm seat, and such a hold upon the root of the forehead, 
 that they oftener are broken than displaced. 
 
 From the external angular process there extends backwards 
 and upwards the temporal ridge or spine. 
 
 At the inner end of the superciliary ridge, is that bump 
 which marks the place of the frontal sinus, which also indi- 
 cates their size ; for where this rising is not found, the sinuses 
 are wanting, or are very small ; but this is no sure nor absolute 
 mark of the presence of these sinuses, which often, in the flat- 
 test foreheads, are not entirely wanting. 
 
 The sinuses* of the os frontis are two in number, one on 
 either side above the root of the nose : they are formed by a 
 receding of the two tables of the skull from each other: they' 
 are formed at first with the common cancelli, and at first they 
 resemble the common cancelli, as if they were only laiger 
 cells : gradually they enlarge into two distinct cavities, often 
 of very considerable size, going backwards into the orbitary 
 plate, or sideways into the orbitary' ridge, or upwards through 
 one half of the frontal bone; and.Ruysch had, in a giantess 
 (puella gigantica,) seen them pass the coronal suture, and ex- 
 tend some way into the parietal bones. 
 
 The two sinuses of either side are divided by' a partition ; 
 but still they' communicate by a small hole : sometimes the par- 
 tition is almost wanting, and there are only' crossings of the 
 common lamellated substance ; and though the communica- 
 tion with one another is not always found, they never fail to 
 communicate with the nose : this indeed seems to be their 
 chief use ; for the frontal sinuses are the beginning of a great 
 train of cells, which, commencing thus in the frontal bone, ex- 
 tend through the tethmoidal, sphenoidal, and maxillary bones, 
 so as to form an organ of great extent and use belonging to 
 the nose ; but perhaps not so much for extending the organ of 
 smelling, as for making a more sonorous voice ; for we have 
 no proof that the sinuses are part of the organ of smell ; un- 
 less we should accept of this as a proof, that, by smelling of 
 strong volatiles, pain shoots upwards into the forehead ; though 
 
 * The word ninus is used in two senses ; we call the cavities or cells, within the substance 
 of a bone, the sinuses of that hone ; as the sinuses of the forehead, of the sphenoid, sthinoid 
 or m ixilhry bones we call also certain great veins by the same name of sinuses ; thus the 
 great veins being enlarged where they a[tproach the heart, and the veins being particularly 
 large in the bi’ain and the womb, we call them the sinuses of the heart, of the bi-ain, and of 
 the womb. 
 
38 
 
 DESCRIPTION OF THE 
 
 by the same rule, the eyes should be also a part of the same 
 organ, since they are pained, and tears begin to flow : but we 
 do Cpiow that they belong to the voice, and raise its tone, for 
 we feel the trembling note resound through all these cells, so 
 that the voice is sonorous while they are free ; is damped 
 when the sinuses are oppressed by their membranes being 
 thickened by cold ; or is almost suppressed when the sinuses 
 are entirely closed ; or when, by venereal ulcers, the curtain 
 of the palate is consumed, no part of the voice passing 
 upwards into the nose, it is almost lost. 
 
 This has given rise to a very common mistake : that as 
 these sinuses are wanting in the child whose forehead is flat, 
 as they enlarge gradually, and are fully formed about the fif- 
 teenth year, the vox rauca, the breaking of the voice, which 
 is observed about that time, must be owing to the evolution of 
 these cells : but the female voice does not undergo the same 
 change by the evolution of these cells ; and castration, which 
 surely can have no effect on these cavities, keeps down the 
 eunuch’s to the treble key of the female voice.* The mis- 
 take lies ill supposing these cavities to raise the tone or note 
 in which we speak, while they only add clearness and strength. 
 The membrane which lines these cavities is thin, exquisitely 
 sensible, and is a continuation of the common membrane of 
 the throat and nose. A thin humour is poured out upon its 
 surface to moisten it and keep it right. This the ancients did 
 not consider as a mere lubricating fluid, but as a purgation of 
 the brain, drawn from the pituitary gland, which could not be 
 diminished without danger, and which it was often of conse- 
 quence to promote. 
 
 They are subject to one accident chiefly, viz. insects which 
 nestle there, and produce inconceivable distress; and it is par- 
 ticular, that they more frequently lodge in the frontal sinuses, 
 than in the cavities of any of the other bones. In sheep and 
 dogs such insects are very frequent, as in seeking their food, 
 they carry their nose upon the ground ; and it has been prov- 
 ed, or almost proved, that in man they arise from a like cause. 
 Indeed, what can we suppose, but that they get there by 
 chance ; thus, a man having slept in barns, was afflicted with 
 dreadful disorders in the forehead, which were relieved upon 
 discharging from the nose, a worm of that kind which is pecu- 
 liar to spoiling corn ; while others have had the complaint, 
 by sleeping upon the grass. But there is something very par- 
 ticular in this, that far the greater number of these worms have 
 
 * I have seen a boy of four years of age, whose parts of generation were prematurely 
 developed with busby hair upon tlie pubes. This man-ebild had the rough broken voice, 
 though the bones of the forehead were flat. C. B. 
 
INDIVIDUAL BONES OF THE SKULL. 
 
 39 
 
 been of the centipede kind ; generally long, an inch in length, 
 with one hundred, or, according to Linnseus, one hundred and 
 twelve feet, and not unfrequently covered with hair. There 
 are reports which seem to prove, that some have died of this 
 complaint, and in a very miserable way. In many cases it has 
 been attended with delirium ; and in almost every instance it 
 has continued for years. No wonder, then, that the trepan- 
 ning of these sinuses has often been proposed ; but I have 
 never read of a well marked case, so that we could be assur- 
 ed beforehand of finding worms : they have, in most cases, 
 been discovered rather by chance. The patient might be re- 
 lieved on easier terms, by the injection of aloes, assafoetida, 
 myrrh, the use of snuff or smoaking, and pressing the fumes 
 upwards into the nose. Much should be tried, before under- 
 taking a dangerous operation on such slender proofs. 
 
 It maybe right in cases of fractures, to decline applying the 
 trepan above the sinuses, unless a fracture cannot be raised in 
 any easier way ; and we must be especially careful to distin- 
 guish a fracture of the outer table only, from entire fractures 
 of this bone. For Palfin says, that the outer table being bro- 
 ken, and the natural mucus of the sinus being corrupted and 
 flowing out, has been mistaken for the substance of the brain 
 itself. And Paree, who first gives this caution, affirms, “ that 
 “ he had seen surgeons guilty of this mistake, applying the 
 “ trepan, and so killing their unhappy patients.”* 
 
 The SPINE or ridge which runs upon the internal surface of 
 the frontal bone, is to be observed, as it gives a firm bold to 
 the falx, or that perpendicular membrane, which running in the 
 middle of the head, divides and supports the brain. This is 
 more or less prominent in different skulls, and according to the 
 age. The spine is more prominent at its root ; but as it ad- 
 vances up the forehead, it decreases, and often ends in a 
 groove. The spine gives firm hold for the falx, and the groove 
 lodges the great longitudinal sinus, or in other words, the great 
 vein of the brain, which runs along the head, in the course of 
 the perpendicular partition, or falx. At the root of this spine, 
 there is a small blind hole ; it is named blind, because it does 
 not pass quite through the bone, and the beginning of the falx, 
 dipping down into this hole, gets a firmer bold. The ancients, 
 thinking that the hole descended through both tables into the 
 nose, believed that the dangerous and ungovernable bleedings 
 at the nose must be througii this hole, and from the fore end, 
 or beginning of the longitudinal sinus. 
 
 * For a more perfect account of the pathology of the sinuses, see the Sui'gery, 4t». 
 vel. ii. 
 
40 
 
 DESCRIPTION OP THE 
 
 The ORBITARY PROCESS already described, is the most re- 
 markable point of the frontal bone. Tlie orbitary process- 
 es are two thin plates, departing from the general direction of 
 the bone, and standing inwards at right angles : they cover the 
 eye, and support the brain. By the continual rolling of the 
 eye, and the pressure of the brain, they are extremely thin 
 and transparent ; the rolling of the eye makes them exqui- 
 sitely smooth below, and on their upper surfaces, they are im- 
 pressed with the frequent convolutions of the brain ; so that a 
 ■wound through the eye endangers more than the eye ; for it 
 passes easily forward into the brain, and is instantly fatal ; it is 
 the aim of the fencer, and we have known in this country 
 a young man killed by the push of a foil, which had lost its 
 guard. 
 
 Upon the orbitary plate, and just under the superciliary 
 ridge, there are two depressions in the socket pf each eye; 
 the one is very small, and deeper at the inner corner of the 
 eye, under the superciliary hole, which is the mark of the 
 small cartilaginous pulley, in which the tendon of one of the 
 muscles of the eye plays ; the other, a more gentle and diffu- 
 sed hollow, lies under the external angular process, is not 
 deep, but is wide enough to receive the point of a finger, and 
 is the place w'here.the lachrymal gland lies, that gland which 
 secretes the tears, and keeps the eye moist.* 
 
 PARIETAL BONE. — The parietal bones form much the 
 greater share of the cranium : they are more exposed than 
 any others, are the most frequently broken, and the most easily 
 trepanned ; for the parietal bones are more uniform in their 
 thickness, and more regular in their two tables and diploe, than 
 any others. But the accidental varieties of pits and depression 
 are very frequent in them, and the sinus or great vein, and the 
 artery which belongs to the membranes of the brain, both 
 make their chief impressions upon this bone. 
 
 The square form of the bone produces four angles ; and in 
 surgery, we speak of the frontal, the occipital, the mastoidean, 
 and temporal angles, of the parietal bone.| It has deeply ser- 
 rated edges, which unite the two bones with each other, and 
 with the occipital and frontal bones. All the corners of this 
 bone are obtuse, except that one which lies in the temple, and 
 which, running out to a greater length than the other corners, 
 is sometimes named the spinous or temporal process of the 
 parietal bone, though there can be no true process in a bone so 
 
 * )n addition, as points of demonstration, we may add the emineniix frantales, and su- 
 purdliares. 
 
 + It enters into the wonal, tlie sagittal, the lamhdmdal, and the sijmrwm sutures. 
 
INDIVIDUAL BONES OF THE SKULL. 
 
 41 
 
 sjegular and flat. The lower edge of the bone is a neat semi- 
 circle, which joins the parietal to the temporal bone ; and the 
 edge of each is so slaunted off, that the edge of the temporal 
 overlaps the edge of the parietal, with a thin scale, forming the 
 squamous suture. About- an inch above the squamous suture, 
 there is a semi- circular ridge, where the bone is particularly 
 white and hard ; and rays extend downwards from this, con- 
 verging towards the jugum. The white semi-circular line 
 represents the origin of the temporal muscle ; and the con- 
 verging lines express the manner in which the fibres of the 
 muscle are gathered into a smaller compass, to pass under the 
 jugum, or arch of the temple. The sagittal suture, or meet- 
 ing of the two parietals, is marked with a groove as big as the 
 finger, which holds the longitudinal sinus, or great vein of the 
 brain ; but the groove is not so distinctly seen, unless the two 
 bones are put together ; for one half of this flat groove belongs 
 to each bone. 
 
 The great artery of the dura mater touches the bone at that 
 angle of it which lies in the temple. It traverses the bone 
 from corner to corner, spreading from the first point, like the 
 branches of a tree : it beats deep into the bone w'here it first 
 touches it ; but where it expands into branches, its impressions 
 are very slight ; commonly it makes a groove only, but some- 
 times it is entirely buried in the bone ; so that at the lower 
 corner of the parietal, we cannot escape cutting this vessel, if 
 we are forced to operate with the trepan. 
 
 There is but one hole in the parietal bone : it is small and 
 round, is within one inch of the meeting of the lambdoidal and 
 sagittal sutures, and gives passage to a small external vein, 
 which goes inwards to the sinus, and to a small artery which 
 goes also inwards to the dura mater, or rather to the falx. 
 
 On the inner surface of the bone, and near the sagittal edge, 
 we very often see a pit or foveae, which receives one of those 
 bodies which are called glands, of the dura mater. 
 
 The lateral sinus makes a depression on the inside of the 
 mastoid ean angle. 
 
 The meeting of the frontal and parietal bones, being imper- 
 fect in the child, leaves that membranous interstice which, by 
 some, is named folium or folliolum, from its resembling a 
 trefoil leaf, and was named by the ancients hypothetically, 
 bregma, fons,'* or fountain ; they thinking it a drain of moisture 
 from the brain ; and so the parietal bones are named ossa 
 bre£;matis. 
 
 O 
 
 *■ The word piilsatilis, or fons pulsatile, or beating fountain, was added, because we feel 
 the beating of the arteries of the brain there. 
 
 VOL. I. F 
 
42 
 
 DESCRIPTION OF THE 
 
 OS OCCIPITIS, has also the names of os memorice, and 
 os nervosum.* It is the thickest of the cranial bones, but it is 
 the least regular in its thickness, being transparent in some 
 places, and in others swelling into ridges of very firm bone. 
 It gives origin or insertion to many of the great muscles, which 
 move the head and neck ; it supports the back part of the 
 brain, contains the cerebellum or lesser brain, transmits the 
 spinal marrow, and is marked with the conflux of the chief 
 sinuses, or great veins of the brain. 
 
 This bone is united to the parietal bones by tlie lambdoid 
 suture, to the mastoidean portions of the temporal bone by 
 the additamentum suturae lainbdoidalis, laterally and forward 
 it is attached to the petrous portion of the temporal bone, and 
 at its lower and most anterior part, it is attached to the sphe- 
 noid bone, by that peculiar bond of union called synostosis. 
 
 The EXTERNAL SURFACE is exceedingly' irregular, by the 
 impressions of the great muscles of the neck : betwixt the 
 insertions of the muscles, projecting lines are on the bone. 
 In the middle of the bone, and betwixt the muscles of oppo- 
 site sides, there runs a ridge from above downward ; at the 
 upper margin of the insertion of the trapezius, there is formed 
 a superior transverse spine or ridge, and in the same way, di- 
 rectly above the insertion of the recti, which make two irre- 
 gular depressions, there is an inferior transverse spine. In a 
 strong man, advanced in years, where the ridges and hollows 
 are strongly marked, the point where the superior transverse 
 crosses the perpendicular one, it is so very promine t, as to be 
 named the posterior tuberosity of the occipital bone. 
 
 The INTERNAL SURFACE. Opposite to these ridges there 
 are similar crucial ridges within ; but larger, more regular, 
 smooth, and equal, and making only one transverse line, and 
 one perpendicular line. The tentorivm cere.bdln super-exte.n- 
 sum, is a diaphragm or transverse partition, wiiich crosses the 
 skull at its back part ; cuts off from the rest of the cranium 
 the hollow of the occipital bone, appiopriates that cavity for 
 tlie cerebellum, and defends the cerebellum from the weight 
 and pressure of the brain. This tentorium, or transverse 
 membrane, is attached to the gre.ivt internal ridge of the 
 occipital bone. In the angle where this membrane is fixed to 
 the ridge, lies the great sinus or vein, which is called longitu- 
 dinal sinus, while it is running along the head ; but the same 
 
 * In Hejinning the demonstration, we point out its divisions : I. Pars orcipitalis. 2. Pars 
 lateralis or condyloidea. 'i Pars hasilaris or cunifnrinis ; wliich at birth are distinct hones 
 di\ id.-d by cartilage It is also necessary to name its angles, viz. the superior or parietal 
 angle, and the mastoidean angle. 
 
INDIVIDUAL BONES OF THE SKULL. 
 
 43 
 
 sinus, dividing in the back of the head, into two great branches, 
 changes its name with its direction ; and the forkings of the 
 vessel are named the right and left lateral sinuses, which go 
 down through the basis of the skull ; and being continued 
 down the neck, are there named the great or internal jugular 
 veins. This forking of the longitudinal, into the lateral sinuses, 
 makes a triangulak or tripoo-ltke groove, which follows 
 the internal ridges of the occipital bone : and above and be- 
 low the transverse ridge there are formed four plain and 
 smooth hollows. The two upper ones, are above the tento- 
 rium, and contain the posterior lobes of the brain ; the two 
 lower ones are under the tentorium, and hold the lobes of the 
 cerebellum or little brain. 
 
 Processes. The processes or projections of the occipital 
 bone are few and simple. 1. There is a part of the bone 
 which runs forward from the place of the foramen magnum, 
 lies in the very centre of the base of the skull, joins the occi- 
 pital to the sphenoidal bone, and which, both on account of 
 its place, (wedged in the basis of the skull,) and of its shape, 
 which is rather small, and somewhat of the form of a wedge, 
 is named the cuniform, or wedge-like process of the occi- 
 pital bone. On the inside of this part of the bone is a slight 
 hollow, to which the name of fossa basilaris is given, and lateral 
 to this the groove of the lower petrous sinus may be observ- 
 ed. And there are two small oval processes, or button like 
 projections, which stand olF from the side, or rather from the 
 forepart of the foramen magnum, or great hole, and which, 
 being lodged in joints belonging to the upper bone of the 
 neck, form the hinge on which the head moves. These two 
 processes are named the condyles of the occipital bone. 
 They are not very prominent, but rather flattened ; are of an 
 oval form, and have their fore-ends turned a little towards 
 each other ; so that by this joint the head moves directly 
 backwards or forwards, but cannot turn or roll. The turning 
 motions are performed chiefly by the first bones of the neck. 
 Round the root of each condyle, there is a roughness, which 
 shows where the ligament ties this small joint to the corres- 
 ponding bone of the neck. 
 
 On the low’er part of the cuniform process, there are tw'o 
 tubercles for the attachment of the recticapitis anteriores. 
 Near the condyle, and immediately behind the foramen lacer- 
 um there is a tubercle for the rectus capitis lateralis. 
 
 Holes. — These condyles stand just on the edge of the fora- 
 men magnum, or great hole of the head, which transmits the 
 spinal marrow, or continuation of the brain ; and the edges of 
 this hole (which is almost a regular circle) are turned and 
 
44i 
 
 DESCRIPTION OF THE 
 
 stnootlied ; a little thicker at the lip, and having a roughness 
 behind that giving a firna hold to a ligament, which, departing 
 from this hole, goes down through the whole cavity of the 
 spine, forming at once a sheath for the spinal marrow, and a 
 ligament for each individual bone. There passes down 
 through this great hole the spinal marrow, and the vertebral 
 vein. There comes up through it the vertebral arteries, 
 which are of great importance and size ; and a small nerve, 
 which, from its coming backwards from the spine to assist 
 certain nerves of the brain, is named the spinal accessory 
 nerve. 
 
 The second hole is placed a little behind the ring of the 
 foramen magnum, and, just at the root of either condyle, is 
 round and large, easily found, and sometimes it is double ; it 
 transmits the ninth pair, or great lingual nerve. 
 
 There is another hole smaller, and less regular than this last. 
 It is exactly behind the condyle, while the lingual hole is be- 
 fore it. It is for permitting a small vein of the neck to enter 
 and drop its blood into the great lateral sinus ; but often it is 
 not formed, and this trifling vein gets in by the great occipital 
 hole. 
 
 We shall describe with the temporal bone that wide hole 
 which is common to the temporal and occipital bones, and 
 which transmits the great lateral sinus. 
 
 TEMPORAL BONE. — The temporal bone is, in the child, 
 two bones ; which retain their original names of pars petrosa 
 and pars squamosa. The whole bone is very irregular in its 
 thickness, and hollows, and processes. The pars sq,uamosa is 
 a thin or scaly part, rises like a shell over the lower part of the 
 parietal bone, and is smoothed and flattened by the rubbing of 
 the temporal muscle. The pars petrosa, often named os 
 L.APIDOSUM, or stony bony, is hard, irregular, rocky; just in- 
 wards towards the basis of the skull ; , contains the organs of 
 hearing, and, of course, receives and transmits all the nerves 
 which are connected with the ear.* There is a third portion 
 of this bone, viz. the mastoidean angle, which is thick and 
 hard, is divided into cells, and forms those caverns which are 
 supposed to be chiefly useful in reverberating the sound. 
 
 The squamous part is grooved, to make the squamous suture ; 
 is scolloped or fringed ; and exceedingly thin on its edge ; it 
 is radiated, in consequence of its original ossification shooting 
 out its rays. The petrous part again is triangular, unequal by 
 the cavities of the ear; it has a very hard, shining, polished- 
 like surface ; exceeded in hardness by nothing but the enamel 
 
 * Theiaterior and posterior semi-circular canals are protuberant upon its surfaces. 
 
1^'D1VIDUAL BONES OF THE SKULL. 
 
 43 
 
 the teeth. Where it projects into the base, it has several 
 open points, which are filled up with cartilaginous or ligamen- 
 tous substance ; and its occipital angle is connected with the 
 other bones by the additamentum suturs squamosae. 
 
 The temporal bone closes the cranium, upon the lower and 
 lateral part ; backwards it is connected by the additamentum su- 
 turaelambdoidalis to the occipitalbone ; by the squamous suture 
 and the additamentum sutura: squamosa, it isjoined to the parie- 
 tal bone ; whilst anteriorly it is united to the sphenoid bone by 
 the spheno-temporal suture, the spinous process of the sphe- 
 noid bone being deeply wedged betwixt the petrous and squa- 
 mous portions of the temporal bone. 
 
 Processes. The zygomatic process rises broad and flat 
 before the ear ; grows gradually smaller as it stretches for- 
 ward to reach the cheek-bone : it forms w'ith it a zygoma, 
 yoke, or arch of the temple, under which the temporal muscle 
 plays. The temporal muscle is strengthened by a firm cover- 
 ing of tendon, which stretches from the upper edge of this 
 zygoma to the white line on the parietal bone ; and several 
 muscles of the face arise from the low'er edge of the zygoma, 
 particularly one named inasseter, which moves the jaw; and one 
 named zygomaticus, or distorter oris, because it draws the an- 
 gle of the mouth. The zygomatic process is united by a short 
 suture to the cheek bone. 
 
 The STYLOID process is so named from a slight resem- 
 blance to the stylus, or point with which the ancients engraved 
 their writings on tables of w'ax. It is cartilaginous long after 
 birth ; even in the adult, it is not completely formed ; it is ex- 
 ceedingly delicate and small ; and when its cartilaginous point 
 is fairly ossified, as in old men, it is sometimes two inches 
 long. It stands obliquely out from the basis of the head, and 
 is behind the jaws ; so that it gives convenient origin to a 
 ligament which goes downwards to support the os hyoides, or 
 bone of the tongue ; and it is the origin of many curious mus- 
 cles, chiefly of the throat and jaws. One slender muscle going 
 downwards from the styloid process, and expanding over the 
 pharynx, is called stylopharyngeus ; one going to the os 
 hyoides, is the stylohyoideus ; one going to the tongue, is the 
 stylo-glossus : and since the process is above and behind these 
 parts, the muscles must all pull backw'ards and upwards, rais- 
 ing according to their insertions, one the pharynx, another the 
 os hyoides, another the tongue. 
 
 Processus vaginalis will not be easily • found, nor ac- 
 knowledged as a process ; for it is only a small rising of a 
 ridge of the bone, with a rough and broken-like edge, on the 
 middle of which the styloid process stands : it is, in short, the 
 
46 
 
 DESCRIPTION OF THE 
 
 root of the styloid process which anatomists have chosen to 
 observe, though it gives origin to no particular part ; and which 
 they iiave named vaginalis, as if it resembled a sheath for the 
 styloid process. 
 
 Mastoidcus or mammillaris, is a conical nipple-like bump, 
 like the point of tlie thumb ; it projects from under the ear, 
 and is easily felt with the finger without ; it is hollow, with 
 many cells which enlarge the tympanum, or middle cavity of 
 the ear, and are thought to reverberate and strengthen the 
 sound. Under its root, there is a deep and rough rut which 
 gives a firm hold to the first belly of the digastric muscle ; and 
 the point or nipple of this process is the point into which the 
 mastoid muscle is inserted from before ; and the complexus 
 obliquus and trachelomastoideus muscles from behind. It has 
 been proposed of late years, that, in certain cases of deafness, 
 we should open this part with the trepan. 
 
 The AUDITORY HRocKss is just the outer margin of the hole 
 of the ear. It is in a child a distinct ring, which is laid upon 
 the rest of the bone.* The membrane of the ear is extended 
 upon this ring, like the head of a tambour upon its hoop, 
 whence this is named the circle of the tambour by the French, 
 and bv us the drum of the ear. In the adult, this ring is fair- 
 ly united to the bone, and is named the processus auditorius; 
 and may be defined a circle, or ring of bone, with a rough ir- 
 regular edge; the drum or membrane of the ear is extended 
 upon it, and the cartilaginous tube of the ear is fixed to it; and 
 this ring occupies the space trom the root of the mamillary to 
 the root of the zygomatic process. 
 
 Betwixt this and the mastoid process there is a kind of fis- 
 sure, the rima mastoidea. 
 
 The lower jaw is articulated with this bone bj a shallow 
 fossa, which is anterior to the auditory process, and at the 
 root oi the zygomatic process. A tubercle immediately be- 
 fore this articulating surface deepens it. A fissure may be 
 observed in nearly the middle of the cavity, which is for the 
 attachment of the ligament, which unites the intermediate 
 cartilage of tliis articulation This fissure divides the proper 
 articular or glenoid cavity from that fossa which gives lodge- 
 ment to a deep portion of the j>arotid gland 
 
 Holcs. The temporal bone is perforated with many holes, 
 each of which relates to the organ of hearing ; some for per- 
 mitting nerves to enter; others to let them out; others for 
 the free passage of air to the internal ear. 
 
 The MKATUs AiJDiToRius F.xTEKNUs (the circlc of which 
 has been dercribed) is covered with the membrane of the 
 * In brutes it is indeed a process standing out. 
 
'INDIVIDUAL BONES OF THE SKULL. 
 
 47 
 
 drum, and communicates the vibratory motion of the air for 
 moving and exciting the internal organs. 
 
 The MEATUS AuniTOKius JNTERNUS is that hole by which 
 the auditory nerves have access to the ear. It is a very large 
 hole, seated upon the back of the pars petrosa, which is of a 
 triangular form. The hole is at first large, smooth, almost a 
 regular circle, with a sort of round lip. Within this are seen 
 many small holes, the meaning of which is this: the auditory- 
 nerve is double from its very origin in the brain : it consists, 
 in fact, of two distinct nerves, the portio dura, and the portio 
 mollis. The portio mollis is a large, soft and delicate nerve, 
 which constitutes the true organ of hearing; and when it is 
 admitted into the ear, it is expanded into a thin web which 
 spreads over all the cavities of the ear, as the cochlea, semi- 
 circular canals, &c. The portio dura, the smaller part of the 
 nerve, passes indeed through the ear, but it is quite a foreign 
 nerve; it is not distributed within the ear; it keeps the form 
 of a distinct cord, and, passing through the temporal bone, it 
 conies out upon the cheek, where it is expanded ; so that the 
 portio dura is a nerve of the face, passing through the ear, but 
 forming no part of that organ. Thus the two nerves, the 
 portio dura and mollis, enter together; they fill the greater 
 hole, and then they part : the portio dura, entering by one 
 distinct hole, takes its course along a distinct canal, the aque- 
 duct of Fallopius from which it comes out upon the cheek; 
 while the portio mollis, entering by many smaller holes into 
 the cochlea, semi-circular canals, and other internal parts of 
 the ear, is expanded in these cavities to form the proper organ 
 of hearing. 
 
 There is a small hole which will admit the point of a pin 
 upon the fore part of the petrous bone. This hole receives a 
 small twig reflected from the fifth pair of nerves : the nerve is 
 as small as a sewing thread ; it can be traced along the petrous 
 bone by a small groove, which conducts it to the hole ; and 
 when it enters the ear, it goes into the same canal with the 
 portio dura, and joins itself to it. 
 
 The hole by which the portio dura passes out upon the 
 cheek, is found just before the mastoid, and behind the stv- 
 loid process ; and being betwixt the two, it is named the sxv- 
 Lo-MASToiD hole, and is so small, as just to admit a pin. 
 
 The hole for the Eustachian tube is very irregular. No air 
 can pass through the membrane of the drum ; and as air is ne- 
 cessary within the ear, it is conveyed upwards from the palate 
 by the itek a palato ad aurem, or, as it is commonly called, 
 the Eustachian tube. This tube is long, and of a trumpet 
 form ; its mouth, by which it opens behind the nostril, is wide 
 
48 
 
 DESCRIPTION OF THE 
 
 enough to receive the point of the finger, it grows gradually 
 smaller as it advances towards the ear: it is cartilaginous in 
 almost its whole length ; very little of it consists of firm bone ; 
 so that the student, in examining the skull, will hardly find the 
 Eustachian tube for the cartilage being rotten away, nothing 
 is left but that end of the canal that is next the ear, and 
 which opens both above and below, ragged, irregular, and 
 broken. 
 
 When we have a sore throat, the pain extends up along this 
 tube into the ear; when we have a cold, both our voice and 
 our hearing is hurt ; the one by the stuffing of the sinuses, the 
 other by the stuffing of the Eustachian tube. When we shut 
 the nose and mouth, and blow strongly, we feel a crackling in 
 the ear, as in the place of the Eustachian tube ; when we dive, 
 we feel the same, by the condensation of the air ; and sometimes 
 by forcing the air strongly upwards through the ear, or by vo- 
 mits, obstruction of the Eustachian tube, and the deafness 
 which attends that accident, are very suddenly, and, we may 
 say, violently removed ; or sometimes the cure is attempted 
 by syringing, or by cleaning the mouth of this tube with a 
 probe, just as we do the external ear. 
 
 Above and to the outside of the Eustachian tube there is a 
 narrow canal which conveys the nerve called corda tympani. 
 This nerve, traversing the tympanum, enters into the aqueduct 
 of Falopius, and unites with the facial nerve. 
 
 On the inside of the Eustachian tube we may observe a ca- 
 nal which, leading backwards, opens into the cavity of the tym- 
 panum with a mouth like a spoon, it gives lodgement to the 
 long muscle of the maleus. 
 
 The other holes do not relate to the ear, and are chiefly for 
 transmitting the great blood vessels of the brain. 
 
 The CAROTID ARTERV, the chief artery of the brain, enters 
 into the skull near the point of the petrous bone, and just 
 before the root of the styloid process. The artery goes first 
 directly upwards, then obliquely forwards through the bone, 
 and- then again upwards, to emerge upon the inside of the 
 skull; so that the carotid makes the form of an Italic S, wdien 
 it is passing through the substance of the bone ; and, in place 
 of a mere hole, we find a sort of short canal, wide, a little 
 crooked, and very smooth within. There seems to be a par- 
 ticular design in this angle, which the artery is forced to make : 
 perhaps it is designed to abate the violence with which the 
 blood would drive forwards into the brain ; for in many of the 
 lower animals, there are still more particular provisions than 
 this, the arteiy being prevented from entering the brain in 
 one great trunk, by a curious division into many branches,. 
 
INDIVIDUAL BONES OF THE SKULL. 
 
 49 
 
 which meet again. It is at this particular point that we are 
 sensible in our own body of the beating of these two great ar- 
 teries ; and Haller is at pains to inform us, that, during a fever, 
 he felt this beating in a very distressing degree. 
 
 The CHEAT LATERAL SINUS comcs out in part through the 
 temporal bone, to form the interna! jugular vein. The course 
 of the sinus may be easily traced by the groove of the occi- 
 pital bone downwards, behind the pars petrosa : there also it 
 makes a deep groove, and ends with a large intestine-like 
 turn, which makes a large cavity in the temporal bone, big 
 enough to receive the point of the finger. The sinus passes 
 out, not by any particular hole in the temporal bone, but by 
 what is called a common hole, viz. formed one half by the 
 temporal and one half by the occipital bone. This hole is 
 very large ; is lacerated or ragged-like. It is sometimes di- 
 vided into two openings, by a small point, or spine of bone. 
 The larger opening on one side of that point transmits the 
 great sinus, where it begins to form the jugular vein ; and the 
 smaller opening transmits the eighth nerve of the skull, or 
 par vagum, which goes down towards the stomach, along with 
 the jugular vein. 
 
 There is a small furrow upon the very angle or ridge of the 
 petrous bone, which is made by a small vein of the brain, the 
 superior petrous sinus going towards the end of the lateral si- 
 nus. 
 
 There is a small hole on the outside of this bone, in the 
 occipital angle ; or rather the hole is oftener found in the line 
 of the suture (the additamentum sutura' squamosa). Some- 
 times it is in the occipital bone ; or sometimes it is wanting : 
 it transmits a trifling vein from without, into the great sinus, 
 or a small artery going to the dura mater. 
 
 There are two very small canals, which probably carry lym- 
 pbatics from the inner cavities of the ear; they have been 
 called aqueductus vestibuli, and aqueductus cochlea; they 
 open on the petrous bone, near the internal auditory foramen. 
 
 Among the irregular depressions on the different faces of 
 this bone are sometimes enumerated these: the groove al- 
 ready mentioned on the mastoid process for the lodgement of 
 the head of the digastricus ; certain cerebral fossas, which are 
 the impressions of the convolutions of the brain upon the in- 
 side of the squamous portion; the jugular fossa,' or thimble- 
 like depression, made by the first turn of the great jugular 
 vein ; the temporal sinuosity for the lodgement of the tempo- 
 ral muscle ; and, lastly, we observe in a well marked bone, 
 the sulci for the artery of the dura mater. 
 
 G 
 
50 
 
 DESCRIPTION OF THE 
 
 The ETHMOID BONE — Is perhaps one of the most 
 curious bones of the human body. It appears almost a cube, 
 not of solid bone, but exceedingly light, spongy, and consist- 
 ing of many convoluted plates, which form a net-work like 
 honey-comb. It is curiously enclosed in the os frontis, 
 betwixt the orbitary processes of that bone. One horizontal 
 plate receives the olfactory nerves, which perforate that plate 
 with such a number of small holes, that it resembles a sieve, 
 whence the bone is named cribriform, or sethmoid bone. 
 Other plates, dropping perpendicularly from this one, re- 
 ceive the divided nerves, and give them an opportunity of 
 expanding into the organ of smelling ; and these bones, upon 
 which the olfactory nerves are spread out, are so much con- 
 voluted, as to extend the surface of this sense very greatly, 
 and are named spongy bones. Another flat plate lies in the 
 orbit of the eye, which being very smooth, by the rolling of 
 the eye, is named the os planum, or smooth bone ; so that 
 the aethmoid bone supports the forepart of the brain, receives 
 the olfactory nerves, forms the organ of smelling, and makes 
 a chief part of the orbit of the eye ; and the spongy bones, 
 and the os planum, are neither of them distinct bones, but 
 parts of this sethmoid bone. Thus the aethmoid is united to 
 the frontal bone, by the linea aethmoidea frontalis, and to 
 the sphenoid bone by a similar line of contact, visible on the 
 inside of the base of the cranium. Looking into the orbit, we 
 again see a union with the frontal, and with the sphenoidal 
 and palate bones. Its perpendicular plate stands connected 
 to the back part of the nasal process of the frontal bone ; the 
 vomer is attached to the back part of this plate. The ossa 
 unguis close the cells of this bone anteriorly. 
 
 The CRIBRIFORM PLATE is exceedingly delicate and thin, 
 lies horizontally over the root of the nose, and fills up neatly 
 the space betwixt the two orbitary plates of the frontal bone. 
 The olfactory nerves, like two small flat lobes, lie out upon 
 this plate, and, adhering to it, shoot down like many roots 
 through this bone, so as to perforate it with numerous small 
 holes, as if it had been dotted with the point of a pin, or like 
 a nutmeg grater. 
 
 This plate is horizontal ; but its processes are perpendicular, 
 one above, and three below. 
 
 The first perpendicular process is what is called crista 
 OALL i, a small perpendicular projection somewhat like a cock’s 
 comb, but exceedingly small, standing directly upwards from 
 the middle of the cribriform plate, and dividing that plate 
 into two ; so that one olfactory nerve lies upon each side of 
 the crista galli ; and the root of the falx, or septum, betwixt, 
 the two hemispheres of the brain, begins from this process. 
 
INDIVIDUAL BONES OF THE SKULL. 
 
 51 
 
 The foramen caecum, or blind hole of the frontal bone, is 
 formed partly by the root of the crista galli, which is very 
 smooth, and sometimes, it is said, hollow or cellular. 
 
 Exactly oposite to this, and in the same direction with it, 
 {i. e.) perpendicular to the aethmoid plate, stands out the 
 NASAL PLATE of the aethmold bone. It is sometimes called 
 the azygous, or single process of the aethmoid, and forms the 
 beginning of that septum or partition which divides the two 
 nostrils. This process is thin, but firm, and composed of solid 
 bone ; it is comonly inclined a little to one or other side, so as to 
 make the nostrils of unequal size. The azygous process is uni- 
 ted with the vomer, which forms the chief part of the parti- 
 tion ; so that the septum, or partition of the nose, consists of 
 this azygous process of the aethmoid bone above, of the vomer 
 below, and of the cartilage in the fore or projecting part of the 
 nose; but the cartilage rots away, so that w'hatever is seen of 
 this septum in the skull, must be either of the aethmoid bone 
 or the vomer. 
 
 The lateral parts of the aethmoid bone consists of a series of 
 cells communicating with each other, and which are called 
 the labyrinths. The cells of the labyrinth are closed by the 
 external plate called os planum. These cells belong to the 
 organ of smelling, and are useful by detaining the effluvia of 
 odorous bodies, and by reverberating the voice. 
 
 From each of these labyrinths there hangs down a spongy 
 BONE, one hanging in each nostril. They are each rolled up 
 like a scroll of parchment ; they are very spongy ; are covered 
 with a delicate and sensible membrane, and when the olfac- 
 tory nerves depart from the cribriform plate of the Jethmoid 
 bone, they attach themselves to the septum, and to these upper 
 spongy bones, and expand upon them so, that the convolutions 
 of these bones are of material use in expanding the organ of 
 smelling, and detaining the odorous effluvise till the impres- 
 sion be perfect. Their convolutions are more numerous in the 
 lower animals, in proportion as they need a more acute sense. 
 They are named spongy, or turbinated bones, from their con- 
 volutions, resembling the many folds of a turban. 
 
 The ORBITARY PLATE of the aethmoid bone is a large sur- 
 face, consisting of a very firm plate of bone, of a regular 
 square form, exceedingly smooth and polished : it forms a 
 great part of the socket for the eye, lying on its inner side. 
 When we see it in the detached bone, we know it to be just 
 the flat side of the aethmoid bone ; but while it is incased in 
 the socket of the eye, we should believe it to be a small square 
 bone ; and from this, and from its smoothness, it has got the 
 distinct name of os planum. 
 
52 
 
 BESCRIPTION OF THE 
 
 The os UNGUIS sliould also, perhaps, be counted as a part 
 of this bone ; lor though the os unguis, when observed in the 
 orbit, seems to be a small detached hone, thin, like a scale, 
 and of the size of the finger nail (whence it has its name,) yet 
 in the adult the os unguis is firmly attached to the r tlmioid 
 bone, comes along with it when we separate the pieces of the 
 sknll, and when the os unguis is pared olf from the sethmoid 
 bone, it exposes the cells. 
 
 This os unguis, then, is a small scaly-like plate, in the inner 
 corner of the orbit just over the nose. We find in it' that 
 groove which holds the lachrymal sac, and conducts it to the 
 nose ; and it is this thin bone that we perforate in making the 
 new passage into the nose, when there is an obstruction in the 
 natural duct. 
 
 The cells of the sethmoid bone, which form so important a 
 share of the oigan of smell, are arranged in great numbers, 
 along the spongy bone. They are small neat cells, much like 
 a honey-comb, and regularly arranged in two rows, pai’ted 
 from each other by a thin partition ; so that the os planum 
 seems to have one set of cells attached to it, while another 
 regular set of cells belong in like manner to the spongy bones. 
 The cells are thus twelve in number,* opening into each other, 
 and into the nose. 
 
 These cells are frequently the seat of venereal ulcers, and 
 the spongy bones are the surface where polypi often sprout 
 up. And from the general connections and forms of the bone, 
 w'e can easily understand how the venereal ulcer, when deep in 
 the nose, having got to these cells, cannot be cured, but un- 
 dermines all the face ; how the venereal disease, having af- 
 fected the nose, soon spreads to the eye, and how even the 
 brain itself is not safe- We see the danger of a blow upon 
 the nose, which, by a force upon the septum, or middle par- 
 tition, might depress the delicate cribriform plate, so as to 
 oppress the brain with all the elfects of a fiactured skull, and 
 without any operation which could give relief. And we also 
 see much danger in pulling aw'ay polypi, which are firmly at- 
 tached to the upper spongy bone. 
 
 SPHENOIDAL BONE. — The sphenoidal bone completes 
 the cranium, and closes it below. It is named sphenoid cu- 
 NiFOHM, or WEUGE-LiKE bone, from its being incased in the 
 very basis of the skull; or it is named os multifohme, from 
 its irregular shape. It is united to fourteen distinct bones. It 
 is much of the shape of a bat, whence it is often named the 
 
 * Tlie number is commonly twelve, but not regularly so. 
 
IJ^DIVIDUAL BONES OF THE SKULL. 
 
 53 
 
 PTERYGOID BONE, its temporal processes being like extended 
 wings ; its proper pterygoid processes like feet ; its middle 
 like the body and bead of a bat ; its wing-like processes, are 
 in the hollow of the temple, forming a part of the squamous 
 suture, and also composing a part of the orbit of the eye. 
 Its pterygoid processes hang over the roof of the mouth, 
 forming the back of the nostrils : the body is in tbe very cen- 
 tre of the skull, and transmits five of the nerves from the brain, 
 besides a reflected nerve ; but still the body bears so small a 
 proportion to the bone, that we have not a regular centre to 
 which all tbe processes can be referred ; so that we are al- 
 ways, in describing this bone, moving forwards from point to 
 point, from one process or hole to the next. 
 
 PROCESSES. — The ala:, or avings, often named tempo- 
 ral processes, rise up in the temple, to form part of the hollow 
 of the temple ; and the wings of the sphenoid bone meeting 
 tbe frontal, parietal, and temporal bones, by a thin scaly edge, 
 they make part of the squamous suture, and give a smooth 
 surfece for the temporal muscle to play upon. 
 
 The other side of this same process looks towards the socket 
 of the eye, and has a very regular and smooth surface ; it is 
 opposite to the os planum. As the tethmoid bone forms part 
 of the inside of the orbit, the wing of the sphenoid bone forms 
 part of the outside of the orbit; and so the surface turned 
 towards the eye is named the okbitaky process of the sphe- 
 noid bone, or okbitary plate of the great ala. 
 
 The surface of the great wing which looks backwards, re- 
 ceives the middle lobe of the cerebrum and is called tbe 
 CEREBRAL FOSSA ; and that which is external and receiving 
 the temporal muscle, is called the temporal fossa. 
 
 The lower, or back part of this bone runs out into a nar- 
 row point, which sinks in under the petrous portion of tbe 
 temporal bone, and being sharp pointed, it is named the spi- 
 nous PROCESS. It is very remarkable for a small hole which 
 permits the great artery of the dura mater to enter. 
 
 The point of this spinous process projects in the form of a 
 very small peak, which will hardly be found by the student. 
 It projects from the basis of the skull just within the condyle 
 of the lower jaw, and being a small point, like the point of the 
 stylus, or iron-pen, it also is named styloid process. 
 
 Tiie lesser wing of Ingkasias next attracts the eye. It 
 is that part of the bone which unites (by harmonia) with the 
 orbitary plate of the frontal bone, and with theiethraoid bone. 
 
 This lesser wing projects laterally into the transverse spi- 
 nous PROCESS. 
 
54 
 
 DESCRIPTION OF THE 
 
 The PTERYGOID PROCESSES* are four in number, two on 
 either side. They are those processes, upon which (with the 
 spinous process) the bone naturally stands, and which, when we 
 compare it with a bat, represent the legs ; one of each side, 
 is named external pterygoid, the other is named the internal 
 pterygoid process. 
 
 Each EXTERNAL PTERYGOID PROCESS is thin and broad, and 
 extends farther backwards. Each internal pterygoid pro- 
 cess is taller and more slender, and not so broad. It has its end 
 rising higher than the other, and tipped with a small neat hook, 
 named the hook of the pterygoid process, (viz. the hamular 
 PROCESS.) The inner pterygoid processes, form the back of 
 the nostrils. The hook of the pterygoid process, is called 
 the hook of the palate, of which it forms the backmost point. 
 The musculus circumdexus vel tensor palati, rising from the 
 mouth of the Eustachian tube, turns with a small tendon round 
 this hook, like a rope over its pulley; and the great muscles 
 of the lower jaw, the only ones for moving it sideways, or for 
 its grinding motions, arise from the pterygoid processes. Be- 
 twixt the two processes there is a hollow which is called the 
 fossa pterygoidea. 
 
 The AZYGOUS PROCESS,! so named, from its being single, 
 because it is seated in the centre of the bone, so that it can 
 have no fellow. It stands perpendicularly downwards, and 
 forwards, over the centre of the nose, and its chief use is to 
 give a firm seat or insertion for the vomer or bone which 
 forms the septum. The vomer, or proper bone of the par- 
 tition, stands with a split edge, astride over this process, so as 
 to have a very firm seat. A kind of union which has been 
 called gomphosis. 
 
 The CLYNOJD PROCESSES have, like many parts of the human 
 body, a very whimsical name, very ill suited to express their 
 form ; for it is not easy, in this instance, to acknowledge the 
 likeness of four little knobs to bed-posts ; yet the clynoid pro- 
 cesses are very remarkable. The two anterior clynoid 
 PROCESSES are small bumps, rather sharp, projecting back- 
 wards, and terminating in two flat projecting points. The 
 POSTERIOR CLYNOID PROCESSES rise about an inch farther 
 backwards, and are, as it were, opposed to the others. They 
 rise in one broad and flat process, which divides above into 
 
 * There ii some confusion in ■ this name, since pterygoid signifles aliform, or wing-like 
 processes. 
 
 f Azygous is a term, which is applied to such parts as have no fellow ; because almost al- 
 .^vays the parts on one side of the body are balanced by similar and corresponding parts on the 
 other side. When tliey stand in tl)e centre of the body, or are otherwise single, we call 
 them azygous, and so the azygous process of the sethmoid and sphenoid, and other bones ; or 
 the azygous vein, which runs in the centre of the thorax, and is single. 
 
INDIVIDUAL BONES OF THE SKULL. 55 
 
 two points, small and round, or nobby at their points ; and they 
 look forwards towards the anterior clynoid processes. 
 
 The TUBERCULUM OLIVARE is an eminence betwixt the an- 
 terior clynoid process and before the sella turcica. 
 
 The SELLA TURCICA EPHiPPUM, Or Turkish saddle, is the 
 space enclosed by these four processes, and is well named. 
 The sella turcica, supports the pituitary gland, an appendage 
 of the brain, the use of which is unknown. The carotid ar- 
 teries rise up by the sides of the sella turcica, and mark its 
 sides with a broad groove. The optic nerves lie upon a 
 groove at the fore part of the sella turcica, betw'ixt the two 
 anterior clynoid processes ; and sometimes the two anterior 
 processes stretch backwards, till they meet the posterior ones, 
 and form an arch, under which the carotid artery passes. 
 Often the posterior clynoid knobs cannot be fairly distinguish- 
 ed ; since, in many skulls, they form but one broad process. 
 
 On the side of the posterior clynoid process, the carotid ar- 
 tery as it rises impresses its form upon the bone. 
 
 The cone or triangular process is singularly placed in obscu- 
 rity, when the bones are in union, and in separating the sphe- 
 noid bone it is very apt to be broken olF. This process closes 
 the cell, and projects laterally towards the deepesLpart of the 
 orbit, but so as to be concealed by the palate bone. 
 
 This bone has also its cells, for all that part w'hich we call 
 the body of the bone, all the sella turcica, that space which is 
 betwixt the clynoid processes within and the azygous process 
 without, is hollowed into one large cell, divided with a middle 
 partition. It is, indeed, less regular than the other cells ; it is 
 sometimes very large, sometimes it is not to be found ; it has 
 other trifling varieties which it were idle to describe. As it 
 communicates with the sethmoid cells, it probably performs 
 one office with them, is almost a continuation of them, so that 
 when any one is less or wanting, the others are proportionally 
 larger. 
 
 HOLES. — The sphenoid bone is so placed in the very 
 centre of the skull, that its holes transmit the principal nerves 
 of the skull, and it bears the marks of the chief arteries. 
 
 The OPTIC HOLES are large round holes, just under each 
 anterior clynoid process. We trace the optic nerves by a 
 large groove into each optic hole ; and an artery goes along 
 with them, named the opthalmic artery, nearly the size of a 
 crow-quill, twisting round the optic nerve, and giving arteries 
 to the eye-lids, muscles, and lachrymal gland, but most espe- 
 cially to the ball and humours of the eye itself. This ocular 
 or ophthalmic artery comes off from the great carotid, while 
 it lies by the side of the sella turcica ; and it is a branch again 
 
56 
 
 DESCRIPTION OP THE 
 
 of this ocular artery, which goes out upon the forehead, 
 through the superciliary notch, or hole. 
 
 The FOHAiWKN LACEKUM is next in order, and is so named, 
 because it is a wide slit. It is also called superior orbitary 
 fissure. The foramen lacerum is wide near the sella turcica, 
 grows gradually narrower, as it goes out towards the temple, 
 till it terminates almost in a slit. The upper line of the fora- 
 men lacerum is formed by the transverse spinous process, ex- 
 tending outwards, sharp and flat. 
 
 The nerves of the skull are counted from before backwards. 
 There are nine nerves, proper to the skull ; the 1st, or olfac- 
 tory nerve, perforates the cribriform bone ; the 2d, or optic 
 nerve, passes through the optic hole ; the 3d, 4th, part of 
 the 5th and 6th pairs of the nerves, pass through this foramen 
 lacerum, or wide hole, to go also into the orbit. The optic 
 nerve forms the proper organ of vision. The smaller nerves 
 of the 3d, 4th, 5lh, and 6th pairs, go to animate its muscles, 
 and passing through the orbit, to mount upon the forehead, or 
 go downwards into the nose. 
 
 The FORAMEN ROTUNDUM is named from its round shape. 
 The foramen opticum is indeed round, but it has already got 
 an appropjiated name. Now to give the young anatomist a 
 regular notion of this, and of the next hole, we must enume- 
 rate the branches of the 5fh pair. The fifth nerve of the 
 brain is as broad as the little finger, and lies by the side of the 
 sella turcica, where it divides into three lesser nerves, which 
 are called branches of the 5th pair. The first branch of the 
 5th pair is destined for the eye ; the second branch of the 5th 
 pair for the upper jaw; the third branch of this 5th pair for 
 the lower jaw : so the first branch of the 5th pair passes 
 through the foramen lacerum to the eye ; the second branch 
 of the 5th pair passes through the foramen rotundum to the 
 upper jaw ; the third branch of this great nerve passes through 
 the foramen ovale to the lower jaw; and if we had any faith 
 in the docirines of nervous sympathy, we should say, here is 
 a wide sympathy provided among the nerves of the eye, the 
 face, and the lower jaw. 
 
 The foramen rotundum then, is a hole exactly round, pretty 
 large, opening immediately under the inner end of the fora- 
 men lacerum, and transmitting the second branch of the 5th 
 pair of nerves to the upper jaw. 
 
 The FoitiMEiN OVALF is an oval hole, larger than the foramen 
 rotundum ; about half an inch behind it; and transmitting the 
 third branch of the 5th pair to the lower jaw. 
 
 The FORA.MEN setNALE, OF SPINOUS HOLE, is a Very small 
 round hole, as if made with a large pin; is in the very point 
 
INDIVIDUAL BONES OF THE SKULL. 
 
 67 
 
 of the spinous process : is one third of an inch behind the oval 
 hole, and transmits the small artery, less than a crow-quill, 
 which constitutes the chief artery of the dura mater, viz. 
 that artery which makes its impression upon the parietal 
 bone. 
 
 There is still another hole, which transmits a nerve, curious 
 in this respect, that it is not going out from the skull but re- 
 turning into it ; for the second branch of the 5th pair, or the 
 superior maxillary nerve, sends a small branch backwards, 
 which having come within the skull, enters the temporal bone, 
 and goes to join itself to the portio dura of the 7th pair, and in 
 its wav, gives a small branch, to help out the slender begin- 
 ning of the great sympathetic nerve. This retrograde branch 
 of the maxillary nerve gets back again into the skull, by a hole 
 which is found just under the root of each pterygoid process, 
 whence it is named ptkiiygoid HOLe :* or by many, is named 
 after its discoverer, the Vidian HoLc.f This hole is almost 
 hidden under the point of the petrous bone, is not to be seen 
 unless in the separated bones, and is nearly of the size of the 
 spinous hole. 
 
 If there are found some minute holes about the sella tur- 
 cica, they are the marks of some blood vessels entering the 
 bone to nourish it. 
 
 When the bones of the cranium are united, there is appa- 
 rent an irregular hole, which corresponds well with tjie name 
 foramen lacerum medius. It is the continuation of the carotid 
 foramen, but belongs equally to the sphenoid, temporal, and 
 occipital bones. The petrous portion of the temporal bone 
 points to it. 
 
 There is a second common hole formed betwixt the sphe- 
 noid, the maxillary, and the cheek-bone. It is called the 
 spheno-maxillary fissure. 
 
 There is a third common hole betwixt the cell of the palate- 
 bone (in the separate bone a groove may be noticed on the 
 back part of this cell,) and the root of the pterygoid process. 
 This hole transmits an artery, and a twig of the 5th pair of 
 nerves, into the membrane of the nose. 
 
 * This retrograde twig is tire little nerve, which perforates the os petrosum on its fore- 
 »art. 
 
 ' Vidus Vidius, a professor of Paris, and physician to Francis the First. 
 
 H 
 
58 
 
 OF THE BONES 
 
 CHAP. IV. 
 
 OF THE BONES OF THE FACE AND JAWS. 
 
 The face is composed of a great number of small bones^ 
 which are grouped together, under the common name of up- 
 per-jaw. There are six bones on either side of the face j but 
 as their names could convey no, distinct notion of the uses, 
 forms, or places of these bones, to enumerate them were but 
 waste of time : they have indeed sutures, and their sutures 
 have been very regularly enumerated ; bui these bones meet 
 each other by such thin edges, that no indentation nor proper 
 suture is formed. None of these sutures run for any length, 
 or are of any note, therefore I have only this to say, concern- 
 ing the sutures of the face, that they are acknowledged to be 
 purely a consequence of the ossification having begun in many 
 points : no particular design of nature has been supposed. 
 The sutures, if they require names, are to be named after the 
 bones which they unite together. 
 
 OSSA NASL — The ossa nasi are small bones, rather thin, 
 having no cancelli, being merely firm and condensed plates. 
 They are convex outwardly, so that the two together form 
 nearly an arch. They are opposed to each other by a pretty 
 broad surface, so that their thin arch is firm. They have a flat 
 rough surface, by which they are laid upon the rough surface 
 of the frontal bone 5 so that there also their connection is 
 strong. They are enclosed by a branch of the upper jaw- 
 bone, which, stretching upwards, is named its nasal process : 
 and they lie with their edges under it in one part, and above it 
 in anotlier, in such a way that they cannot easily be forced in. 
 Lastly, their lower edge is rough, for the firm attachment of 
 the cartilages of the nose ; and theirlowest point, or that where 
 the bones of the nose and the gristles of the nose are joined, 
 is the most prominent point (or, as it is vulgarly called, the 
 bridge) of the nose ; from which connection, notwithstanding 
 its firmness, the cartilages are sometimes luxated. 
 
 The only point like a process in these bones, is that rough 
 ridge formed by their union which projects towards the cavity 
 to give attachment to the nasal plate of the aethmoid bone. 
 
 Os UNGUIS, so named from its being of the size and shape of 
 the nail ; or sometimes named the os lachrymale, from its 
 holding the duct which conveys the tears, is that thin scale of 
 bone which I have described as belonging to the os sethmoides. 
 
OF THE FACE AND JAWS. 
 
 59 
 
 Ft is commonly described as a distinct bone ; it is a thin flat 
 bone, a single scale, without any cancelli, having only one 
 sharp ridge upon it ; it forms a groove for lodging the lachry- 
 mal sac, and is of course found in the inner angle of the eye 
 at its forepart, and just touching the top of the nose. One 
 half of this bone is behind the groove, and there the eye rolls 
 upon it. One half of it is occupied by the groove for the nasal 
 duct; and the other side of the groove is formed by the rising 
 branch or nasal process, as it is called, of the upper jaw-bone. 
 The os unguis is delicate, and easily broken, being as thin as 
 a sheet of paper. It is this bone which is pierced in the ope- 
 ration for the fistula lachrymalis, which is easily done, almost 
 with a blunt steel or probe ; and the chief caution is to perfo- 
 rate in the place of the groove, as that will lead into the nose, 
 and not behind it, which would carry the perforating instru- 
 ment into the sethmoidal sinuses, and perhaps wound the 
 spongy bone ; nor more forward, as that would be ineffectual 
 from the strength of the nasal process of the maxillary bone. 
 
 This bone seems peculiarly liable to caries, which is per- 
 haps the nature of all these thin bones ; for as they have no 
 marrow, they must depend entirely on their periosteum for 
 their blood vessels, which they are no sooner robbed of than 
 they die. 
 
 Ossa maxillaria superiora. — The upper jaw-bones are 
 particularly worthy of notice ; for here we find all that is cu- 
 rious in the face, even to its size and shape. The upper jaw- 
 bones are of a very great size, forming, as it were, the founda- 
 tion or basis of the face. They send a large branch upwards, 
 which forms the sides of the nose ; a broad plate goes back- 
 wards, which forms the roof of the palate. There is a circu- 
 lar projection below which forms the alveoli, or sockets of the 
 teeth. The upper jaw-bones are quite hollow within, forming 
 a very large cavity, which is capable of containing an ounce 
 of fluid, or more ; and the size of this cavity seems to deter- 
 mine the height of the cheek bone and the form of the face ; 
 and the diseased enlargement of this cavity raises the cheek- 
 bone, lessens the eye, and deforms the face in a very extraor- 
 dinary degree. 
 
 These processes, and this cavity of the bone, are what de- 
 serve most particular notice. 
 
 The surfaces or plates of the bone, are these : External or 
 malar surface ; The superior or orbital ; The internal oxiiasal; 
 The inferior or pa'atme. 
 
 From this description we shall understand the connections 
 of the bone. It is attached forward and upward to the nasal 
 and frontal bones. Laterally to the cheek-bone, and in the 
 
60 
 
 OF THE BONES 
 
 orbit it is connected with the lachrymal and aethmoid bones j 
 towards the nasal cavities, it has the vomer palate- hone and 
 lower spongy bones attached to it, and at the back part it 
 touches the sphenoid bone. 
 
 Tile first process is the nasal process, which extends up- 
 wards to form the sitie of the nose. It is arched outwards, to 
 give the nostrils shape. Its sides support the nasal bones ; 
 and the cartilages of the al;e nasi, or wings of the nose, are 
 fixed to the edges of this process. On the inside and root of 
 the nasal process there is a rough horizontal ridge, which gives 
 atlacliment to the forepart of the inferior spongy bone. 
 
 A plate of this bone is called the orbitary process. This 
 thin plate is the roof of the great cavity, which occupies this 
 bone entirely. It is at once as a roof to the antrum maxillare, 
 and as a floor for the eye to roll upon. There is a wide groove 
 along the upper surface of this plate, in which the chief 
 branch of the upper maxillary nerve lies : and this nerve, na- 
 med infra orbitary nerve, from its lying thus under the eye, 
 comes out by a hole of the jaw-bone under the eye, which is 
 named infra orbitary hole. And thus the nerve appearing up- 
 on the cheek, becomes a nerve of the face. 
 
 This great bone is the basis upon which the cheek-bone 
 stands ; and that it may have a firm place, there is a rough and 
 (as anatomists call it) scabrous surface, which makes a very 
 firm suture with the cheek-bone ; and as this surface rises a 
 little, it is named the malar process. 
 
 From the lower circle of the upper bone, there projects a 
 semi-circle of bone, which is for lodging the teeth of the up- 
 per jaw. This circle of bone is as deep as the fangs of the 
 teeth are long. And it may be very truly named a process 
 (processus alveolar^s,) since it does not exist in the foetus, 
 nor till the teeth begin to be formed'; since it grows along 
 with the teeth, and is absorbed and carried clean away when 
 in old age the teeth fall out. The sides of the sockets in which 
 the teeth are lodged are extremely thin, and surround them 
 closely. The teeth are so closely embraced by their sockets, 
 and we are so far from being possessed of any instrument by 
 which they can be pulled perpendicularly out, that the sockets 
 can seldom escape ; they are broken or splintered in perhaps 
 one of four extractions, even by the most dexterous artists in 
 that line. 
 
 The PALATE process is a plate of bone which divides the 
 nose from the mouth, constituting the roof of the palate, and 
 the floor or bottom of the nostrils. This plate is thinner in 
 its middle, and thicker at either edge : thus, it is thick where 
 it first comes olf from the alveolar process : it is thin in its 
 
OF THE FACE AND JAWS. 
 
 61 
 
 middle ; and it is again thick where it meets its fellow of the 
 opposite side. For at the place where the two upper jaw- 
 bones meet, the palate-plate is turned upwards, so that the 
 two hones are opposed to each other in the middle of the 
 palate by a broad flat surface, which cannot he seen but b\" 
 separating the bones. This surface is so very rough, that the 
 middle palate suture almost resembles the sutures of the skull ; 
 and the maxillary bones are neitlier easily separated, nor easi- 
 ly joined again. This meeting of the palate-plates by a broad 
 surface, makes a rising spine, or sharp ridge, towards the nos- 
 trils, so that the broadness of the surface by which these bones 
 meet, serves a double purpose ; it joins the bones securely, 
 and it forms a small ridge upon which the split edge of the vo- 
 mer, or partition of the nose, is planted. Thus we find the 
 palate-plate of the maxillary bones conjoined, forming almost 
 the whole of the palate, while what are properly called the 
 palate-bones form a very small share of the back part only. As 
 these thinner bones of the face have no marrow, they are 
 nourished by their periosteum only ; they are of course per- 
 forated w'ith many small holes. A great many minute holes 
 are found along the palate-plate, about the place of the sock- 
 ets, and indeed all over the maxillary bones ; and this is 
 particular in the palate, that the hard membrane, or covering 
 of it, is fixed to the bony plate by many rough tubercles, and 
 even by small hooks, which are easily found in the dried bone. 
 
 Since we are describing the plates of the bone as processes, 
 we ought to enumerate the facies interna nasalis as an inter- 
 nal NASAL PLATE. This is the side of the bone which is to- 
 wards the cavity of the nose, on which the lower spongy bone 
 hangs, and which is perforated to allow a communication be- 
 twixt the great cell and the nose. 
 
 The ANTRUivi MAXiLLAHE, Or cavity of the jaw-bone, is com- 
 monly named antrum highmorianum, after its discoverer, 
 Highmore. We have gone round the antrum on all its sides, 
 in describing these processes of the bone : the palate-plate 
 makes the floor of the antrum ; the orbitary process makes its 
 roof ; the cheek quite up from the sockets of the teeth to the 
 lower part of the eye, forms its walls or sides : so that when the 
 antrum enlarges, it is the cheek that becomes deformed ; and 
 when we design to open the antrum, we either perforate the 
 cheek, or pull one of the teeth. The antrum is round towards 
 the cheek, but it has a flat side towards the nose ; it is divided 
 fri>ai the caviiy of the nostril by a flat and very thin plate of 
 bone ; it seems in the naked skull to have a very wide ope- 
 ning ; but in the skull, covered with its soft parts, we find the 
 antrum almost closed by a membrane which stretches over the 
 
62 
 
 OF THE BOiNES 
 
 opening, and leaves but one or two very small holes, of the 
 size of tbe smallest pea, by which, perhaps, the reverberation 
 of sound in the antrum is more elfectual in raising the voice, 
 and by which small hole, the mucus, which is secreted in the 
 antrum, drops out into the nose. The cavity of the antrum, 
 like the inner surfaces of the nostrils, is covered with a mem- 
 brane, and is bedewed with mucus ; and the mucus drops more 
 or less freely in various positions of the head. Sometimes by 
 cold or other accidents, inflammations and swellings of the 
 membrane come on ; the holes are closed ; the drain of mat- 
 ter is suppressed and confined within, and the cheek swells. 
 Perhaps there may be some particular disease of the mem- 
 brane with which the cavity is lined, or of the bone itself: in 
 one way or other, diseases of this cavity, and collections of 
 matter, dreadful pain and caries of the bone, are very frequent: 
 then the cheek rises; the face is irrecoverably deformed. 
 Sometimes the matter makes its way by the sides of the teeth, 
 or at last it bursts through the bones, makes an ulcer in the 
 cheek ; and then there is a natural cure, but slow and uncer- 
 tain. There is no very sure mark of this disease ; it may be 
 known by an attentive retrospect of all the circumstances. 
 The disease is not to be easily nor certainly discovered ; but 
 a very long continued tooth-ache, an uncommon degree of 
 pain or greater affection of the eye, with a swelling and redness 
 and gradual rising of the cheek, are very suspicious signs. 
 The pulling of the second or third of the grinding teeth, often 
 brings a splinter away with it, which opens a road for the mat- 
 ter to flow ; or though there be no breach of the socket, often 
 the confined matter follows the tooth, because not unfrequent- 
 ly the longer fangs of the grinders naturally penetrate quite 
 into this cavity of the jaw: if the matter should not flow, the 
 floor of the antrum is easily perforated, by introducing a sharp 
 stillet by the socket of the tooth that is pulled. The flow of 
 the matter gives relief, and injections complete the cure. But 
 as this opening is sometimes a cure, it is sometimes also a 
 disease ; for the breaking of a socket, sometimes opening a 
 way into this antrum, there follows inflammation of its internal 
 surface, a running of matter, and sometimes caries of the 
 bone. 
 
 Holes. — There is only one perfect hole in this bone ; but, 
 by its union with other bonesi it forms four more : The infra- 
 orbitary hole, for transmitting the infra-orbitary nerve from 
 the bottom of the eye, is the opening of the canal which 
 comes along under the eye. It is just under the margin of the 
 orbit, or sometimes the nerve which it transmits, divides, and 
 nialies two smaller holes in its passage upon the cheek. A 
 
OF THE FACE AND JAWS. 
 
 63 
 
 hole in the palate-plate, which belongs equally to each of the 
 palate-bones may be counted the second foramen ; for it ig 
 betwixt the two bones in the fore part, or beginning of the 
 palate-suture behind the two first cutting teeth. This hole 
 is named forajMEN incisivum, as opening just behind the inci- 
 sive or cutting teeth ; or it is named anterior palatine hole, 
 to distinguish it from one in the back of the palate. This hole 
 is large enough to receive the point of a quill ; it is single to- 
 wards the mouth ; but towards the nose, it has two large ope- 
 nings, one opening distinctly into each nostril. 
 
 But it will be well to explain here a third hole, which is 
 common to the maxillary, with the proper palate-bones. It is 
 formed on the back part of the palate (one on either side,) in 
 the suture which joins the palate-bones to the jaw-bones : it is 
 named posterior palatine hole : It is as large as the ante- 
 rior palatine hole, but it serves a much more important pur- 
 pose ; for the upper maxillary nerve sends a large branch to 
 the palate, which branch comes down behind the back of the 
 nostril, perforates the back of the palate by the posterior pala- 
 tine hole, and then goes forward in two great branches along 
 the palate. Thus the chief, or, we might say, the only nerves 
 of the palate comes down to it through these posterior palatine 
 holes. The use of the anterior palatine hole has long been a 
 a problem. It looks almost as if it were merely designed for 
 giving the soft palate a surer hold upon the bone ; but Scarpa, 
 the Italian anatomist, describes a nerve from the 5th pair, ta- 
 king its course in this way to the soft palate. 
 
 The fourth foramen is formed by the union of the lower 
 spongy bone, to the internal nasal plate of the bone ; and is 
 for the transmission of the lachrymal duct. 
 
 The LATERAL ORBITARY FISSURE, Called alsO SPHENO MAX- 
 ILLARY FISSURE, is a slit formed by this bone and the sphenoid 
 bone ; it is a communication betwixt the orbit and temple. 
 
 The whole surface of the bone which forms the antrum is 
 perforated with frequent small holes, especially towards its 
 back part, transmitting small arteries and nerves to the teeth ; 
 and the back part of the antrum forms with the orbitary part 
 of the sphenoid bone a second foramen lacerum for the orbit, 
 which is an irregular opening tow'ards the bottom of the socket, 
 and is for the accumulation of fat, rather than for the trans- 
 mission of nerves j and it is from the wasting of this fat, taken 
 back into the system, that the eye sinks so remarkably in fe- 
 vers, consumptions, and such other diseases as waste the body. 
 At the termination of the alveolar circle, backwards, there are 
 two or three holes, into which the branches of the internal 
 maxillary artery enter, which go to supply the teeth of the up- 
 
64 
 
 OF THE BONES 
 
 per jaw. There is a trifling hole for the transmission of an 
 artery on the nasal plate of this bone. 
 
 The OSSA PALATI, OR PALATE BONES — are very 
 small, but have such a number of parts, and such curious con- 
 nections as are not easily explained. They seem to eke out 
 the superior maxillary bones, so as to lengthen the palate, and 
 complete the' nostrils behind: they even extend upwards into 
 the socket, so as to form a part of its circle ; although, in 
 looking for them upon the entire skull, all these parts are so 
 hidden, that we should suppose the palate-bones to be of no 
 greater use nor extent than to lengthen the palate a little 
 backwards. 
 
 The parts of the palate-bone are these : 
 
 The PALATAL PLATE, OP process of the palate-bone, whence 
 it has its name, lies horizontal in the same level with the pala- 
 tal process of the jaw-bone, which it resembles in its rough 
 and spinous surface ; in its thinness ; in its being thinner in the 
 middle, and thicker at either end ; in its being opposed to its 
 fellow by a broad surface, which completes the middle palate 
 SUTURE ; and it is connected with the palate process of the 
 jaw, by a suture resembling that by which the opposite bones 
 are joined ; but this suture, going across the back part of the 
 palate, is named the transverse palate suture. Where the 
 two palate-bones are joined, they run backwards into an acute 
 point ; on either side of that middle point, they make a semi- 
 circular line, and again run out into two points behind the 
 grinding teeth of each side. By this figure of the bones, the 
 back line of the palate has a scolloped or waved form The 
 velum palati, or curtain of the palate, is a little arched, fol- 
 lowing the general line of the bones; the uvula, or pap, hangs 
 exactly from the middle of the velum taking its origin from 
 the middle projecting point of the two bones ; and a small 
 muscle, the azygus uvulae, runs down in the middle of the ve- 
 lum, taking its origin from this middle. 
 
 The small projecting point of the palate-bone, just behind the 
 last grinding tooth, touches the pterygoid process of the sphe- 
 noid bone, it is therefore named the pte ygoid proce^'S of 
 the palate-bone : but it is so joined with the pterygoid process 
 of the sphenoidal bone, that they are not to he distinguished 
 in the entire skull The posterior pterygoid hole, or third 
 hole of the palate, is just before this point. 
 
 The NASAL PLATE, or PROc ss, is a thin and single plate ; 
 rises perpendicularly upwards from the palate; lies upon the 
 side a/id back part of tlie nostrils, so as to form their opening 
 backwards into the throat ; it is so joined to the upper jaw- 
 
OP THE FACE AND JAWS, 
 
 66 
 
 bone, that it lies there like a sounding-board upon the side of 
 the antrum Highmorianum, and completes that cavity forming 
 the thin partition betwixt it and the nose. 
 
 This nasal process extends thus up from the back arch of 
 the palate to the back part of the orbit; and, though the nasal 
 plate is very thin and delicate in its whole length, yet, where it 
 enters into the orbit, it is enlarged into an irregular kind of knob 
 of a triangular form. This knob is named its orbitaky pro- 
 cess ; or, as the knob has two faces looking two ways in the or- 
 bit, it is divided sometimes (as by Monro the father), into two 
 orbitary processes, the anterior and posterior ; the anterior one 
 is the chief. This orbitary process, or point of the palate-bone, 
 being triangular, very snmll, and very deep in the socket, is not 
 easily discovered in the entire skull. 
 
 This orbitary pjocess is most commonly hollow or cellular, 
 and its cells are so joined to those of the sphenoid bone, that 
 it is the palate-bone that shuts the sphenoid cells, and the sphe- 
 noid and palatine cells of each side constitute but one ge- 
 neral cavity. 
 
 On the inside of the nasal plate of this bone, we may per- 
 ceive a ridge corresponding with that on the nasal process of 
 the maxillary bone, and which is for giving attachment to the 
 lower spongy bone. 
 
 The OSSA SPONGIOSA, or TURBINATA INFERI- 
 ORA, are so named, to distinguish them from the upper 
 spongy bones, which belong to the os lethmoides; but these 
 lower spongy bones, are quite distinct, formed apart, and con- 
 nected in a very slight way with the upper jaw-bones. 
 
 The OSSA SPONGIOSA iNFERioRAare two bones, much rolled 
 or convoluted, very spongy, much resembling puff-paste, having 
 exactly such holes, cavities, and net-work, as we see in raised 
 paste, so that they are exceedingly light. They lie rolled up, 
 in the lower part of the nose; are particularly large in sheep; 
 are easily seen either in the entire subject or in the naked skull. 
 Their point forms that projection which we touch with the 
 finger in picking the nose ; and from that indecent practice, 
 very often serious consequences arise ; for in many instances, 
 polypi of the lower spongy bones, which can be fairly traced to 
 hurts of this kind, grow so as to extend down the throat, 
 causing suffocation and death. 
 
 One membrane constitutes the universal lining of the cavi- 
 ties of the nose, and the coverings of all the spongy bones. 
 This continuity of the membrane prevents our seeing in the 
 subji ct how slightly the spongy bones are hung : but in the bare 
 and dissected skull we find a neat small hook upon the spongy 
 
66 
 
 OF THE BONES 
 
 bone, by which it is hung upon the edge of the antrum maxil- 
 lare ; for this lower spongy bone is laid upon the side of the 
 antrum, so as to help the palate-bone in closing or covering 
 that cavity from within. One end of the spongy bone, rather 
 more acute, is turned towards the opening of the nostril, and 
 covers the end of the lachrymal duct : the other eni> of the 
 same bone points backwards towards the throat. The curling 
 plate hangs down into the cavity of the nostril, with its arched 
 side towards the nose. This spongy bone differs from the spon- 
 gy process of the sethmoid bone, in being less turbinated or 
 complex, in having no cells connected with it, and perhaps it 
 is less directly related to the organ of smell. If pol)pi arise 
 from the upper spongy bone, we can use less freedom, and 
 dare hardly pull them away, for fear of injuring the cribriform 
 plate of the sethmoid bone. We are indeed not absolutely pro- 
 hibited from pulling the polypi from the upper spongy bone ; 
 but we are more at ease in pulling them from the lower one, 
 since it is quite an insulated bone. When peas, or any such 
 foreign bodies, are retained in the nose, it must be from swell- 
 ing, and being detained, among the spongy bones. 
 
 The spongy bones are not absolutely limited in their num- 
 ber ; there is sometimes found bewitxt these two a third set of 
 small turbinated bones, commonly belonging to the sethmoid 
 bone. 
 
 VOMER. — The nose is completed by the vomer, which is 
 named from its resemblance to a plough-share, and which di- 
 vides the two nostrils from each other: It is a thin and slen- 
 der bone, consisting evidently of two plates, much compres- 
 sed together, very dense, and strong, but still so thin as to be 
 transparent. The two plates of which the vomer is composed 
 split or part from each other at every edge of it, so as to form 
 a groove on every side. 1. On its upper part, or, as we may 
 call it, its base, by which it is fixed to the skull, the vomer 
 has a WIDE groove, receiving the projecting point of the aeth- 
 moid and sphenoid bones : thus it stands very firm and secure, 
 and capable of resisting very violent blows. 2. Upon its low- 
 er part its groove is narrower, and receives the rising line in 
 the middle of the palate-plate, where the bones meet to form 
 the palate suture. At its forepart it is united by a ragged sur- 
 face, and by something like a groove to the middle cartilage 
 of the nose ; and, as the vomer receives the other bones into 
 its grooves, it is in a manner locked in on all sides: it re- 
 ceives support and strength from each ; and if the vomer and 
 its cartilage should seem too slender a support, for the fabric 
 of the nose, let it be remembered, that they are all firmly 
 
OF THE FACE AND JAWS. 
 
 67 
 
 connected, and covered by one continuous membrane, which 
 is thick and strong, and that this is as a periosteum, or rather 
 like a continued ligament, which increases greatly the thick- 
 ness and the strength of every one of these thin plates. The 
 vomer, in almost every subject, bends much towards one or 
 other nostril, so as sometimes to occasion no small apprehen- 
 sion, when it happens to be first observed. 
 
 OS MALAE, or the bone of tbe cheek, is easily known. 
 It is that large square bone which forms the cheek : it has 
 four distinct points, which anatomists have chosen to demon- 
 strate with a very superfluous accuracy. The upper orbita- 
 ry PROCESS stands highest, running upwards to form part of 
 the socket, the outer corner of the eye, and the sharp edge of 
 the temple. The inferior orbitary process, which is just 
 opposite to this, forming tbe lower part of the orbit and the edge 
 of the cheek. The maxillary process is that broad and rough 
 surface, by which it is joined to the upper jaw-bone. The one 
 the best entitled to the name of process, because it stands out 
 quite insulated, and goes outwards and backwards to unite 
 with the temporal bone, forming the zygoma or temporal arch, 
 is named the zygomatic process. The plate, which goes 
 backwards to form a part of the orbit, is named the internal 
 orbitary process, a small hole is observed on the outer sur- 
 face of the bone which transmits an artery, and sometimes a 
 very small nerve from the orbit. 
 
 OS MAXILLAE INFERIORIS.— The lower jaw-bone 
 is likened to a horse shoe, or to a cresent, or to the letter U, 
 though we need be under no anxiety about resemblances, for 
 a form so generally known. There is such an infinite compli- 
 cation of parts surrounding the ja\\^, of glands, muscles, blood- 
 vessels, and nerves, that it wxre endless to give even the slight- 
 est account of these. They shall be reserved each for its proper 
 place, while I explain the form of the lower jaw, in the most 
 simple and easy way. The lower jaw is divided into the chin, 
 viz. the space betwixt the two mental foramina ; the base, 
 properly the sides, extending backward to the angle ; and the 
 upright portion of the bone. 
 
 The forepart, or chin, is, in a handsome and manly face, 
 very square ; and this portion is marked out by this square- 
 ness, and by two small holes, one on either side, by which the 
 nerves of the lower jaw come out upon the face. 
 
 The base of the jaw is a straight and even line, terminating 
 the outline of the face. It is distinctly traced all along, from 
 the first point of the chin, backwards to the angle of the jaw. 
 Fractures of this bone, are always more or less transverse, and 
 are easily known by the falling down of one part of this even 
 
68 
 
 OP THE BONES 
 
 line, and by feeling the crashing hones when the fallen part is5 
 raised. Such fractures happen from blows or falls ; but not 
 by pulling teeth, for the sockets of the teeth bear but a small 
 proportion to the rest of the jaw ; even in children this cannot 
 happen ; for in them the teeth have shorter roots, and have no 
 hold nor dangerous power over the jaw : though (as I have 
 said) the sockets often suffer, the jaw itself never yields. 
 
 The, angle of the jaw is that corner where the base of the 
 jaw ends, where the bone rises upwards, at right angles, to be 
 ai liculated with the head. This part, also, is easily felt, and 
 by it we judge well of the situation of veins, arteries, and 
 glands which might be in danger of being cut, in wounds or in 
 operations. There are two processes of the jaw of particular 
 importance, the coronoid or horn-like process, for the inser- 
 tion of its strong muscles, especially, of the temporal muscle, 
 and the condy loid or hinge process, by which it is joined with 
 the temporal bone. 
 
 The couoNoin process, named from its resemblance tp a 
 horn, is, like the rest of the jaw-bone, flat on its sides, and 
 turned up with an acute angle, very sharp at its point, and 
 when the bone is in its place, lying exactly under the zygoma 
 or temporal arch. The temporal muscle runs under this arch, 
 and lays hold on the coronary process, not touching it on one 
 point only, but grasping it on every side, and all round. And 
 the process is set so far before the articulation of the jaw, that 
 it gives the muscle great power. This process is so defended 
 by the temporal arch, and so covered by muscles that it cannot 
 be felt from without. 
 
 The CONDYLOID PROCESS, or the articulating proccss of the jaw 
 is behind this. This also is of the same flat form with the rest 
 of the jaw. The condyle, or joint of the jaw-bone, is placed 
 upon the top of the rising branch. The condyle, or articula- 
 ting head, is not round, but fiat, of a long form, and set across 
 the branch of the jaw. This articulating process is received 
 into a long hollow of the temporal bone, just under the root of 
 the zygomatic process ; so that by the long form of the con- 
 dyles, and of the cavity into which it is received, this joint is a 
 mere hinge, not admitting of lateral nor rotatory motions, at 
 least of no wider lateral motions than those which are necessa- 
 ry in grinding the food ; but the hinge of the jaw is a complex 
 and very curious one, which shall be explained in its proper 
 place. The line of continuation between these two last pro- 
 cesses forms what is called the semilunar notch. 
 
 The ALVEOLAR PROCESS, OP the long range of sockets for the 
 teeth, resembles that of the upper jaw. The jaw, as the body 
 grows, is slowly increasing in length, and the teeth are added 
 
OF THE FACE AMD JAWS. 
 
 69 
 
 in proportion to the growth of the jaws. When the jaws have 
 acquired their full size, the sockets are completely filled ; the 
 lips are extended, and the mouth is truly formed. In the de- 
 cline of life the teeth fall out, and the sockets are re-absorbed, 
 and carried clean away, as if they had never been ; so that the 
 chin projects, the cheeks become hollow, and the lips fall in, 
 the surest marks of old age. 
 
 The SPINA INTERNA, 01’ internal tubei*cle of the lower jaw, 
 is just behind the symphysis, or on Ae inside of the circle of 
 the chin. It gives origin to muscles which move the tongue 
 and larynx. On the inside of the lateral portion of the jaw, 
 we observe an oblique ridge for the attachment of the rnylo 
 hyoideus. On the inside of the angle, the bone is rough for 
 the attachment of the pterygoid muscle. 
 
 The successive changes of the form of the jaw are worthy 
 of being mentioned once more ; first, that in the child the jaw 
 consists of two bones, which are joined slightly together in 
 the chin. This joining, or symphysis, as it is called, is easily 
 hurt, so that in preternatural labours it is, according to the 
 common method of pulling by the chin, always in danger, 
 and often broken. During childhood the processes are blunt 
 and short, do not turn upwards with a bold and acute angle, 
 but go off obliquely from the body of the bone. The teeth 
 are not rooted, but sticking superficially in the alveolar pro- 
 cess ; and another set lies under them ready to push them' 
 from the jaws. 
 
 Secondly, That in youth the alveolar process is extending, 
 the teeth are increasing in number. The coronoid and arti- 
 culating processes are growing acute and large, and are set off 
 at right angles from the bone. The teeth are now firmly root- 
 ed ; for the second set has come up from the body of the 
 jaw. 
 
 Thirdly, In manhood the alveolar process is still more elong- 
 ated. The dentes sapienthe are added to the number of 
 the teeth ; but often, by this, the jaw is too full, and this last 
 tooth coming up from the backmost point of the alveolar pro- 
 cess in either jaw, it sometimes happens that the jaw cannot 
 easily close ; the new tooth gives pain ; it either corrupts, or 
 it needs to be drawn. 
 
 Fourthly, In old age the jaw once more falls flat ; it shrinks 
 according to the judgment of the eye, to half its size ; the 
 sockets are absorbed, and conveyed away ; and in old age the 
 coronoid process rises at a more acute angle from the jaw- 
 bone, and by the falling down of the alveolar process, the coro- 
 Boid process seems increased in length. 
 
70 
 
 OF THE TRUNK. 
 
 HOLES. — The holes of the jaw are chiefly two : 
 
 A LARGE HOLE Oil the inner side, and above the angle of 
 the jaw, just at the point where these two branches, the con- 
 dyloid and the coronoid processes part. A wide groove, from 
 above downwards, leads to the hole ; and the hole is, as it 
 were, defended by a small point, or pike of bone, rising up 
 from its margin. This is the great hole for admitting the 
 LOWER MAXILLARY NERVE into the hollow of the jaw, where it 
 goes round within the circle of the jaw, distributing its nerves 
 to all the teeth. But at the point where this chief branch of 
 the nerve goes down into the jaw, another branch of the nerve 
 goes forward to the tongue. And as nerves make an impres- 
 sion as deep as that of arteries in a bone, we find here two 
 grooves, first, one marking the great nerve, as it advances to- 
 wards its hole ; and, secondly, a smaller groove, marking the 
 course of the lesser branch, as it leaves the trunk, and passes 
 this, hole to go forward to the tongue. 
 
 Along with this nerve, the lower maxillary artery, a large 
 branch enters also by the hole; and both the nerve and the 
 artery, after having gone round the canal of the jaw, emerge 
 again upon the chin. 
 
 The second hole of the lower jaw is that on the side of the 
 chin, which permits the remains of the great nerve and artery 
 (almost expended upon the teeth) to come out upon the chin ; 
 it is named the mental hole. 
 
 CHAP. V. 
 
 OF THE BONES OF THE TRUNK; OR, OF THE SPINE, THORAX, 
 AND PELVIS. 
 
 The spine is so named from certain projecting points of 
 each bone, which, standing outwards in the back, form a con- 
 tinued ridge ; and the appearance of continuity is so complete, 
 that the whole ridge is named spine, which, in common lan- 
 guage, is spoken of as a single bone. This long line consists 
 of twenty-four distinct bones, named vertebrae, from the Latin 
 vertere, to turn. They conduct the spinal marrow, secure 
 from harm the whole length of the spine, and support the 
 whole weight of the trunk, head, and arms ; they perform, at 
 certain points, the chief turnings and bendings of the body ; 
 
OF THE TRUNK. 
 
 71 
 
 and do not suffer under the longest fatigue, or the greatest 
 weight which the limbs can bear. Hardly can any thing be 
 more beautiful or surprising than this mechanism of the spine, 
 where nature has established the most opposite and inconsist- 
 ent functions in one set of bones ; for these bones are so free 
 in motion, as to turn continually, yet so strong as to support 
 the whole weight of the body ; and so flexible as to turn quick- 
 ly in all directions, yet so steady within, as to contain and de- 
 fend the most material and the most delicate part of the 
 nervous system. 
 
 The vertebrae are arranged according to the neck, back, 
 and loins, and the number of pieces corresponds with the 
 length of these divisions. The vertebrse of the loins are live 
 in number, very large and strong, and bearing the whole weight 
 of the body. Their processes stand out very w'ide and free, 
 not entangled with each other, and performing the chief mo- 
 tions of the trunk. The vertebrse of the back are twelve in 
 number. They also are big and strong, yet smaller than those 
 of the loins their processes are laid over each other; each 
 bone is locked in with the next, and embarrassed by its con- 
 nection with the ribs ; this is, therefore, the steadiest part of 
 the spine, a very limited motion only is allowed. The verte- 
 bra of the NECK are seven in number; they are more simple, 
 and like rings ; their processes hardly project ; they are very 
 loose and free ; and their motions are the widest and easiest of 
 all the spine. 
 
 The seven vertebra; of the neck, twelve of the back, and 
 five of the loins, make twenty-four in all, which is the regular 
 proportion of the spine. But the number is sometim'es chang- 
 ed, according to the proportions of the body; for, where the 
 loins are long, there are six vertebrre of the loins, and but 
 eleven in the back ; or the number of the pieces in the back 
 is sometimes increased to thirteen ; or the neck, according as 
 it is long or short, sometimes has eight pieces, or sometimes 
 only six. 
 
 The general form, processes, and parts of the vertebra, are 
 best exemplified in the vertebra of the loins ; for in it the body 
 is large, the processes are right-lined, large, and strong ; the 
 joint is complete, and all its parts are very strongly marked. 
 Every vertebra consists of a body, which is firm for supporting 
 the weight of the body, and hollow behind, for transmitting 
 the spinal marrow; of two articulating processes above, and 
 two below, by which it is jointed with the bones which are 
 above and below it ; of two transverse processes, which stand 
 out from either side of the bone, to give hold and purchase to 
 those muscles which turn the spine ; and of one process, the 
 
72 
 
 OF THE TRUNKi 
 
 spinous process, which stands directly backwards from the 
 middle of the bone ; and these processes being felt in distinct 
 points all the way down the back, gi\ e the whole the appear- 
 ance of a ridge ; whence it has the name of spine. 
 
 The BOOY of the vertebra is a large mass of soft and spongy 
 bone ; it is circular before, and flat upon the sides. It is 
 hollowed into the form of a crescent behind, to give the shape 
 of that tube in which the spinal marrow is contained. The 
 body has but a very thin scaly covering for its thick and spon- 
 gy substance. It is tipped with a harder and prominent ring 
 above and below, as a sort of defence, and within the ring, the 
 body of the vertebra is hollowed out into a sort of superficial 
 cup, which receives the ligamentous substance by which the 
 two next vertebrae are joined to it ; so that each vertebra goes 
 upon a pivot, and resembles the ball and socket joints. And 
 in many animals it is distinctly a joint of this kind. 
 
 On the fore and back part of the body of the vertebra are 
 several holes which are for the transmission of blood-vessels 
 and for the attachment of ligaments. 
 
 The BODY is the main part of the vertebra to which all the 
 other processes are to be referred ; it is the centre of the 
 spine, and bears chiefly the weight of the body : it is large in 
 the loins where the weight of the whole rests upon it, and 
 where the movements are rather free : it is smaller in the 
 veftebrffi of the back, where theje is almost no motion and less 
 w'eight ; and in the vertebrae of the neck, there is hardly any 
 body ; the vertebrae being joined to each other chiefly by the 
 articulating processes. 
 
 The ring or circle of bone or the arch which, together with 
 the body itself, forms this circle, next attracts our notice, for 
 the arches of the vertebra, forming a continued tube, give 
 passage to the spinal marrow. We observe a notch on each 
 side of the arch for transmitting the nerves which go out from 
 the spinal marrow, 
 
 The ARTICULATING PROCESS is a small projection, standing 
 out obliquely from the body of the vertebra, with a smooth 
 surface, by which it is joined to the articulating process of the 
 next bone ; for each vertebra has a double articulation with 
 that above and with that below. The bodies of the vertebrae 
 are united to each other by a kind of ligament, which forms a 
 more fixed, and rather an elastic joining ; and they art united 
 ag dll by the articulating processes, which makes a very move- 
 able joint of the common form. The articulating proces.ses 
 are .sometimes named oblique processes, because they stand 
 rather obliquely. The upper ones are named the ascending 
 
OF THE TRUNK. 73 
 
 oblique processes, and the two lower ones are named the in- 
 ferior or descending oblique processes. 
 
 The SPINOUS PROCESSES are those which project directly 
 backwards, whose points form the ridge of the back, and whose 
 sharpness gives the name to the whole column. The body of 
 each vertebra sends out two arms, which, meeting behind, 
 form an arch or canal for the spinal marrow; and fi’om the 
 middle of that arch, and opposite to the body, the spinous 
 process projects. Now the spinous, and the transverse proces- 
 ses, are as so many handles and levers by which the spine is 
 to be moved, which, by their bigness, give a firm hold to the 
 muscles, and by their length, give them a powerful lever to 
 work their effects by. Tlie spinous processes, then, are for 
 the insertion of these muscles which extend and raise the 
 spine. 
 
 The TRANSVERSE PROCESSES Stand out from the sides of the 
 arms or branches which form this arch. They stand out at 
 right angles, or transversely from the body of the bone ; and 
 they also are as levers, and long and powerful ones for moving 
 and turning the spine. Perhaps their chief use is not for turn- 
 ing the vertebnx , for there is no provision for much of a late- 
 ral motion in the lower part of the spine, but the muscles 
 which are implanted into these, are more commonly used in 
 assisting those which extend and raise the spine. 
 
 These and all the processes, are more distinct, prominent, 
 and strong ; more direct and larger in the loins, and more 
 easily understood than in the vertebrae of any other class. But 
 this prepares only for the description of the individual verte- 
 bra, where we find a variety proportioned to the various offices 
 and to the degrees of motion which each class has to perform. 
 
 Of the vertebra of the loins. — I have chosen to repre- 
 sent the general form of a vertebra, by describing one from 
 the loins, because of the distinctness with which all its parts 
 are marked. In the lumbar vertebrae, the perpendicular height 
 of the body is short, the intervertebral substance is thicker in 
 the other parts of the spine, and the several processes stand 
 off from each other distinct and clear ; all which are provisions 
 for a freer motion in the loins. The arch of the lumbar ver- 
 tebra is wider than in the back, to admit the looser texture of 
 the spinal marrow. 
 
 The BODY of a lumbar vertebra is particularly large, thick, 
 and spongy, and its thin outer plate is perforated by many ar- 
 teries going inwards to nourish this spongy substance of the 
 bone. The length of the body is about an inch, and the in- 
 tersticial cartilage is nearly as long; so that the vertebras of 
 the loins present to the eye, looking from within the body, a 
 
 VOL. j. K 
 
74 
 
 OF THE TRUNK. 
 
 large, thick, and massy column, fit for supporting so great a 
 weight. 
 
 The SPINOUS PROCESS is short, big, and strong. It runs hori- 
 zontally and directly backwards from the arch of the spinal 
 marrow. It is flattened, and about an inch in breadth ; and it 
 is commonly terminated by a lump or knob, indicating the 
 great strength of the muscles which belong to it, and the se- 
 cure hold which they have. 
 
 The TRANSVERSE PROCESS is also short, direct, and very 
 strong, going off horizontally from the side of the bone, ter- 
 minated like the spinous, by a knotty point, where large mus- 
 cles are implanted. We find the spinous process divided into 
 two unequal parts by a spine from the inferior articulating 
 process ; in the same manner we see the transverse process 
 divided by a ridge extending from the superior articulating 
 process. 
 
 The ARTICULATING PROCESSES of the lumbar vertebrae stand 
 so directly upwards and downwards, that the name of oblique 
 processes cannot be applied here. 
 
 Of the VERTEBR® OF THE BACK. — The character of the ver- 
 tebrae of the back is directly opposite to that of the loins. 
 The BODIES of the vertebrae are still large to support the 
 great weight of the trunk ; but they are much longer than in 
 the loins, and their intervertebral substance is thin, for there 
 is little motion here. The spinous processes in the verte- 
 brae of the back are very long and aquiline. They are broad 
 at their basis, and very small or spinous at their further end ; 
 and in place of standing perpendicularly out from the body, 
 they are so bent down, that they do not form a prominent nor 
 unsightly spine, but are ranged almost in a perpendicular line, 
 that is, laid over each other, like the scales of armour, the 
 one above touching the one below, by which the motions of 
 these vertebra3 are still further abridged ; and the further to 
 sustain the column, there is a groove on the under surface of 
 the spinous process, which receives the superior edge of the 
 one below. And, lastly, the transverse processes, which 
 are short and knobby, in place of standing free and clear out 
 like those of the loins, stand obliquely backward, are tramel- 
 led and restricted from motion, by their connection with the 
 ribs ; for the ribs are not merely implanted upon the bodies 
 of the dorsal vertebrse, but they are further attached firmly by 
 ligaments, and by a regular joint to the transverse process of 
 each vertebra. Now the rib being fixed to the body of one 
 vertebra, and to the transverse process of the vertebra below, 
 the motions of the vertebra; are much curbed. And we also 
 get another mark by which the dorsal vertebrie may be known, 
 
OF THE TRUNK. 
 
 75 
 
 viz. thM each vertebra bears two impressions of the rib w'hich 
 was joined to it, one on the flat side of its body, and the other 
 on the fore part of its transverse process. The articulating 
 processes are so short, that they can hardly be described as dis- 
 tinct projections, as they stand out so directly from the trans- 
 verse process, appearing as parts of it. 
 
 We may distinguish the first vertebra of the back, by its 
 having the whole of the head of the rib impressed upon its 
 side. 
 
 The 12th, or lowest dorsal vertebra, has also the entire head 
 of the rib impressed upon it, and it has no articulating surface 
 on the extremity of the transverse process. 
 
 Of the vERTEBKiE OF THE NECK. — The Vertebra; of the neck 
 depart still farther from the common form. Their bodies are 
 flattened on their fore parts, so as to make a flat surface on 
 which the windpipe and gullet lie smooth. The body is very 
 small in all the vertebrae of the neck. In the uppermost of 
 the neck there is absolutely no body ; and the next to that has 
 not a body of the regular and common form. There is not in 
 the vertebrae of the neck, as in those of the loins, a cup or hol- 
 low for receiving the intervertebral substance, but the surfaces 
 of the body are flat or plain, and the articulating processes are 
 oblique, and make as it were, one articulation with the body ; 
 for the lower surface of the body being not hollow, but plain, 
 and inclined forwards, and the articulating processes being also 
 inclined backwards, the two surfaces are plain, opposed to each 
 other, and the one prevents the vertebrae from sliding forwards, 
 and the other prevents it from sliding backwards, while a pretty 
 free and general motion is allowed. The spinous processes 
 of the neck are short and project directly backwards; they are 
 ior the insertion of many muscles, and therefore they are split. 
 This bifurcation of the spinous process is not absolutely pe- 
 culiar to the cervical vertebras ; for sometimes, though rarely, 
 the others are so : and it is only in the middle of the neck 
 that even they are forked ; for the first vertebra is a plain ring, 
 with hardly any spinous process, because there are few mus- 
 cles attached to it ; and the process hf the last vertebra of the 
 neck is not bifurcated, so that it approaches to the nature of 
 the dorsal vertebrae ; the spinous process is long and aquiline; 
 is depressed towards the back, and is so much longer than the 
 others, as to be distinguished by the name of vertebra 
 
 promine NS. 
 
 The TRANSVERSE PROCESSES of the neck are also bifurcated, 
 because there are a great many small muscles inserted into 
 them also. But the most curious peculiarity of the transverse 
 processes is that each of them is perforated for the transmission 
 
76 
 
 OF THE TRUNK. 
 
 of the great artery, which is named vektebral artery, because 
 it passes through these holes in the vertebrae, which form alto- 
 gether a bony canal for the artery. This artery, which is de- 
 fended with so much care, is one of the chief arteries of the 
 brain, for there are two only ; and often when the other, the 
 carotid, has been obstructed, this continues to perform its 
 office. 
 
 So that the character of these cervical vertebrie is, that they 
 are calculated for much free motion ; and the marks by which 
 they are distinguished are, that the bodies are particularly 
 small ; the aiticulating processes oblique, with regard to their 
 position, and almost plain on their surface. The spinous pro- 
 cess, which is nearly wanting in the uppermost vertebrse, is 
 short and forked in all the lower ones ; the transverse process 
 also is forked ; and the transverse processes of all the verte- 
 br<E, except sometimes the first and last, are perforated near 
 their extremities with the large hole of the vertebral artery. 
 
 ATLAS AND DENTATUS. — But among these vertebrae 
 of the neck, two are to be particularly distinguished, as of 
 greater importance than all the rest ; for though the five lower 
 vertebrae of the neck be ossified and fixed, if but the two up- 
 permost remain free, the head, and even the neck, seem to 
 move with perfect ease. 
 
 The first vertebra is named atlas, perhaps, because the 
 globe of the head is immediately placed upon it ; the second 
 is named dentata or axis, because it has an axis or tooth-like 
 process upon which the first turns. 
 
 The atlas has not the complete form of the other vertebrae 
 of the neck, for its processes are scarcely distinguishable : it 
 has no body, unless its two articulating processes are to be 
 reckoned as a body : it is no more than a simple ring ; it has 
 hardly any spinous process ; and its transverse process is long 
 but not forked. On the upper margin of the ring may be ob- 
 served the mark of the ligament which unites it to the margin 
 of the occipital bone ; and on the lower margin of the ring the 
 mark of attachment of a similar ligament, which attaches it to 
 t' 0. c rcle of the dentata. The boj)t is entii’cly wanting ; in its 
 place, the vertebra has a flat surface looking backwards, which 
 is smooth and polishc d by the rolling of the tooth-like process ; 
 there is also a sharp point rising perpendicularly upwards to- 
 wards the occipital bone, and this point is held to the edge of 
 the occipital hole by a strong ligament. The smooth mark 
 of the tooth-like process is easily found ; and upon either side 
 of it, there projects a small point from the inner circle of the 
 ring : these two points have a ligament extended betwixt them, 
 
OF THE TRUNK. 
 
 11 
 
 called the transverse ligament, which, like abridge, divides the 
 ring into two openings ; one the smaller, for lodging the tooth- 
 like process, embracing it closely ; the greater opening is for 
 the spinal marrow : the ligament confines the tooth-like pro- 
 cess ; and when the ligament is burst by violence (as has hap- 
 pened,) the tooth-like process, broken loose, presses upon the 
 spinal marrow; the head, ho longer supported by it, falls for- 
 ward, and the patient dies. On the inside and lateral part of 
 the circle, the origin of the lateral ligaments of the dentatus 
 may also be observed. 
 
 The articulating process may be considered as the body 
 of this vertebra ; for it is at once the only thick part, and the 
 only articulating surface. This broad articulating substance is 
 in the middle of each side of the ring : it lias two smooth sur- 
 faces on each side, one looking upwards, by which it is joined 
 to the occiput ; and one looking directly downwards, by which 
 it is joined to the second vertebra of the neck. The two up- 
 per articulating surfaces are oval, and slightly hollow to receive 
 the occipital condyles : they are also oblique, for the inner 
 margin of each dips downwards ; the outer margin rises up- 
 wards ; and the fore end of each oval is turned a little towards 
 its fellow. Now, by the obliquity of the condyles, and this 
 obliquity of the sockets which receive them, all rotatory mo- 
 tion is prevented, and the head performs, by its articulations 
 with the first vertebra or atlas, only the nodding motions ; and 
 when it rolls, it carries the first vertebra along with it, moving 
 round the tooth-like process of the dentatus. The articula- 
 tion with the head is a binge joint, in the strictest sense : it 
 allows ol no other motion than that backwards and forwards ; 
 the nodding motions are performed by the head upon the atlas, 
 the rotatory motions are performed by the atlas moving along 
 with the head, turning upon the tooth-like process of the den- 
 tatus. 
 
 Now the upper articulating surface of the atlas is hollowed 
 to secure the articulation with the head ; but the lower arti- 
 culation, that, with the dentatus, being secured already by the 
 tooth-like process of that bone, no other properly is required 
 in the lower articulating surface of the atlas, than that it should 
 glide with perfect ease ; for which purpose, it is plain and 
 smooth ; it neither receives, nor is received into the dentatus 
 by any hollow, but lies flat upon the surface of that bone. It 
 is also evident, that since the office of the atlas is to turn along 
 with the head, it could not be fixed to the dentatus, in the 
 common way, by a body and by inteiwertebral substance ; and 
 since the atlas attached to the head move,', along with it, turn- 
 ing as upon an axis, it must have no spinous process ; for 
 
78 
 
 OF THE TRUNK. 
 
 the projection of a spinous process must have prevented its 
 turning upon the dentatus, and would even have hindered in 
 some degree, the nodding of the head ; therefore the atlas has 
 a simple ring behind, and has only a small knob or button 
 where the spinous process should be, which, however, has a 
 small notch on it. The transverse process is not forked, 
 but it is perforated with a large hole for the vertebral artery ; 
 and the artery, to get into the skull, makes a wide turn, lying 
 flat upon the bone, by which there is a slight hollow or impres- 
 sion of the artery, which makes the ring of the vertebra ex- 
 ceedingly thin. 
 
 But the form of the dentatus best explains these peculiarities 
 of the atlas, and this turning of the head. 
 
 The DENTATA or AXIS is so named from its projecting 
 point, which is the chief characteristic of this bone. When the 
 dentata is placed upright before us, we observe, 1. That it is 
 most remarkably conical, rising all the way upwards, by a 
 gradual slope, to the point of its tooth-like process. 2. That 
 the ring of the vertebra is very deep, that is, very thick in its 
 substance, and that the opening of the ring for transmitting the 
 spinal marrow is of a triangular form. 3. That its spinous pro- 
 cess is short, thick, and forked ; and that it is turned much 
 dowawards, so as not to interfere, in any degree, with the ro- 
 tation of the atlas. 4. That its tooth-like process, from which 
 the bone is named, is very large, about half an inch in length ; 
 very thick, like the little finger ; that it is pointed ; and that 
 from this rough point a strong ligament goes upwards, by which 
 the tooth is tied to the great hole of the occipital bone. We 
 also observe a neck or collar, or smaller part, near the root of 
 the tooth-like process, where it is grasped by the ring of the 
 atlas; while the point swells out a little above ; so that with- 
 out the help of ligaments, it is almost locked in its place. We 
 find this neck particularly smooth ; for it is indeed upon this 
 collar that the head continually turns. And, we see on either 
 side of this tooth-like process abroad and flat articulating sur- 
 face, one on either side. These articulating surfaces are pla- 
 ced like shoulders ; and the atlas being threaded by the tooth- 
 like process of the dentatus, is set flat down upon the high 
 shoulders of this bone, and there it turns and performs all the 
 rotatory motions of the head. 
 
 On the side of the tooth-like process we may observe the 
 insertion of the lateral ligaments, and its point is grasped by 
 the perpendicular ligament. 
 
 We may observe, that the superior articulating process is 
 
OF THE TRUNK. 
 
 79 
 
 horizontal. The lower surface of this vertebra resembles the 
 other inferior vertebra of the neck. 
 
 Of the medullary tube, and the passage of the 
 NERVES. — All the vertebrse conjoined make a large canal of a 
 triangular or roundish form, in which the spinal marrow lies, 
 giving off and distributing its nerves to the neck, arms, and 
 legs ; and the whole course of the canal is rendered safe for 
 the marrow, and very smooth by lining membranes, the outer- 
 most of which is of a leather-like strength and thickness, and 
 serves this double purpose ; that it is at once a hollow liga- 
 ment to the whole length of the spine upon which the bones 
 are threaded, and by which each individual bone is tied and 
 fixed to the next ; and it is also a vagina or sheath which con- 
 tains the spinal marrow, and which is bedewed on its internal 
 surface with a thin exudation, keeping the sheath moist and 
 soft, and making the enclosed marrow lie easy and safe. 
 
 All down the spine, this spinal medulla is giving off its 
 nerves : One nerve passes from it at the interstice of each ver- 
 tebra ; so that there are twenty-four nerves of the spine, or 
 rather forty-eight nerves ; twenty-four being given towards each 
 side ; these nerves pass each through an opening or small hole 
 in the general sheath ; there they pass through the interstice 
 of each vertebra ; so that there is no hole in the bone requir- 
 ed, but the nerve escapes by going under tbe articulating pro- 
 cess. This, indeed, is converted into something like a hole, 
 when the two contiguous vertebrae are joined to each other. 
 
 THE INTERVERTEBRAL SUBSTANCE— The in- 
 tervertebral substance is that which is interposed betwixt the 
 bodies of two adjoining vertebrae, and which is (at least in the 
 loins) nearly equal in thickness to the back of the body of the 
 vertebra to which it belongs. We give it this undefined name, 
 because there is nothing in the human system to which it is 
 entirely similar ; for it is not ligament, nor is it cai’tilage, but it 
 is commonly defined to be something of an intermediate nature : 
 It is a soft and pliant substance, which is curiously folded and 
 returned upon itself, like a rolled bandage with folds, gradual- 
 ly softer towards the centre, and with the rolled edges as if cut 
 obliquely into a sort of convex. The cut edges are thus turn- 
 ed towards the surface of the vertebra, to which each interver- 
 tebral substance belongs : it adheres to the face of each ver- 
 tebra, and it is confined by a strong ligament all round : and 
 this substance, though it still keeps its hold on each of the two 
 vertebrae to which it belongs, though it permits no true motion 
 of one bone on another, but only by twisting of its substance, 
 yields, nevertheless, easily to whichever side we incline, and it 
 
80 
 
 OF THE TRUNK. 
 
 returns in a moment to its place by a very powerful resilience. 
 This perfect elasticity is the chief character and virtue of this 
 intervertebral substance, whose properties indeed are best ex- 
 plained by its uses; for, in the bendings of the body, it yields 
 in a very considerable degree, and rises on the moment that 
 the weight or the force of the muscles is removed. In leaping, 
 in shocks, or in falls, its elasticity prevents any harm to the 
 spine, while other less important joints are luxated and destroy- 
 ed. During the day. it is continually yielding under pressure ; 
 so that we are an inch taller in the morning than at night; we 
 are shorter in old age than in youth ; and the aged spine is 
 bended forwards by the yielding of this part. These curious 
 facts were first observed by a sort of chance, and have since 
 been ascertained with particular care. 
 
 Since pressure, in length of years, shortens the forepart of 
 the column of the spine, and makes the body stoop, any un- 
 due inclination to either side will cause distortion : the sub- 
 stance yields on one side, and rises on the other; and at last 
 the same change happens in the bones also, and the distortion 
 is fixed, and not to be changed : this is peculiarly apt to hap- 
 pen with children whose bones are growing, and whose gristles 
 and intervertebral substances are peculiarly soft; so that a 
 tumour on the head or jaw, which makes a boy carry his head 
 on one side, or constant stooping, such as is used by a girl in 
 working at the tambour, or the carrying of a weakly child al- 
 ways on one arm by a negligent or awkward nurse, will cause 
 in time a fixed incurable distortion. 
 
 We are now qualified to understand the motions of the ver- 
 tebrae, and to trace the degree of motion in each individual 
 class. The degrees of motion vary with the forms of the ver- 
 tebra;, in each part of the spine : the motion is freest in the 
 neck, more limited in the loins, and in the back (the middle 
 part of the spine) scarcely any motion is allowed : the head 
 performes all the nodding motions upon the first vertebra of 
 the neck : the first vertebra of the neck performs again all the 
 quick and short turnings of the head, by moving upon the den- 
 tatus : all the lower vertebra; of the neck are also tolerably 
 free, and favour these motions by a degree of turning ; and all 
 the bendings of the neck are performed by them. The dor- 
 sal vertebrae are the most limited in their movements, bending 
 chiefly forwards by the yielding of their intervertebral sub- 
 stance. The vertebrae of the loins again move largely, for 
 their intervertebral substance is deep, and their processes quite 
 unentangled and free. To perform these motions, each ver- 
 tebra has two distinct joints, as different in office as in form : 
 first, each vertebra is fixed' to those above and below by the 
 
©F THE TRUNK. 
 
 81 
 
 intervertebral substance, which adheres so to each, that there 
 is no true motion : there is no turning of any one vertebra up- 
 on the next ; but the elasticity of the intervertebral substance 
 allows the bones to move a little, so that there is a general 
 twisting and gentle bending of the whole spine. The second 
 joint is of the common nature with the other joints of the 
 body, for the articulating processes are faced with cartilage, 
 surrounded with a capsule, and lubricated with a mucus. And 
 I conceive this to be the intention of the articulating processes 
 being produced to such a length, that they may lap over each 
 other to prevent luxations of the spine ; and they must, of 
 course, have these small joints, that they may yield to this 
 general bending of the spine. 
 
 RIBS AND STERNUM. 
 
 Of the kibs. — The ribs, whose office it is to give form to 
 the thorax, and to cover and defend the lungs, also assist in 
 breathing : for they are joined to the vertebra by regular 
 hinges, which allow of short motions, and to the sternum by 
 cartilages, which yield to the motion of the ribs, and return 
 again when the muscles cease to act. 
 
 Each rib, then, is characterised by these material parts ; a 
 great length of bone, at one end of which there is a head for 
 articulation with the vertebrae, and a shoulder or knob for arti- 
 culation with its transverse process ; at the other end there is a 
 point, with a socket for receiving its cartilage, and a cartilage 
 joined to it, which is implanted into a similar socket in the 
 side of the sternum, so as to complete the form of the chest. 
 
 The ribs are twelve in number, according to the number of 
 the vertebrae in the back, of which seven are named true ribs, 
 because their cartilages join directly with the sternum ; and 
 five are named false ribs, because their cartilages are not sepa- 
 rately nor directly implanted into the sternum, but are joined 
 one with another; the cartilage of the lower rib being joined 
 and lost in that of the rib above, so that all the lower ribs run 
 into one greater cartilage. But there is still another distinction, 
 viz. that the last rib, and commonly also the rib above, are not 
 at all implanted in the sternum, but are loosely connected only 
 with the muscles of the abdomen, whence they are named the 
 loose or floating ribs. 
 
 The ribs are, in general, of a flattened form, their flat sides 
 being turned smooth towardsthe lungs. But this flatness of the 
 fib is not regular, it is contorted, as if the soft rib had been 
 seized by either end, and twisted betwixt the hands : the mean- 
 ing of which is, to accommodate the flatness of the rib to the 
 
 VOL. r. L 
 
82 
 
 OF THE TRUINK. 
 
 form which the thorax assumes in all its degrees of elevation ; 
 for when the I'ib rises, and during its rising through all the de- 
 grees of elevation, it still keeps its Hat side towards the 
 lungs. Though of a flattened form, the rib is a little rounded 
 at its upper edge, is sharp and cutting at its lower edge ; 
 and its lower edge seems double ; for there is a groove 
 made there by the intercostal artery and nerve. They 
 are named intercostal, from lying betwixt the ribs, the artery 
 being rather within the rib, is defended in some degree by its 
 groove, the lip of which forms the lower edge of the rib, but 
 still this artery is not without reach of the knife, in some sur- 
 gical operations ; we are careful, therefore, to mark, that it runs 
 on the lower edge of the rib, and is of the size of a crow-quill j 
 and that, if it be wounded, it will bleed largely from its near- 
 ness to the greatest artery of the body; that it is easily shun- 
 ned, by keeping the knife nearer to the rib below. 
 
 On each rib we find the following parts : 1. The head, or 
 round knob by which it is joined to the spine. The head of 
 each rib has indeed but a small articulating surface ; but that 
 smooth surface is double, or looks two ways. For the head of 
 the rib is not implanted into the side of one vertebra, it is 
 rather implanted into the interstice betwixt two vertebrae, the 
 head touches both vertebra ; all the vertebra except the first 
 and last bear the mark of two ribs, one above, and one below. 
 The mark of the rib is on the edge of either vertebra, and the 
 socket may be said to lie in the intervertebral substance be- 
 twixt them. 
 
 2. The NECK of the rib is a smaller part, immediately before 
 the head. Here the rib is particularly small and round. 
 
 3. About an inch from the head, there is a second rising,, 
 or bump, the articulating surface by which it touches and 
 turns upon the transverse process of the vertebra below. 
 These two articulations have each a distinct capsule or bag, 
 each is a very regular joint, and the degree of motions of the 
 rib, and direction in which it moves, may be easily calcula- 
 ted, from the manner in which it is jointed with the spine ; for 
 the two articulating surfaces of the rib are on its back part; 
 the back of the rib is simply laid upon the side of the spine ; 
 the joints with the body of the vertebrae, and with its trans- 
 verse process, are in one line, and form as if but one joint, so 
 that the rib being fixed obliquely, and at one end only, that 
 end continues firm, except in turning upon its axis ; the two 
 heads roll upon the body of the vertebrae, and upon the trans- 
 verse process ; and so its upper end continues fixed, while its ^ 
 lower end rises or falls ; and as the motion is in a circle, the 
 
OF THE TRUNK. 88 
 
 head being the central point, moves but little, while the lower 
 end of the rib has the widest range. 
 
 4. Just above the second articulating surface there is a se- 
 cond tubei’cle, which has nothing to do with the joints, but is 
 intended merely for the attachment of the ligaments and mus- 
 cles from the spine, which suspend and move the rib. 
 
 5, The angle of the rib is often mentioned, being a common 
 mark for the place of surgical operations. There is a flatness 
 of the thorax behind, forming the breadth of the back ; the 
 sharpness where this flatness begins to turn into the roundness 
 of the chest is formed by the angles of the ribs. Each rib is 
 round in the place of its head, neck, and tubercles ; it grows 
 flatter a little, as it approaches the angle ; but it is not com- 
 pletely flattened till it has turned the angle which is the proper 
 boundary betwixt the round and the flat parts of the rib. 
 This anatomy of the ribs is sufficiently simple, but it is not 
 equally easy to observe how it bears on the practice of surgery. 
 It is in some degree useful in the more advanced parts of 
 anatomy, to remember the names, and it is necessary, even in 
 speaking the common language of surgeons, to know these 
 parts, viz. the head of the rib ; the tubercle, or second articu- 
 lating surface ; the angle, or turning forward of the rib ; the 
 upper round, and the lower flat edge; and especially to re- 
 member the place and the dangers of the intercostal artery. 
 It is, however, more important to consider the connections of 
 parts, as the seat of the artery, the manner in which the ribs 
 are lined with the pleura, and their nearness to the surface of 
 the lungs. There are some peculiarities in individual x'ibs, 
 the chief of which are these : the size or length of the ribs 
 gradually decreases from the first to the last, the first being 
 exceedingly short and circular, the lower ones longer, and al- 
 most right lined ; so that the thorax is altogether of a conical 
 shape, the upper opening so small as just to permit the trachea, 
 oesophagus, and great vessels to pass ; the lower opening so 
 large, that it equals the diameter of the abdomen : the first rib 
 is consequently very short ; it is thick, strong, and of a flat- 
 tened form ; of which flatness one face looks upwards, and 
 another downwards, and the great axillary artery and vein lie 
 upon its flat upper surface. We do not see any groove on the 
 lower surface for the intercostal artery. It is also particularly 
 circular, making more than half a circle from its head to the 
 extremity where it joins the stei’iium ; it has, of course, no an- 
 gle, and wants the distorted twisting of the other ribs: the 
 second rib is also round, like the first rib. The eleventh and 
 twelfth, or the floating ribs, are exceedingly small and delicate, 
 and their cartilage terminates in an acute point, unconnected 
 
84 
 
 OF THE 
 
 with the sternum ; and lastly, the heads of the first, and of the 
 twelfth ribs, are rounder than any of the others ; for these 
 two have their heads implanted into the flat side of one verte- 
 bra only, while all the others have theirs implanted hetwixt the 
 bodies of two vertebrae. And there is this further difference, 
 that in the eleventh and twelfth ribs there are no tubercles for 
 the articulation with the transverse processes. 
 
 The cartilages of the ribs complete the form of the thorax, 
 and form all the lunated edge of that cavity ; and it is from 
 this cartilaginous circle that the great muscle of the diaphragm 
 has its chief origin, forming the partition betwixt the thorax 
 and the abdomen. The farther end of each rib swells out 
 thick and spongy, and has a small socket for lodging the carti- 
 lage ; for these cartilages are not joined like the intervertebral 
 substances with their bones : but there is a sort of joint very 
 little moveable indeed, but still having a rude socket, and a 
 strong capsular ligament, and capable of luxation by falls and 
 blows; the implantations into the sternum are evidently by 
 fair round sockets, which are easily distinguished upon the 
 two edges of that bone. These cartilages may be enumerated 
 thus. The cartilages of the first and second ribs descend to 
 touch the sternum. The cartilage of the third rib is direct. 
 The cartilages of the fourth, fifth, and sixth ribs rise upwards, 
 in proportion to their distance from this central one. The first 
 five ribs have independent cartilages ; the eighth, ninth, and 
 tenth ribs run their cartilages into the cartilage of the seventh 
 rib ; and the eleventh and twelfth ribs have their cartilages 
 small, unconnected, and floating loose. 
 
 By the motion of the ribs, the thorax is alternately dilated 
 and diminished in capacity, the lungs thereby having tiieir 
 play. A rib has two motions. 1 . Its sternal end rises and 
 falls, the centre of motion being in the articulation with the 
 spine. 2. It moves on its own axis ; a line drawn through the 
 two extremities is the centre of this motion. The former mo- 
 tion enlarges and diminishes the diameter of the thorax, from 
 the spine to the sternum, this enlarges the lateral diameter of 
 the thorax. 
 
 The Sternum. — ^The sternum is that long and squared 
 bone, which lies on the forepart of the breast over the heart, 
 and which being joined by the cartilages of the ribs, 
 completes the cavity of the chest; it is for corapleiing the 
 thorax, and defending the heart, for a medium of attachment 
 to the ribs, and for a fulcrum or point, on which the clavicles 
 may roll. 
 
 This bone is light and spongy, and has a thin outer cortex, 
 but depends in a great measure on the attachment of liga- 
 
OF THE TRUNK. 85 
 
 ments and tendons for its strength. From its structure it is 
 liable to scrofulous disease. 
 
 We find the sternum consisting in the child of eight distinct 
 pieces, which run together in the progress of life, and which 
 in old age, are firmly united into one ; but in all the middle 
 stage of lile, we find three pieces in the sternum, two of which 
 are properly bone, the third remains a cartilage till very late 
 in life, and is named the ensiform cartilage, from its sword- 
 like point. 
 
 It is found to have eight pieces, even in the child of six 
 years old ; some years after, it has but five or six ; and the sa- 
 lient white lines which traverse the bone, mark where the in- 
 termediate cartilages have once been. 
 
 1 . The upper piece of the sternum is very large, roundish 
 or rather triangular, resembling the form of the heart on play- 
 ing-cards : it is about two inches in length, and an inch and a 
 half in breadth ; and these marks are easily observed. The 
 APEX, or point of the triangle, is pointed downwards to meet 
 the second bone of the sternum. The base of the tri- 
 angle, which is uppermost, towards the root of thd throat 
 seems a little hollowed, for the trachea passing behind it. On 
 each upper corner, it has a large articulating hollow, into which 
 the ends of the collar bones are received ; (for this bone is the 
 steady fulcrum upon which they roll.) A little lower than 
 this, and upon its side is the socket for receiving the short car- 
 tilage of the first rib ; and the second rib is implanted in the 
 interstice betwixt the first and second bone of the sternum ; 
 so that one half of the socket for its cartilage is found in the 
 lower part of this bone, and the other half in the upper end of 
 the next. 
 
 2. The second piece of the sternum, is of a squared form, 
 very long and flat, and composing the chief length of the ster- 
 num ; for the first piece receives only the cartilage of the 
 first rib, and one half of the second ; but this long piece re- 
 ceives, on each side or edge of it, the cartilages of eight ribs: 
 but as three of the lower cartilages are run into one, there are 
 but five sockets or marks. The sockets for receiving the car- 
 tilages of the ribs, are on the edges of the sternum ; they are 
 very deep in the firm substance of the bone, and large enough 
 to r'eceive the point of the finger with ease : and whoever com- 
 pares the size and deepness of these sockets, with the round 
 heads of the cartilages which enter into them, will no more 
 doubt of distinct joints here, than of the distinct articulation of 
 the vertebras with each other. 
 
 3. This is, in truth, the whole of the bony sternum ; and 
 what is reckoned the third piece, is a cartilage merely, and 
 
86 
 
 QF THE TRONK. 
 
 continues so down to extreme old age. This cartilage which 
 ekes out, and lengthens the sternum, and which is pointed like 
 a sword, is thence named cartilago mucronata, the pointed 
 cartilage, or cartilago ensjformis, or xiphoides, the sword- 
 like cartilage. One half of the pit for the attachment of the 
 seventh rib is on this portion. This cartilaginous point extend- 
 ing downwards over the belly, gives a sure origin and greater 
 power to the muscles of the abdomen, and that without embar- 
 rassing the motions of the body ; but this cartilage, which is 
 commonly short and single pointed, is sometimes forked, 
 sometimes bent inwards, so (it has been thought) as to occa- 
 sion sickness and pain ; and once was produced to such a 
 length, as to reach the navel, and ossified at the same time, 
 so as to hinder the bending of the body, and occasion much 
 distress. 
 
 The sternum and the ribs, and all the chest stand so much 
 exposed, that did we not naturally guard them with the hands, 
 fractures must be very frequent, but indeed when they are 
 broken, and beaten in, they hurt the heart or lungs, and not un- 
 frequently the most dreadful consequences ensue. I have al- 
 ready explained that this class of bones, defending the most 
 noble viscera (next to the brain,) the injuries are almost as 
 fatal as injuries of the brain ; often by a wheel passing over 
 the body, the sternum is broken, its pieces press inwards upon 
 the heart, which is sometimes burst ; but more commonly the 
 patients die a slow and miserable death ; for the inflammation, 
 which begins in the place of the w'ound is extended to the 
 lungs, is propagated still onwards to the heart, and the heart 
 being once inflamed, there comes anxiety, oppression, faint- 
 ings and palpitations; anxious breathing, quick and interrupt- 
 ed pulse ; still more frequent faintings, and then death. The 
 ribs cover more properly the lungs, where the wound or in- 
 flammation is not always fatal ; for the wound by the point of 
 the rib, is no deeper than just to puncture the lungs ; but 
 through this small wound on their surface, the lungs breathe 
 out their air into the cavity of the chest, and at last it escapes 
 under the cellular substance of skin ; the man is blown up to a 
 prodigious degree with continually increasing anxiety, the 
 breathing more and more interrupted, and were he not assisted, 
 he would die. 
 
 PELVIS. 
 
 To give a steady bearing to the trunk, and to connect it 
 with the lower extremities by a sure and firm joining, the pel- 
 
OF THE TRUNK. 
 
 87 
 
 vis is interposed, which is a circle of large and firm bones, 
 standing as an arch betwixt the lower extremities and the 
 trunk. Its arch is wide and strong, so as to give a firm bear- 
 ing to the body ; its individual bones are large, so as to give a 
 deep and sure socket for the implantation of the thigh-bone ; 
 its motions are free and large, bearing the trunk above and 
 rolling upon the thigh bones below ; and it is so truly the 
 centre of all the great motions of the body, that when we be- 
 lieve the motion to be in the higher parts of the spine, it is 
 either the last vertebra of the loins bending upon the top of 
 the pelvis, or the pelvis itself rolling upon the head of the 
 thigh bones. 
 
 The PELVIS is named partly, perhaps, from its resembling 
 a basin in its form ; or perhaps, from its office of containing 
 the urinary bladder, rectum, vagina, and womb; it consists 
 in the child of many pieces, but in the adult it is formed of 
 four large bones, of the os sacrum behind the ossa innominata 
 on either side, and the os coccygis below. 
 
 Os SACRUM. — The names os sacrum, os basillare, &c. seem 
 to relate rather to its greater size than to its ever having been 
 offered in sacrifice. This bone, with its appendix the os coc- 
 cygis, is called the false spine, or the column of the false ver- 
 tebrse ; authors making this distinction, that the true vertebrae 
 are those of the back, neck, and loins, a column which grows 
 gradually smaller upwards ; the false vertebrae are those of the 
 sacrum and coccyx, which are conical, with the apex or point 
 downwards, and the base, viz. the top of the sacrum, turned 
 upwards to meet the true spine. 
 
 The bones of which the sacrum is composed, had driginally 
 the form of distinct small vertebrae. These distinctions are 
 lost in the adult, or are recollected only by the marks of former 
 lines, for the original vertebrae are now united into one large 
 and firm bone, which is named the column of false vertebrae ; 
 because, having no motion, it wants the chief character and 
 use of the true ones. 
 
 We can recognize the original vertebrae, even in the adult 
 bone, for we find it regularly perforated with holes, for the 
 transmission of the spinal nerves ; we find these holes regular- 
 ly disposed in pairs ; we see a distinct white and rising line 
 which crosses the bone, in the interstice of each of the ori- 
 ginal vertebrae, and marks the place where the cartilage once 
 was ; and by these lines being five in number, with generally 
 five pairs of holes, we know this bone to have consisted once 
 of five pieces, which are now joined into one. The remains 
 of former processes can also be distinguished, and the back of 
 the bone is rough and irregular from the old spines. 
 
«F THE TRENK. 
 
 •as 
 
 The os sacrum, thus composed, is among the lightest bones 
 of the human body, with the most spongy substance, the thin- 
 est tables, the most easily broken, and its injuries of the most 
 formidable nature ; but then it is a bone the best cemented, 
 and confirmed by strong ligaments, and the best covered by 
 thick and cushion-like muscles. The os sacrum is of a trian- 
 gular shape : the base of the triangle turned upwards to re- 
 ceive the spine ; its inner surface is smooth, to permit the head 
 of the child in labour to glide easily along, and its outer sur- 
 face is irregular and rough, with the spines of former vertebrae, 
 giving rise to the great glutaei muscles, (which form the con- 
 tour of the hip,) and to all the strongest muscles of the back 
 and loins. 
 
 It has in it a triangular cavity under the arch of its spinous 
 processes; which cavity is continued from the canal in the ver- 
 tebrae of the spine ; and this cavity of the sacrum contains the 
 continuation and the end of the spinal marrow, which being 
 in this place divided into a great many thread-like nerves, has 
 altogether the form of a horse’s tail, and is therefore named 
 cauda equina. 
 
 From this triangular cavity, the nerves of the cauda equina 
 go out by the five great holes on the forepart of the sacrum, 
 holes large enough to receive the point of the finger: the first 
 three nerves of the sacrum, joining with the last two nerves of 
 the loins, form the sacro-sciatic nerve, the largest in the body, 
 which goes downward to the leg, while the two lower nerves 
 of the sacrum supply the contents of the pelvis alone. 
 
 The back of the sacrum is also perforated with holes, whose 
 size is nearly equal to those on its fore part, but whose use* 
 are not so distinctly known ; for the small nerves which pass 
 outwards by them to the muscles of the loins or hips, are in 
 no degree proportioned to the size of the holes. 
 
 All the edges of this triangle form articulating' points, by 
 which it is joined to other bones. The base, or upper part of 
 the sacrum, receives the last vertebra of the loins on a large 
 broad surface, which makes a very moveable joint; and indeed, 
 the joining of the last true vertebra, with the top of the sacrum, 
 is a point where there is more motion than in the higher parts 
 of the spine. The sacrum has two articulating surfaces which, 
 stand perpendicular, and correspond with those of the lower 
 lumbar vertebra. The apex, or point of the sacrum, has the 
 os coccygis joined to it ; which joining is moveable till the age 
 of twenty in men, and till the age of forty-five in women ; and 
 the meaning of its continuing longer moveable in women, i.s 
 very plain, since we distinctly feel the lower point of the coc- 
 cyx in women yielding in the time of labour, so as to enlarge 
 
OP THE TRUNK. 
 
 89 
 
 greatly the lower opening of the pelvis. The sides of the os 
 saprum form a broad, rough, and deeply indented surface, 
 which receives the like rough surface of the haunch bones; and 
 here the surfaces are so rough, and the cartilage so thin, that 
 it resembles more nearly a suture ; and by the help of the 
 strong ligaments, and of the large muscles which arise in com- 
 mon from either bone, makes a joining absolutely im- 
 moveable, except by such violent force as is in the end fatal. 
 
 Thus the original state of this bone is easily recognised and 
 traced by many marks ; it stands in a conspicuous place of the 
 pelvis, and its chief office is to support the trunk, to which we 
 may add, that it defends the cauda equina, transmits its great 
 nerves, forms chiefly the cavity of the pelvis ; and that it is 
 along the hollow of this bone that the accoucheur calculates 
 the progress of the child’s head in labour. 
 
 The os coccYGis, so named from its resemblance to the 
 beak of a cuckow, is a small appendage to the point of the 
 sacrum, terminating this inverted column with an acute point, 
 and found in very different conditions in the several stages of 
 life. In the child it is merely cartilage, and we can find no 
 point of bone ; during youth it is ossifying into distinct bones, 
 which continue moveable upon each other, till manhood : then 
 the separate bones gradually unite with each other, so as to 
 form one conical bone, which bulgingsand marks of the pieces 
 of which it was originally composed ; but still the last bone 
 continues to move upon the joint of the sacrum, till, in ad- 
 vanced years, it is at last firmly united, later in women than in 
 men, with whom it is often fixed at twenty or twenty-five. 
 The first bone is flat, with two transverse process ; the others 
 become gradually of a roundish form, convex without, and 
 concave inwards, forming, with the sacrum, the lowest part 
 of the pelvis behind. It has no distinct holes, but the last sa- 
 cral hole is frequently completed by a groove on the upper 
 surface of the first bone ; it has no communication with the 
 spinal canal, but points forwards to support the lower part of 
 the rectum ; thus, it contracts the lower opening of the pelvis, 
 so as to support effectually the rectum, bladder, and womb, 
 and yet continues so moveable in women, as to recede in time 
 of labour, allowing the head to pass. 
 
 The OSSA iNNOMiNATA — Are the two great irregular bones, 
 forming the sides of the pelvis, which have a form so difficult 
 to explain by one name, that they are called ossa innominata, 
 the nameless bones. But these bones having been in the 
 child formed in distinct and separate pieces, these pieces re- 
 tain their original names, though united into one great bone : 
 we continue to explain them as distinct bones, by the names 
 
 VOL. I. M 
 
90 
 
 OF THE THUNK. 
 
 of os iliuiM, os ischium, and os pubis. The os ilium, the 
 haunch-bonc, is that broad and expanded bone on which lie 
 the strong muscles of the thigh, and which forms the round- 
 ing of the haunch. The os ischium, the hip-bone, the lowest 
 point of the pelvis, that on which vve rest in sitting. The os 
 PUBIS, or share-bone, on which the private parts are placed. 
 All these bones are divided in the child ; they are united in 
 the very centre of the socket for the thigh-bone ; and we find 
 in the child a thick cartilage in the centre of the socket, and a 
 prominent ridge of bone in the adult ; which ridge, far from in- 
 commoding the articulation with the thigh-bone, gives a firmer 
 hold to the cartilage which lines that cavity, and is the point 
 into which a strong ligament from the head of the thigh-bone 
 is implanted. 
 
 The os ILIUM, or haunch-bone, is named from its forming 
 the flank. It is the largest part of the os innorninatum. It 
 rises upwai’ds from the pelvis in a broad expanded iving, which 
 forms the lower part of the cavity of the abdomen, and sup- 
 ports the chief weight of the impregnated womb (for the 
 womb commonly inclines to one side.) The os ilium is cover- 
 ed with the great muscles that move the thighs, and to its 
 edge arc fixed those broad flat muscles which form the walls 
 of the abdomen. This flat upper part is named the ala, or 
 WING, while the lower, or rounder part, is named the body of 
 the bone, where it enters into the socket, and meets the other 
 bones. 
 
 The ALA, or flat expanded wing, has many parts which must 
 be well remembered, to understand the muscles which arise 
 from them. 1. The whole circle of this wing is tipt with a 
 ridge of firmer bone, which' encircles the whole. This is a 
 circular cartilage in the child, distinct from the bone, and is 
 ossified and fixed only at riper years. All this ridgy circle is 
 called the spine, and is the origin for several muscles, 2. The 
 two ends of this spine are abrupt, and the points formed upon 
 it are consequently named spinous processes, of which there 
 are two at its fore and two at its back end. The two posteri- 
 or SPINOUS processes are close by each other, and are mere- 
 ly two rough projecting points near the rough surface, hy 
 which the os ilium is joined to the os sacrum; they jut out 
 behind the articulation, to make it firm and sure ; and their 
 chief uses seem to be the giving a firm hold to the strong li- 
 gaments which bind this joint. 3. The two anterior spinous 
 processes arc more distinct, and more important marks; foy 
 the ANTERIOR SUPERIOR SPINOUS PROCESS, is the abrupt end- 
 ing of the spine, or circle of the ilium, with a swelling out; 
 from which jutting point the sartorious muscle, the longest 
 
OF THE TRUNK. 
 
 91 
 
 and amongst the most beautiful in the human body, goes 
 obliquely across the thigh, like a| strap, down to the knee ; 
 another, which is called the tenser vagina; femoris, also arises 
 here ; and from this point departs the ligament, which passing 
 from the os ilium to the pubis, or fore point of the pelvis, is 
 called the ligament of the thigh ; how necessary it is to mark 
 this point, may be easily deduced, from knowing that it is un- 
 der the arch of this femoral ligament that the great artery 
 passes down to the thigh, and that the femoral hernia is form- 
 ed. The LOWER ANTERIOR spinous process is a small bump, 
 or little swelling, about an inch under the first one, which 
 gives rise to the rectus femoris muscle, or straight muscle of 
 the thigh, which lies along its fore part, and upon the inside 
 there is a depression lodging the iliacus internus and psoas 
 magnus. 
 
 The back, or dorsum of the os ilium, is covered with the 
 three great glutaei muscles; we remark in a strong bone a se- 
 micircular ridge which runs from the upper part of the anteri- 
 or inferior spinous process, to the lower part of the bone (the 
 notch.) The inner surface is hollowed, so as to be called the 
 cup or hollow, or sometimes the venter. 
 
 This bone (the os ilium) has a broad rough surface, by 
 Avhich it is connected with the os sacrum at its side, the very 
 form of which declares the nature of this joining, and is suffi- 
 cient argument and proof that the joinings of the pelvis do not 
 move. 
 
 The acute line, which is named linea innominata, is seen 
 upon the internal surface of the bone, dividing the ala, or wing, 
 from that part which is in the socket for the thigh. This line 
 composes part of the brim of the pelvis, distinguishes the ca- 
 vity of the pelvis from the cavity of the abdomen, and marks 
 the circle into which the head of the child descends at the 
 commencement of labour. 
 
 We find particularly on the dorsum many irregular ridges 
 for the origin of muscles, and in many parts of the bone we 
 see holes for transmitting vessels; we find one particularly 
 large in the cup. 
 
 The os ISCHIUM, or hip-bone, is placed perpendicularly 
 under the os ilium, and is the lowest point of the pelvis upon 
 which we sit. It forms the largest share of the socket, whence 
 the socket is named acetabulum ischii, as peculiarly belong- 
 ing to this bone. The bump or round swelling upon which 
 we rest is named the tuber ischii ; and the smaller part, which 
 extends upwards to meet the os pubis, is named the ramus, or 
 branch, which meets a similar branch of that bone, to form 
 the thyroid hole. 
 
92 
 
 0F THE TRUNK. 
 
 The BODY is the uppermost, and thicker part of the bone, 
 which helps in forming the socket; and among the three 
 bones this one forms the largest share of it ; nearly one half. 
 From the body, a sharp pointed process named spinous pho- 
 CEss of the ischium, is projected backwards, which pointing 
 towards the lower end of the sacrum, receives the uppermost 
 of two long ligaments, which, from their passing betwixt the 
 ischium and sacrum, are named sacro-sciatic ; by this ligament 
 a semi-circle of the os ilium, just below the joining of the ili- 
 um with the sacrum, is completed into a large round hole, 
 which is in like manner named the sacro-sciatic hole, and 
 gives passage to muscles, and to the great nerve of the lower 
 extremity, named the great sacro-sciatic nerve. 
 
 The TUBEK, or round knob, being the point upon which we 
 rest, this bone has been often named os sedentakium. The 
 bump is a little flattened where we sit upon it. It is the mark 
 by which the lithotomist directs his incision, cutting exactly 
 in the middle betwixt the anus and this point of bone. It 
 is remarkable as the point towards which the posterior or 
 lower sacro-sciatic ligament extends, and as a point which 
 gives rise to several of the strong muscles on the back of the 
 thigh, and especially to those which form the ham-strings. 
 
 Between the scabrous surface on the tuber, and the edge of 
 the acetabulum, there is a smooth surface rather depressed 
 which is called the cervix. It is covered with a cartilage 
 which allows the tendon of the obturator to move easily. 
 
 The RAMUS, or branch, rises obliquely upwards and for- 
 wards, to join a like branch of the pubis. This branch, or 
 arm, as it is called, is fiat, and its edges are turned a little for- 
 wards and backwards, so that one edge forms the arch of the 
 pubis, while the other edge forms the margin of the thyroid 
 hole. 
 
 The os PUBIS, or share-bone, is the last and smallest piece 
 of the os innominatum, and is named from the mons veneris 
 being placed upon it, and its hair being a mark of puberty. 
 It forms the upper, or fore part of the pelvis, and completes 
 the brim, and, like the ischium, it also is divided into three 
 parts, viz. the body, angle, and ramus. 
 
 The body of the os pubis is thick and strong, and forms 
 about one-fifth of the socket for the thigh-bone. It is not 
 only the smallest, but the shallowest part of the socket. The 
 bone grows smaller, as it advances towards its angle, it again 
 grows broad and flat, and the two bones meet with rough sur- 
 faces, but with two cartilages interposed. Over the middle of 
 this bone, two great muscles, the iliac and psoas muscles, pass 
 out of the pelvis to the thigh ; and where they run under the 
 
OF THE TRUNK. 
 
 9S 
 
 ligament of the thigh, they make the pubis very smooth. On 
 the angle or crest there is a process which is frequently called 
 tuberous angle : from this process there are two ridges traced; 
 one goes to meet the line on the ilium, and forms the linea 
 ileo pectinea ; the other goes down towards the edge of the 
 acetabulum ; between these two ridges there is a flat surface 
 giving origin to the pectineus. The ramus, or branch, is that 
 more slender part of the pubis, which, joining with the branch 
 of the ischium, forms with it the arch of the pubis, and the 
 edge of the thyroid hole. Just under the body of the bone, 
 there is a groove which forms that part of the thyroid hole 
 which transmits the obturator nerve and artery. 
 
 This completes the strict anatomy of the pelvis ; but when 
 we consider the whole, it is further necessary to repeat, in short 
 definitions, certain points which are oftener mentioned as marks 
 of other parts. 
 
 The PROMONTORY of the sacrum is the projection formed by 
 the lowest vertebra of the loins, and the upper point of that 
 bone. The hollow of the sacrum is all that smooth inner 
 surface which gives out the great nerves for the legs and pel- 
 vis. The LESSER ANGLE, in distinction from the greater angle 
 or promontory of the sacrum, is a short turn in the bone near 
 where it is joined with the os coccygis. The crest of the 
 PUBIS is a sharper ridge or edge of the bone over the joining 
 or symphysis pubis. The posterior symphysis of the pelvis 
 is the joining of the sacrum with the ilium, while the symphy- 
 sis pubis is distinguished by the name of anterior symphysis 
 of the pelvis. The spine, the tuber, and the ramus of the 
 ischium are sufficiently explained. The ala, or wing, the 
 spine, the SPINOUS processes, and the linea ini^minata of 
 the ilium, are also sufficiently explained. The acetabulum, 
 so named from its resemblance to a measure which the ancients 
 used for vinegar, is the hollow or socket for the thigh-bone, 
 composed of the ilium, ischium, and pubis ; the ridge in its 
 centre shows the place of its original cartilage, and points out 
 what proportion belongs to each bone ; that it is made, two- 
 fifths by the os ilium, two-fifths by the os ischium, and one-fifth 
 only by the os pubis : but the ischium has the greatest share ; 
 the ischium forming more than two fifths, and the ilium less. 
 The cavity, however, is not entirely completed by bone, for 
 there is a ligament stretched across the inner and lower margin. 
 
 The BRIM of the pelvis is that oval ring which parts the 
 cavity of the pelvis from the cavity of the abdomen ; it is 
 formed by a continued and prominent line along the upper 
 part of the sacrum, the middle of the ilium, and the upper 
 part er crest of the pubis. This circle of the brim supports 
 
94 
 
 OF THK TRUNK. 
 
 the impregnated womb, keeps it up against the pressure of the 
 labour pains ; and sometimes this line has been “ as sharp as 
 “ a paper-folder, and has cut across the lower segment of the 
 “ womb and so, by separating the womb from the vagina, 
 has rendered the delivery impossible ; and the child escaping 
 into the abdomen among the intestines, the woman has died. 
 The OUTLET of the pelvis is the lower circle again, composed 
 by the arch of the pubis, and by the sciatic ligaments, which 
 is wide and dilatable, to permit the delivery of the child, but 
 which being sometimes too wide, permits the child’s head to 
 press so suddenly, and with such violence upon the soft parts, 
 that the perineum is torn. The thyroid hole is that remark- 
 able vacancy in the bonp which perhaps lightens the pelvis, or 
 perhaps allows the soft parts to escape from the pressure, dur- 
 ing the passage of the head of the child. 
 
 The marks of the female skeleton have been sought for in 
 the skull, as in the continuation of the sagittal suture 5 but the 
 truest marks are those which relate to that great function by 
 which chiefly the sexes are distinguished : for while the male 
 pelvis is large and strong, with a small cavity, narrow openings, 
 and bones of greater strength, the female pelvis is very shal- 
 low and wide, with a large cavity, and slender bones, and with 
 every peculiarity which may conduce to the easy passage of 
 the child. And this occasions that peculiar form of the body 
 which the painter is at greater pains to mark, and which is in- 
 deed very easily perceived ; for the characteristic of the manly 
 form is firmness and strerigth ; the shoulders broad, the 
 haunches small, the thighs in a direct line with the body, which 
 gives a firm and graceful step. The female form again is 
 delicate, soft, and bending ; the shoulders are narrow ; the 
 haunches ttfoad ; the thighs round and large ; the knees of 
 course, approach each other, and the step is unsure : the wo- 
 man even of the most beautiful form, walks with* a delicacy 
 and. feebleness, which we come to acknowledge as a beauty in 
 the weaker sex. 
 
 The bones of the pelvis compose a cavity which cannot be 
 fairly understood in separate pieces, but which should be ex- 
 plained as a whole. Though perhaps its chief office is sup- 
 porting the spine, still its relation to labour deserves to be ob- 
 served ; for this forms at least a curious inquiry, though it 
 should not be allowed a higher place in the order of useful 
 studies. 
 
 Wc know, from much experience, that where the pelvis is 
 of the true size, w'e have an easy and natural labour : that 
 where tlie pelvis is too large, there is pain and delay ; but not 
 'hat kind of difficulty which endangers life ; that where, by 
 
OF THE TRUNK. 
 
 95 
 
 distortion, the pelvis is reduced below the standard size, there 
 comes such difficulty as endangers the mother, and destroys 
 the child, and renders the art of midwifery still worthy of 
 serious study, and an object of public care. 
 
 There was a time when it was universally believed, that the 
 joinings of the pelvis dissolved in every labour ; that the bones 
 departed, and the openings were enlarged ; that the child 
 passed with greater ease ; and “ that this opening of the basin 
 “ w'as no less natural than the opening of the womb.” By 
 many accidents, this opinion has been often strengthened and 
 revived ; and if authority could determine our opinion, we 
 should acknowledge, that the joinings of the pelvis were always 
 dissolved as a wise provision of nature for facilitating natural, 
 and preventing lingering labour, compensating for the frequent 
 deviations btoh in the head and pelvis, from their true and 
 natural size. This unlucky opinion has introduced, at one 
 time, a practice the most reprehensibly simple, as fomentations 
 to soften these joinings of the pelvis in circumstances Avhich 
 required very speedy help; while, at another time, it has 
 been the apology for the most cruel, unnatural operations of 
 instruments, not merely intended for dilating and opening the 
 soft parts, but for bursting up these joinings of the bones. 
 And those also, of late years, who have invented and performed 
 (too often, no doubt,) this operation of cutting the symphysis 
 pubis to hasten the labour, say, that they do not perform an 
 unnecessary cruel operation, but merely imitate a common 
 process of nature. 
 
 How very far nature is from intending this, may be easily 
 known from the very forms of these joinings, but much more 
 from the other offices which these bones have to perform ; for 
 if the pelvis be, as I have defined it, an arch standing betwixt 
 the trunk and the lower extremities on which the body rolls, 
 its joinings could not part without pain and lameness, perhaps 
 inability for life. 
 
 One chief reason drawn from anatomy, is this : that in 
 women dying after labour, the cartilages of the pelvis are ma- 
 nifestly softened ; the bones loosen ; and though they cannot 
 be pulled asunder, they can be shuffled or moved upon each 
 other in a slight degree : all which is easily accounted for. 
 The cartilage that forms the symphysis pubis is not one carti- 
 lage only, as was once supposed, but a peculiar caAilage co- 
 vers the end of each bone, and these are joined by a membra- 
 nous or ligamentous substance : this ligamentous substance is 
 the pai;k which corrupts the soonest : it is often spoiled, and in 
 the place' of it a hollow only is found ; that hollow of the cor- 
 rupted ligament may be called a separation of the bones ; but 
 
96 
 
 OF THE TRUNK. 
 
 it is such a separation “ as equals only the back of a common 
 “ knife in breadth, and will not allow the bones to depart from 
 “ each other the joining is still strong, for it is surrounded 
 by a capsular ligament, is not like the loose ligament of a 
 moveable joint, but adhering to every point of each bone : 
 and this ligament d(»es perform its office so completely, that 
 vhile it remains entire, though the bones shuffle sideways 
 ipon each other, no force can pull them asunder : “ Even 
 
 when the fore part of the pelvis is cut out, and turned and 
 “ twisted betwixt the hands, still though the bones can be 
 “ bent backwards and forwards, they cannot be pulled from 
 “ each other the tenth part of an inch.” These inquiries 
 were made by one, who, though partial to the other side of 
 this question, could not allow himself to disguise the truth, 
 whose authority is the highest, and by whose facts I should 
 most willingly abide. 
 
 Now, it is plain, that since a separation, amounting ony to 
 the 12lh of an inch, occasions death, this cannot be a provi- 
 sion of nature ; and since the separation in such degree could 
 not enlarge the openings of the basin, there again it cannot be 
 a provision of nature. 1 know that tales are not wanting of 
 women whose bones were separated during labour; but what 
 is there so absurd, that we shall not find a precedent or paral- 
 lel case in our annals of monstrous and incredible facts Or, 
 rather, where is there a fact of this description which is not 
 balaneed and opposed by opposite authorities and facts? I have 
 dissected several women who have died in lingering labour, 
 where I found no disunion of the bones. I have seen women 
 opened, after the greatest violence with instruments, and yet 
 found no separation of the bones. We have cases of women 
 having the mollities ossium, a universal softness, and bending 
 of the bones, who have lived in this condition for many years, 
 with the pelvis also affected ; its openings gradually more and 
 more abridged ; the miserable woman suffering lingering la- 
 bour, and undergoing the delivery by hooks, with all the vio- 
 lence that must he used in such desperate cases, and still no 
 separation of the bones happening. How, indeed, should 
 there be such difficult labours as these, if the separation of the 
 bones could allow the child to pass ? 
 
 If it be said, “ the joinings of the pelvis are sometimes 
 dissolved,” I acknowledge that they are just as the joint of the 
 thigh is dissolved, that is, sometimes by violence, and some- 
 times by internal disease ; but if it be affirmed that “ the join- 
 “ ings of the pelvis are dissolved to facilitate labour,” I would 
 observe, that wherever separation of the bones has happened, 
 it has both increased the difficulties of the labour, and been in 
 
OF THE TRUNK. 
 
 97 
 
 itself a very terrible disease ; for proofs of which, I must refer 
 to Hunter, Denman, and others, to whose peculiar province 
 such cases belong. But surely these principles will be uni- 
 versally acknowledged : that the pelvis supporting the trunk is 
 the centre of its largest motions : that if the bones of the pel- 
 vis were loosened, such motions could nolongerbe performed : 
 that when, by violence or by internal disease, or in the time of 
 severe labour, these joinings have actually been dissolved or 
 burst, the woman has become instantly lame, unable to sit, 
 stand, or lie, or support herself in any degree ; she is rendered 
 incapable of turning, or even of being turned in bed ; her at- 
 tendants cannot even move her legs without intolerable an- 
 guish, as if torn asunder :* there sometimes follows a collec 
 tion of matter within the joint, (the matter extending quite 
 down to the tuber ischii), high fever, delirium, and death ;f 
 or, in case of recovery, (which is indeed more frequent), the 
 recovery is slow and partial only ; a degree of lameness re- 
 mains, with pain, weakness, and languid health ; they can 
 stand on one leg more easily than on both ; they can walk 
 more easily than they can stand ; but it is many months before 
 they can walk without crutches; and long after they come to 
 walk upon even ground, climbing a stair continues to be very 
 difficult and painful. In order to obtain even this slow re-uni- 
 on of the bones, the pelvis must be bound up with a circular 
 bandage very tight; and they must submit to be confined long : 
 by neglect of which precautions, sometimes by the rubbing 
 of the bones, a preternatural joint is formed, and they conti- 
 nue lame for years, or for life ;| or sometimes the bones are 
 united by ossification ; the callus or new bone projects towards 
 the centre of the pelvis, and makes it impossible for the wo- 
 man to be delivered again of a living child, 
 
 Now this history of the disease leads to reasons independent of 
 anatomy, and surer than it ; which prove, that this separation 
 of the bones (an accident the existence of which cannot be 
 questioned) is not a provision of nature, but is a most serious 
 disease. For if these be the dreadful consequences of separa- 
 tion of the bones, how can we believe that it happens, when 
 we see women walking during all their labour, and, in place 
 of being pained, are rather relieved by a variety of postures, 
 and by walking about their room f who often u’alk to bed after 
 being delivered on chairs or couches who rise on the third 
 day, and often resume the care and fatigues of a family in a 
 
 * Denman. f Huntn. 
 
 t Denman savf twenty-five or thirty years. 
 
 ? Sneure’s cases. 
 
 N 
 
 TOL. r. 
 
98 
 
 BONES OF THE 
 
 few days more r or can we believe, that there is a tendency 
 to separation of the bones in those who, following the camp, 
 are delivered on one day, and walk on the» following i’ or in 
 those women who, to conceal their shame, have not indulged 
 in bed a single hour ? or can we believe, that there is even 
 the slightest tendency to the separation of the bones in those 
 women whose pelvis resists the force of a lingering and severe 
 labour, who suffer still further all the violence of instruments, 
 who yet recover as from a natural delivery, and who also rise 
 from bed on the third or fourth day ? 
 
 
 CHAP. VI. 
 
 BONES OF THE THIGH, LEG, ANI> FOOT. 
 
 r r 
 
 A HE THIGH-BONE is the greatest bone of the body, and 
 needs to be so, supporting alone, and in the most unfavourable 
 direction, the whole weight of the trunk ; for though the body 
 of this bone is in a line with the trunk, in the axis of the body, 
 its neck stands off almost at right angles with the body of the 
 bone ; and in this unfavourable direction must it carry the 
 whole weight of the trunk, for the body is seldom so placed 
 as to rest its weight equally upon either thigh-bone ; com- 
 monly it is so inclined from side to side alternately, that the 
 neck of one thigh-bone bears alone the whole weight of the 
 body and limbs, or is still loaded with greater burdens than the 
 mere weight of the body itself. 
 
 The thigh-bone is one of the most regular of the cylindri- 
 cal bones. Its body is very thick and strong, of a rounded 
 form, swelling out at either end into two heads. In its middle 
 it bends a little outwards, with its circle or convex side turned 
 towards the forepart of the thigh. This bending of the thigh- 
 bone has been a subject of speculation abundantly ridiculous, 
 viz. w'hether this be an accidental or a natural arch. There 
 are authors who have ascribed it to the nurse carrying the 
 child by the thighs, and its soft bones bending under the 
 weight. There is another author, very justly celebrated, who 
 imputes it to the weight of the body, and the stronger action 
 of the flexor muscles, affirming, that it is straight in the child, 
 and grows convex by age. This could not be, else we should 
 find this cnrve less in some, and greatest in those who had 
 
THIGH, LEG, AND FOOT. 
 
 99 
 
 walked most, or whose muscles had the greatest strength; and 
 if the muscles did produce this curve, a little accident giving 
 the balance to the flexor muscles, should put the thigh-bone 
 in their power to bend it in any degree, and to cause distor- 
 tion. But the end of all such speculations is this, that we find 
 it bended in the foetus, nor yet delivered from the mother’s 
 womb, or in a chicken, while still enclosed in the shell ; it is 
 a uniform and regular bending, designed and marked in the 
 very first formation of the bone, and intended perhaps, for the 
 advantage of the strong muscles in the back of the thigh, to 
 give them greater power or more room. 
 
 The HEAD of the thigh-bone is likewise the most perfect of 
 any in the human body, for its circumference is a very regular 
 circle, of which the head contains nearly two-thirds : it is 
 small, neat, and completely received into its socket, which is 
 not only deep in itself, and very secure, but is further deepen- 
 ed by the cartilage which borders it, so that this is naturally, 
 and without the help of ligaments, the strongest joint in all the 
 body ; but among other securities which are superadded, is 
 the round ligament, the mark of which is easily seen, being a 
 broad dimple in the centre of its head. In the surface of the 
 head or ball we observe a small pit for the attachment of the 
 round ligament of the hip-joint. 
 
 The NECK of this bone is the truest in the skeleton ; and 
 indeed it is from this neck of the thigh-bone, that we transfer 
 the name to other bones, which have hardly any other mark 
 of neck than that which is made by their purse-like ligament 
 being fixed behind the head of the bone, and leaving a rough- 
 ness there. But the neck of the thigh-bone is more than an 
 inch in length, thick, and strong, yet hardly proportioned to 
 the great weights which it has to bear ; long, that it may allow 
 the head to be set deeper in its socket ; and standing wide up 
 from the shoulders of the bone, to keep its motions wide and 
 free, and unembarrased by the pelvis ; for without this great 
 length of the neck, its motions had been checked even by the 
 edges of its own socket. 
 
 The TROCHANTERS are the longest processes in the human 
 body for the attachment of muscles, and they are named tro- 
 chanter (or processes for turning the thigh,) from their office, 
 which is the receiving those great muscles which not only 
 bend and extend the thigh, but turn it upon its axis ; for these 
 processes are oblique, so as to bend and turn the thigh at 
 once. 
 
 The TROCHANTER MAJOR, the outcimost and longer of the 
 two, is that great bump which represents the direct end of 
 the thigh-bone, while the neck stands off from it at one side ; 
 
too 
 
 OF THE BONES 
 
 therefore the great trochanter stands above the neck, and u' 
 easily distinguished outwardly, being that great bump which we 
 feel so plainly in laying the hand upon the haunch. On the 
 upper and forepart of this great process, are two surfaces for 
 the insertion of the gluteus medius and minimus. 
 
 The extremity of the great trochanter hangs over a pit into 
 which principally the small rotator muscles of the thigh are in- 
 serted, viz. the pyriformis, the gernini, the obturator interims 
 and externus. On the lower part there is a very strong mark- 
 ed ridge, which is for the insertion of the gluteus maximus. 
 
 The TKOCHANTER MINOR, or lessci’ trochautcr, is a smaller 
 and more pointed rising on the inner side of the bone, lower 
 than the trochanter major, and placed under the root of the 
 neck, as the greater one is placed above it. It is deeper in the 
 thigh, and never to be felt, not even in luxations Its muscles 
 also, viz. the flexors of the thigh, by the obliquity of their in- 
 ■sertion into it, turn the thigh, and bend it tov.'ards the body, 
 such as the psoas and iliacus internus, which passing out from 
 the pelvis, sink deep into the groin, and are implanted into 
 this point. From the one trochanter to the other, there is a 
 very conspicuous roughness, which marks the place of the cap- 
 sule or ligamentary bag of the joint; for it encloses the whole 
 length of the neck and of the thigh-bone. This roughness 
 begins the great rough line, and is what is regularly named 
 linea aspera. 
 
 Betwixt the greater and lesser trochanters, there runs a 
 rough line, the inter trochantral line, to which the capsular li- 
 gament is attached, and into which the quadratus femoris is 
 inserted. 
 
 The LINEA ASPERA is a rising or prominent line, very rag- 
 ged and unequal, which runs all down the back part of the 
 thigi) : it begins at the roots of the two trochanters, and the 
 rough lines from each trochanter meet about four inches down 
 the bone ; thence the linea aspera runs down the back of the 
 bone a single line, and forks again into two lines, one going 
 towards each condyle, and ending in the tubercles at the lower 
 end of the bone, so that the linea aspera is single in the middle, 
 and forked at either end. 
 
 Tiie CONDYLES are the two tubers into which the thigh- 
 bone swells out at its lower part. There is first a gentle and 
 gradual swelling of the bone, then an enlargement into two 
 broad and flat surfaces, which are to unite with the next bone 
 in forming the great joint of the knee. The two tuberosi- 
 ties, which, by their flat faces, form the joint, swell out above 
 the joint, and are called the condyles. The inner condyle 
 is larger, to compensate for the oblique position of the thigh- 
 
10} 
 
 THIGH, LEG, AND FOOT. 
 
 bone ; for the bones are separated at their beads, by the 
 whole width of the pelvis, but are drawn towards a point be- 
 low, so as to touch each other at the knees. On the forepart 
 of the bone, betwixt the condyles, there is a broad smooth sur- 
 face, upon which the rotula, or pulley-like bone glides. The 
 outer side of this trochlea is the largest and most prominent. 
 On the back part of the thigh-bone, in the middle, betwixt the 
 condyle, there is a deep notch, which gives passage to the 
 great artery, vein, and nerve of the leg. 
 
 The great nutritious artery enters below the middle of this 
 bone, and smaller arteries enter through its porous extremities ; 
 as may be known by many small holes, near the head of the 
 bone. 
 
 The HEAD of the thigh-bone is round, and set down deeply 
 in its socket, to give greater security to a joint so impor- 
 tant, and so much exposed as the hip is. The neck stands 
 off from the rest of the bone, so that by its length it allows 
 a free play to the joint, but is itself much exposed by its trans- 
 verse position, as if nature had not formed in the human 
 body any joint at once free, moving, and strong. The neck 
 is not formed in the boy, because the socket is not yet 
 deep, nor binders the motions of the thigh, and the head is 
 fox'med apart from the bone, and is not firmly united with it till 
 adult years, so that falls luxate or separate the head in young 
 people, but they break the neck of the bone, in those that are 
 advanced in years. The thochanteks, or shoulders, are large, 
 to receive the great muscles which are implanted in them, and 
 oblique, that they may at once bend and turn the thigh. The 
 SDAFT or BODV is Very strong, that it may bear our whole 
 weight, and the action of such powerful muscles : and it is 
 marked with the rough line behind, from which a mass of flesh 
 takes' its rise, which warps completely round the lower part of 
 the thigh-bone, and forms what are called the vasti muscles, 
 the greatest muscles for extending the leg. The condyles 
 swell out to give a broad surface, and a firm joining for the 
 knee. But of all its parts, the great trochanter should be 
 most particularly observed, as it is the chief mark in luxations 
 or fractures of this bone : for when the greater trochanter is 
 pushed downwards, we find the thigh luxated inward ; when 
 the trochanter is higher than its trae place, and so fixed that 
 it cannot roll, we are assured that it is luxated ; but when the 
 trochanter is up wards, with the thigh rolling freelj", we are as- 
 sured its neck is broken, the trochanter being displaced, and 
 the broken head remaining in its socket ; but when the tro- 
 chanter remains in its place, we should conclude that the joint 
 :s but little injured, or that it is only a bruise of those glands 
 
102 
 
 BONES OF THE 
 
 or mucous follicles, which are lodged within the socket, for 
 lubricating the joint. 
 
 The TIBIA is named from its resemblance to a pipe ; the 
 upper part of the tibia, representing the expanding or trumpet- 
 like end, the lower part representing the flute end of the pipe. 
 The tibia, on its upper end, is flat and broad, making a most 
 singular articulation with the thigh-bone ; for it is not a ball 
 and socket like the shoulder or hip, nor a hinge-joint guarded 
 on either side with projecting points, like the ankle. There is 
 no security for the knee-joint, by the form of its bones, for 
 they have plain flat heads ; they are broad indeed, but they 
 are merely laid upon each other. It is only by its ligaments 
 that this joint is strong ; and by the number of its ligaments it 
 is a complex and delicate joint, peculiarly liable to disease. 
 
 The UPPER HEAD of the tibia, is thick and spongy, and we 
 find there two broad and superficial hollows, as if impressed, 
 while soft, with the marks of the condyles of the thigh-bone ; 
 and these slight hollows are all the cavity that it has for re- 
 ceivingthe thigh-bone, A pretty high ridge rises betwixt these 
 two hollows, so as to be received into the interstice betwixt the 
 condyles, on the back part, which is the highest point of the 
 ridge. There is a pit on the fore and on the back part for the 
 attachment of the crucial ligaments. The spongy head has 
 also a rough margin, to which the capsular ligament is tied. 
 On the fore part of this bone, just below the knee, there is a 
 bump for receiving the great ligament of the patella, or, in 
 other words, the great tendon of all the extensor muscles of 
 the leg ; and lastly, there is upon the outer side of this spongy 
 head, just under the margin of the joint, a smooth articulating 
 surface, (like a dimple impressed with the finger,) for re- 
 ceiving the head of the fibula. It is under the margin of the 
 joint, for the fibula does not enter at all into the knee joint ; 
 it is only laid upon the side of the tibia, fixed to it by liga- 
 ments, but not received into any thing like a cavity. 
 
 The BODY of the bone is of a prismatic or triangular form, 
 and its three edges or acute angles are very high lines running 
 along its whole length. The whole bone is a little twisted to 
 give a proper position to the foot. One line, the anterior an- 
 gle, a little waved, and turned directly forwards, is what is 
 called the shin. At the top of this ridge, is that bump into 
 which the ligament of the rotula or patella is implanted ; and 
 the whole length of this acute line is so easily traced through 
 the skin, that we can never be mistaken about fractures of this 
 bone. Another line less acute than this, is turned directly 
 backwards; and the third acute line, which completes the tri- 
 angular form, is turned towards the fibula, to receive a broad 
 
THIGH, LEG, AND FOOT. 
 
 103 
 
 ligament, or interosseous membrane, which ties the two hones 
 together. 
 
 The lower extremity of the tibia has a deep pit or cavity of 
 articulation, which is called the scaphoid cavity; it receives 
 the astragalus. 
 
 The middle of the posterior surface of the bone is hollowed 
 for the lodgement of the muscles, which extend the foot, and 
 bend the toes ; and the anterior and outer surface is hollowed 
 by the lodgement of that muscle, which is called tibialis anti- 
 cus, and the long extensors of the toes. 
 
 On the back part of the bone, near its head, there is a flat 
 surface made by the insertion of the popliteus muscle, which 
 is bounded on the lower part by a ridge giving origin to one of 
 the flexors. 
 
 The lower head of the tibia composes the chief parts of 
 the ankle-joint. The lower head of the tibia is smaller than 
 the upper, in the same proportion, that the ankle is smaller than 
 the knee. The pointed part of this head of the tibia repre- 
 sents the mouth-piece, or flat part of the pipe, and constitutes 
 the bump of the 1N^ER ankle. The lower end of the fibula 
 lies so upon the lower end of the tibia, as to form the outer 
 ankle ; and there is on the one side of the tibia a deep hollow, 
 like an impression made with the point of the thumb, which 
 receives the lower end of the fibula. The acute point of the 
 tibia, named the process of the inner ankle, passes beyond the 
 bone of the foot, and, by lying upon the side of the joint, 
 guards the ankle, so that it cannot be luxated outward, with- 
 out this pointed process of the raaleolus internus, or inner 
 ankle, being broken. 
 
 On the back of the lower head of the bone there is a groove 
 which transmits the tendon of the tibialis posticus muscle, and 
 at its apex a pit giving origin to the deltoid ligament. 
 
 On the back part of the tibia, and a little below its head, 
 we have to observe the hole for the transmission of the nutri- 
 tious artery, to the centre of the bone. In amputation of the 
 leg, this artery is sometimes cut across just where it has entered 
 the bone, and the bleeding proves troublesome. 
 
 The tibia is a bone of great size, and needs to be so, for it 
 supports the whole weight of the body. It is not at all as- 
 sisted by the fibula, in bearing the weight, the fibula, or slender 
 bone, being merely laid upon the side of the tibia, for uses 
 which shall be explained presently. The tibia is thick, with 
 much cancelli, or spongy substance w'ithin ; has pretty firm 
 plates without ; is much strengthened by its ridges, and by its 
 triangular form : its ridges are regular with regard to each 
 i?ther, but the whole bone is twisted as if it had been turned 
 
104 
 
 BOi\£S OF THE 
 
 betwixt tbe hands when soft : this distortion makes the process 
 of tbe inner ankle lie not regularly upon the side of that joint, 
 but a little obliquely forward, determining the obliquity 
 of the foot, which must be of much consequence, since there 
 are many provisions for securing this turning of the foot, viz. 
 the oblique position of the trochanters ; the oblique insertion 
 of all the muscles, and this obliquity of the ankles ; tbe inner 
 ankle advancing a little before the joint, and the outer ankle 
 receding in the same degree behind it. 
 
 The FIBULA, which is named so from its resemblance to 
 the Roman clasp, is along slender bone, which is useful part- 
 ly in strengthening the leg, but chiefly in forming the ankle- 
 joint ; for the tibia only is connected with the knee, while the 
 fibula, which has no place in the knee-joint, goes down below 
 tbe lower end of the tibia, forming the long process of the 
 outer ankle. 
 
 The fibula is a long and slender bone, the longest and slen- 
 derest in the body. It lies by the side of the tibia like a 
 splint, so that when at any time the tibia is broken without 
 the fibula, or when the tibia having spoiled, becomes carious, 
 and a piece of it is lost, the fibula maintains the form of the 
 limb till the last piece be replaced, or till the fracture be firm- 
 ly re-united. It is like the tibia, triangular in the middle 
 part, but square towards the lower end, and has two heads, 
 which are knots, very large, and disproportioned to so slender 
 a bone. The sharpest line of the fibula is turned to one sharp 
 line of the tibia, and the interosseous membrane passes betwixt 
 them. The other lines or spines are in the interstices of the 
 attachment of muscle, which, arising from this bone, are called 
 peronei. The bone lies in a line with the tibia, on the outer 
 side of it, and a little behind it. The upper head of the fibula 
 is rough on the outer surface, for tbe insertion of the lateral 
 ligament, and of the biceps cruris, smooth and light, with car- 
 tilage within, and is laid upon a plain smooth surface, on the 
 side of the tibia, a little below the knee ; and though the fibula 
 is not received deep into the tibia, this want is compensated 
 for by the strong ligaments by which this little joint is tied by 
 the knee, being completely wrapped round with the expanded 
 tendons of those great muscles which make up the thigh, by 
 the knee being still farther embraced closely by the fascia, or 
 tendinous expansion of the thigh 5 but above all, by the ten- 
 dons of the outer ham-strings being fixed into this knot of the 
 fibula, and expanding from that over the forepart of the tibia. 
 
 The lower head of the fibula is broad and flat, and is let 
 pretty deep into the socket on the side of the tibia; together, 
 they form the ankle-joint for receiving the bones of the fool. 
 
THIGfH, LEG, AND FOOT. 
 
 106 
 
 Tlie extreme point of tlie thin extremity gives attachment to 
 the outer ligament of the joint, and is sometimes called the 
 coronoid process. On the back part of this lower head, there 
 is a furrow which lodges the tendons of the peronei muscles. 
 The ankle-joint is one of the purest hinge joints,' and- is very 
 secure ; for there is the tibia at the process of the inner ankle, 
 guarding the joint within ; there is the fibula passing the joint 
 still further, and making the outer ankle still a stronger guard 
 without. These two points, projecting so as to enclose the 
 bones of the foot, making a pure hinge, prevent all lateral mo- 
 tion ; make the joint firm and strong, and will not allow of lux- 
 ations, till one or both ankles be broken. We know that there 
 is little motion betwixt the tibia and fibula | none that is 
 sensibly outwardly, and no more in truth than just to give a 
 sort of elasticity, yielding to slighter strains. But we are well 
 assured, that this motion, thou^ slightest and imperceptible, 
 is very constant ; for these jointings of the fibula with the 
 tibia are always found smooth and lubricated ; and there are 
 no two bones in the body so closely connected as the tibia 
 and fibula are, which are so seldom anchylosed, (z. c.) joined 
 into one by disease. 
 
 The fibula may be thus defined : it is a Iqng slender bone, 
 which answers to the double bone of the fore-arm, completes 
 the form, and adds somewhat to the strength of the leg ; it 
 gives a broader origin for its strong muscles, lies by the side of 
 the tibia like a splint; and, being a little arched towards the 
 tibia, supports it against those accidents which would break it 
 across, and maintains the foi’m of the leg when the tibia is ca- 
 rious or broken; the fibula, though it has little connection 
 with the knee, passes beyond the ankle-joint, and is its chief 
 guard and strength in that direction in which the joint should 
 be most apt to yield ; and in this ofiice of guarding the ankle, 
 it is so true, that the ankle cannot yield till this guard of the 
 fibula be broken. 
 
 Rotula or PATELLA, OP KNEE-PAN, is a Small thick bone, of 
 an oval, or rather triangular form. The basis of this rounded 
 triangle is tui’ned upwards to receive the four great muscles 
 which extend the leg ; the pointed part of this triangle is turned 
 downwards, and is tied by a very strong ligament to the bump 
 or tubercle of the tibia, just under the knee. The convex 
 surface is rough, the concave smooth, and divided by a ridge 
 into two equal parts : round the margin of the bone there is a 
 slight depression for the attachment of the capsular ligament. 
 This ligament is called the ligament of the patella, or of the 
 tibia, connecting the patella so closely, that some anatomist? 
 of the first name, choose to speak of the patella as a mere 
 
 VOL. r. O 
 
106 
 
 BONES OF THE 
 
 process of the tibia, (as the olecranon is a process of the ulna,) 
 only flexible and loose ; an arrangement which I think so far 
 right and useful, as the fractures of the olecranum and of the 
 patella are so much alike, especially in the method of cure, 
 that they may be spoken of as one case ; for these two are the 
 only exceptions to the common rules and methods of setting 
 broken bones. 
 
 The patella is manifestly useful, chiefly as a lever; fcr it is 
 a pulley, which is a species of lever, gliding upon the forepart 
 of the thigh-bone, upon the smooth surface which is betwixt 
 the condyles. The projection of this bone upon the knee re- 
 moves the acting force from the centre of motion, so as to 
 increase the power ; and it is beautifully contrived, that while 
 the knee is bent, and the muscles at rest, as in sitting, the pa- 
 tella sinks down, concealed into the hollow of the knee. When 
 the muscles begin to act, the patella begins to rise from this 
 hollow; in proportion as they contract, they lose their 
 strength, but the patella, gradually rising, increases the power; 
 and when the contraction is nearly perfect, the patella has 
 risen to the summit of the knee, so that the rising of the pa- 
 tella raises the mechanical power of the joint in exact propor- 
 tion as the contwiction expends the living contractible power 
 of the muscles. What is curious beyond almost any other fact 
 concerning the fractures of bones, the patella is seldom broken 
 by a fall or blow ; in nine of ten cases, it is rather torn, if we 
 may use the expression, by the force of its own muscles, while 
 it stands upon the top of the knee, so as to rest upon one 
 single point ; for while the knee is half bended, and the patella 
 in this dangerous situation, the leg fixed, and the muscles con- 
 tracting strongly to support the weight of the body, or to raise 
 it as in mounting the steps of a stair, the force of the muscles 
 is equivalent at least to the weight of a man’s body ; and often, 
 by a sudden violent exertion, their power is so much increas- 
 ed, that they snap the patella across, as we would break a stick 
 across the knee. 
 
 The TARSUS, or instep, is composed of seven large bones, 
 which form a firm and elastic arch for supporting the body ; 
 which arch has its strength from the strong ligaments with 
 which these bones are joined, and its elasticity from the small 
 movements of these bones with each other; for each bone and 
 each joint has its cartilage, its capsule or bag, its lubricating 
 fluid, and all the apparatus of a regular joint; each moves since 
 the cartdages are always lubricated, and the bones are never 
 joined by anchylosis with each other ; but the efieCt is rather 
 a diffused elasticity than a marked and perceptible motion in 
 any one joint. 
 
THIGH, LEG, AND FOOT. 
 
 107 
 
 The seven bones of which the tarsus is composed are, 1. 
 The ASTKAGALus, ivliich, united with the tibia and fibula, 
 forms the ankle-joint, 2. The os calcis, or heel-bone, 
 which forms the end or back point of that arch upon which 
 the body stands. 3. The os navjculare, or boat-like bone, 
 which joins three smaller bones of the forepart of the tarsus 
 to the astragalus. 4. The os cuboides, which joins the 
 smaller bones of the forepart of the os calcis. The 5th, 6th, 
 and 7th, are the smaller bones making the forepart of the tar- 
 sus: they lie immediately under the place of the shoe-buckle, 
 and are named the three cuneiform bones, from their wedge- 
 like shape ; and it is upon these that the metatarsal bones, 
 forming the next division of the foot, are implanted. 
 
 These bones of the tarsus form, along with the next rank, 
 or metatarsal bones, a double arch ; first from the lowest pointof 
 the heel to the ball of the great toe, is one arch ; the arch of 
 the sole of the foot which supports the body; and again, there 
 is another arch within this, formed among the tarsal bones 
 themselves, one within another, (*. e.) betwixt the astragalus, 
 os calcis, and jiaviculare, through which hole in my drawing 
 there is passed a pencil. It is this second arch which gives a 
 perfect elasticity to the foot, and must prevent the bad effects 
 of leaping, falls, and other shocks, which would have broken 
 a part less curiously adapted to its office. 
 
 1. The ASTRAGALUS is the greatest and most remarkable 
 bone of the tarsus, and which the surgeon is most concerned 
 in knowing. The semi-circular head of this bone forms a cu- 
 rious and perfect pulley The circle of this pulley is large; its 
 cartilage is smooth and lubricated ; it is received deep be- 
 twixt the tibia and fibula, and rolls under the smooth articular 
 surface of the latter, w'hich being suited to this pulley of the as- 
 tragalus, with something of a boat-like shape, is often named 
 the scaphoid cavity of the tibia. 1. We remark in the astra- 
 galus its articulating surface, which is arched, high, smooth, 
 covered with cartilage, lubricated, and in all respects a com- 
 plete joint. Its form is that of a pulley, which, of course ad- 
 mits of but one direct motion, viz. forwards and backwards. 
 2. We observe its sides, which are plain, smooth, and flat, 
 covered with the same cartilage, forming a part of the joint, 
 and closely locked in by the inner and outer ankles, so as to 
 prevent luxations, or awkward motions to either side. 3. We 
 observe two large irregular articulating surfaces backwards, 
 and downwards, by which it is joined to the os calcis. 4. 
 There is on the forepart, or rather the fore end of the astra- 
 galus, a large round head, as regular as the head of the 
 
108 
 
 BONES OP THE 
 
 shoulder-bone by which it' is articulated with the scaphoid 
 bone. 
 
 POINTS OF DEMONSTP-ATION. 
 
 1. Superior surface corresponding with the scaphoid cavity 
 of the tibia. 2. Internal •articulating surface for the nialeolus 
 internus. 3. External articulating surface for the extremity 
 of the fibula. 4 Inferior articulating surface joining with the 
 body of the os calcis. 5. Inferior and lateral surface articu- 
 lating also with a corresponding surface of the os calcis. 6. 
 Deep fossa dividing these two inferior articulating surfaces. 
 7. The ball or anterior articulating surface which enters into 
 the socket of the naviculare. 8. A smooth part which is like 
 a continuation of this last, but which rests upon a cord or 
 tendon which is stretched betwixt the os calcis and navi- 
 /Culare. 9. Furrow for attachment of the capsular ligament. 
 
 2. The os CALCIS is the large irregular bone of the heel ; it is the 
 tip or end of the arch formed by the tarsal or metatarsal bones. 
 There is an irregular surface on the highest part of the pro- 
 jection backwards to which the tendo achilles is inserted. The 
 lo wer and back part of the bone is rough but peculiar in its 
 texture for the attachment of the cartilaginous and cellular sub- 
 stance on which it rests. We next notice an irregular articular 
 surface, or rather two surfaces covered with cartilage, by 
 which this bone is joined with the astragalus. Another articu- 
 lating surface by which it is joined with the os cuboides. A 
 sort of arch downwards, under which the vessels and nerves 
 and the tendons also pass on safely into the sole of the foot, 
 and on this part a depression for the peroneus longus. 
 
 On the upper surface of the bone, and betwixt the surfaces 
 wiiich articulate with the astragalus, there is an irregular rough 
 fossa, which is opposite to a corresponding depression in the 
 astragalus, and which gives attachment to powerful ligaments 
 which unite the bones, and, on the lower and outer part, the 
 sinnuosity. 
 
 We further notice the tubercle whlcb stands internally, and 
 gives attachment to the ligamentum inter os calcem naviculare 
 et astragalum. 
 
 3. The next bone is named os naviculare, or os scaphoi- 
 DF.S, from a fanciful resemblance to a boat. But this is a 
 name of which anatomists have been peculiarly fond, and 
 which they have used vviih very little discretion or reserve : 
 the student will hardly find any such resemblance. That con- 
 cave side w’hici) looks backwards, is pretty deep, and receives 
 the head of the astragalus : that fiat side which looks forwards 
 
THIGH, LEG, AND FOOT. 
 
 109 
 
 has not so deep a socket, but receives the three cuneiform 
 bones upon a surface rather plain and irregular. From the 
 inner and lower part of this bone a tubercle stands out for the 
 attachment of a powerful ligament, already described. 
 
 The cuNEiFOHJi BONES are so named, because they resem- 
 ble wedges, being laid to each other like the stones of an arch. 
 The most simple and proper arrangement is, 1. 2. and 3.; 
 counting from the side of the great toe towards the middle of 
 the foot; but they are commonly named thus : the first cu- 
 neiform bone, on which the great toe stands has its cutting 
 edge turned upwards ; it is much larger than the others, and 
 so is called os cuneiform magnum. The second cuneiform 
 bone, or that which stands in the middle of the three cu- 
 neiform bones, is much smaller, and is therefore named os 
 CUNEIFORM MINIMUM. The third in order, of the cuneiform 
 bones, is named os cuneiform meuium.* These cuneiform 
 bones receive the great toe and the two next to it. The 
 fourth and fifth toes are implanted upon the last bone in the 
 row, the os cuboides. 
 
 Os cuBOiuES. — The os cuboides is named from its cubical 
 figure, and is next to the astragalus in size, greater than the 
 scaphoid bone. The three cuneiform bones are laid regularly 
 by the side of each other ; and this os cuboides is again laid 
 on the outer side of the third cuneiform bone and joins it to 
 the os calcis. Its anterior point is divided into two surfaces 
 for two metatarsal bones. The place and effect of the cuboid 
 bone is very curious; for, as it is jammed in betwixt the third 
 cuneiform bone and the os calcis, it forms a complete arch 
 within an arch, which gives at once a degree of elasticity and 
 of strength which no human contrivance could have equalled. 
 There is first a great arch on which the body rests, and the 
 heel and the great toe are the horns of that bow: and, second- 
 ly, there is a complete circle among the metatarsal bones, 
 leaving an opening betwixt the astragalus and the os calcis. 
 Tbe os cuboides has several irregular depressions on its lower 
 surface, but one particularly marked for the peroneus longus. 
 
 THE TOES. — The last division of the foot consists of three 
 distinct bones ; and as these bones are disposed in rows, they 
 are named the first, second and third phalanges or ranks of the 
 toes. 
 
 * The confusion in these names arises from sometimes counting tlieni by their place, and 
 sometimes reckoning according to their size. It is only in relation to its size that we call 
 one of these bones os cuneiforai medium ; for the os cuneiform medium is not in the middle 
 of the three; it is the middle bone with respect to size; it is the smallest of the cnneiform 
 bones that stand_in the middle betwixt the other two. 
 
110 
 
 BONES OE THE 
 
 The great toe has but two phalanges ; the other toes have 
 three ranks of bones, which have nothing particular, only the 
 joints are round and free, formed by a round head on one bone, 
 and by a pretty deep hollow for receiving it in the one above 
 it ; they are a little flattened on their lower side, or rather they 
 have a flattened groove which lodges the tendons of the last 
 joint of the toes 
 
 Thk sl SAMom BONES are more regularly found about the 
 toes than any where else. They are small bones, like peas, 
 found in tendons, at any point where they suflier much friction ; 
 or rather they are like the seeds of the sesamum, whence their 
 name. They are found chiefly at the roots of the great toe, 
 and of the thumb ; at each of these places we find two small 
 sesamoid bones, one on each side of the ball of the great toe, 
 and one on each side of the ball of the thumb ; but these 
 bones do not enter into the joint; they are within the substance 
 of the tendons ; perhaps, like the patella, they remove the act- 
 ing force from the centre of motion, and so, by acting like pul- 
 leys, they increase the power; perhaps also by lying at the 
 sides of the joint in the tendons of the shorter muscles of the 
 toes, they make a safe gutter for the long tendons to pass in. 
 They are not restricted to the balls of the great toe and thumb, 
 but sometimes are also found under the other toes and fingers, 
 and sometimes behind the condyles of the knee ; or in the 
 peron ci tendons, which run under the sole of the foot. In 
 short, they are so far from being regular bones, that they are 
 found only in adults, and are so often found in irregular places, 
 that they almost seem to be produced by chance, or by the 
 eflect of friction. 
 
 Metatarsus, — The metatarsus, so named from its being 
 placed upon the tarsus, consists of five bone.s, which differ very 
 little from the first bones of the fingers. The metatarsal bones 
 are five in number ; they are rather flattened, especially on 
 their lower sides, where the tendons of the toes lie ; they have 
 a ridge on their upper or arched surface ; they are very large 
 at their ends next the tarsus, where they have broad flat heads, 
 that they may be implanted with great security ; they grow 
 smaller towards the toes, where again they tei’minate, in neat 
 small round heads, which receive the first bones of the toes, 
 and permit of a very free and easy motion, and a greater de- 
 gree of rotation than our dress allow's us to avail ourselves of, 
 the toes being cramped together, in a degree that fixes them 
 all in their places, huddles one above another, and is quite the 
 reverse of that free and strong-like spreading of the toes, which 
 the painter always represents. It should be remarked, that 
 the nearer extremity of the metatarsal bone of the little toe 
 
THIGH, LEG, AND FOOT. 
 
 Ill 
 
 makes a salient angle projecting over the tarsus, in a point 
 which is easily felt outwardly, on the side of the foot. This 
 and all the other marks of the metatarsal bones are chiefly 
 useful as directing us where to cut in am utating these bones ; 
 and the surgeon will save the patient much pain, and himself 
 the shame of a slow and confused operation, by marking the 
 places of the joints. The metatarsal bone of the great toe is 
 the strongest and shortest. The articulating surface of its 
 nearer extremity is larger and deeper; and its anterior articula- 
 ting surface is marked by a ridge which corresponds with the 
 interstice of the sesamoid bones. 
 
 CHAP. VII. 
 
 BONES OF THE SHOULDER, ARM, AND HAND, 
 
 OF THE SCAPULA, OR SHOULDER-BLADE. 
 
 This is the great peculiarity of the superior extremity, that 
 it is connected not directly with the trunk, like the thigh-bone 
 with the haunch, but is hung by a moveable intermediate bone, 
 which not only is not immediately joined to the trunk by liga- 
 ments, nor any other from of connection, but is parted from it 
 by several layers of muscular flesh, so that it lies flat, and 
 glides upon the trunk. 
 
 The SCAPULA is a thin bone, which has originally, like the 
 skull, two tables, and an intermediate diploe ; but by pressure, 
 and the action of its own muscles, it grows gradually thinner, 
 its tables are more and more condensed, till in old age it has 
 become perfectly transparent, and is supported only by its pro- 
 cesses, and by its thicker edges ; for its spine is a ridge of 
 firm and strong bone, which rises very high, and gives a broad 
 origin and support for its muscles. The acromion in which 
 the spine terminates, is a broad and flat process, a sure guard 
 for the joint of the shoulder. The coracoid process is a 
 strong but shorter process, which stands out from the neck of 
 the bone ; and the costa, or borders of the bone, are also 
 rounded, firm, and strong, so that the processes and borders 
 support the flat part of the bone, which is as thin as a sheet of 
 paper, and quite transparent. 
 
112 
 
 BONES OF THE 
 
 There is no part nor process of the scapula which does Hot 
 require to be very carefully marked ; for no accidents are more 
 frequent than luxations of the shoulder; and the various luxa- 
 tions are explained best by studying in the skeleton, and being 
 able to recognize on the living body all the processes and 
 projecting points. 
 
 The FLAT SIDE of the scapula is smooth, somewhat concave, 
 and suited to the convexity of the ribs : it is sometimes ab- 
 surdly called VENTER. The scapula is connected with no bone 
 of the trunk, tied by no ligaments, is merely laid upon the 
 chest, with a large mass of muscular flesh under it, upon which 
 it glides; for there are below it two layers of muscles, by one 
 of which the shoulder-bone is moved upon the scapula, while 
 by the other, the scapula itself is moved upon the ribs. The 
 muscle, lying in the hollow of the scapula, marks it with many 
 smooth hollows, and wave-like risings, which are merely the 
 marks of the origin of its muscles, but which were mistaken 
 even by the great Vesalius for the impressions of the ribs. 
 
 The upper flat surface is like the lower one, but that it is 
 traversed by the spine, which is a very acute and high ridge 
 of bone : it is called the dorsum. Now the spine thus travers- 
 ing the bone from behind forwards, divides its upper surface 
 into two unequal parts, of which the part above the spine is 
 smaller, and that below the spine is larger. Each of these 
 spaces has its name, one supra spinatus, and the other infra 
 spinatus ; and each of them lodges a muscle, named, the one 
 the musculus supra spinatus scapulae, as being above the spine ; 
 ihe other musculus infra spinatus scapulae, as being below the 
 spine. A third muscle is named subscapularis, as lying under 
 ihe shoulder-blade, upon that concave surface which is towards 
 the ribs ; so that the whole scapula is covered with broad flat 
 muscles, whose offices are to move the shoulder-bone in 
 various directions, and which impress the scapula with gentle 
 risings, and hollows on its upper as wel} as on its lower surface. 
 
 The TRIANGULAR form of the scapula must be next observed. 
 The upper line of the triangle is the shortest ; it is named the 
 COSTA or border. This superior costa of the scapula receives 
 those strong and flat muscles that raise the shoulder upwards. 
 On this superior edge is seen the notch, through which a nerve, 
 and sometimes an artery passes. The lower border, which is 
 named the costa inferior, or the lower border of the scapula, 
 receives no muscles ; because it must be quite free, to 
 move and glide as the scapula turns upon its axis, which is, in- 
 deed, its ordinary movement. But it gives rise to two smaller 
 muscles, which, from being a little rounded, are named the 
 
SHOULDER, ARM, Afto HAND. 113 
 
 musculi teretes, which round muscles being implanted into the 
 arm-bone, pull it downwards. 
 
 The long side of the scaphla, w'hich bounds its triangular 
 form backwards, is named the basis of the scapula, as it re- 
 presents the base of the triangle. This line is also like the 
 two borders, a little thicker or swelled out ; and this edge re- 
 ceives many powerful muscles, which lie flat upon the back, 
 and coming to the scapula, in a variety of directions, can turn 
 it upon its axis, sometimes raising, sometimes depressing the 
 scapula ; sometimes drawing it backwards ; and sometimes 
 fixing it in its place, according to the various sets of fibres 
 which are put into action. 
 
 The angles of the scapula are two, the superior more obtuse, 
 and the inferior more acute. From the inferior angle the teres 
 major takes its it origin, and the outer surface of the bone is 
 made smooth by the passage of the latissimus muscle. 
 
 The GLENOID or articulating cavity of the scapula, is on 
 the point or apex of this triangle. The scapula is more strict- 
 ly triangular in a child, for it terminates almost in a point or 
 apex ; and this articulating surface is a separate ossification, 
 and is joined to it in the adult. The scapula towards this point 
 terminates in a flat surface, not more than an inch in diameter, 
 very little hollowed, and scarcely receiving the head of the 
 shoulder-bone, which is rather laid upon it than sunk into it : 
 it is indeed deepened a little by a circular gristle, which tips 
 the edges or lips of this articulating surface, but so little, that 
 it is still very shallow and plain, and luxations of the shoulder 
 are infinitely more frequent than of any other bone. 
 
 This head, or glenoid cavity of the scapula, is planted upon 
 a narrower part, which tends towards a point, but is finished by 
 this flat head ; this narrower part is what is named the neck of 
 the SCAPULA, which no doubt sometimes gives way, and breaks, 
 A rough line bordering the glenoid cavity receives the capsu- 
 lar ligament, or rather the capsule arises from that bordering 
 gristle, which I have said tips this circle. 
 
 The SPINE of the scapula is that high ridge of bone which 
 runs the whole length of its upper surface, and divides it into 
 two spaces for the origin of the supra and infra spinatus mus- 
 cles. It is high, and very sharp, standing up at one place to 
 the height of two inches. It is flattened upon the top, and 
 with edges, which, turning a little towards either side, give 
 rise to two strong fasciae {i. e.) tendinous membranes, which 
 go from the spine, the one upwards to the upper border of the 
 scapula, the other downwards to the lower border : so that by 
 these strong membranes, the scapula is formed into two trian- 
 gular cavities, and the supra and infra spinatus muscles rise not 
 
 VOL. I. P 
 
114 
 
 BONES OP THE 
 
 only from the back of the scapula, and from the sides of its 
 spine, but also from the inner surface of this tense membrane. 
 The spine traverses the whole dorsum, or back of the scapula; 
 it receives the trapezius muscle, that beautiful triangular mus- 
 cle which covers the neck like a tippet, whence it has its 
 name ; and the spine beginning low at the basis of the scapula, 
 where a certain triangular space may be observed, gradually 
 rises as it advances forwards, till it terminates in that high point 
 or promontory which forms the tip of the shoulder, and over- 
 hangs and defends the joint. 
 
 This high point is named the acromion process. It is the 
 continuation and ending of the spine, which at first rises per- 
 pendicularly from the bone, but by a sort of turn or distortion, 
 it lays its flat side towards the head of the shoulder-bone : 
 here it is hollow, to transmit the supra and infra spinati mus- 
 cles. At this place, it is thickened, flat and strong, overhangs 
 and defends the joint, and is not merely a defence, but almost 
 makes a part of the joint itself; for, without this process, the 
 shoulder-bone could not remain a moment in its socket ; every 
 slight accident would displace it. The acromion prevents luxa- 
 tion upwards, and is so far a part of the joints that when it is 
 full under the acromion, the joint is safe ; but when we feel a 
 hollow, so that we can push the points of the fingers under the 
 acromion process, the shoulder is luxated, and the socket 
 empty. The point of the acromion forming the apex of the 
 shoulder, a greater projection of this point, and a fulness of 
 the deltoid muscle which arises from it, is a chief cause, and 
 of course a chief mark of superior strength. 
 
 But there is still another security for the joint ; for there 
 arises from the neck of the scapula, almost from the border 
 of the socket, and its inner side, a thick, short and crooked 
 process, which stands directly forwards, and is very conspi- 
 cuous ; and which, turning forwards with a crooked and sharp 
 point, somewhat like the back of a crow, is thence named the 
 coRACOin PROCESS. This also guards and strengthens the 
 joint ; though it cannot prevent luxations, it makes them less 
 frequent, and most probably when the arm is luxated inwards 
 it is by starting over the point of this defending process. This 
 process has three surfaces for the attachment of muscles. 
 
 Now the glenoid surface, and these two processes, form the 
 cavity for receiving the shoulder-bone. But still, as if nature 
 could not form a joint at once strong and free, this joint, which 
 performs quick, free, and easy motions, is too superficial to be 
 strong. Yet there is this compensation, that the shoulder-joint, 
 w’hich could not resist, if fairly exposed to shocks and falls, be- 
 longs to the scapula, which, sliding easily upon the ribs, yields, 
 
SHOULDER, ARM, AND HAND. 
 
 116 
 
 and so eludes the force. Falls upon the shoulder do not dis- 
 locate the shoulder; that accident almost always happens to us 
 in putting out the hand to save ourselves from falls ; it is lux- 
 ated by a twisting of the arm, not by the force of a direct 
 blow. 
 
 Thk clavicle. — The clavicle, or collar-bone, named clavi- 
 cle from its resemblance to an old fashioned key, is to the sca- 
 pula a kind of hinge or axis on which it moves and rolls; so 
 that the free motion of the shoulder is made still freer by the 
 manner of its connection with the breast. 
 
 The clavicle is placed at the root of the neck, and at the 
 upper part of the breast ; it extends across from the tip of the 
 shoulder to the upper part of the sternum ; it is a round bone, 
 a little flattened towards the end which joins the scapula; it is 
 curved like an Italic/ having one curve turned out towards 
 the breast ; it is useful as an arch supporting the shoulders, 
 preventing them from falling forwards upon the breast, and 
 making the hands strong antagonists to each other, which, 
 without this steadying, they could not have been. 
 
 The thoracic end, that end next the sternum,, or what may 
 be called the inner head of the clavicle, is round and flat, or 
 bulton-like ; the articulating surface is triangular, and is re- 
 ceived into a suitable hollow on the upper piece of the ster- 
 num. It is not only like other joints surrounded by a capsule 
 or purse ; it is further provided with a small moveable carti- 
 lage, which (like a friction-wheel in machinery) saves the parts, 
 and facilitates the motion, and moves continually as the clavi- 
 cle rolls. From this inner head there stands out an angle, 
 which, when the clavicles are in their places, gives attachment 
 to the interclavicular ligament; it ties them to the sternum 
 and to each other. The lower surface has a groove in it for 
 the subclavius ; the upper surface is marked by several mus- 
 cles. 
 
 But the outer end of the clavicle is flattened as it approach- 
 es the scapula, and the edge of that flatness is turned to the 
 edge of the flattened acromion, so that they touch but in one 
 single point. This outer end of the clavicle, and the correspond- 
 ing point of the acromion, are flattened and covered with a 
 crust of cartilage ; and on the under surface of it, there is a 
 groove corresponding to the groove under the aci’omion ; there 
 is also a small tubercle for a ligament ; but the motion here is 
 very light and quite insensible ; they are tied firmly by strong 
 ligaments; and we may consider this as almost a fixed point; 
 for there is little motion of the scapula upon the clavicle ; but 
 there is much motion of the clavicle upon the breast ; for the 
 clavicle serves as a shaft or axis, firmly tied to the scapula, up- 
 
116 
 
 BONES OF THE 
 
 on which the scapula moves and turns, being connected with 
 the trunk only by this single point, viz. the articulation of the 
 clavicle with the breast-bone. 
 
 The os HUMERI is one of the truest of the cylindrical bones j 
 it is round in the middle ; but it appears twisted and flattened 
 towards the lower end ; and this flatness makes the elbow-joint 
 a mere hinge, moving only in one direction. It is again regu- 
 lar and round towards the upper end, dilating into a large 
 round head, where the roundness forms a very free and move- 
 able joint, turning easily in all directions. 
 
 The HEAD of this bone is very large j it is a neat and regular 
 circle ; but it is a very small portion of a large circle, so that 
 it is flat ; and this flatness of the head, with the shallowness 
 of its glenoid cavity, makes it a very weak joint, easily dis- 
 placed, and nothing equal to the hip-joint for security and 
 strength. 
 
 The NECK of this bone cannot fairly be reckoned such ; for, 
 as I have explained in speaking of the neck of the thigh-bone, 
 this neck of the humerus, and the necks of most bones (the 
 thigh-bone still excepted) are merely a rough line close upon 
 the head of the bone, without any straightening or intermedi- 
 ate narrowness, which we can properly call a neck. The 
 roughness round the head of the shoulder-bone is the line into 
 which the capsular ligament is implanted. 
 
 The TUBEROSITIES of the os humeri are two small bumps 
 of unequal size, (the one called the greater, the other the 
 smaller tuberosity of the os humeri,) which stand up at the 
 upper end of the bone, just behind the head : they are not 
 very remarkable. Though infinitely smaller than the tro- 
 chanter of the thigh-bones, they serve similar uses, viz. re- 
 ceiving the great muscles which move the limb. The great- 
 er TUBEROSITY is higher towards the outer side of the arm, 
 and receives the supra spinatus muscle; while the infra spinatus 
 and teres minor muscles, which come from the lower part of 
 the scapula, are implanted into the bone a little lower. The 
 LESSER TUBEROSITY bas also a great muscle fixed into it, viz. 
 the subscapularis muscle. 
 
 The two tuberosities form betwixt them a groove, which is 
 pretty deep ; and in it the long tendon of the biceps muscle of 
 the arm runs : and as it runs continually, like a rope in the 
 groove of a pulley, this groove is covered in the fresh bones 
 wit!) a thin cartilage, smooth, and like the cartilages of joints. 
 On the outside of this groove there is a ridge for the pectora- 
 lis, on the inside one for the latissimus. On the body of the 
 bone, about one- third part of its length from the head, there is 
 an irregularity for the attachment of the deltoid muscle ; and 
 
SHOULDER, ARM, AND HAND. Il7 
 
 on the inside of the bone, near its middle, is the hole for the 
 nutritious artery. 
 
 The os humeri at its lower part changes its form, is flattened 
 and compressed below, and is spread, out into a great breadth 
 of two inches or more ; where there is formed on each side a 
 sharp projecting point, (named condyle,) for the origin of 
 great muscles; and in the middle, betwixt the two condyles, 
 there is a grooved articulating surface, which forms the hinge 
 of the elbow. At the lower extremity the bone is somewhat 
 twisted. 
 
 At the lower end of the bone, there are two ridges, one lead- 
 to either condyle, which it is of some consequence to observe ; 
 fo t':e elbow-joint is a mere hinge, the most strictly so of any 
 jfii in the body: it has, of course, but two motions, viz. 
 fl( ion and extension; and it has two muscles chiefly, one for 
 extending, ttie otlier for bending the arm, : the flexor muscle 
 lie;, on liie forepart, and the extensor on the back part of the 
 ar.ii ; and so the whole thickness of the arm is composed at 
 this place of these two muscles and of the bone : but that the 
 fore and back parts of the arm might be thoroughly divided, 
 the bone is flattened betwixt them ; and that the division 
 might extend beyond the mere edges of the bone, there are 
 two fascicE or tendinous webs which go oflf from either edge of 
 the humerus, and which continue to divide the fore from the 
 back muscles, giving these muscles a broader origin ; they are 
 named, from their office, intermuscular membranes ; and this 
 is the meaning of the two ridges which lead to the two con- 
 dyles. 
 
 The two projections in which these edges end, are named 
 CONDYLCS. The condyles of the thigh-bone are the broad 
 articulating surfaces by which that bone is joined with the 
 tibia, while the condyles of the shoulder-bone are merely two 
 sharp projecting points for the origin of muscles, which stand 
 out from either side of the joint, hut which have no connection 
 with the joint. The chief use of the condyles of the shoulder- 
 hone is to give a favourable origin, and longer fulcrum, for the 
 muscles of the fore-arm, which arise from these points. The 
 outer tubercle being the smaller one, gives origin to the exten- 
 sor muscles, where less strength is required. But the inner 
 tubercle is much longer, to give origin to the flexor muscles 
 with which we grasp, which require a bolder and more pro- 
 minent process to arise from ; for greater power is needed to 
 perform such strong actions as grasping, bending, pulling; 
 while the muscles which extend the fingers need no more 
 power than just to antagonize or oppose the flexors ; their on- 
 
118 
 
 BONES OP THE 
 
 Jy business being to unfold or open the hand, when we are to 
 renew the grasp. 
 
 It is further curious to observe, that the inner tubercle is 
 also lower than the other, so that the articulating surface for 
 the elbow-joint is oblique, which makes the hand fall naturally 
 towards the face and breast, so that by being folded merely 
 without any turning of the os humeri, the hands are laid across. 
 
 The articulating surface wliich stands betwixt these condyles 
 forms a more strict and limited hinge than can be easily con- 
 ceived, before we explain the other parts of the joint. The 
 joint consists of two surfaces ; first a smooth surface, upon 
 which the ulna moves only backwards and forwards ; and 
 secondly, of a small knob upon the inner tubercles, which has 
 a neat round surface, upon which the face or socket belonging 
 to the button-like end of the radius rolls. These two surfaces 
 are called the small head, and the cartilae;inous pulley of the 
 humerus. 
 
 Belonging to the joint, and within its capsular ligament, there 
 are two deep hollows, which receive certain processes of the 
 bones of the fore arm. One deep hollow on the forepart of 
 the humerus, and just above its articulating pulley, receives the 
 liorn-like or coronoid process of the ulna, viz. fossa coronidea ; 
 the other receives the olecranon, or that process of the ulna 
 which forms the point of the elbow, viz. fossa olecranalis. 
 
 IIADIUS AND ULNA, 
 
 The radius and ulna are the two bones of the fore arn). The 
 radius, named from its resemblance to the ray or spoke of a 
 wheel ; the ulna, from its being often used as a measure. The 
 radius belongs more peculiarly to the wrist, being the bone 
 which is chiefly connected with the hand, and which turns 
 along with it in all its rotatory motions : the ulna, again, be- 
 longs more strictly to the elbow-joint, for by it we perform all 
 the actions of bending or extending the arm. 
 
 The ULNA is in general of a triangular or prismatic form, 
 like the tibia, and the elbow is formed by the ulna alone ; for 
 there is a very deep notch or hinge-like surface, which seems 
 as if it had been moulded upon the lower end of the humerus, 
 embraces it very closely, and takes so sure a hold upon the 
 humerus, that it allows not the smallest degree of lateral mo- 
 tion, and almost keeps its place in the dry skeleton : without 
 the help of ligaments or muscles, it presents, in profile, some- 
 what of the shape of the letter S, and therefore is named the 
 sioMoin CAvjTv of the ulna. But this sigmoid cavity were a 
 
SHOULDER, ARM, AND HAND. 1 
 
 very imperfect hinge without the two processes by which it is 
 guarded before and behind ; the chief of these is the olecra- 
 non, or large bump, which forms the extreme point upon which 
 we rest the elbow. It is a big and strong process, which, 
 checking into a deep hollow on the back of the humerus, serves 
 tw’o curious purposes ; it serves as a long lever for the muscles 
 which extend or make straight the fore arm ; and when by 
 the arm being extended, it checks into its place, it takes so 
 firm a hold upon the hinge or joint of the os humeri, as to se- 
 cure the joint in pulling, and such other actions as might cause 
 a luxation forwards. The other process which guards the 
 elbow-joint is named the cokonoid process, from its horn or 
 poiiited form ; it stands up perpendicularly from the upper or 
 forepart of the bone ; it forms the forepart of the sigmoid 
 cavity, and completes the hinge. On the root of the coronoid 
 pi’ocess there is a rough tubercle for the attachment of the 
 brachialis internus. The coronoid process is useful, like the 
 olecranon, in giving a fair hold and larger lever to the muscles, 
 and to secure the joint ; for the arm being extended, as in 
 pulling, the olecranon checks into its place, and prevents luxa- 
 tion forwards ; and the arm again being bent, as in striking, 
 pushing or saving ourselves from falls, the coronoid process 
 prevents luxation backwards; so the joint consists of the olecra- 
 non and the coronoid process as the two guard.s, and of the 
 sigmoid cavity or hollow of articulation betwixt them ; but the 
 smaller or upper head of the radius also enters into the joint, 
 and lying upon the inner side of the coronoid process, it makes 
 a small hollow there, in which it rolls; and this second hollow, 
 touching the edge of the sigmoid cavity, forms a double sig- 
 moid cavity, of which the first, or greater sigmoid cavity, is 
 for receiving the lower end of the humerus ; and the second, 
 or lesser sigmoio cavity, for receiving the upper head of the 
 radius. Betwixt these there is a pit for receiving the glandu- 
 lar apparatus of the joint. The form of the bone being pris- 
 matic or triangular, it has, like the tibia, three ridges, one of 
 which is turned towards a corresponding ridge in the radius, 
 and betwixt them the interosseous ligament is stretched ; and 
 this interosseous ligament fills all the arch or open space be- 
 twixt the radius and ulna, and saves the necessity of much 
 bone; gives as firm an origin to the muscles as bone could 
 have done, and binds the bones of the fore arm together so 
 strongly, that though the ulna belongs^entirely to the elbow- 
 oint, and the radius as entirely to the wrist, they have never 
 been known to depart from each other. On the outside of the 
 greater extremity of the ulna, there is a triangular surface for 
 the attachment of the annconeus muscle. The ulna, bigger 
 
120 
 
 BONES OF THE 
 
 at the elbow, grows gradually smaller downwards, till it termi" 
 nates almost in a point. It ends below in a small round bead, 
 which is named the lowek head ol the ulna, which scarcely 
 enters into the joint of the wrist; but being received into a 
 hollow on the side of the radius, the radius turns upon the 
 lower bead of the ulna, like an axis or spoke. 
 
 Below this little head, the oone ends towards the side of the 
 little linger, in a small rounded point, which is named the 
 STYLOiD PROCESS of the ulna.; it is chiefly useful in giving a 
 strong adhesion to the ligaioent which secures the wrist there. 
 And as the styloid process and the olecranon, the two extremi- 
 ties of the ulna, are e- ^ ' V and distinctly felt, the length of this 
 bone has been used a. a measure, and so it was named cubitus 
 by the ancients, Hud is named ulna by us. 
 
 Raimus. — r.'ic radius is the second bone of the fore arm, 
 has its position exactly reversed with that of the ulna : for the 
 ulna, heiongiog io the elbow, has its greater end upwards; the 
 radius, belonging to the wrist, has its greater end downwards; 
 and while the ulna only bends the arm, the radius carries the 
 wrist with a rotatory motion, and so entire!} belongs to the wrist, 
 that it is called the manubrium manus, as if the handle of the 
 hand. 
 
 The BODY of the radius is larger than that of the ulna. The 
 transverse strength of the arm depends more upon the radius, 
 which has more body and thickness, is more squared, and is 
 arched in some degree so as to stand off* from the ulna, with- 
 out approaching it, or compressing the other parts. The 
 radius lies along the upper edge of the fore arm, next to the 
 thumb, and being, like the ulna, of a prismatic or triangular 
 form, it has one of its angles or edges turned towards the ulna 
 to receive the interosseous ligament. 
 
 The UPPER HEAD of the radius js smaller ; of a round, flat- 
 fish, and button-like shape, and lies so upon the lower end of 
 the humerus, and upon the coronoid process of the ulna, that 
 it is articulated with either bone ; for, 1st, The hollow of its 
 head is directly opposed to the little head of the os humeri ; 
 and, 2dly, The flat side of its button-like head rubs and turns 
 upon the side of the coronoid process, making a socket there, 
 which is called the lesser sigmoid cavity of the ulna. 
 
 Immediately behind the round fiat head, is a narrowness or 
 straightening,called the neck of the radius; round this neck there 
 is a collar or circular ligament, (named the coronoid ligament 
 of the radius,) which keeps the bone securely in its place, 
 turning in this ligamentous band like a spindle in its bush or 
 socket ; for the radius has two motions, first accompanying the 
 ulna in its movements of flexion and extension ; and, secondly, 
 
SHOULDER, ARM, AND HAND. 1^1 
 
 its own peculiar rotation, in which it is not accompanied in 
 return by the ulna ; but the ulna continuing steady, the radius 
 moves, and turns the wrist. 
 
 luinTediately under this neck, and just below the collar of 
 the bone, there is a prominent bump, like a flat button sol- 
 dered upon the side of the bone, which is the point into 
 which the biceps flexor cubiti, or bending muscle of the fore 
 arm is inserted. On the outside of the bone, and near the 
 middle, there is a roughness for the insertion of the pronator. 
 Where the face of the radius is towards the ulna, there is a long 
 sharp spine for the attachment of the interrosseous ligament. 
 
 The upper head is exceedingly small and round, while the 
 LOWER HEAD swells out, broad and flat, to receive the bones 
 of the wrist. There are two greater bones in the wrist, which 
 form a large ball, and this ball is received into the lower end 
 of the radius : the impression which these two bones make 
 there is pretty deep, and somewhat of a boat-like shape ; 
 whence it is called (like the articulating surface of the tibia) 
 the scaphoid cavity of the radius; it is sometimes partially 
 divided by a ridge ; and on the edge of the radius, next to the 
 thumb, the bone ends in a sort of peak or sharper point, which 
 is named, (though with very little meaning,) the styloid pro- 
 cess of the radius. 
 
 So the scaphoid cavity of the radius forms the joint with 
 the wrist; but there is another small cavity, on the side of the 
 radius, near to the little head of the ulna, into which the lesser 
 head of the ulna is received, and this is enclosed in a proper 
 and distinct capsule. The little head of the ulna does not de- 
 scend so low as to have any share in forming the wrist. There 
 are properly two distinct joints ; the great joint of the wrist, 
 moving upon the radius, the other a little joint within this of 
 of the radius, rolling upon the ulna, and carrying the wrist 
 along with it. On the flat extremity of the radius, we find a 
 ridge in the groove ; on each side of this spine the extensor 
 tendons run. The extensors of the thumb also make im- 
 pressions. 
 
 OF THE HAND AND FINGERS. 
 
 The wrist is the most complex part of all the bony system, 
 and is best explained in a general w'ay, by marking the three 
 divisions of the hand, into the carpus, or wrist bones ; the 
 metacarpus, or bones that stand upon the wrist ; and the fin- 
 gers, consisting each of its three joints. 1. The carpus, or 
 wrist, is a congeries of eight small bones, grouped together, 
 mto a veiy narrow space, very firml'v tied together, by cross 
 VOL. I. Q 
 
122 
 
 BONES OF THE 
 
 ligaments, making a sort of ball or nuclseus, a solid foundation, 
 or centre for the rest of the hand. 2. The metacarpus is 
 formed of five long bones, founded upon the carpal bones, 
 and which, departing from that centre in somewhat of a radia- 
 ted form, give, by their size and strength, a firm support to 
 each individual finger, and by their radiated or spoke-like, form 
 allow the fingers freer play. 3. The fingers, consisting each 
 of three very moveable joints, are set free upon the metacar- 
 pus, so as to show a curious gradation of moving in all these 
 parts ; for the carpal bones are grouped together into a small 
 nuclaeus, firm, almost immoveable, and like the nave of a wheel ; 
 then the metacarpal bones founded upon this are placed like 
 f the spokes or fellies of the wheel, and having a freer motion j 
 and, lastly, the fingers by the advantage of this radiated form, 
 ill the bones upon which they are placed move very nimbly, 
 and have a rotatory as well as a hinge-like motion ; so that the 
 motion is graduated and proportioned in each division of the 
 hand ; and even where there is no motion, as in the carpus, 
 there is an elasticity, which, by gentle bendings, accommodates 
 itself to the more moveable parts. 
 
 The CARPUS, or wrist. — Looking upon the external surface 
 of the carpus, we count eight small bones disposed in two rows, 
 with one bone only a little removed from its rank ; and we ob- 
 serve that the whole is arched outwards to resist injuries, and 
 to give strength ; and that the bones lie like a pavement, or 
 like the stones of an arch, with their broader ends turned out- 
 wards. On the internal surface, again, we find the number of 
 bones not so easily counted ; for their smaller ends are turned 
 towards the palm of the hand, which being a concave surface, 
 the narrow ends of the wedges are seen huddled together in a 
 less regular form, crowded, and lapped over each other 5 but 
 in this hollow, the four corner bones are more remarkable, pro- 
 jecting towards the palm of the hand, so as to be named pro- 
 cesses : ^and they do indeed perform the office of processes; 
 for there arises from the four corner points a strong cross liga- 
 ment, which binds the tendons down, and makes under it a 
 floor or gutter for them to run in. 
 
 The individual bones of the carpus are small, cornered, and 
 very irregular bones, so that their names do but very poorly 
 represent their form. To describe them without some help 
 of drawing, or demonstration, is so very absurd, that a desci’ip- 
 tion of each of them seems more like a riddle, than like a 
 serious lesson : it cannot be understood, and indeed it need 
 hardly be remembered ; for all that is useful, is but to remem- 
 ber the connection and place, and the particular uses of each 
 bone ; in reading of which, the student should continually re- 
 
SHOULDER, ARM, AND HAND. 12S 
 
 turn to the plates, or he must have the bones always in his 
 hand. 
 
 1. ROW FORMING THE WRIST : viz. 
 
 OS 3CAPHOIDES, LUNARE, CUNEIFORME, MAGNUM, PISIPORMK. 
 
 Os scAPHOiDES. — The boat-like bone. This name of boat- 
 like bone, or boat-like cavity, has been always a favourite 
 name, though a very unmeaning one. The scaphoid bone is 
 not worthy of notice merely from its being the largest, but also 
 as it forms a chief part of the joint of the wrist; for it is this 
 bone which is received into the scaphoid cavity of the radius ; 
 it is a very irregular bone, in which we need remember only 
 these points ; the large round surface covered with cartilage, 
 smooth, and answering to the cavity in the head of the radius ; 
 the hook-like or projecting process, which forms one of the 
 corner points of the carpus, and gives a hold to one corner of 
 the ligament which binds down the tendons of the wrist. 
 There is also a furrow for the capsular ligament ; the concavity 
 -from which this bone takes its name, and by which it is arti- 
 culated with the trapezium and trapezoides, and on its inner 
 surface an oval cavity for the os magnum. 
 
 The os i.uNARE is named from one of its sides being some- 
 what of the shape of a half moon ; it is next in size to the sca- 
 phoid bone, and is equal to it in importance ; for they are 
 joined together, to be articulated with the radius. This bone 
 takes an equal share in the joint with the scaphoid bone ; and 
 together, they form a great ball, fitting the socket of the radius, 
 and of a long form, so that the wrist is a proper hinge. The 
 chief marks of this bone are its greater size, its lunated edge, 
 and its round head forming the ball of the wrist-joint. These 
 are its surfaces : 
 
 1. The surface of a semilunar shape, and on the radial side, 
 attached to the last bone. 2. The convex surface for articu- 
 lation with the radius. 3. The ulnar surface for articulation 
 with the os cuneiforme. 4. The hollow surface for articulation 
 with the os magnum. 
 
 Tho os CUNEIFORME, Or wcdge-Hke bone, is named rather 
 perhaps from its situation, locked in among the other bones, 
 than strictly from its form. Its side forming the convex of the 
 hand, is broader; its point towards the palm of the hand is 
 narrower : and so far we may say, it is a wedge-like bone ; but 
 it is chiefly so from its situation closely wedged in betwixt tbe 
 lunare and pisiform bones. 
 
 1. We may readily distinguish the surface articulated with 
 
124 
 
 BONES OF THE 
 
 the os lunare. 2, Opposite to this the surface of attachment 
 of the os pisiforrne. 3. The further surface, that is, the side 
 most remote from the fore arm, is interposed betwixt this bone 
 and the end of the ulna. 
 
 The os pisiFOKMK is a small, neat, and round bone, named 
 sometimes orbiculak, or round bone, but oftener pisiform, 
 from its resemblance to a pea. It is placed upon the cuneiform 
 bone, and it stands olf from the rest into the palm of the hand, 
 so as to be the most prominent of all the corner bones ; of 
 course, it forms one of the corner points or pillars of that arch, 
 under which the tendons pass. The pisiform bone is a little 
 out of its rank, is very moveable, and projects so into the 
 palm, as to be felt outwardly, just at the end of the styloid 
 process of the ulna ; it can be easily moved and rolled about, 
 and is the point into which the ligament of the wrist is implan- 
 ted, and the flexor carpi radialis, one of the strong muscles 
 for bending the wrist. 
 
 2. ROW SUPPORTING THIT METACARPAL BONES : viz. OS TRA- 
 PEZIUM, TRAPEZOIDES, MAGNUM ET UNCIFORME. 
 
 The second row begins with the trapezium, a pretty large 
 bone, which, from its name, we should expect to find of a 
 regular square form ; while it has, in fact, the most irregular 
 form of all, especially when detached from the other bones. 
 The chief parts to be remarked in the bone, are the great 
 socket, or rather the trochlea for the thumb : and as the 
 thumb stands off from one side of the hand, this socket is ra- 
 ther on one side. There is also a little process which makes 
 one of the corner points, and stands opposite to the hook of the 
 unciforme. 
 
 Opposite to the surface of articulation with the thumb, and 
 towards the first row', there is a semilunar surface which 
 touches the convexity of the scaphoides, and another which 
 articulates w'ith the trapezoides. The fourth articulating sur- 
 face of this bone is opposed to the head of the metacarpal 
 bone of the finger. 
 
 The TRAPEZOiuES is next to the trapezium, is somewhat 
 like the trapezium, from which it has its name. It also re- 
 sembles the cuneiform bone of the first row in its shape and 
 size, and in its being jammed in betwixt the two adjoining 
 bones. 
 
 It is articulated by its nearer surface to the scaphoides, on 
 its further surface, by two planes, to the metacarpal bone of 
 
SHOULDER, ARM, AND HAND. 12.> 
 
 the fore finger, on the radial surface to the trapezium, and 
 on the ulnar surface to the os magnum, having thus five planes 
 or surfaces. 
 
 The os MAGNUM is named from its great size ; not that it is 
 the largest of all, nor even the largest bone of the second row, 
 for the unciforme bone is as big ; but there is no other circum- 
 stance by which it is well distinguished. It is placed in the 
 centre of the upper row, has a long round head, which is 
 jointed with the socket formed of the os lunare and scaphoides: 
 on the radial surface the magnum is articulated with the tra- 
 pezoides; on the ulnar surface with the unciforme; on the 
 further surface it has three planes, and receives the whole head 
 of the metacarpal of the middle finger, and part of the meta- 
 carpal of the fore finger and of the ring finger. 
 
 The os UNCIFORME, or hook-like bone, is named from a 
 flat hook-like process, which projects towards the palm of the 
 hand. This is one of the corner bones, and standing in the 
 end of the row, it is wedged betwixt the os magnum of its own 
 row, and the os lunare and cuneiforme of the first row. It is 
 large and squared ; but the thing chiefly remarkable is that 
 process from which it takes its name ; a long and flat process 
 of firm bone, unciforme, or hook-like, and projecting far into 
 the palm of the hand, which being the last and highest of the 
 corner points, gives a very firm origin to the great ligament 
 by which the tendons of the wrist are bound down. On its 
 further surface, it has two articulating surfaces corresponding 
 with the metacarpal bones of the ring and middle fingers. 
 
 All these bones of the carpus, when thy are joined to each 
 other, ai’e covered with a smooth articulating cartilage, are 
 bound to each other by all forms of cross ligaments, and are 
 consolidated, as it were, into one great joint. They are in 
 general so firm as to be scaicely liable to luxation ; and al- 
 though one only is called cuneiform, they are all somewhat of 
 the wedge-like form, with their broader ends outwai’ds, and 
 their smaller ends turned towards the palm of the hand ; they 
 are like stones in an arch, so that no weight nor force can 
 beat them in ; if any force do prevail, it can beat others in 
 only by forcing one out. A bone starting outwards, and pro- 
 jecting upon the back of the hand, is the only form of luxation 
 among these bones, and is extremely rare. 
 
 METACARPUS. — The metacarpus is composed of four 
 bones, upon which the fingers are founded. They are big, 
 strong bones, brought close together at the root, but wider 
 above ; for the lower beads are small and flat, and grouped 
 very closely together, to meet the carpal bones. But they 
 
126 
 
 BONES OF THE 
 
 swell out at their upper ends into big round heads, which keep 
 the bones much apart from each other. Nothing of impor- 
 tance can be said concerning the individual bones. To speak 
 of them individually is a mere waste of time. We may observe 
 of the metacarpal bones in genera! ; 1. That their nearer 
 
 heads, being flat and squared, gives them a firm implantation 
 upon their centre or nuclaius, the carpus; and they have scarce- 
 ly any freer motion upon the carpal bones, than the carpal 
 bones have upon each other. 2. Their further heads are 
 broader, whereby the articulating parts of the bone are kept 
 apart, which gives freedom to the lateral motions of the bones 
 of tile fingers. 3. Each metacarpal bone is slightly bent ; 4. 
 and being smaller in the middle, there is a space left betwixt 
 the bones for the lodgement of the interossii muscles. 5. 
 These bones taken collectively still preserve the arched form 
 of the carpal bones, being, with the carpal bones, convex 
 outwardly, and concave inwardly, to form the hollow of the 
 hand; and though they have little motion of flexion or exten- 
 sion, they bend towards a centre, so as to approach each other, 
 increasing the hollowness of the hand, to form what is called 
 Diogenes’s cup. 6. The articulating heads of the further ex- 
 tremities of these bones are flattened, or somewhat grooved, 
 for the play of the tendons of the interossii muscles. It is far- 
 ther necessary to observe, into how small a space the carpal 
 bones are compressed, how great a share of the hand the me- 
 tacarpal bones form, and how far down they go into the hol- 
 low of the hand. For I have seen a surgeon, who, not having 
 the smallest suspicion that their lower ends were so near the 
 wrist as they really are, has, in place of cutting the bone neat- 
 ly in its articulation with the carpus, broken it, or tried to cut 
 it across in the middle. 
 
 FINGERS. — We commonly say that there are five meta- 
 carpal bones ; in which reckoning we count the thumb with 
 the rest : but what is called the metacarpal of the thumb is 
 properly the first phalanx, or the first proper bone of the thumb, 
 so that the thumb, regularly described, has, like the other fin- 
 gers, three joints. 
 
 Thumb. — The first bone of the thumb resembles the meta- 
 carpal bones in size and strength, hut it differs widely in being 
 set upon the carpus, with a large and round head ; in being 
 set off from the line of the other fingers, standing out on one 
 side, and directly opposed to them, it rolls widely and freely : 
 it is opposed to the other fingers in grasping, and, from its 
 very superior strength, the thumb is named pollex, from pol- 
 lere. 
 
SHOULDER, ARM, AND HAND. 
 
 127 
 
 The FINGERS have each of them three bones : — 1. The 
 first bone is articulated with the metacarpal bones by a ball 
 and socket ; the socket, or hollow on the lower part of the 
 first finder-bone, being set down upon the large round head of 
 the metacarpal bone. 2. The second and third joints of the 
 fingers are gradually smaller, and though their forms do a good 
 deal resemble the first joint ; they are quite limited in their 
 motions ; haveno rolling; are as strictly hinge-joints as the knee 
 is. 3. Here, as in other hinge-joints, the capsule is so particu- 
 larly strong at the sides, as to be named lateral ligaments. 
 When these lateral ligaments are burst or cut, the finger turns 
 in any direction ; so that the motions of the fingers are limited 
 rather by their lateral ligaments, than by any thing peculiar 
 in the forms of the bones. 4. The face of each finger-bone 
 is grooved, so that the tendons, passing in the palm of the 
 hand run upwards along this groove or flatness of the fingers ; 
 and from either edge of this flatness there rises a ligament of 
 a bridge-like form which covers the tendons like a sheath, 
 and converts the groove into a complete canal. 5. The last 
 joint or phalanx of each finger is flattened, rough, and drawn 
 smaller gradually towards the point of the finger ; and it is to 
 this roughness that the skin and nail adhere at the point. 
 
 OF THE TEETH.* 
 
 The structure, and growth, and decay of the teeth, forms 
 a subject of considerable interest, as it gives principles to 
 guide the operations of the dentist, and chiefly as it afibrds 
 some very remarkable phenomena illustrative of the animal 
 economy. 
 
 Considering the teeth generally, as belonging to man and 
 brutes, they are for masticating the food ; they are for retain- 
 ing the prey ; they are weapons of defence ; in some classes 
 they are for digging and searching for food ; and in some ani- 
 mals we can see no other use than for defending the eyes, as 
 in the sus aethiopica. Nor are we to consider them as exclu- 
 sively belonging to the jaws, for they are sometimes seated in 
 the back part of the mouth ; and in fishes, we find them in the 
 beginning of the oesophagus, or at its termination, as in the 
 vrab and lobster. 
 
 By diaries Bell. 
 
m 
 
 OF THE TEETH. 
 
 The teeth difler from common bone : they are harder ; they 
 are covered with a peculiar substance, the enamel, which is 
 not found elsewhere in the body : though they stand exposed, 
 they do not suffer as bone would do in the same circumstan- 
 ces ; though worn by friction, they are not excited to diseased 
 action ; their mode of formation is peculiar, and so is the man- 
 ner of their decay, and all these instances of their being dif- 
 ferent from common bone, are so many reasons for instituting 
 a distinct enquiry into their structure. 
 
 DESCRIPTION OF THE HUMAN ADULT TEETH. 
 
 The human adult teeth are divided into four orders. 1, 
 The iNcisoREs. 2. The cuspidati or canini. 3. The bi- 
 
 CUSPIDES. 4. The MOLARES Or GRINDING TEETH. 
 
 The incisores are four in number in each jaw. Every 
 tooth has three parts ; the crown, neck, and fang or root. 
 The crown of the incisor tooth is a wedge, having its anterior 
 and posterior surface inclined and meeting in a sharp edge. 
 On the forepart the surface is convex ; on the inside the sur- 
 face is concave ; and viewing the tooth laterally, it is broader 
 and flat near the neck, and rising pyramidal towards the cut- 
 ting edge. The cortex or enamel covers the crown of the 
 tooth ; it descends on the back and anterior surface further 
 than on the side. The fangs of the incisores are long and 
 straight, and of a pyramidal form, so that they are deeply 
 socketed in the jaw. 
 
 From their position in the jaw, the upper incisor teeth pro- 
 ject more than the lower, and, in chewing, their edges do not 
 meet. They pass each other so as to cut, and yet do not 
 meet, and this prevents the rapid wasting of the edge which 
 would otherwise take place, as we see in the horse.* 
 
 The incisor teeth of the horse, being subject to attrition, 
 have a provision against this, in the cavity lined with enamel, 
 which is observed in their centre ; nevertheless, we see them 
 worn down even below the bottom of that cavity ; thus the 
 surface of the tooth is smooth, and the horse has lost the 
 maik. 
 
 In some animals, as in the rodentia, the front teeth are still 
 better formed for cutting, but as they suffer attrition, and in or- 
 der to preserve the outer edge sharp, they have a peculiar 
 structure. They are so deeply socketed, that they reach the 
 
 * And as indeed we sonietimcs see hi the human tctdi. See specimens in my Collec- 
 tion. 
 
0P THE TEETH. 
 
 129 
 
 whole length of the jaw, and they are provided with a continual 
 growth from behind, which pushes the tooth out in propor- 
 tion as it is worn away on the forepart. The enamel in these 
 animals is more accumulated on the anterior edge of the tooth, 
 so that the edge stands up fine and sharp. 
 
 The cuspiDATi, or canine teeth, are next in order, count- 
 ing backwards. They are two in number in each jaw. They 
 have a general resemblance to the incisor teeth, for when their 
 points are worn off, they are hardly distinguishable. Their 
 fangs are longer, and being the corner teeth of the jaw, and 
 deep socketed, they form the strength of the front , teeth. 
 Their principal distinction is in the form of the upper part of 
 the crown, which is like a spear, having a point with two lateral 
 shoulders. 
 
 In the larger carnivorous mammalia, this order of teeth are 
 of terrific length, whilst the front teeth are small and carved. 
 The spiral tusk of the narwhal and the tusks of the walrus be- 
 long to this division of the teeth : so does the tusk of the barbi- 
 roassa, which project in a spiral direction. The use of these 
 teeth Blumenbach cannot comprehend, but Sir Everard Home 
 conceives, that they are provided to defend the eyes of the 
 animal as it rushes through the underwood. There is a small 
 imperfect tooth, called the tush, in a horse, which belongs to 
 this order of teeth, as it is placed betwixt the incisors and the 
 grinding teeth. 
 
 The BicuspiDES are four in each jaw : they stand betwixt 
 the canine teeth and the grinding teeth, and in form are in- 
 termediate betwixt these two orders. They are sometimes 
 called the lesser molares, being in truth grinding teeth. The 
 crown of the bicuspis rises in two sharp points, so that they are 
 like two cuspidati incorporated, and their fangs prove this to 
 be the case ; for whilst they are always flatter and shorter than 
 those of the cuspidati, they have often a division, and some- 
 times there are distinctly two fangs ; their roots are oftener 
 curved than those of the other teeth. The second bicuspis is 
 sometimes wanting. 
 
 Molares or grinding teeth, are six in each jaw. The 
 form of the crown is an oblong square. They have four or 
 more projections on their upper surface, and they are covered 
 with enamel to a uniform level. The lower grinders have two 
 broad fangs, and those of the upper jaw three. 
 
 The molares are best considered as cuspidati united, in 
 which idea four cuspidati are incorporated to form one grinder. 
 The projections on the grinding surface correspond with the 
 points of the cuspidati, and the fangs correspond with the pro- 
 jections of the cro^vn ; for although there are only two or three 
 
 VOL. I. R 
 
130 
 
 OF THE TEETH. 
 
 roots to each grinding tooth, yet we may discover that there 
 would be always four fangs if they were disjoined. 
 
 The term grinder is not good in comparative anatomy, for 
 in brutes of prey they are compressed, and terminate in three 
 sharp processes, and these in the closing of the jaw intersect 
 each other like the blades of scissars. 
 
 These four orders make the full number of thirty-two in the 
 adult jaws. 
 
 OP THE FIRST SET OF THE TEETH, THE MILK OR DECIDUOUS 
 
 TEETH. 
 
 The first set of teeth are twenty in number : these are divi- 
 ded into three classes; the incisures, four in each jaw ; the 
 cuspiDATi, two in each jaw ; and the molares, four in number 
 in each jaw. 
 
 The teeth of a child generally appear in this order : first 
 the central incisores of the lower jaw pierce the gum. In a 
 month after, perhaps, their counterparts appear in the upper 
 jaw. These in a few weeks are succeeded by the lateral in- 
 cisores of the lower jaw ; then the lateral incisores of the up- 
 per jaw, though sometimes the lateral incisores of the upper 
 jaw appear before those of the lower jaw. Tlie growth of the 
 teeth is not after this in a regular progression backwards ; for 
 now, instead of the cuspidati, which are immediately lateral to 
 the incisores, the anterior molares of the lower jaw show their 
 white surface above the gum about the fourteenth or fifteenth 
 month. Then the cuspidati pierce the gum ; and lastly, the 
 larger molares make their appearance, the teeth of the low'er 
 jaw preceding those above. The last tooth does not rise till 
 the beginning of the third year. 
 
 The teeth do not always cut the gum in this order ; but it 
 is the more regular and common order. When the teeth ap- 
 pear in irregular succession, more irritation and pain, and more 
 of those symptoms which are usually attributed to teething, 
 are said to accompany them. 
 
 The deciduous set of teeth terminates with the rising of the 
 second molaris ; for the third molaris being formed about the 
 eighth year, when the jaw is advanced towards its perfect form, 
 is not shed, but is truly the first permanent tooth. The mo- 
 lares of the adult are properly the permanent teeth (immuta- 
 BiLEs), for they alone arise in this part of the jaw, and remain 
 in their original places; yet we must recollect that, in oppo- 
 sition to Albinus, in this arrangement, it is more common to 
 speak of the whole set of the adult teeth as the immutabiles. 
 
OF THE TEETH. 
 
 131 
 
 In the sixth and seventh years the jaws have so much en- 
 larged, that the first set of teeth seems too small, spaces are 
 left betwixt them, and they begin to fall out, giving place to 
 the adult teeth. But the shedding of the teeth is by no means 
 regular in regard to time; the child is already no longer in a 
 stale of nature, and a thousand circumstances have secretly 
 alfected the health and growth. The teeth even fall out 
 three years earlier in one child, than in another: nay, so fre- 
 quently are some of them retained altogether, that it would 
 appear necessary to be'assured of the forward state of the adult 
 tooth before the tooth of the first set should be thoughtlessly 
 drawn. 
 
 The jaw-bones are still so small, that the second set of teeth 
 must rise slowly and in succession, else they would be crowd- 
 ed into too small a circle, and of course turned from their 
 proper direction. 
 
 The in'dsores of the under jaw are loose commonly when 
 the anterior of the permanent molares are thrusting up the 
 gum. The permanent central incisores soon after appear, 
 and in tw'o or three months more those of the upper jaw ap- 
 pear. In three or four months the lateral incisores of the 
 lower jaw are loose, and the permanent teeth appear at the 
 same time with the anterior molares. The lateral incisores of 
 the upper jaw follow next ; and in from six to twelve months 
 more, the temporary molares loosen, the long fangs of the cus- 
 pidati retaining their hold some time longer. 
 
 The anterior molaris and the cuspidati falling, are succeeded 
 about the ninth year by the second of the bicuspides and the 
 cuspidati. The posterior of the bicuspides take place of the 
 anterior molares about the tenth or eleventh year ; the second 
 permanent molaris does not appear for five or six years from 
 the commencement of the appearance of the permanent teeth. 
 The jaw acquires its full proportion about the age of eighteen 
 or twenty, when the third molaris, or the dens sapientire, makes 
 its appearance. This tooth is shorter and smaller, and is in- 
 ' dined more inward than the others. Its fangs are less regular 
 , and distinct, being often squeezed together. From the cus- 
 pidati to the last grinder, the fangs are becoming much shorter, 
 and from the first incisor to the last grinder, the teeth stand 
 less out from the sockets and gums. 
 
 OF THE STRUCTURE OF THE TEETH. 
 
 A tooth consists of these parts : — The enamel, a peculiarly 
 hard layer of matter composing the surface of the body of the 
 
132 
 
 0F THE TEETH. 
 
 tooth. The internal part, or inner substance of the tooth, is 
 less stony and hard than the enamel, but of a firmer structure 
 and more compact than common bone. In regard to the form 
 of the tooth, we may observe, that it is divided into the crown, 
 the neck, and the fangs, or roots of the tooth, which go deep 
 into the jaw. There is a cavity in the body of the tooth, and 
 the tube of the fangs communicates with it. This cavity re- 
 ceives vessels for supplying the remains of that substance upon 
 which the tooth w'as originally formed. The roots of the 
 teeth are received into the jaw by that kind of articulation 
 which was called gomphosis. They are not firmly wedged into 
 the bone, for in consequence of maceration, and the destruc- 
 tion of the soft parts, the teeth drop from the skull. There 
 is betwixt the tooth and its socket in the jaw a common pe- 
 riosteum. 
 
 Of the enamel. The surface of a tooth, that which ap- 
 pears above the gum, is covered with a very dense hard layer 
 of matter, which has been called the enamel.* In this term 
 there is some degree of impropriety, as assimilating an atiimal 
 production with a vitreous'substance, although the enamel very 
 widely difiers from the glassy fracture when broken. This 
 matter bestows the most essential quality of hardness on the 
 teeth ; and when the enamel is broken off, and the body of 
 the tooth exposed, the bony part quickly decays. 
 
 The enamel is the hardest production of the animal body. 
 It strikes fire with steel : in church-yard skulls it is observed to 
 remain undecayed when the centre of the tooth has fallen into 
 dust. It has been found that the component parts of the ena- 
 mel are nearly the same with those of bone. In bone the 
 phosphate of lime is deposited on the membranes, or carti- 
 lage, but this hardening matter of bones is a secretion from 
 the vessels of the part, and is accumulated around the vessels 
 themselves : it is still within the controul of their action, and 
 is suffering the succession of changes peculiar to a living part. 
 In the enamel, the phosphate of lime has been deposited in 
 union with a portion of animal gluten, and has no vascularity, 
 nor does it suffer any change from the influence of the living 
 .system. Although the hardening matter be principally phos- 
 phate of lime, a small proportion of the carbonate of lime 
 enters into the composition both of bone and of enamel. But 
 in enamel, according to Morichini and Gay Lussac, there is 
 Jluat of lime, to which ingredient these chemists attribute the 
 hardness of this crust, f 
 
 * Jn brutes thei'e is a considerable variety in the relative form of the enamel and bone of 
 the tootli. 
 
 ' T By Mr. Hatchetts’s Experiments, (Philos. Transact. 1799,) we learn that bone con- 
 sists of phasphate of lime, with a small propmtion of caibonate of lime. The shell of the 
 
OF THE TEETH 
 
 133 
 
 Although we call the earthy deposite, the hardening matter, 
 yet it is the union of the glutinous matter which bestows the 
 extreme hardness, for, when the tooth is as yet within the jaw, 
 and in an early stage of its formation, the depositation is soft, 
 and its surface rough ; but, by a change of action in the sur- 
 face, which throws out this secretion, the first depositation is 
 penetrated with gelatinous secretion, which, either by this 
 penetration simply, or by causing a new apposition of its parts, 
 (its structure indeed looks like chrystallization,) bestows the 
 density and extreme hardness on this crust. 
 
 When an animal is fed with madder, the colouring matter 
 coming, in the course of the circulation, in contact with the 
 earth of bone, is attracted by it, and is deposited upon it in a 
 beautiful red colour. This colouring matter penetrates more 
 than injection can be made to do in the dead body ; and, as 
 by this process of feeding, the enamel is not tinged, we have 
 a convincing proof that the vascular system has no opei’ation 
 on the enamel after it is formed. 
 
 Id the marmot, beaver, and squirrel, the enamel is of a nut 
 brown colour, on the anterior surface of the incisor teeth. 
 The molares of some of the cloveh-lioofed animals are cover- 
 ed with a black vitreous matter, and sometimes they have a 
 crust of a shining substance like bronze. In the grinding teeth 
 of the granivorous animals, the arrangement of the enamel is 
 quite peculiar. 
 
 From the composition of the enamel, we must be aware of 
 the bad elfect of acidulated washes and powdei’s to the teeth ; 
 they dissolve the surface, and give a deceitful whiteness to 
 the teeth ; they erode the surface, which it is not in the consti- 
 tution of the part to restore. 
 
 OF THE CENTRAL BONY PAKT OF THE TOOTH. 
 
 The chemical composition, and the manner of combination 
 
 crab and lobster consists of phosphate of lime and carbonate of lime, the latter being in the 
 greatest quantity. The testaceous shells comist entirely of carbonate of h’me. The mat- 
 ter of hone and teeth consists of phosphate of lime and a small portion of carbonate deposi- 
 ted in the intei-stice of an animal substance, which is of the nature of cartilage, and proves 
 to be gelatine. The bones of 6sh diflfer from those of man and brutes, in the larger propor- 
 tion of animal substance. These chemichai facts are, however, of little import to the ana- 
 tomist : he is desirous of knowinv what property of life th<“se parts are endowed with; 
 whether they are formed by a final depositation, or are still under the influence of tlie circu- 
 lating vessels, whether they possess a principle of self-preservation independent of vascularity, 
 or are like common dead matter altogether out of the system. 
 
 The formation of bone has been very fully described. The formation of shell is more 
 like that of teeth. The testaceous shell consists of layers ; the layers are formed successive- 
 ly by secretion from the animal body, and each successive la}’er is broader than the prece- 
 ding, answering to the encreased circumference of the animal. Reaumeur broke the shell 
 of a snail, and he found that when he covered the surface of tlie creature and prevented the 
 exudation, no shell was formed. There has been a question agitated regarding the possibi- 
 lity of nutrition, without the intervention of vessels, which b^rs upon this subject, of the 
 nature of shell and teeth. 
 
334 
 
 OF THE TEETH. 
 
 of the matter forming the central part of the tooth, and of the 
 fang=:, is similar to other bones of the body ; but when we 
 examine the hardness and the density of the tooth, and see that 
 it is not even porous, or apparently capable of giving passage 
 to vessels, we conclude that it is not vascular, and are apt to 
 suppose that it holds its connection with the living jaw-bone by 
 some other tenor than that of vessels, or the circulation of the 
 blood through it. The body and fangs of a tooth are cover- 
 ed with a periosteum like other bones. The vascularity of the 
 periosteum, which surrounds the tooth, and the vessels which 
 enter by the fangs to the cavity of the tooth, seem to be a pro- 
 vision for supplying them plentifully with blood ; but on further 
 examination, it will prove to be a means only of fixing the tooth 
 in the socket, and of preserving the sensibility of the nerve in 
 the cavity of the tooth. As the bony part of the tooth has 
 often been coloured by feeding young animals with madder, it 
 might deceive some to suppose that there is blood circulating 
 through the body of the tooth, and that the tooth undergoes 
 the same changes by absorption which the other bones are pro- 
 ved to do. But these experiments may have been made while 
 the teeth were forming by a secretion from the pulp, and of 
 course they might be coloured without the experiment affording 
 a fair proof that the circulation continues in the tooth after it is 
 formed. 
 
 OF THE VASCULARITY AND CONSTITUTION OF THE BONY PART 
 OF THE TOOTH. 
 
 The teeth undergo changes of colour in the living body, to 
 which it would appear they could not be liable as dead mat- 
 ter. They become yellow, transparent, and brittle with old 
 age ; and when a tooth has been knocked from its socket, 
 and replaced, dentists have observed that it loses its whiteness, 
 and assumes a darker hue. 
 
 The absorption of the roots in consequence of the caries of 
 the body of the tooth, and the absorption of the fangs of the 
 deciduous teeth, are further alleged in proof of their vascula- 
 rity ; not only the pressure of the rising tooth on the fangs of 
 the temporary teeth will cause an absorption of the latter, but 
 the fangs of the temporary teeth will waste and be absorbed, so 
 as to drop out without the mechanical pressure of the permanent 
 teeth, and before they have advanced to be in contact with the 
 former. 
 
 The teeth seem acutely sensible ; but a little consideration 
 teaches us that the bard substance of the teeth is not endowed 
 
OF THE TEETH. 
 
 135 
 
 ■with sensibility, and that it must be the remains of the vascular 
 pulp, presently to be described, occupying the centre of tbe 
 tooth, which being supplied with nerves, gives the acute pain 
 in tooth-ache. It is as a medium communicating or abstract- 
 ing heat, that the tooth itself gives pain. When wu’ought upon 
 by the dentist, no sensation is produced unless the tremor be 
 communicated to the centre, or unless the abrading, or cut- 
 ting instruments, be so plied as to heat the tooth then an 
 acute pain is produced from the heat communicated to the 
 centre ; and so ice or extremely cold liquids, talien into the 
 mouth, produce pain, from the cold affecting the pulp through 
 the body of the tooth. 
 
 As living parts, the teeth have adhesion to the periosteum, 
 and are connected with their internal pulp ; but when they 
 spoil, and are eroded, the disease spreads inwardly, probably 
 destroying the life of the bony part of the tooth, tbe progress 
 of which disease is marked by a change of colour penetrating 
 beyond the caries towards the centre of the tooth. When 
 this discolouration has reached the internal surface, the pain 
 of tooth-ache is excited ; the pulp vascular, and supplied with 
 nerves, inflames, from a want of accordance with the altered 
 state of the tooth, just as the dead surface of a bone will in- 
 flame the central periosteum and marrow. The extreme pain 
 produced by this state of the tooth probably proceeds from 
 the delicate and sensible pulp swelling in the confinement of 
 the cavity of the tooth. 
 
 In caries of the teeth, the body of the tooth is discoloured 
 deep in its substance long before the pulp of the central cavity 
 is exposed by the progress of the caries. No exfoliation, or 
 exostosis, takes place upon that part of the tooth which is 
 above the gum, which may be owing to the mere compactness 
 of the ossific depositions. 
 
 In the further consideration of this subject, there are circum- 
 stances which will make us conclude that there is no vascular 
 action in the teeth, and incline us to believe that they possess a 
 low degree oflife, independent of vascular action. Supposing the 
 bony part of the tooth to be vascular, and to possess the princi- 
 ple of life, is not the firm adhesion and contact of the enamel 
 to the body of the tooth a curious instance of a part destitute of 
 life adhering to the surface of a living part without producing 
 the cornmon effects of excitement and exfoliation, or inflam- 
 mation in the latter 
 
 In rickets, and molities ossium, and other diseases of debility 
 in which the bone wastes, or the growth is retarded, the grown 
 teeth are not altered in their form or properties. The effects 
 which we perceive in the beny system under these diseases, 
 
136 
 
 OF THE TEETH. 
 
 are produced by the activity of the absorbents prevailing over 
 the action of the red vessels; while in the teeth no such effect 
 can take place, if they are formed by a deposition of bony mat- 
 ter which is not re-absorbed, nor subject to the revolution of 
 deposition and re-absorption, which takes place in other parts 
 of the body. Accordingly, we find in rickets, where the hard- 
 est bone yields, where the jaw-bone itself is distorted or alter- 
 ed in its form, that the teeth remain distinguished for their size 
 and beauty. In molities ossium, I have fdhnd the teeth loose, 
 but hard in their substance. In rickets the teeth are large, and 
 perfectly formed, while the jaws are stinted and interrupted in 
 their growth. The consequence of this is, that the teeth form 
 a larger range than the jaw, and give a characteristic protube- 
 rance to the mouth. 
 
 I must here observe, however, that if a child is in bad health 
 during the formation of the teeth, they are often deficient in 
 form, or in the crust of enamel which covers them, instances of 
 which my reader may see in my Collection. 
 
 When an adult tooth of one jaw is lost, there appears to be 
 a growth of the tooth of the opposite jaw ; but I believe the 
 tooth only projects from its socket a little further, in conse- 
 quence of the want of that pressure to which it is naturally ac- 
 commodated. The teeth of the are wasted by attri- 
 
 tion and seem to grow. This is indeed a growth, but it is of 
 the nature of the first formation of the tooth proceeding from 
 the pulp.* 
 
 Much has been said of balls being found in elephants’ teeth, 
 as they are found in bones, the bony matter accumulated 
 around the ball, a proof of the inflammation of the tooth, and 
 of course of its vascularity. The specimens in the collections 
 of Haller, Blumenbach and Monro, are quoted. I possess a 
 great variety of these specimens, of both iron and leaden balls 
 immersed in the ivory of the elephant’s tusk, but they prove 
 that the pulp continuing to secrete bony matter, has envelop- 
 ed the ball after it has pierced the shell of the tooth. 
 
 The roots of the teeth are sometimes found enlarged, dis- 
 torted, or with exostosis formed upon them. Again the ca- 
 vity of the tooth is found filled up with what appears to be new 
 matter, or around the fangs we often find a small sac of pus, 
 which is drawn out in extracting the tooth. Nevertheless, in 
 these examples of disease, there are no unequivocal marks of 
 vascular action in the tooth; the unusual form, or exostosis of 
 the routs, is produced by an original defect in the formation. 
 The filling up of the cavity of the tooth is caused in the same 
 
 * Pee the ingenious Inaugural Dissertation of Dr. Blake. 
 
OP THE TEETH. 
 
 137 
 
 way, or by the resumed ossific action of the pulp, in conse- 
 quence of the disease and destruction of the body of the tooth ; 
 and the abscesses which surround the fangs are caused by the 
 death of the tooth, in consequence of which it has lost its 
 sympathy with the surrounding living parts, and becomes a 
 source of irritation like any other foreign body. 
 
 The transplanting of teeth presents another very interest- 
 ing phenomenon. A tooth recently drawn, and placed accu- 
 rately into a socket from which one has been taken, will ad- 
 here there : nay, it will even adhere to any living part, as in 
 the comb of a cock. This, however, proves only that the 
 tooth possesses vitality; for after if is taken from the natural 
 socket, if it be kept any time it will not adhere ; it has become 
 a dead part, and the living substSnce refuses to unite with it. 
 Again, and in opposition to this, is it not very extraordinary 
 that a tooth may be burnt by chemical agents, or the actual 
 cautery, down to the centre, and yet retain its hold ; or that 
 the body of the tooth may be cut off, and a new tooth fixed 
 into it by a pivot Had the teeth any' vascular action, this 
 torturing would cause re-action and disease in them. Some- 
 times the most terrible effects are produced by these opera- 
 tions, as tetanus, abscess in the jaws, &tc. ; but this happens in 
 consequence of the central nerve being bruised by the wedg- 
 ing of the pivot in the cavity of the tooth, or by the roots of 
 the tooth becoming, as dead bodies, a source of irritation to 
 the surrounding sockets. 
 
 Of the gums. — The necks of the teeth are surrounded by 
 the gums, a red, vascular, but firm substance, which covers 
 the alveolar processes. To the bone and to the teeth the 
 gums adhere very strongly, but the edge touching the tooth 
 is loose. The gums have little sensibility in their healthy and 
 sound state ; and by mastication, when the teeth are lost, they 
 gain a degree of hardness which proves almost a substitute for 
 the teeth. The use of the gum is chiefly to give firmness to the 
 teeth, and at the same time, to give them that kind of support 
 which breaks the jar or bony contact. Like the alveolar pro- 
 cess, the gums have a secret connection with the state of the 
 teeth. Before the milk-teeth appear, there is a firm ridge 
 which runs along the gums,* but this is thrown off, or wastes 
 with the rising of the teeth : and as the teeth rise, the proper 
 gums grow, and embrace them firmly. The gum is firm, and 
 in close adhesion, when the teeth are healthy ; loose, spongy, 
 or shrunk, when th(>y are diseased. The only means of ope- 
 rating upon the general state of the teeth is through the gums; 
 and by keeping them in a state of healthy aetien, by the brush 
 
 * -See Herissant. 
 
 s 
 
 VOt. li 
 
138 
 
 OF THE TEETH. 
 
 and tinctures, the dentist fixes the teeth, and preserves them 
 healthy ; but when they are allowed to be loose and spongy, 
 and subject to frequent bleeding, (which is improperly called 
 a scorbutic state,) the teeth become loose, and the gums 
 painful. If a healthy tooth be implanted in the jaw, the gum 
 grows up around it, and adlieres to it ; but if it be dead or 
 diseased, the gum ulcerates, loosens, and shrinks from it; 
 and this shrinking of the gums is soon followed by the absorp- 
 tion of the socket. 
 
 We must conclude, that the whole of the phenomena dis- 
 played in the formation, adhesion, and diseases of the teeth, 
 show them to be possessed of life, and that they have a corres- 
 pondence or sympathy with the surrounding parts. But are 
 we prepared to acquiesce in the opinion of Mr. Hunter, that 
 they possess vitality while yet they have no vascular action 
 within them ? We naturally say, how can such vitality exist 
 independently of a circulation ? But there are not wanting ex- 
 amples of an obscure and low degree of life existing in animals' 
 ova, or seeds, for seasons without a circulation ; and if for 
 seasons, why not for a term of life We never observe the 
 animal economy providing superfluously ; and since there is no 
 instance to be observed in which the teeth have shown a 
 power of renovation, why should they be possessed of vascula- 
 rity and action to no useful end ^ All that seems necessary to 
 them is, that they should firmly adhere without acting as a 
 foreign and extraneous body to the surrounding parts, and 
 this, vitality, without vascular action, seems calculated te* 
 provide. 
 
 OF THE FORMATION AND GROWTH OF THE TEETH. 
 
 In the jaws of a child newly born, there are contained two 
 sets of teeth as it were in embryo : the deciduous, temporary, 
 or milk-teeth ; and the permanent teeth. The necessity for 
 this double set of teeth evidently is to be found in the incapa- 
 city of alteration of shape or size in the teeth, as in other parts 
 of the body ; the smaller teeth, which rise first, and are adapt- 
 ed to the curve and size of the jaw-bone of an infant, require 
 to be succeeded by others, larger, stronger, and carrying their 
 roots deeper in the jaw. 
 
 Each tooth is formed in a little sac, which lies betwixt the 
 plates of bone that form the jaw-bone of the foetus, or child, 
 under the vascular gum, and connect with it. 
 
 When we open one of these sacs at an early period of the 
 formation of the tooth, a very curious appearance presents 
 itself: a little shell of bone is seen within the sac, but no ena- 
 
OF THE TEETH. 
 
 139 
 
 Biel is yet formed. Upon raising the shell of bone, which is 
 01 the shape of the tooth, and is the outer layer of the bony 
 substance of the tooth, a soft vascular stool, or pulp,* is found 
 to have been the mould on which this outer layer of ossific 
 matter has been formed ; and a further observation will lead 
 us to conclude, that this bony part of the tooth is in the pro- 
 gress of being formed by successive layers of matter thrown 
 out from the surface of this vascular pulp ; though many have 
 explained the formation of the tooth, by supposing that the 
 layers of this pulp were successively ossified. 
 
 If we now lurn our attention to the state of those teeth which 
 we know to be later of rising above the gum, we shall find the 
 ossification still less advanced, and a mere point, or perhaps 
 several points of the deposited matter on the top of the 
 pulp. 
 
 The pulp, or vascular papilla on which the tooth is formed, 
 has not only this peculiar property of ossification, but, as the 
 period of revolution advances, where it forms the rudiments 
 of the molares for example, its base splits so as to form the 
 mould of two, three, or four fangs, or roots ; for around these 
 divisions of the pulp the ossific matter is thrown out so as to 
 form a tube, continued downwards from the body of the tooth. 
 Gradually, and by successive layers of matter on the inside of 
 this tube, it becomes a strong root, or fang, and the bony 
 matter has so encroached on the cavity, that only a small canal 
 remains, and the appearance of the pulp is quite altered, 
 having shrunk in this narrow space. 
 
 We have said that the tooth forming on its pulp, or vascu- 
 lar bed, is surrounded with a membrane giving the whole the 
 appearance of a little sac. This membrane has also an impor- 
 tant use. It is vascular also as the pulp is, but it is more con- 
 nected with the gums, and receives its vessels from the sur- 
 face, while the pulp, lying under the shell of the tooth, re- 
 ceives its blood-vessels from that branch of the internal maxil- 
 lary which takes its course in the jaw. 
 
 The enamel is formed after the body of the tooth has con- 
 siderably advanced towards its perfect form. It is formed by 
 a secretion from the capsule, or membrane, which invests the 
 teeth, f and which is originally continuous with the lower part 
 of the pulp. The enamel is thicker at the point, and on the 
 body of the tooth, than at its neck. Mr. Hunter supposed 
 that the capsule always secreting, and the upper part of the 
 tooth being formed first, it would follow, of course, that the 
 
 * Le noyau, la coqiie, or le germe de la dent, by the French authors. 
 
 t This outer sac has been called chorion, from the numerous vessels distributed upon i' 
 See Herissant 
 
14 ^ 
 
 ©F THE TEETH. 
 
 point and body of the tooth would be covered with a thicker- 
 deposition ; but it rather appears that that part of the sac op- 
 posite to the upper part, and body of the tooth, has a greater 
 power of secreting, being in truth more vascular and spongy; 
 for the whole of the body of the bony part of the tooth is 
 formed before the enamel invests the tooth. 
 
 We are indebted to M. Herissant for much of the explana- 
 tion of the manner in which the enamel is formed. He des- 
 cribes the sac,* its attachment to the pulp and to the neck of 
 the teeth, — as the tooth advances to its perfect form, the sac 
 also changes. At first it is delicate and thin, but it thickens 
 apace. And he asserts, that if after this progress is begun you 
 examine the inner surface of it with a glass, you will perceive 
 it to be composed of little vesicles in regular order, and which 
 sometimes have a limpid fluid contained in them. This liquid 
 exuded upon the surface of the teeth he supposes to form the 
 enamel. He explains also how this sac, originally investing 
 the body and neck of the tooth, being pierced by the edge of 
 the tooth, and the tooth rising through it is inverted, and by 
 still keeping its connection with the circle of the crown of the 
 tooth, rises up in connection with the gum, and in some 
 degree forms the new gum which surrounds the tooth. 
 
 The sac which encloses the rudiments of the tooth consists 
 of a double membrane. The outer membrane is of a looser 
 texture, and vascular; the inner is vascular also, but delicate 
 and soft. Mr. Hunter said, that while the tooth is within the 
 gum, there is always a mucilaginous fluid, like the sinovia in the 
 joints between this membrane and the pulp of the tooth. I 
 do not imagine that the enamel is produced by the concretion 
 of this humour, which we may find at any period of the growth 
 of the body of the tooth ; but that the secreting surface chan- 
 ges the nature of its action, when the bone of the tooth is per- 
 fected in its outer layer. 
 
 This subject of the formation of teeth would be incomplete 
 if we left unexplained the peculiar structure of the teeth of 
 gramenivorous animals. 
 
 Mr. Corse, in a curious paper in the Philosophical Transac- 
 tions of London for the year 1799, describes the grinding tooth 
 of an elephant in the following terms : In describing the struc- 
 ture of the grinders, it must be observed, that a grinder is 
 composed of several distinct lamina; or teeth, each covered 
 with its proper enamel ; and that these teeth are merely joined 
 to each other by an intermediate softer substance, acting like 
 cement. 
 
 * Ressemble assez a une petite bourse fermee. 
 
OF THE TEETH. 
 
 141 
 
 The structure of the grinders, even from the first glance, 
 must appear very curious, being composed of a number of 
 perpendicular laminje, which may be considered as so many 
 teeth, each covered with a strong enamel, and joined to one 
 another by the common osseous matter This being much 
 softer than the enamel, wears away faster, by the mastication 
 of the food ; and, in a few months after some of these teeth 
 cut the gum, the enamel remains considerably higher, so that 
 the surface of each grinder soon acquires a ribbed appearance, 
 as if originally formed with ridges. 
 
 The pulp of gramenivorous animals is not shaped like that 
 which forms the human tooth ; it consists of several processes 
 united at their base. The capsule has also processes which 
 hang into the interstices of the pulp ; the pulp forms a shell 
 of bone which in time covers it. The processes of the cap- 
 sule, which of course hang into the interstices of this layer of 
 bone, (which has taken the exact form of the pulp,) form over 
 the bone layers of enamel. The tooth now consists of conical 
 processes of bone, united at their roots, and the surfaces of 
 these processes have deposited on them the enamel. The 
 membranous productions of the capsule having completed the 
 enamel, change the nature of their secretion somewhat, and 
 throw out a bony matter, which Dr. Blake has called the 
 ervsta petrosa. By the formation of this last matter of the 
 tooth the processes which secrete are encroached upon so 
 much, that they shrink altogether, and into the place left by 
 them after they have lost their power of secreting, foreign 
 matter is sometimes introduced by mastication.* 
 
 The effect of this formation is to make the layers of the 
 enamel pervade the whole substance of the tooth, the better 
 to make it stand against the continued attrition necessary in 
 the grinding and rumination of the herbiverous and grameni- 
 vorous animals. The grinding teeth of the purely carnivorous 
 animals, as of the lion and tiger, close like the blades of scis- 
 sars : they are prevented by the long canine teeth from mo- 
 ving laterally ; and as they are not subject to attrition, the 
 enamel only covers their surfaces. 
 
 OF THE GROWTH OF THE SECOND SET OF TEETH, AND THE 
 SHEDDING OF THE FIRST. 
 
 The first, or deciduous set of teeth, being adapted only for 
 
 * See a paper of Mr. Home’s in the Philosophical Transactions, and Dr. Blake’s Inaugu 
 •al Dissertation. 
 
142 
 
 OF THE TEETH. 
 
 the jaws of a child, are destined to be shed, and to give place 
 to the adult, or permanent set of teeth. Accordingly, in ob- 
 serving tlie progress of the formation of the first teeth, the 
 rudiments of the second may also be seen in the fauus of the 
 seventh or eighth month ; and in the fifth and sixth month af- 
 ter birth, the ossification begins in them. The rudiments of 
 the permanent teeth may be observed even when the sac is 
 very small, and appear like a filament stretching up to the neck 
 of the sac of the deciduous teeth.* These sacs lie on the 
 inner side of the jaw-bone, and when further advanced, the 
 necks of the two sacs (both as yet under the gum) are united ; 
 but when the first teeth are fully formed, and have risen above 
 the gum, the alveolar processes have been at the same time 
 formed around them, and now the sacs of the permanent teeth 
 have a connection with the gums through a small foramen in 
 the jaw-bone, behind the space through which the first teeth 
 have risen. 
 
 The opinion entertained, that the second set of teeth push 
 out the first, is erroneous, for the change on the deciduous and 
 the growing teeth seems to be influenced by laws of coincidence, 
 indeed, but not of mechanical action. Sometimes we observe 
 the falling tooth wasted at the root, or on the side of the fang, 
 by the pressure of the rising tooth. Now here we should sup- 
 pose that the newly formed tooth should be the most apt to be 
 absorbed by the pressure of the root of the deciduous tooth, 
 did we not recollect that the new tooth is invested with the 
 hard enamel, while the pressure on the other is upon the bony 
 root. But there is more than this necessary to the explanation 
 of the shedding of the teeth, for often the fang is wasted, and 
 the tooth adheres only by the gum, and the permanent tooth 
 has made little progress in its elevation, and has not pressed 
 upon it. 
 
 This decay and wasting of the fangs of the teeth looks 
 more like a satisf?ictory proof of their vascularity, than any 
 other change to which they are subject. Yet there seems to 
 be no reason why we should not suppose, that as the rudiments 
 of the teeth rise into action at a particular time, and form the 
 bony centre of the tooth, the decomposition should be effect- 
 ed by similar laws ; that at a particular period the tooth should 
 decay, and that the decay of the tooth should begin with the 
 destruction of the fangs. Has the bony part of the tooth a 
 tendency to dissolution independently of a circulation of blood 
 through it ^ and as the roots waste, do the surrounding vascu- 
 lar parts absorb its substance ^ or, does the surrounding vascu- 
 
 * See the plate of the Teeth. 
 
OF TEE TEETH. 
 
 143 
 
 lar substance operate on the tooth dissolving, and absorbing it, 
 as it is said a dead bone is absorbed, when placed upon an 
 ulcer ? 
 
 When the internal vascular substance of a tooth is destroy- 
 ed, it does not waste : when teeth are pivoted, tbeir roots re- 
 main twenty years without wasting or being absorbed ; and 
 when the vascular centre of the milk-teeth is destroyed, their 
 roots waste no more, and they continue adhering to the gum. 
 This seems to point to the internal membrane of the tooth as 
 the means of its absorption. 
 
 It is no proof of the first set being pushed out by the second 
 set of teeth, that if the permanent teeth do not rise, the first 
 will remain, their roots unwasted and firm even to old age ; for 
 still I contend, that there is an agreement and coincidence, 
 betwixt the two sets of teeth in their changes, and also in the 
 alveoli, by which they are surrounded ; hut this is not pro- 
 duced by the pressure of the rising teeth. When a dentist 
 sees a tooth seated out of the proper line, and draws it, and 
 finds that he has made the mistake of extracting the adult 
 tooth, letting the milk-tooth remain, he must not expect that 
 the milk-tooth will keep its place, for the contrary will hap- 
 pen ; it will in general fall out. 
 
 The old and the new teeth are lodged in distinct compart- 
 ments of the jaw-hone, and what is more curious, their alveoli are 
 distinct ; for as the roots of the first teeth decay, their alveolar 
 processes are absorbed, while again, as tbe new teeth rise from 
 their deep seat in the jaw-bone, they are accompanied with 
 new alveoli ; and the chief art of the dentist in shifting the 
 seat of the teeth, is gradually to push them along the jaw, not- 
 withstanding the hony partitions or alveoli and processes, so 
 as to bring them into equal and seemly lines. It is curious to 
 observe, that the alveoli will, by the falling out of one tooth, or 
 the operation of wedging betwixt the teeth, change their place 
 in the jaw’. 
 
 When a tooth is lost, it appears as if the space it occupied 
 were partly filled up by an increased thickness of the adjacent 
 teeth, and partly by the lengthening of that which is opposite : 
 indeed, this appearance has been brought as proof of the 
 continual growth of teeth. But there is a fallacy in the obser- 
 vation ; for when the space appears to have become narrow 
 by the approximation of the two adjacent teeth, it is not owing 
 to any increase of their breadth, but to their moving from that 
 side where they are well supported to the other side where 
 they are not. From this reason they get an inclined direc- 
 tion ; and this inclination may be observed in several ef the 
 adjoining teeth. 
 
144 
 
 OF THE TEETH. 
 
 No circumstance can better illustrate how perfect the depen- 
 dence of the alveoli is upon the teeth, than that of their being 
 thrown off with them in extensive exfoliations. I have aspecimen 
 of this in my Collection, where the whole circle of the alveolar 
 processes and teeth is thrown off. This happened after the 
 confluent small-pox. I think I recollect a similar case occur- 
 ring to Dr. Blake. In those tumours which arise from the 
 alveoli and gums, filling the mouth with a cancerous mass, and 
 softening the upper part of the jaw, there is no eradicating 
 the disease but by the taking away the whole adventitious part of 
 the jaw which belongs to the teeth, and leaving only the firmer 
 base. But even this operation will be too often unsuccessful. 
 
BOOK II. 
 
 OF THE MUSCLES. 
 
 CHAP. I. 
 
 MUSCLES OE THE FACE, EYE, AND EAR. 
 
 1. MUSCLES OF THE FACE. 
 
 A HE occiPiTO FRONTALIS is a broad and thin muscular ex- 
 Dansion, which covers all the upper part of the cranium. It 
 consists of two bellies, with an intermediate sheet of flat ten- 
 don. The one belly covers the occiput, the other covers the 
 forehead, and the tendinous expansion covers all the upper 
 part of the head ; by which it has happened that the most 
 eminent anatomists, as Cowper, (p. 29.) have misnamed its 
 tendon, pericranium ; many have reckoned it two dis- 
 tinct muscles, viz. the occipital and frontal, while 
 others (because of a sort of rapha, or line of division in the 
 middle of each belly ,) have described four muscles, viz. two 
 frontal, and two occipital muscles. But it is truly a double- 
 bellied muscle ; and the broad thin tendon, which belongs 
 equally to both bellies, lies above the true pericranium, and 
 slides upon it. The muscle is therefore named, with strict 
 propriety, occlpito-frontalis, sometimes epicranius, sometimes 
 
 BIVENTER, or DIGASTRICUS CAPITIS. 
 
 Origin. — The occipital portion is the fixed point of this 
 muscle arising from the superior ti’ansverse ridge of the occi- 
 pital bone, and covering the back part of the head, from the 
 mastoid process of one side, round to that on the opposite side 
 of the head. And by the perpendicular ridge of the occiput, 
 it is marked with a slight division in the middle. 
 
 Insertion. — The fore belly of the muscle which covers the 
 forehead, is fixed more into the skin and ey^e-brows than into 
 the bone ; it is slightly attached to the bone, near the inner 
 end of the orbitary ridge, and especially about the inner corner 
 of the eye, and the root of the nose, by a smaller and acute 
 
 VOL. I. T 
 
146 
 
 MUSCLES OF THE 
 
 pointed process ; but still its chief attachment is to the eye-lids 
 and skin. 
 
 The TENDON or thin membraneous expansion which joins 
 the two bellies, is exceedingly thin : it has on its inner side 
 much loose cellular substance, by which, though attached to 
 the true pericranium, it slides easily and smoothly upon it j 
 but its outer surface is so firn)ly attached to the skin, and its 
 fore belly adheres so firmly to the eye-brows, that it is very 
 difficult to dissect it clean and fair. 
 
 I consider the occipital belly as the fixed point, having a 
 firm origin from the ridge of the bone; its frontal belly has 
 the loose end attached, not to the os frontis, but to the eye- 
 brow and skin, and its office, that of raising the eye-brows, 
 wrinkling tbe forehead, and corrugating the whole of the hairy 
 scalp, like that muscle under the skins of animals, which shrinks 
 when they are cold or rudely touched, and by which they 
 shake off flies or insects. But it is a muscle more employed 
 in expressing passions, than in performing useful motions, and 
 it is often so thin, as hardly to be perceived. In some it is 
 entirely wanting, and many who have the muscle, have no 
 command nor power over it. 
 
 There is a small, neat, and pointed slip of the occipito fron- 
 talis, which goes down with a peak towards the nose, and is 
 inserted into the small nasal bone. This process being much 
 below the end of the eye-brow, must pull it downwards ; so 
 that while the great muscle raises the eye-brow and skin of 
 the forehead, this small nasal slip pulls the eye-brow down- 
 wards again, restoring it to its place, and smoothing the skin. 
 It may be considered as the antagonist of the great occipital 
 and frontal bellies, and might almost be described as a dis- 
 tinct muscle. It is so mingled with the compressor nasis, and 
 part of the levator labii superioris alae que nasi, that there i,s 
 some difficulty in dividing them. 
 
 II. The coRRUGAToK suPERCiLii is another slip which 
 might be fairly enough referred, like this, to the occipital 
 muscle ; but being in many subjects particularly strong, it is 
 best described as distinct.* The lower end of the nasal slip 
 of the occipito frontalis is fixed to the nasal bone. The lower 
 end of the little slip, the corrugator supercilii, is fixed into the 
 internal angular process ; and from the inner angle of the eye, 
 the fibres sweep round the edge of the orbit, and going ob- 
 liquely upwards and outwards, are so mixed with the fibres of 
 the frontal muscle, and of the orbicularis oculi, where these 
 two touch each other, that it is doubtful to which of these 
 
 * It lies entirely under the frontal niujcle : it is firmer and smoother in its fibres. 
 
FACE, EYE, AND EAR. 
 
 147 
 
 greater muscles this little one might be most properly referred. 
 So this slip of oblique fibres, rising from the inner angle of the 
 eye, and being fixed into the eye-brow, also antagonizes the 
 occipito frontalis, and drawing the eye-brows together, and 
 wrinkling the space betwixt them, is very rightly named cor- 
 RUGATOR suPERCiLii. We frequently find a slip running from 
 the outer and lower part of the muscle to join the levator labii 
 superioris proprius. 
 
 III. Orbicularis oculi, or palpebrarum, is a neat and 
 regular muscle, surrounding the eye, and covering the eye-lids 
 in a circular form. It is exceedingly flat and thin ; is about an 
 inch in breadth ; lies immediately under the skin of the eye- 
 lids, and is immediately attached to them, and but little con- 
 nected with the bone. It has one small tendon in the inner 
 corner of the eye, which is both its origin and insertion ; for it 
 begins and ends in it. This small tendon is easily felt through 
 the skin in the inner corner of the eye. It arises by a little 
 white knot from the nasal process of the upper jaw-bone. Its 
 fibres immediately become muscular, and spread out thin over 
 the upper eye-lid. They pass over it to the outer corner of 
 the eye, where they cross a little, and having covered just the 
 edge of the temple with their tbin expanded fibres, they re- 
 turn in a circular form round by the lower eye-lid to the point 
 from whence they had set out. This is, in all its course, a very 
 thin muscular expansion, with regular orbicular fibres. It is 
 rather a little broader over the lower eye-lid, extends itself a 
 little upon the face beyond the brim of the socket, both at the 
 temple, and upon the cheek ; and its fibres cross each other a 
 little at the outer angle ; so that some understanding this cross- 
 ing as a meeting of fibres from the upper and from the lower 
 muscle, have described it as two semi-circular muscles. And 
 those fibres which are next to the tarsus or cartilaginous circle 
 of the eye-lids, were distinguished by Riolan, under the title of 
 MUscuLus ciLiARis. Oui’ name expresses the common opi- 
 nion, that it is a circular muscle, whose chief point or fulcrum is 
 in the inner corner of the eye, and which serves as a sphincter 
 for closing the eye. It squeezes with spasmodic violence, 
 when the eye is injured, as by dust. And by its drawing down 
 the eye-lids so firmly, it presses up the ball of the eye hard 
 into the socket, and forces the lachrymal gland that is within 
 the socket, so as to procure a flow of tears. 
 
 IV. Levator palpebre superioris. — This small muscle 
 arises deep within the socket, from the margin of that hole 
 which gives passage to the optic nerve. It begins by a small 
 flat tendon in the bottom of the optic cavity, becomes gradu- 
 ally broader as it goes over the eye-hall ; it ends in the eye- 
 
148 
 
 MUSCLES OE THE 
 
 lid, by a broad expansion of muscular fibres, which finally ter- 
 minate in a short flat tendon. It lies under the orbicularis pal- 
 pebrae, is inserted into the whole length of the cartilage of the 
 tarsus, and raises and opens the upper eye-lid. And the divi- 
 sion of the orbicularis oculi into two, by the older anatomists, 
 was a consequence of their not knowing of the true levator pal- 
 pebrae, and their not being able to describe any muscle by 
 which the upper eye-lid could be raised, except the upper 
 half of the orbicularis. 
 
 The occipito frontalis, but especially its occipital belly, 
 raises the eye-brows ; the pointed slip of the same muscle pulls 
 them downwards; the corrugator pulls them directly inwards, 
 and knits the brows; the levator palpebras opens the eye-lid 
 and the orbicularis oculi closes the eye. Whether certain 
 fibres from the platysma-myoides, (a thin flat muscle which 
 mounts from the neck over the cheek,) may not pull down the 
 lower eye-lid, or whether some straggling fibi’es, arising from 
 the zygoma, may not have the appearance of a depressor of 
 the lower eye-lid, it is not necessary to determine, since there 
 is no regularly appointed muscle, and the lower eye-lid is 
 almost immoveable, at least in man. 
 
 MUSCLES OF THE NOSE AND MOUTH. 
 
 V. Levator labh superioris and al® nasi. Cowper 
 describes the levator labii superioris as an irregular production 
 of the frontalis, extending along the nostrils. But it is a neat 
 and delicate muscle, which arises, by a small double tendon, 
 from the nasal process of the upper jaw-bone, close by the ten- 
 don of the orbicularis oculi. It is one little fasciculis of mus- 
 cular fibres above ; but as it approaches the nose, it spreads out 
 broader, dividing into two small fasciculi, one of which is im- 
 planted into the wing or cartilage of the nose, and the other 
 passing the angle of the nose, goes to the upper lip : thus it is 
 pyramidal with its base downwards, and was named pyramida- 
 lis by Casserius, Winslow, and others. It is called by Cowper 
 dilator al* nasi ; it raises the upper lip, and spreads the nostrils 
 Avide, as is observed in a paroxysm of rage, or in asthmatics. 
 
 VI. The levator labii superioris proprius is distinguish- 
 ed by the name of levator proprius, because there are two 
 others ; one belonging to the angle of the mouth, and conse- 
 quently to both lips ; and one common to the lip and nostril. 
 
 The levator proprius is often named musculus incisivus, be- 
 cause it arises from the upper jaw, just above the incisores, or 
 cutting teeth, and consequently just under tbe edge of the 
 
FACE, EYE, AND EAR. 14i> 
 
 orbit : it is broad at its origin ; it lies flat and runs downwards, 
 and obliquely inwards, to the middle of the lip till it meets its 
 fellow just in the filtrum.* It pulls the upper lip and the sep- 
 tum of the nose directly upwards. It generally receives a slip 
 from the orbicularis oculi. 
 
 VII. The LEVATOR ANGULI ORIS, is Called alsO LEVATOR 
 COMMUNIS LABiORUM, because it operates equally on both lips. 
 
 It is named caninus ; for as the last named muscle rises from 
 the upper jaw-bone above the incisores or cutting teeth, this 
 arises above the canini or dog-teeth, or above the first grinder, 
 by a very short double tendon. The exact place of its origin 
 is half way betwixt the first grinder and the infra orbitary hole : 
 it is mixed with the orbicularis oris, at the corner of the mouth, 
 so that it raises the angle of the mouth upwards. 
 
 VIII. The zYGOMATicus MAJOR has nearly the same direc- 
 tion and use with this one : for it arises from the cheek-bone 
 near the zygomatic suture ; runs downwards and inwards to the 
 corner of the mouth ; is a long and slender muscle, which ends 
 by mixing its fibres with the orbicularis oris and the depressor 
 of the lip. 
 
 IX. The ZYGOMATICUS MINOR ai'ises a little higher upon the 
 cheek-bone, but nearer the nose ; it is much slenderer than 
 the last, and is often wanting. In negroes we frequently find 
 three zygomatic muscles. 
 
 It is the zygomatic muscle that marks the face with that 
 line which extends from the cheek-bone to the corner of the 
 mouth, and which is so strong in many. The zygomatic mus- 
 cles pull the angles of the mouth upwards as in laughter ; or 
 one of them distorts the mouth, whence the zygomatic muscle 
 has got the name of distortor oris ; the strong action of the 
 muscle is particularly seen in laughter, rage, grinning. 
 
 X. Buccinator. The buccinator was long thought to be 
 a muscle of the lower jaw, arising from the upper alveoli, and 
 inserted into the lower alveoli to pull the jaw upwards ; but its 
 origin and insertion, and the direction of its fibres, are quite 
 the reverse of this. For this large flat muscle, which forms, 
 in a manner, the walls of the cheek, ai’ises chiefly from the 
 coronoid process of the lower jaw-hone and partly also from 
 the end of the alveoli or socket process of the upper jaw, close 
 by the pterygoid process of the sphenoid bone ; it arises also 
 from the upper jaw ; it goes forwards with direct fibres to be 
 implanted into the corner of the mouth ; it is thin and flat, 
 and forms the walls of the cheek ; it is perforated in the mid- 
 dle of the cheek by the duct of the parotid gland. Albinus 
 
 ^ Thp filtrum is thp siipprficial gutter along the upper lip from tho partition of tlie nose to 
 ■ he tip of the lip. 
 
150 
 
 MUSCLES OP THE 
 
 describes two irregular sets of fibres besides mentioning those 
 which are running directly to the angle of the mouth : 1 . One 
 
 narrow slip which runs in a semi-circular direction and joins the 
 inner surface of the upper lip. 2. Another considerable slip 
 which runs much in the direction of the orbicularis towards 
 the middle of the lip, this he calls the appendix of the buccina- 
 tor. These are its principal uses; that it flattens the cheek, 
 and so assists in swallowing liquids ; that it turns, or helps to 
 turn, the morsel in the mouth while chewing, and prevents its 
 getting without the line of the teeth : in blowing wind instru- 
 ments, it both receives and expels the wind : it dilates like a 
 bag,vso as to receive the wind in the cheeks ; and it contracts 
 upon the wind so as to expel the wind, and to swell the note : 
 In blowing the strong wind instruments, we cannot blow from 
 the lungs, for it stresses the breathing, but reserve the air in the 
 mouth, which we keep continually full ; and from this it is 
 named, from blowing the trumpet, the buccinator. 
 
 XI. Dbpressor ANGULi ORIS. — The depressor anguli oris is 
 a neat small triangular muscle, and is indeed very commonly 
 named musculus triangularis labiorum, from its shape. 
 The base of the triangle is at the line of the lower jaw, where 
 the muscle rises with a flat fleshy head about an inch in breadth. 
 It grows smaller gradually as it rises towards the corner of the 
 mouth, where it is implanted, small almost in a point, and 
 directly opposite to the zygomatic and levator muscles ; and 
 as the zygomatic muscle makes a line from the cheek down to 
 the angle of the mouth, this makes a line from the chin up to 
 the corner of the mouth. It is chiefly active in expressing the 
 passions, and gives form to the chin and mouth. In cheerful 
 motions, as laughter, smiling, &lc. the zygomatics and levators 
 pull the angles of the mouth upwards. In fear, hatred, re- 
 venge, contempt, and the angry passions, the ti’iangulares pull 
 the corners of the mouth downwards ; and at the place w'here 
 these meet, there is formed a sort of rising at the angle of the 
 mouth : for a great many tendons are crowded into this one 
 point ; the zygomatic, levator, depressor, and orbicularis oris 
 muscles meeting and crossing each other at this place. 
 
 XII. The oEPREssoR LABii iNEERiORis is a Small muscle, 
 the discovery which Cowper claims for himself. It is a small 
 muscle, lying on each side of the chin, which, with its fellow, 
 resembles very much the levators of the upper lip. The de- 
 pressor labii inferioris arises on each side of the chin, from the 
 lower jaw-bone, under the line of the triangular muscle. It 
 grows obliquely upwards and inwards, till it meets its fellow in 
 the middle of the lip ; and where the muscles of the opposite 
 side meet, there is a little filtrum or furrow on the lower lip, as 
 
151 
 
 FACE, EYE, AND EAR. 
 
 ou the upper one. It mixes its fibres with the-orbicularls, and 
 its use is to pull the lip downwards ; each muscle is of a square 
 form, and thence has been often named quadratus gena;, the 
 square muscle of the chin. 
 
 XIII. The OKBicuEARis ORIS, or muscle round the mouth, 
 is often named constrictor oris, sphincter, or osculator. 
 It is very regular; it is an inch in breadth, and constitutes the 
 thickness of the lips : it lies in the red part of the lips, and is of 
 a circular form, surrounding the mouth after the same manner 
 that the orbicularis oculi encircles the eye. We see a degree 
 of crossing in the fibres at the angles of the mouth, whence it 
 has been considered by many not as a circular muscle, but as 
 one consisting of two semi-circular muscles, the semi orbicu- 
 laris SUPERIOR, and semi orbicularis inferior. Its fixed 
 points are the two angles of the mouth ; at that swelling which 
 is formed by the union of the zygomatic, triangular, and other 
 muscles, part of it takes origin from the alveolar process of the 
 canine teeth. The chief use of this muscle is to contract the 
 mouth, and antagonize the other muscles which I have just de- 
 scribed. Often a small slip runs up from the middle of the up- 
 per lip, to the tip of the nose ; it is the nasalis labii superio- 
 Ris of Albinus ; it lies exactly in the furrow of the filtrum, and 
 is occasionally a levator of the upper lip, or a depressor of the 
 tip of the nose. 
 
 These muscles of the nose and lips are not useful merely in 
 expressing the passions ; that is but a secondary and accidental 
 use, while their great office is to perform those continual move- 
 ments, which breathing, speaking, chewing, swallowing, require. 
 There are muscles for opening the mouth in various directions, 
 which are all antagonized by this one, the orbicularis oris. 
 The levator labii superioris, and the depressor labii inferioris, 
 separate the lips and open the mouth. The levator anguli oris, 
 along with the zygomatic muscles, raises the cheek, and dilates 
 the corners of the mouth. The buccinator pulls the corner of 
 the mouth directly backwards, opening the mouth. The an- 
 gularis oris also dilates the mouth, pulls the angles of the mouth 
 downwards and backwards, and forms it into a circle, if the 
 others act at the same time; but the orbicularis oris is the largest 
 and strongest, (formed as it were, by the fibres of all these 
 taking a new direction, and turning round the lips,) shuts the 
 mouth, and antagonizes them all, and from an opening as wide 
 as the mouth can require, shuts the mouth at pleasure, so 
 closely, as to retain the very breath against all the force of the 
 lungs. It is the true antagonist of all the other muscles, and 
 they and the orbicularis mutually re-act on each other, in 
 alternately opening and closing the. month. This phenome- 
 
152 
 
 MUSCLES OE THE 
 
 non of the orbicularis muscle, dilating to such a wideness, and 
 in an instant closing the mouth again, with such perfect accura- ij 
 cy, as to retain the breath, puts to nought all the vain calcula- | 
 tions about the contraction of muscles, as that they can con- | 
 
 tract no more than one third of their length ; for here is an |) 
 
 infinite contraction, such as no process can measure. It is a “ 
 
 paralysis of these muscles that so often occasions a hideous | 
 
 distortion of the face ; for when the one side of the body falls < 
 
 into palsy, the muscles of one cheek cease to act ; the mus- ^ 
 
 cles of the other cheek continue to act with their usual degree j 
 
 of power. This contraction of the muscles of one cheek ex- 
 cites also the orbicularis oris to act, and so tbe mouth is pursed 
 up, and the lips and angles of the mouth are drawn towards 
 one side. 
 
 There are some smaller muscles, which, lying under these, 
 could not be described without danger of confusion; as — 
 
 XIV. The UKPRESSOR labii suPERiORis and alje nasi, 
 
 which is very small, and lies concealed under the other mus- j 
 
 cles. It rises from the gum or socket of the fore teeth, and > 
 
 thence is named, by Winslow, incisivus medius. It goes into 
 the root of the nostril, and pulls it, and, of course, the upper 
 
 lip down, and is named, by Albinus, depressor alae nasi. 
 
 XV. The CONSTRICTOR NASI, or compressor of the nose, is 
 
 a small scattered bundle of muscular fibres, which crosses the | 
 wings, and goes to the very point of the nose ; for one arises 
 from the wing of the nose on each side, and meets its fellow j 
 in the middle ridge, where both are fixed into the middle car- 
 tilage, or into the lower point of the nasal bones, meeting with | 
 
 the peak of the frontal muscle, or its scattered fibres. But this | 
 
 muscle is so difficultly found, that when Cowper saw it dis- ' 
 
 tinctly marked in Bidloe’s 12th table, be considered it as a 
 fiction, having sought for it very carefully, but in vain, ]l| 
 
 And XVI. The LEVATOR MENTi, which arises from the lower ni 
 jaw, at the root of the cutting tooth, has been named incisi- 
 vus INFERIOR. It is inserted into the skin, on the very centre 
 of the chin : by its contraction it draws the centre of the chin 
 into a dimple ; and from its moving the under lip at the same 
 time, it is named levator labii inferiores. 
 
 MUSCLES OF THE EXTERNAL EAR. 
 
 Though perhaps not one of ten thousand has the power of 
 moving the outward ear, yet there are many thin and scattered 
 fibres of muscles about the root of the cartilage of the ear, to 
 which we cannot refuse the name and distinction of muscles ; 
 
FACE, EYE, AND EAR. 
 
 las 
 
 and which serve, indeed, to indicate, that nature had intended 
 a degree of motion, which, perhaps by the manner of covering 
 the heads of children, we may have lost. But in a few, these 
 fasciculi of fibres, have not the form only, but the uses of mus- 
 cles. The celebrated Mr. Mery, was wont, when lecturing on 
 this subject, to amuse his pupils, saying, pleasantly, “ that in 
 one thing, he surely belonged to the long ear’d tribe upon 
 which he moved his ears very rapidly backwards and forwards.* 
 
 XVII. SuPEKioR AURis is named attollens because it lifts 
 the ear upwards : it is a very thin, flat expansion, which can 
 hardly be distinguished from the fascia of the temporal mus- 
 cle, upon which it lies ; it arises broad and circular, from the 
 expanded tendon of the occipito frontalis, and is inserted into 
 the back part of the antihelix. 
 
 XVIII. Anterior aukis is a very delicate, thin, and nar- 
 row expansion, arising about the zygoma, or rather from the 
 fascia, with which the zygoma is covered ; it is inserted by a 
 tendon into that eminence of the helix which divides the 
 concha. 
 
 XIX. The POSTERIOR ATjRis is also a small muscle, very de- 
 licate and thin ; but the anterior rises in one small and narrow 
 slip only, while this, the posterior, rises commonly, in three 
 narrow and distinct slips, from about the place of the mastoid 
 process whence it is often named triceps auris- These 
 fibres are often described as two distinct muscles, retrahentes : 
 it goes directly forwards to be inserted into the back part of 
 the concha, opposite the septum that divides the concha, by 
 two slips. 
 
 But there are still other muscles enumerated, which are not 
 for moving the outward ear upon the head, but for moving, or 
 rather giving tension to the cartilages of the outward ear. 
 Those fibres, are merely muscular membranes, which have 
 none of the marks nor offices of true muscles ; they have sel- 
 dom fleshy fibres, and the parts upon which they lie are fixed. 
 Heister denies them the title of muscles, and calls them mus- 
 eular membranes only. 
 
 The ring and other bendings of the outward ear are called 
 helix and antihelix, tragus and antitragus ; and this determines 
 the names of these ambiguous fibres, which are sometimes 
 found lying upon these circles of the outward cartilage, just 
 under the skin. 
 
 XX. The MuscuLus helicis major lies upon the upper, or 
 sharp point of the helix or outward ring ; rising from the upper 
 
 Vide PaKn, who was his pupil. The celebrated Albinus could move has ears. 
 
 f Fibrae oameae transverse, a nobis descriptse. Vaisalya. 
 
 VOL. I.. U 
 
164 
 
 MUSCLES OP THE 
 
 and acute point of the helix, and inserted into the same carti" 
 lage a little above the tragus. 
 
 XXL Helicis MiNOK rises lower than the former, upon the 
 forepart of the helix, and runs across the notch wiiich is in 
 that part of the helix that projects into the concha, the muscle 
 having its origin above the notch, and its insertion below it. 
 
 XXII. The TRAGicus lying upon the concha, and stretching 
 to the tragus; takes its origin from the middle of the concha 
 to the root of the tragus, and is inserted into the tip of the 
 tragus. 
 
 XXIII. The ANTiTKAOicus Hes OH the antitragus, running 
 up from this cartilage to be inserted into the edge of the 
 concha, at the notch on the termination of the helix. 
 
 XXIV. And, lastly. There is the transvkrsus aukis of 
 Albinus, which runs in scattered fibres on the back part of the 
 ear from the prominent part of the concha to the outer side of 
 the antihelix. 
 
 MUSCLES OF THE EYE-BALL. 
 
 The eye-ball is entirely surrounded by muscles, which turc 
 it in all directions. There is one muscle on either side, one 
 above and one below ; these arise from the very bottom of the 
 socket, spread out upon the ball of the eye, and are implanted 
 into its forepart, where the expansions of their colourless ten- 
 dons form what is called the white of the eye. Now these 
 four muscles, coming in a straight course from the optic fora- 
 men to the anterior part of the eye-ball, are called the recti, 
 or straight muscles : for their pulling is from the bottom of the 
 socket. But there are two other muscles which are named 
 the oblique muscles, because they pull from the edges of the 
 socket, and turn the eye obliquely ; for they go in a direction 
 exactly opposite to the recti. The recti come directly forwards, 
 from the bottom of the orbit ; these go obliquely backwards, 
 from the edge of the orbit; one rises from the lower edge of 
 the socket, and goes backwards under the eye-ball ; the other 
 rises, indeed, along with the recti, in the bottom of the socket, 
 but it has a cartilaginous pulley on the very edge of the socket, 
 at its upper part ; and its small round tendon first runs through 
 this pulley, and then turns down upon the eye, and goes back- 
 wards; so that the straight muscles press down the eye-ball 
 deep into the socket, while the oblique muscles bring the eye- 
 ball forwards, pulling it outwards from the socket. 
 
 The truest description of the recti is as of one muscle, since 
 their only variety is that dilference of place, which is expres- 
 
FACE, EYE, AND EAR. 
 
 156 
 
 aed by tbe name of each. They all agree in these chief cir- 
 cnmstances, that they arise by flat, but small tendons, round 
 the margin of the optic hole, arising from the circle of that 
 hole, or rather from the periosteum there ; and there being 
 one above, one below, and one on eitheir side, they com- 
 pletely suiroundthe optic nerve, and adhere to it. They are 
 neat and delicate muscles, which gradually expand each into a 
 fleshy belly, which surrounds and covers the middle of the ball 
 of tbe eye. They still go on expanding, till they at last terminate, 
 each in a broad, flat, and very white tendon, which covers 
 all the forepart of the eye, up to tbe circle of the lucid cor- 
 nea or w’indow ; and their white and shining tendons form that 
 enamelled-like part, which lies without the coloured circle, 
 and which is named the white of the eye, or the tunica al- 
 buginea, as if it were absolutely a distinct coat, 
 
 Now, the only difference in these straight muscles is in res- 
 pect to length 5 for the optic nerve enters tbe eye, not regu- 
 larly in the centre, but a little towards the inner side, so that 
 tbe rectus internus, or muscle nearest the nose, is a little shorter, 
 The rectus externus, or muscle nearest to the temple, is a little 
 longer : but the rectus superior and the rectus inferior are of 
 equal length. The uses of these muscles are exceedingly plain. 
 
 XXV. The RECTUS superior, lifting the eye directly up- 
 wards, is named the musculus attollens, tbe levator ocu- 
 Li or SUPER3US, as expressive of haughtiness and pride, 
 
 XXVI. And the rectus inferior, which is directly op- 
 posite to it, is named oeprimens oculi or humilis, as ex- 
 pressing modesty and submission. 
 
 XXVII. The rectus internus is called adducens, as car- 
 rying the eye towards the nose, or bibitorius, because it di- 
 rects the eye to the cup. 
 
 And XXVIII. the rectus externus, the outer straight mus- 
 cle, as it turns the eye from the nose, is named abductor oculi, 
 or ivDiGNABUNDUs, expressing anger or scorn. Such is the 
 effect of these muscles, that when they act in succession, they 
 roll the eye ; but if they act all at once, the power of each is 
 balanced by the action of its opposite muscle, and tbe eye is 
 imraoveably fixed. So that sometimes in our operations, 
 when the couching needle approaches the eye, fear comes 
 upon the patient, and the eye is fixed by a convulsive action, 
 more firmly than it could be by the instruments, or by the fin- 
 ger ; so that the speculum oculi is after such an accident of no 
 use. The eye continues fixed during all the operation, but it 
 is fixed in a most dangerous wa}', by a power which we cannot 
 controul, and which sometimes, when our operation is for 
 extracting one of the humours only, squeezes out the whole. 
 
166 
 
 MUSCLES OF THE 
 
 XXIX. The GBLiquus SUPF.RIOK arises along with the rectf 
 in the bottom of the eye, above and towards the inner side, 
 directing its long tendon towards the inner angle of the eye; 
 and there it passes its tendon through that pulley, whose hol- 
 low I have marked in describing the os frontis, as under the su- 
 perciliary ridge, and near to the inner corner of the eye. It 
 arises by a small tendon like one of the recti ; it goes over the 
 tipper part of the eye-ball, a long and slender muscle, whence 
 it is often named longissimus oculi, the longest muscle of 
 the eye. It forms a small smooth round tendon, which passes 
 through the ring of the cartilaginous pulley, which is in the 
 margin of the socket. The pulley is above the eye, and pro- 
 jects farther than the most prominent part of the eye-ball, so 
 that the tendon returns at an acute angle, and bends down- 
 wards before it can touch the eye-ball. And it not only re- 
 turns backwards in a direction opposite to the recti muscles, 
 but it slips Bat under the body of the rectus superior, and is 
 spread out under it upon the middle or behind the middle of 
 the eye, viz. about half way betwixt the insertion of the rectus, 
 and the entrance of the optic nerve. 
 
 XXX. The OBLiQ,uus inferior is, with equal propriety, 
 named the musculus brevissimus oculi. It is directly oposite 
 to the obliquus superior, in form, place, office, &ic. ; for it 
 arises from the orbitary process of the superior maxillary bone, 
 near its union with the os unguis : it is short, flat, and broad, 
 with a strong fleshy belly : it goes obliquely backwards and 
 outwards, lying under the ball of the eye ; and it is inserted 
 broad and flat into the ball, exactly opposite to the insertion 
 of the obliquus superior muscle. 
 
 These two muscles roll the eye, whence they are named 
 musculi circumagentes, or amatorii. But they have still an- 
 other important office, viz. supporting the eye ball, for the 
 operation of its straight muscles ; for when the obliqui act, they 
 pull the eye forwards, the straight muscles resist, and the in- 
 sertion of the oblique muscles at the middle of the eye-ball 
 becomes, as it were, a fixed point, a centre or axis round 
 which the eye-ball turns under the operation of the recti mus- 
 cles. The conjoined effect of the oblique muscles is to bring 
 the eye-ball forwards from the socket, as in straining the eye 
 to see at some distant point. The particular effect of the up- 
 per oblique muscle is not to bring the eye forward, but to roll 
 the eye so as to turn the pupil downwards, and towards the 
 nose. And the particular effect of the lower oblique muscle 
 is to reverse this action, to turn the eye again upon its axis, 
 and to direct the pupil upwards and outwards ; but the succes- 
 sive actions of all these muscles move the eye in circles, with 
 
LOWER JAW, THROAT, AND TONGUE. 
 
 157 
 
 gradations so exquisitely small, and with such curious combi 
 nations as cannot be explained by words. 
 
 CHAP. II. 
 
 MUSCLES OF THE LOWER JAW, THROAT, AND TONGUE. 
 
 MUSCLES OF THE LOWER JAW. 
 
 The lower jaw requires muscles of great power to grind the 
 food ; and accordingly it is pulled upwards by the strong tem- 
 poral, masseter, and pterygoid muscles ; but in moving dowm- 
 wards, the jaw almost falls by its own weight, and having 
 little resistance to overcome, any regular appointment of mus- 
 cles for pulling down the jaw is so little needed, that it is pul- 
 led downwards by muscles of such ambiguous office, that they 
 are equally employed in raising the throat, or pulling down 
 the jaw, so that we hardly can determine to which they be- 
 long; for the chief muscles of the throat, coming from the 
 lower jaw, must, when the jaw is fixed, pull up the throat, or 
 when the throat is fixed, depress the jaw. 
 
 XXXI. The TEMPORAL MUSCLE is the great muscle of the 
 jaw. It arises from all the flat side of the parietal bone, and 
 from the sphenoid, temporal, and frontal bones, in that hol- 
 low behind the eye, where they meet to form the squamous 
 suture. It arises also from the inner surface of that strong 
 tendinous membrane which is extended from the jugum to 
 the semi-circular ridge of the parietal bone. The fibres are 
 bundled together and pressed into a small compass, so that they 
 may pass under the jugum : there they take a new hold upon 
 the inner surface of the jugum : the muscle is of course pyra- 
 midal, its rays converging towards the jugum ; its muscular 
 fibres are intermixed with strong tendinous ones ; it is particu- 
 larly tendinous, where it passes under the jugum; and it has 
 both strength and protection from that tendinous plate which 
 covers it in the temple. Its insertion is into the coronoid pro- 
 cess of the lower jaw-bone ; not merely into the tip of the 
 horn, but embracing it all round, and down the whole length 
 of the process, so as to take the firmest hold. 
 
 XXXII. The MASSETER is a short, thick, and fleshy muscle, 
 which gives the rounding of the cheek at its back part. It 
 arises from the upper jaw-bone, at the back of the antrum, and 
 
168 
 
 MUSCLES OF THE 
 
 under the cheek-bone, and from the lower edge of the zygoma. 
 
 It lies upon the outside of the coronoid process, covering the 
 the branch of the lower jaw quite down to its angle. It is 
 particularly strong, has many massy bundles of flesh, inter- 
 spersed with tendinous strings ; the parotid gland lies on its 
 upper part, and the duct of the gland (as it crosses the cheek) 
 lies over this muscle. The jaw is very firmly pulled up by 
 these two, which are its most powerful muscles ; and when we • 
 bite, we can feel the temporal muscle swelling on the flat part 
 of the temple, and this the rnasseter upon the back part of the 
 cheek. 
 
 XXXIII. XXXIV. The two pterygoid muscles (of which 
 there are four in all, two on either side,) are named from their 
 origin in the pterygoid processes of the sphenoid bone. The 
 I'TEHYGoiDEUs iNTERNUs is that One which rises from the in- 
 ternal or flatter pterygoid process, and which goes downwards 
 and outwards to the angle of the jaw on its inside; it fills up the 
 fossa pterygoidea. I'he pterygoid eus externus arises from 
 the external pterygoid process, and goes not downwards, but 
 almost directly outwards, and is implanted high in the jaw- 
 bone, just under its neck, and connected with its capsular liga- 
 ment. Now the pterygoideus internus descending to be fixed 
 to the angle of the jaw, is longer and bigger, and is named 
 PTERYGOIDEUS MAJOR. The external one going directly across, 
 and rather backwards, has less space to traverse, is shorter, and 
 is named PTERYCoiDEtrs minor. 
 
 The jaw is moved chiefly by these muscles; the temporalis 
 acting upon the coronoid process like a lever, the rnasseter 
 acting upon the angle, and before it, and the pterygoideus in- 
 ternus balancing it within, like an internal rnasseter fixed on 
 the inside of the angle. All these pull strongly upwards for 
 biting, holding, and tearing with the teeth ; and the external 
 or lesser pterygoid muscle going from witbin outwards, pulls 
 the jaw from side to side, and performs the motion of grind- 
 ing. 
 
 muscles of THE THE THROAT AND TONGUE. 
 
 The muscles of the throat and tongue cannot be under- 
 stood without a previous acquaintance with certain cartilages 
 and bones, which form the basis of the throat and tongue, and 
 the centre of those motions which we have next to describe. 
 
 The os HYOiDES is a small bone resembling in shape at least 
 the lower jaw-bone. It has a middle thicker part, named its 
 basis, which is easily felt outwardly ; it corresponds in place 
 with the chin, and during life it is distinguished about an inch 
 
LOWER JAW, THROAT, AND TONGUE. 159 
 
 below the chin, the uppermost of the hard points which are 
 felt in the forepart of the throat. Next, it has two long horn- 
 like processes, which go backwards along the sides of the 
 throat, called the cornua, or horns of the os hyoides, and which 
 are tied by a long ligament to the styloid process of the tetnpo- 
 ral bone. And, lastly, it has small cartilaginous pieces or join- 
 ings, by which the horns are united to the basis; and often in 
 the adult this joining is converted into bone. At this point, 
 where the two horns go backwards, like the legs of the letter 
 U, there are commonly, at the gristly part of the os hyoides, 
 two small perpendicular processes which stand up from the 
 joining of the horns to the body, and these are named the 
 appendices of the os hyoides or the lesser cornua. 
 
 Now, this os hyoides forms by its basis the root of the tongue, 
 thence it is often named the bone of the tongue. It forms at 
 the same time a part of the larynx, which is the collection of 
 cartilages forming the top of the trachea, or windpipe ; and it 
 carries upon it that cartilage named epiglottis, which, like a 
 valve, prevents any thing getting down into the windpipe. Its 
 horns extend along the sides of the throat, keeping the open- 
 ings of the windpipe and gullet extended, as we would keep a 
 bag extended by two fingers. The chief muscles of the tongue 
 and of the windpipe arise from its body ; the chief muscles of 
 the gullet arise from its horns, and especially from their points ; 
 it receives the chief muscles which either raise or depress the 
 throat ; and it is the point d’appui, or fulcrum for all the mus- 
 cles of the throat and tongue, and the centre of all their motions. 
 It is the centre of the motions of the tongue, for it is the origin of 
 these muscles which compose chiefly the bulk of the tongue ; 
 of the motions of the trachea or windpipe, for it forms at once 
 the top of the windpipe, and the root of the tongue, and joins 
 them together; of the motions of the pharynx or gullet, for its 
 horns surround the upper part of the gullet, and join it to the 
 windpipe; and it forms the centre for all the motions of the 
 throat in general : for muscles come down from the chin to 
 the os hyoides, to move the whole throat upwards ; others 
 come up from the sternum, to move the throat downwards ; 
 others come obliquely from the coracoid process of the scapu- 
 la, to move the throat backwards, while the os hyoides still 
 continues the centre of all these motions. 
 
 The TRACHEA, or WINDPIPE, is that tube which conveys the 
 air to the lungs ; and the larynx is the head or figured part of 
 that tube w'hich is formed like a flute for the modulation of the 
 voice, and consists of cartilages, that it may stand firm and un- 
 compressed, either by the passage of the food or by the weight 
 of the outward air ; and that it might resist the contraction of 
 
160 
 
 MUSCLES OF TME 
 
 the surrounding parts, serving as a fulci’um for them in the mo- 
 tions of the jaw, tongue, and gullet. Its cartilages are first, the 
 ■ scuTiFORM, or THYROID Cartilage, which is named from its re- 
 semblance to a shield, or rather it is like the flood-gates, or 
 folding-doors of a canal, the meeting of the two sides being in 
 the middle line of the throat. This prominent line of the thy- 
 roid cartilage is easily felt in the middle of the throat, is about 
 an inch in length, and makes that tumour which is called the 
 pomum Adami. The flat sides of the thyroid cartilage form 
 the sides of the flute-part of the trachea. And there are two 
 long horns at its two upper corners, which rise like hooks above 
 the line of the cartilage, and are joined to the horns of the os 
 hyoides, and two similar but shorter hooks below, by which it 
 embraces the cricoid cartilage. 
 
 The CRICOID CARTILAGE is next to the thyroid, and below 
 it; it is named from its resemblance to a ring : It is indeed 
 like a ring or hoop, but it is not a hoop equally deep in all its 
 parts, it is shallow before; where it ekes out the length of the 
 thyroid cartilage, and is deeper behind, where it forms the 
 back of this flute-like top of the trachea ; it is the top ring of 
 the trachea, and the lower ring of the larynx or flute-part of the 
 w'ind-pipe. And upon its back, or deeper part, are seated 
 those two small cartilages, which, with their ligaments, form 
 the opening for the breath. 
 
 The ARYTENOID CARTILAGES ale two Small triangular bodies, 
 seated within the proteciton of the thyroid cartilage. They 
 are foolishly described with cornua ridges and surfaces, when 
 they are so small that nothing further can be observed of their 
 forms, than thaf they are somewhat conical ; that the base or 
 broad part of each sits down upon the upper edge of the cri- 
 coid cartilage at its back; that the point of each stands direct- 
 ly upwards, and is a very little crooked, or hook-like ; that 
 standing, as they do, a little apart from each other, they form 
 together an opening something like the spout of a ewer, or 
 strouped bason, whence their names. And these cartilages 
 being covered with the common membrane of the throat, 
 w'hich is thick, and full of mucous glands, the opening gets a 
 regular appearance with rounded lips. From these cartilages 
 to the back part of the thyroid cartilages, ligaments are extend- 
 ed ; over these ligaments the lining membrane of the larynx 
 is laid, and betwdxt the arytenoid ligaments is formed the chink 
 or rima glottidis ; viz. the opening of the wind-pipe. The 
 voice is, in a considerable degree, formed by the motion of 
 these cartilages and their ligaments; and the action of the mus- 
 cles of the arytenoid cartilages are so exquisitely minute, that 
 for every changing of the note (and there are some thousand 
 
LOWER JAW, THROAT, AND TONGUE. 161 
 
 gradations in the compass of the voice) they move in a propor- 
 tioned degree. 
 
 The EPIGLOTTIS is a fifth cartilage of the trachea, belonging 
 to it both by connection and by office. It is a broad triangular 
 cartilage, not so hard as the others, very elastic, and so exactly 
 like an artichoke leaf, that no other figure can represent it so 
 well. Its office is to defend the opening of the glottis. It is 
 fixed at once to the os hyoides, to the thyroid cartilage, and to 
 the root of the tongue, an^ it hangs obliquely backwards over 
 the opening of the rima, or chink of the glottis ; it is suspend- 
 ed by little peaks of the membrane, which we call ligaments 
 of the glottis, and it is said to be raised or depressed by mus- 
 cles, which yet are not very fairly described. But the rolling 
 of the morsel which is swallowed, and the motion of the tongue, 
 are suflicient to lay it flat over the rima, so that it is a perfect 
 guard upon the wind-pipe. 
 
 Then this is the constitution of the larynx. It is of hard 
 cartilages to resist compression, and of a flute form at its ope- 
 ning, to regulate the voice. The thyroid cartilage is the 
 great one, the chief defence before, and which has edges 
 slanting far backwards, to defend the opening of the larynx. 
 The CKicoiD cartilage, which forms the upper ring of the tra- 
 chea, supports the arytenoid cartilages, and by its deepness be- 
 hind, raises them so that the opening of the glottis is behind 
 the middle of the great thyroid cartilage, and in the deepest 
 part of it, well defended by its projecting wings. The ary- 
 tenoid cartilages form the rima glottidis, the chink by which 
 we breathe ; which as it is narrower or wider, modulates and 
 tunes the voice ; the opening of which is so exquisitely moved 
 by its muscles in singing, widening or contracting in most deli- 
 cate degrees, and which is so spasmodically shut by the same 
 muscles when it is touched by a drop of water, or by a crumb 
 of bread ; but the valve of the glottis, the epiglottis stand- 
 ing over it, flaps down like the key of a wind instrument, so 
 that the rareness of such accidents is wonderful, when we con- 
 sider that the least attempt to draw the breath, while we are 
 swallowing, will produce the accident. 
 
 The muscles which move the tongue and throat must be far 
 too complicated to be explained at all, without some previous 
 knowledge of these parts ; and still, I fear, not easily to be ex- 
 plained with every help of regularity and order. 
 
 muscles op the throat. 
 
 By this arrangement, I mean to include under one class, all 
 those muscles which move the os hyoides, or the larynx, and 
 
 VQL. I. X 
 
162 
 
 MUSCLES OF THE 
 
 through these, as centrical points, move the jaws, gullet, and 
 tongue, and which, though they are inserted into the larynx, 
 have more relation to swallowing, or the motions of the gullet, 
 than to breathing, or to the motions of the wind -pipe. 
 
 The muscles which pull the throat down are these : 
 
 XXXIV. The sTEKNO-HYOiDRUs, which passes from the 
 sternum to the os hyoides ; a flat, broad, ribband-like muscle, 
 arises from the upper piece of the sternum, rather within the 
 breast, and partly also from the clavicle and cartilage of the first 
 rib, goes flat and smooth along the forepart of the throat, 
 mounts nearly of the same breadth to the os hyoides, and is 
 implanted into its basis, or that part (which in resembling the 
 os hyoides to the jaw) we should compare with the chin. 
 
 XXXV. The STEKNO-THYROIDEUS, w'liich passes in like 
 manner from the sternum to the thyroid cartilage, is like the 
 last, a flat, smooth, ribband-like muscle, rather thicker and 
 more fleshy, but very uniform in its thickness. As the thyroid 
 cartilage is below the os hyoides, the sterno-thyroid muscle 
 must lie under the sterno-byoideus muscle. It arises under 
 the sterno-byoideus muscle from the sternum and cartilage of 
 the rib, and is implanted into the rough line-of the lower edge 
 of the thyroid cartilage, and a little to one side, but not so much 
 as is represented in Cowper’s drawings. It immediately co- 
 vers the thyroid gland, and the operation of bronchotomy is 
 sometimes performed by piercing the wind-pipe betwixt these 
 two muscles. 
 
 XXXVI. The OMo-HYOiDEUs, which-was once named cora- 
 co-HYOiDEUs, being thought to arise from the coracoid process, 
 is a muscle of great length, and very slender; reaches from the 
 shoulder to the os hyoides ; it is like these last mentioned, a 
 long, flat, strap-like muscle, as flat and as fleshy, but not so 
 broad as either of the former. It lies along the side of the 
 neck ; is pinched in a little in the middle, where it is divided 
 by a tendinous cross line, which separates the fleshy belly into 
 two heads, whence it has frequently the name of digastricus 
 inferior. It arises from the upper edge of the scapula, near its 
 notch, and is implanted into the side of the os hyoides, where 
 the born goes off from the body of the bone. 
 
 These three muscles pull down the throat. The sterno-hy- 
 oides, and sterno-thyroideus pull it directly downwards : one 
 of the omo-hyoidei acting, pulls it to one side but if both act, 
 they assist in pulling directly down, and brace the trachea at 
 the same time a little down to the back. 
 
 The muscles which move the throat upward are : 
 
 XXXVII. The MYXo-HYoiDEUs, a flat and broad muscle, 
 which arises from the whole semi-circle of the lower jaw, {i. c.) 
 
LOWER JAW, THROAT, AND TONGUE. 163 
 
 from the backmost grinders to the point of the chin. It rises 
 from the inner surface of the jaw-bone, goes down to the basis 
 of the os hyoides, proceeds with very regular, straight, distinct, 
 and orderly fibres, from the jaw to the os hyoides, is plainly 
 divided in the middle from the symphysis of the jaw to the 
 middle of the os hyoides, by a middle tendinous and white 
 line. And though Cowper denies the authority of Vesalius, 
 who divides it thus, it is plainly two distinct muscles, one be- 
 longing to either side. 
 
 XXXVIII. The GENio-HYOiDEUs is a small neat pair of 
 muscles arising from the chin at a rough point, which is easily 
 distinguished within the circle of the jaw. The mylo-hyoideus 
 is named from the whole jaw. The genio-hyoideus is named 
 from the chin, arising from a small tubercle behind the chin ; 
 its beginning is exceedingly narrow : as it proceeds downwards, 
 it grows flat and broad ; it is implanted into the basis of the os 
 hyoides, by a broad edge, and is a beautiful and radiated mus- 
 cle. The sub- maxillary gland lies flat betwixt this muscle and 
 the last, and in the middle the sub-maxillary duct pierces the 
 membrane of the mouth, to open under the root of the tongue. 
 The two muscles move the os hyoides forwards and upwards 
 .when the jaw is fixed ; but when the os hyoides is fixed by the 
 muscles coming from the sternum, these muscles of the os 
 hyoides pull down the jaw. 
 
 XXXIX. The STVLO-HYOiDEUs is one of three beautiful and 
 slender muscles, which come from round the styloid process, 
 which all begin and end with slender tendons, and with small 
 fleshy bellies ; and one going to the pharynx or gullet, another 
 to the os hyoides, and a third to the tongue, they coincide in 
 one common action of drawing back the tongue, and pulling 
 the throat upwards. 
 
 This one, the stylo-hyoideus, arises from about the middle 
 of the styloid process, and going obliquely downwards and for- 
 wards, is fixed into the side of the os hyoides, where, the basis 
 and horn are joined. Above its insertion, its fibres are split, 
 so as to make a neat small loop, through which the tendon of 
 the digastric muscle runs. This stylo-hyoideus is sometimes 
 accompanied with another small fleshy muscle like it, and of 
 the same name, which was first, perhaps, observed by Cowper, 
 and has been named by Innes, stylo-hyoideus alter; but it 
 is not regular, nor has it ever been acknowledged as a distinct 
 muscle. 
 
 XL. The DIGASTRICUS Or BIVENTER MAXILLiE INEERIORIS 
 
 muscle, is named from its having two bellies. One belly arises 
 from a rugged notch along the root of the mastoid process, 
 where the flesh is thick and strong ; going obliquely forwards 
 
164 
 
 MUSCLES OF THE 
 
 and downwards, it forms along slender tendon, which passes by 
 the side of the os hyoides ; and as it passes, it first slips through 
 the loop or noose of the stylo-hyoideus, and then is fixed by 
 a tendinous bridle to the side of the os hyoides ; and then turn- 
 ing upwards towards the chin, it ends in a second fleshy belly, 
 which, like the first, is flat and of a pyramidal shape, lying 
 above the mylo-hyoideus. 
 
 Though this muscle is often called biventer maxillae inferio- 
 ris, as belonging to the lower jaw, perhaps it does more regu- 
 larly belong to the throat. No doubt, when the os hyoides is 
 fixed by its own muscles, from the shoulder and sternum, the 
 digastricus must act on the jaw ; an office which we cannot 
 doubt, since we often feel it taking a sudden spasm, pulling 
 down the chin with severe pain, and distortion of the neck. 
 But its chief office is raising the os hyoides; for when the jaw 
 is fixed, as in swallowing, the os hyoides pulls up the throat; 
 and this is the true meaning of its passing through the noose 
 of the stylo-hyoideus, and of its connection with the side of 
 the os hyoides. Then the digastric and stylo-hyoideus mus- 
 cles pull the throat upwards and backwards. 
 
 The muscles which move the parts of the larynx upon each 
 other are much smaller, and many of them very minute. 
 
 XLI. The HYo-THYKOiOEus goes down, fleshy and short, 
 from the os hyoides to the thyroid cartilage. It arises from 
 the lower border of the thyroid cartilage where the sterno-thy- 
 roideus terminates, and goes up along the side of the thyroid 
 cartilage, like a continuation of the sterno-thyroideus muscle. 
 It passes the upper border of the thyroid cartilage, and is fixed 
 to the lower edge of the os hyoides, along both its base and 
 part of its horn. 
 
 XLII. The CKico tiiyhoioeus is a very short muscle, pass- 
 ing from the upper edge of the cricoid to the lower margin of 
 the thyroid cartilage, chiefly at its side, and partly attached to 
 its lower horn, which comes dow'n clasping the side of the 
 CRICOID ring, so that it is broader above, and a little pointed 
 below. 
 
 These two small muscles must have their use, and they 
 bring the thyroid cartilage nearer to the os hyoides, and the 
 cricoid nearer to the thyroid cartilage ; and by thus shortening 
 the trachea, or compressing it slightly, they may perhaps af- 
 fect the voice ; but the muscles on which the voice chiefly de- 
 pends are those of the kima glottidis ; for there are many 
 small muscles which have their attachment to the arytenoid 
 cartilages, and which by their operation on the tbyro-aryte- 
 noid ligament govern the rima glottidisj. 
 
LOWER JAW, THROAT, AND TONGUE. 
 
 165 
 
 XLIIL The MUscuLus aiiytenoideus transversus, is that 
 delicate muscle which contracts the glottis by drawing the 
 arytenoid cartilages towards each other. It lies across, betwixt 
 them at their back part ; it arises from nearly the whole length 
 of one arytenoid cartilage to go across, and be inserted into 
 the same extent of the opposite one. 
 
 XLIV. Arttenoidetjs obliq,uus is one which crosses in a 
 more oblique direction, arising at the root of each arytenoid 
 cartilage, and going obliquely upwards to the point of the op- 
 posite one. These two muscles draw the arytenoid cartilages 
 together, and close the kima : frequently we find only one 
 oblique muscle. 
 
 XLV. The CRico-ARYTENOiDEUs POSTICUS, is a small py- 
 ramidal muscle, which arises broader from the back part of 
 the cricoid cartilage, where the ring is broad and deep ; and 
 going directly upwards, is implanted with a. narrow point, into 
 the back of the arytenoid cartilage. This pair of muscles 
 pulls the arytenoid cartilages directly backwards, and lengthens 
 the slit of the glottis : perhaps they assist the former, in closing 
 it more neatly and in producing more delicate modulations of 
 the voice. 
 
 XJjVI. The CRICO-ARYTENOIDEUS oBLiquus is one w’hich 
 comes from the sides of the cricoid cartilage, where it lies 
 under the wing of the thyroid, and being implanted into the 
 sides of the arytenoid cartilages, near their roots, must pull 
 these cartilages asunder, and (as the origin in the cricoid lies 
 rather before their insertion in the arytenoid cartilages) it must 
 also slacken the lips of the slit ; for the lips of the slit are 
 formed by two cords, which go within the covering membrane, 
 from the tip of each cartilage, to the back of the thyroid car- 
 tilage, and the crico-arytenoideus posticus must stretch these 
 cords, and the crico-arytenoideus lateralis must relax them. 
 
 XLVII. The THYREO ARYTENOiDEUs is a muscle very like 
 the last one, and assists it. It arises not from the cricoid car- 
 tilage, but from the back surface of the wing of the thyroid, 
 from the hollow of its wing, or where it covers the cricoid ; is 
 implanted into the forepart of the arytenoid cartilage, and by 
 pulling the cartilage forward and sideways, directly slackens 
 the ligaments', and widens the glottis.* 
 
 * There is in Alhinus, a second set of fibres, which he calls thyreo ar5’tenoideus alter, 
 arising from the inner and upper part of the tliyroid cartilage, and inserted into the arytenoid 
 cartilage just above the in-ertion of the crico-arytenoideus obliqtms ; this muscle must have 
 much the same action as the other. 
 
 There is another muscle which has been omitted in the te.\t, thyreo epiglottideus. It is 
 composed of a number of fibres, which run from the concavity of the thyroid cartilage to the 
 side of the epiglottis ; it has been divided by Alhinus into major and minor, but this we cannot 
 expect to find always, as it is onlv in very muscular bodies thn't we see fibres running from 
 
166 
 
 MUSCLES OP THE 
 
 These are all the muscles which belong to the larynx ; and 
 in our arrangement the muscles of the palate and pharynx 
 come next in order. 
 
 When a morsel is to be thrown down into the oesophagus, or 
 tube which leads to the stomach, the velum palati, or cur- 
 tain of the palate, is drawn upwards; the opening of the throat 
 is dilated ; the morsel is received ; then the curtain of the pa- 
 late falls down again. The arch of the throat is contracted, 
 the bag of the pharynx is compressed by its own muscles ; and 
 the food is forced downwards into the stomach. 
 
 XLVIII. The azygosuvuljU.— ( he velum PENmmuM palati 
 is that pendulous curtain which we see hanging in the back 
 part of the mouth, in a line with the side circles of the throat: 
 and the uvula is a small pap, or point of flesh, in the centre of 
 that curtain. The azygos uvul/e, or single muscle of the 
 uvula, is a small slip of straight fibres, which goes directly 
 down to the uvula in the centre of the curtain. It arises from 
 the peak, or backmost sharp point of the palate bones, and 
 pulls the uvula, or pap of the throat directly upwards, re- 
 moving it out of the way of the morsel which is to pass. 
 
 XLIX. Levator palati mollis arises from the point of the 
 os petrosuin, and from the Eustachian tube, and also from 
 the sphenoid bone.* These parts hang over the roof of the 
 velum, and are much higher than it ; so this muscle descends 
 to the velum, and spreads out in it ; and its office is to pull up 
 the velum, to remove it from being in the way of the morsel, 
 which is about to pass, and to lay the curtain back at the same 
 time, so as to be a valve for the nostrils, and for the mouth of 
 the Eustachian tube, hindering the food or drink from entering 
 into these passages. 
 
 L. The ciRcuMFLEXus PALATi,f and the constrictor isthmi 
 faucium, have a very different use. The circumflexus palati 
 is named from its fibres passing over, or rather under the hook 
 of the internal pterygoio, process; the muscle arises along with 
 the levator palati, (/. e.) from the sphenoid bone at its spi- 
 nous process ; and from the beginning of the Eustachian tube, 
 
 the thyroid cartilage to the epiglottis. Along with this muscle may he claspd the set of fibres 
 which are seen sometimes running from the arytenoid cartilage to the epiglottis, and called 
 aryteno epigloLtideus. 
 
 * From the Eustachian tube, it was named salpingo staphilinus ; from the sphenoid 
 bone, spheno staphilinus ; from the pterygoid process, pterygo staphilinus ; from the 
 petrous process it was named petro salpingo staphilinus ; as if there were_ no science but 
 where tliere were hard names, and as if the chief mark of genius were enriching the hardest 
 names with all possible combinations and contortions of them. 
 
 t This also, has got a tolerable assortment of hard names, as circumelexus palati, 
 TENSOR palati, palato salpi.ngeus, staphelinus, externus, spheno-salp^go-staphy- 
 IlNUS, MUSCULUS TUB.E, viz. EUSTACHIANA3 NONUS. PtERYGO-STAPHILINUS of CowpeP, &C. 
 
LOWER JAW, THROAT, AND TONGUE. 167 
 
 it runs down along the tube, in the hollow betwixt the ptery- 
 goid processes ; it then becomes tendinous, turns under the 
 book of the internal pterygoid process, and mounts again to 
 the side of the v»lum. Now the levator and circumflexus arise 
 from the same points ; but the levator goes directly downwards 
 into the velum and so is useful in lifting it up. The circumflexus 
 goes round the hook, runs on it as on a pulley, turns upwards 
 again, and so it pulls down the palate, and stretches it, and 
 thence is very commonly named the tEi'isor palati mollis, 
 or stretcher of the palate.* 
 
 LI. The constrictor isthmi faucitjm arises from the 
 very root of the tongue on each side, goes round to the mid- 
 dle of the velum, and ends near the uvula.f This semi-circle 
 forms that first arch which presents itself, upon looking into the 
 mouth. , 
 
 LII. The PALATO-PHARYNGEUsf again forms a second arch 
 behind the first ; for it begins in the middle of the soft palate, 
 goes round the entry of the fauces, ends in the wing or edge 
 of the thyroid cartilage ; and as the first arched line (that form- 
 ed by the constrictor,) belonged to the root of the tongue, 
 the second arched line belongs to the pharynx or gullet.^ 
 The circumflexus palati makes the curtain of the palate tense, 
 and pulls it downwards : the constrictor faucium helps to pull 
 down the curtain, and raises the root of the tongue to meet it; 
 the palato-pharyngeus farther contracts the arch of the fauces, 
 which is almost shut upon the morsel now ready to be forced 
 down into the stomach, by those muscles which compress the 
 pharynx itself. 
 
 The PHART.Nx, which is the opening of the gullet, that it 
 may receive freely the morsel of food, is expanded into a large 
 and capacious bag, which hangs from the basis of the skull, is 
 chiefly attached to the occipital bone, the pterygoid processes, 
 and the back parts of either jaw-bone. The (esophagus again 
 is the tube which conveys the food down into the stomach, 
 and this bag of the pharynx is the expanded or trurapet-like 
 end of it ; or it may be compared with the mouth of a funnel. 
 Towards the mouth, the pharynx is bounded by the root of the 
 tongue, and by the arches of the throat ; behind, it lies flat and 
 
 * Some of its posterior fibres mix with the constrictor pharyngis superior and palate 
 pharyngeus. 
 
 f Named glosso staphiliots, from its ori^n in the tongue, and insertion into the 
 
 UVULA. 
 
 X The SALPiNGO-PHARVNGEcs of Alhious, Is no more tlian that part of the palato-pha- 
 ryngeus which arises from the moutli of the Eustachian tube. 
 
 ) In its passage down, its fibres are mixed with the stylo-pharyngeus, and in its insertion, 
 fhey are mingled with the inferior constrictors. 
 
168 
 
 MUSCLES OF THE 
 
 smooth along the bodies of the vertebrse; before, it is protect- 
 ed, and in some degree surrounded by the great cartilages of 
 the larynx ; the horns of the os byoides embrace its sides, and 
 it is covered with flat muscular fibres, which,* arising from the 
 os byoides and cartilages of the throat, go round the pharynx 
 in fair and regular orders, and are named its constrictors, because 
 they embrace it closely, and their contractions force down the 
 food. 
 
 LIII. The STYLO-PHARYNGEus arises from the root of the 
 styloid process. It is a long slender and beautiful muscle ; ir 
 expands fleshy upon the side of the pharynx ; extends so far 
 as to take a hold upon the edge of the thyroih' cartilage ; it 
 lifts the pharynx up to receive the morsel, and then straightens 
 and compresses the bag, to push the morsel down, and by its 
 hold upon the thyroid cartilage it commands the larynx also, 
 and the whole throat. 
 
 The pharynx being surrounded by many irregular points of 
 bone, its circular fibres or constrictors have many irregular 
 origins. The constrictor might fairly enough be explained as 
 one muscle, but the irregular origins split the fibres of the mus- 
 cle, and give occasion of dividing the constrictor into distinct 
 parts; for one bundle arising from the occipital bone and os 
 petrosum, from the tongue, the pterygoid process, and the two 
 jaw-bones, is distinguished as one muscle, the constrictor- 
 superior.* Another bundle arising from the os hyoides is 
 
 named the constrictor medius.f A third bundle, the lowest 
 of the three, arising from the thyroid and cricoid cartilages, is 
 named the constrictor inferior. J 
 
 LIV. The CONSTRICTOR SUPERIOR arising from the basis of 
 the skull, from the jaws, from the palate, and from the root of 
 the tongue, surrounds the upper part of the pharynx ; and it 
 is not one circular muscle, but two muscles divided in the mid- 
 dle line behind, by a distinct rapha, or meeting of the opposite 
 fibres.l^ 
 
 LV. The CONSTRICTOR MEDius rises chiefly from the 
 round point in which the os hyoides terminates ; it also arises 
 from the cartilage of the os hyoides (f. e.) where the horns 
 are joined to the body. The tip of the horn being the most 
 prominent point, and the centre of this muscle, it goes upwards 
 
 * These good opportunities of names have not been disregarded ; this muscle has been 
 
 named CEPHALO-rllARYNGEUS, PTEHYG0-PI!AEYNQEU8, MtlO PIIARYNGEUS, GLOSSO-PHARYN- 
 GEUS. 
 
 f This one is named hyopharyngeus, or syndesmo pharyncegs, from its origin in the. 
 cartilage also of the os hyoides. 
 
 t This, of course, is named thyero-phabyngeus, and crico-pharysgeus. 
 
 ’ It is connected with the buccinator, the root of the tongue, and palate. 
 
LOWER JAW, THROAT, AND TONGUE. 
 
 169 
 
 and downwards, so as to have something of a lozenge-like 
 shape ; it lies over the upper constrictor like a second layer, 
 its uppermost peak, or pointed part, touches the occipital bone, 
 and its lower point is hidden by the next muscle. 
 
 LVI. The CONSTRICTOR INFERIOR arises partly from the 
 thyroid and partly from the cricoid cartilage ; and it again goes 
 also obliquely, so as to overlap or cover the lower part of the 
 constrictor raedius. This, like the other two constrictors, 
 meets its fellow in a tendinous middle line ; and so the morsel 
 admitted into the pharnyx by the dilatation of its arches, is 
 pushed down into the oesophagus by the forces of these con- 
 strictores pharyngis, assisted by its styloid muscles.’ 
 
 LVII. The (ESOPHAGUS is merely the continuation of the 
 same tube. It lies flat upon the back-bone, and it is covered 
 in its whole length by a muscular coat, which is formed, not 
 like this of the pharynx, of circular fibres, but of fibres running 
 according to its length chiefly. And this muscle, surrounding 
 the membraneous tube of the oesophagus like a sheath, is 
 named (LVIII.) vaginalis gulje. 
 
 MUSCLES OF THE TONGUE. 
 
 The muscles of the tongue are large bundles of fle^ which 
 come from the os hyoides, the chin, and the styloid process. 
 Their thickness constitutes the chief bulk of the tongue. Their 
 actions perform all its motions. 
 
 LIX. The HYOGLossus is a comprehensive name for all 
 those which arise from the os hyoides. The muscles from the 
 os hyoides go oflT in three fasciculi, and were once reckoned 
 as distinct muscles. That portion which arises from the basis 
 of the os hyoides was called basioglossus ; that which arises 
 from the cartilaginous joining of the body and horn was called 
 CHONDROGLOSsus; and that which arises from the horn itself 
 was named ceratoglossus ; or the terms were all bundled to- 
 gether in the perplexed names of basio-chondro-cerato-glos- 
 sus. 
 
 The hyoglossus, then, is all that muscular flesh which arises 
 from the whole length of the os hyoides, and which, by the 
 changing form of the bone in its basis, cartilage, and horn, has 
 a slight mark of division, but which lie all in one plain, and 
 need not have distinct names. 
 
 T.X. The GENio HYOGLOSSUS arises from the rough tubercle 
 behind the symphisis of the chin. It has a very narrow or 
 pointed origin ; it spreads out fan-like, as it goes towards the 
 
 VOL. I. Y 
 
170 MUSCLES OE THE LOWER JAW, &C. 
 
 tongue and base of the os hyoides ; and it spreads with radii., 
 upwards and backwards, making the chief part of the substance 
 of the tongue. 
 
 LXI. The LiNGUALis is an irregular bundle of fibres, which 
 runs according to the length of the tongue ; it lies betwixt the 
 genio hyoglossus and the byoglossus, and as it is in the centre, 
 and unconnected with any bone, it is named lingualis, as aris- 
 ing in the tongue itself. 
 
 The genio hyoglossi muscles from by far the larger part of 
 the tongue, and lie in the very centre. They go'through the 
 whole length, (i. e.) from the root to the tip of the tongue, and 
 from the radiated form of their fibres they perform every 
 possible motion ; whence this was named by Winslow, mus- 
 culus POLYCHRESTUS, fop its rays proceed from one point or 
 centre, and those which go to the point of the tongue pull the 
 tongue backwards into the mouth. Those which go backwards 
 thrust the tongue out of the mouth. The middle fibres acting, 
 make the back of the tongue hollow, while the tip and the root 
 of the tongue both rise. 
 
 The hyoglossi muscles lie on either side of the genio- 
 hyoidasi, and make up the sides of the tongue, and their chief 
 action would seem to be this, that the hyoglossus muscle of 
 either side acting, the edges of the tongue would be pulled 
 downwards, and the back rounded, the opposite of which 
 motion is the genio-byoidaei acting, by which the middle of 
 the tongue is made into a groove, the edges rising, and the 
 centre being depressed. Lastly, The styloglossus is plainly 
 intended for drawing the tongue deep into the mouth, parti- 
 cularly affecting the point of the tongue. 
 
( ni ) 
 
 CHAP. III. 
 
 OF THE MUSCLES OF THE ARM, 
 
 INCLUDING THE MUSCLES OF THE SCAPULA, ARM, FORE-ABM, 
 AND HAND. 
 
 MUSCLES OF THE SCAPULA. 
 
 The great peculiarity of the arm is, the manner of its con- 
 nection with the breast, to which it is fixed by the slight liga- 
 ments of the clavicle only : but its union to the body is secured 
 by its strong and numerous muscles, by which indeed it may 
 be said both to be fixed and moved. Though it were perhaps 
 more regular to describe first the muscles of the trunk, it will 
 be more easy and natural to describe first the broad muscles, 
 belonging to the scapula, which cover almost the whole trunk, 
 and hide its proper muscles, viz. those which move the ribs 
 and spine. For the muscles which move the scapula lie upon 
 the trunk ; those which move the arm lie upon the scapula ; 
 those which move the fore-arm lie upon the arm ; and those 
 for moving the hand and fingers lie upon the fore-arm. The 
 leg requires but one chief motion, viz. backwards and forwards, 
 flexion and extension. It has no other motions than those of the 
 thigh and of the knee ; but the arm requires an easy and cir- 
 cular motion, and its joints are multiplied : for it has the wrist 
 turning round ; it has the elbow for hinge-like motions ; it has 
 the shoulder-joint upon which the arm rolls ; and to assist all 
 these, the scapula, which is the centre of all these motions, is 
 itself moveable ; after a certain point of elevation, all the mo- 
 tion in raising the arm is performed, not by the motions of the 
 shoulder-bone upon the scapula, but by the scapula upon the 
 trunk. For whenever the shoulder-bone rises to the horizon- 
 tal direction, it is checked by the acromion, which hangs over 
 it; and if the arm is to be raised higher still, the scapula must 
 roll ; it turns upon the point of the clavicle, and in turning, it 
 glides upon those muscles, which are like a cushion betwixt it 
 and the trunk. 
 
 The muscles which move the scapula, come from the breast 
 to move it forwards ; from the neck, to move it upwards ; from 
 the spines of the vertebrae, to move it backwards ; and from 
 the side, that is, from the ribs, to move it downwards. 
 
 LXII. The TRAPEZIUS is named from its lozenge form ; or 
 is often named cucularis, from its resembling the monk’s 
 cowl, hanging back upon the neck, It is one of the most 
 
17!i MUSCLES OF THE ARM, &C. 
 
 beautiful muscles in the body ; and the two muscles together 
 cover all the shoulders and neck, with a lozenge-like form, 
 with neat and sharp points, extending from the lip of one 
 shoulder to the tip of the other, and from the nape of the 
 neck quite down to the loins. It arises from the most pointed 
 part of the occipital bone, and along the transverse spine quite 
 to the mastoid process, by a thin membranous tendon ; from 
 this point all down the neck, it has no hold of the vertebrae, 
 but arises from its fellow in a strong tendon, which, extending 
 like a bow-string down the neck, over the arch of the neck, 
 and not touching the vertebrae, till it comes down to the top 
 of the back, is named ligamentum noch.®. The tendon be- 
 gins again to take hold of the spines of the two last vertebrae of 
 the neck, and arises from all the spinous processes of the back, 
 dovftnwards; from this long origin its fibres converge towards 
 the tip of the shoulder : it also comes a little forward over the 
 side of the neck. 
 
 It is implanted into more than one-third of the clavicle near- 
 est the shoulder; into the tip of the acromion ; into tlie whole 
 length of the spine, from which the acromion rises ; and its 
 fibres arising from along the neck and back, and converging 
 almost into a point, must have various elfects, according to the 
 different fibres which act : for those which come downwards 
 must raise the scapula; those which come from the middle of 
 the back must carry it directly backwards ; those which come 
 from the lower part of the back must depress it ; and those 
 different fibres acting in succession, must make the scapula 
 roll. The trapezius is chiefly a muscle of the scapula, but it 
 must be also occasiDnally a muscle of the bead, pulling the 
 head backwards, and bending the neck. 
 
 Three other muscles which raise the scapula, or carry it 
 backwards, lie so much in the same plane, and are so little 
 divided from each other, that they might almost be reckoned 
 different portions of the same. 
 
 LXIil. Levatok scapul®, named also levator propjuus 
 ANGULAKis, is a Small thin slip of flesh, which arises from the 
 four or five uppermost vertebrae of the neck, at their transverse 
 processes, by three or four and sometimes five distinct heads. 
 The heads join to form a thin and flat stripe of muscle, about 
 three inches in breadth, which is fixed by a flat thin tendon to 
 the upper corner of the scapula, to pull it upwards, as in shrug- 
 ging the shoulders ; whence itis named musuulus patientije. 
 
 LXIV. and LXV. The rhomboid muscle stretches flat, 
 neat, and of a square form, betwixt the spine and the Avhole 
 line of the base of the scapula. One part arises from the three 
 lower spinous processes of the neck, and is implanted into the 
 
MUSCLES OP THE ARM, &C. 17^ 
 
 base of the scapula higher than the rising of the spine of the 
 scapula j another portion arises from the spinous processes of 
 the first four vertebrae of the back, runs exactly in the same 
 plane with the other into the base of the scapula below the 
 spine.* The part arising from the three vertebras of the neck 
 is slightly divided from that which arises from the four verte- 
 brae of the back, though not distinctly, and often not at all. I 
 would reckon this but one muscle, but it has been commonly 
 distinguished into (LXIV.) the rhomboideus minor, the up- 
 permost portion, and (LXV.) the rhomboideus major, the 
 lower portion. These are seen after raising the trapezius ; 
 and the uses of the trapezius, levator scapulae, and rhomboi- 
 deus, are to raise the scapula or to carry it backwards. The 
 muscles which move the scapula downwards and forwards, viz. 
 the pectoralis minor and the serratus major anticus, lie upon 
 the forepart of the breast. 
 
 LXVI. The SERRATUS major anticus lies upon the side: 
 of the chest arising from the ribs ; and as the ribs have in- 
 terstices betwixt them, every muscle arising from the ribs arises 
 by distinct portions from each rib : all such distinct and point- 
 ed slips are named digitations, tongues, or serrae, from their 
 resembling the teeth of a saw; and every muscle arising from 
 the ribs must be a serrated muscle. Tbe serratus major anticus 
 is that great and broad muscle, the chief part of which lies un- 
 der the scapula ; and nothing of which is seen but the fleshy 
 tongues, by which it arises from the sides of the ribs. It is all 
 fleshy, and is of a considerable breadth and strength : it arises 
 from all the true ribs : it sometimes misses the first rib; and 
 from three of the false ribs : its indigitations, of course, spread 
 all over the side of the thorax like a fan : its upper indigitations 
 lie under the pectoralis major, and its lower indigitations are 
 mixed with the beginning of the external oblique muscle of the 
 abdomen. Its middle indigitations are seen spreading upon 
 the sides of the thorax : it lies thick and fleshy under the 
 scapula, and is a part of that cushion on which the scapula 
 glides : its fibres converge towards a narrower insertion ; and 
 the muscle ends thick and fleshy in the whole length of that 
 line which we call the basis of the scapula, and is as it were 
 folded round it ; so that this muscle, which comes from before, 
 is implanted along with the rhomboideus, which comes from 
 behind. 
 
 Perhaps, in difficult breathing, the shoulder-blade being- 
 raised and fixed by its own muscles, the serratus major may 
 
 ^ We frequently indeed almost find that the rhomboideus major tates al-Jo an origin from 
 '.he 7th cendcal vertebra ; it i? so expressed in Albinus. 
 
174 MUSCLES OP THE ARM, &C. 
 
 assist in heaving up the ribs ; but its chief operation is upon 
 the scapula ; for when the whole acts, it pulls the scapula 
 downwards and forwards. When only the lower portions act, 
 it pulls the lower angle of the scapula forwards, by which the 
 scapula rolls, and the tip of the shoulder is raised ; when the ] 
 upper part acts in conjunction with the little pectoral muscle, j 
 the tip of the shoulder is fixed and pulled downwards towards I 
 
 the chest, and the lower corner of the scapula rolls back- I 
 
 wards. j 
 
 LXVII. The PECTORALis MINOR lies under the pectoralis 
 ina,jor, close upon the ribs ; and as it arises from the third, 
 fourth, and fifth ribs, it sometimes takes its origin from the 
 second, third, and fourth ribs, and sometimes only from the 
 third and fourth ; it also is a serrated muscle, and was named 
 serratus minor anticus : its three digitations are very thick and 
 fleshy ; they soon converge so as to form a small, but thick and 
 fleshy muscle, which, terminating in a point, is inserted into • 
 the very apex of the coracoid process : by pulling the coracoid 
 process forwards and downwards, it will roll the shoulder. 
 
 LXVIII. The SUBCLAVIAN muscle is another concealed 
 muscle of the scapula ; for the clavicle is just the hinge upon 
 which the scapula moves, and the subclavian muscle arises by 
 a flat tendon from the cartilage of the first rib ; it becomes flat 
 and fleshy, and lies along betwixt the clavicle and the first rib ; | 
 
 it arises at a single point of the rib, flat and tendinous ; but it | 
 
 is inserted into a great length of the clavicle, beginning about 
 two inches from the sternum, and being inserted all along the j 
 clavicle, quite out to where it is joined to the acromion pro- i 
 cess : its chief use (since the rib is immoveable) must surely : 
 be to pull the clavicle, and consequently the shoulder down- Ml 
 wards, and so to fix them. > 
 
 Many have affected to find other muscles of respiration than ™' 
 those which directly belong to the ribs. Among these are 
 reckoned the serratus major, the pectoralis minor, &ic. ; but 
 there is much reason to doubt whether any muscles can have 
 much effect which do not belong properly to the ribs : and it 
 is manifest, that the subclavian can have none, since the first 
 I’ib is quite rigid, has so little length of cartilage, that it cannot 
 bend nor move. 
 
 The scapula is thus moved in every possible direction up- 
 wards, by the levator and the trapezius ; backwards by the 
 rhomboideus, assisted by the middle portions of the trapezius ; 
 downwards and backwards by the lowest order of fibres in the 
 trapezius; downwards and forwards by the serratus major anti- 
 cus ; directly downwards by the serratus, balanced by the 
 
175 
 
 MUSCLES OF THE ARM, &C. 
 
 trapezius, and assisted by the subclavius ; and directly forwards 
 by the pectoralis minor. 
 
 MUSCLES OF THE AHM; 
 
 VIZ. THOSE MOVING THE OS HUMERI, OR ARM-BONE. 
 
 LXIX. The PECTORALEs MAJOR is a large, thick, and fleshy 
 muscle which covers all the breast. It arises from the half of 
 the clavicle next the sternum ; from all the edge of the sternum, 
 the cartilaginous endings of the three lower true ribs.*— 
 Where it arises from the sternum, it is tendinous, and the fibres 
 from the opposite muscles cross and mix, so as to make a sort 
 of fascia covering the bone. It is fleshy where it arises from 
 the ribs, and there it mixes with the external abdominal mus- 
 cle. The fibres approach each other till they form a flat ten- 
 don about an inch in breadth ; and as the fibres approach each 
 other, they cross in such a way, that the lower edge of the 
 muscle forms the upper edge of the tendon, which is still flat, 
 but twisted ; its implantation is into the edge, if I may call it 
 so, of the groove or rut of the biceps tendon. That part 
 which arises from the clavicle is a little separated from that 
 which arises from the sternum ; a fatty line makes the distinc- 
 tion ; and they are sometimes described as two parts : it is 
 those two bundles chiefly which cross ^ach other to make the 
 plaited appearance. The pectoralis, among others, has been 
 made a muscle of respiration.f 
 
 LXX. The LATissiMus dorsi is the broadest, not only of 
 the back, but perhaps of the whole body. It is a beautiful 
 muscle, covering all the lower part of the back and loins, and 
 reaching to the arm, to be the antagonist to the pectoral mus- 
 cle. It arises by a broad, flat, and glistening tendon, which co- 
 vers all the loins, and which is in some degree the root of other 
 muscles, especially of the longissimus dorsi. This broad sil- 
 very tendon begins exactly in the middle of the back ; it arises 
 from the lower vertebrae of the loins, from the spines and knobs 
 
 * We frequently find slips running as distinct muscles from the 7th and 8th rib to the hu- 
 merus ; they have been remarked, in the Windmill-street dissecting-room, more 'frequently 
 in Lascars and Negroes tlian in Europeans. In December 1814, a body was dissected, in 
 wliich there was found on both sides a slip of fibres 1 8 indies long, extending from the 4th 
 and 5th rib to the fascia, between the triceps and brachialis interims, and a distinct slip 
 tendon might be traced even to the inner condyle. 
 
 t Haller tells us, that when, at any time, he had rheumatism in this muscle, his breath- 
 ing was checked ; and when he had dilficult breathing, he found great relief by fixing the 
 hands, raising the shoulders, and acting with the pectoral muscles. It seems confirmed by 
 these facts, tliat asthmatics take this posture ; women in labour fix their arms, by resting 
 upon the arms of tlieir chair ; those who play on wind rastjraments raise the shoulders in 
 strammg. 
 
176 MUSCLES OP THE ARM, &C. 
 
 of the back of the sacrum, and from the back part of the cir- 
 cle of the os ilium ; this last is the only part that is fleshy. 
 The flat tendon gradually passes into a flat and regular muscle, 
 which wraps round the side of the body, and as it lies over the 
 corner of the scapula, it sometimes receives a small fleshy 
 bundle from it ; and as it passes over the four lower ribs, it 
 has some tendinous slips sent into it, by which it is attached to 
 the ribs. Its fibres converge : for the lower ones ascend ; the 
 upper ones go directly across. And these different orders not 
 only meet to form its flat tendon, but they cross each other, 
 like those of the pectoral muscle : here also the tendon is 
 twisted, and the upper edge of the muscle forms the lower 
 edge of the flat tendon ; which, passing into the axilla, turns 
 under the arm-bone, and is implanted into it, on the inner edge 
 of the bicipital groove ; so the tendons of the pectoralis and 
 latissimus meet each other; they, in fact, join face to face, as 
 if the one tendon ended directly in the other ; and both uni- 
 ted, make a sort of lining for the groove, or a tendinous sheath, 
 for the long tendon of the biceps to run on. 
 
 These two muscles form the axilla or arm-pit ; and although 
 each has its peculiar offices, their chief operation is when they 
 coincide in one action ; and that action is exceedingly power- 
 ful, both by the great strength of either muscle, and by their 
 being implanted into the arm-bone, four inches below its head. 
 The pectoralis major is for pulling the arm forwards, as in lay- 
 ing the arms across the breast, or in carrying loads in the arms ; 
 and it forms the border of the axilla before. The latissimus 
 dorsi has a wider range ; when the arm is raised, it brings it 
 downwards as in striking with a hammer, or downwards and 
 backwards, as in striking with the elbow, or in rolling the arm 
 inwards and backwards, as in turning the palm of the hand be- 
 hind the back, whence it has the obscene name of musctjlus 
 scALPTOR ANi, OP TERSOR ANi ; and it forms the back edge of 
 the axilla. The edges of these two muscles receive the pres- 
 sure of crutches, and defend the vessels and nerves ; when both 
 muscles act, the arm ispressed directly downwards, as in rising 
 from our seat, or in holding a bundle under the arm ; or when 
 the arm is fixed, these muscles raise the body as in the exam- 
 ple just mentioned, of rising from our seat, or in walking with 
 a short stick, or in raising ourselves by our hands over a high 
 beam. 
 
 LXXI, The DELTOiDES is the first of those muscles which 
 arise from the scapula, to be inserted into the shoulder-bone. 
 It is named deltoid muscle, from its resembling the letter A of 
 the Greeks ; it is thick and fleshy, and covers the top of the 
 shoulder, filling up the space betwixt the' acromion process and 
 
17 ? 
 
 MUSCLES OF THE ARM, &C. 
 
 the shoulder-bone ; it arises from all that part of the clavicle, 
 which is not occupied by the pectoralis muscle, and is separated 
 from it only by a fatty line ; it arises again in another bundle, 
 from the point of the acromion process, and this middle bun- 
 dle is also insulated by a fatty line on either side of it. The 
 third bundle arises from the spine of the scapula, behind the 
 acromion process, and which is also attached to the base by a 
 strong ligamentous fascia, which covers the infra spinatus mus- 
 cle. And thus the muscle has three converging heads, viz. a 
 head from the outer end of the clavicle, a head from the acro- 
 mion, or tip of the shoulder, a head from the ridge of the spine, 
 each divided from the other by a fatty line.* These heads or 
 bundles of fibres, meeting about one-third down the humerus, 
 form a short, flat, and strong tendon, which grasps or almost 
 surrounds the shoulder-bone. 
 
 These three distinct heads must be observed in speaking of 
 the use of the muscle ; for though the chief use of the muscle 
 be to raise the arm, this is not the use of it in all circumstan- 
 ces ; for the outer and inner heads, lying by the side of the 
 shoulder-bone, and below the joint, do, when the arm is lying 
 flat by the side, assist the pectoral, and latissimus dorsi muscles 
 in drawing it close to the side. But when the middle bundle 
 raises the arm, in proportion as the middle bundle raises the 
 arm, it loses of its power ; and in proportion as it loses of its 
 power, the side portions, having come into a new direction, be- 
 gin to help : nay, when the arm is raised to a certain point, 
 more power still is required, and the clavicular part of the pec- 
 toral muscle also comes to assist. It is in this succession, that 
 the several bundles of fibres act ; for if they began all at once 
 to act, the arm should rather be bound down by the lateral por- 
 tions, than raised by the middle one. 
 
 LXXII. CoRAco BRACHiALis. — The coraco brachialis, so 
 named from its origin and insertion, is a long and rather slender 
 muscle. 
 
 It arises from the coracoid process of the scapula, along 
 with the short head of the biceps muscle, and it is closely con- 
 nected with this head, almost its whole length : it is small at its 
 beginning ; it grows gradually thicker as it decends ; it is all 
 fleshy, and is inserted by a very short tendon into the os hu- 
 meri, nearly about its middle, betwixt the bracbialis and the 
 third head of the triceps. It is perforated by the external cu- 
 taneous nerve. This was observed by Casserius, an Italian 
 anatomist ; and the muscle is often named musculus perfo- 
 
 RATUS CASSERII. 
 
 * Albinus has distinguished it into seven fasciculi or bundles; a very saperfliioa® aecora'oy 
 
 VOL. I. Z 
 
178 
 
 MUSCLES OF THE ARM, &C. 
 
 Its action is very simple, to raise the arm obliquely forwards 
 and upwards, and consequently to give a degree of rotation. 
 It will also have a chief effect in pulling the arm towards the 
 side of the body. 
 
 LXXIIL The supra spinatus is so named from its oc- 
 cupying the hollow of the scapula above the spine. 
 
 It arises from the back of the scapula, reaching to the base, 
 from the spine, and from the superior edge or costa; it is ex- 
 ceedingly thick and fleshy, filling up all the hollow between 
 the spine and superior costa ; and it is firmly enclosed in this 
 triangular hollow, by a strong tendinous expansion, which 
 passes from the superior edge of the scapula, to the ridge of 
 the spine ; it is consequently a muscle of a triangular figure, 
 thick and strong ; it passes under the acromion, and degene- 
 rates into a tendon there, and going under the acromion, as 
 under an arch, and over the ball of the humerus, it adheres to 
 the capsule of the shoulder-joint, and is at last implanted by a 
 broad strong tendon into the upper part of the great tuberosity 
 on the head of the bone. 
 
 It is evidently designed for raising the humerus directly 
 upwards, and by its attachment to the capsule, the capsule is 
 drawn up when the arm is raised, so that though lax, it cannot 
 be caught in the joint. It exactly performs the same motion 
 with the middle part of the deltoiues, lies in the same direc- 
 tion with it, and assists it. 
 
 LXXIV. Infra spinatus, is like the former in all respects, 
 of the same use, and assisting it. 
 
 This also is of a triangular shape, and is fully one half larger 
 than the supra spinatus ; and the supra spinatus arises from all 
 the triangular cavity above the spine : this arises from almost 
 all the triangular cavity below it. 
 
 It arises fleshy from all the back of the scapula below the 
 Spine, except that part giving origin to the teres major and 
 minor, from the spine itself, and from all the base of the sca- 
 pula, below the beginning of the spine, and also from the 
 greater part of the lower costa of the scapula. It i« 
 very thick and strong, almost filling up the triangular 
 cavity, and it is closed in like the former, by a strong 
 tendinous expansion ; it begins to grow tendinous about 
 its middle, but it continues also fleshy till it passes over 
 the socket of the shoulder-joint : it also is connected with the 
 capsular ligament, is inseried into the middle of the same tu- 
 berosity with the former, and has exactly the same uses, viz. 
 preventing the capsule from being caught in the joint, and 
 raising the arm upwards, and inclining it a little outwards, by a 
 slight degree of rotation. And I do believe, that one great use 
 
179 
 
 MUSCLES OF THE ARM, &C. 
 
 •f these two muscles is, when the arm is much extended back- 
 wards, to prevent the head of the humerus from starting out of 
 its superficial socket. 
 
 LXXV. The TCftKs MINOR is a third muscle which co-ope- 
 rates with these. This and another are so named from their 
 appearance, not from their shape, for they seem round when 
 superficially dissected, because then their edges only are seen : 
 but when fully dissected from the other muscles, they are ra- 
 ther flat. The teres minor is a long, small, fleshy muscle ; it 
 arises from the angle, and all the lower edge of the scapula : it 
 is like the infra spinatus; it becomes earl} tendinous ; but the 
 tendon is accompanied with fleshy fibres from below ; its flat 
 tendon, in passing over the joint, is attached to the capsule, 
 and is finally inserted into the great tuberosity of the shoulder- 
 bone, so that it must have exactly the same uses as the two 
 former muscles. It is separated from the infra spinatus by 
 that tendinous expansion with which the latter is covered ; it 
 looks like a part of the same muscle in its origin, where it lies 
 upon the scapula ; but is very distinct in its tendon. The su- 
 pra spinatus, infra spinatus, and teres minor, raise the arm. 
 
 LXXVI. The TEKEs MAJOR is in shape like the former, lies 
 lower upon the edge of the scapula than the teres minor, and 
 is thicker and longer than it. 
 
 It arises chiefly from the angle of the scapula ; partly from 
 the lower edge of the scapula, at its back part ; it is connected 
 with the TERES minor, and infra spinatus. It is a large, 
 thick, and flat muscle, and forms a flat strong tendon, which 
 passes under the long head of the triceps; it passes under the 
 os humeri ; turns round it, and is inserted into the ridge, on 
 the inner side of the groove, and gives some tendinous fibres 
 to line the groove. In short, it accompanies the tendon of the 
 latissimus dorsi, is inserted along witjj it, and may be consider- 
 ed as the congenor of the latissimus dorsi ; and the two ten- 
 dons are inclosed in one common capsule, or sheath of cellular 
 substance. 
 
 Its use, then, is evidently to draw the humerus downwards 
 and backwards, and to perform the same rotation of the arms, 
 which the latissimus dorsi does. 
 
 LXXVII. The subscapularis lines all the concavity of 
 the scapula like a cushion. It is like the surface of the scapula 
 on which it lies, of a triangular shape ; and from the conver- 
 gence of all the fibres it is completely l adiated or fan-like ; it 
 is very fleshy, thick, and strong ; the radii are each minutely 
 described by Albinus; but Sabatier says, with good sense, that 
 he cannot distinguish them, so as to describe them accurately; 
 and he might have added, that there was not the shadow of a 
 
180 MUSCLES OF THE ARM, &1C. 
 
 motive for wasting time in so trivial an employment as counting 
 the bundles. 
 
 It arises from the two costae, the base and all the internal 
 surface of the scapula. And indeed it is to favour this origin 
 that the inner surface of the scapula is full of little risings and 
 hollows, to every one of which the muscle adheres closely. 
 Just under the coracoid process, is the only part from whence 
 it does not arise. That little space is filled up with cellular 
 substance. 
 
 Its alternately tendinous and fleshy fibres are so rooted in 
 the scapula, and so attached to its risings and depressions, that 
 it is difficultly cleaned away from the bone. 
 
 The tendon and upper edge of the muscle is almost conti- 
 nuous with the supra spinatus ; but from the manner of its in- 
 sertion, its effect is very opposite from that of the supra spina- 
 tus, for it goes round the os humeri to its insertion, and it is 
 fixed to the lesser tuberosity, therefore it both pulls the arm 
 backwards and downwards, and performs the rotation like the 
 teres major, and latissimus dorsi. It is also like all the other 
 tendons, attached to the capsule, so as to prevent its being 
 caught ; and it is particularly useful by strengthening the shoul- 
 der-joint. 
 
 OF THE MOTIONS OF THE HUMERUS. 
 
 Having thus described all the muscles which move this bone, 
 I shall review the order in which they are arranged, and mark 
 their place and effects. 
 
 To distinguish clearly the function of each muscle, we have 
 but to mark the point to w'hich it is attached. 
 
 1. Those implanted above the head of the bone must raise 
 the arm. Now the supra spinatus, infra spinatus, and teres 
 minor, are implanted into the great tubercle, and raise the arm ; 
 and the deltoides is implanted in the same direction, and still 
 lower, so that it performs the same action with a still greater 
 degree of power. 
 
 2. There is implanted into the opposite, or lower part of 
 the head, the subscapularis, which, of course, draws the arm 
 directly downwards and backwards. 
 
 3. There is implanted into the outer edge of the bicipital 
 groove, the pectoralis major, and also the coraco-brachialis, 
 which comes in the same direction ; and these two pull the 
 arm inwards, towards the side and forwards. 
 
 4. There are inserted into the inside, or lower side of the 
 groove, the latissimus dorsi, and teres major, both of which pul! 
 
181 
 
 MUSCLES OF THE ARM, &C. 
 
 the arm directly backwards, as they bend under the arm, to 
 reach their insertion. They also roll the palm inwards and 
 backwards. And it is easy to observe in what succession those 
 muscles must act, to describe the circular and rotary motions 
 of the arm. 
 
 Joints are more strengthened by the origin and insertion of 
 muscles around them, than by elastic ligaments, which yield 
 or tear; whereas the muscles, having a living power, re-act 
 against any separating force. They contract, or, in other words, 
 they are strong in proportion to the violence that the joint suf- 
 fers. Thus, in the shoulder the capsule is so lax, that there is 
 a mechanical contrivance to prevent its being checked in the 
 joint, and it is moreover so weak, that, independent of its 
 yielding easily, it is also very easily torn ; but these muscles 
 surround the joint so fairly, ttiat their strength and their tendi- 
 nous connections with the head of the bone are more than a 
 compensation for the looseness of its capsular ligament. Were 
 not the muscles thus closely attached, the shoulders would be 
 very often displaced, the glenoid cavity is so superficial, and 
 the bursa so lax ; and surely it is for some such purpose, that 
 the muscles are planted so closely round the head ; for when 
 they are implanted at a distance from the centre, as one mus- 
 cle, the deltoid, is, or as the biceps and triceps of the arm, or 
 the ham-strings, or tendo Achillis, the power is much increased. 
 Here, in the muscles arising from the scapula, power is sacri- 
 ficed to the firmness of the joint, and they are all implanted 
 closely round the head of the bone. 
 
 The connection of the bones in this joint is in a manner 
 formed by these muscles, for the supra spinatus, infra spinatus, 
 teres major and minor, and the subscapularis, surround the 
 joint very closely, cover the joint with their flat tendons, and 
 so thicken the capsule, and increase its strength. 
 
 The muscles of the fore-arm are only four, the biceps and 
 BRACHiALis for bending, and the triceps and anconaius for 
 extending. 
 
 LXXVIII. Biceps erachii flexor is universally named 
 BICEPS, from its having two very distinct heads. It is an ex- 
 ceedingly thick and strong muscle, for when it contracts, we 
 leel it almost like a hard firm ball upon the forepart of the 
 arm, and at the upper and most conspicuous part of this ball 
 is the union of the two heads. 
 
 The larger and thicker head arises from the coracoid pro- 
 cess, by a tendon which extends three inches along the forepart 
 of the muscle, in the form of an aponeurosis, but at the back 
 part the tendon is short, and the muscle is attached there to 
 the fleshy belly of the coraco-brachialis. 
 
182 
 
 MUSCLES OF THE ARM, &G. 
 
 The second, or long head, arises from the edge of the gle- 
 noid cavity, at its upper part ; it is exceedingly small and ten- 
 dinous, and this long tendon runs down in its proper groove, 
 till about the third part down the humerus the two heads meet. 
 And though below this it is but one fleshy belly, yet here, as 
 in other muscles, the common division betwixt its two origins 
 may be still observed.* 
 
 It is earlier tendinous at the forepart and outer side; the 
 tendon here sends off that aponeurotic expansion which covers 
 all the arm below, and encloses the muscles as in a sheath. 
 The tendon, at first flat and large, becomes gradually smaller 
 and rounder ; it turns a little in its descent, so as to lay one 
 flat edge to the radius, and another to the ulna ; and it is at 
 last implanted into that round tubercle, which is on the forepart 
 of the radius a little below its neck ; but it has also an insertion 
 into the fascia of the fore-arm. 
 
 The great use of the biceps is to bend the fore-arm with 
 great strength. But as it is inserted into the tubercle of the 
 radius, when the arm and hand are turned downwards, it, by 
 acting, will pull them upwards, {i. e.) it will assist the supinators. 
 Since both its heads are from the scapula, it will occasionally 
 move the humerus, as well as the fore-arm. 
 
 LXXIX. The BRACHiALis intjbrnus lies immediately un- 
 der the biceps, and is a very strong fleshy muscle for assisting 
 the biceps in bending the arm. It is called brachialis, from 
 its origin in the fore-arm, and internus, from its being within 
 the biceps. 
 
 It arises from two-thirds of the os humeri at its forepart, by 
 a sort of forked head ; for it comes down from each side of the 
 deltoid. It continues its attachment all the way down the fore- 
 part of the humerus, to within an inch of the joint. It is very 
 thick, fleshy, and strong ; it is tendinous for about two inches 
 in its forepart ; and is inserted by a flat strong tendon into the 
 coronoid process of the ulna. 
 
 Other uses are ascribed to it, as the lifting up the capsule to 
 prevent its being pinched. But the chief use of it is to bend 
 the fore-arm. In a strong man, it is exceedingly thick, and its 
 edge projects from under the edge of the biceps, and is seen 
 in the lateral view. 
 
 LXXX. Triceps extensor. — Upon the back part of the 
 arm three muscles have been described : the extensor longus, 
 the extensor brevis, and the brachialis externus ; but there is, 
 in fact, only one three-headed muscle. 
 
 * It is not uncommon to find a third head to this muscle, which takes an origin (rom the 
 forepart of the humerus. 
 
18S 
 
 MUSCLES OF THE ARM, &C. 
 
 The longest head of this muscle is in the middle. It arises 
 by a flat tendon ; from an inch of tbe edge of the scapula un- 
 der the neck, and a little way from tbe origin of the long head 
 of the biceps ; and it is under this head that the tendon of the 
 teres major passes to its insertion. 
 
 The second head is on tbe outside of the arm, next in length 
 to this. It arises from the arm-bone under the great tuber, 
 and just below the insertion of the teres minor. The long 
 and second heads meet about the middle of the humerus. 
 
 The third, or internal head, is the shortest of all. It begins 
 at the inner side of the humerus, just under the insertion of 
 the teres major ; and it arises from the inner part of the hume- 
 rus, all the way down, and joins just where the second head 
 joins (z. e.) about the middle. All these heads still continue 
 adhering to the humerus (as the brachialis does on the fore- 
 side,) quite down to within an inch of the joint, and then a 
 strong thick tendon is formed, by which it is implanted strongly 
 in the projecting heel of the ulna, named olecranon, by which 
 projection of the bone the muscle has great power, and the 
 power is increased by an increased length of the process in dogs, 
 and other animals which run or bound. 
 
 The whole forms a very thick and powerful muscle, which 
 covers and embraces all the back part of the arm ; and its use 
 is too simple to admit of any farther explanation, than just to 
 say that it extends the hinge-joint of the elbow with great 
 power ; and that by its long head it may assist also to bend 
 the arm-bone outwards and backwards. 
 
 Besides bones, there is also another source of attachment 
 for muscles, that is, the tendinous expansions : for the expan- 
 sions, which go on the surface like sheaths, also dive betwixt 
 the muscles, and form septa, or partitions, from which their 
 fibres arise. 
 
 One tendinous expansion begins from the clavicle and acro- 
 mion process, or rather comes down from the neck : it is then 
 strengthened by the tendon of the deltoid muscle ; it descends, 
 covering all the arm ; and before it goes down over the fore- 
 arm, it is again reinforced chiefly by the biceps, but also by the 
 tendon of the triceps extensor. One remarkable process, or 
 partition of this general fascia, is sent in from tbe sheath to be 
 fixed to the outside of the humerus, all the way down to the 
 ridge of the outer condyle. Another partition goes down, in 
 like manner, to the inner condyle, along the ridge which leads 
 to it ; then the fascia, taking a firm hold on the condyles, is 
 greatly strengthened about the elbow, and goes over the fore- 
 arm, enelosing its muscles in a very firm and close sheath ; and 
 
184 MUSCLES OF THE ARM, &£C. 
 
 it sends partitions down among the several layers of muscles ii< 
 the fore arm, which gives each of them a firm hold. 
 
 LXXXI. The anconjEus is a small triangular muscle, pla- 
 ced on the back part of the elbow. It arises from the ridge 
 and from the external condyle of the humerus, by a thick, 
 strong, and short tendon. From this it becomes fleshy, and 
 after running about three inches obliquely backwards, it is in- 
 serted by its oblique fleshy fibres into the outer part of the ridge 
 of the ulna. 
 
 It is manifestly designed for the extension of the fore-arm. 
 and has only that one simple action. 
 
 MUSCLES OF THE FORE-ABM, CARPUS, AND FINGERS. " 
 
 The whole fore-arm is covered with a mass of muscles of 
 great strength, and so numerous and intricate, with a catalogue 
 of names so difficult, and so distracting, that they should be ar- 
 ranged and classed with much care, explaining to the student 
 the reason and value of their names, and the place and effect 
 of each class. 
 
 The fore-arm is covered with a fascia, or strong tendinous 
 web, which, like that which covers the temporal muscle, gives 
 both origin and strength to the muscles which lie under it, 
 which divides the several layers one from another, and helps 
 them in their strong actions, with that kind of support which 
 workmen feel in binding their arms with thongs. This fascia 
 is said to proceed from the small tendon of the biceps muscle, ^ 
 though that were but a slender origin for so great a web of ten- S 
 don, which not only covers the surface of the muscles, but ^ 
 enters among their layers. This fascia really begins in the ^ ; 
 shoulder, and has an addition and an increase of strength from 
 every point of bone ; it is assisted by each tendon, because the 
 tendons and fascia are of one nature over all the body, and its ;n 
 connection with the tendon of the biceps is quite of another * 
 kind from that which has been supposed. I would not allow 
 that the biceps tendon expands into the fascia, but rather that 
 the web receives the biceps tendon, W'hich is implanted into it, 
 and for this wise purpose, that when the fore-arm is to strike, 
 or the hand to grasp, the biceps first moves, and by making the 
 fascia tense, prepares the fore-arm for those voilent actions 
 which are to ensue. Thus, it may be defined, a web of thin 
 but strong tendon, which covers all the muscles of the fore-arm, 
 makes the surface before dissection firm and smooth, sends 
 down partitions which are fixed into the ridges of the radius j 
 and ulna, enabling those bones to give a broader origin to the 
 
aiUSCLES OF THE ARM, &C. 185 
 
 muscles, establishing a strong connection among the several 
 layers, and making the dissection more difficult. 
 
 The motions to be performed by the muscles which lie upon 
 the fore-arm are these three ; to roll the hand, to bend the 
 wrist, to bend the fingers. 
 
 1. The turning of the hand, which is performed by rolling 
 the radius on the ulna, is named pronation and supination. 
 When we turn the palm down, it is said to be prone ; when 
 we turn the palm upwards, it is supine. This is pronation and 
 supination. The muscles which perform these motions are the 
 PRONATOKS and the supinators, and the motion itself is best 
 exemplified in the turning a key in a lock, or in the guards of 
 fencing, which are formed by a continual play of the radius 
 upon the ulna, carrying the wrist round in the half circle. 
 
 2. The wrist is called the carpus, and therefore those mus- 
 cles which serve for bending or extending the wrist are the 
 FLEXORS and extensors of the carpus. 
 
 3. The bending and extending of the fingers cannot be mis- 
 taken, and therefore the flexors and extensors of the fingers 
 need not be explained. 
 
 These muscles are denominated from their uses chiefly ; but 
 if two muscles perform one motion, they may be distinguished 
 by some accident of their situation or form. And thus, if there 
 be two benders of the fingers, one above the other, they are 
 named FLEXOR sublimis, and flexor puofunous, (i. e.) the 
 the superficial and deep flexors. If there be two flexors of the 
 carpus, one is named flexor radialis carpi, by its running 
 along the radius, the other flexor ulnaris’ carpi, from pass- 
 ing in the course of the ulna. And if there be two pronators, 
 one may be distinguished pronator teres, from its round shape, 
 the other pronator quadratus, from its square form. And this, 
 I trust, will serve as a key to what is found to be a source of 
 inextricable confusion. 
 
 It will be easy to make the origins and insertions still more 
 simple than the names ; for all the muscles arise from tw'O 
 points, and have but two uses. 
 
 This assertion shall be afterwards qualified with a few excep-i 
 tions ; but at present it shall stand for the rule of our demon- 
 stration ; for all the muscles arise from tw'o points, the external 
 and internal condyle. The internal condyle is the longer one, 
 and gives most po-wer : more power is required for bending, 
 grasping, and turning the hand inwards ; therefore alt the mus- 
 cles which bend the hand, all the muscles which bend the lin- 
 gers, and the principal pronator, or that muscle which turns the 
 palm downwards, arise from the internal condyle. 
 
 The external condyle is shorter; it gives less power; there 
 
 VOL. I. A a 
 
186 
 
 MUSCLES OF THE ARM, &C. 
 
 is little resistance to opening the hand and little power is re- 
 quired in extending the fingers ; and so all the muscles whick 
 extend the wrist or the fingers, or roll the hand outwards to turn 
 it supine, arise from the external cond}’le. So that when we 
 hear a pronator or a flexor named, we know that the origin 
 must be the internal condyle, and the insertion is expressed by 
 the name. Thus a pronator radii goes to the radius ; a flexor 
 carpi goes to the wrist : a flexor digitorum goes to the fingers; 
 and a flexor pollicis goes to the thumb : and they all issue from 
 the inner condyle as from a centre. 
 
 And, again, when a supinator or extensor is named, we know 
 where to look for it ; for they also go out from one common 
 point, the external condyle ; and the supinator radii goes to 
 the radius ; the extensor carpi goes to the wrist; tlie extensor 
 pollicis goes to the thumb ; and the extensor indicis to the 
 fore finger. 
 
 FLEXORS. 
 
 The MUSCLES closing and bending the hand arise from the 
 internal condyle. They are. 
 
 The PRONATOR TERES, rolling the radius inward. 
 
 PALMARIS LONGUS, 
 
 FLEXOR CARPI RADIALIS, 
 
 ULNARIS, ) 
 
 DIGITORUM SUBLIMIS, ^ 
 
 PROFUNDUS, > 
 
 bending the wrist. 
 
 bending the 
 
 L< NGUS pollicis. 
 
 and thumb. 
 
 fingen? 
 
 And, lastly^, the pronator quadratus, which is the single 
 muscle out of that schemd which I have proposed.* 
 
 LXXXII. The pronator teres radii is of the outermost 
 layer of muscles, is small and round ; named pronator from its 
 
 * Mr. Cliarles Bel) in liis Lecture, varies this arranvenient. He observes that a kind of 
 artificial memory of the muscles of the fore-arm may he had by arranging them in numbers; 
 for example, if we take the bicep.s flexor as supinator in this instance, which it truly is, and 
 the mass of the flexor muscles as one great pronator, for such is their conjoint operation, the® 
 the muscles go in threes — thus : 
 
 For the motion of the wrist, three flexors, the ulnaris, radialis, and medius, commonly 
 called palmaris longus. — Three extensors, ulnaiis, radialis longior, and brevior. — Three 
 pronators, the teres, quadratus, and the mass of flexor muscles. — Three supinators, the 
 supinator longus, brevis and biceps cubiti. There are three extensors of the fingers, extensor 
 communis digitorum, extensor prirai digiti, extensor minimi digiti.— Three extensors of the 
 thumb, extensor primus, secundus, and tertius. — 'Three flexors of the fingers and thumb, 
 flexor digitorum sublimis, flexor digitorum profundus, flexor pollicis longus. In the arrange- 
 ment of the muscles of the fore-arm, it is correct to say that the flexors arise from the inner 
 condyle, and the extensors from the outer condyle ; but the supinators and pronators are tet- 
 ter distinguished by their insertion : — thus, all muscles inserted into the radius turn the wrist, 
 and thus the supinator longus, the supinator brevis, the pronator teres, the pronator quadia- 
 tiis, and tlie biceps, are employed in turning tlie hand. 
 
187 
 
 MUSCLES OF THE ARM, fec. 
 
 office of turning the radiusi, and teres from its shape, or rather 
 to distino-uish it from the pronator quadratus, which is a short 
 square muscle, and which lies deep, being laid flat upon the 
 naked bones. 
 
 The pronator teres arises chiefly from the internal condyle 
 of the humerus, at its lower and forepart. It has a second 
 origin from the coronoid process of the ulna ; these form two 
 portions, betwixt which passes the radial nerve. The muscle 
 thus formed is conical, is gradually smaller from above down- 
 wards, is chiefly fleshy, but is also a little tendinous, both at its 
 origin and at its insertion ; and stretches obliquely across the 
 fore-arm, passing over the other muscles to be inserted in the 
 outer ridge of the radius, about the middle of its length. 
 
 Its use is to turn the hand downwards, by turning the radius; 
 and it will also, in strong actions, be brought to bend the fore- 
 arm on the arm, or the reverse, when the fore-arm is fixed, 
 and we are to raise the trunk by holding with the hands. 
 
 LXXXIII. The palmaris po.vGtJS is a long thin muscle, 
 which, although it seems to have another use in its expansion 
 into the aponeurosis, yet is truly, by insertion into the annular 
 ligament of the wrist, a flexor of the wrist, and, in some de- 
 gree, a pronator of the radius. 
 
 It arises from the internal condyle of the os humeri, and is 
 the first of five muscles which have one common tendon going 
 out, like radii, from one common centre, viz. the palmaris ; the 
 flexor radialis ; the flexor ulnaris ; the flexor digitorum subli- 
 mis ; the flexor digitorum profundus. 
 
 The palmaris longus arises from the inner condyle of the os 
 humeri, and also from the intermuscular tendon, which joins it 
 with the flexor radialis and flexor digitorum sublimis, and from 
 the internal surface of the common sheath. Its fleshy belly is 
 but two inches and a half or three inches in length ; and its 
 long slender tendon descends along the middle of the fore-arm 
 to be inserted into the forepart of the annular ligament of the 
 wrist, just under the root of the thumb. This tendon seems to 
 give rise to the very strong thick aponeurosis of the palm of the 
 hand, (under which all the muscles of the hand run, and which 
 conceals the arch of blood-vessels, and protects them,) thence 
 the muscle has its name. But it is a very common mistake to 
 think, that because tendons are fixed to the sheaths, the sheaths 
 are only productions of the tendons ; whereas the sheaths do 
 truly arise from bones. The fascia, which the deltoldes is 
 thought to fort»y arises from the acromion and clavicle ; and 
 the fascia, which the biceps is thought to produce, arises from 
 the condyles of the humerus ; and that great sheath of tendon 
 which is made tense by the musculus fascielis of the thigh, does 
 
188 
 
 MUSCLES OF THE ARM, &tC. 
 
 not arise from that muscle, but coi^es down from the spine of 
 the ilium, strengthened by expansions from the oblique mus- 
 cles of the abdomen ; in the present instance, we have the 
 clearest proof of fascia being derived from some other source 
 than the tendons, for sometimes the palmaris muscle is want- 
 ing, when still the tendinous expansion is found, and some pre- 
 tend to say, that the expansion is wanting wheruthe muscle is 
 found. The aponeurosis, which covers the palm, is like the 
 palm itself, of a triangular figure; it begins from the small ten- 
 don of the palmaris longus, and gradually expands, covering 
 the palm down to the small ends of the metacarpal bones. Its 
 fibres expand in form of rays; and towards the end there are 
 cross bands which hold them together, and make them stronger; 
 but it does not cover the two outer metacarpa.1 bones, (the 
 metacarpal of the fore finger, or of the little-finger,) or it only 
 covers them with a very thin expansion. 
 
 Now this palmar expansion also sends down perpendicular 
 divisions, which take hold on the edges of the metacarpal 
 bones: and thus there being a perpendicular division to each 
 edge of each metacarpal bone, there are eight in all, which 
 form canals for the tendons of the fingers, and for the lumbri- 
 eales muscles.* 
 
 LXXXIV. The palmaris brevis is a thin flat cutaneous 
 muscle, which arises properly from the edge of the palmar 
 aponeurosis, near to the ligament of the wrist ; whence it 
 stretches across the hand in thin fasciculi of fibres, which are 
 at last inserted into the os pisiforme, and into the skin and fat 
 on the ulnar edge of the palm. This is the palmaris cutaneus 
 of some authors, for which we can find no use, except of draw- 
 ing in the skin of the hand, and perhaps making the palmar 
 expansion tense. 
 
 LXXXV. The plexor carpi radialis is a long thin mus- 
 cle arising from the inner condyle, stretching along the middle 
 of the fore-arm somewhat in the course of the radius, and . is 
 one of the five muscles which rise by one common tendon,' '' 
 and which are, for some way, tied together. 
 
 It arises tendinous from the inner condyle ; the tendon very 
 short and thick. This tendon at its origin is split into many 
 (seven) heads, which are interlaced with the heads of the subli- 
 mis, profundus palmaris, he . ; consequently this muscle not 
 only arises from the internal condyle, but also from the inter- 
 muscular partitions (as from that betw'ixt it and the sublimis) : 
 it forms a long tendon, which, becoming at last very small and 
 
 * There is a great irregularity in thi'' muscle ; it is frequently wanting, and it is not uh- 
 cominon to find two. We have found more than once, that tlie tendinous part of the mus- 
 cle was next to the condyle, and the fleshy part connected with the fascia palmaris. 
 
MUSCLES OF THE ARM, &C. 
 
 189 
 
 round, runs under the annular ligament : it runs in a gutter 
 peculiar to itself ; but in this canal it is moveahle, not fixed ; 
 it then expands a very little, and is inserted into the metacar- 
 pal bone of the fore-finger, also touching that which supports 
 the thumb. 
 
 Its use is chiefly to bend the wrist upon the radius. But 
 when we consider its oblique direction, it will also be very 
 evident that it must have some effect in pronation ; and this, 
 like many of the muscles of the fore-arm, although designed 
 for a different purpose, will also have some effect in bending 
 the fore-arm at the elbow-joint. 
 
 LXXXVI. The flexok carpi ulnaris is a long muscle, 
 much like the former; but as its coui’se is along the radius, or 
 upper edge of the fore-arm, this runs along the ulna or lower 
 edge. 
 
 It comes off tendinous from the inner condyle of the os hu- 
 meri, by the common tendon of all the muscles; it has also, 
 like the pronator teres, a second head, viz. from the olecra- 
 non process of the ulna, which arises fleshy, and the ulnar 
 nerve perforates betwixt these heads. The flexor ulnaris 
 passes all along the flat side of the ulna, betwixt the edge of 
 the sublimis and the ridge of the bone : and here it has a third 
 origin of oblique fibres, which come from the edge of the ulna, 
 two-thirds of its length. Its tendon begins early on its upper 
 part, by which it has somewhat the form of a penniform mus- 
 cle. It has still a fourth origin from the inter-muscular parti- 
 tion, which stands betwixt it and the flexor sublimis; and is 
 also attached to the internal surface of the common fascia of 
 the arm. Its long tendon is at last inserted into the os pisi- 
 forme at its forepart, where it sends off a thin tendinous ex- 
 pansion to cover and strengthen the annular ligament ; and 
 also a thin expansion towards the side of the little-finger to 
 cover its mucles. 
 
 This is to balance the flexor radialis : acting together, they 
 bend the wrist with great strength ; and when this muscle com- 
 bines in action with the extensor carpi ulnaris, they pull the 
 edge of the hand sideways. 
 
 LXXXVII. The flexor uigitorum communis sublimis, 
 is named sublimis from being the more superficial of the two 
 muscles; perforatus, from its tendon being perforated by 
 the tendon of that which lies immediately below. It lies be- 
 twixt the palmaris longus and flexor ulnaris : it is a large fleshy 
 muscle ; and not only its tendons, but its belly also, is divided 
 into four fasciculi, corresponding with the fingers which it is 
 to serve. 
 
 It arises from the internal condyle, along with the other 
 
190 
 
 MUSCLES OF THE ARM, &C. 
 
 four muscles; from the ligament of the elbow-joint ; from the 
 coronnid process of the ulna; and fram the upper part of the 
 radius, at the sharp ridge. By these origins, it becomes very 
 fleshy and thick ; and, a little above the middle of the fore-arm, 
 divides into four fleshy portions, each of which ends in a 
 slender tendon. The tendons begin at the middle of the fore- 
 arm, or near the division, but they continue to be joined to 
 each other by fleshy fibres some way down : and indeed the 
 fleshy fibres cease only when it is about to pass under the an- 
 nular ligament of the wrist. At this place, a cellular stringy 
 tissue connects the tendons with each other, and with the ten- 
 dons of the profundus; but after they have passed under the 
 ligament, they expand towards the fingers which they are to 
 serve. They each begin to be extended and flattened, and to 
 appear cleft ; they pass by the edge of the metacarpal bones, 
 and escape from under the palmar aponeurosis; and where it 
 ends, viz. at the root of the fingers, a tendinous sheath be- 
 gins, in which these tendons continue to be enclosed. 
 
 The tendons are fairly split just opposite to the top of the 
 first phalanx ; and it is at this point that the tendons of the 
 deeper muscle pass through this splitting. The flattened ten- 
 don parts into two, and its oppo.site edges diverge ; the back 
 edges meet behind the tendons of the profundus, and form a 
 kind of sheath for them to pass in ; and then they proceed for- 
 ward along the second phalanx, into the forepart of which they 
 are implanted. 
 
 This muscle is exceedingly strong : its chief office is to bend 
 the second joint of the fingers upon the first, and the first upon 
 the metacarpal bone. And in proportion to the number of 
 joints that a muscle passes over, its offices must be more nume- 
 rous ; for this one not only moves the fingers on the metacar- 
 pus, but the hand upon the wrist, and even the fore-arm upon 
 the arm. 
 
 LXXXVin. The flexor digitorum profundus vel per- 
 FORANS, has so nearly the same origin, insertion, and use, so 
 that the description of the last is applicable to this muscle in 
 almost every point. This is of a lower stratum of muscles; it 
 lies deeper, and under the former, whence its name : and by 
 this deeper situation it is excluded from any hold upon the tu- 
 bercle of the humerus. 
 
 It arises from the ulna, beginning at the coronoid process, 
 and extending all along its internal surface, from the whole 
 surface of the interosseous ligament, from the inner edge ol 
 radius, and also, in in some degree, from the inter-muscular 
 membrane, which separates this from the sublimis. 
 
191 
 
 MUSCLES OF THE ARM, &C. 
 
 This muscle is small, we may say compressed above ; but it 
 grows pretty strong and fleshy, tiear the middle of the arm ; it 
 divides above the middle of the arm into four portions, cor- 
 responding with the four fingers; and it is about the middle of 
 the arm that the tendons begin, and continue to receive mus- 
 cular fibres from behind, all down to the ligament of the wrist: 
 at the wrist, these tendons are tied to each other, and to the 
 tendons of the sublimis, by loose tendinous and cellular fibres. 
 They diverge from each other, after passing under the annular 
 ligament; and going along in the hollow of the bones, under 
 the tendons of the sublimis, they first pass through the bridges 
 formed by the palmar aponeurosis, then enter the sheaths of the 
 fingers, and finally pass through the perforations of the subli- 
 mis, a little below the second joint of the fingers : at this place 
 the perforating tendons are smaller and rounder for their easy 
 passage, and after passing, they again expand and become flat. 
 They also, above this, appear themselves to split in the middle 
 without any evident purpose ; they pass the second phalanx, 
 and are fixed into the root of the third. And every thing that 
 is said of the use of the sublimis may be applied to this, only 
 that its tendons go to the furthest joint. 
 
 LXXXIX. Lumbricales. — I shall here describe, as a natu- 
 ral appendage of the profundus, the lumbricales muscles, 
 which are four small and round muscles, resembling the earth- 
 worm, in form and size ; whence they have their name. They 
 arise in the palm of the hand, from the tendons of the profun- 
 dus, and are therefore under the sublimis, and under the pal- 
 mar aponeurosis. They are small muscles, with long and very 
 delicate tendons. Their fleshy bellies are about the length of 
 the metacarpal bones, and their small tendons stretch over two 
 joints, to reach the middle of the second phalanx. The first 
 lumbricalis is larger than the second, and the two first larger 
 than the two last. 
 
 The first arises from the side of the tendon of the fore- 
 finger, which is next to the radius; the others arise in the forks 
 of the tendons; and though they rise more from that tendon 
 which is next the ulna, yet they have attachments to both. 
 Their tendons begin below the first joint of each finger ; they 
 run very slender along the first phalanx, and they gradually 
 wind around the bone, so that though the muscles are in the 
 palm of the hand, the tendons are implanted in the back parts 
 of the fingers, and their final connection is not with the bend- 
 ing tendons of the sublimis and profundus, but with tendons 
 of the extensor digitorum, and with the tendons of the external 
 interossei muscles, with which they are united by tendinow^ 
 
 ■ breads. 
 
192 
 
 MUSCLES OF THE ARM, &C. 
 
 Hence their use is very evident; they bend the first joint, 
 and extend the second ; they perform alternately either office ; 
 when the extensors act, they assist them by extending the 
 second phalanx or joint: when the flexors act, and keep the 
 first and second joint bended, the extending effect of these 
 smaller muscles is prevented, and all their contraction must be 
 directed so as to affect the first joint only, which they then 
 bend. 
 
 They are chiefly useful in performing the quick short mo- 
 tions, and so they are named by Cowper, the musculi fidici- 
 iiales, as chiefly useful in playing upon musical instruments. 
 
 XC. The FLEXOR LONGUS poLLicis is placed by the side of 
 the sublirnis, or perforatus, and lies under the supinator and 
 flexor carpi radialis. It runs along the inner side of the radius 
 whence chiefly -it arises. 
 
 Its origin is from all the internal face of the radius down- 
 wards, from the place where the biceps is inserted, and from 
 the interrosseous ligament, all the length down to the origin of 
 the pronator quadratus : nor does it even stop here ; for the 
 tendon continues to receive fleshy slips all the way down to the 
 passage under the ligament of the wrist. It has also another 
 head, which arises from the condyle of the humerus, and the 
 forepart of the ulna ; which head is tendinous, and joins that 
 origin which comes from the radius. 
 
 The muscle becomes again tendinous, very high, [i, e.) above 
 the middle of the arm ; and its small tendon passes under the 
 annular ligament, glides in the hollow of the os metacarpi pol- 
 licis, and separates the short flexor into two heads, passes be- 
 twixt the two cesamoid bones in the first joint of the thumb, 
 and running in the tendinous sheath, it reaches at last the end 
 of the farthest bone of the thumb, to be inserted into the very 
 point of it. 
 
 There is sometimes sent off from the lower part of the 
 muscle a small fleshy slip, which joins its tendons to the indi- 
 cator tendon of the sublirnis. 
 
 Its uses, we conjecture, are exactly as of those of the other 
 flexors, to bend the last phalanx on the first, the first on the 
 metacarpal bones, and, occasionally, the wrist upon the radius 
 and ulna. 
 
 XCl. The PRONATOR Q,UADRATus, SO named from its shape 
 and lorm, is one of the most simple in its action, since it 
 serves but one direct purpose, viz. turning the radius upon the 
 ulna. 
 
 It lies flat upon the interosseous ligament upon the forepart 
 of the arm, about two inches above the wrist; it is nearly 
 square, and is about three inches in length and breadth. Its 
 
193 
 
 SlUSCLES OF THE ARM, &C. 
 
 fibres go obliquely across, betwixt the radius and ulna. It arises 
 from the edge of the ulna, adheres to the interosseous ligament, 
 and goes to be implanted into the edge of the radius ; it 
 turns the radius upon the ulna. This muscle, and in some 
 degree also the flexor pollicis, are the only muscles which do 
 not come fairly under that arrangement, by which I have en- 
 deavoured to explain the muscles of the fore-arm. 
 
 EXTENSORS. 
 
 The muscles which lie upon the outer side of the fore-arm, 
 the supinators, and the extensors of the fingers and wrist, all 
 arise from one point, the external condyle of the humerus, and 
 are all delivered in this list : 
 
 The EXTENSOR CARPI RAOIALIS LONGIOR, 
 
 The EXTENSOR CARPI RAOIALIS BREVIOR, > • , 
 
 mi , I wrist. 
 
 The EXTENSOR CARPI ULNARIS, ) 
 
 The SUPINATOR LONGUs, — tums the palm upwards. 
 
 The EXTENSOR COMMUNIS DiGiToRUM, — extends all the fingers, 
 and unfolds the hand. 
 
 The EXTENSOR PRTMI INTERNODII 
 POLLICIS, 
 
 The EXTENSOR sECUNDi INTERNODII I extend the several joints 
 
 POLLICIS, I of the thumb. 
 
 The EXTENSOR TERTII INTERNODII | 
 
 POLLICIS, J 
 
 The EXTENSOR PRiMi DiGiTi vel INDICATOR, — extends the fore- 
 finger. 
 
 The EXTENSOR MINIMI DiGiTi vel AURicuLARis, — extends the 
 little-finger. 
 
 All these muscles arise from one point, the external condyle. 
 They all roll the radius outwards, or extend the wrist, or ex- 
 tend the fingers. As the muscles which are bent, need more 
 fibres, and greater strength, they arise from the internal con- 
 dyle, which is the larger ; they lie in a deep hollow, for the 
 bones of the fore-arm are bent to receive them, and they form 
 a very thick fleshy cushion : but the extensors requiring less 
 power, arise from the shorter process of the outer condyle, are 
 on the convex side of the arm, and are thin, having few fibres j 
 for though there is a large mass of flesh on the inner side of 
 the arm, forming two big flexors, there is only a thin layer on 
 the outer side of the arm, forming one flat and weak exten- 
 sor. 
 
 XCII. Supinator radii longus. This muscle forms the 
 very edge of the fore arm : it arises by many short tendinous 
 fibres, from the ridge of the humerus, above the external con- 
 VOL. i. B b 
 
194 
 
 MUSCLES OF THE ARM, &C. 
 
 dyle, which origin is fully two inches in length above the con- 
 dyle. It also arises from the intermuscular membrane ; and, 
 as it stands on the very edge of the fore-arm, it runs betwixt 
 the flex(tr and extensor radialis. It becomes thicker as it pas- 
 ses the joint of the humerus, and there gives a very peculiar 
 form to the arm : it then becomes smaller, and forms a flat 
 tendon, which is quite naked of flesh I'rom the middle of the 
 radius, or a little below, down to the wrist. This tendon be- 
 comes gradually smaller, till it reaches the wrist, where ex- 
 panding a little, it is inserted into the styloid process of the 
 lower head of the radius. 
 
 Its use is, perhaps, chiefly as a supinator, but it is placed just 
 upon the edge of the arm ; it stands as a sort of intermedium 
 betwixt the two sets of muscles ; it is fixed, indeed, rather upon 
 the internal surface of the radius ; but yet when the supina- 
 tion is complete, when the hand is rolled very much outward 
 it will become a pronator. 
 
 It is at once supinator and pronator, and for a most evident 
 reason, a flexor also of the fore-arm, since its origin is at least 
 two inches up the humerus, above the joint of the elbow. 
 
 XCIII. The EXTENSOR CARPI RADIALIS LONGioR, has the 
 additional name of longior or primus, to distinguish it from the 
 next. It is almost entirely covered with the last muscle, the 
 supinator. 
 
 It arises from the ridge of the humerus above the external 
 condyle and just under the origin of the supinator ; it de- 
 scends all along the back of the radius ; and after having be- 
 come a thick fleshy belly, it degenerates a little lower than the 
 middle of the radius, into a thin flat tendon, which becomes 
 slender and small as it descends ; and turning a little more to- 
 wards the back of the radius, it then passes over the wrist, and 
 goes along with the tendon of the extensor, under the annular 
 ligament, passing in a groove of the radius ; at last it is inserted 
 into the root of the metacarpal bone of the fore-finger, in that 
 edge next the thumb. 
 
 It is chiefly an extensor of the wrist : in pronation, it pulls 
 the wrist directly backwards ; in supination, it moves the hand 
 sideways. It is also a pronator, when the hand is turned back 
 to the greatest degree ; and from its origin, high upon the 
 arm-bone, it is also a flexor of the fore-arm. 
 
 XCIV. Extensor carpi radialis brevior. — This mus- 
 cle is almost the same in description, name, and use, with the 
 former. It arises from the external condyle ; and here a com- 
 mon tendon for many muscles is formed, just as in the internal 
 condyle ; for from this point arise the extensor carpi radialis 
 
MUSCLES OF THE ARM, &C. 195 
 
 brevior, extensor digitorum, extensor minimi digiti, extensoi’ 
 oarpi ulnaris. 
 
 The extensor carpi radialis brevior arises from the outer 
 condyle of the humerus, by the common tendon ; it also arises 
 from the aponeurosis, wllich lies betwixt the extensor digito- 
 rum and this ; it grows a pretty large, fleshy body, and begins, 
 like the last, to be tendinous below the middle of the radius ; 
 so that this muscle continues fleshy lower than the last one, 
 and its tendon is also much larger and thicker ; it runs under 
 the annular ligament, in the same channel with the extensor 
 longior ; it expands a little before its insertion, which is into 
 the back part of the metacarpal bone of the middle finger, a 
 little towards that edge which is next the radius : some little 
 fibres pass from this tendon to the metacarpal bone of the fore- 
 finger. 
 
 All that was said concerning the extensor longus, may be 
 said of this ; for all the three last muscles lie so ambiguously 
 on the edge of the arm that though they are regularly supina- 
 tors and extensors, they become pronators and flexors, in cer- 
 tain positions of the hand. 
 
 XCV. Extensor carpi ulnaris. — By the name merely of 
 this muscle we know its extent and course, its origin, insertion, 
 and use. 
 
 It is one of the muscles which belong to the common ten- 
 don, arising from the external tubercle of the os humeri : it 
 lies along the ulnar edge of the arm ; it also arises from the in- 
 termuscular membrane, which separates this from the exten- 
 sor digitorum and the extensor digiti minimi ; and chiefly it is 
 attached to the internal Surface of the common sheath. It 
 arises also from the face and edge of the ulna, the wkole way 
 down ; its tendon begins in the middle of its length, and is ac- 
 companied all down to the wrist with feather-like fleshy fibres. 
 
 It is fixed into the outside of the lower head of the metacar- 
 pal bone of the little-finger. 
 
 Its use is to extend the carpus. And it may be now observ- 
 ed, that when the two extensors of the wrist, the radialis and 
 ulnaris act, the hand is bent directly backwards ; that when 
 the flexor radialis and extensor radialis act together, they bend 
 the thumb towards the radius ; and that when the flexor ulna- 
 ris and extensor ulnaris act, they draw down the ulnar edge of 
 the hand. 
 
 XCVI. Extensor oigitorum communis. — ^This muscle 
 corresponds with the sublimis and profundus, and antagonizes 
 them, and resembles them in shape as in use. It covers the 
 middle of the fore-arm at its back, and lies betwixt the exten- 
 sor radialis brevior and the extensor minimi digiti. 
 
196 MUSCLES OF THE ARM, &C. 
 
 Its origin is chiefly from the outer condyle, by a tendon 
 common to it, with the extensor carpi radialis brevior ; it 
 comes also from the intermuscular membrane, which separates 
 it on one side from the extensor minimi digiti, and on the other 
 from the extensor carpi radialis brelHor, and lastly, from the 
 back part of the common sheath. It grows very fleshy and 
 thick, as it descends, and about the middle of the fore-arm it 
 divides itself into three slips of very equal size. But though 
 the tendons begin so high they continue like those of the flex- 
 ors, to receive fleshy penniform fibres all down, almost to the 
 annular ligament. These tendons are tied together by a loose 
 ■web of fibres, and being gathered together they pass under the 
 ligament in one common and appropriated channel. Baving 
 passed this ligament they diverge and grow flat and large. And 
 they all have the appearance of b<*ing split by a perpendicular 
 line. They are quite different from the flexor tendons in this, 
 that they are all tied to each other by cross bands ; for a little 
 above the knuckles, or first joint of the fingers, all the tendons 
 are joined on the back of the hand by slips from the little- 
 finger to the ring, from file ring to the mid-finger, and from 
 that to the fore-finger. So that it seems to be one ligament 
 running quite across the back of the hand. It would be fool- 
 ish to describe them more minutely : for the cross bands 
 change their places, and vary in every subject, and in some 
 they are not found. 
 
 After this, the tendons pass over the heads of the metacar- 
 pal bones, along the first phalanx of the fingers, and being 
 there joined by the tendons of the interossei and lumbricales, 
 they all together form a strong tendinous sheath, which sur- 
 rounds the back of the fingers. 
 
 Now it is to be remembered, that this muscle serves only 
 for the fore, middle, and ring fingers : that if it moves the lit- 
 tle-finger, it is only by a small slip of tendinous fibres, which it 
 often gives off at the general divergence, but sometimes not ; 
 sometimes it gives one slip, sometimes two, often none at all. 
 And so the little-finger has its proper extensor quite distinct 
 from this. 
 
 The use of the muscle is to extend all the fingers ; and when 
 they are fixed, it will assist the extensors of the wrist, as in 
 striking backwards with the knuckles. 
 
 XCVIl. The EXTENSOR MiNJMi DIGITI, named also auri- 
 cuLARis, from its turning up the little finger, as in picking the 
 ear, should really be described with the last muscle ; if we see 
 the origin, course, and use of this muscle exactly the same with 
 it, why should we not reckon it as a slip of the common ex- 
 tensor, appropriated to the little finger ? 
 
19T 
 
 MUSCLES OF THE ARM, &C. 
 
 Its origin is from the outer condyle, along with the other 
 tendons. It also adheres so closely both to the tendinous par- 
 titions, and to the internal surface of the common fascia, that 
 it is not easily separated in dissection. It begins small, with a 
 conical kind of head ; it gradually increases in size ; it is 
 pretty thick near the wrist; it adheres all along to the com- 
 mon extensor of the fingers ; it begins to be tendinous about 
 an inch above the head of the ulna ; it continues to receive 
 fleshy fibres down to the annular ligament ; and it passes under 
 the annular ligament, in a channel peculiar to itself, which is 
 indeed the best reason for making this a distinct muscle. 
 
 This channel has a very oblique direction, and the tendon, 
 like all the others, expands greatly in escaping from ihe liga- 
 ment of the wrist. It is connected with the other tendons, in 
 the manner I have described. Close to the wrist, it is con- 
 nected with the tendon of the ring finger, by a slip which 
 comes from it ; and at the knuckle, and below it, it is again 
 connected with the tendons both of the ring finger, and of all 
 the others, by the cross bands or expansions. 
 
 Whatever has been said of the use of the last muscle, is to 
 be understood of this ; as its extending its proper finger, assist- 
 ing the others by its communicating band, and in its extending 
 the wrist, when the fist is clenched. Its insertion is into the 
 back of the second joint of the little-finger, along with the in- 
 terossei and lumbricales. Its tendon has also a small slit; for 
 the head of the proper extensor of the little finger, and the 
 heads of the common extensors of the others, are inserted into 
 the top of the second phalanx, just under the first joint. They 
 send ofl‘ at the sides tendinous slips, which, passing along the 
 edges of the bones, do, in conjunction with the tendons of the 
 interossei and lumbricales, form a split tendon, which meets by 
 two curves at the foot of the last bone of the fingers, to move 
 the last joint. 
 
 XCVIII. The EXTENSOR PRIMUS poLLicis 16 the shortest of 
 the three. It is named by Albinus, and others, abductor 
 LONGUs ; but since every muscle that extends the thumb must 
 pull it away from the hand, every one of them might be, with 
 equal propriety, named abductors. 
 
 The extensor primus lies just on the fore edge of the radius, 
 crossing it obliquely. 
 
 It arises about the middle of the fore-arm, from the edge of 
 the ulna, which gives rise to the interosseous membrane itself, 
 and also from the convex surface of the radius. 
 
 The fleshy belly commonly divides itself into tw'o or three, 
 sometimes four fleshy slips, with distinct tendons, which, cross- 
 ing the radius obliquely, slip under the external ligament of 
 
198 
 
 MUSCLES OF THE ARM, &C. 
 
 the carpus, and are implanted into the trapezium and the root 
 of the first metacarpal bone, or rather of the first phalanx of 
 the thumb, towards the radial edge, so that its chief use is to 
 extend the thumb, and to incline it a little outwards towards 
 the radius. It has also frequently a tendon inserted in the ab- 
 ductor pollicis. It must also, like the extensors of the fingei’s, 
 be an extensor of the wrist : and it evidently must, from its 
 oblique direction, assist in supination. 
 
 XCIX. The EXTKNSOR SECUKDUS POLLICIS is loiiger than 
 the fii’st. It is named by Douglas the extensor secundi inter- 
 nodii pollicis ; by Albinus, the extensor minor pollicis. 
 
 This muscle lies close by the former. It arises just below it 
 from the same edge of the radius, and from the same surface 
 of the interosseous membrane, it runs along with it in the same 
 bending course ; and, in short, it resembles it so much that 
 Winslow has reckoned it as part of the same muscle. 
 
 Its origin is from the edge of the ulna, the interosseous 
 ligament, and the radius. Its small round tendon passes some- 
 times in a peculiar channel, sometimes with the extensor pri- 
 mus. It goes over the metacarpal bone of the thumb ; it ex- 
 pands upon the bone of the first phalanx ; and it is inserted 
 just under the second joint. 
 
 It extends the second bone of the thumb upon the first ; it 
 extends the first bone also ; and it extends the wrist, and, by 
 its oblique direction, contributes to supination. 
 
 C. Extensor teutius pollicis. — This which bends the 
 third joint is called in common the extensor longus pollicis. 
 And here is a third muscle, which in form, and place, and 
 function, corresponds w'ith the two former ones. 
 
 Its origin is from the ridge of the ulna, and from the upper 
 face of the interosseous membrane ; and it is a longer muscle 
 than the others, for it begins high, near the top of the ulna, and 
 continues the whole way down that bone, and is very fleshy 
 and thick. It is penniform all the way down to the ligament 
 of the wrist ; and its small tendon passes the ligament in a pe- 
 culiar ring. This tendon appears split, like those of the fin- 
 gers ; it goes along the ulnar side of the first bone of the thumb, 
 reaches the second, and is implanted there by a small slip of 
 tendon ; and being expanded, it still goes forward, to be in- 
 serted once more into the third bone of the thumb at its root. 
 
 Its use is evident, after describing the others. For we have 
 only to add another joint for motion. It moves the last joint 
 of the thumb, then the second, then its metacarpal bone upon 
 the carpus ; and if that be held firm, it will extend the carpus ; 
 and it will, in its turn, contribute to supination, though in a less 
 degree than the others. 
 
199 
 
 MUSCLES OF THE ARM, &C. 
 
 CL Indicator. — The extensor indicis proprius has 
 very nearly the same origin, and exactly the same course Avith 
 the last, and lies by the side of it. 
 
 Its origin is from the ulna, by the side of the extensor longus 
 pollicis. It has also some little attachments to the interosseous 
 membrane. It, like the others, is feathered with fibres, in an 
 oblique direction, down to the ligament of the aatIsL 
 
 This muscle lies under the extensor communis digitorum : 
 its tendon passes along with the common tendon, through the 
 annular ligament; and near the top of the metacarpal bone, 
 or about the place of the common junctions of all these ten- 
 dons, this one joins with the indicator tendon of the common 
 extensor. 
 
 Its use is in extending all the three joints of the fore-finger; 
 assisting the common extensor in pointing with that finger; in 
 acting independently of the common extensor; and in helping 
 to extend the wrist, when the fingers are closed. 
 
 CII. The SUPINATOR BREVIS is an internal muscle, Avhich 
 forms, with the muscles of the thumb and of the fore-finger, a 
 kind of second layer ; and this one lies concealed, as much as 
 the pronator quadratus does, on the inner side of the fore-arm. 
 It is a short muscle, but very thick and fleshy, and of great 
 power. 
 
 It arises from the outer condyle of the os humeri, and from 
 the edge of the ulna, and from the interosseous ligament : it is 
 then lapped over the radius, and is inserted into its ridge ; so 
 that this supinator brevis is very directly opposed to the pro- 
 nator teres, the insertion of the two muscles almost meeting 
 on the edge of the radius. It is almost circumscribed to one 
 use, that of performing the rotation of the radius outwards ; 
 but, perhaps, it may also have some little effect in extending 
 the ulna, and of assisting the anconeus. 
 
 MUSCLES SEATED ON THE HAND. 
 
 Besides these muscles which bend and extend the fingers, 
 there are other smaller ones seated on the hand itself, which 
 are chiefly for assisting the former, and for quicker motions j 
 but most especially for the lateral motions of the fingers, and 
 which are named adductors, abductors, and flexors, 
 Avhen they belong to the thumb and to the little-finger. 
 
 That they are chiefly useful in assisting and strengthening 
 the larger muscles, is evident from this, that much power 
 being required for flexion, we find many of these smaller mus- 
 cles added in the palm ©f the hand ; but as there is little 
 
200 MUSCLES OF THE ARM, &C. 
 
 power of extension needed, no more almost than to balance 
 the power of the flexors, there are no small muscles on the 
 back of the hand, the interossei extern! excepted, which are 
 chiefly useful in spreading the fingers. 
 
 The short muscles in the palm of the hand are for bending 
 the thumb, the fore-finger and the little-finger; and the little- 
 finger and the thumb have each of them tliree distinct muscles; 
 one to pull the thumb away from the hand, one to bend it, 
 and one to pull it towards the hand, opposing it to the rest of 
 the fingers, and so of the little-finger, which has also three 
 muscles. 
 
 ARRANGEMENT OF THESE MUSCLES. 
 
 1 . LUMBRiCALES, whicli bend the fingers. 
 
 2 . ABDUCTOR POLLieis, removing the thumb from the fingers. 
 
 carrying the thumb tow’ards 
 
 3 . 
 
 4 . 
 
 
 6 . 
 
 the palm, as in grasping. 
 
 the fore-finger towards 
 
 I FLEXOR AND OPFONENS 
 
 < POLLICIS, 
 
 ( ADDUCTOR POLLICIS, 
 
 S which carries 
 
 ABDUCTORlND.es, 
 
 C ABDUCTOR MINIMI DiGiTi, i wliicli bend the little-finger, 
 
 < ADDUCTOR MINIMI DIGITI, > and cariy it, like the thumb, 
 ^FLEXOR MINIMI DIGITI, ) outwards or inwards. 
 
 f which are small muscles, lying betwixt the 
 1 metacarpal bones, and assisting the liimbri- 
 iNrEROssEi< bending the fingers, and perform the 
 
 (^lateral motions of the fingers. 
 
 All the muscles of the thumb are seated on the inside, to 
 form the great ball of the thumb; and it is not easy at first to 
 conceive how muscles having so much the same place should 
 perform such opposite motions ; yet it is easily explained, by 
 the slight variation of their places; for the abductor arises 
 from the annular ligament near the radius, and goes towards; 
 the back of the thumb. 
 
 The flexors arise deeper, from the bones of the carpus, and 
 from the inside of the ligament, and go to the inside of the 
 thumb. The adductor arises from the metacarpal of the 
 mid-finger, and goes to the inner edge of the thumb. 
 
 cm. The ABDUCTOR POLLICIS is only covered by the com- 
 mon integuments. It begins a little tendinous from the out- 
 side of the annular ligament, just under the thumb, and by 
 some little fibres from the trapezium ; and, from the tendon 
 of the long abductor or extensor primus, it bends gradually 
 round the thumb, and is at last inserted in the back of the first 
 joint, just above the head of the metacarpal bone. But it 
 
201 
 
 MUSCLES OF THE ARM, &C. 
 
 does not stop here ; for this flat tendon is now expanded into 
 the form of a fascia, which, surrounding the first bone of the 
 thumb, goes forward upon its back part, quite to the end, along 
 with the common tendon of the extensor. This muscle, like 
 the others, is covered by a thin expansion from the tendon of 
 the palmaris, as well as by the common integuments. 
 
 Its only use is to pull the thumb from the fingers, and to 
 extend the second bone upon the first. 
 
 Albinus describes a second muscle of the same name, 
 having the same course, origin, insertion, and use : it also 
 arises from the outer side of the ligament of the wrist, and is 
 fixed into the side of the thumb, and lies upon the inside of 
 the former muscle. 
 
 These two are inserted into the first bone of the thumb ; but 
 the next is inserted into the metacarpal bone. 
 
 CIV. The oppoNENS poelicis is often called the flexor of 
 the metacarpal bone of the thumb. It is placed on the inside, 
 and implanted into the side of the thumb : its oflBce is to draw 
 the thumb across the other fingers, as in clenching the fist ; 
 and from its thus opposing the fingers it has its name of oppo- 
 nens. 
 
 It lies immediately under the last described muscle, and is 
 like it in all but its insertion. 
 
 It arises from the trapezium, and from the ligament of the 
 wrist. It is inserted into the edge and forepart of the meta- 
 carpal bone of the thumb : and its use is to turn the metacar- 
 pal bone upon its axis, and to oppose the fingers ; or in other 
 words, to bend the thumb : for I can rmdie no distinction. 
 Therefore, this muscle and the next, which lies close upon it, 
 may be fairly considered as but two different heads of one thick 
 short muscle. 
 
 CV. The FLEXOR BREVIS polllicis is a two-headed muscle, 
 placed quite on the inside of the thumb, betwixt the fore-finger 
 and the thumb, and extends obliquely across the two first me- 
 tacarpal bones. It is divided into two heads by the long flexor 
 of the thumb. 
 
 The edge of this muscle lies in close contact with the edge 
 of the last, or opponens ; and indeed they may fairly be consi- 
 dered as one large muscle surrounding the basis of the thumb. 
 
 One head arises from the os trapezium, or base of the 
 thumb, and from the ligament of the wrist. The other head 
 comes from the os magnum and unciforme, and from the liga- 
 ments which unite the bones of the carpus. 
 
 The first head is the smaller one : it terminates by a pretty 
 considerable tendon in the first sesamoid bone. The second 
 head runs the same course ; it is implanted chiefly in the se- 
 
 VOE. I. Cc 
 
202 
 
 MUSCLES OF THE ARM, &C. 
 
 cond sesamoid bone, and also Into the edge of the first bone 
 of the thumb close by it. The second head is exceedingly 
 muscular and strong : the heads are completely separated 
 from each other by the tendon of the flexor longus passing 
 betwixt them. 
 
 The oflice of this muscle is to bend the first joint upon the 
 second, and the metacarpal bone upon the carpus : and in- 
 deed the office of this, and of the opponens, is the same. It 
 is in the tendons of this double-headed muscle that the sesa- 
 moid bones are found. 
 
 CVl. The ADDUCTOR POL.LICIS arises from the metacarpal 
 bone of the middle-finger, where it has a flat extended base. 
 It goes frjnn this directly across the metacarpal bone of the 
 fore-finger to meet the thumb. It is of a triangular shape, and 
 flat : its base is at the metacarpal bone ; its apex is at the 
 thumb : it is inserted into the lower part or root of the first 
 phalanx : its edge ranges with the edge of the flexor brevis ; 
 it concurs with it in office ; and its more peculiar use is to 
 draw the thumb towards the fore-finger, as in pinching. 
 
 Thus do these muscles, covering the root of the thumb, 
 form that large ball of flesh which acts so strongly in almost 
 every thing we do with the hand. 
 
 The ball of the thumb is fairly surrounded ; it is almost one 
 mass, having one office : but as the deltoldes will, in some 
 circumstances, pull the arm downwards, some portions of this 
 fleshy mass pull the thumb outwards obliquely ; some directly 
 inwards ; but the great mass of muscle bends the thumb, and 
 opposes it to the hand : and as this one muscle is to oppose the 
 whole hand, the baU of flesh is very powerful and thick. 
 
 The short muscles of the little finger surround its root, just 
 as those of the thumb surround its ball. 
 
 evil. The ABDUCTOR MINIMI DiGiTi is a thin fleshy muscle, 
 which forms the cushion on the lower edge of the hand, just 
 under the little finger. It is an external muscle : it arises from 
 the os pisiforme, and metacarpal bone of the little-finger, and 
 from the outer end of the annular ligament. It is inserted la- 
 terally into the first bone of the little-finger ; but a production 
 of it still goes forward to the second bone of the little-finger. 
 
 Its use is to spread the little-finger sideways, and perhaps to 
 assist the flexors. 
 
 CVIII. The FLEXOR PARVUS MINIMI DIGITI is a Small thin 
 muscle which rises by the side of the last, and runs the same 
 course, with nearly the same insertion. 
 
 Its origin is from the ligament of the wrist, and in part from 
 the crooked process of the unciforme bone. Its use is to bend 
 the little-finger. And indeed the office and place of both is 
 
208 
 
 MUSCLES OF THE ARM, &C. 
 
 EO much the same, that I have marked the last as a flexor; 
 the little difierence there is, is only that this performs a more 
 direct flexion 
 
 CIX. The ADDUCTOR MINIMI DiGiTi is Sometimes called the 
 metacarpal of the little-finger. It lies immediately under the 
 the former muscle. Its origin is from the hook of the unciforme 
 bone, and the adjoining part of the carpal ligament. 
 
 It is inserted into the outside of the metacarpal bone which 
 it reaches by turning round it. Its use is to put the little-fin- 
 ger antagonist to the others : it is to this finger what the op- 
 ponens is to the thumb. It also, by thus bending one bone of 
 the metacarpus, affects the whole, increases the hollow' and 
 external convexity of the carpus, and forms what is called Di- 
 ogenes’s cup. 
 
 CX. The ABDUCTOR iNDicis is a flat muscle of considerable 
 breadth, lying behind the adductor pollicis, and exactly re- 
 sembling it, being like the second layer. It arises from the 
 os trapezium, and from the first bone of the thumb ; and it is 
 inserted into the back part of the first bone of the fore-finger, 
 and pulls it towards the thumb. 
 
 The iNTEROssEi are situated betwixt the metacarpal 
 bones. They are small, round, and neat, something like the 
 lumbricales in shape and size, and in office resemble the 
 adductors and abductors. Four are found in the palm which 
 bend the fingers and draw their edges a little towards the 
 thumb ; three are found on the back of the hand, for ex- 
 tending the fingers ; they at the same time perfoi'm the lateral 
 motions of the fingers. 
 
 CXI. The INTEROSSEI iNTERNi arise from betwixt the 
 metacarpal bones. They are also attached to the sides of 
 these bones. They send their tendons twisting round the 
 sides to the backs of these bones. And they are inserted 
 along with the tendons of the lumbricales and extensors, into 
 the back of the finger. They are thus flexors of the first 
 joint, and extensors of the second joint, as the lumbricales 
 are. 
 
 CXII. The INTEROSSEI EXTERNi are three in number. 
 They arise, like the interni, from the metacarpal bones and 
 their interstices, and from the ligaments of the caipal bones. 
 They are peculiar in having each two heads, therefore' 
 named interossei bicipites. They join their tendons to 
 those of the extensor and lumbricales ; they have therefore 
 one common office with them, that is, extending all the 
 joints of the fingers. Many have chosen to describe the 
 origin and insertion w'ith most particular care, marking the 
 degree of obliquity, and ascertaining precisely their office, 
 
204 
 
 MUSCLES OF RESPIRATION, 
 
 and giving particular names to each, as prior indicis for the 
 first external ; all which I forbear mentioning, because they 
 must be more liable to perplex than assist : if we but re- 
 member their common place and office, it is enough. The 
 tendons of the flexor muscles bend round the finger, along 
 with the interossei and lumbricales, for a surer hold ; con- 
 sequently the tendons of the lumbricales, of the interossei 
 interni, of the extensors, and of the interossei externi, 
 meet upon the backs of the fingers, which are by them 
 covered with a very strong web of tendinous fibres. 
 
 CHAP. IV. 
 
 MUSCLES OF RESPIRATION ; OR, OF THE 
 RIBS. 
 
 The whole back is clothed with strong muscles, and all 
 its holes, irregularities, and spines, are ci’ossed with many 
 smaller ones. These muscles are related either to the arm, 
 to the ribs, or to the spine, (i. e.) the vertebrse, whose motions 
 they perform ; and from this we obtain an arrangement not 
 inconsistent with the regular order of their office, and yet 
 corresponding with the best order of dissection. 
 
 The first, or uppermost layer of muscles, viz. the 
 trapezius, the rnusculus patientiae, the rhomboides, the latis- 
 simus dorsi, belong to the arm. The serrated muscles which 
 lie ^next under these, are the muscles of respiration, and 
 belong to the ribs; while the splenius and complexus, the 
 muscles of the neck, the longissimus dorsi, sacro-lumbalis, 
 and the quadratus lumborum, which are muscles of the back, 
 and the innumerable smaller muscles which lie betwixt the 
 vertebrae, belong entirely to the spine. 
 
 Respiration is indeed pei'formed chiefly by the muscles of 
 the belly, that is, in ordinary and easy breathing. In high 
 breathing, the difficulty is relieved by the co-operation of al- 
 most all the muscles of the trunk, of which there is scarcely 
 one that may not assist in some slight degree. But yet the 
 muscles of the abdomen have many other offices. And the 
 muscles of the spine, and of the scapula, again belong pro- 
 perly to the arm and trunk, and therefore I call those the 
 muscles of respiration, by which the ribs are moved in 
 
OR, OF THE RIBS- 
 
 205 
 
 breathing, and which have no direct relation to almost any 
 other motion, but merely that of the ribs. 
 
 The muscles which are appropriated to the ribs, per- 
 
 forming no other motion. 
 
 are. 
 
 1. The SERRATUS POSTICUS 
 SUPERIOR, 
 
 POSTICUS, 
 
 C which comes from the neck, 
 
 < and lies fleshy over the ribs, 
 
 ( to pull them upwards, 
 f which comes from the lumbar 
 2. The SERRATUS INFERIOR J Vertebrae, and lies flat on the 
 
 j lower part of the back, to 
 (^puU the ribs downwards. 
 f which are twelve flat mus- 
 { cles arising from the trans- 
 J verse process of each ver- 
 k The LEVATORES cosTARUM,<( ^ebra, and going down to 
 
 the rib below, they raise 
 the ribs. 
 
 which lie betwixt the ribs, 
 and fill up all the space be- 
 
 4. The INTERCOSTAL MUSCLES,<j 
 
 ^ raise the ribs. 
 
 And there may be added to these, that muscle, which, 
 lying under the sternum, and within the thorax, is called 
 triangularis sterni, and pulls the ribs downwards. 
 
 CXIII. The SERRATUS SUPERIOR POSTICUS lies flat upon 
 the side of the neck, under the trapezius and rhomboides, 
 and over the splenius and complexus muscles. It arises by 
 a flat and shining tendon from the spines of the three lower 
 vertebra: of the neck, and the two uppermost of the back. 
 It goes obliquely downwards under the upper corner of the 
 scapula, and is inserted into the second, third, fourth, and 
 fifth ribs, by three or four neat fleshy tongues. 
 
 The ligamentum nuchae is chiefly formed by the meeting of 
 the trapezii muscles; but the flat tendons of these upper 
 serrated muscles help to form it. 
 
 They are purely levators of the ribs ; their effect upon the 
 vertebrae, if they have any, must be very slight. 
 
 CXIV. The SERRATUS INFERIOR POSTICUS is a very 
 broad thin muscle, situated at the lower part of the back, 
 under the latissimus dorsi, or over the longissimus dorsi 
 muscle. 
 
 It arises in common with the latissimus dorsi, from the 
 spines of the two lower vertebrae of the back, and the three 
 uppermost vertebrae of the loins. Their origin, like that of 
 the latissimus, is by a thin tendinous expansion ; it soon 
 becomes fleshy, and, dividing into three, sometimes four 
 
206 
 
 AIUSCLES OP RESPIRATION, 
 
 fleshy strips or tongues, each of them is inserted separately 
 into the ninth, tenth, eleventh, twelfth lower ribs, near their 
 cartilages. So that this muscle, spreading so wide out from 
 the centre of motion, has vast power ; for it has the whole 
 length of the rib as a lever. 
 
 The office of it is to pull the ribs downwards and back- 
 wards, the effect of which must be to compress the chest, 
 and in certain circumstances to turn the spine. 
 
 CXV. The LEVATOREs cosTARUM are twelve muscles on 
 each side, for the direct purpose of raising the ribs ; they lie 
 above or upon the ribs, at their angles, and are thence 
 named, by some supra costales. 
 
 They are almost a portion of the external intercostal 
 muscles. The first of the levators arises from the transverse 
 process of the last vertebra of the neck, and goes down to 
 be inserted into the first rib, near its tuberosity ; and so all 
 that follow arise from a transverse process, and go to the rib 
 below, being very small and tendinous at either end ; but the 
 tliree last levators arise from the second process above the 
 rib to which they belong : they pass one rib to go into the one 
 below it ; they are consequently twice as long as the nine 
 first are, and are therefore named levatores costarum 
 LONGiOREs, from the ninth dowmwards. 
 
 Thus, the levatores costarum are a succession of small mus- 
 cles, arising from the transverse processes of the vertebrs, and 
 going to the angles of the ribs, beginning from the last verte- 
 bra of the neck, and ending with tbe last but one of the back. 
 They lie under the longissimus dorsi, and sacro-lumbalis ; and 
 often they have connections with these muscles, sometimes very 
 close. 
 
 CXVI. The iNTERCOSTALES extemi run obliquely from the 
 ower edge of one rib, downward and forward, or in a direction 
 from behind forward, to be inserted into the upper edge of the 
 rib below ; the muscle is not continued into the space betwixt 
 the cartilages of the ribs. The internal, again, are perfect be- 
 twixt the cartilages of the ribs, but they proceed no further back 
 than the angles of the ribs. They are further different from 
 the internal muscles, inasmuch as they pass obliquely back- 
 ward and downward from the margin of the one rib to the 
 other. 
 
 These two rows were thought to antagonize each other ; the 
 one to pull the ribs downwards, the other to raise them ; but I 
 shall not stop to explain this, nor to refute it ; it is sufficient to 
 declare their true use, which is (both external and internal) to 
 raise the ribs and assist inspiration.* 
 
 ^ I remember many years ago, to have beard Dr. Monro explain tbe office of the intercos- 
 
OR, OF THE RIBS. 
 
 201 
 
 The ninth, tenth, eleventh, and twelfth ribs, have a freer mo- 
 tion ; and it appears to me that this is the true use of the 
 levatores longiores; and for the same reason, we find, that 
 from the sixth rib and downwards, there are certain slips of the 
 internal intercostals, which pass over one rib, and go to the 
 second below ; and as the levatores longiores were called supra- 
 costales, these have been named jnfra-costales, and costa- 
 rum DEPKESSORES PROPRii. They were discovered by Verhein, 
 and bear his name ; they were explained as depressors of 
 the ribs by Haller, but they are little different from the inter- 
 costals in form, and not at all in office, for they raise the ribs, 
 along w'ith the intercostal muscles. 
 
 CXVIl. The TRIANGULARIS STERNI, Or STERNO COSTALIS, is a 
 depressor of the ribs; an internal muscle lying chiefly on the 
 inner face of the sternum, and the cartilages of the ribs. It is 
 very generally considered as a triangular muscle on each side, 
 but some consider it as three or four muscles, under the title 
 of sterno-costales. 
 
 There are generally four slips lying on the cartilages of the 
 third, fourth, fifth, and sixth ribs. The lower portion of the 
 triangularis arises from the ensiform cartilage, and is inserted 
 into the third or fourth rib ; the third arises from the middle 
 of the sternum, and goes off from the edges of that bone, to be 
 inserted into the third rib. 
 
 The fourth or uppermost portion is often wanting ; it goes 
 off in part, also, from the inner surface of the sternum, but more 
 commonly from the third rib, and goes to the second rib. 
 
 In a dog they are much longer than in a man. Their office 
 is to depress the ribs ; and these portions are all conjoined at 
 their roots, which gives the whole muscle the triangular shape. 
 
 The true uses of the intercostales, subcostales, and triangula- 
 ris sterni, have been disputed ; but if the first rib be more fixed 
 than the other ribs, then the intercostals proceeding down- 
 wards, from the first rib, must raise all the thorax ; and if the 
 sternum be more fixed than the ribs, then the sterno-costales 
 muscles going upwards from the sternum, must pull down the 
 ribs. 
 
 tal musrles by a diagram, deducing from that argument, the more powerfol effect of all nuiS- 
 eles having oblique fibres. 
 
208 
 
 MUSCLES OF THE 
 
 CHAP. V. 
 
 MUSCLES OF THE HEAD, NECK, AND TRUNK. 
 
 The serratus superior posticus being raised, the splenii come 
 into view, and the splenii being also liftedj the complexus is _ 
 fully exposed. 1 
 
 CXVIH. Splenius. — The two splenii are so named from 
 their lying like surgical splints, along the side of the neck ; 
 both together they have the appearance of the letter Y ; the 
 complexus being seen betwixt them in the upper part of the 
 angle. They lie immediately under the trapezii, and above 
 the complex!. 
 
 Each splenius is a flat and broad muscle, which arises from 
 the spinous processes of the neck and back, and is implanted 
 into the back part of the head. It arises from the four upper 
 spines of the back, and the five lower of the neck ; it parts 
 from its fellow at the fifth vertebra of the neck, so as to show 
 in the interstice two or three of the uppermost spines of the 
 neck, with the upper part of the complexus muscle ; each 
 splenius goes obliquely outwards to be inserted into the occipi- 
 tal ridge, and all along to the root of the mastoid process. 
 
 At the third vertebra of the neck, where the two splenii mus- 
 cles part from each other, the tendons of the opposite splenii 
 are closely connected both with each other and with the com- 
 mon tendon, which is called ligamentum nuchas. 
 
 This is the splenius capitis ; but there is a portion of this 
 same muscle which lies under this, and which has the same 
 common origin, but which terminates by four or five distinct 
 tendons in the transverse processes of the upper vertebras of the 
 neck. This portion may be dissected apart, and has been con- 
 sidered by many as a muscle, the splenius colli of Albinus ; 
 who has distinguished as splenius capitis all that part arising 
 from the spines of the neck, and implanted into the head ; and 
 as the splenius colli, all that part which arises from the verte- 
 bral of the back, and is implanted into the transverse proces- 
 ses of the neck. 
 
 These splenii are the right antagonists of the mastoid mus- 
 cles ; both the splenii acting, pull the head directly backward ; 
 one acting turns the head and neck obliquely to one side ; one 
 acting along with the corresponding mastoid muscle, lays the 
 ear down upon the shoulder. 
 
 CXIX. The complexes is named from the intricacy of its 
 
HEAD AND NECK. 
 
 209 
 
 muscular and tendinous parts, which are mixed ; from the 
 irregularity of its origins, which are very wide, it has the names 
 of coMPLExus JMPLicATUs TRIGEMINUS, by which the student 
 is warned of the^ifficulty of understanding this muscle. 
 
 It lies immediately under thesplenius; arises by distinct 
 tendons, with ten or more tendinous feet from the four lower 
 transverse processes of the veitebrae of the neck, and from the 
 seven uppermost of the back ; having also some less regular 
 origins as from two spines of the back and from four oblique 
 processes in the neck. It grows into a large muscle, which is 
 not like the splenius, flat and regular, but thick, fleshy, com- 
 posed of tendon and flesh mixed, filling up the hollow, by the 
 sides of the spines of the neck, and terminating in a broad 
 fleshy head, which is fixed under the ridge of the occipital 
 bone ; and this is the part which is seen in the angle or forking 
 of the splenii. 
 
 This may stand as the general description of the muscle con- 
 sidered as one. But Albinus has chosen to describe it as two 
 muscles, under two different names, with a minuteness which, 
 far from clearing the demonstration of any difficulties, makes 
 it less distinct ; and if any thing could complete the confusion, 
 it was his humour of calling that biventer, which had been 
 hitherto named complexes, and naming the lower part of the 
 muscle complexes, though it never had been distinguished 
 from the rest. 
 
 The BIVENTER of Albinus is the upper layer of the muscle, 
 that part which appears in the fork of the splenii : and if we 
 have hitherto named it complexus, from its mixture of ten- 
 dons and flesh, it was particularly improper to transfer that 
 name to another part of the muscle which is less complicated. 
 This upper layer, the biventer cervicis, is attached by a 
 large broad head to the occipital bone ; in the centre of this 
 belly there is a confusion of tendon ; then there is a middle 
 tendon about the middle of the arch of the neck, and the low- 
 er part of the biventer arises from two parts; first by one slip 
 of flesh from the two uppermost spines of the back; and, se- 
 condly, by a larger fleshy portion which comes from the fourth, 
 fifth, sixth, and seventh transverse processes of the back. And it is 
 from the upper and lower fleshy heads and the confused mid- 
 dle tendon that it is called biventer. 
 
 The COMPLEXES of Albinus lies below this one. It arises 
 by three tendinous and fleshy slips, from the three upper trans- 
 verse processes of the back. Then it has four other slips from 
 four oblique or articulating processes of the neck; which va- 
 rious origins are gathered into one thick irregular fleshy belly, 
 which is implanted into the occiput under the great head of 
 VOL. 1. D d 
 
210 
 
 MUSCLES OF THE 
 
 the biventer, and mixed with it. This I have chosen to ex- 
 plain, lest the student should be embarrassed by false names; 
 referring bim to the first paragraph for the true and simple des- 
 cription of this muscle. 
 
 CXX. Trachelo-mastoideus.* — The lafl muscle is often 
 named complexus major, and this complexus minor; but 
 a fitter name is the trachelo-mastoioeos, from its origin 
 in the neck, and its insertion in the mastoid process. 
 
 Its origin is from the three first vertebras of the back, and 
 from the five lowest of the neck at their transverse processes. 
 Its origins are by distinct tendons, and its belly is in some de- 
 gree mixed of tendon and flesh, whence its name of com- 
 plexus minor. It is inserted into the mastoid process just under 
 the insertion of the occipital part of the splenius ; and indeed its 
 long and flat belly lies all along under that muscle, so that the 
 order of dissection is this: 1. The trapezius. 2. The 
 
 SPLENIUS CAPITIS. 3. The SPLENIUS CERVicis. 4. The 
 TKACHELO-MASTOIDE US. f ? 
 
 It is needless to speak of its use, since the use of all these 
 muscles is to draw the head backwards directly, when both 
 act ; obliquely, when one acts alone. 
 
 The RECTI MUSCLES are two deep-seated muscles, which go 
 immediately from the vertebrze to the occiput, to be inserted 
 into its lower ridge. They are called major and minor, 
 
 CXXI. The RECTUS minor is the shorter of the two, arising 
 from the first vertebra of the neck. Its place of origin is a 
 small tuber which stands in the place of the spinous process of 
 the first vertebra, and from that point, where it is tendinous, 
 it goes up to the occipital ridge, and is inserted fleshy. 
 
 CXXII. The RECTUS major is larger. It arises, in like 
 manner, tendinous, from the second vertebra of the neck at 
 its spinous process, and mounting from that, is inserted fleshy 
 into the lower ridge of the occiput without the former. These 
 are so placed that the recti minores appear in the interstice of 
 the recti majores. And though we call them both recti, yet 
 they cannot truly be so ; for the recti minores must be, in 
 some degree, oblique, and the recti majores still more so : 
 and, consequently, although their chief use be conjointly to 
 draw the head directl)’^ backwards, yet one acting must turn 
 the head to its side. And indeed the same may be said of all 
 the muscles of the neck. 
 
 The OBLiQuus SUPERIOR and OBLiquus inferior, cor- 
 respond very closely in all things with the recti ; but, in their 
 
 * It is the TRACHEI.O-MASTOIDEUS, the MASTOIDEUS LATERALIS, the CAPITIS PAR-TEBTipj., 
 
 ihe coMPLEECs^MiNOR : by some it is considered as a part pf the complexus. 
 
HEAD AND NECK. 
 
 211 
 
 oblique direction the uppermost, as being much shorter, has 
 been named obliquus minor, the lower one obliquus major. 
 
 CXXIII. The OBLIQUUS supe“.ior arises from the trans- 
 verse process of the atlas, and is inserted into the end of the 
 lower occipital ridge. Its use, notwithstanding its oblique po- 
 sition, is not to turn, but to bend the head backwards, for the 
 occipital condyles standing obliquely, do not permit the rota- 
 tory motion of the head on the first vertebra. Its insertion in- 
 to the occiput is under the splenius and complexus : but one 
 edge of it is above the insertion of the rectus major. 
 
 CXXIV. The OBLIQUUS inferior rises from one verte- 
 bra and goes to another. It arises from the spine of the se- 
 cond vertebra : it goes to the transverse process of the first, 
 and it meets the superior oblique muscle ; and this one obtains 
 great power, by the lateral projection of the atlas giving it a 
 lever power. The first vertebra or atlas rolls on the tooth-like 
 process of the dentatus; and while the great and slow motions 
 of the neck in general are performed by other muscles, there 
 is a presumption, that the short and quick turnings of the 
 head are performed by these oblique muscles. 
 
 MUSCLES OF THE TRUNK. 
 
 The great muscles which move the back and loins are the 
 
 QUADRATDS LUMBORUM, 8ACRO-LUMBALIS, aild LONGISSIMUS 
 DORSl. 
 
 The sacro-lumbalis and longissimus dorsi run by the side of 
 the spine, and lie immediately under the latissimus dorsi, 
 which is the outer layer ; the quadratus lumborum lies again 
 under these, and next to the abdominal cavity. Although the 
 quadratus lumborum lies deep under the longissimus dorsi mus- 
 de, I shall describe it first for the sake of a connection which 
 will be presently understood. 
 
 CXXV. The QUADRATUS LUMBORUM is a flat squared mus- 
 cle named quadratus from its square, or rather oblong form. 
 It arises fleshy from two or three inches of the back part of the 
 os ilium, and from the ligaments of the pelvis, which tie the 
 hack part of the ilium to the side of the sacrum, and to the 
 transverse processes of the loins. As it goes upwards along 
 the side of the lumbar vertebrie, it takes hold of the points of 
 the transverse processes of each, by small tendinous slips ; so 
 that we are almost at a loss whether to consider these as new ori- 
 gins or as insertions : butits chief insertion is into the lower edge 
 wfthe last rib, and a small production ef it slips under the arch 
 
212 
 
 BIUS€LES OF THE TRUNK, 
 
 of the diaphragm, to be implanted into the body or forepart; 
 of the last vertebra of the back. 
 
 The LONGissiMUs Doiibi and sacho-lumbalis have their 
 origin in one common and broad tendon coming from the sa- 
 crum, ilium, and loins ; the two muscles lie alongside of each 
 other; the longissimus dorsi is nearer the spine, and keeps its 
 tendons closer by the spine. The sacro-lumbalis is farther 
 from the spine, and spreads its tendinous feet broader upon 
 the sides of the thorax : and if one be a little under the other, 
 it is the outer edge of the longissimus dorsi, which is a little 
 under the edge of the lumbar muscle. 
 
 The common tendon and muscle (for there is for some way 
 but one muscle) begins thus : it may be said to have two kinds 
 of adhesion ; for, first externally it appears a broad, fiat, and 
 shining tendon, which arises tendinous from all the spines of 
 the lumbar vertebrae ; from the spines of the sacrum, and from 
 the back part of the os ilium. But the inner surface of this 
 broad tendon is strongly fleshy ; for it arises fleshy from the 
 back part of the ilium ; from the deep hollow betwixt the 
 ilium and sacrum ; from the sides of the long spines of the lum- 
 bar vertebrae ; and from their articulating processes, and the 
 roots of their transverse processes. In short, its origin is all 
 tendinous without, and all fleshy within ; and its flesh arises 
 from all that irregular surface which is on either side of the 
 spine betwixt the os ilium and the vertebrae of the loins ; and 
 thus it continues one strong tendinous and fleshy muscle, fill- 
 ing up all the hollow of the loins. There is an appearance of 
 separation, something like a split in the tendon, which shows 
 in the loins what part of the tendon belongs to each muscle ; 
 but it is only in the back that they are fairly divided. 
 
 Just oppisite to the lowest rib, the longissimus dorsi and sa- 
 cro lumbalis break off from the common tendon ; and the lon- 
 gissimus keeps close by the vertebra, while the sacro lumbalis 
 is implanted into the ribs. 
 
 CXXVI. The LONGISSIMUS dorsi is a muscle of the spine. 
 It is not a flat muscle, but round, thick, and firm, filling up all 
 the hollow betwixt the spine and the angle of the ribs. It is of 
 a long form, as its name implies, terminating towards its top 
 almost in a point. It has two distinct sets of feet by which it 
 is inserted ; one set of feet more fleshy, but small and neat, go 
 outwards from the side, as it were, of the muscle, to be im- 
 planted near the heads of the ribs ; the lower ones farther out 
 than the heads of the ribs ; the upper ones close to the head, 
 and consequently closer to the spine. These heads are nine 
 or ten in number, corresponding with the nine orten uppermost 
 ribs. Another set of heads, which are not so well seen as this 
 
MUSCLES OF THE TRUNK. 
 
 2IS 
 
 set, because they lie more under the muscle, are small, neat, 
 and tendinous ; they go in an opposite direction, \dz. inwards 
 and upwards; keep closer by the spine, and are inserted i o 
 the transverse processes of the vertebrae of the back. This set 
 of heads is thirteen in number, implanted into the transverse 
 processes of all the back, and of one vertebra of the neck. 
 
 CXXVn. The SACHo-LUMBAJUS separates from the longis- 
 slmus dorsi at thelat rib, and is a flatter and less fleshy muscle : 
 its twelve tendons are flatter than those of the longissimus dor- 
 si, and go out wider from the spine. The tendons next to the 
 longissimus dorsi run highest up, and are the longest ; those 
 farthest from the spine, (?. e.) farthest out upon the chest, are 
 the shortest. It has a flat tendon for each rib, wljich takes 
 hold upon the lower edge of the rib. But it has another order 
 of small muscles which mix with it ; for as the longissimus 
 dorsi has a double row of insertion, this has another set of 
 attachment, for there arises from the surface of each rib, at 
 least of the six or seven lowest ribs, a small slip of flesh, which 
 runs into the substance of the sacro-Iumbalis, and mixes with 
 it ; and these fleshy slips go by the name of the auditamentum 
 
 AD SACRO-EUMBALEM Or MUSCULl ACCESSORII. 
 
 Both these muscles, viz. the longissimus and sacro-lumbalis, 
 terminate in points which reach towards the neck, and under 
 the point of each there lie the roots of two small muscles, which 
 go up to move the neck. Many have referred these slips go- 
 ing up into the neck entirely to the muscles I am now descri- 
 bing, calling one an ascending slip of the longissimus dorsi, and 
 the other a slip of the sacro-lumbalis, while others have des- 
 eribed them as distinct muscles, having but slight connections 
 with the longissimus and sacro-lumbalis. Their proper names 
 are cervicalis descendens, and transversalis colli. 
 
 CXXVIII. The CERVICALIS descendens is connected with 
 the sacro-lumbalis muscle ; it cannot be entirely referred to it, 
 for the cervicalis descendens arises as a distinct muscle from 
 the five lower vertebrae of the neck, at their transverse pro- 
 cesses, goes downwards very small and slender, to be inserted 
 into the six uppermost ribs, to get at which it slips under the 
 longest tendons of the sacro-lumbalis ; but that the cervicalis 
 descendens does not belong to the sacro-lumbalis may be in- 
 ferred from its having distinct tendons from six ribs, and from 
 five transverse processes of the neck, and from these tendons 
 being in a direction which does not at all correspond with the 
 heads of the sacro-lumbalis. Indeed the longissimus dorsi has 
 a better claim to this muscle ; for a long slip, partly tendinous 
 and partly fleshy, runs upwards from the longest tendon of the 
 longissimus dorsi, to join itself to the cervicalis descendens, ner - 
 
214 
 
 MUSCLES OF THE TRUNK. 
 
 haps it would be better to consider it a continuation of the ac- 
 cessorii ad sacr. lumbal.* 
 
 CXXIX. The TRANS VERS ALis COLLI is that which Sabatier 
 refers to the longissimus dorsi ; but it is a distinct muscle, ari- 
 sing partly tendinous, and partly fleshy, from the five upper 
 transverse processes of the hack ; lies betwixt the trarhelo- 
 mastoideus and the cervicalis descendens; goes from the 
 transverse processes of the back to the transverse processes of 
 the neck, and has no more than a confused and irregular con- 
 nection with any other muscle. 
 
 The ^UADRATus LUMBORUM keeps the trunk erect, by the 
 action of both muscles at once ; inclines it to one side, or turns 
 it upon its axis, when one only acts ; and by its insertion into 
 the ribs, must assist in high breathing, by pulling down the ribs. 
 The LONGISSIMUS DORSI has no power but over the spine, 
 which it bends backwards, acting continually in keeping the 
 trunk erect. This is also the chief use of the sacro-lumbalis j 
 but the SACRO-LUMBALIS going out further upon the ribs, takes 
 such hold upon them, that besides its common action of raising 
 the trunk, it may, on occasions, pull them down, assisting the 
 quadratus and the lower serrated muscle. And it will have 
 greater power in turning the trunk of the body upon its axis 
 than the longissimus dorsi, which pulls almost directly back- 
 wards. The CERVICALIS DESCENDENS co-operates with the 
 trachelo-mastoideus, and others, which turn the head to one 
 side ; and the cervicalis descendens bends the neck to one side, 
 both the one and the other being independent muscles. 
 
 These two muscles bring us to mention that intricate set of 
 muscles which fills up all the hollows and interstices among the 
 spines and irregular processes of the vertebrae, which might be 
 fairly reckoned as one muscle, since they are one in place and 
 in office, but which the anatomist may separate into an infinite 
 number, with various and perplexing names ; an opportunity 
 which anatomists have been careful not to lose. 
 
 The surface of the back, from the bulge of the ribs on one 
 side, to the bulge of the ribs on the opposite side of the 
 thorax, is one confused surface, consisting of innumerable 
 hollows, processes, and points of bone ; and it is tied from 
 point to point with innumerable small muscles, or unequal 
 bundles of mixed tendon and flesh. There are many points, 
 
 * Hence it is plain that the sacro-lumbalis and longissimus dorsi have nearly an equal 
 claim to this cervicalis descendens. For, first, the longissimus dorsi sends its longest tendon 
 fairly up into the cervicalis de.scendens, so far, tiiat the slip is implanted into the transverse 
 processes of the neck. And, secondly, tlie feet of the cervicalis descendens begin under tlie 
 last tendons of tlie sacro-lumbalis, so as to have tlie appearance of arising from itssupplemen- 
 tary muscle, tiie additamentum, and being a part of it ; and indeed Sabatier has described it 
 according to this view. 
 
MUSCLES OF THE TRUNK. 
 
 215 
 
 as the spinous, transverse, and oblique processes of the ver- 
 tebrce, and the bulging heads and angles of the ribs ; and 
 each process, or at least each set of processes, has its distinct 
 sets of muscles and tendons. 
 
 1 . There is one long continuity of muscular and tendinous 
 fibres going from spine to spine, and lying on the side of the 
 spinous processes along the whole length of the back and 
 neck. This is divided into the spinalis cervicis, and the 
 
 SPINALIS DO RSI. 
 
 2. There is a similar continuation of fibres, with less 
 tendon and more flesh, belonging one half to the spinous, and 
 the other half to the transverse processes, whence it is named 
 
 SEMI-SPINALIS DORSI. 
 
 3. There is a great mass lying all along the hollow of the 
 back, on each side of the spinous processes, which passing 
 alternately from the transverse process of one vertebra to the 
 spinous process of the next above, is of course split into 
 many heads, but yet having such connection as to give it the 
 form and name of a single muscle, the mdltifidus spin^;. 
 
 4. and 5. There are yet smaller muscular fasciculi which 
 stand perpendicularly betwixt every two transverse and every 
 iwo spinous processes; thence they are named inter-trans- 
 VERSARii and inter-spinales. 
 
 CXXX. The spinalis cervicis is that which is im- 
 planted into the spines of the cervical vertebrae ; but because 
 it does not go from spine to spine, like the spinalis dorsi, 
 but from transverse processes to spines, it has been named by 
 Winslow, SEMI-SPINALIS, or transverso-spinalis colli. 
 It arises from the transverse processes of the six upper verte- 
 bra of the back, and is inserted into all the spinous process 
 of the vertebriP of the neck, except the first and last ; and it 
 extends the neck, or by its obliquity may contribute to the 
 turnings of the neck, or to bending it to one side.* 
 
 C5Q5X1. The spinalis dorsi arises from two spinous pro- 
 cesses of the loins, and from the three lower spines of the 
 back, and passing two spines untouched, it is implanted into 
 all the spines of the back, except the uppermost. This 
 muscle is very slender and long, and consists fully more of 
 tendon than of flesh : it has five feet below, rising from the 
 lower spines of the back and loins ; and nine feet above, im- 
 planted into the upper spines of the back. Its action must 
 raise the spine, but perhaps it may be equally useful, as a 
 muscular and tendinous ligament. 
 
 * The TP.ANsvERSALis cERvicts (vide p. 214.) is that which goes from the transverse 
 processes of the back to the transverse processes of the neck ; while this, the sn?j.\Tis- 
 cERvins. goes from the transverse processes of the back to the spines of the neck. 
 
216 
 
 MUSCLES OP THE TRUNK. 
 
 rXXXII. The SEM1-SP11VA.L1S dorsi arises from the trans- 
 verse processes of the seventh, eighth, ninth, and tenth ver- 
 tebr® of the back, and is implanted into the six or seven 
 upper dorsal spinous processes and into the two last of the 
 neck.* 
 
 CXXXIII. The MULTiFiDus spin® runs from the sacrum 
 along all the spine to the vertebrae of the neck; and" is a compre- 
 hensive and true way of describing many irregular portions of 
 flesh, which authors have divided into distinct muscles.f It 
 is a continued fleshy indentation, from transverse process to 
 spine, through all the vertebr® of the back, neck, and 
 loins. 
 
 It begins both tendinous and fleshy, from the upper convex 
 surface of the os sacrum, which is rough with spines, from the 
 adjoining part of the illium ; and in the loins, it arises from 
 oblique processes: in the back, from transverse processes; 
 and again from oblique processes, among the cervical ver- 
 tebrae. 
 
 Its origin in the loins, is close to the spine ; being from the 
 upper oblique processes, and from the root of the transverse 
 processes. In the back it arises from the transverse processes, 
 and therefore arises there by more distinct heads. In the |] 
 neck again, it arises from the lower oblique processes, more 
 confusedly. 
 
 Its bundles or fasciculi are inserted into the spinous pro- 
 cesses, sometimes into the second, or even into the third or 
 fourth spine, above that from which the bundle arises ; for the m 
 tendons do not stop at that spinious process which they first 
 touch, but go upwards, taking attachments to other two or 
 three, and mixing their tendons with those of the fasciculi, 
 above and below ; and these tendons reach from the first of 
 the loins to all the vertebrae up to the atlas, which is the only 
 one not included. 
 
 The use of the multifidus spinse, is to retain the spine from 
 being too much bent forward ; for these muscles serve (as I 
 have observed) the purpose of a ligament, and the best of 
 all ligaments, having a degree of strength, exactly pro- 
 portioned to the necessity for strength. It also moves the 
 spine backwards, though perhaps it is less useful in this than 
 as a ligament ; for we find it as strong in the vertebrae of the 
 back, which have little motion betwixt the individual bones, 
 and what little there is, must consequently be general. It ' 
 
 * This is of coui'se the transverso spinalis dorsi of Winslow. | 
 
 f TrANSVERSO-SPINALIS LUMBOP.l'M, SACER ; SEMI-SPINAI.IS INTERNUS, Sive TRANSVERSO- 
 spiNALis DOR.'i, sEMi-spiNALis, >ive TRANSVERSO-spiNAi.is COLLI, pars interna. — Winslow, 
 Transvehsalis lumborum, vulgo sace;r. Thansversalis dorsi. Trajssversahs 
 COIII. 
 
MUSCLES OF THE TRUNK. 
 
 217 
 
 seems rather intended to moderate the lateral motions of the 
 vertebrae than to produce them : when it acts, its chief use is 
 either to resist the spine being bent forward by a weight, or to 
 erect the spine. 
 
 CXXXIV. The inter-spinales colli, dorsi, and lum- 
 BORUM, have varieties, so little interesting, that they need 
 hardly be described. The inter-spinales colli are 
 stronger, because the neck has many and quick motions, and 
 the bifurcated spines of the neck give broader surfaces for 
 these muscles. The inter-spinales dorsi are almost 
 entirely wanting, because the spines of the back are close 
 upon each other, and the vertebrae are almost fixed. The 
 INTER-SPINALES in the LOINS, are rather tendons or liga- 
 ments, than proper muscles. 
 
 CXXXV. The iNTER-TiiANSTERSALES are again stronger 
 and fuller in the neck, because of the lateral motions of the 
 neck being free, and its transverse processes forked. They 
 are in more numerous bundles, where the motion is greatest, 
 viz. betivixt the atlas and dentatus ; and it is there, that 
 Alhinus coimts his inter-transversales cervicis, prio- 
 RES-LATERALES, &c. The inter-lransversarii are wanting in 
 the BACK, giving place to the hgaments, by which they are 
 tied to each other, and to the ribs; but in the loins, the 
 inter-transversarii are again strong, for the lateral or twisting 
 motions of the loins. 
 
 The muscles on the forepart of the head and neck will 
 complete the catalogue of those belonging to the spine, and 
 they are the chief antagonists to the muscles which I have 
 been describing. 
 
 CXXXVl. The PLATYSMA-MYOiDEs* is a very thin muscu- 
 lar expansion, like the cutaneous muscle in animals. It is 
 spread over the other muscles, immediately under the skin, 
 and covers the whole neck and lower part of the face. 
 
 It arises from the cellular substance and aponeurosis, which 
 cover the pectoral muscle, the deltoid muscle, and the clavi- 
 cle. Its origin is by long separate fleshy slips ; it goes like a 
 thin integument over the neck, and is first inserted about the 
 depressor anguli oris, and then going over the masseter, is lost 
 betwixt the muscles and the integuments of the cheek. 
 
 Perhaps it serves also to pull down the skin of the cheek, 
 and the angle of the mouth ; but its chief insertion is into the 
 lower jaw, and its use is partly to pull it downwards, but prin- 
 cipally to act as a fascia, binding the parts in the neck, and in 
 
 * The PiATTSMA-MTOiDEs IS also named muscl trs cuta!5ei.'s latissimus coin, 
 
 VOL. I. E e 
 
MUSCLES OF THE TRUNK. 
 
 21 a 
 
 violent respiration to press down the blood contained in the 
 great veins of the neck. 
 
 CXXXVII. Mastoideus. — This muscle arises partly from 
 the clavicle, partly from the sternum. Albinus reckons it two 
 muscles; the steuno-mastoideus, and cleido-mastoidkus ; 
 a more common name is the steuno-cleido-mastoideus ; but 
 here, as in other things, I adhere to what is plainest. And 
 the most familiar and easy name is musculus mastoideus, | 
 considering the clavicular portion, as an addition only. 
 
 Its origin, from the upper part of the sternum, is pretty round. 
 
 It arises again flat from the forepart of the clavicle ; and this 
 second origin is broad and fleshy, while the first one is tendi- 
 nous and pointed. These two heads form together a very 
 big strong- bellied fleshy muscle, which is inserted into the 
 mastoid process by a broad tendon, which indeed surrounds 
 the mastoid process, and from that extends still backwards, 
 towards the lambdoidal suture. When one of the mastoid 
 muscles acts, it turns the head to one side; when both act^ 
 they pull the head directly forwards. 
 
 CXXXVTII. Rectus inteknus capitis major. — There 
 are three muscles on each side, lying under the oesophagus, 
 trachea, and great vessels, flat upon the forepart of the verte- 
 brae ; and this is the first and longest. 
 
 Although this be called rectus, it is oblique, and runs ra- 
 ther on one side ; for it arises from the transverse processes of 
 the five lower vertebrae of the neck, and it is inserted into the 
 cuneiform process of the occipital bone, just before the fora- 
 men magnum. 
 
 CXXXIX. Rectus internus minor. — This is an exceed- 
 ingly small muscle. It lies immediately under the rectus 
 MAJOR : it arises from the forepart of the body of the first ver- 
 tebrae, the atlas, and going (like the other rectus) obliquely in- 
 Avards, it is inserted into the occipital bone, near the condyle. 
 
 CXL. And the rectus capitis lateralis is another small 
 piuscle like the former, which arises from the transverse pro- 
 cesses of the first vertebra, and is inserted into the side of the 
 cuneiform process of the occipital bone. It lies immediately 
 under the exit of the great jugular vein. 
 
 CXLI. Lonrus colli. — This is the chief of those muscles 
 which lie upon the forepart of the neck ; it is very long, arising 
 from the flat internal surface of the vertebrae of the back, to 
 go up along those of the neck. 
 
 Its origin is first within the thorax, from the three upper- 
 most vertebrai of the back, from the flat part of their bodies, 
 and then from all the transverse processes and bodies of the 
 neck, except the three upper ones. It is inserted tenUinoift 
 
MUSCLES OP THE TRUNK. 219 
 
 into the forepart of the second vertebra; of the neck, where 
 the opposite large muscles meet in one point almost* 
 
 x\Il these muscles, which lie thus flat upon the plain surface 
 of the vertebrte of the neck, pull the head and neck directly 
 forwards ; or when one acts, they are of use in pulling it to- 
 wards one side ; though I rather suppose this motion is perform- 
 ed by the external muscles chiefly. 
 
 CXLIl. The SCALENUS I consider as one muscle ; for it is 
 one in origin, insertion, and office. Its origin is from the 
 rvhole upper surface of the first rib, from its cartilage backwards, 
 and also from the second rib ; and its insertion is into the 
 transverse processes of the vertebrae of the neck. But by its 
 broad origin, and its very long insertion, it gives opportunity 
 for dividing it into several fasciculi ; and accordingly it has 
 been so divided; but these divivions are entirely modern, ar- 
 tificial, and unnatural. The ancients considered it as one 
 triangular muscle. Winslow divided it into two, the primus 
 and secundus ; Cowper into three; Douglas into four; and 
 Albinus divides it into five muscles. The ancients called it 
 scalenus, from its resemblance to the scalen triangle ; and the 
 true anatomy is, to consider it as one great triangular muscle, 
 flat, and stretching from the ribs to the neck, closing the tho- 
 rax above, and giving passage to the nerves and vessels of the 
 arm. 
 
 If it were to be described in distinct portions, it would be in 
 in three parts. The anterior portion arises from the trans- 
 verse processes of the fourth, fifth, and sixth vertebrae of the 
 neck, and is inserted into the flat part of the first rib hard by 
 its cartilage. The middle portion from the transverse pro- 
 cesses of all the vertebrae of the neck goes to the outer edge of 
 the rib, and extends along all its length. The posterior portion 
 arises from the transverse processes of the fourth, fifth, and 
 sixth vertebras. It is inserted into the upper edge of the 
 second rib, about an inch or more from its articulation with 
 the spine. 
 
 The first head is tendinous and fleshy at its insertion into 
 the rib; but the second and third heads are tendinous, both 
 in their origins and insertions. 
 
 The nerves pass in the interstice betwixt the first and se- 
 cond portions. 
 
 The oflBce of the scalenus muscle is to pull the neck to one 
 side, or to bend the head and neck forward, when both act ; 
 and when the neck is fixed backwai’ds, they may perhaps raise 
 the ribs ; for asthmatics are observed to throw the head back- 
 wards, in order to raise the chest with greater power. 
 
 * The longas coUi raascle h in part covered by the recto? 
 
220 
 
 MOSCLES of the ABDOMEKj 
 
 CHAP. VI. 
 
 OF THE MUSCLES OF THE ABDOMEN. AND OF 
 THE DIAPHRAGM. 
 
 The abdominal muscles cover in the belly, contain the 
 bowels, and take a firm hold upon the pelvis and the trunk. 
 The diaphragm, again, is a moving partition betwixt the tho- 
 rax and the abdomen ; and the diaphragm, pressing down the 
 bowels upon the abdominal muscles, enlarges the thorax ; and 
 the abdominal muscles re-acting, push the bowels bark upon 
 the diaphragm, and compress the thorax. Thus, the alternate 
 yielding and re-action of the abdominal muscles and diaphragm 
 perform breathing, agitate the bowels, promote the circulation, 
 expel the fceces and urine, assist the womb in the delivery of 
 the child. And, with all these important uses, the abdominal 
 muscles bend and turn the trunk, and fix it for the stronger ac- 
 tions of the limbs. They steady the body in lifting weights, 
 in bearing loads, in all our more violent exertions they often 
 give way under this double office of breathing, and of strain- 
 ing, along with the rest of the body; and the bowels coming 
 out through their natural openings, or by bursting through the 
 interstices of their fibres, form hernias of various kinds. 
 Whence the anatomy of these muscles is most interesting to 
 the surgeon. 
 
 The muscles of the abdomen are five on each side. 1. The 
 outer oblique muscle, to which the names of nnscEMiENS, 
 DECLivis, and ma.tor, are added, because it is the outermost of 
 all the abdominal muscles; because it is the largest, covering 
 all the side of the abdomen with its fleshy belly, and all the 
 forepart of the abdomen with its broad expanded tendon ; 
 and it is called declivis, or descendens, because its fleshy 
 belly begins above, upon the borders of the thorax ; and be- 
 cause both its muscular and tendinous fibres, w'hicb lie paral- 
 lel to each other, run obliquely from above downwards and 
 inwards. 
 
 2. The OBLiquus internus is named from its being within 
 the first, and has the names of ascend ens vel minor super- 
 added, because its fleshy belly is smaller than that of the 
 first, arises below, chiefly in the hailnch-bone, and all its fibi’es 
 go from below upwards. 
 
 3. The TRANSVEUSALis lies under all the others, and next 
 to the cavity of the abdomen, and has but one name which, 
 
AND OF THE DIAPHRAGM. 221 
 
 also is derived from the direction of its fibres running across, 
 or round the abdomen. 
 
 4. The RECTUS, so named, because of its running on the 
 forepart of the abdomen, in one straight line from the os 
 pubis to the sternum. 
 
 6. The pvKAMiDAL muscle is the only one named from its 
 shape. It is a small, neat, conical muscle, which arises from 
 the os pubis, by a broad basis, and has its apex turned up- 
 wards ; but it is not always found, for it is only as a supplement 
 to the recti muscles, and as a part of them, whence it has 
 been named musculus succenturiatus, or supplementary 
 muscle. 
 
 CXLIII. The EXTERNAL OBLiQ,UE musclc arises from the 
 ribs, and, like all the others which arise from ribs, is a ser- 
 rated muscle. It comes from the eight lower ribs, by distinct 
 fleshy tongues, one from each rib. These serrae are mixed 
 with the indentations of the serratus major anticus muscle, 
 which goes off in an opposite direction, and with the origin 
 of the pectoralis major and latissimus dorsi. The origin of 
 the muscle lying broad upon the border of the chest, it is its 
 thickest and most fleshy part, whence its fibres go down all 
 in one direction, parallel with each other, but oblique with 
 respect to the abdomen. Its fleshy belly ceases about the 
 middle of the side. Its flat sheet of tendon goes over the 
 forepart of the belly, till it meets its fellow exactly in the 
 middle, so that one half, or the back part of the abdomen, 
 is covered by its fleshy belly, and the forepart by its tendi- 
 nous expansion. 
 
 The muscle meets its fellow in the middle of the belly j 
 and this meeting forms (along with the other tendons) a white 
 line from the pubes to the sternum, which is named linea 
 ALBA. It also, before it reaches the middle, adheres to the 
 flat tendon of the Internal oblique. This meeting is about 
 four inches on either side of the linea alba, and is a little in- 
 clined to the circular, whence it is named linea semilunaris. 
 And, finally, this muscle is implanted into the spine of the 
 ilium, fleshy about the middle of the ilium, tendinous at the 
 forepart, or spinous process of the ilium, and still tendinous 
 into the whole length of that ligament, which extends from 
 the spine of the ilium to the crest of the pubes. 
 
 This is the whole of its insertion, viz. all the length of the 
 linea alba, fronj the pubes to the sternum, the forepart of 
 the spine of the ilium, and the ligament of Paupart, which, 
 though it is commonly thought to be but the tendon of the 
 external oblique reaching from point to point, is, in truth, a 
 
222 MUSCLES OF THE ABDOMEN, 
 
 distinct ligament, independent of the tendon, and stronger 
 than it. 
 
 CXLIV. Obliquus internus abdominis. — The chief part 
 of this muscle arises thick and fleshly from all the circle of 
 the spine of the ilium, with its fibres directed upwards. But, 
 to be accurate, we must describe it as arising from the whole 
 length of the spine of the ilium, from the joining of the ilium 
 and sacrum, from the spines of the sacrum itself, and from 
 the three lower spinous processes of the loins ;* and, lastly, 
 it arises from nearly half of the ligament of the thigh, at its 
 end next to the ilium ; but still the chief belly is at the iliac 
 spine. From that it spreads upwards in a radiated form ; the 
 central fibres only are direct, going across the abdomen to the 
 linea alba ; the higher fibres ascend and go towards the 
 sternum, and the lower ones go obliquely downwards to the 
 pubes. Its flat tendon is like that of the external oblique, 
 and it is inserted into the cartilages of the seventh, and all 
 the false ribs, into the ensiform cartilage of the sternum, and 
 into the linea alba, through its whole length, and the os 
 pubis. 
 
 CXLV. The transversalis abdominis forms the internal 
 layer, it runs directly across the belly. It arises fleshy from 
 the inner surface of the seven lower ribs, where its digitations 
 mix with those by which the diaphragm arises; tendinous 
 from the transverse processes of the four lower lumbar verte- || 
 br^, and last of the back ; from the whole spine of the os 
 ilium internally, and from a part of the femoral ligament. 
 Upon the whole, its origin is like that of the inner oblique 
 , muscle ; its fibres go across the abdomen, and its tendon is 
 inserted into the whole length of the linea alba, cartilage 
 ensiformis and os pubis. 
 
 The succession in which these three muscles arise from the 
 chest, is this : the external oblique muscle lies broad upon 
 the outside of the chest, and so its tongues mix with the 
 tongues of the serratus anticus major. The internal oblique 
 muscle again rises lower down the thorax, frorn its edge, 
 from the cartilages of the ribs. The transverse muscle arises 
 within the thorax, from the internal surface of the ribs, oppo- 
 site to where the tongues of the external oblique lie ; and the 
 diaphragm arising from the same ribs, mixes its indigitations 
 with the transversalis, so that Gaspar Bartholin, observing 
 this indigitation to be very curious in the larger animals, be- 
 lieved the diaphragm and transverse muscles to be but one 
 great trigastric, or three-bellied muscle, surrounding all the 
 
 * This origin from the spinous processes of the loins, is a thin tendon, common with Ihs 
 serratus and latisshnus dorsi muscles. 
 
and of the diaphragm. 
 
 223 
 
 abdomen. But the transversalis, with the other abdominal 
 muscles, are the antagonists of the diaphragm. 
 
 CXLVI. The KKCTi muscles cover the abdomen on its 
 forepart, in a line from the pubes to the sternum, and they 
 belong so equally to the sternum and to the os pubis, that it 
 is indifferent which we call their origin, and which their 
 insertion. The origin (as I should call it) of each rectus 
 muscle is in the sternum, is broad and fleshy, lies upon the 
 outside of the sternum, covering part of it, and all the 
 xiphoid cartilage, and touching and mixing its fibres with the 
 great pectoral muscle, and likewise taking part of its origin 
 from the cartilages of three of the ribs. It is about four 
 inches broad all down die abdomen, and terminates at the 
 side of the symphysis pubis, with a flat and pointed tendon 
 about an inch in length, and about an inch broad. This 
 muscle is crossed at intervals by four tendinous intersections, 
 which divide it into five distinct bellies. Commonly there 
 are three bellies above the umbilicus, and two below ; but 
 the recti muscles are the least regular of all the muscles of 
 the abdomen. Vesalius, Albinus, and Sabatier, were thought 
 to have found the recti abdominis extending up to the throat. 
 But it is now found that Vesalius had only represented the 
 muscles of a monkey, or of a dog, which - are very long, 
 upon the thorax of a human subject. Sabatier, upon revising 
 his notes, retracts what he had said : and Albinus also is sup- 
 posed to have seen only a production of the mastoid muscle, 
 extending down the breast ; for irregularities of this kind have 
 been found. 
 
 CXLVII. The pyramidal muscles are as a supplement to 
 the recti. There is a small neat pyramidal muscle on each 
 side, or rather a triangular muscle, fleshy through its whole ex- 
 tent and length, with its base turned towards the pubes, and 
 its apex towards the umbilicus ; so that its origin is in the crest 
 of the pubes, and its pointed insertion in the linea alba : and 
 though the recti muscles have been supposed byMassa to re- 
 late to the penis, or by Fallopius to belong to the urinary blad- 
 der, their true use is only to assist the rectus to draw down the 
 sternum, and tighten the linea alba, and so to give greater 
 power to the oblique and transverse muscles. The pyramidalis 
 is so irregular a muscle, that sometimes two are found on one 
 side, and none at all on the other. Sometimes two on each 
 other; sometimes there is but one, and very often they are 
 wanting, the belly of the rectus coming quite dowm to the 
 pubes. 
 
 1. The LINEA ALBA is the common meeting of all the thin 
 flat tendons, and therefore w'e call it their insertion, being the 
 
224 MUSCLES OF THE ABDOMEN, 
 
 common point towards which they all act; it is white, by the 
 gathering of all the colourless tendons. 
 
 2. The LiNEA SEMILUNARIS is a line of the same white ap- 
 pearance, of a circular form, and produced by the meeting of 
 all the tendons, on the edge of the rectus muscle, to form a 
 sheath for it. 
 
 3. The SHEATH for the rectus muscle does not admit of 
 so brief a definition as this: it has been commonly supposed 
 to be formed in a very curious manner, chiefly by the broad 
 tendon of the obliquus internus, which being the central mus- 
 cle, betwixt tbe two other layers, is supposed to have its ten- 
 don split into two thin sheets ; that the outermost sheet ad- 
 heres to the outer oblique muscle, forming tbe outer part of 
 the sheath, while its inner sheet adheres to the tendon of the 
 transverse muscle, forming the inner part of the sheath ; but 
 this is loo intricate, and can hardly be proved by dissection. 
 Cowper expresses his doubts about this doctrine of the tendon 
 of tbe inner oblique muscle being split into two layers ; and I 
 think the truest description is this, that all the tendons meet 
 and adhere in the semilunar line ; that they immediately part 
 to form this sheath ; that the flat tendons of both the oblique 
 muscles go upon tbe outer surface of the rectus, to form that 
 side of the sheath ; that the tendon of the transverse muscle 
 only lies under the rectus, forming the lower part of the sheath, 
 and that it is unassisted by any lamella of the inner oblique 
 muscle ; that the sheath is complete at the forepart, or over 
 the muscle ; but that under the muscle the sheath stops about 
 five or six inches above the pubes, and that there the recti mus- 
 cles (or in their place the pyramidal muscles) lie bare upon the 
 bladder, and other abdominal viscera, lined only by the thin 
 peritonaeum.* And that this back layer of the sheath is thin- 
 ner and more delicate, and but little attached to the back part 
 of tbe rectus muscle, which is easily raised in dissection, while 
 the forepart of the sheath adheres firmly to the forepart of the 
 muscle, forming those cross bands, or tendinous intersections 
 which divide the rectus into bellies, and the sheath where it 
 lies over the muscle cannot be dissected without a degree of 
 violence, either to the sheath, or to these tendinous intersec- 
 tions. 
 
 4. The UMBILICUS is that opening in the centre of the abdo- 
 men, in the middle of the linea alba, through which the nutri- 
 tious vessels of the foetus pass. The vessels have degenerated 
 
 * Cowper had never observed this but once, that the lower part of the rectus was not 
 lined by the tendon of the transversalis. He concluded, that in this instance it was a sport 
 ing of nature: “so much a liisns naturse, that accidents like this might he the cause ofcer 
 tain rupture".*' 
 
AND OF THE DIAPHRAGM. 
 
 225 
 
 Tato ligaments in the adult, and the umbilicus is closed in the 
 form of a ring; but sometimes it is forced by violent action, 
 and the viscera come out by it, forming umbilical hernia. 
 
 5. The RING of the abuominal muscles isthat opening near 
 the lower part of the abdomen, just over the pubes, through 
 which the spermatic cord passes in men, and the round liga- 
 ment of the womb in women. 
 
 Cowper (p. 5.) says that the spermatic cord passes through 
 separate rings, in each of the three abdominal muscles ; and, 
 like older authors, he makes nature exceedingly wise, in pla- 
 cing the rings not opposite to each other, but one high, and 
 another lower, and a third lower still, so as to prevent the 
 bowels falling out. But the truth is, that neither the internal 
 oblique nor the transverse muscles have any share at all in the 
 ring, which belongs entirely to the external oblique muscle, 
 and is formed in this way : all the tendinous fibres of the exter- 
 nal oblique are, like the muscle itself, oblique, running from 
 above downwards ; and the tendinous fasciculi are in some 
 places wider, a little disjoined from each other, and resembling 
 stripes, crossed by small threads of tendon, as if the long fibres 
 were in danger of parting from each other, so as to leave a 
 gap, and were held together by these cross threads ; and it is 
 in fact a wider and perfect separation of two fibres that forms 
 the ring, and a stronger interlacement of cross fibres, that se- 
 cures it from splitting farther up. But the chief security of the 
 ring is by the form of the opening ; for it is not a ring, as we 
 call it, but a mere split in the tendon, which begins about an 
 inch and a half above the pubes, is oblique, and looking to- 
 wards the pubes, like the fibres which form it, and consists of 
 two legs, or pillars of the ring, as they are called ; for the up- 
 per slip which forms the upper part of the opening, goes direct- 
 ly towards the crest, or highest point of the pubes ; the lower 
 pillar, or the slip which- forms the lower line of the slit, turns in 
 behind, gets under the upper one, and is implanted into the 
 pubes, within and behind the upper pillar: this lower slip 
 forms at once the lower pillar of the ring and the edge of the 
 femoral ligament. 
 
 Now this crossing of the pillars of the ring secures it ; for the 
 more the muscle pulls, in pressing upon the abdominal viscera, 
 the tighter is the slit drawn ; and the obliquity of the opening 
 gives the direction to hernise of the groin, which always point 
 towards the pubes, so as to fall into the scrotum in men, or in- 
 to the labia pudendi in women, keeping close by the groin. 
 
 The spermatic cord, formed of the vessels belonging to the 
 testicle, passes through this ring of the external oblique mus- 
 cle; but as the internal and oblique transverse muscles form no 
 
 VOL. I. F f 
 
'226 
 
 MUSCLES OF THE ABDOMEN, 
 
 share in the ring, the cord passes by their lower edge, but noi 
 through them. At the place where the cord passes obliquely 
 under the edge of the internal oblique muscle, it sends a bun- 
 dle of fleshy fibres down along the cord, which go all along the 
 cord, gradually extend towards tl>e testicle, expanding and 
 growing thin upon the upper end of the testicle, and gradually 
 disappearing on the tunica vaginalis. 
 
 CXLVIIl. The CKEMASTEii MUSCLE of the TESTICLE, which 
 is a thin slip of fibres from the internal oblique muscle of the 
 abdomen, which is designed for suspending the testicle, and 
 for drawing it up, is very thick and strong in the lower animals, 
 as in bulls, dogs, &c. ; is easily found in man, but not always, 
 being sometimes thin and pale, and hardly to be known from 
 the coats upon which it lies. It appears to grow more fleshy 
 in old age and to be thickened in enlargements of the testicle, 
 the better to support the weight. 
 
 6. The LIGAMENT of the thigh* is a distinct ligament, and 
 not merely the tendon of the external oblique, rounded and 
 turned in. It arises from the spinous process of the ilium, and 
 is inserted into the crest of the pubis. It receives the external 
 oblique muscle, for the tendon is implanted into it. Part of 
 the flesh of the internal oblique muscles arise from the outer 
 end of the ligament. It forms an arch over the psoas and 
 iliacus internus muscles, where the great artery of the thigh, 
 and its anterior nerve pass out, and it is tied down at both sides || 
 of the passage for the vessels by the fascia of the thigh. The 
 great vein and the lymphatics of the limb, return under it to get 
 into the abdomen ; the lymphatic glands of the groin lie here ; 
 the whole interstice is surrounded and filled up by cellular sub- 
 stance and fat, but it is not firm ; the playing of the muscles 
 and the fat, and inguinal glands, keep it open and lax ; and the 
 bowels are apt to fall down here, especially in women, where 
 the point of the ilium is high, and the arch wide. 
 
 It often happens, that in vomiting, in violent coughing, in 
 straining at stool, or in lifting heavy weights, the natural ope- 
 nings are forced, and the bowels descend. The umbilicus is 
 very seldom forced by sudden exertion, for it is a very firm i 
 ring; but it is slowly dilated in pregnancy, and hernia of the 
 navel is infinitely more frequent with women than with men. 
 The opening of the king is often kept dilated by the bowels 
 following the testicle when it descends ; forming the congenital 
 hernia ; most frequently of ail, the ring is forced in strong 
 young men by hard and continued labour or by sudden strain- 
 
 This ligament of the thigh is named also the inguinal ligamhnt ; the guubal arch : 
 tlie LIGAMENT of PaUPART ; the LIGAMENT of FaLI.OMUS, &C. 
 
AND OF THE DIAPHRARM. 
 
 227 
 
 »ng; but women are safer from this kind of hernia, because 
 the round ligament of the womb is smaller than the spermatic 
 cord, and the ring in them is very close. — Abdominal HERNia; 
 are those which come not through any natural opening, but 
 through the interstices of the muscles, or their tendons; some- 
 times hernia follows a wound 4jf the abdomen ; for a w'ound 
 of the abdominal muscles may not heal so neatly as not to 
 leave some small interstice, through which the bowels pro- 
 trude. Thus any point may be forced by violence ; any of 
 the openings, or all of them, may be relaxed by weakness, as 
 in dropsical or other lingering diseases : for it is from this cause 
 that heruiae are more frequent in childhood and in old age, by 
 the laxity which is natural to childhood, or by the weakness 
 natural to the decline of life. Often there seems to be a 
 hereditary disposition to hernias in certain houses, the form of 
 the openings of the abdomen being wider in a whole family, 
 just as the features of the face are peculiar. And I have seen a 
 child with all these openings so particularly wide, that upon the 
 slightest coughing or crying, herniae came down at every pos- 
 sible point, at the navel, the scrotum, the thigh, and in the sides 
 of the abdomen, all at once; or, as one tumour was reduced, 
 another arose. 
 
 The eifects of the abdominal muscles in moving the trunk 
 cannot be mistaken. The recti pull the ribs downwards in 
 breathing, flattening the belly, and bending the body forwards. 
 The two uBLiQUE MUSCLES of One side acting, turn the trunk 
 upon its axis ; but the oblique muscles of the opposite side 
 acting, co-operate with the rectus in flattening the belly, and, 
 bending the body ; and the transverse muscles tighten the 
 linea alba, so as to give effect to all the others ; and particularly 
 they brace the sheath of the recti muscles, so as to give them 
 their true effect. 
 
 CXLIX. The DiAPHRAGMA is a Greek word, translated 
 inter-septum, the transverse partition betwixt the abdomen and 
 the thorax, the midrilf; but it is not merely a transverse 
 partition, it is a vaulted division betwixt the thorax and abdo- 
 men ; and not only is the middle raised into a vaulted form, 
 but its obliquity is such, that though its forepart be as high as 
 the sternum, its lower and back part arises near the pelvis from 
 the lowest vertebra of the loins. 
 
 It is a circular muscle, which is fleshy towards its borders, 
 and tendinous in the centre ; which is convex towards the 
 thorax, and concave towards the abdomen ; becoming plain, 
 or almost so, when it presses against the abdominal muscles 
 in drawing the breath ; and returning to its convex form, when 
 the abdominal muscles re-act in pushing it back into the thorax. 
 
!228 
 
 MUSCLES OF THE ABDOMEN, 
 
 The diaphragm arises, by one broad fleshy attachment fronj 
 all the borders of the chest, forming the upper or greater mus- 
 cle of the diaphragm : and it arises below, by many small ten- 
 dinous feet from the forepart of the loins, which meeting, 
 form what is called the lesser muscle of the diaphragm. 1st, 
 The GREAT or upper muscle arises, first, from under the 
 xiphoid cartilage, and from the lower surface of the sternum. 
 2dly, From all the false ribs ; from the cartilage of the seventh, 
 eigth, and ninth ribs ; and from the bony parts of the tenth and (1 
 eleventh ribs, and from the tip of the twelfth rib. All these 
 origins are, of course, fleshy digitations or tongues which inter- 
 mix with those of the transverse muscle of the abdomen. 3dly, 
 From the tip of the twelfth rib to the lumbar vertebrae, there 
 is a ligament extended, which, going like an arch over the 
 psoas and quadratus lunr;borum muscles, is named me amentum 
 ARCUATUM ; and from this another part still of the great mus- 
 cle of the diaphragm arises. Thus, the upper muscle of the 
 diaphragm has four chief origins, viz. from under the sternum 
 and xiphoid cartilage ; from all the false ribs ; from the Jiga- 
 mentum arcuatum ; and, in short, from all the borders of the 
 chest, from the xiphoid cartilage quite round to the vertebrae 
 of the loins. 
 
 2. The lesser mulcle of the diaphragm, which arises 
 from the spine, begins by four small slender tendinous feet on 
 each side. The first of these, the longest one, arises from the || 
 second vertebra above the pelvis : it goes from the flat forepart 
 
 of its body, and adheres to the forepart of all the lumbar ver- 
 tebrae as it mounts upwards. The second rises from the third 
 vertebra, but farther out towards the side of the vertebra. The 
 third arises from the side of the fourth vertebra. And the 
 fourth tendon of the diaphragm arises from the transverse pro- 
 cess of the same fourth vertebra of the loins. But indeed we 
 ought, in place of this minute demonstration, to say, that it 
 arises from the four uppermost lumbar vertebrae by four tendi- 
 nous feel, flat and glistening, and adhering closely to the shining 
 ligament with which the bodies of the vertebrae are strength- 
 ened ; that these tendons soon join to form two strong round 
 fleshy legs, which are called the crura diaphragmatis ; of which 
 crura, the left is the smaller one : and these crura having 
 opened to admit the aorta betwixt them, and then joining, mix- 
 ing, and crossing their fibres, form a fleshy belly, the lesser | 
 muscle of the diaphragm. i 
 
 3. The TENDON in the centre of the diaphragm is deter- , 
 mined in its shape by the extent of these fleshy bellies ; for the 
 great muscle above almost surrounds the central tendon. The 
 smaller muscle below meeting it, the two divisions give it a 
 
AND OF THE DIAPHRAGM. 
 
 229 
 
 pointed form behind ; the tendon has the figure of a trefoil leaf, 
 or of the heart painted upon playing cards. The middle line 
 of this tendinous centre is fixed by the membrane which di- 
 vides the thorax into two ; the two sides go upwards into the two 
 sides of the chest, each with a form like the bottom of an in- 
 verted basin : their convexity reaching within the thorax, quite 
 up to the level of the fourth true rib : the proper centre of 
 the diaphragm is fixed by this connection with the mediasti- 
 num, that its motion might not disorder the action of the heart, 
 which rests upon this point, and whose pericardium is fixed to 
 the tendon : but the convexity of either side descends and as- 
 cends alternately as the diaphragm contracts, or is relaxed ; so 
 that it is chiefly these convexities on either side which are 
 moved in breathing. 
 
 Thus is the diaphragm composed of one great and circular 
 muscle before ; of one smaller circular muscle behind ; and of 
 the triangular tendon, as the centre betwixt them : and, both 
 in its fleshy and tendinous parts, it is perforated by several ves- 
 sels passing reciprocally betwixt the thorax and the abdomen. 
 
 First, the aorta, or great artery of the trunk, passes be- 
 twixt the crura or legs of the diaphragm, which, like an arch, 
 strides over it to defend it from pressure. The thoracic duct 
 passes up here also. 
 
 Secondly, The cesophagus passes trough the diaphragm, a 
 little above this, and to the left side : its passage is through the 
 lower fleshy belly, and through the most fleshy part of the 
 diaphragm : and the muscular fibres of the crura diaphragma- 
 tis first cross under the hole for the cesophagus ; then surround 
 it; then cross again above the hole; so that they form the fi- 
 gure of 8 : and the (esophagus is so apparently compressed by 
 these surroimding fibres, that some anatomists have reckoned 
 this a sort of spincter for the upper orifice of the stomach. 
 
 Thirdly, The great vena cava goes up from the abdomen 
 to the heart, through the right side of the diaphragm ; and this 
 hole being of a triangular form, being in the firm tendon, there 
 is no danger of strangulation, or of the blood being impeded in 
 the vein. 
 
 The tendon is composed of fibres which come from the va- 
 rious fasciculi of this muscle, meet and cross each other with a 
 confused interlacement, which Albinus has been at much pains 
 to trace, but which Haller reports much more sensibly : “ In- 
 tricationes varia; el vix dicendae ;” irregular and confused, cros- 
 sing chiefly at the openings, and especially at the vena cava, 
 the triangular form of which seems to be guarded in a most 
 particular way. 
 
 The lower surface of the diaphragm is lined with the peri- 
 
230 MUSCLES OF THE ABDOMEN, &C. 
 
 tonaeum, or membrane of the abdomen ; and the upper surface 
 is covered with the pleura, or membrane of the chest. The 
 hole for the vena cava is so large that the peritonajum and 
 pleura meet, and nearly touch each other through this open- 
 ing, all round the vein. 
 
 The chief use of the diaphragm is in breathing, and in this 
 office it is so perfect, that though there be a complete anchy- 
 losis of the ribs (as has often happened), the person lives and 
 breathes, and never feels the loss. The diaphragm is, in its 
 natural state, convex towards the thorax; when it acts, it be- 
 comes plain, the thorax is enlarged, and, by the mere weight 
 of the air, the lungs are unfolded, and follow the diaphragm. 
 No vacuum is ever found betwixt the diaphragm and the lungs; 
 but the lungs follow the ribs and diaphragm as closely as if 
 they adhere to them : and indeed when they do adhere, it is 
 not known by any distress. So we draw in the breath, and 
 when the abdominal muscles re-act, the diaphragm yields, goes 
 back into the thorax, and grows convex again, by which we 
 blow out the breath ; and while the diaphragm is acting, the 
 abdominal muscles are relaxed, yield, and are pushed out, 
 and leave the ribs free, to be raised by their levator muscles. 
 And again, when the abdominal muscles re-act, the dia- 
 phragm in its turn yields so, that they at once force up the 
 diaphragm, and pull down the borders of the thorax, assisting 
 the serrated muscles which depress the ribs. 
 
 There is also in every great function, such a wonderful com- 
 bination of actions conspiring to one end, as cannot be even 
 enumerated here. But the alternate action and re-action of 
 of the abdominal muscles draws in and expels the breath, pro- 
 motes the circulation, and gently agitates the bowels, while 
 their more violent actions discharge the f-tces and urine, and 
 assistthe womb; and vomiting, yawning, coughing, laughing,cry- 
 ing, hiccup, and the rest, are its stronger and irregular actions. 
 The diaphragm might well be named by Haller, “Nobilis- 
 simus post cor musculus.” And Buffon, who affected the cha- 
 racter of anatomist with but little knowledge of the human 
 body, might mistake its central tendon for a nervous centre, 
 the place of all motions, and almost the seat of the soul. For 
 the ancients confounded the names and ideas of tendon and 
 nerve. And, in sickness and oppression, lowness and sighing, 
 in w'eeping or laughing, in joy or in fear, all our feelings seem 
 to concentrate in this part. 
 
( 231 ) 
 
 CHAP. VII. 
 
 THE MUSCLES OF THE PARTS OF GENERATION, 
 AND OF THE ANUS, AND PERINEUM. 
 
 The muscle of tbe parts of generation follow the division of 
 of the abdominal muscles more naturally than any other. 
 
 The ERECTOU, PENIS is a small and slender muscle, which 
 goes over the crus penis, and braces it back to the pubes. 
 The erectoi’es are supposed (by pressing tbe penis against the 
 pubis) to compress the great vein, and so cause erection. The 
 EJACULATOK sEMiNis is a Riusclc wbich surrounds all the bulb 
 of the urethra, and acts by a sort of subsultus in discharging the 
 last drops of the urine, and in throwing out the semen. And 
 tbe TRANsvERSALis perinid, which goes across the perinaeura, 
 belongs rather to the anus than to the penis. 
 
 The SPHINCTER ANi is a circular bundle of fibres, which sur- 
 rounds the orifice of the anus, and contracts it ; and the leva- 
 tor ani is a flat thin muscle, which lines the pelvis, surrounds 
 the rectum like a funnel, and being fixed round the margin of 
 the anus, raises it up; and the coccvciEcs is but a part of it. 
 The DETRUSOR DRiN^ is the muscular coat of the bladder, and 
 the SPHINCTER VEsic\«: is not easily distinguished from the de- 
 trusor urinse, being but the fibres of it, only thicker and stronger 
 at tbe lower and narrower part of the bladder. 
 
 The penis is composed of two ci’ura, or cavernous bodies, 
 which arise from the branch of each os ischium, which soon 
 meet to form the body of the penis ; and of the corpus caver- 
 nosum urethra;, which surrounds the urethra, is attached to no 
 bone, but begins just before the circle of tbe anus, by a bulg- 
 ing,. which is called the bulb of the urethra; and the erector 
 penis lies along the crura, to draw them back to the pubes ; 
 and the ejaculator surrounds all the bulb, and acts in expelling 
 the semen or the last drops of urine. 
 
 CL. The ERECTOR PENIS is a delicate and slender muscle, 
 about two inches in length. It lies along the face of tbe crus 
 penis on each side. And when the crura penis are inflated, 
 the erectors are seen of their proper length and form. The 
 erector of each side rises by a slender tendon from the tube- 
 rosity of the os ischium. It goes fleshy, thin, and flat, over 
 the crus penis, like a thin covering. It ends in a delicate and 
 flat tendon, upon tbe crus penis, about two inches up ; and the 
 tendon is so thin and delicate, that it is hardly to be distin- 
 guished from the membrane of the cavernous body. 
 
MUSCLES OF THE PARTS OF 
 
 232 
 
 The erectors lying thus on the sides of the penis, have been 
 called coLATEKALES PENIS OP 1 scH lO-CAVERNOsi frona their 
 origin in the ischium, and their insertion into the cavernous 
 bodies. 
 
 CLI. The TRANSVERSALis perina;i is often named trans- 
 versalis penis; but its origin being in the tuberosity of the os 
 ischium, by a delicate tendon, and its insertion into the very 
 backmost point of the bulb of the urethra, where it nearly 
 touches the anus, and where there is a meeting of severd 
 muscles, its course is directly across the perinaeum, and its re- 
 lation to the perinaeum and anus is very direct and evident, 
 while its relation to the penis is rather doubtful. Often there 
 is a second muscle of the same origin and insertion, running 
 like this, across the perinaeum, named transversalis PERiNiEi 
 
 ALTER.* 
 
 This transverse muscle may, by bracing up the bulb to the 
 arch of the pubis, have some effect in stopping the vein on the 
 back of the penis, and so producing erection ; but its chief use 
 must be in preventing the anus from being too much protruded 
 in discharging the faeces, and in retracting it when it is already 
 protruded. 
 
 CLII. The EJACULATOR muscle is not a single muscle, as it 
 is often described. It is manifestly a pair of muscles surround- 
 ing the whole of the bulb of the urethra. They arise on each 
 side from the side of the bulb, and crus of the penis, and from 
 the triangular ligament of the urethra. From their arising 
 from this ligament, they have been frequently described as 
 arising from the ramus of the pubes. There is along the lower 
 face of the bulb a white and tendinous line, corresponding 
 with tbe outward line or seam of the perinaeum. This line 
 distinguishes the bellies of the two muscles, and is formed by 
 their tendinous insertions ; or sometimes this central line is 
 considered as the origin of the muscle : in that case, the fibres 
 of each side surround their proper half of the bulb with circu- 
 lar fibres, winding obliquely round the bulb ; and each muscle 
 ends in its separate tendon, which is delicate and small, and 
 which, leaving the bulb of the urethra, turns off obliquely to 
 the side, so that the tendon of each side goes out flat and thin 
 
 * There is great irregularity in this muscle. There is very frequently a slip called trans- 
 versalis alter, which, however, would be better named obliquus. In some bodies the trans- 
 versalis is hardly perceptible, while in otlrers it is very strong ; there is also a great variety 
 in the size of it on comparing the two sides of the same body ; thus we see frequently in Las- 
 cars and N egroes, that on one side there is a very large muscle, while on the other there is a 
 small transversalis, and a large obliquus. 
 
 W e n>ay also frequently see a muscle, the transversalis profundus ; it has exactly the same 
 origin and insertion with the other, but lies deeper. At first view it appears to be part of the 
 levator ani, but tbe fibres run directly across, while those of the levator run in a descending 
 direction. 
 
GENERAGTION, anus, and PERINiEUIVr. 233 
 
 open the crus penis of its own side, a little higher than the in- 
 sertion of the erector penis. We know and feel its convulsive, 
 involuntary action in throwing out the seed ; and we are con- 
 scious that we use it as a voluntary muscle in emptying the 
 urethra of the last drops of urine. 
 
 CLIII. The SPHINCTER ANi muscle is abroad circular band 
 of fibres, which surrounds the anus. It arises from the point 
 of the os coccygis behind. It sends a neat small slip forwards, 
 by which it is attached to the back part of the ejaculator mus- 
 cle ; but the great mass of the muscle is inserted into the com- 
 mon angle of the union of the ejaculator, transversales, and 
 this muscle. It is of a regular oval form, and is, for a verj'" 
 obvious reason, stronger in man than in animals. Some choose 
 to enumerate two sphincter muscles, of which this is the ex- 
 ternal, or cutaneous ; and what they describe as the internal 
 one, is merely the circular fibres, or muscular coat of the 
 intestine, strengthened a little towards the anus, but not a dis- 
 tinct muscle. Its effect is to shut the anus. 
 
 CLIV. The LEVATOK ani muscle is described as a pair of 
 muscles, one from each side ; but it is properly one broad and 
 thin muscle, which arises from the internal surface of all the 
 forepart of the pelvis, and, from its breadth, it has been named 
 MuscuLDs ANI LATUS. »It continues its origin from the inter- 
 nal surface of the pubes, from the edge of the foramen thy- 
 roideum, from the thin tendinous sheath that covers the ob- 
 turator internus and coccygeus muscles, and from the body and 
 spine of the os ischium. It grows gradually smaller, as it 
 goes downward to surround the anus. So it is inserted into 
 the circle of the anus, into the point of the os coccygis, and is 
 mixed with the sphincter ani muscle. The whole pelvis is 
 lined with it like a funnel, or inverted cone, the wider part 
 representing its origin from the pelvis, the narrower part its 
 insertion into the anus. The whole bladder is surrounded, 
 and covered by this muscle ; the urethra passes through a split 
 in its fibres, and no operation of lithotomy can reach the blad- 
 der from below, without cutting through this muscle. It 
 raises the anus, and at the same time dilates it, opening tbe 
 anus for the passage of the f.cces, and supporting it, so as to 
 prevent its being protruded. Thus, it is not for shutting the 
 anus, as some have supposed, but is the direct antagonist of 
 the sphincter ani muscle. By enclosing the bladder, the le- 
 vator ani acts upon it also ; for the neck of the bladder pass- 
 ing through a slit in its fibres, while the levator ani is acting, 
 this slit is drawn, jfis it were, round the neck of the bladder, 
 and so the urine is for the time prevented from flowing. It is 
 as a sphincter to the bladder, which prevents^ our passing the 
 
 VOE. I. G g 
 
234 
 
 MUSCLES OF THE PARTS OF 
 
 urine and fseces at the same moment. By surrounding the 
 lower part of the bladder, and enclosing the prostrate gland, 
 and the vesicula- seminales, which lie upon the back of the 
 bladder, this muscle affects these parts also, and is perhaps the 
 only muscle which may be supposed to empty the vesiculie, 
 or to compress the gland, pulling upwards at the same time, 
 so as to press the back of the penis against the pubes, to main- 
 tain the erection, and to assist the accelerator muscles. By 
 enclosing the bladder, vesicul , prostrate and anus, this muscle 
 produces that sympathy among the parts, which is often very 
 distressing, as in gonorrhoea, the stone in the bladder, consti- 
 pation, piles, and other diseases of these parts; for piles, con- 
 stipation, or any cause which may excite the action of the le- 
 vator muscles, will cause erections, a desire to pass the urine; 
 and an obstruction in the discharge of it.*^ 
 
 CLV. The MUscuLus coccyga;us is a thin, flat muscle, 
 which arises by a narrow point from the inside of the pelvis, 
 at the spine of the os ischium; is implanted, expanded and 
 fleshy, into the whole length of the os coccygis ; can be useful 
 only by pulling up the point of the os coccygis ; which is just 
 equivalent to raising the circle of the anus; so that from every 
 circumstance of its form and use, it might be fairly enough 
 described as being merely the back part of the levator ani 
 muscle. 
 
 The perinasum, where the bulb begins, is the point int® 
 which ail the muscles are united ; for the ejaculator muscle, 
 and the sphincter ani muscle, touch at the beginning or point 
 of the bulb : and a small pointed slip of the sphincter ani, 
 going upon the bulb, connects them firmly together. The 
 transversales perincei come across the perinaeum from either 
 side ; and the levator ani muscle comes down to meet the 
 sphincter, so that the sphincter ani, the levator ani, the trans- 
 versalis perinaei, and the ejaculator muscles, all meet in one 
 point, viz. the back of the bulb. They secure the perinaeum, 
 and support the heavy viscera of the abdomen ; if they be 
 unskilfully cut in performing lithotomy, it will be difiicult to 
 extract the stone. In that operation, the incision passes by 
 the side of the anus, and on the inside of the tuber ischii ; 
 and our knife accordingly cuts clean across the transverse 
 muscles, which stand as a bar across the perinaeum ; it passes 
 by the side of the erector muscle, need not touch it, or 
 
 * There is a muscle described Iiy Mr. Wilson, as a levator, or compressor urethrse. The 
 origin of tliis muscle is from the arch of the pubes, and its fibres run round the membranous 
 part of the urethra, being inserted on the lower part into each other : it is situated between 
 the Cowper’s gland and the levator ani, being separated from tlie I3st muscle by a thin fascia, 
 and some small veins. In order to make out this muscle distinctly, and with as large a ten.’ 
 dim as Mr. Wilson describes it, it is necessary to sacrifice several of tlie fascia>. 
 
GENERATION, ANUS, AND PERINEUM. 235 
 
 Couches it slightly, and by a sort of chance : it must not touch 
 the ejaculator muscle ; for whoever says he cuts the ejacu- 
 lator cuts too low, and performs his operation ill.* After the 
 first incision we get deep into the pelvis, and cut the levator 
 ani. The surgeon does not observe these muscles, on 
 account of any danger which may attend wounds of them, 
 hut takes them as marks for the true place of his incision; 
 and a good operator will be careful to have them fairly cut, 
 that they may be no hindrance to the extraction of the stone.f 
 We find of course a difference in the muscles in the female 
 perineum. There is an erector clitoridis, which has the 
 same origin as in the male, and it is inserted into the crura 
 clitoridis, in the same manner that the erector penis is in- 
 serted into the crura penis. The next muscle is the sphincter 
 vaginre, which is a large muscle taking an origin from the 
 sphincter ani and posterior side of the perineum ; it is in- 
 serted into the union of the crura clitoridis. We find like- 
 wise a transversalis which, though taking the same origin as 
 in the male, is a very small muscle ; its insertion is into the 
 union between the sphincter vagiute and sphincter ani : in the 
 two next muscles, viz. sphincter ani and levator ani, there is 
 no difference, except that they are attached to the vagina 
 instead of the penis. 
 
 CHAP. VIII. 
 
 MUSCLES OF THE THIGH, LEG, AND FOOT. 
 
 MUSCLES MOVING THE THIGH-BONE. 
 
 The muscles belonging to the thigh-kone arise all from the 
 pelvis or trunk. The psoas magnus, and iliacus internes, 
 come from within the pelvis, and its forepart, and passing 
 under the femoral ligament, go down to be implanted into 
 the trochanter minor ; and by this obliquity of tbeir insertion, 
 they turn the toes outwards, and bend the thigh. Other 
 
 * Those anatomists who desci ibe the origin of the ejaculator to be from the ramus isehii 
 object to this. 
 
 t The detrusor urin» is but the mascular coat of the b'adder ; the sphincter vesie® ia 
 but a denser fasciculus of tliis common coat of the bladder. I should no more think of 
 describing them here than of.describing the coats of the intestines or stomach. These 
 muscles of internal parts, with the muscles of the internal ear, &c. 1 reserve for (lio^. 
 ^ooks which describe the organs and viscera. 
 
MUSCLES MOVING THE THIGH-BONE. 
 
 2SG 
 
 muscles come from the lower and forepart of the pelvis, a? 
 
 the I’ECTINALIS, TRICEPS, and OBTURATOR EKTEUNUS, which 
 
 arise from the arch of the os pubis, and go down to be im- 
 planted into the linea aspera and lesser trochanter ; and, they 
 pulling the thigh towards the body, are called the adductors. 
 Others arise from the sacrum and back part of the pelvis, as 
 the GLUTiEi, which coming directly forwards to be implanted 
 into the greater trochanter, pull back the thigh ; and a fourth 
 set coming also from the internal surface of the pelvis ; viz. 
 the OBTUKATOR INTERN US and the pyramidalis come out 
 through the back opening, turn round the pelvis, as round a 
 pulley, and roll the thigh, and draw it back. This completes 
 the catalogue of those muscles which move the thigh, 
 
 1. The PSOAS MAGNUS, ILIACUS INTERNUS, PECTINEUS, 
 TRICEPS, OBTUKATOR EXTEHNUs, wliich, coming froiD before, 
 are inserted into the line of the minor trochanter, and bend 
 the thigh. 
 
 2. The GLUTEI, GEMINI, PYRIFORMIS, OBTURATOR INTER- 
 NUS, and Q.UADRATUS, which come from behind, are implanted 
 into the line of the great trochanter, and extend the thigh ; 
 and it hardly need be remembered, that as, when the arms 
 being fixed, their muscles raise the weight of the body, as in 
 climbing or in turning over a bar, by grasping with the hands ; 
 so the muscles of the thigh move that thigh only which is 
 loose, and free from the weight of the body, while the 
 muscles of the other thigh, which is fixed by the weight of the 
 body, move not the thigh, but the trunk upon the thigh ; so 
 that our walking is performed not so much by the muscles of 
 the thigh moving the limb, as by their moving the pelvis, (z. e.) 
 rolling the trunk upon the limb. 
 
 MUSCLES MOVING THE THIGH. 
 
 1. THE THIGH IS MOVED BACKWARDS AND OUTWARDS, 
 
 By the glutaeus inaximus, i which is I linea aspera, 
 
 niedius, > implanted J trochanter major, 
 
 minimus, 5 into the ^ top of trochanter. 
 
 2. THE THIGH IS MOVED BACKWARDS, AND ROLLED UPON IT 
 
 AXIS, 
 
 which is 
 
 By the pyryformis, 
 
 Lturator extemus, J 
 
 • uiternus, \ 
 
 quadratus, J 
 
 ; root of the trochanter. 
 
 betwixt the trochanters. 
 
MUSCLES MOVING THE THIGH-BONE. 
 
 237 
 
 3. THE THIGH IS MOVED FORWARDS AND INWARDS, 
 By the oioor, 
 
 Fascialis. I begin with this muscle, as it is necessary in 
 the dissection. The thigh is enclosed in a very strong sheath, 
 which, like that of the arm, sends down among the muscles 
 strong tendinous septa or partitions ; and the muscles are 
 enclosed in these septa, and the great muscles of the leg are 
 supported by it, in their strong and continual actions. The 
 tendinous fascia of the thigii arises chiefly from .the spine of 
 the ilium, partly (over the groin) from the external oblique 
 muscle of the abdomen. Every fascia has something added 
 by each muscle, and takes a new increase and adhesion at 
 each bone which it passes. It is always strengthened by ad- 
 hesions to joints, and comes down from them thicker upon 
 the muscles below ; and so this fascia of the thigh, which 
 arises chiefly from the spine of the ilium, descends, covering 
 all the muscles of the thigh : it sends partitions down to the 
 linea aspera and trochanters ; it has a new adhesion, and a 
 new source of tendinous fibres at the knee ; it adheres most 
 remarkably at the inner side of the tibia, and then descends 
 to the calf ; it covers all the leg, and is again re-inforced at the 
 ancle ; and this I believe to be a juster history than the com- 
 mon idea of making it an expansion of the small tendon of 
 the small muscle, which I am now to describe ; for the fascia 
 is too essential to the strength of the leg, and would be found 
 there, though this muscle were away, as is the case with the 
 palmar expansion. 
 
 This fascia rightly consists of two plates ; one is that which 
 comes down from the crest of the ilium, and from the muscles 
 of the belly ; the other, that which arises purely from the ten- 
 don of themusculus fascialis, and which is at the same time con- 
 nected with the capsular ligament of the femur, and with the 
 trochanter ; and so the muscle lies betwixt the two plates of 
 the fascia; and as the fascia, at this part, takes at least a re- 
 inforcement from the capsular ligament and from about the 
 trochanter major, the fascialis muscle may be said to be insert- 
 ed into the trochanter. 
 
 So this great tendinous fascia has these connections : the 
 crest of the ilium ; the ligament of Paupart, at the rim of the 
 belly ; the crest and arch of the os pubis ; the tuber ischii, and 
 so back along the coccyx, to the ridge and processes of the 
 
238 
 
 MUSCLES MOVING THE THIGHtBONE. 
 
 sacrum; the ligament of the joint, the great trochanter; and 
 the linea aspera, all the way down to the knee, where its last 
 adhesion is very strong, and from whence it comes off again, 
 much strengthened. 
 
 It is thicker on the outer side and back part, and very thin 
 on the inner side of the thigh ; and it dives with perpendicular 
 divisions among the muscles of the thigh. 
 
 CLVI. The FAsciALis Mcsc! K. — The muscle is named ten- 
 sor vagin.j femoris. It arises from the upper spinous process 
 ol’ the ilium, (/. e.) from the forepart, or very point of its spine, 
 by a tendon of about an inch in length. It is very small at its 
 origin, and at its termination. It is thick and fleshy in the 
 middle, swelling out; it extends downwards, and obliquely back- 
 wards, airnust to the middle of the thigh, and there it termi- 
 nates obliquely, betwixt the two lamellas of the membrane to 
 which it belongs. 
 
 Its use is chiefly as an ahductor, and to make the fascia 
 tense, to prepare the muscles for strong action ; and perhaps, 
 by its adhesions about the trochanter, it may have some little 
 effect in rolling the thigh, so as to turn the toes inwards, and 
 oppose the Gemini. 
 
 CLVII. Psoas magxus. — This and the following muscle 
 come from within the body to move the thigh forwards. This 
 is a very long and fleshy muscle, of considerable strength, of 
 constant use, perpetually employed in moving the thigh for- 
 ward or in supporting the pelvis upon the thigh-hone, so as to 
 preserve the equilibrium of the body. 
 
 It is named from the psoas lumbps ; is a large round mus- 
 cle, very strong, of great length, filling up all the space upon 
 either side of the spine, and bounding the pelvis at its side. It 
 comes from under the ligamentum arcuatum of the diaphragm; 
 for it arises first by its uppermost head from the last vertebra 
 of the back, then successively from each of the vertebrae of the 
 loins It sticks close to the lumbar vertebrae ; for it arises not 
 only from the transverse processes but from the sides of the 
 bodies. These heads do not appear, for they are covered by 
 the body of the muscle, which goes down thick and round, till 
 it reaches the sacro iliac symphyisis, and then being united to 
 the internal iliac muscle, they descend through Paupart s liga- 
 ment. 
 
 CLVIII. The psovs parvus does not, like this, belong to 
 the thigh, but is a muscle of the loins, which arises along with 
 this one from the last vertebra of the back, and the first of loins. 
 
 It is a small and delicate muscle, ends in a slender tendon, 
 which goes down by the inner side of the great psoas, but does 
 not go out of the pelvis along with it : it stops short, and is im- 
 
Muscles moving the thigh-bone. 239 
 
 planted into the brim of the pelvis, into the os ilium near the 
 
 ? lace of the acetabulum : it bends the spine upon the pelvis. 
 
 "his muscle is more regular in the monkey : in the dog it is 
 seldom wanting. It is said to be more frequently found in 
 women than in men ; in both, it often is not to be found : b-ut 
 sometimes, in strong and big men, three psoas muscles have 
 been found. 
 
 CLIX. The iLiAcus internus is a thick, very fleshy, and 
 fan-like muscle, which occupies the whole concavity of the os 
 ilium. 
 
 Its origin is from the internal lip of the crista ilii and trans- 
 verse process of the last lumbar vertebrae : it adheres to all the 
 concave surface of that bone, down to the brim of the pelvis ; 
 to the forepart of the bone under the spinous process ; and to 
 a part also of the capsular ligament of the joint : all its radiated 
 fibres are gathered together into a tendon at the ligament of 
 Paupart. This tendon is longer on the lower than on the up- 
 per surface : for below, it slides on the pubis as upon a pulley, 
 and continues tendinous that it may bear the friction ; but 
 above itis unconnected, or it is connected only by loose cellular 
 substance j and there it is quite fleshy. Just under the liga- 
 ment, the two tendons are joined, whence they bend obliquely 
 round, to be implanted into the lesser trochanter. 
 
 The psoas magnus and iliacus internus are tw'o very powerful 
 muscles. Their chief use is to bend the thigh, and more pe- 
 culiarly of the lumbar one to support the body. The great 
 blood vessels come down along with these two muscles : the 
 muscles and vessels are both surrounded with loose cellular 
 substance ; matter often forming behind the abdomen, round 
 the psoas muscle, is named the psoas abscess, and penetrating 
 under Paupart’s ligament, bursts in the thigh at last and is 
 commonly fatal. 
 
 CLX. The PECTiNEus or pectinalis, so named from its 
 arising at the pecten or os pubis, is a broad flat square muscle : 
 it lies along-side of the last described muscles, and is inserted 
 with their common tendon. It arises flat and fleshy from that 
 part of the os pubis which is bbunded on the upper part by the 
 linea ileo pectihea, and on the low’er by a ridge running from 
 the tuberous angle of the pubes to the upper part of the aceta- 
 bulum, and is implanted into the linea aspera, immediately be- 
 low the trochanter minor, by a tendon flat and long, pretty 
 nearly of the same extent and shape with its origin. 
 
 This muscle lies immediately under the skin and fascia lata; 
 and by its bending round under the thigh-bone, it has three 
 actions ; to close the knees together ; to pull the thigh forward; 
 to perform rotation, turning out the toe; and, in certain posi- 
 
240 MUSCLES MOVING THE THIGH-BONE. 
 
 tions of the limb, it will pull the thigh back, assisting the exten- 
 sor muscles. 
 
 CLXI. The TRICEPS femobis is a broad flat muscle, with 
 three heads, arising from the os pubis, and inserted into the 
 whole length of the linea aspera down to the condyle, and 
 serving for pressing the knees together, or bringing the thigh 
 forwards. 
 
 The triceps consists of three beads, which lie in different 
 layers, one above the other ; and have so little connection 
 among themselves, that they have been more commonly, and 
 I think properly, described as three muscles. These three 
 parts of the muscle are indeed for one common use : but they 
 are of very different forms ; for they do not even lie on the 
 same plane : one is long, another shorter by one half, a third 
 longer than both the other two ; so that they have been com- 
 monly described under the names of adductor primus or 
 LONGUS ; adductor SECUNDUS or BREVIS ; adductor TERTIUS 
 or MAGNUS. 
 
 1. The ADDUCTOR LONGUS is the uppermost layer; its bor- 
 der (for it, like the pectinalis, is a flat muscle,) ranges with the 
 border of the pectinalis. It arises from the upper and forepart 
 of the pubis and the ligament of the symphysis by a short 
 roundish tendon, very strong ; it swells into a thick fleshy bel- 
 ly, not round, but flattened ; the belly grows flatter as it goes 
 down towards the thigh-bone ; it ends in a flat and short ten- 
 don, which is inserted into the linea aspera in all its middle 
 part, viz. about four inches. Thus, the muscle is of a trian- 
 gular form, with its base in the linea aspera, and its apex on the 
 os pubis. Its head or origin lies betwixt the pectinalis and the 
 gracilis : its upper edge ranges with the pectinalis ; its lower 
 edge lies upon the triceps raagnus. It is called longus, because 
 it is longer than the next muscle. 
 
 2. The ADDUCTOR BREVIS lies Under the adductor longus, 
 and is of another layer of muscles ; for as the first layer con- 
 sists of the pectinalis, triceps longus, and gracilis, this layer 
 consists of the obturator externus, triceps brevis, and triceps 
 magnus. The triceps brevis is»exceedingly like the former, in 
 rising near the symphysis pubis, by a thick and flattened tendon, 
 swelling like it into a strong fleshy belly ; like it, it grows flat, 
 and is inserted by a short flat tendon into the inner trochanter 
 and linea aspera. But it differs in these points ; that it is less 
 oblique, for this muscle being shorter, goes more directly across 
 betwixt the ffelvis and the thigh : that it is placed higher than 
 the last, so that whereas the layers are inserted into the middle 
 of the thigh-bone, this one is inserted into the lesser trochanter, 
 and only the upper part of the linea aspera; and the triceps 
 
MUSCLES MOVING THE THIGH-BONE., 
 
 241 
 
 longus is a superficial muscle, while this is hidden under it, 
 and behind it. The longus takes its rise from the very crest of 
 the os pubis ; this takes its origin from the forepart of the os 
 pubis, from the limb just under the crest, so as to be imme- 
 diately under tlie head of the longus. 
 
 3. The ADDUCTOR MAGNUS, the third head of the triceps, is 
 a very long and flat muscle, lying behind the other heads. It 
 arises by a short tendon, just under the tendon of the adductor 
 brevis ; it continues to have a fleshy origin all down to the 
 ramus, and to the tuber ischii, {i. e.) from the flat edge of the 
 thyroid hole. From this broad origin, it goes to be implanted 
 into the thigh-bone the whole length of the linea aspera, its 
 fibres having various degrees of obliquity, according to their 
 insertion, for the uppermost fasciculi go almost directly across, 
 to be inserted flat into the upper part of the linea aspera; the 
 succeeding fasciculi go more and more obliquely as they de- 
 scend, the lower part of the muscle following that rough line 
 which leads to the condyle, and the last fibres of all are im- 
 planted, -by a tendon of considerable length, into the condyle 
 itself. This adductor magnus makes as it were a flat partition 
 betwixt the fore and the back parts of the thigh ; and it is 
 about three inches above the condyle that the great artery 
 passes betwixt this tendon and the bone perforating the triceps, 
 to get from the fore to the back part of the thigh, and down 
 into the ham. 
 
 The use of all these muscles is entirely the same, making 
 allowance for their various degrees of oblique insertion ; and 
 they must be very powerful, by the great distance of their 
 origins from the centre of that bone which they move, so that 
 while other muscles pull in a direction very oblique, these 
 three heads of the triceps must pull more at I’ight angles, and 
 therefore at a more favourable direction. 
 
 CLXII. The OBTURATOR EXTERNUs is named after the ob- 
 turator ligament, from which it arises. The ligament and the 
 muscles shutting up the foramen thyroideurn are named obtu- 
 rators, and it is sometimes named rotator femoris ex- 
 TRORSUM, from its turning the thigh outwards. It arises from 
 the ramus of the ischium and os pubis, where they form the 
 margins of the thyroid hole ; and from the outer surface of the 
 ligament, which it occupies entirely, leaving only room for the 
 obturator vessels and nerves. It is a short muscle ; its origin 
 is broad, and its insertion narrow, so that it is of a conical form ; 
 for the flesh of its muscles is gathered very soon into a round 
 short tendon, which twists under the thigh-bone betwixt it and 
 the pelvis ; so that it is in a manner rolled round the thigh- 
 bone, being inserted into the root of the great trochanter. It 
 
 you. I. H li 
 
242 
 
 ]\IUSCL£S MOVING THE THIGH-BONE. 
 
 pulls the thigh forwards, but is more peculiarly a rotator of 
 the thigh. This muscle is of the second layer, and the succes- 
 sion of all the muscles is this ; the upper layer consists of the 
 psoas and iliacus, where they come out from the abdomen, of 
 the pectinalis, and of the long head of the triceps; the second 
 layer consists of the short head of the triceps; and the third 
 layer consists of ihe obturator externus at the upper part, and 
 the triceps magnus, or third head of the triceps, all down to 
 the condyle. 
 
 GlutjEi. — There are three glutaei muscles, each under the 
 other, and each smaller than the muscle which covers it. The 
 FIRST, arising from the back part of the ilium, the back of the 
 sacrum, and the sacro-sciatic ligament, forms the whole hip, and 
 descends so low as to be inserted into one-third of the length 
 of the linea aspera, and into the root of the great trochanter. 
 
 The SECOND arises from all that portion of the ilium which 
 is before this one, and from the back of the bone, and goes 
 down to be inserted into the very top of the great trochanter- 
 
 The THIRD arises from the back, of the bone below the last ; 
 and it is inserted into the root betwixt the apex of the great 
 trochanter and the neck of the bone. 
 
 CLXIII. The GLUTffius maximus arises from the back of the 
 ilium nearly one half its length ; from the joining of the ilium 
 and sacrum ; from all the spines and irregularities of the sa- 
 crum; and from the sacro-sciatic ligament. Its thick fleshy 
 fasciculaj come in a winding and oblique direction down to the 
 thigh-bone ; and, being gathered into a flat and pretty broad 
 tendon, it is inserted into the root of the trochanter major, and 
 down three inches of the linea aspera. This is one of the 
 largest and most fleshy muscles of the body ; covers all the 
 other muscles of the hip ; forms the contour of the hip ; pulls 
 the thigh backwards, or the body forwards upon the thigh, 
 when the thigh is fixed : and being a wide spreading muscle, 
 which, in a manner, surroundsits joint, its different portions act 
 with different effects; not only according to their natural di- 
 rection, but according to the accidental positions of the pelvis 
 with regard to the thigh-bone. 
 
 CLXIV. The glutjEus medius or minor Is smaller than 
 the former, but like it. It arises from all the outside of the 
 ilium not occupied by the glutieus major. It, like the other, 
 is a fan-formed muscle ; for its fibres converge from its broad 
 origin in all the back of the ilium, to form a short flat tendon 
 which is inserted into the back, or into the very top of the 
 great trochanter. It lies in part under the glutieus maximus ; 
 but its chief part lies before the glutasus mgximus ; and as cer- 
 tain portions of the muscle are before the thigh-bone, there 
 
MUSCLES MOVING THE THIGH-BONE. 243 
 
 are positions of the pelvis and thigh-bone in which it will pull 
 the thigh forwards, although its proper office is to assist the 
 glutfeus magnus in pulling the thigh backwards, and moving it 
 outwards from the body. 
 
 CLXV. The GLUTa;us minimus is a small radiated muscle, 
 which lies deep, and quite under the former. It has, compared 
 with the former, a very narrow origin; for it arises chiefly 
 from the lowest part of the back of the ilium, viz. that part 
 which forms the socket for the thigh-bone, and a little higher 
 up, and from the border of the sciatic notch. Its origin from 
 the dorsum ilii is bounded by a ridge, which extends from the 
 upper part of the acetabulum to the notch. It forms a short, 
 flat, and strong tendon, which is fixed under the root of the 
 trochanter major, betwixt the trochanter and the neck of the 
 bone; so that these muscles are inserted in this succession; 
 first, the great glutasus, below the root of the trochanter, and 
 into the linea aspera; the middle gluteus into the back and 
 top of the trochanter; and the smallest of the glutei is im- 
 planted into the roughness under the root of the trochanter. 
 
 Gemini. — The gemini are two muscles, or rather one biceps 
 muscle ; but the heads are so distinct, that they are reckoned 
 two, and so much alike, that they are named gemini. 
 
 CLXVI. The uppermost, the larger and stronger muscle, 
 arises from the spinous process of the os ischium. 
 
 CLXVII. The second or smaller head arises in like manner 
 from the tuber ischii, upon its ball or outer end. They are 
 fleshy in their whole length. They meet, and unite their 
 tendons at the great trochanter. They are inserted firmly 
 along with the following tendon, at the root of that process. 
 
 CLXVIII. The pyriformis, or pyramidalis, comes from 
 the hollow of the sacrum, runs in the same line with the lesser 
 glutffius, and is inserted with the two last-named muscles in 
 the root of the great trochanter. 
 
 Its origin is from the hollow of the sacrum, rising from the 
 vertebras of that bone, by three or four small fleshy digits ; 
 and from the sacro-sciatic notch, it runs betwixt the glutieus 
 minor and the gemini, and its round tendon is inserted betwixt 
 them, somewhat connected with each.* 
 
 The pyriformis, gemini, obturator internus, and quadratus, 
 form what some anatomists have called musculi q,uadri-ge- 
 MiNi ; and they are so much alike in insertion and use, that it 
 would be waste of time to repeat what has been said of the 
 gemini and obturator. 
 
 This muscle, the pyriformis, like the others, rolls the thigh 
 outwards. Its name is from its shape. 
 
 '■ This miisrle is frequently iivided by the great sacro sciatic nprve. 
 
244 MUSCLES MOVING THE THIGH-BONE. 
 
 CLXIX. The OBTFRATOR INTERNUS, ODCe named MARSU- 
 piALis, or uuRBALis, arises from all the internal surface of the 
 obturator ligament, and from all the edges of the thyroid hole, 
 from the ilium, ischium, and pubis. Its origin is therefore 
 circular and fleshy. It runs along the inside of the os ischium, 
 turns round that bone betwixt the spinous process and the tu- 
 ber. The hollow there is guarded with cartilage, and this 
 tendon runs in the hollow, like a rope round a pulley; passing 
 this, it runs betwixt the two legs of the gemini, and its tendon 
 is united to theirs : and the three appearing almost like one 
 tendon, are inserted together into the root of the trochanter 
 major. These, then, might with some propriety be named 
 one muscle; all the three, viz. the two gemini muscles, and 
 the obturator muscle passing between them, were once ac- 
 counted as one muscle, and then it seemed to be a muscle 
 with two bellies, and an intermediate tendon ; and this inter- 
 mediate tendon, with two fleshy ends, give it the appearance 
 of a purse, thence named marsupiams, or bursalis 
 
 CLXX. The ciuadratus femokis is a thin flat muscle, 
 passing in a transverse direction betwixt the tuber ischii and 
 the thigh-bone. 
 
 It arises from the lower and flattened surface of the tuber 
 iscHii by a strong tendinous beginning. It goes a little 
 obliquely upwards and outwards, and is inserted into the back 
 of the great trochanter, in that roughness which is found just 
 where the trochanter is joined to the bone, and goes obliquely 
 betwixt the trochanter major and the trochanter minor. 
 
 It rolls the thigh-bone, so as to turn the toe outwards, and 
 pulls it almost directly backwards. 
 
 The MOTIONS of the thigh must be performed by many 
 very strong muscles, as it moves under the weight of the whole 
 body; and it seems to be curiously contrived, that the muscles 
 fit for moving the thigh forward, should in certain positions of 
 the thigh, move it backwards ; also giving an increase of 
 strength to that motion of the thigh in which most strength is 
 required. 
 
 There are but fwo or chiefly two points for insertion ; the 
 trochanter major and trochanter minor. These two points are 
 so oblique, that no one muscle, nor set of muscles, performs 
 any direct motions ; for they all twist round the bone’s axis, to 
 get at their insertion. The glutiei, the pyriformis, the gemini, 
 the quadratus, the obturator internus, and obturator externus, 
 all bend round the axis of the thigh-bone to reach the tro- 
 chanter major. These now may be called the abductors of 
 the thigh, to pull it outwards ; but we should conclude from 
 
MUSCLES MOVING THE LEG. 
 
 246 
 
 this direction, that they could not pull the thigh backwards, 
 for the thigh-bone would turn on its axis and elude their ac- 
 tion. 
 
 The psoas magnus, the iliacus internus, the pectinalis, and 
 the triceps, do in the same manner go round the inner side of 
 the bone : the two first to be implanted into the trochanter 
 minor, the two latter into the linea aspera, just below it. These 
 are justly named adductors of the thigh : their chief use is to 
 draw the thighs together, and this is their combined effect : 
 when the adductors act by themselves, they pull the thigh 
 forwards, moving the leg, rolling the thigh-bone, and turning 
 the toe out in a graceful step ; which is most peculiarly the 
 effect of the pectoralis and triceps. But when we are to finish 
 the motion, by pulling forward the body, which is the same 
 with pulling back the thigh, it is not merely the antagonists 
 of these muscles, as the glutaei, the gemini, &c. which must 
 act. Were the glutasi to act alone, they would rather turn 
 the thigh upon its axis outwards than pull it back ; but the tri- 
 ceps, £c. act again in conjunction with the glutaei, &c. and 
 by the action of the triceps, the inner trochanter is fixed : the 
 further rolling of the thigh is prevented ; the full effect is given 
 to the glutfei muscles. When the glutrei act, they pull the 
 thigh directly backwards, assisted by the triceps, pectinalis, 
 and others : for now the thigh-bone is so far advanced before 
 the body, that those muscles, as the triceps which were benders 
 of the thigh in its first position, are extensors when it is ad- 
 vanced a step before the body ; or, perhaps, it will be more 
 explicit to say, that when the thigh is moved one step before 
 the body, the iliacus internus, psoas magnus, and triceps mus- 
 cles, agree with the glutffii muscles in bringing the trunk for- 
 wards to follow the limb, and then in fixing and stiffening the 
 trunk upon that limb, till the other thigh is advanced again a 
 step before the body. , 
 
 The MUSCLES of the leg are the most simple of all ; for the 
 knee is a mere hinge, at least, it is so in all our ordinary mo- 
 tions, so that there is no action to be performed, but those of 
 mere flexion and extension, and there are only two classes of 
 muscles to be described, the extensors and the flexors of the 
 leg. 
 
 1. The EXTENSORS of the leg. The only muscles which 
 extend the leg are those four- which may be very fairly reckon- 
 ed a quadriceps extensor cruris. Indeed the French anato- 
 mists arrange tiiem so. Sabatier calls them the triceps femoris. 
 These muscles, which all converge to the patella, and are in- 
 
246 
 
 MUSCLES MOVING THE LEG. 
 
 serted in It, are, rectus femoris, — crur^eus, or femorjeus, — 
 
 VASTUS EXTERNUS, VASTUS INTERNUS. 
 
 And these are all implanted by one tendon; because the 
 joint being a hinge, bending only in one direction, its muscles 
 could have given but one motion, however oblique their origin 
 and course had been. 
 
 2. The FLEXORS of the leg are one on the outside, and four 
 on the inside of the leg; the tendons of the outside being im- 
 planted into the upper knob of the fibula, and those in the in- 
 side into the rough head of the tibia, forming the ham-strings, 
 and extending their tendons or aponeurotic expansions down- 
 wards upon the leg. 
 
 INSIDE FLEXORS. 
 
 Sartorius, Gracilis, 
 
 Semitendinosus, Semimembranosus. 
 
 OUTSIDE FLEXOR. 
 
 Biceps. 
 
 EXTENSORS OF THE LEG. 
 
 CLXXI. The RECTUS FEMORIS, sometimes rectus cruris, 
 IS so named from its direction ; it arises by two heads. The 
 first or greater head arises from the lower spinous process of 
 the ilium by a short round tendon ; its second head is in a dif- 
 ferent, and somewhat of a curved direction ; for it comes from 
 the edge of the acetabulum, and from the capsular ligament. 
 These join together, and form a flat tendon of four inches in 
 length, which becomes gradually fleshy and larger down to its 
 middle, and then again contracts towards the patella. There 
 is a middle tendinous line, running the whole length of the 
 muscle, especially conspicuous on its back part, and towards 
 that central line all the muscular fibres converge. 
 
 The rectus is united at the sides to the vasti, at the back part 
 of the crurseus ; and its tendon, along with that of the cruraeus, 
 goes to be directly implanted into the rotula or patella. 
 
 The rectus cruris is the first of those muscles which Sabatier 
 calls the triceps femoris ; they may be more properly named 
 the q,uadriceps cruris. 
 
 This large mass of muscle or flesh enwraps the whole of the 
 thigh-bone behind as well as before; for, first, the crur^us 
 
MUSCLES MOVING THE LEG. 
 
 247 
 
 arises fleshy from all the forepart of the bone. The vastus 
 UXTEBNUS from the great trochanter, and all the back part and 
 outer side of the bone ; and the vastus internus arises, in 
 like manner, from the lesser trochanter, and all the inner side 
 of the bone, from the trochanter major all round to the origin 
 of the cruraeus. 
 
 CLXXII. The crukseus arises from the forepart of the 
 femur, between the two trochanters, and it continues its origin 
 from the forepart of the femur, the whole way down to within 
 two inches, or little more, of the patella. About three inches 
 from its origin it is joined by the vastus externus, which 
 unites with it at the outer edge and forepart ; and the vastus 
 iNTERNUs comes into it about five inches below its origin, and 
 it joins it at the inner edge and forepart. At its lower part it 
 is joined to the tendon of the rectus, to form but one large ten- 
 don, which is inserted into the rotula. By Albinus, the plate 
 of this muscle is given in union with the two vasti, which is the 
 best method of describing the muscle, as it is very seldom to 
 be made out distinct from these two muscles. 
 
 Under the cruraeus are sometimes found two little muscles, or 
 rather two little slips of this muscle, which are quite distinct. 
 They arise on the forepart of the thigh-bone, two or three 
 inches above the capsule of the joint; and they are inserted into 
 the capsule on each side of the patella, evidently for the pur- 
 pose of pulling it up, to prevent its being catched; and when 
 these two (subckuk^j) are not found as distinct muscles, some 
 fibres of the cruraeus supply their place. 
 
 CLXXIII. The vastus externus is the largest of these 
 three muscles. 
 
 Its origin is, by a pretty thick and strong tendon, from the 
 lower and forepart of the trochanter major; and it continues 
 its origin from the root of the trochanter all down the linea as- 
 pera, to that rough line which goes to the outer tuberosity of 
 the thigh-bone. 
 
 It touches the end of the cruraeus about four inches below its 
 origin, and continues attached to it the whole way down ; and 
 then it forms a fiat tendon which connects itself with the ten- 
 don of the RECTUS EEMOKis, and then embraces, in a semi- 
 circular manner, the outside of the patella. And several of 
 the fibres of this aponeurosis not only cross over the rotula, but 
 go dow'ii over its opposite side to glide along the head of the 
 tibia, and to be inserted into the inner side of the knee. 
 
 CLXXIV. The VASTUS internus is neither so large nor so 
 fleshy as the vastus externus ; but it is exceedingly like it in 
 all other respects. 
 
24a 
 
 MUSCLES MOVING THE LEG. 
 
 Jt arises from the forepart of the trochanter minor, just un- 
 tier the insertion of the psoas magnus; and it continues its ori- 
 gin from the linea aspera the whole way down to the inner 
 condyle, exactly opposite to the origin of the vastus externus ; 
 they Jeave just a channel betwixt them. The vastus internus^ 
 very soon after its origin, joins itself to the cruraeus, or middle 
 portion, and accompanies it in all its length; and, at the dis- 
 tance of two inches from the rotula, it unites itself with the 
 tendon of the cruraiusat its internal edge; and this tendon com- 
 pletes that junction which unites the four muscles into a quadri- 
 ceps cruris. This vastus internus descends much lower, in a 
 fleshy form, than the external vastus does, and forms that fleshy 
 cushion which covers the inner side of the knee-joint. Its ten- 
 don embraces the rotula, somewhat in the same circular form 
 with the vastus externus ; and, like the externus, it sends some 
 fibres across the knee-pan, to be inserted in the outer part of 
 the head of the tibia. 
 
 The KECTijs, and the vastus externus, jnternus, and 
 CRUR^us, form one large mass of flesh, which embraces and 
 encloses all the thigh-bone ; and they are so connected, that 
 the cruraeus cannot be separated, and cannot be neatly dis- 
 tinguished. 
 
 The use of these four muscles is evident; to extend the 
 leg, and to bend the thigh on the trunk, or reciprocally to 
 bend the trunk on the thigh. This, or these two motions al- 
 ternately, is the common use of these muscles, as in walking ; 
 and they are most peculiarly useful in running and leaping. 
 
 After describing a large mass, conjoined in one tendon, and 
 concurring in one simple action, it is superfluous to say that its 
 power must be great. This power must be still farther in- 
 creased by the rotula, which removes the force from the 
 centre, and gives the advantage of a pulley, which it really 
 and truly is ; without this pulley, these muscles could be of 
 no use in certain situations ; for instance, in the recumbent 
 posture ; for then the extending muscles, being in the same 
 line with their bones, could have no further power ; but the 
 rectus, by the pulley of the rotula, and by its attachment to 
 the basin, raises the trunk, or at least helps the psoas, the 
 iliacus, and the muscles of the belly. 
 
 The rotula is again attached to the tibia by a strong ligament 
 to sustain the pulling of these great muscles.* 
 
 * Theje muscles are in continual action : for their office is to resist the bending of tlie 
 knee, which would happen by tliis encumbent wekht of the body; so that the continual 
 support of the body depends wholly on these muscles ; and they are the great agents in 
 running, leaping, walking, &c. Since by extending the knee they raise the weigjit of the 
 pelvis and trunk, and of all the body, they must be very powerful ; and accordingly, when 
 they are weighed against their antagonist muscles, we find them greatly to exceed, for the 
 
MUSCLES MOVING THE LEG. 
 
 249 
 
 FLEXORS OF THE LEG. 
 
 CLXXV. The sARTORius or taylor’s muscle, is so 
 named from its bending the knees, and drawing the legs 
 across. It is the longest muscle, and a very beautiful one ; 
 extends obliquely across the whole length of the thigh, cros- 
 sing it like a fillet or garter, about two inches in breadth. 
 
 It arises from the upper spinous process of the os ilium, by 
 a tendon about half an inch in length ; its thin flat belly ex- 
 tends obliquely across the thigh, like a strap, and is inserted 
 into the same oblique form into the inner tubercle of the bead 
 of the tibia ; its aponeurosis spreads widely, going over the 
 whole joint of the knee, a thin sheet of tendon. 
 
 From the oblique position of the muscle, it might in action 
 change its place ; but it is so far embraced by the fascia lata, 
 and is tied by such adhesions, as to form something like a pe- 
 culiar sheath of itself. 
 
 It turns the thigh like the quadratus gemini, and obturator 
 muscles. It also bends the leg upon the knee ; and when the 
 leg does not yield, it bends the thigh upon the pubes ; or 
 where the thigh is also fixed, it bends the body forwards ; but 
 in performing that action, whence it has its name, it does all 
 these ; for first the leg and thigh are rolled, then the thigh is 
 raised, then the leg is bent to draw it across. Though a small 
 muscle, yet it is of great power from its origin, and in some 
 degree, its insertion also, being much removed from the 
 centre of motion. 
 
 CLXXVI. The gracilis, sometimes called rectus in- 
 TERNUs FEMORis,* is a Small, flat, thin muscle, in its general 
 shape somewhat like the sartorius. 
 
 It arises by a flat tendon of two Inches in length from the 
 ramus of the os pubis, and near the symphysis ; and it passes 
 immediately under the integuments down to the knee ; it passes 
 by the inner condyle of the knee, in the form of a short 
 round tendon, and, as it bends behind the head of the tibia, 
 it is bound down by a bundle of tendinous fibres, which, 
 crossing it, go the back part of the leg. After passing the 
 head of the tibia, it turns obliquely forwards and downwards ; 
 it here runs behind the tendon of the sartorius, and before 
 that of the semitendinosus. It is inserted with the sartorius 
 into the side of the tuberosity, at the top of the tibia. 
 
 etiADRicEPS. (i. e.) the rectus, crurseus, and vast!, will weigh four pounds, while the biceps 
 &c. tlieir antagonists, weigli but two pounds. This experiment was often repeated by the 
 great Cowper, for Mr Brown, who was delivering lectures on muscular motion. 
 
 * Gracius, is from its smallness ; rectos interxus, is from it? straight direction. 
 
 VOL. I. h i 
 
250 
 
 MUSCLES MOVING THE LEG. 
 
 This muscle runs also in a line so wide from the centre of ^ I 
 motion, that its power is very great. It serves chiefly as a ' 
 flexor of the leg : when the leg is fixed, it must by its origin 
 from the pubes be a flexor of the thigh, and an adductor in 
 nearly the same direction with the pectineus and triceps; and ■ 
 it is worth observing, that while the knee is straight, the sar- 
 torius and the gracilis cannot bend the knee ; they, on the 
 contrary, keep it steady and firm ; but when the knee is bent, 
 they come into action ; for in proportion as the muscles which 
 have made the flexion are contracted, they are less able to 
 contract farther, and therefore it is desirable, that more 
 muscles should come into play. 
 
 CLXXVII. The semitendinosus is so named from its 
 lower half being composed of a small round tendon ; and a& ^ 
 tendon was once misnamed nerve, this is the seminervosus 
 of Winslow, Douglas, and others. 
 
 Its origin is from the tuberosity of the ischium (along with 
 the semimembranosus and touching the biceps,) by a short 
 thick tendon. It also arises by many oblique fasciculi of 
 fibres, from the posterior portion of its opposite muscle the 
 biceps cruris. This cross connection betwixt the two muscles 
 continues for three inches down from the tuber ischii ; it then 
 departs from the biceps, goes obliquely inwards, and is 
 flattened and contracted into a tendon, six inches from the 
 knee, and getting round the he?id of the tibia, it comes for- 
 ward to be inserted into the tuber, at the head of that bone. 
 
 At this place, the tendon grows broad and flat ; it is expanded 
 and as it were grasps the inner side of the knee ; its upper 
 edge is joined to the lower edge of the tendon of the gracilis, 
 so that the sartorius, gracilis, and semitendinosus are im- : 
 planted like one muscle ; and this tendinous expansion seems 
 like a capsule, for enclosing the heads of the tibia and femur, 
 and for strengthening the knee-joint. The semitendinosus 
 bends the leg. I 
 
 CLXXVni. The semimembranosus has its name from the 
 muscle, which is flat, thick, and fleshy, beginning and ending [ 
 with a flattened tendon, somewhat like a membrane, but infi- 
 nitely thicker and massier than such name should imply. 
 
 It arises from the tuber ischii, before the semitendinosus 
 and biceps. It arises a broad, thin, and flat tendon, of about 
 three inches in length. It becomes fleshy and thick in its 
 middle, but it soon becomes thinner again, and terminates in | 
 a short tendon, which, gliding behind the head of the tibia, 
 is inserted there.* 
 
 * The tn o tendons of this muscle, the membranous tendon at the liead, and this smaller 
 one by which it is inserted, stand so obliquely, that the muscular fibres betwixt them must 
 
MUSCLES MOVING THE LEG. 
 
 251 
 
 This muscle has little connection with any other. It lies 
 i ttnder, or more particularly speaking, on the inside of the se- 
 I mitendinosus, and the two together form the inner ham-strings. 
 ' The ham-string muscles contribute also to another motion. 
 
 Though when extended the tibia cannot roll, yet when we sit 
 : with our knees bent, it can roll slightly ; and such rolling is 
 
 accomplished by these muscles. All these muscles which 
 bend the leg, and which consequently extend the thigh at the 
 same time, are muscles of great power, because they arise 
 in one common point, the tuber ischii, and that point is veiy 
 far distant from the centre of motion. 
 
 There is still one small muscle, a flexor of the leg, which 
 performs this rotation during the bent state of the knee, with 
 most particular power. 
 
 CLXXIX. The musculus poplit^us, Avhich is so named 
 from its lying in the ham, is a small triangular muscle, lying 
 across the back part of the knee-joint, very deep under the 
 ham-strings, and under the muscles of the leg. 
 
 Its origin is from the outer condyle of the thigh-bone, and 
 from the back part of the capsule of the joint. Its tendon is 
 short and thick, but of no great extent. It passes fleshy behind 
 the knee-joint ; and it is inserted broad into a ridge on the 
 back part of the tibia; so that by .its small origin and broad 
 insertion, it is a fan-like muscle, its upper fibres being almost 
 transverse, and its lower fibres nearly perpendicular. Besides 
 bending the leg, it is useful by pulling aside the capsule to 
 prevent its being caught. ^ 
 
 CLXXX. The biceps cruris, so named from having two 
 heads, a long and short one, lies immediately under the skin, 
 in the back part of the leg, running down from the pelvis to 
 the knee, to form the outer ham-string. 
 
 It is the single flexor on the outside of the thigh. Its origin 
 is from the outer part of the tuber ischii, by a tendon of an 
 inch and a half in length. And this tendon is, in its origin, 
 closely united with that of the semitendinosus for two inches,or 
 at least the whole length of the tendon. After a short, but very 
 thick fleshy belly, it degenerates into a tendon, especially on 
 its back part; and this tendon, which begins above the middle 
 of the thigh, is continued the whole way down. 
 
 About one- third down the bone is the beginning of the 
 second, or short head, which has its origin all the way down 
 the linea aspera, to the line above the outer condyle of the 
 thigh-bone ; and here it is somewhat connected with the origin 
 of the vastus externus muscle, and the insertion of the glutseus 
 
 be very oblique ; for the membranous tendon descends low upon the back part or edge, and 
 ?he tendon of insertion begins high upon the fore edge of the muscle. 
 
252 
 
 MUSCLES MOVING THE LEG. 
 
 inagnus. The tendons of the two heads are joined a little 
 above the inner condyle, and go outwards to be inserted into 
 the outer part of the head of the fibula, forming the outer ham- 
 string. 
 
 Its insertion surrounds the head of the fibula, and a small 
 portion also sinks betwixt the bump of the fibula and the inner 
 head of the tibia, to be implanted into it also. 
 
 This muscle, like the opposite ones, serves for bending the 
 leg. The short head simply bends the leg. The long head 
 assists the short one in bending the leg, and is also a muscle 
 of the thigh. 
 
 The muscles of the foot are six extensor and two flexor 
 
 MUSCLES. 
 
 EXTENSORS. 
 
 Gastrocnemius vel gemellus, 
 
 Pt .ANTARIS, 
 
 Gastrocnemius internus vel soleus. 
 Tibialis posticus, 
 
 Peroneus longus, ) . , » , , 
 
 ^ > on the outside of the leg. 
 
 lying on the back 
 part of the leg. 
 
 — BREVIS, 
 
 The plexors are, 
 
 The tibialis anticus, ) , . ^ , 
 
 TLo > lying on the forepart of the leg. 
 
 Ihe PERONEUS TERTIUS, S ® ^ ° 
 
 CLXXXI. The gastrocnemius is often divided into three 
 muscles, named gastrocnemii or gemelli. But, far from 
 counting thus, we should rather favour the arrangement of 
 Douglas, who couples this with the next muscle, as forming a 
 quadriceps, or two muscles joined with two heads each, and 
 he calls it the extensor suralis. 
 
 The gastrocnemius is the great muscle of the calf of the 
 leg, its two heads are two very large and fleshy bellies, which 
 arise from the tubercles of the thigh-bone. The inner head 
 is the larger, and arises b)" a strong tendon from the back of 
 the inner condyle, and a little way up the rough line; and it 
 has also a strong adhesion to the capsular ligament of the 
 knee. 
 
 The outer head is shorter than this : it arises in the same 
 way, from the outer tubercle of the thigh-bone ; and the two 
 muscles meet and run down together, forming the appearance 
 of a rapha, by the direction of their fibres ; but the two bellies 
 continue distinct till they meet in the middle of the leg. They 
 are distinct at their back part; but, at their forepart, they 
 
MUSCLES MOVING THE LEG. 
 
 253 
 
 are connected by a tendinous aponeurosis, or strong but flat 
 tendon ; and the two bellies being about the middle of the leg, 
 united firmly, they form a large flat tendon, very broad at its 
 beginning, which unites with that of the soleus a little above 
 the ankle. 
 
 CLXXXIL Soleus. — This name is from its resemblance 
 to the soal fish ; and it is often named gastrocnemius inter- 
 Nus This, like the last muscle, has two heads, which arise 
 from either bone. 
 
 One head arises from the head of the fibula, and continues 
 to adhere to one-third of the upper part of the bone ; another 
 head arises from about three inches of the part of the tibia, 
 immediately below the insertion of the popliteus. The first 
 of these heads is large and round ; the second is smaller and 
 round; they unite immediately; and a large fleshy belly is 
 formed, with still a conspicuous division betwixt the flesh of 
 the two heads. The great tendon begins about half-way down 
 the leg, but still is intermixed with fleshy fibres till it approach 
 the heel. A little below the middle of the leg, this tendon is 
 united with the tendon of the gastrocnemius, to form the great 
 back tendon, named tendo Achillis ; and sometimes, though 
 very rarely, chorda magna. 
 
 The tendon is large ; it grows smaller as it approaches the 
 heel ; when it touches the extremity of the heel-bone, it ex- 
 pands to take a firmer hold. 
 
 In running, walking, leaping, &ic. this muscle, with the 
 extensors of the leg, are the principal agents. The ex- 
 ternal gastrocnemius has double power ; for, arising from the 
 tubercles of the thigh-bone, it is both an extensor of the 
 foot and a flexor of the leg ; but the gastrocnemius internus is 
 a mere extensor of the foot, and both together have such 
 strength as often to break the tendo Achillis. 
 
 CLXXXIIl. Plantaris. — This muscle is named from a 
 mistaken notion of its going to the planta pedis, or sole of the 
 foot, to form the plantar aponeurosis, like the palmaris of the 
 hand : but. in fact, it does not go to the sole, but is a mere 
 extensor of the foot, inserted along with the tendo Achillis. 
 
 This long and slender muscle is situated under the gastroc- 
 nemius externus. It arises from the external condyle of the 
 femur, wholly fleshy ; it also has an attachment to the capsular 
 ligament of the joint ; after an oblique fleshy belly, of about 
 three inches, it forms its small flat tendon. The tendon runs 
 beUvixt the inner head of the gastrocnemius and the soleeus ; 
 and when the tendo Achillis begins, the tendon of the plantaris 
 attaches itself to the inner edge, and forepart of the Achillis 
 tendon ; it accompanies it down to the heel, running in a 
 
2154 
 
 MUSCLES MOVING THE LEG. 
 
 groove which seems made to receive it ; and it is implanted 
 with the tendo Achillis, into the inner side of the heel-bone. 
 It is often wanting. 
 
 The use of this muscle is to tuck up the capsule, in the great 
 bendings of the knee joint, and to assist the gastrocnemii mus- 
 cles. 
 
 The PERON^i muscles are those which arise from the fibula. 
 They are named from their length being different; the pero- 
 N.^;us longus being as long again as the brevis, for it is one- 
 half longer in its origin, the one rising at the head, the other 
 at the middle of the bone ; and again, it is one-half longer at 
 its insertion, going fully round under the foot to the opposite 
 side, while the shorter peronteus stops at the side of the foot 
 to be inserted. 
 
 CLXXXIV. The peron^eus longus is so named from its 
 lying along the fibula. It arises partly tendinous, chiefly 
 fleshy, from the upper knob of the fibula, and from the ridge 
 of the bone down to within three inches of the ankle. It has 
 another small slip of a head from the upper part of the tibia, 
 above where the fibula joins ; it has also adhesions to the ten- 
 dinous partition, which separates this from the extensor digi- 
 TORUM COMMUNIS and the soleus. 
 
 Its tendon begins very high, above the middle of the leg, 
 and it continues to receive the fleshy fibres, almost at right 
 angles in the penniform manner. The tendon is concealed 
 down to about or below the middle of the leg. Then it is 
 seen immediately under the integuments, and we can easily 
 distinguish it through the skin, being that acute line or string, 
 which runs down behind the outer ankle, and which gives shape 
 to that part. 
 
 i In passing the outer ankle it runs down through a cartilagi- 
 nous pulley, or annular ligament, which also transmits the pero- 
 nKus brevis : it leaves the peronteus brevis on the side of the 
 foot ; and passing by itself in a groove of the heel-bone it 
 bends obliquely across the arch of the foot, goes quite down 
 to the opposite side, and is inserted into the metatarsal hone 
 of the great toe, and the great cuneiforme hone on which it is 
 founded. Under the eminence of the os cuboides, it sufiers 
 great friction, so as to be thickened to a degree of ossification, 
 and to resemble a sesamoid bone. It is also thickened in a 
 lesser degree, as it passes the outer ankle ; and in all this length, 
 it is tied down by a strong ligamentous expansion. 
 
 It is a powerful extensor of the leg ; it also gives that obli- 
 quity to the foot, which is .so handsome and natural, and use- 
 ful in walking. This muscle particularly turns down to the 
 ground, the inner edge of the foot j so it presses to the ground 
 
MUSCLES M0VIN6 THE LEG. 
 
 256 
 
 tbe ball of the great toe, and that is the part which touches the 
 ground, and which feels sore after long walking, or violent 
 leaping or running : It is by that part we push, in making a 
 step ; so that this muscle is perceived to be continually active 
 in all motions of walking, leaping, running, and more particu- 
 larly in dancing. 
 
 CLXXXV. The peron^us brevis is like its fellow except 
 in length and insertion. Its origin is from the ridge of the 
 fibula, beginning about one-third down the bone, and continu- 
 ing its adhesion the whole way to the ankle. It also has adhe- 
 sions to the tendinous partition which is betwixt it, and the 
 common extensor; so that these two muscles are, by such ad- 
 hesions, very difficult to dissect. It is smaller at its origin, but 
 increases in its fleshy belly as it descends ; and it is fleshy 
 low'er down than the peronteus longus. It is, like it, a penni- 
 Ibrm muscle. The tendons of the two peronaei pass together, 
 by the outer ankle, in the same ring ; but the tendons cross 
 each, other ; for the peron^us longus is in its belly more for- 
 ward. The brevis lies under and behind it, quite covered by 
 it, and yet tbe tendon of the brevis, by creeping under the lon- 
 gus, gets before it, just under the outer ankle : and from that it- 
 runs in a separate groove, superficially upon tbe outer edge of 
 the foot, to be inserted into the metatarsal bone of the little 
 toe. In both muscles the tendon is upon the outer edge, and 
 begins almost as high as the upper head of each muscle. This 
 tendon of the peronaeus brevis, the shorter one, is small where 
 it passes through the pulley, and expands w'hen it reaches its 
 insertion, that it may grasp the metatarsal bone firmly. The 
 tendon of the longer muscle also expands a little, and some- 
 what in the form of a hand and fingers, taking hold of two 
 bones by three little heads. 
 
 This muscle assists the former in extending the foot, and co- 
 incides well in its oblique action with the last ; for, as the last 
 turned down the inner edge of the foot, this turns the outer 
 edge upwards, which is exactly the same motion. 
 
 CLXXXVI. The peronaeus terxius is a third muscle, 
 having its origin from the fibula ; but as its tendon passes be- 
 fore the maleolus externus, and as it is inserted into the outside 
 of the foot, it has a contrary action to tbe peronaeus longus and 
 peromeus brevis. The peromeus tertius lies on the forepart of 
 the fibula, and rises from the middle of that bone, and down to 
 near its lower head. Its tendon does not pass into tbe same 
 sheath wdth the peronEeus longus and brevis, but goes under the 
 annular ligament on the forepart of the ankle-joint to be inser- 
 ted into the root of the metatarsal bone, which sustains the 
 little toe. It is so much connected with the extensor commu- 
 
'256 MUSCLES MOVING ’I'Hfi LEG. 
 
 nis digitorum, that there is often great difficulty in dividing the 
 two. The action of this muscle balances the connection of 
 the tibialis anticus, and the two together bend the foot, that is, 
 bring it to an angle with the leg. 
 
 CLXXXVII. The tibialis posticus is a penniform mus- 
 cle ; its tendon goes round the cartilaginous pulley of the inner 
 ankle. 
 
 It is named tibialis from its origin, and posticus from its 
 place. 
 
 It arises from the back part and ridge of the tibia, from the 
 opposite part of the fibula, and from the interosseous membrane 
 below these. Some fibres pass between the bones at the up- 
 per part, and take an origin from the forepart of the tibia ; and 
 it continues its attachment to the interosseous ligament, quite 
 down to the ankle. It has also strong attachments to the sur- 
 rounding tendinous partitions. Its fibres are all oblique and 
 go to the middle tendon, which is in the heart of the muscle. 
 About the middle of the tibia, this tendon begins to emerge 
 from the fleshy belly ; it grows gradually smaller, but still con- 
 tinues to receive flesb quite down to the ankle. It passes in 
 the groove of the inner ankle, and is retained there by such a 
 ligament as holds the peronasi. After passing the ligament, it 
 expands in the hand-like form, to grasp the bones of the tarsus ; 
 and it is expanded much more than the peronaeus, for it sends 
 roots down among the bones both of the tarsus and metatarsus, 
 so as to take hold first on the lower rough part of the naviculare 
 in passing over it. Then it is implanted into the two first me- 
 tatarsal bones, then into the calcaneum, and lastly into the os 
 cuboides ; and where it passes over the os naviculare, it is 
 hardened into a sort of sesamoid bone. In short, it is im- 
 planted in the sole of the foot by a tendon like a hand, which 
 sends down its fingers among the tarsal and metatarsal bones, 
 to take the surest hold. This muscle pulls the foot in, so as to 
 put the toes together, and, when balanced by the peronsei, it 
 directly extends the foot. 
 
 CLXXXVIII. The tibialis anticus crosses obliquely the 
 forepart of the leg. It arises from the forepart and outside of 
 the tibia, part of the fibula, and interosseous ligament. It be- 
 gins just under the outer tuber, and continues its adhesion down 
 two-thirds of the bone ; then the tendon begins to be formed : 
 and this muscle, like almost all the smaller ones of the leg, ad- 
 heres to the tendinous partitions, and to the fascia, with which 
 they are covered. The tendon begins almost with the origin 
 of the muscle, but continues covered by the flesb, and not ap- 
 pearing till within four inches or so of the ankle, when it begins 
 to pass obliquely over the leg, and having completed the cross- 
 
MUSCLES MOVING THE TOES. 
 
 257 
 
 ing above the ancle, it goes under the annular ligament in a 
 peculiar ring, it runs along the side of the foot, and is implanted 
 into the os cuneiforme internum, and a small production of the 
 tendon goes forward to be inserted into the metatarsal bone of 
 the great toe. 
 
 This muscle turns the great toe towards the leg, and 
 when assisted by the peronasus tertius directly bends the 
 foot. 
 
 MUSCLES OF THE TOES. 
 
 The long muscles of the toes are just four, two flexors, 
 and two extensor muscles. The flexor muscles lie upon 
 the tibialis posticus, or behind, betwixt it and the soliEus. The 
 extensor muscles again lie under the tibialis anticus, or at least 
 their heads are under it, and their bellies only appear from 
 under it, about the middle of the leg. 
 
 The flexor tendons follow the tendon of the tibialis posti- 
 ticuS, over the pulley of the inner ankle into the hollow of the 
 foot. The tendons of the extensor muscles keep with that of 
 the tibialis anticus, and cross over the forepart, or raising of 
 the ankle, where the tibia is united with the astragalus. And 
 in dissection, we must follow these in an opposite order to 
 that in which they are described, for next to the forepart of the 
 solasus is, 1st, the flexor pollicis ; 2dly, the flexor oigi- 
 TORUM ; and 3dly, the tibialis posticus. 
 
 CLXXXIX. The flexor longus pollicis is small and 
 pointed at its origin, and arises fleshy from three-fourths of 
 the fibula, to within an inch of the outer ankle, and interosse- 
 ous ligament. It grows thicker and larger as it descends, and 
 adheres to the tendinous partitions of the tibialis posticus, and 
 of the peroniui. Its tendon can be seen only about an inch 
 above the joint of the ankle. It passes down behind the inner 
 ankle, where it is bound in a sort of annular ligament. It there 
 passes under the heel-bone, in the arch of the foot, betwixt 
 the bones and the abductor pollicis ; it then glides into the 
 channel made by the two heads of the flexor pollicis brevis; 
 it then passes betwixt the two sesamoid bones at the root of 
 the great toe ; it then goes forward in a sheath, to be inserted 
 into the last bone of the great toe, at which implantation it is 
 enlarged. 
 
 Its office is to bend the great toe ; but it is also continually 
 useful at every step in extending the foot, or in keeping the 
 toe firm to the ground, while the gastrocnemii raise the heel ; 
 
 VOL. I. " K k 
 
268 
 
 MUSCLES MOVING THE TOES. 
 
 and therefore we should not be rash in cutting away the great 
 toe, for in it consists not the strength of the foot only, but of 
 the leg. 
 
 CXC. The FLEXOii longus digitorum pedis is named in 
 addition the pehforans, because, like the perforans of the 
 hand, it runs its tendons through the split tendon of a smaller 
 muscle, which is lodged in the sole of the foot. It is named 
 also FLEXOR COMMUNIS, although there be less reason here, 
 where there are no flexors for the individual toes, than in the 
 hand, where there are separate flexors for the individual fin- 
 
 It arises from the back and inner part of the tibia, its whole 
 length, that is, from the end of the popliUcal muscle, and from 
 the septum tendinosum, by which it is divided from the 
 tibialis anticus, which lies immediately before it ; and it con- 
 tinues this origin from the tibia down to within three inches 
 or so of the ankle. About the middle of the muscle we find 
 fibres coming across to join it from the outer edge of the 
 tibia, and between these two sets of fibres the tibialis posticus 
 passes. Its origin is not easily separated before from' the 
 tibialis posticus, nor behind from the flexor pollicis. 
 
 The tendon is not formed till near the ankle, (within two 
 inches of it,) and the flesh still accompanies it quite down to 
 the joint. It crosses the tendon of the tibialis posticus behind 
 the ankle-joint, and goes forward in the groove of the os cal- 
 cis, tied down by a sort of capsule, or annular ligament. In 
 the arch of the foot, it crosses the tendon of the flexor pollicis, 
 from which it receives a slip of tendon ; and thus the office of 
 either is assisted by the other, and could he wholly supplied 
 by it ; it then passes over to the middle of the sole, and grow- 
 ing flatter and thickei’, divides into four flat tendons. These go 
 forward, diverging till they arrive at the ends of their metatar- 
 sal bones; then they emerge from the aponeurosis plantaris, 
 along with the common short flexor. Now both these tendons 
 run under a ligamentous sheath, and are included in it under 
 the first and second bones of the toes ; and having perforated 
 the short flexor opposite to the second joint, they are finally 
 inserted into the root of the third or last bone of each toe. 
 These tendons, like the corresponding ones of the hand, seem 
 to be split with a sort of longitudinal fissure. 
 
 The proper use of this muscle is to bend the four lesser 
 toes, to bend all their joints, but more peculiarly the last bone ; 
 and also to extend the foot, keeping the point of the toes to 
 the ground, consequently assisting, the gastrocnemii, and all 
 the muscles used in walking, &c. 
 
MUSCLES MOVING THE TOES. 
 
 259 
 
 CXCl. The MASSA CARNEA JaCOBI SvLVII, OF PLANTS 
 PEDIS, flexor accessorius, lies in the sole of the foot; it is a 
 small body of flesh, naturally connected with the flexor longus. 
 The massa carnea arises from the lower part of the heel-bone, 
 in two divisions, one (the external one) tendinous, the other 
 fleshy. It is, upon the whole, pretty nearly of a square form ; 
 it joins the tendon of the flexor longus, before its division into 
 tendons for each toe, and by the advantage with which it acts 
 in consequence of its origin from the heel -bone, it must be of 
 great assistance to the flexor. It is more generally considered 
 in the light of a supplementary muscle ; by some, it is con- 
 sidered as a distinct muscle, and by others, as the origin and 
 first beginning of the lumbricales pedis. 
 
 Thus Cowper considers the massa carnea, and the lumbri- 
 cales, as one and the same : that the massa carnea joins the 
 tendon, covers it with its flesh, continues fleshy along the com- 
 mon tendon, till at the bifurcation it also parts along with the 
 four tendons, into four small fleshy muscles, which are called 
 lumbricales. 
 
 Albinus, again, paints the massa carnea distinctly, termina- 
 ting at the common tendon, and the lumbricales as arising dis- 
 tinct from each of the divided tendons. 
 
 CXCII. The FLEXOR BREVIS Di oiTOBUM is also named the 
 flexor sublirais or perforatus. It arises from the lower part of 
 the heel-bone, or the bump upon which we stand. It arises 
 by very short tendinous fibres, and being placed immediately 
 under the plantar aponeurosis, it takes hold of it, and also of 
 the tendinous partitions betwixt it, and the two abductors of the 
 small and of the great toe, which are on either side of it. 
 Under the metatarsal bones, it divides itself into four heads; 
 their tendons begin earlier upon the side next the foot ; they 
 grow round, emerge from betwixt the dentations of the plantar- 
 aponeurosis; they then pass into the vagina, or sheath of 
 each toe ; and on this, the first phalanx, they lie over the ten- 
 dons of the long extensors. About the root of the first bone, 
 they divide into two little bands, wfliich form a split (like 
 the perforatus of the fingers) for the passage of the long 
 temlon. 
 
 The long tendon passes through it upon the second joint of 
 the toe, and immediately after the perforated tendon fixes it- 
 self by the two forks to each side of the second bone, or 
 phalanx of the toe. 
 
 Its use is to bend the first and second joints of the toes, but 
 most peculiarly the second. The obliquity of the long flexor 
 is exactly balanced by a corresponding obliquity of the short 
 flexor; for the tendon of the long flexor coming round the 
 
260 
 
 MUSCLES MOVING I'HE TOES. 
 
 inner circle, runs obliquely outwards to reach the toes, while 
 the short flexor coming from the heel, which is towards the 
 outer edge of the foot, runs in a like degree obliquely im 
 wards and meets the other at an acute angle near the toes. 
 
 CXCIII. The LuniBRiCALEs must be dissected after the 
 §hort flexor. They need no description, since they exactly 
 correspond with those of the hand. They rise, like them, in 
 the forks of the flexor tendons. They, like them, pass through 
 the digitations of the aponeurosis. They pass on to the first 
 bone of the toes, and, like the lumbricales of the hand, creep 
 over the convexity of the bone, to be united along with the 
 tendons of the extensors. Their insertion is always at the 
 side of the toe next the great toe, and their use is to bend the 
 first joint of the toes, and to draw them towards the great one, 
 making an arch in the foot, and assisting the transversalis 
 pedis. The flexor brevis lies most superficially upon the 
 sole of the foot, having its origin from the inner surface of the 
 aponeurosis. The massa carnea lies deeper, having no 
 origin but from the tip of the heel-bone, and being soon im- 
 planted into the tendon of the long flexor. The lumbricales 
 again rise from the tendons of the long flexor, beginning just 
 where the massa carnea ends in it: and the lumbricales are 
 the flexores primi intemodii; the short flexor muscle, the 
 flexor secundi intemodii ; the long flexor, the flexor tertii 
 intemodii digitorum. 
 
 EXTENSORS OF THE TOES. 
 
 CXCIV. The EXTENSOR LONGus DIGITORUM PEDIS is Very 
 difficult to dissect, from its numerous adhesions. 
 
 It arises properly from the head of the tihia, at its outer and 
 forepart, just under the Imee ; but it has also strong adhesions 
 to the inner surface of the fascia, to the tendinous partitions 
 betwixt it and the tibialis anticus before and betwixt it, and 
 the peronasi behind, and also to the interosseous ligament, 
 and to the edge of the fibula. Its small origin soon becomes 
 thick, and is divided even from the beginning very perceptibly 
 into three distinct portions. These soon form three round 
 tendons, which go obliquely inwards, pass under the annular 
 ligament of the ankle, and run in a ring of it, peculiar to 
 them and the peronaeus tertius. They then traverse the two 
 bands of the annular ligament, upon the forepart of the foot, 
 and now they change their direction a little, and go from 
 within outwards, and diverge towards their proper toes. 
 There are three portions of muscle, and four toes to b€ 
 
MUSCLES MOVING THE TOES. 
 
 261 
 
 moved ; the first portion divides its tendon into two, at the 
 joint, so that the first portion serves both the first and second 
 toe, the second the third toe, and the third serves the fourth 
 toe. Here the tendon of the long extensor receives four other 
 tendons ; first, of the interossei externi ; secondly, of the 
 interrossei intern! ; thirdly, of the long flexor ; fourthly, of 
 the lumbricales ; and these form a very large sheath, quite 
 surrounding the toe. 
 
 These do not only, like other extensors, extend the toes, 
 but also, by the divergence of the tendon, expand them, or 
 separate them one from another. 
 
 CXCV. The EXTENSOR digitorum brevis is so connected 
 with the extensor longus, that it is natural to describe them 
 together. It is placed just where the buckle lies, upon the 
 ri^ng of the foot, having its origin from the heel-bone, and 
 running obliquely inwards. 
 
 Its origin is from the outer side, and forepart of the heel- 
 bone, and also from part of the annular ligament. It is smaller 
 where it arises by a short tendon from the heel-bone, but it 
 gradually encreases in size ; it divides early into four heads, 
 which are muscular, and very distinct ; the two inner of which 
 are larger, the two outer more slender : each head has already 
 formed an oblique tendon under its flesh, which begins to 
 appear naked about half way down the metatarsal bones. 
 These tendons cross those of the long extensor, and pass 
 under them nearly about the end of the metatarsal bones. 
 Then one is implanted into the first bone of the great toe, and 
 on the inside of the long tendon under which it had turned. 
 The second, third, and fourth tendons are inserted into their 
 respective next toes, and the little toe is left without one. 
 The three last of these tendons form a sort of slit, the two 
 sides of which pass along- the sides of the toes, surrounding 
 the long tendon, something like a perforatus ; so that the 
 three last tendons are inserted along with the long tendons into 
 the last bone of the toes. 
 
 The obliquity of this short muscle counteracts the obliquity 
 of the long ; and it serves to extend and to spread the toes, 
 and to pull them away from the great toe. 
 
 CXCVI. The EXTENSOR poLE!Cis PROPRius is a very 
 slender muscle running from the top of the leg to the second 
 joinc of the great toe. It arises from the fibula, a little below 
 its head, takes fibres from the interosseous ligament, grows 
 tendinous as it approaches the foot, then passing under the 
 annular ligament, and the cross ligament of the foot, it goes 
 onwards to the second joint of the toe over the first. 
 
 The succession in which these muscles lie, under and be- 
 
262 
 
 MUSCLES MOVING THE TOES. 
 
 hind each other, is this ; first, the tibialis anticus, the outei- 
 most muscle, arises from the forepart of the tibia, nearest 
 the forepart of the leg, at the ridge of the tibia : secondly, 
 the extensor pollicis lies immediately behind, and under the 
 tibialis anticus; thirdly, the extensor digitorurn communis 
 lies behind that : and fourthly, the peroneus tertius lies behind 
 the common extensor, like a part of that muscle. 
 
 These extensor tendons are bound down by cross bands, 
 resembling the annular ligaments of the wrists. The general 
 fascia of the thigh is continued over the knee, and dowm the 
 leg : it is much strengthened at the knee, where it adheres to 
 each point of bone ; it descends very thick and strong over 
 the leg, binding down and strengthening the tibialis anticus 
 and extensor muscles. The sheath grows thinner towards the 
 ankle, but where it passes over the joint it is so remarkably 
 strengthened by its adhesions to the outer and inner ankles, 
 that it seems to form two distinct cross bands, which, going 
 from the point of the outer ankle, across the extensor 
 tendons, to the point of the inner ankle, forms a strong crucial 
 ligament, i-esembling the annular ligament of the wrist ; so 
 that this, which is called the ckucial ligament of the ankle 
 or foot, is plainly but a strengthening of the common sheath. 
 
 The remaining muscles in the foot are the interossei, 
 which, in the foot, are found single on the lower surface or 
 sole, but double, and two-headed upon the upper part of 
 the foot. The abductor, flexor, and adductor pollicis, 
 which surround the great toe, something like those of the 
 thumb; and the abductor and flf.xob minimi digiti, sur- 
 rounding the little toe ; and there is a small slip of muscle, 
 the TRANsvERSALis PEDIS, whicli gocs across the sole of the 
 foot. 
 
 CXCVII. The ABDUCTOR pollicis arises by very short 
 tendinous fibres from the knob of the os calcis, and also from 
 a ligament which stretches from this knob to the sheath which 
 belongs to the tibialis posticus ; and it arises also from the ten- 
 dinous partition betwixt it and the short flexor of the toes; and 
 although it forms a tendon beginning opposite to the cunei- 
 form bone, the tendon is not naked, till it has reached the mid- 
 dle of the long metatarsal bone. It unites with the short flex- 
 or of the same toe, and is inserted into the first bone or phalanx 
 of the toe at its root, and os sesamoideum. Its use is to pull 
 aside the toe, and at the same time to bend it a little ; it also 
 curves the foot itself, for a joint, or any loaded part, is much 
 better supported by muscles than by ligaments; and this arch 
 requires support more than almost any other part. 
 
MUSCLES MOVING THE TOES. 26^ 
 
 CXCVIIL Flexor BREVIS POLLicis. This muscle is much 
 shorter than the last, and lies betwixt the abductor and the 
 adductor; it lies immediately upon the metatarsal bone. 
 
 Its origin is by a pretty long tendon from the heel-bone, and 
 from the os cuxeiformi- externum, by two separate slips, 
 from the heel-bone, being a full inch in length ; it also adheres 
 to the membranous partitions on either side of it. It is soon 
 divided into turn heads ; one goes to the abductor, and the 
 other goes to the adductor, to have the tendons inserted with 
 theirs, into the root of the first bone or phalanx. These ten- 
 dons contain the sesamoid bones ; and the parting of the two 
 heads makes a channel for the tendon of the long flexor to run 
 in. 
 
 Its use is to bend the first joint of the great toe. 
 
 CXCIX. The ADDUCTOR pollicis is the third and last por- 
 tion of the muscle which encircles the great toe. 
 
 It arises from the heel-bone, by a tendon as long almost as 
 that w'hich it gives the abductor : it does not immediately arise 
 from the heel-bone ; but there is a ligament extended from the 
 heel-bone to the os cuboides, and it arises from that ligament : 
 this is the ligament, under which the tendon of the peroneus 
 longus glides. It takes likewise an origin from the cuneiforme 
 externum. The adductor is divided into two fleshy fasciculi 
 or heads ; these unite, and going obliquely inwards, are inserted 
 either into the sesamoid bone, or directly into the first bone of 
 the great toe. 
 
 CC. The TRANsvERSALis PEDIS cxtends transversely across 
 the sole of the fbot, at the head of the metatarsal bones ; it is 
 a very small muscle, and resembles a good deal the palmaris 
 brevis. 
 
 It arises from the forepart of the metatarsal bone of the 
 great toe, and the sesamoideum internum, and is inserted into 
 the under and outer part of the anterior extremity of the 
 metatarsal bone of the little toe and ligament of the next toe. 
 
 Its use is said to be, to make a sort of gutter in the foot, by 
 drawing the beads of the metatarsal bones together; but is it 
 not evident, that this is one of many instances of muscles be- 
 ing a more perfect suppoi't than ligaments.^ — It is a support, 
 having a sort of intelligence, contracting or relaxing, according 
 to the necessity or degree of force ; indeed, except this use, it 
 is not easy to assign any, for there is very little occasion for 
 hollowing the foot in this direction- 
 
 CCI. The ABDUCTOR MINIMI DiGiTi, like the abductor pol- 
 licis, is a pretty long muscle, but very slender, lying on ihe 
 outer side of the foot. 
 
264 MUSCLES MOVING THE TOES. 
 
 Its origin is from the knob of the heel-bone, and from the 
 tendinous septum, which covers the flexor brevis : it forms two 
 small tendons in the same direction : one small and shorter 
 tendon is fixed into the metatarsal bone, at its root : the other 
 goes forward, to be inserted into the root of the first bone of 
 the toe, so that this muscle clearly performs both the offices 
 ascribed to the other flexors. It bends the toe to which it be- 
 longs, and it extends and supports the tarsus in walking ; and 
 it carries the toe a little outwards, from which it has its name. 
 
 cell. The FLEXOR BREVIS MINIMI oiGiTi is ncxt, and is 
 almost the same muscle in place and office : it is an exceeding- 
 ly small muscle ; it just measures the length of the metatarsal 
 bone, and arises from it. Its origin is from the root of the 
 metatarsal bone of the little toe, and from the ligament by 
 which that bone is connected with the os cuboides ; its small 
 belly runs the length of that bone, and it is implanted by a short 
 tendon, into the root of the first bone of the little toe. 
 
 Its use is to bend the toe. 
 
 CCIII. The iNTEROssEi iNTERNi are three small muscles, 
 seated in the planta pedis, as the interossei manus are in the 
 palm of the band. Their slender tendons pass through the 
 openings of the aponeurosis plantaris, and, going on the inside 
 of the toes, are, like the lumbricales, inserted along with the 
 extensor tendons. 
 
 These pull the toes towards the great toe, bend the first joint, 
 and extend the second and third. 
 
 CCIV. The INTEROSSEI EXTERNi are, like the correspond- 
 ing muscles of the hand, four in number, and double headed, 
 and have been named bicipites. They rise from the metatar- 
 sal bones, on each side of them : each has some little variety 
 in its origin or course ; but it is far from being worth our while 
 to describe each individually, as many do : it is sufficient to 
 observe their origin, and that their tendons all meet the ten- 
 dons of the long and short extensors of the lumbricales, and 
 of the INTEROSSEI INTERNI, upoo the backs of the toes ; so that 
 the whole forms a web, aponeurosis, or sheath, which covers 
 the upper part of the toe, and adheres to its point. 
 
 The office of these muscles is to extend the toes. 
 
 Plantar aponeurosis. — The palm and the sole are much 
 exposed, and are specially defended by a thick tendinous 
 aponeurosis. In the palm, there is the more reason to suspect 
 expansion to proceed from the tendon of one muscle, because 
 the tendon of the palmaris is inserted into it ; yet that is not 
 probable ; for the tendon is very slender,, and quite unfit for the 
 generation of so broad a sheet of aponeurosis. In the foot, 
 such an origin is ?=^tillless probable; for the plantaris tendon 
 
MUSCLES MOVING THE TOES. 265 
 
 does not terminate in the plantar aponeurosis, but is inserted 
 into the heel-bone. 
 
 The plantar aponeurosis arises most distinctly from that part 
 of the tuber of the heel-bone upon which we stand : it is divid- 
 ed into three sheaths. Sabatier makes a middle, external, 
 and internal portion of the same aponeurosis. Albinus also 
 describes it as three distinct aponeurosis ; one for the middle 
 of the foot ; one for the abductor of the great toe ; and one the 
 aponeurosis of the abductor of the little toe; all connected 
 together only by their edges. Cowper considers it as a general 
 expansion from the plantaris ; and it is from this prejudice 
 that the muscle has its name. 
 
 But its true origin is from that part of the knob of the heel- 
 bone on which we stand. The middle and more pointed ten- 
 don arises from the very point of the knob. The inner fascia 
 arises from the inside of this; and the outer one from the out- 
 side. And though thus divided into three heads, yet the whole 
 origin is from the heel-bone. From this point the aponeurosis 
 goes forward, expanding till it is as broad as the roots of the 
 toes ; so that the whole has the shape of a sandal; and as it 
 expands, its fibres are scattered, so as to have a radiated 
 appearance. Accordingly the part nearest the heel is thicker, 
 while the broader part is thinner. 
 
 It goes forward like the sole of a shoe, till having approached 
 the heads of the metatarsal bones, it is divided into five heads, 
 corresponding with the five knobs ; and each of these heads 
 again subdivides itself in two bands, which, passing on each 
 side of the heads of the metatarsal bones, is fixed into the sides, 
 so as to leave room for the passing of the tendons, and nerves, 
 and arteries. 
 
 Now this middle aponeurosis sends down a deep strong 
 partition on each side of it ; which is the best reason that I 
 know for making these three distinct aponeurosis; for by these 
 perpendicular partitions, the hollow of the foot is separated 
 into three distinct chambers : under the middle one are con- 
 cealed the tendons of the long flexors, with the luinbricales 
 and short flexor muscles : under the outer one the flexor and 
 abductor of the little toe : and under the inner one the ad- 
 ductor, flexor, and the abductors of the great toe. 
 
 The uses of this great and very strong aponeurosis are : that 
 it protects all the parts, <he blood vessels, muscles, and nerves 
 that lie under it: that it supports the arch of the foot, both in 
 standing and in motion, passing from heel to toe like a bow- 
 string across its arch : that it binds down the muscles, and 
 consequently supports and assists them in their strong actions : 
 that it gives origin or part of their origin, to many of the mus^ 
 
 VOL. I. ‘ LI 
 
OF THE MUSCULAR POWER. 
 
 266 
 
 cles ; wliicb, by their frequent and irregular adhesion to it, are 
 very difficult to dissect : that it forms openings or rings, in 
 'vhich the tendons of the other muscles pass. 
 
 CHAP. IX. 
 
 OF THE MUSCULAR POWER. 
 
 That contractile power which resides in the muscular os' 
 living fibre, is a phenomenon the most wonderful and perplex- 
 ing of all. When we cannot reach the true point, the mind too 
 often condescends to the most trifling pursuits ; and so, when 
 the older physiologists could not understand the intrinsic nature 
 of this muscular power, they endeavoured to discover the size, 
 the colour, and other external properties of the fibre ; foolishly 
 desiring to knov/, what if known, could be of no avail. Colour was 
 believed to be essential to the constitution of a muscle : but in 
 fowls, in amphibious animals, in fishes, in worms, and insects, 
 through all the gradations of animals of different species or dif- 
 ferent sizes, the colours of the m uscular fibre change. In fishes and 
 in insects, it is entirely white ; even in the human body, it is 
 not essentially red : the blood which makes the fibre red may 
 be washed away. Then why should we define a muscle by 
 that accidental property which it so often wants, and of which 
 it may be so easily deprived, while we may define it more 
 truly by its contractile power, the only evidence of its nature, 
 and its chief distinction in the system ; for the contraction of 
 the iris constitutes its nature ; it is a muscle by truer marks 
 than by its colour: and, by the same rule, the muscles of the 
 least insect are as perfect as the muscles of a man. 
 
 Philosophers of the last age had been at infinite pains to find 
 the ultimate fibre of muscles, thinking to discover its properties 
 in its form ; but they saw just in proportion to the glasses which 
 they used, or to their practice and skill in that art, which is 
 now almost forsaken. Some found the fibres to be of one 
 equal size in all creatures, however various : others found them 
 them proportioned to the size, or age, or strength, of their sub- 
 ject; but even such discrepancies are trivial to those which, in 
 one of the greatest of these minute philosophers, are found al- 
 most in the same page; sometimes affirming the ultimate fibre to 
 be greater or smaller, according to the strength of the subject. 
 
OF THE MU3CDLAR POWER. 267 
 
 and again making them of equal size, in the whale and in the 
 insect. 
 
 Others, less troubled about the ultimate size of these fibres, 
 had conceived notions of their form, which, in the credulity of 
 the times, rose into the importance of doctrines, and, from the 
 first raw conceptions of their authors, were finally proved by 
 the microscope, forsooth ; and while one author was drawing 
 his rhomboidal fibres, all conjoined in regular succession, and 
 another describing them also from the microscope, as consist- 
 ing of six cylindrical fibres, involved in a spiral one, a third 
 reckoned the fibres a succession of spherical bodies : and 
 Cowper thought that he was injecting with quicksilver, chains 
 of bells jointed with each other. For the honour of the age, 
 these vanities are forgotten now. And why, indeed, should we 
 seek the ultimate fibres of the muscle, or study their forms, 
 when the discovery could not advance us one single step in the 
 knowledge of its nature or essence ? What avails it that we 
 have discovered (if we have really discovered) the shape of 
 the particles of the blood ; the wave-like fibres within the sub- 
 stance of the nerves ; or the jointed appearance in the smaller 
 fibres of muscles.^ We do not understand the nature of the 
 blood, the properties of the nerves, nor the contractile power 
 of the muscles at all better by this peculiar form of the internal 
 structure, than we do by the grosser marks of their external 
 form. 
 
 Physiologists have, by a late sense of their own weakness, 
 been at last humbled to this becoming, but unwilling acknow- 
 ledgement, that this contractility of the muscles is an original 
 endowment of this living matter derived from the Creator, 
 imparted in a w’ay which we cannot know, and so attached to 
 the organization of the muscular fibre, that where its organiza- 
 tion is destroyed, this power is lost. We have resigned the 
 search after a mechanical or physical cause, and seek only to 
 learn the properties of this living power, and the excitements 
 by which it is moved. To this end it is necessary to define this 
 power, distinguishing it from those feelings or motions which 
 result from the nerves.. The vis insita, being that power which 
 belongs to muscles, is the source of motion and animal life. 
 The vis nervea, being that property which is peculiar to nerves, 
 is the seat of feeling, and the cause of voluntary motion, rela- 
 ting chiefly to the enjoyments and consciousness of life ; for 
 life and motion exist even in plants, and in many creatures, 
 which, not having nerves, harve neither consciousness nor en- 
 joyment, and in which the place of feeling is supplied by a 
 less perfect instinct, by this vis insita, or some analogous inhe.- 
 rent power. 
 
OF THE MUSCULAR POWER. 
 
 268 
 
 This iiritable power residing in muscles, may be defined 
 the property by which muscles feel and re-act, upon certain 
 stimuli being applied, without that feeling being conveyed to 
 the sensorium, without a consciousness of action, without any 
 other natural dependence on the system than that, while cer- 
 tain orders of muscles are obedient to their own stimuli only, 
 as the heart to the blood, other orders of the muscles are ready 
 to receive the commands of the will. And above all, so little 
 dependent is this action upon the nerves, that it is as perfect 
 in animals which have no nerves, and is for a time very perfect 
 in the parts which have been severed from the systems to which 
 they belonged. This power, inherent in the muscular fibre, 
 belonging to its constitution, and not derived from without, is 
 the vis insita, or irritability of Haller,* the vis vitalis of Goerter, 
 the oscillation of Boerhaave, and the tonic power of Stahl. 
 It is seen in the spontaneous and tremulous contractions of 
 muscles when lacerated ; as in wounds, when cut in operations, 
 when entirely separated from the body ; as in experiments 
 upon animals, like that tremulous motion which we often feel 
 in various parts of the body, wuthout any evident cause, and 
 independent of the will. Even when the body is dead to all 
 appearance, and the nervous power gone, this contractile 
 power remains ; so that if a body be placed in certain attitudes, 
 before it be cold, its muscles will contract, and it will be fixed 
 in that posture till the organization yields and begins to be dis- 
 •solved ; it is the same inherent power by which a cut muscle 
 contracts and leaves a gap. This is but a feint indication of 
 that latent power, which can be easily excited to the most 
 violent motions, and on which all the strength of the muscles 
 depends : for the ligaments, tendons, bursas of joints, and all 
 those parts which have no living power, are capable of bearing 
 the same weight when dead as when alive. But such is the 
 connection betwixt the organization of a muscle and its con- 
 tractile power, that the moment it dies its power is gone ; and 
 the muscle whicli could lift a hundred pounds while alive, can- 
 not bear the weight of a few pounds when dead. This latent 
 power may be brought into full action by various stimuli. The 
 latent power itself is called vis insita, the acting power put into 
 action, or the proof of the vis insita, upon applying stimuli, is 
 called the irritability of muscles. This irritability is so far in- 
 
 * Tlie ii'rilablity of a musde is, perhaps, more properly the vis insita, or inherent powc-i' 
 •■ailrd into iimnediatp. action, by tlie presence ofstimuli ; and as for the names of Tonic Power , 
 Vital I’owcr, and the rest, 'he terms are quite undefined, and may, perhaps, tiave refinrec' 
 ■^thcr to tlie combined effect of ail the powers of life, and of all the properties of inaniinalr 
 matter, of nervous sympathy, elosticit}', and of muscular power comhiaed. 
 
OF THE MUSCULAR POWER. 
 
 269 
 
 dependent of nerves, and so little connected with feeling, which 
 is the province of the nerves, that upon stimulating any muscle 
 by touching it with a caustic, or irritating with a sharp point, 
 or driving the electric spark through it, or exciting with the 
 metallic conductors, as of silver and zinc,* the muscle instantly 
 contracts ; although the nerve of that muscle be tied, although 
 the nerve be cut so as to separate the muscle entirely from all 
 connection with the system, although the muscle itself be se- 
 parated from the body, although the creature upon which the 
 experiment is performed may have lost all sense of feeling, 
 and have been long apparently dead. Thus, a muscle cut 
 from the limb, trembles and palpitates for long after; the 
 heart separated from the body contracts when irritated ; the 
 bowels wiien torn from the body continue their peristaltic mo- 
 tion, so as to roll upon the table, ceasing to answer to stimuli 
 only when they become stiff and cold ; and too often in the 
 human body the vis insita loses the exciting power of the 
 nerves, and then palsy ensues; or, losing all the governance 
 of the nerves, the visinsista, acting without this regulating pow- 
 er, falls into partial and general convulsions. Even in vegetables, 
 as in the sensitive plant, this contractile power lives. Thence 
 comes the distinction betwixt the irritability of muscles and 
 the sensibility of nerves ; for the irritability of muscles sur- 
 vives the animal, as when it is active after death ; sui’vives the 
 life of the part, or the feelings of the whole system, as in uni- 
 versal palsy, where the vital motions continue entire and per- 
 fect, and where the muscles, though not obedient to the will, 
 are subject to irregular and violent actions ; and it survives 
 the connection with the rest of the system, as where animals 
 very tenacious of life are cut into parts: but sensibility, the 
 property of the nerves, gives the various modifications of sense, 
 as vision, hearing, and the rest ; gives also the general sense 
 of pleasure or pain, and makes the sj^stem, according to its 
 various conditions, feel vigorous and healthy, or weary and 
 low. And thus the eye is sensible, and the skin is sensible ; 
 but their appointed stimuli produce no motions in these parts; 
 they are sensible, but not irritable. The heart, the intestines, 
 the urinary bladder, and all the muscles of voluntary motion, 
 answer to stimuli with a quick and forcible contraction ; and 
 yet they hardly feel the stimuli by which these contractions 
 are produced, or at least they do not convey that feeling to 
 the brain. There is no consciousness of present stimulus in 
 
 * See a most iogenious dissertation by my pupil Mr. Fowler, the first writer io this coun 
 tiT, on this very interesting no\ eIty, wliere ttie operations of this new excitement are ex 
 plained. 
 
270 
 
 OP THE MUSCULAR POAVER. 
 
 those parts which are called into action by the impulse of the 
 nerves, and at the command of the will ; so that muscular 
 parts have all the irritability of the system, with but little feel- 
 ing, and that little owing to the nerves which enter into their 
 substance ; while nerves have all the sensibility of the system, 
 but no motion. 
 
 The VIS iNsiTA is a power that is in continual force, pre- 
 serving the parts ready for their proper stimuli, whatever these 
 may be : one set obeying their own peculiar stimuli chiefly, 
 w'hile others are obedient to the nervous power, and the in- 
 fluence of the will. 1 he heart is stimulated by the quantity 
 or quality of its blood ; the stomach by the presence of food ; 
 the intestines by their contents : the urine stimulates the 
 bladder ; the venereal appetite stimulates the genital system ; 
 the foetus stimulates the womb ; and the voluntary muscles (if 
 we may be allowed to guess at a thing so little known,) are 
 excited by the nerves, and so are obedient to the will ; for, 
 to our limited view, the nerves seem to be the sole messen- 
 gers of these commands, and any stimulus to the nerves 
 moves the muscles like the commands of the will. The ab- 
 sence of the due stimulus to each, or the presence of the 
 ordinary stimuli in too great power, will excite enormous and 
 irregular motions, as fulness of blood in the heart, poisons in 
 the stomach, acrimonies in the intestinal canal, or the passions 
 of anger or fear in the system of the voluntary muscles. The 
 due stimuli preserve their right tone and action ; but these 
 violent stimuli hurt their irratibility, or moving power ; the 
 heart acts weakly after fevers ; the appetite is languid after 
 debauch ; the limbs are weakened by labour ; and the whole 
 system is ruined by excess. Thus, the functions by which 
 the system lives, the heart, the stomach, the bowels, and the 
 womb, the various sorts of vessels by which the fluids are 
 conveyed, are providently removed from the influence of the 
 will ; for these are the machines of the system, whose motions 
 could not stop, must not be interrupted, nor lowered, nor raised, 
 but must move and act according to the needs of the system. 
 Not left to the irregularities or carelessness of voluntary 
 motions, they are governed each by its own peculiar stimulus, 
 and act in a continued and equal course. 
 
 Thus, there are in the body two living powers, which are 
 as cause and effect in all the motions of our system. The 
 NERVES stand as an intermedium betwixt all external objects 
 and our general sense ; by the impressions through these 
 come pleasure and pain, and all the motives to action ; by the 
 will, returned through the nerves, all voluntary motions ensue. 
 Thus are the nerves, as internuncii, betwixt the external im- 
 
OF THE MUSCULAR POWER. 
 
 271 
 
 pression and the moving power. But nerves were never 
 known to move under the inGuence of stimuli ; the moving 
 power is another property of a distinct part of our body, 
 having its own arrangement of particles, and its own peculiar 
 form. All motion then proceeds from the joint operation of 
 either power : the nerves convey .he impressions, while the 
 muscles contain the power ; and it is here, as in other natural 
 effects, the external cause changes, while the inherent pro- 
 perty, the subject of its operation, remains the same. The 
 nervous power is the regulator of the system ; it is the 
 property suited to all the supports of life, upon which they 
 act, and by which they maintain their power over our body ; 
 but is subject to continual changing : it rises and it falls, is per- 
 fect or low; but the energy of the muscle, which is to 
 answer to this power, remains ever the same, while its orga- 
 nization remains : the nervous poweris exhausted and languid ; 
 but the muscular power is always perfect, always ready for 
 the excitement of stimuli, or for the commands of the 
 will. 
 
 There is (if we may be allowed any expression so loose and 
 indefinite) the will of the system, and the will of the mind; 
 it is the will of the system, that, through the medium of nerves 
 of wide sympathy and consent, governs and leads in harmony 
 all the consenting functions of the body, and lowers and raises 
 their powers, according to the weakness or strength, or fulness 
 or wants of the body ; while the will of the mind commands 
 those voluntary motions, which it is its choice to perform. So 
 natural seems that notion which has long prevailed, of an 
 archseus, or presiding spirit, which, like a latent instinct regu- 
 lates and preserves the system, prompts to what is right, and 
 creates an aversion to what is wrong, and raises or allays the 
 actions of the vital organs, preserving the system in health, 
 and striving against disease. The voluntary muscles are put 
 under the command of the will, while the involuntary muscles, 
 by which the vital organs move, are insulated and mechani- 
 eal, and depend less on our spiritual part : for life and exist- 
 ence depend less on feeling, or that which is allied to our spiri- 
 tual part, and more on the irritable and moving power ; and it 
 was fit that this irritable power should be divided from our feel- 
 ings and our will, which are irregular and transitory, and apt 
 rather to derange than to preserve the system. 
 
 How this division is accomplished, we do not know in any 
 surer way ; but we see that the heart, the lungs, the stomach, 
 and the intestines, have a proportion of nerves, so much lower 
 than the muscles of voluntary motion, that their very existence 
 lias been denied. Yet there are nerves proper to the vital 
 
272 
 
 OF THE MUSCULAR POWER. 
 
 parts; the phrenic nerve goes to the diaphragm ; the par va~ 
 gum to the heart, lungs, and stomach ; the sympathetic nerve j 
 to the heart, to the intestines and other viscera ef the abdo- 
 men : these nerves are appropriated and distinct. Now, this 
 question occurs : if the irritable power be in these organs, if ! 
 they be endowed with the quality of feeling their own peculiar I 
 stimuli, and answering to their impulses, what need is there 
 for nerves ^ but they also have their nerves, that they may not 
 want some living connection with that system to which they [ 
 belong : that they may flourish in its health, and languish inks 
 diseases; that they may act according to the needs, and be 
 subject to the will of the system ; that the grand movers of 
 the mechanical system may be affected in their turns by the 
 spiritual part, and thus the digestion, the circulation, the vene- 
 real appetite, and every vital power, are languid and depressed, 
 or lively and perlect, according lo the conditions of the whole : 
 and bow these functions are moved by anger, or joy, or fear, 
 needs not be told. But the vital functions also lose their ac- 
 tion : “The heart acts weakly after fevers; the appetite is 
 languid after a debauch ; the limbs are weakened by labour; 
 and the whole system is ruined by excess.” These organs 
 have less dependence on nerves, and so suspicions arise, that 
 the irritable power, the very basis of life, may also fail ; but 
 how should it fail ^ If the motions of our system cease, it I 
 
 must be either from the incapacity of the muscles, or from the 
 loss of exciting power in the nerves. The nerves are liable ^ 
 to change, but the muscle retains its power till its organization 
 be destroyed. When the irritable power of a muscle ceases, 
 when the heart, for instance, begins to fail, whence can that 
 loss arise ? Its power is not mechanically exhausted, else from 
 what source could it ever be renewed It is not from any 
 injury to its nerves ; for the heart, when cut out from the body, 
 may be wearied out wnth constant stimuli, till it cease to act; 
 and it will recover by rest, without communication with the 
 nerves : but it is perhaps such a derangement as happens in a 
 spring, which, being long bent, loses of its elastic power: the 
 arrangement of its particles suffers by straining ; they are com- 
 posed by rest : and if the elastic power be thus restored in an 
 inanimate spring, much more should the contractile pow'er re- 
 cover by rest in the muscular fibres of a living system. 
 
 The VIS iNsiT.\ cannot be wearied nor exhausted ; so the 
 heart is unwearied in its function, or if languid or too violent 
 ir its actions, that must be from the pow’er of stimulus being 
 lowered or increased, not from any change on the inherent 
 power. The voluntary muscles also are unwearied; and so, 
 after great fatigue, v/e are sensible of cramps and irregular con- 
 
OF THE MUSCULAR POWER. 
 
 275 
 
 tractions, showing that they are still active, but more loosely 
 governed by the nerves, and not so fully under the command 
 of the will. But the nervous system is more subject to 
 weariness and to decay ; the senses become tired ; the feelings 
 of the system are exhausted. It is from this failing of the 
 nervous power, that violent exertions bring fatigue and pain ; 
 from this also that we need the refreshment of sleep ; but 
 during sleep, the heart, and all the involuntary muscles, un- 
 wearied in their functions, proceed still in the same regular and 
 orderly course. 
 
 This irritability, or inherent power, not only keeps the mus- 
 cles ready, each for its peculiar stimulus, but preserves a 
 balance over the whole system of the muscles. We know that 
 muscles maintain a constant action, independent of the nerves. 
 The muscles of one side balance the opposite muscles ; and if 
 the muscles of one side be relaxed by palsy, the action of the 
 opposite muscles instantly appears : or if a limb be luxated, 
 and its muscles displaced, they persevere in a violent and 
 spasmodic action, till they be restored each to its place. Have 
 we not reason to believe, that if muscles were absolutely and 
 entirely quiescent, they could not be so instantaneously called 
 into action ; but that by this continual tension or tone, they 
 more readily follow the commands of the will : that by this 
 lesser tension, they are prepared for greater action, and inclined 
 to harmonize ? for if all the muscles were quiescent, and one 
 suddenly moved by the will, its antagonist would rise into undue 
 action, and the co-operating or assisting muscles would be un- 
 prepared. Whereas, by this continual tension of all the mus- 
 cles, one set is opposed to another, is consenting with it, and is 
 ready to co-operate with it, or to oppose it in the due degree ; 
 the mind has but to incline the power towards one set, and 
 immediate and orderly motions ensue. 
 
 The NERVOUS INFLUENCE, again, is as a mere stimulus to 
 the voluntary muscles, as blood is to the heart, or the foetus, 
 or any foreign body to the womb. It loses its influence over 
 the system faster than the ordinary powers of life do; and 
 tbe irritable state of the muscles continues long after the 
 voluntary motion, or the power of excitement from the nerves 
 is gone : for when we die slowly, this inherent power is exr 
 hausted in the struggles for life. If, while in perfect health, 
 we are killed by a sudden blow, the irritable power of the 
 muscles survives the nervous system many hours or days, and 
 the flesh trembles, and . the absorbents continue to absorb ; 
 and often, as after suffocation, we can, by operating upon 
 this poor remains of life, restore the circulation, re-aiiimate 
 the nervous system, and recover that life, which seemed to 
 VOL. I. M m 
 
,274 
 
 OF THE MUSCULAR POWER. 
 
 have entirely left the body ; and thus, the nervous influence,; 
 which seemed to animate the system, and to be the prime 
 mover aixl source of life, owes it restoration to that which 
 was thought to be but a secondary power. It is this remains 
 of contractile power which fixes the dead body in whatever 
 posture it is placed : it is this remains of irritability, which 
 preserves freshness in the animal which seemed dead, but 
 which is really dying still : for the moment this lingering por- 
 tion of life is gone, the body dissolves, and falls down 5 and 
 so we judge of freshness, by the rigidity of the flesh, and 
 foresee approaching putrefaction, by its becoming soft. There 
 is no putrefaction in creatures suddenly killed, as in the acci- 
 dents which happen to man, or in killing animals by a sudden 
 blow ; in these the body continues fresh and susceptible of 
 stimuli long after death : but if this inherent power, this irri- 
 table nature of the fibre, be exhausted before death, or in the 
 moment of death, then does the body fall quickly into the 
 condition of dead matter, running through those changes, 
 which are the only true marks of death. The fish, which is 
 allod'ed to struggle till it be dead ; the ox, over-driven before 
 it be brought to the slaughter ; the animal killed by lightning, 
 which suddenly explodes (if we may be allowed the expres- 
 sion) all the powers of life ; in these the contractile power is 
 eflectually exhausted ; no mark of irritability remains ; putre- 
 faction comes quickly on : and so in those who die of the 
 plague, of poison, of fevers, or of any. sudden and violent 
 disease, w'hich at once extinguishes life in the vulgar sense, 
 and robs the system of that remnant of life, which the physi- 
 ologist could produce to view ; in all these cases, the body 
 becomes putrid in a few hours. If a body becomes putrid so 
 early in warm climates, it is not merely because putrefaction 
 is favoured by heat ; but it is because heat exhausts the vital 
 pow'er, and often a part of the body has lost its organized 
 power, and is almost putrid before the whole be dead. We 
 find, that we are wrong in this, that when a body has lost all 
 feeling and motion, we pronounce it dead ; the nerves indeed 
 have ceasfed to do their office ; all feeling and consciousness is 
 gone; but the mere animal power survives the nerves, and 
 through it the whole system may be recalled into perfect life. 
 
 The powers and privileges of the nervous system must not 
 be ranked too high, nor valued too low ; the perfect animal 
 feels and moves by the nervous power ; but surely its muscles 
 are actuated by a law of their own nature : the heart of the 
 chick begins to move, before we dare presume, that there is 
 any organ for distributing this nervous power. The punctum 
 saliens, is the heart of the chick : it is seen beating w'hile the 
 
OF THE MUSCULAR POWER. 
 
 27o 
 
 body of the chick is but a rude, unformed, and gelatinous 
 mass ; daily this active centre encreases in strength and 
 power; and it has a delicate feeling of stimuli, and it quickly 
 re-acts, so as “ to fly out into angry and perturbed motions,” 
 by the application of a stimulus. It is excited by increased 
 heat, and languishes when cold, till at last it dies ; then it 
 ceases to act, but still heat restores it to life : and is not the 
 proof stronger in the grown animal, when we cut out the 
 heart, which answers to stimuli for some time ; at last, seems 
 to have its power exhausted ; it lies dead for some time, till 
 it again recovers its power ? If this power proceeded from the 
 nerves, how could it be renewed ? but if it reside in the 
 muscle only, it may have been wearied, and may revive ; its 
 organization may have been deranged, and may be restored 
 by rest from stimuli ; and its parts may be composed again, 
 resuming their relative situation, and their active arrangement 
 and form ; or though it may be insensible to a stimulus long 
 applied, it may be still alive, even to a lower stimulus of 
 another kind ; or it may awake again to the feeling of that 
 stimulus, which, by being too long applied, had lost its 
 power.* 
 
 Sensibility depends upon the nerves ; motion on the mus- 
 cles: both are equally admirable and inscrutable; the one 
 conducing to all the enjoyments and all the sufferings of life, 
 and to the intellectual faculties of man ; the other being the 
 chief support of animal life, and the source of all the bodily 
 powers. 
 
 As for the mechanical powers, by which the contractions 
 of the muscular fibre is forwarded or retarded, they are not what 
 they have been believed ; for we find few circumstances in the 
 origin, insertion, or forms of muscles, to favour their power, 
 but many by which their power is abridged. There are cer- 
 tain points, where the length of lever gives an encrease of 
 power. The mastoid process and the occiput are as levers for 
 the head ; the spines of the vertebrse for the back ; the olecra- 
 non for the arm; and the pisiform bone for the hand. The 
 pelvis, and the jutting trochanters are as the leVers for the 
 thigh ; the patella is a lever for the leg ; the heel-bone is a 
 lever for the whole foot ; and the arch of the foot is as a lever 
 
 *_There Is a consideration which is not attended to ; sf^sibilily and contractility are tw(> 
 distinct endowments of the living body, the one the property of the nervous matter, tire 
 other of the luuacnlar fibre. Wlicn a sharp point is thrust into a muscle, it is not tlic 
 muscular fibre wliich feels this injury, but the nervous matter in intimate distribution with 
 the proper fibre ; and we have here, no more than on other occasions, a proof of muscular 
 ■. ontraction being the direct result of a stimulus to the muscular fibre. Sensibility must re 
 side in a part, before that irart be capable of receiving excitement, the contraction of the 
 muscle Is ttieieforethe conjoint operation of the nerves and muscular fibres. U. B. 
 
276 
 
 OF THE MUSCULAR POWER. 
 
 for the toes. These are not the whole, but they are, perhaps, 
 the chief levers in the human body. In all the other implanta- 
 tions the muscle is fixed, not behind the joint, but betwixt the 
 joint and the weight that is to be moved. There is a greater 
 loss of power, when inserted near to the joint : there is less loss 
 of power, when the tendon is inserted far from the joint, and 
 though we call such insertion a longer or shorter lever, there 
 is always some loss of power, and the true levers in the body 
 are very few ; far from providing mechanical forms to encrease 
 the power, nature has provided such a quantity of contractile 
 power as to compensate for any loss of effect : so, in place of 
 cncreasing the effect of muscles by levers, pulleys and hinges, 
 there is in almost every muscle a great abatement of its force, 
 by the form of the bones which it is destined to move ; for 
 muscles lose of their effect, by their being implanted, not be- 
 hind the joint, but betwixt the joint and the body to be moved ; 
 by the insertion of almost all muscles being very oblique, with 
 respect to the motions which they are to perform, so that half 
 their force is lost upon the immoveable end of the bone. Mucli 
 force is lost by a muscle passing over many joints ; one set of 
 fibres in a muscle hinders the action of adjoining fibres, and 
 every degree of contraction takes from that muscle an equal 
 proportion of its power. Thus, every where in the human 
 body, is power sacrificed to the form and fitness of the part ; 
 that the joints may be smaller than the limbs; that the limbs 
 may be proportioned to the body : and beauty and convenien- 
 cy is gained by the sacrifice of that power, which is not needed 
 in the system, since the wisdom and goodness of the Creator 
 has appointed a degree of force in the muscles, more than 
 proportioned to all this loss of the mechanical power. Those 
 who will admire the ways of Providence, should know how to 
 admire ! Nature is notseeking to compensate for want of power, 
 by the advantages of pulleys, and levers, and mechanical 
 helps ; nor is it in the forms of the parts that the Infinite Wis- 
 dom is to be found : for among other gifts, such a portion of 
 this spirit is given to man, that he has used the pulleys, and 
 levers, accelerations of motion, and all the mechanical powers 
 that result from it ; he has invented valves of Infinite variety, 
 each perfect and true, to its particular office ; he has anticipa- 
 ted all that he has found, in the mechanism of the human 
 body ; but the living power which compensates for the want 
 of levers, which allows every where power to be sacrificed to 
 the beauty of form, which has strength in convulsive and 
 violent actions, to break the very bones; this is the act of In- 
 finite Wisdom, on which our admiration should chiefly dwell. 
 
277 
 
 OF THE TENDONS, LIOAMENTS, &C. 
 
 It is but the very elements of so deep a subject that can be 
 delivered here. I must proceed to explain those provisions 
 for easy motion, which may be considered as belonging to the 
 muscles and bones, and as preparing us for a knowledge of 
 the joints. 
 
 CHAP. X. 
 
 OF THE TENDONS, LIGAMENTS, BURSjE, AND ALL THE PARTS 
 WHICH BELONG TO THE BONES OR MUSCLES, OR WHICH 
 ENTER INTO THE CONSTITUTION OF A JOINT. 
 
 The bones and muscles themselves are but the smallest 
 part of that beautiful mechanism by which the motions of the 
 human body are performed ; for the parts by which the bones 
 are joined to each other, or the muscles fixed into the bones, 
 are so changed, and varied in their forms, according to the 
 uses of each part, as to give a natural and easy shape to the 
 limbs, security and firmness to their motions, and lubricity and 
 smoothness to the joints by w'hich these motions are perform- 
 ed ; and this apparatus deserves our attention, not merely that 
 we may know the forms of these joinings, but that we may 
 learn something of the nature and uses of each part, and the 
 various degrees of sensibility with which each is endowed ; 
 for, from this kind of study conclusions will arise, which may 
 lead us to the knowledge of their diseases, suggesting the 
 means of their prevention and cure. 
 
 There is a difference in the parts of the human body, ac- 
 cording to the several uses for which they are designed ; some 
 are vascular and soft, others bony and hard ; some sensible, 
 and very prone to inflammation and disease, others callous 
 and insensible, having little action in their natural state, and 
 little proneness to disease. — The greater part of the human 
 body is merely inanimate matter, united into a moving and 
 perfect whole by the system of the nerves which abound in 
 each creature, according to its wants, and are distributed in 
 each system according to the uses and functions of every part. 
 In some places there is such a conflux of nerves, as form the 
 most delicate and perfect sense, endowing that part with the 
 fullest life ; while others are left without nerves, almost inani- 
 
278 
 
 OP THE TENDONS, 
 
 mate and dead, lest feeling, where it ought not to be, should 
 derange the whole system. 
 
 The living parts of the system are the muscles and nerves j 
 the muscles to move the body, and perform its offices, each 
 muscle answering to its particular stimuli, and most of them 
 obeying the commands of the will; the nerves to feel, to suf- 
 fer, and to enjoy, to issue the commands of the will, and to 
 move the muscles to action : but still the muscles have their 
 own peculiar kind of life, superior to the nerves, and indepen- 
 dent of them, always acting, always capable of greater action, 
 always ready to receive the impulse of the nerves. It is a 
 power which survives that of the nerves, acting even when 
 severed from the general system ; and acting often on the 
 living body, without the impulse of the nervps, and sometimes 
 in opposition to the will. The dead matter of the system* 
 joins these living parts, and performs for them every subservi- 
 ent office, forms coverings for the brain, coats for the nerves, 
 sheaths for the muscles and tendons, ligaments and bursse, and 
 all the ap]oaratus for the joints ; unites them into one whole by 
 a continued tissue of cellular substance, which, from part to 
 part through all its various forms, has no interruption, and suf- 
 fers no change, but still preserves its own inanimate nature, 
 while it joins the living parts to each other. The tendons, liga- 
 ments, periosteum, and bursae, are all composed of this cel- 
 lular substance, which, by its elasticity, binds and connects the 
 parts, and, by its dead and insensible nature, is less exposed to 
 disease, and is a fitter medium of connection for the living 
 system. 
 
 OF THE FORMS OF THE CELLULAR SUBSTANCE. 
 
 Under various modifications and shapes, the cellular sub- 
 stance performs most important offices among the living parts : 
 1. It forms CELLS over all the body, which allow the parts 
 to glide and move easily, which contain the fluid that makes 
 all the motion of parts more easy and free, which store up fat 
 to fill the interstices, to support the parts in their action, to 
 give a plumpness to all the body, and to be re-absorbed for 
 the needs and uses of the system. This cellular substance is 
 peculiarly useful to the muscles, dives in among them, keeps 
 their fibres at sucb due distance, that each may have its action, 
 supports and lubricates them ; so that perhaps the difference 
 
 * This expression of the dead matter of the system must only be considered as a relative 
 term, for these parts are not dead nor insensible, although their sensibility be ordered witl) 
 aucli a relation to their office, as not to obstruct the play and motion of the limbs. C. B 
 
279 
 
 LIGAMENTS, BURS^, &C. 
 
 of strength, in health and disease, depends, at least, in some 
 degree, upon this support. The thinner halitus makes the 
 play of the fibres easy and free ; and the fat not only supports 
 the fibres in their action, but lubricates them so, that a want 
 of it is painful, while a superabundance of it encumbers the 
 body. And Haller seems to have believed, that a diseased in- 
 crease of it might not only oppress, but almost annihilate the 
 muscular fibre. 
 
 2. But it is still further essential to a muscle, that while it 
 moves, it should neither be hurt itself, nor harm the surround- 
 ing parts. Therefore, where one muscle moves over another 
 muscle, soft flesh upon soft flesh like itself, there can be no 
 hurtful friction, and the cellular substance is loese and natural, 
 preserving its common form. But where tendons rub upon 
 tendons, or bones upon bones, or where tendons rub upon 
 muscles, or upon each other, some defence is needed, and the 
 cellular substance assumes a new form. The cells are run to- 
 gether into one large cell, with thicker coats, and a more copi- 
 ous exudation, so that, being more liberally bedewed with a 
 gelatinous mucus, it prevents the bad effects of friction, and is 
 called a bursa mucosa, or mucous bag. These mucous bags 
 are placed under rubbing tendons, and chiefly about the great- 
 er joints; some are large, and othei-s small ; their glairy liquor 
 is the same with that which bedews the cellular substance, or 
 the cavities of the joints ; and the provision of nature is so 
 perfect, that the occasions which require bursa; seem to form 
 them by friction, out of the common cellular substance. 
 
 3. It is often useful that an individual muscle should be en- 
 closed in a tendinous sheath, to give it strength and firmness, 
 and to preserve it in its shape, or to direct its force. All mus- 
 cles, or almost all muscles, form for themselves individual 
 sheaths, such as are seen enclosing the supra-spinatus and infra- 
 spinatus of the scapula, the biceps humeri, and most of the 
 muscles of the leg and thigh ; but it is especially necessary 
 that the whole muscles of the limb should be enclosed in some 
 stronger membrane than the common skin, both to give form 
 to the limb, and strength to its muscles, and to keep the indi- 
 vidual muscles in their proper places, which otherwise might 
 be luxated and displaced. And so the trunk of the body, the 
 arm, the thigh, the leg, are bound each with a strong, smooth, 
 and glistening sheath, formed out of the cellular substance, 
 condensed and thickened by continual pressure. And this 
 also is thicker and stronger, according to the need that there 
 may be for such a help ; for it is weaker over the flat muscles 
 of the back, or of the abdomen, stronger en the arm, stronger 
 still over the strong muscles of the thigh. It is hardly to be 
 
280 
 
 OF THE TENDONS, 
 
 distinguished in the child ; grows thicker and stronger as we 
 advance in years and in strength, and in the arms of workmen 
 it grows particularly thick and strong, encreasing in the back, 
 shoulder or limbs, according to the particular kind of labour. 
 These are the membranes, which, by enclosing the muscles 
 like sheaths, are called the vagina, or fascia of the arm, the 
 leg, the thigh, &c. 
 
 4. Tendons or ropes were needed, for the muscles could 
 not be implanted thick and fleshy into each bone, without a 
 deformity of the limbs, and especially of the joints, which 
 would have been not unshapely only, but which must have 
 abridged them of their motions and uses. Where a muscle is 
 not implanted directly into a bone, tendons are seldom required ; 
 and so there are no tendons in the heart, the tongue, the oeso- 
 phagus, the stomach, intestines, or bladder. But where ten- 
 dons pass over bones, or traverse the joints, their force is con- 
 centrated into narrower bounds ; and long tendons are fixed 
 to the ends of the muscles, to pull the bones. These tendons 
 were once believed to be but the collected fibres of muscles, 
 gathered into a more condensed form ; by which condensa- 
 tion, their properties of feeling and motion were lost, while 
 they became hard, white, and glistening ; and it was believed, 
 that parts which were fleshy in the child, became tendinous in 
 the adult. But we know by the microscope, that the tendon 
 is not truly continued from the flesh ; that the fibres of the 
 tendon, and of the flesh, are not in the same line, the fibres of 
 all penniform muscles running into their tendon, in a direction 
 more or less oblique ; and good anatomists have been able to 
 separate the tendon from the flesh, without any violence, and 
 Avith the bluntest knives. — Muscles are irritable, and have 
 nerves ; tendons are quit dead, have no visible nerves, have 
 neither feeling nor motion, nor any endowment by which we 
 should believe them to be allied to the living parts of the sys- 
 tem ; and many tendons, as the expansion of the palmaris, 
 may be unravelled into mere cellular substance.* 
 
 5. The PERIOSTEUM is merely a condensation of the com- 
 mon cellular substance, formed in successive layers : and the 
 tendons are of the substance of the periosteum ; they mix with 
 the periosteum, and are implanted into it. In dissecting a 
 child, we tear up the periosteum along with tendons and with- 
 out hurting the bones ; but in process of time, the periosteum., 
 and consequently the tendons, are inseparably fixed to the 
 bones. The periosteum, tendons, fasciae, and burs® mucosae, 
 
 * Tlie tendons are the continuation of the interaticial cellular membrane of tlie muscle; 
 and 1 have succeeded in unravelling them into a web. C. B. 
 
281 
 
 LIGAMENTS, BURS^, &C. 
 
 are all of one substance, and of one common nature ; they are 
 various modifications of that dead matter, which having but 
 little vascularity, and no feeling, and hardly any disposition to 
 disease, is the fittest for its office, and bears the roughest usage 
 in our experiments, and the most violent shocks in the mo- 
 tions of the body, without any signs of feeling, and without 
 falling into disease. 
 
 6. These tendons must be bound firmly down, for if they 
 were to rise from the bones, during the actions of the muscles 
 to which they belong, the effect of contraction would be lost, 
 and they would disorder the joint, starting out in a straight line 
 from bone to bone, like a bow-string over the arch of a how. 
 The same inanimate substance still perfortns this office also ; 
 for the tendons of one muscle often split to form a sheath or 
 ring for the next, or their tendons, after taking hold of the 
 bone, spread their expansion out over all the bone, so as to 
 form an entire sheath for the finger and toe ; or there is a wide 
 groove in the bone which receives the tendons, and it is lined 
 with a cartilage, and with a lubricated membrane ; the mem- 
 brane comes off from, the lips of the groove, or from corners 
 or edges of the bone, passes over the tendons, so as to form a 
 bridge, or often it forms a longer sheath, as in the fingers, or 
 where the peronaei muscles pass behind tbe ancle, and thus the 
 VAGINA or SHK '.THS of the TENDONS are connected with the ten- 
 dons, periosteum, and other modifications of the common cel- 
 lular membrane. 
 
 7. The periosteum which has run along one.bone, leaves it 
 at the head, and, forming a bag for the joint, goes onwards 
 to the next bone. Thus, the periosteum of all the bones is 
 one continued membrane, passing from point to point ; each 
 bone is tied to tbe next by its own periosteum, and this mem- 
 brane, betwixt the end of one bone and the beginning of the 
 next, is so thickened into a strong and hard bag, as to form the 
 capsule of the joint ; and the periosteum is assisted in perform- 
 ing this office, by the tendons, fasciae, bursae, and all that 
 confusion of cellular substance which surrounds the joint. The 
 CAPSULE of the JOINT is then a firm and thick bag, which, like 
 a ligamenf, binds the bones together, keeps their heads and 
 processes in their right places, contains that glairy liquor with 
 which the heads of moving bones are bedewed, and prei'ents 
 the adjacent parts falling inwards, or being catched betwixt 
 the bones in the bendings of the joints. The capsule of every 
 joint proceeds from the periosteum, and is strengthened by 
 the tendons; it is formed like these parts, out of the cellular 
 membrane; and when a bone is broken, or its periosteum 
 destroyed by any accident or disease, when a tendon snap« 
 
 VOL. i. N n 
 
282 
 
 OF THE TENDONS, 
 
 across, Avhen a joint is luxated, and the capsule torn, the in- 
 jury is soon repaired by a thickening of the cellular substance 
 round the breach ; and wherever a bone being luxated, is left 
 unreduced, a new socket, new periosteum, new ligaments, 
 and new bursae, are formed out of the common cellular sub- 
 stan< e : and though the tendons may have been torn away 
 from the head of the bone, they are fixed again, taking a new 
 hold upon the bone. 
 
 8. There are other ligaments of a joint which prevent its 
 luxation, guarding it at its sides, or round ail its circle, accord- 
 ing to its degree of motion ; and those ligaments are of the 
 same nature with the first, or bursal ligaments arise like them, 
 from the periosteum chiefly, or indeed are truly but a thicken- 
 ing of the bursal ligament at certain points. 
 
 The universal connection of these parts is now sufficiently 
 explained, since we have followed the several forms of cellular 
 substance; 1st, Clothing the bones with a thick membrane, 
 which, though insensible, and almost inanimate in its own na- 
 ture, conveys blood vessels, the means of life, to the bones, and 
 is named periosteum : 2dly, The same periosteum, thickened 
 and strengthed by the adhesion of surrounding parts, so as to 
 form the capsules for the joints : 3dly, The tenden also con- 
 tinued from the periosteum, and not growing from the muscle, 
 but merely joined to it: 4thly, We see that smaller tendon, 
 expanded into a thinner tendinous sheet, as in the braivn of the 
 leg where the ham-strings (whose expansion strengthens the 
 the knee-joint) go down over the muscles of the leg : 5thly, 
 We see the perpendicular partitions of this fascia going down 
 among the muscles, and dividing them from each other; and 
 the cellular substance which lies under the fascia, and imme- 
 diately surrounds the muscle, cannot be distinguished from the 
 inner surface of the fascia itself : 6thly, And as for the burss, 
 we see that they are formed wherever the tendon rubs over a 
 bone. The upper surface of the bursa is formed by the ten- 
 don which rubs over the bone : the lower surface of the same 
 bursa is formed by the periosteum of the bone which it de- 
 fends : the sides are formed by the common cellular substance. 
 Its cavity appears to be merely an enlarged cell : and the 
 bursae mucosae and capsular ligaments are plainly of one and 
 the same nature: their liquors are the same, they often open 
 into one another naturally, or if not naturally, at least it is ne 
 disease, since no bad effects ensue. 
 
 I must now explain more fully the constitution and nature of 
 all the less feeling parts : for what I have said might be thought 
 to imply absolute insensibility and total exemption from dis- 
 ease or pain : whereas the sensibility of tendons, ligament?, 
 
283 
 
 LIGAMENTS, BURS^, &C. 
 
 faursse, and joints,- stands on the same footing with the feeling 
 of bones : they are insensible in health; not easily injured; 
 entering slowly into disease ; but their diseases are equally 
 dreadful from their duration and from their pain : for by in- 
 flammation, their organization is deranged, their healthy con- 
 sistence destroyed, and their sensibility excited in a dreadful 
 degree. 
 
 The tendons of animals have been cut or pierced with 
 erabowelling needles ; they have been pinched with nippers, 
 and torn and cauterized ; they have been burnt with a lighted 
 stick, while the creature neither struggled nor shrunk from the 
 irritation, nor ever gave the smallest sign of pain. Oil of vitriol 
 has been poured upon each of the parts belonging to a joint, 
 and a piece of caustic has been dropped into its cavity, but still 
 no pain ensued ; nay, some have been so bold, may I not say 
 so vicious, as to repeat these experiments upon the human 
 body, pinching, pricking, and burning the tendons of the leg, 
 and piercing them with knives, in a poor man, whose condi- 
 tion did not exempt him fiom this hard treatment; who was 
 ignorant of this injustice that was done to him, whtle his cure 
 was protracted, and he was made a spectacle for a whole city. 
 Without such cruel and inhuman practices we do not want 
 oppqrtunities of knowing, that, in the human body also, the 
 tendons and bursas have no acute feeling. When we cut open a 
 fascia or tendinous membrane, there is little pain : when (as in 
 amputation) we cut the ragged tendons even and neat, there is 
 no pain : when we snip with our scissars the ragged tendons of 
 a bruised finger to cut it off, the patient does not feel : when 
 we see tendons of suppurating fingers lying flat in their sheaths, 
 we draw them out. with our forceps, or touch them with probes 
 ^ without exciting pain. In the old practice of sevving tendons, 
 there was some danger, but no immediate pain : when we 
 cut down into the cavity of a joint, still the pain is but slight. 
 In a luxation, there is comparatively little pain.* There is no 
 pain when the ligament of the patella is broken away from 
 the tibia, nor when the great Achillis tendon is torn. There 
 is but little pain in the moments of those accidents which ap- 
 pear slight in the time, but which turn out to be the most 
 dreadful sprains. Yet, after rupture of the patella, the knee 
 inflames and swells : after rupture of the Achillis tendon, 
 
 * I cannot let tliis pass without again entering a protest. The pain of a dislocation is ex- 
 cessive. It is the greatest which tlie ingenuity of man has invented as a torture, and so it 
 is incorr^t to say, as above, that tendons have been pinched and torn without giving pain. 
 
 , In the joints the_ parts are endowed with a sensibility well adapted to be a check on undue 
 exertion, adinonisliing us of that degree of violence which would be injurious to tlir 
 structure. Yet tuey are certainly not sensible like the other parts of tlie frame, and verv 
 happily so, as then we could neither sit, stand, nor walk. 
 
OF THE TENDONS, 
 
 28’4i 
 
 there is swelling and inflamation, with such adhesion of the 
 parts as makes the patient lame ; after the slightest sprain, i 
 such inflammation sometimes comes on as destroys the joint. 
 There is but little pain when we first make an opening into any 
 joint ; yet it often brings on such pain and fever, that the 
 patient dies. In short, every thing conspires to prove; that ! 
 though in wounds of the less feeling parts, there is indeed 
 future danger, there is no immediate pain. Still there are 
 many accidents which prove to us, that even in health, the [ 
 joints are not entirely exempted from pain : a smart stroke on 
 the knuckles, or a blow on the elbow, or a fall upon the knee, 
 are not perhaps the purest instances of feeling in joints ; for 
 such blow may have hurt some external nerve ; but when a 
 small moveable cartilage forms within the joint of tlie knee, 
 though it be small and very smooth, and lodged fairly within 
 the cavity of the joint, it often gets betwixt the bones, causing 
 instant lameness ; the moment it causes this lameness, it 
 brings dreadful pains : the pain, the lameness, and all the 
 feeling of inconveniency subside the instant that this cartilage 
 is moved away from betwixt the bones ; and the joint con- 
 tinues easy till this moving cartilage chances again to fall in 
 betwixt the heads of the bones. Even the pain from a blow 
 upon the knee, for example, is plainly within the joint, and is 
 caused by the force with which the patella is struck Sown 
 against the ends of the bones. What indeed is a sprain, but a 
 general violence and twisting of all the parts which compose 
 the joint ? These parts are of one common nature, and may 
 be arranged and enumerated thus : a joint is composed of the 
 heads of the bones swelling out into a broader articulating 
 surface, and of a thin plate of cartilage, which covers and 
 defends the head of each bone : sometimes of small and 
 moveable cartilages which roll upon the bones, and follow all 
 the motions of the joint, and, like friction wheels in machines .w|j 
 of human invention, abate the bad effects of motion. There 
 are mucous glands, or rather mucous bags, which convey a 
 lubricating fluid : and there is a bursal ligament which forms 
 the purse of the joint, binds the bones together, contains the 
 synovia, and prevents the surrounding parts from being catched [ 
 in the joint: there are lesser ligaments on the outside of this, ' 
 going along the sides of the joint, and passing from point to 
 point : there are great tendons moving over the joint, and 
 bursae, or raucous bags, which accompany these tendons, and i 
 prevent the violence which their continual rubbing might do 
 to the bones. All these parts are of one constitution and na- 
 ture ; we cannot say that they are insensible, for their feeling 
 is only deferred; it is slow, but not the less severe. The eye 
 
LIGAMENTS, BURS^, &.C. 285 
 
 feels the instant that a mote falls upon it ; but the skin does 
 not feel a blister till it has been some hours applied ; the liga- 
 ments and joints feel still less in the instant that any injury is 
 done : but as the inflammation of the blister excites the feel- 
 ing, and destroys the fabric of the skin, producing pain and 
 derangement of its parts, the inflammation of joints, and of all 
 the parts belonging to them, breaks up the organization of the 
 part, evolves the feeling, *and then in them also comes disease 
 and violent pain. They are slow in entering into action, hut 
 once excited, they continue to act with a perseverance quite 
 unknown in any other part of the system. Their mode of 
 action, whatever it may be at the time, is not easily changed : 
 if at rest, they are not easily moved to action, and their ex- 
 cessive action once begun is not easily allayed. The diseases 
 are infinite to which these parts are subject. They are sub- 
 ject to dropsical elfusions ; they are subject to gelatinous con- 
 cretions ; they are subject to slight inflammation, to suppura- 
 tion. to erosions of their cartilages, and to exfoliation, of their 
 bones, corresponding with the dropsies, suppurations, and mor- 
 tifications of the softer and more feeling parts. Rheumatism 
 is an inflammation round the joints, with a slighter effusion, 
 which is soon absorbed : chronic rheumatism is a tedious and 
 slow inflammation, with gelatinous effusions round the tendons, 
 and permanent swelling and lameness of the joints. Gout, in 
 a joint, is a high inflammation, with a secretion of earthy mat- 
 ter into its cavity. The inflammation of tendons is sprain : 
 effusion of gelatinous matter round them is ganglion: suppura- 
 tions in the tendinous sheaths is whitloe : the inflammation 
 tion of bursae is false white swelling, not easily distinguished 
 from the true : the disease of the joint itself is either a dropsy, 
 where the joint, though emptied by the lancet, is filled up again 
 in a few hours, showing, how continual, and how profuse, both 
 the exhalation and absorption of joints naturally is : or it is 
 white swelling, which, next to consumption, is the most dread- 
 ful of all scrophulous diseases, which begins by inflammation 
 in the joint itself, is marked by stiffness, weakness, loss of mo- 
 tion, and pain : which goes on through all the stages of high 
 inflammation, dreadful pain, destruction of cartilages, enlarge- 
 ment of bones, suppurations and spontaneous openings of the 
 joints j which sometimes stops by an effusion of callus and con- 
 cretion of the bones, forming a stilf joint, but which oftener 
 ends in hectic fever, diarrhoea, morning sweats, and extreme 
 weakness^ so that the patient dies, exliausted with fever and 
 pain. 
 
BOOK III. 
 
 OF THE JOINTS. 
 
 
 CHAP. 1. 
 
 JOINTS OF THE HEAD AND TRUNK. 
 
 JOINTS OF THE HEAD AND SPINE. 
 
 At (MOST every tiling relating to the beads and processes 
 of the bones, and every proposition concerning the motions 
 which they have to perform, has been already explained, anti- 
 cipating much of the <^natomy of the joints : and the principles 
 of motion mentioned in describing the bones, shall form the 
 chief propositions on which my descriptions of joints shall be 
 arranged, seeking that method chiefly by which the joints may 
 be easily and rapidly explained ; for it is a subject on which 
 volumes might be bestowed, and not in vain. 
 
 VVe may compare, in the following order, the chief motions 
 of the head and trunk. The head is so placed upon the 
 oblique surfaces of the atlas, that it cannot turn in circles ; but 
 at that joint all the nodding motions are performed. The atlas 
 rests so upon the dentatus, that there all the turning motions 
 are performed. The neck and loins have their vertebral so 
 loosely framed, with such perpendicular processes and easy 
 joints, that there all the bending motions are performed, while 
 the back is fixed, or almost fixed, by its connection with the ribs 
 and by the obliquity and length of its spines ; and though, 
 upon the whole, the spine turns many degrees, yet it is with 
 a limited and elastic motion where the whole turning is great, 
 but the movement of each individual bone is small. 
 
 To secure these motions, we find, 1. The occipital condyles 
 received into hollows of the atlas, where the oblique position 
 of the condyles secures the joint, the occipital condyles look- 
 ing outwards, the articulating surfaces of the atlas looking to- 
 wards each other, the occiput set down betwixt them, so as to 
 he secured towards either side, and the obliquity of the joint 
 
JOINTS OF THE HEAD AND SPINE,. 
 
 287 
 
 being such withal as to prevent the head from turning round. 
 These joints of the occiput with the atlas, are, like the greater 
 joints of the body, secured with regular capsules, or bag-like 
 ligaments for each condyle, each rising from a rough surface 
 on the vertebrae, and being fixed into a roughness at the root 
 of the condyle. 2. VVe find a flat membranous ligament, which 
 extends from the ring of the atlas to the ring of the occipital hole, 
 closing the interstice betwixt the occiput and the atlas : it is 
 confounded at the sides with the capsules of the articulating 
 processes ; is very strong before ; and at the middle short 
 point of the atlas it seems a distinct ligament, which is 
 strong only at this point, and very lax and membranous 
 behind.* 3. We find the atlas tied to the dentatus, by a more 
 complete order of ligaments. These are, 1st, (as betwixt the 
 atlas and dentatus,) regular capsules, or bags, fixing the con- 
 dyles of one vertebrae to the condyles of the other. 2dly. A 
 cross ligamentf which, crossing the ring of the first vertebrfe, 
 makes a bridge, embraces the neck of the tooth-like process, 
 and ties it down in its place. 3dly, A smooth and cartilaginous 
 surface all round the root of the tooth-like process, where this 
 tooth of the dentatus turns in the ring of the atlas, and is bound, 
 by the ligament ; and this rolling of the atlas upon the axis of the 
 dentatus is so fair and proper a joint, that it also is all included 
 in a capsular ligament. 4thly, The point of the tooth-like 
 process having threaded the ring of the atlas, almost touches 
 the occipital hole ; and there another ligament ties it by its 
 point to the occipital hole.J 
 
 All the other vertebrae have another kind of articulation : 
 to which the occiput, atlas, and dentatus are the only excep- 
 tions, for their motions are particular, and quite different from 
 the rest. The atlas and dentatus bend, turn and roll by con- 
 nections resembling the common joints of the body; but the 
 other vertebrae are united, each by its intervertebjial sub- 
 stance, to the bones above and below ; they are also united 
 by their articulating processes to each other : each articulating 
 process is held to another by a distinct capsule ; each inter- 
 
 * Tbi9 is part of what Winslow called lioamentum infusdibiliforme, a FuxfiEL-LiKE 
 HGAMENT, joining the first vertebrae to the occiput. 
 
 f Viz. Ligamentum transversale, or transverscm ; and what are called the 
 APPENDICES of the transverse ligament, are merely its edges, extending upwards and 
 downwards, to be fixed into the dentatus, and into the occipital hole, so as to enclose the 
 tooth-like process of the dentatus in a capsule. 
 
 ; There are two flat ligaments which come from about the neck or root of tlie tooth-lilce 
 process, and which m obliquely upwards, to be fixed into the groove just behind the lip of 
 the occipital hole ; but the ligament from the point of the tooth-like process is not what it has 
 been supposed, a lair round ligament of some strength ; there is nothing more than a few 
 straggling fibres of ligament going from the point to the occiput, though Enstachius has drawn 
 it round and strong. 
 
288 
 
 JOINTS OF THE HEAD AND SPINE. 
 
 vertebral substance is secured, bound down, and strengthened 
 by strong ligaments ; for the intervertebral substance, which of 
 itself adheres very strongly to the periosteum, and to the rough 
 socket-like surface upon the body of each vertebra, is further 
 secured by a sort of cross ligament, which go from the rim or 
 edge of one vertebra to the edge of the next, over the inter- 
 vene oral substance; and so, by adhering to the intervertebral 
 substance, they strengthen it. These ligaments cross each 
 ol icr over the interstice betwixt each vertebra, and are very 
 strung. They are very regular, beautiful, and shining, and are 
 named intervertebral ligaments. 
 
 The spine is further secured by a general ligamentous or 
 tendinous expansion, which goes over the foreparts of all the 
 vertebrae, from top to bottom of the spine. It begins at the 
 forepart of the atlas; it almost passes the body of the denta- 
 tus, or is but very slightly attached to it. It is at first pointed, 
 small, and round ; it begins to expand upon the third verte- 
 bra of the neck, so as to cover almost all its body. It goes 
 down along the bones, chiefly on their foreparts, and is but little 
 observed on their sid^s. • It is weaker in the neck, where there 
 is much motion : stronger in the back, where there is none ; 
 weaker again in the loins, where the vertebrae move ; but still 
 on the bodies of all the vertebrae it is seen white, shining, and 
 tendinous. We can distinguish all along the spine interrup- 
 tions and fasciculi, or firmer bundles going from piece to piece 
 of the spine ; which fasciculi are indeed very seldom continued 
 without interruption, further than the length of two or three 
 vertebras ; yet the whole is so much continued, that it is consi- 
 dered as one uninterrupted sheath, and is called the external 
 
 or ANTERIOR VAGINA, Or LIGAMENT of the SPINE. ^ 
 
 But still the canal of the spine were left open and undefend- 
 ed, rough and dangerous to the spinal marrow, if internal liga- 
 ments were not added to these. The rings of the vertebrae 
 are held at a considerable distance from each other by the 
 thickness of the intervertebral substance, and by the corres- 
 ponding length of the oblique processes; but this space is 
 filled up by a strong flat ligament, which goes from the edge 
 of one ring to the edge of another, and so extending from the 
 articulating processes, backwards to the spinous processes, 
 they fill up all the interstice, complete the canal of the spinal 
 marrow, and bind the bones together with great strength :f 
 these are assisted in their office of holding the vertebrae to- 
 
 * The LIGAM3NTUM COMMUNE ANTERIUS, FASCIA LONGITUDINALIS ANTERIOR, FASCIA LIGA 
 MENTOSA, &c. !' :'wm tills ligameiil in the loins that the crura diaphragraatis arise, witte 
 
 tendons flat and glisLCUing like the.iligament itself, and hardly to be distinguished from it. 
 
 t They are named the iigamenta subflava crubum PBOCESsuuti sfinosorum. 
 
JOINTS OF THE HEAD AND SPINE. 
 
 289 
 
 ^ether, by a* continuation of the same ligament, or of a liga- 
 mentous membrane connected with it, which runs all the way 
 onwards to the ends of the spinous processes, where they are 
 strengthened by accidental fasciculi ;* and in the middle verte- 
 bra of the back, but not of those of the loins or neck, similar 
 ligaments are found also betwixt the transverse processes.^ 
 Next, there is another internal ligament, which is not inter- 
 rupted from bone to bone, but runs along all the length of the 
 spine, within the medullary canal, and it corresponds so with 
 the external vagina, or anterior ligament of the spine, that it is 
 called the posteriok or internal ligament.J It begins at the 
 occiput, lies flat upon the back part of the bodies of the verte- 
 brae ; at the interstice of every vertebrae it spreads out broad 
 upon the intervertebral substance, doing tbe same office within 
 that the intervertebral ligaments do wflthout. It is broader 
 above ; it grows gradually narroiver towards the loins. Al- 
 though it is called a vagina, or sheath, it does by no means sur- 
 round nor enclose the spinal marrow, but is entirely confined 
 to tbe covering of the bodies of the vertebra, never going be- 
 yond the setting off of the articulating surfaces, or the place 
 where the nerves go out. It adheres firmly to the bones, and 
 does not belong at all to the spinal marrow. It should rather 
 be called a ligament for the bones, than a sheath for the me- 
 dulla. The anterior ligament prevents straining of the spine 
 backwards: this one prevents the bending of the spine too 
 much forwards, and they enclose betwixt them the bodies of 
 the vertebrie, and their intervertebral substances. 
 
 There is yet a third internal ligament, which belongs entirely 
 to the neck; it is called apparatus ligaivientosus colli ; it 
 begins from the edge of the occipital bone, descends in the ca- 
 nal of the vertebrae, is thin and flat, and adheres firmly to the 
 body of each vertebra, covering the tooth-like process. The 
 irregular fasciculi, or bundles of this ligament, stretch from 
 bone to bone ; and the whole of the apparatus ligamentosus 
 extends from the edge of the occipital hole to the fourth ver- 
 tebra of the neck, where it ends. Its chief use is also as a liga- 
 ment, merely fixing the head to the neck. The dura mater is 
 within these, immediately enclosing the spinal marrow. The 
 ligaments which I have just named, may be well enough allow- 
 ed to be “ at once ligaments for tbe bones, and a sheath for 
 
 * Theseare named the mkmbhan« intebspinales, and ligamenta apices spinariim comi- 
 TANTE9. The iigaments which tie the points of tbe spines, running from point to point, make 
 a long ligament, which stretches doivn all the spine. 
 
 t Called LIGAMENTA PHOCESsuuM TnANSVERSORL'M, and found only from the 6fth to the 
 tenth vertebra of the back. 
 
 t Fascia liqamentosa postica, i.^fsciA longiti'dinalis postica, lioamentum commune 
 
 S03TERIU3. 
 
 VOL. I. O o 
 
290 JOINTS OF THE HEAD AND SPINE. 
 
 the medulla.” But there is no such sheath as that called liga^ 
 mentum itifundibilifonne by Winslow ; for either they are 
 peculiar and distinct ligaments for the bones, such as 1 have 
 described, or they belong exclusively to the medulla, as the 
 dura mater, which is indeed strengthened at certain points, 
 into the thickness of a ligament ; but the only close connec- 
 tion of the spinal marrow with the ligaments of the spine, is 
 just at the hole ol the occipital bone; and for a little way 
 down through all the rest of the spine, the connection is by the 
 loosest cellular substance. 
 
 OF THE LOWER JAW. 
 
 The LOWER JAW is, by its natural form, almost a strict ||| 
 
 hinge, and the lateral motion, in grinding is but very slight. 
 
 The joint is formed by a deep hollow or socket in the temporal 
 bone, by a ridge which stands just before the proper socket, 
 at the root of the zygomatic process, and by a long small 
 head, or condyle, which is placed across the long branch, or 
 condyloid process of the jaw. These form the joint ; and the 
 condyle, the hollow of the temporal bone, and the root of the 
 zygomatic process, are all covered with articulating cartilage. 
 
 I'he joint is completed by a capsule of the common form, 
 which arises from the neck of the condyle, and which is so 
 fixed into the temporal bone as to include both the proper 
 •socket and the root of the zygomatic process. Thence it is 
 manifest, that in the motions of the jaw, this transverse ridge 
 is required as a part of its articulating surface ; that the com- 
 mon and lesser motions are performed by the condyle moving 
 in the deepest part of its socket ; that the larger and wider 
 openings of the mouth are performed by such depression of 
 the jaw as makes its condyle mount upon the root of the zygo- 
 matic process. While the luxation of the jaw is a starting 
 forwards of the condyle, till it is lodged quite before and under 
 the zygomatic process, and the condyle standing upon the [ 
 highest ridge, is the dangerous position in which luxation i? 
 most easily produced. 
 
 To render these motions very easy and free, a moveable 
 cartilage is interposed. We find such cartilages in the joints 
 of the clavicle, wrist, knee, and jaw, because the motions are 
 continual and rapid. The moveable cartilage is thin in its 
 centre, and thicker towards its edges, by which it rather 
 deepens than fills up the hollow of the joint. It corresponds 
 in shape with the head or condyle of the jaw, and with the 
 hollow of the temporal bone. It moves with every motion of 
 
JOINTS OF THE HEAD AND SPINE. 291 
 
 tlie jaw, facilitates the common motions, and prevents lux- 
 ation ; but the joint is still more strongly secured by the 
 strength of its pterygoid and temporal muscles, which are 
 inserted close round the joint, than by any strength of its 
 capsule. It is the muscles which prevent luxation ; and it is 
 their action also that makes luxation, when it has happened, 
 so difficult to reduce. 
 
 RIBS. 
 
 The ribs have two joints, and a hinge-like motion, rising 
 and falling alternately, as we draw in or let out the breath. 
 The two joints of the ribs are thus secured : First, the proper 
 head of the ribs being hinged upon the intervertebral sub- 
 stance, and touching two vertebrae, it is tied to the bodies of 
 each by a regular capsule ; the bag is regular, is lubricated 
 within, and is as perfect as any joint in the body ; it is radiated 
 without, so as to expand pretty broad upon the sides of the 
 vertebrae, and has a sort of division, as if into two fasciculi, 
 the one belonging to the vertebra above, the other to the ver- 
 tebra below : they gradually vanish, and mix with the perios- 
 teum upon the bodies of the vertebrae ; these are named 
 LiGAMENTUM CAPiTELLi cosTARUM, as belonging to the little 
 heads of the ribs. 
 
 The back of the rib touches the forepart of the transverse 
 process, and is articulated there : consequently there is a 
 small capsular ligament belonging to this joint also ; but this 
 joint is further secured, by two small ligaments, which come 
 from the transverse process of the vertebra, and take hold on 
 the neck of the rib : one short ligament coming from the 
 point of the transverse process, is behind the rib, and is thence 
 named ligamentoivi transversarium externum; another, 
 rather longer, comes from the inner face of the transverse 
 process, goes a little round the neck of the rib, is implanted 
 into the lower edge of the rib, and is named ligamentum 
 TRANSVERSARIUM INTERNUM : another Small ligament exactly 
 opposite to this, going into the neck of the rib, upon its back 
 part, is also very regular ; and other subsidiary ligaments from 
 different points assist these or supply their place. 
 
 Tbe ribs are fixed into the sternum by their cartilages, each 
 of which has a round head, a distinct socket, a regular capsule, 
 and ligaments which expand upon the surface ofthe sternum, 
 much in the same way that the ligamenta capitelli expand up- 
 on the bodies of the vertebr* : a tendinous membrane also 
 inds the cartilages of the ribs, one to another, crosses over 
 i e interstice, and so covers the intercostal muscles with a sort 
 
292 
 
 JOINTS OF TITe 
 
 of fascia ; and the whole surface of the sternum and that of the 
 cartilages is covered with this tendinous expansion, which be- 
 longs, confusedly, to the origins of the pectoral muscles, to the 
 ligaments of the ribs and sternum, and to the periosteum of 
 that bone. 
 
 CHAP. II. 
 
 JOINTS OF THE SHOULDER, ARM, AND HAND. 
 
 CLAVICLE. 
 
 The joining of the clavicle with the sternum is the hinge 
 upon which the whole arm moves, and is the only point by 
 which the arm is connected with the trunk : the round button- 
 like head of the clavicle rolls upon the aiticuiating surface of 
 the upper bone of the sternum : it is in such continual motion, 
 that some particular provision is required ; and accordingly it 
 has, like the condyle of the jaw, a small moving cartilage, which 
 rolls betwixt this head and the sternum. The cartilage is titin, 
 and of a mucous nature ; it is moveable in some degree, yet it 
 is fixed by one edge to the head of the clavicle. This joint is 
 enclosed in a strong capsule, consisting first of a bag, and then 
 of an outer order of fibres, which go out in a radiated form, 
 upon the surface of the sternum, like the ligaments of the nhs; 
 and they cross and cover the sternum, so that the ligaments of 
 the opposite side meet ; and this meeting forms a cord across 
 the upper part of the sternum, which is named interclavicu- 
 LAR LIGAMENT. Thus is the clavicle fixed to the sternum, and 
 another broad ligament also ties it to the first rib. 
 
 The joining of the clavicle with the scapula is by the edge 
 of the flat clavicle touching the edge of the acromion processes | 
 with a narrow but flat articulating surface : both surfaces, viz.fe 
 of the acromion and of the clavicle, are covered with a thih1‘! 
 articulating cartilage : in some subjects a moveable cartilageds 
 also found here ; it is a regular joint, and is very seldorn^ 
 obliterated ; yet its motion, though continual, is not vbry free j 
 it is rather a shuffling and bending of the scapula upon this 
 bone, favouring the play of the other joints: it is secured first' 
 by a capsular ligament, which is in itself delicate and thin, but" 
 which is strengthened by many ligamentous bands, which pass ^ 
 ^over the capsule) betwixt the clavicle and the acromion pro--'|| 
 
SHOULDER, ARM, AND HAND. 293 
 
 cess ; the clavicle, as it passes over the point of t,he coracoid 
 process, is tied down to it by ligaments of considerable strength ; 
 one comes from the root of the coracoid process to the clavi- 
 cle, and is called ligamentum commune conoidks ; another 
 from the point of the coracoid process, is implanted into the 
 lower or inner edge of the clavicle, and is named ligamentum 
 COMMUNE TUAPEZoiDES ; trapczoid, on account of its square 
 form, and commune, because it goes from the scapula to the 
 clavicle ; while other ligaments, going from one process of the 
 scapula to another, are named proper or peculiar ligaments of 
 the scapula. The ligamentum proprium triangulare stretches 
 from the coracoid process to the acromion process of the scapu- 
 la, The LIGAMENTUM SCAPULA: PROPRIUM POSTERIUS is of leSS 
 importance, being that which completes the notch of the 
 scapula into a bole, and gives attachment to the omo-hyoideus 
 muscle. 
 
 SHOULDER-JOINT. 
 
 The SHOULDER is one of the most beautiful joints, loose and 
 moveable, very free in its motions, but very liable to be displa- 
 ced. To form this joint, the humerus has a large round and 
 flattened head ; the cavity of the scapula,* which receives this 
 head, is oval, or triangular, small and very shallow ; it is eked 
 out with a thick cartilaginous border, which increases the hol- 
 low of the socket, but still it is so shallow, that the humerus 
 cannot be so much said to be lodged in the glenoid cavity as 
 to be laid upon it Its capsule or bag is very loose and wide, 
 coming from the edges of the glenoid cavity, and implanted 
 round the neck of the bone : the joint is richly bedewed with 
 mucus, or rather with a mixed secretion, which is partly secre- 
 ted by a fimbriated organ, consisting of lacunas or bags, the 
 common organ for this secretion through all the joints, and by 
 a thinner exudation from those extreme arteries, w’hich termi- 
 nate, with open mouths, upon the internal surface of the bag. 
 
 By the shallowness of its socket, and the largeness of its 
 head, by the looseness of its capsule, by all the forms and cir- 
 cumstances of its structure, the shoulder is exceedingly loose, 
 and very liable to be displaced ; it has this loose structure, and 
 superficial socket, that its motions may be free, but seldom is 
 there any great advantage gained in the human body, without 
 a counterbalance of weakness and danger; and every where 
 in the limbs we obseiwe that a joint is w eak and liable to luxa- 
 
 ^ It is called glenoid cavity, from tha Greek Dame of a joint, and the name is not abso 
 lately appropriated to tlio scapula. 
 
29-4 
 
 JOINTS OP THE 
 
 tion in proportion as its motions are free and large. Yet the 
 shoulder-joint is not vvitfiout some kind of defence ; its socket 
 is oliallow, but it is guarded by the largest projecting processes 
 in all the body, b) the acromion projecting and strengthening 
 it above, and by tl)e coracoid process within; its ligament is 
 lax, easily torn, and useful rather for confining the synovia, 
 and keeping the head of the liumerus opposite to its proper 
 cavity, than in securing the joint by any strength it has : there- 
 fore a ligament extends from the coracoid to the acromion 
 process, (ligamentum pkophium tiuangulare scapulae,) 
 which completes the defences of the joint above, and at its in- 
 ner side. The capsule is perforated by the long tendon of the 
 biceps muscle, and the hole by which it enters is called/o?-amcw 
 ovale, and on each side of this hole the ligament is much 
 strengthened ; and there comes also from the point of the 
 acromion process an additional ligament, which adheres to the 
 capsule : but the circumstance from which the chief strength 
 of the shoulder-joint is derived, is the insertion of the four 
 muscles which come from the scapula close round the head of 
 the bone, so that they adhere to the capsular ligament, pull it 
 up to prevent its being checked in the motions of the joint, 
 strengthen it by their thickness, for they are spread upon it : 
 and the contraction of the muscles hold the humerus in its 
 place ; their total relaxation (as in certain cases of weakness) 
 suffers the humerus to drop away from the scapula, without any 
 fall or accident, forming what we are accustomed to call a luxa- 
 tion of the humerus, from an internal cause ; and the shoulder 
 cannot be luxated by a fall, without such violence as tears up 
 the tendons of these muscles. We must add to this anatomy 
 of the joint, that it is surrounded by numbers of bursas or mu- 
 cous bags one under the tendons of the subscapularis ; one 
 under the short head of the biceps muscle; one betwixt the 
 coracoid process and the shoulder-bone ; and one under the 
 acromion process of the scapula, exceedingly large : and these 
 are so fairly parts of the joint, that very commonly they open 
 into it with communications, either perfectly natural or at least 
 not hurtful, either originally existing or formed by continual 
 friction. It should also be remembered, that the long tendi- 
 nous head of the biceps muscle comes from the margin of the 
 socket, directly over the ball of the os humeri, and through 
 the capsule, by the foramen ovale. 
 
 * Vide Monro’s tables of the bursy mucosse, where all these parts are represented, the 
 knowledge of wiiich is so very useful for the surgeon. I have opened this great bursa under 
 the acromion process, and let out four pounds of the peculiar mucus and gelatinous lumpS: 
 nvith wiiich the diseased bursae arc commonly 611 ed. 
 
SHOULDER, ARM, AND HAND. 
 
 295 
 
 ELBOW. 
 
 The ELBOW-JOINT is formed by three bones ; the humerus, 
 tadius, and ulna : the ulna bends backwards and forwards upon 
 the shoulder-bone ; the radius bends upon the shoulder-bone 
 along with the ulna ; it always must accompany the ulna, but 
 it also has a motion of its own, rolling in circles ; its round 
 button-like head rolling continually with its edge upon a socket 
 in the ulna, and with its flat face upon the tubercle of the hu- 
 merus. The whole composes one joint, and is enclosed in one 
 capsule ; the bones accompany each other in their luxations, 
 as well as in their natural motions : the ulna is never dislocated 
 without the radius being also displaced ; a circumstance w'hich 
 is but too little noticed, and, so far as I remember, hardly con- 
 sidered or known. 
 
 The radius and ulna are united principally by the interos- 
 seous LIGAMENT, which, as it extends in the whole length of 
 the bones, has great strength. Towards the elbow' this liga- 
 ment is deficient for a space, and it is perforated by vessels. 
 The CHORDA TRANsvERSALis cuBiTi is an oblique slip of li- 
 gament which passes from the tubercle of the ulna obliquely 
 downwards and across to the radius. 
 
 LIGAMENTS OF THE ELBOW-JOINT. 
 
 The general capsule arises from the humerus, from both 
 the tubercles, and all round the two hollows which receive the 
 olecranon and coronoid processes of the ulna ; it is implanted 
 again into the tip of the olecranon, and all round that sigmoid 
 cavity which receives the lower end of the humerus, and all 
 round the edge of the coronary process. It is also fixed round 
 the neck of the radius; it comprehends, in one bag, the 
 humerus, radius, and ulna ; and unites them into one joint, 
 performing two motions, viz. flexion and extension by the 
 ulna, and rolling by the radius; the joint is lubricated by 
 mucus* and by fat, which is found chiefly about the olecranon : 
 and that the bones may be further secured, additional liga- 
 ments are spread out upon them, which are all without the 
 common capsule of the joint lying upon it, and strengthening 
 it at the necessary points. 
 
 1. There is the common capsule enclosing the whole. 2. 
 It is the form of every hinge-joint (and this is one of the purest) 
 
 * The oil contained in the adipose membrane never exudes in the living body, and cannot 
 iubricate. 
 
296 
 
 JOINTS OF THE 
 
 to have its capsule strengthened at the sides ; and the sides of 
 this, the elbow-joint, are strengthened by two fasciculi, or 
 ligamentous heads, which, coming from the tubercles of the 
 humerus, spread a little upon the capsule, and adhere to it 
 like part of its substance. One, from the outer condyle, 
 spreads upon the neck of the radius, and sends a strong division 
 to be attached to the rough spine of the ulna, which is near the 
 lesser sigmoid cavity of the ulna. This is of course the ex- 
 ternal LATERAL LIGAMENT. Another ligament, from the in- 
 ner condyle of the humerus, goes upon the inside of the capsule 
 and strengthens it there : it is implanted in the prominence on 
 the inner edge of the coronoid process of the ulna, and is 
 named the internal lateral ligament.* The continual 
 rolling motion of the radius requires a peculiar ligament, and 
 this peculiar ligament of the radius is named ligamentum 
 COGONARKJM, or ANNULARE, because it encircles the neck of 
 the radius; annulare or orbiculare from its hoop or ring- 
 like from : it is a very strong and narrow stripe or band, which 
 arises from that part of the ulna where the radius rolls upon it, 
 and surrounds the radius, making at least two thirds of a cir- 
 cle ; and so having turned over the neck of the radius, is in- 
 serted into the opposite side of the ulna. This is commonly 
 described as a distinct ligament surrounding the neck of the 
 radius, and having the common capsule, implanted into its 
 upper edge ; but, in truth, it is like the others, a thicker band 
 of the common capsule, but with a distinction much more 
 particular here by the contrast of the great thickness of the 
 coronary ligament, and the extreme thinness of the capsule 
 at the fore part : for the capsule of every hinge-joint is strong 
 only at its sides ; other bands from the outer condyle, and 
 from the coronary process of the ulna, strengthen this liga- 
 ment of the radius, and are known by the name of accessory 
 LIGAMENTS of the coronoid ligament, as the lateral ones are 
 known by the name of accessory ligaments to the cap- 
 sule.f 
 
 So that there is, 1. A complete capsule which encloses all 
 the bones; 2. Lateral ligaments which make the main 
 strength of the joint ; 3. A coronary ligament which regulates 
 
 * I see anntlier ligament behind the internal lateral ligament, viz. arising from the ex- 
 ternal condyle, and inserted into the side of the olecranon. There are in truth two internal 
 lateral ligaments, and their operation is not merely to confine the motion of the joint 
 laterally, but to check the flexion and extension of the arm ; the one being made tense by 
 tlie flexion, the other by the extension, of the fore-arm. 
 
 t But the cap.sule ought to be called merabrana capsiilaris ; it is not a ligament, and 
 these which are called acceseoly are proper ligaments. The ligament which is on the fore 
 part of the joint, and which runs towards the Ligamentum Annulare, is properly called 
 Acerssorium Annuli Aniicum; it crosses from the ulna to the external condyle; and 
 another coming round from the olecranon, and being on the back of the joint, Accestonum 
 Annulare Fosticum. 
 
SHOULDER, ARM, AND HAND. 
 
 297 
 
 and strengthens the rolling motions of the radius, and keeps 
 it firm, turning like a spindle in its bush. The whole joint 
 is surrounded with cellular substance : the regularity of its 
 ligaments is confounded by the adhesions of muscles and 
 tendons : though it is, on the whole, weak behind and be- 
 fore, and very strong at its sides, yet tendinous and ligamen- 
 tous fibres cross it in all directions : so that the capsule and its 
 assisting ligaments are irregular and rough without ; but gela- 
 tinous, smooth, and glossy within. 
 
 WRIST. 
 
 The WRIST is one of the most moveable joints in the 
 body, having the strength of a mere hinge-joint ; (because 
 it is almost a strict hinge, by the connection of the long ball 
 of the carpus with the long hollow of the radius,) and hav- 
 ing, at the same time, all the properties of the most move- 
 able joint by the free turning of the radius, without the 
 weakness which is peculiar to the circular and free moving 
 joints. These distinctions divide the wrist-joint into its two 
 parts. 
 
 1. The articulation formed by the scaphoid and lunated 
 bones, which form an oval ball of articulation, and the great 
 scaphoid cavity of the radius which receives this ball : the end 
 of the ulna does not properly enter into the cavity of the 
 wrist, but its end, or little round head, is covered with a 
 moveable cartilage, and that cartilage represents the end of 
 the ulna. It is called cartilago intermedia triangularis. 
 Now, this first joint, viz. of the scaphoid and lunated bones, 
 the head of the radius, and the moveable cartilage which re- 
 presents the head of the ulna, are surrounded by the general 
 capsule or bag of the joint. The capsule arises from the 
 ends of the radius and of the ulna ; from the styloid point of 
 the one, round to the same point of the other ; and is im- 
 planted near the lower rank of the carpal bones ; though it 
 adheres first to the scaphoid and limated bones, it passes them 
 going over all the bones of the carpus, especially in the palm, 
 so as to add strength to their peculiar ligaments ; and in the 
 palm, 'the tendons for the fingers run over it : so it forms on 
 one side an additional ligament for the carpus ; on the other, 
 it forms the floor of the tendinous sheath, a smooth and lu- 
 bricated surface for the tendons to run upon. This general 
 ligament is strengthened by particular ones coming from the 
 styloid processes of the radius and of the ulna, which spread 
 upon the bones of the carpus, and may be described as lateral 
 
 VOL. I. Pp 
 
298 
 
 JOINTS OP THE 
 
 ligaments ; for although the wx’ist joint is not accurately a 
 hinge, yet it partakes most of that character, and the liga- 
 ments are strongest at the radial and ulnar edges of the wrist. 
 But there are so many irregular points of bone about the 
 wrist, that the little fasciculi, with which this capsule is 
 covered and strengthened, are innumerable. Within this 
 joint, and stretching from the groove betwixt the scaphoid and 
 lunated bones, there is an internal ligament of a soft and pulpy 
 nature ; it is named ligamentum mucosum ; but the very name 
 shows, that it is less valuable as a ligament (since the joint is 
 already well enough secured,) than as a conductor for the 
 lacunee or ducts which separate the mucus. 
 
 2. The articulation by which the hand performs all its turn- 
 ing motions is that of the radius with the ulna : this is set apart 
 altogether from the general articulation of the joint. The 
 lateral cavity of the radius receives the little round head of 
 the ulna; they are enclosed in their own peculiar capsule, 
 which is so loose about the bones, that although it is a regular 
 capsule of the common form, it has the name of meiyterana 
 CAP suLARis SACCiFORMis. Tlius there is one joint within 
 another ; a moveable cartilage betwixt them, and the capsule 
 of the one, the more moveable joint, peculiarly wide, and 
 not so strong ; all which should be considered in thinking 
 about luxations of the wrist. 
 
 The carpal bones are connected with each other so very 
 closely, that the name of joint can hardly be used. They are 
 rather fixed than jointed together. Each bone has four 
 smooth articulating surfaces, by which it is united to the ad- 
 joining bones. The first two bones form the great ball of the 
 wrist ; the second row again is united with the first, by a sort 
 of ball and socket ; for the os magnum, which is the central 
 hone of the second row, has a large round head, which is re- 
 ceived into the lunated hollow of the os lunare, which is the 
 central bone of the first row. The first row is thus united to 
 the second, by a distinct and general capsule, in addition to 
 which each single bone is tied to the next adjoining, by a re- 
 gular capsular ligament within, and by flat cross ligaments 
 without, or rather by many bundles of ligaments, which cross 
 each other in a veiy complicated manner, and the little flat 
 and shining fasciculi give the whole a radiated, or star-like 
 form.* 
 
 The metacarpal bones are also joined to the carpal in one 
 
 * These are the ligaments which are really so unimportant to the anatomist, or to the 
 -urgeon, but which are so laboriously described under the titles of ligamenta brevja, 
 oBLiQUA TRANsvERSARiA, and PROPRIA ossiuffl Carpi ; for they do in fact cross and traverre 
 ' he earprrs in every possible direction. 
 
SHOULDER, ARM, AND HAN». 29 ^ 
 
 VOW, by a line of joints, which are as one joint ; besides their 
 common capsule, the metacarpal of each finger has its pecu- 
 liar ligaments proceeding in a radiated or star-like form from 
 the carpal bones, and going out broad upon the metacarpal 
 bones, and so numerous, that each metacarpal bone is se- 
 curely tied by ligaments to one or two of the bones of the 
 carpus ; * and at their heads, where the fingers are implant- 
 ed upon them, forming the knuckles, they are again tied by 
 flat ligaments, which go from head to head of the metacarpal 
 bones,f binding them together, permitting a slight bending 
 towards each other, so as to make a hollow' in the hand, but 
 no such wide motion as might assist the fingers ; they are 
 but as a foundation upon which the fingers stand and move. 
 
 FINGERS. 
 
 The joints of the fingers are formed by round heads in the 
 upper end of one row of bones, and by hollow sockets on 
 the lower ends of the next row ; each joint is qualified by 
 the round form of its heads, to be a circular and free moving 
 joint ; but it is restricted by the forms of its ligaments, to the 
 nature of a hinge-joint ; for each finger-joint is included first 
 in a fair round capsule, or bag, of the ordinary form, but that 
 capsule is strengthened by very distinct lateral ligaments 
 upon its sides, which lateral ligaments form the chief strength 
 of the joints ; above these lateral ligaments the joint is 
 strengthened by a broad fascia, or sheath, which comes from 
 the tendons of the interossei muscles, covers the backs of 
 all the fingers, which is especially strong over the joints. One 
 part of the apparatus of the wrist-joint is the smooth and 
 lubricated sheath, in w'hich the tendons of the fingers run. 
 It is formed in part by the outer side of the capsule of the 
 wrist, and in part by that bridge of ligament which proceeds 
 from the four corner points of the carpal bones. This sheath 
 is lined with a delicate and softer modification of the common 
 tendinous membrane, is fully bedewed with mucus, and is 
 fairly to be ranked with the bursfe mucosBe, as it is indeed, 
 like them a shut sack. But it is farther crossed in such a 
 manner by partitions belonging to each flexor tendon, that 
 each of them may be said to have its appropriated bursa 
 mucosa. And these bursae, to prevent the bad conse- 
 quences of friction, are put both betwixt the cross ligament 
 and the tendons, and also betwixt the tendons of the upper- 
 
 * And these also are named according to their several directions, uoamksta AKTirc 
 
 Lir.IA, LATERALIA, RECTA PERPENDICULARIA, &C. 
 
 t These are named the uoament.v ia'terossea. 
 
300 
 
 JOINTS OF THE 
 
 most muscle, and of the deeper one, and again betwixt the 
 tendons of the fingers and of the thumb. 
 
 In the same way the sheaths of the tendons, as they run 
 along the fingers, may be considered as part of the apparatus 
 of their joints ; for the first set of burs®, viz. those which lie in 
 the palm of the hand, stop before they reach the first joints 
 of the fingers, and then other longitudinal burs® begin from 
 the first joint of the fingers, and go all along them to the last 
 joint, forming a sheath for the tendons to run in, which does 
 at once the office of a strong ligament, binding them dowm in 
 their places, and which is so lubricated on its internal surface, 
 as to save the necessity of other burs®. These sheaths are 
 thicker in certain points, so as to form cross rings of strong 
 ligament; but the common sheath, and these thicker rings, 
 still form one continued canal; these are named the sheaths 
 and ANNULAR LIGAMENTS, Or CROSS LIGAMENTS * of the 
 fingers, and are of the same nature with the burs®. Be- 
 sides these, there are no distinct burs® on the fingers, but 
 there are several about the wrist, and one especially of consi- 
 derable size at the root of the thumb.f 
 
 CHAP. III. 
 
 .lOlNTS OF THE THIGH, LEG, AND ANKLE. 
 OF THE HIP-JOINT. 
 
 1 HE acetabulum, which is rough in the naked bone, is natu- 
 rally lined with a thick and very smooth cartilage. The head 
 of the thigh-bone is covered with a similar cartilage, also very 
 thick and smooth ; and these cartilages almost fill up that deep 
 dimple which is seen in the centre of the bead of the thigh- 
 bone, and smooth that hole which is formed in the centre of 
 the socket, by the meeting of the several pieces of which it is 
 composed. The socket is not only deep in its bones, but is 
 further deepened by the cartilage which tips the edge of the 
 socket, and which stands up to a considerable height. The 
 socket is imperfect at that side which looks towards the thyroid 
 hole ; the bony edge is entirely wanting there, and the space 
 
 * LiGAMHNTA VAGINALl/, LIGAMEKTA CRUCIATA, PHALAKGGM, &€. 
 
 t Vide Monro’s Bureae Mucosae. 
 
THIGH, LEG, ANB ANKLE. 
 
 301 
 
 is filled up by a strong cartilaginous ligament, which goes 
 across this gap, from the one point to the other, and from its 
 going across is named the ligamentum labhi cartilagin^i 
 TRANSVERSALE.'*^ The capsular ligament of the hip-joint is 
 the thickest and strongest of all the body. It is, like other cap- 
 sules, a reflection and thickening of the periosteum ; the peri- 
 osteum coming along the outside of the bone, leaves it at the 
 edge of the socket. The periosteum, or rather perichondrium 
 from the inside of the socket, comes up to the edge, and meets 
 the outer layer. They unite together, so as to form the gene- 
 ral capsule enclosing the ring-like cartilage, which tips the 
 edge of the socket between them. This ligament encloses all 
 the bones from the edges of the socket to the roots of the tro- 
 chanters, embracing not only the head, but the neck of the 
 thigh-bone. The outer plate, continuous with the periosteum, 
 is thick and strong, and is assisted by much cellular substance 
 condensed round it, and it is further thickened by slips which 
 come from the iliacus, gluteus, and other muscles which pass 
 over the joint, while the external plate of the ligament lines 
 the whole with a soft and well lubricated coat. 
 
 In addition to this general capsule, there are two internal 
 ligaments, 1st, The round ligament, as it is called, which comes 
 from the centre of the socket to be fixed into the centre of 
 the ball of the thigh-bone. It is not round, but flat or trian- 
 gular. It has a broad triangular basis, rooted in the socket 
 exactly at that place where the several bones of the socket 
 meet, forming a triangular ridge, which gives this triangular 
 form to the central ligament. It has three angles, and three 
 flat sides. It is broad where it arises from the bottom of the 
 socket, is about an inch and a half in length, grows narrower 
 as it goes outwards towards the head of the bone, and is al- 
 most round where it is implanted into the dimple in the head 
 of the thigh-bone, at which point it is so fixed, as to leave a 
 very remarkable roughness in the naked bone. But round the 
 roots of this ligament, and in the bottom of the socket, there 
 is left a pretty deep hollow, which is said to be filled up with 
 the synovial gland. It is w'onderful how easy authors talk of 
 the synovial gland, as if they had seen it ; they describe very 
 formally its affections and diseases, as when hurt by a blow 
 upon the trochanter ; yet there is no distinct gland to be found. 
 There is a fringed and ragged mass lodged in the bottom of 
 the socket, hanging out into the hollow, and continually rubbed 
 by the ball of the thigh-bone in its motions : the fringes and 
 
 • This ligament is double, that is, there is one on the inside of the edge, and one on the 
 outside; tlience it is often reckoned as two ligaments, viz. ligamentpm thansversale k- 
 
 TesiU'M et IITEHNCM. 
 
302 
 
 JOINTS OP THE 
 
 points certainly are ducts from which we can squeeze ©ut 
 mucus ; but it is by no means proved that they belong to a 
 synovial gland, and it looks rather as if the ducts were them- 
 selves the secreting organ, like the lacunae, or mucous bags 
 in the tongue, or in the urethra, vagina, oesophagus, and 
 other hollow tubes. Such a structure is fitter for suffering the 
 strong pressure and continual action of the thigh-bone, than 
 any determined gland. We see, then, nothing but mucous 
 ducts of a fringed form, hanging down from this hollow into 
 the cavity of the joint, a quantity of fat accompanying these 
 fringes, and a pappy mucous membrane, which keeps these 
 fringes and fatty membranes orderly, and in their places, and 
 which ties them so to the angles of the triangular ligament, 
 that they must move with the motions of the joint. This 
 mucous membrane, which keeps these fatty fringes orderly, 
 has two or three small bridles in different directions, whence 
 they are named the ligamenta mucosa, or ligamentula 
 massee adiposfe glandulosa ; and this may be considered as the 
 continued inflection of the softer internal lamella of the cap- 
 sule, which not only lines the socket, but is reflected over the 
 central ligament, and over the globe of the thigh-bone, cover- 
 ing them also with a delicate mucous coat. Other fringes of 
 the same kind are found at the lower part of the joint, lying 
 round the neck of the thigh-bone, near the angle where the 
 capsular ligament is implanted into the root of the great 
 trochanter : the liquor from these mucous fimbriae, with the 
 general serous exudations, are mixed and blended for lubri- 
 cating the joint. 
 
 This capsule, which is naturally the thickest and strongest 
 in the body, almost a quarter of an inch in thickness, is farther 
 strengthened by many additions ; for a slip of very strong 
 tendinous or cellular substance condensed, comes down from 
 the lower spinous process of the os ilium, and spreads out over 
 the capsule, and strengthens it very much on its forepart ; the 
 smallest of the glutaei muscles adheres to the capsule, and 
 strengthens it behind ; the psoas magnus and iliacus internus 
 pass by the inner side of the capsule, and though they do not 
 absolutely adhere to it, they deposit much cellular substance, 
 which is condensed so as to strengthen the capsule, forming at 
 the same time a large bursa mucosa, betwixt their tendinous 
 fibres and the joint. That tendon of the rectus muscle which 
 comes from the margin of the socket, lies upon the outer side 
 of the capsule, adheres to it, and strengthens it. The secu- 
 rity of the hip-joint seems to depend more upon the strength 
 of its capsular ligament, than that of almost any other joint. 
 
THIGH, LEG, AND ANKLE. 
 
 303 
 
 THE KNEE-JOINT. 
 
 The knee-joint is one of the most superficial joints, and 
 one of the weakest, so far as relates to the bones, for the flat 
 condyles of the thigh-bone are merely laid upon the flat head 
 of the tibia. There is here no fair cavity, receiving a large 
 head as in the joint of the hip ; no slighter ball and socket, as 
 in the fingers ; no strong over-hanging bones, as in the 
 shoulder; no hook-like process, as in the ulna. This is not 
 a hinge-joint, like the ankle, secured between two points of 
 bone. We do not find the means of strength in its bones, 
 but in the number, size, and disposition of the great liga- 
 ments with which its bones are joined ; by virtue of these 
 ligaments it is the strongest joint of the human body, the 
 most oppressed by great loads, the most exercised in continual 
 motions, yet less frequently displaced than any other. But 
 this complication of ligaments, which gives it mechanical 
 strength, is the very cause of its constitutional weakness, 
 makes it very delicate, and very liable to disease. 
 
 The bones which compose this joint are the tibia, thigh- 
 bones, and patella; and they are united by many ligaments, 
 both within and without the joint. 
 
 1. The CAPSULE of the knee is naturally very thin and 
 delicate, transparent as a cobweb. This thin capsule comes 
 from the forepart of the thigh-bone, all round the articula- 
 ting surfaces, whence it goes downwards by the sides of the 
 condyles ; from this origin it is inserted into all the edge of the 
 rotula, and in such a way as to keep the rotula properly without 
 the cavity of the joint, the capsular ligament going over its inner 
 surface, and lining it with a smooth and delicate coat. It is 
 fixed below into all the circle of the head of the tibia, and 
 thus completes its circle, embracing all the bones. This 
 capsule, naturally so thin and delicate, is made up from all 
 the surrounding parts to a considerable thickness ; first, it is 
 covered behind by the heads of the gastrocnemii ; at the 
 sides, by the biceps, and other muscles of the ham-strings ; 
 on its forepart, it is strengthened by the general fascia of the 
 thigh, which goes down over the knee, and being there re-in- 
 forced both by its adhesion to the bones, and by the broad 
 expansion of the vastus internus, sartorius, biceps, and other 
 muscles, which go out over the patella, it adheres to the cap- 
 sule, and makes tlie whole very strong ; besides which, there 
 is a ligament, which, lying in the ham, upon the back part 
 of the capsule, is named, in compliment to Winslow, liga- 
 MENTim posTiGUM WiNSLowH. It is a ligament somewhat 
 
304 
 
 JOINTS OF THE 
 
 resembling the lateral ligaments of the elbow. It arises from 
 the outer condyle, goes obliquely across the back part of the 
 joint, adheres to it, and strengthens it ; but often it is not 
 found at all, or in such straggling fibres as cannot be account- 
 ed a ligament.* It is manifest that the knee requires some 
 such additional ligaments behind, to serve as a check, and to 
 prevent its yielding too far. 
 
 2. The knee, as being a hinge-joint, has strong ligaments 
 at the sides, and here the lateral ligaments are particularly 
 distinct, and can be raised from the capsule ; on the inner 
 side of the joint, there comes down from the internal con- 
 dyle of the thigh-bone, a broad fiat ligament, which is fixed 
 into the inner head of the tibia, and is named the internal lateral 
 ligament ; on the outside of the knee, there descends from 
 the tip of the outer condyle a much stronger ligament, not 
 quite so flat, rather round : it extends from the condyle of the 
 thigh-bone to the bump of the fibula which it embraces. It 
 is a little conical from above downwards; it is from two to 
 three inches in length, and is named ligamentum laterale 
 EXTEKNUM JLONGIOK, to distinguish it from the next; for be- 
 hind this first external ligament, there arises a little lower from 
 the same condyle, along the outer head of the gastrocnemius 
 muscle, a ligament which is called the ligamentum laterale 
 EXTERNUM BREvioR, and it is not shorter only, but so sparse 
 as not to be easily distinguished, not having the true form of 
 a lateral ligament coming down from the condyle, but of a 
 mere strengthening of the capsule, coming upwards from the 
 knob of the fibula.f 
 
 3. The joint is still further secured by internal ligaments 
 which are within the cavity of the joint ; they are named the 
 CRUCIAL LIGAMENTS of the knee. They arise betwixt the 
 hollow of the condyles of the thigh-bone, and are implanted 
 into the back part of the middle rising of the tibia : they lie 
 in the back part of tbe joint, flat upon the back of the cap- 
 sule, and the one crossing a tittle before the other (but yet in 
 contact with each other, at the place of crossing ;) they are 
 distinguished by the names of anterior and posterior cru- 
 cial LIGAMENTS. 
 
 The POSTERIOR CRUCIAL ligament is more perpendicular; 
 it arises from the hollow betwixt the condyles of the thigh- 
 bone, and is implanted into a roughness on the back of the 
 tibia, betwixt its two cup-like hollows, and behind the tubercle 
 which divides these hollows from each other. While the 
 
 * Often it is irregular, or in straggling fibres ; but I have never found it wanting. 
 
 I Some strong, but irregular accessory ligameDts go down to that part of the head of 
 the tibia which is before the head of the fibula. 
 
THIGH, LEG, AND ANKLE. 
 
 305 
 
 posterior arises rather from the internal condyle, the anteri- 
 or LIGAMENT arises properly from the external condyle, passes 
 obliquely over the tuber, in the articulating surface of the 
 tibia, and terminates in the cup-like hollow. The effect of 
 these two ligaments is more particular than is commonly ob- 
 served ; for the one goes obliquely out over the articulating 
 surface of the tibia, while the other goes directly down behind 
 the joint ; and of course when the knee is bended, the poste- 
 rior ligament is extended ; when the leg is stretched out, the 
 anterior ligament is extended ; they both are checks upon the 
 motions of the joint : the anterior ligament prevents the leg 
 going too far forwards, the posterior ligament prevents its be- 
 ing too much bent back upon the thigh.* 
 
 4. The most admirable part of the mechanism of this joint, 
 is the two SEMILUNAR CARTILAGES. They are so named from 
 their semilunar form : they lie upon the top of the tibia, so 
 as to fill up each of them one of the hollows on the top of 
 that bone. They are thicker towards their convex edges, thin- 
 ner towards their concave edges ; they end by two very acute 
 and long horns, named the cornua of the lunated cartilages. 
 In short, they resemble the shape of the label which we put 
 round a wine decanter ; and the two horns are tied to the 
 tubercle, or ridge that stands in the middle of the articular 
 surface of the tibia, and consequently they are turned towards 
 each other, so as to touch in their points. There are here, as 
 in the other joints, masses of fat enclosing the fimbriated ends 
 of the mucuos ducts. These fimbria;, and fatty bundles, are 
 formed chiefly round the circumference of the patella, common- 
 ly surrounding it with a complete fringe ; they are also found at 
 the back of the cavity, about the crucial ligaments, and in all 
 the interstices of the joint ; the fatty bundles filling up the 
 interstices, protecting the mucous ducts from more violence 
 than what is just necessary to empty them, and perhaps mix- 
 ing their exudation with the mucus of the ducts. 
 
 These masses of fat lie covered by the delicate internal 
 surface of the capsule, and the mucous fimbriae project from it. 
 
 The inner surface of the capsule is so much larger than the 
 joint which it lines, that it makes many folds or lurks, and se- 
 veral of these are distinguished by particular names. Thus, 
 at each side of the patella there are two such folds, the one 
 
 * Tliere is not attention enough paid to tlie origins of these ligaments from the femur :, 
 for it is tile origin from tlie thigh-bone whicli determines their operation. The posterior 
 ligament com'es from the root of the internal condyle, and depth of tlie semilunar notch, 
 anterior to tiie centre of motion of the lower head of the femur on the tibia ; it is conse- 
 quently strctclied in extending the leg. Tiie anterior ligament arises from tlie root of the 
 external cop,dyle,,posterior to tiie centre of motion ; it is coasequently sfiretchcd is the 
 flexion of tlie knee-joint. 
 
 VOL. I. 
 
306 
 
 JOINTS OF THE 
 
 larger than the other, whence they are named licamentuha 
 
 ALAKE MAJUS, and LIGAMENTUM ALARE MINDS. TheSe tWO 
 folds are like two legs, which join and form one middle fold, 
 which runs across in the very centre of the joint, viz. from the 
 lower end of the patella to the point of the thigh-bone, in 
 the middle betwixt the condyles. It keeps the looser fatty 
 bundles and fimbriated ducts in their place, (viz. the hollow 
 betwixt the condyles, where they are least exposed to harm ;) 
 thence it has been long named the ligamentum mucosum. 
 The internal membrane of the joint covers also the semilunar 
 ligaments, as a perichondrium ; it comes off from the ridge of 
 the tibia, touches the horns of the semilunar cartilages, moves 
 over the cartilage, so as to give them their coat, and at the 
 point where it first touches the horns, it forms four little liga- 
 ments, two for the horns of each cartilage. These tags by 
 which the four points of the lunated cartilages are tied, are 
 named the ligamenta caktilaginum lunatacum, or more 
 simply named the four adhesions of the lunated cartilages. 
 There is a little slip of ligament, which goes round upon the 
 forepart of the knob of the tibia, and ties the foreparts of 
 these two cartilages to each other. It is named ligamentdm: 
 TRANsvERSALB COMMUNE, because it gocs across from the fore 
 edge of the one cartilage to the fore edge of the other, and 
 because it belongs equally to each ; but for their further se- 
 curity, these cartilages also adhere to their outer circle, or 
 thick edge, to the internal surface of the general capsule of 
 the joint by the ligamentum coronarium, and that again ad- 
 heres to the lateral ligaments which are without it; so that 
 there is every security for these cartilages being firm enough 
 in their places, to bear the motions of the joint, and yet loose 
 enough to follow them easily. 
 
 This joint has the largest burs:e mucosae of all, and these 
 perhaps the most frequently diseased. There is one bursa 
 above the patella, betwixt the common tendon of the ex- 
 tensor muscles and the forepart of the thigh-bone, which is no 
 less than three inches in length. There is a smaller bursa 
 about an inch below the patella, and under the ligament of 
 the patella, protecting it from friction, upon the head of the 
 tibia. These .bursaj, I am persuaded, are often the seat of 
 disease when it is judged to be in the joint itself. But the 
 truth is very easily known ; for if a swelling appear under the 
 patella, projecting at the s;des, and raising the patella from 
 the other bones, we are sure that it must be in the main cavity 
 of the joint : but if swellings appear above and below the pa- 
 tella, then there is reason to believe that these belong to the 
 great bursae, which are placed above and below the patella, a 
 
THIGH, LEG, AND ANKLE» 
 
 307 
 
 oojiiplaint which is far less formidable than a swelling of the 
 joint itself: I would almost say, easily cured ; for openings 
 into these bursas, though they should be avoided, are less 
 dangerous than openings into the joint. It is from mistaking 
 such tumours for collections in the capsule itself, that authors 
 speak of openings into the joint as a familiar or easy thing, or 
 think that they have done such operations safely, when pro- 
 bably they were puncturing the bursae only.* 
 
 These bursae mucosae lie under the tendon of the extensor 
 muscles, and under the ligament of the patella : they are of 
 the same substance with the capsule of the joint itself: they 
 lie over the capsule, united to it by cellular substance, and 
 the bundles of fat which are disposed irregulairly about the 
 joint, belong partly to the bursse and partly to the capsule ; 
 one end projecting into the cavity of the bursae, while the 
 other end of the same fatty bundles projects into the cavity 
 of the joint. 
 
 Thus the knee-joint, which is the most important in all the 
 body ; the most oppressed by the weight of the trunk, and by 
 the accidental loads which we carry ; the most exercised in 
 the common motions of the body, and the most liable to 
 shocks and blows, which is the most superBcial and the 
 weakest in all that respects its bones, is the strongest in its 
 ligaments, and the most perfect in all the provisions for easy 
 motion. 
 
 1. The great capsule of the joint encloses the heads of the 
 bone, secretes (in part) and contaihs the synovia : lines the 
 joint with a smooth and delicate membrane, and, by turning 
 over all the parts, and adhering to them, it forms the peri- 
 chondrium for the cartilaginous heads of the bones, and the 
 covering and ligaments for the moving cartilages of the 
 joint. 
 
 2. This capsule, which is exquisitely thin, and which was 
 formed for other uses than for giving strength to the joint, is 
 surrounded on all sides with such continuations of the common 
 fascia, and such particular expansions of the ham-string and 
 other muscles, as by adding outwardly successive layers to the 
 capsule, brings it to a considerable degree of strength. 
 
 3. The capsule having no stress upon its forepart, is very 
 thin upon its forepart, viz. at the sides of the patella, but is 
 strengthened at the sides by fair and distinct ligaments, going 
 from point to point of the three great bones, and so large and 
 particular as to deserve, more than any others in the body, 
 
 f 1 believe that the great bursae and the joint always communicate largely ; and that 
 being consequently one continnous surface, the opening of the bars* would be highly im- 
 proper. 
 
JOINTS OF THE 
 
 tl08 
 
 the name of lateral ligaments ; at the back part of the 
 joint, the same strength is not required as at the sides ; yet it 
 must be stronger than at its forepart, wherefore it is strength- 
 ened by the additional bands which are sometimes general and 
 confused, but often so perfect and distinct, as to be known by 
 the name of the posterior ligament of Winslow; and as 
 the lateral ligaments prevent all lateral motions, this strength- 
 ening of the capsule serves as a check-band behind. 
 
 4. It is only in the greatest joints that we find the additional 
 security of internal ligaments, and the only joints where 
 they are perfect, are the joints of the hip and of the knee ; 
 the former having its round, or rather triangular ligament, 
 which secures the great ball of the thigh-bone, and fixes it in 
 its place ; the latter having its crucial ligaments, which, 
 coming both from one point nearly, and going the one over 
 the face of the tibia, and the other down the back of that 
 bone, serve the double purpose of binding the bones firmly 
 together, and of checking the larger and dangerous motions 
 of the joint, the fore ligament preventing it going too far for- 
 wards, and the back ligament preventing it bending too much. 
 
 5. A MOVING cartilage for facilitating motion and lessen- 
 ing friction is not common, but is peculiar to those joints 
 whose motions are very frequent, or which move under a 
 greater weight ; such are the inner head of the clavicle, the 
 articulation of the jaw, and the joints of the wrist and of the 
 knee ; and it is in the knee that the moveable cartilages have 
 their most perfect forms and use, are large and flat semilunar, 
 to correspond with the forms on the head of the tibia ; thicker 
 at their outer edges to deepen the socket; and though move- 
 able, yet so tied with ligaments, as never to go out from their 
 right place. 
 
 And, 6. The mucous folicular bundles of fat, and the 
 bursas mucosae, which complete the lubricating apparatus of 
 the joint, and the mucous frenulas or ligaments, which both 
 conduct the mucous fringes and keep them in their place, are 
 more perfect in the knee, and greater in number and size, 
 than in any other joint. 
 
 I may well call this the most complicated, and (by daily 
 and melancholy proofs) it is known to be the most delicate 
 joint of the body. 
 
 fibula. 
 
 The FIBULA is a support to the tibia in its various accidents ; 
 it gives a broader origin to the muscles, and it is the chief 
 defence of the ankle-joint. It has no motion upon the tibia; 
 
THIGH, LEG, AND ANKLE. 309 
 
 the best authors speak of it as a symphysis, which classes it 
 with the joinings of the pelvis, and excludes it from the list 
 of true and moveable joints. It is united with the tibia by a 
 sort of flat cartilaginous surface upon either bone ; it is merely 
 laid upon the tibia, not sunk into it. It is tied by a close cap- 
 sule : it has no particular ligament for itself ; but is strengtli- 
 ened by the external lateral ligament of the knee, which ad- 
 heres to this knob, and by the insertion of the biceps tendon, 
 which is implanted into this point, and which spreads its 
 expanded tendon over the forepart of the tibia, and holds the 
 bones together ; and the firmness of the fibula is further 
 secured by the great interosseous ligament, w^hich goes from 
 bone to bone. Towards the head of the bones the interos- 
 seous ligament is deficient. 
 
 ANKLE. 
 
 The ANKLE-JOINT owes less of its strength to ligaments than 
 to the particular forms of its bones ; for while the strong-lateral 
 ligaments of the knee guard it so that it cannot be dislocated 
 till they are torn, the lower heads of the tibia and fibula so 
 guard the foot, that when luxated, these bones are often broken. 
 First, the fibula is so connected with the tibia, at its lower 
 end, that they form together one cavity for receiving the as- 
 tragalus, with two projecting points, the fibula forming the 
 outer ankle, and the tibia forming the process of the inner 
 ankle ; the joining of the fibula to the tibia here, is like that 
 of its upper end, too close to admit of the smallest motion, 
 and it is thoroughly secured by particular ligaments, one of 
 which passing from the fibula to the tibia on the forepart, is 
 named the ligamentum superius anticum, consisting, in 
 general, of one or two distinct flat bands. Another more con- 
 tinued and broader ligamentous membrane goes from the 
 fibula to the tibia across the back part, and is named liga- 
 mentum posTicuM SUPERIUS ; the ligamentum posticum in- 
 EERius, being but a slip of the same. Next comes the cap- 
 sule of the joint, which joins the astragalus to the lower heads 
 of the tibia and fibula ; it is thinner both before and behind, 
 than we should expect from the strength of a joint which 
 bears all the weight, and the most violent motions of the body. 
 But, in fact, the capsule every where serves other purposes 
 than giving strength to the joint, and never is strong, except 
 by additional ligaments from without ; so it is with the ankle- 
 joint, the capsule of which is exceedingly thin before ; but it 
 is strengthened at the back part, and especially at the sides, by 
 
^10 .iOlNTS OF THE 
 
 supplementary ligaments: First, a strong ligament comes 
 down from the acute point of the inner ankle, expands in a 
 radiated form upon the general capsule ; adheres to it, and 
 strengthens it, and is fixed all along the sides of the astragalus 
 to the os calcis and naviculare. This ligament, coming from 
 one point, and expanding to be inserted into a long line, has 
 a triangular form, whence itis named ligamentum deltoides; 
 and while the general ligament secures the joint towards that 
 side, the oblique fibres of its fore edge prevent the foot being 
 too much extended, as in leaping, and its oblique fibres on the 
 back edge prevent its being too much bended, as in climbing ; 
 but the ligaments of the outer ankle, tying it to the outer side 
 of the astragalus, are indeed distinct, one going forwards, one 
 going backwards, and one running directly downwards ; one 
 goes from the point or knob of the fibula, obliquely down- 
 wards and forwards to be inserted into the side of the astra- 
 galus ; it is square and flat, of considerable breadth and 
 strength, and is called ligamem'um fibulae anterius. Ano- 
 ther ligament goes perpendicularly downwards, from the acute 
 point of the outer ankle, to spread upon the side of the as- 
 tragalus, and of the capsule, and is finally inserted into the 
 heel-bone ; this is named the ligamentum fibul® perpen- 
 DicuLARE. A third ligament goes out still from the same 
 point, to go backwards over the back part of the capsule, ad- 
 heres to the back of the capsule, and strengthens it, and is 
 named ligamentum inter fibulam et astragalum pos- 
 TERius. There is nothing very particularly worthy of notice 
 in the ankle-joint, for it is covered with cartilages, lined with 
 a soft and mucous membrane, and lubricated with mucous 
 fimbria) and masses of fat, such as are found in all the joints. 
 It is stronger than the other joints; it can hardly be luxated, 
 without a laceration of its ligaments, and breaking of the 
 bones which guard it at either side ; and it is the great vio- 
 lence which is required for completing, this dislocation, and 
 the terrible complication of dislocation, fracture, and lace- 
 ration of the skin, which makes this accident so dangerous 
 beyond any other luxation. 
 
 UNION BETWIXT THE BONES OF THE TARSUS. 
 
 The ASTRAGALUS, OS CALCIS, OS NAVICULARE, and all the 
 bones of the tarsus, are united to each other by large heads, 
 and have distinct and peculiar joints; besides which, the bones 
 are cross-tied to one another by ligaments, so numerous and 
 c'omplicated, that they cannot nor need not be explained. 
 
THIGH, LEG, AND ANKLE. 
 
 311 
 
 They pass across from bone to bone, in an infinite variety of 
 directions, some longitudinal, some transverse, and some ob- 
 lique. There is a curious complication, which we may call a 
 web of ligaments, covering either side of the foot with 
 shining and star-like bundles ; each bone has its capsular liga- 
 ments for joining it to the next ; each joint of each bone has 
 its articulating cartilages always fresh and lubricated ; each 
 joint has, besides its capsule, flat strips of oblique, longitu- 
 dinal, and transverse ligaments, joining it to the nearest bones, 
 and the greater bones have larger and more important liga- 
 ments ; as from the astragalus to the os calcis, from the os 
 calcis to the os naviculare, and from that again to the sca- 
 phoid bone, &c. 
 
 The metatarsal bones have their capsular ligaments joining 
 them to the tarsal bones, and they have ligaments strength- 
 ening their capsules, and tying them more strongly to the 
 tarsal bones ; and, as in the metacarpal bones, the several 
 ranks., are tied one to another by cross ligaments which pass 
 from the root of one bone to the root of the next ; so we have 
 ligaments of the same description and use, holding the meta- 
 tarsal bones together, both on the upper and on the lower sur- 
 face of the foot ; and all the ligaments of the foot are of 
 great strength and thickness. The lower ends of the meta- 
 tarsal bones have also transverse ligaments by which they are 
 tied to each other. The toes have hinge-joints formed by 
 capsules, and secured by lateral ligaments, as those of the 
 fingers are ; and, except in the strength or number of liga- 
 ments, the joinings of the carpus, metacarpus, and fingers, 
 exactly resemble the joinings of the tarsus, metatarsus, and 
 toes. 
 
 But these ligaments, though helping to join the individual 
 bones, could not have much eflect in supporting the whole 
 arch of the foot. It is further secured by a great ligament, 
 which extends in one triangular and flat plate, from the point 
 of the heel to the roots of each toe. This is named the 
 APONEUROSIS PLANTARis PEDIS, which is not merely an 
 aponeurosis for covering, defending, and supporting the 
 muscles of the foot ; that might have been done on easier 
 terms with a fascia, very slight compared with this ; but the 
 chief use of the plantar aponeurosis is in supporting the arch 
 of the foot. It passes from point to point, like the bow- string 
 betwixt the two horns of a bow, and, after leaping, or hard 
 walking, it is in the sole of the foot that we feel the straining 
 and pain ; so that, like the palmar aponeurosis, it supports 
 the arch, gives origin to the short muscles of the toes, braces 
 them in their action, and makes bridges under which the long 
 
312 
 
 JOINTS OF THE 
 
 tendons are allowed to pass : it comes olf from the heel in 
 one point ; it grows broader in the same proportion as the sole 
 of the foot grows broad. It is divided into three narrow 
 heads, which make forks, and are inserted into the roots of 
 the second, third, and fourth toes ; and the great toe and the 
 little toe have two smaller or lateral aponeurosis, which cover 
 their own particular muscles, and are implanted into the roots 
 of the great toe and of the little toe. 
 
 The bursce mucosas surround the ankle and foot in great 
 numbers. None of them having any very direct connection 
 with the joint, and most of them accompanying the long ten- 
 dons as tliey pass behind the ankle, or in the sole of the foot, 
 are of that kind which we call tendinous sheaths. First, there 
 are sheaths of two or three inches long, which surround the 
 tendons of the tibialis posticus, and of the peronasi muscles, 
 as they pass down behind the ankle. The sheaths of the pe- 
 ronaei begin from that point where the tendons first begin to 
 rub against the bone, and are continued quite down into the 
 sole of the foot ; making first a common sheath for both ten- 
 dons, and then a bursa peculiar to the tendons of the peronaeus 
 brevis muscle, and about an inch in length. When the pero- 
 nasus longus begins to pass under the sole of the foot, the 
 sheath which enclosed it behind the ankle is shut, and a new 
 bursa begins ; in the same manner where the tendons of the 
 flexor pollicis, and flexor digitorum pedis, pass behind the 
 inner ankle, a bursa of three inches in length surrounds them, 
 and facilitates the motion. As the tendons of the flexor 
 muscles go under the arch of the foot, they lie among soft 
 parts, and rub chiefly against the flesh of the massa carnea, 
 and the belly of the short flexor muscles : but whenever they 
 touch the first joints of their toes, they once more rub against 
 a hard bone. New bursfe are formed for the tendons ; each 
 bursa is a distinct bag, running along the flat face of the toe, 
 and is of a long shape, and the tendon is carried through the 
 centre of the lubricated bag, so that we see once more, that 
 there is no true distinction betwixt bursfe mucosas and ten- 
 dinous sheaths ; nor betwixt the tendinous sheaths and the 
 capsules of joints. 
 
 Joints have been arranged under various forms, but not with 
 much success; and I do not know that enumerating the joints 
 in any particular order will either explain the motions of in- 
 dividual joints, or assist in recording their various forms ; 
 some joints are loose and free, capable of easy motions, but 
 weak in proportion, and liable to be displaced ; such is the 
 JOINT of the SHOULDER, which rolls in every direction ; other 
 rolling joints, more limited in their motions, are better secured 
 
THIGH, LEG, AND ANKLE. 
 
 313 
 
 with ligaments of peculiar strength ; such is the joiiw of the 
 HIP, where the ligaments are of great strength both within 
 and without; some wanting all circular motions, are hinge- 
 joints, by the mere form of their bones ; such are the low'er 
 JAW, the VERTEBRiE, the ELBOW, and the ankle-joints ; 
 some are hinges by their ligaments, which are then disposed 
 only along the sides of the bones ; such are the knee, the 
 RIBS, the fingers, and the toes. Sojne joints partake of 
 either motion, with all the freedom of a ball and socket-joint, 
 yet with the strength and security of the strictest hinge : thus the 
 WRIST having one joint by which its turning motions are 
 performed, and another joint by which it rolls, has the two 
 great endowments so rarely combined in any joint of the 
 freest motion, and of great strength ; so also has the head, 
 by the combination of two joints of opposite uses and forms ; 
 for its own condyles play like a mere hinge upon the atlas, 
 and the axis of the dentatus secures all the properties of a 
 circular joint ; this combination gives it all the motions of 
 either joint, without their peculiar defects. But there is still 
 a third order of joints, which have such an obscure and 
 shuffling motion, that it cannot be observed. The carpus and 
 METACARPUS, the TARSUS and metatarsus, the tibia with 
 the fibula, have these shuffling and almost immoveable 
 joints ; they are not intended for much motion among them- 
 selves, but are appointed by a diffused and gradual yielding, 
 to facilitate the motions of other joints. 
 
 VOL. I. 
 
 Rr 
 
:. tWM'^ ' '^' ' f I "T 'A *>!&# 
 
 .:.i,.'.;?^ '.^ t- V'-.' : '' 
 
 
 It ^ 
 
 , ' , ' ,v ' •'. ;■ ■ '- ,V ’t- 
 
 .,,i.r':;, ';,T.' ,,, ■’ '. '‘' " V^; >‘‘ , , .•■:'\-'a '>'> t<t*HW»t#<* 
 
 I:i'm »iiTT»J't«' «ttfii^'4HJ'!.»i#' ##lf“ 
 
 itii <*, 1 , >(, » 
 
 ,'i’i^im - 'xii r 'M?' fte triW' 
 i46j i t iiit}!ttpt:tm .,fjJto't \iiHf nr 
 
 ,^rfi 'k* f.imi$om^'! chfr fl-it -si'irw rwH'ti* 
 
 <,sir';;|Mr«vW ft'fiff- 
 
 ■,; if4‘' “ 
 
 /uf*4(wilofa^trr-9 y.i- HVtfiNr ■)iili' W* M 
 
 i< 5 ' 3 «(rt '' ) Irt*^ 
 
 J^iiir ’ -»|ifl«;;; '»',r ^t#- ^«o-'>'>'»' ' 
 
 •fi> ijsar ,_^s^.WjjS?!ifi(<i irioit c >'l/'nff!fT ::'.h:i stilt 
 
 v' jt T^J.r timostsrq' wt- oofflkt I'fw^l'tOMiTii ■.irmm 
 
 ■ynui (mf •fi^.:'-r.ifw>: •■ 
 
THE 
 
 OF THE 
 
 HEART AND ARTERIES. 
 
 BOOK L 
 
 OP THE HEART. 
 
 CHAP. I. 
 
 OF THE MECHANISM OP THE HEART. 
 
 The heart is placed nearly in the centre of the human 
 body, and is itself the centre of the circulating system. The 
 system of vessels which it excites and moves, consists of arte- 
 ries and of veins ; — the arteries act with great strength, with 
 a pulsation like that of the heart itself, and convey the blood 
 over all the body ; the veins are in greater numbei’, exceed- 
 ingly large, pellucid almost in their coats, incapable of that 
 energetic action with which all the functions of the arteries 
 are performed ; they return the blood to the heart with a slow, 
 equable, and gentle motion, and deposite at the right side a 
 quantity of blood equal to that which is at each pulsation 
 driven out from the left. The heart is placed betwixt the ar- 
 teries and the veins, to regulate and enforce their action ; to 
 2'eceive the blood from the veins by a slow dilatation, and to 
 restore, by a sudden contraction, that force which the blood 
 loses in passing round the circle of the body. But the heart 
 has also another and more important office to perform : for by 
 having four great cavities and two orders of arteries, it per- 
 forms in the same instant two circulations, one for the lungs 
 and one for the body ; it receives from the lungs nothing but, 
 pure blood, it delivers out to the body nothing but what is fit 
 for its uses : and this purifying of the blood, and this excite- 
 
316 
 
 OF THE MECHANISM 
 
 ment of the arteries, are two chief points of modern physio- 
 logy, which every step of the following demonstration will 
 tend to explain. 
 
 It will be most easy to conceive at first the idea of a more 
 simple heart, of one circle of actions, of one simple circu- 
 lation ; of one bag for receiving, and another joined to it for 
 propelling the blood- Indeed a heart consists merely of these 
 essential parts ; a great vein, an auricle, a ventricle, and 
 a great artery : of a vein which returns the blood from all 
 the body ; of an auricle or smaller bag, which receives that 
 blood and retains it till the action of the heai’t is relaxed : of 
 a ventricle (which is the proper heart) strong, muscular, very 
 irritable, and easily excited, into which the auricle pours its 
 blood ; of an artery which is allied to the ventricle in strength 
 and action, (as the auricle is to the vein in the delicacy of its 
 coats,) and which carries on the blood to the extremities of 
 the body ; — and the vein and artery meeting at their extre- 
 mities in the body, and uniting, the whole is a circle, and the 
 heart is the central power. 
 
 If an animal do not breathe, its system will be what I have 
 now described ; it will have but one vein, one auricle, one 
 ventricle, one artery ; it will have one simple heart : but with 
 us, and other breathing animals, it is not so ; and I am now to 
 describe a more complex and curious circulation. For sup- 
 pose this blood, so essential to our existence, to have in it 
 some principle of life, which is continually lost, or in its pas- 
 sage through the body, to be impregnated with something 
 which should be thrown off, that principle must be continually 
 renewed, or an opportunity given to send off what is offensive 
 to life : the heart which fills the arterial system, must not be 
 taken from its appointed office, nor disturbed ; nature appoints 
 a second heart, which belongs entirely to this most important 
 of all functions, viz. renewing the blood ; and it may be re- 
 newed in many various ways. It might, for example, circu- 
 late in some peculiar viscus, like the liver or spleen ; in the 
 foetus it does circulate in such a mass, for the placenta is a 
 thick and flat cake, whose office we know to be equivalent to 
 that of the lungs, but whose structure we do not understand : 
 ill the chick w'e see its blood circulating over the yolk, (for the 
 yolk is inclosed within the membranes of the unhatcbed 
 chick,) and we perceive the blood redder as it returns to the 
 heart, and plainly changed : in fish we find the blood circu- 
 lated over the gills, exposed thoroughly to the water in which 
 they swim, and thus the gills perform to them the function of 
 lungs. But in all breathing creatures, the lungs do this office ; 
 the lungs are, next to the heart itself, essential to life ; in those 
 
OF THE HEART. 
 
 31 ? 
 
 who die from bleeding, we can perceive from the livor of the 
 face, from the sobbing and struggles of the chest, from the 
 regular convulsive sighs of those creatures which are butchered, 
 rather a desire for air than a want of blood. It is for the pur- 
 pose of this second circulation that nature has appointed in all 
 the wai’m blooded animals two hearts, a heart for the lungs, 
 and a heart for the body ; two veins, two auricles, two ventri- 
 cles, and two great arteries, one the pulmonic artery, or artery 
 of the lungs, the other the aorta, or artery of the body. 
 
 There are other varieties which distinguish animals into 
 creatures of cold or of warm blood ; for there are certain con- 
 stitutions which do not require that the blood should be thus 
 continually renewed. It is not because animals are amphi- 
 bious, or go into the water, that they have peculiar lungs; 
 for the Land Tortoise, the Newt, the Cameleon, never go 
 into the water ; yet they have membranous lungs : nor indeed 
 can the amphibi.T, as the Seal, the Porpoise, the Sea-Lion, 
 &c. dive and exist under water more than a man can do, 
 though for whole days they lie in herds basking upon the 
 shore : it is their peculiar constitution to need less than other 
 creatures the office of the lungs. The cold-blooded animals 
 are generally creeping animals, sluggish, languid, cold, inert, 
 difficultly moved, and tenacious of life to a wonderful degree. 
 They can bear all kinds of stimuli; they can bear to have 
 their heads, legs, bowels, cut away ; and among other pecu- 
 liarities of this constitution, they can live long without air : 
 they will rise from time to time above water, if you allow 
 them ; they can bear again to be kept under w ater, if you 
 force them : but if they can live long under w’ater, they can 
 also live at least as long after you have cut off their heads, or 
 cut out their hearts. 
 
 Of those cold-blooded creatures always either the heart or 
 the arteries are peculiar ; the heart is so in many amphibise, 
 as in the Turtle, where the heart seems to consist of three 
 ventricles, but with partitions so imperfect betwixt them that 
 they are absolutely as one : this one ventricle gives out both 
 the great arteries ; the blood of the lungs and the blood of 
 the body are both mixed in the heart : and since there are two 
 arteries conveying this mixed blood, if the two arteries be 
 nearly equal in size, then it is just one half of the blood 
 thrown out by the heart at each stroke that receives the bene- 
 fit of the lungs. In many others, as the frog, the newt, the 
 toad, the peculiarity is in the arteries alone ; they have one 
 single and beautiful heart ; there is one large auricle as a re- 
 servoir for all the blood both of the body and of the lungs ; 
 there is one neat, small, and very powerful ventricle placed 
 
318 
 
 OF THE MECHANISM 
 
 below the reservoir, having strength quite sufficient for mov- 
 ing both the blood of the lungs and the blood of the body ; and 
 this ventricle gives off an aorta, which soon divides into two 
 branches, one for the body, and one for the lungs ; and these 
 of course have but half the blood of this heart exposed to the 
 air : these also are cold-blooded animals. 
 
 But all breathing creatures, such as are called animals of 
 hot blood, have two hearts: the one heart is sending blood 
 through the lungs, while the other heart is pushing its blood 
 over the body ; not the half only, but the whole blood which 
 is sent by each stroke of the heart over the body must have 
 first passed through the lungs ; no blood can reach the heart of 
 the body which has not been sent to it through the lungs ; or, 
 in other words, the veins of the lungs, and they alone, feed the 
 left side of the heart. 
 
 Words alone will never explain any of the endless difficul- 
 ties which concern the mechanism of the heart; but at every 
 point, in every kind of difficulty, in explaining the form, the 
 parts, the posture, even the coats or coverings of the heart, I 
 shall have recourse to plans, such as cannot fail to make all 
 this intricate mechanism be easily conceived. 
 
 The most simple form of the heart, which is represented in 
 the plan. No. 1. has a vein marked (a,) — and auricle (6,) — a 
 ventricle (c,) — an artery {d ;) — it has no provision for purify- 
 ing the blood ; it has no resemblance to that kind of heart 
 which is connected with lungs ; but the blood is received by 
 the vein, falls into the auricle, is driven by its force into the 
 ventricle, by the ventricle it is thrown into the artery, and 
 courses round all the body, till at length, reaching the extremi- 
 ties of the veins, it passes by the veins to the auricle a second 
 time, and so this single circle is perfect. 
 
 The heart of the amphibious creature is represented in No. 
 2. ; it is a frog’s heart : it has the most simple form, and the 
 fewest parts; it has the same vein, auricle, ventricle, and ar- 
 tery ; but its great artery divides into two chief branches, of 
 which [d) — the aorta goes to the body, — (e) the pulmonic ar- 
 tery goes to each side of the lungs. 
 
 The heart of a breathing creature is represented in No. 3. 
 in its most intelligible form ; and the double circulation of the 
 human body may be traced easily in the following way. — Here 
 the heart of the lungs is set off from the heart of the body, 
 being as distinct in office as in form and parts; on the right 
 side is the heart of the lungs, on the left side is the heart of 
 the body. — (a) Is the great vein called vena cava from its im- 
 mense size ; — there is an ascending and a descending cava ; 
 the one brings the blood from the head and arras, the other 
 
VoI.E. 
 
 .jYrn/j /j/ ^//r Yf/r/lZ 
 
 Liin 
 
 isr‘'2 
 
 N":i 
 
 ]N-“+ 
 
 F./^. 
 

 t 
 
 i V" ' 
 
 " r 'it' . 
 
 .:,r- 
 
 't, ' ' ' ■■■ / 
 
 ’•'tv' 
 
 ! '''■ 
 
 ‘ ' . a ■ .i V v. ' -Vl ten'ii- 
 
 '■■■ •><: .. ■ ' 
 
 h yi-’, y^’yr\<:- ' ■ ■ r-/: ;v; > f’U; ydr- "«•<;" s '.i'. 
 
 •!■;-■; /•;■ t-jJ- - '.■> ' 
 
 ,, B'lS 1-1 
 
 ' ’"s‘ ‘'‘-' y'iiia d ><*> 4*Mvjt • .. ;a 
 
 '.fi; .'•li'i M: ,:t 
 
 ■ ' > ■'■ 'boft fitfjluoyt'ne \ j‘ . < ni lA 
 
 i:,; > ( I i o-v.» if <i ..•\[j^#s.‘* a.avsdi : y- d' ' 
 
 ■>■'; jb-iisihif 8i li. :.*. .•'4 ■>‘Ai’if(^ vf 
 
 i dV'ff ii. aUii (>liit ,‘frinh '» 
 
 r ■ (■.'? tKi irti'v- ..■,,r :. : v. IV, '.,' i' i?3 ■■ r.'^v. I ; 
 
OF THE HEART. 
 
 319 
 
 brings the blood from all the lower parts of the body ; they 
 meet at (a,) and form by their dilatation there, a chief part of 
 that bag which is called the auricle, — in it they deposite all 
 the returning blood of the body, and thus present it at the right 
 side of the heart to be moved through the lungs. — (h) Is the 
 right sinus, or right auricle ; it is in part formed by a dila- 
 tation of these veins, but it puts on a strong and muscular na- 
 ture as it approaches the heart ; it is the first cavity of the 
 heart, and, like all its parts, is strong and irritable ; it is filled 
 by the returning blood of the cavre ; it receives, dilates, is op- 
 pressed by this great quantity of blood : it is strongly excited 
 to act; in its action the blood goes down into the ventricle or 
 lower cavity of the heart. — (c) Is the right ventricle, thick 
 and strong in its walls, and of great muscular power : it is filled 
 by the auricle, and is strongly stimulated both by the stroke of 
 the auricle, and by the weight and quantity, and also, in some 
 degree, by the qualities of the blood ; its action is sudden and 
 violent, and it drives the blood through all the system of the 
 lungs.— (d) Is the pulmonic artery, — the artery of the lungs, 
 which receives all the blood of the right side of the heart; it 
 is filled by the stroke of the right ventricle, from whose cavity 
 it arises ; it carries the blood in many branches through all the 
 substance of the lungs ; and thus that blood which had returned 
 imperfect and robbed of its vital quality to the right auricle of 
 the heart, is by this circulation through the pulmonic artery 
 ventilated and renewed, and made fit for the uses of the sys- 
 tem; and thus the lesser circulation, or the circulation of the 
 lungs, the circulation of the right side of the heart is completed, 
 and the purified blood is brought round to the left side of the 
 heart to undergo the greater circulation or the circulation of 
 the body. 
 
 Thus it is from the extremities of this first circle that the 
 second circle begins ; it consists of like moving powers, of an 
 auricle, ventricle, vein, and artery ; for as the right heart re- 
 ceives the contaminated blood of the body from the veins of 
 the body, the left heart receives the purified blood of the lungs 
 from the veins of the lungs. — (e) Represents the veins of the 
 LUNGS, which are sometimes three, sometimes four in number; 
 two enter from each side of the lungs, and return the blood pu- 
 rified in the lungs to the left auricle of the heart. — (/) Is the 
 LEFT AURICLE, Smaller, but more muscular, and stronger than 
 the right; it receives easily whatever quantity of blood the 
 lungs convey to it ; it is irritated, contracts, forces the mouth 
 of the ventricle, and fills it with this purified and redder 
 blood.-:— (^) Is the left ventricle, whose form is longer, its 
 fleshy walls thicker, its cavity smaller, its power greater far 
 
320 
 
 OF THE MECHANISM 
 
 than that of the right side ; this ventricle is thus small that it 
 may he easily filled and stimulated, and thus strong that it may 
 propel all the blood of the body. — (A) Is the aoeta or great 
 artery of the body, arising from this left ventricle, just as the 
 pulmonic artery arises from the right : the left ventricle, by its 
 strong and sudden stroke, not only delivers itself of its own 
 blood, but propels all the blood of the body, communicates 
 its vibratory stroke to the extremest vessels, and excites the 
 whole ; this is the greater circle or circulation of the body, 
 as opposed to the shorter circulation or lesser circle of the 
 lungs. 
 
 That there are strictly two hearts, is now clearly made out ; 
 they are different in office ; there are two distinct hearts, two 
 systems of vessels, two kinds of blood, and two circulations. 
 These two hearts might have done their offices, though placed 
 in the opposite sides of the breast; it is in order to strengthen 
 mutually the effect of each other that they are joined ; for the- 
 fibres of the two hearts intermix ; they are both inclosed in one 
 membranous capsule, viz. the pericardium ; the veins, auri- 
 cles, ventricles, and arteries, correspond in time and action 
 with each other, and harmonize in a very beautiful manner. 
 But this, I believe, will be more easily explained by marking 
 the succession of motions, by a suite of figures placed upon 
 the several parts of the heart, by which the successive motions 
 are performed. 
 
 In No. 4. I have joined the right and left hearts; both that 
 it may be seen how the left heart locks in behind the right 
 heart, how the right heart comes to be the anterior one, and 
 how the aorta seems to arise from the centre of the heart while 
 its root is covered by the great artery of the lungs; and also 
 that the synchronous parts, (i. e.) the parts which beat time with 
 each other may be correctly seen. — 1. The cavas are receiv- 
 ing the blood from all parts of the body, and in the same in- 
 stant the pulmonic veins are receiving blood from the lungs. 
 2. The BIGHT AUBicnE is gradually filling with the contami- 
 nated blood of the body ; the left auricle, marked also with a 
 second figure, is filling with purified blood from the lungs. 3. 
 The niGHT VENTRICLE is stimulated by its auricle, and throws 
 its contaminated blood into the lungs ; and in the same moment 
 the left ventricle throws its purified blood over the body. 4. 
 The PULMONIC ARTERv re-acts upon the blood driven into it 
 by the heart; and in the same moment the aorta re-acts upon 
 the blood thrown into it, and that re-action works it through all 
 this great system of vessels from this the centre to all the ex- 
 tremities of the body. 
 
OP THE HEART. 
 
 321 
 
 Thus it Is easy to perceive how the successive actions ac- 
 company each other in the opposite sides of the heart : 1. The 
 two veins swell; 2. The two auricles are excited; 3. The 
 two ventricles are filled with blood ; 4. The two arteries take 
 up and continue this pulsating action of the heart. It is thus 
 that the two hearts assist and support the actions of each other, 
 and there seems almost a physical necessity for their being 
 joined ; yet on the very best authority, and after deliberate 
 dissection, we are entitled to affirm, that the heart is found, 
 not with its apex sharp and conical, but cleft ; the two ventri- 
 cles plainly distinct from each other, and divided by a great 
 space. “Latro, quse poenas scelerum luebat, quando exente- 
 raretur a carnifice, cor habuit singularis figurae, mucrone non 
 acuto, ut fieri solet, sed bifido ; ut distinct! ventriculi raanifes- 
 tius externa facie apparuerint, dexter nempe et sinister, inter- 
 jecto magno hiatu,”* 
 
 OF THE PARTS OF THE HEART. 
 
 As yet I have explained only the general plan of the circu- 
 lation, without having described those curious parts which are 
 within the cavities of the heart, and which support the actions 
 in this beautiful harmony and perfect order, each part subordi- 
 nate to some other part, and each action succeeding some 
 other action with perfect correctness, often without one un- 
 steady motion or alarming pause, during the course of a long 
 irregular life. 
 
 1. The VEN^ CAVJE are two in number ;f they are named 
 venae cavae from their very great size ; the one brings the 
 blood from the upper, and the other from the lower parts of 
 the body, and they are formed of these branches: the upper 
 vena cava (a) is properly termed the descending cava, be- 
 cause it carries the blood of the head and arms downwards to 
 the heart : this great vein is properly a continuation of the 
 right jugular vein, which joins with the right axillary vein, 
 and then descends into the chest a great trunk ; and in the 
 upper part of the chest it is joined at (6) — by a great branch, 
 containing tbe axillary and jugular veins of the left side, wdiich, 
 in order to reach the cava, crosses the upper part of the chest, 
 and lies over the carotid arteries. The lower vena cava, or 
 
 * Bartholini Epist. p. 170. There are examples in the lower animals, of the hearts 
 %eing actually in distinct parts of the System. 
 
 f Let the reader observe, that the whole of this description of the various parts of the 
 heart is, as it were, an explanation of the plans No. 5. and 6. j of which tlie No. [>. shows 
 the right side of the heart, or the heart of the lungs opened ; while No. 6. shows only the 
 left heart, or the heart of the body opened. 
 
 vofc. I. S s 
 
322 
 
 OF THE MECHAISISM 
 
 CAVA ASCENDENS, brings in like manner all the blood from the 
 belly and lower parts of the body by two great branches. One, 
 marked (c,) — is the great vein which lies in the belly along 
 the left side of the spine, and brings the blood from the legs, 
 the pelvis, and parts of generation, the kidneys, &ic. ; it is 
 named the vena cav a aboominalis, because of its lying in the 
 abdomen. Another, marked (ddd,) — arises in three or four 
 great branches from the liver ; it is named the branches of the 
 vena cava in the liver, or the vena cava uebatica ; and these 
 two make up the lower cava; and the lower and the upper cavas 
 now join themselves at (c,) — to form the right sinus of the heart. 
 
 2. The RIGHT SINUS of THE HEART, marked (e,) is of con- 
 siderable extent ; it is just the gradual dilatation of the two 
 veins forming the auricle or reservoir which is incessantly to 
 supply the heart ; the veins grow stronger as they approach 
 the sinus, and the sinus still stronger as it approaches the auri- 
 cle or notched and pendulous part (/,) and the auricle again 
 approaches in its nature to the ventricle of the heart ; for it is 
 crossed with very strong muscular fibi-es, which make veiy 
 deep risings and furrows upon its inner part. To say that these 
 veins, or the sinus which they form, are not muscular, merely 
 because they are not red nor fleshy, is very ignorant; for the 
 ureters, arteries, intestines, the iris, and many other parts of the 
 human body, are, at the same time, perfectly muscular and 
 perfectly pale ; and the heart of a fish is as transparent as a 
 bubble of water, and yet is so irritable that after it is brought 
 from market, if you lay open the breast, and stimulate the 
 heart with any sharp point, it will renew its contractions, and 
 in some degree the circulation. 
 
 3. The TUBERCULUM Loweri should be looked for in this 
 point, if it were not really an imagination merely of that cele- 
 brated anatomist. The whole matter is this ; the two veins 
 meet, not directly, but at a considerable angle within the vein, 
 as at (g). Lower conceived a projection of the inner coats of 
 the vein at this point much more considerable than what I 
 have here represented. It was thought to do the office of a 
 valve, to break the force of the descending blood, to defend 
 from pressure that blood which is ascending from the lower 
 cava, and to direct the blood of the upper cava into the right 
 auricle of the heart. But there is no such thing; although 
 anatomists were at one time so fond of this trivial observation 
 that not one of them would demonstrate the heart, without 
 demonstrating the tuberculum Loweri; whereas, if the blood 
 of the lower cava needs any screen above it to defend it from 
 the pressure, it is (as I shall show presently) quite of another 
 kind ; and in the place appointed for finding this tuberculum 
 
OF THE HEART. 
 
 S2.3 
 
 Lower! vve can find nothing but on the inside of the natural 
 angle of the two veins, and on the outside some fat cushioned 
 up in that angle in the line (A). Though generally wanting, I 
 have found the tuberculum Loweri very distinct in the hu- 
 man heart. 
 
 4. The AURICLE is, as I have said, a small appendix to the 
 great bag or sinus, and is marked (/). It is small, semi-circu- 
 lar, notched or scolloped, and somewhat like a dog’s ear ; 
 whence its name. In general, we name the whole of this bag 
 auricle ; but by this plan the names of sinus and auricle must 
 be easily understood. The point chiefly to be noted is this, 
 that the veins, as they approach the auricle, are thin, delicate, 
 trans[)arent ; that where they expand into the sinus they be- 
 come fleshy, thick, and strong ; that in the auricle itself the 
 muscular fibres at (/) are very strong, have deep sulci like 
 those of the ventricle, cross each other so as to make a net- 
 work; and these strong fibres (/) are what are named the 
 musculi pectinati auriculas. Where these muscles run, as in 
 cords, across the auricle, they are very thick and opaque ; but 
 in the interstice of each stripe or muscular fibre, the auricle is 
 transparent, like the membranes of the veins ; and these stripes 
 of muscular fibre which are laid upon this thin membrane are 
 almost as regular as the teeth of a comb ; and thus they are 
 named musculi pectinati. 
 
 5. The VALVES of the auricle are placed at the circle (i), 
 where the auricle enters into the ventricle, and the valves ai’e 
 marked (A) ; and how necessary these are for regulating the 
 
 auricular valves. 
 
 AoRiruLAR Valves explained. 
 
 Fig. 7. shows the Auricle and Ventricle cut open, and the valve hanging in three great 
 divisions. — (a) Part of the inside of the Auricle.-— (4) Part of tlie inside of the Ventricle. — 
 The tendinous Circle from which the membrane of the valve arises. — (d) The Columnse 
 Carneas.— (e) The Cordae Tendinece . — {^) The three great divisions of the Valve. — 
 No. 8. shows the circle of the entrance of the Auricle still entire ; where — (g) — marks the 
 entrance into the Auricle.— A j 55^) The tiiree great division? of the Valve. — (d) TheCo- 
 lumna; Carneae ; and-*(e) The Cordre Tendinete. 
 
324 
 
 OF THE MECHANISM 
 
 movements of the heart will be easily understood by consi- 
 dering the conditions in which the auricle and ventricle act. 
 First the cavie pour in a flood of blood upon the sinus and 
 auricle, with a continual pressure ; the moment the auricle 
 has contracted it is full again ; the pressure from behind ex- 
 cites it to act, and while it is acting there is no occasion for 
 valves to guard those veins whose blood is pressing forwards 
 continually, because they are continually full, and have be- 
 hind them the whole pressure of the circulating blood. But 
 when the auricle acts, it throws its blood into the ventricle, 
 fills it, and stimulates it; the auricle then lies quiescent for 
 a moment, while it is gradually filling from behind with blood ; 
 but during this quiescent state the whole blood from the ven- 
 tricle would rush back into it, were it not guarded by valves. 
 The valves, then, whicb rise whenever the ventricle begins 
 to act, are of this kind : there is, first, a tendinous circle or 
 hole, by which the auricle communicates with the ventricle. 
 The opening is large enough to admit two or three fingers to 
 pass through it ; it is smooth, seems tendinous, is plainly the 
 place of union betwixt the auricle and ventricle, which are 
 in the fcctus (in the chick, for example,) distinct bags ; and 
 from all the circle of this hole arises a membrane, thin, and 
 apparently delicate, but really very strong ; not divided into 
 particular valves at this root or basis, but as the membrane 
 hangs down into the ventricle, it grows thinner and is divided 
 into fringes. How these fringes can do the office of valves is 
 next to be explained. The tags and fringes of this membrane 
 ai’e actually tied to the inside of the ventricle by many strings, 
 which being, like the valves, of a tendinous nature, are called 
 CORD® TENDiNE/E, Or tendinous cords ; and these cords being 
 attached to little processes projecting from the muscular sub- 
 stance of the hpart, these processes are named coLUMNiE 
 carnea:, or fleshy columns. Of these tyings of the valves 
 there are three chief points ; the whole circle seems to be di- 
 vided into three sharp-pointed valves ; they are named vae- 
 vuLiE TRicuspiDES, 01’ tliree-pointed, or they are still some- 
 times called Triglochine Valves. The valves fall down easily 
 when the blood goes down through them, and they rise readily 
 and quickly whenever the blood gets behind them : when the 
 ventricle is full the valves are still open, but when the ventricle 
 contracts, the blood throws up the valves, and closes the open- 
 ing into the auricle, and now the tendinous cords and fleshy 
 columns support the margins of the valves, so that they give 
 them strength to support the heart’s action. 
 
 6. The VENTRICLE of the right side (Z/) is like its auricle, 
 larger than the same parts on the left side; for this auricle 
 
OF THE HEART. 
 
 325 
 
 and ventricle of the right side have the weight of the whole 
 blood of the body pressing upon them. They are subject to 
 occasional fulness, for they must be dilated by many acci- 
 dents, as labour, violent struggles, &zc. which send the blood 
 too quickl)^ upon the heart ; while the left auricle and ven- 
 tricle, on the other hand, can never be over loaded, as long 
 as the pulmonic artery preseiwes its natural size, for that artery 
 continues always the measure of the quantity of blood which 
 they receive. The ventricle is thick, strong, fleshy. Its in- 
 ner surface is extremely irregular ; it puts out from every 
 part of its surface very strong fleshy columns. These fleshy 
 columns are irregular in size, big, strong, running along the 
 length of the ventricle ; some across the ventricle, so as to 
 connect its opposite walls together ; some have the tendons 
 of the valves fixed to them ; all of them have perfect con- 
 tractile power, and are indeed tire strongest muscles of the 
 heart. Betwixt the fleshy columns, there are, of course, very 
 deep and irregular grooves ; and among the confused roots 
 of these fleshy columns the blood often coagulates after death, 
 seldom before it, into the form of what are called polypi of 
 the heart. Yet still the walls of the right ventricle (//) — are 
 thinner, the fleshy columns smaller, the cavity greater, than 
 those of the lelt side ; the right ventricle of the heart has also 
 a peculiar form for the septum cordis, a partition betwixt 
 the righi anti left heart, is not, as generally supposed, a part 
 coniu :a to both; but the left ventricle is much longer and 
 more than the right one ; the septum belongs almost 
 
 entnv^ r to Lhe left ventricle ; the right ventricle which is much 
 bigger, laxer, flatter, and thinner in the tvalls, is, as it were, 
 wrapped round the left ; and thus the left ventricle alone 
 forms he acute apex of the heart, and the left ventricle of 
 necessity bulges very much into the cavity of the right, since 
 the right ventricle is so much larger, and in a manner wrapped 
 round it. In both ventricles, it is very remarkable, that to- 
 wards the opening of the auricle the surface of the ventricle 
 is very rugged, ii-regular, and crossed with columns; carnete, 
 while a smooth and even lubricated channel marked (m) leads 
 towards the artery. 
 
 7. The PULMONIC artery arises from the right ventricle, 
 to carry out the blood close by the great opening at which 
 the auricle pours it in ; the aiTery rises at its root in a very 
 bulging triangular shape. It is the valve within the mouth of 
 the artery that gives it this very peculiar shape without ; for 
 the bulging root is divided into three knobs, indicating the 
 places of the three valves, the artery dilating behind each valve 
 into a little bag, which, when it is described, is called its sinus. 
 
326 
 
 OF THE MECHANISM 
 
 8. -This VALVE of the pulmonic artery (n) — has a more 
 perfect and simple form than that of the auricle. The valves 
 in the mouth of each of the great arteries are three in num- 
 ber ; they are thin but strong membranes, rising from the circle 
 of the artery, where it comes off from the heart : each valve 
 is semilunar : its larger and looser edge hangs free into the 
 cavity of the artery ; the edge is a little thicker than the rest 
 of the valve ; the three valves together form one perfect cir- 
 cle, which closes the mouth of the artery so that no grosser 
 fluid, nor hardly air, can pass. When they are filled till they 
 become very tense, each valve forms a kind of bag ; so that 
 when you look at the mouth of a dried artery, they appear 
 like neat round bags ; and when they are likely to be forced, 
 the little horns or tags by which each valve is fixed into the 
 coats of its artery, become so tense as to do the office of a 
 ligament : these are called the semilunar or sigmoid 
 
 VALVES. 
 
 Now the eondition of the ventricle while it is contracting 
 is well understood : the auricle by its action lays down the 
 tricuspid or auricular valve, and fills the ventricle ; the ven- 
 tricle cannot feel the stimulus of fulness till its valves rise, and 
 its cordae tendineae begin to pull ; and the ventricle could not 
 be close for acting, nor its walls perfect, it could not in short 
 be an entire cavity, till the tricuspid or auricular valves were 
 completely raised. But there is another opening of the ven- 
 tricle, viz. that into the artery, which must be also shut ; this 
 is one of the several instances of the subordination of these 
 actions one to another ; for, first, the auricle acts, then the 
 ventricle, then the artery; so that the auricle and the artery 
 are acting in the same moment of time ; the artery by acting 
 throws down its valve, and closes that opening of the ventricle, 
 while the auricle is filling it with blood ; and again, the 
 moment that the ventricle is filled, both the auricle and 
 artery are in a state of relaxation, the auricular valve rises so 
 as to close the ventricle on that side ; and the arterial valve 
 falls down, both because the artery has ceased acting, and 
 because the valve is laid flat by the whole blood of the ven- 
 tricle rushing through it. Hence it is very obvious, that the 
 right ventricle could neither be filled nor stimulated, unless the 
 opening toward the artery were close during the time of its 
 filling ; and again, it is obvious that this valve cannot be laid 
 down by any other power than that of the artery itself ; who 
 then can doubt that the artery has in itself (like the ventricle) 
 a strong contractile power ? That it is the stroke of the 
 artery succeeding that of the heart that lays down this valve 
 so closely, is proved by this, that in many animals, in fishes, 
 
/'ol.JL 
 
 
 Jlr/ur,n,/n„, rh. t.urk /um ,r t!u H, ,nt _rhr ,,rn,t fr,r„„rv \ _n,c 
 ■ v,„/,r nfrhrAvrirlr_uml H,r rnt,;nu;- of thr JM„„.w,rv Vn„.i 
 
 /'. /S. 
 
 N."y 
 
 brJ/. , 
 
 Lriny 
 
OF THE HEART. 
 
 327 
 
 for example, the aorta is as plainly muscular as the heart it- 
 self, it is like a second heart ; and in fishes the vessel returning 
 from the gills, and often in human monsters, the artery alone, 
 by its own muscular power, moves the whole circulation with- 
 out any communication with the heart. In fishes there is no 
 second heart for the circulation of the body ; and in monsters 
 the heart is sometimes wanting, and there is found nothing but 
 a strong aorta to supply its place. This stroke of the pulmo- 
 nic artery, then (which the heart excites,) pushes the blood 
 through the lesser circle or circulation of the lungs, and by 
 the pulmonic veins it is poured into the left side of the heart. 
 
 9. The LEFT AURICLE of the heart is unlike the right auricle 
 in these respects : the sinus, or that part which consists of the 
 dilatation of the pulmonic veins, is smaller, while the auri- 
 cula, which is the more muscular part, is larger, the pulmonic 
 veins come in four great trunks from the lungs, two from the 
 right side and two from the left ; two great veins then enter at 
 each side of the left auricle, by which it gets a more square 
 form.; the whole of the left sinus, which forms the chief 
 bulk of this part, is turned directly backwards towards the 
 spine, and is not to be seen in any common \new of the heart ; 
 but I have here added a plan of the back part of the heart,* 
 shewing, 1. How the left ventricle lies behind ; 2. How the 
 left auricle is turned still more directly backwards ; 3. How 
 the pulmonic veins enter into it in four great branches, so as to 
 give a square or box-like form, compared with the gliding, 
 gentle shape of the right auricle ; 4. How the pulmonie 
 artery comes out from under the arch of the aorta, dividing 
 into its two great branches for each side of the lungs ; and, 5. 
 How the aorta arches over it, towers above all the other ves- 
 sels, and is known always among the vessels of the heart by 
 the carotid and subclavian arteries which come off from its 
 arch. On the plan. No. 6. are seen — (00) the two pulmonic veins 
 entering from each side of the lungs — {j}p) the opening of 
 these into the auricle — [qq) the sinus formed in part by the 
 dilatation of these veins, and, — (r) the auricula or little ear, 
 from which the whole bag is named auricle. 
 
 10. The valves which guard the left auricle are seen heref 
 (ss) ; — Now it is to be remembered that the left auricle is 
 
 * Explanation of the back view of the he-abt, No. 9. 
 
 1. The loft V'^entricle — -2, The left Auricle — 3S3 3, The four Pulmonic Veins — 4 4. 
 The two great branches of the Pulmonic Artery — 5, Tlie Aorta — 6, Tlia Carotids and 
 Subclavians— 7, The Cava Descenderis — 8, The Cava Ascendens, with all its branches 
 from the Liver — 9, The great Coronary Vein running along the back of the Heart betwixt 
 the Auricle and Ventricle in a groove surrounded by fat. 
 
 t This begins the description of the left side of the heart, and the description follow* 
 the plan, No. 6. 
 
328 
 
 OF THE MECHANISM 
 
 smaller than the right, that the circle or opening of the left 
 auricle is of course smaller than that of the right ; that while 
 it requires a valve divided into three points to fill the opening 
 of the right auricle, a valve divided only into two points 
 suffices for the opening of the left auricle ; this is the reason 
 of this slight variety of shape betwixt the two auricular valves, i 
 and is also the reason of the valve of the right side being 
 called TRICUSPID or three-pointed, while this of the left side, 
 from some very slight resemblance to a mitre, is named 
 VALVULA MiTKALis, tile MITRAL VALVE. Ill all Other points 
 this valve is the same with that of the right side, it has the ; 
 same apparent thinness, for it is even transparent, the same 
 real strength, the same column^e carneie and tendinous 
 strings to support it ; the same rough irregular surface towards 
 the opening of the auricle ; the same smooth gutter leading j 
 
 towards the artery. The constitution of all these parts, in | 
 
 short, is expressly the same ; so that even concerning the left 
 ventricle there is nothing further to be observed, but that 
 while it is much longer than the right ventricle, it is much 
 smaller in its whole cavity, is much stronger in its columnar 
 carnea:, and much thicker in its fleshy walls, as at (it) where 
 it is seen to be thicker than the right ventricle, it is indeed 
 nearly three times as thick. 
 
 11. The SEMILUNAR VALVES of the aorta are also seen in 
 this general plan at (w) — where manifestly the general struc- 
 ture, and general intention of the valves are the same as in i 
 those of the pulmonic artery; but still we find at every point 
 marks of superior strength and more violent action in the left 
 side of the heart ; for though this valve be expressly like that 
 of the pulmonic artery, and named like it semilunar, yet it 
 
 is thicker and stronger in its substance, and is peculiarly 
 guarded by three small hard tubercles, which being placed ^ 
 one in the apex or point of each valve, meet together when 
 the valve is close, and give a more perfect resistance to the 
 blood, and prevent the valve being forced open. These are to 
 be seen chiefly in the opposite drawing, and from their being 
 of the size of sesamum seed, they have the name of Corpora 
 Sesamoidea ; sometimes they are named Corpuscula Arantii. 
 
 12. The AORTA arises from its ventricle very large and 
 strong ; it swells still more at its root than the pulmonic artery 
 does ; the three subdivisions of this sw'elling, which mark the 
 places of the semilunar valves, are very remarkable ; the cur- 
 vature at the arch of the aorta is called its great sinus, and 
 these three smaller bags are called the three lesser sinuses ol 
 the aorta. 
 
OF THE HEART. 
 
 329 
 
 Fig. 10. shows the 
 aorta entire, but its root 
 within the heart opened 
 so as to show its valve-(a) 
 The body of the aorta ; 
 the arch is marked by bh, 
 the carotids and subcla- 
 vians — (c) Shows one of 
 the coronary arteries or 
 artery of the heart. — (d) 
 A part of the walls of the 
 heart. — (e e e) The three 
 valves stuffed and turgid 
 
 towards the heart. 
 
 N“ 11. shows the lower 
 part of the aorta cut open, 
 and two of the valves — ^ 
 (a«) — entire ; and the 
 the third valve — {bh ) — 
 cut in two by slitting up 
 the artery. — And (rr) 
 shows the mouths of the 
 two coronary arteries. — 
 N° 12. shows the aorta 
 slit only in its lower part, 
 and the valves {aa) and 
 the mouths of the coro- 
 nary arteries { h) are 
 seen in their natural si- 
 tuation. — N. B. In these 
 two last drawings the 
 corpora sesamoidca are 
 distinctly seen in the 
 central part of the edge 
 of each valve, and they 
 need no letter to dis- 
 tinguish them. 
 
530 
 
 «F THE JlECHANlSjr 
 
 OF THE CORONARY VESSELS. 
 
 But there still remains to be explained that peculiar circi!' 
 lation by which the heart itself is nourished, and yet there is 
 nothing in it very different from the usual form of arteries and 
 Veins ; it is a part of the general circulation of the body, for 
 the heart is nourished by the two first branches which the 
 aorta gives off. The circulation destined for the nourishment 
 of the heart is peculiar in this chiefly, that the forms of the 
 arteries and veins of the heart are beautiful, and that the ar- 
 teries rise just under the valves of the aorta, while the veins 
 end with one great mouth in tlie right auricle. The coronary 
 arteries are two in number, of the size of crow-quills ; we see 
 from the inside of the artery their mouths opening above the 
 sigmoid valves. One artery comes from the lower side of the 
 aorta ; it lies towards the right ; it belongs chiefly to the right 
 ventricle ; it comes out first betwixt the roots of the aorta and 
 pulmonic arteries ; it passes in the furrow betwixt the right 
 ventricle and auricle, and turning round arrives at the back 
 part of the heart, and runs down along the middle of that flat 
 surface which lies upon the diaphragm ; and when it arrives at 
 the apex of the heart, its extreme arteries turn round the 
 point and inosculate with the opposite coronary. The other 
 coronary belongs in like manner to the left side of the heart, 
 and arises from the upper side of the aorta ; it first goes out 
 betwixt the pulmonic artery and the left auricle, and then 
 turning downwards upon the heart, it runs along that groove 
 which is betwixt the ventricles, and marks the place of the 
 partition or septum ventriculorum ; its chief branches turn 
 towards the left ventricle, and branch out upon it; it belongs 
 as peculiarly to the left side of the heart as the other does to 
 the right side : after supplying the left ventricle, &ic. it turns 
 over the point of the heart to meet the extremity of the first, 
 and inosculate will) it. Both these arteries give branches not 
 only to the flesh of the ventricles, but to the auricles, and also 
 to the roots of the great arteries, constituting the vasa vaso- 
 RUM, as such minute branches sent to vessels are called. 
 
 The GREAT coronary vein which collects the blood of 
 these arteries, arises in small branches all over the heart ; 
 these meet so as to form a trunk upon the forepart of the 
 heart where the septum or union of the ventricles is. While 
 small, the veins accompany their respective arteries ; but after 
 the great trunk is formed, the vein takes its own peculiar 
 route. When the trunk of the great coronary vein (accom- 
 panied by several lesser veins) arrives at the auricle, it runs in 
 
OP THE HEART. 
 
 331 
 
 feetwcen the left auricle and left ventricle ; it turns all round 
 the back of the auricle till it gets to the right side of the 
 heart ; it lies in the deep groove betwixt the auricle and ven- 
 tricle, surrounded with much fat ; and having almost entirely 
 encircled the heart, it discharges its blood into the I'ight 
 auricle, close by the entrance of the lower cava. The open- 
 ing is very large ; it lies just above the tendinous circle of the 
 auricle, and it is guarded with a strong semilunar valve. This 
 is the great coronary vein ; all the veins which appear upon 
 the heart are but branches of it ; what are called the middle 
 vein of the heart, the vein of the right auricle, the vena in- 
 nominata, &ic. are all but branches of the great coronary vein 
 running along the right side or lower surface of the heart ; if 
 there were to be any marked distinction, it should be into the 
 GREAT CORONARY VEIN belonging to the left side of the heart, 
 and the vena innominata belonging to the right side. But 
 one thing more is to be observed ; viz. that upon the inner 
 surface of the right auricle may be seen many small oblique 
 and very curious openings, which serve for the mouths of 
 veins, while their obliquity performs the office of a valve. 
 This name of coronary vessels is a very favourite one with 
 anatomists, and is applied wherever vessels surround the parts 
 which they belong to, however little this encircling may be 
 like a crown ; and it is thus that we have the coronary arteries 
 of the stomach, coronary arteries of the lips, and coronary 
 arteries of the heart. But these vessels of the heart are really 
 very beautiful, and have some things very peculiar in their cir- 
 culation : first, with regard to the coronary arteries, they lie 
 with their mouths under the sigmoid valves ; or at least in so 
 equivocal a manner, that their peculiar posture has given rise 
 to violent disputes ; viz. whether they be filled, like all the 
 other arteries, by the stroke of the heart, or whether they be 
 covered by the valve so as to let the blood rush past them during 
 the action of the heart. 
 
 We see the opening of the coronary arteries rather, as I 
 imagine, under the valve; though Haller says they are above 
 the valve, and that the highest point to which the margin of 
 the valve reaches in very old men is below the opening of the 
 coronary artery, and half way betwixt it and the bottom of the 
 sinus or little bag behind the valve. But let this be as it will, 
 if the condition of the aoi'ta be considered, it will be found to 
 make no difference ; for though the valves rise and fall, are at 
 one time fully opened, and at another time closely shut, still 
 in both these conditions of the valve the aorta is as full as it 
 can hold ; its contraction instantaneously follows that of the 
 heart, but its contraction is not, like that of the heart, surh 
 
332 
 
 OF THE MECHANISM 
 
 as to bring its sides together ; on the contrary, the aorta is 
 full when tlie heart strikes, the action of the heart distends it 
 to the greatest degree, the aorta re-acts so as to free itself of 
 this distention, but still it remains in some degree full of blood ; 
 else how could this, like every other artery, preserve always 
 its form and apparent size? In this condition of matters, it is 
 obvious that the coronary branches are on the same footing 
 with all the other branches of the aortic system ; that, like all 
 the other arteries, they first feel the stimulus of fulness from 
 the push of the heart, and along with it the stroke of the 
 aorta. 
 
 Secondly, with regard to the coronary veins a dispute has 
 arisen more violent than this ; for it has been doubted whe- 
 ther the coronary veins, large as they are, do actually convey 
 the whole of the blood which the coronary artery gives out. 
 Veussens believed that some of the coronary arteries opened 
 directly into the cavities of the heart, without the interposi- 
 tion of veins, Thebesius, after him, believed that there 
 were some shorter ways by which the blood was returned ; not 
 by a long circle into the right auricle, but directly into the 
 ventricles of the heart. Veussens, Thebesius, and others who 
 belong to their party, pretended to prove this fact by injec- 
 tions : but what doctrine is there which such clumsy anatomy 
 and awkward injections may not be made to prove ? They 
 used mercury, tepid water, and air; and they forced these, 
 the most penetrating of all injections, till they exuded upon 
 the inner surface of the heart ; but if they had fixed their 
 tubes, not into the coronary artery, but into the aorta, and 
 had proceeded to inspect, not the heart, but all the viscera of 
 the body, they would have found their injections exuding from 
 every surface; of the pleura and lungs; of the peritoneum, 
 and intestines ; of the brain and dura mater ; of the mouth 
 and tongue; and universally through the cellular membrane 
 of the whole body ; but if any coarse injection, as tallow or 
 wax, be used, following this natural course, it keeps within the 
 arteries and veins, and if thin and well prepared, finds its 
 way back to the auricle of the heart ; but this injection 
 also is extravasated and is found in the cavities of the 
 heart. 
 
 Du Verney was so far engaged in this question, that having 
 an opportunity of dissecting the heart of an elephant, he tied 
 up the coronary arteries and veins, washed and cleaned very 
 thoroughly the cavities of the heart; and then tried, by 
 squeezing, and all kinds of methods, to make that blood 
 wdiich \ras tied up in the coronary arteries and veins exude 
 upon the inner surface of the heart, but with no effect. 
 
^7'07?l f/u'I£f(f7'f- of (( (7u7d 
 (xhout S 07'^ j/oo7\? old . 
 
 of t/ie diatffs , b.b, f7ie jPer'icaj^iium hj/ io7nc7t t7ieJfoa7t /j sns- 
 ■/fonded , c.c,t7ieJ7mfr7c7t’s of t7tt\Hfa7^, d.d. t7ze^oTta eziczrcled t7e 
 d^er7oei7'dium , e.e.e.e. t7ie frzZ^edznoazz a7id Cczroizd uir-tenes, g. t7ie jzrzidoff' 
 ptrrt of t7iediT7/7ft^7t7^c7c, ~\\.f7zr (^rroa de^rozzdozis- 7h/ 7o7uc7i t7ieJfeoTt 
 j?ort S7{^j?e7ide7f , \.x.t7ie Cava Offrezidezz^c ioit7i ajoenczl jzazfsed uj? into dz.r 
 dii^^/zt.AiznWo , t7u‘sj7 077077 is- boTiind 777e^7istac7iia77J7i77'o,/'7te-Enstar7aa7f 
 TTili^o itself IS 7nnr7ied k, tTie h'ttloT'alve oft7ze CoTonary Tiiii ivbizo/i is oon- 
 Tieotf’ii ivitT? if is marA'od m . 
 
OF THE HEART. 
 
 333 
 
 On the present occasion, a theoretical answer happens to 
 be as satisfactory as the most correct experiments : and it is 
 this, If there really were to be formed (by disease, for ex- 
 ample,) those numerous openings which Thebesius and Veus- 
 sens describe, then the blood flowing all by these shorter and 
 easier passages, none could come to the great coronary vein ; 
 its ofiice would be annihilated ; and itself, contracting gradu- 
 ally, would soon cease to exist. 
 
 OF THE EUSTACHIAN VALVE. 
 
 There remains to be explained in the mechanism of the 
 heart one point ; and which I have separated from the others j 
 not because it is the least Important, but because it is the 
 most difiicult, and, if I may be allowed to say so, not yet 
 thoroughly understood ; I mean the anatomy of the Eusta- 
 chian valve; which, if it bad been easily described, should 
 have been first described ; for it is a valve which lies in the 
 mouth of the lower cava, just where that vein enters the right 
 auricle of the heart. How imperfect a valve this is, how 
 difficult to dissect or to explain, may CEisily be known from 
 this, that Winslow was first incited to look for the valve by 
 some hints in Sylvius : he was soon after fairly directed to it 
 by finding it in the tables of the Eustachius, which were then 
 first found and published by Lancisi, after the author had 
 been dead 150 years ; and yet with all this assistance Winslow 
 sought for it continually in vain, till at last he reflected, that 
 by cutting the heart in its forepart, he must have always in 
 his dissections destroyed any such valve ; by opening the 
 back part of the cava he at last saw the valve, and demonstra- 
 ted it to the Academy of Sciences in France ; and having just 
 received from Lancisi his edition of the Eustachian Table, 
 so long hidden, and since so outrageously praised, he called 
 it VALVULA Eustachiana, a name which it has retained to this 
 day, and he added keticulakis, to express its lace-like netted 
 appearance at its upper edge. From Winslow’s time to this 
 present day, that is, for eighty years, there has been no good 
 drawing, nor even any perfect description of the valve ; and 
 in the confusion of opinions upon the subject, what its use 
 may be no one knows. 
 
 The Eustachian valve lies in the mouth of the ascending 
 cava, just where that great vein is joined to the auricle of the 
 heart. It looks as if formed merely by the vein entering at 
 an acute angle, and by the inner edge of the vein, or that 
 which is joined to the auricle, rising high, so as to do the 
 
334 
 
 OF THE MECHANISM 
 
 office of a valve. The very first appearance of the valve, ant! 
 its place just over the mouth of the cava, seems to point out 
 that use which Lancisi has assigned it, viz. to support the 
 blood of the upper cava, and prevent that column of blood 
 which descends from the cava gravitating upon the opposite 
 column which comes from the liver and lower parts of the 
 body ; and yet this, most likely, is not its use. The valve 
 somewhat resembles a crescent, or the membrane called hy- 
 men. It occupies just that half of the cava which is nearest 
 the auricle. Its deepest part hangs over the mouth of the 
 cava, and is nearly half an inch in breadth, seldom more, 
 often less, sometimes a mere line. Its two horns extend up 
 along the sides of the auricle ; the posterior horn arises from 
 the left of the isthmus, as it is called, or edge of the oval hole ; 
 its anterior horn arises from the vena cava, where it joins the 
 auricle. Behind the valve the remains of the foramen ovale 
 may be seen, now shut by its thin membrane, but still very 
 easily distinguished ; for its arch-like edges are so thick, 
 strong, and muscular, that they look like two pillars, and 
 thence are called the columns; fokaminis ovalis : these two 
 pillars were called isthmus Vieussenii, and by Haller are 
 named annulis fossae ovalis, while the remains of the hole 
 itself is so deep that it is named the fossa ovalis. Before 
 the Eustachian valve lies the great opening into the ventricle ; 
 but betwdxt that and the valve there is a fossa or hollow, in 
 which lies the opening of the great coronary vein ; and the 
 valve which covers the coronary vein is a neat small slip of 
 w'hite and very delicate membrane, the one end of which con- 
 nects itself with the forepart of the Eustachian valve ; so that 
 both valves are moved and made tense at once. 
 
 The Eustachian valve is in general thick and fleshy ; it is 
 sometimes reticulated or net-like even in the foetus, but by no 
 means so often as to vindicate Winslow, in adding reticulare 
 to the name; it grows reticulated chiefly in the adult. The 
 only beautiful drawing that we have of a reticular Eustachian 
 valve is in Cowper • and that was from a man of eighty years 
 of age. Perhaps in eight or ten hearts you will not find one 
 that is reticulated in the least degree ; in old men it is reticu- 
 lated, just as all other valves of the heart are, not by any thing 
 peculiar to the constitution of this valve; not by the pressure 
 of the blood and continual force of the vessels, as Haller re- 
 presents ; but by the gradual absorption which goes on in old 
 age, and which spares not the very bones, for even they grow 
 thin and in many places transparent. 
 
 This is the simple description of a valve, which has been 
 the occasion of more controversy than the circulation of the 
 
©F THE HEART. 
 
 335 
 
 foetus and the use of the oval hole Winslow first began about 
 eighty years ago to observe the connections and uses of this 
 valve ; he laid it down as an absolute fact that this valve was 
 almost peculiar to the foetus ; that it was perfect only while 
 the foramen ovale was open ; that it vanished gradually as the 
 foramen ovale closed ; that in the adult it was seldom seen 
 unless the foramen ovale was also open by chance. It is in- 
 credible what numbers of anatomists followed this opinion ; for 
 the difficulty of dissecting the valve made it always easier to 
 say that it was only in the foetus that it could be found : it is 
 also incredible what absurd consequences arose from this doc- 
 trine, which, after all, is but a dream, for in fact the valve is 
 more easily shown in the adult heart.^' 
 
 The foundation being now laid for connecting this valve with 
 the peculiar circulation of the foetus, they conceived the folloAV- 
 ing theory, which has come down to this very day ; viz. that 
 in the child, the great object of nature in arranging its vessels, 
 was to convey the blood which came fresh from the mothers 
 system directly into the carotids, and so plump into the head 
 at once. The pure blood from the mother comes through 
 the liver by the ductus venosus ; it is deposited in the lower 
 cava at the right side of the heart; and these anatomists sup- 
 posed that this current oi fresh blood was directed by the Eu- 
 stachian valve into the oval hole, through that into the left auri- 
 cle and ventricle, and from these directly into the aorta and 
 carotids ; w’bile the foul blood of the upper cava went down 
 into the right auricle and ventricle, and from that into the 
 ductus arteriosus, and so away down to the lower and less noble 
 parts of the body, and to the umbilical arteries, and so out of 
 the system ; for the ductus arteriosus, which comes from the 
 right ventricle in the foetus, joins the aorta only as it goes down 
 the back, and none of its blood can pass upwards into the head. 
 
 This is the puerile theory, which, modified in various ways, 
 has amused the French Academy, or rather been the cause of 
 a perpetual civil war in it, for a hundred years. This doctrine 
 began with Winslow, it is still acknowledged by Sabatier; 
 and Haller, after announcing a theory not at all differing from 
 this, challenges it as his own theory ; “ hanc meam conjectii- 
 
 * One author, I 6nd in the Acta Vindobonensia, is exceedingly angry indeed with all tiie 
 great anatomists, for not connecting more strictly with eacli other, the anatomy and accidents 
 of the foramen ovale, and Eustachian valve ; with Morgani, Albinus, and V/iedbriecht, he 
 IS oftended for saying that tliey had seen the foramen ovale open, without saying one word 
 concerning the state of this valve ; and witli Lieutaud, Portal and others again, he is equally 
 offended that they should have had opportunities of seeing the Eustachian valve entire with- 
 out inquiring into the condition of the oval hole. The reason of all this is very plain ; the 
 oval hole had not been oiien, neither in the one sifuafion nor in the other, else it is veiy un - 
 likely that such correct and anxious anatomists should have described that valve which arises 
 Irom one of the borders of the oval hole, without observing it open, if it was so ; especially as 
 the oval hole, bdng open, is by no means an nnusin! occurrence. 
 
336 
 
 OF THE MECHANISM 
 
 ram etiam a Nichols video proponi.” Of the truth of this 
 theory Haller was so entirely satisfied, that he not only pub- 
 lished it as peculiarly his own, but reclaimed it when he thought 
 it in danger of being thus apprt>priated by another. Sabatier 
 is the last in the train of authors ; and in order that there might 
 remain no ambiguity in what they had said or meant, he pro- 
 nounces plainly that the Eustachian valve is useful only in the 
 fcetus, and that there are two opposite currents in the right 
 auricle of the heart; that the one goes from the lower cava 
 upwards to the foramen ovale, while the other from the upper 
 cava descends right into the opening of the ventricle. What 
 shall we say to anatomists, who, in the narrow circle of the 
 auricle, conceive two currents to cross each other directly, and 
 to keep as clear of each other as the arrows by which such 
 currents are usually represented. This error in reasoning is 
 below all criticism ; it carries us backwards a hundred years 
 in anatomy and in physics ; and yet this is alt that Winslow, 
 Haller, Sabatier, and a mob of others, have been able to say 
 in proof of the connection of the Eustachian valve with the 
 circulation of the fcetus. 
 
 Lancisi, again, believed that it was chiefly useful by support- 
 ing the blood of the lower cava, defending it from the weight 
 of that column of blood which is continually descending from 
 above ; and Winslow and. others approved of this, as being 
 perhaps one use of the valve. But they have all of them for- 
 gotten a little circumstance, which must afiect the office of the 
 valve, and which should have been regarded especially by those 
 who said it was useful chiefly before birth ; they have forgot- 
 ten a little circumstance, which John Hunter also forgot, when 
 theorvzing about the gubernaculum testis, viz. that the child 
 lies with its head downmost for nine months in the mother’s 
 womb. 
 
 Nothing is more certain than that the Eustachian valve is 
 not peculiar to the fcetus; that it has no connection with the 
 oval hole ; that the valve is often particularly large after the 
 foramen ovale is closed ; that the valve is often obliterated 
 where yet the foramen ovale remains open ; that in adults it is 
 more easily demonstrated than in children ; that in old age it 
 is often reticulated as the other valves are. Its use relates 
 neither to the foramen ovale, nor to the ascending cava ; it re- 
 lates to the auricle itself, and therefore it is found in all the 
 stages of life, smaller or larger, according to the size or form 
 of the heart. 
 
 The auricle on the side towards the venae cav® is imperfect; 
 the anterior part of the auricle chiefly is muscular, and when it 
 contracts, the laxity ofthecavas and the great width of the sinus 
 
VOL.I/. 
 
 
 Lriiry. I'rll/pt . 
 
 n.i rj thr i^jiJar/nav 'Va! I'fi . 
 
 p.td. 
 
 N” 10 
 
OF THE HEART. 
 
 337 
 
 VENOSDS, {i. e.) of almost the whole auricle, would take away 
 from its contraction all effect ; but to prevent this, and to make 
 the auricle perfect, the vena cava and auricle meet so oblique- 
 ly, that the side of the cava makes a sort of wall for the auricle 
 on that side. This wall has entirely and distinctly the reticu- 
 lated structure of the auricle itself, with fleshy bands of mus- 
 cular fibres in it; this wall falls loosely backwards when the 
 auricle is quite relaxed, as, for example, when we lay it open ; 
 and thus it has got the appearance and name without the uses 
 of a valve ; but when the heart is entire, tense, and filled with 
 blood, this valve represents truly a part of the side of the auri- 
 cle : and that this part of the wall of the auricle should be oc- 
 casionally a little higher or lower, looser or tenser, we need not 
 be surprised. This further may be observed, that wherever, 
 as in a child, this valve is very thin and delicate, the anterior 
 part of the fossa ovalis goes round that side of the auricle par- 
 ticularly deep and strong. Let it also be remembered, that 
 in certain animals this valve is particularly large and strong ; 
 now, in a creature which goes chiefly in a horizontal posture, it 
 may strengthen and make up the walls of the auricle, (the chief 
 use wiiich I have assigned for it in man ;) but surely it cannot- 
 protect the blood of the lower cava from the weight of blood 
 coming from above, since the body of an animal lies horizon- 
 tally, and there is no such weight. The Parisian academicians 
 describe the heart of the Castor in the following terms ; “ Un- 
 der the vena coronaria we find the valve called nobilis (viz. 
 the Eustachian valve,) which fills the whole trunk of the vena 
 cava, and which is so disposed that the blood may be easily 
 carried from the liver to the heart by the vena cava, but which 
 is hindered from descending from the heart towards the liver 
 through the same vein.”* 
 
 * Eustachian Valve. 
 
 No. 14 explains merely the placecf the Eustachian valve, which is seen at (m.)— No. 15. 
 explains both * he place of the valve and its relation to the oval hole (e) — behind it, and to 
 the month of the ventricle (n) — wliich lies before it. 
 
 In both these plans— (o) Is the cava decendens — (6) The aorta rising behind it — (cc) 
 The back of the auricle slit open— (d) The cava ascendens, in the mouth of which the valve 
 IS — (e)^ The foramen ovale — (Jf) Its two rising borders, named pillars, isthmus of Vieus- 
 sens, annulus ovalis, &c. — (m) The Eustachian valve, of which the two cornua, or sharp 
 Mints are .seen in the lower plate, terminating in the pillars of the foi-amen ovale on one 
 hand, and in the walls of the auricle on tae otlier. The opening of the foramen ovale (e) 
 — is behind and above the valve; the opening into the right ventricle (n) — is before and 
 under the valve. 
 
 No 14. erplains more particularly the uses of the valve. Some authors conceived that 
 it directed the blood rising in the line (o)— upwards into tho ov ,'iole : others that it direct- 
 ed tue co'umn of blo.>J, represented by the arrow (p)— into tlie right ventricle; otheisthat 
 it protected the column (o)— from the weight of the column (?).—! r;a ler suppose that it 
 aompletes the auricle in the direction of the dotted hue (?)— and so strengthens it? action. 
 
 VOI.. I. U U 
 
338 
 
 OF THE ACTION 
 
 OF THE IRRITABILITY AND ACTION OF THE HEART. 
 
 But even this curious mechanism of the heart is not more 
 Tvonderful than its incessant action, which is supported by the 
 continual influx of stimulant blood, and by its high irritability 
 and muscular power ; for though we cannot directly trace the 
 various courses of its muscular fibres, there is not in the human 
 body any part in which the muscular substance is so dense and 
 strong. In the heart there can be no direct or straight fibres ; 
 for let them go off from the basis of the heart in what direction 
 they may, still as they belong to the one or the other ventricle, 
 they must by following the course and shape of that ventricle, 
 form an oblique line. Vesalius has not indeed represented 
 them so, he has drawn straight fibres only ; because in the lat- 
 ter end of his great work he was without human subjects, and 
 betook himself to drawing from beasts. 
 
 The fibres of the heart are all oblique, or spiral, some lying 
 almost transverse ; they all arise from a sort of tendinous line 
 which unites the auricle to the ventricle ; they wind spirally 
 down the surface till the fibres of the opposite ventricles meet 
 in the septum and in the apex of the heart. The fibres of 
 each ventricle pass over the convex or upper surface of the 
 heart, then over the apex, and then ascend along the flat side 
 of the heart, which lies upon the diaphragm, till they again 
 reach the basis of the heart. The second layer or stratum of 
 fibres is also oblique ; yet many of the fibres run almost trans- 
 versely, uniting the oblique fibres ; but when we go down into 
 the thick substance of the heart, we find its fibres all mixed, 
 crossed, and reticulated in a most surprising manner; so that 
 we at once perceive both that it is the strongest muscle in the 
 body, and that the attempt to extricate its fibres is quite ab- 
 surd.* Their desire of giving more correct and regular des; 
 criptions has been the cause why those who have particularly 
 studied this point have been fatigued and disappointed ; the 
 most sensible of them have acknowledged with Vesalius, Albi- 
 nus, and Haller, that the thing could not be done ; while those, 
 again, who pretended to particular accuracy, and who have 
 drawn the fibres of the heart, have represented to us such ex- 
 travagant, gross, and preposterous things, as have satisfied us 
 more than their most ingenuous acknowledgments could have 
 done, that they could also could accomplish nothing. 
 
 Tliickening the ivalls of the heart by vinegar, strong acids, alum, or boiling the heart, 
 have assisted us in unrayelling its structure but very little. 
 
OF THE HEAKT 
 
 339 
 
 There is no question that irritability is variously bestowed 
 in various creatures, that it is variously appointed in various 
 parts of the body, that this property rises and falls in disease 
 and health ; without hesitation we also may pronounce that the 
 heart is in all creatures the most irritable part ; it is the part 
 first to live and the last to die : “ Pulsus et vita pari ambulant 
 passu.” When we see the punctum saliens in the chick, we 
 know that there is life ; and when we open the body of an 
 animal soon after death, still the heart is irritable and con- 
 tracts. 
 
 In the very first days in which the heart appears in the 
 chick, while yet its parts are not distinguished, and the punc- 
 tum saliens is the only name vfe can give it, the heart, even in 
 this state, feels the slightest change of heat or cold ; it is 
 roused by heat, it languishes when cold, it is excited when 
 heated again. It is stimulated by sharp points or acids, it 
 works under such stimuli with a violent and perturbed motion. 
 In all creatures it survives for a long while the death of the 
 body; for when the creature has died, and the breathing and 
 pulse have long ceased, and the body is cold, when the other 
 muscles of the body are rigid, when the stomach has ceased 
 to feel, when the bowels which preserve their contractile pow- 
 er the longest have ceased to roll, and they also feel stimuli 
 no more, still the heart preserves its irritability; it preserves 
 it when torn from the body and laid out upon the table ; heat, 
 caustics, sharp points, excite it to move again. 
 
 We know also another thing very peculiar concerning the 
 irritability of this organ, viz. that it is more irritable on its in- 
 ternal than on its externa] surface ; for if instead of cutting 
 out the heart, we leave it connected with the body, seek out 
 (as the old anatomists were wont lo do) the thoracic duct, or 
 pierce any great vein, and blow a bubble of air into the heart, 
 it pursues it from auricle to ventricle, and from ventricle to 
 auricle again, till, wearied and exhausted with this alternate 
 action, it ceases at last, but still new stimuli will renew its 
 force. 
 
 Thus it is long after apparent drowning or other suffocation 
 before the principle of life is gone ; and long after the death 
 of the body before the heart be dead; and just as in this pe- 
 culiar part of the system irritability is in high proportion, there 
 are in the scale of existence certain animals endowed in a 
 wonderful degree with this principle of life. They are chiefly 
 the amphibious creatures, as they are called, needing little air, 
 which have this power of retaining life ; no stimuli seem to 
 exhaust them, there seems especially to be no end to the action 
 
340 
 
 OF THE ACTION 
 
 of their heart; a Newt’s or aToad’s heart beats for days after 
 the creature dies : a Frog, while used in experiments, is often 
 neglected and forgotten, its limbs mangled, and its bead gone, 
 perhaps its spinal marrow cut across, and yet for a whole night 
 and a day its heart does not cease beating, and continues obe- 
 dient to stimuli for a still longer time. It seems as if nothing 
 but the loss of organization could make this irritable muscle 
 cease to act ; or rather it seems as if even some degree of de- 
 ranged organization could be restored : breathe upon a heart 
 which has ceased to act, and even that gentle degree of heat 
 and moisture will restore its action. Dr. Gardiner having left 
 a turtle’s heart neglected in a handkerchief, he found it quite 
 dry and shrivelled, but by soaking it in tepid water its plump- 
 ness and contractility were restored. 
 
 Since, then, this irritable power supports itself in parts long 
 after they are severed from the body, what doubt should we 
 have that there is in the muscular fibre some innate contractile 
 power or vis insita independent of nerves.^ And when we talk 
 on a subject so difficult and so abstruse, what other proof can 
 we expect or wish for, than the power of one peculiar and in- 
 sulated muscle surviving the separation of the head and brain, 
 the destruction of its nerves, or its total separation from that 
 living system to which it belongs? If the heart be tlie mbst 
 irritable muscle of the body, if all this irritability arise from 
 the nerves, how can it be that this muscle, which is thus an- 
 nounced as the most dependent on its nerves, is really the 
 most independent.^ that the muscle which of all the body 
 needs this nervous supply oftenest should want it the least, and 
 should survive the loss of its nerves so much longer than the 
 other muscles of the same body ' 
 
 Although the ancients knew how irritable the heart was, 
 although they often opened living creatures, and saw the heart 
 struggling to relieve itself, because it was oppressed with blood, 
 yet they continued entirely ignorant of the cause : and why the 
 heart should alternately contract and relax without stop or in- 
 terruption, seemed to them the most inexplicable thing, in 
 nature. Hippocrates ascribed it to the innate fire that is in the 
 heart ; Sylvius said, that the old and alkaline blood in the 
 heart mixing with the new and acid chyle, and with the pan- 
 creatic lymph, produced a ferment there ; Swammerdam, 
 Pitcairn, and Friend, thought that the heart, and every 
 muscle which had no antagonist muscle, was moved by a less 
 proportion of the vital spirit than other muscles required. 
 Others believed that each contraction of a muscle compressed 
 the nerves of that muscle, and each relaxation relieved it ; 
 
OF THE HEART. 
 
 341 
 
 and that this altarnate compression and relief of the nerve 
 was the cause of the alternate movements of the heart: 
 another physician of our own country, a great mechanic, and 
 a profound scholar in mathematics, and all those parts of 
 science which have nothing to do with the philosophy of the 
 human body, refined upon this theory most elegantly ; for ob- 
 serving that the nerves of the heart turned round the aorta, 
 and passed down betwixt it and the pulmonic artery, he ex- 
 plained the matter thus : “ These great arteries, every time 
 they are full, will compress the nerves of the heart, and so 
 stop this nervous fluid, and every time they are emptied (a 
 thing which he chose to take for granted, for in truth they 
 never are emptied,) they must leave the nerves free, and let 
 the nervous fluid pass down to move the heart.’’ 
 
 Des Cartes, who studied every thing like a right philosopher 
 of the old breed, viz. by conjecture alone, supposed that a 
 small quantity of blood remained in the ventricle after each 
 stroke of the heart : which drop of blood fermented, became 
 a sort of leaven, and operated upon the next blood that came 
 into the heart, “ like vitriol upon tartar so that every suc- 
 cessive drop of blood which fell into the ventricle swelled and 
 pufied up so suddenly as to distend the heart, and then burst 
 ont by the aorta. Philosophers have been so bewitched with 
 the desire of explaining the phenomena of the human body, 
 but without dihgence enough to study its structure, that from 
 Aristotle to Buffbn, it is all the same, great ignorance and 
 great presumption. But on this subject of the pulse of the 
 heart, physicians almost surpassed the philosophers in the ab- 
 surdity of their theories, till at last they were reduced to the 
 sad dilemma of either giving up speaking upon this favourite 
 subject, or of contenting themselves with saying, “ that the 
 heart beat by its facultas pulsifica, its pulsative faculty as if 
 they had said, the jaws chew by their mandicative faculty, 
 and the bladder pisses by its expulsive faculty, and the womb 
 expels children by its parturient pow'er. 
 
 The ancients, I have said, often opened living creatures, 
 and saw the heart struggling to relieve itself because it was op- 
 pressed with blood : this blood is itself the stimulus which 
 moves the whole ; for important as this function is, it is equally 
 simple with all the others : and as urine is the stimulus to the 
 bladder, food an excitement to the intestines, and the full 
 grown foetus a stimulus to the womb ! — so is blood the true 
 stimulus to the heart. When the blood rushes into the heart, 
 the heart is excited and acts ; when it has expelled that blood, 
 it lies quiescent for a time ; when blood rushes in anew, it is 
 
342 
 
 OF THE ACTION 
 
 voused again : so natural is both the incessant action and regu- 
 lar alternation of contraction and relaxation in the heart. 
 
 It is when we are so cruel as to open a living creature that 
 we see best both the operation of the blood as a stimulus, and 
 the manner in which the heart re-acts upon it. When we tie 
 the two vena cavas so as to prevent the blood from arriving at 
 the heart, the heart stops ; when we slacken our ligatures and 
 let in the blood, it moves again ; when we tie the aorta, the 
 left ventricle being full of blood will continue struggling, 
 bending, turning up its apex, and contracting incessantly and 
 strongly, and will continue this struggle long after the other 
 parts have lost their powers. One author, whether from his 
 awkwardness, or the delicacy of the subject, or really from 
 the strength of the ventricle, assures us, that often while he 
 has held the aorta of a Frog close with pincers, it has burst by 
 the mere force of the heart. If, after violent struggles of this 
 kind, you cut the aorta, even of so small a creature as an eel, 
 it will throw its blood to the distance of three or four inches. 
 
 Thus we not only know that we can excite the heart by ac- 
 cumulating blood in it, but that by confining the blood in it 
 we can carry that excitement to a very high degree ; and in 
 short, by keeping the one or the other ventricle incessantly 
 full of blood, we can make the one heart work continually, 
 while the other lies quiet, or is only slightly drawn by the other’s 
 motion, showing the true distinction betwixt the heart of the 
 body and the heart of the lungs. And this is a memorable 
 fact, that it is not merely the stimulus of the blood, but the 
 sense of fulness that makes the heart contract; for the auricle 
 often beats twice or thrice, sometimes it makes its push four 
 or five times, before it can force the ventricle to contract. 
 
 When we empty the heart, and tie all its veins, all its parts 
 cease to act ; stimuli applied outwardly make it contract par- 
 tially ; it trembles in particular fibres : but it is only letting in 
 the blood, or blowing it up with air, that can bring it into full 
 action again. When we look with cruel deliberation upon the 
 strokes of the heart in any living creature, we observe that at 
 first, during the full and rapid action of the heart, there is 
 hardly any perceptible interval among the several parts ; but 
 towards the end of each experiment, when the pulse flags, 
 and the creature falls low, the swelling of the great veins, and 
 the successive strokes of auricle and ventricle, are distinctly 
 told. The dilatation and contraction of each part is what we 
 cannot observe, they are so quick ; but these things we dis- 
 tinctly observe : the auricle contracts and dilates the ventricle ; 
 the ventricle contracts, subsides, and fills the aorta ; the aorta 
 turns and twists with the force of the blood driven into it, and 
 
OF THE HEART. 
 
 343 
 
 by its own re-action, and the ventricle, every time that it con- 
 tracts, assumes a form slightly curved, the point turning up 
 like a tongue towards the basis, and the basis in some degree 
 bending towards the point. The basis, indeed, is in some 
 degree fixed to the diaphragm and spine, but the heart in its 
 contraction always moves upon its basis as upon a centre ; its 
 ventricles, and especially its apex, are free ; the point rises 
 and curves so as to strike against the ribs ; and the dilatation of 
 the heart is such (together with the posture and relation of its 
 several parts,) that during the dilatation the heart turns upon 
 its axis one way ; the contraction of the heart reverses this, 
 and makes it turn the other way, so that it seems to work per- 
 petually mth the turning motions of a screw. All this is most 
 striking, while we are looking upon the motion of the heart in 
 a living creature. 
 
 The posture of the human heart is very singular, and will 
 illustrate this turning motion extremely well ; for in the hu- 
 man heart the posture is so distorted, that no one part has 
 that relation to another which we should beforehand expect. 
 In the general system, the human heart is placed nearly in 
 the centre, but not for those reasons which Dionis has assign- 
 ed ; it is not in order that by being in the centre it may feel 
 less the difiiculty of driving the blood to any particular limb 
 or part of the body; it is the place of the lungs that regu- 
 lates the posture of the heart ; and wherever they are, it is. 
 Except the Oyster, I hardly know of any creature in which 
 the heart lies expressly in the centre of the body. In Frogs, 
 Toads, Newts, and Snakes, tbe lungs are not moved by any 
 diaphragm ; they are filled only by the working of the bag 
 attached to the lower jaw, the lungs then begin under the 
 jaws, and the heart is lodged at the root of the jaws, leaving, 
 as in a Newt or Cameleon, Crocodile, Adder, Serpent, &c. 
 the whole length of their trailing body behind. In a fish, 
 the gills serve the creature for lungs ; the gills are lodged un- 
 der the jaws, and the heart is placed betwixt them. In in- 
 sects, as in the common Caterpillar, (the aurelia of our com- 
 mon Butterfly,) the air enters by many pores on its sides ; 
 and accordingly its heart is not a small round bag, but may be 
 easily seen running all down its back, working like a long 
 aorta, but having regular pulsations, denoting it to be the 
 heart ; and this you easily see through the insect’s skin, for it 
 is more transparent along the back where the heart is. 
 
 The breast in man is divided into two cavities by a mem- 
 brane named the mediastinum. This membrane passes di- 
 rectly across the breast from the sternum before till it fixes 
 
344 
 
 OF THE ACTION OF THE HEART. 
 
 itself into the spine behind. It is on the left side of this 
 mennbrane, in the left cavity of the breast, that the heart is 
 placed, lying out flat upon the diaphragm, as upon a floor, by 
 which it is supported ; ^ and that surface {a) — which lies thus 
 upon the diaphragm, is perfectly flat, while the upper sur- 
 face (6) — or what we usually call the forepart of the heart, 
 is remarkably round. The whole heart lies out flat upon the 
 diaphragm ; its basis (c) — where the auricles are, is turned 
 towards the spine and towards the riL,ht side ; the apex {d ) — • 
 or acute point is turned foi wards and a little obliquely towards 
 the left side, where it strikes the ribs ; the vena cava (e) — 
 enters in sueh a manner through a tendinous ring of the 
 diaphragm,f that it ties down the right auricle to that floor 
 (as I may term it) of the thorax ; the aorta (/) does not rise 
 in that towering fashion in which it is seen when we take a 
 dried-up heart, which naturally we hold by its apex, instead 
 of laying it out flat upon tbe palm of our hand ; nor in that per- 
 pendicular direction in which hitherto, for the sake of distinct- 
 ness, I have represented it in these plans ; but the aorta goes 
 out from its ventricle towards the right side of the thorax ; it 
 then turns in form of an arch, not directly upwards, but ra- 
 ther backwards towards the spine ; then it makes a third twist 
 to turn downwards ; where it turns downwards it hooks round 
 the pulmonic artery, (^) — just as we hook the fore-fingers of 
 our two hands within one another. The right heart \h1i ) — 
 stands so before the other, that we see chiefly the right auricle 
 and ventricle before, so that it might be named the anterior 
 heart ; the pulmonic artery [g ) — covers the root of the aorta; 
 the left ventricle {i,) — from which the aorta rises, shows little 
 more than its point at the apex of the heart ; the left auricle 
 {k ) — is seen only in its very tip or extremity, where it lies just 
 behind the pulmonic artery ; and the aorta (/) — arises from 
 the very centre of the heart. From this view any man may 
 understand these vessels by other marks than the mere colours 
 of an injection ; and he will also easily understand why the 
 heart twists so in its actions, and how it comes to pass that its 
 posture is difficult for us to conceive, no one part having that 
 relation to any other part which we should beforehand sup- 
 pose. 
 
 * The true pasition of the heart is what is represented in No. 16. and 17. ; where No. 
 
 16. shows the heart set upright, as I have hitherto represented it in’aU my plans, while No. 
 
 17. represents its inclined position lying almost horizontally upon the floor of the 
 diaphragm. 
 
 t Let it be observed, that (e) in this drawing, marks the jrtint where the lower cava was 
 tied close upon the diapliragm, to prevent the injection going down into the veins of the 
 liver and abdominal cav». 
 

 X.SrU ilf! . J'.Mentrtck A*. 
 
of ///r. Pcricordiiorii of vliitJi ix o true, drawinfj/ If 19 aP]//,n 
 shewi its / /ifUxirjri- ow.r tt/j’, Ife^rC 
 
 I 
 
 P.3,. I 
 
OF THE PERICARDIUM. 
 
 345 
 
 OF THE PERICARDIUM. 
 
 But the PERICARDIUM, purse, or capsule, in which the 
 heart is contained, affects and regulates its posture, and makes 
 the last important point concerning the anatomy of the heart. 
 It is a bag of considerable size and great strength, which 
 seems to us to go very loosely round the heart, because when 
 we open tbe pericardium, the heart is quite empty and re- 
 laxed ; but I believe it to surround the heart so closely as to 
 support it in its palpitations, and more violent and irregular 
 actions ; for when we inject the heart, its pericardium remain- 
 ing entire, that bag is filled so full that we can hardly lay it 
 open with a probe and lancet without wounding the heart ; 
 and still further, when we open the pericardium before we in- 
 ject the heart, the heart receives much more injection, swells 
 to an unnatural bulk for the thorax that it is contained in, and 
 loses its right shape. The pericardium is formed, like the 
 pleura and mediastinum, of the cellular substance ; it is rough 
 and irregular without, and fleecy with the threads of cellular 
 substance, by which it is connected with all the surrounding 
 parts ; within it is smooth, white, tendinous, and glistening, and 
 exceedingly strong. As the heart lies upon the floor of the 
 diaphragm, the pericardium, which lies under the heart, is 
 connected with the diaphragm a little to the left of its ten- 
 dinous centre, and so very strongly that they are absolutely 
 inseparable. The pericardium surrounds the whole heart, 
 but it is loose every where except at the root of the heart, 
 where it is connected with the great vessels : for the pericar- 
 dium is not fixed into the heart itself, but rises a considerable 
 way upon the great vessels, and gives to the roots of the 
 vessels, which are seen on opening the pericardium, an out- 
 ward coat, and surrounds each vessel with a sort of ring, as 
 may be seen in the plan.* For, 1st, It surrounds the pulmo- 
 nic veins where they are entering the heart ; there the peri- 
 cardium is short : 2dly, It mounts higher upon the vena cava 
 than upon any other vessel ; the cava of course is longer with- 
 in the pericardium, and it also is surrounded with a sort of 
 ring : 3dly, It then passes round the aorta and pulmonic ar- 
 tery, surrounding these in one greater loop : 4thly, The cava 
 inferior is the vessel which is the shortest within the pericar- 
 dium : for the heart inclines towards the horizontal direc- 
 tion : it lies in a manner flat upon the upper surface of the 
 diaphragm, while the lower surface of the diaphragm ad- 
 
 * Vide Plan, No. 18. 
 
 VOU. I. X X 
 
346 
 
 OF THE PERICARDIUM. 
 
 Iieres to the upper surface of the liver. Thus it happens that 
 the liver and the right auricle of the heart are almost in con- 
 tact, the diaphragm only intervening ; thence the lower cava 
 which passes from the liver into the right auricle of the heart 
 cannot have any length. While the pericardium thus passes 
 round the great vessels, it must leave tucks and corners ; and 
 these have been named the cohnua, or horns of the peri- 
 cardium. 
 
 But there is another peculiarity in the form of the pericar- 
 dium, which I have explained in this second plan;* viz that 
 the pericardium constitutes also the immediate coat of the 
 heart; for the pericardium having gone up beyond the basis 
 of the heart so as to surround the great vessels, it descends 
 again along the same vessels, and from the vessels goes over the 
 lieart itself. I have marked the manner of this more delicate 
 inflection of the pericardium at (aa ,) — where the pericardium 
 is loose ; at (6//,) — the angle where it is reflected ; and at (cc,) 
 — where it forms the proper coat of the heart, and where it is 
 intimately united to its substance. The pericardium where it 
 forms this coat becomes extremely thin and delicate, almost 
 cuticular, but strong ; under this coat the coronary arteries 
 pass along in the cellular substance ; under it the fat is gather- 
 ed sometimes in a wonderful degree, so as to leave very little 
 to be seen of the dark or muscular colour of the heart. 
 
 The pericardium then is a dense and very strong membrane, 
 which I would compare with the capsule of any great joint, 
 both in office and in form : for it is rough and cellular without, 
 shining and tendinous within; bedewed with a sort of halitus 
 like the great joints, though perfect yet delicate in the child, 
 but increasing in thickness by the continual frictions of the 
 heart, just as a capsular ligament does by the working of its 
 joint ; and its uses are to keep the heart easy and lubricated 
 by that exhalation which proceeds from its exhalent arteries, 
 (and which can be imitated so easily by injecting tepid water 
 into its arteries) to suspend the heart in some degree by its 
 connections with other parts, especially by its connections 
 with the mediastinum and diaphragm. The pericardium 
 limits the distention of the heart, and checks its too violent ac- 
 tions; just as we see it prevent too much of our injections from 
 entering the heart. How strong the pericardium is, and how 
 capable of supporting the action of the heart, even after the 
 most terrible accidents, we know from this : that the heart or 
 coronary arteries have actually burst, but with a hole so small 
 -as not to occasion immediate loss of life ; then the pericardium 
 
 w. 
 
OF THE PERICARDIUM. 
 
 347 
 
 receiving tbe blood which came from the rupture, has dilated 
 in such a manner as to receive nine or ten pounds of blood, 
 but bas yielded so slowly as to support the heart in some kind 
 of action, and so preserved life for two or three days. 
 
 If I have not mentioned any fluid under the direct name of 
 AQUA PERICARDII, ortlie Water of the pericardium, it is because 
 I consider the accident of water being found as belonging not 
 to the healthy structure but to disease. Yet this same water 
 occupied the attention of the older authors in a most ludicrous 
 degree. Hippocrates believed that this water of. the pericar- 
 dium came chiefly from the drink we swallow, which found 
 some way or other (as it passed by the pericardium) to insinu- 
 ate itself into this bag. Some after him said, it was the fat of 
 the heart melted down by incessant motion and the heat of the 
 heart ; some said it was from humours exuding through the 
 heart itself, and retained by the density of the pericardium, that 
 this water came ; and it is but a few years since this clear and 
 distinct account of it was given, viz. “ that it proceeds from the 
 aqueous excrementitious humour of the third concoction.” The 
 same “ sad and learned men,* viri graves et docti,” declare 
 to us, that the uses of the aqua pericardii are to cool the heart, 
 for it is the very hottest thing in the body ; or by its acrimony 
 to irritate the heart, and support its motions ; or to make the 
 heart by swimming in it seem lighter. By this it is pretty ob- 
 vious what absurd notions they had of the quantity of water 
 that may be found in the heart. But of all the outrages against 
 common sense and common decorum, the most singular was 
 the dispute maintained among them, whether it was or was 
 not the water of the pericardium which rushed out when our 
 Saviour’s side was pierced with the spear ? The celebrated 
 Bardius, in a learned letter to Bartholine, shows how it was 
 the water of the pericardium that flowed out ; but Bartholine, 
 in his replication thereunto, demonstrates, that it must have 
 been the water of the pleura alone. This abominable and lu- 
 dicrous question, I say, they bandied about like boys rather 
 than men : Bartholinus, Arius, Montanus, Bertinus Nicelius, 
 Fardovius, Laurenbergius, Chiprianus, with numberless other 
 Doctors and Saints, were all busy in the dispute ; for which 
 they must have been burnt every soul of them, at the stake, 
 had they done this in ridicule ; but they proceeded in this 
 matter with the most serious intentions in the world, and with 
 the utmost gravity .f The whole truth concerning water in the 
 
 * They are thus denominated in all the charters of the College of Physicians from the 
 time of Henry VIII. downwards. 
 
 + The shocking indecencies of their reasonings on this subi’ect I will not condescend to 
 draw out from the obscurity of that barbarous idi«n in which it was delivered : “ Sed non 
 
348 
 
 OF THE PERICARDIUM. 
 
 pericardium is, that you find water there whenever at any time 
 you find it in any of the other cavities of the body. If a per- 
 son have laboured uader a continued weakness, or have been 
 long diseased, if a person have Iain long on his death-bed, if the 
 body have been long kept {ifter death, there is both a conden- 
 sation of the natural halitus in all the parts of the body, and an 
 exudation of thin lymph fi om every vessel ; there is water 
 found in every cavity, from the ventricles of the brain to ihe 
 cavity of the ankle-joint, and so in the pericardium among the 
 rest. But ifyouopen any living animal, as a Bog. or if you 
 open suddenly the body of a suicide, or a criminal who has 
 been just hanged, not a drop of water will be found in the pe- 
 ricardium. When such fluid is to be found, it is of the same 
 nature with the dropsical fluids of other cavities : in the child, 
 and in young people, it is reddish, especially if the pericardium 
 be inflamed ; in older people it is pellucid, or of a light straw 
 colour; in old age and in the larger animals it is thicker, and 
 more directly resembles the liquor of a joint. 
 
 Thus does the pericardium contribute in some degree to set- 
 tle the posture of the heart ; but still the heart is to a certain 
 degree loose and free. It is fixed by nothing but its great ves- 
 sels as they run up towards the neck, or are connected with the 
 spine ; but how slight this hold is, how much the heart must 
 be moved, and these vessels endangered, by shocks and falls, 
 it is awful to think. The pericardium is no doubt some re- 
 straint : its connections with the diaphragm and wdth the me- 
 diastinum, make it a provision, in some degree, against any 
 violent shoek ; its internal lubricity is, at the same time, a 
 means of making the heart’s motions more free : yet the heart 
 rolls about in the thorax ; we turn to our left side in the bed, 
 and it beats there ; we turn over to our right side, and the 
 heart falls back into the chest, so that its pulse is no where to 
 be perceived ; we incline to our left side again, and it beats 
 quick and strong. The heart is raised by a full stomach, and is 
 pushed upwards in dropsy ; and during pregnancy its posture 
 is remarkably changed ; it is suddenly depx’essed again wiien 
 the child is delivered, or the waters of a dropsy drawn olF; It 
 is shaken by coughing, laughing, sneezing, and every violent 
 elfort of the thorax. By matter collected within the thorax it 
 
 cogai- hue me conferre. Fateor enim nativam Chiisli temperiem nihil pravonim huniorum 
 produxissp, quia perfuctissima ; at a eausis externis, vigiliis.cruciatibus, itineribii?, '. iirnci'i- 
 busetmihe tormentis quid non prfeter con uetam natura? divinas perfectionem prorltictum 
 erefiimuii ? Ad hire sanosensu id aceifiienduiii, nihil pravoruin huinorum in corpore Cliiisti 
 generatiiin.” Bartholini Epistola-, p. 290. “ Idque de Salvatore innoxie dixeiis', quern 
 
 ^ciiiiT’.s ;n iidueasse, hibisse, dormivisse, ainbulatse, et quid non egisse, ut se lioinineni mnetis 
 actio i'liT qus -ecundumnatui'amsunl, fubinitteret : sputum emisit, quum Into mtsceret ad 
 curaviiimn 't.'ou.'j, et sudavit ing’uente mai'tyrio, et sine dubio non paiumseri in thorace 
 collegit, quod, aperto post moideip latere, qmanavit.” Bartholini Ejnstolce., p. 300. 
 
OF THE PERICARDIUM. 
 
 349 
 
 may be displaced to any degree. Dr, Farquharson cured a 
 fine boy, about eight years old, of a great collection of matter 
 in the chest, whose heart was so displaced by a vast quantity 
 (no less than four pounds) of pus, that it beat strongly on the 
 right side of the breast while his disease continued, and as 
 soon as the pus was evacuated, the beating of the heart re- 
 turned naturally to the left side. Who could have believed 
 that, without material injury, the heart could be so long and so 
 violently displaced.^ Felix Platerus tells us a thing not so 
 easily believed, that a young boy, the son of a printer, having 
 practised too much that trick which boys have of going upon 
 their bands with their head to the ground, began to feel ter- 
 rible palpitations in the left breast ; these gradually increased 
 till he fell into a dropsy from weakness, and died ; and upon 
 dissecting his body, the situation of his heart was found to have 
 been remarkably changed by this irregular posture. Now we 
 are not to argue that such change of posture of the heart couid 
 not happen merely frflm this cause, because professed tumblers 
 have not these diseases of the heart ; it were as silly to argue 
 thus against the authority of Platerus, as to say that every post- 
 boy has not aneurisms of the ham, or that every chimney- 
 sweeper has not a cancer of the scrotum. 
 
 We may now close this chapter on the mechanism of the 
 heart ; in which all the parts have been successively explained. 
 We know how the heart is suspended by the mediastinum, and 
 by its great vessels ; how it is lubricated, supported, and re- 
 gulated in its motions, by the pericardium ; its nerves, which 
 remain to be explained at a fitter time, are extremel}^ small, 
 while its vis insita, or irritability, is great beyond that of all the 
 other parts. We can easily follow the circle of the blood, 
 which, as it arrives from all the extremities, irritates the auri- 
 cle, is driven down into the ventricle, is forced thence into the 
 pulmonic artery, pervades the lungs, and then comes round to 
 the left side of the heart, or to that heart w'hich supplies the 
 body ; and there begins a new circulation, called the greater 
 circulation, viz. of the body, as the other is called the lesser 
 circulation of the lungs. Thus we recognise distinctly the 
 functions of the double heart, with all its mechanism ; the 
 stronger heart to serve the body, the weaker heart to serve the 
 lungs ; and we see in the plainest manner two distinct functions 
 performed by one compound heart : the right heart circulates 
 the blood in the lungs, w'here it is purified and renew-ed ; the 
 left delivers out a quantity of blood, not such as to fill all the 
 vessels, nor such as to move onwards by this single stroke of 
 the heart to the very extremities of the body, but such merely 
 its to give a sense of fulness and tension to the vessels : the 
 
350 
 
 OP THE HEART. 
 
 force Is merely such as to excite and support that action which 
 the arteries every where perform in the various organs of the 
 body, each artery for its appropriated purposes, and each in 
 its peculiar degree. 
 
 By understanding thus the true mechanism and uses of the 
 heart, we can conceive how the ancients were led into strange 
 mistakes, by very simple and natural appearances. We un- 
 derstand why Galen called the right auricle the “ ultimum 
 “ moriens,” or the part which died last; for, upon opening 
 the body soon after death, he found the right auricle filled with 
 blood, and still palpitating with the remains of life, when all 
 the other parts seemed absolutely dead ; and if the blood al- 
 ways accumulates on the right side of the heart before death, 
 -it is plain that the stimulus of that blood will preserve the I’e- 
 mains of life in the right side, after all appearance of life on 
 the left side is gone. But the cause of this accumulation of 
 blood in the right side is very ill explained by Haller, though it 
 seems to have employed his thoughts during half his life. He 
 says, that in our last moments we breathe with difficulty ; the 
 lungs at last collapse, and cease to act ; and when they are col- 
 lapsed, no blood can pass through them, but must accumulate 
 in the right side of the heart. That there is really no such 
 collapse of the lungs, I propose hereafter to show ; but, in 
 the meanwhile, this is the true reason, viz. that when the 
 ventricles of the heart cease to act, and the beating of the 
 heart subsides, the two auricles lie equally quiet, but in very 
 different conditions ; the right auricle has behind it all the 
 blood of the body pouring in from all parts during the last 
 struggles ; but the left auricle has behind it nothing but the 
 empty veins of the lungs ; nothing can fill it but what fills the 
 vessels of the lungs ; or, in other terms, nothing can fill the 
 left auricle but the stroke of the heart itself: but instead of 
 acting the heart falls into a quiescent state, the left auricle re- 
 mains empty, while the blood oozes into the right auricle from 
 all the extremities of the body till it fills up. 
 
 Nothing is more agreeable than to find such phenomena 
 described faithfully long before the reason of them is under- 
 stood. In the Parisian dissections I find the following des- 
 cription : “ When the breast of a living Dog is opened by 
 taking away the sternum, with the cartilaginous appendices of 
 the ribs, the lungs are observed suddenly to sink, and after- 
 wards the circulation of the blood and the motion of the 
 heart to cease. In a little time after that the right ventricle of 
 the heart and the vena cava are swelled, as if they were ready 
 to burst.”* This was what deceived the ancients, and was the 
 
 » Page 261. 
 
OF THE HEART. 
 
 351 
 
 cause of all their mistakes. When they found the right ven- 
 tricle thus full of blood, they conceived that it alone conveyed 
 the blood ; they found the left ventricle empty, and believed 
 that it contained nothing but vital spirits and air ; and so far 
 were they from having any notions of a circulation, that they 
 thought the air and vital spirits went continually forwards in the 
 arteries ; that the gross blood which \vas prepared in the liver 
 came up to the heart to be perfected, and went continually 
 forwards in the veins, or, if they provided any way of return 
 for these two fluids, it was by supposing that the blood and 
 spirits moved forwards during the day-time, and backwards 
 in the same vessels daring the night. 
 
 These things next explain to us why they called the right 
 ventricle ventriculus sanguineus ; they found it full of 
 blood, and thought its walls were thinner, because it had 
 only to contain the very grossest parts of the blood ; and why 
 they called the left ventricle ventriculus spirituosus and 
 NOBiLis because they saw it empty, and concluded that it con- 
 tained the animal spirits and aerial parts of the blood, and its 
 walls were thicker, they said, to contain these subtile spirits- 
 They explain to us their names of arteria venosa and vena 
 ARTERiosA ; for they would have veins only on the right side 
 of the heart, and arteries only on the left ; and although they 
 saw plainly that the pulmonic artery was an artery, they called 
 it Arteria. Venosa : and although, on the left side again, they 
 saw plainly that the pulmonic vein was merely a vein, they 
 would still cheat themselves with a name, and call it Vena Ar- 
 teriosa : the veins, they said, were quiet, because they con- 
 tained nothing but mere blood ; the arteries leaped, they said, 
 because they were full of the animal spirits and vital air. 
 
 The very name and distinction of arteries which -we now use, 
 arise from this foolish doctrine about air and animal spirits. 
 To the oldest physicians there was no vessel known by the 
 name of artery, except the aspera arteria; and it was 
 named Artery becausfe it contained air ; so that Hippocrates, 
 when he speaks of the carotids, never names them arteries, 
 but calls them the leaping veins of the neck. But when 
 Eristratus had established his doctrine about the vessels which 
 go out from the heart, carrying vital spirits and air, the name 
 of artery was transferred to them ; and then it was that the an- 
 cients began to call the vessels going out from the left side of 
 the heart, arteries, naming the aorta the arteria magna and 
 the pulmonic vein the ap.teria venosa. 
 
 When a vein was cut, they saw nothing but gross blood, 
 and of a darker colour ; but when an artery was cut, they 
 observed that the blood was red ; that it was full of air bub - 
 
3.52 
 
 OF THE HEAni. 
 
 bles ; that it spurted out, and was full of animal spirits ; and 
 thus it became easy for them to show how safe it was to open 
 a vein where nothing was lost but gross blood, how terribly 
 dangerous it was to open an artery which was beating with 
 the spirit of life; and this they considered as such an awful 
 difference, that when arteriotomy in the temple was first pro- 
 posed. they pronounced it murderous, and on this reasoning 
 it was absfilutely forsaken for many ages. 
 
 But the oldest of our modern physicians soon found a ne- 
 cessity of mixing this blood and animal spirits together, and 
 for a long while could hit on no convenient way by which 
 this mixture might be effected : as a last shift, they made the 
 blood exude through the septum of the heart ; and then the 
 current doctrine was, that of the blood which came from the 
 liver, one half went into the pulmonic artery to nourish the 
 lungs : the other half exuded through the septum of the heart, 
 to mix with the animal spirits. Riolanus was the bitter enemy 
 of Harvey and of his noble doctrine ; and this is the misera- 
 ble and confused notion, not to call it a doctrine, which he 
 trumpeted through Europe in letters and pamphlets. To 
 make good this miserable hypothesis, Riolanus, Gassendus, 
 and many others, saw the necessity of having side passages 
 through the septum of the heart. I really believe from their 
 mean equivocating manner of talking about these passages, 
 that they had never believed them themselves.* “ The 
 chyle,” says Bartholine, “ and the thinner blood, passes 
 through the septum of the heart, when the heart is in systole 
 and the pores and passages are enlarged.” Thus did the 
 celebrated Bartholine believe the septum perforated. Wal- 
 Ifeus, and Merchetti, and Mollinettus and Monichen, believed 
 it, and Mr. Broadbecquius of Tubingin proved it.f But I 
 believe most potently with Haller, that whenever they wanted 
 to show those perforations, they managed their probes so as 
 to make passages as wide and as frequent as the occasion re- 
 quired : “ Solebant foramina parare adigendo stylos argenteos 
 in resistens septum,” says Haller; and this is a full and true 
 account of all the authors who have described side passages 
 through the septum of the heart ; they needed them, and 
 they made them. 
 
 Amidst all this ignorance, we cannot wonder that a thou- 
 sand childish imaginations prevailed, nor that the qualities of 
 the mind were deduced from the physical properties of the 
 
 * That 1 may not seem to speak too liarshly of this knot of conspirators against Harvey, 
 
 I will quote what Boerhaave says of Riolanus, who was at the head of them ; “ Non ipse 
 callidus cavillationura artifex Riolanus,” &c. 
 
 t Experimento perforatum ostendit Broadbecquius Tubinga;, 
 
OF THE HEART. 
 
 353 
 
 heart. We have heard the vulgar, for example, speak of the 
 bone of the heart. And from whom did this arise ? From 
 Aristotle ! who explains to us, that there is at the root of the 
 heart a bone which serves for its basis; and not a physician 
 has written upon the heart since his time who has not spoken 
 more or less mysteriously about this bone ; while in truth the 
 whole story means nothing more than this, that where the 
 basis of the arteries are fixed into the hard ring or basis of 
 the heart, the place is extremely firm, almost cartilaginous, 
 especially in old age, when often the roots of the arteries 
 are ossified or converted into what anatomists have chosen to 
 call bone. 
 
 Often also we have heard the vulgar talk, not figuratively, 
 but in the plain sense of the words, of a little or big heart, as 
 synonymous with a timorous or courageous heart. But when- 
 ever we hear mistakes of this kind among the vulgar, w’e may 
 be assured they have some time or other come from high 
 authority. Bartholine was so much convinced that a small 
 heart begot courage, and a great one irresolution and fear, 
 that he is thoroughly surprized when he finds the contrary; 
 “ Cor vastus fuit homo, tamen audax fuerat, ut cicatrices in 
 capite frequentes et rimss in cranio testabantur.” But if Bar- 
 tholine be right, Kirkringius is quite wrong, and has mistaken 
 the doctrine; for he says, “An magnanima fuerit h^ec niagni 
 cordis foemina, nescio,” &c. “ I do not know whether this wo- 
 
 man’s courage was as big as her heart; but this I do know, 
 that she was a famous toper. Whether this drinking dilates 
 the heart, and makes your staunch drinkers such famous fight- 
 ers, I cannot pretend to decide.” We have heard the vulgar 
 talk also of a hairy heart, as familiarly as of a hairy man, be- 
 ing the mark of high courage and strength ; but what shall 
 we think of it, when we find that this report is to be deduced 
 fairly from Pliny, through the most celebrated names among 
 our old physicians He it was who began with telling bow 
 the Messenians, that unhappy people, who lived for so m my 
 ages the slaves or helots of Greece, lost their great 
 general Aristomenes. But how great he was, never, accord- 
 ing to Pliny, came to be known till after his death ; for the 
 Lacedemonians having catched him three limes, resolved at 
 last to open his breast; and there as a proof of his most in- 
 vincible courage and daring, they found his heart filled with 
 hair. This from Pliny was nothing, if such dissections bad 
 not been made since then an hundred times. “ There was a 
 robber, (says Benivinius,) one Jacobus, who having beeii taken 
 down from the gibbet apparently dead, but really having in 
 him the remains of life, was laid carefully, recovered, was 
 VOL. j. Y y 
 
354 
 
 OF THE HEART. 
 
 perfectly restored, betook himself to his old ways again ; and 
 so in the natural course of things came round to his old mark 
 the gallows, and was this time very thoroughly hanged. 
 Wondering (says Benivinius) at the perfect wickedness of this 
 man, I longed very anxiously to dissect the body, and I actu- 
 ally found the heart, not covered, but (refertum pilis) crammed 
 with hair.” 
 
 But there is, in fact, no end of wonders and wonderful dis- 
 sections among these robbers of his. His next subject was 
 not a bold robber, but a poor sneaking thief (de corde furis 
 cujusdam ;) there was no hair to be expected in his heart ; but 
 as he was a thief only, it was consistent with this doctrine that 
 he should be first very heartless ; secondly, have very little 
 brain ; thirdly, that he should have very inordinate appetites 
 and desires. Now there was first a great two-legged vein 
 carrying the atrabilis, the source, no doubt, of all his inordi- ■ 
 nate cravings, directly into to stomach. Secondly, there was 
 a great abscess full of pus wasting the left side of his heart ; 
 and, thirdly and lastly, the back part of the head (which all I 
 
 the anatomists of that time knew very well was the seat of j 
 
 memory) was in him so small that it could hardly contain a j 
 
 spoonful of that kind of brain ; and this want was the reason | 
 (having so little memory) that he was so persevering a thief; i 
 
 for let you whip him, banish him, clap him in the stocks, he j 
 
 forgot it straightway, and was back at his old tricks again, like j 
 
 a dog to his vomit.* | 
 
 But these are now almost forgotten, though perhaps the ,[ 
 
 history of the absurdities of the human genius should no n)ore ji 
 
 be neglected than of its beauties. Is it not delightful to feel, 1 
 
 that after floating in this ocean of conjecture, after all these 
 disorderly and wild dreams, we are come to have an idea of i; 
 
 the heart, simple and beautiful; of a heart containing within | 
 
 itself two functions; first, the otfice of renewing the blood ; | 
 
 secondly, the office of animating the arteries, and by them S 
 
 preserving in life and action the whole system of the body ? 
 These are the two offices which I shall now proceed to 
 explain. 
 
 ii 
 
 * “ Non videntur silentio esse pratereunda, quse nuper in inciso Jacobi cujusdam furis J 
 insignis cadavere annotavimus : hifurcatarn scilicet venam quae a lieue ad ventriculum atram i 
 defert bilem, turn et ahscessum in sinistro cordis ventre pituita redundantem; postiemo et 
 posteriorem ejus capitis partem, uhi memoiiae sedes est, adeo brevem, ut tantillam cerebri ' 
 portiunculam contineret. Quam oh causam, cum priorum scelerum et eorum quae pro his 
 saepe passus fuerat, tormenta scilicet, exilia et carceres initiime recordaretur, toties ad vo~ 
 mitum tanquani canis impudens reversus est, ut in laqueum tandem incident, vitseqiie ae 
 fttrti finem fecei'it.” — Vid. Bmwinins. 
 
( 355 ) 
 
 CHAP. II. 
 
 t~S THE APPEARANCE AND PROPERTIES OP THE BLOOD, Olj 
 
 THE CHEMISTRY OF OUR FLUIDS, AND ON THE INFLUENCE 
 
 AVHICH AIR HAS UPON THEM. 
 
 By the simplest methods the blood can be resolved into 
 various parts, but chiefly into these three ; the red globules, 
 which give colour to the blood ; the gluten, which gives con- 
 sistency and nutritious qualities to the blood ; and the serum, 
 which dilutes, mixes, and suspends the whole. 
 
 Though the serum and gluten did not pass entirely unnoticed, 
 the red globules were the part of the blood which first excited 
 the attention of physicians, and seemed to promise a rich har- 
 vest of discoveries ; a promise which too surely never was ful- 
 filled. The red particles have always appeared important, be- 
 cause they seem to give the colour, the useful qualities, and 
 the whole character to the blood. It is by the rolling of the 
 red particles only that we see the circulation in the micros- 
 cope ; it is red blood only that we ever name as blood ; and 
 the colour of the red blood changes in health and disease. 
 But when physicians studied this part alone, when they gave 
 it the mark of chief importance, and annexed to it alone the 
 name of blood, they little thought how far they over-rated 
 its importance, how far the red particles are from nourish- 
 ing the system, from being essential to the blood, from being 
 universal in all creatures. They bad not considered what 
 myriads of animals, great as well as small, want the red par- 
 ticles, and (if these red particles are to be the characteristic) 
 want blood ; while philosophers of less contracted notions 
 have continued to call that fluid blood, which fills the vessels 
 of plants. 
 
 The Harveian doctrine had no sooner produced a revolu- 
 tion in the general doctrines of physiology, or physicians be- 
 gun to think of the heart and its circulation, of the great ar- 
 teries, and extreme vessels, of the difference betwixt arteries 
 and veins, and of the ways in which the fluids move through 
 the smaller tubes (for they saw them moving by their micros- 
 copes;) no sooner did all these phenomena and new wonders 
 present themselves to their imaginations, than they thought 
 also of curious ways by which these motions and secretions 
 might be explained. They then began to estimate the calibres 
 
356 
 
 OF THE BLOOD. 
 
 of the arteries, to calculate with great affectation of care the 
 shape, the size, the composition, as they choose to call it, of 
 the particles of the blood ; chimeras and fancies sprung up 
 innumerable ; and it happened unfortunately that for a long 
 while physicians studied nothing but angles, and logarithms, 
 and algebraical equations ; they reasoned according to those 
 sciences only which have no connection with the physiology 
 of the animal body ; they calculated the force, the thickness, 
 the dimensions of the heart ; the diameter, and the strength 
 of walls, and the direction of the aorta ; their experiments 
 consisted in fixing clumsy tubes into the arteries, or in calcu- 
 lating the whole quantity of blood by bleeding an animal to 
 death ; they applied nothing but the laws of hy'draulics, {i. e.) 
 of fluids rising and falling in rigid tubes, to explain the active 
 arteries of a living body : in short, in explaining the living 
 body they forgot that it was alive. But now the age of infal- 
 lible proofs and demonstrations has passed over, and the works 
 of Keill, Pitcairn, Borelli, are quite neglected. 
 
 This disordered and miserable state of science, which con- 
 tinued for a century nearly, arose from those red particles of 
 the blood engrossing too much attention, and from their being 
 allowed an importance which does not belong to them; al- 
 though one must still acknowledge that they are very sur- 
 prising, because they are very unaccountable, at least 1 do 
 not know that any natural or likely use for them has been yet 
 assigned. 
 
 Leeuwenhoek, looking through his glasses, saw that this 
 which gave the red colour was the most permanent character- 
 istic part of the blood ; he saw that this part consisted of red 
 particles floating in the serum ; he found, or pretended to find, 
 that they were of the same size in a man as in a fo tus ; in a 
 chick as in a hen ; in a whale or elephant, he found them the 
 same as in a mouse or minnow ; merely because it was con- 
 venient for him to find it so. 
 
 But poring still longer over these particles, he perceived 
 that the great globules were so far imperfect as often to break 
 in pieces, and roll about in the serum in separate parts ; and 
 he always found that there were six less parts composing the 
 greater globule of the blood. By looking more and more, he 
 pretended to observe, that these smaller parts into which (he 
 red globules broke down still preserved their form ; that these 
 were the particles of the serous part of the blood; and that 
 the great or red particles frequently^ broke dov/n into serous 
 particles, and these again as frequently united and composed 
 afresh a red globule. He pretended to find, that exactly six 
 smaller globules went to make up one great one ; and he 
 
OF THE BLOOD. 357 
 
 called the red and serous globules the globules of the first and 
 second order. 
 
 By this notion of orders it was plain that he intended to 
 plunge deeper into this hypothesis, and to have at least a third 
 and fourth order ; besides, these orders and particles were at 
 his call, he might do as he pleased ; and he was almost the 
 only person possessed of glasses which could enable the physi- 
 ologist to see and tell about them. He pored till he believed, 
 or at least made others believe, that he saw globules of a third 
 order, six times smaller than the serous globules, and of course 
 thirty-six times smaller than the red globules. And thus he 
 had lymphatic particles, six of which made up one serous 
 particle ; and serous particles, six of which niade one red 
 globule. 
 
 To the geometrical physiologists of that day all this in- 
 struction concerning the structure of the blood was most de- 
 lightful ; it corresponded very notably with their calculations 
 about regularly descending series of vessels ; and a most 
 curious method did they find out for settling this law of the 
 branching of arteries. They took the plates of Eustachius, 
 measured with compasses the arteries and veins, estimated the 
 angles at which each branch goes off, compared the several 
 branches with the parent trunk; and from such calculations 
 they settled the general law as heartily and freely, as if, in- 
 stead of the most extravagant plates in all anatomy, they had 
 been measuring actually the human body itself. Thus they 
 had set up their doctrine of angles, branches, anastomoses, 
 trunks, and extreme vessels : they had found that there was a 
 a regular series of descending arteries; they had a tube now 
 suited to every descending particle that Leeuwenhoek could 
 invent : and when a particle had got into a wTong vessel, it 
 could go back till it found a tube that suited it : or if driven 
 into a wrong bore, it could break itself down into serous or 
 lymphatic particles. But when many particles did stick hard 
 in the straight places, then there was an error loci : then the 
 big particles were out of their peculiar vessels, and then the 
 part began to be red: thence came inflammations, fevers, 
 deeper obstructions : and from such causes, or from the break- 
 ing down of the bood and humours, came every disease that 
 could be named. 
 
 So very greatly were they delighted with the discovery, that 
 Dr. Martin, who had measured the vessels, as I have just told, 
 and had dreamt over this the longest and soundest of them all 
 speaks of it in these rapturous terms. “ But we are moreover 
 certain from the observations of that most Accurate and curious 
 observer of the minima naturas, that there are innumerable 
 
35B 
 
 OF THE BLOOW. 
 
 vessels of such a smallness that none of these globules eould 
 pass; so that it is necessary to suppose inferior classes of 
 globules of the fourth, fifth, sixth, and other orders. — Whence 
 by analogy we are to conceiv'e globules of the third order made 
 up of six globules of the fourth order, and these of six of the 
 fifth order, and so on ad infinitum through various degrees, the 
 number of which we are not to take upon us to determine.” 
 This is a pleasant addition of Dr. Martin’s ; and makes it a most 
 manageable system of most dilatable materials, stretching so 
 as to suit all occasions. This rider or codicil to the doctrine 
 made it easy for every particle to pass every vessel ; but, alas ! 
 it leaves no room for that old catchword of the system, the er- 
 ror loci, nor any provision for making diseases. 
 
 How ail the physicians in Europe could digest this absurdity, 
 of yellow particles, by aggregation and arrangements in sixes 
 and sixes, becoming red, is not easy to conceive ; nor is it easy 
 to conceive how men, w'hose education in mathematics and 
 algebra should have taught them to think accurately and rea- 
 son closely, could believe that globules should break down into 
 six particles each, and that these particles, being themselves 
 particles of serum, should yet be distinctly seen floating in the 
 serum. How could these geometrical physicians possibly be- 
 lieve, that these particles, from large to small, should descend, 
 not gradually and imperceptibly, but by sixes and sixes, one 
 after another like steps of stairs.^ In all his mathematics, I do 
 not belive that Martin could find any contrivance fit to help him 
 out of these difficulties. Martin observes, in his own way of 
 geometry, and proceeds to prove it by most laborious schemes, 
 “that just six small sphericles should go to make up one larger 
 globule, if you were to choose the most convenient and firm- 
 est way of constructing it and then he winders at Leeuwen- 
 hoek finding it exactly so. But if Leeuwenhoek knew this as 
 well as Dr. Martin, I cannot for my heart think it any wonder 
 that Leeuwenhoek chose “the most convenient and firmest 
 way of constructing a red globule, viz. out of six smaller ones.” 
 Seeing that he had the affair entirely in his own hands, “what 
 a beautiful haumony and rkgulaktiy do we perceive,” says 
 Martin, “ in the mass of blood ! Magnum certe opus oculis vi- 
 deo.” In plain truth, they desired but a little of this harmo- 
 ny, a little consistency in their doctrine, and all was well. 
 
 But the mistakes concerning the formation or organizing of 
 this blood are worse than these; for they came from men truly 
 learned, and diligent in anatomy, led on by too strong a desire 
 of finding out the uses of several parts of the human body, as of 
 the spleen and thymus, parts hitherto unexplained Mr. Hew- 
 son supposed that the lymphatic glands, which seem at first to 
 
0F THE BLOOD, 
 
 359 
 
 be mere convoluted vessels, but which being injected with 
 mercury, and cut into, are seen to consist of numerous cells, 
 form in these cells the priniorciia of the red blood ; for each 
 red particle he supposes to consist of a central particle, which 
 is solid and dark-coloured, surrounded by a vesicle which is 
 transparent or white ; and this dark or central part he supposes 
 is formed in the lymphatic cells; for he finds a sort of lound 
 particles in the lymph, and often he finds the lymphatics full 
 of red blood. 
 
 Next, be has supposed that in the child there is required a 
 much greater supply of blood; for this purpose is the thymus 
 appointed ; viz. to assist the lymphatic glands in organizing 
 blood. This gland lies in the upper part of the chest, is great 
 in the child, has vanished in the adult, but while it exists, he 
 finds it full of a milky juice or whitish mucus, fit to make cen- 
 tral particles for the blood ; and the lymphatics, as he supposes, 
 are the excretories for this gland. He next conjectures, that 
 this work, begun thus by the lymphatic glands, and thymus, is 
 perfected by the spleen ; that the lymphatics make central par- 
 ticles only, while the vesicular coverings are formed in the 
 spleen; so that there only do the particles become perfect; 
 and accordingly of these parts it is in the spleen alone that the 
 red blood is found. 
 
 As the central particles are formed in the cells of the lym- 
 phatic glands, the vesicular parts are formed in the cells of the 
 spleen, and the lymphatics unload these cells of the particles 
 when completely formed ; but there appears no other proof 
 that they do this office than that there are cells in the spleen 
 which may make vesicles ; and that the lymphatics being tied, 
 and the spleen squeezed, red gloubles are sometimes found in 
 them. 
 
 Long poring over a wearisome subject, and an intense de- 
 sire to finish that account of the blood which he had so success- 
 fully begun, are strong apologies for all these mistakes. No 
 man will venture to deny, that the glands and lymphatic ves- 
 sels probably accomplish some important changes upon all 
 fluids which pass through them ; but that they alone organize 
 the blood, is not to be conceived. Their containing round 
 white particles, argues nothing; these exist in the chjle, and 
 probably in that condition pass into the blood. But if the foe- 
 tus requires a great supply of blood, and the thymus assists the 
 lymphatic glands, bow comes it, when both lymphatic glands 
 and thymus are working in concert to prepare a great quantity 
 of blood, that the spleen, which is to finish all these particles, 
 and to make vesicles for them, is not in a child as big as its 
 liver is ? 
 
360 
 
 OF THE BLOOD. 
 
 That red globules are found in the lymphatics, and most 
 especially in the lymphatics of the spleen, is a most ordinary 
 occurence, and quite intelligible. There are not found any 
 where, not even in the spleen, imperfect globules advancing in 
 their organization ; on the contrary, those which we do find 
 are full formed globules which have been forced out of the 
 common line of circulation ; they are extravasated, and taken 
 up by the absorbents before death ; or they are squeezed into 
 them by handling after death. If we want to have an example 
 of the first, we have but to inflame a part and tie up its lym- 
 phatics, and then many red particles are found in them; the 
 second we see every time we either look for, or prepare the 
 lymphatics of the spleen, or of any other soft viscus; for by 
 handling and squeezing, the blood passes through the small 
 breaches occasioned by this violence into the lymphatics ; if 
 we allow the part to spoil, then air is generated, and, by hand- 
 ling it, air passes into the lymphatics in the same way. 
 
 But the spleen is essential to finish the work ; it makes the 
 vesicles, and has cells for the business ; and yet this part, 
 which has the most important of all offices, viz. that of organi- 
 zing the general mass of blood, may be cut out from dogs 
 and other animals, and they never feel the loss, nor decline in 
 health. There is not the smallest doubt that the spleen has 
 protruded at wounds, and been strangled, and so cut off. 
 Every day we find it more or less diseased ; sometimes it has 
 swelled to thirty or forty pounds ; sometimes it has been re- 
 duced to an extremely small size ; sometimes it has been 
 found like an empty bag. 
 
 In the foetus, as in a chick, for example, red blood circulates 
 in great profusion long before its lymphatics, spleen, or thy- 
 mus, can be seen to exist : whereas, on the contrary, since the 
 chick is insulated, and has no red blood from the mother, the 
 spleen should have been first coloured, and all the red blood 
 of the system should have emanated from the spleen. 
 
 It is but a poor evasion to say, in answer to these objec- 
 tions, “ some other part may perform this office of the spleen.” 
 What other parts will perform the office of the liver, if it be 
 wanting ’ or of the kidney, or of the testicle, or of any other 
 gland ? or will the testicle secrete urine, or the kidney secrete 
 bile ? What gland, then, will be able to perform so peculiar an 
 office as this of adding vesicles or coverings to the central parts 
 of the blood ? 
 
 After all this long dream about the vesicles and their cen- 
 tral parts, the best physiologists of the present day seem to 
 deny that they exist. 
 
 But one author has finished this career of useless specula- 
 
OF THE BLOOD. 
 
 361 
 
 tion, by maintaining that the life is in the blood : and thus 
 ive have seen this simple and beautiful subject of the blood 
 tortured through all kinds of imaginations, and running its 
 fiery ordeal, first through mathematics, then through anatomy 
 and all its glands, then through metaphysics ; till at last we 
 are come to talk with the most perfect ease and confidence 
 about the most monstrous of all absurdities, the life of the 
 blood. 
 
 “ For in the blood is the life thereof,” might be a useful 
 doctrine among the Jews, if it moderated their desire for 
 blood ; and if among physicians this were to be the tendency 
 of such a doctrine, it were very cruel and unnatural to disturb 
 it : but, in serious earnest, it introduces into modern physiolo- 
 gy nothing but a jargon of words, and perverts every idea that 
 the mind of man can form of parts which excite and parts 
 which act. Whimsical theories creep faster into physic than 
 useful facts ; and the business is fairly enough begun when 
 surgeons, dissecting aneurisms of the carotid arteries, and 
 who should be employed in recording how and from what 
 causes they have arisen, or how such diseases affect the arterial 
 coats, choose rather to inform us “ that this state of the blood, 
 or rather of the coagulable lymph, may arise from some con- 
 nection or sympathy it may have with the diseased state of 
 the artery.” “ By lightning, (says a celebrated author,) death 
 is so instantaneously produced in the muscles, that they can- 
 not be affected by the stimulus of death.” Connections, and 
 unknown sympathies, and living powers in fluids, and energies, 
 and efforts, and intentions, and “ sympathetic congelations in 
 the blood,” and “ immediate sympathetic contiguous harmo- 
 nies of cut parts,” and the “ diffused principle of life,” and 
 “ the stimulus of death are words which physiology would 
 gain by losing, and are the very cant belonging to the doctrine 
 which I propose to refute. 
 
 It is not merely the doctrine of a living principle existing in 
 the blood that is now to be spoken of, but a doctrine attri- 
 buting the life of the solids to this living principle of the 
 blood ; so that it may be entitled “ the new theory concerning 
 the blood, which is itself alive, which gives life to all the other 
 parts, and which in the beginning forms all the parts out of 
 itself in the mother’s womb ; so that a foetus is merely a speck 
 of blood, and all the parts being formed from that speck of 
 blood, the whole of physiology is abrogated henceforward, 
 and totally annulled, except this theory itself. It is like the 
 staff of Moses converted into a serpent, which ate up the ser- 
 pents of all the magicians who had thrown down the staff be- 
 fore him ; for if this theory were once established, there would 
 
 VOL. I. Z z 
 
3G2 
 
 OF THE BLOOD. 
 
 remain nothing to be done in all the animal body but what 
 was done by the blood ; nothing to wont'er at, nothing to 
 guess about, nothing to study, but this vital and plastic power 
 of the blood. 
 
 The author of this doctrine shows us two or three specks 
 in an incubated egg ; he tells us that they are dots of blood ; 
 he tells us that this blood forms the vessels in whicli this blood 
 itself is to move ; it forms the limbs of the chick which these 
 vessels are to serve ; the bones, muscles, bowels, glands, the 
 whole creature is formed out of it; and when the bird is deli- 
 vered from the egg, the living principle of the blood still con- 
 tinues to support it. The blood heals its flesh or bones when 
 they are broken ; “ the blood moves in the living solids, whicli 
 it both forms and supports.” 
 
 It is not easy to say on which of all his proofs Mr. Hunter 
 chiefly relies for establishing a doctrine so important as this 
 is ; whether he considers it as a perfect proof of the vitality 
 of the blood that it coagulates, or that this coagulum has 
 moreover the power of becoming perfectly alive, and of form- 
 ing new vessels within itself; or that blood seems to assist the 
 union of contiguous parts ; or that by taking away its blood a 
 creature dies ; or that a limb falls into immediate gangrene 
 when its vessels and its supply of blood are cut off. But 
 chiefly he seems to rely on coagulation as a proof of the vi- 
 tality of the blood ; for he considers the coagulation of the 
 chyle as a proof that it also is alive ; and he says, “contrac- 
 tion is the life of the solids ; and if we can find any thing like 
 it (by which he means coagulation,) we shall call it tbe living 
 principle of the blood.” 
 
 But what harmony he can find betwixt the occasional, vo- 
 luntary,. regulated, contractions, of the living solid and this 
 sudden, irretrieveable, inorganic, coagulation of the blood, I 
 cannot conceive. Does not jelly coagulate ; and what is it 
 but a part of the blood Does not glue congeal, dissolve, and 
 congeal again, yet what is it but an animal jelly? Does the 
 blood itself ever congeal till it is out of the body, orextrava- 
 sated in aneurismal sacs.^* When it is out of the body it co- 
 agulates ; when it coagulates, It is dead : coagulation is so far 
 from resembling the contractions of the living body, that it is 
 the marked character of dead animal matter, which you melt 
 and coagulate again and again. Shall we then define life by 
 saying, coagulation is the mark of the vital principle ? If so, 
 we give the mark of its death as the proof of its living power. 
 
 But in his awkward attempts, to prove this point, the author 
 
 * From tbe most recent inquiries no jelly appears to be in the blood. C. B, 
 
OF THE BLOOD. 
 
 363 
 
 bas brought himself into great suspicion, and of course into 
 great dishonour, by two experiments, in which he endeavours 
 to show how this vital power, like the life of a perfect crea- 
 ture, is affected by cold first. In page 79, we are informed, 
 that a fresh egg, in consequence of being alive, resists the 
 cold, and is frozen with great difficulty ; but being once frozen 
 and thawed again, it loses its living principle and its power of 
 resisting cold at once ; it freezes now at the same tempera- 
 ture with other animal matter, show’ingno longer any power of 
 generating heat, or resisting cold. 
 
 But we are told,* that the blood having a determined pe- 
 riod for coagulating, you may during that time freeze the blood, 
 and it will thaw again, and yet congeal at its proper time ; and 
 he tells us, that be had very cleverly frozen blood in the very 
 time of its flowing from the vein, then thawed the cake, and 
 still in due time it congealed. Now since the egg resists cold 
 by its living principle, why did it die or lose that living prin- 
 ciple when converted into ice ? or rather since the blood co- 
 agulates through its living principle, and by a living effort, how 
 did it preserve its living principle after being frozen.^ This 
 proves surely, either that the blood’s coagulation lias no re- 
 lation to any living principle, and therefore is not affected by 
 the cold : or that the egg has a living principle of a very dif- 
 ferent kind, which is absolutely and totally extinguished b)'^ 
 cold. I am sure that had Mr. Hunter seen these two experi- 
 ments brought face to face in this manner, he would have put 
 one of them at least back quietly into the portfolio from 
 which they both came. I have always observed, that your 
 great tellers of experiments need to have good memories; 
 and I am come to look on a suite of experiments as coolly as 
 upon a set of neat plans and figures by w’hich the author 
 chooses to illustrate his hypothesis. 
 
 That this coagulurn, being once formed, has the power of 
 becoming more perfectly alive, and forming vessels within 
 itself, it is not easy to conceive. Nothing indeed is more 
 common than clots of blood, or depositions of 4he coagula- 
 ble part, becoming highly vascular, by vessels shooting into 
 them from surrounding parts ; but this is of no value in 
 Mr. Hunter's doctrine ; this is not the fact which he means to 
 speak of ; this is much too natural and easy for him : and that 
 his meaning may neither be misrepresented nor mistaken, I 
 quote his words; “ When new vessels are formed, they are 
 not ahvays elongations from the original ones, but vessels 
 newly formed, which afterwards open a communication with 
 the original.” That a clot of mere blood should have in it 
 
 Page 87. 
 
364 
 
 OF THE BLOOD. 
 
 a living principle, and should possess through that prin- 
 ciple the power of forming within itself arteries and 
 veins, a new and independent circulation ; that it should 
 have the privilege of knowing when it should exert itself thus, 
 is really wonderful ; that it should have some kind of intelli- 
 gence, or consciousness, by means of which it could under- 
 stand when it were within and w'hen without the body ; and 
 whether in certain circumstances it were fit that such vessels 
 should be formed ! That clots should have been busied 
 forming vessels within them for ages, and no body ever have 
 seen the process going on ! That Mr. Hunter, who has been 
 looking out for vascular clots for thirty years, never should 
 have seen this phaenomenon is all very surprising. Mr. Hunter 
 falls into a deeper blunder in this business than in the affair of 
 the frozen egg; he absolutely never saw a proper vascular 
 clot. He informs us most deliberately in page 92., “ that he 
 thinks he has been able to inject what he suspected to be the 
 beginning of a vascular formation in a coagulum, when it 
 could not derive any vessels from the surrounding parts.” 
 From whence then did this clot derive its injection ^ This 
 is a question which detects at once what Mr. Hunter was do- 
 ing, and puts this experiment pretty much upon a footing 
 with the frozen egg. 
 
 To say “ that the blood, in some circumstances, unites liv- 
 ing parts by a sort of contiguous sympathy as certainly as the 
 yet recent branches of one tree unite it with another,” is to 
 put forth a syllogism, in which both major and minor proposi- 
 tions are untrue. First, it is not true, that it is the juices of 
 the tree which unite the graff to the stock ; it is the living 
 fibres, and the living vessels of both ; and unless both be 
 alive, the process must fail, living juices would do no good. 
 Secondly, though the juices did so unite or glue together the 
 branches of a tree, that were no proof of the juices being 
 alive; but only that good juices, whether alive or not alive, 
 were necessary to the process. 
 
 Any man who affirms that in surgical operations it is the 
 blood, “ that by a contiguous sympathy unites the parts,” 
 should have supported his assertion by this further argument, 
 that without blood they will not unite. Prove to me only that 
 fresh cut parts are not alive, and cannot naturally unite with- 
 out the assistance of some foreign power, and then I will 
 acknowledge v/illingly that they are altogether beholden to the 
 intermediation of the blood, with its living principle, and sym- 
 pathy of contiguity. 
 
 But it is very singular that any person, even the least in- 
 ■ structed in forms of reasoning, should have advanced this as 
 
OF THE BLOOD. 
 
 365 
 
 any proof of living principle in the blood, “ that mortification 
 immediately follows where the circulation is cut off for this 
 proves merely, that the blood is one of many stimuli, by which 
 the system is supported, insomuch, that each limb is affected 
 just as the whole body would be ; and whether you stop the 
 blood, which is one stimulus, or take away its heat, which is 
 the stimulus next in power to the blood, the limb will equally 
 die. 
 
 To say that the life is in the blood, because the blood be- 
 ing taken away the limb dies, or because an animal may be 
 bled till it dies ; what is this but to jumble all distinction of 
 cause and effect The water, no doubt, is the life of the mill, 
 and the plough-horse is the very life of the plough ; for the 
 mill and the plough are dead the moment that the horse is 
 gone or the water fails. 
 
 Lastly, we are told “ that it is by the contiguous sympathy 
 of the blood and body both being alive, “ that they both work 
 upon each other mutually : but it is not very strange for any 
 physiologist to forget, that the blood is at least in part a foreign 
 body, that it must be continually impregnated with air, that it 
 is neither its original constitution, nor these presumed sympa- 
 thies that make it vital blood, that it becomes vital blood only 
 by exposure to air, and that if this foreign principle be not 
 continually added, the solids are not wrought upon by the 
 blood ? 
 
 The natural difficulties of this doctrine are very great ; for 
 it seems to be against all the laws of nature that any fiuid should 
 be endowed with life. A fluid is a body whose particles often 
 are not Homogeneous, have no stable connection with each 
 other, change their place by motion, change their nature by 
 chemical attractions and new arrangements ; a body which can 
 have no perfect character, no permanent nature, no living 
 powers connected with it. But the definition of a solid is the 
 reverse of this : a solid among every kind of metals, earths, or 
 fossils, is recognized by its peculiar form, and arrangement of 
 parts: and in the animal body, the arrangement of particles 
 gives the permanent unchanging character of each part ; and 
 in the muscles, for example, or in the nerves, where feeling 
 and irritability chiefly reside, the form and mechanism of the 
 solid is in each most peculiar, and is always the same. 
 
 What is this blood, that it should begin life and support it, 
 and distribute it through all the system Is it not a fluid which 
 varies every hour, now richer, now poorer, now loaded with 
 salts, now drowned in serum, now much, now sparingly sup- 
 plied with air, now darker coloured, now red, now fully sup- 
 
 * There is no proof tiiat oxygen is absorbed in respiration, but only carbon removed. 
 
366 
 
 OP THE BLOOD. 
 
 plied with chyle, and row starvedof its usual supply? Is it not 
 lost in astonishing quantities in hirmorrhages, and drawn very 
 freely from our veins upon the slightest disease ? That such 
 qualities are consistent with, life in the blood, is what I cannot 
 believe. But I can most easily imagine how the system, 
 having by successive operations converted the food into chyle, 
 the chyle into blood, and fashioned the nutritious part of the 
 blood into various solids; these new solids may partake of the 
 vitality of all the parts to which they are applied, and to 
 which they have been assimilated by so peculiar and so slow 
 a process. 
 
 The question is plainly this : Shall we follow the general 
 laws of the system, such as physiology acknowledges ? or 
 shall we admit an absurd novelty without proof? Shall we 
 allow of the simple accident of coagulation (an accident com- 
 mon to dead fluids) as a proof of life ? or shall we forget those 
 stupendous proofs of the irritability residing in the heart, 
 muscles, and other forms of our living solids, and which is the 
 source of all the various actions of the body ? Shall we for- 
 get that polypi, worms, insects, the bloodless parts of fishes, 
 the uncoloured parts of the human body, even plants almost 
 inanimate, all partake of life, without having red blood in 
 their system, or having it restricted to the central parts P All 
 these have life and vitality, but where is their blood ? In 
 short the question plainly resolves itself into this, Shall we 
 have two living parts, fluid and solid ; two agents acting on 
 each other ^ or shall we follow the common law of the oeco- 
 nomy, call the one an exciting power, while the other receives 
 that excitement, being alive only that it may feel and act ac- 
 cording to the degree in which it is moved ? Shall we have 
 the blood communicating life to all the body; or the body 
 only alive, and the blood, like various other excitements, act- 
 ing upon it with those powers w’hich it is continually acquir- 
 ing, without acquiring along with them any share of life ? 
 
 But Mr. Hunter, ill contented with his doctrine himself, he 
 even who began with giving to the blood a vital principle, and 
 calling it the former of new parts, and the substance whence 
 the living solid derives its life, hatches a new doctrine out 
 of the confusion of the first; takes from the blood all those 
 high privileges in the system which he had so freely bestowed 
 upon it, and gives them in full perpetuity to a new principle, 
 a principium vit:c dilfusae, which he announces thus : 
 
 “ I would consider that something similar to the substance 
 of the brain is diffused through the body, and even contained 
 in the blood ; and between this (viz. the matter diffused in the 
 blood) and the brain the coraimmication is kept up by nerves." 
 
OP THE BLOOD. 
 
 367 
 
 This matter he does not like to define, but be must name it; 
 and having observed, as others have done, that a mouthful of 
 nonsense sounds infinitely better in Latin than in our mother 
 tongue, he calls it the “ Materia vitas diffusa.” — Concerning 
 this diffused principle of life, he tells us, that every part of an 
 animal has its due proportion ; it unites all the body into one ; 
 ‘‘ it is as it were diffused through the whole solids and fluids, 
 making a necessary constituent part of them, and forming with 
 them a perfect whole.” — The terms in which this doctrine is 
 proposed are hardly more intelligible than those in which he 
 argues about the life of the blood ; the matter itself resembling 
 the substance of the brain, is' supposed! the manner of its 
 union with the blood is supposed ! its connection at once with 
 the fluids, and with the living solids, is supposed ! the sort of 
 a manner, in which this matter harmonizes the whole, is sup- 
 posed ! and now the coagulation, and life of the blood, 
 is no longer an effort of the life of the blood, but of the ma- 
 teria vit£B diffusa ; and the blood does not form the solids, the 
 blood no longer communicates life to the solids, but the blood 
 and the solids are both at once animated by this DiFeuseo 
 
 PRINCIPLE OF LIFE. 
 
 No one need triumph over a doctrine which thus falls by 
 its own weight ; but this must not be forgotten, that the doc- 
 trine of the life of the blood leads to a mean, contracted, nar- 
 I’ow view, not merely of this but of higher subjects. 
 
 Plants have active and irritable fibres ; by the most curious 
 actions they drink in w'ater ; water alone they can convert, by 
 the most simple mechanism, into most delicate perfumes, into 
 delicious fruits, or into terrible poisons. “ There stands,” 
 says Blumenbach, “ a hyacinth before me ; generations of 
 these flowers, of which this is the last, have grown there suc- 
 cessively, touching the surface merely of a little water;” but 
 shall Mr. Hunter persuade me that this water is alive ? “ vel 
 hyacinthi me monent.”* 
 
 I think I may safely conclude, that these theorists have done 
 the science no good ; themselves no honour ; and us no kind 
 of benefit, unless it be an advantage to knovv that by none of 
 these ways can we arrive at a knowledge of the blood.f 
 
 QUALITIES OF THE BLOOD. 
 
 Blood is a fluid of a rich and beautiful colour ; it is ver- 
 milion-coloured in the arteries, strong purple in the veins, and 
 
 * Page 27. 
 
 t Notwithstanding the force of this criticism, which is too valuable not to be left on re- 
 cord, the doctrine of tlie life of tho blood is in my mrnd the best established doctrrae ®f 
 'Tiodem physiology', C. E. 
 
368 
 
 OF THE BLOOD. 
 
 black, or almost so, at the right side of the heart ; it feels 
 thick and unctuous betwixt the fingers, is of a slightly saline 
 taste, is various in various parts of the body, in tbe heart or 
 at tile centre of the circulation different from what it is in the 
 glands, excretories, and all the extremeties of the body ; dif- 
 ferent in the liver, among the intestines, in the cheeks and lips, 
 in the reservoir or sinuses of the head and womb. In various 
 individuals, but much more in different animals, it varies with 
 their functions and manner of life ; it is more or less perfect 
 in animals, in birds, in fishes, in insects ; it is thick or thin ; 
 has gross particles or small ; is red or pale ; hot or cold ; ac- 
 cording to the creature’s life : and from this last variety, viz. 
 of the manner of life, comes our division of animals into those 
 of hot and cold blood. 
 
 It is by the most simple and natural methods that we exa- 
 mine the blood; since almost spontaneously it resolves itself 
 into the crassamentum, the serum, and the red globules, 
 suspended in the crassamentum, and forming a part of it. In 
 a cup of blood, the crassamentum, or clot, the hepar sangui- 
 neum, as it was called long ago, floats in the serum ; the red. 
 globules are engaged in this clot, and give it colour ; the serum 
 may be poured off, the coagulum may be washed till it is freed 
 of the red parts of the blood ; and then the red particles are 
 found in the water with which the coagulum was washed, and 
 the coagulum remains upon the strainer, little reduced in size, 
 pure and white, the fibrine or gluten. Or we may separate 
 this part by a method which Ruysch first taught us ; we may, 
 while the blood is congealing, stir it with a bunch of rods, 
 when the pure and colourless fibrine gathers upon the rods, 
 and the serum, with the red particles suspended in it, remains 
 behind. 
 
 OF THE RED GLOBULES. 
 
 The red globules, as we have observed, are not universal ; 
 yet in all creatures, even in colourless insects, there seem to 
 be formal particles in the blood ; in white Insects they are 
 white, in green insects they are green, in most insects they are 
 transparent. 
 
 The red globules of the human blood are easily seen ; they 
 are best examined with a simple lens, the globules being dilu- 
 ted in serum and laid upon an inclined plane, not in water, 
 which dissolves them quickly, but in serum which has tbe pro- 
 perty of preserving their globular form. — The size of the par- 
 ticles of the blood varies in various creatures ; in the foetus, 
 
OF THE BLOOD. 
 
 369 
 
 tliey are bigger than in a grown animal ; and though Leeuwen- 
 hoek thought it essential to his doctrine, to say, that they were 
 alike in all creatures, we know beyond a doubt that there are 
 in respect to the size of the animals the strangest reverses. 
 The Skate has red globules much larger, and the Ox has glo- 
 bules much smaller, than those of a Man. Fish have large 
 globules. Serpents smaller ones, and Man smaller still. In 
 Man the diameter of each globule is much less than the three 
 thousandth part of an inch. 
 
 There is in the effect of lenses, or in the nature of these 
 globules, some strange refraction, by which there seems a 
 darkness in the centre of each globule, and thence a deception 
 which has been universal; so that no single description has 
 tallied with that which went before. Leeuwenhoek believed, 
 that he saw them consisting each of six well compacted smaller 
 globules : Hewson believed that they were bladders, which had 
 within them soine central body, loose and moveable ; that 
 often the central part might be seen rolling in its bag ; and 
 that sometimes the bladder was shrunk and shrivelled around 
 the central body, and could, by putting a drop of water upon 
 it, be plumped up again. The Abbe Torre examined them 
 with simple lenses too ; but they magnified so highly, that 
 from this cause all his noisy mistake has arisen ; for he used 
 not ground lenses but small sphericles of glass formed by drop- 
 ping melted glass into water ; they magnified so much, that to 
 him the central spot appeared much darker ; he said that these 
 were not globules, but rings. He sent his sphericles of glass 
 and his observations from Italy, his own country, to our Royal 
 Society ; and for a long while, though nobody could see them, 
 still the public were annoyed by Abbe Torre’s rings. Fal- 
 coner, with all the zeal of a friend, published Hewson’s dis- 
 coveries after he was dead ; lamenting, as we all must do, the 
 loss of a promising young man. Falconer thought he saw 
 these globules, not as spheres, but as flattened spheres ; he 
 thought he saw them often as they rolled down the inclined 
 plane upon which he placed them, turning their edges, their 
 sides, their faces, towards the eye ; he even compared their 
 flatness with that of a coin. Many authors have conjectured 
 that these globules are compressed w'hen they come into nar- 
 row passages, and expand again when they ^t into wider arte- 
 ries. This Reichell says he has seen, and Blumenbach be- 
 lieves ; but Blumenbach, less easy of belief with regard to all 
 these strange forms ascribed to the particles of the blood, 
 pronounces his dissent in plain terms. “ They appear,” says 
 he, “ to my eye no other than simple globules apparently of 
 
 VOL. I. A a a 
 
370 
 
 OF THE BLOOD. 
 
 mucus : that lenticular or oval form which authors speak of, I 
 have not seen.” 
 
 The following are their chief properties with regard to the 
 rest of the blood. When blood stands, they fall to the bot- 
 tom, because they are heavier than the other parts of the 
 blood ; and although the fibrine or gluten entangles them while 
 it is forming, still it is to be noticed that the cake is always 
 redder at the bottom ; and when by weakness or disease this 
 coagulation is very slow, some globules escape the grasp of 
 the coagulum, and the serum is tinged with red, and the cake, 
 though coloured at the bottom, is white at the top, or has the 
 huffy coat. Their form they preserve only while in the blood, 
 and seem to be supported more by the qualities of the serum 
 than by their own properties ; for if mixed with water, they 
 mix easily, and totally dissolve ; the water is red, but the glo- 
 bules are gone ; when we mean to preserve their forms for ex- 
 periment, we must keep them in serum, or must make an arti- 
 ficial serum by impregnating water with salts. Their quantity, 
 in regard to the whole mass, varies so, that the appearance of 
 the blood is a real index of health or disease : in disease and 
 weakness, the blood is poor and colourless ; in health and 
 strength, it is rich and florid ; by labour, red particles may be 
 accumulated in a wonderful degree ; in hard working men they 
 abound ; they may be accumulated by exercise into particular 
 parts, as in the wings of Moorfowl or Pidgeons, and in the legs 
 of common Hens. In short, the red globules are numerous 
 in health ; in large and strong creatures ; and in the centre of 
 the system, where they often circulate, when (as in fishes) all 
 the flesh is colourless ; in such a system, particular glands 
 only, or viscera, as the liver, stomach, or spleen, are coloured 
 with blood, and but a small proportion circulates in the great 
 vessels round the heart. 
 
 The redness of these particles is a peculiarity for which we 
 know no meaning nor cause. The greatest physiologists have 
 ascribed it to the iron of the blood ; but when we reflect how 
 many various colours iron gives in its various states ; when we 
 reflect, that the unknown cause which gives colour to the iron 
 may give colour to the blood ; when we reflect, that of this 
 crocus of iron we can hardly procure one poor grain from four 
 hundred grains of these red particles of the blood ; we 
 cannot but be conscious that this peculiarity is not yet ex- 
 plained.* 
 
 According to BerzeliuJ, about one-fourth of the dry colouring matter is oxj’deofiroB; 
 
OF THE BLOOD. 
 
 sn 
 
 COAGULABLE LYMPH. 
 
 The coagulable part, the cake which is left when we wash 
 away the red globules, that which has been called the gluten, 
 and now by chemists the fibrine, is by far the most important 
 part of the blood, the most universally diffused in the animal 
 system, the most necessary for the supply and growth of parts. 
 It forms all the solids, and in its properties resembles them 
 most curiously; for this cake, when washed, is white, insipid, 
 extremely tenacious, and very fibrous; can be drawn out 
 greatly ; and it is the coagulation of this part that makes the 
 long fibrous strings which we find in the tub when bleeding a 
 patient in the foot in very hot water. Being slightly dried, it 
 shrinks into a substance like parchment ; being hardened by 
 heat, it becomes like a piece of horn or bone : when burnt, it 
 shrinks and crackles, with a very fetid smell, like the burning 
 of feathers, wool, flesh, or any other animal substance ; 
 by which we know it to be the part of the blood which is the 
 most perfectly animalized, and the most ready to be assimi- 
 lated with the living solids. When distilled, it gives ammo- 
 niacal salt and alkaline water, and a very thick heavy fetid oil, 
 and much mephitis, which are the marks of the most perfect 
 animal nature; and after burning it, the residuum is a 
 phosphate of lime, or, in other words, the earth of bones. 
 
 Its peculiar properties, as it appears in the blood, are few ; 
 its relation to the body is very surprising. 
 
 What passes within the animal body, or how^ this gluten is 
 directly applied, we never can know ; but we see how the 
 greater part of the body is composed of gluten, and no 
 analysis of any single part has ever disappointed us. A mus- 
 cle being squeezed, and thoroughly cleansed of blood, washed 
 in spirits of wine, and again cleaned, is seen plainly to be but 
 a peculiar form of coagulable lymph. A bone being infused 
 in any mineral acid, or in vinegar, its earthy parts are dis- 
 solved even to its centre ; it becomes soft and flexible, still 
 retains the form of a bone ; but what remains consists princi- 
 pally of coagulable lymph. And though Fourcroy is certainly 
 right in saying that coagulable lymph is that part upon which 
 nature fixes irritability, or the contractile power, he should 
 have added, “ but this gluten is moreover in the animal body 
 the basis of every part which possesses life ;” it constitutes, 
 in truth, no less than nine-tenths of the solids of the whole 
 body. The membranes, ligaments, tendons, periosteums, 
 and all the white parts of the animal body, consist chiefly of 
 this. It is this fibrous part, then, which is secreted by the 
 
372 
 
 OF THE BLOOD. 
 
 vessels for repairing all the wastes, and all the accidents of the 
 body ; when a muscle is wasted by violent action, or by fevers, 
 or by long confinement is absorbed, gluten is secreted to fill it 
 up ; when a bone is broken, much of this jelly is deposited in 
 a bed for vessels to stretch into, and a new bone is quickly 
 formed ; when soft parts are cut, gluten is poured out betwixt 
 them ; when viscera are inflamed, pure gluten, white, and 
 membranaceous-like, is poured out betwixt them ; when the 
 uterus is to be prepared for receiving the impregnated ovum, 
 gluten is poured out into the womb ; and in all these cases it is 
 the foundation of a union with the surrounding parts. In short, 
 this gluten forms, nourishes, supports, restores the parts of the 
 animal body ; but far from considering it either simply, or 
 along with the red globules, as containing the principle of life, 
 I find it as perfect in dead vegetables as in living animals ; and 
 view it only as that particular form of matter which nature 
 has wisely appointed for our chief nourishment and support. 
 
 THE SERUM. 
 
 The serum is the thinnest and most fluid of the parts of the 
 blood, into which it spontaneously separates. And it contains 
 those substances which one is almost tempted to call extrane- 
 ous : this must be kept in view when its properties are to be 
 told, for though it so exactly resembles the white of an egg, 
 that some have, in comparing the two, written whole pam- 
 phlets on the subject, and named it the Albuminous Fluid, al- 
 though it coagulates like gluten, although it putrefies like 
 flesh, although it gives out, upon distillation, ammonia and a 
 black and fetid oil ; yet it is most natural that, along with these, 
 it should contain also some foreign bodies, as a saccharine or 
 extractive matter, belonging to vegetables, and some propor- 
 tion of the oxalic, malic, or other vegetable acids.* 
 
 Serum is a fluid like whey, of a yellowish, or rather greenish 
 colour, of an unctuous or slippery feeling among the fingers; 
 it is slightly saline, and contains soda, sulphur, and phosphate 
 of iron. It contains soda completely formed, by which it turns 
 vegetable reds to green ; it coagulates with a heat much lower 
 than that which makes it boil; being dropped into hot water it 
 coagulates as it falls ; by 150 degrees of heat, it coagulates 
 into an albumen like the white of an egg. 
 
 But by this influence of heat the whole does not coagulate, 
 but only the albumen, a substance like the white of an egg; 
 
 * The lactic acid is the only free acid hitlierto found in it. C. B. 
 
OF THE BLOOD. 
 
 375 
 
 what remains fluid is the serosity. On cooling, the serosity 
 coagulates like size or jelly. This coagulation arises from the 
 gelatin dissolved in the water ; and this gelatin may be preci- 
 pitated by various re-agents, but especially by tanin, and by 
 alcohol. After the separation of the gelatin, thei’e remains 
 only the salts in watery solution ; these are muriate of soda, 
 phosphate of soda, and phosphate of lime. 
 
 This analysis of the blood contains the analysis of almost all 
 the humours or secretions of the body. Observe how nearly 
 the urine resembles the serum ; indeed the urine, like the 
 serum, preserves the peculiar form of the red globules, and 
 sweat is but a serum loaded wuth salts ; observe how little 
 saliva differs from the serum ; observe how perfectly the serum 
 resembles milk, since mixing serum Avith water produces a 
 milky fluid, that is, a fluid wdiich gathers cream on the top, 
 and coagulates with acids and heat. The water of dropsies 
 is purely serum ; the mucus of hollow passages is little else 
 than inspissated serum ; the bile itself is said to be imitated 
 by keeping putrid blood.* In short it is obvious that on the 
 coagulable lymph depend all the internal secretions, (?’. e.) for 
 supplying the waste of the system, for enabling it to grow, 
 for repairing bruised or cut flesh, or broken bones ; that on 
 the serum which dilutes the blood, and contains all such foreign 
 bodies as might be injurious to the system, all the excretions, 
 as urine, sweat, saliva, tears, &c. &c. depend. 
 
 I have said, “ that the blood is a fluid of a rich and beauti- 
 ful colour ; vermilion-coloured in the arteries, strong purple 
 in the veins, and black, or almost so, at the right side of the 
 heart.” When we open the thorax of a living Dog, the lungs 
 collapse, the heart soon ceases to play, the Dog languishes, ex- 
 pires, is revived again when we blow up its lungs : — then begins 
 again the motion of the heart, the black blood of the right 
 auricle is driven into the lungs ; the blood goes round to the 
 left side of the heart of a florid red ; and this purple blood of 
 the veins, the vermilion blood of the arteries, the change hap- 
 pening so plainly from access of air, is a phenomenon of the 
 most interesting nature, and binds us to look into the doctrines 
 of chemistry for the solution of a phenomenon to which there 
 is in all the animal economy nothing equal. 
 
 It is the study of air and aerial fluids that has brought to 
 light all the beautiful discoveries of which modern chemistrv 
 can boast. The simplicity of the facts in chemistry, the cor- 
 rectness of the reasoning, the grandeur which now the whole 
 science assumes, is very pleasing; and makes us not w'ithout 
 
 * With the exception of the water of dropsies, all the fluids mentioned here have been 
 found very cflfferentfrom semm. 
 
374 
 
 OF THE BLOOD. 
 
 hope, that by this science, all others, and ours in an especial 
 manner, may be improved ; for the action of vessels will do 
 much in forming and changing our fluids: all the rest is 
 chemistry alone. 
 
 The older chemists were coarse in their methods, bold in 
 their conjectures, in theory easily satisfied with any thing 
 which others would receive. They condescended to repeat 
 incessantly the same unvarying process over each article of 
 the materia medica ; and among hundreds of medicinal plants 
 which they had thus analysed, they could find no variety of 
 principles, nor any other variety of parts and names than those 
 of i.hlegm, and oil, and alkali, and acid, and sulphur, and 
 coal. By tliis they disburthened their consciences of all they 
 knew, pleased their scholars, and set the physicians to work, 
 forming magnificent theories of salts, sulphurs, and oils ; for 
 such has ever been the connection of chemistry with physi- 
 ology, that, good or bad, they have still gone hand in hand. 
 
 The older chemists thought that they had arrived at the 
 pure elements, while they were working grossly among the 
 grosser parts of b dies. They could know nothing of the 
 aerial forms of bodies, for they allowed these parts to escape. 
 When their subjects by extreme torce of heat, rose upwards 
 in the form of air, no further investigation was attempted ; it 
 was supposed that the subject of their operation was consumed, 
 annihilated, wasted into air, and quite gone. When they thus 
 stopped at airs, they stopped where only their analysis became 
 interesting or simple ; stopping where they stopped, among 
 their oils and sulpliurs, they made their science a mere I’hap- 
 sody of woi ds. Philosophy they considered so little, as not 
 to know that the lightest air is really a heavy body, and that 
 with weight and substance other properties must be presumed. 
 
 Modern chemistry begins by assuring us, that these airs are 
 often the densest bodies in the rarest forms; that airs are as 
 material, as manifest to the senses, as fairly subject to our ope- 
 rations, as the dense bodies from which they are produced : 
 that it is heat alone (a substance which irresistibly forces its 
 way into all bodies) that converts any substance into the aerial 
 form : that some bodies require for their fluidity merely the 
 heat of the atmosphere, and so cannot appear on this planet in 
 any solid form : that others require some new principle to be 
 added, in order to give them the gaceous or aerial form : that 
 others require very intense heat to force them into this state; 
 but that all aerial fluids arise, or must be presumed to arise, 
 from some solid body or basis, which solid basis is dilated by 
 heat into an air. The solid basis of some airs can be made appa- 
 rent, as of fixed air, which proceeds from charcoal ; others, as 
 
OP THE BLOOD. 
 
 375 
 
 pure air, or azotic air, (the great constituents of our atmos- 
 phere,) cannot be produced to view in any solid form. But 
 those airs which cannot be exhibited in any solid form, can yet 
 be so combined with other bodies as to increase their weight, 
 and give them qualities of a very peculiar nature ; and these 
 airs can be alternately combined with a body and abstracted 
 again, adding or abstracting from its weight and chemical pro- 
 perties, not only in a perceptible, but in a wonderful degree ; 
 so that these abstractions and combinations constitute some of 
 the most general and important facts. When the old chemists, 
 then, neglected to examine these airs, they refrained from ex- 
 amining the last elements of bodies at the very moment in 
 which they came within their power. 
 
 That these must be the most material and important facts 
 in all the science, it is easy to explain ; for chemistry, ever 
 since it has been a science, has rested upon one single point. 
 There are certain great operations in chemistry which we per- 
 ceive to have the strictest analogy with each other, or rather 
 to be the same ; the operations are, the combustion of inflam- 
 mable bodies, the respiration of animals, the calcination of me- 
 tals ; and whatever theory explains one explainsthe whole. The 
 older chemists observed, that when they burnt an inflamma- 
 ble body, the surrounding air was contaminated, the substance 
 itself was annihilated, nothing remained of its former existence 
 but the foul air; and they supposed that this inflammable body 
 consisted of a pure inflammable principle, which was the sub- 
 stance which spoiled the air, lessening its bulk, and making it 
 unfit for supporting any longer either combustion or animal 
 life. When an animal breathed in confined air, they found the 
 phenomenon still the same; the animal contaminated the air, 
 and expired itself ; left the air unfit for burning or breathing, 
 loaded, as they supposed, with the inflammable principle. 
 When they calcined a metal, (which is done merely by heat- 
 ing the metal and exposing it to air,) they found, as in these 
 other operations, the air contaminated, the metal losing its me- 
 tallic lusti’e, ductility, and all the marks of a metal, — acquir- 
 ing (in certain examples) new qualities, like those of some mi- 
 neral acid, and becoming of course a most caustic drug; but 
 above all, they uniformly observed the metal to increase in 
 weight. 
 
 To account for all these discordant changes was the most 
 difficult part of all : it was indeed easy to say, that combustion 
 was the giving out of an inflammable principle to the air ; and 
 to say concerning respiration, that it was the business of the 
 air to take away continually the superabundant phlogiston of 
 the blood ; but how a metal should pass from a mild to a most 
 
376 
 
 OF THE BLOOD. 
 
 acrimonious and caustic state ; and above all, how by the loss 
 of its inflammable principle it should not lose in weight, but 
 increase in weight ! This was the Gordian knot which they 
 had to untie, and which they cut lustily, betaking themselves, 
 in defiance of all philosophy, to the absurd project of a prin- 
 ciple of absolute lightness. They all agreed to call the phlo- 
 gistic principle, a principle of absolute levity; and thus 
 their doctrine stood for many years, viz. that when phlo- 
 giston, or inflammable principle, was added to the calx of any 
 metal, as to red lead, by roasting it with any inflammable bo- 
 dy — the metallic lustre, tenacity, ductility, were restored, and 
 the metal became lighter withal, because it now had within it 
 the principle of levity. But that when by heat and air it was 
 calcined, this principle was driven out, and then the metallic 
 lustre, tenacity, ductility, &tc. were lost by the absence of the 
 inflammable principle upon which they all depended ; but the 
 weight of it was encreased, for the principle of levity was 
 gone. This is the brief abstract of the theory to which the 
 very best chemists have addicted themselves down to the pre- 
 sent times. 
 
 But the chief perfection of modern chemistry is, that its 
 apparatus is so perfect, that it can employ exactly a certain 
 quantity of air in calcining a metal ; it can collect that air 
 again to the twentieth part of a grain ; it can prove whether 
 the metal has really been giving out any inflammable principle 
 to the air, or whether it has received matter from the air, and 
 how much expressly it has gained or lost. Modern chemis- 
 try proves to us, that it is not the loss of any principle that 
 endows a metal, for example, with negative powers : but the 
 direct acquisition of a new principle, which endows it with 
 positive powers. Thus if you take a quantity of mercury, 
 and expose it slowly, that is, for a long time to heat and air, 
 the following changes take place ; it gradually loses its metalic 
 lustre, the upper part of it assumes first a yellow and then a 
 red colour, small red particles are seen floating on the sur- 
 face of the mercury ; and these are the mercurius precipita- 
 tes per se, a most acrid calx of mercury. If, first, you esti- 
 mate how much air has been expended during the process, 
 you find that the weight of the mercury is increased in exact 
 proportion ; if you put that calx into a gun-barrel, put the 
 gun-barrel into the fire, and by mere force of heat drive out 
 this air, you find the quantity of air exactly equivalent to the 
 quantity expended in the process ; you find the metal grow 
 lighter, and recover its metalic qualities and lustre in propor- 
 tion as the air is expelled. In short, we find the metal hea- 
 vier when combined with air, lighter when the air is drives 
 
OF THE BLOOD. 
 
 377 
 
 out ; we find it having the qualities of a metal when uncom- 
 bined with air, — when combined with air having the quali- 
 ties of a calx : then plainly this caustic form of the metal is 
 not a negative quality, it is a positive one, proceeding from 
 the infusion of this new principle from the air. 
 
 By such proofs as these chemistry has explained, in a most 
 philosophical way, how all these phlogistic processes, as they 
 were called, depend, not on the abstraction of phlogiston, but 
 on the addition of a new principle : that they all arise from 
 one positive power, that the same principle gives life to fuel, 
 increase of weight (and other effects of calcination) to metals, 
 acidity to acids, and redness to the blood. These are all 
 performed by one power ; they are all essentially one pro- 
 cess; they are all effected by the communication of one sole 
 principle, viz. the basis of pure air. 
 
 Upon our atmosphere and its surprising harmony with all 
 parts of nature ; viuth animal and vegetable life ; witb water, 
 metal, acids, and all the solid bodies into which it enters — 
 much more depends than it is easy to conceive. Could we have 
 supposed that it was the cause, not merely of life in all living 
 creatures, but almost the cause of all the properties that re- 
 side in the most solid forms ? Could we have supposed that 
 the air rendered heavy bodies heavier, changed metals into 
 the most caustic substances, converted many bodies into acids, 
 changed inflammable air into the pure element of water, 
 which at least we have hitherto conceived to be pure? 
 Yet if there be one word of truth in chemistry, all this is 
 true. 
 
 The atmosphere contains various gases or airs ; but one 
 only, viz. vital air or oxygene gas, is useful to respiration, 
 combustion, and animal life ; that purer air must, like eveiy 
 other, arise from some solid basis : that basis cannot be shown 
 in any substantial form, but it can be combined with many va- 
 rious bodies, so as to give them an increased weight and new 
 qualities ; and thence we presume to say, whenever we see 
 a body, by such a process, acquiring such qualities, that it 
 acquires tbem by absorbing the basis of pure air ; for pure 
 air is nothing but this presumed basis dilated into the form off 
 air by heat ; and when it combines with any body, it gives 
 out its heat ; so that in all these processes heat is produced. 
 And although inflammable bodies, metals, acids, and animal 
 blood, seem very distinct from each other ; although combus- 
 tion, breathing, calcination, and the forming of acids, are pro-'* 
 cesses seemingly very unlike ; yet they are all in thcir.essential 
 points the same, viz. a change of qualities and a production of 
 heat in consequence of the absorption of pure air. 
 von, I. B b b 
 
378 
 
 OF THE BLOOD. 
 
 First, when an inflammable body is burnt or consumed by 
 fire, the basis of pure air is combining with the combustible 
 body; the air is entering into a new combination, and there- 
 fore must give out its heat ; it combines rapidly, gives out its 
 heat rapidly, is wasted ; the inflammable body burns and seem# 
 to be consumed ; but if we catch that air which escapes from 
 the inflammable body, we find it to be equal exactly to the 
 whole weight of the air and of the burning body that have 
 been consumed ; and this air consists of two parts, viz. of the 
 substance that was burnt, and of the basis of pure air. Thus, 
 for example, when we burn charcoal or carbon, the whole 
 substance of it, weight for weight, is converted into an air, 
 w'hich is called fixed or carbonic acid gas ; the same which is 
 discharged from stoves, the same also which is found in pits, 
 the same which oozes through the ground in the Grotto del 
 Cane, the same which floats upon the surface of fermenting 
 vats, and which is so much heavier than common air that it 
 can be taken out from a vat in basons, and poured from dish 
 to dish. Combustion, then, is a process which consists in the 
 rapid assumption of the basis of pure air, and a consequent 
 conversion of the burning body into an air or gas endowed 
 with peculiar qualities and powers. 
 
 If, then, the oxygenation of the blood be a process like 
 this, it must differ chiefly in degree ; it might in certain cir- 
 cumstances become too rapid, and resemble an actual com- 
 bustion ; and so in certain circumstances it does, for our at- 
 mosphere is so tempered that no more than 27 parts out of 
 100 consist of pure air;* the rest is food for vegetables, but 
 not fit to maintain flame or animal life. This is the reason 
 that even burning as well as breathing are slow processes, and 
 that an animal, if made to breathe pure air or vital air as it 
 is called, gets oxygene too rapidly supplied, is consumed and 
 inflamed quickly, and dies. 
 
 Secondly the process of calcination is the same in all me- 
 tals ; it also is an assumption of the pure air, or rather of its 
 basis, with a change of qualities and increase of weight: if you 
 calcine lead slowly, it becomes first yellow, then orange, then 
 red ; it becomes heavier, so that from 100 pounds o( lead you 
 have 1 10 pounds of lytharge, or calx of lead : if you calcine 
 mercury, it also becomes first yellow, then red, and much 
 heavier than at first : if you distill any of these metals, you can 
 by heat merely drive out the purest air from them ; they re- 
 ^ cover their brilliancy, and grow lighter, because the basis of 
 air is expelled. The basis of pure air is expelled, not in that 
 solid form in which it was embodied by the calx, but being 
 now combined with heat, it appears in the form ol vital air ; 
 
 * TMe'nIy-one by weiglit of oxygene. 
 
OF THE BLOOD. 
 
 379 
 
 the air is much purer than that of the atmosphere which was 
 used in the process, because the metal absorbs or appropriates 
 to itself nothing but the purest air, leaving the azotic or foul 
 air behind ; and finally, if you wish to see the harmony be- 
 twixt combustion and calcination, or to be assured that calcina- 
 tion is truly the burning of a metal, take some of this pure air, 
 which is three times purer than the atmosphere, and raises an 
 intenser flame; plunge into it a piece of iron wire, which is 
 made red hot ; and this wire (which would only have wasted 
 or rusted into a calx in the common atmosphere) will in the 
 pure air burst out into a brilliant white flame, and burn entirely 
 while it has such air ; nay, some metals, as zinc, burn even in 
 our common atmosphere with a most brilliant flame. 
 
 From this second process, must it not be presumed that the 
 principle w hich gives an increase of weight and such singular 
 properties to various metals, must have very interesting effects 
 upon the blood ? 
 
 Thirdly, it is from this principle also that all acids are form- 
 ed ; and as oxyd is the Greek name for acid, the great Lavo- 
 sier has thought fit to give a name to the basis of air, or that 
 principle which is obvious only when operating in such proces- 
 ses as these. He adds m the Greek name for acid that verb 
 which implies the generation of any substance; he calls it 
 thus oxygene, or the principle which generates acids. It were 
 easy to show how truly this great point is supported by all the 
 particular operations in chemistry ; it shall be sufificient to ob- 
 serve a few.* When we burn sulphur in open air, it seems to 
 be consumed ; but when we burn it in close vessels, still giving 
 a free access to air, we find it converted into an acid the most 
 ponderous of all, weighing greatly more than the sulphur from 
 which it was procured. The operation is done in close ves- 
 sels : nothing can pass but what is known, and nothing is more 
 certain than that the w hole of this wonderful and rapid change 
 is the mere effect of the sulphur, which is an acidifiable base, 
 assuming the acidifying principle by which alone it can become 
 an acid. Phosphorus being burnt in a close glass upon the 
 point of a wire, the vital part of the atmosphere is consumed, 
 the azotic air (which the ancients mistook for their phlogiston) 
 remains, the whole phosphorus is changed into phosphoric acid, 
 and the whole acid, when weighed, expressly equals the phos- 
 phorus which was burnt, and the air which w'as consumed along 
 with it. Nay, arsenic, which is a metal, being calcined, is con- 
 verted into a perfect acid. Thus we see, first, that calcination 
 is a mere combustion, since it can be made so rapid as to be 
 attended with heat and flame ; next we see that acidification 
 
 * To this doctrine numerous objections occur : — oxygene by union with liydrogene fornis 
 water; sulpluir by union with hydrngene forms suipliuretted hydrogene, an acid, &c &c. 
 
o80 
 
 or THE BLOOD. 
 
 is, like calcination, attended with heat and flame, and an acqui- 
 sition of weight and of properties like those of calces. We 
 see some metals converted into proper acids; acids and me- 
 tals mixing in qualities with each other ; acids and metals are 
 both acidificable bases, both ai-e capable of receiving new and 
 similar properties, by assuming into their composition the ba- 
 sis of pure air; and in one single process the whole set of phe- 
 nomena are exemplified, for in burning arsenic we have com- 
 bustion, calcination, and generation of acid, alt in one process, 
 the product being named indifferently oxyd of arsenic, or 
 white calx of arsenic.* , 
 
 But if most acidifiable bases be thus forced by combination 
 to forsake their solid and assume their aerial form, others more 
 singular still are recalled from their aerial form, and condensed 
 into the fluid form of a strong acid. Thus azotic or nitrogene 
 air, which forms the great bulk of our atmosphere, is convert- 
 ed by oxygenous or pure air into an acid form ;f it becomes 
 nitrous acid, nitric acid, nitrous air, strong or weak according 
 to the various degrees of oxygenation communicated to it ; 
 and thus nitrous air, by its appetite for oxygene, and by its 
 change of colour and its condensation, whenever it takes oxy- 
 gene from the air, makes an eudiometer or measure for the 
 purity of the air; and, according to the purity of the atmos- 
 phere, more turbidness and more redness is produced in the 
 nitrous air, and a greater loss of bulk, which may be marked 
 on a scale. 
 
 The oxydation of the blood makes a fact no less important 
 in physiology than those are in chemistry ; for as there are va- 
 rious marks of the influence of oxygene on the blood itself, 
 there are terrible proofs of its importance in the system, and 
 how miserable the person is who has imperfect organs, or an ill 
 oxygenated blood.J 
 
 Nature, disregarding all occasional supplies, as by the ab- 
 sorption of the skin, the assimilation of aliments, &c. has ap- 
 pointed one great organ for the oxygenation of the blood, viz. 
 the lungs. In opening the breast of a living creature we best 
 see the connection of respiration with the great system; but 
 
 ^ It is nPcessary to add nitre to make it burn. Tlie result is not directly an acid, but a 
 neutral salt formed of tbe arsenical acid joined to the alkali of nitre'; without the help of 
 nitrous acid it is only an oxyd or imperfect acid ; and it is necessary to use the hy pei-oxyge- 
 nated muriatic acid for communicating to it a sufficiency of oxygene to constitute it a j.-er- 
 feet acid. 
 
 f N. B. It i.s necessary to inclose tliem in one vessel, and to pass the electric spark 
 through them that they may unite. 
 
 t Yet ! must here again observe that thei'e are no decided proofs of the o.vydatinn of l!« 
 blood. C. B. 
 
OF THE BLOOD. 
 
 381 
 
 it is out of the body that we can best understand its particular 
 effects upon the blooo. 
 
 The most obvious effect of air is its heigbting the colour 
 of the blood. If we expose blood to fixed air, or azotic air, it 
 continues dark; these fluids communicate nothing, they have 
 no effect on the colour of the blood : when we expose blood 
 to atmospheric air, it assumes a florid colour , for in the at- 
 mosphere there is a large proportion of oxygene gas : if, lastly, 
 we expose it to oxygene gas, the purest of all air, it grows 
 extremely florid ; and whenever it changes its colour, it is by 
 absorbing oxygene, for it reduces in the same proportion the 
 quantity of air ; what it absorbs is the oxygene or pure air, what 
 it leaves is mephitis, unfit for combustion or animal life.* 
 
 Blood when exposed to the air becomes red chiefly on the 
 surface, it remains black beneath, but by turning up the clot to 
 the air all the surfaces become red. If air be blown into a 
 tied vein, the blood which was black in the vein becomes flo- 
 rid ; and when the air is pressed out again, it becomes black. 
 If the air-pump be exhausted over a dish of blood, the blood 
 becomes dark in the vacuum ; and it becomes florid when the 
 air is allowed to rush in again. If you expose blood in a 
 moist bladder, the blood is oxygenated through the walls of 
 the bladder ; which brings this experiment as close as may be 
 to the phenomenon of blood oxygenated, through the walls of 
 the lungs. Though serum or milk be interposed, or urine, 
 still the blood is oxygenated, because these are perfect ani- 
 mal fluids ; but it is not oxygenated, if oil, mucilage, or mere 
 water, be interposed. 
 
 When we open a Frog, orNewt,f or other amphibious crea- 
 ture, we see a long and slender artery accompanied by a slen- 
 der vein, running from top to bottom along the whole surface 
 of their lungs; and while their heart continues to beat, we see 
 this pulmonic artery black, the vein red, the lungs themselves 
 most delicate and pellucid, like the swimming bladder of a 
 fish : even in the extremities of the human system the blood 
 of a vein is dark, of an artery red ; so that surgeons distin- 
 guish venous and arterial haemorrhagies in this way. 
 
 From these facts we may understand why the blood of the 
 Avonib, of sinuses, of varices, and of all stagnant veins, is so 
 offensive and black ; and why that blood is so very pure and 
 florid which is coughed up from the lungs. Is not the face 
 livid in apoplexies or strangulations, in hanging or drowning, 
 in fits of passion or of coughing, or in any accident which in- 
 terrupts the lungs ? The face of a child during a paroxysm of 
 
 ' Carbonic acid gas is formed; the absorption of pure oxygene is doubtful. 
 
 f See Chap. Ilf 
 
382 
 
 OF THE BLOOD. 
 
 the hooping cough, is it not completely black ? Is not the hand 
 livid when the arm is compressed or tied up, and its blood pre- 
 vented from returning to the lungs and heart? Are not tu- 
 mours dark coloured from dilated veins which return their 
 blood too slowly ? Are not these mulberry marks which are 
 born with us just small aneurisms full of ill oxygenated blood ’ — 
 Then this first effect of oxygenation is a reddening of the 
 blood. The menstrual blood, the blood of ecchymosis, (as 
 in those who have been whipt,) the blood of aneurismal bags, 
 are all black ; and the blood of varices is so very black, that 
 the ancients said they were filled with atrabilis or black bile. 
 The stripes inflicted on a soldier as a punishment are at first of 
 the most lively red, but soon become black. 
 
 The next effect of oxygenation is the endowing the blood 
 with a peculiar power, by which it is continually operating 
 upon the living solid : this is a power which it is continually 
 losing ; which it is every moment giving up to the solids ; and 
 which no other process but respiration can restore. This sti- 
 mulant power the blood gradually loses as it circulates round 
 the body ; it is quite effete when it returns to the right side 
 of the heart : the heart of a creature never moves^ if we allow 
 its lungs to lie collapsed ; but the heart returns to act the very 
 instant that pure air is forced into the lungs, and so communi- 
 cated to the blood. This stimulant power is most of all appa- 
 rent when w'e force a living creature to breathe nothing but 
 the purest air ; for oxygenated or vital air makes this process 
 too rapid ; the pulse rises, the eyes become red and promi- 
 nent, the creature seems drunk with the new stimulus, too 
 great for its system. The universal heat of its body is greatly 
 increased, the eyes are turgid and red, and at last a sweat 
 breaks forth all over it; and when dead, the lungs (it is said) 
 are mortified or inflamed. But whatever the marks are, 
 whether these signs of inflammation be really true, it is plain, 
 since the creature dies, that pure air is fatal by a too rapid 
 oxygenation of the blood. If, in our experiments upon a dy- 
 ing animal, we inflate the lungs with mephitic air, the heart 
 does not act ; if we inflate its lungs with common air, the 
 heart begins to act ; if we Inflate its lungs with oxygene air, 
 the heart is irritated to a still more powerful action. 
 
 If vvfc open the breast of a Frog and stop its breathing, we 
 observe, first, its pulmonic blood florid, and the heart beating 
 strongly : secondly, in half an hour the pulmonic blood has 
 become dark, and the heart’s motion has grown languid ; in a 
 little while the pulmonic blood becomes black, and the pulsa- 
 tion of the heart ceases: and, lastly, the trachea of the Frog 
 
OF THE BLOOD. 383 
 
 Seing untied, and the creature allowed to breathe again, the 
 blood becomes florid, and the heart acts. 
 
 OF THE HEAT OP THE BLOOD. 
 
 The next effect of oxygene is said to be the communica- 
 ting of HEAT to the lungs. But I suspect that if the small 
 quantity of oxygene which can enter by the lungs do commu- 
 nicate heat, it must be not to the lungs, nor to the blood, but 
 to the whole body through the medium of the blood. There 
 are some who pretend to say, that when they draw in vital air, 
 they feel a genial warmth in the breast, diffusing itself over all 
 the body ; but it is easy to feel in this way, or any way, when 
 a favourite doctrine is at stake, while those who know nothing 
 about doctrines, breathe the vital air without any peculiar feel- 
 ing which they can explain. 
 
 There are many circumstances which make it hard to be- 
 lieve that there is in consequence of the oxydation of the 
 blood, any remarkable generation of heat in the lungs. Oxyd- 
 ation of the blood, out of the body, is attended with no in- 
 crease of heat, and yet we operate on a quantity of blood 
 much greater than that which circulates through the lungs. 
 
 To suppose, but for a moment, that all the heat which 
 warms the whole body emanates from the lungs, were a gross 
 error in philosophy : it were to suppose an accumulation of 
 heat in the lungs equal to this vast effect of heating the whole 
 body. But were it so, we should feel a burning heat in the 
 centre, a mortal coldness at the extremities, and marked dif- 
 ferences in the heat of each part in proportion to its distance 
 from the lungs. In fevers, we should feel only the intense 
 heat of the centre ; we should be distressed, not with the 
 heat in the soles of the feet or palms of tbe hands, or in the 
 mouth and tongue; we should feel only the heat of the lungs. 
 When the limbs alone were cold, would the lungs warm them 
 How could it warm them up to the right temperature without 
 overheating the whole body When a part were inflamed, how 
 could the heat go from the lungs, particularly to that point, and 
 rest there ? 
 
 From the lungs the heat could not be regularly diffused; 
 for in almost all the Amphibiae the lungs are far distant from 
 the centre of the body, and could not communicate any de- 
 gree of heat to the extremities without the g^reatest waste ; 
 they would, according to this theory, have lungs for crying 
 with, if they pleased to cry, but by no means for distributing^ 
 heat. 
 
 But in reflecting upon this most diflicult of all subjects, the 
 
384 
 
 OF THE BEOOD. 
 
 generation of heat in the living body, many things are to be ta- 
 ken into the calculation, which seem, on the slightest glance, 
 to be far more important than this deposition of oxygene from 
 the blood. It is a law of nature, to which, as far as we know, 
 no exception is found, that a body, while it passes from an 
 aerial to a fluid form, or from a fluid to a solid form, gives out 
 heat. Now, what is the whole business of the living system 
 but a continual assimilation of new parts, making them con- 
 tinually pass from a fluid into a solid form ? The whole nourish- 
 ment of the body goes on in the extreme vessels, and is a 
 continual assumption of new parts. The extreme vessels are 
 continually employed in forming some acids, which appear 
 naked in the secretions ; in forming oxyds, as the fat and the 
 jellies of the membranous and white parts ; in the various de- 
 positions of muscle, bone, tendon. Sic. for these are all con- 
 tinually absorbed, thrown off by the urine, and incessantly re- 
 newed. They are continually employed in filling all the inter- 
 stices of the body with a bland fluid or halitus ; they are con- 
 tinually employed in forming secretions of various kinds. In 
 performing all this the power of the vessels may do much ; 
 but the ultimate effect in each process must be a chemical 
 change, and perpetual changes will produce a constant heat. 
 Place the organ and focus of this animal heat in the centre of 
 the body, and you are embarrassed in a thousand difficulties ; 
 allow this heat to arise in each part according to its degree of 
 action, and each part provides for itself. 
 
 But how then, some will say, shall this heat be regulated 
 I say plainly by the heart and lungs. The lungs regulate the 
 stimulant power of the blood, the heart regulates the action 
 of the arteries, in so far as regards the stimulus of fulness and 
 distention ; and with these to regulate the centre, nothing can 
 alter the heat of the extremities except partial actions, that is, 
 disease. 
 
 I will conclude then, that oxygene, if it do communicate 
 heat, does so, “ not to tlie lungs, nor to the blood, but to the 
 whole body through the medium of the blood.” 
 
 OF THE RESPIRATION OF ANIMALS. 
 
 The effects of oxydatlon then are, to redden the blood, to 
 renew its stimulant power, and to communicate heat, not so 
 much to the blood, as to the whole body through the medium 
 of the blood, and to assist in the secretions and chemical 
 changes which are incessantly going on in all parts of the 
 system. This is accomplished by the perpetual and rapid 
 
OF THE BLOOD. 
 
 385 
 
 motion of the blood through the lungs ; and there it is ex- 
 posed to our atmosphere, which is a mixed fluid very diflerent 
 from what we at first conceive, or what our ignorant wishes 
 might desire to have it ; not consisting merely of air fit to be 
 breathed, but for the greatest part formed of an air which is 
 most fatal to animal life, whence it has the name of Azotic 
 Gas. Of an hundred measures of atmospheric air, we find 
 twenty-seven only to consist of vital or pure air, that is oxygene ; 
 seventy-two consist of azotic air, or nitrogene, as it is called, 
 fatal to animal life ; and one measure only is fixed air, or car- 
 bonic acid, which is also an unrespirable air. But of these 
 twenty-seven parts of pure air, seventeen parts only are af- 
 fected by respiration ; so that in respiration we use much less 
 than a fifth part, even of the small quantity of air which we 
 take in at each breath. 
 
 The change of the air by respiration is this chiefly ; that 
 the quantity is diminished by the abstraction of a part of the 
 oxygene ; that there is formed a quantity of carbonic acid gas 
 by the union of the carbon of the blood with the oxygene res- 
 pired ; and that there is discharged along with these a quantity 
 of watery halitus. Therefore atmospheric air, after it has 
 been breathed, is found to have suffered these changes : First, 
 It contains now a considerable proportion of carbonic acid, 
 which is easily discovered, and even weighed ; because wdien 
 a caustic alkali is exposed to it, the alkali absorbs the fixed 
 air and becomes mild. Secondly, It has less of the vital air, 
 as is easily ascertained by the eudiometer which measures the 
 purity of the whole : And, thirdly. All that remains is merely 
 azotic air, unfit for animal life, or for supporting flame. The 
 oxygene, then, in part unites itself with the blood : in part it 
 forms fixed air by combining with the carbon of the lungs ; in 
 part it forms water by combining with the hydrogene of the 
 blood. Respiration frees the blood of two noxious principles, 
 the hydrogene and carbon ; and it insinuates a new principle, 
 viz. the oxygene, into the blood.* 
 
 * Such has been the opinion of chemists up almost to the present day ; but the rapid 
 changes of opinion, and indeed of whole systems, and the confusion into which the dis- , 
 coveries of to-day throws the result of all preceding labours, would almost provoke an 
 anatomist to put out of Ills system the chemical discussion altogether, until the masters of 
 that science have better arranged their materials, and have arrived at acknowledged prin- 
 ciples. More careful experiments have proved that the volume of air expired is the same 
 with that inspired, — ^the respired air differing only in the variable proportion of carbonic 
 acid gas, and aqueous vapour ; that all the oxygene taken from the atmosphere by respi- 
 ration, is consumed in the formation of the carbonic acid gas found in the respired air ; and 
 that the heat evolved by respiration is not the heat of the body, but the heat of tlie air 
 respired, latent before, and now become sensible, owing to a change of capacity in the 
 gases. 
 
 The change produced in the blood during the circulation in the lungs, is simply to free it 
 of the superabundance of carbon with which it is loaded in consequence of the secretions 
 performed in the extreme vessels of the system of the body. 
 
 As to the heat of the body, chemists seem to have agreed, that full confidence is to be 
 
 vor.. I. C c c 
 
386 
 
 OF THE BLOOD. 
 
 Nature has appointed but a small proportion of vital air for 
 our use ; our atmosphere is so constituted as to hold but a 
 fourth part of vital air, and of that small proportion one half 
 only is used in the lungs. We see by this how necessary this 
 contamination of our atmosphere is which seems so unfavour- 
 able to life ; nature intended that we should breathe slowly 
 a modified atmosphere ! With nothing but the purest air to 
 breathe, our life would be quickly consumed, like that defla- 
 gration of iron, which is so rapid in vital air, while it burns so 
 moderately and slowly in the common air. 
 
 These assistances which we have from chemistr)^ are but a 
 promise of what that science may do ; nothing of all that we 
 know conceming the chemistry of the blood is either perfect 
 or sure : we have our expectations still of seeing things more 
 completely explained : but our expectations are not like those 
 of Mr, Moises, who, in a certain dissertation on the blood, 
 seems so full of his new lessons in chemistry, and so confident 
 of his future achievements in that science, as to expect that 
 muscular motion shall be very thoroughly explained, and that 
 it will be’found to be nothing else, in all the world, but “ an 
 explosion of hydrogene and oxygene,” and God knows what ! 
 but it is after the manner of “ a steam engine and if his 
 scheme holds, they are to be fired off “ by means of the 
 nervous electricity of Galvani !”* 
 
 OF THE MEMBRANES OF CAVITIES, AND PARTICULARLY OF 
 THE MEMBRANES OF THE THOKAX.f 
 
 Every part of an animal body, with the exception of the 
 fluids, the matter of the nerves, of the muscles, and of the 
 
 put in tlin pxperimenis anti opinions of Dr. Crauforel, v.-hose theories l)ave been criticiscrl in 
 Ibnner editions of tliis work. The brief abstract of ivlilcli doctrine is this. Tlie venom 
 blood has less capacity for retaining heat than arterial blood. AVhen the blood of the 
 arteries of the body is converted into purple blood, and enters the. small veins, beat is let 
 loose and becomes sensible, giving warmth and a stimulus to the operations of the animal 
 economy. When this venous blood is, in the round of the circulation, brought back to the 
 lungs, while it throws out its siiperaliuiidant carbon, and when this carbon unites with 
 oxygene of the air res|ii.red, and forms carbonic acid, heat is evolved. Wliile this action 
 of respiration is producing heat, it is also forming of venous blood artei'ial blood. And as 
 the ai'lnrial bloorl, in its conversion into venous blood, gave out heat, so now, being re- 
 converted into artei'ial blood, it takes up brat, and that is not sensible heat, but latent, 
 rhere is, therefore, no central fire, as it were, in the breast, and yet there is a source of 
 heat to the whole body from the o[jeration of the lungs. And what degree of heat more 
 ihan necessary for the conversion of the blood, and which might be injurious, i.- expended 
 in forming the vapour exhaled from tlie lungs. C. B. 
 
 Vide page 236. 
 
 f By Charles Bell. 
 
OF THE MEMBRANES OF CAVITIES. 
 
 387 
 
 bones, is resolvable into membrane by masceration and the 
 contrivances of the anatomist. 1 he fine web which supports 
 the retina in the eye, and the strong cord on which the 
 gastrocnemius acts, are formed of the same kind of tissue, the 
 cellular texture. Another remarkable circumstance is, that 
 this cellular texture no where terminates, or that the mem- 
 branes of the body are every where in continuity. If, for 
 example, we begin our investigation with the tendon of a 
 muscle, we shall find that it is resolvable into a twisted mem- 
 brane, we may trace this membrane into the muscle, and we 
 shall find it enveloping the muscular fibres, and extending 
 through the muscle, and uniting again to form the tendinous 
 insertion of the muscle into the bone. From the tendon the 
 continuation is direct to the periosteum ; the periosteum is con- 
 tinued into the ligaments and capsule of the joint ; from this 
 again we may trace the fascia, and intermuscular septa. These 
 firmer structures we shall find loosening into the common cel- 
 lular texture, and that texture, as has been already explained, 
 may be traced over the whole animal frame. 
 
 But we have now particularly to consider the structure 
 and connections of the membranes of the great cavities of 
 the body; and, in the first place, the membranes of the 
 thorax. 
 
 A membrane is an expansion or web of animal matter, 
 having extension with a scarcely measureabie thickness : it 
 ■ has one surface, free or disunited, and smooth, and lubri- 
 cated with a secreting fluid. It has the other surface rough 
 and attached, being more like the common cellular texture, 
 of which, in fact, the whole membrane is a composition. 
 
 The membranes of the viscera are arranged in two grand 
 divisions, viz. the mucous membranes, and the serous mem- 
 branes ; all of which are remarkable for their extent of surface, 
 but especially the former. The difference of the two great 
 classes of membranes is referable to the nature of their secre- 
 tions. The object of the secretions is to prevent adhesion of 
 contiguous surfaces, which is most effectually done by the mu- 
 cous secretion. But as the mucous secretion is not readily 
 soluble nor prepared for absorption ; as when secreted it must 
 be thrown off from the surface, and urged out of the body 
 altogether; it is obvious that this is a secretion calculated 
 solely for the membranes which are open, and from which it 
 may be discharged. 
 
 The serous fluid is finer, more watery, and very readily 
 absorbed ; so that it is supplied to moisten the surfaces of shut 
 sacs, and membranes which are continuous and have no out- 
 let, such as those lining the great cavities. But if there be 
 
388 
 
 OF THE MEMBRANES OF CAVITIES. 
 
 any tendency to inflammation on tliese surfaces, they are 
 more prone to adhesion than the mucous membranes, be- 
 cause the inflammatory action will more quickly convert se- 
 rum to coagulable lymph (which is the medium of adhesion) 
 than it will the mucous secretion. 
 
 The mucous membrane is tbe continuation of the skin ; it 
 is every where continuous, but it admits of a natural division, 
 viz. J. The mucous lining of the lungs; 2. The mucous 
 lining of the alimentaiy canal, and the ducts which open into 
 it ; and, 3. The mucous lining of the urinary organs. 
 
 We may trace the first from the nostrils up into the cavities 
 of the nose, and from that into the lining membrane of the 
 cells of the face. We may then trace it backwards into the 
 throat, into the larynx, the trachea, the bronchi, and, finally, 
 into the bronchial cells, an extent perhaps equal to the whole 
 surface of the body. 
 
 To trace these continuous surfaces is not an idle minute- 
 ness ; for we require to know, that inflammation will creep 
 along the surface by a prevailing action, which has got the 
 name of continuous sympathy. Thus we are sensible in 
 catarrh of a sense of pain and weight in the forehead, com- 
 mencing with a dryness of the cavities of the nose ; then we 
 have increase of secretion, and tickling in the larynx ; this is 
 followed by pain and a sense of rawness in the throat ; lastly, we 
 have pain in the chest, or an uneasy tickling sensation in the 
 very margin of the lungs, and thus the inflammatory action 
 terminates only with the extremity of this long line of con- 
 nection. 
 
 The second division of the mucous membrane is the lining 
 membrane of the mouth, which we trace into the asophagus, 
 into the stomach, into the intestines ; and, after a course of 
 full seven times the length of the body, it appears on the 
 verge of tbe anus, terminating, as it began, in the skin ; and 
 along the whole of this mucous lining we may sometimes trace 
 the course of inflammatory action. An erysipelatous blush, 
 visible in the throat, will sometimes take its course in a very 
 dangerous manner, over the whole extent of the canal, even 
 to the anus. 
 
 The third division of this membrane is where the fore-skin 
 is reflected over the extremity of the penis into the urethra ; 
 here the mucous secretion commences, and it characterizes 
 the whole extent of the canal, tracing it through the bladder 
 to |the pelvis of the kidnies. 
 
 Thus we shall find, that the mucous membranes form the 
 internal surface of all the hollow viscera, and now we shall also 
 see that that the serous membranes form all the outward sur- 
 
OF THE PLEURA. 
 
 389 
 
 face of the same viscera. The course of the serous mem- 
 branes are, however, by no means so simple nor so easily 
 comprehended by the student as that of the mucous mem- 
 brane. I shall at present confine myself to the anatomy of the 
 membranes of the thorax or chest. 
 
 OF THE PLEURA. 
 
 The thorax is the superior cavity of the trunk, and contains 
 the heart and great vessels, the lungs, and the thymus gland: 
 it transmits into the abdomen the oesophagus and nerves ; and 
 these parts are involved and supported by the processes of the 
 pleura. 
 
 The pleura is the fine serous membrane which lines the two 
 cavities of the chest, and is reflected upon the lungs. We shall 
 consider it first as it lines the ribs (and where it is called 
 PLEURA cosTAHs ;) 2. then as it is reflected on the diaphragm ; 
 3. as it forms the septum dividing the chest; 4. as it is re- 
 flected to cover the lungs (where it is the pleura pul- 
 
 MONALIS.) 
 
 The pleura costalis is the lining of the walls of the chest. 
 These walls consist of the ribs, their cartilages, and the 
 sternum, their interstices being filled up with the intercostal 
 muscles. The lining membrane of course is attached in 
 part to the inside of the ribs, in part to the muscular tex- 
 ture which intervenes. It is a simple membrane ; for so we 
 call it, although like every other membrane it may be di- 
 vided into layers of cellular membrane. On its outer surface 
 it is most loose and cellular in its textui’e ; on the surface to- 
 wards the cavity it is smooth and bedewed with secretion, and 
 is consequently unattached. The pleura lining the ribs is 
 very thin, and is immediately attached to the periosteum. 
 
 As the ribs and sternum form the walls of the chest on the 
 lateral and foreparts, the diaphragm forms the floor of divi- 
 sion betwixt the cavity of the chest and the lower cavity, the 
 abdomen. From the ribs, the membrane is reflected upon 
 the diaphragm, to which it adheres ; and .fi'om the diaphragm 
 and lateral parts of the chest, it is reflected to form the di- 
 vision of the chest which is called mediastinum ; which com- 
 pletes the circle of connections, as far as relates to the lateral 
 cavity of the chest. 
 
.590 
 
 OF THE PLEURA. 
 
 i'LAN 1. plan 2, 
 
 In the first plan here, the dotted line represents the course 
 of the pleura, in a supposed section of the chest. Two late- 
 ral cavities are seen with a partition ; that partition or septum 
 is the mediastinum, and passes from the spine to the sternum, 
 dividing the chest into two lateral cavities. The second plan 
 shows the manner in which the pleura is reflected to cover the 
 lungs and form the pleura pulmonalis : a dotted line still marks 
 the course of the membrane ; and here we may observe, that 
 when the pleura has formed the septum, 'called mediastinum, 
 it is there again reflected over the vessels going to the lungs, 
 and covering the vessels protects them, and forms what is call- 
 ed the ligament of the lungs. Tracing the membrane in its 
 course, w'e do not find that it terminates any where ; we find 
 that it is every where continuous, and that the pleura pulmo- 
 nalis and pleura costalis are the same continued surface of 
 membrane. 
 
 But in these plans a liberty is taken to represent the lungs 
 shrunk, and leaving the sides of the chest, a thing which never 
 takes place in nature. This is done that my reader may fol- 
 low the line distinctly ; properly the surface of the lungs, 
 (that is, the pleura pulmonalis,) and the inner surface of the 
 ribs, (the pleura costalis,) should have been in contact ; for al- 
 though we continually speak of the cavity of the chest, yet 
 there is no cavity but in disease, or when by wounds the air 
 is permitted to escape from the lungs, and then, indeed, the 
 circumstances are as represented in this- plan; for the lungs 
 leaving the side of the chest, there is a cavity which is then 
 filled with air. 
 
 The 1st Plan shews the two cavities of the thorax formed by the pleura costalis, and the 
 septum or mediastinum formed by tl'.e meeting of the membranes. 
 
 The 2d Plan shews, by the continuation of the dotted line, how the pleura costalis ir 
 continued into the pleura pulmonaHs. 
 
OF THE PLEURA. 
 
 39 i 
 
 When we trace the raembrane of the ribs over the lungs, we 
 comprehend how the smooth and proper surface of the one 
 is internal, and the other external ; and yet that these surfaces 
 are continuous and the same. We understand too how the 
 surface of the pleura pulmonalis and costalis are in close con- 
 tact, and yet do not adhere, and that consequently freedom is 
 given to the motion of the lungs. At least, if in respiration 
 the lungs do not move from the sides of the chest, they are 
 not prevented by the adhesion of the pleura, when in a healthy 
 and natural state ; but by a circumstance already in part ex- 
 plained. The lungs cannot recede from the pleura covering 
 the ribs, because no air can be admitted to fill the space 
 which would be then necessarily formed betwixt the lungs and 
 ribs. 
 
 The LIGAMENTS of the lungs are understood when my read- 
 er comprehends the manner in w'hich the pleura is reflected 
 from the ribs over the spine, and from the spine over the great 
 vessels and over the lungs. Where this reflection of the pleu- 
 ra takes place, embracing the tubes and vessels going to the 
 substance of the lungs, it forms ligamentous roots, the only 
 natural connection of the lungs to the chest. 
 
 The MEDiASTi.NUM is a partition dividing the great cavity 
 of the chest into two lateral parts : it is stretched from spine 
 to sternum. This is a common, and it may be a true descrip- 
 tion of the mediastinum as far as it goes, yet it is a most im- 
 perfect one. This partition of the thorax is esteemed a pro- 
 vision for our safety, worthy of all admiration ; and so indeed 
 it is. But when it is said, that this partition provides that a 
 man, being diseased in the lungs of one side, or wounded be- 
 twixt the ribs of one side, may still breathe with the other, 
 I would venture to say, that it is a wrong reading in that vo- 
 lume which it ought to be our pride to preserve pure. Every 
 motion of the natural system has its proper check ; every de- 
 licate part has its guard against the violent motions of the na- 
 tural system ; and is constituted with a due provision against 
 the injuries we are liable to in a state of nature. But nature 
 had it not in contemplation that we should be exposed to the 
 gun and bayonet, nor can I think with a celebrated anatomist 
 that she has provided for sustaining the prolonged existence of 
 him who is slowly wasted by pulmonary consumption- I can- 
 not believe that there is either in the foramina of the heart, 
 or the mechanism of the chest, a provision against tbe ^ffects 
 of disease. I have therefore to show that the mediastinum 
 has a reference to the support of the heart and great vessels, 
 against the unequal pressure to W'hich, wnthout this guard they 
 would be exposed in the necessary and natural changes to 
 
392 
 
 OF THE MEDIASTINUM. 
 
 which the body is subject in health. But I have said that the 
 description of the mediastinum is imperfect; and really, 
 though seemingly simple, it is difficult to represent by words 
 the connection of the membranes of the thorax. 
 
 The two distinct sacs of the pleura, each forming a lining 
 membrane to the two sides of the thorax, approach towards 
 the centre of the cavity, and would absolutely unite but for 
 the intervention of the heart and its appendages. And so in- 
 deed it is, that anterior and posterior to it, these membranes 
 nearly touch. Where the sacs of the pleura approach each 
 other anterior to the heart, they form the anterior mediasti- 
 num ; and in the same manner behind the heart and near the 
 spine, they form the posterior mediastinum. 
 
 The anterior, or pectoral mediastinum, has, in the embrace 
 of the membranes, much cellular membrane ; and when in 
 dissection we raise the sternum, this loose cellular membrane 
 allows the pleura to be drawn separate so as to form a cavity, 
 which cavity did not previously exist. The anterior medias- 
 tinum contains the thymus gland, some absorbent glands, a 
 considerable trunk of the lymphatic system, which has been 
 called the ductus thoracicus anticus. 
 
 The posterior mediastinum, called sometimes dorsale, 
 contains the extremity of the trachea and part of its branches 
 called bronchi, and part of the pulmonic artery and veins ; the 
 oesophagus, for the greater extent of its course, the descending 
 aorta, and the great trunk of the absorbents, the thoracic duct, 
 the eighth pair of nerves, and the dorsal lymphatic glands. 
 
 Both the mediastina are a little towards the left side, and 
 the posterior one is much the longest. 
 
 I now leave authority, and proceed to describe the more im- 
 portant connections of the membranes of the chest with the 
 heart and great vessels. The pleura, which is a very thin and 
 weak membrane where it invests the lungs or adheres to the 
 inside of the ribs, is particularly strong where it is reflected 
 from the diaphragm. And from the diaphragm to the upper 
 and more contracted part of the chest, all along the tract of 
 the cava, it is of a ligamentous firmness, and is more like a 
 fascia or tendon than those layers of cellular tissue, which 
 have of late got that name in connection with the subject of 
 hernia. Towards the upper part of the chest, the pleura, or 
 rather the mediastinum, covers and embraces the branches of 
 the cava, and posteriorly it covers and protects the aorta and 
 thoracic duct ; in short, were it not the fear of confounding 
 the ideas of the younger student, I would say, that this struc- 
 ture of membranes excludes all but the lungs from the cavity 
 of the chest ; and consequently from the effect of the chest’s 
 
OF THE MEDIASTINUM. 
 
 393 
 
 jnotion in respiration. How the respiration does not affect the 
 veins and cavities of the heart, will now, I trust, he easily con- 
 <;eived, and consequently the use of the mediastinum be un- 
 derstood. 
 
 But before I proceed further, I must here observe that the 
 pleura, where it is reflected to form the mediastinum, is dou- 
 ble ; that is, the cellular texture acquires a different structure, 
 has a ligamentous firmness, and performs the ofiice of a fascia 
 around the vessels, an ofiice which could not have been 
 done by the mere reflection of the lining membrane of the 
 chest. 
 
 The enlarged capacity of the thorax in every direction, the 
 raising the of the ribs, the thrusting out of the sternum, is 
 attended with the contraction and sinking the arch of the dia- 
 phragm. But this motion which expands the cells of the 
 lungs, and draws the air into them, would disorder the heart’s 
 motion, would cause a lodgement of the blood and distention 
 of the great veins and sinues, were they under the influence 
 of the motion of respiration. But the diaphragm moves only 
 on its lateral parts, or it is checked and intercepted at the 
 middle part by the connections of the mediastinum. In pro- 
 portion as the lateral cavities of the chest and the lungs con- 
 sequently suffer the influence of this expansion of the chest, 
 and have the pressure taken from them, (which bore against 
 the weight of the atmosphere,) the parts contained in the 
 mediastinum suffer pressure by the action of the diaphragm 
 and rising of the sternum. If the veins near the heart were 
 exposed to the same influence that the lungs are, they would 
 be subject to the same change of quantity of what they con- 
 tain ; the blood would be accumulated in inspiration, and forced 
 out from them in expiration, and the regular action of the 
 heart interrupted or disturbed. 
 
 There is a further use in these connections of the mem- 
 branes surrounding the great vessels with the diaphragm, viz. 
 to preserve an equilibrium or equal pressure upon the great 
 vessels of the trunk during the violent action of the muscles. 
 Thus in leaping, pulling, or straining, in any way, there is a 
 sudden and great pressure on the viscera and veins of the ab- 
 domen, and at the same time there is a powerful acceleration 
 of the blood from every remote part towards the great veins 
 and right sinus of the heart. These vessels would be over- 
 powered and burst but for the protection of the mediastinum, 
 and the support which the diaphragm gives by its connection 
 with the mediastinum, and by acting in opposition to the ab- 
 dominal muscles. 
 
 VOL. I. 
 
 D dd 
 
394 
 
 OF THE PERICARDIUM. 
 
 OB THE PERICARDIUM. 
 
 The pericardiuna, or heart purse, is the third cavity of the 
 thorax ; but here again I must caution my readers on the use 
 of the term cavity. The pericardium closely embraces the 
 heart, retains the lubricating fluid, and restrains and limits the 
 heart’s motion. But this being already explained, I have 
 only to add a circumstance not noticed under the former 
 head. The pericardium is a double membrane : the inner 
 layer of membrane belongs to the class of serous membranes ; 
 the outer is quite of a different character, being a tissue of 
 strong fibres which form a web as strong as a fascia. It is this 
 external layer of the pericardium which is continued upon 
 the great vessels as they arise from the heart, and which 
 forms their supporting sheath ; and what the closer texture of 
 the sheath does to restrain and support the arteries and veins, 
 is done by this outward layer of the pericardium to the 
 heart. 
 
 The next point left unexplained is the manner in which the 
 heart and pericardium are embraced by the pleura. 
 
 In this plan we see how the heart, surrounded by the peri- 
 cardium, is further embraced by the mediastinum, by which 
 it is not only supported, but the great vessels are surrounded 
 and led securely out of the thorax, until they reach their pro- 
 per sheaths in ascending upon the neck or passing out into the 
 axilla. 
 
 n The heart, h the pericardium, cc the pleiira of ilic ri^lit aud of the left, side, 
 embiacingThe peiitardiura belwist them. 
 
OF THE THYMUS GLAND. 
 
 395 
 
 OF THE THYMUS GLAND. 
 
 The thymus is a gland of a pale colour and soft consistence, 
 having many divisions or lobuli. It lies immersed in the cel- 
 lular membrane of the anterior mediastinum, but stretches 
 upwards on the neck, and its extremities are betwixt the tra- 
 chea and carotid arteries, but it lies principally on the peri- 
 cardium. It has two superior cornua, and two inferior, 
 the right of which is the longest. On puncturing this gland 
 a white fluid may be expressed, and when we blow into this 
 puncture the air pervades the whole gland, giving the appear- 
 ance of a cellular texture ; but no ducts have been disco- 
 vered. The thymus occupies a very considerable space in the 
 chest of the foetus, while it diminishes rapidly during child- 
 hood ; therefore it is presumed, that it has a function adapted 
 to some peculiarity of the foetal circulation : but not even a 
 probable conjecture has been offered further. It has been 
 supposed a kind of diverticulum chyli. It has been supposed 
 to secrete a fluid to attenuate the blood ; it has been supposed 
 to separate a peculiar fluid which was again thrown into the 
 blood through the small veins. It has been supposed useful 
 to fill up the thorax during the contracted state of the lungs 
 in the foetus ; forgetting altogether that it is large in the 
 foetus and diminishes after birth, it has been supposed to 
 protect the lungs from the pressure of the sternum ; all which 
 are suppositions merely, that have not the most distant proof 
 to support them, and yet possess not sufficient absurdity to 
 make them worthy to be recollected on that account. 
 
 OF THE LUNGS. 
 
 The lungs are the soft compressible bodies which fill the 
 two lateral cavities of the chest ; and their use is to convey 
 the atmospheric air into contact with the circulating blood. 
 They consist principally of a cellular texture, and air tubes 
 communicating with the atmosphere through the trachea. 
 The degree of fleshy consistence and solidity which they 
 have, is owing to the many vessels which carry blood through 
 them, and the firm texture of membrane necessary to support 
 them. Their function is respirstion. 
 
 Respiration carries away the superfluous carbon of the 
 blood, bestows heat, and stimulates the system, endows ns 
 
or THE TRACHEA AND BRONCHI. 
 
 th the power of speech, and affords us the sense of smelling, 
 
 ' grc iiiy contributes to the perfection of the sense, 
 in form, the lungs correspond to the cavity which contains 
 thiin. When taken from their place and extended, they are 
 wide below, forming a base, and rise conicaUy upward ; con- 
 cave where they lie on the arch of the diaphragm, obtuse- 
 above, convex forward, and more slightly so on the sides ; the 
 borders of the lungs behind are obtuse, pointed and thin be- 
 fore. The lungs have a deep sulcus behind left for the spine, 
 and within the projecting lobes there is a place of lodgment- 
 for the pericardium and heart. 
 
 Attending to this general form, we see why the lungs are 
 spoken of as double, for unless by the connection of their 
 common wind-pipe there are two great lateral portions, each 
 ot which belongs to a distinct cavity. And when we look to 
 the lungs of the two sides, we discover that they are not per- 
 fectly alike. On each lung a fissure begins a little above the 
 apex, and runs obliquely forward and downward to the base., 
 This fissure on the left side divides the lung into two lobes. 
 On the right side there is a lesser fissure, which consequently 
 forms a lesser intermediate triangular lobe. 
 
 OF THE TRACHEA AND BRONCHI. 
 
 The trachea is that extent of the wind-pipe which is be- 
 twixt the LARYNX (already described) and the division of this 
 tube where it is about to enter the lungs. It is seated on the 
 forepart of the neck and anterior to the oesophagus or gullet. 
 It is covered by the thyroid gland and the flat muscles going 
 from the sternum to the os hyoides and thyroid cartilage, and 
 all around, it has a very loose and elastic cellular membrane. 
 
 The trachea is not a perfect cylinder, it is flat on the back 
 part ; it is rigid to admit of the easy passage of the air through 
 It; and this rigidity is derived from the cartilaginous hoops of 
 W 'dch it is principally formed. These are not perfectly re- 
 fe’ iar : above they are most so, and are broader, and have 
 w r :er cornua the nearer the bifurcation : they are united by 
 Hi- mtermediate ligamentous substance, which appears to be 
 ;■ :rcuiar ; and these cornuae have transverse fibres uniting 
 them, which also appear to be muscular. 
 
 The membrane lining the trachea, and continued from the 
 larynx into the cells of the lungs is as we have already said a 
 mucous membrane ; it is soft, elastic, and vascular ; many 
 pores of foramina open upon it, especially about the larynx 
 and epiglottis. These are the openings of the ducts of glands, 
 
OF THE TRACHEA AND BRONCHI. 
 
 397 
 
 and on the outside of the membrane round and oval glands 
 are visible. The moisture which bedews the trachea is a 
 limpid bland mucus which subsides in water, unless air bub- 
 bles be in it. The thinner part of this secretion is carried off 
 by the air which passes through the trachea, and the thick 
 matter is expectorated. 
 
 This secretion which in the healthy state is of the con- 
 sistence of thin jelly, transparent and of a bluish colour’, be- 
 comes, from inflammation of the catarrhal kind, thinner and 
 more transparent, and is copiously expectorated. In more 
 chronic inflammation the matter becomes thick, opaque, and 
 of the colour of straw. And in a still later stage it may come 
 purulent, without implying lesion of surface. The firmer 
 modules of viscid secretion which are brought up are probably 
 from the sacculi laryngis. 
 
 From its exposed situation, its sensibility and vascularity, 
 the membrane of the trachea is very s’ubject to disease. I 
 have now before me examples of general inflammation, of in- 
 flammatory crust, of suppuration and deep ulcer in the inside 
 of the trachea. Often lesser degrees of inflammation change 
 the nature of the bland secretion, making it more saline, 
 acrid, and stimulating. Sometimes the inflammatory action 
 will mix a portion of coagulable lymph with the mucus secreted, 
 and which, by this addition, will take a tubular form, as in 
 the croup. But let it be remembered, that coagulable lymph, 
 in the form of tubes or vessels may be coughed up from the 
 lungs, a consequence of blood poured into the bronchi with- 
 out the presence of inflammation. 
 
 On entering the thorax the trachea inclines backward, and 
 passes into the posterior mediastinum, and behind the arch of 
 the aorta and before the cesophagus ; opposite to the third 
 vertebrae of the back it divides into two branches, passing to 
 the right and left; these and their subdivisions are the 
 bronchi. 
 
 When we follow one of these tubes we find it entering the 
 substance of the lungs, accompanied by blood-vessels, branches 
 of the pulmonary artery, with their corresponding veins ; and 
 lesser arterial branches enter here, which are derived from the 
 aorta, and are called the bronchial arteries. 
 
 The bronchi divide and subdivide in regular order, branch- 
 ing like a tree through all the substance of the lungs, until 
 their tender extremities terminate in their air cells ; for the 
 cartilaginous rings of the bronchi which near the trachea re- 
 semble those of the trunk, become weaker and further re- 
 moved from each other, until the extremities seem only to be 
 membranous tubes. 
 
398 
 
 OF THE BRONCHIAL CELLS. 
 
 BKONCHIAL CELLS. 
 
 The BRONCHIAL CELLS, into which the air is admitted in 
 respiration, have been represented as very regular sphericles 
 attached to the branches of the bronchi, and having no com- 
 munication with each other. I rather believe that they are 
 not regular in figure nor in size, and that they freely commu- 
 nicate. Perhaps I am mistaken in supposing I see that the 
 cells not only communicate, but that the air is drawn through 
 them, and made to circulate among them in a series. Taking 
 this as a question to be judged of more by the probable effect 
 of the structure, than by what we can demonstrate, would 
 not the air, in the supposition of its being drawn through the 
 communications from cell to cell, in connection with the ex- 
 tremity of a branch of the bronchus, be more effectually 
 brought into contact with the blood, than if the extreme 
 branch of the wind-pipe terminated in a cell which had one 
 opening only, and which cell contracted during expiration, 
 only in a slight degree.? 
 
 On these cells the ultimate branches of the pulmonary arte- 
 ries and veins ramify and inosculate, and the thin membrane 
 of the cell and the coats of these minute vessels do not pre- 
 vent the influence of the air upon the circulating blood. My 
 reader must well distinguish betwixt this regular cellular 
 structure, for the admission of air which is drawn through the 
 trachea and bronchi, and that cellular texture of the lungs 
 which is common to them and every part of the body ; a tissue 
 which supports the air-cells, the bronchi, and the three 
 several kinds of blood-vessels, and the lymphatics which col- 
 lectively constitute the substance of the lungs. This common 
 cellular substance supports the air-cells, and unites the lobules, 
 and conveys the vessels to their destination. 
 
 Sometimes the air escapes from the proper bronchial cells 
 into thin cellular texture; then there is emphysema of the 
 lungs ; then the lungs are distended with air ; but that air does 
 not minister to the oxygenation of the blood, on the con- 
 trary, the patient dies suffocated. And still more frequently 
 it happens that the lungs being exerted as byi difficult respi- 
 ration, a watery effusion takes place in the common cellular 
 texture of the lungs, which effectually compresses the proper 
 air cells, and after much oppression suffocates. 
 
OF THE BLOOD IN THE LUNGS. 
 
 399 
 
 COURSE OF THE BLOOD IN THE LUNGS. 
 
 Coloured water, or size, or oil of turpentine, being injected 
 into the pulmonary artery, returns by the pulmonic veins, run- 
 ning in what is called the lesser circulation. The same fluids 
 being injected into the vein, return by the artery.* The fluid 
 being more forcibly propelled into the pulmonary artery, 
 flows by the trachea, and the exudation of the fluid is facilita- 
 ted, if the action of respiration be imitated by blowing into the 
 trachea at the time of the injection. These coarse experi- 
 ments in the dead body prove little ; but the course of the 
 blood from the extreme pulmonic arteries into the veins, hav- 
 ing been seen in the rnembranous lungs of the lacertfe, the 
 chemical phenomena exhibited by respiration, leave little for 
 us to wish further in explanation of the functions of the lungs.f 
 
 There are some reflections which naturally occur in taking 
 leave of this subject of respiration, which may have the fur- 
 ther efiect of confirming in my^ reader the accurate knowledge 
 of the anatomy. 
 
 Although the lungs are very often found adhering to the in- 
 side of the chest, and although this union occurs where we 
 cannot discover that the person during life was subject to any 
 inflammation of the chest, yet it is a preternatural appearance. 
 The lungs. (covered with the pleura) lie in contact with the 
 sides of the chest, and consequently with the pluera costalis, 
 but without adhesion. They are passive in the motion of res- 
 piration. The muscles of respiration clothing the thorax are 
 the agents in this function. The bony and cartilaginous tex- 
 ture of the thorax in the machinery put in motion, and the ef- 
 fect is the dilatation of the lungs ; for as the sides of the chest 
 rise, the lungs being in close contact, they must follow this ris- 
 ing, and as the dilatation of the lungs is freely permitted by the 
 entrance of the atmosphere through the trachea into their 
 cells, the effect of the action of the muscles of inspiration is the 
 drawing of the atmospheric air into the bronchial cells, and 
 the contact of that air with the blood circulating in the lungs. 
 In expiration the lungs are equally passive as in inspiration. 
 The muscles which contract the diameters of the thorax, force 
 the compages of bones and cartilages upon the lungs, and com- 
 pressing them, throw out the air by the trachea. 
 
 * In an experiment which was made this season by a pupil of mine, the mercury, wliich 
 ■was thrown into the veins of a live ass, was found at the end of a month to be lodged in the 
 cells of the lungs : it had not been forced into the pulmonary veins. 
 
 t For the consent or sympathy of the lungs with othei- part?, see the observations under 
 the head oi Par^vag^m, in the description of the nerves. 
 
400 
 
 OF THE BLOOD IN THE LUNGS, 
 
 That any other idea should arise in the student’s mind is 
 owing to two circumstances ; first, the not comprehending the 
 principles of natural philosophy, and puzzling himself with the 
 expression that the air fills the lungs by its weight ; which is 
 true, but it is as true that the milk enters the mouth of a suck- 
 ing infant by the weight of the atmosphere, or that in using a 
 syringe, it is the weight of air which forces the fluid into the 
 syringe. The air enters the lungs by suction ; the motion 
 of the thoi’ax produces that suction ; or, in other words, the 
 operation of the weight of the air is permitted to take effect 
 by the tendency to a vacuum which the rising of the sides of 
 the thorax produces ; the pressure of the atmosphere then 
 causes the air to descend into the bronchial cells. 
 
 The second circumstance which gives occasion to miscon- 
 conception, is the lungs seeming to have a motion independent 
 of the chest. 
 
 Thus when a man is wounded betwixt the ribs, the lungs 
 protrude, and this rising of the lungs appears to be owing to 
 a power inherent in them ; but attention to the true circum- 
 stance will explain the occasion of this. When the wound is 
 received, the air enters the chest, and the lungs fall collapsed, 
 the cavity is therefore full of air, and the lobes of the lungs 
 hang loose. The air plays freely out and in through the hole 
 in the chest. But when by change of posture the flapping 
 edge of the lungs fall against the hole in the side, the air 
 which is in the chest can no longer make its exit, without 
 forcing the lungs through the wound. Accordingly, in the act 
 of expiration, the same compression which 'forces the air out 
 in breathing pushes out the lungs from the side. We may 
 have the proof from anatomy that the lungs lie in close con- 
 tact with the pleura costalis. 
 
 When the intercostal muscles are dissected off*, and the pleu- 
 ra costalis exposed, the surface of the lungs is seen in contact 
 with that transparent membrane, and when the pleura is punc- 
 tured with the lancet, the air rushes in, and visibly the lungs 
 retire in proportion as the air is admitted. This proximity of 
 the lungs to the ribs explains the effect of fracture of these 
 bones in producing the tumour called emphysema, for thus it 
 happens. The broken end of the rib piercing tbe pleura cos- 
 talis, tears also the pleura pulmonalis, and breaks the surface 
 of the lungs, and opens the bronchial cells. Now when the 
 chest is expanded, a little air is drawn through the rugged 
 opening, and lodges in the cavity of the chest, (now truly a 
 cavity, the air occupying the space betwixt tbe lungs and 
 chest.) By little and little the small portion of air which is 
 drawn into the cavity of the chest at each inspiration accumu- 
 
Firet plan exhibits a section of the thorax, with the rib broken, and entering the lungs A. 
 Air has already begun to accumulate in the cavity of the chest B. The air insinuating itself 
 by the side of the broken rib forms the tumour on the side C. The second plan exhibits the 
 extent of the evil. The lungs D are compressed. The cavity of the chest left by the retrac- 
 tion of the lungs is full of air. The emphysematous tumour E is extended over the body. 
 The right side of the diaphragm E is pushed down, the heart and mediastinum F is forced 
 towards the opposite side, encroaching on the lungs of the left side. 
 
 OF THE BLOOD IN THE LUNGS. 401 
 
 lates until a distressing quantity fills the whole of that side of 
 the chest. 
 
 The chest being now full of air, the action of expiration, 
 compressing the air in the chest, it insinuates itself by the ^de 
 of the. fractured ribs into the cellular texture, consequently a 
 crepitating tumour of air is formed over the part hurt, and this 
 quickly extends over the whole body, until the skin is blown 
 up like a sac ! and the man is in danger of suffocation. The 
 suffocation is not a consequence of this distention of the cel- 
 lular substance of the body, but of the fulness of the cavity of 
 the chest on that side wounded. For, at length, the chest being 
 kept distended, and the diaphragna pushed down, and the me- 
 diastinum passed to the opposite side, both sides of the chest 
 are oppressed, and the breathing is so checked, that if not 
 quickly relieved the patient would die. 
 
 These plans will explain the common case of emphysema : 
 
 VOL, I. 
 
 E e e 
 
402 OF THE BLOOD IN THE LUNGS. 
 
 The emphysema of the body may take place in a different 
 way. The lungs may be diseased ; air may be drawn through 
 the abscess, and collect in the cavity of the chest ; or the 
 bronchial and true air cells may be hurt by exertion, so that 
 the air gets access into the common cellular texture of the 
 lungs ; and from the lungs it may find its way betwixt the liga- 
 ments of the lungs into the cellular texture of the mediasti- 
 num, and hence up into the neck and over the body. These 
 last instances are rare compared with that proceeding from 
 fractured rib. 
 
 END Of the first volume. 
 
 I